| in vitro recombinants of ground squirrel and woodchuck hepatitis viral dnas produce infectious virus in squirrels. | hepatitis b viruses of humans, woodchucks, ground squirrels, and ducks are similar biochemically but differ with respect to host range and pathogenicity. to pursue the genetic basis of these properties in the absence of a cell culture system for virus growth, we exploited the demonstrated infectivity of cloned hepatitis b virus dna in whole animals. we constructed several recombinant molecules in vitro between cloned infectious genomes of woodchuck hepatitis virus (whv) and ground squirrel hepat ... | 1987 | 3041044 |
| rabies in rodents and lagomorphs in the united states, 1971-1984: increased cases in the woodchuck (marmota monax) in mid-atlantic states. | a review of surveillance data on animal rabies from the centers for disease control revealed 104 cases of rabies in rodents and lagomorphs for 1971 through 1984 in the united states; 80% of these were reported between 1980 and 1984. woodchucks (marmota monax) accounted for 64% of the cases. most of the cases of rabies in woodchucks were associated with an epizootic of rabies in raccoons (procyon lotor) in the mid-atlantic states. in rabies endemic areas, humans exposed to woodchucks should recei ... | 1986 | 3520029 |
| in vitro activation assays with hepatic s9 preparation from wild and laboratory reared woodchucks in the salmonella mutagenicity test. | the salmonella mutagenicity assay was utilized to compare hepatic s9 fractions derived from wild and laboratory reared woodchucks (marmota monax). two promutagens, 7,12-dimethylbenz[a]anthracence (dmba) and 2-amino-fluorene (af) were tested at 5 concentrations with the tester strains ta98 and ta100, against 2 levels of s9 fraction. af produced similar number of revertants with the s9 fraction from wild and laboratory-reared animals. dmba produced 2-4 times more revertant colonies at 50 microlite ... | 1988 | 3122370 |
| evidence for replication of hepatitis delta virus rna in hepatocyte nuclei after in vivo infection. | examination of a naturally infected human liver and experimentally infected chimpanzee and woodchuck livers by in situ hybridization showed that hepatitis delta virus (hdv) rna was restricted to hepatocytes. genomic rna was 20-30 times more abundant than antigenomic rna and was predominantly single-stranded while antigenomic rna was predominantly double-stranded. in acute delta hepatitis, viral rna was a more reliable marker of virus infection in single cells than hepatitis delta antigen (hdag) ... | 1988 | 3188398 |
| propagation of woodchuck hepatitis delta virus in primary woodchuck hepatocytes. | monolayer cell cultures of primary woodchuck hepatocytes, prepared by perfusing the liver in situ with collagenase type i, yielded hepatocytes with a viability of greater than 90% which could be held in culture for up to 3 months. cultures of primary woodchuck hepatocytes were infected one day after plating with hepatitis delta virus (hdv) which had been passaged five times in woodchucks and was therefore identified as woodchuck hepatitis delta virus (whdv). replication of whdv was demonstrated ... | 1988 | 3201748 |
| vertical transmission of woodchuck hepatitis virus. | one newborn and 24 fetal woodchuck litters from a woodchuck hepatitis virus (whv) endemic population were examined for serological or hepatic evidence of whv. in 18 of 24 fetal litters, there was detectable whv dna in the livers, either at explant culture or tissue extract. most of those whv dna-positive liver extracts, which were examined by southern blot, showed integration of whv. however, whv dna replicative forms without integration were demonstrated in livers of two litters from late gesta ... | 1988 | 3204365 |
| testicular teratoma and seminoma in a woodchuck. | | 1988 | 3232316 |
| mitogen-induced replication of woodchuck hepatitis virus in cultured peripheral blood lymphocytes. | peripheral blood lymphocytes (pbls) isolated from woodchucks chronically infected with the woodchuck hepatitis virus (whv) carry low levels of nonreplicating whv dna. when pbls from chronic carrier woodchucks were activated in culture with the generalized mitogen lipopolysaccharide (lps), whv dna replication was initiated in cells obtained from one of three animals examined. intracellular whv core particles, containing whv dna replication intermediates, rna/dna hybrid molecules, and an active en ... | 1988 | 3261887 |
| liver tumors in rodents: extrapolation to man. | man is a poor model for the prediction of agents that are hepatocarcinogenic for laboratory rodents. relatively few agents are known to cause any form of primary liver cancer in man. the most important is hepatitis b virus, for which there is possibly a model in the woodchuck but not one in rats or mice. the only other agents known to cause primary liver cancer in man are certain steroid hormones, vinyl chloride, and thorium dioxide. there are animal models for the first two of these and a reaso ... | 1987 | 3300204 |
| characterization of proteins associated with hepatitis delta virus. | the number and size of proteins associated with hepatitis delta virus (hdv) from serum and liver (human, chimpanzee and woodchuck) in the acute and chronic stages of hdv infection were analysed by immunoblotting. hdv particles in serum were separated from serum proteins by gel filtration and peak fractions of hdv antigens were subjected to page. immunoblotting with human anti-hdv-positive sera and 125i-labelled protein a revealed two bands of 27k and 29k. it was not possible to identify any core ... | 1987 | 3316487 |
