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Biomedical subjects

M Olmer

Publications and source records attributed to M Olmer.

At least 37 records · Page 2Linked to original sources

High-affinity interaction of long-chain fatty acids with serum albumin in nephrotic syndrome.

1. We have examined the effect of hypoalbuminaemia, a hallmark of nephrotic syndrome, on the albumin-fatty acid equilibrium in the plasma of 11 adult patients with nephrosis compared with 12 healthy subjects and six subjects with normoalbuminaemic hyperlipoproteinaemia. 2. We used a dialysis exchange rate method which allows the evaluation in relative terms of the binding affinity of albumin for plasma fatty acid and the fatty acid availability, tentatively equated with the unbound fatty acid fraction. 3. In nephrotic patients, an increase (P < 0.001) in albumin affinity for fatty acid was seen compared with healthy subjects, which was negatively correlated with albuminaemia (r = -0.69, P < 0.02). No change in fatty acid availability was seen for the group as a whole, but individual values showed a wide scatter, with the highest values in four patients with the highest fatty acid-albumin molar ratios. The increase in albumin affinity for fatty acid was specific to nephrotic syndrome since no such effect was seen in subjects with hyperlipoproteinaemia, who only showed a moderate increase (P < 0.01) in fatty acid availability. 4. The increased albumin affinity for fatty acid in nephrotic syndrome supports the hypothesis that an albumin component with lower affinity for fatty acid might filter out through the diseased glomerular membrane and leave the high-affinity albumin in plasma.

Adolescent↗

Serum erythropoietin and reticulocyte maturity index after renal transplantation: a prospective longitudinal study.

Improvement in erythropoiesis following renal transplantation (RT) was assessed in 74 consecutive patients by serial measurements of serum erythropoietin (EPO), hematocrit, absolute reticulocyte count (ARC) and serum creatinine during the first month after RT. The reticulocyte maturity index (RMI) which provides an objective measure of red-cell maturity was assessed in 31 patients by flow cytometry using thiazole orange. In group I (n = 39) with immediate graft function, EPO levels increased rapidly from day 2 and remained elevated at the plateau between two and three times the upper limit of normal during the first 2 months. In group II (n = 29) with delayed graft function, EPO levels increased gradually from day 10 when renal function improved significantly. No particular significant biphasic pattern of secretion was detected in group I or II. In both groups, hematocrit rose to over 35% approximately 3 months after RT. In a third group (n = 6) with immediate postoperative acute blood loss and severe anemia, a hematocrit fall was followed by a steep increase in EPO levels with a negative correlation between hematocrit and EPO levels during the first 4 days. During acute rejection, EPO diminished significantly by more than 50% either on the day of diagnosis or on the following days in 8 patients. RMI increased by 25% over the pretransplantation values by 7 days on average before the ARC rose. Thus the RMI seems to be an early sensitive predictor of erythropoiesis after RT. EPO response after RT depends on graft function, and the early transient increase in EPO observed in patients with acute blood loss may explain the apparent biphasic response previously reported.

Adolescent↗

[Outcome of kidney transplants with multiple arteries].

OBJECTIVES: To evaluate the morbidity of multiple artery renal transplants (> 1 artery) and to assess the value of this parameter as a risk factor for complications of renal transplantation in adults. METHODS: 140 renal transplants derived from brain dead donors with multiple arteries (2 arteries = 123, 3 arteries = 17) were reviewed with a mean follow-up of 3 years (6-120 months). Pedicle restoration was performed in 57 cases (end-to-side reimplantation of a polar artery = 17, composite aortic patch graft = 14, multiple procedures = 10, ligation of a polar artery = 8, arterial wound = 5, "gun barrel" anastomosis of 2 arteries = 4). Arteriography was performed systematically in 57 cases, in the absence of any signs suggestive of a vascular complication. RESULTS: 2 recipients died from a vascular complication. 40% of transplants were functional at 5 years. 10 transplantectomies were performed for a vascular complication. 14 recipients returned to dialysis because of a vascular complication. 7.5% of systematic arteriographies revealed stenosis of the transplant artery. 54 transplants developed a vascular complication: thrombosis = 19, stenosis = 25. Three-artery transplants had a vascular morbidity of 50%. "Gun-barrel" anastomoses and polar reimplantations into the main trunk had a vascular morbidity of 40%. The urological morbidity was 10%. CONCLUSION: Multiple artery renal transplants, especially 3-artery transplants and certain pedicle restorations, are associated with a high risk of vascular complications. Arterial anatomy is a selection criterion for the donor and recipient which must be taken into account in renal transplantation.

Adolescent↗

Chronic and intradialytic effects of high-flux hemodialysis on tumor necrosis factor-alpha production: relationship to endotoxins.

