Publications

seroepidemiological survey of feline retrovirus infections in domestic and leopard cats in northern vietnam in 1997.	the prevalence of infections with three feline retroviruses (feline immunodeficiency virus (fiv), feline leukemia virus (felv) and feline syncytial virus (fsv)) was examined in northern vietnam in 1997. we collected a total of 77 blood samples from 69 domestic and 8 leopard cats, and examined the presence of anti-fiv and fsv antibodies and felv p27 antigen in the plasma samples by the indirect immunofluorescence and/or two commercial kits. none of the samples was positive for fiv and felv. the o ...	1998	9853314
prevalence of igg and igm antibodies specific to toxoplasma gondii in cats.	igg and igm antibodies specific to toxoplasma gondii were determined simultaneously by ifat in cats. group 1 included 357 cats with various diagnoses, but negative for felv and fiv. specific igg antibodies in titres ranging from 10 to 2560 (mean 247) were detected in 61.3% animals, specific igm antibodies were found only in one cat (0.28%) in titre 1:40 showing an igg titre of 160. oocyst shedding was demonstrated in one cat (0.28%) showing an igg titre of 1:40. group 2 included 33 cats positive ...	1998	9870370
retrovirus receptor pit-1 of the felis catus.	we isolated a cdna encoding a feline homolog of human pit-1, a sodium-dependent phosphate symporter which is utilized by gibbon ape leukemia virus (galv) as a receptor for entry into host cells. the overall homology between the human and feline receptors is 92 and 93% at the nucleotide and deduced amino acid levels, respectively. hydropathy analyses implied ten potential membrane spanning regions and, in analogy to human and murine homologs, five extracellular and four intracellular loops. strik ...	1998	9878855
feline viruses in wildcats from scotland.	few data are available on the prevalence of feline viruses in european wildcats (felis silvestris). previous surveys have indicated that wildcats may be infected with the common viruses of domestic cats, apart from feline immunodeficiency virus (fiv). in the present study, 50 wildcats trapped throughout scotland (uk) between august 1992 and january 1997 were tested for evidence of viral infection. all were negative for fiv by several serological or virological methods. by contrast, 10% of the ca ...	1999	10073361
t-cell-rich b-cell lymphoma in the cat.	the clinical and pathological features of eight cases of feline t-cell-rich b-cell lymphoma are described. the disease occurred in older cats (mean age 11.4 +/- 3.9 years), which on initial examination generally showed enlargement of a single submandibular or cervical lymph node. after excision, there was no recurrence of the lesions at 6 months in three cats. in one further case, however, the lesion had recurred 6 months later; it was again excised but recurred after an additional 6 months. mic ...	1999	10087489
recombinant feline leukemia virus (felv) variants establish a limited infection with altered cell tropism in specific-pathogen-free cats in the absence of felv subgroup a helper virus.	feline leukemia virus subgroup b (felv-b) is commonly associated with feline lymphosarcoma and arises through recombination between endogenous retroviral elements inherited in the cat genome and corresponding regions of the envelope (env) gene from felv subgroup a (felv-a). in vivo infectivity for felv-b is thought to be inefficient in the absence of felv-a. proposed felv-a helper functions include enhanced replication efficiency, immune evasion, and replication rescue for defective felv-b virio ...	1999	10098636
feline leukemia virus long terminal repeat activates collagenase iv gene expression through ap-1.	leukemia and lymphoma induced by feline leukemia viruses (felvs) are the commonest forms of illness in domestic cats. these viruses do not contain oncogenes, and the source of their pathogenic activity is not clearly understood. mechanisms involving proto-oncogene activation subsequent to proviral integration and/or development of recombinant viruses with enhanced replication properties are thought to play an important role in their disease pathogenesis. in addition, the long terminal repeat (lt ...	1999	10233955
the fit-1 common integration locus in human and mouse is closely linked to myb.	the fit-1 locus was originally identified as a common insertion site for feline leukemia virus (felv) in thymic lymphosarcomas induced by felv-myc recombinant viruses, suggesting that it harbors a gene that cooperates with myc in t-cell leukemogenesis. we have previously mapped the fit-1 locus to feline chromosome (chr) b2. we have now identified conserved sequences that allow the mapping of the murine homolog using the european interspecific backcross (eucib). this shows that fit-1 is located o ...	1999	10341084
assignment of tcrb encoding the t-cell receptor beta chain gene to cat chromosome a2q25-q26 by fluorescence in situ hybridization.		1999	10343121
a putative cell surface receptor for anemia-inducing feline leukemia virus subgroup c is a member of a transporter superfamily.	domestic cats infected with the horizontally transmitted feline leukemia virus subgroup a (felv-a) often produce mutants (termed felv-c) that bind to a distinct cell surface receptor and cause severe aplastic anemia in vivo and erythroblast destruction in bone marrow cultures. the major determinant for felv-c-induced anemia has been mapped to a small region of the surface envelope glycoprotein that is responsible for its receptor binding specificity. thus, erythroblast destruction may directly o ...	1999	10400745
lymphokines modulate the growth and survival of thymic tumor cells containing a novel feline leukemia virus/notch2 variant.	tumorigenesis occurs through a multistep process initiated by genetic lesions and facilitated by endogenous and external growth/survival signals. in many malignancies, specific oncogenic mutations correlate with phenotypic characteristics, inferring lineage-specific pathogenic mechanisms. to characterize these relationships in a unique feline tumor, we studied primary cells and two-cell lines independently-derived from a thymic lymphoma that contained and actively expressed a novel feline leukem ...	1999	10507363
treatment of feline leukemia virus (felv) infection.	felv infection is still considered to account for most disease-related deaths in pet cats. different treatment attempts with various drugs were performed in the past but none resulted in healing or complete virus elimination. therefore, it caused a sensation when horber and mayr [horber, d., mayr, b., 1991. prax. 19, 311-314; horber, d., schnabl, w., mayr, b., 1992. tierarztl. umschau 47, 556-560; mayr, b., horber, d., 1992. kleintierprax. 37, 515-518] published that they were able to cure 80 to ...	1999	10515279
