92 research outputs found
Cardiac and Vascular α1-Adrenoceptors in Congestive Heart Failure: A Systematic Review
As heart failure (HF) is a devastating health problem worldwide, a better understanding
and the development of more effective therapeutic approaches are required. HF is characterized by
sympathetic system activation which stimulates α- and β-adrenoceptors (ARs). The exposure of the
cardiovascular system to the increased locally released and circulating levels of catecholamines leads to a
well-described downregulation and desensitization of β-ARs. However, information on the role of α-AR
is limited. We have performed a systematic literature review examining the role of both cardiac and
vascular α1-ARs in HF using 5 databases for our search. All three α1-AR subtypes (α1A, α1B and α1D) are
expressed in human and animal hearts and blood vessels in a tissue-dependent manner. We summarize
the changes observed in HF regarding the density, signaling and responses of α1-ARs. Conflicting
findings arise from different studies concerning the influence that HF has on α1-AR expression and
function; in contrast to β-ARs there is no consistent evidence for down-regulation or desensitization of
cardiac or vascular α1-ARs. Whether α1-ARs are a therapeutic target in HF remains a matter of debate
Ectopic Cushing' syndrome caused by a neuroendocrine carcinoma of the mesentery
BACKGROUND: ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTH-secreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed. CASE PRESENTATION: A 41 year-old man presented with clinical features and biochemical tests suggestive of ectopic Cushing's syndrome. First, subtotal thyroidectomy was performed without remission of hypercortisolism, because an octreotide scan showed increased activity in the left thyroid gland and an ultrasound revealed nodules in both thyroid lobes one of which was autonomous. In addition, the patient had a 3 mm hypoenhancing lesion of the neurohypophysis and a 1 cm large adrenal tumor. Surgical removal of the pituitary lesion within the posterior lobe did not improve hypercortisolism and we continued to treat the patient with metyrapone to block cortisol production. At 18-months follow-up from initial presentation, we detected an ACTH-producing neuroendocrine carcinoma of the mesentery by using a combination of octreotide scan, computed tomography scan, and positron emission tomography. Intraoperatively, use of a gamma probe after administration of radiolabeled (111)In-pentetreotide helped identify the mesenteric neuroendocrine tumor. After removal of this carcinoma, the patient improved clinically. Laboratory testing confirmed remission of hypercortisolism. An octreotide scan 7 months after surgery showed normal results. CONCLUSION: This case underscores the diagnostic challenge in identifying an ectopic ACTH-producing tumor and the pluripotency of cells, in this case of mesenteric cells that can start producing and secreting ACTH. It thereby helps elucidate the pathogenesis of neuroendocrine tumors. This case also suggests that patients with ectopic Cushing's syndrome and an octreotide scan positive in atypical locations may benefit from explorative radioguided surgery using (111)In-pentetreotide and a gamma probe
Type B insulin resistance syndrome with Scleroderma successfully treated with multiple immune suppressants after eradication of Helicobacter pylori infection: a case report
Market reaction to director independence at Borsa Istanbul
This study investigates the market reaction to appointments and departures of independent directors to boards and various board committees, as well as the magnitude of the market reaction based to the expertise and busyness of these directors. The findings suggest that investors in Turkish capital markets do not value the existence of independent directors on boards or committees of boards. In addition, the findings suggest that investors do not value the expertise of independent directors. However, investors appear to value the busyness of independent directors. The findings are robust to various model specifications. © 2015 The Author
Genotype × environment interaction and stability analysis of sweetpotato (Ipomoea batatas) genotypes
Nine introductions of sweetpotato (Ipomoea batatas) of diverse origin and two local genotypes were evaluated for storage root yield and average storage root weight in four locations of Turkey (Diyarbakir and Sanliurfa representing semi-arid environment and Adana and Hatay representing Mediterranean environment) in 2000 and 2001. The genotype × environment (GE) interaction was evaluated for two yield components (mean storage root weight and storage root yield) using the joint regression analysis and the Additive Main Effects and Multiplicative Interaction (AMMI) analysis. Stability of the genotypes over environments was estimated by using different stability parameters. GE interaction was found to be significant for both yield components, and genotype main effect contributed more than environment and GE interaction to total variability. Total storage root yield varied from 6.72 to 112.60 t ha-1, depending on genotypes and environments. The introduced genotypes produced a higher yield than local genotypes. Our study revealed that sweetpotato has a great adaptability and yield potential in irrigated Mediterranean-type and semi-arid environments, whereas non-traditional production areas such as Adana, Diyarbakir, and Sanliurfa may be more suitable for sweetpotato production than Hatay, the traditional production area, because of the potential for higher yield. The AMMI model appeared to be a better option for evaluating both GE interaction and the stability of sweetpotato genotypes in multilocational trials. The stability parameters tested in this study could not identify high yielding and stable genotypes. © 2007 Taylor & Francis Group, LLC
