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Biomedical subjects

D Cowan

Publications and source records attributed to D Cowan.

At least 37 records · Page 2Linked to original sources

Group therapy for anxiety disorders using rational emotive behaviour therapy.

This paper reports a pilot study designed to investigate Rational Emotive Behaviour Therapy in the group treatment of selected clients suffering from anxiety disorders. A convenience sample of 17 clients who completed the treatment programme was selected for the study. Biographical information was sought and data were collected on subject anxiety and depression. Intervention was targeted at identifying and correcting irrational beliefs via the application of a range of Rational Emotive Behaviour Therapy techniques. Pre- and postintervention data were analysed by two-tailed t-tests for paired samples and found to be significant at P < 0.001. The results suggest that the treatment approach was successful in modifying irrational beliefs and anxiety.

Adult↗

Transmission of the results of tests for International Olympic Committee-defined drugs of abuse.

The hardware and software facilities for electronic storage, transfer and handling of data is such that multipurpose databases can be made accessible without geographic restriction at low cost. The versatile and flexible underlying structures allow for ease of access and retrieval of data and gives presentation formats fully comparable to printed counterparts. Because of the apparent ease of use and because of the wider distribution of the information, misinterpretation is more likely to occur than in oral or written presentation for more restricted and more culturally homogeneous audiences. This necessitates some degree of harmonisation/standardisation of data on transfer, while allowing local expression forms at sender and receiver ends (Fig. 1). This document is part of an ongoing international effort to agree on some sort of "standardisation" of the transmission and presentation of "laboratory results". It centers on the domain of drugs of abuse as defined by the International Olympic Committee.

Clinical Laboratory Information Systems↗

Healing response of the canine prostate to Nd:YAG laser radiation.

The objective of the study was to characterize the healing response of the canine prostate to laser thermal injury. The study included 20 canine prostates that underwent transurethral laser radiation. The prostates were retrieved 1 hr after laser radiation in 7 dogs (acute group), and from 3 days to 9 weeks in 13 dogs (chronic group). Two distinct features were observed. First, reepithelialization of the prostate urethra resulted from mobilization of proliferating epithelial cells from acinar and ductal prostatic epithelium into the cavity surface, and not from the edges of the wound at the bladder neck. Squamous cell metaplasia was a prominent feature of reepithelialization. Second, the healing process in the canine prostate was relatively unimpeded. The large glandular component provided abundant germinal epithelial growth, and the absence of stromal elements allowed for complete sloughing of necrotic tissue without residual eschars. Further, the lesions in the chronic group had a tendency to be larger than those in the acute group, suggesting that extended delayed necrosis may occur at deep prostatic tissue layers.

Animals↗

A prospective randomised controlled trial of postoperative autotransfusion with and without a heparin-bonded circuit.

Autotransfusion has been included in the routine protocol in some units as an effort towards blood conservation. In this study we aimed to measure the efficacy and limitations of autotransfusion and whether a heparin-bonded circuit had any advantage. One hundred five patients were randomised to one of three post-operative treatments. Group 1 (n = 34) was not autotransfused whereas groups 2 (n = 36) and 3 (n = 35) received autotransfusion with the circuit of group 3 coated with heparin. Homologous blood and blood products were given according to strict protocols identical for all groups. Transfused and circulating blood was analysed for haemostatic variables and the requirement for homologous blood was recorded. Autotransfused blood contained no intact platelets and very high levels of D-Dimers (a peptide fragment released when fibrin is lysed) which resulted in high levels of systemic D-Dimers in patients receiving autotransfusion. Flow cytometric analysis revealed that whilst platelet glycoprotein 1 b receptors were severely reduced immediately following surgery, there was no additional damage caused by autotransfusion. Furthermore, there was no difference in platelet aggregation, von Willebrand factor (vWF) multimetric analysis or clotting profiles between the groups. Median (interquartile range) blood loss was 898 ml (638-1195) in group 1, 853 ml (595-1348) in group 2 and 770 ml (615-1000) in group 3 (Kruskal-Wallis P = 0.46). Median transfusion requirements were 2 units in each group. Whilst auto-transfusion does not appear to compromise haemostasis, it does not reduce the requirement for homologous blood and heparin-bonding of the circuit has no impact.

Aged↗

Mammoscintigraphy with technetium-99m-sestamibi in suspected breast cancer.

