Stressful Life Events and Perimenstrual Symptoms

Abstract

The purpose of this study was to determine whether the effects of stressful life events on perimenstrual symptoms were due to operational confounding of the instruments used to measure the independent and dependent variables. Women aged 18 to 35 (n = 179) completed the Schedule of Recent Events (SRE) and the Moos Menstrual Distress Questionnaire during a home interview. When variance in PMS scores attributable to age, parity, education, and contraceptive method was controlled using hierarchical multiple regression, total SRE scores were correlated with premenstrual and menstrual negative affect, menstrual water retention, and menstrual performance impairment. When health-related components of the SRE score were controlled in a similar manner, however, the residual SRE scores explain a diminished amount of the variance in premenstrual and menstrual negative affect and menstrual performance impairment. Future investigations are needed to clarify whether the effects of health-related life events on perimenstrual symptoms are simply a matter of operational confounding of measures of the independent and dependent variables, or whether women who recently have experienced personal illness or injury are at greater risk of developing perimenstrual symptoms.     

23S rRNA base pair 2057-2611 determines ketolide susceptibility and fitness cost of the macrolide resistance mutation 2058A-->G

The 23S rRNA A2058G alteration mediates macrolide, lincosamide, and streptogramin B resistance in the bacterial domain and determines the selectivity of macrolide antibiotics for eubacterial ribosomes, as opposed to eukaryotic ribosomes. However, this mutation is associated with a disparate resistance phenotype: It confers high-level resistance to ketolides in mycobacteria but only marginally affects ketolide susceptibility in streptococci. We used site-directed mutagenesis of nucleotides within domain V of 23S rRNA to study the molecular basis for this disparity. We show that mutational alteration of the polymorphic 2057-2611 base pair from A-U to G-C in isogenic mutants of Mycobacterium smegmatis significantly affects susceptibility to ketolides but does not influence susceptibility to other macrolide antibiotics. In addition, we provide evidence that the 2057-2611 polymorphism determines the fitness cost of the 23S rRNA A2058G resistance mutation. Supported by structural analysis, our results indicate that polymorphic nucleotides mediate the disparate phenotype of genotypically identical resistance mutations and provide an explanation for the large species differences in the epidemiology of defined drug resistance mutations.     

Effects of some chemical and physical agents on the metacestode Taenia solium in spicy meat and sausage

OBJECTIVE: To assess the effect of different cooking times and temperatures, as well as of some seasonings, on the viability of Taenia solium metacestodes in spicy meat and hot sausage. MATERIAL AND METHODS: This study was conducted by the Universidad Autónoma de Guerrero (Guerrero State Autonomous University), Mexico in 1999. Infected pork meat was bought in the community of Azacoaloya, in the municipality of Chilapa de Alvarez, Guerrero State. It was used to prepare spicy meat (adobada) and hot sausage (chorizo). Only the meat in which metacestode viability was proven was used. The products obtained underwent a) room temperature for 12 to 100 hours; b) temperatures of -10 to 37 degrees C for 24 hours; c) boiling (97 degrees C) from 1 to 15 minutes. To determine the effect of the seasonings, batches were prepared using twice the amount of a specific seasoning. Trials were done and assessed three times. Proportion differences were established using the chi-squared test. RESULTS: At room temperature the lowest evagination occurred after 100 hours for both products (p<0.05). After 24 hours, the lowest evagination occurred at -10 degrees C in spicy meat and at 37 degrees C in hot sausage (p<0.05). At boiling temperature there was no evagination after 10 minutes (p<0.05). In spicy meat, adding salt caused the most significant reduction; in hot sausage, thyme caused the most significant reduction (p<0.05). CONCLUSIONS: Meat with metacestodes should not be eaten, yet, it is being sold and used to prepare spicy meats. Adding spices can hide the metacestode, thus, adequate cooking of these meat products is necessary. These meats may be consumed at least four days after its preparation and spicy meat after a minimum of four days of refrigeration. The English version of this paper is available at: http://www.insp.mx/salud/index.html.     

Validation of the NAFLD fibrosis score in a Chinese population with low prevalence of advanced fibrosis

OBJECTIVES:  Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence worldwide. This study aimed to validate the NAFLD fibrosis score in the Chinese population.
METHODS:  NAFLD patients were prospectively recruited for liver biopsy and blood tests. The NAFLD fibrosis score was calculated as −1.675 + 0.037 × age (yr) + 0.094 × BMI (kg/m²) + 1.13 × impaired fasting glucose/diabetes (yes = 1, no = 0) + 0.99 × AST/ALT ratio–0.013 × platelet (×10⁹/L)−0.66 × albumin (g/dL). Advanced fibrosis was defined as stage 3 to 4 fibrosis.
RESULTS:  One hundred sixty-two patients (age 46 ± 10 yr, male 59%) were included in the study. Advanced fibrosis was found in 18 (11%) patients. Only 11 of 128 patients with the NAFLD fibrosis score below the proposed low cutoff point (<−1.455) were under-staged, resulting in a high negative predictive value of 91%. Only two patients exceeded the proposed high cutoff point (>0.676), but neither had advanced fibrosis. If the NAFLD fibrosis score was implemented in the Chinese population, 79% of liver biopsies could be avoided.
CONCLUSIONS:  The NAFLD fibrosis score has high negative predictive value in excluding advanced fibrosis in the Chinese population, and can reduce the burden of liver biopsy in the vast majority of cases. Since there were few cases of advanced fibrosis in this cohort, this study had limited power in validating the high cutoff point.     

