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Biomedical subjects

M E Payton

Publications and source records attributed to M E Payton.

At least 19 recordsLinked to original sources

Bovine viral diarrhoea virus (BVDV) subgenotypes in diagnostic laboratory accessions: distribution of BVDV1a, 1b, and 2a subgenotypes.

The prevalence of bovine viral diarrhoea virus (BVDV) biotypes and subgenotypes was determined from 131 BVDV positive samples from a diagnostic laboratory. The majority of the isolates were from Oklahoma; however, other states including Kansas, Texas, and Arkansas were represented. These BVDV samples were from submissions of 76 live animals and 55 necropsy samples. There were 131 BVDV samples represented by 117 noncytopathic (NCP), 11 cytopathic (CP) and 3 cases with mixed NCP and CP biotypes. The NCP isolates were more common (P < 0.05) than the CP and NCP/CP combination. The BVDV samples were segregated into three subgenotypes by differential PCR and sequencing of a viral genomic region, 5'-untranslated region (5'-UTR). There were more BVDV1b subgenotypes 60/131 (45.8%) than BVDV1a, 37/131 (28.2%) or BVDV2a, 34/131 (26.0%) (P < 0.05). The organ system involvement included the major categories such as respiratory, digestive, mixed/multiple organs, abortions, and persistent infections (PI). All three BVDV subgenotypes were found in persistently infected (PI) cattle and respiratory diseases, both major requests for BVDV diagnosis. Only one of the 131 viruses was genetically similar to the strains present in U.S. vaccines.

Animals↗

Comparison of topical lidocaine/prilocaine anesthetic cream and local infiltration of 2% lidocaine for episioplasty in mares.

Local anesthesia and tissue inflammation associated with lidocaine infiltration and lidocaine/prilocaine topical anesthetic cream for episioplasty in mares were compared. Twenty-two mares were randomly assigned to lidocaine or lidocaine/prilocaine topical anesthetic cream treatment groups. Perineum and vulva were cleaned, 8-12 g (approximately 1 g/cm per side of vulva) of topical anesthetic cream was applied, and the area was covered by plastic wrap 30 min prior to beginning procedure. Alternately, lidocaine was injected (1 mL) every centimeter just prior to the procedure. Episioplasty was conducted using standard methods, but employing simple interrupted sutures. Horses were not sedated and use of a twitch was recorded. Four millimeter punch biopsies were harvested 1, 3, and 10 days following episioplasty and scored for degree of inflammation by a blinded pathologist. Clinical inflammation scores were assigned when biopsies were obtained. Seven of 11 horses receiving lidocaine infiltration required twitching, but none of the horses that received the anesthetic cream required twitching. Six of 11 and seven of 11 of the lidocaine and anesthetic cream groups, respectively, required twitching for episioplasty. Except for the clinical scores on day 3, no statistical differences for clinical and histopathologic scores between samples from the two treatment groups for a given day were identified. Use of lidocaine/prilocaine topical anesthetic cream was as effective as lidocaine infiltration in providing local anesthesia when performing episioplasty in mares. Its use decreased the need for twitching horses as well as the risk of deformation of the labia caused by lidocaine infiltration.

Administration, Cutaneous↗

Influence of nutrient intake and body fat on concentrations of insulin-like growth factor-I, insulin, thyroxine, and leptin in plasma of gestating beef cows.

