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Biomedical subjects

A Dawson

Publications and source records attributed to A Dawson.

At least 19 recordsLinked to original sources
PubMed1992

Familial mesothelioma. Details of 17 cases with histopathologic findings and mineral analysis.

Nine new cases of mesothelioma clustering in four families are described, and additional information is provided on four previously reported families. All of the members of these families had some exposure to asbestos. Diagnoses were confirmed histologically, and the relevance of the histologic pattern is discussed after the literature review. The lung mineral fiber burden was quantified in patients by transmission electron microscopic examination and energy-dispersive x-ray analysis, and this confirmed significant exposure to amphibole asbestos in all patients. Evidence supporting an increased incidence of mesothelioma in family members is discussed.

Aged↗
PubMed1992

Efficacy of traditional Chinese herbal therapy in adult atopic dermatitis.

There has been considerable interest in traditional Chinese herbal therapy (TCHT) as a new treatment for atopic dermatitis. To establish the efficacy and safety of this treatment, a daily decoction of a formula containing ten herbs that has been found to be beneficial in open studies was tested in a double-blind placebo-controlled study. 40 adult patients with longstanding, refractory, widespread, atopic dermatitis were randomised into two groups to receive 2 months' treatment of either the active formulation of herbs (TCHT) or placebo herbs, followed by a crossover to the other treatment after a 4-week washout period. The main outcome measures were extent and severity of erythema and surface damage as judged by standardised body scores. The patients' own assessments of the overall response to treatment were also sought. The geometric mean score for erythema at the end of active treatment was 12.6 (95% confidence interval [CI] 5.9 to 22.0) and at the end of the placebo phase was 113 (65 to 180). The geometric mean score for surface damage was 11.3 (5.8 to 21.8) and 111.0 (68 to 182), respectively. The 95% CI for the mean geometric ratio for the two values with active treatment was 0.04 to 0.22 for erythema (p less than 0.0005) and 0.04 to 0.27 for surface damage (p less than 0.0005). Of the 31 patients who completed the study and expressed a preference, 20 preferred that phase of the trial in which they received TCHT whereas 4 patients preferred placebo (p less than 0.02). There was a subjective improvement in itching (p less than 0.001) and sleep (p less than 0.078) during the TCHT treatment phase. No side-effects were reported by the patients although many commented on the unpalatability of the decoction. TCHT seems to benefit patients with atopic dermatitis. Palatability of the treatment needs to be improved and its safety assured.

Administration, Oral↗
PubMed1992

Nuclear factor I is specifically targeted to discrete subnuclear sites in adenovirus type 2-infected cells.

During the S phase of the eukaryotic cell cycle and in virus-infected cells, DNA replication takes place at discrete sites in the nucleus, although it is not clear how the proteins involved in the replicative process are directed to these sites. Nuclear factor I is a cellular, sequence-specific DNA-binding protein utilized by adenovirus type 2 to facilitate the assembly of a nucleoprotein complex at the viral origin of DNA replication. Immunofluorescence experiments reveal that in uninfected cells, nuclear factor I is distributed evenly throughout the nucleus. However, after a cell is infected with adenovirus type 2, the distribution of nuclear factor I is dramatically altered, being colocalized with the viral DNA-binding protein in a limited number of subnuclear sites which bromodeoxyuridine pulse-labeling experiments have identified as sites of viral DNA replication. Experiments with adenovirus type 4, which does not require nuclear factor I for viral DNA replication, indicate that although the adenovirus type 4 DNA-binding protein is localized to discrete nuclear sites, this does not result in the redistribution of nuclear factor I. Localization of nuclear factor I to discrete subnuclear sites is therefore likely to represent a specific targeting event that reflects the requirement for nuclear factor I in adenovirus type 2 DNA replication.

Adenovirus Infections, Human↗
PubMed1992

Puberty in birds: the reproductive system of starlings does not respond to short days until birds are fully grown.

