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Biomedical subjects

C Fuchs

Publications and source records attributed to C Fuchs.

At least 145 records · Page 8Linked to original sources
PubMed1983

Quantitative assessment of carnitine loss during hemodialysis and hemofiltration.

Carnitine deficiency has been claimed to be responsible for the myo- and cardio-myopathy observed in dialysis patients and has been attributed to the loss of carnitine during dialysis. To quantitate carnitine loss, we determined the carnitine concentrations in 29 patients on chronic hemodialysis, 10 patients on chronic hemofiltration, and 8 patients on CAPD. Mean plasma carnitine levels in hemodialysis and hemofiltration patients (39.8 +/- 2.7 mumoles/liter; N = 39) were significantly lower (P less than 0.01) than in controls (49.8 +/- 2.0 mumoles/liter; N = 43). Hemodialysis or hemofiltration led to a further reduction (33.2 +/- 3.5 mumoles/liter; P less than 0.001). There was no significant difference in the mean plasma carnitine level between CAPD patients (40.0 +/- 5.7 mumoles/liter) and controls. Hemofiltration treatment resulted in a weekly loss of 795 +/- 84 mumoles of carnitine. This was significantly lower (P less than 0.0001) than the urinary carnitine excretion in healthy controls (1534 +/- 134 mumoles per week; N = 27) and the carnitine elimination in the dialysate of CAPD patients (1905 +/- 236.6 mumoles per week; N = 8). It is concluded that carnitine deficiency in dialysis patients cannot be explained by loss into dialysate or filtrate. Because intestinal reabsorption of carnitine does not seem to be impaired, decreased endogenous carnitine synthesis is considered as the most plausible explanation for the moderate degree of carnitine deficiency observed in dialysis patients.

Adult↗
PubMed1982

The effect of dimethylsulfoxide on the mutagenicity of the hair dye p-phenylenediamine.

Published data on the mutagenicity of the oxidative hair dye intermediate p-phenylenediamine in the Ames test are conflicting. The work reported here resolves the discrepancies, showing that the activity of p-phenylenediamine in the Ames Salmonella/microsome test is markedly influenced by the use of dimethylsulfoxide as solvent, and by the age of the solution prior to plating. Thus, aqueous solutions of p-phenylenediamine are non-mutagenic; fresh solutions in DMSO are equally non-mutagenic, but become highly active on standing at room temperature for 4 hr. These results suggest the need for caution in the choice of solvents and tight controls in the execution of the test.

Dimethyl Sulfoxide↗
PubMed1982

[Biochemical changes with continuous ambulant peritoneal dialysis (CAPD)].

During the past few years continuous ambulatory peritoneal dialysis (CAPD) has become well established in the home treatment of uremia. CAPD, however, may induce certain biochemical abnormalities. Using glucose as an osmotic agent of the dialysate the peritoneal glucose load may vary between 75 and 200 g per day, depending upon how often high osmotic dialysate is needed. If the latter is restricted to one bag per day a long-term disturbance of the glucoregulatory hormones insulin, GIP an glucagon seem to be inprobable. Investigations into glucose tolerance after 23 til 34 months of CAPD treatment in 4 patients did not indicate any exhaustion of the pancreatic beta-cells. Long-term evaluation into the metabolism of lipoproteins, total plasma proteins, aminoacids and trace elements did not show significant abnormalities induced by CAPD itself. Biochemical alterations observed are more or less related to the uremic state of the patients.

Adult↗
PubMed1981

The Israeli National Medical Library's new minicomputerized on-line integrated system (MAIMON).

An in-house library system based on a dedicated mini-computer has been in operation in the Israel National Medical Library since the summer of 1979. The integrated system, called MAIMON, features on-line access to bibliographic and circulation records. It replaces manual procedures in cataloging, searching, lending, and reservations. The system provides previously unavailable statistics on items in heavy use and demand, items to be removed from the active collection, and who uses what in the library. It is designed to be user cordial and to save users' time. The system has been very favorably accepted by patrons, and frees professional librarians from time-consuming clerical routine tasks. The system is evaluated in terms of performance, convenience, and cost.

Cost-Benefit Analysis↗
PubMed1980

Biochemical studies on patients undergoing continuous ambulatory peritoneal dialysis.

Biochemical studies are being performed in chronically renal insufficient patients undergoing treatment by CAPD. Serum protein and albumin levels have remained stable during treatment as have the ratios of essential/non-essential amino acids and valine/glycine in plasma. Dietary intake therefore appears to adequately compensate dialysate losses. Serum calcium and phosphate as well as immunoreactive parathyroid hormone concentration and alkaline phosphatase levels did not change during the treatment. The glucose load due to the high concentrations of glucose in the dialysate may have adverse effects on the glucose tolerance and insulin secretion of CAPD patients. However, in fasting patients it could be shown that only the 4.25% glucose dialysate causes any increase in plasma glucose levels with a concommitant rise of insulin secretion, an exchange with a 1.5% glucose dialysate having relatively little effect on these parameters. Quantification of the individual serum lipoproteins is also being performed during CAPD. No changes were observed in alpha-cholesterol levels, but 50% of the patients have shown significant increases in total serum cholesterol, beta-cholesterol and serum triglycerides in the course of treatment. In these cases dietary consequences must be considered in order to minimise the potential artherosclerotic risk.

Adolescent↗
PubMed1980

[First observations with continuous ambulatory peritoneal dialysis (author's transl)].