Pregnant Angus x Hereford cows (n = 73) were used to determine the effects of amount of nutrient intake and BCS on concentrations of IGF-I, insulin, leptin, and thyroxine in plasma. At 2 to 4 mo of gestation, cows were blocked by BCS and assigned to one of four nutritional treatments: high (H = a 50% concentrate diet fed ad libitum in a drylot) or adequate native grass pastures and one of three amounts of a 40% CP supplement each day (M = moderate, 1.6 kg; L = low, 1.1 kg; or VL = very low, 0.5 kg; as-fed basis). After 110 d of treatment, all cows grazed dormant native grass pasture and received 1.6 kg/d of a 40% CP supplement. At 68, 109, and 123 d of treatment, cows were gathered, and plasma samples were collected by tail venipuncture (fed sample). After 18 h without feed and water, a second plasma sample was collected (fasted sample). At 109 d of treatment, BCS was greatest (P < 0.05) for H cows, similar for M and L cows, and least for VL cows. Concentrations of insulin and leptin were greater (P < 0.05) for H cows than for M and VL cows at 68 and 109 d, but similar for all groups at 123 d. Thyroxine in plasma was greatest (P < 0.05) for H cows at 68 d and similar for cows on all treatments at 123 d. Concentrations of IGF-I, insulin, and leptin in fed and fasted cows were positively correlated with BCS at 109 d. Body condition was predictive of concentrations of IGF-I, insulin, and leptin when cows had different nutrient intakes, but BCS accounted for less than 12% of the variation in plasma concentrations of IGF-I, insulin, and leptin when nutrient intake was the same for all cows. We conclude that amount of nutrient intake has a greater influence than body energy reserves on IGF-I, insulin, and leptin concentrations in the plasma of gestating beef cows.

Animal Nutritional Physiological Phenomena↗

Effect of repeated oral administration of hypertonic electrolyte solution on equine gastric mucosa.

REASONS FOR PERFORMING STUDY: Electrolyte supplementation is common in horses during endurance competitions, but the effect on the gastric mucosa is unknown. HYPOTHESIS: Repeated oral administration of hypertonic electrolyte solution is associated with exacerbation of gastric ulcers in mature horses. METHODS: The study design was a randomised, blinded, crossover trial. Fourteen horses were divided randomly into equal groups and administered either 60 ml water (placebo) or 56.7 g commercial electrolyte supplement mixed with 60 ml water by dose syringe orally once an hour for 8 h. The minimum concentration of individual constituent electrolytes/28.35 g dry commercial product used was: sodium (5528 mg); chloride (11,886 mg); potassium (3657 mg); calcium (754 mg); and magnesium (153 mg). Gastric lesions were scored prior to and after oral treatments, and analysis of variance procedures were then performed. RESULTS: Administration of hypertonic electrolytes resulted in a significant increase in mean ulcer number (P = 0.0174) and severity (P = 0.0006) scores in the nonglandular stomach. Mean ulcer number score was 3.6 and mean ulcer severity score 2.7 after hypertonic electrolyte treatment. CONCLUSIONS: Oral hypertonic electrolyte administration to horses in this model was associated with exacerbation of gastric ulcers. POTENTIAL RELEVANCE: Our findings suggest that one schedule of electrolyte supplementation used commonly in endurance horses may be harmful to the gastric mucosa.

Administration, Oral↗

Soy protein may alleviate osteoarthritis symptoms.

Alternative and complementary therapeutic approaches, such as the use of a wide array of herbal, nutritional, and physical manipulations, are becoming popular for relieving symptoms of osteoarthritis (OA). The present study evaluated the efficacy of soy protein (SP) supplementation in relieving the pain and discomfort associated with OA. One hundred and thirty-five free-living individuals (64 men and 71 women) with diagnosed OA or with self-reported chronic knee joint pain not attributed to injury or rheumatoid arthritis were recruited for this double-blind, placebo-controlled, parallel design study. Study participants were assigned randomly to consume 40 g of either supplemental SP or milk-based protein (MP) daily for 3 months. Pain, knee range of motion, and overall physical activity were evaluated prior to the start of treatment and monthly thereafter. Serum levels of glycoprotein 39 (YKL-40), a marker of cartilage degradation, and insulin-like growth factor-I (IGF-I), a growth factor associated with cartilage synthesis, were assessed at baseline and at the end of the study. Overall, SP improved OA-associated symptoms such as range of motion and several factors associated with pain and quality of life in comparison to MP. However, these beneficial effects were mainly due to the effect of SP in men rather than women. Biochemical markers of cartilage metabolism further support the efficacy of SP in men as indicated by a significant increase in serum level of IGF-I and a significant decrease in serum level of YKL-40 compared to MP. This study is the first to provide evidence of possible beneficial effects of SP in the management of OA. Examining and verifying the long-term effects of SP on improving symptoms of OA, particularly in men, is warranted.

