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Biomedical subjects

C H Beck

Publications and source records attributed to C H Beck.

At least 37 records · Page 2Linked to original sources
PubMed1982

Processing of symbolic and nonsymbolic events: a review of comparisons in selected cognitive activities.

The cognitive processing of symbolic and nonsymbolic events was compared. Evidence was drawn from the clinical and experimental literature on normal processing, on hemispheric asymmetry and on brain damage sequelae. It was concluded that several basic cognitive activities were manifest both symbolically and nonsymbolically. The cognitive activities included analysis of rapidly changing stimuli, categorical perception, categorical production, hierarchical organization and the production of complex movements. Damage to subcortical as well as cortical structures may contribute to the covariation of symbolic and nonsymbolic deficits. Suggestions were made for future research and the implications for the understanding of aphasia were described.

Animals↗
PubMed1981

How accurate is ultrasonography in detecting hydronephrosis in azotemic patients?

Screening for hydronephrosis continues to be an essential part of the evaluation of patients with azotemia of unknown cause. To determine whether sonography is as reliable as nephrotomography for screening purposes, we carried out a prospective, comparative study. Sixty-two patients were evaluated. Mean serum creatinine was 4.3 mg/dl. Of 116 kidneys, 45 were obstructed according to urographic criteria and 42 of these were correctly called hydronephrotic by sonography. The 3 false negative sonographic studies occurred in 2 patients. All 3 kidneys contained radiopaque calculi visible on the plain abdominal film. Of the 71 nonobstructed kidneys, 5 were mistakenly called hydronephrotic by ultrasound, giving a false positive rate of 7%. We believe it is appropriate to use gray-scale ultrasound as a screening test for urinary obstruction in azotemic patients providing the plain abdominal radiograph shows no calcifications.

Adolescent↗
PubMed1981

Mapping of forelimb afferents to the cuneate nuclei of the rat.

Stumps of rat forelimb peripheral nerves were soaked in horseradish peroxidase solution. Impregnation of the median, ulnar, radial, and musculocutaneous nerves revealed that each nerve had definite projection zones in the cuneate nuclei. The radial nerve projected quite heavily to the lateral cuneate nucleus and to a narrow band along the dorsal edge of the main cuneate nucleus. Staining of the deep radial and superficial radial nerves showed that they projected heavily to the lateral and main cuneate respectively. The ulnar and median nerves projected primarily to medial and lateral portions of the main cuneate nucleus, ventral to the terminal field of the radial nerve. The rostral and caudal portions of the main cuneate nucleus were discriminable by cytoarchitectural characteristics and by terminal fibre orientation.

Afferent Pathways↗
PubMed1978

Functional implications of changes in the senescent brain: a review.

The morphological, chemical, and physiological changes in the brain accompanying old age are reviewed. The deterioration of the striatal and hypothalamic dopaminergic systems were implicated in the onset of age related Parkinsonian-like slowing of performance and altered affect. Cholinergic hippocampal and neocortical systems were chemically and physiologically abnormal in the aged. The implications for slowed cognitive processing and persistance of the memory trace are presented.

Acetylcholine↗
PubMed1978

The no-show patient in the model family practice unit.

Appointment breaking by patients causes problems for the physician's office. Patients who neither keep nor cancel their appointments are often referred to as "no shows." Twenty variables were identified as potential predictors of no-show behavior. These predictors were applied to 291 Family Practice Center patients during a one-month study in April 1977. A discriminant function and multiple regression procedure were utilized ascertain the predictability of the selected variables. Predictive accuracy of the variables was 67.4 percent compared to the presently utilized constant predictor technique, which is 73 percent accurate. Modification of appointment schedules based upon utilization of the variables studies as predictors of show/no-show behavior does not appear to be an effective strategy in the Family Practice Center of the Community Hospital of Sonoma County, Santa Rosa, due to the high proportion of patients who do, in fact, show. In clinics with lower show rates, the technique may prove to be an effective strategy.

Appointments and Schedules↗
PubMed1976

Dual dorsal columns: a review.

Recent evidence indicates that Wall (1970) may have been premature in concluding that dorsal column lesions produce no discernable sensory defects. Much of the negative evidence Wall presented to support this view is inconclusive. In addition several studies have reported significant sensory deficits in animals with severed dorsal columns. On the other hand, the literature strongly supports Wall's view that dorsal column lesions cause motor disturbances. A review of the anatomical and electrophysiological literature reveals growing evidence for the dissociation of two major subsystems relaying in the dorsal column nuclei. The possible functions of these two systems are discussed.

