| trichinella britovi from japan. | although parasites of the genus trichinella have been collected from wild animals in japan, they have never been studied at species level. muscle larvae of trichinella collected from a black bear (ursus thibetanus japonicus) and from a raccoon dog (nyctereutes procyonoides viverrinus) in japan have been identified as trichinella britovi by random amplified polymorphic dna analysis. the presence of t. britovi in japan shows that this parasite has a wide distribution in the palaearctic region, fro ... | 1996 | 8885903 |
| use of protein ag in an enzyme-linked immunosorbent assay for screening for antibodies against parapoxvirus in wild animals in japan. | using protein ag in an enzyme-linked immunosorbent assay (elisa), we tried to detect antibodies against parapoxvirus in 9 species of wild animals in japan: the japanese badger (meles meles anakuma), japanese black bear (ursus thibetanus japonicus), japanese deer (cervus nippon centralis), japanese monkey (macaca fuscata), japanese raccoon dog (nyctereutes procyonoides viverrinus), japanese serow (capricornis crispus), japanese wild boar (sus scrofa leucomystax), masked palm civet (paguma larvata ... | 1999 | 10225841 |
| characterization of semen collected from beagles and captive japanese black bears (ursus thibetanus japonicus). | this study characterized semen collected from the japanese black bear, ursus thibetanus aponicus, to provide information on semen cryopreservation for artificial breeding. preliminary studies using a beagle dog as the model species showed that sperm concentration and total sperm count were lower in semen collected by electroejaculation than in semen collected by digital manipulation, but that sperm motility, viability and morphology were similar. characterization of semen obtained from japanese ... | 2001 | 11245261 |
| characteristics of a hepatozoonosis in lungs of japanese black bears (ursus thibetanus japonicus). | in a survey of pathologic agents in the wild animals of central japan, we found a hepatozoon sp. in the lungs of japanese black bears in fukui, shiga, and gifu prefectures, japan. histopathologic examination of organs and tissues from the 18 bears inspected showed hepatozoonosis in all. immature and mature meronts were found in all lobules and between alveoli, with a few found between pleura and in connective tissue. in the lungs, inflammatory cells were not found around meronts, merozoites, or ... | 2003 | 12679571 |
| seroprevalence of tularemia in wild bears and hares in japan. | tularemia is a zoonotic disease caused by francisella tularensis. the distribution of the pathogen in japan has not been studied well. in this study, seroprevalence of tularemia among wild black bears and hares in japan was determined. blood samples collected from 431 japanese black bears (ursus thibetanus japonicus) and 293 japanese hares (lepus brachurus) between 1998 and 2009 were examined for antibodies against f. tularensis by micro-agglutination test (ma) or enzyme-linked immunosorbent ass ... | 2011 | 21824374 |
| sex identification of japanese black bear, ursus thibetanus japonicus, by pcr based on amelogenin gene. | a method for sex identification of the japanese black bear was examined using a polymerase chain reaction (pcr) and sequencing of a part of the amelogenin gene. this gene is located on the x and y chromosomes, and there are 54 nucleotide deletions on the y chromosome-specific gene. forty-seven (26 male and 21 female) dna samples and 23 (13 male and 10 female) dna samples, respectively extracted from white blood cells and hairs of japanese black bears were analyzed. the primers se47 and se48 from ... | 2002 | 12130835 |
| chemical characterization of milk oligosaccharides of the polar bear, ursus maritimus. | two trisaccharides, three tetrasaccharides, two pentasaccharides, one hexasaccharide, one heptasaccharide, one octasaccharide and one decasaccharide were isolated from polar bear milk samples by chloroform/methanol extraction, gel filtration, ion exchange chromatography and preparative thin-layer chromatography. the oligosaccharides were characterized by 1h-nmr as follows: the saccharides from one animal: gal(alpha1-3)gal(beta1-4)glc (alpha3'-galactosyllactose), fuc(alpha1-2)gal(beta1-4)glc (2'- ... | 2000 | 10913842 |
