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Biomedical subjects

C Thomas

Publications and source records attributed to C Thomas.

At least 307 records · Page 17Linked to original sources
PubMed1992

Pediatric cardiology: auscultation from 280 miles away.

New long-distance audio/video and data communications links among health-care facilities promise to reduce rural patients' travel time and waiting time for subspecialty consultations. To offer a satisfactory alternative to face-to-face examination, the long-distance system must meet the subspecialty's minimum criteria. For pediatric cardiology in particular, the system has to permit satisfactory cardiac auscultation. A preliminary test of remote auscultation that uses an electronic stethoscope involved two pediatric cardiologists, one listening hands-on with an acoustic stethoscope, the other listening independently at long distance with the electronic instrument. Taking the acoustic findings as the reference standard, the electronic stethoscope did not miss the one case of heart disease, correctly recommended echocardiogram follow-up in the two cases requiring it, and agreed on 80% of the murmurs' qualitative specifics. The patients' parents also indicated that the system was highly acceptable. We are following up these results with a full-scale study of the effectiveness and parental acceptance of remote auscultation.

Cardiology↗
PubMed1992

[Renal toxicity of intraperitoneal cisplatin: a case report].

The new technique of treating ovarian tumours by giving cisplatin intra-peritoneally does have its risks. This case history reports the case of a patient who was treated in this way and following the treatment had renal failure severe enough to require dialyses. The methods of administering cisplatin through this route have not yet been worked out completely. It is absolutely to over hydrate the patient beforehand.

Acute Kidney Injury↗
PubMed1991

Twenty five years of case finding and audit in a socially deprived community.

OBJECTIVE: To evaluate audit and case finding (whole population care) in a community over 25 years. DESIGN: Contemporary screening for and audits of care of chronic disease and risk factors; retrospective review of computerised practice records; and comparisons of mortality and social indices with neighbouring communities. SETTING: One general practice in Glyncorrwg, West Glamorgan. SUBJECTS: 1800 people registered with the practice in 1987 and 558 people who died from 1964 to 1987, whose records had been retained. MAIN OUTCOME MEASURES: Detection of high blood pressure, smoking, airways obstruction, obesity, diabetes, and alcohol problems in adults aged 20-79; prevalence of smoking in this population and in hypertensive and diabetic groups; age standardised mortality ratios in relation to indices of social deprivation. RESULTS: In the population aged 20-79 (1207 patients) 249 (21%) had peak expiratory flow rate less than 50% of expected value or which improved by 15% or more with an inhaled beta agonist, 207 (17%) had body mass index at or over 30 kg/m2, 118 (10%) had untreated mean arterial pressures greater than 159/104 mm Hg (three readings), 80 (7%) (65 (16%) men, 15 (4%) women) had recognised alcohol problems, and 35 (3%) had diabetes. The proportion of men aged 20-64 who said they smoked fell from 61% (290/476) in 1968-70 to 36% (162/456) in 1985 whereas that of women who smoked was unchanged (43%, 187/436 v 42%, 190/448 respectively). In 116 screened hypertensive patients group mean blood pressure fell from 186/110 mm Hg before treatment to 146/84 mm Hg at 1987 audit, as did the proportion of smokers (56% v 20%), but body mass index and total cholesterol concentration showed no significant change. In 34 diabetic patients mean blood pressure and the proportion of smokers fell (171/93 mm Hg v 155/81 mm Hg; 44% v 12%). The age standardised mortality ratio in 1981-6 was lower than in a neighbouring village without a developed case finding programme (actual to expected deaths less than 65 = 21 to 22 in Glyncorrwg, 48 to 30 in control village). CONCLUSIONS: Whole population care through organised case finding and audit is feasible but only with a labour intensive approach combining accessibility, flexibility, and continuity, as well as a planned and structured approach, which requires substantial expansion of staff numbers and assiduous recording. It may reduce risks for at least some high risk groups. Despite their shortcomings the available data are consistent with the hypothesis that whole population care helps reduce mortality. Incentives in the new contract, which encourage the uncritical development of structured process, may diminish health outputs.

Adult↗
PubMed1991

[Assessment of musculoskeletal disorders using a questionnaire].

The standardized illustrated questionnaire on musculoskeletal disorders of the Japanese Committee on Occupational Cervico-branchial Disorders was translated into German. This questionnaire, composed of 37 items about the occurrence (never/seldom, occasionally, almost daily) of symptoms (pain, stiffness, fatigue) in twelve body regions, was used together with medical examinations (pressure points), and further information was gathered on the consumption of analgetics and medical visits prompted by musculoskeletal symptoms. The questionnaire's reliability and validity were tested in 644 persons from twelve occupational groups within the service sector. Factor analysis showed that symptoms can be grouped into four distinct regions of occurrence: neck/shoulder/area, back/low back, and both left and right upper extremities. Indices based on these regions are consistent (Cronbach alpha approximately 0.8). Palpation findings steadily increase with increasing index values. The consumption of medicaments and medical visits positively correlate with the indices. Consequently the questionnaire is judged to be a valid instrument for studying musculoskeletal disorders at the workplace.

