Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
transduction noise induced by 4-hydroxy retinals in rod photoreceptors.new visual pigments were formed with 4-hydroxy retinals in isolated vertebrate rod photoreceptors by exposing bleached rods from the tiger salamander, ambystoma tigrinum, to lipid vesicles containing the analogues. formation of physiologically active pigment was demonstrated by the restoration of sensitivity and by a shift of approximately 50 nm in the peak of both the visual pigment absorptance spectrum and rod spectral sensitivity spectrum from approximately 520 to approximately 470 nm for 11- ...19902297557
comparison of serum and plasma taurine values in bengal tigers with values in taurine-sufficient and -deficient domestic cats.a white bengal tiger was determined to have a central retinal lesion and a central visual defect. because of the known association between feline central retinal degeneration (crd) and taurine deficiency in domestic cats, plasma concentrations of taurine were measured in this tiger. serum concentrations of taurine, methionine, and cystine also were measured in white bengal tigers, orange bengal tigers, taurine-sufficient domestic cats, and taurine-deprived and tissue-taurine-depleted visually im ...19902298663
modeling the repetitive firing of retinal ganglion cells.a kinetic model for the repetitive firing of retinal ganglion cells was synthesized from voltage-clamp data and evaluated by comparison with whole cell recordings from ganglion cells in the intact tiger salamander retina. five distinct channels were included in the model and were sufficient to describe the physiologically observed frequency/current relationship in response to various levels of cell depolarization.19902331606
patch testing of 11 common herbal topical medicaments in hong kong.11 common herbal topical medicaments in hong kong were selected for patch testing to study whether they could cause skin reactions under occlusive conditions. these included white flower oil, hung far oil, kwan loong medicated oil, tiger oil, jaminton oil, bee brand oil, tiger balm, au kah chuen skin lotions, mopiko ointment, oronineh ointment and mentholatum. the former 7 were traditional chinese herbal medicaments, the last one was made in usa and the remaining 2 were japanese products. 20 pat ...20072335084
spatial organization of the bipolar cell's receptive field in the retina of the tiger salamander.1. the spatial properties of rods, horizontal cells and bipolar cells were studied by intracellular recording in the isolated, perfused retina of the tiger salamander, ambystoma tigrinum. low stimulus intensities were used in order to keep cell responses close to, or within, their linear intensity/response range. 2. spatial properties of bipolar cell receptive fields, measured while perfusing with normal ringer solution, were compared with those measured during exposure to agents that eliminated ...19902348392
the lateral spread of signal between bipolar cells of the tiger salamander retina.when mapped with a small spot of light, the central receptive fields of bipolar cells in the salamander retina are much larger than the extent of bipolar cell dendrites. furthermore responses of bipolar cells to distant spots of light are considerably delayed relative to proximal spots. using quantitative modelling, electrical coupling between bipolar cells is examined and rejected as a sufficient explanation of the data. an active process appears to shape signal waveform as signals spread later ...19902357478
synaptic organization of serotonin-like immunoreactive amacrine cells in the larval tiger salamander retina.immunoelectron microscopy was used to investigate the ultrastructural features and synaptic relationships of serotonin-like immunoreactive amacrine cells in the larval tiger salamander retina. serotonin-positive somas exhibited an evenly distributed peroxidase reaction product throughout their cytoplasm. their nuclei were unstained and possessed indented nuclear membranes. serotonin-immunoreactive processes were generally stained throughout with the exception of their mitochondria, whose morphol ...19902381521
sensitization of bleached rod photoreceptors by 11-cis-locked analogues of retinal.photoactivation of rhodopsin initiates both excitation and adaptation in vertebrate rod photoreceptors. bleaching of rhodopsin to free opsin and all-trans-retinal in isolated rods produces a stable desensitization (bleaching adaptation) that is much larger than expected from pigment depletion alone. in our experiments, a 93% bleach produced a 500-fold increase in the light intensity required for saturation of the light response. this component of adaptation was 32-fold larger than the 16-fold in ...19902395874
electrical properties of the light-sensitive conductance of rods of the salamander ambystoma tigrinum.the light-sensitive conductance of isolated rods from the retina of the tiger salamander was studied using a voltage-clamp method. the membrane current of the outer segment was collected with a suction electrode while the internal voltage was measured and controlled with a pair of intracellular electrodes. saturating light blocked the outer segment current at all potentials, the residual conductance usually becoming less than 20 ps. this suggests that light-sensitive channels comprise the main i ...19862422346
neuropeptide-like immunoreactive cells in the retina of the larval tiger salamander: attention to the symmetry of dendritic projections.light microscopic immunocytochemistry was used to study the morphology of cells that showed immunoreactivity (ir) to antisera against substance p (sp), glucagon (glu), met enkephalin (enk), and somatostatin (ss) in the retina of the larval tiger salamander. both vertical sections and retinal whole mounts were studied. all four antisera labeled amacrine cells in the inner nuclear layer and cells in the ganglion cell layer (gcl). glu-ir cells had processes stratified throughout the inner plexiform ...19862424942
the light microscopic localization of substance p- and somatostatin-like immunoreactive cells in the larval tiger salamander retina.light microscopic immunocytochemistry was utilized to localize the populations of substance p (sp)- and somatostatin (som)-like immunoreactive cells in the larval tiger salamander retina. of 104 sp-immunostained cells observed, 82% were type 1 amacrine cells. another 8% of the sp-cells were classified as type 2 amacrine cells, while 10% of the sp-cells had their cell bodies located in the ganglion cell layer and were designated as displaced amacrine cells. each type of sp-like immunoreactive cel ...19862426132
