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Biomedical subjects

K Thomas

Publications and source records attributed to K Thomas.

At least 181 records · Page 10Linked to original sources
PubMed1994

Osteomalacia--fifty five patients seen in a teaching institution over a 4 year period.

A retrospective analysis of 55 cases of osteomalacia shows that poor calcium intake and poor sunlight exposure are the most common causes for osteomalacia. However, in patients with normal nutritional history, other disorders such as renal tubular acidosis and tumour induced osteomalacia should be looked for. A careful drug history, particularly anticonvulsant use is essential. In 4 patients there was an association between anti-tuberculous drug use and osteomalacia. Further prospective studies are needed to determine the relationship between Rifamicin use and osteomalacia.

Adult↗
PubMed1994

Quality of minor surgery by general practitioners in 1990 and 1991.

BACKGROUND: The 1990 contract for general practitioners encouraged them to undertake minor surgical procedures in their practices. AIM: A study was undertaken to determine whether the subsequent expansion of general practitioner minor surgery activity was accompanied by changes in quality of care. METHOD: Data were analysed relating to minor operations conducted in 22 practices during April-June 1990 and April-June 1991. RESULTS: The volume of general practitioner minor surgery increased by 41% between the two study periods. Waiting time, accuracy of diagnosis, use of histology, adequacy of excision, complications and the need for corrective treatment in hospital did not change significantly between the two periods. CONCLUSION: The findings do not support suggestions that the expansion of general practitioner minor surgery activity following the 1990 contract has been associated with an erosion of quality of care.

Clinical Competence↗
PubMed1994

Thermoregulation in neonates.

Thermoregulation is a critical physiologic function that is closely related to the transition and survival of the infant. An understanding of transitional events and the physiologic adaptations that neonates must make is essential to helping the nurse provide an appropriate environment and help infants maintain thermal stability. This article reviews neonatal thermal regulation, heat loss and gain, and the thermal response that is generated when thermal stability is threatened.

Adaptation, Physiological↗
PubMed1993

A regression model for the rate of success of in vitro fertilization.

The treatment of infertility by in vitro fertilization involves several aspects of human reproductive physiology. Since failures are still numerous and since improved techniques are becoming increasingly available, it is important to develop a model where the components of success are identified, allowing estimation of the occurrence of these components of success in the infertile population. The model of Speirs reduces these components to two: uterine receptivity and embryo viability. The probabilities of uterine receptivity and embryo viability were estimated here in a retrospective study of patients in a Belgian hospital sample. For comparison, Australian and U.S. data were used. It was shown that the estimate of uterine receptivity for the Belgian sample is located between the estimates for Australian and U.S. samples. In view of the psychological problem of repeated unsuccessful attempts at in vitro fertilization in some patients, it is important to be able to single out some prognostic factors that would allow more precise estimation of the probability for success in each case. A regression method was developed for that purpose. Only the effect of age, in the Belgian sample, was found to influence uterine receptivity significantly.

Adult↗
PubMed1993

Minor surgery by general practitioners under the 1990 contract: effects on hospital workload.

OBJECTIVE: To determine the extent to which minor surgery undertaken by general practitioners after the introduction of the 1990 contract substituted for hospital outpatient workload. DESIGN: Before and after observational study. SETTING: Four English family health services authorities. SUBJECTS: Patients in 22 practice populations who were operated on by their general practitioner or referred to hospital for minor surgery during April to June 1990 or April to June 1991. MAIN OUTCOME MEASURES: Numbers of minor surgical procedures undertaken in general practice and in hospital, numbers of referrals to hospitals for conditions treatable by a minor surgical procedure, and the mix of diagnoses and procedures undertaken in each setting. RESULTS: General practitioners claimed reimbursement for 600 minor surgical procedures during April to June 1990 and for 847 during April to June 1991, an increase of 41%. Referrals to hospital for comparable conditions showed no compensatory decrease (385 during April to June 1990 and 388 during April to June 1991, 95% confidence interval for change in referrals -51 to 57), and the number of hospital procedures resulting from those referrals also remained constant (187 in the first period, 189 in the second, 95% confidence interval for change in procedures -36 to 40). The mix of procedures did not change significantly from one study period to the next in either setting. CONCLUSIONS: Many or all of the additional patients receiving minor surgery under the terms of the 1990 contract may not have previously been referred to hospital. General practitioners seem not to have systematically shifted towards treating the more trivial cases. The overall increase in minor surgical activity may reflect an improvement in accessibility of care or changes in patients' perceptions and attitudes.

