Factors affecting the distribution and prevalence of oral mucosal lesions in complete denture wearers

Gerodontology 2010; doi: 10.1111/j.1741‐2358.2009.00351.x
Factors affecting the distribution and prevalence of oral mucosal lesions in complete denture wearers Objective: To determine the frequency of the oral lesions related to gender, age, the length of time of denture usage, education level and economic status. Methods: The 153 patients with old complete dentures (CD) were asked to participate in the investigation. The subjects (76 male and 77 female) were 37–85 years of age with a mean age of 61.8 ± 9.8 years. Education, economic status and age factors were estimated in subgroups. The data obtained were evaluated by one‐way anova , Mann–Whitney U‐test, Kruskal–Wallis test, Student’s t‐test and chi‐squared test. The level of statistical significance was set at p < 0.05. Results: The patients who had denture stomatitis and traumatic ulcers were statistically significantly older than the ones who did not have these lesions (p < 0.05). Based on the length of denture usage, patients who had a flabby ridge, fibrous inflammatory hyperplasia, traumatic ulcers (p < 0.01) and denture stomatitis (p < 0.05) were using their dentures statistically significantly longer than the ones who had healthy tissues. Conclusions: The CD wearers should be advised to visit their dentist regularly to prevent oral mucosal lesions due to the changing supporting tissues during the length of denture usage and to improve their quality of life.     

The effects of β-glucan on iron levels and lipid peroxidation in intra-abdominal sepsis in rats

Sepsis is defined as a systemic response of organisms to microorganisms and toxins. Sepsis is associated with the enhanced generation of reactive oxygen metabolites, leading to multiple organ dysfunctions. β-glucan is accepted to be one of the most powerful immune response modifiers. The aim of this study was to investigate the putative protective effect of β-glucan on changes of iron and malondialdehyde (MDA) levels in various tissue and blood after experimental sepsis in rats. Sepsis was induced by cecal ligation and perforation (CLP) in 32 male Wistar albino rat. To evaluate this, rats were divided into four groups as sham operated, β-glucan treated sham operated, CLP and β-glucan treated CLP. Sixteen hours after operation, rats were decapitated and MDA and iron levels were measured in the liver, kidney, heart, diaphragm tissues and blood. Also, whole tissue histopathology was evaluated by a light microscope. The results demonstrate that sepsis significantly decreased iron levels of all tissues and blood. The decrease in tissue iron levels and the increase MDA levels demonstrate the role of trace elements and free radicals in sepsis-induced tissue damage. Our results indicate that the given dose of β-glucan was probably insufficient to prevent sepsis-induced organ injury.     

Advanced cell therapies with and without scaffolds

Tissue engineering and regenerative medicine aim to produce tissue substitutes to restore lost functions of tissues and organs. This includes cell therapies, induction of tissue/organ regeneration by biologically active molecules, or transplantation of in vitro grown tissues. This review article discusses advanced cell therapies that make use of scaffolds and scaffold-free approaches. The first part of this article covers the basic characteristics of scaffolds, including characteristics of scaffold material, fabrication and surface functionalization, and their applications in the construction of hard (bone and cartilage) and soft (nerve, skin, blood vessel, heart muscle) tissue substitutes. In addition, cell sources as well as bioreactive agents, such as growth factors, that guide cell functions are presented. The second part in turn, examines scaffold-free applications, with a focus on the recently discovered cell sheet engineering. This article serves as a good reference for all applications of advanced cell therapies and as well as advantages and limitations of scaffold-based and scaffold-free strategies.     

MDR1 single nucleotide polymorphism C3435T in Turkish patients with non-small-cell lung cancer

We assessed whether single nucleotide polymorphisms (SNPs) in MDR1 gene C3435T predicted the outcome of platinum-based chemotherapies and survival in our non small cell lung cancer (NSCLC) patients. A total of 79 non-small cell lung cancer patients were enrolled to study. We determined the MDR1 C3435T single nucleotide gene polymorphisms. Median age was 60years: 91.7% male, 8.9% female. We found that CC, CT, TT genotype and T, C allele frequencies in lung cancer patients as 24.1%, 62%, 13.9% and 44.3%, 55.7%, respectively. Patients with CT genotype had a higher response rate (11.4%) than the other genotypes. However, this difference is not statistically significant (p=0.743). Cox regression analysis for overall survival showed that ECOG PS status 0 (HR PS 1 vs. 0, 5.68 p=0.002; HR of PS 2 vs. 0 is 21.579, p=0.001; HR of PS 3 vs. 0 is 35.35, p=0.001), stage ≤II (HR of stage III vs. I+II is 17.77; p=0.016, HR of stage IV vs. I+II is 26.97, p=0.006), and albumin level ≥3g/dl (HR of albumin <3g/dl vs. ≥3g/dl is 2.46, p=0.044) were the most important prognostic factors (also, time to progression was related to these factors). There was no significant association between the genotypes and clinicopathologic parameters; however, good performance status, early stage and ≥3g/dl albumin level were found to be the most important prognostic factors for overall survival and progression-free survival.     