Adult↗

Humoral immune response and assessment of vaccine virus shedding in calves receiving modified live virus vaccines containing bovine herpesvirus-1 and bovine viral diarrhoea virus 1a.

Susceptible calves were administered modified live virus (MLV) vaccines containing bovine herpesvirus-1 (BHV1) and bovine viral diarrhoea type 1 (BVDV1a) strains intramuscularly, with one vaccine containing both MLV and inactivated BHV-1 and inactivated BVDV1a. There was no evidence of transmission of vaccine (BHV-1 and BVDV1a) strains to susceptible non-vaccinated controls commingled with vaccinates. No vaccinates had detectable BHV-1 in peripheral blood leucocytes (PBL) after vaccination. Each of three vaccines containing an MLV BVDV1a strain caused a transient BVDV vaccine induced viremia in PBL after vaccination, which was cleared as the calves developed serum BVDV1 antibodies. The vaccine containing both MLV and inactivated BHV-1 induced serum BHV-1 antibodies more rapid than MLV BHV-1 vaccine. Two doses of MLV BHV-1 (days 0 and 28) in some cases induced serum BHV-1 antibodies to higher levels and greater duration than one dose.

Animals↗

Predicting cholesterol, progesterone, and days to ovulation using postpartum metabolic and endocrine measures.

The objective of this study was to examine relationships among metabolic and endocrine factors that may influence ovarian activity during early lactation. Holstein cows (n = 19) were bled twice each week to determine plasma concentrations of insulin (INS), glucose, cholesterol, insulin-like growth factor-1 (IGF-I), and progesterone (P4). Feed intake and milk production were recorded daily while body weights and milk composition were recorded weekly. Relationships among plasma cholesterol and P4, and days to first and second postpartum ovulation were modeled with energy balance (EB), dry matter intake, milk yield and composition, plasma metabolites, and hormones using the backward elimination technique of multivariate regression analysis. Variables that contributed the most to predicting plasma cholesterol concentrations were dry matter intake x SNF using model 1 (production variables) and the square of glucose (i.e., glucose2) using model 3 (plasma hormones and metabolites). For plasma P4 concentrations, EB (model 2, production variables) and IGF-I (model 3, plasma hormones and metabolites) were the major predictors. The production variables EB and percentage of milk lactose were the greatest contributors to the models predicting days to first and second postpartum ovulations, respectively. Of the plasma hormones and metabolites evaluated, IGF-I2 was the most significant predictor of days to first postpartum ovulation, whereas glucose2 and INS were the significant predictors of days to second postpartum ovulation. Plasma IGF-I, glucose, and INS have been implicated in ovarian functions and their significant contributions to these models are consistent with possible important roles in postpartum return to ovarian competence.

Animals↗

Evaluation of carbon dioxide laser and conventional incisional techniques for resection of soft palates in brachycephalic dogs.

OBJECTIVE: To compare clinical outcome, healing, and effect of tracheostomy in conventional incisional and carbon dioxide (CO2) laser techniques for resection of soft palates in brachycephalic dogs. DESIGN: Prospective randomized trial. ANIMALS: 20 adult brachycephalic dogs. METHODS: Dogs were randomly allocated into 4 groups, and 1 of the following was performed: palate resection by use of a CO2 laser; incisional palate resection and closure with suture; and palate resection by use of a C02 laser or incision with tracheostomy. A clinical score for respiratory function was assigned to each dog at 0, 2, 8, 16, and 24 hours. Biopsy specimens of incision sites obtained at days 0, 3, 7, and 14 were examined. Data were analyzed to determine the effects of technique on clinical and histologic outcome. RESULTS: Mean surgical time for laser (309 seconds) was significantly shorter than for sharp dissection (744 seconds). Surgical technique significantly affected clinical scores at 3 of the 5 postoperative time points, but differences were not clinically apparent. Tracheostomy significantly affected clinical scores at 3 of 5 postoperative time points. After tracheostomy tube removal, clinical scores were similar to those of dogs without tracheostomies. Inflammation, necrosis, and ulceration were evident in all groups at day 3; these lesions had almost resolved by day 14. Most complications were associated with tracheostomy. CONCLUSIONS AND CLINICAL RELEVANCE: Clinical outcomes appear to be similar with the laser and incisional techniques. Regarding surgical time and ease, laser resection of the soft palate appears advantageous. Tracheostomy is not warranted in dogs that have uncomplicated surgeries and recoveries.

