PubMed Health⌕ Search

Biomedical subjects

E W Gray

Publications and source records attributed to E W Gray.

At least 19 recordsLinked to original sources
PubMed2004

Radioactivity in cathode ray tubes.

While surveying used computer equipment out of a zone posted as a Contamination Area, 100% of the computer monitors surveyed had levels of radioactivity that were significantly above background. The radioactivity was primarily on the front face of the cathode ray tube and was not amenable to decontamination. Hot spots were found also along the edges and seals of the cathode ray tube. Similar surveys of computer monitors that were never in Contamination Areas confirmed that radioactivity was incorporated into the monitor. Surveys were made of recently manufactured television sets with similar results. Gamma spectroscopy indicates that the radioactivity is due to naturally occurring radioactive materials. Since most surveys of cathode ray tubes in the literature were made while the units were energized and indicated low-energy x-rays, the use of naturally occurring radioactive materials in the manufacture of cathode ray tubes has not been widely recognized. This paper presents the results of these surveys, the results of gamma spectroscopy, and a method for releasing existing computer equipment having naturally occurring radioactive materials.

Beta Particles↗
PubMed1999

Development of the first black fly (Diptera: Simuliidae) management program in Argentina and comparison with other programs.

In response to increasing pest populations of black flies, the government of Argentina initiated a pilot program to evaluate the effectiveness of larval control in the irrigation system of the Negro River Valley, an 18,240-km2 area in Patagonia. The extensive system of irrigation canals, drainage ditches, and natural waterways not only provides water for agriculture and general habitation but also affords habitat for immature black flies. Three species (Simulium bonaerense, Simulium wolffhuegeli, and Simulium nigristrigatum) are primary pests of humans and animals in this area. Trials were conducted using Vectobac AS in representative irrigation canals, a drainage ditch, and a medium-sized river. Most trials resulted in effective larval mortality and insecticide carry. Based on a comparison with 11 black fly suppression programs throughout the world, a suppression program for the Negro River Valley has a projected cost of approximately $1,623,360/year. This study represents the initial steps in development of the 1st areawide black fly suppression program in Argentina.

Animals↗
PubMed1999

Ticks of South Carolina (Acari: Ixodoidea).

County and host records are reported for 19 species of ticks from South Carolina: Amblyomma americanum, Amblyomma maculatum, Amblyomma tuberculatum, Aponomma latum, Boophilus annulatus, Boophilus microplus, Dermacentor albipictus, Dermacentor variablis, Haemaphysalis leporispalustris, Ixodes affinis, Ixodes brunneus, Ixodes cookei, Ixodes marxi, Ixodes minor, Ixodes scapularis, Ixodes texanus, Ixodes woodi, Rhipicephalus sanguineus, and Ornithodoros capensis. Ixodes woodi is recorded from South Carolina for the first time. Boophilus annulatus and Boophilus microplus probably no longer exist in South Carolina, and Aponomma latum is an exotic species that is not established in South Carolina. Brief notes follow each species.

Animals↗
PubMed1996

Economic impact of black flies (Diptera:Simuliidae) in South Carolina and development of a localized suppression program.

The membership of a private golf club in South Carolina's Piedmont Physiographic Region was surveyed to determine perceptions regarding local black fly populations and the effects of these populations on golfing habits. The economic impact of black fly annoyance at this club was estimated to be $27,202. Adult monitoring indicated that the pest species were members of the Simulium jenningsi group; larval monitoring identified the Enoree River, Laurens County, as the primary source of the pest species. A localized suppression program was initiated during the late summer of 1994 and continued through the fall of 1995. Four larvicide applications were conducted in 1994 and 11 in 1995, using the biological insecticide Vectobac. Larval mortalities of 94.5 and 97% were produced during 1994 and 1995, respectively. Adult black fly populations were reduced 92 and 88% during 1994 and 1995, respectively, from pre-program populations. Improvements for future suppression programs are proposed.