the felv-945 ltr confers a replicative advantage dependent on the presence of a tandem triplication.	feline leukemia virus (felv), like other naturally occurring retroviruses, is characterized by a high degree of genetic diversity. felv-945 is a natural isolate derived from non-b-cell non-t-cell lymphomas classified anatomically as multicentric. felv-945 exhibits a unique structural motif in the ltr composed of a 21-bp tandem triplication downstream of a single copy of enhancer. the unique felv-945 ltr is precisely conserved among eight independent multicentric lymphomas collected in a geograph ...	1999	10544118
x-ray diffraction study of feline leukemia virus fusion peptide and lipid polymorphism.	the structural effects of the fusion peptide of feline leukemia virus (felv) on the lipid polymorphism of n-methylated dioleoylphosphatidylethanolamine were studied using a temperature ramp with sequential x-ray diffraction. this peptide, the hydrophobic amino-terminus of p15e, has been proven to be fusogenic and to promote the formation of highly curved, intermediate structures on the lamellar liquid-crystal to inverse hexagonal phase transition pathway. the felv peptide produces marked effects ...	1999	10567693
comparison of two surgical techniques for renal transplantation in cats.	to compare two surgical techniques for renal transplantation in cats with respect to graft warm ischemia time, total surgical time, operative and postoperative complications, and return to normal renal function based on measurement of plasma creatinine concentrations.	1999	10582737
use of nested polymerase chain reaction (pcr) for detection of retroviruses from formalin-fixed, paraffin-embedded uveal melanomas in cats.	thirty-six formalin-fixed, paraffin-embedded enucleated globes from cats with a diagnosis of diffuse anterior uveal melanoma were obtained. sections of tumor were excised, deparaffinized, and subjected to nested polymerase chain reaction (pcr) to identify proviral dna sequences from the feline leukemia virus (felv)-feline sarcoma virus (fesv; 36 eyes), and the feline immunodeficiency virus (fiv; 18 eyes). all samples tested were negative for fiv dna. three samples were positive for felv-fesv dna ...	1999	11397251
high prevalence of borna disease virus in domestic cats with neurological disorders in japan.	a total of 15 (t-1-t-15) domestic cats with neurological disorders in tokyo area were examined for association with borna disease virus (bdv). none had detectable antibodies to feline immunodeficiency virus (fiv), feline leukemia virus, feline infectious peritonitis virus and toxoplasma gondii, and only cat t-8 had detectable antibody to fiv. serological and molecular epidemiological studies revealed a significantly high prevalence of bdv infection in these cats: antibodies against bdv p24 and/o ...	1999	10596800
protein stabilization: a common consequence of mutations in independently derived v-myc alleles.	myc is overexpressed in many cancers as a result of gene rearrangement or amplification, but coding sequence changes which cluster in the n-terminal transactivation domain also appear to play a role in tumour progression. the prototypic v-myc gene of mc29 virus differs from avian c-myc by a series of mutations, including a change at a regulatory phosphorylation site within the mutational hotspot (thr-61) which is known to potentiate transformation in vitro. we now show that the mutation at thr-6 ...	1999	10602514
epidemiology of feline leukaemia and feline immunodeficiency virus infections in the czech republic.	commercial serological sets were used for the examination of 727 cats kept in larger towns of the czech republic. felv antigen and antibodies to fiv were demonstrated in 96 (13.2%) and 42 (5.8%) of the animals, respectively. seven (0.96%) animals were positive for both felv and fiv. most of the felv and/or fiv positive patients were intact rambling males aged 1-4 years. chronic gastrointestinal and respiratory diseases were found in 54.2% and 43.8% of the felv-positive patients, respectively. ch ...	1999	10676143
the effects of feline retroviruses on cytokine expression.	to identify potential roles of cytokines in retroviral pathogenesis, we used reverse transcription-quantitative competitive polymerase chain reaction (rt-qcpcr) assays to characterize mrna levels of 19 different lymphokines, chemokines, monokines and hematopoietic growth factors in three feline cell lines productively infected with subgroup a feline leukemia virus (felv-a) or various feline immunodeficiency virus (fiv) strains. infection of a cd8+, cd5- large granular lymphocyte (lgl) cell line ...	1999	10628677
cloning of the cellular receptor for feline leukemia virus subgroup c (felv-c), a retrovirus that induces red cell aplasia.	feline leukemia virus-c (felv-c) causes red cell aplasia in cats, likely through its interaction with its cell surface receptor. we identified this receptor by the functional screening of a library of complementary dnas (cdna) from feline t cells. the library, which was cloned into a retroviral vector, was introduced into felv-c-resistant murine (nih 3t3) cells. the gene conferring susceptibility to felv-c was isolated and reintroduced into the same cell type, as well as into felv-c-resistant ra ...	2000	10648427
new insights into the pathophysiology of acquired cytopenias.	this review addresses three related bone marrow failure diseases, the study of which has generated important insights in hematopoiesis, red cell biology, and immune-mediated blood cell injury. in section i, dr. young summarizes the current knowledge of acquired aplastic anemia. in most patients, an autoimmune mechanism has been inferred from positive responses to nontransplant therapies and laboratory data. cytotoxic t cell attack, with production of type i cytokines, leads to hematopoietic stem ...	2000	11701533
prevalence of fiv and felv infections in cats in istanbul.		2000	11716594
a hematological study on thirteen cats with myelodysplastic syndrome.	hematological abnormalities were investigated in 13 cats with myelodysplastic syndrome (mds). examination of the peripheral blood samples from the 13 cats revealed anemia in 11 cats, leukopenia in 9 cats, and thrombocytopenia in 9 cats. four cats had pancytopenia (30.8%) and 9 cats had bicytopenia (69.2%). dysplastic changes of erythrocytes, neutrophils, and platelets in the peripheral blood were found in 5, 10 and 8 cats, respectively. bone marrow examination of the 13 cats revealed that ratios ...	2000	10676891
bone marrow necrosis in a cat infected with feline leukemia virus.	a one-year old castrated male cat was admitted to the hospital with vomiting and diarrhea. laboratory examination revealed pancytopenia and positive for felv antigen. a bone marrow examination indicated necrosis of the nucleated cells. based on these findings, the cat was diagnosed as bone marrow necrosis. pancytopenia was effectively treated with corticosteroids. re-examination of the bone marrow confirmed a recovery of normal hematopoietic cells with a infiltration of many macrophages. it is s ...	2000	10676902
