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Biomedical subjects

G Wilson

Publications and source records attributed to G Wilson.

At least 145 records · Page 8Linked to original sources
PubMed1995

Medullary carcinoma of the thyroid metastatic to breast.

Medullary carcinoma of the thyroid commonly spreads to the lymphatics and later on in the disease process, to distant sites such as lung, liver and bone. Spread to the breast is rare (only two previous reported cases) and presents a major diagnostic dilemma. We report a case of metastatic medullary carcinoma of the thyroid which presented as a primary breast nodule with ipsilateral axillary lymphadenopathy. Clearly it was important to distinguish this tumour from a breast primary as each are managed differently. Both cytological and radiological investigations were inconclusive but excision biopsy was diagnostic.

Breast Neoplasms↗
PubMed1995

Rapid protection of rat spermatogenic stem cells against procarbazine by treatment with a gonadotropin-releasing hormone antagonist (Nal-Glu) and an antiandrogen (flutamide).

GnRH antagonist (Nal-Glu) treatment combined with the antiandrogen flutamide was used to suppress rat spermatogenesis to achieve protection of spermatogonial stem cells against the anticancer drug procarbazine. Daily injections with Nal-Glu alone suppressed spermatogenesis in a dose-responsive manner. However, it was necessary to combine Nal-Glu (600 micrograms/kg.day) with flutamide at 20 mg/kg.day to decrease testicular weight in 2 weeks to less than 0.6 g, a level previously demonstrated sufficient to protect stem cells in our model system. The Nal-Glu-flutamide pretreatment suppressed serum gonadotropin levels and intratesticular testosterone levels (6% of control) and action, resulting in a reversible decrease in the number of late spermatids to 1% of control levels. When rats were given Nal-Glu-flutamide for 2 weeks before a 250 mg/kg dose of procarbazine, recovery of spermatogenesis, as measured by testis weight, testicular sperm head counts, and repopulation indexes, was significantly better than in control rats (no hormonal pretreatment). The protection achieved with Nal-Glu-flutamide was better than that achieved with 2 weeks of testosterone and estradiol treatment. The present results show that Nal-Glu-flutamide protects spermatogonial stem cells against procarbazine and suggest a method of hormonal pretreatment to achieve rapid and efficient protection of spermatogenesis in humans.

Animals↗
PubMed1995

Protection against procarbazine-induced testicular damage by GnRH-agonist and antiandrogen treatment in the rat.

Suppression of spermatogenesis in LBNF1 rats by treatment with the GnRH agonist Zoladex combined with the antiandrogen flutamide was evaluated in order to rapidly achieve protection of spermatogenic stem cells against procarbazine with clinically used drugs. Zoladex-flutamide treatment required 3 weeks to suppress the completion of spermatogenesis; only a small degree of suppression was observed with Zoladex alone. The suppression of spermatogenesis was reversible. In rats pretreated for 3 weeks with Zoladex-flutamide, the recovery of spermatogenesis at 9 weeks after a single injection of procarbazine as measured by testis weight, testicular sperm head counts, or a histological end point was significantly better than without hormonal pretreatment. Thus Zoladex-flutamide treatment enhanced the recovery of spermatogenesis from stem spermatogonia after procarbazine treatment in the rat and might be applicable to protect spermatogenesis in patients undergoing chemotherapy for cancer.

Androgen Antagonists↗
PubMed1995

Strength and power assessment. Issues, controversies and challenges.

