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Biomedical subjects

J Stephens

Publications and source records attributed to J Stephens.

At least 73 records · Page 4Linked to original sources
PubMed1983

Diabetes mellitus and coronary artery bypass. Short-term risk and long-term prognosis.

A consecutive series of 3,707 patients over a 12 year period undergoing isolated coronary artery bypass grafting (CABG) included 250 diet/oral medication-controlled and 162 insulin-dependent patients with diabetes mellitus. Analysis of 20 pre- and 18 intra-operative variables revealed a higher incidence of hypertension, left ventricular hypertrophy, and tobacco consumption for both diabetic groups. The extent of diffuse coronary disease as judged angiographically and at operation was significantly greater in both diabetic groups than in nondiabetic CABG patients. No difference was noted in the incidence of localized coronary disease between the groups. Average number of grafts was greater in both diabetic groups. The perioperative mortality was greater for both diabetic groups (5.1% for non-insulin-dependent diabetes, 4.5% for insulin-dependent diabetes) than for nondiabetic CABG patients (2.5%). The incidences of sternotomy complications and renal insufficiency were equal in the diabetic groups and both were significantly greater than in the nondiabetic group. The number of total hospital days was also greater in both diabetic groups. Actuarially determined survival and cardiac event-free curves revealed no difference between the diabetic groups but a significant difference between both diabetic groups as compared to the nondiabetic patient population, with follow-up extending to 10 years after CABG. Results indicate that diabetic patients have quantitatively and qualitatively more coronary artery disease than nondiabetic patients and have higher perioperative morbidity and mortality and a lower long-term survival rate than nondiabetic patients. However, results continue to justify selection of patients for CABG based on clinical and anatomic criteria regardless of diabetic status. Diabetes mellitus should be considered a patient-related risk factor, both short- and long-term, following CABG.

Aged↗
PubMed1980

Use of the AML scale to identify adjustment problems in fourth-, fifth-, and sixth-grade children.

This paper summarizes a series of studies of the technical merit of the AML scale when used to detect school maladaptation in a sample of 684 fourth, fifth, and sixth-grade children. Teachers, who did the rating, readily accepted this screening device. Preliminary norms are offered. Reliability and factor analytic studies show a reasonable degree of uniqueness and internal consistency among the three AML subscales. Relationships to other children's personality and behavioral indices (State-Trait Anxiety Inventory for Children and Cooper-smith's Self-Esteem Inventory) were found to be modest. The one-item L Scale correlated well (r = .65) with the California Achievement Test. First developed as a measure of school maladaptation in primary grade youngsters, the AML appears to be readily applicable at intermediate grade levels as well.

Age Factors↗
PubMed1980

Assessment of function of contractile segments in patients with left ventricular aneurysms by quantitative first pass radionuclide ventriculography. Haemodynamic correlation at rest and exercise.

Thirteen patients with left ventricular aneurysms complicating myocardial infarction were studied by contrast angiography and by first pass radionuclide ventriculography. The ejection fraction of the contractile segment (EFCS) was measured from both studies using a double hemishperoid model, and the values correlated closely. There was a monotonic relation between EFCS and stroke volume index measured from thermodilution cardiac outputs carried out simultaneously with the radionuclide study. When radionuclide ventriculography was performed at submaximal supine exercise, changes in EFCS paralleled changes in the total left ventricular ejection fraction in 10 of the 13 cases. In nine patients, changes in EFCS paralleled changes in stroke volume index and the relation between EFCS and stroke volume index was maintained at exercise. After administration of the vasodilator isosorbide dinitrate to 12 patients, repeat exercise radionuclide ventriculography showed an improvement in left ventricular ejection fraction and in eight patients EFCS improved. First pass radionuclide ventriculography can accurately estimate EFCS, which may be an important factor in predicting the likely response to aneurysmectomy. Changes in EFCS on exercise are reflected in changes in total left ventricular ejection fraction and stroke volume index. Isosorbide dinitrate may improve contractile segment function on exercise.