Psychometric properties of the Zephyr bioharness device: a systematic review

Background

Technological development and improvements in Wearable Physiological Monitoring devices, have facilitated the wireless and continuous field-based monitoring/capturing of physiologic measures in healthy, clinical or athletic populations. These devices have many applications for prevention and rehabilitation of musculoskeletal disorders, assuming reliable and valid data is collected. The purpose of this study was to appraise the quality and synthesize findings from published studies on psychometric properties of heart rate measurements taken with the Zephyr Bioharness device.

Methods

We searched the Embase, Medline, PsycInfo, PuMed and Google Scholar databases to identify articles. Articles were appraised for quality using a structured clinical measurement specific appraisal tool. Two raters evaluated the quality and conducted data extraction. We extracted data on the reliability (intra-class correlation coefficients and standard error of measurement) and validity measures (Pearson/Spearman’s correlation coefficients) along with mean differences. Agreement parameters were summarised by the average biases and 95% limits of agreement.

Results

A total of ten studies were included: quality ratings ranged from 54 to 92%. The intra-class correlation coefficients reported ranged from 0.85–0.98. The construct validity coefficients compared against gold standard calibrations or other commercially used devices, ranged from 0.74–0.99 and 0.67–0.98 respectively. Zephyr Bioharness agreement error ranged from ??4.81 (under-estimation) to 3.00 (over-estimation) beats per minute, with varying 95% limits of agreement, when compared with gold standard measures.

Conclusion

Good to excellent quality evidence from ten studies suggested that the Zephyr Bioharness device can provide reliable and valid measurements of heart rate across multiple contexts, and that it displayed good agreements vs. gold standard comparators – supporting criterion validity.

     

The Tougher the Better: An Economic Analysis of Increased Payment Thresholds on the Performance of General Practices

We investigate whether and how a change in performance‐related payment motivated General Practitioners (GPs) in Scotland. We evaluate the effect of increases in the performance thresholds required for maximum payment under the Quality and Outcomes Framework in April 2006. A difference‐in‐differences estimator with fixed effects was employed to examine the number of patients treated under clinical indicators whose payment schedules were revised and to compare these with the figures for those indicators whose schedules remained unchanged. The results suggest that the increase in the maximum performance thresholds increased GPs' performance by 1.77% on average. Low‐performing GPs improved significantly more (13.22%) than their high‐performing counterparts (0.24%). Changes to maximum performance thresholds are differentially effective in incentivising GPs and could be used further to raise GPs' performance across all indicators. Copyright © 2013 John Wiley & Sons, Ltd.     

Donor sex,age and ethnicity impact stored red blood cell antioxidant metabolism through mechanisms in part explained by glucose 6-phosphate dehydrogenase levels and activity

Red blood cell (RBC) storage in the blood bank promotes the progressive accumulation of metabolic alterations that may ultimately impact the erythrocyte capacity to cope with oxidant stressors. However, the metabolic underpinnings of the capacity of RBC to resist oxidant stress and the potential impact of donor biology on this phenotype are not known. Within the framework of the REDS-III RBC-Omics study, RBC from 8,502 healthy blood donors were stored for 42 days and tested for their propensity to hemolyse following oxidant stress. A subset of extreme hemolysers donated a second unit of blood, which was stored for 10, 23, and 42 days and profiled again for oxidative hemolysis and metabolomics (599 samples). Alterations of RBC energy and redox homeostasis were noted in donors with high oxidative hemolysis. RBC from females, donors over 60 years old, donors of Asian/South Asian race-ethnicity, and RBC stored in additive solution- 3 were each independently characterized by improved antioxidant metabolism compared to, respectively, males, donors under 30 years old, Hispanic and African American race ethnicity donors, and RBC stored in additive solution-1. Merging metabolomics data with results from an independent genome-wide association study on the same cohort, we identified metabolic markers of hemolysis and glucose 6-phosphate dehydrogenasedeficiency, which were associated with extremes in oxidative hemolysis and dysregulation in nicotinamide adenine dinucleotide phosphate and glutathione- dependent detoxification pathways of oxidized lipids. Donor sex, age, ethnicity, additive solution and glucose 6-phosphate dehydrogenase status impact the metabolism of the stored erythrocyte and its susceptibility to hemolysis following oxidative insults.