Biomedical subjects
L Goldman
Publications and source records attributed to L Goldman.
Value of noninvasive testing in adults with suspected aortic stenosis.
To determine the predictors of surgically correctable aortic stenosis in patients with systolic murmurs, 231 patients were evaluated. Five variables (carotid upstroke timing, carotid upstroke volume, aortic valve calcification on chest radiography, single or absent second heart sound, and a murmur with its maximal intensity at the right upper sternal border) were significant multivariate correlates. Two echocardiographic factors (a maximal aortic valve leaflet separation of 7 mm or less and hypertrophy of the posterior wall of the left ventricle to 12 mm or more) and one systolic time interval factor (a rate-corrected ejection time of more than 340 msec) added significant incremental information. When prospectively tested on an independent set of 86 patients with suspected aortic outflow obstruction, the combined clinical and noninvasive information correctly placed 10 patients (12 percent) into a low-risk group in which catheterization may not be indicated and 15 patients (17 percent) into a high-risk group in which it might be avoided or limited to coronary arteriography. This approach to predicting aortic stenosis deserves wider prospective testing.
Psychiatric treatment of erectile dysfunction in urology outpatient clinic.
This study examined the feasibility of establishing a satellite psychiatry service in a urology outpatient clinic for the express purpose of engaging men with inhibited sexual excitement in psychiatric treatment. This approach appeared to be more successful as judged by complete referrals and symptom remission than referral to a psychiatry clinic.
Internal cesium and the sodium inactivation gate in Myxicola giant axons.
Internal cesium (CSi), relative to internal potassium (Ki), alters Na current (INa) time course in internally perfused Myxicola giant axons. CSi slows the time to peak INa, slows its decline from peak and increases the steady state to peak current ratio, INainfinity/INapeak. Neither activation nor deactivation kinetics are appreciably affected by CSi. Na current rising phases, times to half maximum and tail current time courses are similar in CSi and Ki. Inactivation time constants determined by both one (tau h) and two (tau c) pulses are also little changed by CSi. The CSi effects are due largely or entirely to an increased INainfinity/INapeak. CSi decreases the steady level of inactivation reached during a step in potential, preventing some fraction of inactivation gates from closing at all, the rest apparently closing normally. Inactivation block in CSi decreases with increasing inward current magnitude and in Ki inactivation block is appreciable only for outward Na channel current, suggesting the site of action is located somewhere in the current pathway. If this site mediates the normal operation of the inactivation gate, then a possible mechanism for gate closure could involve a positively charged structure moving to associate with a negative site near or into the inner channel mouth.
Geographical distribution and inactivation kinetics in internally perfused Myxicola giant axons.
In some preparations the time constant of Na current inactivation determined with two pulses (tau c) is larger over some range of potentials than that determined from the current decay during a single pulse (tau h), while in others tau c(V) and tau h(V) are the same. Myxicola giant axons obtained from specimens collected from coastal waters of northeastern North America display a tau c - tau h difference under all conditions we have tested. In these axons tau c(V) and tau h(V) are unchanged by reduction of Na current density, addition of K-channel blockers, or internal perfusion. Specimens of the same species, Myxicola infundibulum, collected from a different geographical location, the south coast of England, have been studied under internal perfusion with K as the major cation internally, with reduced external Na concentration and in the presence of K-channel blockers. In these axons tau c(V) and tau h(V) approximately superpose, raising the possibility that dramatic differences in Na current kinetics may not necessarily reflect basic differences in the organization of the Na channel gating machinery.
Clinical response to coronary artery reoperations.
Repeat coronary artery bypass operations were performed on 112 patients at a university hospital between 1971 and 1981. When compared with patients who did poorly after a first operation but did not have repeat surgery, patients undergoing repeat surgery tended to be younger, to have a higher smoking rate and to have fewer prior myocardial infarctions, fewer diseased vessels and fewer lesions in distal vessels. At least 1 graft was occluded in 83% of patients undergoing reoperation, and a mean of 1.7 grafts were placed at reoperation. The operative mortality rate was 4%, with a follow-up mortality rate of 6% at a mean of 3.8 years. After reoperation, patients initially showed improvement to a mean specific activity scale class of 1.6, compared with 2.4 before the first operation and 2.7 before the second operation. The principal correlate of a better long-term symptomatic response compared with that in the period before the first operation was a lower serum cholesterol level, whereas the principal correlate of a better symptomatic response compared with that in the period just before the reoperation was the left ventricular ejection fraction. As recurrent symptoms after a first coronary artery operation become more prevalent, consideration of the selection factors and prognostic correlates of reoperation will become increasingly important.
Benefits of experience. Treating coronary artery disease.
The authors examined the issue of learning by doing in terms of both the cost and outcome of treating coronary artery disease at one hospital between 1977 and 1981. Over time, the quality of outcome improved for both medical and surgical patients. During this time of cost-plus reimbursement, there was less conclusive evidence of concurrent technical efficiency gains. These findings are consistent with the hypothesis that the benefits of experience can be substantial but they do not just happen: they require proper provider motivation.
Autopsy: seventy-five years after Cabot.
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Serum enzyme assays in the diagnosis of acute myocardial infarction. Recommendations based on a quantitative analysis.