Adult↗
PubMed1991

Anatomical basis of the anterior vertebral graft using a pediculated rib.

The rib is frequently used as a bone graft in the surgery of the anterior spine. The advantage of the rib is that it is easily used as a pediculated vascularized graft when it is transferred to the anterior vertebrae. The average length of the pedicle is over 5 cm for the ribs number 3 to 10. Their useful length of bone is 12 cm. With this technique fusion of 4 to 6 lumbar or thoracic vertebrae is possible.

Cadaver↗
PubMed1991

Myopathy in Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a disorder of unknown aetiology. The classical features of the syndrome include a typical ('elfin') facies, mental retardation and heart defects. Myopathy has not so far been part of the spectrum of WBS. We studied six patients with WBS aged 3-25 years, five of whom showed clinical and morphological evidence of myopathy. The clinical manifestations of myopathy included hypotonia in infancy, walking delay, joint contractures, scoliosis, and increased exhaustion on exertion. These symptoms were present in variable expression but part of a typical postural pattern. Examination of muscle biopsies showed lipid storage in four patients and increased variability of fibre size in three. In one patient a muscle biopsy gave normal results. Biochemical investigation in four patients with morphological evidence of lipid storage in muscle revealed muscle carnitine deficiency in three. In addition, enzyme activities of fatty acid beta-oxidation were low in one of two specimens tested. It is concluded that a clinically relevant myopathy is part of the multi-system manifestation of WBS and a clinical trial of carnitine supplementation is justified.

Adult↗
PubMed1991

Popliteal lymph node enlargement and antibody production in the mouse induced by drugs affecting monoamine levels in the brain.

Drugs that affect monoamine levels in the brain were screened for their potential to cause immunological changes in the popliteal lymph node (PLN) of mice after injection into the hind paw. The tricyclic antidepressant (TCA) drugs, imipramine and amitriptyline, and the serotonin reuptake blocker, zimeldine, induced a prominent PLN weight gain in C57BL/6 mice. Ketanserin and ritanserin appeared less effective while nomifensine, serotonin and the antigen, sheep erythrocytes, lacked significant activity. In BALB/c mice all agents induced an increase of PLN cell number, the TCA drugs and zimeldine appeared superior in this respect. Increased IgM as well as IgG production on a per cell basis was only induced by the TCA drugs, zimeldine and, especially, sheep erythrocytes. Data indicate that induction of PLN responses is not a general property of agents affecting monoamine levels. Structural, i.e. antigenic, characteristics of the drugs rather than their pharmacological properties are probably at play.

Animals↗
PubMed1991

High CA-125 concentrations in peritoneal fluid of normal cyclic women with various infertility-related factors as demonstrated with two-step immunoradiometric assay.

OBJECTIVE: To determine CA-125 concentrations and total amounts in peritoneal fluid (PF) of women with various infertility-related factors throughout the menstrual cycle. DESIGN: Peritoneal fluid was obtained at laparoscopy. CA-125 was determined using the assessed two-step immunoradiometric assay (IRMA) which, in contrast to the one-step IRMA, gives valid results. SETTING: University Hospital Nijmegen, Nijmegen, The Netherlands. PATIENTS: One hundred six infertile women with a regular and ovulatory cycle were included. INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): The mean PF CA-125 concentration and total amount were significantly lower during the luteal phase as compared with other phases of the menstrual cycle. No correlation was found with the presence or absence of endometriosis, adhesions, a male and/or cervical mucus infertility factor, and with patent or closed fallopian tubes. RESULTS: Peritoneal fluid CA-125 concentrations varied from 630 to 12,000 arbitrary units/mL (mean +/- SD = 3,437 +/- 2,286). Total PF CA-125 amounts (concentration x PF volume) varied from 1,760 to 13,300 arbitrary units (mean +/- SD = 30,219 +/- 26,841). CONCLUSIONS: CA-125 secretion into the abdominal cavity varies during the menstrual cycle. Retrograde menstruation is not the main source of CA-125 in PF.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

Diagnostic conundrum of oppositional defiant disorder and conduct disorder.