a 13-amino-acid pit1-specific loop 4 sequence confers feline leukemia virus subgroup b receptor function upon pit2.	feline leukemia virus subgroup b (felv-b) and gibbon ape leukemia virus (galv) utilize the human protein pit1 but not the related protein, pit2, as receptor. a stretch of 9 amino acids, named region a, was identified in the putative fourth extracellular loop of pit1 (residues 550 through 558) as critical for felv-b and galv receptor function. however, the presence of pit1 region a did not confer receptor function for felv-b upon pit2, while it did so for galv. we have here shown that the presenc ...	2000	10684313
fungal flora on cutaneous and mucosal surfaces of cats infected with feline immunodeficiency virus or feline leukemia virus.	to compare cutaneous and mucosal mycoflora in cats infected with fiv or felv with that in noninfected cats.	2000	10685687
prevalence of enteric zoonotic organisms in cats.	to determine prevalence of enteric zoonotic organisms in cats in north-central colorado.	2000	10707683
neurophysiologic and immunologic abnormalities associated with feline immunodeficiency virus molecular clone fiv-ppr dna inoculation.	although direct feline immunodeficiency virus (fiv) proviral dna inoculation has been shown to be infectious in cats, long-term studies to assess the pathogenic nature of dna inoculation are lacking. we have recently reported that direct feline leukemia virus (felv) dna inoculation resulted in infection and the development of felv-related disease end points with similar temporal expression and virulence to that of cats infected with whole virus. we show in this study that pfiv-ppr dna inoculatio ...	2000	10708051
identification of a cellular cofactor required for infection by feline leukemia virus.	retroviral infection involves continued genetic variation, leading to phenotypic and immunological selection for more fit virus variants in the host. for retroviruses that cause immunodeficiency, pathogenesis is linked to the emergence of t cell-tropic, cytopathic viruses. here we show that an immunodeficiency-inducing, t cell-tropic feline leukemia virus (felv) has evolved such that it cannot infect cells unless both a classic multiple membrane-spanning receptor molecule (pit1) and a second cor ...	2000	10710311
expression of viral proteins in feline leukemia virus-associated enteritis.	fourteen cases of feline leukemia virus (felv)-associated enteritis were immunohistologically examined for the expression of felv proteins gp70, p27, and p15e in the jejunum, mesenteric lymph nodes, spleen, and bone marrow. results were compared with those of felv-infected cats without intestinal alterations. other viral infections and specific bacterial, fungal, and parasitic infections were excluded by standard microbiologic methods, histopathology, immunohistology, and in situ hybridization. ...	2000	10714641
chronic myelomonocytic leukemia in a cat.	a 1-year-old spayed domestic short-haired cat was referred with anorexia and weight loss. hematologic findings indicated nonregenerative anemia, severe neutropenia and monocytosis. the feline leukemia virus (felv) antigen test was positive reaction by enzyme-linked immunosorbent assay. dysgranulopoiesis with slight increase in blast cells were observed in bone marrow smears. on the basis of blood and bone marrow findings, the cat was diagnosed as chronic myelomonocytic leukemia (cmmol), which po ...	2000	10720191
diagnosis of feline herpesvirus infection by immunohistochemistry, polymerase chain reaction, and in situ hybridization.	an adult domestic shorthair cat had severe chemosis due to purulent and necrotizing blepharitis and conjunctivitis. purulent rhinitis, necrotizing glossitis, and dermatitis were also diagnosed. the cat was positive for feline immunodeficiency virus and feline leukemia virus. histologically, intranuclear cowdry type a inclusions were found within numerous epithelial cells adjacent to the lesions in skin, conjunctiva, and tongue. electron microscopic examination revealed herpesviral particles with ...	2000	10730956
prevalence and pathogenicity of retroviruses in wildcats in france.	feline leukaemia virus (felv) and feline immunodeficiency virus (fiv) are frequently encountered in domestic cats (felis catus) and in wild felids, but only felv has been previously identified in wildcats (fellis silvestris). thirty-eight wildcats, either captured alive or found dead, were sampled in eastern and central france. nine of them (23.7 per cent) carried the felv p27 antigen, and three (7.9 per cent) had antibodies to fiv. there was a significant relationship between two measures of bo ...	2000	10766116
safety and efficacy of a recombinant felv vaccine combined with a live feline rhinotracheitis, calicivirus and panleukopenia vaccine.		2000	10803986
weakly coupled hyperbolic systems modeling the circulation of felv in structured feline populations.	global existence and regularity results are provided for weakly coupled first order hyperbolic systems modeling the propagation of the feline leukemia virus (felv), a retrovirus of domestic cats (felis catus). in a simple example we find a threshold parameter yielding endemic stationary states.	2000	10804261
long-term impact on a closed household of pet cats of natural infection with feline coronavirus, feline leukaemia virus and feline immunodeficiency virus.	a closed household of 26 cats in which feline coronavirus (fcov), feline leukaemia virus (felv) and feline immunodeficiency virus (fiv) were endemic was observed for 10 years. each cat was seropositive for fcov on at least one occasion and the infection was maintained by reinfection. after 10 years, three of six surviving cats were still seropositive. only one cat, which was also infected with fiv, developed feline infectious peritonitis (fip). rising anti-fcov antibody titres did not indicate t ...	2000	10811262
feline leukemia virus envelope sequences that affect t-cell tropism and syncytium formation are not part of known receptor-binding domains.	the envelope protein is a primary pathogenic determinant for t-cell-tropic feline leukemia virus (felv) variants, the best studied of which is the immunodeficiency-inducing virus, 61c. we have previously demonstrated that t-cell-tropic, cytopathic, and syncytium-inducing viruses evolve in cats infected with a relatively avirulent, transmissible form of felv, 61e. the envelope gene of an 81t variant, which encoded scattered single-amino-acid changes throughout the envelope as well as a 4-amino-ac ...	2000	10846053
