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Biomedical subjects

S Goldstein

Publications and source records attributed to S Goldstein.

At least 397 records · Page 22Linked to original sources
PubMed1987

The Beta Blocker Heart Attack Trial: recruitment experience.

The Beta Blocker Heart Attack Trial (BHAT) recruited 3837 patients who within the previous 5-21-day period had experienced a myocardial infarction. The purpose of the trial was to test the efficacy of propranolol in decreasing total mortality after such an event. Recruitment was carried out over a 28-month period and involved 31 clinics, 134 hospitals, and 136 acute coronary care units. Of the 157,771 patients admitted to these units, 16,358 met the BHAT criteria for a myocardial infarction, and 23% of those eligible were ultimately randomized. The use of a coronary care unit log was helpful for tracking patients to maximize recruitment and to provide information in regard to the universe from which patients were recruited.

Adrenergic beta-Antagonists↗
PubMed1987

Prognostic significance of ventricular ectopic activity in survivors of acute myocardial infarction.

Twenty-four hour ambulatory electrocardiography was performed on 3,290 survivors of acute myocardial infarction participating in the Beta-Blocker Heart Attack Trial (BHAT). History of myocardial infarction before the qualifying event, congestive heart failure and age were independently associated with the frequency and complexity of ventricular premature beats. Of the 1,640 patients randomized to placebo therapy, 163 died (76 suffered sudden death) during a 25 month average follow-up period. Ventricular ectopic activity was an independent predictor of total mortality after taking into consideration 16 other prognostic factors describing past history, risk factors, physical examination and laboratory investigations. Seven categoric definitions of ventricular ectopic activity predicted mortality, with similar odds ratios ranging from 2.27 to 2.69. A reciprocal relation of the sensitivity and specificity of each definition in predicting mortality was observed. Three clinical criteria (ST depression, cardiomegaly and prior infarction) allowed stratification of patients into four subsets with respective mortality rates of 35.5% (three criteria present), 19.0% (two criteria), 11.5% (one criterion) and 4.7% (none). Presence of ventricular ectopic activity (greater than or equal to 10 ventricular premature beats/h or pairs, ventricular tachycardia or multiform complexes) was associated with higher mortality rates in all four risk strata. The relative risk was higher (3.86) in the lowest risk stratum (mortality 2.4% without and 9.1% with ventricular ectopic activity). Thus, in survivors of acute myocardial infarction, ventricular ectopic activity was more pronounced in patients with prior myocardial infarction and congestive heart failure. It predicted mortality independently of other factors. Although mortality ratios were similar for all seven arrhythmia definitions, a reciprocal relation between sensitivity and specificity of the definitions in predicting mortality existed; ventricular ectopic activity was associated with increased mortality in all risk strata, but with a higher risk ratio in the numerically larger, low risk subset.

Arrhythmias, Cardiac↗
PubMed1987

Mechanism of reduction of bleomycin-Cu(II) by CO2- and oxidation of bleomycin-Cu(I) by H2O2 in the absence and presence of DNA.

The reduction reaction of bleomycin-Cu(II) by CO2- has been studied by gamma and pulse radiolysis at pH7. The CO2- radical reduces bleomycin-Cu(II) at a rate of (6.7 +/- 0.7) X 10(8) dm3 mol-1 s-1. In the presence of calf thymus DNA the rate of the reduction decreased as the concentration of DNA increased, indicating that the reduction reaction proceeds through free bleomycin-Cu(II). The stoichiometry and the kinetics of the oxidation of bleomycin-Cu(I) by H2O2 in the presence and absence of DNA have been studied. Our observations suggest that the OH. radical is not produced during this reaction and the degradation of the drug occurs in the absence and presence of DNA. We assume that bleomycin-Cu(II) in the presence of a reducing agent and molecular oxygen or H2O2 does not cleave DNA since the oxidizing species, which are formed during the oxidation reaction by H2O2, attack the drug even in the presence of DNA.

Bleomycin↗
PubMed1987

Nutrition and somatomedin. XV. Growth plate, growth factor and biologically active somatomedins in rats with streptozotocin-induced diabetes.

