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G Nanni

Publications and source records attributed to G Nanni.

At least 19 recordsLinked to original sources
PubMed2006

Restoration of normal glucose tolerance in severely obese patients after bilio-pancreatic diversion: role of insulin sensitivity and beta cell function.

AIMS/HYPOTHESIS: The aim of this study was to analyse the mechanisms underlying the improvement in glucose tolerance seen in morbidly obese patients undergoing bilio-pancreatic diversion (BPD). SUBJECTS AND METHODS: We evaluated glucose tolerance (by OGTT), insulin sensitivity (euglycaemic-hyperinsulinaemic clamp and the OGTT index OGIS) and beta cell function (OGTT modelling analysis) in 32 morbidly obese (BMI=52+/-7 kg/m(2), mean+/-SD) patients (12 with NGT, 9 with IGT and 11 with type 2 diabetes), before and after BPD, and in 22 lean control subjects. Patients were studied before and from 7 days to 60 months after surgery. RESULTS: BPD improved glucose tolerance in all subjects, who after surgery all had normal glucose tolerance. Insulin sensitivity was restored to normal levels in all subjects (pre-BPD 341+/-79 ml min(-1) m(-2), post-BPD 511+/-57 ml min(-1) m(-2), lean 478+/-49 ml min(-1) m(-2)). The insulin sensitivity change was detectable within 10 days of BPD. At baseline, beta cell sensitivity to glucose was impaired in diabetic subjects (25 [18] pmol min(-1) m(-2) l mmol(-1), median [interquartile range]) compared with lean subjects (82 [98]; p</=0.05). After BPD, beta cell glucose sensitivity showed a tendency towards improvement but remained impaired in diabetic subjects (30 [62]; p<0.01 vs lean). Total insulin output decreased in parallel with the insulin sensitivity increase in all groups. In the whole patient group, mean OGTT glucose levels were inversely related to both insulin sensitivity and beta cell glucose sensitivity (r (2)=0.67, partial r=-0.76 and -0.41, respectively). NEFAs, leptin and adiponectin were related to insulin sensitivity but could not explain the early improvement. CONCLUSIONS/INTERPRETATION: Following BPD, glucose tolerance was restored mainly as a result of a rapid and large improvement in insulin sensitivity.

Adiponectin↗
PubMed2006

Lymphocele after renal transplantation: the influence of the immunosuppressive therapy.

Lymphocele is a complication of renal transplantation, representing a lymphatic collection around the grafted kidney. The use of the immunosuppressive agent sirolimus (SRL) has been associated with a significant increase in lymphocele formation. This complication has been related to the antiproliferative activity of SRL, which delays surgical wound repair and closure of injured lymphatic vessels. The aim of this study was to relate the incidence of lymphocele with immunosuppression among 158 renal transplant patients operated with routine closure of all the visible lymphatic vessels around the iliac vessels and at the renal hilum. The incidence of lymphocele was not significantly different among the various immunosuppressive regimens.

Drainage↗
PubMed2006

Incidence of posttransplant diabetes mellitus in kidney transplant recipients immunosuppressed with sirolimus in combination with cyclosporine.

Sirolimus (SRL) in combination with Cyclosporine A (CsA) and steroids has been shown to lower the incidence of acute renal allograft rejection episodes, allowing CsA sparing. We retrospectively compared the incidence of posttransplant diabetes mellitus (PTDM) among kidney transplant recipients (KTx) immunosuppressed with SRL + CsA versus CsA alone. Patients were divided into two groups: SRL + CsA (n = 38) versus CsA (n = 48). Mean follow-up was 53.9 +/- 17.1 months. Seventeen/86 subjects (19.8%) developed diabetes after transplantation (7 IFG, 8.1%; 10 PTDM, 11.6%). The incidence was significantly higher in SRL + CsA (12/38 patients, 31.6%) compared with CsA (5/43 patients, 10.4%) (P = .0144, odds ratio 3.97). More patients required treatment in the SRL + CsA compared to CsA alone cohort (13.2% vs 2.1%, P = .051): 4 pts (10.5%) became insulin- dependent among SRL+CsA, vs none in the CsA group. Use of OHD was similar in both groups (2.6% SRL + CsA vs 2.1% CsA). There were no significant differences between the two groups in terms of age, sex distribution, BMI, or serum creatinine at 1 to 3 and 5 years from transplantation. All PTDM patients are alive at follow-up, while two grafts were lost due to chronic renal allograft dysfunction. Within the limits of a small retrospective study, we observed that SRL in combination with CsA increased the diabetogenic potential of CsA. A possible explanation of our findings is that higher CsA doses were used in the early experience with SRL + CsA; therefore the higher incidence of PTDM that we observed in the SRL + CsA combination may be a sign of toxicity. Careful monitoring of blood levels is mandatory in the SRL + CsA combination to avoid pleiotropic toxicity.

