Christos Nikolaidis

Denitrifying polyphosphate accumulating organisms population and nitrite reductase gene diversity shift in a DEPHANOX-type activated sludge system fed with municipal wastewater

Enhanced biological phosphorus removal (EBPR) is a widely applied method for nutrients removal, although little is known about the key genes regulating the complex biochemical transformations occurring in activated sludge during phosphorus removal. In the present study, the nitrite reductase gene (nirS) diversity and the denitrifying polyphosphate accumulating organisms (DPAOs) population, grown in a bench scale, two-sludge, continuous flow plant, operating for biological anoxic phosphorus removal (DEPHANOX-type), fed with municipal wastewater, were examined by means of physicochemical analyses and the application of molecular techniques. The DEPHANOX configuration highly influenced biomass phosphorus as well as polyhydroxyalkanoates content and facilitated the enrichment of the DPAOs population. The application of double probe fluorescent in situ hybridization (double probe FISH) technique revealed that DPAOs comprised 20% of the total bacterial population. Based on clone libraries construction and nirS gene sequencing analysis, a pronounced shift in denitrifying bacteria diversity was identified during activated sludge acclimatization. Moreover, nirS gene sequences distinct from those detected in any known bacterial strain or environmental clone were identified. This is the first report studying the microbial properties of activated sludge in a DEPHANOX-type system using molecular techniques.

Alternaria and Cladosporium calendar of Western Thrace: Relationship with allergic rhinitis symptoms.

Alternaria and Cladosporium are the most important outdoor moulds. The aim of this study was to present fungal spore monitoring data, investigate the relationship of fungal counts with climate conditions, and to explore the clinical significance of Alternaria and Cladosporium species monitoring in allergic rhinitis (AR).

PAX1 methylation as an auxiliary biomarker for cervical cancer screening: A meta-analysis

OBJECTIVE Several studies have implicated PAX1 epigenetic regulation in cervical neoplasia. The aim of this meta-analysis was to assess PAX1 gene methylation as a potential biomarker in cervical cancer screening. METHODS A systematical search of all major databases was performed, in order to include all relevant publications in English until December 31(st) 2014. Studies with insufficient data, conducted in experimental models or associated with other comorbidities were excluded from the meta-analysis. Summary receiver operating characteristics (SROC) for Cervical Intraepithelial Neoplasia grade 2 or worse (CIN2(+)) versus normal, and CIN grade 3 or worse (CIN3(+)) versus normal, were estimated using the bivariate model. RESULTS Out of the 20 initially included studies, finally 7 (comprising of 1385 subjects with various stages of CIN and normal cervical pathology) met the inclusion criteria. The sensitivity of CIN2(+) versus normal was estimated to be 0.66 (CI 95%, 0.46-0.81) and the specificity 0.92 (CI 95%, 0.88-0.95). On the other hand, the sensitivity of CIN3(+) versus normal was 0.77 (CI 95%, 0.58-0.89) and the specificity 0.92 (CI 95%, 0.88-0.94). Moreover, the area under the curve (AUC) in the former case was 0.923, and in the latter 0.931. CONCLUSION The results of this meta-analysis support the utility of PAX1 methylation as an auxiliary biomarker in cervical cancer screening. PAX1 could be used effectively to increase the specificity of HPV DNA by detecting women with more advanced cervical abnormalities.

Public health risk assessment associated with heavy metal and arsenic exposure near an abandoned mine (Kirki, Greece)

The ‘Agios Philippos’ lead–zinc mine in the Kirki region (NE Greece) is now closed, but its legacy of heavy metal contamination remains at the site. At present, management of the contaminated land is of major concern. The area is in a reclamation process and requires immediate remediation action, whereas human risks need to be carefully evaluated. In order to assess these risks, samples from around the mine were collected and analyzed and a scenario involving the oral, dermal, and inhaled doses of arsenic and heavy metals was formulated. A Monte Carlo approach was undertaken, in order to model the average daily dose and quantify the corresponding hazard index and cancer risk. A toxicological risk was associated with samples collected in the vicinity of the mine (floatation, mine tailings) and a pronounced carcinogenic risk for arsenic was evident at the broader occupational/environmental setting. These findings urge for immediate rehabilitation actions that will mitigate population exposures and promote long-term environmental safety in the area.

