Lifestyle factors associated with age-related macular degeneration: Case-control study.

BACKGROUND: Age-related macular degeneration (AMD) is one of the major causes of vision loss in individuals aged ≥ 65 years in developed countries. This study aimed to determine the associations between modifiable risk factors and AMD. This is the first study describing the relationship between lifestyle factors and AMD in the Czech Republic. METHODS: In this cross-sectional case-control study, 93 AMD cases and 58 controls without AMD and cataract were included. All participants were examined by Optical coherence tomography at the Clinic of Eye Treatment at the University Hospital Brno. Data were collected using a pre-tested self-report questionnaire in a face-to-face interview. RESULTS: We found significant associations between those who were living in the city (OR 95% CI: 2.19 (1.0-4.6); p = 0,039), with a positive family history of AMD (OR 95% CI: 12.75 (1.6-98.6); p = 0,015), exposure to cigarette smoke (OR 95% CI: 2.72 (1.4-5.4); p = 0,004), and daily exposure to passive smoking (OR 95% CI: 2.29 (1.0-5.1); p = 0,045) and AMD. In men, we found significant associations between daily sunlight exposure (OR 95% CI: 2.98 (1.0-8.5); p = 0,041), short or long sleep duration (OR 95% CI: 3.98 (1.2-13.2); p = 0,024) and AMD. Men daily exposed to sunlight were at a 2.98 times higher risk of AMD than men with less than daily sunlight exposure. Men with short or long sleep duration (< 6 and > 8 h) were at a 3.98 times higher risk of AMD than men with recommended sleep duration of 6-8 h. CONCLUSIONS: An increased risk of AMD was observed for living in the city, family history of AMD, exposure to cigarette smoke, and daily exposure to passive smoking. Increased risk of AMD was observed for daily sunlight exposure and short or long sleep duration; however, only in men.

Dietary habits and dietary nutrient intake in patients with age-related macular degeneration: A case-control study.

OBJECTIVES: Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among older adults in developed countries. Although many risk factors are known, the pathogenesis of AMD is still unclear. However, oxidative stress probably plays a vital role in the process of AMD. The increasing prevalence of AMD, risk of vision loss, limited treatment of dry form, expensive treatment of wet form, and decreased quality of life are factors that lead to considering modifiable risk factors of AMD, such as nutrition. This is the first study describing the relationship between dietary habits, dietary nutrient intake and AMD in the Czech Republic. METHODS: In this research, a total of 93 cases with AMD and 58 controls without AMD and cataracts participated. All participants were ophthalmologically examined at the Clinic of Eye Treatments at the University Hospital Brno. Data were collected using a pre-tested self-report questionnaire in a face-to-face interview. Food consumption frequency was assessed by an 18-item semiquantitative food-frequency questionnaire (FFQ). Dietary nutrient intakes were calculated from a 24-hour recall. RESULTS: Patients with AMD compared with controls had significantly higher consumption of legumes and lower consumption of meat products, salt and salty products. In men, we found statistically significant differences in alcohol consumption. The case group consumed alcoholic beverages more frequently (median: 2 times a week) than the control group (median: 1-3 times a month). No differences in alcohol consumption were found in women. In comparison to the case group, the control group had a significantly higher dietary intake of energy (5,783.8 vs. 4,849.3 kJ/day; p = 0.002), proteins (65.3 vs. 52.3 g/day; p = 0.002), fats (57.6 vs. 49.4 g/day; p = 0.046), saturated fatty acids (21.7 vs. 18.9 g/day; p = 0.026), carbohydrates (150.4 vs. 127.1 g/day; p = 0.017), dietary fibre (13.2 vs. 11.3 g/day; p = 0.044), vitamin B2 (1.0 vs. 0.9 mg/day; p = 0.029), vitamin B3 (13.9 vs. 10.0 mg/day; p = 0.011), pantothenic acid (3.5 vs. 2.8 mg/day; p = 0.001), vitamin B6 (1.3 vs. 1.0 mg/day; p = 0.001), potassium (1,656.5 vs. 1,418.0 mg/day; p = 0.022), phosphorus (845.4 vs. 718.7 mg/day; p = 0.020), magnesium (176.5 vs. 143.0 mg/day; p = 0.012), copper (1.0 vs. 0.8 mg/day; p = 0.011), and zinc (7.1 vs. 6.1 mg/day; p = 0.012) counted from a 24-hour recall. CONCLUSIONS: According to FFQ, dietary habits in the patients with AMD and controls were similar. In men from the case group, we found statistically significant higher alcohol consumption. According to a 24-hour recall, the controls achieved recommended dietary intakes rather than cases. In comparison to the case group, the control group had a significantly higher dietary intake of energy, proteins, fats, saturated fatty acids, carbohydrates, dietary fibre, vitamin B2, vitamin B3, pantothenic acid, vitamin B6, potassium, phosphorus, magnesium, copper, and zinc.

