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Biomedical subjects

J Nelson

Publications and source records attributed to J Nelson.

At least 307 records · Page 17Linked to original sources

Differential sensitivity of normal human pulp and transformed mouse fibroblasts to cytotoxic challenge.

Six different lines of diploid cells from human pulp and one commonly used transformed-cell line, L929 (a continuous fibroblast line of mouse lung connective tissue origin), were challenged by sera changes, an agar-overlay toxicity test and transfilter-histochemistry-toxicity test. The normal diploid cells showed greater sensitivity than transformed cells in each test. Although a different parameter of cell toxicity was measured in each test, the data indicate greater toxic response in diploid cells by all measurements. These normal diploid human cells are more appropriate cells for toxicity testing materials for human use.

Adult↗

Oxygen toxicity: loss of lung macrophage function without metabolite depletion.

Hyperoxia inhibited concanavalin A stimulated O2- release (respiratory burst) of alveolar macrophages obtained by bronchoalveolar lavage from rats. After 36 h of normobaric 100% O2, a partial reversal (48%) of the inhibition was produced by addition of glucose. Since oxidant-induced, reversible NADPH depletion correlates with reversible inhibition of the respiratory burst, intracellular NADPH was assayed to determine whether irreversible inhibition of the respiratory burst was related to persistent changes in this metabolite. The cellular concentrations of ATP, glutathione, and ascorbate were also measured. After 36 h of hyperoxia, NADPH concentration in alveolar macrophages rose slightly while ATP and glutathione content remained at control levels. Ascorbate levels fell significantly but were not responsible for respiratory burst inhibition. Thus, irreversible loss of cellular function in hyperoxia is not due to persistent alterations in these metabolites. Significant amounts of both glutathione and ascorbate were found in extracellular fractions of lung washings, indicating high concentrations in the aqueous subphase in the lung fluid lining. There was no change in total content of these extracellular antioxidants following O2 exposure.

Animals↗

The use of pergolide and lisuride, two experimental dopamine agonists, in patients with advanced Parkinson disease.

Pergolide, an experimental dopamine agonist, was administered to 56 patients with advanced Parkinson disease who were no longer satisfactorily responding to levodopa, including 45 patients with diurnal oscillations in performance: "on-off" phenomena. Lisuride, an experimental dopamine agonist was administered to 63 patients with advanced Parkinson disease. Pergolide or lisuride, when added to levodopa, resulted in a significant decrease in disability in both the "on" and the "off" period, and an increase in the number of hours in which patients were "on". Forty-one of 56 patients (73%) improved on Pergolide. Thirty-seven of 63 patients (59%) improved on lisuride. Mean dose of pergolide was 2.5 mg. (range 0.2 to 10.0 mg.). Mean dose of lisuride was 2.6 mg. (range 0.2 to 5.0 mg.). Pergolide was discontinued in 18 patients because of adverse effects, including an organic confusional syndrome (six patients), dyskinesias (four patients) and cardiovascular abnormalities (three patients). Lisuride was discontinued in 26 patients because of adverse effects, including an organic confusional syndrome (15 patients), dyskinesias (five patients) and vasospasm (two patients). Pergolide was discontinued in nine patients and lisuride in 12 because of a lack of effect or a declining effect. Both drugs are equally useful in patients with advanced Parkinson disease.

Adult↗

Chymodiactin in patients with herniated lumbar intervertebral disc(s). An open-label, multicenter study.

To extent the safety information for Chymodiactin (chymopapain for injection), 37 neurologic and orthopedic surgeons conducted an open-label, multicenter, phase 3 clinical study. A total of 1,498 patients with one or two herniated lumbar intervertebral discs were enrolled. Therapeutic results were generally favorable, with the percentages of patients achieving either excellent or good (or successful) results ranging from 79.6% to 88.9%, depending on criteria employed in the tabulation. There were 13 cases of anaphylaxis, and 2 of these patients died of complications of anaphylaxis. Two additional patients experienced serious neurologic problems. The first of these two patients developed transverse myelitis and paraplegia approximately 3 weeks following chemonucleolysis. Transdural discograms at three levels had been done approximately 2 days prior to chemonucleolysis, in violation of the protocol. The second patient developed acute cauda equina syndrome, and, despite emergency laminectomy, had permanent neurologic sequelae. Back spasm and stiffness/soreness were the most frequently encountered adverse experiences.