Contract Services↗
PubMed1993

Locative prepositional phrases in severe aphasia.

Six severely aphasic patients were trained on C-VIC, a computerized alternative communication system. Patients with both global and Broca's aphasia were able to produce and comprehend locative prepositions using C-VIC. The Broca's aphasic patients were able to produce and interpret symbol order correctly in C-VIC locative prepositional phrases, despite their difficulties in performing the same tasks using English. One patient's verbal production of locative prepositional phrases improved markedly after C-VIC training. These results suggest that the "mapping" impairment suffered by some Broca's aphasics may be ameliorated by use of alternative communication system, such as C-VIC.

Aphasia↗
PubMed1993

The effect of salbutamol controlled release on airways responsiveness to inhaled methacholine in mild asthmatic subjects.

Single doses of inhaled bronchodilating agents have been shown to reduce airways responsiveness (AR) in both normal and asthmatic individuals. The longer term effects of these treatments on airways responsiveness are less clear. We have studied the effects of 4 weeks of treatment with oral salbutamol controlled release (SCR) (8 mg b.d.) on airways responsiveness in mild asthmatics in a double-blind, placebo-controlled study. Airways responsiveness to inhaled methacholine, baseline FEV1 and plasma salbutamol levels was assessed 6 h, 48 h and 4 weeks after commencing treatment and again 24 h and 72 h after cessation of medication. When compared to placebo, SCR significantly attenuated AR at the 48-h time point only. There were no increases in AR recorded at any of the post-treatment time points. In addition, there were no significant differences in baseline FEV1 at any of the time-points studied, when compared to placebo. The change in AR at 48 h after starting treatment was probably due to functional antagonism of smooth muscle contraction. Importantly, there were no increases in AR recorded at either of the post-treatment time points.

Adult↗
PubMed1993

An improved clinical method for detecting meningeal irritation.

Neck stiffness is the most important sign of meningitis. When the neck is flexed, the inflamed nerve roots and meninges of the cervical region get stretched. This causes protective muscle spasm manifesting as neck stiffness. Kernig's sign represents similar phenomena involving the distal spinal cord and related nerves. A manoeuvre that stretches the neural elements of the whole length of the spinal canal simultaneously will be a more sensitive test for meningeal irritation. Eliciting neck stiffness while the patient sits up with knees extended achieves this. This method is more sensitive, specific, and amenable to objective assessment.

Child↗
PubMed1993

Effects of hyaluronate, strontium and prolonged incubation on different sperm parameters.

The aim of this study was to evaluate the effect of hyaluronate and strontium with short and prolonged incubation periods on different sperm parameters. For sperm intended for in vitro fertilization good progressive motility, a high percentage of normal form, a suitable linear velocity and a low acrosome-reacted proportion of sperm are required. The semen washing procedure in the self-migration method with medium containing hyaluronate Ca2+ after 3 h of incubation complies better with these criteria.

Acrosome↗
PubMed1993

Prostaglandins stimulate the secretion of inhibin from human placental cells.

