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Biomedical subjects

J E Pearson

Publications and source records attributed to J E Pearson.

At least 55 records · Page 3Linked to original sources
PubMed1985

Orbiviruses from Culicoides in Florida.

Between 1980 and 1983, 45,484 Culicoides spp. collected in Florida near cattle have been examined for orbiviruses by attempted isolation in cell cultures and intravenous (IV) inoculations of embryonated chicken eggs. Bluetongue virus (BTV) serotype 2 was isolated from a pool of Culicoides insignis trapped at Ona. This is the 1st recovery of BTV from this species representing the 2nd new world species of Culicoides from which BT viruses have been isolated. C. insignis is a neotropical form which extends from northern Florida through the Caribbean region and much of South America. If this species is proven capable of biological transmission of BTV, it could help explain the distribution of antibodies to BTV in areas lacking C. variipennis. Epizootic hemorrhagic disease virus (EHDV) serotype 2 was recovered from several pools of C. variipennis collected at 2 beef cattle operations in Florida. No viruses were isolated from the small number of C. arboricola, C. stellifer and C. niger examined.

Animals↗
PubMed1985

Bluetongue and related orbivirus diagnosis in the United States.

The serologic test for bluetongue (BT) that was used in the US from 1968 to 1980 to qualify animals for export was the modified direct complement-fixation (MDCF) test. The MDCF test was replaced by the immunodiffusion (ID) test in 1980. In January 1984, there were 70 laboratories approved by the USDA to conduct BT ID export testing. Both tests are used at the National Veterinary Services Laboratories (NVSL) for the serologic diagnosis of suspected cases of BT and/or epizootic hemorrhagic disease (EHD). Serologic surveys were conducted on bovine samples collected from 18 northeastern states in the winters of 1977/1978, 1979/1980, 1982/1983 and 1983/1984. The percents of positive animals were 0.3, 0.3, 5.4 and 0.9. In 1977/1978 samples were collected from all states; 18.5% were positive. The primary technique used for the isolation of BT virus (BTV) at the NVSL is intravenous inoculation of embryonating chicken eggs with subpassage into Vero-M cell line cultures. Baby hamster kidney (BHK) cell line cultures are used for isolation of EHD virus (EHDV). Each virus is identified by staining with specific fluorescent antibody conjugate.

Animals↗
PubMed1984

Standardization of the equine infectious anemia immunodiffusion test and its application to the control of the disease in the United States.

In 1972 the US Department of Agriculture (USDA) established requirements that horses which had immunodiffusion antibody against equine infectious anemia could not be transported interstate. Forty-two states had regulations requiring that horses have a negative equine infectious anemia immunodiffusion test before movement. In order to standardize immunodiffusion testing, it was stipulated in the 1972 regulations that tests must be performed in approved laboratories. The approved laboratories were required to have personnel trained in the immunodiffusion test procedure, to follow the standard protocol, to use licensed reagents, successfully complete proficiency tests, and to report results to federal or state animal health officials. The number of approved laboratories was 160 in June 1983. The number of immunodiffusion tests performed in the United States increased from 82,777 in 1972 to 793,536 in 1977, and has remained at about that level. The percentage of positive samples has decreased from 3.9 in 1972 to 0.6 in 1982. Due to the laboratory standardization program, the reproducibility of test results has been excellent.

Animals↗
PubMed1983

Abortion and stillbirth associated with Chlamydia psittaci var ovis in dairy goats with high titers to Toxoplasma gondii.

During two consecutive breeding seasons in a brucellosis-free dairy goat herd, approximately 40% to 70% of the does (mean herd size, 14.5) had stillbirths or aborted. None of the does aborted or had stillbirths twice. In the first breeding season, 9 of 13 does aborted in the last 2 months of gestation. Three fetuses and 2 fetal placentas from 2 does were examined. Microscopic findings included severe multifocal hepatic necrosis, mild pneumonia, and mild multifocal necrosis in the brain. Cultures for Listeria monocytogenes, Chlamydia psittaci, and Coxiella burnetii were negative. Paired sera from 3 of the does that had aborted or had stillbirths were tested for antibodies to Toxoplasma gondii. On the basis of high titers, a tentative diagnosis of toxoplasmosis was made. During the following breeding season, 6 of 16 does aborted during the last 2 months of gestation. A total of 6 fetuses and 4 fetal placentas from 5 of these does were examined. Microscopic findings included infiltration of mononuclear cells around hepatic vessels and multifocal necrosis and gliosis in the brain. Chlamydia psittaci was isolated from the tissues of 1 fetus, 2 aborting does had persistent, high antibody titers against C psittaci (1:160 and 1:320), and all except 2 other does in the herd had C psittaci titers of 1:20 to 1:40. All but 2 does had T gondii titers of 1:32 to 1:4096. Evidently there was mixed infection with C psittaci and T gondii in this herd, but the former organism probably was responsible for the abortions and stillbirths.