Adolescent↗

Fractures of the hook of hamate: radiographic signs.

Isolated fractures of the hamulus, formerly considered rare, are being seen more frequently. Many of these injuries are sports related, particularly in golf, tennis, racquetball and baseball players. Failure to make an early diagnosis can result in severe pain and sometimes incapacitating disability. We studied the clinical and radiological findings in 12 patients who had fracture of the hook of the hamate. We propose three radiographic signs of fracture that are readily seen on routine PA projections: "absence" of the hook of the hamate; "sclerosis" of the hook; and lack of cortical density, i.e., a barely visible outline, of the hamulus.

Adolescent↗

Host immune status in uraemia. VI. Leucocytic response to bacterial infection in chronic renal failure.

Infection often complicates renal failure and frequently causes death, but the association between renal failure, impaired immunity and infection has not been proved. A recent study showed that patients on dialysis did not show an expected leucocytic response to infection, suggesting that the blunted response was evidence of the immunocompromised state of the uraemic patient. In this study, the relationship between leucocytic responses and infectious challenge was investigated in an animal model of chronic renal failure. Bacteraemia, peritonitis and a chronic lung infection were induced in normal and uraemic rats; the leucocytic response was then monitored. In all three infections, the total white blood cell response was significantly less in the uraemic animals. Neutrophil numbers actually increased, but this response was disguised by a pronounced depression in lymphocyte numbers. Our conclusion is that, although the leucocytic response of the uraemic host to infection may be depressed, the changes to individual leucocyte components in the peripheral blood are sufficiently characteristic to provide useful evidence of infection.

Animals↗

Descriptive epidemiology of the autopsy in Connecticut, 1979-1980.

Knowledge of the differences between deaths for which autopsies are performed and all deaths is pertinent to epidemiologic investigation in such areas as disease trends, chronic disease incidence, and occupationally related disease. A population-based study was undertaken to evaluate these differences for deaths in Connecticut in 1979 and 1980. Analyses for 1979 and 1980 were comparable. Of 28,440 deaths in 1980, 14% underwent autopsy. Differences by sex, race, marital status, age, underlying cause of death, and place of occurrence of death were demonstrated when decedents who underwent an autopsy were compared with all decedents. Non-white men who died at 20 to 29 years of age were the most likely group to undergo an autopsy. Proportions of autopsies, by major category of underlying cause, did not parallel the leading causes of death. Deaths due to trauma accounted for a larger proportion of all autopsies (25%) than of all deaths (6%). If a death certificate indicated a circulatory disorder or neoplasm as the cause of death, an autopsy was less likely to be performed. A disproportionately high number of autopsies were performed for deaths occurring in hospitals; the converse was true for deaths occurring in nursing-convalescent homes. We conclude that knowledge of the ways in which autopsies are biased will permit broader use of the sensitive and specific information that can be obtained from them.

Adolescent↗

Sleep apnea in Alzheimer's dementia: correlation with mental deterioration.

In a prospective study of sleep-disordered breathing among healthy elderly controls (N = 23), major depressives (N = 17), and demented patients with probable Alzheimer's disease (N = 21), sleep apnea (defined as an apnea index of 5 or more) was found in 42.9% of demented patients, 17.6% of depressives, and 4.3% of controls (chi 2 = 9.90, p less than .01). A significant association between sleep apnea and dementia of the Alzheimer type was found in women but not in men. Moreover, severity of dementia was significantly correlated with apnea index. Possible neuropathologic and clinical implications of these findings are discussed.