| sequence comparison of woodchuck hepatitis virus replicative forms shows conservation of the genome. | the complete nucleotide sequence of virion dna from two isolates of woodchuck hepatitis virus (whv 7 and whv 59) was determined along with the sequence of supercoiled dna from one of those isolates (whv 7). the sequences of the two whv isolates were compared with the previously published sequences of two other isolates (whv 1 and whv 8). the range of nucleotide sequence variation of the four isolates (1 to 3.5%) was similar to those of hbvs of the same subtype (1.5 to 2%), but less than those of ... | 1988 | 3336938 |
| establishment of a new cell line from a woodchuck hepatocellular carcinoma. | a new cell line derived from a woodchuck hepatitis surface antigen-positive woodchuck hepatocellular carcinoma has been established and named t3-hep-w1. this new cell line was established directly from a primary woodchuck hepatocellular carcinoma. adaptation of the cells to the in vitro culture condition was completed after 3 months, with the doubling time of 24 hr. the morphologic features of the cell by light microscopy were of an epithelial type. the modal chromosome number was 100. ornithine ... | 1988 | 3338696 |
| presence of antibodies to the polymerase gene product(s) of hepatitis b and woodchuck hepatitis virus in natural and experimental infections. | antibodies against synthetic peptides derived from the polymerase gene of the hepatitis b virus (hbv) were present in 80% of renal dialysis patients infected with hbv and in woodchucks infected with woodchuck hepatitis virus (whv). polymerase antibody (anti-pol) appeared as the earliest marker of both hbv and whv infections in approximately half of the individuals tested, suggesting that these antibodies were generated following early viral replication in the liver during the incubation period a ... | 1988 | 3351482 |
| an experimental transmission of woodchuck hepatitis virus to young chinese marmots. | fourteen young chinese marmots (marmota bobak sibirica radde) were randomly allocated to two groups of seven each. they were injected intrahepatically with a standard woodchuck hepatitis virus challenge pool or a negative pool, prepared from sera of woodchucks with and without woodchuck hepatitis virus infection, respectively. marmot no. 2 in the experimental group experienced an episode of seroconversion from woodchuck hepatitis surface antigen to anti-woodchuck hepatitis antibody. woodchuck he ... | 1988 | 3356418 |
| molecular cloning of hepatitis delta virus rna from an infected woodchuck liver: sequence, structure, and applications. | cdna prepared from the single-stranded circular rna genome of hepatitis delta virus was cloned in lambda gt11 by using rna from the liver of an infected woodchuck. from the sequence of overlapping clones, we assembled the full sequence of 1,679 nucleotides. the sequence indicated an exceptional ability for intramolecular base pairing, yielding a rod structure with at least 70% of the bases paired and a predicted free energy of -805 kcal (-3,368 kj)/mol. three of the lambda clones contained seque ... | 1988 | 3367426 |
| systemic distribution of woodchuck hepatitis virus in the tissues of experimentally infected woodchucks. | to better assess the extent of the tissue tropism of mammalian hepadnaviruses, 10 tissues from each of six woodchucks were examined for the presence and state of woodchuck hepatitis virus (whv) nucleic acids 15 months after experimental whv infection. the tissues examined were peripheral blood lymphocytes, lymph node, spleen, bone marrow, thymus, pancreas, kidney, ovary, testis, and liver. tissue samples from three chronically infected animals and three animals with serologic patterns of recover ... | 1988 | 3388768 |
| a comparison of the response of woodchucks and rats to variations in dietary lipotrope and protein content. | juvenile woodchucks and weanling fisher f344 rats were fed purified diets with or without supplemental lipotropic factors (choline, methionine, folic acid and vitamin b-12). the diets contained 10 or 20% protein. lower weight gain due to low protein was observed in both species, while lipotrope depletion resulted in lower gain in male rats only. urinary excretion of formimino-glutamic acid was higher due to low lipotrope in both species, as was relative liver weight. in rats, lipotrope depletion ... | 1986 | 3772530 |
| the hybrid eia test: a specific and sensitive assay for the detection of woodchuck antibody to hepatitis surface antigen (anti-whs). | 'ausria ii' polystyrene beads (abbott labs, n. chicago) are reacted with woodchuck serum positive for whsag in a dilution predetermined by titration. this modified bead is used in a blocking assay to detect the presence of antibody to the surface antigen of woodchuck hepatitis virus (anti-whs). serum containing woodchuck anti-whs and commercial horseradish peroxidase (hrp) labeled anti-hbs are sequentially added. a drop in optical density at 492 nm of 50% or more due to the blocking of hrp conju ... | 1988 | 3397403 |
| dna-binding activity of hepatitis b e antigen polypeptide lacking the protaminelike sequence of nucleocapsid protein of human hepatitis b virus. | the characteristics of binding of hepatitis b core antigen (hbcag) and hepatitis b e antigen (hbeag) polypeptides to hepatitis b virus (hbv) dna were analyzed. hbcag polypeptide from recombinant hbv core particles and hbeag polypeptide from partially purified serum hbeag were prepared and verified to have molecular weights of 21,500 (p21.5) and of 17,000 (p17) and 18,000 (p18), respectively, by immunoblot analysis. by reaction of these proteins on a nitrocellulose membrane with cloned 32p-hbv dn ... | 1988 | 3404582 |
| malignant lymphoma in free-ranging and captive woodchucks. | | 1987 | 3437760 |