Influence of cytokines on HIV-specific antibody-dependent cellular cytotoxicity activation profile of natural killer cells

There is growing interest in HIV-specific antibody-dependent cellular cytotoxicity (ADCC) as an effective immune response to prevent or control HIV infection. ADCC relies on innate immune effector cells, particularly NK cells, to mediate control of virus-infected cells. The activation of NK cells (i.e., expression of cytokines and/or degranulation) by ADCC antibodies in serum is likely subject to the influence of other factors that are also present. We observed that the HIV-specific ADCC antibodies, within serum samples from a panel of HIV-infected individuals induced divergent activation profiles of NK cells from the same donor. Some serum samples primarily induced NK cell cytokine expression (i.e., IFNγ), some primarily initiated NK cell expression of a degranulation marker (CD107a) and others initiated a similar magnitude of responses across both effector functions. We therefore evaluated a number of HIV-relevant soluble factors for their influence on the activation of NK cells by HIV-specific ADCC antibodies. Key findings were that the cytokines IL-15 and IL-10 consistently enhanced the ability of NK cells to respond to HIV-specific ADCC antibodies. Furthermore, IL-15 was demonstrated to potently activate "educated" KIR3DL1(+) NK cells from individuals carrying its HLA-Bw4 ligand. The cytokine was also demonstrated to activate "uneducated" KIR3DL1(+) NK cells from HLA-Bw6 homozygotes, but to a lesser extent. Our results show that cytokines influence the ability of NK cells to respond to ADCC antibodies in vitro. Manipulating the immunological environment to enhance the potency of NK cell-mediated HIV-specific ADCC effector functions could be a promising immunotherapy or vaccine strategy.     

Docosahexaenoic acid provides protective mechanism in bilaterally MPTP-lesioned rat model of Parkinson's disease

Docosahexaenoic acid (DHA), a major polyunsaturated fatty acid (PUFA) in the phospholipid fraction of the brain, is essential for normal cellular function. Neurodegenerative disorders such as Parkinson's disease (PD) often exhibit significant declines in PUFAs. The aim of this study was to observe the effects of DHA supplementation in an experimental rat model of PD created with '1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine' (MPTP). Adult male Wistar rats were divided into four groups: (1) Control; (2) DHA-treated; (3) MPTP-induced; and (4) MPTP-induced + DHA-treated. Motor activity was investigated using the 'vertical pole' and 'vertical wire' tests. The dopaminergic lesion was determined by immunohistochemical analysis for tyrosine hydroxylase (TH)-immunopositive cells in substantia nigra (SN). Immunoreactivities of Bcl-2, Akt and phosphorylated-Akt (p-Akt) in SN were evaluated by immunohistochemistry. MPTP-induced animals exhibited decreased locomotor activity, motor coordination and loss of equilibrium. Diminished Parkinsonism symptoms and decreased dopaminergic neuron death were detected in the MPTP-induced + DHA-treated group compared to the MPTP-induced group. Moderate decreases in Akt staining were found in the MPTP-induced and MPTP-induced + DHA-treated groups compared to controls. p-Akt immunoreactivity decreased dramatically in the MPTP-induced group compared to the control; however, it was increased in the MPTP-induced + DHA-treated group compared to the MPTP-induced group. The staining intensity for Bcl-2 decreased prominently in the MPTP-induced group compared to the control, while it was stronger in the MPTP-induced + DHA-treated group compared to the MPTP-induced group. In conclusion, DHA significantly protects dopaminergic neurons against cell death in an experimental PD model. Akt/p-Akt and Bcl-2 pathways are related to this protective effect of DHA in experimental PD.     