Animals↗

Effects of butorphanol and carprofen on the minimal alveolar concentration of isoflurane in dogs.

OBJECTIVE: To evaluate the effects of butorphanol and carprofen, alone and in combination, on the minimal alveolar concentration (MAC) of isoflurane in dogs. DESIGN: Randomized complete-block crossover study. ANIMALS: 6 healthy adult dogs. PROCEDURE: Minimal alveolar concentration of isoflurane was determined following administration of carprofen alone, butorphanol alone, carprofen and butorphanol, and neither drug (control). Anesthesia was induced with isoflurane in oxygen, and MAC was determined by use of a tail clamp method. Three hours prior to induction of anesthesia, dogs were fed a small amount of canned food without any drugs (control) or with carprofen (2.2 mg/kg of body weight [1 mg/lb]). Following initial determination of MAC, butorphanol (0.4 mg/kg [0.18 mg/lb], i.v.) was administered, and MAC was determined again. Heart rate, respiratory rate, indirect arterial blood pressure, endtidal partial pressure of CO2, and saturation of hemoglobin with oxygen were recorded at the time MAC was determined. RESULTS: Mean +/- SD MAC of isoflurane following administration of butorphanol alone (1.03 +/- 0.22%) or carprofen and butorphanol (0.90 +/- 0.21%) were significantly less than the control MAC (1.28 +/- 0.14%), but MAC after administration of carprofen alone (1.20 +/- 0.13%) was not significantly different from the control value. The effects of carprofen and butorphanol on the MAC of isoflurane were additive. There were not any significant differences among treatments in regard to cardiorespiratory data. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of butorphanol alone or in combination with carprofen significantly reduces the MAC of isoflurane in dogs; however, the effects of butorphanol and carprofen are additive, not synergistic.

Animals↗

Identifying key cereal aphid predators by molecular gut analysis.

We describe polymerase chain reaction (PCR) primers for gut analysis of aphid predators. The primers amplify aphid mitochondrial COII fragments ranging in size from 77 to 386 bp. Using these primers, we were able to distinguish six species of US Great Plains cereal aphids, including two congeners, Rhopalosiphum maidis (Fitch) and R. padi (L.), and to detect them in extracts of coccinellid and chrysopid predators. We devised a protocol for deriving half-lives of detectability for the DNA of a single aphid consumed by predators maintained under simulated field dietary and temperature conditions. Using this protocol and primers that amplify a 198-bp fragment, we determined statistically different half-lives of detectability for a single R. maidis of 3.95 h in Chrysoperla plorabunda (Fitch) and 8. 78 h in Hippodamia convergens Guerin. The detectability half-life for a 339-bp R. maidis fragment was statistically longer in C. plorabunda but not in H. convergens. The sensitivity of the assay for the 198-bp fragment is 10-7 aphid equivalents. For species-specific predator gut analysis, PCR is superior to monoclonal antibody technology, giving comparable detectability half-lives with lower expense, much shorter development times, and greater certainty of a successful outcome.

Animals↗

Bovine viral diarrhea virus cytopathic and noncytopathic biotypes and type 1 and 2 genotypes in diagnostic laboratory accessions: clinical and necropsy samples from cattle.

