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Biomedical subjects

P L Bedani

Publications and source records attributed to P L Bedani.

At least 19 recordsLinked to original sources

Chick embryo back skin organ and fibroblast cultures. Extracellular matrix changes induced by dialysate fluid and uraemic toxins in relation to proliferation and differentiation processes.

AIM: During uraemia, an increase of middle molecules and acetylpolyamines occurs. In vitro the middle molecules produce cell toxicity, while the acetylpolyamines stimulate cell proliferation and differentiation. These phenomena are related to protein and extracellular glycosaminoglycan production. The aim of the present study was to evaluate the activity of dialysate, dialysate fluid and the chromatographic peaks of dialysate fractionated by G-15 Sephadex column on chick embryo skin development. METHODS: We evaluated the effects of protein and glycosaminoglycan synthesis using monolayer and organotypic cultures. RESULTS: Our data show that dialysate, chromatographic peak II, and 2 x 10(-8)M N1-acetylspermine cause inhibition of chick embryo skin culture development. On the contrary, 10(-8)M N-acetylornithine and dialysate fluid increase protein and extracellular glycosaminoglycan synthesis, whereas chromatographic peak I does not reveal differences when compared to controls. CONCLUSIONS: These extracelluar changes are related to cell proliferation and feather formation in chick embryo organotypic culture. Moreover, the pH changes of culture medium do not influence the biological action of acetylpolyamines and dialysate fluid on protein and extracellular glycosaminoglycan synthesis. Cell death in the presence of N1-acetylspermine, dialysate and peak II appears unrelated to the apoptotic process. The data show that acetylpolyamines, dialysis fluid, dialysate and chromatographic peaks act on fibroblasts, and are able to modify glycosaminoglycan synthesis. The organotypic cultures of chick embryo back skin could represent a model for studying the modifications of the extracellular matrix induced by these substances.

Animals↗

Erythropoietin and cardiocirculatory condition in aged patients with chronic renal failure.

BACKGROUND/AIM: The clearest benefit of recombinant human erythropoietin (rHuEPO) in end-stage renal disease is a substantial reduction in transfusion dependency and an improved quality of life. In this report, we describe the efficacy of weekly subcutaneous administration of rHuEPO in 11 elderly patients with anemia secondary to chronic renal failure. METHODS: The role of rHuEPO therapy in increasing the patient's quality of life and in decreasing the hospitalization rates secondary to cardiac morbidity was verified in 11 elderly patients (age range between 66 and 85 years) with anemia due to chronic renal failure. The mean hemoglobin level at the beginning of the study was 8.2 +/- (SD) 0.7 g/dl, and the serum creatinine concentration was 4.8 +/- 1.36 mg/dl. The patients underwent baseline and annual echocardiography, in addition to an electrocardiogram. RESULTS: Most patients experienced a partial regression of left ventricular hypertrophy, and no congestive heart failure was documented. The mean hemoglobin level during rHuEPO therapy increased to 11.3 +/- 1.2 g/dl, while the mean serum creatinine concentration did not change significantly. CONCLUSIONS: Our results confirm that early anemia correction in aged chronic renal failure patients permits improvement of the quality of life, of exercise performance, and of cognitive functions. Reduced transfusion need and regression of left ventricular hypertrophy favor a minor incidence of cardiac morbidity and contribute to reduce health costs.

Aged↗

Experimental model for studying the effects of 2-ethylhexyl-phthalate and dialysate on connective tissue.

In order to have a model for studying the possible implications of 2-ethylhexyl-phthalate and dialysate on connective tissue, we evaluated their direct effects on the air pouch lining tissue and on fibroblast cultures. Air pouches were formed on the backs of 60 ten-week-old Wistar rats by subcutaneous injections of 10 ml sterile air. On the tenth day 2 ml sterile air, or 2 ml 5 microg/L or 2 ml 10 microg/L 2-ethylhexyl-phthalate in olive oil, or 2 ml olive oil alone, or 2 ml 5 mg/ml or 12 mg/ml lyophilized dialysate were injected into the air pouches. After sampling at seven or twenty-one days, the rats were killed. The biochemical data showed an increase in sulphated glycosaminoglycans with 2-ethylhexyl-phthalate and dialysate. Electron microscopy findings revealed cellular alterations such as vacuolation and cell remnants with 2-ethylhexyl-phthalate, while the cells of the air pouches treated with dialysate showed regular organelles with increased and dilated cisternae of rough endoplasmic reticulum. Moreover, an increase in collagen fibres surrounding the damaged zones was noticed in 2-ethylhexyl-phthalate and dialysate treated rats. The glycosaminoglycan modifications and collagen fibre increase seem to suggest that the morphological changes, with the features of fibrosis, could be the result of 2-ethylhexyl-phthalate and dialysate action on connective tissue. Moreover, the air pouch technique can be considered a good model for studying the direct effects of 2-ethylhexyl-phthalate and other substances, such as uremic toxins, on connective tissue.

