A Prospective study to determine the occurrence of hypothyroidism following treatment with radiation therapy in patients of head and neck carcinomas and factors influencing this

INTRODUCTION: Head and neck malignancies are one of the most common malignancies in world and India. A vast majority of patients of head and neck malignancies are treated with radiotherapy. There has been evidence that such radiation to the neck may result in post radiotherapy hypothyroidism. The incidence of post radiotherapy hypothyroidism in as reported in various literature varies from as low as 6% to as high as 68%. However, there is considerable debate regarding the incidence, influencing factors responsible, relationship with dose and time of development of the same. The available data for Indian patients, as found by Aich et al shows an incidence of 0.57% at 6 weeks and 21.8% at two years. Biochemical investigations are available for determination of hypothyroidism and supplementation with exogenous thyroxin is possible. Hypothyroidism manifests as fatigue, poor appetite, and temper fluctuation, leading to inability to meet social and familial roles. They also do effect on the professional and economic productivity of the patient and the family. This adds to the financial strain that results from the cost of care and loss of work days during the treatment period. Hypothyroidism also results in long term complications with respect to cardiac and general morbidity. Such morbidity in cancer survivors can be of immense physical, emotional, social and economic problems. Thus early detection and treatment of post radiotherapy hypothyroidism can result in avoidance of such complications and help in improving the quality of life. Most of the guidelines have been developed on basis of the western data. The applicability of the same, to Indian population, is not well defined, especially, in view of heterogeneity of data, originating from different population of the world. This not only includes the incidence but also time of occurrence of hypothyroidism post radiotherapy. This study is an endeavor to determine the incidence, associated factors in development of hypothyroidism including the temporal association of the incidence with respect to the population from the Indian subcontinent. AIMS OF THE STUDY: 1. To determine the incidence of clinical and subclinical hypothyroidism in patients undergoing radiation therapy for head and neck carcinomas. 2. To determine the factors influencing the occurrence of hypothyroidism. 3. To evaluate impact on quality of life. MATERIALS AND METHODS: Inclusion criteria: 1. Adult patients[ more than 18 years of age] with non-metastatic Head & Neck carcinoma, without any intracranial extension, of the following sites- a. Nasopharynx, b. Sinonasal cavity, c. Oropharynx, d. Oral cavity, e. Hypopharynx, f. Larynx, g. CUP [Carcinoma of unknown primary], 2. Patients receiving radiotherapy(>45 Gy) as part of treatment, 3. Radiation field extending to lower neck , unilateral or bilateral, 4. Performance score- 0 to 2. Exclusion criteria: 1. Known to have hypothyroidism: a) At the time of screening, b) The history of hypothyroidism in the past, for which he/she is currently on supplements. [Hypothyroidism was defined as TSH more than the maximum of the normal range, or TSH >4.5 micro IU/ml]. CONCLUSION: 1. Hypothyroidism at baseline evaluation was 11% and the incidence of secondary hypothyroidism post radiotherapy was 13.51% -- 2. Surface dose measurements as described in the earlier literature did not correlate with clinical outcome and should be looked into in the light of 3D organ imaging and dose volume relationships in the era of modern radiotherapy. 3. The significant clinical symptoms of secondary hypothyroidism are cold intolerance and weight gain seen as early as six weeks. 4. Iatrogenic hypothyroidism occurred over a variable point of time during the follow up period as early as 6 weeks and at 19 weeks of completion of radiotherapy. 5. Females appeared to be more prone to develop post radiotherapy hypothyroidism. 6. Those patients with TSH levels more than 3 m IU/ml at base line were found to be more prone to develop secondary hypothyroidism. 7. Hypothyrodism is a significant comorbid association at presentation which can worsen with radiotherapy and early institution of treatment results in improvement of quality of life. In view of this, a baseline and follow up TSH as routine should be incorporated in the management schedule. This simple biochemical screening is a cost effective strategy to improve the quality of life in head and neck cancer

Application of Advance Control Logic for Power System Automatic Generation Control