One hundred three bovine samples submitted to the Oklahoma Animal Disease Diagnostic Laboratory (OADDL) that were positive for bovine viral diarrhea virus (BVDV) were typed by a nested reverse transcription-polymerase chain reaction for BVDV genotypes. These BVDV samples included supernatants from virus isolation (79), serums (17), and buffy coats (7). The biotype, cytopathic (CP) or noncytopathic (NCP), was determined by cell culture virus isolation. Twenty-eight of 103 samples were submitted for herd screening for BVDV, 32 from OADDL necropsy cases, and 43 from live cattle with varied clinical conditions. Two samples contained 2 bands indicating presence of both BVDV types 1 and 2. Of the 105 BVDV samples, 26 were type 1 CP strains (24.8%), 38 were type 1 NCP strains (36.2%), 10 were type 2 CP strains (9.5%), and 31 were type 2 NCP strains (29.5%). From the 105 BVDV isolates, NCP biotypes were isolated more frequently (69, 65.7%) than CP biotypes (36, 34.3%), and type 1 genotypes were more frequently isolated (64, 61.00%) than type 2 genotypes (41, 39.0%). The NCP strains were more common than CP in herd screening samples. Cattle with respiratory disease history at time of sampling had more NCP than CP biotypes and more type 1 than type 2 genotypes. Of the necropsy cases, more were type 1 than type 2 genotypes for the respiratory cases with fibrinous pneumonia, more were type 1 than type 2 genotypes in cattle with enteritis/colitis without systemic lesions, and more were CP than NCP biotypes in cattle with enteritis/colitis with systemic lesions. No CP biotype was isolated from serum samples.

Animals↗

Ovarian and endocrine characteristics during an estrous cycle in Angus, Brahman, and Senepol cows in a subtropical environment.

To determine breed differences in ovarian function and endocrine secretion, daily rectal ultrasonography was conducted on multiparous lactating Angus (temperate Bos taurus; n = 12), Brahman (tropical Bos indicus; n = 12), and Senepol (tropical Bos taurus; n = 12) cows during an estrous cycle in summer. Blood was collected daily to quantify plasma concentrations of FSH, LH, progesterone, estradiol, GH, insulin-like growth factor (IGF)-I, IGF-II, IGF binding proteins (IGFBP), insulin, glucose, and plasma urea nitrogen (PUN). Numbers of small (2 to 5 mm), medium (6 to 8 mm), and large follicles (> or = 9 mm) were greater (P < .05) in Brahman than in Angus and(or) Senepol cows. Length of the estrous cycle (SEM = .6 d) was similar (P > .10) among Senepol (20.4 d), Angus (19.5 d), and Brahman (19.7 d) cows. Senepol cows had greater (P < .05) diameters of the corpus luteum (CL) and a delayed regression of the CL as compared with Angus cows. The secondary surge of FSH (between d 1 and 2; d 0 = estrus) was greater in Angus than Brahman or Senepol cows (breed x day, P < .05). Between d 2 and 14 of the estrous cycle, concentrations of progesterone, LH, IGF-II, and binding activities of IGFBP-3, IGFBP-2, and the 27- to 29-kDa IGFBP in plasma did not differ (P > .10) among breeds. Concentrations of GH, IGF-I, insulin, and PUN were greater (P < .001) and binding activities of the 22-kDa and 20-kDa IGFBP tended (P < .10) to be greater in plasma of Brahman than in Angus or Senepol cows. Plasma glucose concentrations were greater (P < .05) in Senepol than in Brahman or Angus cows. In conclusion, Brahman (Bos indicus) and Senepol cows (tropical Bos taurus) had greater numbers of follicles in all size categories and greater diameter of CL than Angus (temperate Bos taurus) cows. These ovarian differences may be due to changes in the pattern of secretion of FSH, insulin, IGF-I, and GH but not LH, IGF-II, or IGFBP-2 or -3.

Animals↗

Comparison of a high power diode laser with the Nd:YAG laser using in situ wound strength analysis of healing cutaneous incisions.