If adult starlings are kept on long days, they rapidly become refractory to long days (photorefractory). The recovery of the ability to respond to long days (photosensitivity) occurs after transfer to short days. Photosensitivity is associated with an increase in hypothalamic content of gonadotrophin-releasing hormone (GnRH), and, in castrated birds, with an increase in plasma LH. If photorefractory adult or juvenile starlings are transferred to short days, these events begin 3 and 4 weeks respectively after transfer. Starlings apparently hatch in a photorefractory state. However, if nestlings are hand-reared under short days, the increases in GnRH and LH begin at 6 and 7 weeks of age respectively. In this 3-week delay, which corresponds to the time to reach adult body size, simply due to a slower response, or are nestlings incapable of responding to short days until fully grown? Castrated male nestling starlings were hand-reared under short days, under long days or under long days initially and transferred to short days at 2, 3, 6 or 9.5 weeks of age. The increase in plasma LH in birds transferred to short days at or before 3 weeks began at the same time as in birds kept on short days (7 weeks). In birds transferred at 3 weeks or later, the increase in LH began 4 weeks after transfer, irrespective of age. Intact female starlings showed similar responses. Birds kept on short days did not moult whereas birds transferred from long days to short days at 3 weeks did.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Enzyme replacement therapy for Gaucher disease.

Four patients with moderately severe type I Gaucher disease were treated with commercially available mannose terminated glucocerebrosidase (Ceredase; Genzyme, Boston, MA) for up to 13 months. The enzyme was administered at the rate of three to four times weekly at one fourth the total recommended dosage, greatly decreasing the cost. Marked regression of hepatomegaly and improvement in liver function tests, peripheral blood counts, and serum angiotensin-converting enzyme levels were documented. The two patients with pulmonary involvement manifested improvement in pulmonary function tests. Skeletal disease remained unchanged.

Adult↗
PubMed1991

Reactivity of the workshop monoclonal antibodies with ovine bone marrow cells and bone marrow-derived monocyte/macrophage and mast cell lines.

The workshop monoclonal antibodies were tested by flow cytometry for reactivity against: (1) ovine bone marrow cells, (2) cultured bone marrow-derived monocyte/macrophage cell lines and (3) cultured bone marrow-derived mast cell lines. Both single and two-colour immunofluorescence tests were performed. The results of these analyses are presented and discussed.

Animals↗
PubMed1991

Effect of daylength on the rate of recovery of photosensitivity in male starlings (Sturnus vulgaris).

Four groups of castrated photorefractory starlings were transferred from a photoperiod of 18 h light/day (18 L) to photoperiods of 6 L, 8 L, 11 L or 12 L. A control group was kept on 18 L. Plasma concentrations of luteinizing hormone (LH) were low in all groups initially. The first significant increase in LH, which signals the recovery of photosensitivity, occurred after 4 weeks in the groups on 6 L and 8 L, after 8 weeks in the 11 L group and after 13 weeks in the 12 L group. There was no increase in the group on 18 L. The rate of recovery of photosensitivity is therefore inversely proportional to daylength, for daylengths between 8 L and 12 L.

Animals↗
PubMed1990

Carotid endarterectomy under cervical plexus block--a prospective clinical audit.

One hundred and twenty-eight patients having carotid endarterectomy under superficial and deep cervical plexus blocks were prospectively audited. The aim of the audit was to determine the incidence of intra-operative and postoperative neurological and cardiovascular complications and to establish patient acceptance of the technique. Twenty-seven patients who had intra-operative neurological changes following carotid artery clamping responded to shunt insertion. Six patients had transient neurological changes after the operation but there were no permanent neurological complications. Tachycardia (55%) and hypertension (67%) were the most common intra-operative cardiovascular changes and there was one clinical postoperative myocardial infarction. Ninety-two per cent of patients who could be adequately assessed preferred to have the same method of anaesthesia for future carotid endarterectomy. The authors concluded that carotid endarterectomy under superficial and deep cervical plexus blocks was associated with a high patient acceptance, low neurological complication rate and an acceptable rate of cardiovascular complications.

