Incidence of acute glaucoma in Finland from 1973 to 1982

The incidence of acute closed-angle glaucoma was studied in 1796 patients derived from the hospital discharge registry of Finland for the years 1973-1982 (469 males and 1327 females). The average incidence was 3.8 cases/100,000 per year. The incidence showed a steep rise with age. The highest incidence was observed in both sexes in the group 80 years of age and older. The incidence was higher (Chi-square 7.81, df = 1, P less than 0.01) among women (5.3/100,000 per year) than among men (2.0/100,000 per year). The age-adjusted incidence for the whole period of 1973-1982 showed no statistically significant rise. The seasonal variation of incidence was statistically significant (P less than 0.001). In winter (December, January, February) and in autumn (September, October, November) the incidences were higher compared to spring (March, April, May) and summer (June, July, August). This association was greater (P less than 0.001) among females than among males (P less than 0.05). Mean sunshine hours showed a reverse association with the incidence of acute glaucoma. The association was statistically significant when both sexes were pooled together (P less than 0.001). There was no sex interaction with regard to the association of incidence of acute glaucoma and mean sunshine hours.

Genetic and environmental effects on oculometric traits

Twenty twin pairs (9 monozygotic and 11 dizygotic) were examined to test the effect of genetic and environmental factors on the etiology of refractive error, axial length of the eyeball, and total astigmatism. The twins pairs were ascertained from the nationwide Finnish Twin Cohort Study (FTCS). The monozygosity was confirmed for nine pairs by a blood group analysis adopted for paternity testing procedures. The mean ages of the monozygotic twin pairs was 69 years and of the dizygotic twin pairs 63 years. Spherical equivalent of refractive error and axial length of the eyeball showed higher intrapair correlations among monozygotic pairs than among dizygotic pairs. This suggests, at least in part, a genetic etiology of these traits. Total astigmatism measured by retinoscopy did not show a significant difference in intrapair correlations between monozygotic and dizygotic twin pairs.

Lens autofluorescence and light scatter in relation to the lens opacities classification system, LOCS III

PURPOSE

To compare values of the human lens autofluorescence and back light scatter measurements with the improved Lens Opacities Classification System, LOCS III.

METHODS

We measured autofluorescence and back light scatter of the lens from 122 smoking males aged 57 to 76 years who participated in a cancer prevention study. The retroillumination and slit-lamp photographs of the lenses were graded according to LOCS III by the Center for Ophthalmic Research in Boston. Lens fluorometry was carried out with a previously described technique using blue-green (495 nm/520 nm) autofluorescence range. Interzeag Lens Opacity Meter 701 was used for light scatter measurements.

RESULTS

LOCS III nuclear opalescence and color grades were statistically significantly correlated with lens autofluorescence as well as with light scatter values. The lens transmission index of autofluorescence measurements showed the highest correlation with the nuclear color (r = -0.71; p < 0.0001) and the light scatter value with nuclear opalescence (r = 0.64; p < 0.0001). There was no correlation between autofluorescence measurements and LOCS III grades of cortical or posterior subcapsular cataract. A weak relation could be found between the grades of cortical cataract and light scatter values.

CONCLUSIONS

The lens fluorometry provides a practical clinical technique to evaluate the yellow coloration and opalescence of the human lens nucleus. It may be a useful additional tool together with a subjective grading system in the follow-up of optical changes occurring in the nuclear region of the lens.

Study of gene-environment effects on development of hyperopia: a study of 191 adult twin pairs from the Finnish Twin Cohort Study

The Finnish Twin Cohort material was used to estimate genetic and environmental effects in the etiology of hyperopia (farsightedness). All twin pairs in the cohort born before year 1927 (age 60 years and over at the time of the study), with both members alive, were sent a questionnaire. The questionnaire included questions of past and present eye diseases, visits to ophthalmologists, use of glasses and other vision-related questions. The hyperopia was assessed by asking the patients to send their last prescription for glasses to the authors. Twins with any eye disease affecting refraction (cataract, corneal damage), operation or trauma to their eyes were discarded from the present study. In 191 pairs (80 monozygotic and 111 dizygotic pairs) one or both members of the pair had a hyperopic refractive error. The correlations of refraction between right and left eyes of both MZ and DZ pairs were high (Spearman Rank Correlations of 0.86-0.89). The intrapair correlations among MZ pairs were higher (0.44 for right and 0.45 for left eyes) than intrapair correlations among DZ pairs (0.24 for right and 0.15 for left eyes). The variances were not significantly different among MZ and DZ pairs. The classical analysis of heritability gave an estimate of 0.75 for hyperopia. The result suggests that genetic factors are important in hyperopia and especially in hyperopia of higher degree.

