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Biomedical subjects

G Piccoli

Publications and source records attributed to G Piccoli.

At least 73 records · Page 4Linked to original sources
PubMed1996

Purification and characterization of the carboxyl-domain of human hexokinase type III expressed as fusion protein.

In mammalian tissues hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) exists as four isoenzymes encoded by distinct genes. These proteins are homologous and are organized in two homologous domains, with the exception of hexokinase type IV which has only one. This organization is believed to be the result of a duplication and tandem fusion event involving the gene encoding for the ancestral hexokinase. In this study, we cloned the carboxyl-domain of human hexokinase type III and expressed it in Escherichia coli as a glutathione S-transferase fusion protein, using the pGEX-2T expression vector. The recombinant protein showed catalytic activity. A comparative study of the kinetic properties of the expressed carboxyl-domain and the enzyme partially purified from human lymphocytes is also shown. The results now allow a better understanding of the role of the carboxyl-domain in determining the catalytic properties of the enzyme.

Amino Acid Sequence↗
PubMed1996

Report on management of renale failure in Europe, XXVI, 1995. Rare diseases in renal replacement therapy in the ERA-EDTA Registry.

The proportion of centres returning the ERA-EDTA Registry questionnaires has decreased considerably in recent years. Demographic information, based on the response rate of centres in 1994 (44%), does not allow reasonable projections for management of renal failure in Europe. To encourage the participation of non-responding centres, the timing was right to show the powerful impact of the ERA-EDTA Registry as a supra-national registry, by studying patients in renal replacement therapy (RRT) suffering from rare diseases. Four such diseases, Fabry's disease, nephropathy due to cyclosporin (CsA), nephropathy due to cisplatin and scleroderma, were studied using the records of 440665 patients on file up to 31 December 1993. There were 83 patients with Fabry's disease (0.0188%), 85 patients with CsA nephropathy (0.0193%), 120 patients with cisplatin nephropathy (0.0272%) and 625 patients with scleroderma (0.142%). Scleroderma was introduced as a primary renal disease (PRD) in the ERA-EDTA Registry in 1977. Seven patients were accepted for RRT in that year, whereas the number increased to over 50 new patients per year after 1986. More than half of the patients were aged over 55 years, and 68% of them were women. Survival rate of dialysis patients suffering from scleroderma was 22% at 5 years, compared to 51% in patients with standard primary renal diseases. The main causes of death were cardiovascular complications (41%), cachexia (15%) and infection (10%). Survival of first graft in a small number of 28 patients was 44% at 3 years, compared to 60% in standard PRD. Patient survival after first transplant, however, was higher by 32% at 3 years compared to that of dialysis patients. Cisplatin nephropathy was introduced as a PRD in the ERA-EDTA Registry in 1985, and since then six to 19 new patients have been accepted for RRT each year. The main reason for undergoing cisplatin treatment was ovarian (32%) and testicular cancer (21%), and the mean interval from treatment to RRT was 21.5 months, ranging widely from 0.1 to 131 months. Patient survival on dialysis was 22% at 5 years, compared to 51% in patients with standard PRD. Malignancy and cachexia accounted for over 60% of the total number of deaths. CsA nephropathy was introduced as a PRD in the ERA-EDTA Registry in 1985 and, despite its rarity, is of particular interest as a new iatrogenic entity resulting from CsA administration, mainly in solid organ transplantation. In 1985, two new patients commenced RRT in Europe, and the number increased to 59 in 1991-93. The main reason for undergoing CsA treatment was heart (68%) and liver transplant (22%), and the mean interval from treatment to RRT was 50.2 months, ranging from 5 to 90 months. Patient survival on dialysis was 46% at 4 years, compared to 58% in patients with standard primary nephropathies. Cardiovascular causes (48%) and infection (17%) were the main causes of death. Fabry's disease was introduced as a PRD in the ERA-EDTA Registry in 1985, and since the four to 13 new patients per year have commenced RRT in Europe. It is a sex-linked recessive disorder primarily affecting males (87%), and the mean age at start of RRT was 38 years. Proteinuria, skin lesions and painful paresthesiae were the most common presenting symptoms, and over 70% of the patients were hypertensive and had significant cardiovascular problems at RRT. Patient survival on dialysis was 41% at 5 years, compared to 68% in patients with standard primary nephropathies. Cardiovascular complications (48%) and cachexia (17%) were the main causes of death. Graft survival at 3 years in 33 patients was not inferior to that of patients with standard nephropathies (72% vs 69%), and patient survival after transplantation was comparable to that of patients under 55 years of age with standard PRD. (ABSTRACT TRUNCATED)

Adolescent↗
PubMed1996

Low-dosage ibopamine treatment in progressive renal failure: a long-term multicentre trial.