distribution of potassium conductance in mammalian müller (glial) cells: a comparative study.the distribution of k+ conductance across the surface of retinal müller cells was determined in 5 mammalian species--rabbit, guinea pig, mouse, owl monkey, and cat--and in tiger salamander. potassium conductance was measured by monitoring cell depolarizations evoked by focal ejections of a high-k+ solution onto the surface of freshly dissociated cells. this technique measured the total k+ conductance of a given cell region (regional conductance), i.e., the specific k+ conductance times the total ...19872441009
regulation of potassium levels by müller cells in the vertebrate retina.the membrane properties of müller cells, the principal glial cells of the vertebrate retina, have been characterized in a series of physiological experiments on freshly dissociated cells. in species lacking a retinal circulation (tiger salamander, rabbit, guinea pig), the end-foot of the müller cell has a much higher k+ conductance than do other cell regions. in species with retinal circulation (mouse, cat, owl monkey) the k+ conductance of the end-foot is greater than the conductance of the pro ...19872441827
gated currents in isolated olfactory receptor neurons of the larval tiger salamander.the electrical properties of enzymatically isolated olfactory receptor cells were studied with whole-cell patch clamp. voltage-dependent currents could be separated into three ionic components: a transient inward sodium current, a sustained inward calcium current, and an outward potassium current. three components of the outward current could be identified by their gating and kinetics: a calcium-dependent potassium current [ik(ca)], a voltage-dependent potassium current [ik(v)], and a transient ...19872442756
barium reverses the transretinal potassium gradient of the amphibian retina.barium chloride (ba2+) was added to the bathing medium of the perfused retina-eyecup preparation of the tiger salamander. the electroretinogram (erg) and intraretinal extracellular potassium activity ([k+]o) were analyzed using a double-barrel electrode, one of which was ion-selective for k+. the action of ba2+ on the erg was to attenuate the c-wave/slow piii complex. in addition, ba2+ dramatically decreased the [k+]o in the outer retina, enough to reverse the transretinal potassium gradient. th ...19872443878
the properties and function of inward rectification in rod photoreceptors of the tiger salamander.1. rod photoreceptors were isolated from the retinae of tiger salamanders and voltage clamped using the whole-cell patch-clamp technique. 2. hyperpolarizing the cell to potentials more negative than -50 mv evoked an inward current termed ih. 3. ih did not turn on immediately following a hyperpolarizing step but showed a marked delay. the activation time course of ih could be described by the sum of two exponential components of opposite polarity. 4. the steady-state chord-conductance was half ac ...19872450992
a presynaptic action of glutamate at the cone output synapse.neurotransmitter release from many central nervous system synapses is regulated by 'autoreceptors' at the synaptic terminal, which bind the released transmitter and alter release accordingly. the photoreceptors of lower vertebrates are thought to use glutamate as a neurotransmitter. glutamate conveys the visual signal to postsynaptic bipolar and horizontal cells, but has been reported not to act on the photoreceptors themselves. we show here that glutamate evokes a current, carried largely by ch ...19882451133
the ionic selectivity of the light-sensitive current in isolated rods of the tiger salamander.1. using the method of hodgkin, mcnaughton & nunn (1985) for rapidly changing the extracellular medium, we analysed the effect of divalent cations on the photocurrent of isolated retinal rods of the tiger salamander. 2. when the extracellular nacl was replaced by equiosmolar amounts of bacl2, srcl2, cacl2, mgcl2 and mncl2 the efficacy in carrying the photocurrent at early times was ba2+ greater than sr2+ greater than ca2+ greater than mg2+ greater than mn2+. at early times ba2+ could carry a pho ...19882466983
the modulation of the ionic selectivity of the light-sensitive current in isolated rods of the tiger salamander.1. by using the method of hodgkin, mcnaughton & nunn (1985) for rapidly changing the extracellular medium, we analysed the effect of the organic compound ibmx (3-isobutyl-1-methylxanthine) on the movement of divalent cations through the light-sensitive channels of isolated retinal rods of the tiger salamander. 2. when the rod is treated with 0.5 mm-ibmx it is possible to observe photocurrents larger than 50 pa carried by ba2+, sr2+, ca2+, mg2+ and mn2+. under these conditions ca2+, mg2+ and mn2+ ...19882474069
incorporation of analogues of gtp and gdp into rod photoreceptors isolated from the tiger salamander.1. analogues of gtp and gdp were introduced into isolated rod photoreceptors using the whole-cell patch clamp technique, while simultaneously recording the photocurrent with a suction pipette. after several minutes of whole-cell recording the patch pipette was disengaged, thus trapping the analogue inside the cell. 2. during the introduction of the hydrolysis-resistant gtp analogues guanosine-5'-o-(3-thio-triphosphate) (gtp-gamma-s) and guanylyl-imidodiphosphate (gmp-pnp) the dark current progre ...19882476554
localization of serotoninlike-immunoreactive amacrine cells in the larval tiger salamander retina.light microscopic immunocytochemistry was used to study the populations of serotoninlike-immunoreactive cells in the larval tiger salamander retina. of 1,135 serotonin-immunostained cells observed in transverse cryosections, 87% were identified as amacrine cells, whereas 13% were tentatively designated as displaced amacrine cells. the somas of the vast majority of serotonin-amacrine cells were situated in the innermost cell row of the inner nuclear layer. only a few serotonin-immunostained amacr ...19892477398
the effect of cadmium on the light-sensitive current of isolated rods of the tiger salamander.the effect of cadmium on the light-sensitive current of isolated rods of the tiger salamander was analysed by rapidly changing the ionic medium using the technique of hodgkin et al. (1985). addition of millimolar amounts of cadmium to the extracellular medium caused a rapid, but transient, decrease of the photocurrent. the effect of cadmium on the movement of divalent cations, such as ba2+ and ca2+, differs according to the experimental protocol: when cadmium is introduced into the bathing mediu ...19882478389
ionic channels of the inner segment of tiger salamander cone photoreceptors.cone photoreceptors were isolated enzymatically and their ionic currents studied by the whole-cell, gigaseal voltage-clamp technique. five nonsynaptic currents were identified. a prominent, poorly selective cation current, ih, activated after a delay during hyperpolarizations and then deactivated with a delay on return to potentials greater than -50 mv. an empirical model for ih gating kinetics is developed with three open and two closed states. depolarization elicits a small, voltage-gated calc ...19892482325