The steady state analysis of voltage stability is vital thing for study of power system stability. The voltage collapse is occurred due to different reason of power system. The main reason is frequency unbalance, and changing of reactive power in transmission line due to change of load. If voltage and frequency is fluctuating a long period whole power system may be collapse. This creates ice landing of grid failure and black out of a major area. So the analysis of this problem is very much essential how to overcome from this problem. The reactive power is changing due to change of excitation, and frequency is changing due to changing of load demand. None of them can be tolerated to the power system. So here research about this small topic how to control the load frequency, when the load is continuously changing and maintain the power system voltage stability. This approach has been analyzed in different ways with using different software by different authors. Here we have analyzed the problem by using MATLAB simulink

Nanoparticles mediated cadmium toxicity amelioration in plants

Application of nanoparticles to address various environmental issues; especially heavy metal contaminated soil restoration is of global interest. Indiscriminate usage of phosphate fertilizer and other anthropogenic activities contribute to Cd contamination of soil, resulting in degradation of soil quality and low crop yield. By the virtue of unique physiochemical characteristics, nanoparticles (NPs) are effective enough for heavy metal stress mitigation. This review has focused on Cd uptake, accumulation and toxicity in plants followed by the successful application of different metallic and non metallic NPs for soil Cd decontamination. Positive impact of NPs as plant growth elicitor under Cd stress has been explored here. Various ways of NP application (soil, foliar, hydroponics), uptake, mode of action and effective treatment concentration have been highlighted. We have collected handful information regarding the use of NPs as nanofertilizer and nanopesticides. The negative effects of NPs have not been considered here. More in depth study to be conducted for better illumination on plant - NPs interaction, mobilization mechanism and biological activities. Though this review summarizes few facts among various aspect of NP but can be counted as a supportive documentation for the better use of NPs in environmental protection in future

The budding yeast protein Chl1p is required to preserve genome integrity upon DNA damage in S-phase

The budding yeast protein, Chl1p, is required for sister-chromatid cohesion, transcriptional silencing, rDNA recombination and aging. In this work, we show that Chl1p is also required for viability when DNA replication is stressed, either due to mutations or if cells are treated with genotoxic agents like methylmethane sulfonate (MMS) and ultraviolet (UV) rays. The chl1 mutation caused synthetic growth defects with mutations in DNA replication genes. At semi-permissive temperatures, the double mutants grew poorly, were less viable and showed nuclear fragmentation. They were, however, not limited in their bulk DNA synthesis. When chl1 cells were treated with relatively low levels of MMS in S-phase, they lost viability. The S-phase DNA damage checkpoint pathway, however, remained active in these cells. Agarose gel electrophoresis of genomic DNA isolated from wild-type and chl1 cells, after recovery from MMS treatment, suggested that the wild-type was more proficient in the repair of DNA damage than the mutant. Our work suggests that Chl1p is required for genome integrity when cells suffer endogenously or exogenously induced DNA damage