A multicentre trial (11 nephrology centres) was carried out to test the effects of ibopamine, an orally active dopamine-like drug, on the progression of chronic renal failure. For a 2-year period 189 chronic renal failure patients (serum creatinine level 1.5-4.0 mg/dl) were observed. They were homogeneous for basic nephropathy, degree of residual renal function, blood pressure, and proteinuria. The patients were randomly divided into two groups: 96 took ibopamine at a dosage of 100 mg/day (group A) and 93 served as controls (group B). All were on a low-protein diet (mean 0.8 g/kg body weight). By the end of the observation period, the rate of decrease of the renal function indexes in time proved significantly slower (1.8 times) in group A than in group B. The survival curves for renal function (pre-established end points were creatinine level increases equal to or > 20% and equal to or > 40% of the basal values) proved significantly better (p < 0.02 and p < 0.002 respectively) in group A than in group B. The mean plasma creatinine values rose by 17% in group A and by 36% in group B. The creatinine clearance decreased by 5% in treated patients and by 14% in the controls. Statistical analysis ruled out any possible centre effect. The trial suggests that low-dosage ibopamine administration may be used as a valid and safe pharmacological adjunct for retarding the progression of renal failure in patients with mild or moderate chronic renal impairment.

Adolescent↗
PubMed1996

[Diabetes mellitus is currently one of the most frequent causes or associated causes of uremia. Data from the Piedmont registry of dialysis and transplantation (update, December 1993)].

A regular dialytic treatment of diabetic patients is until accepted from about twenty years in many areas. Aim of this work was a retrospective analysis of main clinical and survival data of diabetic patients (diabetic nephropathy or diabetes as comorbidous factor = 659 cases) admitted for dialysis in Piedmont (Northern Italy Region about 4,400,000 inhabitants) in the period 1981-1993 (functional recovery and follow-up < 1 month excluded). A progressive increment in incidence of diabetic patients was seen mostly in the aged. At 12/31/1993, 263 of 2404 patients admitted for dialysis were diabetics (10.9%); the majority of them was treated in Hospital Centers with bicarbonate haemodialysis (54.4%), while a small group was treated with CAPD (12.9%). During the years ¿80 was seen a progressive leaving of CAPD as first choice method in this population and in the last period the orienteering is the utilization of mixed methods (diffusive-convective as first choice). As regards the survival are not prominent significant differences between this cohort and the cohort affected by vasculopathy as comorbidous factor (86.2 and 54.2% in diabetics vs 78.6 and 55.2% in patients affected by vasculopathy at 1 and 3 years--p = 0.3481; patients aged 45-64 years). In conclusion the cohort of diabetic patients represent a good marker of the clinical problems of the elder population with high clinic risk, in progressive increasing in our Region.

Adult↗
PubMed1996

[Glomerulonephritis in the elderly].

The authors present a clinical analysis of the literature data regarding aged patients affected with glomerulonephritis (GN) and of 115 GN patients aged more than 65 years, biopsied in their own Center. Complications of renal biopsy, including the subclinical ones, were found in 19.1% of old patients compared to 19.2% of younger patients (p = NS), major complications in 5 and 1.4% respectively (p = NS). The most frequent GN was membranous GN (MGN) (27.8%), followed by IgA-GN (12%) and rapidly progressive GN (RPGN), idiopathic (8.6%) or secondary to vasculitis (8.6%). Eighteen out of 32 old MGN patients treated with alternated courses of steroids and immunosuppressive drugs for 6 months were compared to 32 MGN patients aged < 65 years identically treated. Complete remission was observed in 27.7% of cases and partial remission in 38.8% (p = NS). Complications of treatment were similar in the two groups of patients (p = NS). Patients with RPGN were treated with steroids (17 patients) plus immunosuppressive drugs (15 patients) and plasma exchange (13 patients). Systemic symptoms disappeared in 13/14 patients; ANCA became negative in all the 5 patients in whom they were detected; a 50% reduction of serum creatinine was obtained in 12 patients. These patients were compared to a control group of 26 patients aged < 65 years. Amelioration of renal function was evidenced more frequently among old patients with vasculitis (p < 0.05). Complications of treatment were more frequent among old patients with idiopathic RPGN (p < 0.05), but severe in only 1 case. Our data and data from the literature support the opportunity to perform renal biopsy in aged people, because it is as safe as in the younger population and allows a rational basis for treatment of GN. Clinical responses are similar to those of younger patients. Complications of treatment seem to be more frequent in old patients, but can be limited by some technical precautions and careful clinical monitorization.