The effect of hemolysis on plasma oxidation and nitration in patients with sickle cell disease

This study aimed to determine the effect of haemolysis on plasma oxidation and nitration in sickle cell disease (SCD) patients. Blood was collected from haemoglobin (Hb)A volunteers and homozygous HbSS patients who had not received blood transfusions in the last 3 months. Haemolysis was characterised by low levels of haemoglobin and haptoglobin and high levels of reticulocyte, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), plasma cell-free haemoglobin, bilirubin, total lactate dehydrogenase (LDH) and dominance of LDH-1 isoenzyme. Plasma 8-isoprostane, protein carbonyl and nitrotyrosine levels were measured to evaluate oxidised lipids, oxidised and nitrated proteins, respectively. Plasma nitrite-nitrate levels were also determined to assess nitric oxide (NO) production in both SCD patients and controls. Markers of haemolysis were significantly evident in SCD patients compared to controls. Plasma 8-isoprostane, protein carbonyl and nitrotyrosine levels were markedly elevated in SCD patients compared to controls. Linear regression analysis revealed a significant inverse correlation between haemoglobin and reticulocyte counts and a significant positive correlation of plasma cell-free haemoglobin with protein carbonyl and nitrotyrosine levels. The obtained data shows that increased haemolysis in SCD increases plasma protein oxidation and nitration.     

An <Emphasis Type="Italic">in vitro</Emphasis> model for the development of acquired tamoxifen resistance

The development of resistance to tamoxifen (Tam) remains a challenging clinical problem for ER+ breast cancer patients. To understand the mechanisms underlying of resistance, previous studies have driven the acquisition of Tam resistance by exposing cells to varying concentration of drug for varying lengths of time. However, a detailed protocol for the establishment of Tam-resistant cells remains to be clarified. In the present study, we aimed to determine and compare the effect of different in vitro protocols on the degree of resistance to 4-hydroxytamoxifen (4-OH Tam) for MCF7 cells. For this purpose, MCF7-Tam resistance (MCF7-TamR) cells were developed by treated with different concentrations (100, 200, 400, 600, 800 and 1000 nM) of 4-OH Tam over 3 months. The relative resistance was measured by WST-1 analysis. Studies characterizing of the 4-OH Tam resistance of MCF7-TamR cells were performed by 17 β-oestradiol (E2) and Annexin V/PI analysis. In addition, the expression levels of ABCC1, ABCG2 and ABCG1 were detected by RT-PCR, any changes in morphological of each resistance group were observed at the end of each month and compared with parental MCF7 cells. Consequently, exposure time and concentration can affect the degree of resistance to 4-OH Tam; thus, dose and treatment duration should be chosen according to the desired degree of resistance. This work presents a novel procedure for the generation of MCF7-TamR cells, thus enabling the identification and characterization of MCF7-TamR cells.     

Synthesis and anticandidal evaluation of new benzothiazole derivatives with hydrazone moiety

In this study, we have performed the synthesis of new N′-(arylidene)-4-[(benzothiazol-2-yl)thio]butanoylhydrazide derivatives (3a–s) bearing azole moiety and hydrazone group in a lipophilic structural framework. The target compounds were prepared by a three step synthetic procedure starting from 2-mercaptobenzothiazole. The structures of the target compounds were elucidated by IR, ¹H NMR, ¹³C NMR spectra and elemental analysis. The antifungal activity of the obtained compounds has been determined against a number of clinic and fluconazole-resistant Candida strains by using microdilution method. Compounds (3a–3s) exhibited anticandidal activity in different ratios varying between the range of MIC: 50 and 200?µg/mL.     

Prevalence and Genotyping of Microsporidian Parasites in Dogs in Turkey: Zoonotic Concerns

Microsporidia are opportunistic pathogens that infect a wide range of invertebrates and vertebrates. To assess the potential role of dogs in the transmission of these zoonotic pathogens, a total of 282 fecal samples from dogs in the Central Anatolia Region of Turkey were analyzed by utilizing species specific polymerase chain reaction for the four most frequent human microsporidia. Two microsporidia species were recognized in 41 samples (14.5%). Encephalitozoon intestinalis was detected in 35 samples (12.4%) and it was the most common microsporidium. The second microsporidium, E. cuniculi, was identified in six (2.1%) of the samples. Sequence analysis of the intergenic spacer of the ribosomal ribonucleic acid (RNA) internal transcribed spacer (ITS) gene revealed the presence of three E. intestinalis haplotypes closely associated with each other. No polymorphic region was found among the ITS sequences of E. cuniculi isolates and they were characterized as genotype III. This study provides the first data on the zoonotic microsporidia species from dogs in Turkey.