| chemical characterization of milk oligosaccharides of the japanese black bear, ursus thibetanus japonicus. | two trisaccharides, two tetrasaccharides, one penta-, one hexa-, two hepta-, one deca- and two undeca-saccharides were isolated from several japanese black bear milk samples by chloroform/methanol extraction, gel filtration and preparative thin-layer chromatography. the oligosaccharides were characterized by 1h-nmr as follows: gal(alpha 1-3)gal(beta 1-4)glc (alpha 3'-galactosyllactose), fuc(alpha 1-2)gal(beta 1-4)glc (2'-fucosyllactose), gal(alpha 1-3)(fuc(alpha 1-2))gal(beta 1-4)glc (b-tetrasac ... | 1999 | 10572951 |
| serological evidence of coxiella burnetii infection in wild animals in japan. | one hundred and thirty-four (26%) of 511 sera from 11 wild animal species in eight prefectures in japan had antibody titers to coxiella burnetii by the enzyme-linked immunosorbent assay. high prevalences were observed in japanese black bears (ursus thibetanus) (78%), hokkaido deer (cervus nippon yesoensis) (69%), japanese hares (lepus brachyurus) (63%), japanese deer (cervus nippon centralis) (56%), and to some extent in japanese monkeys (macaca fuscata) (28%). a low prevalence (13%) was observe ... | 1993 | 8355353 |
| comparative studies on soluble protein profiles and isozyme patterns of seven trichinella isolates. | soluble protein profiles and isozyme patterns of eight enzymes were compared for extracts of muscle stage larvae of the seven trichinella isolates, using isoelectric focusing in polyacrylamide gel. soluble protein profiles and isozyme patterns of four enzymes: malic enzyme, glucosephosphate isomerase, phosphoglucomutase, superoxide dismutase of them were clearly divided into four types. t. pseudospiralis from a racoon and the polar strain from a polar bear formed type 1 and type 2. the iwasaki s ... | 1987 | 3615396 |
| the molecular phylogenic tree of the genus trichinella constructed from isozyme patterns. | six zymograms were compared for extracts of muscle-stage larvae of the seven trichinella isolates, using isoelectric focusing in polyacrylamide gels. the isozyme patterns of acid phosphatase among them fell into four types. t. pseudospiralis from a raccoon and the polar strain from a polar bear formed type 1 and type 2, respectively. the iwasaki strain from a japanese black bear and the yamagata strain from a raccoon dog, both from japan, were type 3. type 4 consisted of three remaining strains, ... | 1988 | 3057491 |
| present status of trichinellosis in japan. | there have been three mass outbreaks of human trichinellosis in japan. the first was in 1974 in iwasaki, aomori prefecture, involving a group of hunters who ate raw meat of a black bear they had shot. of the 20 people who ate the bear meat raw, 15 showed clinical symptoms of trichinellosis. the second outbreak was experienced in sapporo, hokkaido, in 1980. the patients had eaten the raw meat of a brown bear served in a local restaurant. twelve people were diagnosed positive on the basis of clini ... | 1991 | 1822910 |
| mhc class ii dqb diversity in the japanese black bear, ursus thibetanus japonicus. | the major histocompatibility complex (mhc) genes are one of the most important genetic systems in the vertebrate immune response. the diversity of mhc genes may directly influence the survival of individuals against infectious disease. however, there has been no investigation of mhc diversity in the asiatic black bear (ursus thibetanus). here, we analyzed 270-bp nucleotide sequences of the entire exon 2 region of the mhc dqb gene by using 188 samples from the japanese black bear (ursus thibetanu ... | 2012 | 23190438 |
| hemotropic mycoplasma infection in wild black bears (ursus thibetanus japonicus). | this is the first report on mycoplasma infection in wild bears. we report a novel hemotropic mycoplasma (also called hemoplasma) detected in a free-ranging black bear (ursus thibetanus japonicus) in japan. we then used real-time pcr to look for hemoplasma dna in blood samples collected from 15 bears and found that eight (53%) were positive. among these eight pcr samples, seven showed a melting temperature of around 85.5°c, while the remaining one showed a single peak at 82.26°c. almost the entir ... | 2013 | 23313325 |