UNLABELLED: Our goal was to determine the clinical usefulness of 99mTc-sestamibi to identify breast cancer in patients prior to biopsy. METHODS: We studied 66 patients who received 20 mCi 99mTc-sestamibi intravenously. Lateral and anterior planar images were gathered within 30 min of the injection. Only focal increased uptake was interpreted as positive. Confirmatory pathologic diagnoses were obtained within 2 mo. The prevalence of breast cancer in our sample was 54%. RESULTS: We report an overall sensitivity of 83% and specificity of 93% for the diagnosis of breast cancer. In palpable lesions, the sensitivity was of 94% with a specificity of 91%, while in nonpalpable abnormalities the sensitivity was of 64% with a 100% specificity. Six patients with a malignancy had negative scans, four of these lesions were nonpalpable. Only two of 31 patients with benign lesions had an abnormal scan. CONCLUSION: Mammoscintigraphy with 99mTc-sestamibi has high specificity and adequate sensitivity for the noninvasive diagnosis of breast carcinomas.

Adult↗

Optimising the recovery of recombinant thermostable proteins expressed in mesophilic hosts.

The purification of a thermostable Caldocellum saccharolyticum beta-glucosidase expressed in Escherichia coli was investigated using heat precipitation of unclarified cell homogenates. Heat treatment at 70 degrees C was capable of purification with respect to cell debris, small particulates and the majority of cell protein, although E. coli proteins were even more efficiently removed at 80 degrees C and above. For thermostable proteins expressed in E. coli, a precipitation temperature of 80 degrees C or greater is recommended for optimal removal of contaminant proteins. In small-scale heating trials, heating rate was found to influence enzyme yield significantly. Losses were minimised when 'flash-heating' was employed. The successful single-step removal of particulates, labile protein and nucleic acids was achieved by simultaneous heat-treatment and polyethyleneimine addition, although the purification achieved was additive rather than synergistic.

Bacteria, Anaerobic↗

Serum is more effective than albumin in promoting human embryo development and implantation.

OBJECTIVE: To compare the effects of serum with those of Albuminar-5 (Armour Pharmaceutical Co., Eastbourne, Sussex, United Kingdom) as medium supplements to Earl's balanced salt solution (EBSS) for IVF and subsequent embryo development. DESIGN: A retrospective study. Gametes and embryos from 318 patients were cultured in the presence of serum (group 1). Gametes and embryos from 130 patients were cultured in the presence of Albuminar-5 (group 2). Embryos obtained from IVF were replaced into the uterus within 48 hours after insemination. Surplus bipronucleate embryos were cultured up to 14 days with either serum or Albuminar-5. SETTING: Two tertiary referral fertility clinics; university teaching hospital. PATIENTS: Four hundred forty-eight patients with a wide spectrum of causes of subfertility, ranging in age from 24 to 43 years. MAIN OUTCOME MEASURES: Fertilization rate, pregnancy rate (PR), implantation rate, and surplus embryo development in vitro. RESULTS: The PR for group 1 patients was higher than that of group 2 (27.0% versus 15.4%, respectively). Although fertilization rates were identical in the two groups, cumulative embryo scores and implantation rates were significantly higher in group 1. There was no difference between the groups in age distribution, types of ovarian stimulation, numbers of patients with day 1 or day 2 transfers, or luteal phase support. Of 31 embryos cultured with serum, 54.8% reached the fully expanded blastocyst stage and 25.8% hatched. Of 19 embryos cultured with Albuminar-5, only 5.3% reached the fully expanded blastocyst stage and none hatched. CONCLUSIONS: The results suggest that, under certain conditions, serum supplementation yields better results than protein supplementation alone. The latter may be suitable only in conjunction with additional components.

Adult↗

Genetic dissection of mechanosensory transduction: mechanoreception-defective mutations of Drosophila.

To identify genes involved in mechanotransduction, Drosophila larvae were screened for X-linked mutations affecting a behavioral response to touch. Many mutations that caused nondevelopmental defects were recovered, among them multiple alleles of the genes uncoordinated (unc) and uncoordinated-like (uncl). Adult flies mutant in these genes showed reduced viability that was associated with behavioral phenotypes ranging from reduced locomotor activity to total uncoordination. Behavioral analysis of mosaic flies indicated that external sensory bristles are a focus of the unc mutant defect. Extracellular recordings from mutant mechanosensory bristles revealed that mechanoreceptor potentials were absent or reduced in both unc and uncl mutants. A second genetic screen, for unc-like uncoordination, yielded mutations in seven genes on the second chromosome; mutations in five of these genes also reduced or eliminated bristle mechanoreceptor potentials. These mutants provide the basis for a genetic, electrophysiological, and molecular dissection of mechanotransduction.

