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N C Pedersen

Publications and source records attributed to N C Pedersen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prophylactic and therapeutic benefits of short-term 9-[2-(R)-(phosphonomethoxy)propyl]adenine (PMPA) administration to newborn macaques following oral inoculation with simian immunodeficiency virus with reduced susceptibility to PMPA.

Simian immunodeficiency virus (SIV) infection of newborn macaques is a useful animal model of human pediatric AIDS to study pathogenesis and to develop intervention strategies aimed at preventing infection or delaying disease progression. In previous studies, we demonstrated that 9-¿2-(R)-(phosphonomethoxy)propylădenine (PMPA; tenofovir) was highly effective in protecting newborn macaques against infection with virulent wild-type (i.e., drug-susceptible) SIVmac251. In the present study, we determined how reduced drug susceptibility of the virus inoculum affects the chemoprophylactic success. SIVmac055 is a virulent isolate that has a fivefold-reduced in vitro susceptibility to PMPA, associated with a K65R mutation and additional amino acid changes (N69T, R82K, A158S, S211N) in reverse transcriptase (RT). Eight newborn macaques were inoculated orally with SIVmac055. The three untreated control animals became SIVmac055 infected; these animals had persistently high viremia and developed fatal immunodeficiency within 3 months. Five animals were treated once daily with PMPA (at 30 mg/kg of body weight) for 4 weeks, starting 24 h prior to oral SIVmac055 inoculation. Two of the five PMPA-treated animals had no evidence of infection. The other three PMPA-treated infant macaques became infected but had a delayed viremia, enhanced antiviral antibody responses, and a slower disease course (AIDS in 5 to 15 months). No reversion to wild-type susceptibility or loss of the K65R mutation was detected in virus isolates from any of the PMPA-treated or untreated SIVmac055-infected animals. Several additional amino acid changes developed in RT, but they were not exclusively associated with PMPA therapy. The results of this study suggest that prophylactic administration of PMPA to human newborns and to adults following exposure to human immunodeficiency virus will still be beneficial even in the presence of viral variants with reduced susceptibility to PMPA.

Adenine↗
PubMed1999

A review of immunologic diseases of the dog.

The following review is based on notes used in the teaching of clinical immunology to veterinary students. Immune diseases of the dog are placed into six different categories: (1) type I or allergic conditions; (2) type II or auto- and allo-antibody diseases; (3) type III or immune complex disorders; (4) type IV or cell-mediated immune diseases; (5) type V conditions or gammopathies; and (6) type VI or immunodeficiency disorders. Separate discussions of transplantation immunology and the use of drugs to regulate unwanted immune responses are also included.

Animals↗
PubMed1999

Outbreak of fatal salmonellosis in cats following use of a high-titer modified-live panleukopenia virus vaccine.

A 14-week-old kitten from a private cattery was examined because of an acute onset of recumbency and epistaxis 10 days after receiving a high-titer modified-live virus vaccine containing panleukopenia virus, calicivirus, and herpesvirus components. The kitten died the following day, and intestinal crypt necrosis; hepatic, splenic, and lymph node inflammation and necrosis; and pneumonia were seen at necropsy. Salmonella typhimurium was isolated from mesenteric lymph nodes and the spleen. The breeder reported that 4 other kittens had died in the previous month, each within 1 to 2 weeks after being vaccinated with the same modified-live virus vaccine. Carcasses of 3 kittens were available for examination, and Salmonella sp was isolated from mesenteric lymph nodes of all 3. Villus crypt necrosis and secondary fibrosis were also found. Three of the remaining 12 kittens in the cattery were also found to be shedding Salmonella sp in their feces. Clinical and pathologic findings in these kittens were likely attributable to salmonellosis and panleukopenia, and suggest that mild immunosuppression induced by vaccination could have facilitated development of fatal salmonellosis in subclinical carrier kittens. However, we cannot prove that vaccination actually played any role.

Animals↗
PubMed1999

One-tube fluorogenic reverse transcription-polymerase chain reaction for the quantitation of feline coronaviruses.