differential pathogenicity of two feline leukemia virus subgroup a molecular clones, pfra and pf6a.	f6a, a molecular clone of subgroup a feline leukemia virus (felv) is considered to be highly infectious but weakly pathogenic. in recent studies with a closely related subgroup a molecular clone, fra, we demonstrated high pathogenicity and a strong propensity to undergo recombination with endogenous felv (enfelv), leading to a high frequency of transition from subgroup a to a/b. the present study was undertaken to identify mechanisms of felv pathogenesis that might become evident by comparing th ...	2000	10846058
effects of a 98% solution of glycerol or sterilization with ethylene oxide on felv in bone allografts and effects on bone incorporation of allografts in cats.	to compare virucidal effects and bone incorporation properties of cortical bone allografts transplanted into specific-pathogen-free (spf) cats. allografts consisted of untreated bone from a spf cat (negative-control group) and bone from 5 felv-infected cats that was subjected to sterilization with ethylene oxide (eto), preservation with glycerol, or no treatment (positive-control group).	2000	10850843
precise gene localization by phenotypic assay of radiation hybrid cells.	a high resolution map of the human genome previously has been constructed by using the g3 panel of human/hamster radiation hybrid cell lines and >15,000 unique human genetic markers. by determining whether human dna sequences are present or absent in each of the hybrids, localization of single genes may routinely be achieved at approximately 250-kb resolution. in this paper we have tested whether similarly precise localization might be achieved by phenotypic screening of the hybrids to facilitat ...	2000	10852967
transduction of feline hematopoietic cells by oncoretroviral vectors pseudotyped with the subgroup a feline leukemia virus (felv-a).	the domestic cat is an outbred species with many identified analogues of human genetic diseases. therefore, it has the potential to serve as a large animal model for evaluating the feasibility of hematopoietic stem cell gene therapy. this study compared gene transfer rates into feline hematopoietic progenitors by oncoretroviral vectors pseudotyped with the subgroup a feline leukemia virus (felv-a), the gibbon ape leukemia virus (galv), and the murine amphotropic virus. gene transfer rates were s ...	2000	10899828
the histologic classification of 602 cases of feline lymphoproliferative disease using the national cancer institute working formulation.	case information and histologic slides for 688 admissions of feline tissues from 12 veterinary institutions were assembled and reviewed to determine tissues obtained by biopsy or necropsy, age and sex of cat, tumor topography, feline leukemia viral antigen status, histologic frequency of mitoses, diagnosis, presence of necrosis, and presence and degree of sclerosis. histologic sections were examined to place the lesions in one of the diagnostic categories of the national cancer institute working ...	2000	10907857
seroepidemiological survey of infection by feline leukemia virus and immunodeficiency virus in madrid and correlation with some clinical aspects.	a study of 180 healthy cats found that 15.6% were feline leukemia virus (felv) positive, 8.3% were feline immunodeficiency virus (fiv) positive, and 1.1% were fiv and felv positive, which corresponded to 30.4, 13.8, and 2.6, of 115 cats with fiv- and felv-related symptoms, respectively. differences were seen in the sexes and ages of the populations studied. anemia, leukopenia, and lymphopenia were the most frequent hematological abnormalities in infected cats.	2000	10970400
contrastive prevalence of feline retrovirus infections between northern and southern vietnam.	the prevalence of infections with three feline retroviruses; feline leukemia virus (felv), feline immunodeficiency virus (fiv) and feline foamy virus (fefv), was examined in domestic cats (felis catus) and leopard cats (felis bengalensis) in southern vietnam in 1998. we then compared this data with our previous study in northern vietnam in 1997. none of the cats had felv antigens in both the northern and southern areas. in contrast, there is a great distinction in the seropositivity of fiv. twen ...	2000	10993195
long terminal repeat regions from exogenous but not endogenous feline leukemia viruses transactivate cellular gene expression.	we have previously reported that the long terminal repeat (ltr) region of feline leukemia viruses (felvs) can enhance expression of certain cellular genes such as the collagenase iv gene and mcp-1 in trans (s. k. ghosh and d. v. faller, j. virol. 73:4931-4940, 1999). genomic dna of all healthy feline species also contains ltr-like sequences that are related to exogenous felv ltrs. in this study, we evaluated the cellular gene transactivational potential of these endogenous felv ltr sequences. un ...	2000	11000248
cellular and species resistance to murine amphotropic, gibbon ape, and feline subgroup c leukemia viruses is strongly influenced by receptor expression levels and by receptor masking mechanisms.	chinese hamster ovary (cho) cells are resistant to infections by gibbon ape leukemia virus (galv) and amphotropic murine leukemia virus (a-mlv) unless they are pretreated with tunicamycin, an inhibitor of n-linked glycosylation. these viruses use the related sodium-phosphate symporters pit1 and pit2, respectively, as receptors in nonhamster cells, and evidence has suggested that the corresponding transporters of cho cells may be masked by tunicamycin-sensitive secreted inhibitors. although the e ...	2000	11000257
feline leukaemia virus: protective immunity is mediated by virus-specific cytotoxic t lymphocytes.	feline leukaemia virus (felv) nucleic acid vaccination of domestic cats affords protection against viraemia and the development of latency without inducing antiviral antibodies.1 to determine the contribution of cell-mediated immunity to the control of virus replication and clearance from the host, felv-specific cytotoxic t lymphocyte (ctl) responses were compared in vaccine-protected, transiently viraemic, and persistently viraemic cats. vaccinal immunity was associated with the detection of hi ...	2000	11012762
feline leukemia virus and feline immunodeficiency virus.	ophthalmic manifestations of felv or fiv infection can occur in all ocular tissues and may be manifestations of direct viral effects or secondary to viral-related malignant transformation. additionally, the manifestations of common feline ophthalmic pathogens may be more severe and poorly responsive to therapy because of the immunosuppressive effects of felv or fiv infection. prompt diagnosis of underlying viral infection in cats with ophthalmic disease is paramount for accurate diagnosis and pr ...	2000	11033869