Abortion, Veterinary↗
PubMed1983

Isolation of bluetongue virus serotype 2 from cattle in Florida: serotype of bluetongue virus hitherto unrecognized in the Western Hemisphere.

A serotype of bluetongue virus (BTV) hitherto unrecognized in the Western Hemisphere was isolated from cattle in the United States. Clinical disease was not seen in the cattle which were part of a sentinel herd system in Florida designed for studying the epizootiology of BTV. The isolation of serotype 2 was the first recovery of a different serotype of BTV in the United States since 1967. At least 21 serotypes of BTV have been reported worldwide; the 5 serotypes of BTV now recognized in the United States are 2, 10, 11, 13, and 17.

Animals↗
PubMed1982

Comparison of effects of cyanide and acetylcholine on renal hemodynamics and sodium excretion.

The present study compared the effects of acetylcholine to cyanide under the same experimental conditions of renal clearance in anesthetized dogs. Since cyanide is one of the few drugs for which the mechanism of action is known (cytotoxic hypoxia), some insight may be gained into the renal effects of acetylcholine since both produce direct natriuresis and diuresis. Infusion of 0.2 microgram/kg/min of acetylcholine and 12.0 microgram/kg/min of sodium cyanide into the left renal artery resulted in similar effects, i.e., increased fractional excretion of sodium, potassium, calcium, and magnesium. These effects were immediate and ipsilateral. Both agents increased the renal plasma flow to the same extent. In addition, regression plots of the relation between changes in sodium excretion and changes in renal plasma flow were similar for both agents. The pattern of similar renal functional changes suggested that acetylcholine is not a mere renal vasodilator but that its action is also medicated through alterations on direct transport of ions.

Acetylcholine↗
PubMed1982

Bluetongue infections in Louisiana cattle.

Bluetongue virus (BTV) serotype 17 was isolated from cattle with clinical signs of bluetongue disease during 1978 and 1979 epizootics. Bovine sera from 6 herds located in an epizootic region were examined in 1979 for antibodies, using an immunodiffusion (ID) test. Of 300 sera, 164 (54.7%) were seropositive. Sera from statewide surveys of Louisiana cattle in July to August 1980 and December 1980 to January 1981 were tested for BTV antibodies, using the ID test. Fifty-eight of 70 herds (82.9%) and 164 of 597 (27.5%) individual cattle tested in July to August 1980 were seropositive. Fifty-four of 63 (85.7%) herds and 170 of 600 (28.3%) individual cattle tested in December 1980 to January 1981 were seropositive. Significant differences (P less than 0.01) were found in the seropositive rates between the various geographic regions of the state during each survey. Adult breeding-age cattle in 3 sentinel herds were tested for BTV antibodies beginning in 1976 and continuing through January 1981. During this interval, the seropositive rate in 2 of 3 herds was increased. Also, individual cattle in all 3 of these herds converted from seronegative to seropositive, indicating exposure during a particular interval for each herd. The age distribution of seropositive cattle in a dairy indicated that 2-year-old cattle had a seropositive rate comparable with that of older animals in the herd, suggesting that the 2-year-old animals had been exposed to a BTV before they entered the breeding herd.

Animals↗
PubMed1981

Bluetongue in cattle: a serologic survey of slaughter cattle in the United States.

Serologic tests for bluetongue virus (BTV) were done on 19,758 blood serum samples systematically collected at brucellosis laboratories throughout the United States from Nov 28, 1977 to Feb 20, 1978. Prevalence of BTV antibody varied from 0 to 79% of the samples collected in various states, with a national prevalence of 18.2%. The prevalence was generally low in the northern states and high in the southwestern states. The highest prevalence rates were found in Puerto Rico and the Virgin Islands.

