Tip 2 diyabetik hastaların birinci derece yakınlarında total homosistein ve asimetrik dimetilargininin plazma düzeyleri

Amaç: Tip 2 diyabetik hastaların birinci derece yakınlarında, ailesinde diyabet öyküsü olmayan sağlıklı olgulara göre kardiyovasküler hastalıklar daha sık görülmektedir. Asimetrik dimetilarginin (ADMA) ve homosistein (Hcy) plazma düzeyleri kardiyovasküler hastalıklar ve endotel disfonksiyonuyla ilişkili göstergelerdir. Bu çalışmada, tip 2 diyabetik hastaların birinci derece yakınlarında ADMA ve Hcy plazma düzeyleri ile bu göstergelerle kardiyovasküler risk faktörleri arasındaki ilişkilerin incelenmesi amaçlandı. Hastalar ve Yöntemler: Dolaşımdaki ADMA ve Hcy düzeyleri 15 tip 2 diyabet hastasının birinci derece yakınında ve ailesinde diyabet öyküsü olmayan 15 kontrol olgusunda ölçüldü. Bulgular: Her iki grup arasında ADMA ve Hcy plazma düzeyleri açısından anlamlı farklılık saptanmadı (p>0.05). Asimetrik dimetilarginin plazma düzeyi tip 2 diyabetik olguların birinci derece yakınlarında, bel çevresi (p=0.02), açlık insülin düzeyi (p=0.03), insülin direnci (p=0.01), total kolesterol (p=0.04) ve HDL kolesterol (p=0.03) ile ilişkiliydi. Sonuç: Bu sonuçlara göre, kardiyovasküler risk faktörlerine sahip olan tip 2 diyabetik olguların birinci derece yakınlarında, ADMA plazma düzeylerinin doğrudan endotel disfonksiyonunun gelişimine katkıda bulunmadığını düşünmekteyiz.Objectives: Cardiovascular diseases are more common among first degree relatives of type 2 diabetic patients than healthy subjects without a family history of diabetes. Plasma asymmetric dimethylarginine (ADMA) and homocysteine (Hcy) levels are markers of endothelial dysfunction and cardiovascular disease. The objective of this study was to evaluate levels of ADMA, Hcy and their association with cardiovascular risk factors in first degree relatives of type 2 diabetic patients. Patients and Methods: The circulating ADMA and Hcy levels were measured in 15 first degree relatives of type 2 diabetic patients and 15 control subjects without a known family history of diabetes. Results: No statistically significant differences were found in plasma levels of ADMA and Hcy between the two groups (p>0.05). Plasma ADMA levels correlated significantly with waist circumference (p=0.02), fasting insulin levels (p=0.03), insulin resistance (p=0.01), total cholesterol (p=0.04) and HDL-cholesterol (p=0.03) levels in the first degree relatives of type 2 diabetic patients. Conclusion: These results suggest that plasma ADMA levels do not directly contribute to the development of endothelial dysfunction in first degree relatives of type 2 diabetic patients with cardiovascular risk factors

Obez hastalarda proinflamatuvar sitokinler ile fibrinolitik sistem arasındaki ilişki

Amaç: Obez kişilerde proinflamatuar sitokinlerden TNF-? ve IL-6, fibrinolitik sistem parametrelerinden t-PA ve PAI-1 ve insülin direnci arasındaki ilişki araştırıldı. Hastalar ve Yöntemler: Çalışmaya obez (VKİ ?30 kg/m2) olarak değerlendirilen 54 kişi (41 kadın, 13 erkek; ort. yaş 33.5) ve obezite sorunu olmayan (VKİ <25 kg/m2) 30 kişi (19 kadın, 11 erkek; ort. yaş 22.3) alındı. Fibrinojen düzeyleri koagülometrik olarak ve TNF-?, IL-6, t-PA, PAI-1 düzeyleri ELISA yöntemiyle ölçüldü. Bulgular: Kontrol grubuyla karşılaştırıldığında, obez kişilerde fibrinojen (p<0.01), PAI-1 (p<0.001), TNF-? (p<0.01) ve IL-6 düzeyleri (p<0.001) anlamlı derecede yüksek, t-PA düzeyi (p<0.001) ve t-PA/PAI-1 oranı (p<0.001) anlamlı derecede düşük bulundu. Obezlerde TNF-? ile t-PA (p=0.007) ve t-PA/PAI-1 oranı (p=0.016) arasında ters ilişki saptandı. İnsülin direnci olan ve olmayan obez kişilerde parametreler arasında fark yoktu. Sonuç: Obezitede adipoz dokudan salgılanan özellikle TNF-? gibi inflamatuar sitokinlerin artması fibrinolizde azalmaya yol açar. Obez kişilerde görülen bu değişiklikler, insülin direncinden bağımsız olarak ateroskleroza neden olabilir.Objectives: The aim of this study was to investigate the relationship between proinflammatory cytokines (TNF-&amp;#945; and IL-6), and fibrinolytic system parameters (t-PA, and PAI-1) and insulin resistance in obese individuals. Patients and Methods: The study included 54 obese subjects (BMI &amp;#8805;30 kg/m2; 41 females, 13 males; mean age 33.5 years) and 30 non-obese healthy individuals (BMI &lt;25 kg/m2; 19 females, 11 males; mean age 22.3 years). Fibrinogen levels were measured by the coagulometric method and the measurements of TNF-&amp;#945;, IL-6, t-PA and PAI-1 were carried out by the ELISA method. Results: Compared with non-obese subjects, obese individuals had significantly higher fibrinogen (p&lt;0.01), PAI-1 (p&lt;0.001), TNF-&amp;#945; (p&lt;0.01), and IL-6 (p&lt;0.001) levels, and significantly lower t-PA level (p&lt;0.001) and t-PA/PAI-1 ratio (p&lt;0.001). We also found an inverse relationship between TNF-&amp;#945; and t-PA levels (p=0.007) and t-PA/PAI-1 ratio (p=0.016) in obese individuals. The presence or absence of insulin resistance did not affect proinflammatory cytokines and fibrinolytic system parameters in obese individuals. Conclusion: Our findings indicate increased inflammatory cytokine levels especially in TNF-&amp;#945; level, and decreased fibrinolysis in obese individuals. These changes may contribute to atherosclerotic process independent from insulin resistance in obesity