Optimization of diagnostic strategy for non-invasive cell-free foetal RHD determination from maternal plasma.

BACKGROUND AND OBJECTIVES: The aim of the study was to optimize routine non-invasive prenatal detection of fetal RHD gene from plasma of RhD-negative pregnant women (the median of gestational age was 25 weeks, range 10-38) to detect RhD materno-fetal incompatibility and to avoid the redundant immunoprophylaxis. MATERIALS AND METHODS: Initially only one exon of RHD gene (exon 10) was investigated in 281 plasma samples (144 verified after delivery), in the second phase three RHD exons (5, 7, 10) were analyzed in 246 samples of plasma and maternal genomic DNA (204 verified) by real-time PCR method. Detection of Y-chromosomal sequence DYS-14 and five X-chromosomal insertion/deletion polymorphisms was used to confirm the fetal cfDNA detectability in plasma. Specific polymorphisms in RHD gene were detected by sequence-specific primer PCR in nine samples. RESULTS: When only the RHD exon 10 was tested, 2·8% of verified samples were false positive and 3·5% false negative. With three RHD exons (5, 7, 10) and maternal genomic DNA testing, only one case was false negative (0·5%). Nine samples were inconclusive due to RHD-positive results in maternal genomic DNA. These samples were analyzed for specific mutations in RHD gene. Combination of both methods for fetal cfDNA verification succeeded in 75% of tested group. CONCLUSION: Implementation of analysis of three RHD exons and maternal genomic DNA to routine practice lowers dramatically the ratio of false positive and negative results. This method enables more accurate determination of fetal RHD status with the reduction of unnecessary medical care and RhD immunoprophylaxis.

If host is refractory, insistent parasite goes berserk: Trypanosomatid Blastocrithidia raabei in the dock bug Coreus marginatus.

Here we characterized the development of the trypanosomatid Blastocrithidia raabei in the dock bug Coreus marginatus using light and electron microscopy. This parasite has been previously reported to occur in the host hemolymph, which is rather typical for dixenous trypanosomatids transmitted to a plant or vertebrate with insect's saliva. In addition, C. marginatus has an unusual organization of the intestine, which makes it refractory to microbial infections: two impassable segments isolate the anterior midgut portion responsible for digestion and absorption from the posterior one containing symbiotic bacteria. Our results refuted the possibility of hemolymph infection, but revealed that the refractory nature of the host provokes very aggressive behavior of the parasite and makes its life cycle more complex, reminiscent of that in some dixenous trypanosomatids. In the pre-barrier midgut portion, the epimastigotes of B. raabei attach to the epithelium and multiply similarly to regular insect trypanosomatids. However, when facing the impassable constricted region, the parasites rampage and either fiercely break through the isolating segments or attack the intestinal epithelium in front of the barrier. The cells of the latter group pass to the basal lamina and accumulate there, causing degradation of the epitheliocytes and thus helping the epimastigotes of the former group to advance posteriorly. In the symbiont-containing post-barrier midgut segment, the parasites either attach to bacterial cells and produce cyst-like amastigotes (CLAs) or infect enterocytes. In the rectum, all epimastigotes attach either to the cuticular lining or to each other and form CLAs. We argue that in addition to the specialized life cycle B. raabei possesses functional cell enhancements important either for the successful passage through the intestinal barriers (enlarged rostrum and well-developed Golgi complex) or as food reserves (vacuoles in the posterior end).

