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Biomedical subjects

A Thea

Publications and source records attributed to A Thea.

36 records · Page 2Linked to original sources

Direct interaction between polymorphonuclear neutrophils and cuprophan membranes in a plasma-free model of dialysis.

Plasma-free, purified, normal, human polymorphonuclear neutrophils (PMN) were recirculated for 60 minutes in an experimental model of dialysis using cuprophan membranes and acetate or bicarbonate dialysate. At different time intervals, the intracellular contents of PMN-derived cationic proteins (NCP), the release of lysosyme, beta-glucuronidase and PAF as well as the occurrence of PMN and platelet aggregating activities in the supernatants were evaluated. The formation of PMN aggregates, the depletion of intracellular contents of NCP together with the release of lysosomal constituents occurred early (5-10 min) in the course of recirculation. These events were concomitant with the occurrence of PMN aggregating activity in the supernatants due to the release of NCP, as it was antagonised (30-40%) by a rabbit anti-human NCP, and to the release of PAF which also accounted for the platelet aggregating activity that was independent from both adenosine diphosphate and cyclo-oxygenase inhibitors. These data suggest that direct interaction occurs between human PMN and cuprophan in in vitro conditions in the absence of plasma factors and point to a role for cellular mediators in the pathogenesis of the intravascular alterations occurring early in haemodialysis.

Cell Aggregation↗

Urokinase treatment for arteriovenous fistulae declotting in dialyzed patients.

Urokinase treatment, previously employed with success in the declotting of deep venous thrombosis and arteriovenous shunts in patients undergoing regular dialytic treatment (RDT), was used in 23 cases of arteriovenous fistula thrombotic occlusion in 18 RDT patients. The treatment was successful in 65.2% of the cases without any negative side effects, except 1 case which may have developed a pulmonary embolism. Patients with severe hypofibrinolysis may need larger doses or may have a recurrence of the thrombotic episode. All therapeutic failures correlated with the presence of fibrosis or sclerosis.

Adult↗

[Basic aspects and current trends in iatrogenic kidney diseases. Correlations between their physiopathological mechanisms and clinical findings for the general practitioner].

Iatrogenic origins may be assigned to any form of kidney disease. Of the pathogenetic mechanisms involved, increasing importance is now attached to immunological responses and intravascular coagulopathies, though other processes long known to medicine have not ceased to play their part. Moreover, recent advances in the improvement of drugs and the standardisation of their use have given a better idea of the potential damage to the kidneys from many substances. A re-examination is made of the main findings in this field with a view to offering a simple summary of the underlying physiopathogenetic mechanisms, and drawing the diagnostic and clinical conclusions therefrom, so as to aid the general practitioner rather than the specialist. An account of the various medical interventions that may lead to kidney lesions, and the circumstances in which such interventions are most likely to be harmful, is followed by an analysis of recent opinions on the correct way of administering drugs in patients with kidney disease, so as to limit their potentially harmful effects as far as possible.

Biological Products↗

[The quarantined dialysis room for Australia-antigen-positive patients. Theoretical, normative, structural, operational, organizational and management aspects].

The technical features of dialysis facilitate the transmission of hepatitis B virus and the outbreak of possibly serious epidemics among patients and hospital staffs. Statistical, epidemiological and clinical data have been collected on many occasions. They serve to emphasise the problem and the need for quarantined centres. The establishment of such a centre for HBsAg-positive patients is discussed in the light of personal experience in the design and setting up of quarantined rooms. The underlying technical and structural requirements are also examined. Reference is also made to two years' experience in the running of a room of this kind. Stress is laid on the importance of having a room for these patients, not only from the clinical standpoint (lessening of contagion), but also from teh social and exonomic standpoint (reduced costs and length of hospital stay, greater rehabilitation).

Cross Infection↗

Three-year follow-up after withdrawal of iron therapy in uremic patients on regular dialytic treatment.

Iron supplementation is commonly recommended in uremic patients undergoing regular dialytic treatment in order to correct a presumed iron deficiency due to impaired absorption and dialytic losses. Serum ferritin levels show an iron overload in 83% of 136 patients on 1.25 g/year i.v. iron therapy. After the withdrawal of iron therapy, directly correlated ferritin levels and percentage transferrin saturation decreased slowly, except in carriers of HLA-A3 antigens and in polytransfused patients. In these latter patients, desferrioxamine reduced but did not normalize the iron balance. The 16 patients who never received iron therapy showed a normal iron balance over a 3-year follow-up. Despite iron-ferritin therapy, 11 patients with baseline ferritin values at the lower normal limits showed a tendency toward further depletion. Orally administered bivalent iron seems to be more promising in normalizing iron-deficient patients without potentially harmful overloading.

Adolescent↗

Extrahepatic immunological manifestations of hepatitis C virus in dialysis patients.