Aged↗
PubMed1989

GTP causes calcium release from a plant microsomal fraction.

Studies on a variety of animal cell types have revealed a GTP-specific calcium-releasing mechanism in a non-mitochondrial, microsomal fraction. Here we report that GTP also induces rapid release of calcium from a zucchini (Cucurbita pepo L.) hypocotyl microsomal fraction. Maximal release occurs at 50 microM, and half-maximal release at 8 microM GTP. GTP is highly specific in its effect, and may not be replaced by UTP, ATP, CTP, TTP, GMP, or by non-hydrolysable analogues of GTP. Reuptake of calcium after release does not normally occur; however, this may be induced by non-hydrolysable GTP analogues. Calcium release is also blocked by prior treatment with these analogues.

Adenosine Triphosphate↗
PubMed1989

Neuroleptic malignant syndrome: a case report with post-mortem brain and muscle pathology.

The neuroleptic malignant syndrome is a rare but dangerous complication of treatment with neuroleptics. The aetiology and pathophysiology of the syndrome are reviewed, and a fatal case is presented where both brain and muscle pathology are described. Striking myopathic changes in this case, accompanied by only minimal and non-specific brain abnormalities, support a peripheral rather than central mechanism for the hyperthermia.

Aged↗
PubMed1989

Sexual maturation in starlings raised on long or short days: changes in hypothalamic gonadotrophin-releasing hormone and plasma LH concentrations.

Is the extended prepubertal period which occurs in most birds due to a juvenile photorefractoriness analogous to photorefractoriness in adults? Starlings were taken from nest boxes 4 days after hatching and hand-reared on long days or short days. In females on long days, hypothalamic gonadotrophin-releasing hormone (GnRH) content and plasma LH concentration remained low. In intact males on long days, plasma LH remained low and the testes remained small, and in castrated birds, plasma LH also remained low. In females reared on short days, hypothalamic GnRH content began to increase dramatically from 4 weeks of age and plasma LH increased from 6 weeks of age. In intact males on short days, there was a slight increase in plasma LH and testicular size, and in castrated males, plasma LH increased markedly from six weeks of age. All birds on long days moulted into adult plumage, whereas those on short days retained juvenile plumage. The changes in birds reared on short days were similar to those found when photorefractory adult birds are transferred to short days. This adds to the evidence that juvenile photorefractoriness is analogous to photorefractoriness in adults, and therefore that the seasonal termination of photorefractoriness is an annual puberty. However, the responses to short days occur later in birds raised on short days than in older birds transferred to short days, which suggests either that short day-induced changes occur more slowly in young birds, or that birds only respond to short days after a certain age.

Aging↗
PubMed1979

A comparison of the effects of labetalol, bendrofluazide and their combination in hypertension.

1 Bendrofluazide (10 mg/day) or labetalol (300 mg and 600 mg/day) produced significant reductions in lying, standing, and post-exercise blood pressure in ten hypertensives. 2 Active treatments were approximately equivalent in anti-hypertensive effect. However, comparing lying and standing determinations, labetalol (600 mg/day) produced significantly greater additional postural falls in systolic blood pressure than during placebo or bendrofluazide treatment. 3 Systolic blood pressure rose after exercise during placebo or bendrofluazide treatment. However, on labetalol, mean changes in systolic blood pressure after exercise were negative and significantly different from those seen on placebo. 4 Greater reductions in lying and post-exercise systolic blood pressure were produced by combination treatment than by either individual drug. Additional postural and exercise-related falls in systolic blood pressure tended to be smaller with combination treatment than during treatment with labetalol alone. 5 Labetalol significantly reduced lying, standing, or post-exercise heart rate by comparison with placebo or bendrofluazide. 6 Labetalol significantly reduced lying, standing, or post-exercise heart rate by comparison with placebo or bendrofluazide. 6 Labetalol moderately reduced plasma renin activity, whereas bendrofluazide caused marked elevation. The effect of bendrofluazide predominated during combination treatment.

Adult↗