Athletic strength and power refer to the forces or torques generated during sporting activity. Their assessment can be used for strength diagnosis or talent identification, to monitor the effects of training interventions and to estimate the relative significance of strength and power to particular athletic pursuits. However, strength and power assessment is a difficult task. Reasons for this include: the fledgling status of research within the area, our limited understanding of the mechanisms underpinning strength and power performance and development, and limitations associated with various forms of dynamometry. This article describes a frame work for the collection of data which may ultimately lead to recommendations for the assessment of strength and power in sporting contexts. Such a framework will be evolutionary and depends upon synergistic improvements in our understanding of: the physiological mechanisms underpinning strength and power development; the effect that various training regimens have upon the development of strength and power; and factors influencing the validity and reliability of dynamometry. Currently, isometric, isoinertial and isokinetic dynamometry are employed in assessment. Each form has its supporters and detractors. Basically, proponents and critics of isokinetic and isometric dynamometry emphasis their apparently high internal and apparently low external [corrected] validity respectively. While the converse applies for isoinertial dynamometry. It appears that all 3 modalities can have acceptable reliability, however this should be established rather than assumed, as the reliability of each can be threatened by a number of considerations (e.g. instruction for isometric tasks, the impact of weight used during weighted jumping tasks, and the effects of gravity and feedback on isokinetic performance). While reliability is a seminal issue in assessment, it is not the only critical issue. Specifically, there has been little research into the correlation between strength and power measures and athletic performance. This work is central to the use of such indices in talent identification. To date, this work has generally been limited to heterogeneous rather than homogeneous groups. More work is required in this area. Furthermore, not all modes of assessment are sensitive or similarly sensitive to various training interventions. This suggests that these modalities are measuring different neuromuscular qualities. How these qualities relate to performance requires more work, and will determine the contexts in which various strength and power assessment modalities and protocols are used.(ABSTRACT TRUNCATED AT 400 WORDS)

Biomechanical Phenomena↗
PubMed1995

Speech pattern audiometry for clinical use.

A new PC-based speech perception testing system ('speech pattern audiometer') is described which aims to provide a simple and efficient clinical tool to assess patients' ability to make use of the acoustic speech pattern information which is fundamental to speech perception. The speech pattern audiometer is likely to find its main application in audiology and speech and language therapy clinics with those who are deaf or who have developmental or acquired speech-perceptual disorders. This system constitutes a module of a complete speech and hearing assessment and teaching/therapy workstation.

Audiometry, Speech↗
PubMed1995

Planning for the future: the implementation of an automated clinical system.

Preparing for automation is as important to the whole automation process as choosing the correct system. Planning should start some time before actual purchase. Once the strategic planning is complete, staff can begin researching what applications are available, what they do, what vendors are reputable, etc. Then the agency can begin the actual implementation.

Ambulatory Care Information Systems↗
PubMed1995

Corneal epithelial fluorescein staining.

BACKGROUND: There is some difference of opinion in the literature about the nature of fluorescein staining of the epithelial surface. Most authors support the view that fluorescein staining is due to drop out of cells and pooling of fluorescein in the footprint. Others believe that fluorescein fills intercellular spaces. Others suggest that cells themselves stain with fluorescein. METHODS: Rabbit corneas were stained with fluorescein and examined with the biomicroscope and later with a higher magnification epifluorescent microscope following excision. RESULTS: Fluorescein staining was shown to be due to staining of individual cells. No evidence was found to support the contention that fluorescein resides in areas of cell drop out, or that staining was due to filling of intercellular spaces. Micropunctate staining is shown to be due to staining of cells in an optimum manner, which is referred to as hyperfluorescence. CONCLUSIONS: The recognition that fluorescein stains cells, even in the case of epithelial abrasion, allows reinterpretation of many staining phenomena, including "salt and pepper" staining.

Animals↗
PubMed1995

The efficacy of isokinetic, isometric and vertical jump tests in exercise science.

This research examined the efficacy of several tests of muscular strength and power in their capacity to be related to performance, their ability to effectively discriminate between individuals of different performance levels and their sensitivity in detecting training induced changes to performance. Thirty healthy active subjects performed the following maximal tests of muscular function: (1) Vertical jump; (2) Isokinetic knee extension at 1.05, 3.14 and 5.24 rads s-1; and (3) Isometric rate of force development. Performance was assessed by the peak power output achieved on a cycle test. In addition, subjects participated in a 10 week resistance training program. The isokinetic and vertical jump tests were significantly related to performance (r = 0.5-0.73) and could be used to discriminate between subjects of differing performance levels. However, the isometric rate of force development test was an ineffective assessment modality. None of the tests were able to effectively monitor training induced changes in performance, as evidenced by non-significant correlations between the pre- to post-percentage changes in cycling performance and the test variables. Consequently, alterations to training programs for athletes should be based on changes in actual performance, as opposed to muscular function tests.

Adult↗
PubMed1995

[Protection from procarbazine induced testicular toxicity by gonadal steroid hormones].

