Insulin-sperm interaction: effects on plasma membrane and binding to acrosome.

In in vitro studies, viable, intact human spermatozoa took up free radioinsulin with an apparently non-receptor-mediated mechanism. However, when a colloidal gold-insulin complex was substituted for the radiotracer, no surface binding was visualized at the ultrastructural level. Upon sperm incubation in the presence of free insulin, a dose-dependent release of phospholipid phosphorus occurred, with a concomitant derangement of head cell membrane. After head membrane removal, spermatozoa-bound radioinsulin in a time- and concentration-dependent manner, the binding was displaceable by unlabeled insulin, and an exclusive localization of the colloidal gold-insulin complex was visualized at the acrosome level. On the basis of this evidence, both the plasma membrane and the acrosome seem to represent cytological targets for insulin.     

Syndiospecific polymerization of styrene with the catalytic system [Ti2(OC2H5)8Cl]2Mg2(μ-Cl)2/methylaluminoxane compared with MgCl2-supported and unsupported Ti(OC2H5)4

As a part of our interest in the performance of [Ti₂(OC₂H₅)₈Cl]₂Mg₂(μ-Cl)₂ as Ziegler-Natta catalyst, the polymerization of styrene with a toluene solution of this compound and methyl-aluminoxane as cocatalyst was performed. It was found that the present catalytic system promotes the syndiospecific polymerization of styrene with high stereoregularity and the results were compared with those obtained with MgCl₂-supported or unsupported Ti(OC₂H₅)₄ catalysts. Determination of the titanium oxidation states and electron spin resonance (ESR) measurements both in the absence and in the presence of styrene were carried out for all the catalytic systems aimed at shedding some light on the nature of the active species.     

Administration of ciprofibrate to lactating mothers induces PPARα-signaling pathway in the liver and kidney of suckling rats

It is well known that the hypolipidemic drug ciprofibrate induces peroxisome proliferation in rodent liver, which in turn leads to the oxidative stress, and modifies some parameters related to cell proliferation and apoptosis. The administration of ciprofibrate to rats during the lactating period determined in their pups significant modifications in hepatic peroxisome enzyme activities, induction of the PPARalpha-target gene, Cyp4a10, and perturbation in cell proliferation and apoptosis, which affected the size of the liver. Moreover, this modification was associated to about two-fold induction of mRNA-PPARalpha. On the contrary, in the kidney, although a similar two-fold up-regulation of PPARalpha was detected, the induction of both peroxisomal enzyme activities and Cyp4a10 were weak, and no alterations were detected, neither in cell cycle nor in the size of the tissue. Our results indicate that the response to ciprofibrate is stronger in the liver than in the kidney of newborn rats.     

Partial purification and characterization of anhydrotetracycline oxygenase of Streptomyces aureofaciens

Anhydrotetracycline oxygenase was purified both by affinity chromatography and by hydrophobic interaction chromatography. Molecular weight of anhydrotetracycline oxygenase was determined to be 115,000 by Sephadex G-200 gel filtration. Using preparative isoelectric focusing the isoelectric point of the enzyme was estimated to be 5.3. The enzyme showed a sensitivity to thiol-specific inhibitors. During the hydrophobic interaction purification step, the activity dropped considerably. Reactivation occurred when a heat treated crude extract was added to the reaction mixture.     

Liver transplantation versus liver resection for colorectal liver metastasis: a survival benefit analysis in patients stratified according to tumor burden score