Diabetic children may exhibit poor growth, yet levels of growth hormone and somatomedins measured by specific radioligand assays usually are normal. In the present studies, biological assays based on costal cartilage from hypophysectomized rats were used to test the possibility that diabetes is associated with decreases in circulating growth-related factors. 'Growth plate growth factor' activity was evaluated with tissue from the osteochondral junction (which resembles epiphyseal cartilage), and 'somatomedin' activity was measured with resting cartilage distant from the growth plate. Diabetes was induced in rats by administration of streptozotocin (STZ) at 40, 80, 160 and 310 mg/kg. Two days later, animals receiving STZ 40 mg/kg exhibited slight hyperglycemia but normal beta-hydroxybutyrate and weight gain; glucose and beta-hydroxybutyrate rose, and weight fell progressively with higher dosage. Gel filtration on Sephadex G-75 at pH 2.4 was used to separate rat serum into somatomedins (KAv 0.50-0.75) and growth plate growth factor (KAv 0.38-0.50). Somatomedins were 102, 92, 83 and 68% of control in STZ-treated animals, i.e. unchanged from control at 40 mg/kg STZ and falling only with higher dosage. In contrast, the growth plate growth factor declined at all doses of STZ to 93, 84, 69 and 57% of control. Thus, the growth plate growth factor began to fall with mild hyperglycemia alone (glucose 190 mg/dl), while a comparable fall in somatomedins was not seen until glucose was greater than 400 mg/dl and beta-hydroxybutyrate was three times normal. Only the growth plate growth factor was correlated with changes in body weight (r = 0.44, p less than 0.025). We conclude that decreases in levels of a circulating growth plate growth factor may contribute to growth impairment in diabetes. Measurements of this factor may be useful in examining underlying mechanisms.

Animals↗
PubMed1987

The hypothalamic-pituitary-adrenal system in panic disorder.

The authors evaluated 24 outpatients with panic disorder by means of the afternoon continuous test for cortisol and the 1-mg dexamethasone suppression test (DST) and compared the results with those of 38 outpatients with major depressive disorder and 61 healthy control subjects. The mean basal cortisol level of the patients with panic disorder was significantly higher than that of the normal control subjects but almost identical to that of the depressed patients. Only three of the patients with panic disorder had abnormal DST results. These results indicate that patients with panic disorder have an abnormality of at least one function of the hypothalamic-pituitary-adrenal system which overlaps the abnormality in major depressive disorder.

Adult↗
PubMed1987

Superior sensitivity of computed tomographic scanning to magnetic resonance imaging in metastatic neoplasia: two case reports.

A case of carcinoma of the breast and a case of melanoma metastatic to the brain were evaluated by both magnetic resonance imaging (MRI) and enhanced computed tomography (CT). In these two cases, enhanced CT was more sensitive and more clearly delineated the extent of disease. Does diagnostic imaging of central nervous system metastatic disease require both MRI and enhanced CT?

Brain Neoplasms↗
PubMed1987

Energy expenditure in patients with chronic obstructive pulmonary disease.

Energy expenditure was studied in ten patients with chronic obstructive pulmonary disease (COPD) and weight loss, and in five malnourished patients without clinical evidence of COPD (control group) prior to and after a two-week refeeding regimen. Patients received 5 percent dextrose solution (plus electrolytes) for 36 hours to establish standard baseline conditions and were then randomly assigned to either a carbohydrate-based (CB; 53 percent of calories) or fat-based (FB; 55 percent of calories) diet for the first week. The alternate diet was given the following week. Total calorie intake was set at 70 percent above the energy expenditure measured prior to institution of nutritional support. During energy repletion, energy expenditure was greater than predicted (116 percent) in patients with COPD and less than predicted (90 percent) in the control patients. Thermic effect of nutrients during administration of either regimen was significantly greater (p less than .05) in patients with COPD than in those without COPD during both diets. The difference between the two groups was enhanced during the CB regimen. These observations suggest that malnourished patients with COPD have an elevated resting energy expenditure, and an enhanced thermic response to nutrients as compared to malnourished patients without COPD. Increased diet-induced thermogenesis may contribute to weight loss in patients with COPD, in addition to factors previously described such as decreased caloric intake and increased resting energy expenditure.