Evidence for a diagnostic distinction of oppositional defiant disorder (ODD) and conduct disorder (CD) is reviewed, and alternative conceptualizations and definitions for the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders are considered. Studies suggest that CD and ODD are strongly and developmentally related but clearly different. Factor analyses indicate that distinct covarying groups of ODD and CD symptoms can be identified, but certain symptoms relate to both (particularly mild aggression and lying). Age of onset for ODD is earlier than for most CD symptoms. Nearly all youths with CD have a history of ODD, but not all ODD cases progress to CD. The disorders demonstrate the same forms of parental psychopathology and family adversity but to a greater degree for CD than for ODD. Alternative conceptualizations for the disorders are presented for further study before the introduction of the DSM-IV.

Aggression↗
PubMed1991

Influence of the 100% w/v perfluorooctyl bromide (PFOB) emulsion dose on tumour radiosensitivity.

The radiosensitizing effect of a 100% w/v emulsion of a fluorocarbon, PFOB, which carries 4 times more oxygen than does Fluosol-DA 20% emulsion, was studied on two human tumour xenografts (HRT18 and HT29) and the murine tumour EMT6. This effect was compared with that obtained with carbogen alone. The fluorocrit (amount of fluorocarbon in the blood) and haematocrit remained unchanged from 7 to 65 min post-injection of the emulsion (8 ml/kg). Tumour-bearing mice were pretreated with 100% w/v PFOB emulsion doses ranging from 2 to 15 ml/kg in the presence of carbogen for 30 min prior to and during irradiation. The fluorocrit increased from 1.5% to 9.5% as the dose of 100% w/v PFOB emulsion increased from 2 to 15 ml/kg. The haematocrit remained the same for all the fluorocarbon emulsion doses used. Tumour radiosensitization varied with the fluorocarbon emulsion dose. Clinically relevant doses (2-4 ml/kg) of the 100% w/v PFOB emulsion plus carbogen produced significantly more radiosensitization than carbogen alone, with sensitizing enhancement ratios of 1.4 for EMT6 and 1.7 for HRT18. The radiosensitivity of HRT18 cells was thus very close to that obtained with normally oxygenated cells. For higher doses (8-15 ml/kg) the radiosensitizing effect of 100% w/v PFOB emulsion plus carbogen becomes comparable to that of carbogen alone. These experiments show that clinically useful doses of 100% w/v PFOB plus carbogen produced tumour radiosensitization only at relatively low fluorocrits. Thus the fluorocrit, and hence the fluorocarbon's oxygen-carrying capacity, is not the only factor involved in radiosensitizing tumour cells by oxygen-carrying fluorocarbon emulsions.

Adenocarcinoma↗
PubMed1991

Screening for antibodies associated with halothane hepatitis.

The diagnosis of halothane hepatitis (HH) may be assisted by detection of antibodies reacting to trifluoroacetylated proteins (anti-TFA antibodies). An enzyme-linked immunosorbent assay (ELISA) utilizing trifluoroacetylated rabbit serum albumin (TFA-RSA) as antigen detected anti-TFA antibodies in 67% of sera from patients for whom a clinical diagnosis of HH was made. Anti-TFA antibodies were detected in 33% of sera when using an ELISA with liver microsomal protein from halothane-treated rabbits as antigen. Absorption of the sera with untreated rabbit liver microsomal protein before using the microsomal protein ELISA resulted in detection of anti-TFA antibodies in 42% of sera. Using the presumptive hapten N-epsilon-trifluoroacetyl-1-lysine to block antibody binding in an ELISA resulted in positive detection in 50% of sera: the results did not always agree with the other ELISA methods. The TFA-RSA ELISA was the most sensitive method and, combined with the TFA-lysine blocking ELISA, resulted in 92% of sera from HH patients testing positive for HH-associated antibodies.

Animals↗
PubMed1991

Immunochemical detection of rodent hepatic and urinary metabolites of cooking-induced food mutagens.

Monoclonal antibodies, previously selected to bind either 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were evaluated to determine their binding properties with several known metabolites of these compounds purified from rat hepatocyte cultures. Both 2-N- and 5-substituted MeIQx metabolites were recognized by antibodies AIA-2 and AIA-11, while antibodies AIA-1 and AIA-12 bound N-substituted metabolites only. Anti-PhIP antibodies bound N-hydroxy-PhIP, N-sulfinamide-glutathione-PhIP and N-hydroxy-glucuronide-PhIP. Immunoaffinity columns incorporating these antibodies were used to concentrate and purify both the unmetabolized parent compounds and several relatively non-polar metabolites from the urine of rats exposed either to MeIQx or PhIP. Several of these metabolites corresponded with available standards of previously identified polar conjugate metabolites, e.g. N-sulfamate-MeIQx and N(OH)-gluc-PhIP, while others are as yet unidentified. Immunoaffinity chromatography is demonstrated as a promising means of selectively concentrating metabolites of PhIP and MeIQx from urine.

Animals↗
PubMed1991

Dexmedetomidine improves neurologic outcome from incomplete ischemia in the rat. Reversal by the alpha 2-adrenergic antagonist atipamezole.