Animals↗
PubMed1980

Survey for antibodies to viruses of bovine virus diarrhea, bluetongue, and epizootic hemorrhagic disease in hunter-killed mule deer in New Mexico.

Sera from male mule deer (Odocoileus hemionus) collected in November 1977 in Otero County, New Mexico were tested fro antibodies to bovine virus diarrhea virus (BVDV), bluetongue virus (BTV), and epizootic hemorrhagic disease virus (EHDV). Neutralizing antibodies were detected in 26 of 76 (34%) sera tested for BVDV (titer greater than or equal to 1:16). Of 46 sera tested for antibodies to BTV and EHDV, 10 (22%) and 3 (7%), respectively, were positive. Three (7%) of 46 sera were suspect (titer < 1:20) for BTV, and 18 (38%) sera were suspect (titer < 1:20) for EHDV.

Animals↗
PubMed1980

Parvovirus infection in translocated raccoons.

Severe enteritis attributed to parvovirus infection was diagnosed in raccoons (Procyon lotor) purchased from a commercial animal dealer for interstate translocation. Intestinal lesions included edema, hyperemia, and focal mucosal necrosis. Microscopically, intestinal villi were reduced markedly, and there was necrosis of the glandular crypts. Intranuclear inclusions were seen in many crypt cells. A parvovirus that was infective for Crandell feline kidney cells and primary canine kidney cells was isolated from the spleen of a sick raccoon. The raccoon virus was distinguished from feline panleukopenia virus by the former's ability to hemagglutinate swine erythrocytes at a pH of 7.2. Serum neutralization testing of infected raccoons indicated that the raccoon isolate differed from feline panleukopenia virus and may have been canine parvovirus.

Animals↗
PubMed1980

Pediatric intensive care unit patients. Effects of play intervention on behavior.

The effects of a 20-min play intervention by a child life teacher on two observed behaviors were investigated in Pediatric Intensive Care Unit (PICU) patients at the Johns Hopkins Hospital Children's Center. Eleven subjects, ranging in age from 2--13 years, were observed using a Preintervention--Intervention--Postintervention design with a 3-min time sampling technique to measure the change occurring when structured play activities were introduced into the PICU environment. Significant positive changes were noted between Preintervention and Intervention in (1) affect and (2) interaction with materials. In the Postintervention period, these behaviors fell close to Preintervention levels, suggesting that the positive changes were not maintained in the absence of the Intervention condition. The results indicate that while play intervention in the PICU environment can have beneficial effects on patient's behavior, the effects of such intervention are short-lived. These data hold important implications for the staffing requirements needed to provide opportunities for the positive behavior changes to occur.

Adolescent↗
PubMed1980

The cardiac and vascular effects of sodium glutamate.

1. The cardiovascular effects of sodium glutamate were investigated in anaesthetized dogs with bolus injections, intravenous infusions and rabbit isolated papillary muscles. 2. The intravenous bolus injections of sodium glutamate resulted in slight, transient decreases in contractile force at doses of 58 and 117 mg/kg, which were followed by brief increases in blood pressure. 3. Sodium glutamate had no effect on contractile responses of isolated papillary muscles at any of the concentrations used. 4. Infusions of glutamate produced no change in blood pressure, an increase in cardiac output, and a decrease in heart rate, total peripheral resistance and femoral vascular resistance. 5. The infusion of sodium glutamate into animals with no renal function resulted in an increased plasma osmolality and a decreased haematocrit. 6. The results from this study show that sodium glutamate had minimal cardiovascular effects. The results from the infusion data suggest that glutamate increases intravascular volume by an osmotic effect.

Animals↗
PubMed1980

Chronic hemodialysis in the anephric goat.

The Spanish brush goat (Capra hiricus) was studied as an animal model for the anephric state. This rugged animal has a hardy appetite and offers ready blood access for dialysis and sampling. BUN, plasma creatinine and potassium could be brought to normal values by daily hemodialysis. Continual weight loss, severe anemia and some tendency for the development of hypertension were observed despite dialysis. Maintenance of a healthy rumen proved a continual challenge but was possible by hyperalimentation and vigorous dialysis immediately postnephrectomy.

Animals↗