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J Beach

Publications and source records attributed to J Beach.

11 recordsLinked to original sources
PubMed1995

Neuropsychological effects of long-term exposure to organophosphates in sheep dip.

Organophosphate-based pesticides are widely used throughout the world. The acute effects of over-exposure to such compounds are well known. Concern has also been expressed that long-term exposure may result in damage to the nervous system. In a cross-sectional study, we compared neuropsychological performance in 146 sheep farmers who were exposed to organophosphates in the course of sheep dipping with 143 non-exposed quarry workers (controls). The farmers performed significantly worse than controls in tests to assess sustained attention and speed of information processing. These effects remained after adjustment for covariates. The farmers also showed greater vulnerability to psychiatric disorder than did the controls as measured by the General Health Questionnaire. There were no observed effects on short-term memory and learning. Repeated exposure to organophosphate-based pesticides appears to be associated with subtle changes in the nervous system. Measures should be taken to reduce exposure to organophosphates as far as possible during agricultural operations.

Adolescent↗
PubMed1995

Emotional and functional impact of DNA testing on patients with symptoms of Huntington's disease.

The potential impact of DNA testing on asymptomatic subjects at risk for Huntington's disease (HD) has been addressed by numerous studies, but the effect of revealing the genetic results to patients with a clinically established diagnosis of HD has not been previously evaluated. We studied 36 patients, with equal distribution of men and women, mean age 53.9 (SD 12.3) years (range 25-76) and mean duration of symptoms of 11.2 (SD 7.7) years (range 2-33), whose clinical diagnosis of HD was confirmed by expanded CAG repeats (> 40). Coping strategies and depression levels were assessed before the results of DNA testing were imparted. The assessments were repeated two weeks and three months after the results were explained to the patients and their relatives and were compared to the baseline assessments. This group of HD patients was compared with 10 patients who had similar symptoms but the diagnosis of HD was excluded by normal CAG repeats (< 30). Although some patients with HD expressed a subjective reaction to the positive result (four were "surprised", one was "frustrated", and one "devastated"), there were no differences in any psychological scores including Beck Depression Inventory, functional capacity, symptom interference, independence scale, and other measures of mood and behaviour two weeks and three months later. Similarly, no change was noted in any of these measures in the non-HD group. These results suggest that mood and coping strategies are unaffected by DNA confirmation of diagnosis in symptomatic patients with HD.

Adaptation, Psychological↗
PubMed1995

Tremor and longevity in relatives of patients with Parkinson's disease, essential tremor, and control subjects.

To study the relation between essential tremor (ET) and Parkinson's disease (PD), we compared the frequency of familial tremor in relatives of patients with PD (N = 391), ET (N = 140), and the combination of ET and PD (N = 125) with the frequency in patients with progressive supranuclear palsy (PSP) (N = 99) and normal age-matched controls (N = 104). Tremor was present in 96 (5.1%) of 1,874 parents and siblings of patients with PD, 152 of 650 (23.4%) relatives of patients with ET, 91 (20.7%) of 439 relatives of patients with ET-PD, 12 of 462 (2.6%) relatives of patients with PSP, and 10 of 448 (2.2%) relatives of normal controls. The high frequency of familial tremor among relatives of patients with PD, and especially those with the ET-PD combination, compared with relatives of patients with PSP or of normal controls suggests that there is an association of PD and familial tremor. Since the most common form of familial tremor is ET, our study provides support for the notion that ET and PD are pathogenetically related. We also found that parents with tremor lived on the average 9.2 years longer than those without tremor. The association of familial tremor with significantly increased longevity suggests that familial tremor confers some anti-aging influence. Alternatively, tremor may be a simple byproduct of the aging process.

Adult↗
PubMed1985

Hypogonadotropic hypogonadism in nephrotic rats: increased sensitivity to negative feedback effects of testosterone.