A one-tube reverse transcription-polymerase chain reaction (RT-PCR) for absolute feline coronavirus (FCoV) quantitation was developed. The assay is based on the 5' nuclease activity of the Thermus flavus (Tfl) polymerase and a fluorogenic probe which generates fluorescence when it is cleaved. The fluorogenic probe, also called TaqMan(TM) probe (Perkin Elmer, Foster City, USA), is an oligonucleotide designed to bind between the two PCR primers to the target cDNA and is labeled with a reporter and a quencher dye. In the intact probe, the quencher dye suppresses the fluorescence of the reporter dye by Forster-type energy transfer. During the polymerase extension steps the Tfl exonuclease activity cleaves the hybridised probe resulting in the generation of fluorescent emission of the reporter dye. The threshold cycle (C(T) value) indicates the increase of reporter fluorescence and is directly related to the initial amount of target cDNA or RNA, respectively. Fluorescence is monitored in real time after each cycle by a Perkin-Elmer ABI Prism 7700 Sequence Detector. After completion of amplification, the C(T) values of the samples are calculated back to a standard curve, generated by amplification of diluted standard molecules. The one-tube RT-PCR described below allows precise quantitation, is highly sensitive, rapid (no separate reverse transcription step and no post-amplification steps), easy to handle, allows for a high sample throughput, shows a very good reproducibility, and can be executed with a low risk of contamination. The design of the primers probe combination enables the detection of all known FCoV strains and is also useful for the detection of canine coronavirus, transmissible gastroenteritis virus and porcine respiratory coronavirus.

Animals↗
PubMed1999

9-[2-(Phosphonomethoxy)propyl]adenine (PMPA) therapy prolongs survival of infant macaques inoculated with simian immunodeficiency virus with reduced susceptibility to PMPA.

Simian immunodeficiency virus (SIV) infection of newborn rhesus macaques is a useful animal model of human immunodeficiency virus infection for the study of the emergence and clinical implications of drug-resistant viral mutants. We previously demonstrated that SIV-infected infant macaques receiving prolonged treatment with 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) developed viral mutants with fivefold reduced susceptibility to PMPA in vitro and that the development of these mutants was associated with the development of a K65R mutation and additional compensatory mutations in reverse transcriptase (RT). To study directly the virulence and clinical implications of these SIV mutants, two uncloned SIVmac isolates with similar fivefold reduced in vitro susceptibilities to PMPA but distinct RT genotypes, SIVmac055 (K65R, N69T, R82K A158S,S211N) and SIVmac385 (K65R, N69S, I118V), were each inoculated intravenously into six newborn rhesus macaques; 3 weeks later, three animals of each group were started on PMPA treatment. All six untreated animals developed persistently high levels of viremia and fatal immunodeficiency within 4 months. In contrast, the six PMPA-treated animals, despite having persistently high virus levels, survived significantly longer: 5 to 9 months for the three SIVmac055-infected infants and > or = 21 months for the three SIVmac385-infected infants. Virus from only one untreated animal demonstrated reversion to wild-type susceptibility and loss of the K65R mutation. In several other animals, additional RT mutations, including K64R and Y115F, were detected, but the biological role of these mutations is unclear since they did not affect the in vitro susceptibility of the virus to PMPA. In conclusion, this study demonstrates that although SIVmac mutants with the PMPA-selected K65R mutation in RT were highly virulent, PMPA treatment still offered strong therapeutic benefits. These results suggest that the potential emergence of HIV mutants with reduced susceptibility to PMPA in patients during prolonged PMPA therapy may not eliminate its therapeutic benefits.

Adenine↗
PubMed1999

Early short-term 9-[2-(R)-(phosphonomethoxy)propyl]adenine treatment favorably alters the subsequent disease course in simian immunodeficiency virus-infected newborn Rhesus macaques.

Simian immunodeficiency virus (SIV) infection of newborn macaques is a useful animal model of human pediatric AIDS to study disease pathogenesis and to develop intervention strategies aimed at delaying disease. In the present study, we demonstrate that very early events of infection greatly determine the ultimate disease course, as short-term antiviral drug administration during the initial viremia stage significantly delayed the onset of AIDS. Fourteen newborn macaques were inoculated orally with uncloned, highly virulent SIVmac251. The four untreated control animals showed persistently high virus levels and poor antiviral immune responses; they developed fatal immunodeficiency within 15 weeks. In contrast, SIV-infected newborn macaques which were started on 9-[2-(R)-(phosphonomethoxy)propyl]adenine (PMPA) treatment at 5 days of age and continued for either 14 or 60 days showed reduced virus levels and enhanced antiviral immune responses. This short-term PMPA treatment did not induce detectable emergence of SIV mutants with reduced in vitro susceptibility to PMPA. Although viremia increased in most animals after PMPA treatment was withdrawn, all animals remained disease-free for at least 6 months. Our data suggest that short-term treatment with a potent antiviral drug regimen during the initial viremia will significantly prolong AIDS-free survival for HIV-infected infants and adults.