Insect trypanosomatids in Papua New Guinea: high endemism and diversity.

The extreme biological diversity of Oceanian archipelagos has long stimulated research in ecology and evolution. However, parasitic protists in this geographic area remained neglected and no molecular analyses have been carried out to understand the evolutionary patterns and relationships with their hosts. Papua New Guinea (PNG) is a biodiversity hotspot containing over 5% of the world's biodiversity in less than 0.5% of the total land area. In the current work, we examined insect heteropteran hosts collected in PNG for the presence of trypanosomatid parasites. The diversity of insect flagellates was analysed, to our knowledge for the first time, east of Wallace's Line, one of the most distinct biogeographic boundaries of the world. Out of 907 investigated specimens from 138 species and 23 families of the true bugs collected in eight localities, 135 (15%) were infected by at least one trypanosomatid species. High species diversity of captured hosts correlated with high diversity of detected trypanosomatids. Of 46 trypanosomatid Typing Units documented in PNG, only eight were known from other geographic locations, while 38 TUs (~83%) have not been previously encountered. The widespread trypanosomatid TUs were found in both widely distributed and endemic/sub-endemic insects. Approximately one-third of the endemic trypanosomatid TUs were found in widely distributed hosts, while the remaining species were confined to endemic and sub-endemic insects. The TUs from PNG form clades with conspicuous host-parasite coevolutionary patterns, as well as those with a remarkable lack of this trait. In addition, our analysis revealed new members of the subfamilies Leishmaniinae and Strigomonadinae, potentially representing new genera of trypanosomatids.

FY*A silencing by the GATA-motif variant FY*A(-69C) in a Caucasian family.

BACKGROUND: The c.1-67C variant polymorphism in a GATA motif of the FY promoter is known to result in erythroid-specific FY silencing, that is, in Fy(a-) and Fy(b-) phenotypes. A Caucasian donor presented with the very rare Fy(a-b-) phenotype and was further investigated. STUDY DESIGN AND METHODS: Genomic DNA was analyzed by sequencing to identify the cause of the Fy(a-b-) phenotype. Samples were collected from some of his relatives to establish a correlation between the serology and genotyping results. Red blood cells were analyzed by gel column agglutination and flow cytometry. Genomic DNA was analyzed on genotyping microarrays, by DNA sequencing and by allele-specific PCR. RESULTS: In the donor, a single-nucleotide polymorphism T>C within the GATA motif was found at Position c.1-69 of the FY promoter and shown to occur in the FY*A allele. His genotype was found to be FY*A(-69C), FY*BW.01. In six FY*A/FY*B heterozygous members of the family, a perfect correlation was found between the presence vs. absence of the FY*A(-69C) variant allele and a Fy(a-) vs. Fy(a+) phenotype. CONCLUSION: The location of the c.1-69C polymorphism in a GATA motif whose disruption is known to result in a Fy null phenotype, together with the perfect correlation between the presence of the FY*A(-69C) allele and the Fy(a-) phenotype support a cause-effect relationship between the two.

Continuous electrochemical monitoring of nitric oxide production in murine macrophage cell line RAW 264.7.

In this study, we realized the continual and long-term electrochemical detection of NO production by stimulated macrophages using modified porphyrinic microsensor. The NO release from RAW 264.7 cells stimulated by lipopolysaccharide started 5 h after the lipopolysaccharide administration. After reaching its maximum at the sixth hour, the stable level of NO production was observed between the seventh and 12th hour of the experiment. This phase was followed by a gradual decline in NO production. A close correlation between the NO signal detected with microelectrode and nitrite accumulation, which had been determined in supernatants removed from stimulated cells, was observed. This finding was utilized for the calibration of the electrochemical experiment. The presence of iNOS enzyme, which constitutes a main requirement for NO production by stimulated macrophages, was confirmed by Western blot analysis of iNOS protein expression at key time points of the corresponding electrochemical experiment. The capability of our microsensor to instantaneously monitor the changes in the NO production by stimulated RAW 264.7 cells was demonstrated by the immediate decrease in the signal due to NO as a response to the addition of iNOS inhibitor into the cell culture medium.