effects of background illumination on the horizontal cell responses in the tiger salamander retina.synaptic transmission between photoreceptors and horizontal cells (hcs) was studied in the flat-mounted isolated retinas of the tiger salamander. background illumination expedited the rise time of the hc light response, and the hc response rise time (hcrrt) reached steady state about 2 sec after the onset of the background illumination. the change in hcrrt is probably responsible for the background-induced enhancement of the hc responses to short light stimuli. the amplitude of the hc responses ...19892538583
gamma-aminobutyrate type b receptor modulation of l-type calcium channel current at bipolar cell terminals in the retina of the tiger salamander.bipolar-cell axon terminals receive direct synaptic input from amacrine-cell processes, suggesting a possible pathway for modulation of transmitter release. in retinal slices, bath-applied baclofen, a gamma-aminobutyrate type b (gabab) receptor agonist, reduced a patch-clamp-recorded l-type calcium channel current in a population of bipolar cells with axon terminals that ramify along the midline of the inner plexiform layer. lucifer yellow staining revealed that this current was found only in bi ...19892557620
effects of cnqx, apb, pda, and kynurenate on horizontal cells of the tiger salamander retina.effects of 6-cyano-7-nitroquinoxaline-2,3-dione (cnqx), 2-amino-4-phosphonobutyrate (apb), cis-2,3-piperidine dicarboxylic acid (pda), and kynurenate (kyn) on the depolarizing actions of glutamate and kainate on horizontal cells (hcs) were studied in the larval tiger salamander retina. apb, pda, and kyn hyperpolarized the hcs, but they failed to block either the actions of glutamate and kainate, or the hc light responses. apb and pda did not cause membrane polarizations in either rods or cones, ...20082577265
distribution of muscarinic acetylcholine receptors on processes of isolated retinal cells.binding of propylbenzilylcholine mustard, a muscarinic acetylcholine receptor antagonist, to isolated retinal cells was examined with light microscopic autoradiography. dissociation of the adult tiger salamander retina yielded identifiable rod, cone, horizontal, bipolar, amacrine/ganglion, and müller cells. preservation of fine structure was assessed with conventional electron microscopy. for all cell types, the plasmalemma was intact and free of adhering debris; in addition, presynaptic ribbon ...19892592618
thrombocytopenia after brown snake envenomation.the marked coagulation disturbances in patients after severe envenomation by brown snakes (genus pseudonaja) were examined with particular emphasis on the sequential platelet counts. the common finding (in almost half the studied patients) of a progressive depletion in platelet numbers leading to thrombocytopenia, which in one case was severe, suggests that thrombocytopenia should be considered as a possible complicating factor in the management of these patients. this trend was not a feature of ...20042593907
signal transfer from photoreceptors to bipolar cells in the retina of the tiger salamander.under conditions of dark-adaptation, in response to weak stimuli, the distal retina behaves as a linear system. during the process of voltage transfer from the rods to the bipolar cells the information encoded in the rod responses is spatially filtered. the spatial filtering is determined by the spatial properties of the receptive field of the bipolar cell. these, in turn, depend upon the spatial properties of three syncytia, those of the receptors, the horizontal cells and the bipolar cells the ...19892594256
the tiger in my life. 19892599896
toxoplasmosis in a siberian tiger (panthera tigris altaica). 20032617817
observations on blood coagulation after snakebite in dogs and cats.blood samples from 13 cases of snakebite, 6 in dogs and 7 in cats, were tested for activated partial thromboplastin time (aptt), prothrombin time (pt) and fibrin/fibrinogen degradation products (fdp). four cases were tested for fibrinogen concentration. based on the results of a commercially available elisa test, 9 cases were caused by tiger snakes (notechis scutatus) and 1 case by a brown snake (pseudonaja textilis). three other cases had clinical signs and increased creatine phosphokinase valu ...19892619650
induction of cloacal and dermal skin glands of tiger salamander larvae, (ambystoma tigrinum): effects of testosterone and prolactin.treatment of male and female tiger salamander larvae with testosterone (0.3 micrograms/g body weight/day) induced precocious formation of ventral cloacal glands and stimulated proliferation and differentiation of mucous and granular (serous) glands in the ventral dermis of the skin. lower doses of testosterone produced no visible glandular effects but did cause hyperemia and edema in the cloacal region. prolactin (0.5 micrograms/g body weight/day) enhanced the action of testosterone on the cloac ...19892707581
carnivora: the amino-acid sequence of the adult sumatran tiger (panthera tigris sumatrae) hemoglobins.the complete amino-acid sequences of the hemoglobins from the adult sumatran tiger (panthera tigris sumatrae) have been determined on automatic liquid- and gas-phase sequenators. the globin chains were isolated by reverse phase hplc on a column of nucleosil-c4. n-acetylserine was detected by fab-mass spectroscopy as n-terminal aminoacid residue of the beta i chain. comparing the sequences of the globin chains of the tiger with that of human hb-a, 23 substitutions were recognized in the alpha, 29 ...19892713095
effects of prolonged light exposure, gaba, and glycine on horizontal cell responses in tiger salamander retina.1. the effects of prolonged light exposure, gamma-aminobutyric acid (gaba), and glycine on the horizontal cell (hc) light responses were studied in the superfused flat-mounted isolated retinas of the larval tiger salamander. 2. under prolonged dark-adapted conditions, the time-to-peak of the hc light response was approximately 2-4 s, and after the termination of prolonged (6-8 min) light exposure, the time-to-peak became approximately 0.5-1 s. 3. this prolonged light-induced change in response r ...19892723728
body politic: lions or paper tigers? 20042726559
8-brcamp-induced capacitance and transport of h2o and na in skin and urinary bladder of urodele amphibians.the effects of 8-bromoadenosine 3',5'-cyclic monophosphate (8-brcamp) on capacitance (c), osmotic water flow (jv), and amiloride-sensitive short-circuit current (ina) were studied in bladder and skin derived from the tiger salamander (aquatic and postmetamorphosed terrestrial phase). 8-brcamp-dependent increases in c, measured from the transepithelial voltage response to constant current pulses, occurred in aquatic (delta c = 44%) and terrestrial (delta c = 61%) bladders and terrestrial skin (de ...19892735392