Adenine↗
PubMed1998

Effect of feline immunodeficiency virus on cytokine response to Listeria monocytogenes in vivo.

Feline immunodeficiency virus (FIV) is a lentivirus that induces an acquired immunodeficiency in domestic cats. The objective of this study was to compare the immune response of chronically FIV-infected cats and specific pathogen free (SPF) cats to Listeria monocytogenes, a facultative intracellular bacterium. Regional lymph nodes were removed at various times after subcutaneous inoculation with L. monocytogenes and evaluated. Lymph nodes of chronically FIV-infected cats enlarged more slowly and to a lesser degree than SPF cats. This was due to delayed and blunted lymphoid follicle formation and markedly diminished histiocyte influx. The cellular response correlated with a marked upregulation in IL10 transcription and delayed increase in TNF-alpha upregulation in FIV-infected cats. Transcriptional upregulation of IFN-gamma, IL4, and the p40 chain of IL12 was similar in lymph nodes of FIV-infected and SPF cats. Clinically, FIV-infected cats had a more severe response at the site of L. monocytogenes injection and showed signs of systemic bacterial dissemination while SPF cats remained clinically normal. FIV-infected cats generated a delayed hypersensitivity response similar to SPF cats but also had a significantly greater antibody response. Taken together, these data suggest excessive IL10 production may be responsible for the deficiency observed in the innate immune response of chronically FIV-infected cats challenged with L. monocytogenes.

Animals↗
PubMed1998

Compartmentalization of Th1/Th2 cytokine responses to experimental Yersinia pseudotuberculosis infection in cats.

Specific pathogen-free cats were inoculated subcutaneously into the drainage areas of the left auricular and popliteal lymph nodes with living Yersinia pseudotuberculosis. Inflammation was evident at the inoculation sites and the regional lymph nodes were palpably enlarged at 48 h post-infection. Lymph node enlargement was due to marked paracortical lymphoid hyperplasia and variable neutrophil infiltrates. Yersinia was cultured from the regional lymph nodes and/or spleens of three of the six cats, indicating systemic spread of bacteria. Specific T-helper 1 and 2 (Th1, Th2) cell-associated cytokine mRNA levels were compared in regional lymph nodes, peripheral blood mononuclear cells (PBMC) and spleen at 48 h post-inoculation. Relative to unstimulated control tissues, there was a significant increase in TNF-alpha, IFN-gamma, IL-12, and IL-10 mRNAs in spleen with down-regulation of IL-4. Significant up-regulation of TNF-alpha and down-regulation of IL-4 were also observed in PBMC. Paradoxically, 48 h stimulated lymph nodes showed only minimal differences in cytokine mRNA expression when compared to lymph nodes from mock-inoculated control animals or unchallenged contralateral lymph nodes from the same animal. This study demonstrated that cats, like mice, respond to an intracellular pathogen such as Y pseudotuberculosis with a predominantly Th1-type immune response. The cytokine responses in regional lymph nodes and spleen were asynchronous, while cytokine stimulation in cells of the spleen was mirrored by PBMC.

Animals↗
PubMed1998

Homologous protection but lack of heterologous-protection by various species and types of Bartonella in specific pathogen-free cats.

