Impact of Stress on Type 2 Diabetes Mellitus Management.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is one among the major health and socioeconomic problems worldwide. It is, however, not a somatic illness for which just symptomatic treatment will suffice. Stress is an important factor in not only causing diabetes onset or exacerbation, but also in hampering proper treatment by interfering with the treatment adherence of patients. Hence, it becomes important for physicians to acquaint themselves with the effects of stress on T2DM in order to ensure proper treatment of the latter. OBJECTIVE: Documentation of effect of stress on the management of T2DM. SUBJECTS AND METHODS: The research was a cross-sectional study on the patients attending Sri Muthukumaran Medical College, Hospital and Research Institute, Mangadu. A total of 400 people, who werepre-established diabetic patients of the hospital of age greater than 30 years, were chosen for the study. The stress levels of the patients were assessed with the Perceived Stress Scale (PSS) and treatment adherence using a questionnaire prepared exclusively for the study. Based on the data, a statistical relationship was framed between the degree of control (treatment adherence) and the stress levels of the patients. RESULTS: The FBS levels were a direct reflection of the stress levels (P<0.05). Stress had a major impact on treatment adherence among the diabetic subjects: Increased levels of stress decreased the adherence (P<0.001). The glycemic index (HbA1C level) was found to be linked to both treatment adherence and stress. Increased adherence kept it at bay (P<0.05) while stress proved abysmal to glycemic control. CONCLUSION: T2DM is the result of an interplay between various factors; environmental, psychiatric and somatic. Hence, a holistic treatment approach is required, one that involves stress management, education and mental health awareness along with pharmacological treatment, to fully control the disease.

Mathematical modeling of regulation of type III secretion system in Salmonella enterica serovar Typhimurium by SirA.

Salmonella enterica serovar Typhimurium invades the intestinal epithelial cells using type three secretion system (TTSS) encoded on Salmonella pathogenicity island-1 (SPI-1). The key regulator of this secretion system is HilA, which is in turn regulated by HilD, HilC and RtsA. It is also known that SirA/BarA system, a two-component regulatory system plays a crucial role in regulating HilA. There are two different mechanisms that have been proposed earlier for regulation of HilD-HilC-RtsA-HilA network by SirA. One considers SirA to be acting through HilA and HilC, whereas the other considers SirA to be acting through HilD. In this paper, we have built mathematical models corresponding to both these scenarios and carried out simulations under different gene knock-out conditions. Additionally, since the two proposed mechanisms based on the experimental data are equally likely, we also considered a mechanism which is a combination of the two proposed mechanisms. The simulations were carried out to check the levels of HilA, the factor regulating the virulence, as well as the levels of the intermediate components in the network, namely HilC and RtsA. The simulation results were used to check the consistency of various models and also to suggest the most probable mechanism of hilA regulation. The results of our study show that while most of the mathematical models are able to predict the virulence data, the models considering SirA to regulate through HilA and HilC fail to predict the levels of intermediate components, HilC and RtsA. Nevertheless, one of the models considering regulation of virulence by SirA via HilD was able to predict results comparable to the experimental data. In addition, combination of this model (regulation by SirA via HilD) with the model considering regulation by SirA through HilA and HilC, also predicted results consistent with experimental observations. Our conclusions were further validated by testing the stability of the results against changes in parameter values, thus confirming the relative robustness of the proposed modeling system.

Responses of the photosynthetic machinery of Spirulina maxima to induced reactive oxygen species.

The photosynthetic machinery of Spirulina maxima was studied when subjected to induced reactive oxygen species (ROS) to examine the organism's responses to stress. Significant decreases in both photosynthetic efficiency and growth rate were observed. Exposure to 0.01 mmol H(2)O(2)/(g cell), which induced the lowest specific intracellular ROS level (siROS) led to a 15% decrease in specific growth rate; an increase in siROS by 70-fold led to a 25% decrease in specific growth rate. Similarly, siROS induced by 0.01 mmol H(2)O(2)/(g cell) led to 15% inhibition in photosynthetic efficiency, while an increase in siROS by 40- or 70-fold led to about 60% inhibition in photosynthetic efficiency. To further understand the effects of induced ROS on photosynthetic machinery, we performed a detailed pigmentation analysis as well as analyzed Phycobilisomes (PBS), Photosystem II (PSII), and Photosystem I (PSI), the three important components of cyanobacterial photosynthetic apparatus. We found carotenoids (beta-carotene and lutein) to be most sensitive to siROS. Also, specific levels of phycocyanin and allophycocyanin, which are important PBS pigments, decreased significantly in response to H(2)O(2). Further, electron transport assays revealed that ROS cause damage primarily to PSII, whereas they do not significantly affect PSI in comparison; siROS induced by 0.01 mmol H(2)O(2)/(g cell) led to a 15% inhibition of PSII, and increase in siROS by 9-, 40-, and 70-fold led to 22%, 36%, and 46% inhibition, respectively.