inhibition of feline leukemia virus subgroup a infection by coinoculation with subgroup b.	feline leukemia virus (felv) subgroup b arises de novo through recombination between the env genes of exogenous felv subgroup a and endogenous felv-like sequences. felv-b, which by itself is poorly infectious, will increase to high titer in the presence of felv-a, and is associated with felv-related neoplastic disease. although the participation of felv-b in disease progression has not been definitively proven, circumstantial evidence supports the hypothesis that the generation of felv-b is link ...	2000	11062034
clonality analysis of various hematopoietic disorders in cats naturally infected with feline leukemia virus.	the clonality analysis of the bone marrow cells was carried out by detecting the integrated proviruses of feline leukemia virus (felv) to understand the pathogenesis of felv-associated hematopoietic disorders in cats. bone marrow cells from 4 cases with acute myeloid leukemia (aml), 9 cases with myelodysplastic syndromes (mds), 2 cases with pure red cell aplasia (prca) and 3 healthy carriers infected with felv were subjected to southern blot analyses using an exogenous felv probe. clonal hematop ...	2000	11073076
evidence that an ires within the notch2 coding region can direct expression of a nuclear form of the protein.	we previously reported the isolation from a thymic tumor of a feline leukemia virus that had transduced a fragment of the notch2 gene. here we present evidence that a nuclear form of notch2 corresponding to the biologically active intracellular domain (n2icd) is expressed from this recombinant retrovirus through internal ribosome entry. internal ribosome entry sites (iress) are rna structural motifs that allow 5' cap-independent recruitment of ribosomal subunits to mrnas. the notch2 ires maps ex ...	2000	11090631
a novel truncated env gene isolated from a feline leukemia virus-induced thymic lymphosarcoma.	we pcr amplified the exogenous feline leukemia virus (felv)-related env gene species from lymphosarcomas induced by intradermally administered plasmid dna of either the prototype felv, subgroup a molecular clone, f6a, or a new molecular clone, felv-a, rickard strain (fra). of the nine tumors examined, six showed the presence of deleted env species of variable sizes in the tumor dna. one env mutant, which was detected in a fra-induced thymic lymphosarcoma, had a large internal deletion beginning ...	2000	10627556
tyzzer's disease in a red panda (ailurus fulgens fulgens).	a debilitated 9-yr-old female red panda (ailurus fulgens fulgens) with a recent history of corticosteroid administration displayed anorexia, depression, and diarrhea for 2 days. blood work revealed a moderate nonregenerative anemia, leukocytosis, hypokalemia, hyperbilirubinemia, and mildly elevated alanine aminotransferase and aspartate aminotransferase. serology was negative for occult heartworm, toxoplasma gondii, feline leukemia virus, feline infectious peritonitis, feline immunodeficiency vi ...	2000	11428405
a comprehensive approach to mapping the interacting surfaces of murine amphotropic and feline subgroup b leukemia viruses with their cell surface receptors.	because mutations in envelope glycoproteins of retroviruses or in their cell surface receptors can eliminate function by multiple mechanisms, it has been difficult to unambiguously identify sites for their interactions by site-directed mutagenesis. recently, we developed a gain-of-function approach to overcome this problem. our strategy relies on the fact that feline leukemia virus subgroup b (felv-b) and amphotropic murine leukemia virus (a-mlv) have closely related gp70 surface envelope glycop ...	2000	10590111
identification of envelope determinants of feline leukemia virus subgroup b that permit infection and gene transfer to cells expressing human pit1 or pit2.	the retroviral vector systems that are in common use for gene therapy are designed to infect cells expressing either of two widely expressed phosphate transporter proteins, pit1 or pit2. subgroup b feline leukemia viruses (felv-bs) use the gibbon ape leukemia virus receptor, pit1, as a receptor for entry. our previous studies showed that some chimeric envelope proteins encoding portions of felv-b could also enter cells by using a related receptor protein, pit2, which serves as the amphotropic mu ...	2001	11435563
combined omental pedicle grafts and thoracodorsal axial pattern flaps for the reconstruction of chronic, nonhealing axillary wounds in cats.	to assess the results of an omental pedicle graft in combination with a thoracodorsal axial pattern flap for the reconstruction of chronic nonhealing axillary wounds in 10 cats caused by forelimb entrapment within a collar.	2001	11443600
immunomodulation therapy for feline leukemia virus infection.	clinically ill feline leukemia virus (felv)-infected cats, treated with staphylococcus protein a (spa) or oral interferon alpha (ifn), or both, were compared with cats treated with saline (sal). nine cats received spa/sal, nine received spa/ifn, 10 received sal/ifn, and eight received sal/sal. twelve cats survived and completed the 100-week therapy. significantly more owners of cats treated with spa/sal thought their cat's health improved during treatment compared to owners of cats treated with ...	2001	11450836
comparative examination of cats with feline leukemia virus-associated enteritis and other relevant forms of feline enteritis.	cats with feline leukemia virus (felv)-associated enteritis (fae), enteritis of other known viral etiology (parvovirus [pv], enteric coronavirus [cov]), and enteritis of unknown etiology with histologic features similar to those of fae and pv enteritis (eue) and felv-negative and felv-positive cats without enterocyte alterations were examined. amount and types of infiltrating leukocytes in the jejunum and activity and cellular constituents of mesenteric lymph nodes, spleen, and bone marrow were ...	2001	11467470
bone marrow colony-forming unit assay in cats with naturally occurring myelodysplastic syndromes.	feline myelodysplastic syndromes (mds) has been diagnosed in many cats infected with feline leukemia virus, although the pathogenesis of this hematopoietic deficiency has been unclear. in this study, we assayed the bone marrow erythroid colony-forming units (cfu-e) and granulocyte-machrophage cfus (cfu-gm) to investigate the pathogenesis of feline mds. the number of cfu-e colonies was decreased in 4 of 7 cats with mds, and the number of cfu-gm colonies was also decreased in 4 cats. furthermore, ...	2001	11503958
feline leukemia virus dna vaccine efficacy is enhanced by coadministration with interleukin-12 (il-12) and il-18 expression vectors.	the expectation that cell-mediated immunity is important in the control of feline leukemia virus (felv) infection led us to test a dna vaccine administered alone or with cytokines that favored the development of a th1 immune response. the vaccine consisted of two plasmids, one expressing the gag/pol genes and the other expressing the env gene of felv-a/glasgow-1. the genetic adjuvants were plasmids encoding the feline cytokines interleukin-12 (il-12), il-18, or gamma interferon (ifn-gamma). kitt ...	2001	11507187
