Systematic review: green tea and gastrointestinal cancer risk

BACKGROUND: Gastrointestinal cancer is one of the leading causes of cancer mortality in the world. Therefore, numerous efforts are being made to find chemoprotective substances able to reduce its incidence. Amongst these, green tea, one of the most popular beverages world-wide, has been reported to provide protective effects against gastrointestinal cancer. AIM: To critically evaluate all epidemiological studies reporting an association between green tea consumption and a reduced risk of gastrointestinal cancer. METHODS: Epidemiological studies of green tea consumption in relation to gastrointestinal cancer or preneoplastic lesions were identified through computerized literature searches using the following databases: Medline (Pubmed), Embase, Amed, CISCOM, Phytobase and Cochrane Library. Only epidemiological studies indicating the type of tea (green tea) and the site of either cancer or precancerous lesions (stomach or intestine) were included. No language restrictions were imposed. RESULTS: Twenty-one epidemiological investigations met our inclusion/exclusion criteria. CONCLUSION: These studies seemed to suggest a protective effect of green tea on adenomatous polyps and chronic atrophic gastritis formations. By contrast, there was no clear epidemiological evidence to support the suggestion that green tea plays a role in the prevention of stomach and intestinal cancer.     

Reductive activation and thiol reactivity of benzazolo[3,2-a]quinolinium salts

Derivatives of benzazolo[3,2-a]quinolium salts (QSDs) are reductively activated by the enzymatic reducing agents hypoxanthine (or xanthine)/xanthine oxidase and NADH dehydrogenase as evidenced by the increase in rates of ferricytochrome c (Cyt(III)c) reduction and oxygen consumption, respectively. No correlation between Michaelis-Menten parameters and QSDs redox potentials was found regarding anaerobic or aerobic Cyt(III)c reduction, although maximum rates were observed for nitro-containing QSDs. However, oxygen consumption rates correlate with QSDs redox potentials when NADH dehydrogenase is used as reducing agent. QSDs bind covalently to bovine serum albumin (BSA) under anaerobic conditions, in the presence, and less in the absence, of HX/XO and only if the nitro group is present at the QSD. QSDs react with glutathione (GSH) in the presence of HX/XO but not in its absence, under anaerobic conditions. The amount of reacted GSH increases, and the relative amount of GSSG formed decreases, with an increase in the QSD reduction potential, thus indicating that GSH reacts with reduced nitro-containing QSDs mainly in a manner which does not involve the production of GSSG, presumably, through the formation of the nitroso-QSD-GSH conjugate. QSDs are, thus, novel nitro-containing heterocyclic compounds which could be bioreductively activated to react with oxygen and thiols.     

Testosterone and dementia: too much ado about too little data

In vitro and animal investigations have indicated that testosterone is neuroprotective and reduces the levels of beta-amyloid and the phosphorylation of tau (which are considered to be critical to the pathophysiological process that leads to the development of Alzheimer's disease (AD)). Such findings imply that testosterone may have an important role in the modulation of cognitive function and in reducing the risk of AD. Currently available clinical evidence of the association between testosterone and cognitive function/AD comes from a small number of cross-sectional studies and five randomised trials of testosterone supplementation for healthy older men. The results suggest that testosterone has a weak association with visuospatial and memory scores, but the findings are inconsistent across different studies, which often included multiple comparisons across a wide range of cognitive domains. In addition, the serum levels of testosterone in men with AD are comparable to those of controls, as are brain levels. In conclusion, currently available evidence does not support the existence of a strong association between testosterone and cognitive function/AD.     

Catheter infection risk related to the distance between insertion site and burned area

A prospective observational study of central venous catheters (CVC) was carried out in order to determine if a CVC inserted near an open burn wound increases catheter infection risk in burned patients. The study was carried out during a 12-month period (1998-1999) at the Benaim Foundation's Burn Unit in Buenos Aires (C.E.P.A.Q.). Eighty-three CVCs were inserted in 20 burned patients during the study period. Twenty-six catheters were inserted near an open wound (NOW) and 57 far from an open wound (FOW). NOW CVCs were considered when 25 cm2 surrounding the catheter's insertion site overlapped the wound. Colonization rates were 84% (22/26 CVCs) in those inserted NOW and 47% (27/57 CVCs) in FOW (P = 0.001). Colonization relative risk of NOW-CVCs was 1.79 (95% confidence interval, 1.3-2.46). Bacteremia rates were 27% (7/26 CVCs) in CVCs inserted NOW and 6% (3/57 CVCs) in FOW (P = 0.004). Bacteremic risk of NOW-CVCs was 5.12 (95% confidence interval, 1.44-18.22). Colonization rates were higher and sooner in NOW-CVCs than in FOW-CVCs. We suggest that insertion of catheters near an open burn wound should be avoided and, if inevitable, should not be left in place for period exceeding 3 days.     

