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Biomedical subjects

H Keller

Publications and source records attributed to H Keller.

At least 253 records · Page 14Linked to original sources
PubMed1984

Pharmacokinetics of ascorbic acid in horses.

The pharmacokinetics of ascorbic acid were studied in 29 horses after intravenous (iv), subcutaneous, intramuscular (im) and oral administration. Following iv injection of 5 and 10 g ascorbic acid, respectively, a biphasic decline of ascorbic acid serum levels was found, indicating that the vitamin distributes in the body according to a two-compartment open model. The apparent volume of distribution (average value for Vd(ss) = 0.6 litre/kg) was approximately equivalent to the volume of total body water. The terminal half-life of the biexponential serum level-time curve (t1/2 beta) varied between 5 and 17 h. Both distribution and elimination were found to be positively correlated with the iv dose administered. Following subcutaneous and im injection, the average bioavailability of ascorbic acid amounted to 82 and 61 per cent, respectively. However, both routes of administration gave rise to marked local irritation. Following oral administration, the systemic availability of ascorbic acid was very poor. Serum levels in most experiments were not increased above the endogenous pre-administration values of the vitamin. Thus, in horses iv injection appears to be the only satisfactory route of administration of ascorbic acid if supplementation is required.

Absorption↗
PubMed1984

Efficacy and tolerability of dibenzepin administered by intravenous drip infusion to severely depressed patients.

46 severely depressed inpatients received 10-hour intravenous infusions supplying a dose of 720 mg dibenzepin daily on 2 or some cases 3 successive days. The patients were kept under close psychiatric surveillance and their cardiovascular function was carefully monitored. The shorter infusions were as effective as infusions of the same dose of Noveril over 48 h, and did not lead to a greater frequency or severity of general or cardiovascular side effects. The 10-hour infusion regimen thus represents a new mode of treatment for severe depression which is less demanding both technically and in terms of nursing care.

Administration, Oral↗
PubMed1983

[The "spill-over" method for flow measurements].

"Spill-over" measurement is a simple method for estimating arterial blood flow during selective angiography. It depends on a direct comparison between a known contrast flow rate and the unknown blood flow in the aortic branch that is being examined. The criterion crucial to the measurement is the back-flow of contrast into the aorta. By means of model and animal experiments, it has been established why back-flow occurs and which factors favour or retard back-flow and thereby falsify the results. The results of "spill-over" measurements were compared with electro-magnetic measurements. A modification of the "spill-over" method is described, which makes it suitable for routine use in visceral angiography.

Animals↗
PubMed1983

[Atrial myxoma in the patients of a general and internal medicine outpatient clinic].

In a medical out-patient clinic, over a period of several years, atrial myxoma was diagnosed in four patients with ages ranging between 32 and 69 years. With the exception of one patient referred for assessment of ventricular premature beats, presentation was not primarily attributable to cardiac causes. In all patients, there was a latency period of years between the onset of symptoms and establishment of the diagnosis. The history of patients with atrial myxoma includes symptoms such as dizziness, syncope, transient cerebral ischemia, weight loss and malaise. The differential diagnosis may encompass consideration of neoplastic disease since laboratory findings can reveal evidence of an inflammatory reaction, accelerated sedimentation rate, anemia, abnormal electrophoresis, hypoproteinemia as well as elevated alkaline phosphatase. One patient had undergone numerous examinations to rule out the presence of malignant disease. Symptoms related to the cardiovascular system include exertional dyspnea, premature beats, tachyarrhythmias and nonspecific chest pain. Auscultatory findings are consistent with those of mitral stenosis. M-mode and two-dimensional echocardiography established the diagnosis in all patients and confirmed the usefullness of this examination technique in the assessment of patients in a general medical clinic.

Adult↗
PubMed1983

[New nutritional index for preoperative evaluation of malnutrition as a risk factor in surgery].

In a retrospective trial preoperative anthropometric and biochemical dates of 72 cancer patients were measured. All patients underwent a major surgical resection. Discriminant analysis and a computer-based stepwise regression procedure were used to identify the most important variables. It was able to compute a linear predictive model of 7 variables, called Nutritional Index, relating risk of operative mortality to preoperative nutritional status. In a prospective control trial it was possible to confirm the predictive value of the Nutritional Index by nutritional assessment of 204 surgical patients undergoing a major surgical procedure. This Nutritional Index provides a quantitative classification in surgical patients at high, low and without increased risk of nutritionally based complications.

Female↗
PubMed1982

[Incidence of accidentally discovered paraproteinemias among the patients of a hospital for internal diseases].

Covering a ten-year period (1970-1979), this retrospective study was performed to determine the frequency of unexpected paraproteinemia in hospitalized patients with various internal diseases. The survey was made possible by the fact that serum protein electrophoresis had been routinely performed in all patients upon admission. In 86 cases (0.66% of all admissions) monoclonal gammopathy was an unexpected finding. 5 out of these 86 cases (0.038% of all admissions) had malignant disease (2 patients with Bence Jones myeloma, 3 patients with Waldenström's macroglobulinemia), and 3 more cases had lymphoproliferative syndromes. In all other cases the abnormal serum protein findings corresponded to asymptomatic ("benign") paraproteinemias when first detected. In addition, the following statistical parameters were analyzed: distribution among immunoglobulin classes; sex; and concomitant diseases. A critical evaluation was possible in 67 cases of so-called idiopathic paraproteinemia.

Aged↗
PubMed1982

Enhancement of formylmethionyl-leucyl-phenylalanine-induced directional locomotion of human neutrophils by serum low-density lipoproteins.

Human low-density lipoproteins (LDL) significantly increased neutrophil locomotion in a gradient of the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP), while LDL alone had no effect on either directional or random locomotion. The enhancing effect on directional locomotion was constantly observed at FMLP concentrations of 10(-8) M and 5 X 10(-8) M after addition of 50 microgram LDL/ml.

Cell Movement↗
PubMed1982

Test-condition-dependent influence of harman and nonharman on benzo[a]pyrene mutagenesis in Salmonella.

The enhancing or decreasing effect of harman or norharman on benzo[a]pyrene mutagenesis depends mainly on the metabolizing system (S9) used. When mammalian activation was performed by using liver homogenates from mice induced by 3-methylcholanthrene, phenobarbital or Aroclor 1254, then the mutagenicity of benzo[a]pyrene in Salmonella typhimurium TA98 decreased upon addition of harman or norharman. In the presence of rat-liver homogenate induced by Aroclor 1154, however, harman enhanced the number of benzo[a]pyrene revertants, whereas norharman did not show any significant alteration of the benzo[a]pyrene mutagenicity. Further tests carried out with phenobarbital-induced mouse-liver homogenate showed that, within certain limits, neither variations of the amount of S9 extract nor the amount of the cofactors nor the relative proportions of the test substances had any influence on the antagonistic effect of harman or norharman on the benzo[a]pyrene mutagenesis.

Alkaloids↗