BACKGROUND AND OBJECTIVE: The laser-tissue interaction of a high power semiconductor diode laser was compared to the continuous wave neodymium yttrium aluminum garnet (Nd:YAG) laser by evaluating primary wound healing of cutaneous incisions in rats. STUDY DESIGN/MATERIALS AND METHODS: Full thickness incisions were made in rat skin using a diode laser (805 nm, 10 W, contact mode), an Nd:YAG laser (1,064 nm, 10 W, contact mode), and a stainless steel scalpel blade (control). In situ wound breaking strength measurements were obtained at 7, 14, and 21 days using a specially designed tensiometer. Cross sectional area of non-disrupted wounds was calculated in two groups prior to testing to allow for calculation of tensile strength. Blinded histopathologic analysis was also performed. RESULTS: Analysis of variance (P < or = 0.05) was used to determine differences in breaking strengths and tensile strengths due to incision method. There was no significant difference in the breaking strengths (group 1) or tensile strengths (groups 2 and 3) of the diode and Nd:YAG laser incisions. As predicted, breaking strengths and tensile strengths of scalpel blade incisions were significantly greater than those of incisions made with laser energy. Histopathologic evaluation revealed that through day 14, the degree of inflammation and collagen production was similar for diode and Nd:YAG laser incisions. Laser incisions had greater inflammation and a lag in fibroblast invasion and collagen production compared with scalpel incisions. By day 21, all incisions were similar in fibroblast population and collagen production, but laser incisions had slightly more inflammation than scalpel incisions. CONCLUSION: In the primary wound healing model described, the tissue effect, cellular response, and development of wound strength were essentially the same for the high power diode laser at 10 W and the Nd:YAG laser at 10 W.

Animals↗

Antibody responses by cattle after vaccination with commercial viral vaccines containing bovine herpesvirus-1, bovine viral diarrhea virus, parainfluenza-3 virus, and bovine respiratory syncytial virus immunogens and subsequent revaccination at day 140.

Calves were vaccinated with four different commercial viral vaccines containing bovine herpesvirus-1 (BHV-1), bovine viral diarrhea (BVDV), parainfluenza-3 virus (PI-3V), and bovine respiratory syncytial virus (BRSV) immunogens. For the initial vaccination certain vaccines were given twice (days 0 and 28), whereas other vaccines were given on day 0. The calves received another injection on day 140 with the vaccine originally given on day 0. The sera were collected at days 0, 7, 14, 21, 28, 42, 56, 84, 112, 140, 154, 168, and 196 and assayed for viral neutralizing antibodies. The calves were seronegative to BHV-1, BVDV, and BRSV at the onset of the experiment; however, the calves were PI-3V antibody positive due to prior active infection. The commercial vaccines were: (I) inactivated; (II) modified live virus (MLV); (III) combination of chemically altered live virus, MLV, and inactivated virus; and (IV) combination of inactivated and MLV. Among the vaccine groups there were differences in onset and duration of antibodies as measured by geometric mean titers to each immunogen in postvaccination collection dates compared to day 0 titers; and likewise compared to day 140 titers after revaccination at day 140. There were also differences in antibody titers to the various viruses among the vaccine groups on specific collection dates. All four vaccines induced increased BHV-1 antibodies by day 14 after the initial injection. The antibody titers induced by MLV BHV-1 and the chemically altered BHV-1 vaccines had greater duration than those induced by the inactivated vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Action of quail and chicken interferons on a quail cell line, QT35.

Production of interferon (IFN) in quail cells (QT35) and the activity of quail IFN and heterologous avian IFN (chicken) on QT35 cells were examined. Quail cells produced IFN after induction by bluetongue virus serotype 10; chicken and quail IFN conferred antiviral resistance on the quail cells. Both chicken and quail IFN induced increased levels of 2',5'-oligoadenylate synthetase (2',5'-OAS) in QT35 cells and reduced levels of intracellular Salmonella typhimurium postchallenge. These results indicate that the quail cells produce IFN and respond to homologous and heterologous avian IFN as evidenced by enhanced (1) resistance to viral infection, (2) production of 2',5'-OAS, and (3) resistance to invasion by bacteria. QT35 quail cell monolayer cultures offer an alternative to primary chicken embryo fibroblasts cultures used for avian IFN studies.

