Prevalence of hepatitis C virus (HCV) antibodies in haemodialysis patients.

The prevalence of antibodies to HCV and the course of hepatitis have been determined in 357 haemodialysed patients treated at a single institution. The prevalence of HCV infection increases with the duration of haemodialysis and with the use of blood transfusions, yet there is high frequency of HCV seropositivity even without blood transfusions. Evolution of HCV hepatitis to chronicity is frequent and biological signs of chronic hepatopathy can coexist with absence of alanine aminotransferase (ALT) abnormalities.

Ultrafiltration and endotoxin removal from dialysis fluids.

Biocompatibility in hemodialysis is now regarded as a multifactorial problem and dialysate represents a main risk. Pyrogenic fractions mostly coming from gram-negative bacteria easily pass through dialysis membrane, either by backdiffusion or by backfiltration, and induce blood cell activation. To demonstrate the long-term efficiency of a 2 m2 polyamide ultrafilter in producing a pyrogen free solution, we used an experimental circuit ultrafiltering for 240 hours (500 ml/min) a bicarbonate dialysate contaminated (5 to 48 EU/ml) by a Pseudomonas aeruginosa filtrate. The efficiency was monitored by LAL-test and IL-1 PBMC so to detect not only lipid A containing endotoxins but also other cytokines inducing bacterial fractions. At the post-ultrafilter sampling port the LAL-test was < 0.005 to 0.034 EU/ml; IL-1 PBMC was below the detection limit (20 pg/ml) being 27 to 63 pg/ml at the pre-ultrafilter level. Polyamide ultrafiltration represents an efficient system to obtain an endotoxin-free dialysate and a single filter works up to 240 hours.

Acid-base balance during biofiltration (BF).

Acid base balance during biofiltration (BF): Six patients on standard acetate hemodialysis (HD) were switched to BF with 1 m2 AN69-S membrane, 12 hours weekly (BF-4h) and, later on, to a stage with 1.2 m2 AN69-S, 9 hours weekly (BF-3h). During BF, in order not to exceed 25 mEq/l in intradialytic arterial HCO3, arterial acid-base was examined hourly and a mean of 178 and 199 mEq of HCO3 respectively were infused in BF-4h and BF-3h. We obtained a better control of acidosis with a reduction of the intradialytic pCO2 decrease and hypoxemia. The amount of HCO3 infused was related to the patients deficit in HCO3 total pool and therefore it can be predicted, to avoid postdialytic alkalosis.

Leaching and corrosion of polyvinyl chloride (PVC) tubes in a dialysis water distribution system.

PVC tubes, from the dialysis water distribution system of a 14 and a 7 year old plant, were analysed by scanner electron microscopy (SEM) and X-ray microanalysis (EDAX). Results showed that the leaching of material occurs depending on time of use. The phenomenon does not modify the chemical composition of the material. Results suggest that PVC alterations, induced by time, could support bacterial proliferation thus reducing the quality of dialysate.

On line filtration of dialysate: structural and functional features of an asymmetric polysulfone hollow fiber ultrafilter (Diaclean).

The endotoxin transfer across dialysis membranes has been investigated using specific in vitro circuits. Backdiffusion and backfiltration have been analyzed and most dialysis membranes have shown to be permeable to LAL positive substances. Synthetic membranes however display the better capacity of retention of these products despite their higher porosity and permeability. For such reason synthetic polysulfone ultrafilters are used as pyrogen filters to obtain ultrapure dialysate. We have investigated the characteristics of a polysulfone ultrafilter named Diaclean and manufactured by Amicon Ireland. The capacity of endotoxin retention has been investigated both in filtration and backfiltration modes on new and used ultrafilters. The capacity of endotoxin adsorption was investigated as well. Used ultrafilters appeared to maintain the retention capacity and the adsorption capacity up to 4 months of use. Only slight differences were noted from the baseline values (p = n.s.). The best adsorption capacity is always displayed by the outer layer of the membrane suggesting its best utilization in back filtration mode with tangential flow. No morphological changes were observed in the used membrane analyzed by scanning electron microscopy.

[Anatomo-clinical studies and therapeutic results in 2 cases of essential mixed cryoglobulinemia with renal insufficiency]. / Osservazioni anatomo-cliniche e risultati terapeutici in due casi di crioglobulinemia mista essenziale decorrenti con insufficienza renale

Two cases of essential mixed cryoglobulinaemia selected from a personal series on account of their clinical features (hyperviscosity syndrome in one case and frank renal involvement in the other) are presented. Extensive seroimmunological examinations were carried out, along with histopathological studies designed to reveal significant changes in organs and tissues, particularly the skin and kidneys. Reference is briefly made to the debate pathogenesis of the immunological phenomenon that probably lies at the root of the disease. A short account is also given of attempts at treatment with corticosteroids, immunosuppressors and plasmapheresis.