| seasonal changes in the expression of energy metabolism-related genes in white adipose tissue and skeletal muscle in female japanese black bears. | bears undergo annual cycles in body mass: rapid fattening in autumn (i.e., hyperphagia), and mass loss in winter (i.e., hibernation). to investigate how japanese black bears (ursus thibetanus japonicus) adapt to such extreme physiological conditions, we analyzed changes in the mrna expression of energy metabolism-related genes in white adipose tissues and skeletal muscle throughout three physiological stages: normal activity (june), hyperphagia (november), and hibernation (march). during hyperph ... | 2017 | 26880364 |
| long-term survey of cadmium and lead contamination in japanese black bears captured in iwate prefecture, japan. | cadmium and lead were measured in liver and kidney samples of 242 japanese black bears (ursus thibetanus japonicus) captured from 1999 to 2014 from two local populations in japan. the median concentration of cadmium was 0.54 (mean: 0.80) mg/kg-w.w. in liver and 7.7 (mean: 11.8) mg/kg-w.w. in kidney. the median concentration of lead was 0.24 (mean: 0.40) and 0.21 (mean: 0.32) mg/kg-w.w. in liver and kidney, respectively. bears in the kita-ou local population had higher concentrations of cadmium a ... | 2016 | 27704187 |
| phylogeographic and demographic analysis of the asian black bear (ursus thibetanus) based on mitochondrial dna. | the asian black bear ursus thibetanus is widely distributed in asia and is adapted to broad-leaved deciduous forests, playing an important ecological role in the natural environment. several subspecies of u. thibetanus have been recognized, one of which, the japanese black bear, is distributed in the japanese archipelago. recent molecular phylogeographic studies clarified that this subspecies is genetically distantly related to continental subspecies, suggesting an earlier origin. however, the e ... | 2015 | 26406587 |
| serosurveillance for francisella tularensis among wild animals in japan using a newly developed competitive enzyme-linked immunosorbent assay. | tularemia, a highly infectious zoonotic disease caused by francisella tularensis, occurs sporadically in japan. however, little is known about the prevalence of the disease in wild animals. a total of 632 samples obtained from 150 japanese black bears, 142 japanese hares, 120 small rodents, 97 rats, 53 raptors, 26 japanese monkeys, 21 japanese raccoon dogs, 20 masked palm civets, and three japanese red foxes between 2002 and 2010 were investigated for the presence of antibodies to f. tularensis ... | 2014 | 24689989 |
| molecular prevalence and characterization of hepatozoon ursi infection in indian sloth bears (melursus ursinus). | hepatozoon species are parasites that infect a wide variety of domestic and wild animals. the objective of the study was to detect the occurrence of hepatozoon ursi in indian sloth bears and to characterize the parasite based on phylogenetic analysis of the partial 18s rrna gene sequence. hepatozoon infection could be detected in 38 (70%) out of fifty-four blood samples of indian sloth bears (captive and wild), suggestive of high prevalence of hepatozoon infection in indian sloth bears. sequenci ... | 2011 | 21723665 |
| the first detection of babesia species dna from japanese black bears (ursus thibetanus japonicus) in japan. | in this study, we tried to detect protozoan blood parasites from the liver or blood of 156 japanese black bears (ursus thibetanus japonicus) in iwate prefecture of japan by polymerase chain reaction. two amplicons (approximately 540 bp and 480 bp) were detected by amplification for v4 hyper-variable regions of the 18s rrna gene. approximately 540-bp products were obtained in 119 samples (76.3%) and were considered to be dna of hepatozoon ursi. approximately 480-bp products were obtained in 22 sa ... | 2011 | 21376138 |
| genetic status of asiatic black bear (ursus thibetanus) reintroduced into south korea based on mitochondrial dna and microsatellite loci analysis. | the asiatic black bear is one of the most endangered mammals in south korea owing to population declines resulting from human exploitation and habitat fragmentation. to restore the black bear population in south korea, 27 bear cubs from north korea and russian far east (primorsky krai) were imported and released into jirisan national park, a reservoir of the largest wild population in south korea, in 2004. to monitor the success of this reintroduction, the genetic diversity and population struct ... | 2011 | 21325020 |