Dobrava Hantavirus Infection Complicated by Panhypopituitarism, Istanbul, Turkey, 2010

We identified Dobrava-Belgrade virus infection in Turkey (from a strain related to hantavirus strains from nearby countries) in a patient who had severe symptoms leading to panhypopituitarism, but no known risk for hantavirus. Our findings emphasize the need for increased awareness of hantaviruses in the region and assessment of symptomatic persons without known risk factors for infection

Investigation on replication of microfluidic channels by hot embossing

In this study, effects of embossing temperature, time, and force on production of a microfluidic device were investigated. Polymethyl methacrylate (PMMA) substrates were hot embossed by using a micromilled aluminum mold. The process parameters were altered to observe the variation of replication rate in width and depth as well as symmetry of the replicated microfluidic channels. Analysis of variance (ANOVA) on the experimental results indicated that embossing temperature was the most important process parameter, whereas embossing time and force have less impact. One distinguishing aspect of this study is that, the channels were observed to be skewed to either side of the channel depending on the location of the protrusions on the mold. The mechanism of the skewness was investigated by finite element analysis and discussed in detail. Results showed that the skewness depends on the flow characteristics of the material and could be reduced by increasing the embossing temperature. The best replication rates were obtained at parameter settings of 115 degrees C, 10kN, and 8min for the molds with minimum 56 mu m wide features of 120 mu m depth. We also showed that the fabricated channels could be successfully sealed by solvent-assisted thermo-compressive bonding at 85 degrees C under 5.5kN force

A normally closed electrostatic parylene microvalve for micro total analysis systems

This paper presents an electrostatically actuated, normally closed microvalve for parylene microfluidics. The proposed valve structure isolates the fluid from the electric field, and hence results in relatively low actuation potentials (<60 V) irrespective of the working fluid. Hereby, the microvalve solves electrolysis or electrode shielding problems observed in electrostatic actuation in micro total analysis systems. To investigate leakage properties, microvalves were tested under pressurized flow with de-ionized (DI) water. No detectable leakage ratio was observed up to 20 kPa inlet pressure, due to the unique semicircular valve seat design. It was shown that the valve seat could be reconfigured to enable sealing at various pressure levels for different applications

Investigation of process-affected zone in ultrasonic embossing of microchannels on thermoplastic substrates

In this paper, the process-affected zone in ultrasonically embossed thermoplastic substrates is investigated both numerically and experimentally. Commercialization of microfluidic devices challenges the need for high-speed manufacturing of plastic chips. Ultrasonic embossing is considered as an alternative method since the cycle time can be as low as a few seconds per chip while keeping the cost relatively low. To examine the ultrasonic embossing process, experiments were carried out to replicate 200 mu m wide and 150 mu m high straight channels on 3 mm thick polymethylmethacrylate (PMMA) substrates. The mold was fabricated by milling on aluminum. The features could be embossed by applying an 85 N static force at 28 kHz ultrasonic vibration and 10 mu m amplitude for 5 s at room temperature with replication rates of 99.5 % and 100 % for the width and the depth, respectively. During the experiments, a clearly visible process-affected zone typically bounded by a half-circle with the center at the channel axis was observed. It was proven that the process-affected zone was bounded by the isothermal surface at the glass transition temperature of the substrate material (107 degrees C), both numerically and experimentally. It was also shown that the composition of the substrate material remains unaffected within the process-affected zone

GENERATION AND CHARACTERIZATION OF HYDROGEL MICRODROPLETS AS BIOINK FOR BIOPRINTING APPLICATIONS

In this study, we present a technique for generation of hydrogel microdroplets as bioink for droplet deposition of tissues and organs. We also characterized the size and dispersion of the microdroplets. For this purpose, we designed a flow-focusing droplet generator chip in which uncured hydrogel flowing through a 120 µm wide channel was pinched at two sides of the stream of oil flowing along 300 µm wide channels. The chip was fabricated by ultrasonically embossing the features on polymethylmethacrylate (PMMA) plate. We used polyethylene (glycol) diacrylate (PEGDA) as the hydrogel and silicone oil as the pinching fluid. PEGDA was preferred since it provides an inherently inert matrix for cell growth. Before dispensing the liquids into the chip, PEGDA was mixed with photoinitiator (Irgacure 2959) to make PEGDA curable under UV exposure. The results showed that PEGDA droplets of 7419 µm diameter could be generated with average dispersion of 42762 µm between two successive droplets at a rate of about 600 Hz. After generating, droplets were cured in the chip by exposing under UV light for 1 minute. We have shown that single cells could be encapsulated in hydrogel microdroplets