| main properties of duck hepatitis b virus dna polymerase: comparison with the human and woodchuck hepatitis b virus dna polymerases. | the main properties of the duck hepatitis b virus (dhbv) dna polymerase have been studied and compared with those of the human hepatitis b virus (hbv) and of the woodchuck hepatitis virus (whv) dna polymerases. all 3 enzymes are active under high salt conditions in the presence of high magnesium concentration. dhbv dna polymerase was found less sensitive to ethanol and to operate at higher optimal ph than the hbv and whv dna polymerases. like the other two viral endogenous dna polymerases, the d ... | 1987 | 3446017 |
| a newly identified hepatitis b type virus in tree squirrels. | virus-associated particles have been isolated from the livers of three common gray tree squirrels (sciurus carolinensis pennsylvanicus) that have histological evidence of hepatitis. two of these livers were also positive by orcein staining, suggesting the presence of surface antigen in the cytoplasm of hepatocytes. fractionation of these particles by cscl density equilibrium gradient centrifugation and assay of the fractions for surface antigen, core antigen, and dna polymerase activities demons ... | 1986 | 3457384 |
| common evolutionary origin of hepatitis b virus and retroviruses. | hepatitis b virus (hbv), although classified as a double-stranded dna virus, has been shown recently to replicate by reverse transcription of an rna intermediate. also, the putative viral polymerase has been found to share amino acid homology with reverse transcriptase of retroviruses. using computer-assisted dna and protein sequence analyses, we examined the genomes of 13 hepadnavirus isolates (nine human, two duck, one woodchuck, and one ground squirrel) and found that other conserved regions ... | 1986 | 3458214 |
| effects of an extract from phyllanthus niruri on hepatitis b and woodchuck hepatitis viruses: in vitro and in vivo studies. | an aqueous extract of the plant phyllanthus niruri inhibits endogenous dna polymerase of hepatitis b virus and binds to the surface antigen of hepatitis b virus in vitro. the extract also inhibits woodchuck hepatitis virus (whv) dna polymerase and binds to the surface antigen of whv in vitro. the extract, nontoxic to mice, was tested for antiviral activity in woodchucks (marmota monax). in a trial using six long-term whv-carrier woodchucks, five treated animals showed a faster decrease in woodch ... | 1987 | 3467354 |
| hepatocarcinogenicity of the woodchuck hepatitis virus. | during investigations of the evolution of experimental laboratory infections of woodchucks (marmota monax) with the woodchuck hepatitis virus (whv), eight hepatocellular carcinomas (hcc) were observed, six in newborns and two in young adult animals, all within 17-36 months after infection. the absence of an external cocarcinogenic effect in the well-monitored woodchucks indicates the carcinogenicity of whv and suggests the same for the genetically and biologically similar human hepatitis b virus ... | 1987 | 3468514 |
| hepadnavirus infection of peripheral blood lymphocytes in vivo: woodchuck and chimpanzee models of viral hepatitis. | the peripheral blood lymphocytes (pbl) of five hepatitis b virus (hbv)-infected chimpanzees and 17 woodchuck hepatitis virus (whv)-infected woodchucks were examined for the presence of viral dna and rna. hbv dna was detected in the pbl of three of three chronically infected chimpanzees but in neither of two animals with acute hbv infection. whv dna was found in the pbl of 11 of 13 chronically infected woodchucks and in the pbl and bone marrow of 1 of 4 woodchucks with antibody to whv surface ant ... | 1986 | 3485201 |
| the hbv hbx gene expressed in e. coli is recognised by sera from hepatitis patients. | we have cloned the x gene (hbx) and the hbc antigen (hbc ag) gene of human hepatitis b virus (hbv) in escherichia coli as fusion products with beta-galactosidase. both hbv genes are expressed in e. coli strain csr 603. expression is detected by u.v. irradiation of the bacteria, metabolic labelling and electrophoresis of the labelled extracts on sds-polyacrylamide gels. the hbc ag protein produced in bacteria can be recognised by anti-hbc sera and peptides derived from the protein are also recogn ... | 1985 | 3891326 |
| congestive cardiomyopathy in the woodchuck, marmota monax. | congestive cardiomyopathy was diagnosed during post mortem examination in eight of 149 adult woodchucks from new york. the eight woodchucks, four males and four females, died spontaneously without clinical signs of heart failure having been detected. the primary lesion was a grossly enlarged and dilated heart. histologic lesions consisted of multifocal myocardial degeneration and necrosis. secondary lesions of congestive heart failure were observed. | 1986 | 3503140 |
| maintenance of woodchuck hepatitis virus activity in woodchuck hepatocyte primary culture. | primary cultures of non-proliferating hepatocytes isolated by the two-step collagenase perfusion method from woodchuck naturally infected with hepatitis virus (whv) were used to study whv propagation in vitro. hepatocytes carrying whv dna exhibited a very high level of survival and retained their morphological characteristics for 2 to 3 months. over this time, they were found to produce virus-specific proteins and release viral particles with dna polymerase activity into the medium. using southe ... | 1987 | 3572356 |