Animals↗

Urinary glycosaminoglycans in recurrent urinary tract infections in kidney transplant patients.

Glycosaminoglycans have generalized antibacterial anti-adherent activity, and cooperate with secretory immunoglobulin-A in anti-infection defense mechanisms of the urinary tract. Cyclosporin A modulates T-lymphocytes and fibroblast functions. In this report we analyze urinary glycosaminoglycans and secretory immunoglobulin-A in renal transplant patients with recurrent urinary tract infections treated with cyclosporin. The results show a significant decrease of total glycosaminoglycans and secretory immunoglobulin-A in recurrent urinary tract infections which is unrelated to cyclosporin treatment. The data support the hypothesis that recurrent urinary tract infections may be the consequence of a genetic pathology rather than cyclosporin-induced alterations.

Aged↗

Prevalence of superficial dermatomycoses in 73 renal transplant recipients.

BACKGROUND: Because of chronic immunosuppressive therapy, the skin of renal transplant recipients (RTR) is considered more liable to fungal infections. AIM: The aim of the study was to analyze the prevalence of superficial dermatomycoses in a chronically immunosuppressed group of RTR who live in northern Italy and to verify the eventual relationship between the onset of mycoses, the immunosuppressive regimen and the interval of time elapsed after the transplantation. METHODS: 73 RTR were submitted to a complete dermatological examination for fungal infection. Skin scrapings were taken from the upper back, from the 4th toe web of all patients and from any suspicious lesion. RESULTS: 31 patients (42.5%) were affected by dermatomycosis. Pityriasis versicolor (PV) was present in 20 RTR (27.4%), fungal infection of the 4th toe web in 10 patients (13.7%) and onychomycosis in 9 RTR (12.3%). Trichophyton mentagrophytes was the most common dermatophyte. The prevalence of dermatomycoses was higher in the group of patients treated with azathioprine-cyclosporine-steroids and in those who had received their renal transplant in the previous 1-5 years. CONCLUSIONS: PV was the most frequent dermatomycosis and showed a higher prevalence than in the normal population. The prevalence of fungal infection of the 4th toe web and onychomycosis was similar to that found in the immunocompetent population, but the length of interval after transplantation seemed to increase the probability of their occurrence and of mixed or simultaneous fungal infections in the same patient.

Adult↗

DEHP-induced alterations in the lining tissue of the rat air pouch.

The direct effects of D(2-ethylhexyl)phthalate (DEHP), on subcutaneous tissue were studied in the rat, using the air pouch technique. Two ml of DEHP either undiluted or diluted in olive oil (10 microm/ml), were introduced into a previously created air pouch in the rats. The air pouch was removed and specimens of the lining tissue examined by optical and electron microscopy. The persistence of DEHP for 7 days is sufficient to cause alterations in the tissue. The major histological changes were the destruction of the tissue organization with cytoplasmic and nuclear alterations resulting in apoptotic bodies. The histochemical data showed an increase of sulphated glycosaminoglycans, showing proof of alterations in fibroblast functions. The authors suggest that the hyperplastic-type alteration induced by DEHP may be connected with the sclerosis of the peritoneal membrane described in uremic patients in CAPD.

Administration, Cutaneous↗

Benign nodular calcification and calciphylaxis in a haemodialysed patient.

Several types of soft tissue calcification can be detected from radiographic evaluation of patients with end-stage renal failure. The factors that predispose to such calcification include an increase in CaxP product in serum, the degree of secondary hyperparathyroidism, the level of blood magnesium, the degree of alkalosis, and the presence of local tissue injury. Three major varieties include calcification of medium-sized arteries, periarticular or tumoral calcification and visceral calcification. Calciphylaxis is a phenomenon consisting of acute ischemic necrosis in presence of calcification of dermohypodermic arterioles. It occurs mostly in chronic renal failure patients with secondary or tertiary hyperparathyroidism with a persistently elevated calcium-phosphorus product. There are few options in treating calciphylaxis and the outcome is generally poor. The authors report the case of a haemodialised patient with benign nodular calcification and calciphylaxis. The coexistence of both entities in the same patient has never been described.

