THE TREATMENT OF MEDIASTINAL TUMORS

Because there can be no certainty of diagnosis without it, thoracotomy is indicated in cases in which there is roentgenographic evidence of mediastinal tumor. “Watchful waiting” is considered unwise because the tumor may be malignant when first observed or may later undergo malignant change. Even if the lesion is and remains benign, an increase in the size of the mass may cause obstructive pressures necessitating operation ultimately. Moreover, infection and inflammation may develop at the site during prolonged observation, making operation more difficult.The hazards of thoracotomy, which have been greatly reduced in the last few years, are less than the hazards of waiting.     

Insulin enhances protein phosphorylation in isolated hepatocytes by inhibiting an amiloride sensitive phosphatase

The effects of amiloride on basal and hormone-stimulated protein phosphorylation were studied in isolated rat hepatocytes labeled with ³²P-phosphate. Two types of effect on basal phosphorylation were detected: 1. an increase in labeling of two proteins with molecular weights 93,000 and 18,000; 2. a decrease in labeling of proteins with molecular weights 46,000, 34,000, 22,000 and 13,000. All these effects were dose-dependent (maximum with 0,8-to 1 mM) and reached a maximum after 30 to 40 min treatment of the cells with the drug. Amiloride inhibited specifically all insulin effects whereas glucagon specific effects were largely unaffected. In pulse-chase experiments, amiloride increased and insulin decreased the rate of dephosphorylation of the same proteins (Mr 46,000, 34,000 and 22,000). The data support the conclusion that in hepatocytes insulin increases the degree of phosphorylation of proteins by inhibiting an amiloride-sensitive phosphatase.     

Molecular analyses of methanogen diversity associated with cattle dung

Methanogen communities were characterized in cattle dung of different ages by using a culture-independent approach. Community structures were determined by the phylogenetic analyses of methyl-coenzyme M reductase A (mcrA) clones of fresh, 8-month-old, and 24-month-old-dry dung samples. The clones in the mcrA libraries of fresh and 8-month old dung samples were identified as belonging to Methanomicrobiales, Methanobacteriales, and Methanosarcinales. However, clones in the library of 24-month-old dung were not affiliated to Methanomicrobiales. Anaerobic digestion of 2-month-old dung produced only 15% less methane compared to fresh dung which indicated the possibility of using dry dung to fuel the biogas plants in areas where unavailability of fresh dung hinders their continuous functioning. Our results first time showed the presence of viable methanogens in dry cattle dung stored for prolonged periods of time.     

Effects of pulse-modulated microwave radiation and conventional heating on sperm production

The effects on testicular function of pulse-modulated microwave radiation (PM MWR, 1.3 GHz) and of conventional heating were studied in the rat. Anesthetized adult males (Sprague-Dawley, 400-500 g) were treated then killed at specific intervals with respect to the 13-day cycle of the seminiferous epithelium. PM MWR at 7.7 mW/g (90 min) yielded a modest decline in daily sperm production (DSP) that derived primarily from effects on primary spermatocytes. PM MWR at 4.2 mW/g was ineffective. The mean intratesticular temperature during the former reached 40 degrees C and did not exceed 38 degrees C during the latter. MWR considerably in excess of 7.7 mW/g yielded decrements in virtually all germ cell types, with primary spermatocytes again being most markedly affected. Using conventional heating, intratesticular temperatures in excess of 39 degrees C for 60 min were required for significant decrements in DSP. Levels of circulating follicle-stimulating hormone and of leutinizing hormone were resistant to either treatment. We conclude that the damage threshold and the differential sensitivity of immature germ cells to PM MWR can be adequately explained by the consequent macroscopic heating.     