| lymphoid cells in the spleens of woodchuck hepatitis virus-infected woodchucks are a site of active viral replication. | lymphoid cells were purified from the spleens of 15 woodchucks and examined for the presence of woodchuck hepatitis virus (whv). lymphoid cells from the spleens of eight of eight chronically infected animals contained high levels of whv rna and dna. a 100-fold lower level of whv dna was found in the spleen from one of five animals that had recovered from acute whv infections 2 years before this analysis. no whv nucleic acids were observed in either of two uninfected animals. whv dna patterns in ... | 1987 | 3573141 |
| nucleotide sequence of the woodchuck hepatitis virus surface antigen mrnas and the variability of three overlapping viral genes. | a cdna library was constructed from the liver of a woodchuck chronically infected with woodchuck hepatitis virus (whv). a clone, pws23, encompassing the entire surface and x genes of whv was isolated. comparison of the complete nucleotide (nt) sequence of pws23 with those of genomic dnas from two different whv isolates showed that it contained a nearly full-length copy of the major mrna encoding the viral surface antigen (s mrna). it was colinear with the whv genome over 1858 nt and terminated 2 ... | 1986 | 3582979 |
| genetic variation between woodchuck populations with high and low prevalence rates of woodchuck hepatitis virus infection. | woodchuck hepatitis virus (whv) infection is known to be endemic in areas of the mid-atlantic states but is apparently absent from populations in new york and much of new england. blood samples of 40 woodchucks (marmota monax) from new york and from delaware were examined by starch gel electrophoresis, and 18 monomorphic and six polymorphic protein-coding genetic systems were identified. mendelian inheritance of variants of the six polymorphic systems was confirmed in 52 laboratory offspring of ... | 1987 | 3586195 |
| a case report of cysticercosis caused by cysticercus longicollis, a larval form of taenia crassiceps in a woodchuck (marmota monax). | cysticercosis was found in one of 18 woodchucks imported from the united states and maintained in our laboratory for study of hepatitis and hepatocellular carcinoma. the lesions found in subcutaneous area, lungs and maxillary sinus were multiple cysts containing numerous cysticerci identified as cysticercus longicollis, a larval form of taenia crassiceps. | 1987 | 3609159 |
| replication of human hepatitis delta virus in primary cultures of woodchuck hepatocytes. | we obtained two lines of evidence that monolayer cultures of primary woodchuck hepatocytes support replication of the genome of human hepatitis delta virus (hdv). (i) from a northern (rna blot) analysis of the hdv-related rna in infected cultures, both genomic and antigenomic 1.7-kilobase rna species were detected at 11 days after infection. the ratio of genomic rna to antigenomic rna was 2:1 to 10:1, comparable to that previously reported in studies of experimentally infected chimpanzees and wo ... | 1987 | 3612956 |
| expression of the hepatitis b virus core gene in vitro and in vivo. | the core gene of hepatitis b virus contains two in-phase aug codons which may both be used in the viral life cycle. by in vitro translation of transcripts produced in vitro, we investigated the corresponding core gene products and their counterparts in vivo. depending on the location of the 5' end of the transcripts, two major core gene-derived proteins were obtained. in transcripts with both in-phase augs, only the first one was efficiently used and resulted in synthesis of a 25-kilodalton prot ... | 1987 | 3625840 |
| acute and chronic delta infection in the woodchuck. | | 1987 | 3628388 |
| analysis of the chromosomal abnormalities of a woodchuck hepatocellular carcinoma-derived cell line (wh257ge10). | the normal woodchuck karyotype was determined by the g-banding technique, and the chromosomal abnormalities of a woodchuck hepatocellular carcinoma-derived cell line (wh257ge10) were analyzed and compared with it. the normal woodchuck karyotype was 38,xy in a male, and 38,xx in a female. autosomes were classified into 2 groups (a and b). group a consisted of 13 pairs (1-13) of metacentric or sub-metacentric chromosomes, and group b consisted of 5 pairs (14-18) of telocentric or sub-telocentric o ... | 1987 | 3679596 |
| parasites of the laboratory woodchuck (marmota monax). | the parasite burden of captive and colony-born woodchucks maintained in laboratory animal facilities was determined and compared to woodchucks recently trapped. microfilariae of ackertia marmotae in blood or dermis were most commonly observed in trapped woodchucks. there was a linear decrease in woodchucks positive for microfilariae after introduction in the laboratory colony, but even after 39 months, 53% were positive. microfilaremia or microfilariderma were never observed in colony born woodc ... | 1986 | 3724058 |
| experimental infection of the woodchuck (marmota monax monax) with woodchuck hepatitis virus. | six woodchucks, 10 1/2 months of age, injected intramuscularly with 0.02 ml of woodchuck hepatitis virus (whv)-positive serum and two woodchucks of similar age and origin injected with phosphate buffered saline were studied by serial blood samples and liver biopsy sections over an 18 week period. serum samples were assayed for whv surface antigen (whsag), its corresponding antibody (anti-whs) and antibody to whv core antigen (anti-whc). whv core antigen (whcag) was detected in liver biopsy secti ... | 1986 | 3724063 |
| protection of chimpanzees from type b hepatitis by immunization with woodchuck hepatitis virus surface antigen. | two chimpanzees immunized with woodchuck hepatitis virus (whv) surface antigen (whsag) developed antibodies cross-reactive with hepatitis b virus (hbv) surface antigen (hbsag). after challenge with hbv, one animal was completely protected and the other experienced a subclinical infection, without evidence of liver disease. three woodchucks immunized with hbsag developed antibodies to hbsag which did not cross-react with whsag. after challenge with whv, all three woodchucks developed typical acut ... | 1986 | 3783820 |