tiger mauling: fatal spinal injury.a 33 year old zoo keeper was attacked by a sumatran tiger in captivity. apart from severe lacerations and penetrating wounds to the head and neck, the patient sustained comminuted fractures of c1 and c2 vertebrae with resultant high laceration of the spinal cord. major vascular injury as well as trauma to pharynx also occurred. the patient survived these injuries for 15 h.19892735879
a theoretical and experimental study of the effects of non-uniform membrane resistance on the shape of single-cell charging curves.the isolated muller glial cell of the neotenous tiger salamander retina is used as an experimental model for studying the effects of non-uniform membrane conductance on the shape of charging curves in response to step current inputs. a simple cable model of the muller cell is formulated and used to interpret the experimental data. the muller cell model is completely described by three parameters: (a) electrotonic length l; (b) the membrane time constant tau m; and (c) the percentage of the total ...19892739908
the asian tiger mosquito, aedes albopictus, in kentucky. 19892746213
immunological properties of notexin, a potent presynaptic and myotoxic component from venom of the australian tiger snake notechis scutatus scutatus.neutralizing antibodies were raised in mice against notexin, the most toxic phospholipase a2 (pla2) from notechis scutatus scutatus venom, without the necessity of detoxifying the toxin prior to immunization. using a sensitive radioimmunoassay we demonstrated that anti-notexin antibodies recognized (i) the parent antigen, (ii) closely related isoforms of notexin and (iii) venoms from notechis genus snakes. in contrast, they failed to recognize other purified pla2 or pla2-containing venoms from o ...19892753144
in-vitro induction of capacitation of fresh and frozen spermatozoa of the siberian tiger (panthera tigris).electroejaculates from 5 tigers were split and half of each was assayed fresh while the remainder was frozen and thawed before being assayed. preincubation time, temperature and removal of seminal plasma were evaluated for their effect on in-vitro capacitation. ability of spermatozoa to penetrate oocytes, as measured by the zona-free hamster egg-sperm penetration assay (spa), was used as verification of capacitation. results of the experiments with fresh semen indicate that: (1) preincubation ti ...19892760889
detection of a baculovirus in the tiger prawn penaeus monodon.in postlarval penaeus monodon from a hatchery in asia a baculovirus was detected in the epithelial cells of the hepatopancreas by electron microscopy. the baculovirus was identified as the monodon baculovirus (mbv).19892763758
[species specific motility patterns of hyperactivated mammalian spermatozoa and quantitative analysis of the hyperactivation of bull spermatozoa].movement tracks of spermatozoa of human, lion, tiger, cow, pig and sheep are recorded by dark field photography (fluid layer thickness 16.7 microns, exposure time 1 s). comparison before and after capacitation by an incubation of 2 h in modified tissue culture medium tcm 199 with 10% fetal calf serum resulted in two quite different patterns of hyperactivated spermatozoa: 1) tracks are broadened due to enlarged lateral head displacement or radius of rotating head movements respectively (tiger, li ...19892774216
purification and properties of a procoagulant from peninsula tiger snake (notechis ater niger) venom.the procoagulant from notechis ater niger was purified by gel filtration and anion exchange chromatography. it is a protein with an approximate mol.wt of 58,000 and in the presence of b mercaptoethanol is reduced to two chains with mol.wts of 37,000 and 23,000. the procoagulant has a pi of 7.3. the whole venom requires factor v to be present to bring about coagulation while ca2+ and phospholipid are not essential, but when present stimulate this process. normal prothrombin, but not decarboxyprot ...19892781577
potassium conductance block by barium in amphibian müller cells.the effect of barium on müller cell k+ conductance was evaluated in the tiger salamander using enzymatically dissociated cells and cells in situ (retinal slice and isolated retina). barium effects were similar in both cases. in dissociated cells, 50 microm ba2+ depolarized cells 14.7 mv and raised cell input resistance from a control value of 16.0 to 133 m omega. for cells in situ, 50 microm ba2+ depolarized cells 6.9 mv and raised cell resistance from 12.5 to 50.4 m omega. at corresponding ba2+ ...20092790485
ultrastructural localization and identification of adrenergic and cholinergic nerve terminals in the olfactory mucosa.pharmacological and ultrastructural methods were used to demonstrate alpha-adrenergic regulation of secretory granule content of acinar cells of bowman's glands and to localize and identify adrenergic and cholinergic axonal varicosities and terminals in the olfactory mucosa of the tiger salamander. the alpha-adrenergic agonist phenylephrine caused secretory granule depletion from bowman's glands; the alpha-adrenergic antagonist phentolamine partially blocked this effect. these observations were ...20082817441
light-dependent synaptic delay between photoreceptors and horizontal cells in the tiger salamander retina.a long delay between the time to peak of the photoreceptor and horizontal cell light responses was observed in dark-adapted tiger salamander retinas. the rise of the hc light responses follows a biphasic time-course which is probably mediated by the removal of the rod and cone transmitters, but not by voltage-dependent mechanisms in the hc membrane. a bleaching white light shortens the signal delay and results in a faster and monophasic rise of the hc light responses mediated predominantly by th ...19872821691
effects of cyclic gmp on the kinetics of the photocurrent in rods and in detached rod outer segments.we investigated the effects of high concentrations of cytoplasmic cyclic gmp on the photocurrent kinetics and light sensitivity of the tiger salamander rod both in intact cells and in detached outer segments. photoreceptors were internally perfused with cgmp by applying patch pipettes containing cgmp to the inner or outer segment. large increases in the concentration of cgmp in the outer segment cytoplasm were achieved only when the patch pipette was applied directly to the outer segment. the da ...19872824661
a comparative analysis of ejaculate and hormonal characteristics of the captive male cheetah, tiger, leopard, and puma.male cheetahs, tigers, leopards, and pumas maintained under the same conditions were anesthetized and 1) serially bled before, during, and after electroejaculation (ee); 2) serially bled only (ao); or 3) serially bled before and after receiving adrenocorticotropin hormone (acth). ejaculates from leopards contained higher (p less than 0.05) sperm concentrations than cheetahs and pumas but lower (p less than 0.05) sperm motility ratings than all other species. tigers produced a larger seminal volu ...19882833943