Cat-scratch disease (CSD) is caused by Bartonella henselae, and possibly by B. clarridgeiae. In immuno-compromised persons, B. henselae is one of the agents causing bacillary angiomatosis. Domestic cats are the main reservoir of these bacteria, which are transmitted primarily from cat to cat by fleas. Possible strategies to prevent the spread of infection among cats are to eliminate flea infestation or to prophylactically immunize cats. In order to develop an appropriate vaccine, it is important to determine if cats become resistant to re-infection by the same strain or various types or species of Bartonella. In a series of experiments, 21 SPF cats were experimentally infected by the intradermal route with 10(5)-10(10) colony-forming units/ml of either B. henselae type II (17 cats), or a new strain 'Humboldt' isolated from a mountain lion (4 cats). The cats were bled weekly to every other week for determination of bacteremia and specific antibody production. After they cleared their infection, they were challenged by a homologous or heterologous strain of Bartonella: 10 cats were challenged with B. henselae type II, three cats with B. henselae type I, four cats with B. clarridgeiae and four cats with the 'Humboldt' strain. Seven of these cats received a third inoculum dose resulting in three cats sequentially infected with sequence B. henselae type II/B. henselae type II/'Humboldt', two cats with sequence B. henselae type II/'Humboldt'/B. clarridgeiae, and two cats with the sequence 'Humboldt'/B. henselae type II/'Humboldt'. All cats challenged with a homologous strain remained abacteremic after challenge and had an increased IgG antibody titer. All cats challenged with either a different Bartonella species or type became bacteremic. The few cats receiving a third inoculum with a strain homologous to the initial strain remained abacteremicafter that challenge. All cats infected with B. clarridgeiae suffered relapsing bacteremia compared to only 36% of the B. henselae infected cats and 22% of the 'Humboldt'-infected cats (p=0.008). The duration of bacteremia was significantly longer in B. henselae primary-infected cats (mean: 34 weeks) than B. henselae heterologously challenged cats (mean: 9 weeks) (p=0.014). These data clearly indicate the lack of cross-protection between B. henselae and B. clarridgeiae and furthermore, indicate the lack of protection between B. henselae types I and II, and a wildlife isolate. A vaccine strategy for CSD prevention in domestic cats will require a multivalent vaccine approach.

Animals↗
PubMed1998

Two doses of PMPA protect newborn macaques against oral simian immunodeficiency virus infection.

BACKGROUND: Simple and affordable intervention strategies are needed to reduce the rate of HIV transmission from mother to infant in developing countries. Simian immunodeficiency virus (SIV) infection of newborn rhesus macaques is considered to be a useful model of human pediatric HIV infection. OBJECTIVE: To investigate whether short-term 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) administration can protect newborn rhesus macaques against perinatal SIV infection. DESIGN AND METHODS: Eight newborn macaques were inoculated orally with highly virulent SIVmac within the first 3 days of life. Four of these animals were untreated controls. The other four animals were given one dose of PMPA (30 mg/kg subcutaneously) 4 h before oral SIV inoculation, and were then given a second and final dose of PMPA 24 h later. RESULTS: All four untreated control animals were persistently SIV-positive within 2 weeks after virus inoculation. In contrast, no virus could be detected in the four animals that received two doses of PMPA; these animals were seronegative and healthy at 10 months. CONCLUSIONS: Two doses of PMPA prevented SIV infection of newborn macaques. Our data suggest that short-term administration of PMPA to HIV-infected pregnant women at the onset of labor and to their newborns after delivery may reduce the rate of intrapartum HIV transmission.

Adenine↗
PubMed1998

Administration of 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) for prevention of perinatal simian immunodeficiency virus infection in rhesus macaques.

Simian immunodeficiency virus (SIV) infection of newborn macaques is a useful animal model to explore novel strategies to reduce perinatal human immunodeficiency virus (HIV) infection. The availability of two easily distinguishable virus isolates, SIVmac251 and the simian/human immunodeficiency virus chimera SHIV-SF33, allows tracing the source of infection following inoculation with both viruses by different routes. In the present study, we evaluated the efficacy of pre- and postinoculation treatment regimens with 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) to protect newborn macaques against simultaneous oral SIVmac251 and intravenous SHIV-SF33 inoculation. Untreated newborns became persistently infected following virus inoculation. When three pregnant macaques were given a single subcutaneous dose of PMPA 2 hr before cesarean section, their newborns became SIV-infected following SIV and SHIV inoculation shortly after birth. In contrast, when four newborn macaques were inoculated simultaneously with SIV and SHIV, and started immediately on PMPA treatment for 2 weeks, only one animal became persistently SIV-infected; the remaining three PMPA-treated newborns, however, had some evidence of an initial transient virus infection but were seronegative and healthy at 8 months of age. Our data demonstrate that PMPA treatment can reduce perinatal SIV infection and suggest that similar strategies may also be effective against HIV.