Age Distribution↗
PubMed1995

High-performance capillary electrophoretic separation of proteins and peptides using a bonded hydrophilic phase capillary.

High performance capillary electrophoresis (HPCE) was applied to the separation of protein and peptide mixtures with molecular masses ranging from 1300 to 96000 Da using a new bonded hydrophilic phase capillary, CElect-P150. This coated capillary reduces the interaction between proteins and silanol groups in capillary walls, allowing a complete recovery of the proteins and peptides of interest. HPCE was also used for the analysis of a complex mixture of tryptic fragments and to monitor the process of enzymatic digestion. Moreover, using a CElect-P150 capillary, highly reproducible analysis was possible without preconditioning the capillary with acid or basic solutions before each new analysis.

Animals↗
PubMed1995

Indium-111-labeled granulocyte head accumulation in patients with Wegener's granulomatosis.

Among the symptoms of systemic vasculitis, purulent rhinorrhea with painful sinusitis is thought to be relatively specific to Wegener's granulomatosis (WG). Sixteen patients with rapidly progressive glomerulonephritis (GN), arteritis and extensive crescents in renal biopsy were studied by head indium-111 (111In)-granulocyte scanning. They included 8 WG, 5 microscopic polyarteritis, 2 necrotizing and crescentic GN and 1 classic polyarteritis nodosa. Autologous granulocytes labeled with 12.3 MBq of 111In-oxine were administered intravenously. Scintigraphic studies were performed at 4 and 24 h post-injection. Compared to the non-WG cases, considered as a whole, significant accumulation of tracer in sinuses was observed in WG patients (Fisher's p = 0.02). Substantial scintigraphic amelioration was obtained in a WG case treated with methylprednisolone pulses and, in another WG case, after high doses of intravenous gamma-globulins. The complete disappearance of facial uptake was obtained after 2 months of intensive therapy (i.e., steroid, cyclophosphamide and plasma exchange) in another WG patient. 111In-oxine granulocyte imaging may be useful in clinical practice as an additional marker of disease activity and a tool of identification of upper respiratory tract involvement.

Adult↗
PubMed1995

HCV viremia in hemodialysis patients: detection by a DNA enzyme immunoassay for amplified HCV sequences.

The aim of this study was the detection of HCV viremia in both anti-HCV antibody positive and negative hemodialysis patients. Sera from 75 patients on extracorporeal blood purification in the same dialysis unit were analyzed. Anti-HCV antibodies were detected using a 2nd-generation ELISA assay and in all positive cases a RIBA 3rd-generation test was performed. HCV-RNA was tested by a reverse transcription-nested polymerase chain reaction (RT-PCR) assay with primers located in the 5' region. PCR products were analyzed by a nonradioactive hybridation assay. The presence of anti-HCV antibodies was detected in 30 (40%) patients by means of ELISA II test; 28 of them were RIBA III positive and two indeterminate. Twenty-four of the 30 HCV Ab ELISA II positive patients (80%) were HCV-RNA positive (23 RIBA III positive and 1 indeterminate). Six anti-HCV Ab ELISA II positive patients tested negative for HCV-RNA (20%); 5 of these patients were also positive for anti-HCV antibodies with a RIBA III test and 1 was indeterminate. None of the anti-HCV negative patients was HCR-RNA positive. In two cases we documented the disappearance of viremia after an acute HCV infection, with the persistence of antibody reactivity. In conclusion, anti-HCV antibody positive hemodialysis patients should be considered as potentially infectious.