Differences in survival and cause-specific mortality in a culturally diverse Greek population, 1999–2008

BACKGROUND Modern urban populations exhibit considerable internal heterogeneity. Several social groups, such as ethnic minorities or immigrants, constitute individual clusters with different demographic and epidemiological characteristics. METHODS Death records were collected from the Municipality Registry between 1999 and 2008. Kaplan-Meier survival analysis was conducted for (i) natively born Greeks, (ii) former USSR-repatriated Greeks and (iii) Roma. Further evaluation was conducted by log-rank (Mantel-Cox) test. Relative mortality rates were assessed by means of cross-tabulation (Pearsons χ(2)). RESULTS Statistically significant differences in median survival were observed among the three social groups (P < 0.001). The relative mortality from infectious diseases was higher in the Roma population compared with natively born Greeks, odds ratio (OR) = 8.31 [confidence interval (CI) 95% 3.19-21.61]. More than 70% of these deaths were attributed to respiratory tract infections and were associated with children under the age of 5. Excess mortality due to external causes, injuries and substance abuse was observed in repatriated males compared with their natively born counterparts, OR = 2.27 (CI 95% 1.35-3.81). CONCLUSIONS Specific public health interventions are required, to improve the survival of different cultural groups. For example, improvement of immunization status and increase in overall hygiene awareness can ameliorate high infant/childhood mortality in Roma population, while social integration can help reduce acculturation-related mortality among repatriated Greeks.

The clinical significance of the pollen calendar of the Western Thrace/northeast Greece region in allergic rhinitis

There are major differences in the clinical pattern of allergic rhinitis (AR) patients among countries, reflecting local aerobiological conditions. We analyzed the correlation between airborne pollen concentrations of the Western Thrace/northeast (NE) Greece region with symptoms scores in AR patients. The above data is the first provided for the Mediterranean climate of Greece and reflects the clinical significance of pollen calendar in everyday clinical practice.

Pharmacotherapy in smoking cessation: Corticotropin Releasing Factor receptors as emerging intervention targets

Smoking represents perhaps the single most important health risk factor and a global contributor to mortality that can unquestionably be prevented. Smoking is responsible for many diseases, including various types of cancer, chronic obstructive pulmonary disease, coronary heart disease, peripheral vascular disease and peptic ulcer, while it adversely affects fetal formation and development. Since smoking habit duration is a critical factor for mortality, the goal of treatment should be its timely cessation and relapse prevention. Drug intervention therapy is an important ally in smoking cessation. Significant positive steps have been achieved in the last few years in the development of supportive compounds. In the present review, we analyze reports studying the role of Corticotropin Releasing Factor (CRF), the principle neuroendocrine mediator of the stress response and its two receptors (CRF1 and CRF2) in the withdrawal phase as well as in the abstinence from nicotine use. Although still in pre-clinical evaluation, therapeutic implications of these data were investigated in order to highlight potential pharmaceutical interventions.

Allergic sensitization prevalence in a children and adolescent population of northeastern Greece region

OBJECTIVES To evaluate the prevalence of allergic sensitization in a childhood and adolescent population, to explore age- and gender-specific variations and finally to discover co-sensitivities among allergens. METHODS A two-stage cross-sectional survey among school-aged children. The two stages of the study involved enrollment of schools and then skin prick testing (SPT) within schools. A total of 675 school children were included in the study. Of those, 231 were diagnosed with allergic rhinitis (AR), according to the medical history as provided by parental-completed questionnaires and positive SPT results. The antigen panel consisted of common allergens and more specifically house dust mites-HDM (Dermatophagoides farinae and Dermatophagoides pteronyssinus), grass mix, trees (olive, cypress and pine), weeds (Parietaria spp.), cat and dog epithelium and moulds (Alternaria spp., Cladosporium spp.). The SPT sensitivity was graded according to SPT-USA Standards. RESULTS The overall prevalence rate of AR was 34.22%. In total, 93 school children (40.3%) were mono- and 138 (59.7%) were poly-sensitized. Overall, the most prevalent sensitizations in decreasing order were to HDM (59.74%), to grasses (48.9%), to Alternaria (34.6%) and to olive (14.71%). There were no age- and sex-specific differences, except for Alternaria mould that showed a significant prevalence among primary school-aged children and predominance in the female gender, by contrast to grass pollen allergy that was predominant to males. A 32% of SPT-positive individuals were not aware of their allergy, with no statistically significant differences between ages. Co-sensitivities were detected for grass pollens and pine and olive trees, for Alternaria and Cladosporium moulds, for cypress and pine trees, and finally for dog and cat danders. CONCLUSIONS Given data among school-aged children should be a baseline from which to monitor disease trends and is considered important for the optimal management of AR patients.

