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Biomedical subjects

S Thomas

Publications and source records attributed to S Thomas.

At least 541 records · Page 30Linked to original sources
PubMed1992

Leftward shift of R-axis on electrocardiogram in patients with panic disorder and depression.

In a prospective study, we have compared R-axis on routine electrocardiograms of panic disorder patients (n = 52) with that of depressed patients (n = 41) and normal controls (n = 65). All subjects were physically healthy and were normotensive. There was a significant leftward shift of R-axis in both depressed and panic disorder patients compared to normal controls. The implications of these findings are discussed.

Adult↗
PubMed1992

Pattern of non-ICU inpatient supplemental oxygen utilization in a university hospital.

Random assessments of SaO2 were performed via pulse oximetry in 274 hospitalized non-ICU patients prescribed supplemental O2 in a large tertiary care university hospital. In 507 assessments performed in patients inspiring the prescribed O2, 426 were receiving excessive amounts of O2 to maintain a SaO2 > or = 92 percent. In 233 of these assessments, SaO2 was > or = 92 percent while breathing ambient air. In an additional 193 assessments, the concentration of inspired supplemental O2 was excessive to maintain a SaO2 > or = 92 percent. However, in 81 assessments performed in patients inspiring O2, the prescribed amount was insufficient to maintain SaO2 > or = 92 percent. These results indicate that O2 prescription in hospitalized non-ICU patients is excessive or not required in the majority of cases. Furthermore, routine use of pulse oximetry in hospitalized patients prescribed O2 may be useful in determining the continued need for supplemental O2 and adjusting the proper concentration needed to avoid hypoxemia.

Baltimore↗
PubMed1992

Revision of the Physical Activity Readiness Questionnaire (PAR-Q).

The original Physical Activity Readiness Questionnaire (PAR-Q) offers a safe preliminary screening of candidates for exercise testing and prescription, but it screens out what seems an excessive proportion of apparently healthy older adults. To reduce unnecessary exclusions, an expert committee established by Fitness Canada has now revised the questionnaire wording. The present study compares responses to the original and the revised PAR-Q questionnaire in 399 men and women attending 40 accredited fitness testing centres across Canada. The number of subjects screened out by the revised test decreased significantly (p < .05), from 68 to 48 of the 399 subjects. The change reflects in part the inclusion of individuals who had made an erroneous positive response to the original question regarding high blood pressure. There is no simple gold standard to provide an objective evaluation of the sensitivity and specificity of either questionnaire format, but the revised wording has apparently had the intended effect of reducing positive responses, particularly to the question regarding an elevation of blood pressure.

Adult↗
PubMed1992

Evaluation of a new non-woven theatre swab.

A new non-woven theatre swab was compared with traditional gauze in laboratory and clinical studies. Results of both clinical and laboratory-based studies showed the non-woven swab to be as effective as traditional gauze in terms of softness, conformability, ability to pad or pack, resistance to snagging and shredding, and ease of counting when wet. The non-woven swabs were also superior to gauze with regard to their ability to retain fluid. Manufactured from polyester and hemisynthetic viscose, the non-woven swabs can be produced to a uniform standard and are less expensive. It is concluded that the new non-woven material has practical and economic advantages over traditional gauze.

Cellulose↗
PubMed1992

[Ureterorenoscopy as a diagnostic procedure in the upper urinary tract].

Ureteropyeloscopy has become a valuable asset in the diagnosis and treatment in the upper urinary tract. From 1984 to 1991 we performed 1635 ureteropyeloscopies, 180 procedures in a diagnostic intention. Rigid ureteropyeloscopes permit endoscopic access into the ureter and the upper calix, actively deflectable instruments are necessary to visualize the middle and lower calix.

Biopsy↗
PubMed1992

Primary cutaneous zygomycosis due to Absidia corymbifera in a patient with AIDS.

A case of primary cutaneous zygomycosis due to Absidia corymbifera in a patient with AIDS is described. The lesions, which were located on the forehead, jaw and chest, were intradermal, extending into the subcutaneous fat and did not appear to be associated with any trauma. No deep-seated infection was evident suggesting that the superficial lesions were exogenous in origin. The possible aetiology of this infection is discussed.

AIDS-Related Opportunistic Infections↗
PubMed1992

Occurrence of multiple antimicrobial resistance among Haemophilus influenzae type b causing meningitis.

