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Biomedical subjects

R H Jones

Publications and source records attributed to R H Jones.

At least 325 records · Page 18Linked to original sources
PubMed1978

Relevance of laboratory colonies of the vector in arbovirus research--Culicoides variipennis and bluetongue.

Relevance for laboratory colonies of Culicoides variipennis (Coquillett) in arbovirus research was determined during colonization by comparing a vector-competence characteristic for the parent (P) field and subsequent colonized generations. Three colonies established in 1972-1973 were used to determine whether each was representative of the field population from which it was derived for oral infection to 2 to 4 serotypes of bluetongue virus (BTV). Two colonies that were based on small numbers of females ovipositing did not represent the field population. Both appeared homogeneous to oral infection with different serotypes, and one was resistant to infection whereas the other was susceptible. The third colony, which was based on about 150 P females that had oviposited, was more representative of the field population: 1) oral susceptibility to BTV for the F6 was not greatly different from that of the P generation, and 2) the colony retained some heterogeneity for response to oral infection with different serotypes of BTV. The number and percentage of P females ovipositing and the numerical growth factor from the P to F1 were used to estimate whether a laboratory colony was apt to represent the field population from which it was derived.

Animals↗
PubMed1978

Heterogeneity of Culicoides variipennis field populations to oral infection with bluetongue virus.

A standard colonized population (000 line) of Culicoides variipennis (Coquillett) was used as the control for comparing the infection rate (IR) responses of different field populations of the vector to oral infection with several strains of bluetongue virus (BTV) that belonged to four serotypes. Three field populations from Colorado and Oregon tested concurrently in 1969 were differently susceptible to three BTV strains representing three serotypes. The IR's of each of the three populations varied greatly for the three serotypes, and the lowest IR for each of two Colorado populations was for a different serotype. The IR's of different populations to the same BTV strain varied greatly, and the lowest and highest IR's for two serotypes with adequate virus concentration occurred in different populations. Two Kentucky field populations in 1971 were completely resistent to oral infection with a BTV strain; in 1972, one population remained resistant and the other became moderately susceptible. The IR's of different field populations in 1971 to a single BTV strain ranged from 0 to 68%. The IR's of an Idaho population to three BTV strains representing three serotypes showed that a susceptibility rate (SR) could be calculated if the IR's were similar for one and for two infective blood meals. The average SR of this population was 42%; the SR's to each serotype were 32%, 40%, and 54%, with the highest response for the serotype that included the BTV strain collected during the BT outbreak from which the vector population was also collected.

Animals↗
PubMed1978

Failure to propagate equine infectious anemia virus in mosquitoes and Culicoides variipennis.

Laboratory-colonized mosquitoes, Culex tarsalis, aedes aegypti, Culiseta inornata, and Anopheles free-borni, and the biting gnat, Culicoides variipennis, were exposed to equine infectious anemia virus. Exposure to the virus was by intrathoracic inoculation for mosquitoes and by oral ingestion of an infective blood meal through a membrane for C variipennis. After various intervals, groups of 15 to 20 insects were homogenized and inoculated into susceptible ponies. Positive immunodiffusion test results were used as criterion for equine infectious anemia infection in ponies. Virus was not detected in the 4 species of mosquitoes at 3, 6, 12, and 18 days after inoculation, or in C variipennis at 6, 8, 12, 14, 21, and 26 days after oral exposure to the virus.

Animals↗
PubMed1977

Haemoperfusion with R-004 Amberlite resin for treating acute poisoning.

Eleven patients who had taken overdoses of barbiturates, glutethimide, tricyclic antidepressants, and chloroquine were treated by resin haemoperfusion using an R-004 haemoperfusion cartridge containing XAD-4 resin. All but one patient showed rapid clinical recovery and the drugs were cleared rapidly from the plasma. There were few complications. Resin haemoperfusion is more effective than dialysis and other perfusion methods, especially in poisoning with tricyclic antidepressants. Although haemoperfusion is expensive, it greatly reduces the length of the patient's stay in an intensive care unit and hence is cost-effective.

Acute Disease↗
PubMed1977

B1-3,5-diiodotyrosine insulin: a valid tracer for insulin.