Adult↗
PubMed1979

Haemodynamic effects of dobutamine with special reference to myocardial blood flow. A comparison with dopamine and isoprenaline.

The haemodynamic effects of dobutamine (2.5 to 10 micrograms/min per kg) were determined in 5 patients without cardiac failure who were undergoing cardiac catheterisation for suspected coronary disease. Myocardial blood flow was determined by the coronary sinus thermodilution technique. Data were compared with those from two groups of 5 patients who received dopamine (4-8 micrograms/min per kg) and isoprenaline (0.005-0.025 micrograms/min per kg). Each drug was given in a lower and a higher dose, and all increased mean cardiac index (dobutamine, 18% and 39%; dopamine, 11% and 23%; isoprenaline, 15% and 44%). These increases were associated with significant increases in mean myocardial oxygen consumption (dobutamine, 38% and 61%; dopamine, 25% and 62%; isoprenaline, 20% and 45%). Mean myocardial blood flow was increased by each drug but mean myocardial oxygen extraction was decreased by isoprenaline, was increased by dopamine, and was unchanged by dobutamine. Each inotropic agent has a similar effect on myocardial oxygen consumption, but isoprenaline has a direct coronary vasodilator action while dopamine has a coronary vasoconstrictor action. Dobutamine has no direct effect upon coronary vascular tone.

Adult↗
PubMed1978

Improvement in exercise haemodynamics by isosorbide dinitrate in patients with severe congestive cardiac failure secondary to ischaemic heart disease.

Seven patients with severe chronic congestive cardiac failure secondary to ischaemic heart disease performed submaximal supine exercise before and after 5 mg sublingual isosorbide dinitrate at the time of cardiac catheterisation. Exercise before isosorbide dinitrate produced a poor response in left ventricular performance. After isosorbide dinitrate this response was significantly improved. Compared with the control exercise period, cardiac index increased from mean 2.6 to 3.1 1/min per m2 (P less than 0.0025), stroke volume index from mean 22 to 27 ml/m2 (P less than 0.0025), and left ventricular stroke work index from mean 21 to 30 g m/m2 (P less than 0.01). Mean left ventricular filling pressure fell from 37 to 26 mmHg (P less than 0.01). Although isosorbide dinitrate reduced left ventricular filling pressure at rest from mean 26 to 17 mmHg (P less than 0.005), there was no significant change in mean cardiac index or stroke volume index, while left ventricular stroke work index decreased from mean 29 to 22 g m/m2 (P less than 0.05). Isosorbide dinitrate effectively reduces left ventricular filling pressure in the resting patient with congestive cardiac failure but produces a more comprehensive improvement in left ventricular performance during exercise.

Aged↗
PubMed1978

Effects of selective and non-selective beta-adrenergic blockade on coronary dynamics in man assessed by rapid atrial pacing.

The effects on coronary dynamics of propranolol and atenolol were studied in 12 patients undergoing cardiac catheterisation for suspected coronary artery disease. Myocardial blood flow was measured using the coronary sinus continuous thermodilution technique. Data were obtained immediately after drug administration and during rapid atrial pacing. The immediate effects were similar for both drugs. A significant reduction in heart rate was accompanied by a small reduction in myocardial oxygen consumption. Changes in coronary sinus flow induced by rapid pacing were closely related to changes in tension-time index. This relation was not modified by propranolol or atenolol. Neither propranolol nor atenolol therefore has significant coronary vasoconstrictor properties. Cardioselectivity appears to be unimportant with respect to beta-adrenergic blockade and the coronary circulation.

Adult↗
PubMed1976

Replication of herpesvirus of turkeys in chick fibroblasts.