Among the 157 children with culture proven pyogenic meningitis who were admitted during 1987-1991, in the Department of Child Health at the Christian Medical College and Hospital, Vellore, 40 had H. influenzae type b (HIB) meningitis; 17 of these had multiantimicrobial resistant HIB (MRHIB) and 23 others had usual susceptibility HIB (USHIB) meningitis. The two groups were compared. Children with MRHIB meningitis who received optimal treatment with cefotaxime had excellent recovery. When cefotaxime therapy was delayed, mortality was noted in all except one child who survived with severe neurological sequelae. MRHIB meningitis treated with drugs other than cefotaxime had 100 per cent mortality. Cefotaxime is therefore recommended in children below 3 yr of age presenting with purulent meningitis, as MRHIB is a possible causative agent in this group.

Anti-Bacterial Agents↗
PubMed1992

Urodynamic evaluation of voiding in women with cystocele.

To determine the effect of cystocele upon voiding, 30 women with various degrees of genitourinary prolapse were studied. The patients were divided into three groups depending on the severity of the cystocele and were evaluated with uroflowmetry, urethrocystoscopy, water cystometry, urethral pressure profilometry and voiding urethrocystometry. The three groups were similar in most parameters except maximum urethral closure pressure (P less than .05). The patients with cystocele did not demonstrate the abnormal voiding patterns characteristic of outflow obstruction.

Adult↗
PubMed1991

Rapid genetic analysis of families with polycystic kidney disease 1 by means of a microsatellite marker.

Presymptomatic diagnosis of polycystic kidney disease 1 (PKD1) is possible by genetic linkage analysis with markers from both sides of the disease locus. The existing proximal markers are not informative in many families, so such analysis is difficult and time-consuming. We sought more useful length polymorphisms on the proximal side of the locus among simple sequence repeats (microsatellites). We identified two microsatellite polymorphisms that lie closer to the PKD1 locus than any previously described highly variable marker. One, SM7, is especially informative; we have found fourteen alleles and the observed heterozygosity in caucasians is 62.7%. Genetic linkage analysis in PKD1 families suggests that both of the markers lie proximal to the disease gene, closer than existing flanking markers. These polymorphisms can be simply assayed by polymerase chain reaction amplification of the variable regions, which generates DNA fragments that can be separated on non-denaturing acrylamide gels and directly examined after gel staining. This rapid, inexpensive, and non-radioactive method of linkage analysis allows the complete study of DNA samples within 8 h.

Alleles↗
PubMed1991

Viewer-centred and object-centred coding of heads in the macaque temporal cortex.

An investigation was made into the sensitivity of cells in the macaque superior temporal sulcus (STS) to the sight of different perspective views of the head. This allowed assessment of (a) whether coding was 'viewer-centred' (view specific) or 'object-centred' (view invariant) and (b) whether viewer-centred cells were preferentially tuned to 'characteristic' views of the head. The majority of cells (110) were found to be viewer-centred and exhibited unimodal tuning to one view. 5 cells displayed object-centred coding responding equally to all views of the head. A further 5 cells showed 'mixed' properties, responding to all views of the head but also discriminating between views. 6 out of 56 viewer and object-centred cells exhibited selectivity for face identity or species. Tuning to view varied in sharpness. For most (54/73) cells the angle of perspective rotation reducing response to half maximal was 45-70 degrees but for 19/73 it was greater than 90 degrees. More cells were optimally tuned to characteristic views of the head (the full face or profile) than to other views. Some cells were, however, found tuned to intermediate views throughout the full 360 degree range. This coding of many distinct head views may have a role in the analysis of social signals based on the interpretation of the direction of other individuals' attention.

Animals↗
PubMed1991

The effects of endogenous or exogenous catecholamines on blood respiratory status during acute hypoxia in rainbow trout (Oncorhynchus mykiss).