Adult↗
PubMed2005

Protein and m-RNA expression of farnesyl-transferases, RhoA and RhoB in rat liver hepatocytes: action of perillyl alcohol and vitamin A in vivo.

We analysed the action, in rats in vivo, of the protein isoprenylation inhibitor perillyl alcohol (POH) and that of vitamin A, alone or in association, on m-RNA and protein expression of farnesyltransferases (FTases alpha and beta subunits) and their protein substrates RhoA and RhoB, in isolated hepatocytes. Combined administration of POH and vitamin A induced a sharp decrease in FTase alpha protein after 96 h, suggesting an involvement not only of farnesyltransferases but also of geranylgeranyltransferases, which share the FTase alpha protein. FTase beta protein did not decrease. POH plus vitamin A, in contrast with POH or vitamin A alone, induced a decrease in RhoB protein, probably because of different cleavages. No modification was observed in RhoA protein. Vitamin A alone increased RhoB m-RNA and protein expression. As one of the functions of RhoB is cell polarisation, these data support our previous hypothesis of a polarised transport of vitamin A from hepatocytes to hepatic stellate cells. As the behaviours of m-RNAs and proteins in this study were often different, cytoplasmic metabolic pathways must be considered for the parameters studied. The behaviour of Rho B, which is thought to have an antioncogene function, is discussed in view of its isoprenylated forms in the membranes. These preliminary findings stress the need, when studying the association of two isoprenoids in cancer therapy, to consider normal as well as tumour-bearing animals.

Alkyl and Aryl Transferases↗
PubMed2005

Severe limb lymphedema in sirolimus-treated patients.

We report two kidney transplant recipients who developed severe limb lymphedema under sirolimus (SRL) immunosuppression. The patients received SRL 10 and 2 mg/d to achieve target levels of 10 to 20 ng/mL with tapering doses of prednisone. Renal function and drug levels were monitored monthly. Patient 1 developed lymphedema of the left upper limb 3 years posttransplantation, after having been exposed to high SRL doses in the preceding 2 years (mean SRL dose-9.5 mg/d, mean trough level-26.3 ng/mL, mean serum creatinine-1.63 mg/dL). In patient 2 lymphedema of both upper and lower right limbs occurred 18 months posttransplantation (mean SRL dose-3.2 mg/d, mean trough level-8.8 ng/mL, mean serum creatinine-2.9 mg/dL). Hypercholesterolemia and hypertriglyceridemia were also observed in both patients before SRL reduction/conversion. No signs of hematopoietic toxicity were observed. In both patients magnetic resonance (MR) angiography of the limb was negative for vascular obstruction, and lymphoscintigraphy revealed lymphatic obstruction. In patient 1 lymphedema improved significantly following SRL reduction and lymphatic drainage massage therapy. Patient 2 was converted to cyclosporine (CsA) improving markedly after conversion. Hypercholesterolemia and hypertriglyceridemia also improved significantly in both patients after reduction/conversion. We conclude that SRL may facilitate the occurrence of lymphatic obstruction by mechanisms that are presently unexplained. Lymphedema of the limbs in renal transplant recipients under SRL treatment, especially if on the same side as the hemodialysis access, should warn the transplant physician to rapidly reduce or withdraw SRL before the occurrence of complete obstruction.

Adult↗
PubMed2005

Sirolimus-based therapy with or without cyclosporine: long-term follow-up in renal transplant patients.