| evaluation of stored body fat in nuisance-killed japanese black bears (ursus thibetanus japonicus). | we evaluated the stored body fat of japanese black bears (ursus thibetanus japonicus) killed as nuisances in gifu and fukushima prefectures, japan, during 2005-2007. we employed femur marrow fat (fmf), modified kidney fat index (mkfi), and abdominal subcutaneous fat (asf) as indices for quantitative evaluation. we examined the basic characteristics of these indices, such as seasonality, age and sex dependency, and the quantitative relationship among them. mkfi and asf increased towards the begin ... | 2011 | 21303202 |
| localization of five steroidogenic enzyme mrnas in japanese black bear (ursus thibetanus japonicus) testes during the mating season by in situ hybridization. | the japanese black bear (ursus thibetanus japonicus) is a typical seasonal breeder that has a mating season in early summer. spermatogenesis and testicular steroidogenesis are known to develop and regress annually; however, its molecular mechanism has not yet been investigated. in the present study, we clarified the mrna sequence of 5 steroidogenic enzymes (p450scc, 3betahsd, p450c17, 17betahsd3 and p450arom) using rt-pcr and race methods and the localization of these gene expressions in the bea ... | 2010 | 20035104 |
| relationship between uterine morphology and peripheral concentrations of sex steroid hormone in wild japanese black bears (ursus thibetanus japonicus). | developing a better understanding of the reproductive physiology and breeding condition peculiar to wild japanese black bears (ursus thibetanus japonicus) is crucial for estimation of their habitat distribution. the aim of this study was to clarify the changes in morphology of the genital organs, cellular proliferation in the endometrium and sex steroid hormone concentrations along with the reproductive cycle in japanese black bears. samples were collected from a total of 24 female japanese blac ... | 2009 | 18790579 |
| hepatozoon ursi n. sp. (apicomplexa: hepatozoidae) in japanese black bear (ursus thibetanus japonicus). | morphological and genetic features of a new hepatozoon species, hepatozoon ursi n. sp., in japanese black bear (ursus thibetanus japonicus) were studied. schizogonic developmental stages were observed in the lungs of japanese black bears. the schizonts were sub-spherical in shape and 45.7+/-4.6 x 42.7+/-4.5 microm in size. each mature schizont contained approximately 80-130 merozoites and 0-5 residual bodies. the merozoites were 7.0+/-0.7 x 1.8+/-0.3 microm in size. intraleukocytic gametocytes w ... | 2008 | 18329332 |
| changes in serum inhibin levels and immunolocalization of inhibin/activin subunits during the breeding season in the wild male japanese black bear (ursus thibetanus japonicus). | the objective of this study was to investigate the changes in secretion of inhibin and cellular localization of inhibin alpha and inhibin/activin (beta(a) and beta(b)) subunits during the breeding season in the wild male japanese black bear. histological observations of testes were performed and seminiferous tubule diameters were measured. the sections of the testes were immunostained by the avidin- biotin-peroxidase complex method (abc) using polyclonal antisera raised against porcine inhibin a ... | 2006 | 16785611 |
| characteristics of captive japanese black bears (ursus thibetanus japonicus) semen collected by electroejaculation with different voltages for stimulation and frozen-thawed under different conditions. | the japanese black bear (ursus thibetanus japonicus) is an endangered species in some areas of japan, and semen collection and cryopreservation are important means to preserve genetic resources and prevent extinction. the aim of the present study was to improve the methods for electroejaculation and cryopreservation in these bears. we collected the semen from captive mature japanese black bears during the mating season by the electroejaculation method using maximum stimulus voltages of 10 v (n=9 ... | 2006 | 16289554 |
| immunohistochemical localization of steroidogenic enzymes in the testis of hokkaido sika deer (cervus nippon yesoensis). | the testes from 15 adult male hokkaido sika deer (cervus nippon yesoensis) were collected during the rutting season (october and november). we investigated the localization of 4 kinds of steroidogenic enzymes (p450scc, 3betahsd, p450c17 and p450arom) immunohistochemically in these testicular samples. the specific immunoreactivities to these enzymes were detected only in the cytoplasm of leydig cells. this differs to the enzyme distributions reported previously in japanese black bear, japanese ra ... | 2004 | 15585968 |
