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Biomedical subjects

D N Snyder

Publications and source records attributed to D N Snyder.

7 recordsLinked to original sources
PubMed1982

Mortality and influenza.

Systematic virologic surveillance in Houston over the past seven years has revealed that influenza virus infections have been epidemic during each respiratory disease season. The peak of the occurrence of acute respiratory illnesses that caused patients to seek medical care always coincided with the peak of influenza virus activity. The peak number of deaths attributed to pneumonia or influenza followed the peak of influenza virus activity by about two weeks. This relationship was constant even though the time of the epidemic peak ranged from as early as the third week of December to as late as the second week of March. No increase in deaths occurred in the absence of influenza virus activity. Therefore, the methods used to predict base-line mortality that show a seasonal rise in the absence of influenza activity may be inaccurate and, if so, lead to underestimation of mortality associated with influenza virus infections.

Adolescent↗
PubMed1977

Changes in site distribution of colorectal carcinoma in Connecticut, 1940-1973.

The proportion of colorectal cancer occurring above the rectosigmoid junction has been increasing over time. The 40,771 cases of colorectal carcinoma reported to the Connecticut Tumor Registry from 1940 through 1973 were analyzed to determine the incidence in the ascending colon, the transverse, descending, and sigmoid colon, and the rectum. The numbers of cases, the proportion, and incidence rates of cancer in the ascending colon and sigmoid have increased over the 34 years. The increases were greatest among people over 65 years old. Only about half of colorectal cancer can now be identified with the rigid sigmoidoscope. Other tests must be used for early diagnosis of the increased numbers of cancers in the upper parts of the colon.

Adolescent↗
PubMed1975

Validity of quantitative tests measuring tremor.

A set of tests measuring tremor with an accelerometer has been developed to assist in objectively evaluating clinical trails. An experiment was designed to examine the consensual validity of the test measures for Resting, Sustention and Static Intention Tremor for 10 multiple sclerosis patients and 10 parkinsonian patients. Motion pictures of the patients performing the tremor tests were viewed by a senior neurologist who rated tremor using a nine-point ordinal scale. Comparisons made between the quantitative measures of tremor and the neurologist's ratings of tremor show that the tests are consensually valid. The methodology of this experiment may prove useful for examining in the future the consensual validity of new clinical instruments useful for evaluating trails.

Age Factors↗
PubMed1975

Quantitative examination of neurological function: reliability and learning effects.

During the last five years, a battery of tests measuring neurological function called the Quantitative Examination of Neurological Function (QENF) has been greatly expanded. To evaluate more effectively the efficacy of clinical trials, the results of a study on reliability of test measures and on long- and short-term effects of learning are reported. Of the 113 test measures that were evaluated using 18 young adult normal subjects, only the fatigue and error measures, the vibration sense and two simulated activities of daily living tests were found unreliable. With respect to learning, the largest improvements in performance were found for arm-shoulder pursuit tracking, followed by many of the tests of coordination, particularly those requiring manual and/or finger dexterity. Only slight changes were found for tests of vision, strength, and speed of hand and foot. There were no important differences between short- and long-term learning. Considering this and other studies, patients are not likely to improve their performance appreciably by learning in a clinical trial.

Activities of Daily Living↗