Search PubMed⌕ Search

Biomedical subjects

B Chernow

Publications and source records attributed to B Chernow.

At least 55 records · Page 3Linked to original sources
PubMed1990

Circulating interleukin-1 and tumor necrosis factor in septic shock and experimental endotoxin fever.

Interleukins (IL) -1 beta and -1 alpha and tumor necrosis factor (TNF-alpha) were measured by radioimmunoassay in plasma samples from 44 healthy individuals, 15 patients in septic shock, and 6 volunteers infused with endotoxin. Plasma IL-1 alpha levels were low (40 pg/ml) or undetectable in all situations. In 67% of the healthy subjects, plasma IL-1 beta levels were less than 70 pg/ml. Septic patients had higher plasma IL-1 beta levels (120 +/- 17 pg/ml, P = .001); those of surviving patients were higher than those of patients who died (P = .05). Plasma TNF-alpha concentrations in septic individuals were elevated (119 +/- 30 pg/ml) and correlated with severity of illness (r = .73, P = .003), but no correlation was observed between plasma IL-1 beta and TNF-alpha concentrations in individual samples. Infusion of endotoxin caused a twofold elevation of IL-1 beta, from a baseline of 35 +/- 5 pg/ml to a maximum of 69 +/- 27 pg/ml at 180 min (P less than .05). Peak TNF-alpha levels after endotoxin infusion were 15 times higher than IL-1 beta levels, were attained more rapidly (90 min), and as with the septic patients, did not correlate with IL-1 beta levels. These data support the concept that plasma IL-1 beta and TNF-alpha concentrations are regulated independently and are associated with different clinical outcomes.

Adolescent↗
PubMed1990

Renal hemodynamics and prostaglandin E2 excretion in a nonhuman primate model of septic shock.

The mechanisms responsible for renal insufficiency in septic shock (SS) have not been well characterized. We therefore investigated renal hemodynamics and the renal excretion of prostaglandin E2 (PGE2) in a nonhuman primate model of severe, low systemic vascular resistance (SVR) SS. In 18 cynomolgus monkeys, SS was induced by an infusion of 3 x 10(10) live Escherichia coli per kg; five saline-treated animals served as nonseptic controls. Systemic and renal hemodynamics, and urine PGE2 concentrations were determined over the 3 h after the induction of sepsis. The septic group demonstrated a significant (p less than .001) and sustained depression in both mean arterial pressure and SVR. Septic animals also had significantly lower effective renal plasma flow (ERPF) (p less than .01) and glomerular filtration rate (GFR) (p less than .01) compared to controls. Furthermore, the renal hemodynamic response to SS was biphasic, with significant increases in ERPF and GFR in the second hour postsepsis, followed by a pronounced decrease in the third postseptic hour. The septic group also demonstrated an increase in the renal excretion of PGE2 (p less than .001) that was temporally associated with the transient recovery in renal hemodynamics during the second postseptic hour. These sepsis-induced renal alterations may be important in the pathogenesis of renal insufficiency complicating clinical SS.

Acute Kidney Injury↗
PubMed1990

Plasma cortisol levels in patients with septic shock.

To investigate the endogenous adrenocortical response to sepsis, plasma cortisol concentrations were measured in 37 patients (53 +/- 3 yr of age) with septic shock. Patients were studied 11 +/- 2 h after shock commenced. Vasopressor therapy was required in 35 of 37 patients (median dopamine infusion rate of 11 micrograms/kg.min, range 3 to 74). Plasma cortisol concentrations were increased markedly (median 50.7 micrograms/dl, range 15.6 to 400) above normal values (10 to 20 micrograms/dl) in patients with septic shock. Neither patients who reversed their shock nor those who survived to hospital discharge had significantly different plasma cortisol concentrations from those who did not. Patients with Gram-positive infections had increased cortisol levels compared with those who had Gram-negative infections (median 83 micrograms/dl, range 32 to 400 vs. median 44 micrograms/dl, range 16 to 81, respectively; p less than .05). The source of infection, amount of vasopressors infused, and severity of shock were not associated with differences in cortisol concentrations. The length of time in shock before collection of the blood sample for measurements of cortisol and mean arterial pressure at the time of blood collection had significant but weak negative correlations with cortisol concentrations (p less than .05, rs = .37 and p less than .05, rs = -.40, respectively). We conclude that plasma cortisol concentrations are increased in patients with septic shock, but that the degree of increase is variable. This variability may, in part, be related to type of infection, length of time in shock, and BP at the time of blood sampling.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Insufficiency↗
PubMed1990

Serum prolactin concentrations in patients with the acquired immunodeficiency syndrome.

