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Biomedical subjects

J R Taylor

Publications and source records attributed to J R Taylor.

At least 163 records · Page 9Linked to original sources
PubMed1990

Susceptibility to effects of UVB radiation on induction of contact hypersensitivity as a risk factor for skin cancer in humans.

Normal, healthy human volunteers and patients with proved history of non-melanoma skin cancer have been tested for their capacity to develop contact hypersensitivity to dinitrochlorobenzene (DNCB) following exposure of buttock skin to acute, low-dose ultraviolet B (UVB) radiation. Using a radiation protocol that achieves virtually complete depletion of normal-appearing Langerhans cells from irradiated skin, it was learned that approximately 60% of healthy volunteers developed vigorous contact hypersensitivity (CH) when 2000 micrograms DNCB was painted on the irradiated site. These individuals were designated UVB-resistant, and were distinguished from other individuals, designated UVB-susceptible, who failed to develop contact hypersensitivity following an identical treatment protocol. It was then discovered that virtually all (92%) skin cancer patients exposed to UVB and DNCB failed to develop CH, i.e., were UVB-susceptible. In subsequent experiments, epicutaneous application of 2000 micrograms DNCB to unirradiated skin of UVB-susceptible individuals revealed a further distinction between normal persons and skin cancer patients. Approximately 45% of the latter (and none of the former) remained unresponsive (failed to develop contact hypersensitivity following this second attempt at sensitization), implying that they had been rendered immunologically tolerant. These tolerant individuals responded normally to the unrelated hapten, diphencyprone. We conclude that human beings resemble inbred strains of laboratory mice in that some individuals are UVB-susceptible, whereas others are UVB-resistant. Because the incidence of UVB-susceptibility was significantly higher in skin cancer patients, and as specific unresponsiveness could be demonstrated only in these patients, we propose that UVB-susceptibility, as we define it in this hapten system, may be a risk factor for the development of skin cancer.

Adult↗
PubMed1990

Adherence of human helper/memory T-cell subsets to psoriatic dermal endothelium.

Dermal lymphocytic infiltrates are characteristic features of psoriasis and may be involved in the pathogenesis of the disease. We have previously shown that specialized endothelial cells are present in the dermis of psoriatic skin and are capable of supporting lymphocyte adherence and promoting lymphocyte extravasation. In this study, we investigated the dermal endothelial binding properties of human lymphocyte subsets and the role of LFA-1 molecules in the adhesion process. It was found that both human T cells and B cells adhered to frozen sections of psoriatic plaques, but with different cell dose-response relationships. In addition, quantitative assessment of lymphocyte adhesion demonstrated that human CD4+T cells and the CDw29+ (helper-inducer) subset adhered preferentially to the papillary dermis as compared with CD8+ T cells or the CD45R+ (suppressor-inducer) subset. Moreover, human lymphocytes adhered to untreated psoriatic plaques, but not to uninvolved skin or to steroid-treated, clinically and histologically resolved lesions. Preincubation of T lymphocytes with saturating amounts of monoclonal antibody 60.3 against the surface membrane CD18 glycoprotein complex inhibited partially their capacity to bind to untreated psoriatic plaques. These observations suggest that the emigration of human CD4+ T cell and the CDw29+ helper-inducer subset is promoted by selective adherence to psoriatic dermal endothelia, with LFA-1 molecules playing an accessory role in the binding process.

Administration, Topical↗
PubMed1990

Debridement of septic physeal lesions in 3 foals.

Radiographically, osteolysis of the physis consistent with a septic physitis was observed in 3 foals. The foals were treated with surgical debridement and antimicrobials. Two of the horses were sound for use as adults; the third was euthanatized due to concurrent infectious arthritis and septicemia.

Animals↗
PubMed1990

Health care management. A tool for the future.

As a result of increasing health care costs in the U.S., the skilled, knowledgeable occupational health nurse can implement a plan to reduce these costs with benefits personnel. Using accepted business principles such as the Deming/Shewart cycle, health data can be obtained from the provider, trends can be analyzed, and strategies can be planned for the population. Health and subsequent costs can be managed through the use of the natural history of disease, the three levels of prevention, occupational health nurses' relationships with people, and their access to confidential data. Short-term strategies should include catastrophic and intermediate case management. These systems ensure results in terms of quality and cost.

Accidents, Occupational↗
PubMed1989

Unsuspected damage to lumbar zygapophyseal (facet) joints after motor-vehicle accidents.

Three zygapophyseal joints from each of 31 lumbar spines of subjects who died of injuries (mostly as a result of motor-vehicle accidents) were sectioned for low-power histological study. Bony injuries, in the form of fractures of the superior articular process or infractions of the subchondral bone plate, were found in 11 of the 31 subjects and soft-tissue injuries to the capsule or articular cartilage were found in one-or-more joints in 24 of the 31 subjects, with capsular and articular-cartilage damage in 77% of cases. Healed injuries of a similar type, which were unrelated to the cause of death, were found in other lumbar spines. None of these lesions was diagnosed by standard radiological examination of the spine post mortem. It is suggested that, in survivors, bony and soft-tissue injuries to zygapophyseal joints may result in considerable pain and dysfunction and may predispose to early arthritis.