Serial assessment of peak VO2 and VO2 kinetics early after heart transplantation

PURPOSE: Serial evaluation of aerobic metabolism and exercise tolerance early after heart transplantation (HT). METHODS: Fifteen heart transplant recipients (HTR), aged 52.0 +/- 9.9 yr (mean +/- SD), not undergoing structured rehabilitation programs, were tested two to four times during the first 2 yr post-HT. As a reference, a group of 11 healthy untrained controls (C) was utilized. Peak heart rate (peak HR), peak O2 uptake (peak VO2), and ventilatory threshold (VT) were determined during incremental bicycle exercise to voluntary exhaustion. VO2 kinetics were evaluated during constant-load exercise below VT, with determination of the duration of the "cardiodynamic" component (TDp) and of the time constant of the "primary" component (taup). RESULTS: Peak VO2 (L.min-1) was positively related to months post-HT (y=1.17 + 0.02x, P=0.003), and it increased by approximately 30% during the investigated period, although values in HTR were lower than in C (2.19 +/- 0.24). Peak HR was lower in HTR (136 +/- 15 beats.min-1) than in C (168 +/- 5), and it was not related to time post-HT. TDp was longer in HTR (31.4 +/- 6.3 s) than in C (23.2 +/- 6.1), and it was not related to time post-HT. A subgroup of HTR with markedly longer taup during the first months post-HT showed a significant decrease of this parameter as a function of time post-HT. CONCLUSIONS: Aerobic metabolism is impaired in HTR. Both central (cardiovascular) and peripheral (skeletal muscle) factors contribute to the reduced exercise tolerance. HTR showed, during the first 2 yr post-HT, a significant increase in peak VO2 and (in the patients with the slowest VO2 kinetics during the first months after HT) a significant improvement of the VO2 kinetics. The main gains seem to occur at the peripheral level.     

Expectations and Outcomes When Moving from Open to Laparoscopic Adrenalectomy: Multivariate Analysis

Abstract Various authors have suggested that laparoscopic adrenalectomy (LA) leads to better surgical outcomes than open surgery. The debate is still open, however, and indications and limitations of minimally invasive surgery have not been completely established. The objective of our study was to compare surgical outcomes of LA and open adrenalectomy (OA), using multivariate analysis to adjust for potential confounding factors (e.g., size of the lesion, histology). Between 1995 and June 2000 at “Careggi” Hospital in Florence, Italy patients with an indication for adrenalectomy were treated laparoscopically if the lesion was < 10 cm and there was no clinical evidence of malignancy. All 79 patients who underwent LA have been included in this study. Among 152 patients who underwent OA at “La Sapienza” University in Rome, 93 had an adrenal lesion < 10 cm and no clinical evidence of malignancy; they were selected for comparison. Multivariate analysis has been used to analyze the effect of the surgical approach (OA vs. LA) on the surgical outcome, controlling for potential confounders. Multiple logistic regression showed that there is no significant difference in intraoperative outcomes (i.e., surgical time > 2 hours, blood loss ≥ 500 ml) between patients operated on through a traditional approach and those who underwent LA. On the other hand, patients operated on laparoscopically have a significantly higher probability than the OA group of experiencing a better recovery from surgery (i.e., require less postoperative analgesics and return to normal activities earlier). The results of the present study show that, although LA does not add much benefit in terms of expected intraoperative outcomes, it dramatically speeds patients’ recovery from surgery. The two approaches are complementary and should both be integrated into the technical background of all endocrine surgeons.     

Videolaparoscopic adrenalectomy in Conn syndrome. Analysis of 39 case observations

The authors retrospectively analyse 39 patients affected by Conn's syndrome, which have been observed since 1985, and discuss the results of surgical approach using the new technologies. In particular, the introduction of laparoscopy, technique that has been applied almost exclusively since the last seven years, has revealed being the "gold standard" for the surgical treatment of this disease. The adrenal underlying lesions are indeed almost always monolateral, small in size and present very rarely malignancy in their biological behaviour. Furthermore, the authors, although lacking of personal experience, propose the possibility of a more conservative treatment of the adrenal lesions with a simple "enucleation", whose feasibility also in laparoscopy has recently been shown by some authors. Anyway, the Authors believe that this technique of a partial adrenalectomy could be chosen in selective cases of bilateral adenomas or hyperplasia or in those lesions which are placed in an easily accessible peripheral site.     

Current indications of bilateral adrenalectomy in Cushing's syndrome: discussion of personal experience

Since 1975 we have observed 68 patients with Cushing syndrome, 48 out of which with an ACTH-independent disease and 20 with an ACTH-dependent one, due to hypophisary adenoma. Out of the latter group of patients, which had a relapse of the disease after a previous trans-sfenoidal procedure, 16 underwent an open bilateral adrenalectomy and 4 a laparoscopic monolateral or bilateral adrenalectomy. Patients from the former group had an open or laparoscopic adrenalectomy, or a bilateral adrenalectomy in case of the rare bilateral diseases, as McCune-Albright syndrome. All patients had a complete healing, except for 2 patients affected by McCune-Albright syndrome who died for cardiopulmonary complications. We conclude that bilateral adrenalectomy plays a fundamental role in the treatment of Cushing disease, after the failure of the trans-sfenoidal procedures. This surgical therapy has been certainly improved by the introduction of the laparoscopic techniques, which allowed us to exert bilateral adrenalectomies in two times with a significant reduction of perioperative morbidity and mortality because of the less severe traumatism and the absence of addisonian complications.