To confirm the claims that the procarbazines (PCZ) effect on stem spermatogonia can be overcome by gonadal steroid hormones,mature,LBNF1 male rats were implanted with silastic capsules containing testosterone (T 200 mm) + estradiol (E 50 mm). The silastic capsules of control and TE groups were removed 24 hours after the PCZ injection and the rats were sacrificed 9 weeks later. The functional status of the testis and the hormonal parameters at the time of the injection of PCZ were measured and correlated with the degree of protection ,as measured by the recovery of sperm counts. The results indicated that testosterone and estradiol does protect spermatogenesis from PCZ intoxification. To determine whether the protection is specific for stem spermatogonia, we also measured body weight loss 3-4 days, lymphocyte counts 1 day, and spermatocyte count 9 days after PCZ treatment. There were no differences in the dose response curves of these three assays between the hormone and sham treated rats. The lack of protection indicates that the hormonal protection of stem spermatogonia was not due to the alterations in either systemic or testicular pharmacokinetics of spermatocyte. We conclude that A3 spermatogonia and preleptotene spermatocyte are sensitive to PCZ and there is no evidence of hormonal protection for the differentiated spermatogonia and preleptotene spermatocyte.

Animals↗
PubMed1994

Barth syndrome: clinical observations and genetic linkage studies.

Barth syndrome is an X-linked recessive condition characterized by skeletal myopathy, cardiomyopathy, proportionate short stature, and recurrent neutropenia, but with normal cognitive function. Some, but not all patients, exhibit carnitine deficiency and/or the presence of 3-methylglutaconic and ethylhydracylic acids in urine. Recently the mutation causing Barth syndrome was localised to the Xq28 region by linkage analysis. We report 6 cases of Barth syndrome from 4 families and highlight the fact that neuromuscular and cardiovascular symptoms and the severity of infections tend to improve with age, while short stature persists. Also previously unreported was myopathic facies and nasal quality to speech in our cases. The urinary organic acid abnormalities and plasma carnitine deficiency were inconsistent findings. We propose that they may be epiphenomena rather than indicators of the primary metabolic defect, and that the primary defect or defects in this disorder may lie in the mitochondrial electron transport chain.

Abnormalities, Multiple↗
PubMed1994

Hormonal protection from procarbazine-induced testicular damage is selective for survival and recovery of stem spermatogonia.

Procarbazine produces long-term sterility in the male by killing stem spermatogonia. The degree and selectivity of protection of stem spermatogonia in rats from procarbazine by pretreatment with steroid hormones were investigated. Male LBNF1 rats were treated for 6 weeks with Silastic implants containing testosterone plus 17 beta-estradiol. The hormone-treated rats and sham-treated controls were given a single injection of graded doses of procarbazine and the hormone implants were removed the next day. Spermatogonial stem cell survival and function, assessed by the repopulation indices and sperm head counts 10 weeks later, showed that stem spermatogonia were protected by testosterone plus 17 beta-estradiol treatment from the toxic effects of procarbazine with a dose-modifying protection factor of about 2.5. In contrast, there was no hormonal protection from the procarbazine-induced killing of differentiating spermatogonia, preleptotene spermatocytes, and spermatocytes in meiotic prophase or from the delay in maturation of round spermatids, assessed 9 days after procarbazine injection by histological or flow cytometric methods. In addition, there was no hormonal protection from the procarbazine-induced decline in body weights and lymphocyte counts, indicating that the gastrointestinal, neurological, and hematological systems were not protected. The specificity of protection indicates that the hormonal protection of the stem spermatogonia is not the result of a systemic or overall testicular decrease in drug delivery, decrease in bioactivation, nor increase in drug detoxification, except possibly within the stem cells themselves. We conclude that the degree of hormonal protection and its specificity would be appropriate for clinical application provided that the mechanism of protection is elucidated and appears applicable to humans.

Animals↗
PubMed1994

Advanced cervical carcinoma presenting with toxic shock syndrome.

