PubMed Health⌕ Search

Biomedical subjects

M S Stevens

Publications and source records attributed to M S Stevens.

14 recordsLinked to original sources
PubMed2000

Hyperkalemia in hospitalized patients.

OBJECTIVE: Evaluate the prevalence of hyperkalemia (potassium > 5.5 mmol/l) in hospitalized patients not on dialysis, as well as the association of medications, impaired renal function and comorbid conditions with hyperkalemia. DESIGN: A retrospective case-control method. SETTING: A tertiary care teaching hospital. PATIENTS: Hyperkalemic adults not on dialysis with age and sex matched controls. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The use of medications associated with hyperkalemia and renal function using a calculated creatinine clearance were compared in the hyperkalemic and control groups. RESULTS: 35 adult patients with hyperkalemia who were not receiving dialysis were identified, with a prevalence in the hospitalized population of 3.3%. The hyperkalemic patients were older than the general hospital population (p < 0.05). Compared with controls, hyperkalemic patients: had a lower creatinine clearance (p < 0.05), were more likely to be taking angiotensin-converting enzyme inhibitors (p < 0.05), and had an increased frequency of diabetes mellitus (p < 0.001). All of the control patients survived their hospitalization, but the mortality rate in the hyperkalemic group was 17% (p < 0.0001). None of the deaths were directly attributable to hyperkalemia. CONCLUSIONS: Hyperkalemia is more frequent in older patients and is usually mild. Hyperkalemia is associated with diabetes mellitus, diminished renal function and the use of angiotensin-converting enzyme inhibitors. An elevated serum potassium level in a hospitalized patient may be a marker for a significantly increased risk of death, which is due to underlying medical problems and is not a consequence of the hyperkalemia.

Adult↗
PubMed1995

Targeted inactivation of the gene encoding the mouse alpha 2c-adrenoceptor homolog.

alpha 2-Adrenergic receptors (alpha 2-ARs) regulate a wide range of physiological functions and are targets for clinically important antihypertensive and anesthetic agents. Three genes encoding alpha 2-AR subtypes have been cloned in humans and mice, but the physiological significance of each subtype has not been completely characterized. The available agonist and antagonist compounds are not sufficiently subtype selective to allow the unambiguous dissection of these receptors in vivo. As an alternative approach, we have used gene targeting in embryonic stem cells to disrupt the Adra2c gene, which encodes the alpha 2c-AR subtype in mice. Adra2c-/Adra2c- animals do not express a functional alpha 2c-AR transcript, as detected by Northern blotting or reverse transcription-polymerase chain reaction analysis. In addition, these mice have markedly reduced [3H]rauwolscine binding in their caudate putamen and in other brain regions normally expressing Adra2c binding sites. Adra2c-/Adra2c- mice, however, are viable and fertile and appear grossly normal. Expression levels of Adra2a and Adra2b mRNA in brain and kidney are not altered by the Adra2c knockout. These data suggest that up-regulation of Adra2a or Adra2b does not compensate for the Adra2c deficiency and that the receptor encoded by Adra2c is not required for normal mouse development or for survival in a laboratory environment.

Animals↗
PubMed1994

Parents coping with infants requiring home cardiorespiratory monitoring.

The investigator used a semistructured interview and McCubbin's Familial Invulnerability Test to examine how mothers and fathers cope with caring for a cardiorespiratory-monitored infant in the home. Content analysis of interview data showed that the persistent gravity of the situation and fears of incompetency in managing their infant's care, coupled with inadequate respite, were the greatest source of hardship for parents. Informational and emotional support from family members and professionals were resources used to manage this experience. Both emotion-focused and problem-focused strategies were used to cope with this situation.

Adaptation, Psychological↗
PubMed1988

Pneumonectomy for severe inflammatory lung disease. Results in 64 consecutive cases.

Severe inflammatory lung disease resulting in severe unilateral pulmonary pathology necessitating pneumonectomy is still encountered in third world populations. A retrospective study of the last 64 patients undergoing pneumonectomy was performed. The underlying lung pathology was: destroyed lung due to tuberculosis in 33 patients; severe bronchiectasis in 25; necrotizing pneumonia in 4; lung abscess in 1 and hypoplastic lung in 1 patient. The perioperative management of these patients is outlined. Perioperative complications included respiratory failure in 4, secondary haemorrhage in 2 and post-pneumonectomy empyema in 5 patients. There were 2 mortalities (3.1%), both due to contralateral spillage with fulminant respiratory failure. Excellent results were achieved in 89% of the patients.

Adolescent↗
PubMed1987

Double valve replacement in a patient with osteogenesis imperfecta.

Successful mitral and aortic valve replacement in a patient with osteogenesis imperfecta (OI) is reported. The potential complications of valvular dehiscence and bleeding in patients with this connective tissue disorder is discussed with a short review of the reported experience of valvular surgery in patients with OI.

Adult↗
PubMed1984

Associated effects of sodium butyrate on histone acetylation and estrogen receptor in the human breast cancer cell line MCF-7.

Sodium butyrate at a concentration of 5mM causes significant hyperacetylation of the core histones in the human breast cancer cell line MCF-7. Histone hyperacetylation was achieved in rapidly-growing cells at 40% confluency after 24 hours in 5mM sodium butyrate. More nearly confluent cells did not reach as high a level of histone hyperacetylation. Upon assaying the estrogen receptors, both cytosolic and KCl-extractable nuclear, we found that butyrate treatment had lowered the estrogen receptor levels in both compartments. To our knowledge this is the first report of an effect of sodium butyrate on estrogen receptor levels.

Acetylation↗
PubMedDate not supplied

A comparison of mothers' and fathers' perceptions of caring for an infant requiring home cardio-respiratory monitoring.

The purpose of this study was to compare (a) what fathers and mothers considered stressful about caring for a cardio-respiratory monitored infant at home and (b) how they coped with this experience. Twenty-three father and mother pairs with infants currently receiving or having received home cardio-respiratory monitoring within the past six months were interviewed in their homes. Content analysis of interview data revealed five types of stressors and ten coping strategies used to manage these stressors. Fathers and mothers described similar stressors and coping strategies. Differences existed in how fathers and mothers interpreted these stressors and the type of strategies used.

Adaptation, Psychological↗