In this study, the effects of prostaglandins (PGs) on inhibin secretion were investigated in primary culture of human placental cells. Isolated trophoblast cells were cultured for 2-5 days with PGE1, PGE2, 6-keto-PGF1 alpha, PGF2 alpha, and thromboxane B2. Inhibin levels in the culture medium were measured by immunoenzymatic assay. PGs significantly stimulated inhibin secretion in the cell culture. The addition of PGs (1 nM to 10 microM) to the culture resulted in dose-dependent increases in inhibin levels in the medium. At a dose of 10 microM, inhibin levels in the medium were increased by 35.2-172.5% compared to the control value. Compared with the efficacies of these PGs, PGE2 and PGF2 alpha enhanced inhibin secretion more potently than other tested PGs. A close correlation between the effects of PGs and the number of trophoblasts seeded in the culture was observed, with an optimal response of the cells to PGs at 1.0-2.0 x 10(6) cells/well. Time-course studies showed that a significant increment in inhibin levels in the PG-treated culture occurred after 48-120 h, but not during the first 24 h, of the culture, indicating a possible involvement of PGs in inhibin biosynthesis in the cells. Epidermal growth factor (EGF) could enhance PG-stimulated inhibin releases in the cell culture. Treatment with EGF (100 ng/mL) increased inhibin in the medium by 83.3% (ED50) in the presence of PGE2 or by 70.3% (ED50) in the presence of PGF2 alpha compared to the control values. The addition of 8-bromo-cAMP (100 microM) and cholera toxin (1000 ng/mL) to the culture also enhanced basal and PG-induced inhibin secretion, but the addition of the 4-bromo-calcium ionophore A23187 (1 microM) did not alter inhibin releases, suggesting that the stimulatory effects of PGs on inhibin secretion in placental cells may be mediated through the cAMP pathway. In the cell cultures treated with PGE and PGF2 alpha, there was no change in cell growth or intracellular DNA content, as measured by 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide assay and DNA determination with fluorescence spectrophotometry. Morphological studies showed that PGE2 alpha (1 microM), alone or combined with EGF (100 ng/mL), significantly accelerated the process of differentiation from cytotrophoblasts to syncytiotrophoblasts, indicating that the actions of PGs may be related to their effects on syncytial transformation, rather than cellular proliferation.(ABSTRACT TRUNCATED AT 400 WORDS)

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1993

Regulation of inhibin secretion in human placental cell culture by epidermal growth factor, transforming growth factors, and activin.

In this study, the effects of epidermal growth factor (EGF), transforming growth factor-alpha (TGF alpha), TGF beta 1, and activin-A on inhibin secretion were investigated in primary culture of human placental cells. Immunoreactive inhibin in the culture medium was measured by immunoenzymatic assay. EGF stimulated testosterone-induced inhibin secretion in placental cells. Although testosterone alone induced only a slight enhancement of inhibin release in the culture, treatment of trophoblast cells with EGF and testosterone caused a significant increase in inhibin secretion, with immunoreactive inhibin levels much higher than those of testosterone or EGF alone. TGF alpha combined with human placental lactogen (hPL) had a stimulatory effect on inhibin secretion in placental cell culture. Simple addition of either TGF alpha or hPL to the culture did not show any effect on inhibin secretion in placental cells. A remarkable augmentation of inhibin secretion was obtained after the trophoblasts were exposed to both TGF alpha and hPL simultaneously. TGF beta 1 and activin-A showed synergistic effects to suppress inhibin secretion in placental cells. TGF beta 1 alone did not show any action on inhibin secretion, and activin-A alone induced a small decrease in inhibin release in the culture. In the presence of activin-A, addition of TGF beta 1 to the culture induced a profound decrease in immunoreactive inhibin levels in the medium. Activin-A could also suppress hCG-induced inhibin secretion in placental cells. Addition of hCG alone resulted in a small, but not significant, increase in inhibin release in the cultured cells, whereas the presence of activin-A combined with hCG in the culture conversely decreased inhibin secretion in the culture, with immunoreactive inhibin levels significantly lower than those in the presence of hCG or activin-A alone. These findings suggest that EGF and TGF alpha, alone or in combination with other hormones, may be stimulators, and TGF beta and activin may act as suppressors of inhibin secretion in human placental cells.

Activins↗
PubMed1993

Profuse epistaxis: an argument for conservative medical management.

A review of 10 years' experience of all patients with profuse epistaxis requiring hospitalisation in a tertiary care centre in India is presented. There were 106 patients among which only 72% of cases had associated medical illness. Hypertension (44%) and bleeding diathesis (11%) were found to be the most frequently associated aetiological medical conditions noted in this study. Although there is controversy regarding the optimum treatment in profuse epistaxis in literature, our experience suggests that it can be successfully managed with conservative medical management alone and surgical intervention with its potential complications may not be necessary in most cases.