Aged↗

Staphylococcal Protein A column: correlation of mitogenicity of perfused plasma with clinical response.

Eleven patients with advanced breast cancer and four with astrocytoma were treated with plasma perfused over columns containing staphylococcal Protein A (SPA). Doses of 5 to 20 mg of SPA were bound to collodion charcoal particles, and this treatment resulted in partial remissions in one patient with astrocytoma and in two patients with breast cancer. Remission duration was 6 wk to 6 mo. Resolution of lymphadenopathy and a decrease in carcinoembryonic antigen were noted in an additional two breast cancer patients. Systemic reactions to infused plasma consisted of fever, chills, and rigors. In brain cancer patients, increased intracranial pressure was also noted. A mitogenic substance was generated in plasma of 11 patients after it was perfused over the SPA charcoal matrix. The mitogenic material induced lymphoproliferation comparable to concanavalin A and required the presence of SPA on the collodion charcoal but was not due to leakage of SPA from the column during plasma perfusion. Of considerable significance was that only patients whose column perfused plasma contained this mitogenic activity exhibited systemic reactions, and five of these patients obtained antitumor responses. This striking correlation implies that the mitogenic factor is an active component of SPA therapy. The ability to demonstrate mitogenicity in column perfused plasma might also be useful for selecting patients amenable to SPA therapy. These findings attest to the therapeutic value of this mode of treatment and provide an initial definition of a mediator of SPA antitumor activity.

Adult↗

The management of persistent menopausal symptoms with oestradiol-testosterone implants: clinical, lipid and hormonal results.

Seventeen patients attending two menopause clinics were treated with combined subcutaneous implants of oestradiol (40 mg) and testosterone (100 mg), because oral oestrogens had not provided adequate symptomatic relief, particularly of decreased libido. There were significant improvements in libido, enjoyment of sex and tiredness (P less than 0.01), and in lack of concentration (P less than 0.05), but there was no significant change in flushes, sweats and depression. Based on an analogue scale, libido increased from a mean basal score of 13.5 to a maximum of 86.1 at 3 mth. Symptomatic improvement was maintained for 4-6 mth. There were no significant changes in total serum cholesterol and triglycerides nor in cholesterol subfractions. When expressed as a percentage of the preimplant values, maximal changes in hormonal parameters were observed at 1 mth. Thus, follicle stimulating hormone (FSH) was 53% of basal, luteinising hormone (LH) 54%, oestradiol 186%, total testosterone 291%, and free testosterone 342%. Only 1 patient complained of hirsutism and weight gain. We conclude that the hormonal implants provided substantial symptomatic relief, particularly of loss of libido, while causing rises to mid-follicular concentrations of oestradiol and maximal testosterone levels about three times normal, without significant effects on plasma lipids.

Adult↗

Integrating cardiovascular health education with an English curriculum in a secondary school.

The purpose of this study was to assess the impact on cognitive and attitude retention of a cardiovascular (CV) health education unit that was integrated within high school English classes. The integrated program was an extension of previous research on the Cardiovascular School Health Curriculum that was developed by the National Heart and Blood Vessel Research and Demonstration Center, Baylor College of Medicine. The results of this study supported the hypotheses that CV health education can be successfully integrated within the English curriculum of secondary schools. This joint effort between health education and a liberal art assisted students in retaining important facts related to CV disease and in maintaining more positive attitudes toward their abilities to control their CV risks.

Adolescent↗

Long-term treatment with pergolide: decreased efficacy with time.

We studied the effect of pergolide (combined with levodopa) in 17 patients with Parkinson's disease, including 15 with "wearing off" or on-off phenomena, who had been taking pergolide for at least 2 years. Mean duration of the study was 27.8 months. All 17 patients improved initially, but the improvement later faded. Mean disability score, which decreased initially by 60% (significant), was decreased only by 20% after 2 years (not significant). Wearing off and on-off phenomena, which improved initially, became prominent again. Four patients lost all the improvement, nine patients lost much of the improvement, and four maintained much of the improvement. Mean dose of pergolide was 2.2 mg (range, 0.8 to 5.0 mg).

