Mehmet Ali Öktem

Prevalence of primary Sjogren's syndrome in Turkey: a population-based epidemiological study.

Objectives:  The aim of this study was to determine the prevalence of primary Sjogren’s syndrome (pSS) in a general Turkish population according to the latest proposed American–European Consensus Group (AECG) criteria and European‐1 (EU‐1) criteria.

Serological Survey for Viral Pathogens in Turkish Rodents

Wild rodents (n=330) were trapped around the villages of Altındere and Coşandere (Maçka, Trabzon Province), Ayder, Ortan, and Yolkiyi (Çamlıhemşin, Rize Province), and Bozdağ (Ödemiş, İzmir Province) in northeastern and western Turkey during April 2004. Samples were tested for arenavirus, hantavirus, and cowpox virus (family Poxviridae, genus Orthopoxvirus, CPXV) antibodies by using immunofluorescence assays (IFAs). Antibodies against arenaviruses were found in eight of 330 (2.4%) rodents. Arenavirus-sero-positive animals were found from all study sites. Antibodies to Puumala virus (family Bunyaviridae, genus Hantavirus, PUUV) were detected in four of 65 Microtus voles tested. Of the PUUV-IFA-positive voles, one Microtus guentheri lydius was caught from Izmir, and one Microtus roberti and two Microtus rossiaemeridionalis were captured near Trabzon. All 264 Apodemus spp. mice tested negative for antibodies to Saaremaa virus (family Bunyaviridae, genus Hantavirus, SAAV); the single Dryomys nitedula tested negative for both PUUV and SAAV antibodies. Only one (0.3%) of the rodents, an Apodemus sylvaticus from Trabzon area, tested seropositive to CPXV. This is the first serologic survey for rodent-borne viruses in their natural hosts in Turkey. Although these preliminary results support presence of several virus groups with zoonotic potential, additional studies are needed to identify the specific viruses that are present in these populations.

Pregnenolone protects the PC-12 cell line against amyloid beta peptide toxicity but its sulfate ester does not

Pregnenolone (P), the main precursor of the steroids, and its sulfate ester, pregnenolone sulfate (PS), are the major neurosteroids produced in the neural tissue. Many neuroendocrinological studies stressed the neuroprotective role of neurosteroids although it has been suggested that the inhibition of P and PS synthesis can delay neuronal cell death. The potential roles of P and PS in vital neuronal functions and in amyloid beta peptide (Abeta) toxicity are not clearly identified. This work aims to investigate the effects of P and PS on cell viability and Abeta peptide toxicity in a concentration and exposure time-dependent manner in rat PC-12 cells. The cells were treated with 20muM Abeta peptide 25-35 and variable concentrations of P and PS ranging from 0.5muM to 100muM. To examine the effects of steroid treatment on Abeta peptide toxicity, 0.5muM (low) and 50muM (high) neurosteroids were used. The cell viability and lactate dehydrogenase release of cells were evaluated after 24, 48 and 72h. Morphological changes of cells were also examined. The treatment with higher than 1muM concentrations of P and PS significantly decreased the cell viability comparing to untreated cells. At lower concentrations, P and PS had no toxic actions until 72h. The Abeta treatment resulted in a significant decrease in cell viability comparing to untreated cells. P showed a dose-dependent protective effect against Abeta peptide in PC-12 cells. But its sulfate ester did not have the same effect on Abeta peptide toxicity, even it significantly decreased cell viability in Abeta-treated cells. Consequently, the discrepant effects of P and PS on Abeta peptide toxicity may provide insight on the pathogenesis of Alzheimers disease.

Seroprevalence and social determinants of varicella in Turkey

Background In Turkey, varicella vaccine was introduced into routine childhood immunization in 2013, with a single dose administered to children aged 12 months. However, there is limited information on the morbidity (incidence and seroprevalence), mortality and burden of disease of varicella in the overall Turkish population. Aim To determine varicella seroprevalence and its social determinants in Manisa Province, Turkey in children aged > 2 years before single-dose varicella vaccination was introduced in 2013. Methods The presence of anti varicella-zoster virus IgG antibodies was determined using enzyme-linked immunosorbent assay in serum samples collected from 1250 participants. Results The overall seroprevalence was 92.8% and the seroprevalence was > 90% among all age groups except 2-9 years (55.7%). Seroprevalence was significantly associated with family size, annual per capita equivalent income, number of people per room and education level. After adjusting by age, only education level remained significantly associated with seroprevalence, reflecting the early age effect. Conclusion High seroprevalance depends on natural exposure to the infectious agent itself and is not associated with social determinants. High vaccine coverage should be maintained for effective varicella control and switching to a 2-dose schedule may also be considered to reduce the number and size of outbreaks in the Turkish population.