| note on dipetalonema (chenofilaria) japonica uni, 1983 from japanese black bear. supplementary description. | supplementary description was made on the specimens of d. (chenofilaria) japonica from the black bear (selenarctos thibetanus japonicus) of japan. scanning electron microscopy (sem) revealed the en face view of the head and the terminal tip of the tail of the female adults. the tail of the male is described in this report, and the microfilaria is confirmed. the adult specimens were found predominantly in the subcutaneous connective tissue near the scapula along with one microfilaria. microfilari ... | 1984 | 6542334 |
| electroejaculation and semen cryopreservation of free-ranging japanese black bears (ursus thibetanus japonicus). | the japanese black bear (ursus thibetanus japonicus) is endangered for extinction in some areas of japan, and semen collection and cryopreservation are an important means to preserve genetic resources. the aim of this study was to characterize and cryopreserve semen of free-ranging japanese black bears. semen was collected by electroejaculation procedure from 4 free-ranging japanese black bears at the capture point in the field. ejaculates containing motile sperm were recovered from all of the a ... | 2004 | 15585951 |
| differences in oligosaccharide pattern of a sample of polar bear colostrum and mid-lactation milk. | although the concentrations of carbohydrate in the colostrum and in the mid-lactation milk of polar bear (ursus maritimus) were similar, the oligosaccharide patterns differed. the colostrum sample contained neu5ac(alpha2-3)gal(beta1-4)glc (3'-n-acetylneuraminyllactose), galnac(alpha1-3)[fuc(alpha1-2)]gal(beta1-4)glc (a-tetrasaccharide), fuc(alpha1-2)gal(beta1-4)glc (2'-fucosyllactose) and gal(beta1-4)glc (lactose). the mid-lactation milk contained gal(alpha1-3)[fuc(alpha1-2)]gal(beta1-4)[fuc(alp ... | 2003 | 14662310 |
| effects of intramuscular administration of tiletamine-zolazepam with and without sedative pretreatment on plasma and serum biochemical values and glucose tolerance test results in japanese black bears (ursus thibetanus japonicus). | to establish a safe anesthetic protocol with little effect on blood biochemical values and iv glucose tolerance test (ivgtt) results in japanese black bears (ursus thibetanus japonicus). | 2012 | 22849689 |
| changes in expression of hepatic genes involved in energy metabolism during hibernation in captive, adult, female japanese black bears (ursus thibetanus japonicus). | hibernating bears survive up to 6 months without feeding by utilizing stored body fat as fuel. to investigate how bears maintain energy homeostasis during hibernation, we analyzed changes in mrna expression of hepatic genes involved in energy metabolism throughout the hibernation period in captive, adult, female japanese black bears (ursus thibetanus japonicus). real-time pcr analysis revealed down-regulation of glycolysis- (e.g., glucokinase), amino acid catabolism- (e.g., alanine aminotransfer ... | 2012 | 22771378 |
| changes in blood glucose and insulin responses to intravenous glucose tolerance tests and blood biochemical values in adult female japanese black bears (ursus thibetanus japonicus). | the metabolic mechanisms to circannual changes in body mass of bears have yet to be elucidated. we hypothesized that the japanese black bear (ursus thibetanus japonicus) has a metabolic mechanism that efficiently converts carbohydrates into body fat by altering insulin sensitivity during the hyperphagic stage before hibernation. to test this hypothesis, we investigated the changes in blood biochemical values and glucose and insulin responses to intravenous glucose tolerance tests (ivgtt) during ... | 2012 | 22458193 |
| estimating the success rate of ovulation and early litter loss rate in the japanese black bear (ursus thibetanus japonicus) by examining the ovaries and uteri. | in order to develop a method for estimating the success/failure rates of reproductive processes, especially those of ovulation and neonate nurturing, in the japanese black bear (ursus thibetanus japonicus), we examined offspring status, corpora lutea (cls), placental scars (pss) and corpora albicantia (cas) in 159 females (0-23 years old) killed as nuisances on honshu island of japan during 2001-2009. pss were found to remain in the uterus at least until november of the year of parturition. ca d ... | 2011 | 21476488 |
