Chromium does not belong in the diabetes treatment arsenal: Current evidence and future perspectives

Chromium is considered to have positive effects on insulin sensitivity and is marketed as an adjunctive therapy for inducing glucose tolerance in cases of insulin resistance("the glucose tolerance factor"). Case reports on patients who received prolonged parenteral nutrition indeed showed that the absence of trivalent chromium caused insulin resistance and diabetes. However, whether patients with type 2 diabetes can develop a clinically relevant chromium deficiency is unclear. This review summarizes the available evidence regarding the potential effectiveness of chromium supplementation on glycemic control(Hemoglobin A1c levels) in patients with type 2 diabetes. No studies investigating the longterm safety of chromium in humans were found. All clinical trials that have been performed had a relative short follow-up period. None of the trials investigated whether the patients had risk factors for chromium deficiency.The evidence from randomized trials in patients with type 2 diabetes demonstrated that chromium supplementation does not effectively improve glycemic control. The meta-analyses showed that chromium supplementation did not improve fasting plasma glucose levels. Moreover, there were no clinically relevant chromium effects on body weight in individuals with or without diabetes. Future studies should focus on reliable methods to estimate chromium status to identify patients at risk for pathological alterations in their metabolism associated with chromium deficiency. Given the present data, there is no evidence that supports advising patients with type 2 diabetes to take chromium supplements.     

Short-term outcomes after laparoscopic ileocolic resection for Crohn's disease. A systematic review

BACKGROUND: No consensus exists whether ileocolic resection for Crohn's disease (CD) should be carried out by a laparoscopic or open approach. A systematic review was conducted to assess the evidence for short-term advantages of laparoscopic compared to open resection for ileocolic CD. METHODS: The literature search was conducted over the period 01/1991 to 02/2006. Only randomized controlled trials (RCTs), clinical controlled trials and comparative studies comparing laparoscopic with open resection for ileocolic CD were included. A quality assessment was performed for all retrieved articles. The main outcome parameters were operating times, conversion rates, major and minor morbidity and hospital stays. RESULTS: 14 publications encompassing 729 patients were included - 2 were RCTs, 12 were non-RCTs of which 2 were case-matched studies. Although pooling data of operating times was statistically not possible, they were longer for the laparoscopic procedure in the individual studies ranging from 75 to 185 min. Conversions varied between 0 and 16.7%. Postoperative complications requiring reoperation or reported overall morbidity were not different (risk difference -0.01 and -0.05, respectively). Hospital stay after the laparoscopic procedure was 1.90 days shorter (95% CI: 0.83-2.97). CONCLUSION: There is evidence that laparoscopic ileocolic resection for CD is associated with shorter hospital stay compared to open ileocolic resection, while morbidity rates are equal and conversion rates are acceptable.     

Interaction of irradiation and microwave-induced hyperthermia in the Dunning R3327G prostatic adenocarcinoma model

The interaction of radiation and hyperthermia was systematically studied in the Dunning R3327G prostatic adenocarcinoma, the preeminent animal model for human prostatic cancer. Subcutaneous tumors (produced by injection of 10(7) cells) were treated when they had reached a volume of about 1 cm3, which occurred about 3 weeks after implantation. With the use of a randomized complete factorial design, four factors were examined. Each agent was used at one of three dose levels. For radiation, these were 5, 15, and 25 Gy; for hyperthermia, 42 degrees C for 15 minutes, 43 degrees C for 30 minutes, and 44 degrees C for 60 minutes. Two sequences (hyperthermia plus irradiation and irradiation plus hyperthermia) and five time delays between agents (0, 12, 24, 48, and 120 hours) were used. The growth delay (the time it took for the initial tumor volume to double) of subcutaneously implanted tumor served to quantitate treatment effect. Significant (P less than .05) statistical interactions were observed for several combinations of factors and individual factors. Hyperthermia plus irradiation was more effective than irradiation plus hyperthermia except at the delay time between treatments of 0 hours. Peak growth delay occurred when the time between treatments was 0-24 hours and depended on agent doses. Many combinations produced therapeutic synergy.     

Role of nitric oxide in the genesis of excitatory amino acid-induced seizures from the deep prepiriform cortex

The role of nitric oxide (NO) in the genesis of motor and electrocortical seizures elicited by administration of excitatory amino acid agonists into the deep prepiriform cortex (DPC) has been evaluated. Motor and electrocortical seizures occurred in rats receiving unilateral microinjections into the DPC of either N-methyl-D-aspartate (NMDA, 5 and 10 nmol) or kainate (KA, 100 pmol). The selective NMDA receptor antagonist 2-amino-7-phosphonoheptanoate (APH), when microinjected into DPC, prevented the development of seizures induced by both NMDA and KA injected in the same site. In addition, methylene blue (20 nmol, which prevents activation of soluble guanylate cyclase) or NG-monomethyl-L-arginine (NMMA, 40 nmol; a specific inhibitor of nitric oxide synthesis), when microinjected into DPC 15 min prior to either NMDA or KA, significantly protected against seizures elicited by both excitatory amino acid agonists. These data confirm the role of excitatory amino acid transmission in the genesis of seizures elicited from the deep prepiriform cortex. They further suggest that activation of excitatory amino acid receptors within the DPC leads to the release of a substance which shares properties with EDRF/NO and contributes to the genesis of seizure activity in this area.