Adolescent↗
PubMed1993

Effect of an educational intervention on nurses' knowledge of a peritoneal dialysis cycler.

The effect of an innovative educational technique using pocket-sized problem-solving cards on staff nurses' knowledge of the peritoneal dialysis cycler was examined. While there was no significant difference on knowledge scores between the experimental and control groups, a significant difference was found on pretest and posttest scores when the groups were combined.

Education, Nursing, Continuing↗
PubMed1992

The C. elegans genome sequencing project: a beginning.

The long-term goal of this project is the elucidation of the complete sequence of the Caenorhabditis elegans genome. During the first year methods have been developed and a strategy implemented that is amenable to large-scale sequencing. The three cosmids sequenced in this initial phase are surprisingly rich in genes, many of which have mammalian homologues.

Animals↗
PubMed1992

Topical glucocorticoids inhibit activation by allergen in the upper respiratory tract.

We have studied the effect of a topically administered glucocorticoid, fluticasone propionate (FP), on infiltration and activation of eosinophils in the nasal mucosa after provocation with allergen. Forty-four patients with seasonal allergic rhinitis entered a double-blind, crossover study in which they underwent treatment with either FP (200 micrograms once daily) or identical placebo for 2 weeks. Patients then underwent nasal-allergen provocation followed by nasal lavage and biopsy at one of several time points between 0 and 8 hours. Patients subsequently received the alternate treatment for 2 weeks before repeat allergen provocation, nasal lavage, and biopsy, as before. Biopsy specimens of nasal mucosa obtained during the immediate allergic response demonstrated an influx of eosinophils (stained by monoclonal antibody EG1) of similar magnitude during both FP and placebo treatment. Significantly, fewer eosinophils in these biopsy specimens were activated (stained by monoclonal antibody EG2) after treatment with FP compared with that after placebo treatment (median values, 8.8 and 36.6 cells per square millimeter, respectively; p less than 0.02). The concentration of eosinophil cationic protein in nasal lavage fluid was significantly elevated above baseline from 2 to 8 hours after allergen, and this increase was abolished by treatment with FP. These results suggest that topical glucocorticoids inhibit allergen-induced activation of eosinophils in allergic rhinitis.

Administration, Topical↗
PubMed1992

Circhoral fluctuations of serum total renin, inhibin and related hormones around the mid-cycle in normal human females.

Total renin and inhibin are secreted by the ovary. Although luteinizing hormone (LH) and/or follicle stimulating hormone (FSH) may stimulate their secretion, the close relationship between fluctuations of gonadotrophins, oestradiol, progesterone, renin and inhibin during the cycle is still conjectural. To investigate the temporal relationship between the short-term fluctuations in the circulating concentrations of LH and FSH and the ovarian hormones (oestradiol, progesterone, renin and inhibin), blood samples were collected at 15-min intervals for 6 h from 15 normal women in the late follicular (n = 4), early luteal (n = 5) or luteal (n = 6) phases of the menstrual cycle. LH levels showed the well-known pulsatile secretion with decreasing frequency and increasing relative amplitude from the late follicular to the luteal phase. Progesterone and oestradiol serum levels were pulsatile, 25% and 35-50% of which were linked to LH pulses, with time lags of 30 and 12-15 min respectively. Renin levels presented significant pulses, 26% of which were related to LH pulses with a time lag of less than 10 min; no coincidence was found between renin and oestradiol pulses. Inhibin levels presented only scattered pulses of small amplitude, which were unrelated to LH or FSH. These results show that, besides the LH-related pulses, pulsatile secretion of some ovarian hormones (oestradiol, progesterone and renin) may also occur independently of LH pulses and may be unrelated to one another. Moreover, contrary to the other ovarian hormones, inhibin seems to follow a tonic, not a pulsatile type of secretion around the mid-cycle.

Adult↗