| normal sperm morphology and changes of semen characteristics and abnormal morphological spermatozoa among peri-mating seasons in captive japanese black bears (ursus thibetanus japonicus). | the objectives of this study were to obtain morphological data for normal spermatozoa and to investigate seasonal changes (the early, mid- and post-mating seasons) in abnormal morphology of spermatozoa and the characteristics of semen in japanese black bears. semen was collected by electroejaculation from 34 captive male japanese black bears a total of 74 times. length of head, width of head, length of midpiece and total length of the spermatozoa were 6.3 +/- 0.4, 4.5 +/- 0.3, 10.4 +/- 0.7 and 6 ... | 2009 | 19194064 |
| annual changes in serum leptin concentration in the adult female japanese black bear (ursus thibetanus japonicus). | in the present study, assay of the serum leptin concentration of the japanese black bear (ursus thibetanus japonicus) was attempted using a canine-leptin-specific sandwich enzyme-linked immunosorbent assay (elisa). the dose-response curve of the bear serum was linear and parallel to the canine leptin standard curve. in mated and unmated bears, the serum leptin concentration was stable at low levels from may to august or september, gradually increased from september or october, and then remarkabl ... | 2008 | 19122415 |
| leptin receptor (ob-r) expression in the ovary and uterus of the wild japanese black bear (ursus thibetanus japonicus). | to verify target organ(s) of leptin in the reproductive system of the japanese black bear, we examined the expression of leptin receptor (ob-r) protein in ovaries and uteri collected from july to december 2006 by immunohistochemical techniques. eleven of 22 female japanese black bears examined had corpora lutea (cls) in their ovaries and were thought to have undergone or to have terminated delayed implantation in the early pregnancy stage. the cls were classified into 3 types based on morphologi ... | 2009 | 19106488 |
| immobilization of japanese black bears (ursus thibetanus japonicus) with tiletamine hydrochloride and zolazepam hydrochloride. | the effect of anesthetizing with a 1:1 combination of tiletamine hydrochloride and zolazepam hydrochloride (tz) was evaluated in 75 japanese black bears. tz was administered to 43 captive and 11 wild, 8 captives and 13 hibernating captive bears at the doses of approximately 9.0 mg/kg (usual dosage), 18.0 mg/kg (high dosage) and 5.0 mg/kg (low dosage), respectively. sufficient anesthetic effects were achieved in all bears, and rectal temperatures, heart rates and respiratory rates did not change ... | 2007 | 17485936 |
| incidence of ovulation without coital stimuli in captive japanese black bears (ursus thibetanus japonicus) based on serum progesterone profiles. | the purpose of this study was to ascertain whether or not japanese black bears (ursus thibetanus japonicus) are induced ovulators. the progesterone levels of female bears kept with a male and allowed to mate (n=2) and female bears allowed contact with a male through bars but not allowed to mate (n=6) during the mating season increased significantly in late october. based on this result, the female bears were considered to have ovulated. females isolated from males (n=3) were ovarioectomized afte ... | 2006 | 17085899 |
| characteristics of frozen-thawed spermatozoa cryopreserved with different concentrations of glycerol in captive japanese black bears (ursus thibetanus japonicus). | seven mature japanese black bears were used as semen donors, and a total of 7 semen samples collected from the animals by the electroejaculation method were cryopreserved in liquid nitrogen. egg yolk-tris-citrate-glucose extender was used, and the effects of different final concentrations of glycerol, at 4-12% (v/v), on frozen-thawed spermatozoa were examined. no significant difference was observed in percent motility or percent abnormal morphology of frozen-thawed spermatozoa among the differen ... | 2006 | 17085891 |
| chemical characterization of sialyl oligosaccharides in milk of the japanese black bear, ursus thibetanus japonicus. | sialyl oligosaccharides were separated from two samples of japanese black bear milk by extraction with chloroform/methanol, gel filtration on bio gel p-2, ion exchange chromatography on deae-sephadex a-50 and high-performance liquid chromatography (hplc) on a tsk gel amido-80 column. they were characterized by (1)h-nmr spectroscopy. the structures of four sialyl oligosaccharides separated from the milk were the following: neu5ac(alpha2-3)gal(beta1-4)glc. neu5ac(alpha2-6)gal(beta1-4)glcnac(beta1- ... | 2004 | 15581791 |