Pituitary-testicular function was examined in adult male rats with aminonucleoside-induced nephrotic syndrome as a model for similar disease in humans. Nephrotic rats developed androgen deficiency, as manifested by decreased prostate and seminal vesicle weights, lower serum total and free testosterone levels, and reduced testosterone release from testes incubated in vitro. Despite hypoandrogenism, the weight and histologic appearance of the testes (light microscopy) were not affected in nephrotic rats. This androgen deficiency seemed to be a consequence of decreased gonadotropin output rather than primary testicular failure, since both pituitary gonadotropin content and serum gonadotropin levels (basally and after luteinizing hormone releasing factor; LHRH) were reduced in nephrotic rats. In addition, the percentage increase in testosterone release by testes incubated in vitro after addition of exogenous gonadotropin was similar in nephrotic and control groups. However, gonadotropin output in nephrotic rats was not impaired in the absence of testis, since no reduction was seen in either post-castration serum gonadotropin levels in vivo or gonadotropin release from pituitaries incubated in vitro. This presumed inhibitory effect of the testis on gonadotropin output in nephrotic rats was confirmed directly by demonstrating an increased sensitivity to testosterone-mediated suppression of gonadotropins in castrate animals in vivo. The presence or absence of albumin also seemed to modulate the suppressive effect of testosterone on gonadotropin output from normal pituitaries incubated in vitro. We conclude that nephrotic male rats develop hypogonadotropic hypogonadism secondary to an increase in sensitivity of the pituitary to the negative feedback effects of testosterone.

Androgens↗
PubMed1984

CT and MR for brain tumor implant therapy using CF-252 neutrons.

Magnetic resonance (MR) imaging of the brain allows very effective localization of tumor in brain, visualization of brain reaction to tumor, peritumoral edema, as well as destruction of normal anatomy and spread of tumor. MR readily imaged the brain in multiple views allowing three dimensional (3D) evaluation and more precise localization of tumor in the depths of the brain. It also assessed the extent of tumor infiltration away from the primary site. In an ongoing study of Cf-252 neutron brachytherapy of hemispheric malignant gliomas of the brain, we have found that the extent of tumor and the planning of the placement of multiple applicators in the brain for implant therapy was facilitated by both CT and MR scanning, but MR allowed better 3D localization, assessment of response and follow-up of tumor response. MR gave additional and different types of information about the tumor than CT scanning based upon proton distribution which greatly aided planning of tumor implant therapy and understanding of patterns of tumor response and recurrence after therapy.

Adult↗
PubMed1982

A double-blind randomized trial of low-dose oral urea to prevent sickle cell crises.

Seventy-nine homozygous SS patients were randomly assigned to control or oral prophylactic urea treatment in a double-blind trial designed to determine whether prophylactic oral urea, in low doses, prevents sickle cell crises. The average follow-up time for these patients was 13.7 months and 33 patients were diagnosed as having one or more crises during the study. No statistically significant treatment differences were found in weight changes, bilirubin changes, or hemoglobin changes over the course of the study or in the distribution of time to first crises or time to second crisis. This study gives no evidence in favor of the hypothesis that prophylactic oral urea, in low doses, prolongs time to crisis.

Administration, Oral↗
PubMed1976

Bone marrow transplantation in children.

Bone marrow transplantation is a new concept in the treatment of leukemia and aplastic anemia. The problems seen in the transplanted patient are abundant and often life-threatening. Caring for these patients offers one of the most exciting challenges of nursing. The nurse not only acquires skill in caring for a patient with leukemia and aplastic anemia, but also becomes knowledgeable in infectious diseases, immunology, fluid and electrolyte balance, and cardiac, respiratory, and renal diseases. The complexity of these patients allows the nurse more direct, comsistent contact with them. As she becomes involved, she is given excellent opportunities for supporting the patient and family through this stressful time. Althoug bone marrow transplantation is an experimental procedure with problems still to be solved, results indicate its value in the treatment of refractory leukemia and aplastic anemia.

Anemia, Aplastic↗