a replication-competent feline leukemia virus, subgroup a (felv-a), tagged with green fluorescent protein reporter exhibits in vitro biological properties similar to those of the parental felv-a.	we previously established that lymphoid tumors could be induced in cats by intradermal injection of ecotropic feline leukemia virus (felv), subgroup a, plasmid dna. in preparation for in vivo experiments to study the cell-to-cell pathway for the spread of the virus from the site of inoculation, the green fluorescent protein (gfp) transgene fused to an internal ribosome entry site (ires) was inserted after the last nucleotide of the env gene in the ecotropic felv-a rickard (fra) provirus. the eng ...	2001	11507228
hbv core particles as a carrier for b cell/t cell epitopes.	in the middle 80s, recombinant hepatitis b virus cores (hbc) gave onset to icosahedral virus-like particles (vlps) as a basic class of non-infectious carriers of foreign immunological epitopes. the recombinant hbc particles were used to display immunodominant epitopes of hepatitis b, c, and e virus, human rhinovirus, papillomavirus, hantavirus, and influenza virus, human and simian immunodeficiency virus, bovine and feline leukemia virus, foot-and-mouth disease virus, murine cytomegalovirus and ...	2001	11509871
feline leukaemia provirus load during the course of experimental infection and in naturally infected cats.	feline leukaemia virus (felv) infection in domestic cats can vary in its outcome (persistent, transient, no infection) for reasons that are not entirely known. it was hypothesized that the initial virus and provirus load could significantly influence the course of retrovirus infection. to determine the role of provirus loads, two methods of pcr, a nested pcr and a fluorogenic probe-based (taqman) real-time quantitative pcr, which were specific to the u3 region of felv-a were established. felv pr ...	2001	11413369
feline leukemia virus detection in corneal tissues of cats by polymerase chain reaction and immunohistochemistry.	to determine the presence of feline leukemia virus (felv) in the corneas of felv-infected cats.	2001	11422993
vaccine-associated sarcomas in cats: a unique cancer model.	epidemiologic evidence supports a relationship between vaccination of cats for rabies and feline leukemia virus with the development of soft tissue sarcomas at the site of administration. these tumors are locally invasive and histologically aggressive. as with high-grade soft tissue sarcoma in humans, combination treatment with radiation therapy and surgery provides for optimum tumor control. feline vaccine-associated sarcoma has become a difficult issue for the veterinary profession for legal, ...	2001	11153990
characterisation of lymphosarcomas in australian cats using polymerase chain reaction and immunohistochemical examination.	to examine tumour tissue of cats with lymphosarcoma for the presence of feline leukaemia virus and feline immunodeficiency virus and analyse the immunophenotype of the tumours.	2001	11221568
feline leukemia virus in a captive bobcat.	an 11-mo-old captive-bred male neutered bobcat (felis rufus) presented with lethargy, anorexia, leukopenia, neutropenia, lymphopenia, and nonregenerative anemia. the animal was diagnosed as feline leukemia virus (felv) positive by immunofluorescent antibody and enzyme-linked immunosorbant assay (elisa) testing. it died despite supportive care. pathologic examination revealed multifocal non-suppurative encephalitis, diffuse interstitial pneumonia, multifocal hepatocellular necrosis, non-suppurati ...	2001	11272497
feline vaccine-associated fibrosarcoma: an ultrastructural study of 20 tumors (1996-1999).	twenty feline vaccine-associated sarcomas were examined by transmission electron microscopy. tumors contained pleomorphic spindle cells, histiocytoid cells, and giant cells. most tumors contained myofibroblasts, which had morphologic features similar to those of fibroblasts. these cells were further distinguished by subplasmalemmal dense plaques and thin cytoplasmic actin myofilaments organized as elongated bundles concentrated at irregular intervals forming characteristic dense bodies. intracel ...	2001	11280376
neutropenia in dogs and cats: a retrospective study of 261 cases.	case records of 232 dogs and 29 cats with neutropenia were reviewed to examine the spectrum of underlying etiologies causing the neutropenia. six etiological categories included nonbacterial infectious disease; increased demand due to marked inflammation, bacterial sepsis, or endotoxemia; drug-associated neutropenia; primary bone-marrow disease; immune-mediated neutropenia; and diseases of unclear etiology. the largest single category associated with the development of neutropenia was nonbacteri ...	2001	11300519
single agent chemotherapy with doxorubicin for feline lymphoma: a retrospective study of 19 cases (1994-1997).	medical records of 21 cats with confirmed lymphoma treated with single-agent doxorubicin were reviewed. nineteen cats met the inclusion criteria for this retrospective study. doxorubicin was given at a dosage of 25 mg/m2 (n = 8) or 1 mg/kg (n = 11) iv, every 3 weeks for a total of 5 treatments. four of 16 tested cats were positive for feline leukemia virus (felv) and all 16 cats tested negative for feline immunodeficiency virus. eight of the 19 cats (42%) responded to doxorubicin for a median du ...	2001	11300595
selection forces and constraints on retroviral sequence variation.	all retroviruses possess a highly error-prone reverse transcriptase, but the extent of the consequent sequence diversity and the rate of evolution differ greatly among retroviruses. because of the high mutability of retroviruses, it is not the generation of new viral variants that limits the extent of diversity and the rate of evolution of retroviruses, but rather the selection forces that act on these variants. here, we suggest that two selection forces--the immune response and the limited avai ...	2001	11352065
feline leukaemia virus neutralising antibodies.		2001	11761301
comparison of endogenous feline leukemia virus rna content in feline vaccine and nonvaccine site-associated sarcomas.	to determine whether feline vaccine site-associated sarcomas (vss) contain a higher amount of endogenous felv (enfelv) rna, compared with feline nonvaccine site-associated sarcomas (non-vss).	2001	11763193