Tumor necrosis factor-alpha (TNF alpha) likely plays a role in hemodialysis-associated complications. As TNF alpha is mainly produced by monocytes in response to endotoxins, we studied its production and the presence of circulating endotoxins in patients dialyzed on polyacrylonitrile (PAN) membrane. Spontaneous production of TNF alpha was observed in patients before the dialysis session and increased during the session. Endotoxins were present in serum from patients chronically dialyzed with PAN and increased during hemodialysis session. In addition, intradialytic decrease in CD14 antigen expression on circulating monocytes, which could be caused by endotoxins, was found. The continuous presence of low amounts of circulating endotoxins between sessions may explain the chronic increase in TNF alpha secretion, while high amounts of circulating endotoxins may account for intradialytic oversecretion of TNF alpha and downmodulation of CD14. We suggest that endotoxin-free dialysates should be a prerequisite for the use of high-flux membranes.

Acrylic Resins↗

Leishmaniasis: a rare cause of unexplained fever in a renal graft recipient.

We report a case of visceral leishmaniasis in a 38-year-old renal transplant recipient living in an endemic country. Antimonial derivatives induced a rapid remission. A review of the literature disclosed 8 cases of this association with a fatal fulminant outcome in 5 cases. We suggest that the specific immunosuppression used in renal transplant patients might facilitate the development of a dormant infection and in these patients the misleading presentation may delay the diagnosis. Moreover special caution with treatment of leishmaniasis must be taken in renal transplant because of possible interactions between antimony compounds and ciclosporin metabolites. In renal transplant patients living in endemic countries, visceral leishmaniasis should be kept in mind as a potential cause of unexplained long-standing fever and considered as an opportunistic infection.

Adult↗

[Disturbances of lipid metabolism during nephrotic syndrome: physiopathology and treatment].

Both increased synthesis and decreased catabolism of lipoproteins may account for the severe hyperlipidemia which frequently occurs in patients with the nephrotic syndrome (NS). Nevertheless the complex relation between hyperlipidemia and proteinuria remains unclear and still debated. Increased levels of serum total cholesterol, of low-density lipoprotein and of apolipoprotein B are the most characteristic reported abnormalities placing these patients at high risks for atherosclerotic vascular disease. Moreover recent experiments have suggested that hyperlipidemia may also play a role in the progression of renal disease. Thus the reasons for using hypolipemic treatment are now growing in number and recent trials with lipid lowering medication have been successful without major side effects.

Cardiovascular Diseases↗

[Physico-chemical mechanisms of the formation of calculi].

Urinary stones are formed in three steps: nucleation, growth and crystal aggregation. These steps are dependent on physicochemical factors such as oversaturation of the urine and presence of substances that promote or inhibit lithogenesis. These mechanisms result in the formation of crystalline particles large enough to be detained in the lumen of renal tubules.

Chemical Phenomena↗

Haemodialysis membranes modulate chronically the production of TNF alpha, IL1 beta and IL6.

As cytokines may play a role in the adverse effects of haemodialysis, TNF alpha, IL1 beta and IL6 were investigated before the haemodialysis session (chronic effect) and after 30 and 60 min (session effect). We found that haemodialysis exerts a chronic effect on cytokines but the type of haemodialysis membrane, Cuprophan or Hemophan, specifically influences each cytokine. Circulating levels of TNF and unstimulated production of TNF and IL1 by monocytes were increased in patients dialysed with Hemophan, whereas a greater LPS-stimulated production of TNF was observed in patients dialysed with Cuprophan. Both types of membrane induced a higher production of IL6 as compared to controls. The alternate use of Cuprophan and Hemophan demonstrated that the production of TNF and IL1 was dependent on the type of haemodialysis membrane. We also found that Cuprophan induced a reversible decrease of spontaneous and LPS-stimulated production of TNF, IL1 and IL6 during the haemodialysis session. Taken together, these results suggest that Hemophan induced a sustained production of cytokines whereas Cuprophan primed monocytes, probably through the activation of the complement pathway.

Aged↗

Using ultrapure water in hemodialysis delays carpal tunnel syndrome.

Since 1977, our patients have undergone chronic HD with ultra-pure dialysate (UPD), defined as having endotoxin levels below 0.008 ng/ml and less than 1 bacteria/ml of dialysate. We evaluated the incidence of carpal tunnel syndrome (CTS) in three groups of patients. Group I (GI), 84 patients, dialysed for 6.1 +/- 3.2 years (mean +/- SD) with UPD only; Group II (GII), 39 patients, first dialysed for 3.7 +/- 2.3 years with non-UPD and afterwards for 8.4 +/- 2.1 years with UPD; Group III (G III), 103 patients treated for 6 +/- 5.9 years exclusively with non-UPD. All patients were dialysed with cuprophan or cellulose acetate membranes. Results, expressed by Kaplan-Meier actuarial survival curves as the percent of patients without CTS, show that CTS occurred significantly less in GI than in GIII. This may be due to less stimulation of monocytes resulting from the absence of bacteria, endotoxins and pyrogens in the dialysate, which would reduce the stimulation of cytokines release, interleukin 1 and 6, and tumor necrosis factor, known to stimulate beta 2 microglobulin synthesis.