An extracorporeal circulation of rainbow trout (Oncorhynchus mykiss) was utilized to continuously monitor the rapid and progressive effects of endogenous or exogenous catecholamines on blood respiratory/acid-base status, and to provide in vivo evidence for adrenergic retention of carbon dioxide (CO2) in fish blood (cf. Wood and Perry 1985). Exposure of fish to severe aquatic hypoxia (final PwO2 = 40-60 torr; reached within 10-20 min) elicited an initial respiratory alkalosis resulting from hypoxia-induced hyperventilation. However, at a critical arterial oxygen tension (PaO2) between 15 and 25 torr, fish became agitated for approximately 5 s and a marked (0.2-0.4 pH unit) but transient arterial blood acidosis ensued. This response is characteristic of abrupt catecholamine mobilization into the circulation and subsequent adrenergic activation of red blood cell (RBC) Na+/H+ exchange (Fievet et al. 1987). Within approximately 1-2 min after the activation of RBC Na+/H+ exchange by endogenous catecholamines, there was a significant rise in arterial PCO2 (PaCO2) whereas arterial PO2 was unaltered; the elevation of PaCO2 could not be explained by changes in gill ventilation. Pre-treatment of fish with the alpha-adrenoceptor antagonist phentolamine did not prevent the apparent catecholamine-mediated increase of PaCO2. Conversely, pre-treatment with the beta-adrenoceptor antagonist sotalol abolished both the activation of the RBC Na+/H+ antiporter and the associated rise in PaCO2, suggesting a causal relationship between the stimulation of RBC Na+/H+ exchange and the elevation of PaCO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Adult Bochdalek hernia--clinical features, management and results of treatment.

We herein present 2 cases of adult Bochdalek hernia. Only a total of 51 such cases have been reported since 1958, and we have reviewed these cases and discussed their clinical features, operative treatment and final outcome. The majority of these patients presented as acute surgical emergencies and a lack of awareness of this condition lead to an incorrect diagnosis in 38 per cent. Intestinal obstruction with left lung signs and a non-distended abdomen in an adult patient should arouse suspicion of this condition. A plain X-ray of the chest and contrast studies of the gastrointestinal tract are necessary to confirm the diagnosis. A previous normal chest X-ray does not rule out a diaphragmatic hernia, as the defect may be plugged by the spleen or by the presence of a confining sac. The high incidence of strangulation emphasises the need for early diagnosis and prompt operative management which gives highly satisfactory results.

Acute Disease↗
PubMed1991

Case report: bilateral massive internal jugular vein thrombosis in carcinoma of the thyroid: CT evaluation.

Superior vena cava syndrome, an uncommon manifestation of carcinoma of the thyroid, is usually due to retrosternal extension of the growth. Rarely, however, there may be direct tumour extension into the great veins of the neck, which may cause sudden death. Only eight such cases have been reported in the English literature. The case reported by us is the first to be documented by computed tomography. Patients with carcinoma of the thyroid with the superior vena cava syndrome should undergo computed tomography to differentiate external compression due to goitre from intraluminal tumour.

Carcinoma↗
PubMed1991

Problems with measuring alexithymia.

Research evaluating the relationship of alexithymia to medical and psychiatric disorders has been compromised by the poor psychometric properties of the instruments that have been used to measure alexithymia. This study evaluated the psychometric properties of a recently introduced measure of alexithymia--the revised Schalling-Sifneos Personality Scale (SSPS-R). While the factor structure of the SSPS-R was found to be reasonably congruent with the theoretical domains of the alexithymia construct, the scale lacked homogeneity and internal reliability. These results are compared with the reliability and validity of other available measures of alexithymia. Recommendations are offered for the improved assessment of alexithymia in future research studies.

Adolescent↗
PubMed1991

Synthesis and pharmacological evaluation of 1-(aminomethyl)-3,4-dihydro-5-hydroxy-1H-2-benzopyrans as dopamine D1 selective ligands.

A series of 3-substituted 1-(aminomethyl)-3,4-dihydro-5-hydroxy-1H-2- benzopyrans were prepared as potential D1 selective antagonists. The compounds were evaluated for their affinity and selectivity for the D1 receptor as well as for their functional antagonism of D1-mediated pharmacological events. The compounds show potent D1 antagonist properties in vitro. The optimum nitrogen substitution was found to be the primary amine and the observed order of potency for substitution at the 6-position is OH greater than Br greater than H greater than OMe. Two representative compounds, the 6-methyl and 6-bromo analogues, were also evaluated in vivo for dopaminergic activity. Interestingly, both compounds behave as potent in vivo agonists.

Adenylyl Cyclase Inhibitors↗