| spermatogenesis, serum testosterone levels and immunolocalization of steroidogenic enzymes in the wild male japanese black bear (ursus thibetanus japonicus). | twenty-one wild male japanese black bears (ursus thibetanus japonicus) were captured in the summer-autumn of 1998-2000 in the vicinity of neo village, gifu prefecture. testes were measured, and testicular samples were biopsied and observed histologically. four steroidogenic enzymes, i.e., cholesterol side-chain cleavage cytochrome p450 (p450scc), 3beta-hydroxysteroid dehydrogenase (3betahsd), 17-alpha hydroxylase cytochrome p450 (p450c17), and aromatase cytochrome p450 (p450arom) were immunoloca ... | 2003 | 14600347 |
| changes in sex steroids, gonadotropins, prolactin, and inhibin in pregnant and nonpregnant japanese black bears (ursus thibetanus japonicus). | we examined changes in the concentrations of serum progesterone (p4), estradiol-17beta (e2), fsh, lh, prolactin (prl), and inhibin to determine their interaction and their effect on the reproductive endocrine controls of pregnant and nonpregnant female japanese black bears. fourteen female bears were used in this study over a 2-yr period. in the first year, six of the bears were divided into two groups; a pseudopregnant group and a nonpregnant group. in the second year, the remaining eight bears ... | 2001 | 11566720 |
| immunolocalization of steroidogenic enzymes in the corpus luteum and placenta of the japanese black bear, ursus thibetanus japonicus, during pregnancy. | the japanese black bear, ursus thibetanus japonicus, is a seasonal breeder and shows delayed implantation for several months during pregnancy. the objective of this study was to clarify the steroidogenic capability of the corpus luteum and placenta during pregnancy, including both delayed implantation and fetal development, by immunolocalization of steroidogenic enzymes in these organs of the japanese black bear. ovaries and placentae from 15 wild japanese black bears, which had been killed lega ... | 2001 | 11277879 |
| serum progesterone and estradiol-17beta concentrations in captive and free-ranging adult female japanese black bears (ursus thibetanus japonicus). | progesterone (p4) and estradiol-17beta (e2) concentrations were measured in serum samples obtained from 23 captive and 23 free-ranging adult female japanese black bears. we then determined the relationship between changes in these sex steroid hormones and pregnancy. in all captive bears, which included animals of both known and unknown reproductive status, serum p4 concentrations were low from april to july, then tended to become higher after august. the levels then became much higher still in n ... | 2000 | 10823729 |
| immunohistochemical demonstration of cytoskeletal proteins in the testis of the japanese black bear, ursus thibetanus japonicus. | the seasonal changes of the cytoskeletal protein expressions were immunohistochemically investigated in the testes of japanese black bear, ursus thibetanus japonicus. a strong immunoreaction for alpha-smooth muscle actin is restricted to the vascular smooth muscle cells and the peritubular cells which surround the seminiferous tubules by several layers throughout the year. weak immunoreactions for b4 antigen and desmin were observed in the vascular smooth muscle cells and in a part of peritubula ... | 1998 | 9652151 |
| seasonal changes in subcellular structures of leydig and sertoli cells in the japanese black bear, ursus thibetanus japonicus. | the fine structure of leydig and sertoli cells in japanese black bears, ursus thibetanus japonicus, was studied at different stages of reproductive activity in different seasons. structures of leydig cells in the testes that were spermatogenically active (may and june), inactive (november and january), and resumptive (march and april) were found to be different. the nucleus and smooth endoplasmic reticulum in leydig cells had regressed when observed in november and january, and began to develop ... | 1997 | 9376170 |
