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Biomedical subjects

M Collins

Publications and source records attributed to M Collins.

At least 37 records · Page 2Linked to original sources
PubMed1992

Rothmund-Thomson syndrome: review of the world literature.

Rothmund-Thomson syndrome is a rare, inherited disorder characterized by poikilodermatous skin changes that appear in infancy. The inheritance is autosomal recessive. Patients exhibit variable features including skeletal abnormalities, juvenile cataracts, and a higher than expected incidence of malignancy. This extensive review of the world literature clarifies aspects of the inheritance, incidence of characteristic features, and malignant potential of this disease. Insight into its origin is provided through a review of the clinical and in vitro studies of endocrine function and possible DNA repair abnormalities.

Adolescent↗
PubMed1992

Prostaglandin E2 gel induction of patients with a prior low transverse cesarean section.

To determine safety and efficacy of induction with prostaglandin E2 gel, we compared the outcome of 25 patients (study group) with an unfavorable cervix, a medical indication for delivery, and one prior low cervical transverse cesarean section to 56 patients (comparison group) with one prior low cervical transverse cesarean section and spontaneous labor. We placed 1 mg of prostaglandin E2 in gel intracervically in the 25 study patients. Common indications for delivery were: diabetes, post dates, and preeclampsia. Although most labor and delivery variables were similar, the study group had a longer mean latent phase (14.2 +/- 13.8 versus 7.3 +/- 3.7 hours: p less than 0.002), but had a shorter mean length of active phase (4.0 +/- 3.5 versus 5.7 +/- 3.0 hours; p less than 0.02). None of the patients in either group had a dehiscence of the uterine scar, nor rupture of the uterus. Both groups had a similar cesarean section rate. Since from the few reported, nonrandomized studies it appears that prostaglandin E2 gel use in patients with a prior low cervical transverse cesarean section may be useful and relatively safe, it may be time to attempt randomized trials of prostaglandin E2 gel versus oxytocin for induction of patients with a prior low cervical transverse cesarean section, unfavorable cervix, and a medical indication for delivery.

Adult↗
PubMed1992

Visceral leishmaniasis in the BALB/c mouse: antimony tissue disposition and parasite suppression after the administration of free stibogluconate.

BALB/c mice with an acute or chronic Leishmania donovani infection were treated with intravenous sodium stibogluconate solution and the parasite suppressions determined in the spleen, liver and femur bone marrow. Antimony concentrations in these and other tissues were determined by hydride generation-atomic absorption spectrophotometry. There was little correlation between tissue antimony levels one hour after treatment and drug efficacy. It would appear that the peak tissue antimony concentration achieved soon after dosing, rather than the lower concentrations which are readily sustained in most tissues, is the most important factor in the antileishmanial activity of stibogluconate. A high peak antimony concentration occurred in the liver, where parasites were significantly suppressed, and was not observed in the two other sites of infection, where the parasites were apparently less susceptible to stibogluconate therapy.

Acute Disease↗
PubMed1992

Controlled trial using computerized feedback to improve physicians' diagnostic judgments.

The goal of this study was to test an innovative method to improve physicians' diagnostic judgments by integrating the use of a computer program (employing cognitive feedback to teach a clinical rule that predicts the probability of streptococcal pharyngitis), a traditional lecture, and periodic disease-prevalence reports. In a controlled trial using pre- and postintervention measures involving 885 patients, the authors compared the effects of the integrated method on the diagnostic judgments of seven experienced physicians at a university health service (from 1982 to 1985) with the effects of the lecture alone on the judgments of seven experienced physicians at a different university health service (1986 to 1987). The integrated method significantly improved the quality of the physicians' judgments as measured by calibration curves and Brier scores, and increased the level of agreement between the physicians' judgments and those made by the clinical prediction rule. The lecture alone produced less improvement in the quality of the physicians' judgments, and decreased the level of agreement with the rule. The authors conclude that this method, based on cognitive psychology, is a promising educational tool.

Computer-Assisted Instruction↗
PubMed1992

Human papillomavirus type 16 E5 gene stimulates the transforming activity of the epidermal growth factor receptor.

We have until recently made several unsuccessful attempts to assign any activity to the human papillomavirus type 16 (HPV-16) E5 gene product. However, studies with the bovine papilloma virus 1 (BPV-1) E5 protein indicated an interaction with the epidermal growth factor receptor (EGFR). In light of the overall similarity between the HPV and BPV E5 proteins we attempted to determine whether the HPV-16 E5 gene had any common activity. In cells expressing high levels of EGFR plus HPV-16 E5 we found a dramatically increased proliferative activity in soft-agar assays in the presence of EGF. The specificity of this activity was monitored by the addition of other mitogenic agents. The phorbol ester phorbol 12-myristate 13-acetate (PMA) had no effect on the E5-containing cells, although insulin weakly stimulated their growth in soft agar. Further analysis revealed the same number of EGF receptors were present on the E5-containing cells as on the control cells, although the E5 cells were more sensitive to lower concentrations of EGF. These results imply that E5 is amplifying the mitogenic signals from the EGFR in an as yet unknown manner, but which may form the basis of interactions with a variety of growth factor receptors. This report brings to three the number of transforming genes encoded by HPV-16.

