Ex Situ Regeneration of Liver Remnants Hypothermically Preserved for 24 Hours

Introduction

After partial hepatectomy (PH), the liver remnant (LR) shows a regenerative response, always keeping a percent relationship with the host. This process has been well described in the literature, but several aspects still need to be understood. There are no studies on hepatic LR regeneration during hypothermic preservation. Thus, the objective of the present study was to analyze LR regeneration after PH under conditions of hypothermal preservation.

Materials and Methods

Twenty adult Wistar rats were divided into 4 experimental groups: PHS (70% PH); PHP (70% PH of an organ perfused and preserved for 24 hours); PWL (perfused whole liver preserved for 24 hours); and NPWL (nonperfused whole liver). The liver was perfused with 250 mL Celsior solution with a catheter connected to a 1.30-cm-high liquid column. Hepatic tissue samples were submitted to immunohistochemical analysis for the evaluation of protein Ki67 expression, related to the mechanism of cell proliferation, to analysis of micro-RNA expression (miR-21 and miR-16) by real-time polymerase chain reaction, and to analysis of mitochondrial function. Nonparametric statistical analysis was used (P < .05).

Results

Ki67 analysis revealed that the PHP group showed 17.41% cell proliferation in LR (P < .01) compared to PHS (42.22%), PWL (11.43%), and NPWL (11.98%). miR-16 expression (proapoptotic) was found to be higher in the NPWL group compared to all others (PHS, PHP, and PWL), with a statistically significant difference between the NPWL group and the PHS and PHP groups.

Conclusion

The animals submitted to PHS and PHP presenting greater Ki67 expression showed low miR-16 expression, indicating a low apoptotic index. In summary, the LR showed ex situ regeneration even under hypothermal conditions. There are no similar data in the literature surveyed.     

Aerobic physical training restores biomechanical properties of Achilles tendon in rats chemically induced to diabetes mellitus

The aim of this study is to evaluate if the application of a moderate aerobic exercise protocol reverses the damage caused by diabetes on the mechanical properties of the Achilles tendon.MethodsForty-four rats were divided randomly into four groups as follows: Sedentary Control Group-SCG, Sedentary Diabetic Group-SDG, Trained Control Group-TCG and Trained Diabetic Group-TDG, the trained groups were submitted to a protocol of moderate physical training on a continuous treadmill. For mechanical testing the tendons were fixed in a conventional mechanical testing machine and pulled to the point of failure of the specimen, the cell load of 500 N. The parameters were: Elastic Modulus (MPa), Stress Maximum Strength (MPa), Strain Specific Maximum Force (mm), Energy / Tendon Area (N.mm/mm²) and Cross-sectional Area (mm²).ResultsThe evaluation of the biomechanical properties of the Achilles tendon of the SDG indicated that the elastic modulus (MPa) is decreased when compared to the TDG and the other groups (p < 0.01). However, the specific deformation (%), the deformation at maximum force (mm), and energy / tendon area (N.mm/mm²) of the SDG were significantly higher than in the other groups (p < 0.01). Moreover, moderate aerobic training on a treadmill caused the biomechanical property values to move closer to the values shown by the control groups (p > 0.01).ConclusionIn summary, our study indicates that moderate-intensity aerobic training restored the normal mechanical properties of tendons in diabetic animals, since the elastic modulus (MPa), the specific deformation (%), the deformation of the maximum force (mm) and energy / tendon area (N.mm/mm²) approached the values shown by the control groups.     

Contributions from the systematic review of economic evaluations: the case of childhood hepatitis A vaccination in Brazil

The aim of this study was to present the contributions of the systematic review of economic evaluations to the development of a national study on childhood hepatitis A vaccination. A literature review was performed in EMBASE, MEDLINE, WOPEC, HealthSTAR, SciELO and LILACS from 1995 to 2010. Most of the studies (8 of 10) showed favorable cost-effectiveness results. Sensitivity analysis indicated that the most important parameters for the results were cost of the vaccine, hepatitis A incidence, and medical costs of the disease. Variability was observed in methodological characteristics and estimates of key variables among the 10 studies reviewed. It is not possible to generalize results or transfer epidemiological estimates of resource utilization and costs associated with hepatitis A to the local context. Systematic review of economic evaluation studies of hepatitis A vaccine demonstrated the need for a national analysis and provided input for the development of a new decision-making model for Brazil.     