| failure to detect polyalbumin-binding sites on the woodchuck hepatitis virus surface antigen: implications for the pathogenesis of hepatitis b virus in humans. | binding sites for polymerized albumin on hepatitis b virus components were reported in human hepatitis b virus chronic carriers predominantly with active viral replication (hb e antigen positive). the presence of comparable albumin-binding sites in the woodchuck hepatitis virus (whv) model was examined on whv components obtained from woodchucks with active viral replication (dna polymerase positive). binding sites for polymerized woodchuck serum albumin were not detected on the intact whv virion ... | 1986 | 3783821 |
| hepadnaviruses and retroviruses share genome homology and features of replication. | the hepadnavirus family includes hepatitis b virus (hbv), woodchuck hepatitis virus (whv), ground squirrel hepatitis virus (gshv) and duck hepatitis b virus (dhbv). these viruses share unique ultrastructural, molecular and biological features. hbv has great medical importance in many parts of the world. more important numerically than acute hepatitis b in high prevalence geographic regions is the liver disease associated with chronic infection. there appear to be more than 200 million chronicall ... | 1987 | 3804216 |
| molecular aspects of persistent woodchuck hepatitis virus and hepatitis b virus infection and hepatocellular carcinoma. | it seems evident that the development of fully malignant hcc is a multistage process with many variables. one possible mechanism by which many of these variables may interact is as follows. during chronic active hepatitis, viral dna integration occurs randomly and at a low frequency in hepatocytes. integration may be stimulated by the increased rate of hepatocyte cell division resulting from liver necrosis and regeneration during chronic disease. the presence of viral integrations in the cellula ... | 1987 | 3804217 |
| some aspects of the hematology and immunology of the hibernating and nonhibernating woodchuck (marmota monax). | | 1973 | 4148988 |
| the circannual variations of some of the hormones of the woodchuck (marmota monax). | | 1973 | 4148989 |
| the effects of hibernation on the chemical composition of cerebrospinal and intraocular fluids, blood plasma and brain tissue of the woodchuck (marmota monax). | | 1974 | 4149000 |
| studies on the red blood cell oxygen affinity and 2,3-diphosphoglyceric acid in the hibernating woodchuck (marmota monax). | | 1974 | 4151835 |
| species survey of glutathione peroxidase and glutathione reductase: search for an animal model of the human lens. | lenses from representative species of eight mammalian orders were assayed for glutathione peroxidase and glutathione reductase activities. wide variation of glutathione peroxidase activity was noted, the lowest activity being that of the prosimian galago while the highest activities were from three old world monkey species of the genera macaca and papio. the hominoids, including the human, all exhibited lower activities of this enzyme. glutathione reductase activity was lowest in the dog, the ra ... | 1986 | 3808594 |
| nucleotide sequence of a cloned woodchuck hepatitis virus genome: evolutional relationship between hepadnaviruses. | we have determined the complete nucleotide sequence of a cloned dna of woodchuck hepatitis virus (whv), the most oncogenic virus among hepadnaviruses. the genome, designated whv2, is 3,320 base pairs long and contains four major open reading frames (orfs) coded on the same strand of nucleotide sequence as in the human hepatitis b virus (hbv) genome. comparison of the nucleotide sequence and amino acid sequences deduced from it among the genomes of various hepadnaviruses demonstrates that each pr ... | 1985 | 3855246 |
| age related changes in the composition of the aorta of the groundhog, marmota monax. | | 1974 | 4423720 |
| duck hepatitis b virus dna in liver and serum of chinese ducks: integration of viral dna in a hepatocellular carcinoma. | the presence of duck hepatitis b virus (dhbv) dna in liver and serum and its state (integrated vs. free) were studied in 23 ducks from chi-tung county in china by spot hybridization and southern blot hybridization, respectively. in 16 of 23 (70%), dhbv dna was detected in serum and/or in liver tissue. these infected ducks showed a variety of pathological changes including advanced chronic disease in the liver. in contrast, none of the virus-negative ducks had advanced hepatic changes. one dhbv d ... | 1985 | 3860852 |
| a comparison of bone marrow leukocytes in hibernating and nonhibernating woodchucks and ground squirrels. | | 1972 | 4636200 |
| annual cycle of spermatogenesis and testis morphology in woodchucks. | | 1972 | 4654238 |
| blood gases of woodchucks at reduced body temperatures. | | 1972 | 4654246 |
| [chromosomal phylogeny of 7 species of sciurinae]. | the sequence of chromosomal rearrangements that leads to the karyotypes of living species of sciurinae is hardly compatible with a dichotomic evolution. the most probable hypothesis is that of a populational chromosomal evolution: the different lineages would have been isolated successively from an ancestral population in which several chromosomal rearrangements would have spread to more or less important fractions of the population. the proposed order in the succession of these isolations (marm ... | 1985 | 3874584 |