[Transcutaneous renal needle-biopsy guided with ultrasonics]. / Agobiopsia renale transcutanea "mirata" con ultrasuoni.

Authors performed percutaneous renal biopsy guided by ultrasounds in 10 patients in whom urography was dangerous or did not provided good renal images. The advantages of this method are in the directional and dimensional accuracy of ultrasound scanning, so that the exact topography of the kidney can be established. The use of ultrasonically guided renal biopsy is mainly recommended in iodine medium idiosyncrasy, in myelomas and renal failure. This method can be preferred in order to establish the exact topography of kidney, in acute anuric renal failure, in chronic failure (when high doses of iodate contrast are needed), and in the presence of cyst.

[Increased muscular irritability syndrome: treatment with nifedipine. Report of a case]. / Síndrome de irritabilidade muscular aumentada: tratamento com nifedipina. Registro de um caso.

In 1980 Alberca et al. described a patient with a syndrome of increased muscle irritability, who presented ondulating muscle rolling movements and electrically silent cramps, myoedema and muscle reactions to mechanical stimulation similar to myotonic response, suggesting a disfunction at myofibrillar level. We saw a similar case, of a male patient, 21 years of age, who complained of cramps of severe intensity for the past four years. These cramps were painful in the upper and lower limbs and impaired his locomotion; they were electrically silent. At percussion the patient showed severe idiomuscular contraction, with a period of increased relaxation, similar to a myotonic reaction and also, prolonged myoedema and rolling muscle contractions. Electromyography was normal, as were histochemical and electron microscopy studies. We carried out a therapeutic trial with niphedipine (a calcium antagonist), on the assumption that the patient showed a disturbance of the myofibrillar function--even though physiopathogenesis of the hyperirritability muscle syndrome was not yet clearly defined--and with a basis on the importance of the intracytoplasmatic level of Ca++ free in the muscle contraction mechanism, not only as the initiating factor of the contractile process, but also as a quantitative controller of the mechanic tension development through regulation of the amount of ATP metabolized during muscle activity. Administration of the drug in a dose of 40 mg daily, per os, brought a remission of the symptoms after two weeks, and the patient could walk normally again. On the introduction of a placebo, on two different opportunities, there occurred a recrudescence of the symptoms after about one week's time.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytogenetical and dermatoglyphic studies in patients affected by Steinert's myotonic dystrophy.

Cytogenetic and dermatoglyphic studies were performed in 10 patients affected by Steinert's myotonic dystrophy. No anomalies were found in karyotype and dermatoglyphs in these patients, except for an occasional chromosomal translocation.

Mitochondrial dysfunction in myasthenia gravis. Report of a case.

The case of an 11-year-old boy with external ophthalmoparesia, tetraparesia and bilateral eyelid ptosis is reported. He was 7-years-old when first symptoms appeared. Anticholinesterasic drugs were used. He was submitted to muscle biopsy. The results of histochemistry analysis showed storage of granulous material at the subsarcolemmal region of muscle fibers by SDH. Increase in the number of mitochondria with electron dense bodies was found at electron microscopy. Anticholinesterasic drugs administration was interrupted and consequently he got worse, and bouts of dyspnea occurred. Due to this worsening anticholinesterasic agents were reintroduced together with prednisone, and he improved. Due to clinical and histological expressions we think it is possible that morphological mitochondrial alterations may occur also in myasthenia gravis.

[Myopathies associated with tubular aggregates]. / Miopatias associadas a agregados tubulares.

The authors report the case of a 58-year-old male patient with clinical and electromyographic features of myasthenia. Muscle biopsy with histochemistry and electronic microscopy made it possible to diagnose a myopathy associated with tubular aggregates. Attention is called to the fact that the anatomical pathologic alterations which were found may be present in a heterogenous group of patients showing a great variety of symptoms. Thus, there is no reason to consider the existence of a myopathy associated with tubular aggregates, since the anatomical and pathologic findings are inespecific and do not characterize any specific disease.

[Congenital fiber disproportion: atrophy of type I fibers. Report of 11 cases]. / Desproporção congênita de fibras: atrofia de fibras tipo I. Relato de 11 casos.

The authors report 11 cases of congenital disproportion of fibers, confirmed through clinical and complementary examinations. In these 11 cases early fibrotendinous retractions were frequent and CK proved to be high. At muscle biopsy histochemistry revealed a selective atrophy of type I fibers. This is a rarely frequent congenital dystrophy, of slow progression and benign evolution.