use of a subunit feline leukemia virus vaccine in exotic cats.three adult bengal tigers, 2 immature white tigers, and 3 adult servals were vaccinated im with three 1-ml doses of a subunit felv vaccine with dosage interval guidelines of the manufacturer. all cats had increased antibody titers to felv gp 70 capsular antigen and feline oncornavirus cell membrane-associated antigen during the vaccination trial. three weeks after the third vaccination, 7 of the 8 cats had gp70 antibody titers greater than 0.2 (optical density), and all 8 cats had feline oncorna ...19882835347
synaptic transmission from rods to horizontal cells in dark-adapted tiger salamander retina.synaptic transmission between rods and horizontal cells (hcs) was studied by simultaneously recording from the pre- and postsynaptic cells in the living retinal slices of the larval tiger salamander. voltage tails after the termination of a flash were observed in dark-adapted rods and hc somata, but not in cones. these simultaneously recorded voltage tails were used to isolate the rod input from the cone input to the hcs. the rod voltage versus the hc voltage in the response tails yielded the in ...19882842959
the centers for disease control's perspective of the introduction of aedes albopictus into the united states.the asian "tiger mosquito" aedes albopictus has become established in the southern united states. the centers for disease control has taken a number of steps to respond to the problem. appropriate state and international agencies have been informed, and data on biology, public health importance and identification have been prepared and distributed to state and local agencies. studies on insecticide susceptibility and vector competence are in progress, as is surveillance throughout the southeast, ...19862853204
neural interactions mediating the detection of motion in the retina of the tiger salamander.the neural circuitry underlying movement detection was inferred from studies of amacrine cells under whole-cell patch clamp in retinal slices. cells were identified by lucifer yellow staining. synaptic inputs were driven by "puffing" transmitter substances at the dendrites of presynaptic cells. spatial sensitivity profiles for amacrine cells were measured by puffing transmitter substances along the lateral spread of their processes. synaptic pathways were separated and identified with appropriat ...20052856477
ventricle morphology in pelagic elasmobranch fishes.ventricle weights of the warm-bodied great white shark, atlantic shortfin mako, and the common thresher shark (the latter presumed to be warm-bodied) are similar to those of ectothermic blue sharks, sandbar sharks, dusky sharks, tiger sharks and scalloped hammerhead sharks. ventricle muscularity, as estimated by the ratio of cortical to spongy layer thickness, is almost twice as great in the former three species than in the latter elasmobranchs. measurements of ventricular volumes suggest that t ...19852866886
photoreceptors of the larval tiger salamander retina.six morphological types of photoreceptor were identified with electron microscopy in radial sections of the retina of the larval tiger salamander, ambystoma tigrinum. in order of predominance these six types are: red rods, large single cones, double cones composed of principal and accessory members, small single cones, and green rods. the different types of photoreceptor can be distinguished by a number of morphological and cytological characteristics. the identification of the small single cone ...19862873578
basic haematological values in carnivores--ii. the felidae.1. basic haematological values in 34 animals of eight carnivorous species are reported. 2. in four northern lynxs (lynx lynx lynx), two male and two female animals, the mean values are given: erythrocyte counts 8.51 x 10(12)/l, haematocrit 0.392/l, haemoglobin content 148.0 g/l and leukocyte count 7.92 x 10(9)/l. 3. in six male pumas (puma concolor missolensis) the mean values estimated are: erythrocyte count 9.35 x 10(12)/l, haematocrit 0.43/l, haemoglobin content 163.9 g/l and leukocyte count ...19872886279
localization of tyrosine-hydroxylase-like-immunoreactive amacrine cells in the larval tiger salamander retina.immunocytochemistry was used to localize the populations of tyrosine-hydroxylase-like (th)-immunoreactive cells in the tiger salamander retina. ninety percent of these cells possessed somas that were situated in the innermost cell row of the inner nuclear layer and were classified as amacrine cells. ten percent of th-immunoreactive somas were located in the ganglion cell layer and were tentatively designated as those of displaced amacrine cells. the processes of th-immunoreactive cells ramified ...19882898490
depolarization-induced alkalinization in proximal tubules. i. characteristics and dependence on na+.we used intracellular ph-sensitive and voltage microelectrodes to examine the effects of depolarization on intracellular ph (phi) in isolated perfused proximal tubules from the tiger salamander ambystoma tigrinum. tubules were depolarized by raising [k+] in the bath (b) or lumen (l), or by adding ba2+ (1 mm) to the bath or lumen, always in nominally hco3-free solutions. increasing [k+]b from 2.5 to 50 mm caused the basolateral membrane to depolarize by an average of 45 mv, and phi to increase by ...19892916666
depolarization-induced alkalinization in proximal tubules. ii. effects of lactate and sits.intracellular ph and voltage microelectrodes were used to further characterize the depolarization-induced alkalinization (dia) observed in isolated perfused proximal tubules of the tiger salamander ambystoma tigrinum. tubules were depolarized by raising basolateral [k+] from 2.5 to 50 mm. the solutions were air equilibrated and nominally hco3- free (estimated [hco3-] = 0.2 mm). in the preceding study we showed that the dia is partially blocked by removal of na+ from only the lumen or only the ba ...19892916667
amacrine cell interactions underlying the response to change in the tiger salamander retina.the neural circuitry and pharmacology underlying transient signal formation at the bipolar-amacrine cell interface were studied. synaptic currents were measured with whole cell patch clamp in retinal slices. cell types were identified with lucifer yellow staining. activity was initiated with puffs of kainate of known time course and spatial spread delivered at bipolar dendrites. off bipolar cells responded to kainate with a sustained inward current, but on bipolar cells were silent. two types of ...19892918384
synaptic transmission from rods to bipolar cells in the tiger salamander retina.synaptic transmission between rods and depolarizing bipolar cells (dbc) was studied by using simultaneous recording techniques in the living retinal slice preparation. current injection into the rod elicited a sign-inverting, sustained voltage change in the dbc. voltage "tails" after the termination of a bright flash were observed in dark-adapted rods and dbc but not in cones. these simultaneously recorded voltage tails were used to isolate the rod input from the cone input and to study the inpu ...19852987955