Actuarial Analysis↗

Urinary supersaturation with respect to brushite in patients suffering calcium oxalate lithiasis.

The urines of 23 stone-formers presenting repeated calcium oxalate lithiasis and 12 control subjects were collected at six different time periods daily. Supersaturations for calcium oxalate and brushite (DCPD) were calculated using ionic and solubility products. Urines of both groups were supersaturated for calcium oxalate but only urines of the stone-formers were supersaturated for brushite, the most simple calcium phosphate which nucleates very easily at the urinary pH. This fact suggests that the core of the calcium oxalate stone could be made of either a calcium oxalate crystallite or a brushite seed onto which hetergeneous nucleation of calcium oxalate can take place.

Adolescent↗

[Hypokalemic quadriplegia and coma in renal tubular acidosis].

A case is reported of an acute episode of severe hypokalaemia (K+ = 1.1 mmol.l-1) associated with hyperchloraemic acidosis and simultaneous high urine pH (pH = 7) in a 24 year old woman with type I distal tubular acidosis and nephrocalcinosis. The flaccid paralysis involved the trunk, neck, facial and pharyngeal muscles. She was in areflexic quadriplegia, coma and respiratory failure requiring endotracheal intubation and positive pressure ventilation. There were no cardiac disturbances, presumably because of the chronic potassium depletion, the patient's youth and healthy myocardium. Despite the usually recommended maximal potassium infusion rate (0.25 mmol.kg-1.h-1), there was a transient worsening of her neuromuscular status. Only 12 h later, the first movements were noticed. In order to prevent such a deterioration, a more rapid potassium infusion could have been used. However, in our case, the occurrence of hypokalaemic extrasystoles was reduced and the patient was still intubated and ventilated. It was therefore decided not to run the risk of myocardial inexcitability carried out with supramaximal infusion rates and to keep the usual protocol. Besides, several pitfalls have to be avoided during the treatment of the numerous metabolic disorders coexisting with severe hypokalaemia, such as metabolic acidosis and hyperglycaemia.

Acidosis, Renal Tubular↗

Aortoiliac reconstruction and renal transplantation: staged or simultaneous.

Aortoiliac atherosclerosis can jeopardize the outcome of renal transplantation. During a five-year period, 176 renal transplants were performed. Of these, four patients underwent prior or simultaneous arterial reconstruction. In two, transplantation was successfully performed three and ten months after abdominal aortic aneurysm repair. In the two others with aortoiliac occlusive lesions, simultaneous arterial reconstruction and transplantation were successfully performed. We conclude that the discovery of aortoiliac lesions in a candidate for renal transplantation warrants consideration for staged or simultaneous arterial reconstruction to widen the indications for transplantation in such individuals and provide satisfactory long-term transplant durability.

Adult↗

Lack of effect of spiramycin on cyclosporin pharmacokinetics.

1. The influence of spiramycin coadministration on cyclosporin pharmacokinetics was studied in five renal transplant patients. The plasma concentrations of cyclosporin were measured both by non-specific radioimmunoassay (RIA) and high-performance liquid chromatography (h.p.l.c.). 2. The kinetics of cyclosporin were followed before treatment, and after 1 day and then 2 weeks of oral treatment with spiramycin (3 X 10(6) iu, twice daily). The main pharmacokinetic parameters (the area under the plasma drug concentration-time curve, the maximum plasma drug concentration and the time to reach it) obtained both by RIA and h.p.l.c. were not modified by spiramycin cotreatment after 1 day, nor after 2 weeks of spiramycin administration. Therefore, the pharmacokinetics of cyclosporin (parent drug and parent drug plus metabolites) are not influenced by the coadministration of spiramycin macrolide at therapeutic dosage. 3. Spiramycin may be preferable to other macrolide antibiotics known to interact with cyclosporin such as erythromycin or josamycin.

Adolescent↗

Determination of blood volume in nephrotic patients.

We assessed blood volume (BV) in 20 edematous patients with nephrotic syndrome and in 32 subjects without renal or other disease liable to induce BV variation. Two methods were chosen, one using 131I-albumin and the other 51Cr red blood cells. Among the 20 patients, 11 presented minimal-change lesions, and 9 had histological glomerular impairment. The BV was significantly higher when measured with 131I-albumin in both nephrotic patients and in controls. However, in patients with nephrotic syndrome, the values obtained from the measurement of BV by 131I-albumin showed an increase of only 1%. Comparison of BV values of nephrotic patients and controls showed that BV is equal or higher in two thirds and lower in one third, respectively. The same incidence of histological glomerular lesions was observed in both groups. In conclusion, this study demonstrates that the method using 131I-albumin to measure BV in nephrotic syndrome is reliable. BV is decreased in one third of the patients and is not related to the presence or absence of histological glomerular lesions.

Adolescent↗