Search PubMed⌕ Search

Biomedical subjects

C Jacobs

Publications and source records attributed to C Jacobs.

At least 397 records · Page 22Linked to original sources

Duocart biofiltration: a new method of hemodialysis.

DuoCart biofiltration (DCB) is a new hemodialysis method using a dialysate with only sodium chloride and bicarbonate obtained from two separate powder cartridges (BiCart and SelectCart, Gambro, Sweden). The ionic complement is directly reinfused in postdilution mode, using one 2 L bag of a specially designed sterile solution. The adaptation of the quantity of these infused substances to their removal through the dialysis membrane is made possible by repeated measurements of ionic dialysance (D), which are automatically performed every 30 min by the Diascan module, systematically available on the Integra dialysis monitor (Hospal, Italy), and by subsequent modification of the infusion rate (Q(R)). An appropriate kinetic model was used to determine the composition of the reinfusion solution (mM: 57 K, 47 Ca, 14.5 Mg, 180 Cl), the conductivity dialysate (set at 14.8 mS/cm) and the ratio Q(R)/D (set at 1/28). This ratio is kept constant by updating Q(R) after each measurement of D. The implementation of this technique requires an Integra dialysis monitor equipped with a two-powder-cartridge dialysate generation system. Fifteen dialysis sessions were performed (duration: 213+/-38 min; blood flow: 238+/-26 ml/min; ultrafiltration rate: 16+/-6 ml/min). The per-dialytic changes of ion plasma concentrations were monitored and found to be within the predicted range. The results substantiate the feasibility of this new hemodialysis method that presents several advantages: dialysate concentrates are in powder form, an alkaline and acetate-free dialysate is used with superior dialysate biocompatibility, no precipitation of Ca and Mg carbonate occurs in the dialysate circuit, the supply of calcium and potassium is easily adapted to individual patients' needs by change in the composition of the reinfusion solution, and a calcium-free dialysate that facilitates citrate anticoagulation is used.

Bicarbonates↗

[Renal tolerance of iodinated low osmolality contrast agents. Clinical and experimental aspects].

The low osmolality iodinated contrast agents (ICA), ionic or non ionic are now suggested too replace the usual high osmolality ICA. The main arguments are the better clinical tolerance and a lower renal toxicity. Recent experimental studies have clearly demonstrated that the low osmolality ICA presents a lower renal toxicity. On the rat, we have confirmed that the in vivo renal toxicity of low osmolality ICA, is lower than the high osmolality ICA toxicity. It is clearly demonstrated on man than the enzyme urinary excretion and proteinuria are little or not modified by the low osmolality ICA, but both are increased by high osmolality ICA. These changes are found with a normal glomerular filtration flow. No difference are noted in the creatinine concentration and clearance follow-up. However it is possible that the necessary population of patient to get statistically significative differences between both agents can be superior to the number of patients studied. In clinical practice, we think, that low osmolality ICA must be used for patients presenting one or several risk factors of acute renal failure.

Animals↗

[Pharmacokinetics of 3'-azido-3 deoxy-thymidine (AZT) in a patient undergoing hemodialysis].

Zidovudine (AZT) is the only effective drug in the treatment of AIDS. No data are available on the pharmacokinetics of this drug in patients with end-stage renal disease (ESRD). We report on the pharmacokinetics of zidovudine between sessions of hemodialysis and during the procedure in one patient with ESRD. In 1987 a 40-year-old man with ESRD treated with hemodialysis had the AIDS-related complex. The T4/T8 ratio was 0.49. An enzyme-linked immunosorbent assay and Western Blot studies revealed IgG antibodies specifically directed against HIV. The patient was then treated with zidovudine (100 mg three times daily). Studies of the pharmacokinetics of the drug, conducted between hemodialysis sessions, were performed on days 1 and 14 after the start of zidovudine treatment. Paired arterial and venous blood samples were obtained simultaneously one hour after the start of a hemodialysis session on day 20. The peak and the trough concentrations of zidovudine were 0.61 and 0.15 microgram per milliliter, respectively. We observed a marked accumulation of the main metabolite of zidovudine, G-AZT, with a concentration of about 65 micrograms per milliliter on day 14. The half-life was 2.9 hours. The hemodialysis clearance of zidovudine and its metabolite were 102 and 71 ml per minute, respectively. The half-life of zidovudine was three times longer in our patient than in a normal subject.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗

[Possible protective role of calcium inhibitors in drug nephrotoxicity].

Many experimental studies have shown that calcium channel blockers could prevent drug-induced acute renal failure. In dog, nifedipine and verapamil prevent decreasing blood flow produced by contrast material. In rat, administration of verapamil has beneficial effects on gentamycin nephrotoxicity. Verapamil improves renal function in rats with acute renal failure due to cyclosporine. Calcium channel blockers have various effects on cisplatinum nephrotoxicity: in rat, nifedipine worsens nephrotoxicity; in man, verapamil prevents nephrotoxicity due to cisplatinum. In addition, nifedipine seems to improve renal function in transplanted patients treated with cyclosporine. In 2 control studies, we did not find any effect of diltiazem on prevention of renal toxicity due to methotrexate and cisplatinum. Calcium channel blockers could prevent nephrotoxicity by reducing calcium transfer across cell membranes and/or inhibiting the action of vasoconstrictive hormones.

Acute Kidney Injury↗

Computerized patient management in a nephrology department.

An integrated approach is described for the computerized management of a nephrology department. On a medical point of view, the system comprises a minimum medical record for every patient, different specialized records and knowledge bases presently covering hypertension, diabetes and chronic renal failure. From a technical point of view, the methodology used integrates data and knowledge management techniques. Various individual reports facilitate patient management. For hypertensive patients, an expert system is combined with the record system. The results of a preliminary evaluation are reported and future developments considered.

Computer Systems↗