Animals↗
PubMed1995

Isolation of a parapoxvirus from a grey seal (Halichoerus grypus).

A grey seal (Halichoerus grypus) developed cutaneous pocks which progressed to involve the skin extensively, necessitating euthanasia. Macroscopically and histologically the lesions resembled previous descriptions of parapoxvirus infections of seals and virus particles were observed in preparations of a scab and a skin lesion. Suspensions of the scab and skin lesion were prepared and inoculated on to monolayer cultures of grey seal kidney cells. After 25 days in culture and three passages, cytopathic effects were observed and parapoxvirus particles were detected by electron microscopy in the supernatant fluid. Both isolates were adapted to cultures of fetal lamb muscle cells and shown to be antigenically related to orf virus.

Animals↗
PubMed1995

Experimental transmission of enzootic intranasal tumors of goats.

The successful experimental transmission of enzootic intranasal tumor (EIT) from goat to goat is described. Ten kids, less than 48 hours old, from a flock free of the disease and seronegative for ruminant lentiviruses were inoculated intranasally or intrasinusally with either nasal fluid from goats with naturally occurring EIT or EIT retrovirus concentrated from such fluids. EIT was induced in three kids after 12-24 months. The EIT retrovirus was demonstrated in tumor material from each of the three kids by western blotting and electron microscopy. All kids were seronegative for ruminant lentiviruses.

Adenocarcinoma↗
PubMed1992

An initial investigation of the status of Borrellia burgodorferi and its suspected primary vector, Ixodes scapularis, in South Carolina.

Based on a survey of hunter-harvested deer, the suspected primary vector of Lyme disease in the Southeast, I. scapularis, is most prevalent in sandhill and coastal plain counties of South Carolina. None of 271 I. scapularis examined were found to be infected with the Lyme disease spirochete. However, many more specimens of I. scapularis, A. americanum, and other tick species must be examined before an accurate estimate of the probability of acquiring Lyme disease in South Carolina can be made.

Animals↗
PubMed1990

The Morgan Recharger: a new horn fly (Diptera: Muscidae) control device for beef cattle.

A 20% diazinon formulation was evaluated for control efficacy against the horn fly, Haematobia irritans (L.), in the Morgan Recharger (Morgan International Products, College Grove, Tenn.). The Morgan Recharger releases insecticide with a wicking system from an insecticide reservoir and can be attached to an animal's ear or tail. This device was most effective against the horn fly when used as an ear tag with two per head; horn fly counts did not exceed five flies per side through 8 wk. The diazinon formulation tested was released from the Morgan Recharger at a decreasing rate. The problems and potential of the Morgan Recharger as an effective horn fly control device are discussed.

Animals↗
PubMed1989

Underinsured and uninsured patients. Basic health care: the Washington State experiment.

During the early 1980s in the state of Washington, a change in access to health care became apparent. This was due to a change in the basic method of financing. Within the state, a shift to a service-dominated economy resulted in minimum wage earning with no fringe benefit for health, and a severe recession resulted in unemployment and under-employment. This article describes the approach taken by the people of Washington in order to solve this problem and documents the results of their work, as of December 1988. The story is not over, but it does illustrate what can be done when members of a society decide to work together to solve a problem.

Health Care Coalitions↗
PubMed1987

The ultrastructure of cell cultures infected with border disease and bovine virus diarrhoea viruses.

The morphology of border disease virus and bovine virus diarrhoea virus in infected bovine embryonic testis cells was examined by electron microscopy. Particles which appeared to be mature virions of both viruses were similar, being roughly circular and approximately 46 nm in diameter with a 20 to 25 nm core. Virus replication took place totally within the cytoplasm in association with structures formed from modified endoplasmic reticulum.

Animals↗
PubMed1984

Infection of specific-pathogen free lambs with a herpesvirus isolated from pulmonary adenomatosis.