Continuous ambulatory peritoneal diaglysis (CAPD) represents a new method for treatment of chronic renal failure whereby patients carry two litres of dialysate with them permanently and are freely mobile. Dialysis is only interrupted by exchange of dialysate in approximately 6-hourly intervals. Due to the long presence of the dialysate in the peritoneal cavity clearance values are superior to intermittent peritoneal dialysis for small-molecular substances and reach elimination values of haemofiltration for medium-molecular substances. The main technical requirements consist of a permanent peritoneal dialysis catheter linked to a plastic dialysate bag by way of a connecting tube. In order to avoid frequent change of bag and thus increased risk of peritonitis bags are folded and carried on the body of the patient during the interval. Thereafter the bag is unfolded, filled with used dialysate and exchanged for a new bag. Six patients were thus treated for over 34 patient-months so far. Changes of chemical pathology were readily acceptable. Even though CAPD has several advantages over conventional dialysis as they are mainly founded on the high degree of rehabilitation of patients, risk of peritonitis is still a considerable factor of uncertainty.

Abdomen↗
PubMed1980

Identification of palindromic sequences recognized by restriction endonucleases, as based on the tabularized sequencing data for seven viral and plasmid DNAs.

Computer search of DNA sequences for phages phi X174, G4, M13 and fd, plasmids pBR322 and pAO3, and virus SV40, was employed to prepare tables specifying the size classes and frequencies of DNA segments located between all possible tetra-, penta- and hexanucleotide palindromes. As described earlier (Fuchs et al., 1978), these tables permit identifying sequences recognized by most of the restriction endonucleases. The effect of sequencing errors on the accuracy of the present identification method is evaluated. Only four of the 224 listed sequences do not appear in any of the seven DNAs, leading to discussion (see Appendix) on the natural sequence distribution.

Bacteriophage phi X 174↗
PubMed1980

On the distribution of the nucleotides in seven completely sequenced DNAs.

Several Markov chain models (up to fourth order) have been fitted to the sequences of the seven DNAs presented in Fuchs et al. (1980). Two methods for determining the order of Markov chain are applied to the data. The two methods lead to different conclusions and we discuss these discrepancies. When the distribution of the nucleotides in a DNA sequence is investigated, it is suggested that the study on the order of the Markov model should be supplemented with additional analysis.

Bacteriophage phi X 174↗
PubMed1980

Pediatric care for exceptional children: an inferential procedure utilizing consumer satisfaction information.

Medical services provided to 402 children with exceptional health and educational needs between 1975 and 1978 were systematically studied to determine consumer satisfaction. Legislation (PL 94-142) has made it mandatory for complete services to be provided to exceptional children from birth to age 21. Although the major responsibility to provide these services lies with local public schools, physicians often are involved and can help to provide optimum care to these children. This report describes a medical-educational system that delivers multispecialty pediatric services. An inferential evaluation procedure has been applied to this system that shows how consumer input can lead to improved medical services. Statistical procedures used to examined the data include analysis of variance, utilized in comparing the satisfaction ratings over time, and multiple linear regression analysis, to predict medical service activities of importance to consumers.

Analysis of Variance↗
PubMed1980

The action of 1,25 (OH)2D3 on turnover kinetic, remodelling surfaces and structure of trabecular bone in chronic renal failure.

Fibroosteoclasia as well as osteoidosis are reduced by 1,25(OH)2D3 treatment if secondary hyperparathyroidism preexists. Fibrosteoclasia completely disappeared after 6 months therapy in some cases. 1,25(OH)2D3 has no or only a very slight effect on the disturbed mineralization in type II of renal bone disorder (osteoidosis only, no signs of secondary hyperparathyroidism). The appositional rate of the osteoblasts increases under 1,25(OH)2D3 treatment if serum PTH values are raised. 1,25(OH)2D3 seemed to have, in the chosen dosage of this study, a self-limiting effect by reducing the bone-forming cells, i.e. the osteoblasts. This state already represents an overtreatment of the underlying bone disease.

Adult↗
PubMed1980

[Bioavailability of monofluoride preparations for dental caries prophylaxis (author's transl)].

Three different preparations containing 1 mg fluoride were given to 12 volunteers: preparation A, 1 hydrous solution, = 1 mg F-/100 ml, preparation B = 2 tablets at 0.5 mg F- and preparation C = 1NaF tablet with 1 mg F-. Representactive kinetic data could be obtained by means of restricted fluoride in the diet, a reproducible method yielding minimum detectable fluoride concentration and selection of suitable volunteers.. The enteral absorption of fluoride from solution A was more rapid (half-life of invasion = 20.2 min and 16.9 min, respectively). The delayed release is a consequence of the galenic mixture. In addition, the maximum concentration in plasma was greater and was reached sooner in preparation A when compared to the other preparations. In contrast, there was no difference in the areas under the curves, indicating that the relative bioavailability of fluoride is the same in all preparations.

Adult↗
PubMed1980

Biochemical investigations of CAPD: plasma levels of trace elements and amino acids and impaired glucose tolerance during the course of treatment.

Investigations have been initiated into the effect of CAPD on the plasma concentrations of trace elements and amino acids, and in particular the response of patients to an oral glucose tolerance test (OGTT) during the course of treatment. Six months CAPD had no effect on the plasma concentrations of aluminium, fluoride, zinc and copper. Levels of aluminium and fluoride were above the normal range. Loss of amino acids in the dialysate correlated with their plasma concentrations. No changes were observed in the E/NE, Val/Gly or Tyr/Phe ratios during nine months treatment. Five CAPD patients demonstrated an impaired glucose tolerance in response to an OGTT after one month of treatment and a further deterioration occurred in the glucose tolerance of three patients after another six months CAPD. In a preliminary investigation with fructose substituted for glucose in the dialysate of one patient, an improvement in the OGTT and rate of insulin secretion was observed after 3 days dialysis against fructose.

Adolescent↗