Multiple sublineages of influenza A virus (H5N1), Vietnam, 2005-2007

Phylogenetic analysis of influenza subtype H5N1 viruses isolated from Vietnam during 2005-2007 shows that multiple sublineages are present in Vietnam. Clade 2.3.4 viruses have replaced clade 1 viruses in northern Vietnam, and clade 1 viruses have been detected in southern Vietnam. Reassortment between these 2 sublineages has also occurred.     

Inconsistencies of Breast Cancer Risk Factors between the Northern and Southern Regions of Vietnam

Background: In recent decades the amount of new breast cancer cases in the southern region has been reported to increase more rapidly than in the northernVietnam. The aim of this study is to compare breast cancer risk factors between the two regions and establish if westernized influences have an impact on any reported differences. Method: Data was collected from the two largest oncology hospitals in the north and the south of Vietnam in 2015. Breast density, demographic, reproductive and lifestyle data of 127 cases and 269 controls were collected in the north and 141 cases and 250 controls were gathered from the south. Baseline differences in factors between cases and age-matched controls in each region were assessed using chi-square tests and independent t-tests. Odds ratios (OR) for independent risk factors for breast cancer were obtained from conditional logistic regression. Results: In northern Vietnam significantly increased risks in developing breast cancer were observed for women with age at first menstrual period less than 14 years old (OR=2.1; P<0.05), post-menopausal status (OR=2.6; P<0.0001), having less than 2 babies (OR=2.1; P<0.05). Southern Vietnamese women having a breast density of more than 75% (OR=2.1; P<0.01), experiencing post-menopause (OR=1.6; P<0.05), having a history of less than 3 pregnancies (OR=2.6; P<0.0001) and drinking more than a cup of coffee per day (OR=1.9; P<0.05) were more likely to be diagnosed with breast cancer. Conclusion: We found that women living in the south had some breast cancer associations, such as increased mammographic density and coffee consumption, which are closer to the risks in westernized populations than women in the north.     

Systemic-to-pulmonary artery pressure ratio as a predictor of patient outcome following liver transplantation

AIMTo assess the value of the mean systemic-to-pulmonary artery pressure (MAP/mPAP) ratio for predicting outcomes following orthotopic liver transplant (OLT).METHODSA retrospective data analysis was performed and data (mean arterial blood pressure, mean pulmonary artery pressure and Cardiac Index) were collected at several points during OLT. Outcomes evaluated were duration of postoperative endotracheal intubation [ET; minutes after intensive care unit (ICU) arrival], length of ICU stay, total hospitalization and frequency of immediate postoperative complications. A total of 91 patients were included in the data analysis. Based on the intraoperative course of the MAP/mPAP ratio, 2 hemodynamic responses were identified: Group 1 (MAP/mPAP ratio increase during anhepatic period with postreperfusion recovery, n = 66); and Group 2 (MAP/mPAP ratio with no change during anhepatic period or decreased without recovery, n = 25).RESULTSThe main finding was that the lack of increased MAP/mPAP ratio in the anhepatic period was associated with: (1) longer intubation times; and (2) prolonged ICU stays and total hospitalization time, when compared to patients with an increase in MAP/mPAP ratio during the anhepatic period.CONCLUSIONThe data from this retrospective study should raise awareness to the mean systemic to pulmonary artery pressure ratio as a potential indicator for poor outcome after OLT. Further prospective studies are needed for validation.     

Nutritional Status in Sick Children and Adolescents Is Not Accurately Reflected by BMI-SDS

Objective: Nutritional status provides helpful information of disease severity and treatment effectiveness. Body mass index standard deviation scores (BMI-SDS) provide an approximation of body composition and thus are frequently used to classify nutritional status of sick children and adolescents. However, the accuracy of estimating body composition in this population using BMI-SDS has not been assessed. Thus, this study aims to evaluate the accuracy of nutritional status classification in sick infants and adolescents using BMI-SDS, upon comparison to classification using percentage body fat (%BF) reference charts.

