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Biomedical subjects

D L Witte

Publications and source records attributed to D L Witte.

50 records · Page 3Linked to original sources
PubMed1979

Dopamine beta-hydroxylase and plasma renin activity in patients with low-, normal-, and high-renin essential hypertension.

The relationship of serum dopamine-beta-hydroxylase (DBH), plasma renin activity (PRA) and urinary catecholamines (IU catechols) in various forms of essential hypertension (EHT) (low, normal and high renin) was evaluated. Eighty-four predominantly white, young (37 +/ 8 years (SD)), mildly hypertensive patients (diastolic pressure 93 +/- 4 mm Hg (SD)) continued their regular diet and received no medications. Thirteen patients had low-renin, 64 had normal-renin, and seven had high-renin EHT. DBH, total IU catechols and urinary norepinephrine were not different between these renin subgroups. DBH was significantly lower in all hypertensives (55.6 +/- 36 IU) and in the low-renin subgroup (46 +/- 30 IU) compared with normal subjects (68 +/- 35 IU) (p less than 0.01). However, the DBH range was so broad that an individual DBH value did not distinguish EHT from normals. After a baseline period, patients were randomly assigned to receive chlorthali done 50 mg q.a.m. or placebo in a double-blind study. In the chlorthalidone group 1 month after therapy, the diastolic pressure decreased, PRA increased, and total IU catechols and urinary norepinephrine increased. Serum DBH did not change during diuretic therapy. A significant correlation could not be shown between pretreatment DBH and the changes in PRA and IU catechols before and after diuretics for all treated EHT patients. However, within the normal PRA EHT subgroup receiving chlorthalidone, the one-third of patients with lowest pretreatment DBH levels (n = 10) were compared with the one-third of patients with the highest pretreatment DBH values (n = 10). The lower DBH patients showed significantly less change in PRA (delta PRA = 2.9 +/- 1.8 ng/ml/hr) compared with the higher DBH patients (delta PRA = 8.2 +/- 1.6; P less than 0.05). In some EHT patients, DBH levels may be related to PRA response to diuretic therapy.

Adult↗
PubMed1978

Effects of bilirubin on detection of hydrogen peroxide by use of peroxidase.

Bilitubin interferes with the quantitation of hydrogen peroxide in reagent systems in which peroxidase is used. Difference spectra suggest that this interference is a combination of chemical and spectral effects. The data presented are most consistent with the following interpretation: (a) bilirubin destroys part of the reactive intermediate formed in the peroxidase reaction and thus decreases the amount of chromophore formed and (b) the spectra for bilirubin and the chromaphore overlap, which also affects the results. The relevance of these results to reagent design and laboratory quality control are discussed.

Bilirubin↗
PubMed1978

Comparison of dewpoint and freezing point osmometry.

Osmolality was measured on 32 clear serum samples and on 23 urines, with dewpoint and with freezing point osmometers. The observed regression equation was dewpoint = 0.96 freezing point +7.6, with a correlation mean for 32 clear sera analyzed by both methods was not significantly different. However, when 14 lipemic sera were analyzed, the dewpoint measurements were higher: X dewpoint = 291.6; X freezing point = 284.1. The between-run standard deviation observed for a normal serum pool yielded a coefficient of variation of 1.04 with the freezing point and 2.38 with the dewpoint instrument. Results indicate that the dewpoint device should be used with caution for lipemic serum samples.

Blood Chemical Analysis↗
PubMed1977

Presence of creatine kinase BB isoenzyme in some patients with prostatic carcinoma.

We have observed creatine kinase isoenzyme BB in the sera of nine of 19 patients with Stage D carcinoma of the prostate. Its presence does not seem to correlate with acid phosphatase activity in serum or the presence of bone metastases as indicated by increased alkaline phosphatase activity in serum. Only three of the nine patients with BB isoenzyme activity detectable in their serum had abnormal values for total creatine kinase activity, but all had abnormal values for alkaline and acid phosphatase activity. All 10 patients with no BB isoenzyme detectable had abnormal acid phosphatase values; however, only seven had increased alkaline phosphatase values and only one had increased creatine kinase activity.

Creatine Kinase↗
PubMed1976

The effects of therapy for mild hypertension on circulating level of dopamine beta-hydroxylase.

Circulating dopamine beta-hydroxylase levels and norepinephrine excretion were measured in 76 mild hypertensive patients. Levels of dopamine beta-hydroxylase, norepinephrine excretion and blood pressure were obtained both before and after the initiation of therapy. Data from 20 patients exhibiting a diastolic blood pressure decrease of 10 mmHg or more were compared with data from 10 normotensive individuals. Changes in dopamine beta-hydroxylase levels were similar for the two groups and were not related to blood pressure changes. Intra-individual variation was small in both groups. There were no detectable functional relationships between diastolic pressure and urinary norepinephrine, norepinephrine and dopamine beta-hydroxylase or dopamine beta-hydroxylase and diastolic pressure. It dose not seem likely that dopamine beta-hydroxylase levels can replace urinary catecholamines as a commonly used index of sympathetic activity.

Blood Pressure↗
PubMed1976

Kinetic determination of serum lipase activity with the Abbott ABA-100.

A turbidimetric procedure for lipase has been adapted for use on the Abbott Bichromatic Analyzer (ABA-100). The method is rapid and results compared well with those by the more traditional method of Cherry and Crandall [Am. J. Physiol. 100, 266 (1932)]. Advantages of this method include shorter incubation time (2 min), smaller sample size (50 mul), neglible interference from bilirubin, and greater dynamic range (to eightfold normal).

Amylases↗
PubMed1976

The anion gap: its use in quality control.

Because the anion gap is useful in classifying acid-base disorders, quantitative information on this variable should be readily available. Three populations were studied and means and central 90% ranges were determined for the anion gap, calculated as sodium-(chloride + bicarbonate). In 1047 hospitalized patients the mean was 12 mEq/liter, 86 faster volunteers had a mean of 13 mEq/liter with a 90% range of 9--17 mEq/liter, and 203 plasmaphoresis donors had a mean of 11 mEq/liter with a 90% range of 7--16 mEq/liter. Most of this variability can be accounted for by analytical rather than physiological variation. This quantitation of the anion gap is useful for interchecking electrolyte values as an additional and inexpensive means of laboratory quality control. In 73 of 75 abnormal anion gaps, for which the data were verified to be correct, the clinical information provided a reasonable explanaation for the abnormality.

Acid-Base Imbalance↗
PubMed1976

Evaluation of a glucose oxidase procedure.

A commerical adaptation of Trinder's glucose oxidase procedure for glucose determination was evaluated by regression analysis. Excellent correlation was found between the glucose oxidase procedure and a hexokinase procedure. Good correlation was observed between an AutoAnalyzer I, the SMA 12/60, and a Beckman Glucose Analyzer, all utilizing variations of the glucose oxidase procedure. This combination provides a system that can handle screening, routine, and emergency requests in essentially the same manner and with comparable true glucose results. No interference was found with common anticoagulants and preservatives. Boehringer Mannheim Corporation's kit for glucose determinations appears to be of equivalent quality to the original method as outlined by Trinder and evaluated by others.

Anticoagulants↗
PubMedDate not supplied

Successful cardiac surgery following plasmapheresis in a patient with hemophilia B.

A case of successful coronary artery bypass grafting in a patient with hemophilia B is described. The patient underwent preoperative plasmapheresis and replacement with fresh-frozen plasma. Fresh-frozen plasma was administered pre- and postoperatively. The use of factor IX concentrate was avoided.

Blood Coagulation Factors↗