Accidents, Traffic↗
PubMed1989

Evidence against expression of an endogenous murine leukemia virus causing cellular resistance to lysis by activated macrophages.

In previous studies we observed that resistance of murine SV40-transformed fibroblast cell lines to cytolysis by activated macrophages was frequently associated with cellular expression of the gp70 of an endogenous ecotropic murine leukemia virus (MuLV). The work described here was initiated to test directly for a causative relationship between MuLV expression and resistance to lysis by macrophages. Northern blot analysis revealed that macrophage-resistant cells contain full length retroviral RNA. A panel of mAb which distinguish among host-range classes of MuLV detected only a non-recombinant ecotropic gp70 in these cells. The ecotropic MuLV from two independently derived macrophage resistant cells were isolated by limiting dilution cloning on Mus dunii fibroblasts. These viruses were then used to infect macrophage-sensitive cell lines and the resultant MuLV-positive cells tested for sensitivity to macrophage cytolysis. The MuLV-infected lines remained highly sensitive to macrophage lysis despite their high levels of cell surface gp70 and release of infectious MuLV. Thus, although we cannot rule out the possibility that MuLV or a product thereof is necessary for development of macrophage resistance in transformed cells, expression of MuLV per se is not sufficient to create the resistant phenotype.

Animals↗
PubMed1989

Symptomatic and asymptomatic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated primates: biochemical changes in striatal regions.

Administration of the neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, to primates produces an excellent behavioral model of idiopathic Parkinson's disease. In the vervet monkey, regional biochemical differences in the striatum of two 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated groups were examined one to two months after treatment and compared with controls; one group displayed no observable gross motor abnormalities after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment (asymptomatic), whereas the other group became markedly parkinsonian (symptomatic). In both 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated groups massive depletions of dopamine and homovanillic acid concentrations were observed in the striatum; generally, dopamine losses in the symptomatic group (greater than 95%) were greater than in the asymptomatic group (greater than 75%). However, in striatum, a marked heterogeneity in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine susceptibility was found; certain striatal regions having 99% depletion of dopamine even in asymptomatic monkeys. Overall, in ventromedial regions of striatum the losses of dopamine and homovanillic acid concentrations were less than in dorsolateral regions at the same coronal level. There was a significant negative correlation between control homovanillic acid/dopamine ratios and susceptibility of examined regions to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity. Unlike idiopathic, but similar to postencephalitic, Parkinson's disease, dopamine and homovanillic acid levels in caudate nucleus were not spared relative to putamen; in fact, in the asymptomatic group caudate nucleus dopamine and homovanillic acid concentrations were depleted to a greater extent than in putamen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

End-plate lesions of the lumbar spine.

It has been suggested that the pattern of development and attrition of blood vessels and notochord remnants leaves congenitally weak points in the cartilage disc plates. There is strong presumptive evidence that nuclear prolapse can take place through these weak spots in the cartilage plates to form Schmorl's nodes. It has been postulated that the development of Schmorl's nodes may also lead to anomalies of the vasculature in the end-plates, which may lead to further end-plate lesions. In the present study, we have examined lumbar intervertebral discs and vertebrae from eight specimens with Schmorl's nodes and 12 specimens without nodes. The specimens examined were from individuals ranging in age from 17 to 90 years. The specimens were sectioned at 150 microns, stained, and the percentage of the bone cartilage interface occupied by marrow spaces was measured using a microscope with an ocular micrometer. The specimens with Schmorl's nodes had a significantly greater proportion of disc marrow contacts than did the normal vertebrae.

Adult↗
PubMed1989

An ultraviolet B radiation protocol for complete depletion of human epidermal Langerhans cells.

We report an ultraviolet B (UVB) protocol that achieves essentially complete depletion of Langerhans cells (LC) from human skin, while leaving the skin clinically intact. Sixteen human volunteers of skin types II and III were exposed to 144 mJ/cm2 of UVB each day for 4 successive days, on a 2-cm-diameter circle of buttock skin. In each case the irradiated skin showed redness and mild edema but no vesiculation or ulceration. One hour after the last exposure a 4-mm punch biopsy was taken from the center of the irradiated site. The epidermal sheet from each sample was separated and exposed to CD-1 antibody (12 samples) or HLA-DR antibody (4 samples) and the density of LC was assessed by immunofluorescence light microscopy. In each case the epidermal LC population was severely depleted to less than 20 cells/mm2, from a baseline of approximately 565 cells/mm2, and in many cases no morphologically normal LC remained. This simple protocol thus provides intact human skin completely depleted of LC. Such skin will provide an appropriate model for the in vivo study of the immune function in human skin deprived of its epidermal antigen-presenting capacity.

Adult↗
PubMed1989

Rectal tears in the horse: an analysis of 35 cases.