2',5'-Oligoadenylate Synthetase↗

Clinicopathological characterization of monkey B virus (Cercopithecine herpesvirus 1) infection in mice.

The purpose of this study was to establish a small animal model for monkey B virus (BV) infection. Mice were inoculated intramuscularly with several BV isolates. Comparisons were based upon the doses required to produce infection (ID50), non-central nervous system (CNS) clinical disease (CS50), CNS disease (CNSD50) and lethal effect (LD50). Strains differed in respect of the dose required to produce clinical disease in BALB/c mice. C57BL/6 mice were more resistant than BALB/c mice to CNS disease. Skin lesions at the inoculation site consisted of epidermal necrosis, ulceration, serocellular crusts and underlying dermatitis. CNS lesions included marked inflammation in the ipsilateral dorsal root ganglion and lumbar spinal cord (point of viral entry). The distribution of the lumbar spinal cord lesions suggested viral entry via sensory afferent neurons, ventral motor tracts, or both. The lesions in the more cranial spinal cord segments suggested ascension to the brain via bilateral spinothalamic and spinoreticular tracts. Brain lesions included encephalitis with neuronal necrosis and white matter destruction located consistently at the base of the brainstem, the reticular system, and rostrally to the thalamus and hypothalamus. Viral antigen was detected immunohistochemically in the lesions. The results indicated an ascending encephalomyelitis syndrome similar to that produced by BV in man.

Animals↗

Comparative pathology of infections with baboon and African green monkey alpha-herpesviruses in mice.

The comparative pathology of Herpesvirus papio 2 (HVP2) of baboons and SA8 virus of African green monkeys relative to that of herpes simplex virus (HSV1) of man was investigated in young adult mice inoculated intramuscularly and observed for 21 days. The 50% infectious dose (ID(50)) for HVP2 was approximately 10(2.0) plaque-forming units (PFU), while the ID(50) for HSV1 and SA8 was 10(2.5) and 10(3.8), respectively. There were marked differences in the ability of these three viruses to invade the central nervous system (CNS) and cause clinical neurological disease. HSV1 produced neurological signs in a few animals given 10(6)PFU, but SA8 did not. In contrast, HVP2 readily invaded the CNS and produced fatal disease with doses as low as 10(2)PFU. Two isolates of HVP2 tested had a 50% CNS disease dose (CNSD(50)) of 10(2.5) and 10(3.0)PFU and an LD(50) of 10(3.8) and 10(4.3)PFU, respectively. Histopathological examination of tissue from HVP2-infected mice revealed severe lesions of inflammation and necrosis in the central, peripheral and autonomic nervous systems, as well as of other tissues including skin, adrenal glands and the gastrointestinal tract. Viral antigens were detected immunohistochemically in lesions. This study showed that while both HVP2 and SA8 could infect mice, there were marked differences in the ability of these two closely related viruses to cause clinical disease and CNS lesions. This murine model may prove useful in the investigation of viral or host determinants responsible for the varying neurovirulence of these simian alpha-herpesviruses.

Animals↗

The effects of a unilateral ultrasound-guided renal biopsy on renal function in healthy sedated cats.

Complications of renal biopsies are well documented except for the change in renal function after a biopsy. Eighteen healthy, adult cats were divided into two groups (n = 9 cats/group). For the measurement of global and split renal function, Group 1 used the renal uptake of 99mTc-DTPA and Group 2 used the renal uptake of 99mTc-MAG3. Scintigraphic data were collected on days (-4), (-3), 0, 1, 2, and 4 post renal biopsy. Using ultrasound guidance, biopsies were taken from the right renal cortex on dO, before acquiring scintigraphic images. P - values less than 0.10 were considered significant due to the limited number of observations. The only statistically significant change (p = 0.08) in global renal function detected was by day following a unilateral renal biopsy. Cats imaged using 99mTc-MAG3 had discernible liver activity. A unilateral, ultrasound guided renal biopsy has minimal effect on renal function in normal, healthy sedated cats.

Anesthetics, Dissociative↗