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Biomedical subjects

S Metz

Publications and source records attributed to S Metz.

At least 55 records · Page 3Linked to original sources
PubMed1992

The progression of untreated HIV-1 infection prior to AIDS.

Using a case-control study of untreated men, we investigated the physical, mental, and economic effects of human immunodeficiency virus (HIV-1) infection prior to the diagnosis of acquired immunodeficiency syndrome (AIDS). Beginning 2 to 2.5 years prior to AIDS, case subjects reported more of 12 HIV-1 related symptoms and during the year prior to AIDS, at least 30.6 extra days of these symptoms than did control subjects. Within the 6 months preceding AIDS, case subjects' unemployment rose to 9% (P < or = .05) and depression to 34.2% (P < or = .001). At 6 to 12 months and within 6 months before AIDS, 17.1% and 31.5%, respectively, were anemic, while 37.7% and 64.7% had CD4+ counts less than 200 x 10(6)/L. Diagnosing AIDS at CD4+ counts less than 200 x 10(6)/L could significantly reduce pre-AIDS morbidity. Other implications of these findings are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Gene expression of type I phospholipase A2 in pancreatic beta cells. Regulation of mRNA levels by starvation or glucose excess.

Messenger RNA from intact rat pancreatic islets, or from transformed hamster beta (HIT) cells, hybridized with the cDNA probe for type I (but not type II) phospholipase A2. The levels of phospholipase A2 mRNA increased in islets from fasted rats; they decreased in islets cultured in a high glucose concentration (control values at 5.5 mM glucose = 150 +/- 6% of those at 22 mM) which impaired subsequent insulin secretion (reduction in second-phase release = 70 +/- 11%). These studies uniquely demonstrate that type I phospholipase A2 is expressed specifically in beta cells and that nutrient availability modulates transcript levels, an effect which could that nutrient availability modulates transcript levels, an effect which could contribute to the detrimental influence of prolonged hyperglycemia on islet function.

Animals↗
PubMed1991

Benefits of a glucose-containing priming solution for cardiopulmonary bypass.

Benefits from the use of glucose-containing intravenous and priming solutions during coronary artery bypass operation have not been documented, but an increased risk of postoperative neurologic deficit by hyperglycemia has been suggested. To determine benefits, 107 patients undergoing coronary artery bypass operation were managed identically except that one group (n = 54) received 5% dextrose in lactated Ringer's solution (D5LR) as the sole intravenous and priming solution during operation and a second group (n = 53) received the same solution without glucose (LR). During cardiopulmonary bypass, the D5LR group required significantly less additional crystalloid to maintain safe oxygenator levels and flow (1.8 +/- 3.3 vs 15.8 +/- 20.9 mL.kg-1.h-1) and produced more urine (3.5 +/- 3.2 vs 1.2 +/- 1.4 mL.kg-1.h-1). By 24 h after operation, fluid balance in the LR group was approximately 2 L more positive than in the D5LR group. Five days after operation, the D5LR group weighed less than preoperatively (-0.8 +/- 2.6 kg), whereas the LR group gained weight (+1.0 +/- 2.8 kg). We conclude that use of glucose-containing solutions during coronary artery bypass operation benefits patients by decreasing perioperative fluid requirements and postoperative fluid retention. Because embolism is the cause of most postoperative neurologic deficits, any increased risk by hyperglycemia is small.

Blood Glucose↗
PubMed1991

[Cystic fibrosis and pregnancy. Current results of a study (1980-1990)].

This study is a recent collection of data on 19 women with cystic fibrosis who became pregnant between 1980 and 1990. The following data have been recorded:--age at diagnosis, progress of disease prior and during pregnancy, and during confinement. Satisfactory clinical score values and the fact that the mean age at diagnosis was 10.5 years indicated a less serious nature of the disease in the group studied. Pregnancy was complicated by pulmonary exacerbations and by poor weight gain in two thirds of cases. No maternal deaths during pregnancy and delivery were recorded. Abortions were induced in two pregnancies. More than one third of newborns were premature. It is noteworthy that of the 22 infants 16 were male. All of the children had negative sweat chloride tests. Eleven women could breast feed successfully. In twelve cases the mother's state of health deteriorated after pregnancy, and did not return to that before gravidity.

