Integration of O-GlcNAc into Stress Response Pathways.

The modification of nuclear, mitochondrial, and cytosolic proteins by O-linked ßN-acetylglucosamine (O-GlcNAc) has emerged as a dynamic and essential post-translational modification of mammalian proteins. O-GlcNAc is cycled on and off over 5000 proteins in response to diverse stimuli impacting protein function and, in turn, epigenetics and transcription, translation and proteostasis, metabolism, cell structure, and signal transduction. Environmental and physiological injury lead to complex changes in O-GlcNAcylation that impact cell and tissue survival in models of heat shock, osmotic stress, oxidative stress, and hypoxia/reoxygenation injury, as well as ischemic reperfusion injury. Numerous mechanisms that appear to underpin O-GlcNAc-mediated survival include changes in chaperone levels, impacts on the unfolded protein response and integrated stress response, improvements in mitochondrial function, and reduced protein aggregation. Here, we discuss the points at which O-GlcNAc is integrated into the cellular stress response, focusing on the roles it plays in the cardiovascular system and in neurodegeneration.

Mineral-nutrient relationships in African soils assessed using cluster analysis of X-ray powder diffraction patterns and compositional methods.

Soil mineral compositions are often complex and spatially diverse, with each mineral exhibiting characteristic chemical properties that determine the intrinsic total concentration of soil nutrients and their phyto-availability. Defining soil mineral-nutrient relationships is therefore important for understanding the inherent fertility of soils for sustainable nutrient management, and data-driven approaches such as cluster analysis allow for these relations to be assessed in new detail. Here the fuzzy-c-means clustering algorithm was applied to an X-ray powder diffraction (XRPD) dataset of 935 soils from sub-Saharan Africa, with each diffractogram representing a digital signature of a soil's mineralogy. Nine mineralogically distinct clusters were objectively selected from the soil mineralogy continuum by retaining samples exceeding the 75 % quantile of the membership coefficients in each cluster, yielding a dataset of 239 soils. As such, samples within each cluster represented mineralogically similar soils from different agro-ecological environments of sub-Saharan Africa. Mineral quantification based on the mean diffractogram of each cluster illustrated substantial mineralogical diversity between the nine groups with respect to quartz, K-feldspar, plagioclase, Fe/Al/Ti-(hydr)oxides, phyllosilicates (1:1 and 2:1), ferromagnesians, and calcite. Mineral-nutrient relationships were defined using the clustered XRPD patterns and corresponding measurements of total and/or extractable (Mehlich-3) nutrient concentrations (B, Mg, K, Ca, Mn, Fe, Ni, Cu and Zn) in combination with log-ratio compositional data analysis. Fe/Al/Ti/Mn-(hydr)oxides and feldspars were found to be the primary control of total nutrient concentrations, whereas 2:1 phyllosilicates were the main source of all extractable nutrients except for Fe and Zn. Kaolin minerals were the most abundant phyllosilicate group within the dataset but did not represent a nutrient source, which reflects the lack of nutrients within their chemical composition and their low cation exchange capacity. Results highlight how the mineral composition controls the total nutrient reserves and their phyto-availability in soils of sub-Saharan Africa. The typical characterisation of soils and their parent material based on the clay particle size fraction (i.e. texture) and/or the overall silica component (i.e. acid and basic rock types) alone may therefore mask the intricacies of mineral contributions to soil nutrient concentrations.

FACTORS INFLUENCING VITAMIN A SUPPLEMENTATION AMONG MOTHERS OF CHILDREN UNDER FIVE YEARS OLD AT MBAGATHI DISTRICT HOSPITAL, KENYA.

