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Biomedical subjects

G Banfi

Publications and source records attributed to G Banfi.

At least 73 records · Page 4Linked to original sources
PubMed1994

Association of pseudothrombocytopenia and pseudoleukopenia: evidence for different pathogenic mechanisms.

A case of spurious automated leukocyte and platelet counts due to EDTA-dependent platelet-neutrophil agglutination is described. Whole blood anticoagulated with K3EDTA, sodium citrate and lithium heparin was analysed at short time intervals up to 6 h from sampling at 37 degrees C and at room temperature (RT = 27 degrees C). A phenomenon of platelet clumping occurred at both temperatures with all the anticoagulants (pseudothrombocytopenia), while platelet-granulocyte agglutination was present only with EDTA at RT. Aggregates consisting of up to 80 neutrophils were seen on the blood smear. The contemporary presence of platelet clumping caused a reduction of WBC count of only 25% the initial, while leukocyte differential was markedly altered (pseudolymphocytosis). Further experiments were performed mixing plasma and serum of the patient with packed cells (PC) from a normal donor in the presence of different anticoagulants and at various dilutions and temperatures. Platelet-neutrophil agglutination occurred only in the presence of EDTA at temperatures lower than 37 degrees C, and was abolished by plasma dilutions from 1:8 onwards. Similarly, it was inhibited by incubation with dithiothreitol (DTT), in contrast with platelet clumping. The latter phenomenon was triggered by an EDTA concentration lower than that necessary to cause platelet-neutrophil agglutination (0.5 mg ml-1 vs. 0.77 mg ml-1). Obtained results suggest the causal association of 2 different phenomena, both transferable to normal cells by means of patient plasma and serum. In the article the pathogenetic implications of the case are discussed.

Anticoagulants↗
PubMed1994

Renal replacement therapy in cryoglobulinaemic nephritis.

Seventeen patients with nephritis due to mixed cryoglobulinaemia were submitted to regular haemodialysis in 11 and continuous ambulatory peritoneal dialysis in six after 145 +/- 55 months from the onset of the disease. Four patients with very poor clinical conditions died within 6 months from the beginning of dialysis. The other 13 patients were followed for a mean period of 78.7 +/- 41.6 months. The actuarial survival rate was 65% at 5 years. Both clinical and immunological signs of mixed cryoglobulinaemia reduced during dialysis but a long-lasting burn out was observed only in one patient. Two patients received a kidney graft. Mixed cryoglobulinaemia nephritis recurred in both of them respectively 5 and 10 months after transplantation. One patient lost his graft 13 months after transplantation because of chronic rejection. The other one still has a functioning kidney 48 months after renal transplantation. The life expectancy with dialysis for mixed cryoglobulinaemia patients is similar to that of patients with standard primary renal disease but some few patients with severe disease at the beginning of dialysis have a poor prognosis. Nephritis may recur after renal transplantation but this does not preclude per se a favourable course in the long term.

Actuarial Analysis↗
PubMed1994

Growth hormone and insulin-like growth factor I in athletes performing a marathon at 4000 m of altitude.

Human growth hormone (hGH) characteristically increases during physical exercise. In sports medicine, hGH changes have mostly been described in short-term performances under standardized laboratory procedures. We studied hGH and insulin-like growth factor I (IGF-I) under field conditions in 7 runners performing a marathon at 4000 m of altitude, to study the hormonal changes under extreme endurance effort and to evaluate the release of 22 kDa and 20 kDa monomers under these conditions, in comparison with a control group. The blood samples were taken at sea level, after 1 week of acclimatization, immediately after the run, and after a recovery of 24 h from the marathon. hGH was quantified by using a polyclonal method, a 22 kDa specific monoclonal method and a monoclonal method recognizing both 22 kDa and 20 kDa isoforms. A significant increase in hGH was noted using all methods after the marathon, followed by a significant decrease after recovery. Significant differences between athletes and controls were found only for the measurement after the marathon. No statistically reliable decrease of IGF-I was observed in athletes and controls. We obtained more limited hGH rises than previously described in athletes; the importance of lactate levels indicates that the use of physical exercise as a stimulation test for hGH should be closely standardized. The 20 kDa monomer and other hGH molecular forms played a limited role in the hormone increase: in our experience, elevation of hGH in heavy exercise corresponds mostly to the 22 kDa isoform. We suggest that the evaluation of hGH elevation in sports medicine could be accurately performed using specific 22 kDa monoclonal assays.