| mutagenicity tests with gallic and tannic acid in the salmonella/mammalian microsome assay. | gallic acid, tannic acid mixture and a purified fraction of tannic acid were evaluated for possible mutagenic activity in three strains of salmonella typhimurium, ta98, ta100, and ta1535. these chemicals were not mutagenic either before or after activation with rat and woodchuck microsomal and cytosolic enzymes. however, tannic acid mixture and tannic acid fraction both gave a significantly (p = 0.05) dose-related reduction in the number of the revertant colonies, compared to the normal spontane ... | 1985 | 3889126 |
| biology of ixodes cookei packard (ixodidae) of groundhogs (marmota monax erxleben). | | 1972 | 5022069 |
| the transmission of ackertia marmotae webster, 1967 (nematoda: onchocercidae) of groundhogs (marmota monax) by ixodes cookei. | | 1972 | 5022070 |
| establishment of a cell line from a woodchuck hepatocellular carcinoma. | a new cell line derived from a woodchuck hepatocellular carcinoma serially transplanted in athymic nude mice has been established and named wh257ge10. the original tumor in the nude mouse system produces woodchuck hepatitis surface antigen and albumin. in addition, woodchuck hepatitis virus dna is integrated into cellular dna. adaptation of the cells to the in vitro culture condition was completed after 15 months with the doubling time of 40 hr. the morphologic features of the cell by light micr ... | 1985 | 3905560 |
| comparative mutagenicity tests in the salmonella/microsome assay with rat and woodchuck s9 preparations. | the salmonella mutagenicity assay was utilized to compare the hepatic s9 fractions from untreated and 3-methylcholanthrene (mc) induced woodchucks with aroclor 1254 induced rats. three known promutagens, benzo[a]pyrene (bp), 7,12-dimethylbenz[a]anthracene (dmba), and 2-aminofluorene (af) were tested at 5 concentrations with the strain ta100 against 3 levels of s9 fraction. both woodchuck s9 fractions were as effective as the rat s9 in activating bp and both were more effective than the rat s9 in ... | 1985 | 3931301 |
| identification and localization of pre-s-encoded polypeptides from woodchuck and ground squirrel hepatitis viruses. | a segment from the pre-s region of the woodchuck hepatitis virus (whv) was inserted into an open reading frame vector allowing for the expression in escherichia coli of viral determinants as part of a fusion protein. the bacterially synthesized fusion molecule contained eight amino acids from beta-galactosidase (beta-gal) at the n terminus, followed by 89 pre-s-encoded amino acids and 219 amino acids of chloramphenicol acetyltransferase (cat) at the c terminus (beta-gal:pre-s:cat). this tribrid ... | 1986 | 3941437 |
| vascular smooth muscle responsiveness in a hibernator: effects of season and temperature. | to determine the effects of season, acclimation state, and hibernation on the reactivity of vascular smooth muscle from a hibernant species, strips of thoracic aorta, renal and femoral arteries, and portal vein obtained from adult woodchucks, marmota monax, were suspended for isometric tension measurements in physiological salt solution. these blood vessels exhibited no seasonal variation in resting tension, connective tissue content, or maximum tension developed to norepinephrine. however, the ... | 1986 | 3942255 |
| serum bile acid determination for assessment of hepatic injury in the woodchuck. | a direct spectrophotometric assay for determination of the serum bile acid concentration in the woodchuck (marmota monax) has been validated. the assay relies on the conversion of 3-hydroxy bile acids to 3-oxo bile acids by 3 alpha-hydroxysteroid dehydrogenase with concomitant reduction of nad+ to nadh. reduction of nad+ is coupled via a diaphorase catalyst to the formation of a diformazan dye from nitrotetrazolium blue and the diformazan product is measured spectrophotometrically at 540 nm. int ... | 1987 | 3599895 |
| emerging models in the u.s.a.: swine, woodchucks, and the hairless guinea pig. | swine have been used in biomedical research for many years, but have generally been limited to those locations with personnel familiar with this species and with specially designed facilities and equipment. there is currently a growing trend in the united states for more swine, both miniature and domestic to be used as research models. commercial availability, education through workshops and symposia, and specific research applicability in the areas such as: organ transplantation, cardiovascular ... | 1987 | 3601991 |
| metabolism of mutagens and carcinogens in woodchuck liver and its relationship with hepatitis virus infection. | thirty-six wild-caught woodchucks (marmota monax) were characterized according to sex, weight, trapping locality, liver pathology, and serum or hepatic markers of woodchuck hepatitis virus. liver subcellular fractions were assayed for microsomal cytochromes p-450, aryl hydrocarbon hydroxylase, glutathione, cytosolic enzymes involved in its metabolism (glutathione s-transferase, glutathione peroxidase, and glutathione reductase), in the hexose monophosphate shunt (glucose 6-phosphate dehydrogenas ... | 1987 | 3607750 |
| field and laboratory studies of skunks, raccoons and groundhogs as reservoirs of leptospira pomona. | | 1965 | 5828180 |
| the utilization of body fat during hibernation in woodchucks. | | 1965 | 5829171 |
| seasonal changes in metabolic activity of non-hibernating woodchucks. | | 1965 | 5838418 |
| circannual changes in serum testosterone concentrations of adult and yearling woodchucks (marmota monax). | testicular volumes and serum testosterone concentrations were determined biweekly in 5 adult and 4 yearling woodchucks maintained indoors from december through august. food and water were provided ad libitum except for 2 mo beginning at the winter solstice when feeding and lighting (12l:12d) supplemental to available natural light were discontinued. temperatures fluctuated with outdoor temperatures greater than 4 degrees c. no significant hibernation occurred. testes in adults were small in dece ... | 1985 | 4005348 |