Aged↗
PubMed1987

Nutrition and somatomedin. XVII. Circulating somatomedin C during treatment of diabetic ketoacidosis.

Although somatomedin levels may be low in animals with experimental diabetes, values in humans have generally been normal. Because humans with severely decompensated diabetes have not been studied, we characterized somatomedin C responses during metabolic restoration in 21 patients with diabetic ketoacidosis. Somatomedin C values were compared with those of 25 outpatient controls. Somatomedin C in controls (mean +/- SE) was 0.72 +/- 0.09 U/ml, 69% of the mean sex-adjusted normal level; 28% of patients had values below the lower limit of normal. In ketoacidotic subjects, initial somatomedin C was 0.43 +/- .06 U/ml, 33% of the mean normal level; 52% of subjects had somatomedin C below the lower limit of normal. Initial levels in ketoacidotic subjects were unrelated to presenting levels of glucose, bicarbonate, ketones, or blood urea nitrogen but were significantly lower in patients of less than ideal body weight (0.30 vs. 0.58 U/ml, P less than .03). Presenting levels of somatomedin C in ketoacidotic subjects were significantly lower than in controls (P less than .02). During insulin-infusion therapy, somatomedin C rose to a peak of 1.16 +/- 0.21 U/ml after 28 h, significantly higher than initial levels (P less than .05). With continued subcutaneous insulin, somatomedin C fell to a nadir after an additional 22 h then rose more slowly to a final value of 0.75 +/- 0.12 U/ml, significantly higher than the nadir (P less than .05) but lower than peak values; final values in the ketoacidotic subjects were comparable to outpatient somatomedin C levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Oxidation-reduction reactions of iron bleomycin in the absence and presence of DNA.

Using the pulse radiolysis technique, we have demonstrated that bleomycin-Fe(III) is stoichiometrically reduced by CO2- to bleomycin-Fe(II) with a rate of (1.9 +/- 0.2) x 10(8) M-1s-1. In the presence of calf thymus DNA, the reduction proceeds through free bleomycin-Fe(III) and the binding constant of bleomycin-Fe(III) to DNA has been determined to be (3.8 +/- 0.5) x 10(4) M-1. It has also been demonstrated that in the absence of DNA O2- reacts with bleomycin-Fe(III) to yield bleomycin-Fe(II)O2, which is in rapid equilibrium with molecular oxygen, and decomposes at room temperature with a rate of (700 +/- 200) s-1. The resulting product of the decomposition reaction is Fe(III) which is bound to a modified bleomycin molecule. We have demonstrated that during the reaction of bleomycin-Fe(II) with O2, modification or self-destruction of the drug occurs, while in the presence of DNA no destruction occurs, possibly because the reaction causes degradation of DNA.

Bleomycin↗
PubMed1987

Comparison of CT-guided and stereotaxic cranial diagnostic needle biopsies.

Needle biopsy of the brain utilizing computerized tomography (CT) scan data is an accepted diagnostic technique that has been performed both with and without the aid of stereotaxic frames. Experience with both techniques has resulted in a specific procedure for CT-guided free-hand biopsy which is performed in the CT suite under local anesthesia. Over the last 6 years the authors have performed 64 CT-guided free-hand biopsies and 13 stereotaxic biopsies with the Brown-Roberts-Wells system. Nonspecific gliosis, tumor, infection, radiation necrosis, or vascular malformation, were diagnosed in all but one biopsy, for a clinically accurate diagnostic yield of 92%. A comparison of diagnostic yield, morbidity, and mortality has shown no significant difference between the free-hand and the stereotaxic techniques. The time required for the procedures and their cost have been compared and have been found to be significantly less for the free-hand biopsy group. Thus, CT-guided free-hand biopsy may still represent the method of choice for histological diagnosis of many intracranial lesions.

