Evaluation of sarcopenia as a prognostic biomarker in locally advanced head and neck squamous cell carcinoma.

Background: We aimed to evaluate the effect of sarcopenia on survival in head and neck squamous cell carcinoma patients treated with chemoradiotherapy. Materials & methods: Disease-free survival and overall survival were compared according to cervical computed tomography for radiotherapy in 123 sarcopenic and non-sarcopenic patients with locally advanced head and neck squamous cell carcinoma treated with chemoradiotherapy with weekly cisplatin. Results: In multivariate analyses, pretreatment sarcopenia was associated with lower disease-free survival (hazard ratio: 2.60; 95% CI: 1.38-4.87; p = 0.003) and overall survival (hazard ratio: 2.86; 95% CI: 1.40-5.85; p = 0.004). Sarcopenic patients experienced more frequent radiotherapy-related toxicities and platinum-related side effects than non-sarcopenic patients. Conclusion: Sarcopenia could be a potential biomarker to predict prognosis and treatment toxicity in head and neck squamous cell carcinoma.

Head and neck cancer is one of the main causes of cancer-related death worldwide. Most patients are diagnosed in the advanced stage. Muscle wasting with significant weight loss occurs in nearly half of the patients at the initial diagnosis. In oncology research, sarcopenia has often been described as the loss of skeletal muscle mass. In this study, we evaluated the effect of sarcopenia on survival in head and neck cancer patients. Muscle mass was calculated using information from head and neck computed tomography before radiotherapy treatment in patients. We showed that patients with low muscle mass had significantly worse survival rates and were more susceptible to treatment-related side effects. Sarcopenia may function as a marker showing the course of disease in patients with head and neck cancer.

Clinical presentation of Von Hippel Lindau syndrome type 2B associated with VHL p.A149S mutation in a large Turkish family.

Von Hippel Lindau (VHL) syndrome is an autosomal dominant disorder characterized by benign and malignant tumors. This study presents the clinical and genetic features of VHL syndrome in a Turkish family. For the diagnosis of pheochromocytoma-related diseases, 49 family members from three generations were evaluated between March 2008 and January 2013. Family members were examined to identify components of pheochromocytoma-related genetic syndromes through physical examination, laboratory tests, and imaging methods. For the causative mutation, sequence analysis of VHL gene was performed. Nine patients were diagnosed with pheochromocytoma. Lumbal spinal hemangioblastoma and pancreatic neuroendocrine tumor without pheochromocytoma were detected in one patient. In patients with pheochromocytoma, additional tumors, such as retinal angioma, renal cell carcinoma, pancreatic serous cystadenoma, and pancreatic neuroendocrine tumors were detected. All patients were diagnosed as VHL syndrome type 2B. Sequence analysis of VHL gene revealed heterozygous p.A149S mutation in all symptomatic patients and in seven of the asymptomatic family members. This is the first study that identified VHL p.A149S mutation in a Turkish family with VHL syndrome. However, VHL p.A149S mutation was identified in an American family by Atuk et al. (J Clin Endocrinol Metab, 83:117-120, 14) and the family was defined as VHL type 2A. In our study, the family was identified as VHL type 2B. This variability in the phenotypic features suggests that further studies are required to beter assess the genotype-phenotype correlation in such cases.

Obstructive sleep apnea syndrome and its association with vitamin D deficiency.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a widespread disorder characterized by recurrent, partial or complete episodes of apnea due to upper airway tract obstruction during sleeping period. Deficiency of vitamin D has roles in development of many diseases. Association between presence and severity of OSAS and vitamin D has recently gained research interest. AIM: The aim of our study was to investigate the association between serum 25-hydroxy [25 (OH)] vitamin D levels and severity of disease in patients with OSAS. MATERIAL AND METHODS: One hundred and fifty OSAS patients (50 patients with mild, 50 with moderate, 50 with severe OSAS) who were diagnosed by polysomnography (PSG) and 32 non-OSAS controls who were referred to the Health Ministry Ankara Numune Training and Research Hospital, Endocrinology and Metabolism Department, from January 2010 to May 2011 were included in the study. Serum 25(OH)D, PTH, calcium and phosphorus levels were evaluated in all the patients who were recruited to the study. RESULTS: There was no statistically significant difference in serum 25(OH)D levels between OSAS and controls (p>0.05). However, in subgroup analysis of OSAS, we found that the patients with severe OSAS had significantly lower levels of 25(OH)D as compared with other groups (p=0.003). Also, the number of patients with serum 25(OH)D deficiency (<10 µg/dl) were higher in OSAS group than in controls (p<0.05). CONCLUSIONS: We found that when the severity of OSAS increases, 25(OH)D deficiency becomes more pronounced.

AgGaSe2 thin films grown by chemical close-spaced vapor transport for photovoltaic applications: structural, compositional and optical properties.

Thin films of chalcopyrite AgGaSe(2) have been successfully grown on glass and glass/molybdenum substrates using the technique of chemical close-spaced vapor transport. The high crystallinity of the samples is confirmed by grazing-incidence x-ray diffraction, scanning and transmission electron microscopy, and optical transmission/reflection spectroscopy. Here, two of the three expected direct optical bandgaps are found at 1.77(2) and 1.88(6) eV at 300 K. The lowest bandgap energy at 4 K is estimated to be 1.82(3) eV. Photoluminescence spectroscopy has further revealed the nature of the point defects within the AgGaSe(2), showing evidence for the existence of very shallow acceptor levels of 5(1) and 10(1) meV, and thus suggesting the AgGaSe(2) phase itself to exhibit a p-type conductivity. At the same time, electrical characterization by Hall, Seebeck and four-point-probe measurements indicate properties of a compensated semiconductor. The electrical properties of the investigated thin films are mainly influenced by the presence of Ag(2)Se and Ga(2)O(3) nanometer-scaled surface layers, as well as by Ag(2)Se inclusions in the bulk and Ag clusters at the layers' rear side.