Experimental evidence suggests that prolactin is an important immunomodulator hormone. Because this endocrine-immune link may represent a potential new therapeutic avenue, we considered its application in states of immunodeficiency. We hypothesized that serum prolactin concentrations might be abnormal in AIDS. To test this hypothesis, we measured serum prolactin concentrations in blood samples obtained from patients who had either AIDS (n = 15) or AIDS-related complex (n = 12), asymptomatic subjects who were antibody-positive for human immunodeficiency virus (HIV) (n = 10), HIV antibody-negative homosexual subjects (n = 10), and heterosexual HIV antibody-negative controls (n = 21). We found no difference in the serum prolactin concentrations between the five subject groups. We conclude that circulating prolactin values are not altered by HIV infection; however, the possibility that prolactin administration may modulate immune function remains to be tested.

AIDS-Related Complex↗
PubMed1990

Hypothyroidism and pleural effusions.

Serous effusions have been thought to be an unusual complication of hypothyroidism and most commonly have been associated with ascites, pericardial fluid and heart failure. Pleural fluid as an isolated finding in hypothyroidism is apparently rare and complete analysis of these hypothyroid-associated pleural effusions has not been described. To determine the frequency, chemical characteristics and clinical associations of hypothyroidism and pleural effusions, the medical records of 128 patients with hypothyroidism (defined by an increased serum TSH concentration) were reviewed. The majority of effusions in patients with hypothyroidism were due to other diseases. Effusions solely due to hypothyroidism appeared to be a real entity. These effusions were borderline between exudates and transudates and showed little evidence of inflammation.

Aged↗
PubMed1989

Transient hypertension after two phenylpropanolamine diet aids and the effects of caffeine: a placebo-controlled follow-up study.

PURPOSE AND PATIENTS AND METHODS: Reports of severe adverse reactions following the ingestion of single (75 mg) or double doses of the sympathomimetic drug phenylpropanolamine (PPA), with and without caffeine, prompted us to undertake a study of the effects of five drug preparations (75 mg PPA, 150 mg PPA, 75 mg PPA plus 400 mg caffeine, 400 mg caffeine, and placebo) in 16 resting, normotensive subjects. The study was of a double-blind, randomized, crossover design. Each subject consented to take the five drug preparations on different study days, which were separated by at least 48 hours. RESULTS: Compared with blood pressure (BP) values obtained after placebo ingestion, significant BP increases occurred over several hours following 150 mg PPA and after 75 mg PPA plus 400 mg caffeine. Significant BP increases after ingestion of 75 mg PPA and after 400 mg caffeine were less frequent. The mean peak BP following 150 mg PPA was 173 +/- 9/103 +/- 4 mm Hg, compared with 148 +/- 4/97 +/- 3 mm Hg after the other three active preparations; after placebo, peak BP reached 137 +/- 8/85 +/- 5 mm Hg. CONCLUSION: These results indicate that 150 mg PPA (the amount in two diet aids) substantially elevates BP. Our findings may explain some of the recent case reports of nontraumatic intracranial hemorrhage in young, healthy persons ingesting PPA at recommended or minimally greater dosages. We suggest physicians inform patients who are likely consumers of PPA (i.e., those with allergies, those with eating disorders, overweight persons, women during the postpartum period) and patients at risk for stroke (i.e., the elderly and hypertensive patients) of the risks of taking more than the recommended amounts of PPA and of combining caffeine with PPA.

Adult↗
PubMed1989

Hypocalcemia in critically ill children.