cyclic gmp increases photocurrent and light sensitivity of retinal cones.like retinal rods, cone photoreceptors contain cyclic gmp and light-activated phosphodiesterase. the cgmp phosphodiesterase cascade is thought to mediate phototransduction in rods. biochemical assays of nucleotide content in cone-dominant retinas, however, have failed to demonstrate light-induced changes in cgmp. changes in cyclic amp following light exposure have been reported, leading to the suggestion that in cone phototransduction camp assumes a role analogous to that played by cgmp in rods. ...20162993915
direct excitatory and lateral inhibitory synaptic inputs to amacrine cells in the tiger salamander retina.two distinct synaptic currents in amacrine cells were measured using whole cell patch clamp in retinal slices. synaptic activity was elicited with transretinal current passed from photoreceptors to ganglion cells to depolarize bipolar cell terminals. recordings made in line with the stimulating electrodes revealed inward synaptic currents that reversed near o mv, positive to spike threshold. recording 400 micron lateral to the stimulating electrodes revealed synaptic currents that reversed near- ...19873032358
synaptic connections between neurons in living slices of the larval tiger salamander retina.synaptic connections between retinal cells were studied by recording simultaneously from pre- and postsynaptic cells in the retinal slice preparation. the time course and waveform of the pre- and postsynaptic light responses were monitored, and the postsynaptic voltage responses to presynaptic current injection were measured. results obtained provide direct evidence showing that the rod-hbc and rod-hc synapses are sign-preserving, and the rod-dbc, hc-hbc and amacrine-dbc synapses are sign-invert ...19873037200
the tiger mosquito in shanghai, by r.c. robertson and stephen m.k. hu, 1935. 20103057116
aedes albopictus in the united states: rapid spread of a potential disease vector.aedes albopictus, the asian "tiger mosquito," was found in houston, texas, in 1985. aedes albopictus is primarily a forest edge inhabiting species that has readily adapted to the container habitats produced by humans. although not yet incriminated in the spread of any disease in the americas, it has been repeatedly implicated in epidemic dengue and dengue hemorrhagic fever transmission in asia. it is a competent laboratory vector of la crosse, yellow fever and other viruses, and can transovarial ...19883058869
the existence of glutathione and cysteine disulfide-linked to erythrocyte carbonic anhydrase from tiger shark.in this study it is shown that the higher molecular weight previously reported for tiger shark carbonic anhydrase (carbonate hydro-lyase, ec 4.2.1.1) compared to other carbonic anhydrases is decreased to a normal value around 30 000 after disulfide reduction of the enzyme. this difference in molecular weight is at least partly due to the existence of disulfide-linked glutathione and cysteine residues. approx. 3 mol glutathione and a similar amount of cysteine are shown to be bound per mol enzyme ...19863083866
incorporation of calcium buffers into salamander retinal rods: a rejection of the calcium hypothesis of phototransduction.the suction-electrode technique was used to monitor the photocurrent of isolated retinal rods from the tiger salamander, by drawing in the light-sensitive outer segment, or sometimes the inner segment. calcium buffers or other agents were then introduced into the rod cytoplasm by the 'whole-cell patch-clamp' technique. a patch pipette was sealed against the region of the rod protruding from the suction pipette (usually the inner segment), and the membrane patch was ruptured to obtain a whole-cel ...20113088263
conservation among the immunoglobulins of carcharhine sharks and phylogenetic conservation of variable region determinants.to study primitive vertebrate recognition molecules we have purified the immunoglobulins of three species of carcharhine sharks. the tiger (galeocerdo cuvieri), the sandbar (carcharhinus plumbeus) and the galapagos sharks (carcharhinus galapagensis) possess 18s high molecular weight and 7s low molecular weight immunoglobulin forms. both within and between species these forms closely resemble each other in polypeptide chain composition, heavy chain mass, carbohydrate content, amino acid compositi ...19863094228
runners' anaemia: a paper tiger. 19873117168
evaluation of the pituitary-gonadal response to gnrh, and adrenal status, in the leopard (panthera pardus japonensis) and tiger (panthera tigris).frequent blood samples were collected to study hormonal responses to gnrh in male and female leopards and tigers. animals were anaesthetized with ketamine-hcl and blood samples were collected every 5 min for 15 min before and 160 min after i.v. administration of gnrh (1 micrograms/kg body weight) or saline. no differences in serum cortisol concentrations were observed between sexes within species, but mean cortisol was 2-fold greater in leopards than tigers. gnrh induced a rapid rise in lh in al ...19883123664
partial characterization of immunoglobulin light chains of carcharhine sharks: evidence for phylogenetic conservation of variable region and divergence of constant region structure.isolated light chains of igm-type immunoglobulins of carcharhine sharks were analyzed by serological and biochemical means. when analyzed by isoelectric focusing analysis, light chains of the tiger shark (galecerdo cuvieri), the galapagos shark (carcharhinus galapagensis) and the sandbar shark (carcharhinus plumbeus) showed a broad, but patterned, spectrum of bands ranging from pi 5.0 to 7.7 in which discrete families were observed. serologically, light chains of the galapagos shark cross-reacte ...19883127255
enhancement of ornithine decarboxylase activity in ambystoma liver slices by ovine prolactin: an evaluation of possible mediators.prolactin has been shown to increase the activity of ornithine decarboxylase in a variety of mammalian tissues and in the pigeon crop sac. this study demonstrates a similar effect of ovine prolactin on ornithine decarboxylase activity in liver slices taken from larval tiger salamanders (ambystoma tigrinum). an evaluation of potential mediators of prolactin action in liver slices revealed that the effect of the hormone on enzyme activity was not blocked by ouabain, an inhibitor of the sodium pump ...20113141245
surgical treatment of laryngeal ossification in a tiger. 19863146564