Adult↗
PubMed1993

Capillary electrophoresis for protein analysis: separation of human growth hormone and human insulin molecular forms.

The capillary zone electrophoresis (CZE) technique was evaluated for separation and quantification of human growth hormone (hGH), human insulin (hI), and proinsulin. Three different molecular forms of biosynthetic hGH (20K, 22K, 44K), methionyl-hGH, biosynthetic hI, and proinsulin, were studied. The hormones were separated with uncoated capillaries, and various analytical conditions were tested (different buffers, ionic strength, pH). The samples were introduced both at positive pressure and electrokinetically, and the voltage applied was varied in each case. Linearity, repeatibility, and limit of detection (0.8 microM for hGH and 1.3 microM for insulin) were determined. Different purification steps were tried in order to find a suitable preanalytical procedure for hGH and hI purification from plasma. Recovery rates from 65 to 80% were obtained.

Electrophoresis↗
PubMed1993

Usefulness of free testosterone/cortisol ratio during a season of elite speed skating athletes.

Free testosterone/cortisol ratio (FTCR) was used in eight elite speed skaters (five males, three females), during an eight-month season, to study the effectiveness of the hormonal parameter as a marker of the condition of overstrain and/or incomplete recovery. We did not find values lower than 0.35 x 10(-3). We confirmed the reliability of the criterion of FTCR decrease of 30% or more to indicate temporary incomplete recovery from intensive training and residual weariness and, consequently, of reduced effectiveness for competitive purposes; a formula was used in this case to calculate FTCR. When FTCR was calculated by using directly measured FT, we remarked that such threshold criterion could not be used and the significant decrease was of 18% or more. The major problem of FTCR is the limitation of its use to male athletes, although the trend found in females was similar to that presented in males. FTCR is a useful index in elite speed skaters: broader application of this index and further investigation are required to set testing times, to use direct measurement of free testosterone and, finally, to find an equivalent support for women.

Adult↗
PubMed1993

Behavior of tumor markers CA19.9, CA195, CAM43, CA242, and TPS in the diagnosis and follow-up of pancreatic cancer.

We compared the recently proposed tumor markers CA195, CA242, and CAM43 with a widely used antigen, CA19.9, and a circulating marker of cellular proliferation, TPS, to define their specificity, sensitivity, and cost-benefit ratio. The tumor markers were measured in 41 pancreatic carcinoma patients and in two control groups, the first comprising 19 patients with benign pancreatic diseases, the second comprising 41 healthy blood donors. Sensitivities were 79% for CA19.9, 57% for CA242, 60% for CAM43, 76% for CA195, and 98% for TPS. Specificities calculated for the group with pancreatic diseases were 60% for CA19.9, 84% for CA242, 95% for CAM43, 53% for CA195, and 22% for TPS. Specificities for the blood donor group were 100% for CA19.9, 93% for CA242, 98% for CAM43, 85% for CA195, and 88% for TPS. Positive values for the tumor markers appeared from second stage (Hermreck classification). Metastases, invasion of lymph nodes, and coupling of cancer-associated antigens did not significantly modify marker sensitivity. In pancreatic carcinoma, CA19.9 showed good sensitivity (79%) and high specificity (60-100%). In view of their own advantages (e.g., high specificity of CAM43, high sensitivity of TPS in recurrences) and limits (e.g., low sensitivity of CAM43, very low sensitivity of TPS), the other markers could be used alone or with CA19.9. Two pairs of tumor markers showed high similarity in our study: CA19.9 and CA195, and CAM43 and CA242.