3T3 Cells↗
PubMed1992

Iron and nutritional status of toddlers.

The iron and nutritional status of 22 clinically well and normal toddlers, aged from one to four years inclusive was determined. Mean energy intake was normal. Protein, fibre and ascorbic acid intakes were high. Total iron intake was low in 73%, and available iron was low in 96%. The percentage availability of the total iron intake was 6.98 +/- 1.2, which is below the 10% assumption of iron availability based on consumption of the recommended daily allowances. Mean haemoglobin was with in the normal range. Low normal serum ferritin suggested poor iron stores. Anthropometric measurements were normal. Although the toddlers; intake of most dietary parameters was normal, the finding of poor iron intake and stores is of concern given recent reports of the role of iron in weight gain and psychomotor development.

Child Nutritional Physiological Phenomena↗
PubMed1991

An exon 5-deleted mRNA encodes a functional interleukin 2 receptor alpha-subunit.

Two polypeptides are involved in interleukin 2 binding: a low-affinity receptor of 55 kD (IL2-R alpha) and an intermediate affinity component of 75 kD (IL2-R beta). We describe the cloning by the Polymerase Chain Reaction of the coding region of IL2-R alpha from a human T-cell lymphoma cell line. One clone presented a 72-bp deletion that precisely corresponds to exon 5. The deleted form and the normal IL2-R alpha cDNA were expressed CHO cells. Stable transfected cellular clones were compared for their immunoreactivity to monoclonal antibodies directed against IL2-R alpha and for their ability to bind radiolabeled IL2. The presence or absence of the protein region encoded by exon 5 did not modify the IL2-binding capacity of the receptor.

Amino Acid Sequence↗
PubMed1991

T-cell receptor alpha chain plays a critical role in antigen-specific suppressor cell function.

Antigen-specific suppressor T-cell hybridomas release soluble suppressor factors (TsF) in the supernatant that modulate both in vivo delayed-type hypersensitivity and in vitro plaque-forming cell responses in an antigen-specific manner. To study the relationship between the T-cell receptor (TcR) and TsF, we developed a series of TcR alpha- or TcR beta- expression variants from suppressor T-cell hybridomas that expressed the CD3-TcR alpha/beta complex. We demonstrate that loss of TcR alpha but not TcR beta mRNA was accompanied by the concomitant loss of suppressor bioactivity. Homologous transfection of TcR alpha cDNA into a TcR alpha- beta+ clone reconstituted both CD3-TcR expression and suppressor function. Furthermore, suppressor activity from TcR beta- variants was specifically absorbed by antigen and anti-TcR alpha antibodies, but not by anti-CD3 or anti-TcR beta affinity columns. These data directly establish a role for the TcR alpha chain in suppressor T-cell function and suggest that the TcR alpha chain is part of the antigen-specific TsF molecule.

Animals↗
PubMed1991

Molecular cloning in Lactobacillus helveticus by plasmid pSA3::pVA797 co-integrate formation and conjugal transfer.

A gene encoding beta-glucanase activity from Bacillus amyloliquefaciens was subcloned in both orientations into plasmid shuttle vector pSA3. In only one orientation could a co-integrate be generated with the conjugative plasmid pVA797. The plasmid co-integrate was conjugated into Lactobacillus helveticus strain CNRZ450, where it was stably maintained without antibiotic selection and exhibited beta-glucanase activity. This method of introducing cloned DNA into thermophilic lactobacilli will facilitate the study of heterologous gene expression in non-transformable species.

Cloning, Molecular↗
PubMed1991

A comparison of fasting serum amino acid profiles of young and elderly subjects.

The fasting serum amino acid profile in 37 healthy young women and men (30-35 years) was compared with the fasting profile in 30 institutionalized elderly women and men (80-89 years), an ambulatory, self-fed senior-residence group. Levels of serum lysine, leucine, methionine, valine, and total essential amino acids were significantly lower in the older group than in the younger group; however, citrulline and hydroxyproline were significantly higher in the older group compared to the younger group. Histidine, threonine, tryptophan, and the ratio of tryptophan to large neutral amino acids (isoleucine, leucine, phenylalanine, tyrosine, and valine) were also generally lower in the older group than in the younger group, while the difference due to age was more pronounced in the females compared to males. The essential/nonessential amino acid ratio was lower in females compared to males.

Adult↗
PubMed1991

In-patient withdrawal from long-term benzodiazepine use.