To determine the prevalence and clinical consequences of hypocalcemia in pediatric intensive care unit patients, we prospectively studied calcium homeostasis in 145 of these patients. The total serum calcium concentration was measured in all patients. The serum ionized calcium concentration was measured in blood samples collected from those 71 (49%) patients who had low total serum calcium values (less than 8.5 mg/dl (2.12 mmol/L). Of the 71 patients, 26 (36.6%) had ionized hypocalcemia. Therefore the prevalence of ionized hypocalcemia was at least 17.9% (26/145). Death occurred in 8 (31%) of 26 patients with ionized hypocalcemia versus 3 (2.5%) of 119 patients with normocalcemia (p less than 0.0001). However, the severity of illness score was higher (p less than 0.05) in the children with ionized hypocalcemia than in normocalcemic children (mean Therapeutic Intervention Scoring System score 33 +/- 17 vs 22 +/- 11, respectively). More of the children with ionized hypocalcemia had sepsis (p = 0.0299) and they required the administration of vasopressor agents more often (p = 0.0002) than their normocalcemic counterparts. Of the 26 patients with ionized hypocalcemia, 17 (65.4%) had biochemical evidence of either absolute or relative hypoparathyroidism, determined by means of an immunoradiometric assay that measures only biologically active parathyroid hormone. We conclude the following: (1) ionized hypocalcemia is common in severely ill children. (2) Patients with ionized hypocalcemia have a higher mortality rate than those with normocalcemia; however, because the former are more severely ill, no causality is apparent or suggested. (3) Functional hypoparathyroidism may occur in critically ill children.

Adolescent↗
PubMed1989

Atropine pharmacokinetics are affected by moderate hemorrhage and hypothyroidism.

Atropine is used both to treat a variety of clinical disorders and as an antidote to cholinesterase poisoning. While various conditions affect the physiologic responses to atropine, little is known of the pharmacokinetics of this drug except under resting conditions. Pharmacokinetic studies were performed in mongrel dogs under two experimental conditions, moderate hemorrhage and hypothyroidism, to determine whether im absorption and elimination of atropine (0.05 mg/kg body weight) were affected by changes in hemodynamic or metabolic status. Using a randomized, crossover experimental design, it was found that during hypovolemia the mean volume of distribution was reduced by 22% (2.50 +/- 0.62 vs. 3.21 +/- 0.63 L/kg), with no changes in peak serum level, total atropine availability, elimination half-life, or whole-body clearance. Hypothyroidism was associated with a significant increase in peak serum atropine concentration (26.4 +/- 3.9 vs. 20.6 +/- 4.9 ng/ml) and drug bioavailability (48.5 +/- 8.8 vs. 30.0 +/- 10.7 ng/ml.h), while the clearance was reduced by 39% (426 +/- 34 vs. 696 +/- 187 ng/ml.min). These results suggest that atropine kinetics are not altered appreciably during moderate hemorrhage. In hypothyroidism, alterations in atropine pharmacokinetics may warrant modification of drug dose and frequency of administration.

Animals↗
PubMed1989

Hypomagnesemia in patients in postoperative intensive care.

In order to study the clinical consequences of postoperative hypomagnesemia, the serum magnesium (Mg) concentration was measured in samples of blood collected from 193 patients admitted to two postoperative ICUs. On admission to the ICU, 117 patients (61 percent) had hypomagnesemia (serum Mg less than 1.5 mEq/dl), 66 patients (34 percent) had normomagnesemia (1.5 to 2.0 mEq/dl), and ten patients (5 percent) had hypermagnesemia (greater than 2.0 mEq/dl). There were no correlations between the severity of illness score (r = 0.145) or the degree of hypoproteinemia (r = 0.01) and the postoperative serum Mg level. Patients with severe hypomagnesemia (serum Mg less than or equal to 1.0 mEq/dl) experienced hypokalemia more often (p less than 0.02) than the others in the study. Furthermore, those with severe hypomagnesemia had a higher mortality rate (7/17 or 41 percent) than the remainder of the population studied (22/176 or 13 percent) (p less than 0.02). Those with severe hypomagnesemia had received aminoglycosides more often (p less than 0.001) than those with normal serum Mg concentrations. The serum Mg level was not a sensitive (68 percent) or specific (37 percent) predictor of survival. Our conclusions were as follows: (1) hypomagnesemia is common in postoperative ICU patients; and (2) patients in the postoperative ICU who have severe hypomagnesemia have a higher mortality and more hypokalemia than similarly ill patients with normomagnesemia. Because of the association between aminoglycoside therapy and severe hypomagnesemia, we recommend measurement of this variable in those patients receiving aminoglycosides. Furthermore, Mg replacement therapy is recommended for those patients with serum Mg values of 1 mEq/dl or less.