asynchronous expression of the alcohol and supernatant malate dehydrogenase loci during barbus hybrid development (cypriniformes, teleostei).the tissue specificity and ontogeny of supernatant malate dehydrogenase (s-mdh) and alcohol dehydrogenase (adh) are reported for the tiger barb (barbus tetrazona), the rosy barb (barbus conchonius) and their reciprocal hybrids. the tissue distribution of s-mdh and adh isozymes in both species is consistent with spatial profiles reported for other teleosts. the expression of alleles of paternal origin at the s-mdh-b and adh loci are delayed in reciprocal hybrids as compared to their expression in ...19853161685
interrenal activity during metamorphosis of the tiger salamander, ambystoma tigrinum.plasma corticosterone concentrations were low in premetamorphic tiger salamander larvae (norman stage i; m. f. norman (1985) anat. rec. 211, 102-109). corticosterone levels were significantly elevated at midmetamorphosis (norman stage iv) but decreased at the end of metamorphosis (norman stage vii). corticosterone levels remained low 2 weeks after metamorphosis. interrenal 3 beta-hydroxysteroid dehydrogenase activity was low in premetamorphic larvae (norman stage i) but was significantly elevate ...20113165899
complete amino acid sequence of a pla2 from the tiger snake notechis scutatus scutatus as deduced from a complementary dna. 19883174443
the tiger and the shaman: towards an understanding of why we tolerate a major cause for death and disability. 19883182250
localization of putative gabaergic neurons in the larval tiger salamander retina by immunocytochemical and autoradiographic methods.putative gabaergic neurons in the larval tiger salamander retina were localized by a comparative analysis of glutamate decarboxylase immunoreactivity (gad-ir), gaba-like immunoreactivity (gaba-ir), and high-affinity 3h-gaba uptake at the light microscopical level. preliminary data showed that all gad-ir neurons were double labeled for gaba-ir. however, because the weak somatic labeling with gad-ir, we could not determine if the converse were true. neurons commonly labeled with gaba-ir and 3h-gab ...19883198798
a slowly inactivating potassium current truncates spike activity in ganglion cells of the tiger salamander retina.voltage-gated ganglion cell membrane currents were studied under whole-cell patch clamp in isolation and in retinal slices. the cells were identified by (1) backfilling their axons with rhodamine and later identifying them by their fluorescence in the slice or the mix of isolated cells or (2) by filling them with lucifer yellow during recording in retinal slices. both methods yielded cells with similar currents. in some cases, isolated cells lacked processes yet showed currents similar to other ...19883199187
hallervorden-spatz syndrome: clinical and magnetic resonance imaging correlations.two women with a presumptive diagnosis of hallervorden-spatz syndrome had a combination of dystonia and parkinsonism. one had retinitis pigmentosa. neuropsychological testing revealed decreased verbal fluency and visuoconstructional and motor deficits. magnetic resonance imaging performed with a high-field-strength unit (1.5 tesla) showed striking abnormalities in the globus pallidus bilaterally ("eye-of-the-tiger" sign). magnetic resonance imaging may prove useful in the diagnosis of hallervord ...20113202617
the blocking effect of l-cis-diltiazem on the light-sensitive current of isolated rods of the tiger salamander.the effect of the organic compound l-cis-diltiazem on the light-sensitive current of isolated rods of the tiger salamander was analysed by rapidly changing the extracellular medium using the method of hodgkin et al. (1985). addition to the extracellular medium of small amounts of l-cis-diltiazem rapidly inhibits the photocurrent. complete suppression of the current was observed with 1 mm l-cis-diltiazem. half blockage of the photocurrent occurred with about 150 microm l-cis-diltiazem. the blocki ...19883208710
blood flow patterns in the salamander, ambystoma tigrinum, before, during and after metamorphosis.the patterns of blood flow through the complex circulation of the tiger salamander, ambystoma tigrinum, were investigated during aquatic normoxia and hypoxia by application of the microsphere technique. the distribution of differently labelled microspheres injected into the bloodstream towards the left and right atria, respectively, was used to evaluate the role of the ductus arteriosus in lung perfusion before, during and after metamorphosis, as well as the general contribution of right and lef ...19883209973
the chinese representation of cosmic elements as graphic symbols.in chinese cosmology, cosmic elements have been deified and assigned life-forms. air, representing ultrasonic energy as a celestial entity, became bird-god, red-bird. water acquired dragon as its representative and fire had tiger as its graphic symbol. earth, as body, was fertile and long-lasting. it was symbolized as tortoise, known to be long-lived. its soul became serpent, long enough to be powerful as cosmic soul. serpent-tortoise, as body-soul, became the god black-warrior in charge of eart ...19883218627
colocalization of gaba and glycine immunoreactivities in a subset of retinal neurons in tiger salamander.alternate serial 1 micron durcupan resin sections of tiger salamander retina were stained with antisera against gaba and glycine using postembed immunocytochemical techniques. although the vast majority of neurons were labeled by either gaba or glycine antiserum, a small percentage of presumed amacrine cells in the inner nuclear layer and cells in the ganglion cell layer were clearly labeled by both antisera, indicative of colocalization of endogenous gaba and glycine. although there is a greate ...19883226620
a comparison of the discriminatory ability and sensitivity of the trigeminal and olfactory systems to chemical stimuli in the tiger salamander.trigeminal receptors can respond to a wide variety of chemical stimuli, but it is unknown whether these receptors mediate discrimination between chemical stimuli matched for equal perceptual intensity. the present electrophysiological and behavioral experiments address this issue using tiger salamanders, ambystoma tigrinum, and four compounds (amyl acetate, cyclohexanone, butanol, and d-limonene). in addition, the relative sensitivities of the trigeminal and olfactory systems to these compounds ...19883236261
variation in venom proteins from isolated populations of tiger snakes (notechis ater niger, n. scutatus) in south australia.pooled venom of peninsula tiger snakes (notechis ater niger) from 11 insular populations and one mainland area, and from a single population of the mainland tiger snake (n. scutatus) were subjected to sds-page and gel filtration chromatography. at least 20 proteins were resolved in the sds-page, some of which were common to all populations, but many others were highly variable. elution profiles produced through gel filtration showed a clustering of some populations with like profiles, while othe ...19883245051