In two experiments, 18 specific-pathogen free (SPF) lambs were inoculated by several routes with the Scottish strain of caprine herpesvirus 1 (CHV 1). Seventeen of the lambs developed interstitial changes in the lungs ranging from focal cellular infiltration to a widespread proliferative pneumonia. Five weeks after the initial inoculation 3 lambs were given a course of corticosteroid by intravenous injection. Subsequently virus was reisolated from all 3 lambs. Virus was also recovered from one of these lambs on one occasion prior to steroid treatment. It has therefore been established that CHV 1 can cause pneumonia and can be reisolated from infected sheep for at least 6 weeks after infection. It is suggested that CHV 1 might cause a latent infection in sheep which is reactivated following the development of pulmonary adenomatosis.

Animals↗
PubMed1984

Experimental cryptosporidiosis in germfree lambs.

Contaminating bacteria were removed from an isolate of calf Cryptosporidium by 3 sequential passages of the parasite in gnotobiotic lambs, together with antibiotic treatment of the lambs. This preparation, which contained no detectable bacteria or viruses, was given by mouth to 8 2-day-old gnotobiotic lambs, 3 of which were dosed at the same time with bacterial flora from a healthy calf. Lambs were killed at intervals from 12 to 288 h post-inoculation and the sequential development of the parasite, of enteric lesions, and of clinical illness was observed. Lesions were characterized by severe villus stunting and fusion. Clinically the most consistent sign was anorexia, with some lambs developing also a severe watery diarrhoea. Lesions and clinical signs were similar in lambs with and without intestinal bacteria. This demonstration of the enteropathogenicity of Cryptosporidium in germfree lambs suggests that it is a pathogen of significance.

Animals↗
PubMed1983

Rapid transmission of sheep pulmonary adenomatosis (jaagsiekte) in young lambs. Brief report.

Jaagsiekte, a contagious lung tumour of sheep, was induced within 3-6 weeks in day-old lambs by intratracheal inoculation of SPA lung fluids concentrated by centrifugation. Electronmicroscopic examination of the tumour revealed retrovirus particles whose morphogenesis and morphology support biophysical and immunological findings that suggest a relationship with type B and type D retroviruses.

Animals↗
PubMed1982

Experimental infection of lambs with Cryptosporidium isolated from a human patient with diarrhoea.

An inoculum containing Cryptosporidium oocysts obtained from an adult human patient with acute transient diarrhoea induced enteritis in two newborn specific pathogen free lambs. Three days after inoculation the lambs became depressed and diarrhoeic, their milk intake was reduced and Cryptosporidium oocysts were detected in their faeces. Mucosal changes observed in the small intestine of one infected lamb were consistent with but less severe than those induced experimentally in lambs by cryptosporidia isolated from calves and lambs.

Animals↗
PubMed1982

Intestinal lesions in specific-pathogen-free lambs associated with a cryptosporidium from calves with diarrhea.

Small and large intestines of seven specific pathogen-free lambs infected with cryptosporidia from calves with diarrhea were examined by scanning and transmission electron microscopy and by light microscopy. The small intestine was infected in all the lambs, and the cecum and colon in three. Small intestinal alterations were severe villous atrophy and dilatation of the crypts of Lieberkühn. Epithelial cross-bridging between contiguous villi caused much villous fusion. Epithelial cells constituting the bridges were connected by desmosomal junctions, and were continuous with the epithelial coverings of the associated villi. The lamina propria was heavily infiltrated with neutrophil leukocytes. Infected crypts in cecum and colon were dilated and devoid of mucus-secreting cells, while the ridges between crypts were hypertrophied, and the lamina propria was infiltrated by neutrophils. Cell vegetations with adherent bacteria were present in the surface intestinal epithelium of two lambs infected for 11 and 14 days, respectively. No adherent bacteria were seen in any site in lambs killed up to six days post-inoculation.

Animals↗