Adolescent↗
PubMed1987

Magnetic resonance imaging of the posterior fossa in ocular motility disorders--four case studies.

The superiority of magnetic resonance imaging (MRI) of the posterior fossa over x-ray computed tomography is demonstrated by four patients with neuro-ophthalmologic disorders. Advantages of this technique include lack of ionizing radiation, direct multiplanar imaging, increased sensitivity to pathology, increased tissue contrast, and no known adverse effects. It is concluded that MR, when available, should be the imaging modality of choice in patients with neuro-ophthalmologic disorders of suspected brainstem origin.

Adolescent↗
PubMed1987

Iodine-123 HIPDM brain imaging findings in subacute spongiform encephalopathy (Creutzfeldt-Jakob disease).

Decreased perfusion of the left frontal and left temporoparietal cortex has been shown in [123I] HIPDM planar and single photon emission computed tomographic images of a patient with Creutzfeldt-Jakob disease (CJD) that was proven by brain biopsy and subsequent autopsy. An EEG showed diffuse, periodic discharges most prominent to the left hemisphere. Concurrent head computed tomography (CT), nuclear magnetic resonance (NMR), and cerebral angiographic studies were negative. Abnormalities demonstrated by [123I]HPDM imaging and by EEG may represent changes in neurophysiological and neurochemical status while cerebral angiography, CT, and possibly NMR register only anatomic or structural lesions. Premortem diagnosis of CJD depends on brain biopsy; the availability of the [123I] HIPDM study may provide regional cerebral neurochemical and neurophysiological information, guiding or avoiding brain biopsy in the appropriate clinical setting.

Aged↗
PubMed1987

Clonazepam versus alprazolam in the treatment of panic disorder: interim analysis of data from a prospective, double-blind, placebo-controlled trial.

The authors present interim results of a prospective, random assignment, double-blind, placebo-controlled trial conducted to determine whether clonazepam is as effective as alprazolam in reducing the frequency of panic attacks and whether both agents are superior to placebo. Analysis on 44 of 60 randomized subjects showed no statistically significant differences between the clonazepam and alprazolam groups on the following clinically meaningful outcome measures: total number of panic attacks and percent of time subjects experienced anticipatory anxiety, extent of phobic avoidance, and fear. Statistically significant differences did exist among the drug and placebo groups on these measures. The authors conclude that this interim analysis of the data supports the inclusion of clonazepam in the treatment of panic disorder.

Adolescent↗
PubMed1987

Three cases of overlap between panic disorder, social phobia, and agoraphobia.

Panic disorder, agoraphobia, and social phobia are subtypes of the anxiety disorders as defined by DSM-III. Panic disorder and agoraphobia are thought to be closely related, whereas social phobia is considered to be distinct on the basis of demographic characteristics, course, symptoms, biological responsiveness, and treatment specificity. Three cases are presented in which these classificatory distinctions are blurred and the course of the illness seems to involve temporally overlapping manifestations of panic attacks, social phobia, and agoraphobia. Diagnostic and treatment issues and implications for research are discussed.

Adult↗
PubMed1987

Reliability and predictive value of salivary theophylline levels.

The reliability and accuracy of salivary theophylline levels as a predictor of serum theophylline levels was investigated in 28 hospitalized chronic asthmatics, free of other chronic diseases, on continuous aminophylline infusion for greater than 24 hours. Twenty paired blood and saliva theophylline levels from 12 patients (group 1) were used to develop a formula for predicting serum theophylline levels from salivary levels. Twenty-one paired blood and saliva theophylline levels from 16 patients (group 2) were used to test the formula obtained. The formula predicted the serum theophylline concentration within 1.51 microgram/mL in 76% of the samples and within 1.88 microgram/mL in 100% of the samples. There was an excellent correlation between the predicted and actual serum theophylline concentrations, r = .93; thus under controlled conditions of steady-state pharmacokinetics in patients free of other diseases, salivary theophylline levels can be used to accurately predict serum levels.

Adolescent↗