BACKGROUND: Hepatitis C virus (HCV) infection may be associated with various extrahepatic immunological disorders. Uremic patients on chronic regular dialytic treatment (RDT) frequently develop immunological abnormalities. The aim of this study was to evaluate the probability that HCV infection creates an increased risk for extrahepatic immunological abnormalities in chronic RDT patients. SUBJECTS AND METHODS: In a series of one hundred sixteen chronic RDT patients, HCV status was determined by anti-HCV antibodies, polymerase chain reaction (PCR) RNA and viral genotyping. After excluding four anti-HCV negative/PCRRNA positive patients, a comparison was made between 51 anti-HCV negative/PCR-RNA negative and 61 anti-HCV positive patients, this latter group including seventeen PCR-RNA negative, fifteen genotype 1, thirteen genotype 2, three genotype 3, four genotype 4, four undeterminable genotype and five mixed genotypes. The following investigations were performed: cryoglobulinemia (presence, titer and, when possible, identification), monoclonal gammopathy, antineutrophil cytoplasm antibodies, antidouble stranded DNA antibodies, circulating immunocomplexes and immunoglobulin levels. RESULTS: Cryoglobulinemia was found in 77% of anti-HCV positive versus 29% of anti-HCV negative patients, and cryocrit > 1% in 50% versus 9.8% respectively, p=<0.01. Also cryoglobulin concentration was higher (logarithmic transformation: 4.38 +/- 0.94 vs 3.11 +/- 1.06, p =< 0.001) in anti-HCV positive versus negative patients. Multivariate logistic regression analysis showed a significantly increased odds ratio (12.0, confidence interval 3.0 to 48.3) for having high levels of cryoglobulins (cryocrit >1%) after adjusting for age and dialytic age. The prevalence of this abnormality did not differ significantly among patients infected with different genotypes, but a tendency towards a lower frequency was observed in the anti-HCV positive/PCR negative subgroup. Cryoglobulins were identified as type I (2 anti-HCV positive case), type II (2 anti-HCV positive and 1 anti-HCV negative case) and type 3 (1 anti-HCV negative case). The frequency of monoclonal gammopathy was not significantly different between anti-HCV positive and anti-HCV negative patients (6.5% versus 2%) as well as that of the other parameters evaluated except for IgG concentration which was higher in the anti-HCV positive group (1,685 +/-605 versus 1349 +/- 352 mg/dl, p 0.006). Five events, potentially linked to HCV infection, occurred in our anti-HCV positive patients: 2 cases of porphyria cutanea, 1 case of unexplained peripheral neuropathy, 1 cutaneous leukocytoclastic vasculitis, 1 death for non-Hodgkin's lymphoma. In one anti-HCV positive patient treated with interferon-alpha, the presence of cryoglobulins, monoclonal gammopathy and high IgG levels strictly paralleled that of viremia, disappearing during the recovery phase under treatment and reappearing shortly after stopping treatment. CONCLUSIONS: HCV infection provides a significantly increased risk for developing extrahepatic immunological abnormalities also in chronic RDT patients. It is possible that the clinical relevance of this event might be scant because of the low level of these abnormalities, but an awareness of its possibility should to be taken into account.

Adult↗

[Costs of dialysis in hospitalised patients with acute or chronic renal failure, according to area of treatment].

BACKGROUND: In Italy, dialysis reimbursement is regulated by the "Tariffario delle prestazioni ambulatoriali" (G.U. N 216, 14/9/1996), which does not take into account separately the dialysis sessions performed in hospitalised patients. In these cases the dialysis activity is considered within the final DRG (Diagnosis Related Group). Aim of the study was an analysis of production costs of dialysis performed in hospitalised patients, according to the setting in which dialysis is performed (Intensive Care Units (ICUs), other Units, hospital dialysis ward). METHODS: The direct production costs were assessed by the "bottom-up" technique logic (cost definition from the single elements needed for producing the treatment) referring to specific Cost Centres. The main items considered were health-care staff, dialysis supplies and hardware, blood tests, dialysis data recording and transmission. RESULTS: During the year 2000, there were 4,450 treatments performed in 490 patients. They included 924 haemodialyses in ICUs; 2,531 in the nephrology hospital dialysis ward; 602 peritoneal dialysis treatments in ICUs-other wards, 393 in the nephrology ward. Direct cost per haemodialysis treatment ranged from 276.05 E (UF) to 413.46 E (HF) in ICU, from 170.47 E (Bicarbonate Haemodialysis) to 275.36 E (Slow Haemofiltration) in hospital dialysis ward; for peritoneal dialysis between 128.95 E (CAPD in dialysis ward) and 282.10 E (CAPD in ICU/other Units). During the year 2000, the global cost of production was 1,038,346.65 E. CONCLUSIONS: The cost of dialysis in hospitalised patients is high. A dedicated budget is needed to avoid deficits, particularly in highly specialised Units of large referral hospitals.

Acute Disease↗