Aged↗

Combined use of benserazide and carbidopa in Parkinson's disease.

The pharmacokinetics of levodopa differs when it is combined with benserazide or carbidopa. Peak dopa levels are higher, occur sooner, but decline more rapidly with benserazide. Although many patients respond better to one drug than the other, we sought to exploit the differences in pharmacokinetics by giving both drugs to the same patient. Benserazide was combined with carbidopa in 38 patients who were experiencing a diminished response to carbidopa, including 22 patients with diurnal oscillations in performance, "wearing off" or on-off phenomena. Previous attempts to change the dose, sequence, or ratio of levodopa to carbidopa in these patients had been unrewarding. Ten of the patients improved on the combination of benserazide and carbidopa, with a 30% decline in disability. The mean dose of levodopa:carbidopa before benserazide was 910:100 (9 to 1 ratio); the mean dose of levodopa:benserazide was 355:90 (4 to 1 ratio). The mean dose of levodopa:carbidopa + benserazide was 925:155 (6 to 1 ratio). The combination of carbidopa with benserazide is useful in some parkinsonian patients.

Adult↗

Stress, ACTH, salt intake and high blood pressure.

Epidemiological evidence supports the thesis that high salt intake is involved in the aetiology of hypertension. If sodium intake is not causal, it appears other factors do not cause high blood pressure in unacculturated societies with low sodium intake. In this context, it is potentially important that stress causing ACTH release, as well as other neurohumoral effects, causes increased salt appetite and can impair renal sodium excretion.

Adrenalectomy↗

Fusion of the first metatarsophalangeal joint in forefoot arthroplasty.

Forefoot arthroplasty is often recommended for the management of metatarsalgia secondary to rheumatoid arthritis. Concurrently, the first metatarsophalangeal (MP) joint can be fused rather than excised. The results in 37 patients with 64 arthroplasty operations (34 with fusion and 30 with excision of the first joint) show that fusion produced a better cosmetic appearance of the foot, facilitated fitting with normal shoes, and improved overall balance. Pedobarograph measurements during gait indicated that relatively more weight was transmitted through the medial ray when the first metatarsophalangeal joint was fused. Residual pain in the foot was often caused by irregular trimming of the metatarsals. There was no difference in relief of pain between fused and unfused patients. Failure of fusion at the first metatarsophalangeal joint generally was painless. Radiologic degeneration of the interphalangeal (IP) joint of the great toe was relatively common following fusion. MP joint fusion is inadvisable if there is already disease in the IP joint.

Adult↗

Infection-induced immunosuppression in pyelonephritis: characteristics of the suppressor cell(s).

Infection-induced suppressor cells may be associated with a depression of cell-mediated immune (CMI) mechanisms in pyelonephritis. In the present study, cell viability and cell to cell contact were established as prerequisites for immunosuppression and the role of mononuclear phagocytic cells and polymorphonuclear leukocytes, as immunoregulatory cells affecting CMI, was also examined. Fractionation of spleen cell suspensions was carried out using carbonyl iron, nylon wool, glass beads, and sephadex. These procedures restored mitogenic responsiveness to splenic lymphocytes from pyelonephritic animals, and it was possible to isolate cells with accessory and suppressor activity from nylon wool columns. Elutable cells (that is, cells which adhere to the column but could be recovered by the addition of EDTA) were characteristically accessory cells and increased the mitogenic responsiveness of normal lymphocytes. Adherent splenocytes which suppress mitogenic responses were isolated from pyelonephritic animals. Additionally, neutrophils, at concentrations readily demonstrable in lesions, depressed CMI responses in vitro. With this information available it should now be possible to carry out a detailed analysis of the cellular mechanism by which CMI in renal infection is depressed.

Animals↗