| hybrid protein synthetic systems: components required to confer poikilothermy to the mammal. | temperature dependency of homologous and heterologous protein synthetic cell-free systems reveals characteristic homeotherm and poikilotherm behavior depending on the source of the enzyme elongation factor 1 and not on any other protein synthetic components. the results for rat and antarctic fish, when compared with previous studies in eurythermal fish and mammals provide the explanation for the phenomenon of true hibernation in animals such as ground squirrels and woodchucks. the killing of the ... | 1985 | 4028684 |
| transcription of woodchuck hepatitis virus in the chronically infected liver. | the transcription of woodchuck hepatitis virus (whv) genome was studied in the liver of chronically infected woodchucks by northern blot, nuclease mapping and primer extension analysis. two major transcripts, 2.1 and 3.7 kb in length, and several minor transcripts were found in samples which supported active whv replication. the 2.1-kb rna represents the major transcript of the s gene, encoding the viral surface antigen (whsag) as demonstrated by blot-hybridization experiments. two transcription ... | 1985 | 4029122 |
| a comparison of the response of woodchucks and rats to variations in dietary lipotrope and lipid content. | a soy protein-based experimental diet for woodchucks (marmota monax) is described. the diet supported growth of juvenile woodchucks for 12 wk. with this diet, the effects on both woodchucks and rats of increasing dietary corn oil from 5 to 15% and of deleting supplemental lipotropic factors (choline, methionine, folic acid and vitamin b-12) were studied in a 2 x 2 factorial experiment. both increased lipid and lipotrope deletion resulted in decreased growth in rats, but only increased lipid caus ... | 1985 | 4032061 |
| hibernation "trigger" alters renal function in the primate. | macaque monkeys acclimatized to a restraint chair were fitted with indwelling venous and urinary catheters. after basal rates of urine production and creatinine clearance were determined, a 50 mg dose of plasma dialysate albumin fraction obtained from the woodchuck was administered intravenously in a total volume of 2.5 ml. plasma fractions were collected during the winter interval of hibernation (hibernation "trigger" or ht), or during the summer active (sawa) period. although the sawa fraction ... | 1985 | 4034698 |
| radioimmunoassay and characterization of woodchuck hepatitis virus core antigen and antibody. | solid-phase radioimmunoassays for woodchuck hepatitis virus core antigen (whcag) and antibody (anti-whc) were developed. whcag in woodchuck liver homogenates was characterized by ultracentrifugation in cscl gradients; both heavy (1.35 g/cm3) and light (1.31 g/cm3) cores were obtained from the liver of an animal during acute whv infection, which is consistent with observations in hepatitis b virus infection in man. endpoint titers of anti-whc were higher in chronic whv carriers than in animals re ... | 1985 | 4036315 |
| the raccoon ascarid. a probable cause of human ocular larva migrans. | the ability of raccoon roundworm larvae, baylisascaris procyonis, to produce ocular larva migrans (olm) was studied in various experimental animals. in addition, the clinical and pathologic lesions were compared to those in suspected cases of human ocular baylisascariasis, in patients with diffuse unilateral subacute neuroretinitis (dusn). ocular larva migrans was produced in squirrel monkeys, cynomolgus monkeys, mice, hamsters, grey squirrels, and woodchucks orally infected with b. procyonis eg ... | 1985 | 4088627 |
| the circannual variations on the serum protein fractions of the woodchuck (marmota monax). | | 1972 | 4117796 |
| the circannual variations in the total serum lipids and cholesterol with respect to body weight in the woodchuck (marmota monax). | | 1973 | 4145769 |
| the circannual variations of thyroid activity in the woodchuck (marmota monax). | | 1973 | 4146623 |
| surface antigenic determinants of mammalian "hepadnaviruses" defined by group- and class-specific monoclonal antibodies. | the hepatitis b-like viruses (human hepatitis b virus, woodchuck hepatitis virus, ground squirrel hepatitis virus, and duck hepatitis b virus) are hepatotropic dna viruses which have been referred to collectively as "hepadnaviruses." using a murine monoclonal antibody (101-2) to the surface antigen of woodchuck hepatitis virus, we have shown that the surface antigens of mammalian hepadnaviruses (hbsag, whsag, and gshsag) are antigenically related via a common determinant (hv/101). furthermore, a ... | 1982 | 6177867 |
| the microscopic structure of the adult raccoon (procyon lotor) and woodchuck (marmota monax) spleens. | | 1967 | 4166267 |
| marmota monax: a model for studies of cardiovascular, cerebrovascular and neoplastic disease. | | 1969 | 4357475 |
| erthyrocyte changes in the hibernating woodchuck (marmota monax). | | 1974 | 4452279 |
| comparison of properties of woodchuck hepatitis virus and human hepatitis b virus endogenous dna polymerases. | the principal properties of the dna polymerases of woodchuck hepatitis virus and human hepatitis b virus were compared. the enzymes of both viruses exhibited optimal activities in the same range of ph, ionic strength, and mgcl2 concentration. like human hepatitis b virus dna polymerase, the woodchuck hepatitis virus dna polymerase was strongly inhibited by phosphonoformic acid but not by phosphonoacetic acid and aphidicolin. similar inhibition patterns for both enzymes were observed with arabino ... | 1984 | 6231885 |