This open-label, phase 3b, extension trial in renal transplant recipients (Sirolimus Study 311) assessed the long-term safety of sirolimus (SRL) administered with cyclosporine (CsA) (SRL + CsA group, n = 98) or without CsA (SRL group, n = 69). Renal transplant recipients who had either completed one of seven previous SRL studies sponsored by Wyeth Research or had participated for > or =3 months and reached a protocol-designated endpoint were eligible for enrollment. Data were available for 167 patients, all of whom initially received steroids. Mean total SRL exposure was 1526 days, including previous study participation. After enrollment in the extension study, there were significantly more acute rejections in the SRL + CsA group (6.1% vs 0%, P < .05). Differences in rates of graft loss (3.1% vs 1.4%) and death (6.1% vs 1.4%) were not significantly different between SRL + CsA and SRL groups, respectively. At 48 months after transplantation, calculated GFR (53.4 vs 70.9 mL/min) and hemoglobin (124.9 vs 136.6 g/L) were significantly better in the SRL group. Lipid values were not significantly different between groups at 48 months. The incidence of treatment-emergent increased creatinine, anemia, hypertension, headache, epistaxis, abnormal kidney function, and upper respiratory infection were significantly higher in the SRL + CsA group, whereas no adverse events were significantly higher in the SRL group. Malignancies were reported more frequently (11.2% vs 0%) with SRL + CsA. Results from this extension study indicate that SRL-based therapy without CsA is a safe alternative to combination therapy with CsA, offering long-term improvement in renal function with no increased risk of late acute rejection.

Adult↗
PubMed2005

Gonadal function and immunosuppressive therapy after renal transplantation.

UNLABELLED: End-stage renal disease is associated with disorders in hypothalamic-pituitary-gonadal function. Immunosuppressive therapies may influence the restoration of normal levels of gonadal hormones after renal transplantation. The aim of the present study was to evaluate the hormonal status of successful renal transplant recipients who were treated with different immunosuppressive agents. METHODS: Testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) were measured in 59 male renal transplant recipients with stable graft function with serum creatinine <2.5 mg/dL. Patients were treated with three different immunosuppressive regimens: group I, calcineurin inhibitors (CI; n = 15), group II, sirolimus without calcineurin inhibitors (SRL; n = 15), group III, sirolimus in combination with calcineurin inhibitors (SRL * CI; n = 29). RESULTS: Testosterone was significantly lower in group II versus group I (3.12 +/- 1.23 versus 4.39 +/- 1.53 ng/mL; P < .0197). Group III had higher testosterone values than group II, but lower than group I. FSH and LH were also higher in the SRL group, but the differences were not statistically significant, perhaps because of the small number of patients. No relationship was found between testosterone blood levels and age, posttransplant follow-up, renal function, time on dialysis, body mass index, steroid use, or posttransplant diabetes. CONCLUSION: Sirolimus seems to impair the improvement of gonadal function after renal transplantation. Further prospective studies are needed to confirm these data before patients are advised of this potential side effect.

Creatinine↗
PubMed2005

Biliopancreatic diversion. Clinical experience.

AIM: Biliopancreatic diversion (BPD) has been accepted as an effective surgical treatment of morbid obesity. The paper presents the results of a personal clinical experience with this procedure, with special focus on the quality of life. METHODS: From January 1, 1992 to June 30, 2002, 122 patients (F/M: 108/14, mean age: 40.2 years, range 21-61) underwent BPD. Mean preoperative body weight was 122.4 kg (range 91-200), with a mean Body Mass Index of 49.1 kg/m2 (range 38-78). Three of these patients were converted from a previous vertical banded gastroplasty to BPD (1 patients with stomach preservation). After at least a 36-month follow-up, 10 patients underwent abdominal dermolipectomy (8 associated to incisional hernia repair, 1 associated to thigh dermolipectomy). RESULTS: Mean postoperative hospital stay was 12 days (range: 11-30). Follow-up is currently in progress in all patients. Weight loss of initial overweight was 75% in 88 patients with a 36-month follow-up, with excellent long-term weight maintenance. Protein deficiency was the main specific complication, encountered in 6 patients (4.9%). Beneficial effects, other than those consequent to weight loss, included permanent normalization of serum cholesterol and glucose without any medication and on a totally free diet. Almost 80% of the patients reported an improvement in their self-esteem, physical activity, work condition and social life. CONCLUSIONS: This clinical experience supports the effectiveness and safety of BPD, despite some criticism. The small number of side effects and complications, the excellent weight loss and the recovery of most co-morbidity leads to a great improvement in quality of life.