Abortion, Therapeutic↗
PubMed1990

Low activated coagulation time during cardiopulmonary bypass does not increase postoperative bleeding.

The activated coagulation time (ACT) is widely used to monitor adequacy of anticoagulation during cardiopulmonary bypass despite absence of data establishing an ACT below which adverse outcomes occur. For anticoagulation before cardiopulmonary bypass, we administered a single dose of heparin (300 U/kg) to 193 patients and measured ACT and heparin levels at intervals after administration. No additional heparin was administered to any patient. Clot formation in the cardiopulmonary bypass circuit and excessive postoperative chest tube drainage were considered outcomes indicating inadequate anticoagulation. Cardiopulmonary bypass averaged 59 +/- 23 minutes (range, 30 to 138 minutes). Activated coagulation time values at every sampling period were normally distributed. In 51 patients (26.4%) ACT values were less than 400 seconds, including 4 less than 300 seconds, at some sampling time after heparinization. Patients with low ACT values did not bleed more postoperatively than those with high ACT values, nor was bleeding related to heparin level. No clots were found in any perfusion circuit. We conclude that a minimum ACT value for adequacy of heparinization is not yet defined but that it is less than 400 seconds.

Blood Coagulation↗
PubMed1987

Rebound hypertension after discontinuation of transdermal clonidine therapy.

Three (and possibly all four) elderly hypertensive patients who were followed sequentially after discontinuation of transdermal clonidine monotherapy manifested a rapid rise in blood pressure to levels above control (pre- and post-therapy) readings. No signs of an "overshoot" in plasma norepinephrine levels or symptoms of beta-adrenergic overactivity were seen. Such rebound hypertension suggests hypersensitivity to alpha-adrenergic receptor stimulation and could pose a heretofore unreported potential hazard to elderly or otherwise compromised patients who discontinue transdermal clonidine therapy.

Administration, Cutaneous↗
PubMed1987

Prior carotid surgery does not affect the reliability of landmarks for location of the internal jugular vein.

Twenty-one volunteer subjects who had undergone prior carotid endarterectomy (CEA) agreed to an ultrasound study of the neck. The transducer was held as one would hold a cannulating needle and ultrasound images were obtained of the great vessels in the neck. Each of two cannulating techniques was simulated on each side of every patient's neck. Photographs of the ultrasound images were analyzed to score "hit" or "miss" for the internal jugular vein (IJV) and the carotid artery (CA), and to measure both the angle between these vessels and the distance from the skin to the IJV. In 11 subjects, the effect of a Valsalva maneuver on IJV width was also determined. Owing to bilateral CEA in 9 of the 21 subjects, there were 12 studies of nonsurgical sides (NSS) and 30 studies of surgical sides (SS). SS and NSS hit frequencies were statistically indistinguishable both for the IJV and the CA. In no photograph did the IJV lie medial to the CA. A Valsalva maneuver did not change IJV width on either the SS or the NSS. These data show that prior CEA does not affect the location of the IJV. Tissue alterations or adhesions may render actual IJV cannulation more difficult or risky. The data suggest but do not prove that prior CEA may not increase the incidence of CA puncture under clinical conditions.

Carotid Arteries↗
PubMed1986

Effect of dextrose-crystalloid priming solution on fluid requirements and urine output during cardiopulmonary bypass.

We examined the influence of the addition of dextrose to crystalloid cardiopulmonary bypass priming solution. Ten patients received only lactated Ringer's solution during the perioperative period and as their cardiopulmonary bypass priming solution, while ten others, managed identically in all other respects, received only 5% dextrose in lactated Ringer's solution (D5LR). During cardiopulmonary bypass, patients who did not receive glucose required more supplementary fluid (20.0 vs 2.2 ml Kg(-1) hr(-1)) to maintain adequate flow rates, but made less urine (1.1 vs 2.8 ml Kg(-1)) than their glucose-treated cohorts. Postoperative hemoglobin was significantly lower in the group receiving lactated Ringer's solution (-14%) but not in the patients receiving D5LR (-6%). We conclude that the addition of dextrose to a crystalloid priming solution decreases intraoperative fluid requirements and helps restore precardiopulmonary bypass hemoglobin without the need for diuretics or blood products.