BACKGROUND: Vitamin A supplementation is one of the best-proven and most costeffective interventions to improve vitamin A status and save children's lives. OBJECTIVE: To assess factors affecting practices and utilisation of Vitamin A supplementation services among mothers with children below five years attending Mbagathi District Hospital. DESIGN: Cross-sectional descriptive study. SETTING: Mbagathi District Hospital (MDH) Maternal and Child Health Clinic (MCH) and Paediatric Out Patient Department (POPD). SUBJECTS: Mothers attending MDH MCH and POPD. MAIN OUTCOME MEASURES: Utilisation, Practices and Awareness of vitamin A supplementation (VAS). RESULTS: A total of one hundred and fifty eight respondents were interviewed. About a half (52%) of the respondents had their children up to date with VAS while less than a half (43%) of the mothers had received vitamin A after delivery. Three quarters of the respondents'children had missed the vitamin A capsule because they were either not aware of schedule (41%) or had stopped coming to clinic (35%). This notwithstanding, 91% of the respondents neither encountered any problems when seeking VAS services nor had negative beliefs or superstitions about vitamin A. CONCLUSION: The main factors affecting utilisation of VAS services was lack of information and awareness among both health workers and mothers. These services are averagely well utilised at MDH though still below the National 80% coverage target.

Clinico-histopathologic types of maxillofacial malignancies with emphasis on sarcomas: a 10-year review.

BACKGROUND: Sarcomas are malignant neoplasms that occur anywhere in the human body. Though their occurrence in the head and neck region is rare vis-a-vis other malignancies, their presence is of tremendous concern due to their often grave prognosis. OBJECTIVE: To determine the pattern of occurrence, histopathologic types of maxillofacial sarcomas and their proportion to other malignant neoplasms of this region based on archival material accumulated over 10 years (2000-2009). DESIGN: A combined retrospective and prospective cross-sectional study. SETTING: The University of Nairobi Dental Hospital (UNDH). SUBJECTS: All cases with a diagnosis of sarcoma registered between 2000-2009 were evaluated. RESULTS: Of the 528 malignancies recorded over the ten-year period, 427 (80.9%) were of epithelial origin while 101 (19.1%) were sarcomas. Patients with epithelial malignancies were older (54.16 +/- 15.94 years) than patients with sarcomas (31.73 +/- 16.78) with the differences having been statistically significant. Osteosarcoma was the most commonly occurring sarcoma (29.7%), followed by Kaposi's sarcoma (KS) (28.7%), fibrosarcoma (FBS) (18.8%), and rhabdomyosarcoma (RMS) (9.9%). Sarcomas peaked in the third decade with 70% occurring below the age of 40 years. The maxilla and the mandible were the most afflicted sites in the maxillofacial region accounting for 52%. The patients on average presented to medical personel about nine months after noticing the lesion with the most frequent complaint having been swelling. CONCLUSION: The present study confirms the relative rarity of maxillofacial sarcomas. It also provides data on the histopathologic types and demographic characteristics of maxillofacial sarcomas in a select Kenyan population. This information is a contribution to the comprehensive documentation of sarcomas that occur globally and is useful in the provision of baseline data upon which future prospective analytical protocols may arise.

Patients' attitudes toward and factors predictive of human immunodeficiency virus testing of academic medical clinics.

INTRODUCTION: More than 1,000,000 persons in the United States are living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome, with 24% unaware of their HIV status. In this study, the authors explored patients' attitudes toward HIV testing in academic medical clinics and investigated the possible impact of the 2006 Centers for Disease Control and Prevention (CDC) HIV screening guidelines. METHOD: Cross-sectional survey study of adult patients in 9 academic internal medicine clinics (response rate 73%). The survey consisted of 76 questions, which assessed demographics, HIV risk factors, knowledge, beliefs, attitudes and characteristics of patient-physician interactions. Patient self-reported HIV testing was the main outcome. Bivariate analyses were performed, and variables with a P-value of <0.1 were included in a logistic regression model to determine characteristics most associated with HIV testing. RESULTS: Four hundred forty-three patients completed the survey (response rate 73%) and 61% reported being screened for HIV. Physician recommendation (P < 0.0001), patient's own request (P < 0.0001), African American race (P < 0.0001) better knowledge about HIV (P = 0.0002), agreement with CDC recommendations (P < 0.0001), being comfortable with their doctor (P < 0.0001) and using street drugs (P < 0.0001) were all strongly associated with testing. In logistic regression, the only factors that remained statistically significant predictors of patients self-reported HIV testing were a patient's request for testing (OR: 103.3) and patient's knowledge about HIV (OR: 1.3). CONCLUSION: In this study, patient request was the strongest predictor for HIV screening and majority of patients accepted the idea of HIV testing in congruence with the CDC recommendations. Therefore, simple waiting room prompts and public education campaigns may represent the most efficient interventions to increase HIV testing rate.