Adult↗
PubMed2004

Posttransplant diabetes mellitus after kidney transplantation with different immunosuppressive agents.

Posttransplant diabetes mellitus (PTDM) is a disturbing side effect of immunosuppression. The aim of this study was to evaluate the effect of different immunosuppressive agents on the development of PTDM in renal transplant recipients (KTx). The incidence of PTDM was evaluated in 538 consecutive KTx. Baseline immunosuppression was azathioprine (AZA), cyclosporine (CSA), or tacrolimus (TAC), or sirolimus in combination with calcineurin inhibitors (SIR). All patients received steroids for both induction and maintenance therapy during the first 6 months posttransplantation. Mean follow-up after KTx was 73 +/- 53.5 months (range 6 months to 16 years). PTDM was defined as two consecutive blood glucose determinations above 126 mg/dL. Thirty-six of 538 (6.7%) recipients experienced PTDM, 31 of whom required insulin treatment and five oral antidiabetic medications. PTDM occurred at 25.3 +/- 38 months posttransplantation in 4.8% of KTx treated with AZA, 4.8% of CSA, 6.5% of KTx treated with TAC and 12.5% of KTx treated with SIR. The time of onset of PTDM was significantly shorter (P =.003) among TAC (2.1 +/- 1.7 months posttransplantation) versus CSA (27.8 +/- 34 months). PTDM disappeared in 6 of 36 patients. We conclude that with current levels of immunosuppression, there is no difference in the incidence of PTDM between TAC- and CSA-treated KTx.

Administration, Oral↗
PubMed2004

Plasma levels of transforming growth factor-beta1 in renal transplant recipients receiving different immunosuppressive regimens.

Experimental and clinical evidence support the role of transforming growth factor beta-1 (TGF-beta(1)), a cytokine with complex immune and nonimmune effects, on the development of chronic renal allograft nephropathy (CAN). We investigated the effects of different immunosuppressive regimens on circulating TGF-beta(1) plasma levels in stable kidney transplant (KTx) recipients. Two hundred ninety-nine TGF-beta(1) plasma levels were measured in 125 kidney transplant (KTX) recipients exhibiting stable renal function, immunosuppressed with cyclosporine (CsA), tacrolimus (TAC), or sirolimus (SIR), and in 18 normal healthy volunteers (C). Activated immunoreactive TGF-beta(1) was detected in platelet-depleted plasma by an enzyme-linked immunoadsorbent assay. Multivariate analyses correlated immunosuppressive regimens with TGF-beta(1) levels. KTX recipients displayed significantly higher TGF-beta(1) levels compared to C (P =.0005). Patients receiving CsA had significantly higher TGF-beta(1) plasma levels compared to those receiving TAC or SIR (P =.0384). Multivariate analyses showed no correlation between TGF-beta(1) levels and immunosuppressive drug trough blood levels or doses, but only correlations with the main immunosuppressive drug. These data show that: (1) TGF-beta(1) production is activated in kidney transplant recipients; (2) CsA patients display significantly higher plasma TGF-beta(1) levels. Follow-up studies seek to assess the possible relationship with clinical events.

Graft Survival↗
PubMed2003

Long-term predictive value of cyclosporine microemulsion C2 level for chronic renal allograft dysfunction.