Adult↗
PubMed1995

Mitochondria-bound hexokinase from rabbit reticulocytes is resistant to the inactivation induced by Fe(II)/ascorbate.

Exposure of rabbit reticulocytes to Fe(II)/ascorbate induced a pronounced decay in hexokinase activity. In reticulocytes, this enzyme is present in at least three different molecular forms, Ia, Ia* and Ib, sub-types of hexokinase type I, which show different intracellular distribution. Hexokinase Ia and Ib are soluble, whereas hexokinase Ia* is almost entirely bound to the mitochondria. Anion exchange chromatography of hexokinase from intact reticulocytes exposed to Fe(II)/ascorbate revealed a selective inactivation of forms Ia and Ib, whereas the form Ia* did not show any decay. Binding to the mitochondrial membrane seems to be responsible for the observed resistance of the form Ia* to the inactivation elicited by Fe(II)/ascorbate. Indeed, by using a cell-free system in which hexokinase Ia* was solubilized using Triton X-100, the decay in hexokinase activity induced by iron/ascorbate involved all three enzymatic forms.

Animals↗
PubMed1995

Rabbit brain hexokinase: evidence for the presence of two distinct molecular forms.

In mammalian brain tissue, most hexokinase is bound to the mitochondria and only a small amount of the enzyme is present in soluble form. In this study we report that, in rabbit brain, hexokinase is present in two distinct molecular forms, which we designated HKH and HKL, both of which are separable using hydrophobic interaction or anion-exchange chromatography. These two molecular forms can be detected when hexokinase is prepared at pH 7.4, whereas at pH 10.0 only the more hydrophobic form, HKH, is present. The two subtypes of hexokinase do not show significant differences in Km values for glucose and ATP, in Ki values for glucose-6-phosphate or in their molecular weights. HKH is able to rebind mitochondrial membranes, while HKL has lost this ability, suggesting that the hydrophobic peptide at the N-terminal has been removed. The susceptibility of the N-terminal peptide to proteolysis is completely inhibited by using antiproteolytic compounds, such as leupeptin or E-64. The results reported in this paper suggest that a cysteine protease, probably belonging to a the class of cathepsins, may be involved in the processing of bindable hexokinase to the non-bindable form in rabbit brain, and that the activity of this protease is pH-dependent.

Animals↗
PubMed1995

Report on intensive treatment of extracapillary glomerulonephritis with focus on crescentic IgA nephropathy.

UNLABELLED: PURPOSE AND DESIGN OF STUDY: In this retrospective analysis the effects of combined treatment with steroid pulses, cyclophosphamide and plasma exchange on six crescentic IgA glomerulonephritis (IgAGN) patients, selected on a histological basis, were examined. The histological criteria included involvement of more than 40% of glomeruli by cellular crescents. The effects of this treatment were compared to those observed in three untreated crescentic IgAGN patients and 12 treated patients who had extracapillary glomerulonephritis of different origins, i.e. ANCA-associated systemic or renal-limited vasculitis. All patients, except the three crescentic untreated IgAGN patients, received the same 2-month treatment according to a standardized protocol: steroid boli 15 mg/kg methylprednisolone for 3 consecutive days by intravenous infusion, followed by prednisone per os (1 mg/kg/day for 4 weeks, 0.75 mg/kg/day for 4 more weeks), cyclophosphamide per os 2.5 mg/kg/day for 8 weeks, and plasma exchange. RESULTS: After this 2-month course of therapy, substantial clinical improvement was observed in both IgAGN and vasculitis patients. However, a second biopsy revealed that florid crescents persisted in IgAGN patients and, unlike the vasculitis group, during the long-term the initial clinical amelioration disappeared in one-half of the treated IgAGN cases. Nevertheless, even in the progressive cases, intensive treatment seemed to substantially delay the onset of dialysis. CONCLUSIONS: Despite some clinical benefits of therapy, short-term reversal of active crescents appears less likely to occur in crescentic IgAGN than in vasculitis-associated crescentic GN. Intensive treatment seems sufficient to arrest, but inadequate to reverse, phlogistic lesions in IgAGN before development of chronic changes.

Adolescent↗