Survival and risk factors for neonatal mortality in a cohort of very low birth weight infants in the southern region of São Paulo city, Brazil

Population studies can help identify the complex set of risk factors for neonatal mortality among very low birth weight infants. A cohort (2000-2001) of 213 live newborns with birth weight < 1,500g in the southern region of S?o Paulo city, Brazil, was studied (112 neonatal deaths and 101 survivors). Data were obtained from home interviews and hospital records. Survival analysis and multiple Cox regression were performed. The high mortality in the delivery room and in the first day of life among neonates < 1,000g and < 28 weeks gestational age and the absence of survival in neonates < 700g suggest that care was actively oriented towards newborns with better prognosis. Increased risk of neonatal mortality was associated with maternal residence in slum areas, history of previous cesarean(s), history of induced abortion(s), adolescent motherhood, vaginal bleeding, and lack of prenatal care. Cesarean section and referral of the newborn to the hospital nursery showed protective effects. Birth weight less than 1,000g and Apgar index < 7 were associated with increased risk. The high mortality was due to poor living conditions and to maternal and neonatal characteristics. Improvement in prenatal and neonatal care could reduce neonatal mortality in these infants.     

Colorectal cancer risk in hamartomatous polyposis syndromes

Colorectal cancer(CRC) is a major cause of morbidity and mortality around the world, and approximately 5% of them develop in a context of inherited mutations leading to some form of familial colon cancer syndromes. Recognition and characterization of these patients have contributed to elucidate the genetic basis of CRC. Polyposis Syndromes may be categorized by the predominant histological structure found within the polyps. The aim of the present paper is to review the most important clinical features of the Hamartomatous Polyposis Syndromes, a rare group of genetic disorders formed by the peutz-Jeghers syndrome, juvenil polyposis syndrome and PTEN Hamartoma Tumor Syndrome(Bannayan-Riley-Ruvalacaba and Cowden Syndromes). A literature search was performed in order to retrieve the most recent and important papers(articles, reviews, clinical cases and clinical guidelines) regarding the studied subject. We searched for terms such as “hamartomatous polyposis syndromes”, “Peutz-Jeghers syndrome”, “juvenile polyposis syndrome”, “juvenile polyp”, and “PTEN hamartoma tumour syndrome”(Cowden syndrome, Bananyan-Riley-Ruvalcaba). The present article reports the wide spectrum of disease severity and extraintestinal manifestations, with a special focus on their potential to develop colorectal and other neoplasia. In the literature, the reported colorectal cancer risk for Juvenile Polyposis, Peutz-Jeghers and PTEN Hamartoma Tumor Syndromes are 39%-68%, 39%-57% and 18%, respectively. A review regarding cancer surveillance recommendations is also presented.     

Self-rated health (SRH) as a predictor of mortality in elderly men living in a medium-size city in Brazil

The objective was to examine the role of SRH as a predictor of mortality in elderly men in a medium-size Brazilian city. In 2 years of follow-up, 120 deaths occurred in the study population, with the following main causes: cardiovascular diseases (40%), neoplasms (22.5%), and respiratory diseases (10%). In practically all of the target variable strata, elderly men with fair or poor SRH showed a higher risk of dying as compared to those with excellent or good SRH. In the final model, the variables fair/poor SRH (hazard risk = HR = 1.88, 95% confidence interval = 95%CI = 1.29-2.72), age (HR = 1.05, 95%CI = 1.03-1.08), public health system as the regular source of care (HR = 1.69, 95%CI = 1.10-2.60), current smoking (HR = 1.94, 95%CI = 1.24-3.04), and acute cardiovascular disease (HR = 1.62, 95%CI = 1.06-2.47) were associated with mortality. We concluded that SRH proved to be a predictive variable for mortality in elderly men after 2 years of follow-up, with nearly a twofold risk of death among men that reported fair or poor health, after adjusting for age, regular use of the public health system, current smoking, and acute cardiovascular disease. Given the importance of poor SRH for predicting mortality in elderly men, health services should incorporate this indicator into health assessments in this population.