This observational study was undertaken in maintenance renal transplant recipients to assess the relationship between cyclosporine C(2) and the long-term risk of chronic renal allograft dysfunction (CRAD). Pharmacokinetic profiling was undertaken twice yearly in 79 patients with stable graft function receiving cyclosporine microemulsion (Neoral) and steroids. Mean time since transplantation at study entry was 56 +/- 49 months posttransplant. At the end of the observational period (mean 43 +/- 14 months) 24 patients (30%) had developed CRAD, defined as proteinuria > 500 mg/24 hours associated with a rising serum creatinine and confirmed by graft biopsy. There were no significant differences at baseline between patients who did vs did not develop CRAD, except for reduced incidence of acute rejection in CRAD-free patients. The cyclosporine AUC was significantly higher among patients without CRAD (5707 ng. h/mL vs 3994 ng. h/mL, P =.0007). Mean C(2) was also significantly higher: 1001 ng/mL in the CRAD-free group versus 640 ng/mL in the CRAD group (P =.002). There was no significant difference in C(0). Regression analysis showed that the best predictors for the occurrence of CRAD were a low AUC (relative risk [RR] 1.54, P <.0001), a low C(2) (RR 1.30, P <.0001) and proteinuria (RR 4.95, P <.0001). Probability of freedom from CRAD was 90% for C(2) > 900 ng/mL. C(2) appears to be a superior strategy to C(0) monitoring of cyclosporine in stable renal transplant patients with regard to the risk of CRAD. C(2) values above 900 ng/mL are appropriate to minimize the risk of CRAD among patients receiving cyclosporine microemulsion and steroids.

Adult↗
PubMed2003

Intramyocitic lipid accumulation and SREBP-1c expression are related to insulin resistance and cardiovascular risk in morbid obesity.

The aim of this study was to investigate the sterol regulatory element-binding protein 1c (SREBP1c) mRNA muscle expression in morbid obese subjects before and after massive lipid malabsorption due to bariatric surgery (bilio-pancreatic diversion, BPD). We studied 11 obese subjects (BMI 49+/-2 kg/m2) before and 24 months after BPD. Skeletal muscle SREBP1c mRNA expression was determined using RT-competitive PCR. Intramyocytic triglycerides were quantified by HPLC. Insulin sensitivity (M/I) was assessed by euglycemic-hyperinsulinemic clamp. Energy expenditure and respiratory quotient (RQ) were measured over 24 h in a calorimetric chamber. Total cardiovascular risk dropped from 2 before to -2.5 after BPD (P<0.0001). The M/I value was normalized after surgery (0.036+/-0.0148 to 0.095+/-0.0147 micromol kgFFM(-1) min(-1) pmoles(-1) P<0.001). SREBP-1c mRNA levels were decreased (from 4.12+/-2.43 to 2.69+/-1.83% of cyclophilin mRNA, P=0.02) after BPD. In a multiple regression analysis, M/I values (P<0.0001) as well as the intramyocytic triglyceride levels (P=0.039) were the most powerful independent variables for predicting cardiovascular risk. Our results show that the reduction of cardiovascular risk after bariatric massive weight loss is strongly related to the reversion of insulin resistance and to the lowering of intramyocytic triglyceride depots. These two parameters are associated with a significant reduction in SREBP-1c mRNA expression in skeletal muscle, suggesting that this transcription factor might be involved in the accumulation of triglycerides in muscle cells of morbidly obese subjects.

Adipose Tissue↗
PubMed2003

Rapid conversion to sirolimus for chronic progressive deterioration of the renal function in kidney allograft recipients.

The aim of this study was to evaluate the safety of conversion to sirolimus (SRL) immunosuppression among 19 renal transplant recipients (KTX) with progressive chronic renal allograft dysfunction (CRAD). Conversion to SRL was performed with concomitant sharp withdrawal of the calcineurin inhibitor (CI). SRL was added at a starting dose of 3 mg, then adjusted to obtain SRL target trough blood levels of 8 to 10 ng/mL. CI were stopped the evening before starting SRL. All patients enrolled in the study have now completed 6 months of follow-up: all are alive without acute rejection or major infection following rapid conversion to SRL. No significant change in the 6 months postconversion hematologic and hepatic profile was observed compared with the preconversion values, while significant dyslipidemia was induced. After conversion to SRL, significant amelioration of the renal function was found in 36% of patients, stabilization in 21%, and continuous deterioration in 43%. Patients whose renal function improved were found to have been converted at a significantly lower creatinine: (pre 2.6 +/- 0.9 vs post 1.9 +/- 0.2; P =.038) with respect to those patients who had continuous renal deterioration. In KTX with CRAD, sharp withdrawal of CI with concomitant conversion to SRL is safe, avoiding major infections, acute rejections, and significant side effects. Short-term amelioration of the renal function is best obtained when early conversion is performed. Long-term follow-up will be necessary to confirm these preliminary data.