Insulin, specifically substituted at the PheB1 position with 3,5-diiodotyrosine, has been tested in several biological and immunological systems. Immunoreactivity was assessed using antisera specific for different parts of the insulin molecule. Biological activity in vitro was estimated on isolated rat fat cells. In vivo bioactivity (hypoglycaemia) and metabolism (metabolic and urinary clearance rates, half-life, apparent distribution space) were measured by infusion of the material into greyhounds. The results indicated that this B1-labelled insulin preparation was biologically fully active and, unlike randomly labelled preparations of iodoinsulin, was metabolised with kinetics indistinguishable from those of the unlabelled hormone. We suggest that this material is a valid tracer for insulin, fulfilling the criteria of high specific activity and biological identity to the native hormone.

Adipose Tissue↗
PubMed1977

Surgical management of chronic pulmonary embolism.

The clinical course of most patients with pulmonary embolism is one of gradual resolution with re-establishment of flow in the pulmonary arteries. In a small but definite group of patients, the emboli do not resolve and a state of chronic pulmonary embolism ensues. The primary thrombotic process in the systemic venous system may persist, and in some instances may be unrecognized. Such patients experience recurrent showers of emboli which may ultimately occlude a large part of the pulmonary arterial circulation with development of severe respiratory insufficiency. Six patients with this syndrome are described, and in each there was a history of dyspnea, cyanoiss, and exercise intolerance associated with a low arterial PO2, right ventricular hypertrophy, and pulmonary hypertension. Pulmonary scans and arteriograms demonstrated that more than half of the major pulmonary arteries were occluded and, in addition, smaller vessels were also obstructed. Pulmonary embolectomy was performed in each patient. Five of the 6 obtained a highly gratifying response, including relief of the dyspnea and cyanosis, an increase in arterial PO2, and a decrease in pulmonary arterial pressure. In each of the five in whom improvement occurred, the back-bleeding from the pulmonary artery at the time of embolectomy was quite good. In the sixth patient, the back-bleeding was very poor, and despite embolectomy, the vessel thrombosed postoperatively with no improvement in the patient's clinical course. Follow-up studies in these patients range up to 8 years with demonstration of continued patency of the pulmonary arteries as well as continued improvement in clinical symptoms and in the arterial PO2.

Adult↗
PubMed1977

Overwintering mechanism for bluetongue virus: biological recovery of latent virus from a bovine by bites of Culicoides variipennis.

Bluetongue virus (BTV) was biologically transmitted by the bites of colonized Culicoides variipennis gnats to recipient sheep from a Hereford bull with latent infection. Four biological recoveries of BTV were mediated over 2 years by multiple feedings of the vector during a 4- to 72-hour interval. Initial stimulation by gnat bites at 0 hour permitted biological recovery of BTV by gnats that fed at later intervals. The 4th biological recovery of the virus from the bull clearly indicated a vector-mediated viral recovery mechanism in which initial vector bites at 0 hours stimulated a "showering" of BTV into the blood stream of the bull. The BTV carrier bull developed no overt signs of illness during these studies. The pertinent BTV assay and serologic results for the 4 1/3 years of the bull's life are summarized in this report.

Animals↗
PubMed1977

Culicoides, the vector of epizootic hemorrhagic disease in white-tailed deer in Kentucky in 1971.

The biting gnat, Culicoides variipennis (Coquillett), was shown to be a vector of epizootic hemorrhagic disease (EHD) in white-tailed deer, Odocoileus virginianus, in Kentucky because of virus isolations from parous females. Epidemiological evidence showed a close relationship of this vector to the animal host during an outbreak of EHD in penned deer. Larval breeding sites of C. variipennis were found and C. variipennis was the most abundant biting fly present during the outbreak. Females of C. variipennis were commonly observed biting deer, swine, cattle and, occasionally, man.

Animals↗
PubMed1977

Transmission of two strains of epizootic hemorrhagic disease virus in deer by Culicoides variipennis.

Two strains of epizootic hemorrhagic disease virus (EHDV), New Jersey (NJ) and Kentucky (KY), of deer were biologically transmitted between white-tailed deer, Odocoileus virginianus, by Culicoides variipennis. The KY strain, isolated from C. variipennis collected during an epizootic in deer, was identified as EHDV by serological tests. Deer exposed to the KY or the NJ strains of EHDV developed an acute hemorrhagic disease; most deer died 6 to 13 days after infection. Sheep inoculated with EHDV developed no clinical signs of disease.

Animals↗