Dexmedetomidine is an alpha 2-adrenergic agonist that decreases central sympathetic activity and reduces the anesthetic requirement for halothane. We evaluated the effect of dexmedetomidine on neurologic and histopathologic outcome from incomplete cerebral ischemia in the rat. Anesthesia was maintained with a 25-micrograms.kg-1.h-1 fentanyl infusion combined with 70% nitrous oxide. Incomplete ischemia was produced by unilateral carotid artery ligation combined with hemorrhagic hypotension to 35 mmHg for 30 min. Arterial blood gas tensions, pH, and head temperature were maintained at normal levels during the experiment. Four ischemic groups were tested: group 1 (n = 15) received an intraperitoneal (ip) saline injection (control); group 2 (n = 10) received an ip injection of 10 micrograms/kg dexmedetomidine 30 min before ischemia; group 3 (n = 10) received 100 micrograms/kg dexmedetomidine; and group 4 (n = 10) received 100 micrograms/kg dexmedetomidine plus 1 mg/kg atipamezole (an alpha 2-adrenergic antagonist). Neurologic outcome was evaluated for 3 days using a graded deficit score. Histopathology was evaluated in coronal section in caudate and hippocampal tissue segments. Dexmedetomidine (10 and 100 micrograms/kg) significantly decreased plasma catecholamines and improved neurologic and histopathologic outcome in a dose-dependent manner compared to control rats (P less than 0.05). Atipamezole abolished the decrease in catecholamines and the improvement in outcome seen with dexmedetomidine, confirming that these effects were mediated by alpha 2-adrenergic receptors. It is concluded that alpha 2-adrenoreceptor stimulation decreases sympathetic activity and decreases ischemic injury in a model of incomplete cerebral ischemia.

Adrenergic alpha-Agonists↗
PubMed1991

Postischemic treatment with hypothermia improves outcome from incomplete cerebral ischemia in rats.

It is known that hypothermia can improve outcome when induced during ischemia. We evaluated whether hypothermia can decrease ischemic injury if it is induced after incomplete ischemia. Rats were anesthetized with 1.4% inspired isoflurane, and ischemia was produced by right carotid ligation combined with hemorrhagic hypotension to 30 mm Hg for 30 min. Hypothermia (31 degrees C) was induced or normothermia (37 degrees C) was maintained for 1 h after completion of the ischemic challenge. Isoflurane anesthesia was maintained during this period. Five of 15 normothermic rats and 3 of 15 hypothermic rats died of stroke after ischemia. For all rats tested, hypothermic-treated animals had a significantly better neurologic outcome than normothermic rats (p less than 0.05). Histopathology showed a correlation of r = 0.67 (p less than 0.05) with neurologic outcome, and neuronal damage was significantly worse in normothermic compared with hypothermic rats (p less than 0.05). These results show that postischemic hypothermia will decrease neuronal injury and improve neurologic outcome associated with incomplete ischemia.

Animals↗
PubMed1991

The 21-aminosteroid U74006F does not markedly improve outcome from incomplete ischemia in the rat.

The 21-aminosteroid U74006F reportedly decreases neuronal injury following head injury or complete cerebral ischemia. We evaluated the ability of U74006F to improve outcome following incomplete cerebral ischemia in the rat. Ischemia was induced by right carotid occlusion combined with 30 min of hemorrhagic hypotension to 30 or 35 mm Hg. Animals in groups 1 and 2 were maintained on 1.4% isoflurane in room air and rats in groups 3 and 4 were ventilated with 70% nitrous oxide (N2O) and 30% oxygen. Rectal temperature was kept at 37C and PaCO2 and pH were maintained constant during ischemia. Group 1 (n = 10) and group 3 (n = 10) received a vehicle treatment. Group 2 (n = 10) and group 4 (n = 10) received 3 mg/kg of U74006F before ischemia and a 3-h infusion of 3 mg/kg/h of the drug after ischemia. Neurologic outcome was measured for 3 days and histopathology was evaluated at the end of the study. U74006F did not significantly improve neurologic outcome or histopathology during either isoflurane or N2O compared to the vehicle-treated groups. These results suggest that U74006F does not substantially inhibit ischemic damage produced in this model of incomplete cerebral ischemia.

Journal Article↗
PubMed1991

Prospective study of cytomegalovirus antigenemia in allograft recipients.

A recently published technique for direct detection of cytomegalovirus (CMV) antigenemia was tested prospectively in 27 transplant recipients. Eighteen patients developed active CMV infections and 10 of the 18 experienced CMV syndrome. All of the infections were detected by classical virus isolation and/or serologic techniques. No antigenemia was demonstrated.

Antigens, Viral↗