diagnosis of pulmonary mycobacterium bovis infection in a tiger. 19873296419
topologic and connectional analysis of the dorsal thalamus of triturus alpestris (amphibia, urodela, salamandridae).a morphological and connectional analysis was performed on the dorsal thalamus of the alpine newt, triturus alpestris. we have used a graphic reconstruction technique for the evaluation of the connectional (hrp) data. on the basis of these reconstructions, we propose a subdivision of the salamandrid dorsal thalamus into subhabenular, anteroventral, and posterodorsal zones. each of these zones is defined by its telencephalic projections ("ascending thalamofugal systems"). the posterodorsal zone p ...20123346376
scanning electron microscopy and electron probe microanalyses of the crystalline components of human and animal dental calculi.a review of the use of scanning electron microscopy (sem) and electron probe microanalyses in the study of dental calculus showed that such studies provided confirmatory and supplementary data on the morphological features of human dental calculi but gave only limited information on the identity of the crystalline or inorganic components. this study aimed to explore the potential of combined sem and microanalyses in the identification of the crystalline components of the human and animal dental ...19883368765
melatonin enhances horizontal cell sensitivity in salamander retina.intracellular electrophysiological recording techniques were utilized to investigate the possible function of retinal melatonin in the larval tiger salamander. endogenous retinal melatonin was present and appeared to bind a membrane-enriched fraction of the salamander retina, as determined by radioimmunoassay and receptor binding studies. melatonin added through the perfusion bath to flat-mounted retinas resulted in a horizontal cell (hc) hyperpolarization of 10-20 mv. additionally, the amplitud ...19883401776
localization of neurotensin-like immunoreactive amacrine cells in the larval tiger salamander retina.light microscopic immunocytochemistry was used to localize the populations of nt-like immunoreactive amacrine cells in the larval tiger salamander retina. seventy-nine percent of nt-immunostained cells observed in transverse cryo-prepared sections were classified as type 1 amacrine cells. another 6% were classified as type 2 amacrine cells, while 15% of the nt-cells had their cell bodies situated in the ganglion cell layer and were tentatively designated as displaced amacrine cells. each type of ...19883402566
responses of mitral/tufted cells to orthodromic and antidromic electrical stimulation in the olfactory bulb of the tiger salamander.1. responses evoked by electrical stimulation of the olfactory nerve and olfactory tracts were analyzed in 46 output cells of the salamander olfactory bulb, in vivo. labeling of several cells with horseradish peroxidase indicated that they were mitral and/or tufted neurons. the responses contained reproducible sequences of depolarizing and hyperpolarizing potentials, which changed with increases in stimulus intensity. 2. stimulation of the nerve with intensities subthreshold for evoking spikes i ...19883404202
the off-overshoot responses of photoreceptors and horizontal cells in the light-adapted retinas of the tiger salamander.depolarizing overshoot responses at the cessation of a test light step were observed in horizontal cells (hcs) and in a population of photoreceptors (rodcs) in light-adapted retinas of the tiger salamander. an anode break regenerative conductance may contribute to the overshoot responses in rodcs(o-wave). the overshoot responses in hcs consist of two components: a fast alpha-wave whose amplitude and time course follow those of the o-wave; and a slow beta-wave whose amplitude and time course vary ...20123409996
cell dynamics in the olfactory epithelium of the tiger salamander: a morphometric analysis.the factors controlling neurogenesis and differentiation of olfactory receptor cells in adults are poorly understood, although it is often stated that these cells undergo continual turnover after a predetermined lifespan. an interesting model in which to study mechanisms which control olfactory receptor neurogenesis and cell turnover is the tiger salamander, since basal cell mitosis varies with epithelial thickness and location in the nasal cavity. this paper presents a quantitative light-micros ...19883416950
light microscopic localization of putative glycinergic neurons in the larval tiger salamander retina by immunocytochemical and autoradiographical methods.putative glycinergic neurons in the larval tiger salamander retina were localized by a comparative analysis of high affinity 3h-glycine uptake and glycine-like immunoreactivity (gly-ir) at the light microscopic level. commonly labeled neurons include at least three types of amacrine cell (type iad, type iab, type iiad; distinguished by soma location and dendritic ramification), cell bodies in the ganglion cell layer (gcl), and rarely observed type ii (inner) bipolar cells. with the increased res ...19883417892
electrical coupling between rods and cones in the tiger salamander retina.electrical coupling between rods and cones was studied in the salamander (ambystoma tigrinum) retina by measuring the light responses and spectral sensitivities of rods and cones and by measuring the voltage responses from a rod to current pulses injected into a cone. a population of 10-20% of the photoreceptors exhibited a mixed-response waveform of the rod and the cone under dark-adapted conditions, and a response waveform closely resembled that of a cone in the presence of background illumina ...19883422423
variation in venom constituents within a single isolated population of peninsula tiger snake (notechis ater niger).venom from seven individuals in a homogeneous isolated population of notechis ater niger on roxby island, off the south australia coast, was subjected to gel filtration liquid chromatography and polyacrylamide gel electrophoresis to determine the extent of homogeneity of the venom constituent profile. the gel filtration chromatograms from six of the specimens were easily equated, while the seventh showed a slight variation. sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the venoms ...19873433295
effect of electroneutral luminal and basolateral lactate transport on intracellular ph in salamander proximal tubules.we used microelectrodes to examine the effects of organic substrates, particularly lactate (lac-), on the intracellular ph (phi) and basolateral membrane potential (vbl) in isolated, perfused proximal tubules of the tiger salamander. exposure of the luminal and basolateral membranes to 3.6 mm lac- caused phi to increase by approximately 0.2, opposite to the decrease expected from nonionic diffusion of lactic acid (hlac) into the cell. addition of lac- to only the lumen also caused alkalinization ...19873440860
Displaying items 201 - 300 of 3651