The mechanism of microsatellite instability is different in synchronous and metachronous colorectal cancer

MLH1 promoter hypermethylation has been described as the primary mechanism for high-frequency microsatellite instability (MSI-H) in sporadic colorectal cancers (CRCs). The underlying molecular mechanism for microsatellite instability (MSI) in synchronous and metachronous CRCs is not well described. A total of 33 metachronous CRC patients and 77 synchronous CRC patients were identified from 2884 consecutive patients undergoing cancer surgery in an academic center. Evaluable tumors were tested for MSI, immunohistochemistry for MLH1 and MSH2 protein expression, and hypermethylation of the MLH1 promoter. MSI-H tumors were found in 12 (36%) metachronous CRC patients and 29 (38%) synchronous CRC patients. MSI-H metachronous CRC patients were younger at index cancer diagnosis (64 vs. 76 years, P = 0.01) and more often were diagnosed before 50 years of age (4 of 12 vs. 0 of 29, P = 0.005). Loss of MLH1 expression associated with promoter hypermethylation was common in all patients, although more common in MSI-H synchronous patients (50% metachronous vs. 83% synchronous, P = 0.03). Overall, MLH1 promoter hypermethylation was seen in 7 of 17 (41%) metachronous and 44 of 54 (81%) synchronous MSI-H CRCs tested (P = 0.004). Although MSI occurred with equal frequency among patients with synchronous and metachronous CRCs, the underlying mechanism for MSI was different. Observed differences in MLH1 promoter hypermethylation and patient characteristics suggest most MSI-H synchronous CRCs in our population were sporadic in origin. In contrast, more MSI-H metachronous CRCs were associated with patient and tumor characteristics suggestive of underlying hereditary nonpolyposis CRC. Presented as a poster at Digestive Disease Week 2001, Atlanta, Georgia, May 20–23, 2001.     

Transvaginal repair of vesicovaginal fistula: surgical techniques to improve access and successful vaginal closure

This video demonstrates surgical techniques to improve closure of high vesicovaginal fistula using the vaginal approach and the Latzko procedure.     

Evidence of zinc deficiency in competitive swimmers

ObjectiveThe aim of this study was to assess the nutritional zinc (Zn) status of elite swimmers during different training periods.MethodsA longitudinal paired study was performed at the University of Sao Paulo in eight male swimmers 18 to 25 y old who had been swimming competitively at the state and national levels for at least 5 y. The swimmers were evaluated over a total period of 14 wk: before the basic and specific preparatory period (BSPP-baseline), at the end of the basic and specific preparatory period (post-BSPP), and at the end of the polishing period (PP). Levels of Zn were determined in the plasma, erythrocyte, urine, and saliva by atomic absorption spectrophotometry. Anthropometric measurements and a 3-d food record were also evaluated.ResultsThe median plasma Zn concentration was below the reference value in all training periods (BSPP-baseline 59 μg/dL, post-BSPP 55.9 μg/dL, after PP 58.8 μg/dL, P > 0.05), as were threshold values for erythrocytes (BSPP-baseline 36.5 μg of Zn/g of hemoglobin, post-BSPP 42 μg of Zn/g of hemoglobin, after PP 40.7 μg of Zn/g of hemoglobin, P > 0.05), urinary Zn (BSPP-baseline 280 μg/24 h, post-BSPP 337 μg/24 h, after PP 284 μg/24 h, P > 0.05), and salivary Zn (BSPP-baseline 66.1 μg/L, post-BSPP 54.1 μg/L, after PP 79.7 μg/L, P > 0.05). Salivary Zn did not correlate with plasma and erythrocyte Zn levels.ConclusionThe results suggest that the elite swimmers studied presented a possible Zn deficiency and that salivary Zn was not adequate to evaluate the Zn nutritional status.     

Ambulatory Blood Pressure Monitoring in Children and Adolescents: Coming of Age?

Over the last years, ambulatory blood pressure monitoring has been introduced into the pediatric population, contributing to a significant increase in the bulk of knowledge of crucial clinically relevant issues. Guidelines have established the currently known conditions where ambulatory blood pressure monitoring is useful and where it will provide additional information in children and adolescents. How common and important the intra-individual differences are within clinical and ambulatory blood pressure is the keystone to the use of ambulatory blood pressure monitoring as a diagnostic tool. By using not only office, but also ambulatory blood pressure, four possible situations arise. Two of these have values in agreement for normotension or hypertension. Two have values that are discrepant. The latter two are known as white coat and masked hypertension. The relationship with hypertension-induced organ damage, the prognostic value and the assessment of treatment goals are key issues of ambulatory blood pressure monitoring. In children, the accurate identification of hypertension at the earliest possible age would, therefore, give health-care providers the opportunity to initiate preventive measures, thereby reducing the chance of developing end-organ damage and its attendant morbidity and mortality.     

Effectiveness of diaphragmatic stimulation with single-channel electrodes in rabbits

Every year, a large number of individuals become dependent on mechanical ventilation because of a loss of diaphragm function. The most common causes are cervical spinal trauma and neuromuscular diseases. We have developed an experimental model to evaluate the performance of electrical stimulation of the diaphragm in rabbits using single-channel electrodes implanted directly into the muscle. Various current intensities (10, 16, 20, and 26 mA) produced tidal volumes above the baseline value, showing that this model is effective for the study of diaphragm performance at different levels of electrical stimulation     

Últimos avances en pancreatitis crónica

The most important advances in chronic pancreatitis concern its etiopathogenesis, nutritional aspects, and improvements in diagnostic techniques and some treatment options. In the etiopathogenesis of this disease, the importance of smoking and its association with alcohol have been confirmed. Exocrine pancreatic insufficiency (EPI) secondary to chronic pancreatitis is associated with bone metabolism alterations (osteopenia and osteoporosis), a reduction in liposoluble vitamins and alterations in essential amino acid levels. Endoscopic ultrasound has been confirmed as the most highly developed technique for the diagnosis of chronic pancreatitis, especially due to new image optimization technologies. Breath tests for the diagnosis of EPI continue to be developed (optimization of the C-13 mixed triglyceride test and the development of a new test based on C-13-labelled bicarbonate determination). Modest results in pain treatment have been achieved with the use of antioxidants, pancreatic enzymes and/or intravenous secretin. The association of chronic pancreatitis with pancreatic cancer requires strict follow-up, especially in patients with inflammatory masses in the context of chronic pancreatitis.