Calcinosis↗

[Causes and risks of hyperlipidemia during dialysis and after renal transplantation].

The most widely studied hyperlipidemies in patients affected by renal insufficiency or subsequent to kidney transplant present phenotype IIa, IIb or IV. The lipidic alteration most frequently observed in chronic renal insufficiency and/or dialytic treatment is represented by hypertrigliceridemia as a result of: 1) altered VLDL metabolism; 2) reduced activity of lecithin cholesterol acyltransferase (LCAT); 3) decrease in Apo-A1 and HDL3. Furthermore, marked anomalies in lipoprotein Lp (a) have been reported in hemodialysis. In patients undergoing peritoneal dialysis, hyperlipidemia arises from both an anomalous retrograde absorption of glucose and protein dispersion. Following kidney transplant the most frequent hyperlipidemia is hypercholesterolemia, consequent to immunosuppressive treatment (mainly steroids and cyclosporin). The documented significant increase of cardiovascular risk in the presence of hyperlipidemia points to the need for a clearer etiopathogenic definition of this anomaly, as well as the necessity to find an efficacious pharmacological treatment.

Humans↗

[Radiographic manifestations in teeth and jaws in chronic kidney insufficiency].

Forty-five patients affected with chronic renal failure (29 men and 16 women; mean age: 47.8 years), treated with hemodialysis for 4 to 245 months (mean: 66.9 months) were examined with panoramic and skeletal radiographs-the latter of the skull, hands, shoulders and clavicles, pelvis and spine. The control group (45 subjects with no renal diseases) was examined only with panoramic radiography. Dental and skeletal radio-graphs were given an 0-6 score and then compared to assess a possible relationship between skeletal and dental changes at radiography. Twenty-six dialysis patients (57.7%) had radiographic abnormalities in the maxillary bones-i.e., osteoporosis (100% of patients), focal osteosclerosis adjacent to the roots (11.5%), lamina dura reduction or loss (26.9%), calcifications of soft tissues or salivary glands (15.3%) and brown tumors (7.6%). In the teeth of dialysis patients, the dental pulp chamber was narrowed in 11.1% and hypercementosis of the roots was observed in 4.5%. Radiographic abnormalities in the hand, shoulder and pelvis were depicted in 51.1% of dialysis patients-in 86.9% of them with maxillary lesions. In the control group, 15.5% had mandibular bone lesions-i.e., osteopenia, cortex reduction at the mandibular angles and cyst-like lesions -but the evidence of caries and periodontal disease did not differ from that in the dialysis group. The diagnosis and follow-up of dialysis patients are currently made with serum biochemistry, radiography and histology. The purpose of skeletal radiology is to monitor the progression or regression of musculoskeletal abnormalities. Panoramic radiography might be useful in monitoring renal osteodystrophy, especially to assess the response to therapy-i.e., parathyroidectomy, calcium or vitamin-D therapy and renal transplant.

Adult↗

Prevention of hepatitis C virus in dialysis units.

To understand how to prevent the diffusion of hepatitis C virus (HCV) in dialysis units, 289 chronic dialysis patients treated in a renal department from the beginning of 1990 to June 30, 1993, were studied. Patients were screened monthly for alanine aminotransferase values and every 3 months for anti-HCV antibodies. At the beginning of the study the prevalence of anti-HCV antibodies was 24.7%. Two study groups were defined. In the first, anti-HCV-positive patients were treated on separate machines; in the second, 13 anti-HCV-positive and 13 negative patients shared the same machines. Patients in the study were treated with traditional dialysis, employing low-permeability membranes and disposable dialysate circuits on machines without an ultrafiltration control device. The 'universal precautions' were rigorously applied. The use of blood transfusions was markedly reduced. Although new patients starting dialysis treatment revealed a high frequency of HCV positivity (10.8%), the overall prevalence of HCV infection in the department did not increase during the follow-up period. Furthermore, no seroconversion was found in patients on dialysis treatment, not only in the section where anti-HCV-positive patients were treated on separate machines, but also in the section where anti-HCV-positive and anti-HCV-negative patients shared the same machines. The possibility of an intradialytic diffusion of HCV appeared to be very low and the treatment of infected patients on separate machines not strictly necessary.

Alanine Transaminase↗