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Biomedical subjects

J D Knoke

Publications and source records attributed to J D Knoke.

29 records · Page 2Linked to original sources
PubMed1978

Cystic fibrosis: the prognosis for five-year survival.

Statistical discriminant analysis is applied to 41 concomitant variables obtained during the first year of study of 226 patients with cystic fibrosis. A discriminant function based on six variables is developed which can be used as a predictive index. This index estimates the probability of 5-year survival for an individual patient and can also be used to classify patients into one of two groups: (1) will live for 5 years or (2) will die within 5 years. Speculation A classification rule for cystic fibrosis is presented which correctly assigns 90% of the 5-year survivors and 84% of those who expire. Such a classification scheme is useful for clinical and research purposes.

Adolescent↗
PubMed1977

Peripheral airways as a determinant of ventilatory function in the human lung.

We have investigated the morphological differences responsible for the variability in two tests of pulmonary function, maximal expiratory flow rates (MEF) and the frequency dependence of dynamic compliance (CDYN ratio). Functional measurements were obtained from 53 normal and minimally diseased postmortem human lungs. Morphological measurements performed on these same lungs included airway diameter at three levels in the bronchial tree, the amount of bronchial gland mass, and the alveolar surface to volume ratio. Multiple regression analysis suggests that the diameter of the peripheral conduction airways (membranous bronchioles) is the major morphological determinant for both MEF and the CDYN ratio in lungs at any particular age. Age-dependent changes in both functional tests were associated primarily with differences in the alveolar surface to volume ratio. Minimal emphysema and a lesion associated with cigarette smoking, respiratory bronchiolitis, have no demonstrable effect on either MEF or the CDYN ratio. These studies provide further evidence that the peripheral conducting airways are a major determinant of ventilatory function in the normal human lung.

Adolescent↗
PubMed1976

On-line systolic time intervals during anesthesia in patients with and without heart disease.

Twenty-four patients with severe, 24 with moderate, and 24 without heart disease were selected for measurements of systolic time intervals (STI) and blood pressure before and during anesthesia. In all patients anesthesia was induced with thiopental, 4 mg/kg. After tracheal intubation, 12 patients from each heart-disease class received halothane-N2O-O2 (halothane) and 12 patients from each class morphine-d-tubocurarine-N2O-O2 (MS-dTc). Thiopental increased the pre-ejection period (PEP), decreased left ventricular ejection time (LVET), and accelerated heart rate (HR). These changes were similar in patients with and without heart disease. Halothane and and MS-dTc lowered systolic blood pressure and increased PEP/LVET. With halothane but not with MS-dTc these changes were more pronounced in patients who had heart disease. Changes of the PEP/LVET ratio during halothane anesthesia were a better discriminating variable among patients without, with moderate, and with severe heart disease than were changes in systolic blood pressure.

Adult↗
PubMed1976

Acute myocardial infarction: prognosis after recovery.

A prognostic index for 2-year survival after recovery from acute myocardial infarction was constructed from variables obtained during its course. One hundred ten of 143 patients survived 2 years, and 27 of 33 patients died of cardiac-related causes. Univariate analysis showed that 12 variables were significantly different between the surviving and nonsurviving groups. Discriminant analysis indicated five variables with meaningful predictive value to be included in a prognostic index: admission systolic blood pressure; highest blood urea nitrogen level in the cardiac care unit: atrial arrhythmias in the cardiac care unit; angina pectoris for more than 3 months or a previous myocardial infarction; and more than one ventricular ectopic beat per hour recorded on a dynamic electrocardiogram during the 17th to 24th hospital day. The prognostic index emphasizes the importance of extensive myocardial impairment and provides a means for identifying patients at risk of early mortality.

Angina Pectoris↗
PubMedDate not supplied

Physiological markers of smoking and their relation to coronary heart disease. The Lipid Research Clinics Coronary Primary Prevention Trial.

Several physiological variables which have previously been found to be associated with extent of cigarette smoking were investigated in a population selected to be free of existing coronary heart disease yet having high circulating cholesterol levels. Of these variables, white blood cell count had the strongest association with the extent of smoking. The addition of hematocrit and heart rate to white blood cell count strengthened the association. Given these three variables, however, other physiological variables had a minor effect on the association. Finally, the combination of these three physiological variables was more strongly predictive of subsequent coronary heart disease than was self-reported smoking level.

Coronary Disease↗
PubMedDate not supplied

Hospitalizations for unexplained illnesses among U.S. veterans of the Persian Gulf War.

Persian Gulf War veterans have reported a variety of symptoms, many of which have not led to conventional diagnoses. We ascertained all active-duty U.S. military personnel deployed to the Persian Gulf War (552,111) and all Gulf War era military personnel not deployed (1,479,751) and compared their postwar hospitalization records (until 1 April 1996) for one or more of 77 diagnoses under the International Classification of Diseases (ICD-9) system. The diagnoses were assembled by the Emerging Infections Program, Centers for Disease Control and Prevention, and are here termed "unexplained illnesses." Deployed veterans were found to have a slightly higher risk of hospitalization for unexplained illness than the nondeployed. Most of the excess hospitalizations for the deployed were due to the diagnosis "illness of unknown cause" (ICD-9 code 799.9), and most occurred in participants of the Comprehensive Clinical Evaluation Program who were admitted for evaluation only. When the effect of participation in this program was removed, the deployed had a slightly lower risk than the nondeployed. These findings suggest that active-duty Gulf War veterans did not have excess unexplained illnesses resulting in hospitalization in the 4.67-year period following deployment.

Adolescent↗