detection of antibodies to borna disease virus in turkish cats by using recombinant p40.	recombinant p40 produced by baculovirus was used in an elisa to screen samples of serum taken from 80 cats in istanbul. the sera were also analysed for feline immunodeficiency virus (fiv) and feline leukaemia virus (felv). antibodies to borna disease virus- (bdv) p40 were detected in 34 (42-5 per cent) of the 80 cats. seventy-three per cent of the sera which were positive for fiv and 26 per cent of the sera which were negative for fiv had antibodies to bdv. there was no difference in the percent ...	2001	11764326
what is new on feline lymphoma?		2001	11795953
commentary: phenotypic screening of radiation hybrid panels.		2001	11707772
specificity in receptor usage by t-cell-tropic feline leukemia viruses: implications for the in vivo tropism of immunodeficiency-inducing variants.	cytopathic, t-cell-tropic feline leukemia viruses (felv-t) evolve from felv-a in infected animals and demonstrate host cell specificities that are distinct from those of their parent viruses. we recently identified two cellular proteins, felix and pit1, required for productive infection by these immunodeficiency-inducing felv-t variants (m. m. anderson, a. s. lauring, c. c. burns, and j. overbaugh, science 287:1828-1830, 2000). felv-t is the first example of a naturally occurring type c retrovir ...	2001	11533152
feline leukaemia virus status of australian cats with lymphosarcoma.	to determine the felv status of sera and tumours from australian cats with lymphosarcoma in relation to patient characteristics, tumour characteristics (tissue involvement, histological grade and immunophenotype), haematological and biochemical values.	2001	11549046
feline babesiosis: signalment, clinical pathology and concurrent infections.	fifty-six cats with naturally occurring babesia felis infection were studied. no breed or sex predilection could be identified, but there was an apparent predilection for young adult cats less than 3 years of age. macrocytic, hypochromic, regenerative anaemia was present in 57% of the cats and in-saline agglutination tests were positive in 16%. no characteristic changes were observed in total or differential leukocyte counts. thrombocyte counts were variable and thrombocytopaenia was an inconsis ...	2001	11563718
comparison of six in-house tests for the rapid diagnosis of feline immunodeficiency and feline leukaemia virus infections.	six rapid tests for the diagnosis of feline immunodeficiency virus (fiv) and feline leukaemia virus (felv) infections which have recently been introduced in europe for use in small animal practice were compared. eight hundred serum samples were tested and those reacting fiv-positive in at least one of the tests were confirmed by western blot, and those reacting felv-positive were confirmed by virus isolation. the specificity and sensitivity of each test and the quality of the results produced we ...	2001	11583125
hematologic abnormalities and outcome of 16 cats with myelodysplastic syndromes.	we investigated the hematologic abnormalities and prognoses in 16 cats with myelodysplastic syndromes (mds). nonregenerative anemia, thrombocytopenia, and neutropenia were observed in 15, 13, and 4, respectively, of the 16 cats with mds. morphologic abnormalities characteristic of mds included megaloblastoid rubricytes (9 cats), hyposegmentation of neutrophils (7 cats), nuclear abnormality of rubricytes (10 cats) and neutrophils (13 cats), and micromegakaryocytes (10 cats). disease in these 16 c ...	2001	11596735
feline pit2 functions as a receptor for subgroup b feline leukemia viruses.	different subgroups of feline leukemia virus (felv) use different host cell receptors for entry. subgroup a felv (felv-a) is the virus that is transmitted from cat to cat, suggesting that cells expressing the felv-a receptor are important targets at the earliest stages of infection. felv-b evolves from felv-a in the infected cat through acquisition of cellular sequences that are related to the felv envelope gene. felv-bs have been shown to infect cells using the pit1 receptor, and some variants ...	2001	11602698
detection of feline leukaemia virus in blood and bone marrow of cats with varying suspicion of latent infection.	the purpose of this study was to determine if polymerase chain reaction (pcr) could be used to detect felv proviral dna in bone marrow samples of cats with varying suspicion of latent infection. blood and bone marrow samples from 50 cats and bone marrow from one fetus were collected, including 16 cats with diseases suspected to be felv-associated. serum enzyme-linked immunosorbent assay (elisa), blood and bone marrow immunofluorescent antibody test (ifa), and blood and bone marrow pcr were perfo ...	2001	11876630
therapy for australian cats with lymphosarcoma.	to determine the response of australian cats with lymphosarcoma to chemotherapy and/or surgery in relation to patient and tumour characteristics, haematological and serum biochemical values and retroviral status.	2001	11837901
altering retroviral tropism using a random-display envelope library.	tissue-specific gene delivery is an important aspect of many gene therapy applications. the experiments reported here constitute the first successful demonstration that cell-specific entry can be obtained by screening a random library of retroviral envelope proteins produced from a mammalian cell system. the library consisted of 10(6) different subgroup a feline leukemia virus envelope protein variants with 10 randomly substituted amino acids in the receptor-determining region. selecting the lib ...	2002	11863424
prevalence of felv and antibodies to fiv and fcov in falkland islands cats.		2002	12503794
chemotherapy with cyclophosphamide, vincristine, and prednisolone (cop) in cats with malignant lymphoma: new results with an old protocol.	this retrospective study in 61 cats with malignant lymphomas examined the efficacy of a well-established chemotherapy protocol (cyclophosphamide, vincristine, and prednisolone [cop]) in the netherlands, a country with a low prevalence of feline leukemia virus (felv). twenty-two cats (36.1%) had mediastinal lymphoma, 11 (18.0%) had alimentary lymphoma, 7 (11.5%) had peripheral lymphoma, 8 (13.1%) had nasal lymphoma, and 13 (21.3%) had miscellaneous lymphoma (including renal lymphoma in 2 [3.3%]). ...	2002	11899035
fusion-defective gibbon ape leukemia virus vectors can be rescued by homologous but not heterologous soluble envelope proteins.	murine leukemia virus (mlv)-derived envelope proteins containing alterations in or adjacent to the highly conserved phq motif present at the n terminus of the envelope surface subunit (su) are incorporated into vector particles but are not infectious due to a postbinding block to viral entry. these mutants can be rendered infectious by the addition of soluble receptor-binding domain (rbd) proteins in the culture medium. the rbd proteins that rescue the infectivity of these defective mlv vectors ...	2002	11932392