| external parasites of the woodchuck, marmota monax, in indiana. | | 1973 | 4708691 |
| maintenance of normal corneal thickness in the cold in vivo (hibernation) as opposed to in vitro. | 1. corneal thickness was measured in vivo in normothermic and hibernating (body temperature = 7-10 degrees c) woodchucks and the [na(+)], [k(+)], [mg(2+)] and water content of woodchuck and rabbit corneas were determined on freshly isolated tissues.2. woodchuck eyes from both normothermic and hibernating animals were incubated in moist chambers at 5 or 11 degrees c and the corneal thickness was measured periodically.3. woodchuck corneas undergo continuous swelling when kept in vitro in a moist c ... | 1973 | 4715370 |
| the blood-borne "trigger" for natural mammalian hibernation in the 13-lined ground squirrel and the woodchuck. | | 1972 | 5045622 |
| tapeworm larvae (taenia crassiceps) in woodchucks. | | 1972 | 5056190 |
| cardiac output and regional blood flow in hypoxic woodchucks. | | 1971 | 5087801 |
| novel forms of woodchuck hepatitis virus dna isolated from chronically infected woodchuck liver nuclei. | we cloned several unique forms of woodchuck hepatitis virus, a dna virus closely related to hepatitis b virus, from a chronically infected woodchuck liver. each of the three clones contained more than two genome equivalents of viral sequences with extensive rearrangements and no detectable cellular sequences. from the frequency by which they were isolated from a library of recombinant clones, we estimate that they are present in approximately one copy per cell. of a total of 11 sites at which re ... | 1982 | 6294334 |
| summer hibernation induced by cryogenically preserved blood "trigger". | summer hibernation induced by transfusions of blood (serum, cells, or whole blood) from hibernating ground squirrels and woodchucks demonstrates that (i) this "trigger effect" can be preserved cryogenically in vitro for at least 5 months, (ii) it cross-reacts between these species of hibernators, and (iii) its effectiveness relates to the donor's previous hibernation history. | 1970 | 5436088 |
| cerebrospinal nematodiasis in groundhogs (marmota monax). | | 1970 | 5452080 |
| woodchuck hepatitis virus infection: serologic and histopathologic course and outcome. | five out of seven american woodchucks inoculated with woodchuck hepatitis virus developed antigenemia after 2 to 13 weeks followed by an antibody response. one animal became a carrier, and another animal exhibited a primary antibody response. clinical disease was not obvious and aminotransferase elevation could not be demonstrated. liver biopsy showed mononuclear portal infiltration and little parenchymal cell necrosis. | 1985 | 3987680 |
| experimental la crosse virus infection of red fox (vulpes fulva), raccoon (procyon lotor), opossum (didelphis virginiana), and woodchuck (marmota monax). | susceptibility to infection, resulting viremia and antibody responses, and potential to provide infectious blood meals for aedes triseriatus were determined and compared for the red fox (vulpes fulva), raccoon (procyon lotor), and opossum (didelphis virginiana) exposed to la crosse (lac) virus transmitted by mosquitoes, ae. triseriatus. woodchucks (marmota monax) were infected with lac virus by needle and syringe. all 5 red foxes became viremic following the bite of a single lac virus-infected f ... | 1985 | 4003669 |
| [great degree of homology between the ancestral karyotype of squirrels (rodents) and that of primates and carnivores]. | the karyotype of 7 species of sciurinae representative of 6 tribes were compared: atlantoxerus getulus, menetes berdmorei, callosciurus flavimanus, heliosciurus gambianus, sciurus vulgaris, eutamias sibiricus, and marmota monax. homoeologies between almost all chromosome segments were found. numerous similarities with the karyotypes of certain primates and carnivora were observed. a presumed ancestral karyotype of the sciurinae is proposed. | 1984 | 6335365 |
| seasonal variations in the food consumption of woodchucks (marmota monax). | | 1971 | 5581371 |
| respiratory functions of the blood of the nutria and the woodchuck. | | 1966 | 5968933 |
| powassan virus: persistence of virus activity during 1966. | powassan virus isolations were achieved from three of 60 pools of ixodes cookei ticks removed from 286 groundhogs (marmota monax) which were collected some 200 miles north of toronto between may 5 and september 5, 1966. virus yields per pool of one to 11 ticks ranged from 10(2.5) to 10(6.0) tcd(50) for primary swine kidney tissue cultures, and positive pools were collected on june 24, july 15 and august 10. powassan neutralizing antibodies were detected by mouse inoculation tests in 143 of 362 a ... | 1967 | 6019677 |
| cardiac performance in hypothermic woodchucks. (marmota monax). | | 1967 | 6060233 |
| nucleotide sequence of an infectious molecularly cloned genome of ground squirrel hepatitis virus. | we have determined the complete nucleotide sequence of an infectious cloned genome of ground squirrel hepatitis virus (gshv), a nonpathogenic member of the hepadnavirus group. the genome is 3,311 base pairs long and contains the major open reading frames described for the related human and woodchuck hepatitis b viruses (hbv and whv, respectively). these reading frames include genes for the major structural proteins (the surface and core antigens), unassigned open reading frames (a and b), the lo ... | 1984 | 6086950 |
| primary hepatoma in a woodchuck (marmota monax) without serologic evidence of woodchuck hepatitis virus infection. | | 1984 | 6097011 |