Twenty-one patients completed an intensive in-patient and out-patient group-based programme, to achieve withdrawal from long-term benzodiazepine dependence. By 6-month follow-up (post-withdrawal), eight patients (38%) had achieved a 'good' outcome. Generally, patients demonstrated moderate levels of psychiatric morbidity and depression in the pre-withdrawal phase; a diagnosis of a depressive disorder being associated with either an 'intermediate' or 'poor' outcome in comparison to patients receiving a diagnosis of anxiety disorder, who showed a predominantly 'good' outcome. Two patients committed suicide some time after withdrawal. Additionally, older patients fared less well than their younger counterparts. We conclude that maintenance benzodiazepine prescription, rather than withdrawal, may be the preferred treatment for some dependent patients. Furthermore, more data are required regarding the association, and causality, between depression and benzodiazepine withdrawal in long-term users.

Adult↗
PubMed1991

A comparison of roxatidine and ranitidine for the acute treatment of duodenal ulcer.

Roxatidine acetate is a new histamine H2-antagonist of about twice the potency of ranitidine on a weight-for-weight basis. Two hundred and thirty-two patients participated in a double-blind randomized trial of duodenal ulcer healing comparing 300 mg ranitidine nocte with 150 mg roxatidine nocte. Endoscopy was repeated fortnightly to 4 weeks in each of four participating centres. Usual exclusion criteria applied but NSAID users were allowed. There were no important demographic differences between treatment recipients. Three analyses were used: protocol (dropouts and violators not included), intention-to-treat I (dropouts considered failures), and intention-to-treat II (dropouts considered failures, but violators outcome included). Healing rates differed markedly (but not significantly) with each analysis. After 2 weeks of treatment ulcers had healed in 51% versus 45% using the intention to treat I analysis with roxatidine and ranitidine, respectively; by the protocol analysis the healing proportions were 60% and 55%. These differences between treatments were not significant. After 4 weeks of treatment healing rates ranged from 71% to 83% on roxatidine and between 69% and 84% on ranitidine depending on the analysis. Differential healing proportions of smokers and non-smokers were non-significant (83% vs. 79%). Both drugs were well tolerated and adverse events were similar with each agent. Roxatidine should prove as effective as ranitidine for acute duodenal ulcer treatment.

Adult↗
PubMed1991

Developmental profile of plasma proteins in human fetal cerebrospinal fluid and blood.

Total protein, alphafetoprotein, albumin, prealbumin, alpha-1-antitrypsin, transferrin and ceruloplasmin levels were measured in samples of human fetal and neonatal cerebrospinal fluid (CSF) (97 cases), obtained between 12 and 41 weeks of gestation. In 39 of these cases (13 to 40 weeks gestation) plasma was also available for comparative analysis. CSF was collected from lateral ventricles in the first half of gestation and from the lumbar region in the second. Since these CSF samples were obtained from different sites, the protein levels in the lateral ventricle (early) samples could not be compared directly with those in the lumbar (later) samples. However, the mean protein levels in the lumbar samples were lower than those in the ventricular samples, which is in accord with the decline in CSF protein levels described in maturing animal fetuses. Despite a wide scatter of results, particularly in the first half of gestation, significant decline in the level of CSF alphafetoprotein was demonstrated during both first and second halves of gestation, and of albumin and prealbumin in the second half. No sex differences were found except for ceruloplasmin in lumbar CSF later in gestation, when males had higher levels than females. In fetal plasma, protein levels increased with increasing gestation apart from alphafetoprotein and prealbumin which both declined progressively. CSF/plasma ratios were dissimilar for different proteins, and changed with increasing gestation. These findings support the concept that the human fetal blood brain barrier matures early.

Blood Proteins↗
PubMed1991

A study of candidosis: the role of fomites.

This study investigates treatment failure and recurrences of vulvo-vaginal candidosis. It reviews the factors possibly associated with both. Patients attending a department of genitourinary medicine with recurrent candidosis (N = 186) were entered in the trial. The patients were investigated for evidence of candidosis from vagina, rectal wall and buccal mucosa and were given antifungal therapy. Prevention and reinfection via fomites was studied by means of a single blind parallel study comparing the effect of soaking undergarments in the amphoteric biocide Tego 103G with the effect of a placebo soak. General and possible contributory factors influencing treatment and failure and recurrences were considered. The success rate of miconazole therapy was typical of any imidazole therapy: 85.4%. There was no evidence that modern oral contraceptives played a role in candidosis. Oral nystan reduced the rectal wall carriage from 39.2% to 23.2%. Oral yeast carriage rate in women was 37.6%. The recurrence rate over a six month period was 47.4%. The laboratory results of Tego soaking reduced the yeast carriage on panties from 85.2% to 23.4%. However, no evidence was found in the trial results that panties were a significant source of reinfection.

Antifungal Agents↗