Cenk Aral

Alternative approach to the preparation of chitosan beads

Abstract A controlled-release protein delivery system was investigated by using bovine serum albumin (BSA) as a model drug. Chitosan was reacted with sodium alginate in the presence of tripolyphosphate for bead formation. Spherical beads were produced with diameter in the range 0.78–0.92 mm and 13–90% encapsulation efficiency. It appeared that encapsulation of BSA was affected by the initial protein and sodium alginate concentrations and the presence of pectin (1%) in the external phase. Bead sizes changed with alginate concentration and pectin addition. Release properties of the beads were affected by their BSA content. Addition of pectin to the external phase decreased the percentage release of BSA from the beads. It can be concluded that alginate-reinforced chitosan beads might be a potential delivery system for protein encapsulation.

Mitochondrial DNA common deletion is not associated with thyroid, breast and colorectal tumors in Turkish patients

Recently, efforts have been focused on mitochondrial DNA changes and their relation to human cancers. Among them, a 4977 bp deletion of mitochondrial DNA, named “common deletion”, has been investigated in several types of tumors, with inconsistent results. In this study, we investigated the presence of the common deletion in tissues from 25 breast, 25 colorectal and 50 thyroid tumors and in the adjacent healthy tissues from Turkish patients. Samples from healthy volunteers were also evaluated for comparison. Two PCR-based methods were used for the detection of the common deletion. First, two pairs of primers were used to amplify wild-type and deleted mtDNA. Then, a highly sensitive nested-PCR was performed, to determine low amounts of deleted genomes. By the first method, wild-type mtDNAs were observed in all samples, but a deletion was observed in only six thyroid samples, by using the nested-PCR method. In conclusion, the mitochondrial common deletion was very rare in our study group and did not appear to be not related with cancer.

Prophylactic feeding with immune-enhanced diet ameliorates chemoradiation-induced gastrointestinal injury in rats.

Purpose: To investigate the protective effect of immune-enhanced diet (IED) on chemoradiation-induced injury of the gastrointestinal mucosa. Materials and methods: Forty-eight Sprague-Dawley rats were divided into control (C, n = 6), irradiation (IR, n = 14), fluoropyrimidine (5-FU, n = 14)-treated, IR + 5-FU (n = 14)-treated groups. Half of each irradiated and/or 5-FU-treated groups were previously fed with IED containing arginine, omega-3-fatty acids and RNA fragments, while the other half were fed a standard rat diet (SD) for eight days before the induction of IR or injection of 5-FU. In IR groups, whole abdominal irradiation (11 Gy) was performed with 6 MV photons. In the 5-FU groups, fluoropyrimidine (100 mg/kg) was administered intraperitoneally 30 min prior to irradiation. All animals were sacrificed on the 4th day of IR or 5-FU injection. Results: Bacterial colony counts in the ceca and mesenteric lymph nodes of IED-fed rats, which have received either 5-FU and/or irradiation were significantly lower than the corresponding SD-fed groups. Morphometric results revealed that gastric, ileal and colonic injuries were less in IED-treated IR or IR + 5-FU + IED groups, as compared to SD-fed groups. However, IED did not alter DNA fragmentation ratios. Conclusion: Prophylactic feeding of IED has a protective effect on chemoradiation-induced gastrointestinal injury, which appears to involve the eradication of bacterial overgrowth.

Effects of lecithin: Cholesterol acyltransferase genotypes, enzyme levels, and activity on high-density lipoprotein levels