Animals↗
PubMed1976

Etiology, incidence, and prognosis of renal failure following cardiac operations. Results of a prospective analysis of 500 consecutive patients.

A prospective study of 500 consecutive patients surviving the first 24 hours following cardiac surgical procedures was undertaken to determine the prevalence, etiology and results of therapy for postoperative acute renal failure (ARF). Thirty-five patients developed either moderate or severe ARF and an additional 102 developed mild preprenal azotemia. Positive risk factors noted inthe development of postoperative renal failure included age, elevated preoperative concentrations of blood urea nitrogen (BUN), serum creatinine, and decreased 24 hour urine creatinine clearance. The duration of cardiopulmonary bypass (CPB), aortic cross-clamping, and the total duration of the operation also closely correlated with the incidence of ARF. In the early postoperative period, clinical assessment of hemodynamic change was most helpful in predicting postoperative ARF. Significant negative risk factors included type of operation performed, New York Heart Association classification, the use of preoperative diuretic therapy, and associated other chronic illnesses. During the operation itself, the lowest and mean blood pressures, flow rates on CPB and the presence of hemoglobinuria failed to correlate with subsequent ARF. The mortality rate for established ARF was extremely poor (88.8 per cent), and there were no survivors among those requiring dialysis. ARF following cardiac surgery is a highly lethal complication which arises in a setting of inadequate cardiac function and is associated with a multiple organ system failure. Therapy of this postoperative complication, therefore, appears to be better directed toward its prevention rather than treatment once established.

Acute Kidney Injury↗
PubMed1975

Renal failure after ruptured aneurysm.

The effectiveness of an intravenous nutritional program plus aggressive dialysis was studied in 32 patients with renal failure following ruptured abdominal aortic aneurysm. Each patient was managed postoperatively with a renal failure fluid regimen, consisting of the eight essential amino acids plus dextrose in conjunction with peritoneal dialysis and hemodialysis. This regimen induced salutary metabolic effects temporarily improving the patient's condition in most instances. No technical or septic complications associated with the intravenous dietary therapy occurred. However, the incidence of recovery of renal function was low, and the overall patient survival was only 12.5%. The experience indicates that although this program has been shown to be efficacious in some patients with acute renal failure, it seems of little benefit in those whose renal failure follows ruptured aortic aneurysm.

Acute Kidney Injury↗
PubMed1975

Motor potentials and the timing of muscular activity.

The purpose of this study was to determine whether dominant components of the motor potential recorded from the scalp, were coincident with the rise and fall of muscular activity in single movements and return movements in serial flexion and extension of the elbow. Electroencephalographic recordings obtained from two right-handed subjects through scalp electrodes were averaged by computer and related to EMG, force and displacement of the limb. In the single movements, coincident events in the motor potential indicated the rise and fall of EMG and force. Events in the motor potential of the return movement coincided with the rise of EMG and of force in the first phase, and the rise of EMG in the second phase. Other time relationships were not clear. Relationships between events were clearer in one subject than in the other. This could have been caused by different characteristics in the performance of the task or by problems related to the location of scalp electrodes. The general waveform of the motor potentials and the EMG traces seemed to be related in a few samples of the single movement task, suggesting that other factors than time may also be related between the motor potential and the EMG.

Elbow↗
PubMed1974

Amino acid metabolism in acute renal failure: influence of intravenous essential L-amino acid hyperalimentation therapy.

A solution of 8 essential I-amino acids and hypertonic dextrose was administered to 5 patients in acute postoperative renal failure in a program of hyperalimentation designed to decrease the patient's catabolic state and to accrue certain metabolic benefits. A sixth patient receiving intravenous glucose alone served as a control. The pretreatment plasma concentrations of amino acids in all 6 patients did not differ significantly from normal; following intravenous essential amino acids at a dose of approximately 12.6 gm/24 hours, no significant elevations out of the normal range of these substances occurred. Since urinary excretion rates did not dramatically increase, urinary loss was excluded as a possible cause for the failure of increase of plasma concentrations. The results suggest that the administration of an intravenous solution of 1-amino acids and hypertonic dextrose is associated with rapid clearance from the blood of these substances and, with a failure of increased urinary excretion, indirect evidence of amino acid utilization for protein synthesis has been obtained. Histidine supplementation in patients with acute renal failure is probably unnecessary based on the lack of significant decreases in histidine concentrations in these patients.

Acute Kidney Injury↗