Growth, yield, and quality of sweet potato (Ipomoea batatas (L.) Lam.) cultivars in the southeastern Anatolian and East Mediterranean Regions of Turkey
The study was carried out to determine the adaptation potential of sweet potato crops to different regions of Turkey. The study included 9 introduced genotypes of diverse origin and 2 local genotypes that were tested in 4 locations (Diyarbak?r and Şanl?urfa representing the southeastern Anatolia region, and Adana and Hatay representing the Mediterranean region) in 2000 and 2001. Haulm and storage root growth of the cultivars were monitored at monthly intervals. Total and graded storage root yield, and some quality parameters were determined at the final harvest. Although haulm and storage growth varied according to location and year, all cultivars showed rapid growth from the 90th to 120th day after planting (DAP), at all locations. Storage root formation started between the 30th and 60th DAP at all locations. Total storage root yield, according to cultivar, location, and year, varied from 6.72 to 112.60 t ha 1, and the introduced genotypes produced higher yields than the local genotypes. Cultivars showed significant diversity in quality traits, such as dry matter content, alcohol insoluble solids content, protein content, and total carotenoid content. This study revealed that sweet potato could be adapted to both the Mediterranean and southeastern Anatolia regions of Turkey, and that high yield values could be achieved in these areas. © TÜBİTAK
Growth and development of Virginia type groundnut cultivars under Mediterranean conditions
The growth and development of groundnut (Arachis hypogaea L.) are under the influence of complex environmental factors. Understanding of the growth responses of the groundnut to environmental factors may improve the application of better management practices and develop better cultivars to overcome the problems causing reductions in yield. A two-year field experiment was conducted to determine the growth and development response of groundnut genotypes to environmental factors in the eastern Mediterranean region of Turkey in 2001 and 2002. Time from sowing to physiological maturity (R8) ranged from 2513°Cd to 2588°Cd in 2001 and from 2514°Cd to 2573°Cd in 2002 while total calendar days varied between 147 and 153 and between 156 and 161 depending on genotypes in 2001 and 2002, respectively. Dry matter accumulation in each part of the plants continued until maturity although accumulation rate differed depending on plant age. Combination of suitable temperature and photoperiod during the reproductive stages resulted in continuous and abundant reproductive plant parts, which led to delayed harvest and increased unmarketable pods. The slower growth rate due to the cooler conditions during early stages caused slower biomass accumulation in successive stages indicating the importance of initial crop growth for final yield. Therefore, the genotypes having high initial growth rate, less reproductive organs, and shorter growing period should be developed for the Mediterranean conditions by breeders. The management studies should also deal with increased initial growth rate and reduced number of flowers, pegs or pods per plant. Based on our results, groundnut has a great yield potential under the Mediterranean conditions. However, further breeding and management studies are needed to improve the yield and profitability and reduce the complications arisen from the Mediterranean climate. © 2008 Taylor & Francis
SOYBEAN MANAGING FOR MAXIMIZE PRODUCTION: PLANT POPULATION DENSITY EFFECTS ON SEED YIELD AND SOME AGRONOMICAL TRAITS IN MAIN CROPPED SOYBEAN PRODUCTION
WOS: 000397418900005Plant density is an essential agronomic practice and affects the productivity of crops. Hence, the optimum plant density to achieve the maximum productivity may vary from crop to crop, genotype to genotype and location to location. Therefore, the current research has been carried out for two consecutive seasons of 2013 and 2014 at the research station of Cukurova University and, the aim of the study was to determine the effect of plant density on seed yield and some agronomical traits in main cropped soybean production. Results of study revealed that seed yield of soybean depends on plant density and highest seed yield (5820.8 kg ha(-1)) was obtained from the 70 cm x 4 cm spacing, while the lowest mean values (3804.5 kg ha(-1)) was obtained from 70 cm x 10 cm spacing. Based on these results, it can be concluded that the maximum seed yield of soybean could be possible with the optimum planting pattern 70 cm x 4 cm or 70 cm x 5 cm for medium early (maturity group 3) varieties in main cropped soybean farming in Adana, Turkey
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