BACKGROUND Lecithin:cholesterol acyltransferase (LCAT) is one of the key enzymes controlling cholesterol homeostasis and plays a primary role in high-density lipoprotein cholesterol (HDL-C) maturation. OBJECTIVE The aim of our study was to evaluate the effects of LCAT gene polymorphisms 511C/T (exon4), 4886C/T (rs5923), and 608C/T (rs5922) on LCAT enzyme level, activity, and HDL-C levels. METHODS The study population was selected from consecutive subjects with low (<35 mg/dL) and high HDL-C levels (>65 mg/dL) seen in our lipid clinic. LCAT polymorphisms were analyzed with a restriction fragment length polymorphism assay. LCAT activity and levels were measured by colorimetric enzymatic and enzyme-linked immunoassay methods, respectively. RESULTS The 4886C/T polymorphism was the most commonly observed variant of LCAT gene. T-allele frequencies in subjects with low (n = 50) and high (n = 50) HDL-C were 0.54 and 0.37, respectively (P = .019). TT genotype was more common among low HDL-C group (30% vs 14%, P = .05). The effects of LCAT enzyme appeared to depend on the HDL-C level. In subjects with low HDL-C, LCAT enzyme levels correlated positively with body mass index (P < .001, r = 0.544), HDL-C (P = .006, r = 0.404), triglycerides (P = .001, r = 0.487), total cholesterol (P < .001, r = 0.541), and low-density lipoprotein-cholesterol (P = .001, r = 0.477) levels. LCAT activity correlated positively with fasting glucose levels (P = .008, r = 0.390). CONCLUSION LCAT genotype, enzyme level, and activity modulate HDL-C metabolism, particularly among subjects with low HDL-C levels.

A novel approach for rapid screening of mitochondrial D310 polymorphism

BackgroundMutations in the mitochondrial DNA (mtDNA) have been reported in a wide variety of human neoplasms. A polynucleotide tract extending from 303 to 315 nucleotide positions (D310) within the non-coding region of mtDNA has been identified as a mutational hotspot of primary tumors. This region consists of two polycytosine stretches interrupted by a thymidine nucleotide. The number of cytosines at the first and second stretches are 7 and 5 respectively, according to the GeneBank sequence. The first stretch exhibits a polymorphic length variation (6-C to 9-C) among individuals and has been investigated in many cancer types. Large-scale studies are needed to clarify the relationship between cytosine number and cancer development/progression. However, time and money consuming methods such as radioactivity-based gel electrophoresis and sequencing, are not appropriate for the determination of this polymorphism for large case-control studies. In this study, we conducted a rapid RFLP analysis using a restriction enzyme, BsaXI, for the single step simple determination of 7-C carriers at the first stretch in D310 region.Methods25 colorectal cancer patients, 25 breast cancer patients and 41 healthy individuals were enrolled into the study. PCR amplification followed by restriction enzyme digestion of D310 region was performed for RFLP analysis. Digestion products were analysed by agarose gel electrophoresis. Sequencing was also applied to samples in order to confirm the RFLP data.ResultsSamples containing 7-C at first stretch of D310 region were successfully determined by the BsaXI RFLP method. Heteroplasmy and homoplasmy for 7-C content was also determined as evidenced by direct sequencing. Forty-one percent of the studied samples were found to be BsaXI positive. Furthermore, BsaXI status of colorectal cancer samples were significantly different from that of healthy individuals.ConclusionIn conclusion, BsaXI RFLP analysis is a simple and rapid approach for the single step determination of D310 polymorphism of mitochondrial DNA. This method allows the evaluation of a significant proportion of samples without the need for sequencing- and/or radioactivity-based techniques.

Glucocorticoid receptor gene polymorhisms and breast cancer: significant association in cancerous tissue samples from Turkish patients

Background and Aims: Glucocorticoid receptor (GR) has been postulated to serve an important role in normal breast and breast carcinoma. On the other hand, studies on its common polymorphisms with breast cancer are very limited. In this study, we aimed to assess the presence and frequency of 4 common polymorphisms of the GR gene in the cancerous tissue samples from breast cancer patients in the Turkish population and compare them with healthy individuals. Methods: DNA samples from 86 Turkish female breast cancer patients and 86 healthy controls analysed for BclI, Tth111I, N363S and ER22/23EK polymorphisms of GR gene by PCR-RFLP. Results: N363S polymorphism was not observed in study samples. Frequency of BclI polymorphism did not differ between cases and controls but it associated with family history of cancer. The polymorphic allele frequency of Tth111I and ER22/23EK was found to be higher in cases compared to healthy samples (p<0.05). Also, a haplotype containing polymorphic variants of these two polymorphisms found to be associated with breast cancer. Conclusion: The data presented here suggest that polymorphisms of GR gene may be an important risk factor for breast cancer predisposition.