genomic structure and evolutionary context of the human feline leukemia virus subgroup c receptor (hflvcr) gene: evidence for block duplications and de novo gene formation within duplicons of the hflvcr locus.	in this paper we sought to analyze the genomic structure and context of human feline leukemia virus subgroup c receptor (hflvcr), a human glucarate transporter-like gene at chromosome 1q31, and compare it to that of a paralog (flvcr14q) at chromosome 14q24. splicing, polyadenylation, and expression patterns, as estimated by in silico analysis, differed between the two flvcr genes despite their similar genomic structures, suggesting active and independent evolution of transcriptional and messenge ...	2002	11943475
a biomimetic approach to the synthesis of an antiviral marine steroidal orthoester.	orthoesterol b, a marine natural product exhibiting antiviral activities, contains a [3.2.1]-bicyclic orthobutyrate bridging the steroid side chain and ring d. a biosynthetic reaction was proposed by which rearrangement of an epoxy ester results in the formation of the orthoester moiety. steroidal model compounds incorporating 16-butyroxy and 20,22-epoxy groups were synthesized from tigogenin and were shown to rearrange to orthoesters under mild acidic catalysis.	2002	11950327
cats differ from mink and ferrets in their response to commercial vaccines: a histologic comparison of early vaccine reactions.	early histologic changes in lesions at vaccine sites were compared in cats, mink, and ferrets. twenty-four 4-month-old cats, 20 4-month-old mink, and 20 12-month-old ferrets were vaccinated with three rabies virus vaccines, two feline leukemia virus vaccines, alum adjuvant, and saline. injection sites were excised at selected time points up to 21 days postvaccination. histologic examination of the tissue revealed significant differences among the cats, mink, and ferrets in the local response to ...	2002	12009059
prevalence of feline leukaemia virus and antibodies to feline immunodeficiency virus and feline coronavirus in stray cats sent to an rspca hospital.	a total of 517 stray cats at an rspca veterinary hospital were tested for feline leukaemia virus (felv), feline coronavirus (fcov) and feline immunodeficiency virus (fiv). the prevalence of felv was 3.5 per cent in all the cats, 1.4 per cent in healthy cats and 6.9 per cent in sick cats. felv positivity was associated only with disease of non-traumatic origin. antibodies to fcov were present in 22.4 per cent of the cats, and their prevalence was significantly higher in cats over two years old an ...	2002	12046785
reassessing the role of region a in pit1-mediated viral entry.	the mammalian gammaretroviruses gibbon ape leukemia virus (galv) and feline leukemia virus subgroup b (felv-b) can use the same receptor, pit1, to infect human cells. a highly polymorphic nine-residue sequence within pit1, designated region a, has been proposed as the virus binding site, because mutations in this region abolish pit1-mediated cellular infection by galv and felv-b. however, a direct correlation between region a mutations deleterious for infection and loss of virus binding has not ...	2002	12097582
protection against oronasal challenge with virulent feline leukaemia virus lasts for at least 12 months following a primary course of immunisation with leukocell 2 vaccine.	the duration of immunity provided by a feline leukemia virus (felv) vaccine, leukocell 2, was determined. kittens were vaccinated when 9 and 12 weeks of age and were challenged 12 months later with felv-a/glasgow-1. an oronasal challenge protocol without corticosteroid enhancement was developed in order to induce a persistent viraemia in a high proportion of adult cats. fourteen of 18 (80%) of the vaccinated cats challenged in this way remained non-viraemic while 9/15 (60%) of age-matched contro ...	2002	12126896
genetic and biochemical analyses of receptor and cofactor determinants for t-cell-tropic feline leukemia virus infection.	entry by retroviruses is mediated through interactions between the viral envelope glycoprotein and the host cell receptor(s). we recently identified two host cell proteins, felix and pit1, that are necessary for infection by cytopathic, t-cell-tropic feline leukemia viruses (felv-t). pit1 is a classic multiple transmembrane protein used as a receptor by several other simple retroviruses, including subgroup b felv (felv-b), and felix is a secreted cellular protein expressed from endogenous felv-r ...	2002	12134012
lack of detection of feline leukemia and feline sarcoma viruses in diffuse iris melanomas of cats by immunohistochemistry and polymerase chain reaction.	diffuse iris melanoma was confirmed by light-microscopic examination in 10 formalin-fixed, paraffin-embedded globes from 10 cats. to determine if feline leukemia virus or a replication defective feline leukemia virus, feline sarcoma virus, was present in these anterior uveal melanomas, immunohistochemistry and polymerase chain reaction for feline leukemia virus were utilized. immunohistochemical staining for feline leukemia virus glycoprotein 70 was performed on all 10 tumors using an avidin-bio ...	2002	12152818
retrospective study of 46 cases of feline haemobartonellosis in israel and their relationships with felv and fiv infections.	forty-six cats with clinical haemobartonellosis were studied; 75 per cent of the cats of known age were two-and-a-half years old or younger, 50 per cent were intact males and 19.5 per cent were castrated males. the predominant signs of the disease were tachypnoea, lethargy, depression, anorexia, infestation with fleas, pale mucous membranes, icterus, emaciation, dehydration, splenomegaly, anaemia, leucocytosis, increased activities of alanine aminotransferase and aspartate aminotransferase, and ...	2002	12164225
effect of preexisting felv infection or felv and feline immunodeficiency virus coinfection on pathogenicity of the small variant of haemobartonella felis in cats.	to investigate the effects of preexisting felv infection or felv and feline immunodeficiency (fiv) coinfection on the pathogenicity of the small variant of haemobartonella felis (hfsm, california variant) in cats.	2002	12171173
virus safety in xenotransplantation: first exploratory in vivo studies in small laboratory animals and non-human primates.	for xenotransplantation, the transplantation of animal cells, tissues and organs into human recipients, to date, pigs are favored as potential donors. beside ethical, immunological, physiological and technical problems, the microbiological safety of the xenograft has to be guaranteed. it will be possible to eliminate all of the known porcine microorgansims in the nearby future by vaccinating or specified pathogen-free breeding. thus, the main risk will come from the porcine endogenous retrovirus ...	2002	12180842