Design: BMI-SDS was calculated from anthropometric measurements and %BF was measured using dual-energy x-ray absorptiometry (DXA) for 393 sick children and adolescents (5 months–18 years). Subjects were classified by nutritional status (underweight, normal weight, overweight, and obese), using 2 methods: (1) BMI-SDS, based on age- and gender-specific percentiles, and (2) %BF reference charts (standard). Linear regression and a correlation analysis were conducted to compare agreement between both methods of nutritional status classification. %BF reference value comparisons were also made between 3 independent sources based on German, Canadian, and American study populations.

Results: Correlation between nutritional status classification by BMI-SDS and %BF agreed moderately (r ² = 0.75, 0.76 in boys and girls, respectively). The misclassification of nutritional status in sick children and adolescents using BMI-SDS was 27% when using German %BF references. Similar rates observed when using Canadian and American %BF references (24% and 23%, respectively).

Conclusions: Using BMI-SDS to determine nutritional status in a sick population is not considered an appropriate clinical tool for identifying individual underweight or overweight children or adolescents. However, BMI-SDS may be appropriate for longitudinal measurements or for screening purposes in large field studies. When accurate nutritional status classification of a sick patient is needed for clinical purposes, nutritional status will be assessed more accurately using methods that accurately measure %BF, such as DXA.     

Re-irradiation with stereotactic body radiation therapy as a novel treatment option for isolated local recurrence of pancreatic cancer after multimodality therapy: experience from two institutions

Limited treatment options exist for isolated local recurrence of pancreatic ductal adenocarcinoma (PDA) following surgical resection accompanied by neoadjuvant or adjuvant chemoradiation therapy (CRT). While select patients are eligible for re-resection, recurrent lesions are often unresectable. Stereotactic body radiation therapy (SBRT) represents a possible minimally invasive treatment option for these patients, although published data in this setting are currently lacking. This study examines the safety, efficacy, and palliative capacity of re-irradiation with SBRT for isolated local PDA recurrence.All patients undergoing SBRT at two academic centers from 2008-2012 were retrospectively reviewed to identify those who received re-irradiation with SBRT for isolated local recurrence or progression of PDA after previous conventionally fractionated CRT. Information regarding demographics, clinicopathologic characteristics, therapies received, survival, symptom palliation, and toxicity was obtained from patient charts. Kaplan-Meier statistics were used to analyze survival and the log-rank test was used to compare survival among patient subgroups.Eighteen patients were identified. Fifteen had previously undergone resection with neoadjuvant or adjuvant CRT, while 3 received definitive CRT for locally advanced disease. Median CRT dose was 50.4 Gy [interquartile range (IQR), 45.0-50.4 Gy] in 28 fractions. All patients subsequently received gemcitabine-based maintenance chemotherapy, but developed isolated local disease recurrence or progression without evidence of distant metastasis. Locally recurrent or progressive disease was treated with SBRT to a median dose of 25.0 Gy (range, 20.0-27.0 Gy) in 5 fractions. Median survival from SBRT was 8.8 months (95% CI, 1.2-16.4 months). Despite having similar clinicopathologic disease characteristics, patients who experienced local progression greater than vs. less than 9 months after surgery/definitive CRT demonstrated superior median survival (11.3 vs. 3.4 months; P=0.019) and progression-free survival (10.6 vs. 3.2 months; P=0.030) after SBRT. Rates of freedom from local progression at 6 and 12 months after SBRT were 78% (14 of 18 patients) and 62% (5 of 8 patients), respectively. Effective symptom palliation was achieved in 4 of 7 patients (57%) who reported symptoms of abdominal or back pain prior to SBRT. Five patients (28%) experienced grade 2 acute toxicity; none experienced grade ≥3 acute toxicity. One patient (6%) experienced grade 3 late toxicity in the form of small bowel obstruction.In conclusion, re-irradiation with hypofractionated SBRT in this salvage scenario appears to be a safe and reasonable option for palliation of isolated local PDA recurrence or progression following previous conventional CRT. Patients with a progression-free interval of greater than 9 months prior to isolated local recurrence or progression may be most suitable for re-irradiation with SBRT, as they appear to have a better prognosis with survival that is long enough for local control to be of potential benefit.Key Words: Stereotactic body radiation therapy (SBRT), pancreatic cancer, local recurrence, re-irradiation     