Adenine↗
PubMed1998

Measurement of feline cytokine gene expression by quantitative-competitive RT-PCR.

We have developed a method to quantitate feline cytokine gene expression using competitive RT-PCR. Feline cytokine specific primers were developed that encompass an intron, thus allowing differentiation of cDNA vs. genomic DNA amplification products. The PCR products of the primers were verified by sequencing and Southern blot analysis. For quantitation, a non-homologous RNA competitor was created for each cytokine of interest. The competitor was designed to yield an RT-PCR product 10-20% larger than the native sequence, thereby allowing differentiation of the two products by electrophoresis on an agarose gel. Both competitor and native sequences used the same primer sequences for RT (oligo dT) and PCR (cytokine specific). The amplification efficiency of the competitor and native sequence was shown to be identical which allowed comparison at any point during the amplification, including the plateau phase. The quantity of starting cytokine mRNA was determined by interpolation from a standard curve. As little as 1 microgram of total cellular RNA was required per cytokine determination. The assay can routinely quantify as few as 1000 copies of template and spans a range of up to 4 log.

Animals↗
PubMed1998

Listeria monocytogenes and Serratia marcescens infections as models for Th1/Th2 immunity in laboratory cats.

Five species of bacteria known to be naturally-occurring pathogens of cats were screened for their ability to grow in feline macrophages in vitro, and to induce antibodies and delayed type hypersensitivity (DTH) responses in vivo. Two of these organisms, L. monocytogenes and S. marcescens, were selected for further study based on clear-cut differences in their in vitro and in vivo behavior. Listeria was macrophage tropic, induced DTH, and evoked poor antibody responses post-recovery, whereas Serratia remained extracellular, did not induce a DTH reaction, and produced high titer of antibodies. Young specific pathogen free cats were then inoculated subcutaneously into the drainage areas of the right and left popliteal and auricular lymph nodes with either L. monocytogenes or S. marcescens. Each of the four lymph nodes were then removed in sequence over a two week period, weighed, cultured for viable bacteria, and RNA extracted for Th1/Th2 cytokine mRNA quantitation. Antibody responses and delayed type hypersensitivity responses were also measured. Identical to pilot studies, cats infected with Serratia developed very high levels of antibody compared to Listeria infected cats but no DTH, while Listeria infected cats produced negligible or low titers of antibodies and strong DTH. Immunity to Listeria occurred around 168 h post infection as evidenced by the disappearance of living bacteria from the nodes, while immunity to Serratia took over 264 h. Pronounced lymph node hyperplasia occurred in both infections, but persisted longer for Serratia. Enlargement of Serratia infected nodes was associated with marked follicular, primary and secondary germinal center and medullary hyperplasia. Germinal center formation in Listeria stimulated nodes was much less intense and dense accumulations of macrophages dissected between follicles downward from the subcapsular sinuses. Although functional and histologic studies showed a clear-cut cell-mediated vs. humoral response in the respective Listeria and Serratia infections, preferential cytokine mRNA upregulation was observed for only two of the five major Th1/Th2 cytokines measured. Interferon-gamma, a Th1 cytokine, was much more elevated in the Listeria stimulated nodes, but TNF-alpha (also a Th1 cytokine) was more elevated in Serratia infected nodes. Interleukin-12, an important Th1 cytokine, was elevated to equal levels in both infections as were the Th2 cytokines IL-4 and IL-10.

Animals↗
PubMed1998

Feline infectious peritonitis viruses arise by mutation from endemic feline enteric coronaviruses.

Feline infectious peritonitis virus (FIPV) strains from six cats and three different geographic areas were compared genetically with feline enteric coronavirus (FECV) isolates obtained from cats inhabiting the same environments. Sequence comparisons were made from 1.2- to 8.9-kb segments on the 3' end of the genome. FECV/FIPV pairs from the same catteries or shelters were 97.3-99.5% related but were genetically distinct from FIPV and FECV strains obtained from cats living in geographically distinct environments. The high genetic similarity between FECVs and FIPVs from the same environment strongly suggested a common ancestry. Based on the presence of deletion mutations in the FIPVs and not in the FECVs, it was concluded that FIPVs evolved as mutants of FECVs. The mutations are deletions in the FIPVs and not insertions in the FECVs since similar sequences are present in other strains that have segregated earlier from a common ancestor. Therefore, the order of descent is form FECV to FIPV. Mutations unique to FIPVs were found in open reading frames (ORFs) 3c in 4 of 6 isolates and/or 7b in 3 of 6 isolates. When the study was extended to include 7 additional FIPV isolates, 11/13 of the FIPVs sequenced were found to have mutated 3c ORFs.