Journal Article↗
PubMed1986

Goitrous Hashimoto's thyroiditis. Lack of association with HLA antigens.

We studied HLA antigen frequency in 54 carefully selected patients with goitrous Hashimoto's thyroiditis. All had an appropriate clinical course, positive family history, antithyroid antibodies and/or a needle biopsy indicating chronic lymphocytic thyroiditis. We found no statistically significant association with any HLA-A, -B, -C or DR specificity.

Female↗
PubMed1985

Halothane concentration does not alter the threshold for epinephrine-induced arrhythmias in dogs.

Halothane lessens the dose of epinephrine necessary to induce ventricular arrhythmias. However, results of a previous study in dogs anesthetized at two halothane concentrations suggested, but did not confirm, that at the higher concentration (1.7%) myocardial sensitization to epinephrine was less pronounced. This study was designed to determine the myocardial sensitizing effect of halothane at four concentrations: 0.5, 1.0, 1.5, and 2%. To define the appropriate time interval between repeated epinephrine infusions, plasma epinephrine decay curves were assessed. These data indicated that at 7 min the contribution of the residual epinephrine level to the peak level was negligible. Therefore, 7 min was selected as the interval between epinephrine infusions. The arrhythmogenic dose of epinephrine (ADE) was measured at four concentrations of halothane, 0.5, 1.0, 1.5, and 2.0%. To determine the ADE at the subanesthetic concentration of halothane (0.5%), anesthesia was supplemented with etomidate. In a preliminary study, the authors confirmed that this intravenous hypnotic agent did not affect the halothane-epinephrine arrhythmogenic interaction. By analysis of variance, halothane concentration was shown to have no significant influence on the ADE (P greater than 0.05). The authors' data indicate that, over a clinically appropriate range, halothane concentration does not alter the threshold for the development of epinephrine-induced ventricular arrhythmias.

Animals↗
PubMed1985

Postcountershock myocardial damage after pretreatment with adrenergic and calcium channel antagonists in halothane-anesthetized dogs.

Transthoracic electric countershock can cause necrotic myocardial lesions in humans as well as experimental animals. The authors investigated the effect on postcountershock myocardial damage of pretreatment with prazosin (0.1 mg/kg), an alpha-1 antagonist; L-metoprolol (0.5 mg/kg), a beta-1 antagonist, and verapamil (0.5 mg/kg), a calcium channel-blocking agent. Twenty dogs were anesthetized with halothane and given two transthoracic countershocks of 295 delivered joules each after drug or vehicle treatment. Myocardial injury was quantitated 24 h following countershock by measuring the uptake of technetium-99m pyrophosphate in the myocardium. Elevated technetium-99m pyrophosphate uptake occurred in visible lesions in most dogs regardless of drug treatment. For each of four parameters of myocardial damage there was no statistically significant difference between control animals and those treated with prazosin, metoprolol, or verapamil. These data suggest that adrenergic or calcium channel-mediated mechanisms are not involved in the pathogenesis of postcountershock myocardial damage.

Anesthesia, Inhalation↗
PubMed1985

Ventilation during transport of postoperative patients: comparison of methods.

Changes in arterial blood gases as a result of transporting 28 stable postoperative cardiovascular surgical patients to the intensive care unit were studied. Three methods of ventilation during the 3-minute transport period were compared. All patients were ventilated with 100% oxygen prior to transport. Nine patients were ventilated with air by a self-inflating, non-rebreathing bag. Ten patients were not ventilated at all. Nine patients were ventilated with oxygen in a closed rebreathing circuit constructed from disposable portions of the anesthesia circuit. Oxygen tension on arrival in the intensive care unit was highest in the group ventilated with the closed rebreathing circuit and lowest in the group ventilated with room air. Carbon dixoide tension rose 6.2 mm Hg/min in unventilated patients, 3.2 mm Hg/min in patients ventilated with the closed rebreathing circuit, and did not change in the group ventilated with air. We conclude that stable patients can be safely transported while breathing air for 3 minutes. For longer periods of transport, the closed rebreathing circuit provides high oxygen tension with acceptable hypercarbia and provides a convenient alternative to the use of portable oxygen tanks.

Journal Article↗