Effects and mechanisms of PCB ecotoxicity in food chains: Algae  fish  seal  polar bear 1

Wildlife populations are adversely affected in polluted environments. Nevertheless, a cause‐and‐effect relationship between excessive exposure to chlorinated hydrocarbons and induction of pathologic disorders in animals, is difficult to demonstrate without verification from experiments following the rationale of Koch's postulates. Deleterious effects of chlorinated chemicals such as DDT on songbird reproduction, as demonstrated by the clutch size of eggs in a nest, however, is an example, where exposure and causation are apparent. With amelioration of DDT pollution, clutch size increases, and the cause‐and‐effect relationship is established. Similar examples of exposure to DDT and PCBs inducing reproductive disorders and endocrine disruption among marine mammals have been documented in industrialized nations of northern Europe and in the upper latitudes of the Northern Hemisphere. Population declines in ringed, grey and harbor seals are apparently due to a rapid decrease in their rates of reproduction¹. These latter observations are best interpreted in light of experiments conducted by Reijnders². Reijnders exposed harbor seals to relatively high dietary levels of PCBs and induced PCB‐blood‐lipids among seals to an average of 25 mg/kg compared to 10 mg/kg among controls. The treated seals had a significantly reduced reproductive rate. A relationship between increased PCB‐blood‐levels in vivo and the decrease in reproductive rates in this experiment is highly instructive for interpreting the decline of fertility in seal populations in polluted Baltic Sea waters. These linked observations are dependent upon demonstration of pathologic mechanisms associated with occlusion and stenosis of the uterine lumen among affected females in seal populations.

PCB congeners apparently disrupt endocrine‐system‐functions leading to, or associated with, increases in endometriosis, fetal abortion, glomerulonephropathies and osteoporosis. This observation is further highlighted by Reijnders experiment, which closely replicated the range of PCB concentrations found in seal populations living in a variety of PCB polluted waters.

Various PCB congeners differentially accumulate in brain, liver and adipose tissues in young and old seals. Further research of PCB toxic effects on organ systems of these animals and other species is thus indicated.

This report, then, examines the process of PCB bioaccumulation within the marine food chain from fish to seals, whales, other marine mammals and to polar bears. Environmental toxic pollutants affect animals within the food chain in different ways but ultimately they affect humans as well.     

Tumor Necrosis Factor α Is Toxic to Embryonic Mesencephalic Dopamine Neurons

Levels of the proinflammatory cytokine tumor necrosis factor α (TNFα) are increased in postmortem brain and cerebral spinal fluid from patients with Parkinson's disease (PD). This observation provides a basis for associating TNFα with neurodegeneration, but a specific toxicity in dopamine (DA) neurons has not been firmly established. Therefore, we investigated TNFα-induced toxicity in DA neurons by utilizing primary cultures of embryonic rat mesencephalon. Exposure to TNFα resulted in a dose-dependent decrease in DA neurons as evidenced by decreased numbers of tyrosine hydroxylase-immunoreactive (THir) cells. TNFα toxicity was selective for DA neurons in that neither glial cell counts nor the total number of neurons was decreased and no general cytotoxicity was evidenced by lactate dehydrogenase assay. Many of the cells which remained immunoreactive for TH had shrunken and rounded cell bodies with broken, blunted, or absent processes. However, TNFα-treated cultures also contained some THir cells which appeared to be undamaged and possibly resistant to TNFα-induced toxicity. Additionally, immunocytochemistry revealed basal expression of TNFα receptor 1 (p55, R1) and TNFα receptor 2 (p75, R2) on all cells within the mesencephalic cultures to some degree, even though only DA neurons were affected by TNFα treatment. These data strongly suggest that TNFα mediates cell death in a sensitive population of DA neurons and support the potential involvement of proinflammatory cytokines in the degeneration of DA neurons in PD.