Biomedical subjects

D L Millar

Publications and source records attributed to D L Millar.

6 recordsLinked to original sources

PubMed1992

Autonomic dysfunction in systemic sclerosis: sympathetic overactivity and instability.

PURPOSE: This study was designed to assess the prevalence and nature of autonomic dysfunction (AD) in 34 patients with systemic sclerosis (SSc). PATIENTS AND METHODS: Patients were questioned for current symptoms possibly related to AD. Five noninvasive cardiovascular autonomic function tests and sequential plasma catecholamine estimations at rest, during standing, and during sustained handgrip were performed. Seven patients with manometrically documented esophageal involvement and high resting plasma adrenaline levels were treated with clonidine (75 to 375 micrograms/d). One month later, resting plasma catecholamine estimations and esophageal motility studies were repeated. RESULTS: Autonomic testing revealed AD in each patient, while symptoms were experienced by 33 of them. Findings on two of the three heart rate tests and both blood pressure tests were significantly impaired as compared with those in 25 matched control subjects. Mean resting plasma adrenaline levels were 18 times higher than in 10 matched controls (p less than 0.001). Plasma catecholamine (adrenaline, noradrenaline, and dopamine) concentrations and mean arterial blood pressures fluctuated inappropriately during standing and sustained handgrip in 28 (82%) of the patients. The presence of headaches correlated significantly with sympathetic overactivity and instability (p less than 0.05). Resting plasma adrenaline concentrations correlated inversely with disease duration (p less than 0.05). Significant suppression of sympathetic overactivity and increases in resting lower esophageal sphincter pressures were observed in the seven patients treated with clonidine. CONCLUSION: AD is extremely common in SSc. It is characterized by parasympathetic impairment and marked sympathetic overactivity, particularly in early disease. The potential role of AD in the pathogenesis of SSc deserves further study.

Adult↗

PubMed1981

Bacterial coryza in turkeys in Texas.

A motile, gram-negative, short bacillus was isolated from the tracheas of turkey poults with coryza. An Escherichia coli also was isolated from the tracheas of poults. The former bacterium possessed characteristics similar or identical to those isolated from coryza outbreaks in other states. The characteristics were similar to those described for Alcaligenes fecalis. Cultures of the turkey coryza isolate produced coryza when inoculated intranasally in 1 to 3-day-old poults. The bacterium was reisolated consistently from the tracheas of the affected poults. In one experiment, poults inoculated with the coryza bacterium and the E. coli isolate had an apparent increased incidence of air sacculitis. No viruses were isolated from the tracheas of coryza-affected poults. Blood serums were negative for precipitating and hemagglutination-inhibition antibodies to avian influenza and Newcastle disease viruses, respectively. The serum neutralizing antibody titers to infectious bursal disease virus in noninoculated poults, and poults inoculated with the coryza bacterium, or E. coli or both, were undetectable or low. Serum agglutination was not a reliable method for determining infection by the coryza bacterium.

Alcaligenes↗

PubMed1980

Ubiquity of infectious bursal disease in East Texas backyard flocks.

Sera from 25 "backyard" flocks were screened by agar-gel precipitin (AGP) and virus-neutralization (VN) tests for antibodies to infectious bursal disease virus. Although titers varied from flock to flock, 100% of the birds screened had virus-neutralizing antibodies. In general, birds with high VN titers had positive AGP reaction.

Animals↗

PubMed1979

Morphologic changes in the bursa of fabricius of chickens after inoculation with infectious bursal disease virus.

Sequential morphologic changes in the bursa of Fabricius were studied after oral inoculation of 1-day-old chicks with infectious bursal disease virus (IBDV). The epithelial surface morphology was studied by scanning electron microscopy, whereas the IBDV replication was sequentially followed by immunofluorescence and transmission electron microscopy. The earliest detectable changes in the bursal epithelium were evident at postinoculation hour (PIH) 48. They were characterized by reduction in numbers and size of microvilli on the epithelial cells accompanied by gradual involution of the button-like bursal follicles. At PIH 96 some specimens showed localized surface erosions due to loss of epithelial cells. As the damage progressed, the infolding of the buttomlike follicles became more pronounced and the surface erosions became more extensive. Loss of surface epithelium exposed the underlying damaged bursal follicles which appeared to be bounded by columnar epithelium. Some follicles had lost almost all the lymphocytes and macrophages and appeared as empty craters. Intrafollicular replication of IBDV was detectable as early as PIH 24 by immunofluorescence technique. Viral replication primarily took place in the lymphoid follicles. Regeneration of the follicles was not seen up to postinoculation day 12, suggesting that the IBDV-induced bursal damage could be permanent.

Animals↗

PubMedDate not supplied

Isolation of Pacheco's disease herpesvirus in Texas.

Pacheco's disease herpesvirus was determined to be the agent responsible for the death of about 200 psittacine birds comprising five species. Clinical signs, necropsy lesions, and virus isolation and identification methods are described.

Animals↗

PubMedDate not supplied

A comparison of avian and mammalian cell cultures for the propagation of avian reovirus WVU 2937.

Two avian and seven mammalian cell lines were evaluated for their application in propagating avian reovirus WVU 2937. Cultures were compared for monolayer-formation time, support of viral replication, passages and postinfection time required for expression of cytopathic effect (CPE), type of CPE, and virus yield. CPE was observed on the first passage with infected egg yolk in primary chicken embryo kidney cells, primary through tertiary chicken embryo liver (CEL) cells, and African green monkey kidney (VERO) cells; on the third blind passage of infected supernatant in Georgia bovine kidney cells, Crandall feline kidney cells, and baby hamster cells; on the fifth blind passage in rabbit kidney cells; and on the tenth blind passage in porcine kidney cells. CPE was not observed after 10 viral passages in rabbit bone-marrow cells. Monolayer formation time and postinfection time for CPE expression occurred sooner, and virus yield was greater, with CEL and VERO cells than with other cell lines.

Animals↗