Seasonal variations of allergenic pollen in a Mediterranean region - Alexandroupolis, north-east Greece.

OBJECTIVES The aim of this study was to describe the aerobiological characteristics of NE Greece, identify the most prevalent taxa, define the duration of the main pollen season and correlate allergen records with meteorological parameters. MATERIALS AND METHOD A 7-day volumetric trap, running continuously throughout the year, was used to collect circulating pollen. Pollen taxa were characterized by standard protocols and counted as grains/m(3) . The main pollen season was deduced from these data and running means (10-day averages) were plotted against time. Correlations with climatic factors (temperature, rain, humidity, wind velocity) were assessed by single linear regression analysis. RESULTS In total, 11 pollen families were identified, including 6 arboreal and 5 non-arboreal taxa. The 5 most prevalent taxa were Oleaceae, Fagaceae, Poaceae, Cupressaceae and Pinaceae. Peak pollen concentrations were detected in April and May, with daily averages exceeding 410 grains/m(3) . Compositeae had the longest pollen season of 135 days and Oleaceae the shortest, extending to only 27 days. Correlations with meteorological parameters showed variable associations among different taxa, with mean temperature (p<0.001), relative humidity (p=0.015), and wind speed (p=0.042) emerging as the most significant determinants as regards total pollen counts. CONCLUSIONS Describing the aerobiological characteristics of NE Greece enabled the identification of allergenic risks that are specific for this region. Records generated in this study can be used to alert sensitized individuals of prevailing seasonal patterns, in order to take necessary precautions against imminent exposures. The monitoring system established here can serve as a reference guide for future epidemiological research focusing on allergic asthma and rhinitis.

Monitoring of Frequency and Antimicrobial Susceptibility of Pathogens on the Hands of Healthcare Workers in a Tertiary Hospital

Abstract Objective: To monitor microbes, focusing on drug resistance, on the hands of the personnel of four departments of a tertiary hospital (ICU, neonatal unit, internal medicine ward and surgical ward) and explore differences between departments, professions and genders. Materials and methods: Hand sampling from 125 healthcare employees was conducted followed by isolation, identification and antibiotic resistance profiling of different microbial species. Results: Staphylococcus spp was the most prevalent microbe (76/125, 60.8%), followed by different Gram-negative pathogens (45.6%). ICU employees had a significant probability to have Gram-negative contamination [OR 3.627 (95% CI 1.220-10.782)], independently of gender or profession. Staphylococcus spp presence was associated with working in the internal medicine ward [OR 6.976 (95% CI 1.767-25.540)] and the surgical ward [OR 5.795 (95% CI 1.586-21.178)]. Staphylococcus spp was more prevalent in males vs. females (81.3% vs. 54.9%, p=0.008) and in medical vs. nursing personnel (76.9% vs. 54.8, p=0.019). In the majority of Gram-negative isolates (56.1%), at least one multi-drug resistant (MDR) or extensively drug resistant (XDR) strain was isolated. A statistically significant higher prevalence of XDR Gram-negative microbes was found on the hands of nursing personnel (22.2% vs. 2.3% for medical doctors, p=0.014). Only 2 methicillin resistant Staphylococcus Aureus (MRSA) out of the 12 Staphylococcus aureus positive samples were identified. Conclusions: Employees in the ICU are more prone to Gram-negative and not to Gram-positive hand contamination. MDR and XDR pathogens are prevalent, and are associated with nursing profession.