Calcium↗
PubMed1989

Alterations in sympathetic nervous system activity with intraoperative hypothermia during coronary artery bypass surgery.

To determine how intraoperative hypothermia associated with coronary bypass surgery (CABS) alters sympathetic nervous system (SNS) activity, we prospectively studied 21 adult CABS patients and measured preoperative, intraoperative, and postoperative circulating catecholamine concentrations. Because thyroid hormone levels change rapidly following CABS, we also serially measured these hormone levels. The measured plasma concentrations for each of the above variables were corrected for hemodilution during CABS by using serum albumin changes as a reference. It was concluded that important alterations in SNS activity and thyroid hormone homeostasis occur in humans during CABS and deep hypothermia, and that changes in core temperature may contribute to these findings. We speculate that these hormonal changes may influence the response to adrenergic receptor therapy in hypothermic patients and may contribute to arrhythmias during rewarming and the immediate postoperative period.

Acetylcholinesterase↗
PubMed1989

The pharmacotherapy of septic shock.

Septic shock is a common clinical problem in the intensive care setting. The high mortality rate associated with septic shock, regardless of age, reflects the inadequacy of available therapeutic approaches. The purpose of this article is to review the current pharmacologic approaches to the treatment of septic shock with an emphasis on the pathophysiologic correlations of these treatments.

Adrenergic Agonists↗
PubMed1989

Catecholamines: study of interspecies variation.

In the last three decades, numerous articles on plasma catecholamine concentrations in various settings have been published in the medical literature. Despite this abundance of information, no summary article has analyzed the species variations in circulating catecholamine concentrations. In this paper, the plasma catecholamine responses to various stresses in 31 animal groups have been compiled from greater than 200 publications (with greater than 5000 animal subjects). Primitive cartilaginous fish such as the shark and the lamprey have the highest reported basal plasma catecholamine concentrations. Birds, mammals, and teleost fish have the lowest concentrations. The lower circulating catecholamine concentrations parallel anatomical changes in the development of the adrenal medulla and the development of the nervous system. Decapitation, hypoxia, hemorrhage, and hypothermia are the experimental conditions associated with the greatest stress-induced changes in plasma catecholamine concentrations. The differences in experimental design are tabulated to afford the reader an opportunity to compare catecholamine levels among species. The table provides a detailed guide to normal concentrations and normal responses in 31 species. This report gives a dynamic overview of catecholamine concentrations in human and animal physiology and may be particularly helpful to investigators involved in catecholamine research.

Animals↗
PubMed1989

Pulmonary manifestations of endocrine and metabolic disorders.

In summary, there are a number of important respiratory manifestations of endocrine diseases. Hypothyroidism may be associated with respiratory failure that can be caused by a reduction in central respiratory drive, upper airway obstruction, and associated restrictive pulmonary function from pleural effusions or an intrinsic decrease in lung volumes. Hyperthyroidism can present with dyspnea as a major clinical manifestation because of the increase in central respiratory drive associated with thyrotoxicosis. Cardiac dysfunction associated with hyperthyroidism may lead to pulmonary edema in some patients. Hypoparathyroidism may occur acutely, especially after thyroid surgery and be associated with hypocalcemia and acute tetany, laryngeal stridor, and muscle weakness. Ovarian tumors, both benign and malignant, may present with unilateral or bilateral effusions. Finally, patients with diabetes mellitus are at increased risk of developing a variety of pulmonary disorders. Acute and chronic pulmonary infections are the most common respiratory abnormalities in patients with diabetes, although cardiogenic and noncardiogenic pulmonary edema can also be a complication of their disease.

Diabetes Complications↗