| seasonal changes in the immunolocalization of steroidogenic enzymes in the testes of the japanese black bear (ursus thibetanus japonicus). | seasonal changes in sites of immunostaining of steroidogenic enzymes were examined in testes of the japanese black bear, ursus thibetanus japonicus. in addition, serum concentrations of testosterone and estradiol-17beta were investigated by radioimmunoassay, and the seasonal changes were compared with the results of immunostaining. on the basis of morphological observations of spermatogenic activity, the reproductive cycle was divided into five periods: an active period in may and june; a degene ... | 1997 | 9271445 |
| spermatogenic cycle in the testis of the japanese black bear (selenarctos thibetanus japonicus). | spermatogenic cycle in the testis of the japanese black bear (selenarctos thibetanus japonicus) was studied by light and transmission electron microscopy. by light microscopy, spermatids were allocated into eleven steps based on morphological changes in the nucleus and the acrosome of spermatids. cellular associations of the seminiferous epithelium were allocated into eight stages based on the changes in the nucleus and acrosome of spermatids, appearance of meiotic figures and time of spermiatio ... | 1996 | 8741265 |
| do small canopy gaps created by japanese black bears facilitate fruiting of fleshy-fruited plants? | japanese black bears often break branches when climbing trees and feeding on fruit in canopies, thereby creating small canopy gaps. however, the role of black bear-created canopy gaps has not been evaluated in the context of multiple forest dynamics. our hypothesis was that small canopy gaps created by black bears improve light conditions, which facilitates fruiting of adult fleshy-fruited plants located beneath the gaps, and also that this chain interaction depends on interactions among the siz ... | 2015 | 26207908 |
| spatial distribution and size of small canopy gaps created by japanese black bears: estimating gap size using dropped branch measurements. | japanese black bears, a large-bodied omnivore, frequently create small gaps in the tree crown during fruit foraging. however, there are no previous reports of black bear-created canopy gaps. to characterize physical canopy disturbance by black bears, we examined a number of parameters, including the species of trees in which canopy gaps were created, gap size, the horizontal and vertical distribution of gaps, and the size of branches broken to create gaps. the size of black bear-created canopy g ... | 2013 | 23758683 |
| changes in plasma gonadotropins, inhibin and testosterone concentrations and testicular gonadotropin receptor mrna expression during testicular active, regressive and recrudescent phase in the captive japanese black bear (ursus thibetanus japonicus). | male japanese black bears (ursus thibetanus japonicus) have an explicit reproductive cycle. the objective of this study was to clarify the variation of plasma testosterone, fsh, inhibin, lh levels and testicular gonadotropin receptor mrna expression of male bears associated with their testicular activity. notably, this study investigated peripheral fsh concentration and localization of gonadotropin receptor mrnas for the first time in male bears. blood and testicular tissue samples were taken fr ... | 2010 | 20364791 |
| change in body weight of mothers and neonates and in milk composition during denning period in captive japanese black bears (ursus thibetanus japonicus). | japanese black bears, ursus thibetanus japonicus, have been classified as a vulnerable species so that data on reproduction are needed to maintain and/or extend their population. they are known to have a peculiar style of reproduction, giving birth to their neonates and raising them during denning, a period of complete fasting. in this study, we investigated the metabolic rate and milk composition of mother bears raising neonates, and the changes in body weight of the neonates under captive cond ... | 2009 | 19593984 |
| development of a noncontact and long-term respiration monitoring system using microwave radar for hibernating black bear. | the aim of this study is to develop a prototype system for noncontact, noninvasive and unconstrained vital sign monitoring using microwave radar and to use the system to measure the respiratory rate of a japanese black bear (ursus thibetanus japonicus) during hibernation for ensuring the bear's safety. ueno zoological gardens in tokyo planned to help the japanese black bear (female, approximately 2 years of age) going into hibernation. the prototype system has a microwave doppler radar antenna ( ... | 2009 | 19504598 |