An ultrastructural study of chick embryo fibroblasts infected with herpesvirus of turkeys (HVT) revealed that infection produced degenerative effects in the cells ranging from alteration of cellular structures to complete lysis of the cells. Infection was indicated by margination of the nuclear chromatin, the presence of nuclear and cytoplasmic virions, destruction of mitochondria, loss of rough and smooth endoplasmic reticulum, and polykaryocytosis. Viruses entered the cell by penetrating the cytoplasmic membrane, and replication took place within the nucleus. Small nuclear particles observed as aggregates in the presence of few herpesvirions appeared to be a part of the replication of the virus. Viruses were released from the cell nucleus either naked or enveloped. Where karyolysis occurred, naked viruses were released as the karyoplasm diffused into the cytoplasm. Enveloped viruses were not observed leaving the nucleus, but it appeared that departure could have occurred by the budding of the viruses through the nuclear membrane. Where complete lysis of the cells occurred, the naked viruses were released into the extracellular fluid. Enveloped viruses were observed only in intact cells. Viruses which were observed extracellularly were naked viruses, and those that were observed entering the cell by penetrating the cytoplasmic membrane were also naked. This evidence suggests that in vitro HVT does not require the envelope to be infective.

Animals↗
PubMed1975

Society of the alone: Freedom, Privacy and Utilitarianism as dominant norms in the SRO.

The social world of the aged SRO tenant is described and analyzed. Charteristic features include an impoverishment of social roles and relationships which result in a "world of strangers". Dominant norms of SRO life which preclude the establishment of intimacy are examined; these include prescriptive norms of privacy, freedom, and utilitarianism

Aged↗
PubMedDate not supplied

Surgical management of thyroid cancer invading the airway.

BACKGROUND: Locally advanced thyroid cancer invading the tracheal cartilage represents a difficult treatment dilemma during thyroidectomy. METHODS: A retrospective chart review was performed to determine the results of laryngotracheal resection or tracheal cartilage shave with adjuvant radiotherapy in patients with locally advanced thyroid cancer invading the upper airway. RESULTS: Of 597 patients undergoing thyroidectomy for thyroid cancer, 40 were found to have laryngotracheal invasion. Thirty-five patients with superficial invasion underwent cartilage shave procedures with adjuvant radiotherapy; five with full-thickness invasion underwent radical resection, including tracheal sleeve resection (n = 3) or total laryngectomy (n = 2). Histologic subtypes included papillary (n = 32), follicular (n = 2), Hurthle cell (n = 1), medullary (n = 3), and anaplastic (n = 2). Of the cartilage shave group, 25 are currently alive with no evidence of disease at a mean follow-up of 81 months (range 1-290). Six developed isolated local/regional recurrence and were managed with total laryngectomy (n = 1), tracheal resection (n = 1), cervical lymphadenectomy (n = 1), or repeat radiotherapy (n = 3). All six patients remain free of disease at a mean follow-up of 5 years. Of those who underwent initial laryngotracheal resection, four remain free of disease at a mean follow-up of 5 years. The rates of 10-year disease-free survival and overall survival for all patients were 47.9% (95% confidence interval [CI] 24.8, 71.0) and 83.9% (95% CI 70.3, 97.5), respectively. CONCLUSIONS: These data suggest that adequate management of thyroid cancer with laryngotracheal invasion can be achieved with a more conservative surgical approach and adjuvant radiotherapy, reserving more radical resections for extensive primary lesions or locally recurrent disease.

Adolescent↗
PubMedDate not supplied

Lack of an association between acute gastroenteritis, acute respiratory infections and malaria in young Gambian children.

The incidence of acute gastrointestinal and acute respiratory infections was measured in 2 groups of approximately 750 Gambian children aged 3-59 months during a 3-year period. One group of children was partially protected against malaria by fortnightly chemoprophylaxis with Maloprim whilst children in the other group were infected much more frequently. Mortality from acute gastroenteritis and from acute respiratory infections was similar in the 2 groups. The proportions of children in each group who complained of gastrointestinal or severe respiratory symptoms on morbidity surveillance were also similar. Thus, no evidence was found to suggest that malaria plays either a direct or indirect role in causing acute gastrointestinal or respiratory infections in young children in The Gambia.

Acute Disease↗