Study of Metal Resistance Potential of the Cd, Cr Tolerant Alligator Weed

Background – Environmental deterioration due to heavy metal pollution is a major global concern for its immense importance in the ecosystem. Indiscriminate use of heavy metals for rapid urbanization and industrial exploration is a pressing threat to human health. Among this Cd and Cr contamination is most dangerous as these metals directly enter into the food chain due to their higher solubility and mobility. Identification of a metal tolerant native plant species would be helpful to decontaminate Cd and Cr polluted land. In our previous study, field investigations were conducted to evaluate the tolerance potential of Alligator weed to Cd and Cr.Alligator weed [Alternanthera philoxeroides (Mart). Griseb ],is the most widely distributed perennial stoloniferous herb in these contaminated areas in and around Kolkata. Purpose of the study – To establish metal tolerant capacity of the species , different biochemical parameters assessing its metal accumulation capacity and reflecting its detoxification mechanism were studied. For these purpose, the same plant collected from the highest metal contaminated area was grown under laboratory condition with external application of various concentration of Cd and Cr individually and synergistically (0.5, 0.8, 1.0, 1.2, 1.5, 1.8 mM). To estimate the hazardous effects of Cd and Cr on this weed, membrane damage was quantified in form of lipid peroxidation i.e MDA production. The metal uptake and accumulation potential was estimated by measuring the Cd and Cr concentration in root and shoot. Some soil parameters such as Orgnaic Carbon, Cation exchange capacity were also studied to explain the bio availability of metals. Various biochemical parameters such as free proline content, non protein- thiol content and zymogram analysis of antioxidative isozymes (such as, Guiacol peroxidase, superoxide dismutase, glutathione reductase and ascorbate peroxidase) were studied to assess its metal resistant capacity. Result: The acidic pH and enhanced Cation Exchange Capacity of soil made both Cd and Cr more bioavailable with increasing metal concentration. Linear increase in metal uptake and accumulation was recorded upto an optimum level at 1.0 mM, 1.2 mM for Cd and Cr respectively, evident from Translocation Factor > 1. Gradual increase in membrane damage reflected the devastating effect of both Cd and Cr. But enhanced free proline content and non protein thiol content provide enough detoxification capacity to tolerate 1.2 mM Cd, Cr after which biochemical defenses declined. Increased activity of glutathione reductase and superoxide dismutase were well documented in 1.2 mM and 1 mM Cd, Cr treated plants respectively. Overexpression of ascorbate peroxidase, superoxide dismutase and glutathione reductase was evident by the appearance of additional bands with respect to control plants which would provide acute detoxification capacity of the plant to cope up with gradual increasing Cd, Cr contamination. Conclusion: This newly emergent Cd and Cr tolerant plant which can thrive well in highly Cd, Cr contaminated soil under field condition is thought to have the potential for phytoremediation of multiple metal contaminated sites of major polluted cities

Fabrication and characterization of GaAs mis devices with N-rich PEVCD Si<SUB>x</SUB>N<SUB>y</SUB> dielectric

It is well known that the native oxide on GaAs is responsible for Fermi level pinning and has hindered the development of GaAs MOSFETs. We report significant improvements in the electrical characteristics of Au/SixNy/n-GaAs structures with NH3 plasma treatment of GaAs prior to plasma enhanced chemical vapor deposition (PECVD) of a SixNy dielectric film followed by annealing at 450&#176;C. The variation of electrical properties was studied with NH3/SiH4 ratios of 1.3, 4, 12.67, 25 and 40 for nitride deposition. It was observed that N-rich dielectric films gave the lowest interface state density. Au/SixNy/n-GaAs MIS structures were thus fabricated with interface state density of 1.1&#215; 1011eV-1cm-2 as determined from G-V measurements. Post-deposition annealing showed marked improvement in device characteristics with decrease in frequency dispersion, conductance and hence interface state density as revealed from C-V to G-V measurements. The C-t studies were also carried out to determine bulk minority carrier lifetime, which was found to remain constant at 1ns before and after annealing

Silicon as a powerful element for mitigation of cadmium stress in rice: A review for global food safety

Every day, agricultural lands are shrinking at an alarming rate and generating heavy metal stress owing to climate change and anthropogenic activities like rapid urbanization, deforestation and industrial development. Being a staple food, high Cadmium (Cd) contaminated rice grain is the prime source of oral Cd intake and poses a serious health risk to consumers. Cd translocation from soil to root cells is achieved by different transporters mainly employed for beneficial mineral uptake in rice. To combat these challenges of food and nutritional security, several feasible approaches have been proposed for Cd mitigation in contaminated landraces. Recently, application of Silicon (Si) is an emerging and fascinating practice to ameliorate Cd inflicted stress conditions. Si plays favourable role to develop elite rice cultivars with consistently low Cd content through vacuolar sequestration, phytochelatins formation, cell wall adsorption etc. In this review, the role of Si against Cd stress with underpinned mechanisms of action has been elaborated