Zinc sulfate in the prevention of total-body irradiation-induced early hematopoietic toxicity

Exposure to ionizing total-body radiation suppresses hematopoiesis, resulting in decreased production of blood cells. Many researchers have demonstrated the critical role of zinc (Zn) in diverse physiological processes, such as growth and development, maintenance and priming of the immune system, and tissue repair. The aim of the present study was to determine the effects of zinc sulfate (40 mg/kg and 80 mg/kg) on early hematopoietic toxicity, caused by total-body irradiation (TBI) of rats with a single dose of 8 Gy. Both in the Zn 40 and in the Zn 80 groups, there were significantly increased white blood cell (WBC) count, when compared with control group. The WBC count was higher in the control group than in the TBI group. This result was statistically significant (p<0.05). Both the TBI+Zn 40 and the TBI+Zn 80 groups had a significantly protected WBC count against TBI. No difference was detected in any final measurement of thrombocyte count and hemoglobin level with direct comparison among all groups, with the exception that the hemoglobin level in the Zn 80 group compared to the control group. Whereas hemoglobin level in the control group was at a median figure of 13.98 g/dL (13.30–14.80), it was at a median figure of 14.25 g/dL (14.10–15.50) in the Zn 80 group. It would be worth while studying the effect of oral zinc sulfate supplements in radiation-treated cancer patients, in the hope of reducing radiation-induced toxicity.     

Lactate and the Lactate-to-Pyruvate Molar Ratio Cannot Be Used as Independent Biomarkers for Monitoring Brain Energetic Metabolism: A Microdialysis Study in Patients with Traumatic Brain Injuries

Background

For decades, lactate has been considered an excellent biomarker for oxygen limitation and therefore of organ ischemia. The aim of the present study was to evaluate the frequency of increased brain lactate levels and the LP ratio (LPR) in a cohort of patients with severe or moderate traumatic brain injury (TBI) subjected to brain microdialysis monitoring to analyze the agreement between these two biomarkers and to indicate brain energy metabolism dysfunction.

Methods

Forty-six patients with an admission Glasgow coma scale score of ≤13 after resuscitation admitted to a dedicated 10-bed Neurotraumatology Intensive Care Unit were included, and 5305 verified samples of good microdialysis data were analyzed.

Results

Lactate levels were above 2.5 mmol/L in 56.9% of the samples. The relationships between lactate and the LPR could not be adequately modeled by any linear or non-linear model. Neither Cohen’s kappa nor Gwet’s statistic showed an acceptable agreement between both biomarkers to classify the samples in regard to normal or abnormal metabolism. The dataset was divided into four patterns defined by the lactate concentrations and the LPR. A potential interpretation for these patterns is suggested and discussed. Pattern 4 (low pyruvate levels) was found in 10.7% of the samples and was characterized by a significantly low concentration of brain glucose compared with the other groups.

Conclusions

Our study shows that metabolic abnormalities are frequent in the macroscopically normal brain in patients with traumatic brain injuries and a very poor agreement between lactate and the LPR when classifying metabolism. The concentration of lactate in the dialysates must be interpreted while taking into consideration the LPR to distinguish between anaerobic metabolism and aerobic hyperglycolysis.     

Occupational health and safety risk assessment in hospitals: A case study using two-stage fuzzy multi-criteria approach

Occupational Health and Safety (OHS) is a basis to reduce occupational accidents in an acceptable level, and it covers employee health, safety, and welfare in the workplaces. Hospitals as the largest employer group in healthcare industry in Turkey face major hazards categorized as chemical, biological, physical, ergonomic, and psychosocial risks. Although Turkey demonstrates rapid economic growth, OHS practices have not been fully put into practice, and necessary attention has not been paid to the health industry. For this reason, this paper aims to assess risks for health staff, contribute for planning of health services, and enhance regulations. A case study was carried out in a leading hospital in Turkey using a two-stage fuzzy multi-criteria approach, which provides more consistency in decision-making process and gives an appropriate final rank of hazard types. Fuzzy Analytic Hierarchy Process (FAHP) is used in weighing five risk parameters, which are severity, occurrence, undetectability, sensitivity to maintenance non-execution, and sensitivity to personal protective equipment (PPE) non-utilization. The fuzzy VIKOR (FVIKOR) approach is then applied for prioritization of hazard types in each department of the hospital. On conclusion of the hazard control hierarchy, measures are overtaken for the hazards, and areas open for improvement are presented.     

Identification and characterization of the rlp1+, the novel Rad51 paralog in the fission yeast Schizosaccharomyces pombe

A new DNA repair gene from fission yeast Schizosaccharomyces pombe rlp1+ (RecA-like protein) has been identified. Rlp1 shows homology to RecA-like proteins, and is the third S. pombe Rad51 paralog besides Rhp55 and Rhp57. The new gene encodes a 363 aa protein with predicted Mr of 41,700 and has NTP-binding motif. The rlp1Delta mutant is sensitive to methyl methanesulfonate (MMS), ionizing radiation (IR), and camptothecin (CPT), although to a lesser extent than the deletion mutants of rhp55+ and rhp51+ genes. In contrast to other recombinational repair mutants, the rlp1Delta mutant does not exhibit sensitivity to UV light and mitomycin C (MMC). Mitotic recombination is moderately reduced in rlp1 mutant. Epistatic analysis of MMS and IR-sensitivity of rlp1Delta mutant indicates that rlp1+ acts in the recombinational pathway of double-strand break (DSB) repair together with rhp51+, rhp55+, and rad22+ genes. Yeast two-hybrid analysis suggests that Rlp1 may interact with Rhp57 protein. We propose that Rlp1 have an accessory role in repair of a subset of DNA damage induced by MMS and IR, and is required for the full extent of DNA recombination and cell survival under condition of a replication fork collapse.     

Timescale dependence in a conditional temporal discrimination procedure

A conditional temporal discrimination procedure was used to test the scope and generality of the principle of timescale invariance (TSI). Rats were trained to make different temporal discriminations following four different auditory stimuli. After shorter stimuli, rats were reinforced for pressing the left lever, and after longer stimuli, rats were reinforced for pressing the right lever. The four auditory stimuli (a pure tone, pulsed tone, click, and white noise) were each presented for different pairs of durations (ranging from 2 vs. 8s to 32 vs. 128 s) within a single session, but the ratio between the shorter and longer duration was maintained constant at 1:4. With the shortest pair of durations (2 vs. 8s), rats showed a clear violation of TSI in both overall and relative response rates. Rats started responding later and persisted relatively longer on the left lever when the shorter duration was only 2s. We interpret these results with regards to a framing hypothesis, whereby TSI does not apply to relatively short durations when animals are simultaneously trained with wide ranges of intervals.     

The ventral hippocampus CA3 is critical in regulating timing uncertainty in temporal decision-making

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