Alleles↗

Primary sarcomas of the heart.

Seventy-five primary sarcomas of the heart were classified by histologic appearance as angiosarcoma (26 cases), undifferentiated sarcoma (18 cases), osteosarcoma (9 cases), fibrosarcoma (6 cases), malignant fibrous histiocytoma (6 cases), leiomyosarcoma (4 cases), myxosarcoma (3 cases), synovial sarcoma (2 cases), and neurofibrosarcoma (1 case). The ages of the patients ranged from 1 to 75 years at the time of presentation (mean, 39 years). Angiosarcomas were predominantly right-sided and osteosarcomas left-sided. Forty patients treated surgically were examined, and survival correlated with clinical and histologic parameters. the survival rate was poor, with a mean of 11 months and median of 6 months. By univariate analysis, the survival rate was more favorable for patients with tumors located on the left side of the heart, without necrosis, with a low mitotic count, and without metastasis at diagnosis. Survival rates were better in patients receiving chemotherapy and radiation therapy. Age, gender, presence of differentiation, and histologic type did not affect prognosis. By multivariate analysis, a low level of mitotic activity and any therapy were the only significant factors affecting survival rate. Immunostaining with commercially available antisera was useful in the diagnosis of sarcoma but not in subclassification of 19 tumors so tested. Although the prognosis for patients with cardiac sarcomas is dismal, histologic grading is useful in predicting outcome, as has been shown for soft tissue sarcomas of other sites.

Adolescent↗

Renal oncocytoma: long-term follow-up and flow cytometric DNA analysis.

We report a retrospective study on the clinicopathologic features and flow cytometric DNA analysis of ten renal oncocytomas compared with a control group of ten randomly selected renal cell carcinomas. Among the oncocytoma patients, no recurrences or metastases were noted over an average follow-up of 6.7 years (range = 6 months to 16 years). Reproducible, high-quality DNA histograms were obtained on the paraffin-embedded specimens by using our modified flow cytometric procedure. One aneuploid (10%) and two hyperdiploid tumors (20%) were found in the oncocytoma group. There was no correlation between these abnormal DNA histographic patterns and survival or tumor stages. On the contrary, a good correlation was found between tumor grades and DNA ploidy in the controls. We conclude that renal oncocytoma is a clinically benign tumor, yet it may exhibit varying degrees of flow cytometric DNA abnormalities, which have no predictive value on survival and probably reflect the characteristics of oncocytes rather than its malignant potential.

Adenoma↗

Planning for community care: the Community Placement Questionnaire.

The article reviews methodological issues relating to planning surveys of long-stay populations and describes the development of an assessment instrument, the Community Placement Questionnaire, designed to aid planning for long-stay patients resident in hospitals scheduled for rundown or closure. Reliability and validity data are presented and the advantages and limitations of the instrument are discussed.

Adult↗

Dental care in Papua New Guinea.

In August, 1989, I visited Papua New Guinea for my elective. During four weeks, in a land sometimes referred to as 'The Last Unknown', I gained an insight into some of the problems of providing primary dental care.

Dental Care↗

Torpedo synaptophysin: evolution of a synaptic vesicle protein.

Synaptophysin is an integral membrane protein of synaptic vesicles found in neurons and endocrine cells. Synaptophysin monomers associate into hexamers forming a large conductance channel. We present an analysis of synaptophysin from the nervous system of the marine ray Torpedo californica. Analysis of cDNA clones reveals a 62% amino acid similarity between the Torpedo and rat sequences. The 4 hydrophobic membrane spanning domains and the glycosylation site are conserved. In contrast, the two intravesicular loops connecting the membrane spanning regions, show varying degrees of sequence conservation, suggesting that portions of these domains may play critical functional roles. The carboxyterminal tail has been proposed to bind calcium and is a major site for tyrosine phosphorylation. The precise sequence of this region has almost completely diverged while the proline-tyrosine rich nature is maintained. Blotting studies reveal the RNA and the protein in nervous system tissues and demonstrate that the molecule copurifies with cholinergic synaptic vesicles.

Amino Acid Sequence↗