The effects of H1-antihistamines on the nitric oxide production by RAW 264.7 cells with respect to their lipophilicity.

H1-antihistamines are known to be important modulators of inflammatory response. However, the information about the influence of these drugs on reactive nitrogen species generation is still controversial. The main aim of the present study was to investigate the effects of selected H1-antihistamines on nitric oxide production by lipopolysaccharide-stimulated murine macrophages RAW 264.7, measured as changes in inducible nitric oxide synthase (iNOS) protein expression in cell lysates by Western blotting and nitrite formation in cell supernatants using the Griess reaction. In pharmacological non-toxic concentrations, H1-antihistamines significantly inhibited nitrite accumulation that was not caused by the scavenging ability of drugs against nitric oxide, measured amperometrically. The degree of inhibition of nitrite accumulation positively correlated with the degree of tested lipophilicity, measured by reversed-phase thin layer chromatography. Furthermore, H1-antihistamines differentially modulated the iNOS protein expression. In conclusion, as was shown in this study, the modulation of nitric oxide production could be caused by the downregulation of iNOS protein expression and/or the iNOS protein activity.

The effects of dithiaden on nitric oxide production by RAW 264.7 cells.

As reported in our previous studies, dithiaden (an antagonist of histamine H(1)-receptor, used clinically as an anti-allergic or anti-emetic drug) in a concentration range of 5×10(-5)-10(-4) M decreased the production of reactive oxygen species by phagocytes. In this study we investigated the influence of dithiaden on nitric oxide (NO) production by LPS-stimulated macrophages.The cell viability in the presence of 10(-4)-5×10(-5) M dithiaden was evaluated by an ATP-test. RAW 264.7 cells (2.5×10(6)/well) were preincubated with dithiaden for 60 mins and subsequently stimulated with 0.1 µg/ml of bacterial lipopolysaccharide. After incubating for 24 hours the NO production was determined spectrophotometrically using Griess reaction as a concentration of nitrites (the end product of NO metabolism) accumulated in the cell supernatants. The expression of inducible nitric oxide synthase (iNOS) in cell-lysates was evaluated using Western blot analysis. Scavenging properties of dithiaden against NO were evaluated amperometrically.Our data demonstrate that dithiaden in the concentration of 5×10(-5) M (approved by ATP test as non toxic) caused a significant decrease in the accumulation of nitrites, and in addition, this decline was followed by a marked reduction of iNOS protein expression. Amperometrical analysis did not show any scavenging properties of dithiaden against NO.From this data it can be suggested that the inhibition effect of dithiaden on macrophage NO production is caused exclusively by the suppression of iNOS protein expression.

Nitric oxide sensor based on carbon fiber covered with nickel porphyrin layer deposited using optimized electropolymerization procedure.

Electropolymerization regime of meso-tetrakis(3-methoxy-4-hydroxyphenyl) porphyrin is optimized to yield films possessing both electrocatalytical and permselective properties towards nitric oxide oxidation. The sensor composed of electrochemically oxidized carbon fiber, covered solely with nickel porphyrin derivative layer electropolymerized using our method, is characterized by high selectivity towards nitrite (1:600), ascorbate (1:8000) and dopamine (>1:80), determined by constant potential amperometry at 830 mV (vs. Ag/AgCl). Selectivity for ascorbate and dopamine as well as detection limit for NO (1.5 nM at S/N=3) is 5-10 times better than parameters usually reported for Nafion coated porphyrinic sensors. Nafion coating can further enhance selectivity properties as well as aids to the stability of the sensors' responses.