Adult↗
PubMed1993

Lupus membranous nephropathy: long-term outcome.

The follow-up of 42 patients affected by lupus membranous nephropathy (LMN) is reported and compared with that of 43 patients affected by diffuse proliferative lupus glomerulonephritis (DPGN), who were the object of a previous study. According to the WHO classification, the patients were subdivided into two groups: pure LMN (Va + Vb class) and LMN with superimposed proliferative lesions (Vc + Vd class). Antiphospholipid antibodies (APA) and lupus anticoagulant were tested in 23 subjects. All the patients were treated with corticosteroids, which were associated to cytotoxic drugs in 28 cases. Although a higher number of complete remissions was obtained in patients with pure LMN, the difference between the 2 groups was not significant (7/26 vs 1/16). At 10 years kidney survival was 93% in all LMN patients with no significant differences between the 2 groups. This 10-year kidney survival rate is very similar to that previously observed by us for DPGN (91%). The WHO histological classification and the chronicity index did not identify the patients who reach end-stage renal failure. Eight patients suffered from thrombotic manifestations which were the cause of death in two cases. Fourteen of the 20 patients studied presented echocardiographic abnormalities. A statistically significant association was found between the occurrence of cardiovascular complications and APA levels. The effectiveness of treatment in LMN remains controversial. We suggest, however, that adequate therapy may significantly improve the prognosis of lupus nephritis thus reducing the differences in the outcome of SLE patients having different histological WHO classes. Cardiovascular illness represents a frequent and severe late complication.

Adult↗
PubMed1992

Reduced levels of free testosterone in four Catania-type alloalbuminemic males.

We studied total testosterone, sex hormone binding globulin, and free testosterone in four males presenting an electrophoretically slow-moving genetic variant of albumin, the alloalbumin Catania. Free testosterone levels were lower in these cases, found in a year of observation, than those expected for the ages. This finding, which is not related to any disease and constantly not recognized in other males with various genetic variants, should induce consideration of a probable difference of the genetic variant in hormone binding.

Adolescent↗
PubMed1992

Acute tubular necrosis caused by gross hematuria in a patient with focal and segmental necrotizing glomerulonephritis.

We describe a patient with gross hematuria, severe renal failure and symptoms suggestive of systemic vasculitis. Renal biopsy showed very focal and segmental necrotizing glomerulonephritis without crescents. A few C3 deposits were seen by immunofluorescence. The tubular lesions, on the contrary, were very severe, consisting of tubular cell necrosis and ruptured tubular basement membrane, associated with large numbers of intraluminal erythrocytes and erythrocytic casts. After gross hematuria had cleared, renal function slowly recovered. Because of biopsy findings and clinical course, acute renal failure in this patient was considered to be due to the tubular lesions caused by gross hematuria.

Acute Kidney Injury↗
PubMed1992

Standardization with synthetic 22-kDa monomer human growth hormone reduces discrepancies between two monoclonal immunoradiometric assay kits.

Discrepancies among different methods for assaying human growth hormone have been described in various studies. The two major sources of discordant results are the heterogeneity of the antibodies and the different standardization bases used by the assay manufacturers. We propose standardizing assays with 22-kDa biosynthetic monomer human growth hormone diluted with the diluents supplied by the kit manufacturers. In a study of two monoclonal immunoradiometric assays (Hybritech, specific for the 22-kDa monomer; Sorin, recognizing also a 20-kDa variant hormone), standardization with 22-kDa monomer human growth hormone reduced by 63% the differences in results for 44 serum samples from children. The use of 22-kDa human growth hormone as a common standard, highly pure and easily available in large quantities, could help limit the interpretative problems in growth diagnostics.

Antibodies, Monoclonal↗