Does consanguinity increase the risk of schizophrenia? Study based on primary health care centre visits

Background Consanguinity has been suggested as a risk factor for the development of schizophrenia in offspring in some Middle Eastern countries.Aim The purpose of this study was to review the frequency, pattern of parental consanguinity, and family history of schizophrenia among schizophrenia patients in Qatar, and to determine their impact on the associated risk factors.Design This is a cross-sectional study which was conducted between January 2009 and December 2010, in the setting of primary health care (PHC) centres of the Supreme Council of Health, State of Qatar.Subjects A total of 1491 patients aged 18–55 years were approached, of whom 1184 individuals agreed to participate in the study, giving a response rate of 79.4%.Methods The study was based on face-to-face interviews using a specially designed questionnaire that covered sociodemographic characteristics and genetic and other biological factors (e.g. obstetric complications), and a diagnostic screening questionnaire which consisted of six questions about the symptoms of schizophrenia. The diagnostic screening questionnaire was reviewed and used to calculate the final score, which determined a provisional diagnosis. The psychiatrists discussed the psychiatric diagnosis and confirmed it using DSM-IV criteria. The degree of consanguinity between the patient''s parents was recorded. Consanguinity was evaluated based on the coefficient of inbreeding (F), which is the probability of homozygosity.Results More than half of the schizophrenia patients were female (57.1%) and over 45 years of age (62.5%). A family history of schizophrenia was significantly more common in parents of schizophrenia patients than in the Arab population without schizophrenia (24.6% vs. 17.1%; P = 0.038). Parental consanguinity was elevated among the patients with schizophrenia (41.3%) with a higher mean coefficient of inbreeding (0.04356 ± 0.028) than in non-schizophrenic subjects (28.7%) with a lower mean coefficient of inbreeding (0.0298 ± 0.035). Schizophrenia diagnoses were more frequent among the offspring of consanguineous parents than among the offspring of non-consanguineous parents.Conclusion The substantial risk observed in the present study reveals that consanguinity is an important risk factor for schizophrenia in Qatar. In addition, the study confirms that the higher familial risks provide strong genetic epidemiological evidence for the overall heritable effects in the aetiology of schizophrenia.     

Liposomal co-delivery-based quantitative evaluation of chemosensitivity enhancement in breast cancer stem cells by knockdown of GRP78/CLU

Resistance to chemotherapy is a key factor in the inefficacy of various forms of treatments for cancer. In the present study, chemo-resistant proteins, including glucose-regulated protein 78 (GRP78)/clusterin (CLU) targeted 1,2-dioleoyloxy-3-trimethylammoniumpropane (DOTAP) liposomes, were developed as a delivery system for co-delivery of camptothecin (CPT) and GRP78 siRNA/CLU siRNA. Their drug/gene co-deliveries were quantitatively assessed in cancer stem cells (CSC) and MCF-7 cells. DOTAP-CPT/siRNA were prepared via electrostatic interaction on GRP78 siRNA or CLU siRNA. The size and ζ-potential of liposomes and lipoplexes were measured by dynamic light scattering techniques and electrophoretic light scattering spectrophotometry. The lipoplexes formation was tested by using gel electrophoresis. Immunofluorescence analysis showed that the expression level of CLU and GRP78 were significantly elevated in CSC compared to MCF-7 cells. Transfection and drug-delivery efficiency of DOTAP-CPT/siRNA were quantitatively compared with Lipofectamine 2000. Compared to free CPT, DOTAP-CPT-siCLU delivery in CSC and MCF-7 cells increased transfection efficiency and chemo-sensitivity by 4.1- and 5.9-fold, respectively. On the other hand, DOTAP-CPT-siGRP78 delivery increased transfection efficiency and chemo sensitivity by 4.4- and 6.2-fold in CSC and MCF-7 cells, respectively, compared to free CPT. It is significant that 3?±?1.2-fold increase in transfection efficiency was achieved by lipofectamine. Consequently, an increase in anti-cancer/gene silencing efficacy was quantitatively observed as an effect of DOTAP-CPT/siRNA treatment, which was relatively higher than lipofectamine treatment. Conclusively, our experimental data quantitatively demonstrate that using DOTAP-CPT-siRNA specifically targeting (CSCs) chemo-resistant protein in vitro offers substantial potential for synergistic anti-cancer therapy.