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Biomedical subjects

R Pollard

Publications and source records attributed to R Pollard.

51 records · Page 3Linked to original sources

T-cell lymphomas of large cell type. A variety of malignant lymphomas: "histiocytic" and mixed lymphocytic-"histiocytic".

Clinical and morphologic features of seven T-cell lymphomas of the large cell type are described. The tumors were grouped into those with irregular (3 cases) and those with round and regular nuclei (4 cases). In both groups, variation in cell size, numerous histiocytes and vessels, and many mitoses were distinguishing features. In only 1 case in the round and regular nucleus group was there relatively little variation in cell size and a paucity of histiocytes. Abundant polyribosomes, long strands of rough endoplasmic reticulum, and lysosomal granules were prominent electron microscopic features in both groups of tumors. The clinical presentations and courses varied considerably, especially in patients with tumors of the round nucleus type. One patient presented initially with chronic lymphocytic leukemia, 1 with Lennert's lymphoma, another with bone marrow infiltration, and a fourth with subcutaneous tumors. Two patients with the round nucleus type are still alive one and a half and two years after the original diagnosis. Two patients died two years after the onset of symptoms. Each of the 3 patients with tumors of the irregular nucleus type had a rapid clinical course and died within ten months.

Aged↗

Relation between vaccination and notification rates for whooping cough in England and Wales.

The number of notified cases of whooping cough in the 1977-79 outbreak in England and Wales was the largest for over 20 years. The percentage of children receiving pertussis vaccine has declined sharply since 1974. Area Health Authorities with low vaccination acceptance had notification-rates 60% above those with higher acceptance. There was a partial correlation coefficient of -0.57 (p less than 0.001) between vaccination and notification rates after elimination of the effects of social class and overcrowding. The 1-4 year age-group, which contained the children most affected by the decline in vaccination-rates, showed a much bigger increase in notifications than other age-groups. The evidence suggests a direct relation between the decline in vaccination-rate and the increase in notifications.

Adolescent↗

Turtle-associated salmonellosis in the United States. Effect of Public Health Action, 1970 to 1976.

We examined the effect of state and federal legislative actions on the incidence of human salmonellosis associated with pet turtles. Using the Salmonella Surveillance System of the Center for Disease Control, we identified Salmonella serotypes that were and were not specifically turtle associated. From 1970 to 1976, there was a 77% reduction in frequency of turtle-associated serotypes and no consistent trend among non-turtle-associated serotypes. Decrease in frequency of turtle-associated serotypes correlated best with decrease in total production of pet turtles. Reduction in turtle-associated sertotypes temporally correlated with an 18% reduction in frequency of salmonellosis in children, aged 1 to 9 years. Frequency of turtle-associated serotypes rapidly fell in states importing turtles, in contrast to states producing them. Continued although infrequent occurrence of salmonellosis in children with pet turtles counsels against relaxing legislation concerned with its control.

Animals↗

Vaccination against influenza: a five-year study in the Post Office.

An injection of influenza vaccine was offered to approximately 60 000 Postal and Telecommunications staff at the beginning of five successive winters. The sickness absence of this group, which included those who accepted the offer of vaccine as well as those who did not, was compared throughout the winter with that of a similar number of employees who were not offered vaccine. The two groups, ;vaccinated' and control, comprised the staff of nearly 400 Post Office units scattered throughout Great Britain, the units of the two groups being matched as far as practicable for numbers employed, type of work, region and type of location.The proportion who accepted vaccine fell from 42% in the first year (when only 26 000 Telecommunications employees were offered vaccine) to 35% in the second year, and 25% by the fifth year.With the exception of Telecommunications employees in 1972-73, the sickness absence rate of the group offered vaccine was less than that of the group not offered vaccine, and the difference was evident during the winter observation periods both when influenza was prevalent and when it was not. In the last four years of the study the average difference in sickness absence between the ;vaccinated' and control groups was 1.26 days per 100 employees per week during and 1.12 days outside the influenza periods. Moreover, the difference during the influenza periods was greater than could be expected from the acceptance rate of vaccine and the estimated attack rate of influenza. The apparent reduction in sickness absence of the group offered vaccine in comparison with the group not offered vaccine represented an appreciable saving in cost.It is suggested than an annual influenza vaccination campaign in industry may produce financial benefit, but that only a proportion of the benefit is due to an improvement in health.