Creatinine↗
PubMed2003

Acquisition of a palatable-food-sustained appetitive behavior in satiated rats is dependent on the dopaminergic response to this food in limbic areas.

Rats exposed to repeated unavoidable stress show decreased dopamine output in the nucleus accumbens shell (NAcS) and do not acquire vanilla sugar (VS)-sustained appetitive behavior (VAB). Rats treated with lithium for 3 weeks also show decreased NAcS dopamine output, yet they acquire VAB. Feeding a novel palatable food increases extraneuronal dopamine levels in the NAcS and medial prefrontal cortex (mPFC) in rats. In order to investigate the role of food-induced dopamine release in VAB acquisition, we studied by microdialysis the dopaminergic response in the NAcS and mPFC to the presentation and consumption of VS in satiated control rats, and in satiated rats exposed to repeated stress or lithium treatment. The dopaminergic response to VS was also studied in rats familiar with VS, or that had acquired VAB. In control rats, VS feeding was accompanied by increased dopamine output in the NAcS and mPFC, and one-trial habituation to this effect developed in the NAcS. Rats exposed to a 7-day stress showed reduced interest in VS pellets, and when fed VS they did not show a dopaminergic response in the NAcS and mPFC. Lithium-treated rats rapidly ate VS pellets and showed increased dopamine output in the NAcS and mPFC, with no habituation in the NAcS response. Rats familiar with VS and rats that had already learned VAB ate VS pellets. The first group showed a lower dopaminergic response to VS consumption than the control group, but the latter showed no dopaminergic response in the NAcS and mPFC. We propose that the limbic dopaminergic response to a novel palatable food plays a role in associative learning and that it is predictive of the competence to learn an appetitive behavior. Moreover, in our experimental conditions a phasic increase in mesolimbic dopamine no longer signals the VS stimulus once it has become a reinforcer in an appetitive task.

Animals↗
PubMed2003

Hypericum perforatum subspecies angustifolium shows a protective activity on the consequences of unavoidable stress exposure at lower doses than Hypericum perforatum perforatum.

Clinical studies have demonstrated that the antidepressant efficacy of Hypericum perforatum extract is comparable to that of classic antidepressants, such as imipramine. The role played by its components, particularly hypericin and hyperforin, has been examined in different experimental models of depression. The present study was carried out in order to verify the hypothesis that hyperforin is the main active antidepressant component. For this purpose we evaluated the activity of a dry extract from a subspecies of H. perforatum, H. perforatum spp. angustifolium, which has a higher hyperforin content than H. perforatum perforatum, in a series of experimental models of depression. The models used are based on the development of hyporeactivity to aversive stimuli induced by unavoidable stress exposure in rats. The extract of H. perforatum angustifolium presented an efficacy that was similar to that obtained with a treatment with imipramine or H. perforatum perforatum. Furthermore, in the models used the H. perforatum angustifolium extract was active at doses eight times lower than those necessary to produce a comparable activity with H. perforatum extract.

Animals↗
PubMed2002

Thioacetamide impairs retinol storage and dolichol content in rat liver cells in vivo.

The aim of this paper was to ascertain whether chronic pretreatment with thioacetamide (TAA) might alter the uptake of a load of retinol and dolichol distribution in hepatocytes (HC), hepatic stellate cells (HSC) (Ito-1 and Ito-2 subfractions), Kupffer (KC) and sinusoidal endothelial cells (SEC). The reason why retinol and dolichol content was studied is that their metabolism and transport might be interrelated and that the two isoprenoids might exert different functions in the cells of the hepatic sinusoid. Rats were treated for 2 and 4 months with TAA, a known fibrogenic hepatotoxin, at a low dosage, to produce an early stage of damage. Three days before sacrifice, the rats were given a load of vitamin A, and cells were isolated to investigate its uptake. In HC, the load of retinol was taken up and accumulated, while a decrease in dolichol preceded retinol increase. In HSC, much less of the retinol load was stored than in controls, and dolichol content also decreased. Various minor modifications were seen in KC and SEC.Collectively, the results show that the distribution of these two isoprenoids, which play important roles in cellular differentiation and proliferation, is differently altered in the multiple cell types that line the hepatic sinusoid, and that both isoprenoids seem to participate in the first steps of liver damage.

Animals↗