Toxic shock syndrome is a multisystem disease which presents with a high fever, rash, gastrointestinal symptoms, and hypotension. A 58-year-old woman presented to the emergency room with these symptoms, hypotension and tachycardia. Because of vaginal spotting a pelvic examination was performed which demonstrated vulvo/vaginal erythema and a large vaginal mass consistent with an advanced cervical cancer with bilateral pelvic sidewall fixation. Cervical/vaginal biopsy demonstrated invasive squamous cell carcinoma and an initial chest X ray demonstrated multiple pulmonary metastases. After a total of 8 days of antibiotic therapy the patient received cis-platinum chemotherapy. The toxic shock syndrome was the presenting symptomatology in this patient with advanced cervical cancer. Toxic shock syndrome has been associated with the use of hyperabsorbent tampons as well as numerous other gynecologic procedures but has not been reported in patients with gynecologic cancer.

Anti-Bacterial Agents↗
PubMed1994

Generality versus specificity: a comparison of dynamic and isometric measures of strength and speed-strength.

Considerable debate exists as to whether the qualities of muscle function exist as general or specific physiological capacities. If there is a generality of muscle function then strong relationships would exist between various measures of function for the same muscle(s), independent of the test contraction, mode or velocity. The purpose of this study was to examine the relationship between isometric and dynamic measures of muscle function to determine the existence of generality or specificity. A group of 22 men, experienced in weight training, were tested for lower and upper body dynamic and isometric measures of strength and speed-strength. The changes in these measures consequent to a resistance training programme were also investigated. The results of this study indicated that whilst isometric and dynamic measures of strength did significantly correlate (r = 0.57-0.61), the relationship was below that required to denote statistical generality. More important, the changes in isometric and dynamic strength consequent to a dynamic heavy resistance training programme were unrelated (r = 0.12-0.15). Thus the mechanisms that contribute to enhanced dynamic strength appeared unrelated to the mechanisms that contribute to enhanced isometric strength. Measures of dynamic and isometric speed-strength were unrelated, as were the changes in these measures resulting from training. The results of this study demonstrated that a generality of muscle function did not exist and that modality specific results were observed. Consequently this study calls into question the validity of isometric tests to monitor dynamically induced training adaptations.

Adult↗
PubMed1994

The Kabuki (Niikawa-Kuroki) syndrome: further delineation of the phenotype in 29 non-Japanese patients.

The Kabuki (Niikawa-Kuroki) syndrome was reported in 1981 by Niikawa et al. and Kuroki et al. in a total of ten unrelated Japanese children with a characteristic array of multiple congenital anomalies and mental retardation. The syndrome is characterized by a distinct face, mild to moderate mental retardation, postnatal growth retardation, dermatoglyphic and skeletal abnormalities. In Japan, the syndrome appears to have an incidence of about 1:32,000 newborns. Outside of Japan, a growing number of patients have been recognized. Clinical data are presented on 29 Caucasian patients; the patients were diagnosed over a relatively short period of time, indicating that the incidence outside of Japan is probably not lower than in Japan. A literature review of 89 patients (60 Japanese and 29 non-Japanese) is given. In 66% of the non-Japanese patients serious neurological problems were present, most notably hypotonia and feeding problems (which were not only related to the cleft palate); this was not reported in the Japanese patients. Inheritance is not clear. Most patients are isolated, sex-ratio is equal. The syndrome can be recognized in patients with cleft (lip/)palate, with mild to moderate developmental delay and in young children with hypotonia and/or feeding problems. In counselling parents, the designation "Kabuki" syndrome seems to be more appropriate than "Kabuki make-up" syndrome.

Abnormalities, Multiple↗
PubMed1994

Depression and unemployment: panel findings from the Epidemiologic Catchment Area study.

Studies that have found an association between unemployment and psychological depression often fail to establish the direction of causal influence. Analyses of Epidemiologic Catchment Area panel data revealed that of employed respondents not diagnosed with major depression at first interview, those who became unemployed had over twice the risk of increased depressive symptoms and of becoming clinically depressed as those who continued employed. Although the increase in symptoms was statistically significant, the effect on clinical depression was not, possibly because of the low power of the test. The reverse causal path from clinical depression at Time 1 to becoming unemployed by Time 2 was not supported. The unemployment rate in the respondent's community at time of interview was not related directly to psychological depression but appeared associated indirectly with depression via its impact on the risk of becoming unemployed. Implications for policy and further research were discussed.

Adult↗