Amino Acid Sequence↗
PubMed1998

Seroprevalence of Bartonella henselae in cattery cats: association with cattery hygiene and flea infestation.

We attempted to determine what factors were common to catteries with high Bartonella henselae antibody prevalence compared with catteries with low prevalence, in order to contribute to better guidelines for the choice of a safe pet cat. The overall seroprevalence in 11 catteries from diverse geographical locations in North America in the present study was 35.8%. There was evidence of B. henselae exposure in all 11 homes tested, with 5 catteries being heavily infected. The distribution of B. henselae exposure was bimodal in catteries: either most or all cats in the home had been exposed, or very few or no cats had been exposed. Prevalence per home was also correlated with the home mean antibody titre. Flea infestation was the most important risk factor for high B. henselae seroprevalence in the catteries we surveyed. Individual cat titres were comparable for male and female cats, cats of various ages, and cats with concurrent infectious diseases. There was no association of B. henselae with cattery size, husbandry practices, presence or absence of rescued cats, dog ownership, attending cat shows, routine visits to a veterinarian, and outside travel. In summary, cattery cats can be easily identified as high or low risk to new potential cat owners.

Animal Husbandry↗
PubMed1998

Identification of a novel enteric Helicobacter species in a kitten with severe diarrhea.

A previously undescribed Helicobacter sp. was recovered from a cat with severe diarrhea. Based upon the absence of any other identifiable cause of diarrhea, this helicobacter may be involved in the development of the disease signs. The organism could not be cultured but was described on the basis of 16S rRNA gene sequence analysis and morphology and appeared to be a new species, with Helicobacter canis being the most genetically similar species. The presence of a diarrhea-inducing helicobacter in a companion animal may pose a risk of zoonosis.

Animals↗
PubMed1998

Cytokine response in multiple lymphoid tissues during the primary phase of feline immunodeficiency virus infection.

Type 1 and 2 cytokine mRNA responses were measured at various time periods and in various lymphoid compartments during the acute stage (first 4 months) of feline immunodeficiency virus (FIV) infection in laboratory cats. Cytokine responses were correlated with virus replication. Virus was detected in plasma and tissue from day 14 postinfection (p.i.) onward, peaked at 56 to 70 days, and declined greatly by 70 days. Virus replication was highest in the thymus, followed by spleen, mesenteric lymph nodes, and cervical lymph nodes. Baseline cytokine levels were highest in the mesenteric lymph nodes and lowest in the cervical lymph nodes. Cytokine upregulation after FIV infection was most dramatic in the cervical lymph nodes, with the greatest increase in interleukin-10 (IL-10) and gamma interferon (IFN-gamma). Cytokine transcription in the mesenteric lymph node increased above baseline by day 14 p.i. for IFN-gamma, IL-12p40, IL-4, and IL-10, while elevations in the spleen were mainly for IFN-gamma, IL-12p40 and IL-10. An increase in IFN-gamma, IL-10, and IL-12p40 occurred in the thymus at day 56 p.i., concomitant with the onset of thymitis. In general, type 2 cytokines (IL-4 and IL-10) were increased greater than 1 log over baseline, while the elevations in type 1 cytokines were less than 1 log. In the tissues tested, CD4(+) cells were the primary source of IL-2, IL-4, and IL-10. Both CD4(+) and CD8(+) cells produced IFN-gamma, while no cytokine mRNA was detected in B cells. These results demonstrate the presence of a heterogeneous cytokine response in lymphoid tissues during the primary stage of FIV infection. The nature and intensity of the response differed from one compartment to the other and, in the case of the thymus, also with inflammatory changes. Although limited in scope, the present study confirms the usefulness of the FIV infection model in studying early cytokine events that lead to the secondary subclinical carrier state typical of most lentivirus infections.

Animals↗