In the last 20 years, serum enzyme and isoenzyme levels have become the final arbiters by which acute myocardial infarction is diagnosed or excluded. We review the characteristics of these enzymes, the methods and limitations of commonly used assays, and data on diagnostic accuracy and clinical implications of enzyme levels in various settings and offer recommendations on their optimal use. Because of the poor sensitivity of single measurements of cardiac enzyme levels, these assays should not be used in the emergency room to exclude myocardial infarction. If myocardial infarction is suspected, levels of creatine kinase and its MB fraction should be measured at admission and about 12 and 24 hours later. If a myocardial infarction may have occurred more than 24 hours before evaluation, then lactate dehydrogenase isoenzyme measurements may increase diagnostic accuracy. Used properly, these assays are remarkably sensitive, but like all tests, optimal interpretation requires insight into technical pitfalls and other causes of misleading results.
Clinical and research training in parallel: the Internal Medicine Research Residency Track at the Brigham and Women's Hospital.
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Detailed, controlled, and documented self-experimentation in dermatology.
Because the skin is easily available, the combination of frequent periods of critical observation, the dermatologist's clinical experience, and carefully controlled documentation of these observations allow for self-experimentation in dermatologic disorders on the part of clinicians. The practical value of such self-experimentation has been shown over many years, especially by the use of skin surface microscopy at moderate magnification to examine various lesions; to document sensitization experiments with nickel, Japanese lacquer, and nitrogen mustard; to examine prolonged use of topical fungicides for the treatment of onychomycoses; and to contribute to extensive and continuing experiments in laser medicine.
Superficial vessels after sclerotherapy.
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Clinical prediction rules. Applications and methodological standards.
The objective of clinical prediction rules is to reduce the uncertainty inherent in medical practice by defining how to use clinical findings to make predictions. Clinical prediction rules are derived from systematic clinical observations. They can help physicians identify patients who require diagnostic tests, treatment, or hospitalization. Before adopting a prediction rule, clinicians must evaluate its applicability to their patients. We describe methodological standards that can be used to decide whether a prediction rule is suitable for adoption in a clinician's practice. We applied these standards to 33 reports of prediction rules; 42 per cent of the reports contained an adequate description of the prediction rules, the patients, and the clinical setting. The misclassification rate of the rule was measured in only 34 per cent of reports, and the effects of the rule on patient care were described in only 6 per cent of reports. If the objectives of clinical prediction rules are to be fully achieved, authors and readers need to pay close attention to basic principles of study design.
Screening procedures in the asymptomatic adult. Comparison of physicians' recommendations, patients' desires, published guidelines, and actual practice.
To assess attitudes and practices regarding screening tests and preventive procedures, we surveyed 83 physicians in a hospital-based ambulatory care practice and compared their recommendations with the recommendations in published guidelines, the desires of 188 of their own patients, and the physicians' actual practice patterns on the surveyed patients. The surveyed physicians recommended screening procedures more frequently than the published guidelines in 48 situations and less frequently in 18 situations. Physicians at earlier levels of training tended to recommend more procedures than those who had completed training. Patients desired far more frequent screening than recommended either by their physicians or by the published guidelines. Physicians did not live up to their own recommendations for four of 14 procedures or to published guidelines for five of 14 procedures, with such failure occurring principally in situations where the test or procedure would normally be done personally by the physician.
Case-control analysis of risk factors for presence of aortic stenosis in adults (age 50 years or older).
To analyze whether atherosclerotic risk factors, including systemic hypertension, an elevated serum cholesterol level, smoking and diabetes, were associated with the presence of aortic stenosis (AS) in adults, 105 adults who had AS without coronary artery disease (CAD) were compared with 110 control subjects who had other types of valvular disease, 170 control subjects who underwent catheterization and had neither valvular disease nor CAD, and 269 matched control subjects who underwent general surgery. When using each control group separately or in combination, no risk factor showed consistent evidence of a significant association with the development of AS. If the true magnitudes of these associations are of the order previously reported for the development of CAD, the power of our study for detecting statistical significance ranges from 56 to 99%. In a supplemental analysis, 45 cases with both AS and CAD did not have a higher prevalence of risk factors than cases without CAD. Although a weak association between atherosclerotic risk factors and AS cannot be excluded, any such association is unlikely to be as strong as for predicting CAD.
Preliminary investigative studies with PDT in dermatologic and plastic surgery.
PDT has been shown to be of value in inoperable basal and squamous skin cancers and in cutaneous metastases. Azone, a new investigative vehicle for HpD, is of value more for intralesional injections than for topical applications in tumors, except perhaps for superficial mucous membrane lesions. The more flexible gold head vapor is of definite value in the PDT program. For test models for PDT studies in dermatology and plastic surgery with HpD and other fluorochromes, single thickened resistant plaques of psoriasis and the common baso squamous acanthoma (seborrheic warty growth) have been used. In all these studies, adequate controls are necessary.
The comparative effects of the argon, Nd: YAG, and argon-pumped dye lasers on human platelets and erythrocytes in vitro.
The effects of three lasers, Argon, Nd:YAG, and Argon-pumped Dye, on three types of platelet preparations were evaluated. Either EDTA or buffered citrate served as anticoagulants. Platelets separated from plasma and suspended in buffer showed no decrease in counts following lasering, but morphologic damage was evident with transmission electron microscopy (TEM). In platelet-rich plasma, a fall in counts was noted for the Argon and the YAG (at high energy only) but was absent when the Dye laser was employed. Morphologic damage (TEM), however, was noted with all three lasers. When whole blood preparations were used, more marked changes in both RBCs and platelets were seen in samples collected in EDTA compared with citrated samples. Morphologic damage (TEM) to platelets and RBCs occurred with all three lasers. An artifactual increase in "platelet counts," the appearance of spherocytes, and an increase in plasma Hb indicated RBC injury. Both platelets and erythrocytes were sensitive to variations in power (wattage) despite constant total energy delivery.