Absenteeism↗

Papaverine hydrochloride: effects on HIV replication and T-lymphocyte cell function.

Papaverine hydrochloride (PAP) has previously been shown to have a potent inhibitory effect on the replication of viruses such as cytomegalovirus (CMV) and measles. In this report the effect of PAP on human immunodeficiency virus (HIV) replication and T lymphocyte cell function were examined. MT4 cells infected with HIV strain 3b were incubated with serial dilutions of PAP (1-30 microM). At selected times postinfection HIV replication was measured by reverse transcriptase activity (RT) or HIV p24 Ag. PAP significantly inhibited HIV replication by more than 99% at doses of 30 microM with an CD50 and ED50 of 32 microM and 5.8 microM respectively. The mechanism of inhibition of HIV caused by PAP appeared independent form its ability to increase intracellular levels of cAMP and was not mediated via a direct effect on RT activity. To examine T cell function, peripheral blood mononuclear cells (PBMC) from normal donors were stimulated with phytohemagglutinin (PHA) or CMV Ag in the presence or absence of PAP (1-30 microM). At selected times proliferative response to PHA and CMV Ag were determined by [3H]thymidine uptake. In addition, interferon (IFN) gamma and interleukin 2 (IL2) response to mitogens were measured by radioimmunoassay (RIA). PAP enhanced PHA induced IFN production at doses of 1-10 microM and CMV Ag induced IFN production at doses of 1-3 microM. Higher doses were inhibitory. PAP did not affect IL-2 production or IL2 receptor expression and had an inhibitory effect on mitogenic responses.

Antiviral Agents↗

A study of school children who had identified virus infections of the central nervous system during infancy.

Forty-nine children who had a virus infection of the central nervous system (CNS) when under 1 year of age were studied. One child had died during the initial illness and three of the survivors were severely disabled. The other survivors, more than 5 years after the initial illness, were all attending normal schools. These 45 children, together with 45 matched controls, were examined. We confirm the findings of other studies that virus infections of the CNS in infancy may cause severe disabilities in some cases, and may depress intellectual abilities in others, even though they appear to have recovered fully. Many of the children who had a virus infection of the CNS in infancy had adverse birth and social histories and so were exceptionally vulnerable, but these factors did not account fully for the findings, and when their influence was included in the analysis, the index children still had a mean performance IQ (WISC) 6 points lower than the control children (P less than 0.05), whereas there was less than 1 point difference between the verbal IQs. Attention is drawn to the problem of virus infections in neonatal units.

Adenovirus Infections, Human↗

Ultrasonographic evaluation of renal autografts in normal cats.

The purpose of this study was to determine changes in resistive index (RI) and renal size that occur in normal feline kidney autografts in the immediate post-transplant period. Qualitative changes in renal parenchymal echogenicity and pelvic dilation were also noted, although this was not a major focus of the study. Fourteen domestic short-haired cats underwent bilateral nephrectomies followed by an autograft of the right kidney to either the aorta or external iliac artery. Due to post-operative complications, only nine of these cats completed the study. Ultrasonographic determination of the RI and renal size was made before transplantation and on days 1, 4, 7, 10, and 13 following transplantation. No significant changes in renal RI were identified during the study. Renal size increased significantly, peaking at 63% above baseline on day 7, and stayed elevated at 50% above baseline on day 13. There was no evidence of rejection or other abnormalities found on histologic evaluation of the transplanted kidneys. It was concluded that the RI of normal feline renal autografts does not significantly change in the immediate post-operative period. However, significant renal enlargement, likely due to a combination of post-operative edema and hypertrophy, does occur. This study provides baseline information for comparison with feline allografts in the immediate post-transplant period.

Animals↗