Liver transplantation (LT) for colorectal liver metastasis (CRLM) may provide excellent survival rates in patients with unresectable disease. High tumor load is a risk factor for recurrence and low overall survival (OS) after liver resection (LR). We tested the hypothesis that LT could offer better survival than LR in patients with high tumor load. LR performed at Padua University Hospital for CRLM was compared with LT for unresectable CRLM performed both at Oslo and Padua. High tumor load was defined as tumor burden score (TBS) ≥ 9, and inclusion criteria were as in the SECA-I transplant study. 184 patients were eligible: 128 LRs and 56 LTs. 5-year OS after LR and LT was 40.5% and 54.7% (P = 0.102). In the high TBS cohort, 5-year OS after LR and LT was 22.7% and 52.2% (P = 0.055). In patients with Oslo score ≤ 2 and TBS ≥ 9 (13 LR; 24 LT) the 5-year OS after LR and LT was 14.6% and 69.1% (P = 0.002). The corresponding disease-free survival (DFS) was 0% and 22.9% (P = 0.005). Selected CRLM patients with low Oslo score and high TBS could benefit from LT with survival outcomes that are far better than what is achieved by LR.     

Prognostic evaluation of patients submitted to surgery for malignant pleural mesothelioma

The role of surgical resection remains controversial in malignant pleural mesothelioma. The assessment of its impact on prognosis is complicated by a poor understanding of the prognostic factors in the disease. We therefore evaluated, through univariate and multivariate analysis, the role on prognosis of 24 variables in 57 patients submitted to surgery from 1985 to 1993. Sixteen patients had only exploratory thoracotomy and 12 minimal residual disease after surgery (no nodules >1 cm in diameter). Thirty-four cases had epithelial histotype, 6 sarcomatous and 17 mixed. Median survival for the whole group was 15.7 months. Multivariate analysis showed a highly significant influence on survival for minimal residual disease after surgery (p=0.0006), followed by TNM stage (p=0.01). Median survival for patients with TNM stage I disease was 36.3 months and for patients with minimal residual disease 33 months. In conclusion, these data suggest that patients with limited disease have a longer survival after surgery than those with extensive disease. At the same time, our results indicate that the achievement of significant disease reduction with surgery has a critical impact on the prognosis of pleural mesothelioma.     

The standardization of a technic for laparoscopic left hemicolectomy with radical lymphadenectomy

A standardized technique of left laparoscopic hemicolectomy is explained based upon the experience of the authors through the study of 166 cases and other cases described in literature. In the above study all of the single steps and the material needed for this technique, which is one of the most complex in laparoscopic surgery, are explained.     

Emergency laparoscopic surgery: a hospital's experience]

BACKGROUND AND AIM: The wide diffusion and increasing use of laparoscopic surgery prompts the authors to broaden discussion to its validity and diagnostic-therapeutic use in emergency abdominal surgery. The aim was to evaluate the efficacy of laparoscopic surgery in the light of reports in the international literature and in relation to the situation in our hospital. METHODS: From April 1994 to May 1998, out of 1016 emergency abdominal operations performed at our hospital, 783 (77.5%) used a laparoscopic approach for diagnostic and therapeutic purposes: intestinal occlusion: 26 cases; gastrointestinal ulcer pathology: 15 cases; hepatobiliary pathology: 398 cases; "pelvic" pathology: 305 cases; colic pathology: 39 cases. These represent 24.4% of all laparoscopic procedures carried out during the same period. We preferred to use immediate laparotomic access in patients with the following characteristics: anamnesis of previous surgery for malignant pathologies; anamnesis of more than two major abdominal operations; massive intestinal distension; patients whose general conditions were a contraindication to a laparoscopic approach. RESULTS: The conversion rate was 6.2% (49 cases) with morbidity of 3.4% (25 cases) and a mortality rate of 0.2% (2 cases). A final diagnosis was made in 763 patients (97.4%) with the possibility of treating 719 of them (94.2%), again using a laparoscopic approach. CONCLUSIONS: It is right to regard the laparoscopic approach in emergency abdominal surgery as a feasible and safe model, offering a high potential for diagnosis and therapy if appropriately performed by an expert and well coordinated team. The increased experience of mini-invasive surgery and the improved range of instruments available make the laparoscopic approach a valid alternative to laparotomy, even in the event of emergency abdominal pathologies.