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Biomedical subjects

C F Starmer

Publications and source records attributed to C F Starmer.

At least 91 records · Page 5Linked to original sources
PubMed1978

Error propagation in quantitative biplane cineroentgenography.

The propagation of errors in quantitative biplane cineroentgenography was investigated to see which variables were the most critical. The analysis was carried out both for the propagation of root-mean-square errors and for errors as derived by a Taylor expansion of the reconstruction equations. The reconstruction is most sensitive to the measured values of the coordinates, as opposed to the parameters of the physical system. It was found that decreasing the error in one parameter to zero does not significantly affect the accuracy of the reconstruction; it is more efficient to reduce the errors for all of the parameters simultaneously.

Animals↗
PubMed1977

Synaptonemal complex karyotyping in spermatocytes of the Chinese hamster (Cricetulus griseus). III. Quantitative evaluation.

Relative length is a constant and distinctive characteristic for each autosomal SC, despite variations in absolute length from cell to cell. Arm ratio is distinctive for each SC except for two of the three sub-acrocentrics, and serves, together with relative length, for identification. The constancy of relative length and arm ratios indicates biological stability and lack of physical distortion in these spread preparations. There is a 1:1 relationship between relative lengths of autosomal SCs and mitotic autosomes: their arm ratios are similar. These close parallels provide strikingly similar SC and somatic karyotypes. Variability was observed in sub-acrocentric arm ratios and in lengths of unpaired X and Y axes, correlated with the presence of constitutive heterochromatin. - Utilizing progressive differentiations of the X and Y chromosomes for staging, it is demonstrated that autosomal SCs decrease in length from late zygotene to mid-pachytene, and then increase at late pachytene. Within a nucleus, synchrony of length changes is maintained. It is concluded that the factors governing autosomal SC length are regular for any given bivalent from cell to cell and may be related to those that control somatic autosome length relationships. - The X and Y axes differ quantitatively as well as qualitatively from autosomal SCs. The SC portion of the X and Y is constant in length through most of pachytene; the unpaired axes shorten and lengthen, but not in proportion to autosomal SCs. X and Y relative lengths ard arm ratios vary throughout pachytene and do not maintain proportionality with somatic values. The evidence suggests, but does not prove, that the long arm of the X is paired with the short arm of the Y.-Twists occur in autosomal SCs at increasing frequencies throughout pachytene but cannot account for length changes. The number of twists per SC is directly proportional to SC length. Intertwining of SCs is random and proportional to SC length. End-to-end associations of autosomal SCs appear to be random; however, the ends of the X and Y are less often involved in such connections. - The length of axial material in all chromosomes at pachytene, expressed as an equivalent length of DNA double helix, represents 0.013% of the diploid DNA complement.

Animals↗
PubMed1977

The relationship between enzymatic and histologic estimates of the extent of myocardial infarction in conscious dogs with permanent coronary occlusion.

Relationships between enzyme estimates (EE) and histologic measurements of infarct size (HIS) were analyzed in 14 conscious dogs with permanent occlusion of the circumflex coronary artery. EE were derived from serial CPK, CPK-MM, CPK-MB, and CPK-BB. Estimates were obtained using methods of Shell et al., Norris et al., and Roberts et al. HIS was determined from multiple histologic sections 5-6 days after infarction. In 14 animals, HIS ranged from 0.1-26.6 grams. Regression analysis demonstrated poor correlation (r2 less than 0.06) between EE by each method and HIS. Using the Shell method and restricting the analysis to HIS of less than 13 grams, improved the correlation (r2 = 0.42). Correlation in this subgroup could be further improved by using CPK-MM and MB data, elimination of animals with high background values, or limiting analysis to the portion of the curve where LDH isoenzymes indicated a cardiac zone. When the analysis was restricted to animals with HIS of less than 13 grams, Norris and Roberts modifications as compared to Shell's method improved correlation with CPK-MB but reduced correlation using CPK and CPK-MM data. In this subgroup, each method overestimated extent of HIS; Shell greater than Norris greater than Roberts. In this study it was not possible to distinguish small from large HIS by serum enzyme measurements.

Animals↗
PubMed1975

The course of acute myocardial infarction. Feasibility of early discharge of the uncomplicated patient.

This report represents our experience with 522 consecutive patients with acute myocardial infarction admitted directly to the Duke Coronary Care Unit. Fifty items of information were used to characterize the patients, their hospital course and follow-up. Serious complications included death, ventricular tachycardia or fibrillation, second- or third-degree heart block, pulmonary edema, cardiogenic shock, persistent sinus tachycardia or hypotension, atrial flutter or fibrillation, and extension of infarction. Forty-nine percent of the patients (252 of 522) experienced a serious complication. All patients who experienced any serious complications had at least one of the above during the first four days of hospitalization. Patients who survived through day 4 were subgrouped on the basis of the occurrence (complicated) or lack of occurrence (uncomplicated) of the above on day 5. Complicated patients had a subsequent hospital mortality of 14% and an incidence of late serious complications of 51%. Patients who were uncomplicated through day 4 had a subsequent hospital mortality of zero and an incidence of late serious complications of zero. These data suggest that it would be feasible and ethically justified to conduct a prospective clinical trial of early discharge (7th day) in patients who meet the above criteria for uncomplicated. The potential economic savings through earlier discharge in uncomplicated patients are of major significance.

Arrhythmias, Cardiac↗
PubMed1975

A new information system for medical practice.

A data bank containing our clinical experience with more than 3,000 patients with suspected and documented ischemic heart disease is being used to expand our ability to care for patients. This report describes how the experience is documented, stored, and retrieved so that it can be used in patient management. Data acquisition is integrated with patient care by means of forms that are part of the patient record. Follow-up information is obtained at six months, one year, and yearly thereafter. All data are stored in a computer information system that allows the doctor to recall the experience of patients like his new patient. Prognostic information is available on each new patient both on-line and in the form of a printed laboratory report. The data bank represents an initial chapter of a computer textbook of medicine.

Beta Particles↗
PubMed1975

Sudden death due to coronary artery disease. A clinical, hemodynamic, and angiographic profile.

The authors followed 536 medically managed patients with angiographically documented coronary artery disease for up to 4 years, and examined antemortem clinical, anatomical, and hemodynamic characteristics of the 29 patients who died suddenly during the follow-up period. These patients are compared in terms of hemodynamic characteristics to those who survived and those who died non-suddenly of coronary heart disease. Of the 29 patients who died suddenly, more than 80% had evidence of moderate to severe impairment of myocardial function many months prior to death. Only a single patient had the combination of relatively mild coronary artery disease and normal ventricular function. This single patient would be the ultimate target of a program designed to prevent sudden death. However, it has been necessary to follow 536 patients with angiographically documented coronary artery disease in order to find this one potential benefactor of sudden death prophylaxis. This study demonstrates that there are patients with coronary artery disease who die suddenly, despite relatively mild disease; however, these patients appear to represent only a small proportion of all sudden deaths.

Adult↗