The records of 35 horses with Grade 3 or 4 rectal tears, presented to the Veterinary Medical Center at Texas A & M University over a five year period, were reviewed. Grade 3 tears were sub-classified according to whether the remaining tissue was serosa (Grade 3a) or mesorectum (Grade 3b). Five horses were destroyed on presentation and 30 were treated by primary suture closure (8 horses), faecal diversion alone (9 horses) or in combination with suture closure (11 horses) and packing of the tear with medicated gauze sponges (two horses). Faecal diversion was achieved with a temporary indwelling rectal liner (TIRL) in 19 horses and colostomy in one. Survival was related to classification of the tear, efficacy of first aid measures administered at time of injury and method of treatment. Seventy-four per cent of horses with Grade 3a tears and 44 per cent of those with Grade 3b tears survived. Grade 4 tears had a grave prognosis. Horses given adequate first aid before admission had a better survival rate. With proper patient selection, primary closure of the tear with sutures yielded excellent results. In horses which were not candidates for suture closure alone, a combination of faecal diversion and suturing gave better results than faecal diversion only. In addition, selected horses were treated successfully by packing the rectal tear with gauze sponges. The results demonstrate the value of a TIRL to divert faeces and appropriate first aid measures in treating rectal tears.

Animals↗
PubMed1989

Facet joint arthrography in lumbar spondylolysis: anatomic basis for spread of contrast medium.

Facet arthrograms in patients with lumbar spondylolyses show spread of contrast medium through pars interarticularis defects into the adjacent ipsilateral facet joint space and across the midline into the contralateral joint space. Transverse and sagittal sections of facet joints from 141 postmortem lumbar spines were studied. Five examples of spondylolysis were found. Anatomic studies of the relationship of the joint recesses to the pars interarticularis demonstrated the basis for the patterns of spread of contrast medium observed radiographically in this and previous series. The pars interarticularis forms the only boundary between the inferior recess of one facet joint and the superior recess of the adjacent joint. Fracture through the pars interarticularis establishes communication between adjacent ipsilateral joints and opens a communication to the retrodural space, through which contrast medium can track to the contralateral joint.

Arthrography↗
PubMed1989

Pregnant women eligible under Medicaid expansion of maternity services. Implications for outreach.

Recent reforms in federal legislation have made Medicaid-financed prenatal care available to pregnant women from households at nearly twice the poverty level. Census and birth certificate data provide little information about the newly eligible group beyond estimates of their size. This article reports on efforts to compare the Medicaid expansion group to traditional Medicaid prenatal care patients in terms of demographics, access problems, and prenatal care adequacy by employing a short-term, hospital-based survey of postpartum women in Michigan. Differences between pregnant women eligible under the expansions and traditionally eligible pregnant women suggested that major changes in outreach and enrollment activities of state Medicaid agencies may be necessary to fulfill the opportunity represented by the Medicaid expansions.

Aid to Families with Dependent Children↗
PubMed1989

Utility of the MMPI in a geriatric population.

Despite the popularity of the Minnesota Multiphasic Personality Inventory (MMPI), there exists a relative dearth of normative and validity research regarding its use with persons over the age of 60. Our investigation was designed to examine the MMPI performance of both a normal and a clinical sample of older men and women. Specifically, a nonpatient community sample of 204 subjects and an outpatient psychiatric sample of 30 subjects, between the ages of 60 and 90, were administered the MMPI as well as structured psychiatric interview, the Psychiatric Status Schedule (PSS). Results revealed that, on most of the MMPI scales, the mean scores were well above the norms (i.e., 5-10 t-score points). Through comparisons between the clinical and community subjects as well as between MMPI and PSS performance, the MMPI demonstrated substantial discriminative and concurrent criterion validity within this geriatric sample. The results of the study suggest that, with a few important exceptions, the MMPI, as generally utilized, is valid for use in the geriatric population.

Aged↗
PubMed1989

Attitudes of mental health professionals toward alcoholism recognition and treatment.

The attitudes of 100 urban mental health professionals toward alcoholism diagnosis and treatment were assessed using a 23-item questionnaire. A significant number of those sampled, physicians more than other professional groups, looked upon alcoholism as a disease in its own right. Physicians, attendings more than residents, subscribed to a more medical history-taking model. While the majority of those surveyed would advise complete sobriety, a large number would not. Likewise, despite a large percentage of our sample who indicated familiarity with alcohol-related concepts, a significant number did not. Referral to Alcoholics Anonymous was highly endorsed by those advocating sobriety. The meaning of these findings is discussed in relation to the marked improvement noted in professionals' attitudes toward alcoholic patients. Based on these findings, methods of further improving the clinician's awareness of alcoholism are considered.

Adult↗
PubMed1989

China: surplus labour and migration.

Surplus labor force and migration trends in China are examined, with emphasis on the impact of underemployment in rural areas. "Government policy encourages surplus labourers to transfer out of crop farming into agricultural sidelines or non-agricultural work. Peasants are urged to stay where they are, shifting jobs without shifting location; however, many rural areas are poorly endowed for providing alternative employment, so their surplus workers must also leave the village to find work. Many do not formally migrate, but rather move on a seasonal basis or set up 'temporary' residence in an urban place. This 'floating' population has been escalating rapidly in recent years....[The authors argue] that China's cities and towns can absorb millions of surplus labourers from rural areas each year, to the mutual benefit of sending and receiving areas."

Agriculture↗