Occurrence of cylindrospermopsin, anatoxin-a and their homologs in the southern Czech Republic - Taxonomical, analytical, and molecular approaches

Water bloom-forming cyanobacteria have a severe impact on freshwater quality. Although some cyanobacterial toxins such as microcystins have been studied extensively, other toxins like anatoxin-a (ATX) and their structural analogs - as well as cyanobacterial taxa producing these toxins remain to be explored in detail. The present study investigated levels of ATX, CYN and their homologs along with the occurrence of anaC and cyrJ genes in water blooms in 16 sites in the Czech Republic that were pre-selected concerning the presence of potential toxin producers. Besides, we also studied toxins and genes in a series of strains available in our laboratories. ATX and its congener HATX were detected in 5 natural biomass samples from the Czech Republic (maximum concentration 2.8 micrograms per gram d.w.). Interestingly, the anaC gene coding for ATX production was not detected in any of these toxin-positive biomass samples. The concentrations of ATX congeners in cyanobacterial laboratory strains were about 10-times higher than those of the original ATX, which calls for further research addressing levels and hazards of ATX analogs. Regarding the CYN and 7-deoxyCYN (other CYN congeners were not analyzed in this study) - these toxins were identified in a single small pond in the Czech Republic at concentrations 4.3 and 2.7 micrograms per gram of biomass d.w., respectively (corresponded to dissolved concentrations higher than 1 microgram per liter). The CYN-positive sample was dominated by CYN-producing taxa Raphidiopsis (basionym Cylindrospermopsis) and Cuspidothrix. We also confirmed the presence of a specific cyrJ gene in this natural bloom sample. To our knowledge, this is the first study pointing to Raphidiopsis (Cylindrospermopsis) and Cuspidothrix as producers of CYN in Europe. This observation calls for further research because of their increasing occurrence in (Central) Europe along with the global change. The present study demonstrates the importance of using combined (taxonomical, analytical, and molecular) approaches in the assessment of hazardous cyanobacteria and their toxins in freshwaters.

Time course of thymoxamine reversal of phenylephrine-induced mydriasis

We conducted a randomized, double-masked, paired comparison of 0.1% thymoxamine vs placebo for the reversal of phenylephrine-induced mydriasis. Mydriasis was induced with 2.5% phenylephrine in each eye of 74 subjects (148 eyes). Each subject then received 0.1% thymoxamine in one eye and placebo in the other eye. Pupillary measurements were obtained at regular intervals during the ensuing 8 hours. At all intervals, a greater percentage of thymoxamine-treated eyes returned to baseline pupillary diameters compared with placebo-treated eyes (P less than or equal to .01). For subjects in whom both pupils returned to baseline, thymoxamine-treated eyes returned to baseline in a mean of 2.2 hours, vs 5.2 hours for placebo (P less than .0001). Among thymoxamine-treated eyes, those with light irides responded more rapidly than those with dark irides, returning to baseline in 1.6 vs 2.8 hours, respectively (P = .0046). After constriction to baseline pupillary diameter had been achieved, no patients experienced a rebound dilation.

Cyanotoxins associated with macrophytes in Berlin (Germany) water bodies - Occurrence and risk assessment

Fatal dog poisoning after uptake of neurotoxic cyanobacteria associated with aquatic macrophytes in Tegeler See (Berlin, Germany) raised concerns about critical exposure of humans, especially children, to cyanotoxins produced by macrophyte associated cyanobacteria during recreational activity. From 2017 to 2021 a total of 398 samples of macrophytes washed ashore at bathing sites located at 19 Berlin lakes were analysed for anatoxins, microcystins, and cylindrospermopsins, as were 463 water samples taken in direct proximity to macrophyte accumulations. Cyanotoxins were detected in 66 % of macrophyte samples and 50 % of water samples, with anatoxins being the most frequently detected toxin group in macrophyte samples (58 %) and cylindrospermopsins in water samples (41 %). Microcoleus sp. associated with the water moss Fontinalis antipyretica was identified as anatoxin producing cyanobacterium in isolated strains as well as in field samples from Tegeler See. Anatoxin contents in macrophyte samples rarely exceeded 1 μg/g macrophyte fresh weight and peaked at 9. 2 μg/g f.w. Based on established toxicological points of departure, a critical anatoxin content of macrophyte samples of 3 μg/g f.w. is proposed. Five samples, all taken in Tegeler See and all associated with the water moss Fontinalis antipyretica, exceeded this value. Contents and concentrations of microcystins and cylindrospermopsins did not reach critical levels. The potential exposure risks to anatoxins for children and dogs are assessed and recommendations are given.

Mixing and Matching of Hybrid Megasynthases is a Hub for the Evolution of Metabolic Diversity in Cyanobacteria

Modular megasynthases, such as polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs), are molecular assembly lines that biosynthesize many pharmaceutically and ecologically important natural products. Understanding how these compounds evolve could inspire the artificial evolution of compound diversity by metabolic engineering. Over the past two decades, a number of seminal studies have significantly contributed to our understanding of natural product evolution. However, the evolution of NRPS and PKS assembly lines remains poorly understood, especially for NRPS/PKS hybrids. Here, we provide substantial evidence for a remarkable cluster-mixing event involving three cyanobacterial biosynthetic gene clusters (BGCs), resulting in the emergence of novel peptide-polyketide hybrids that were named minutumamides. By combining retro-evolutionary analysis with structure-guided genome mining, we could discover a potential evolutionary ancestor that links nostopeptolide and minutumamide biosynthesis. In addition, we were able to trace nostopeptolide-related module and domain blocks in various other biosynthetic pathways, indicating a surprisingly vivid mixing and matching of biosynthesis genes in the evolution of NRPS and cis-acyltransferase PKS/NRPS pathways, which was previously regarded as a unique feature of trans-acyltransferase (trans-AT) PKS. These remarkable insights into the evolutionary plasticity of NRPS-PKS assembly lines provide valuable guidance for pathway engineers looking for productive combinations that yield "nonnatural" hybrid natural products.

Cyanobacterial Genome Sequencing, Annotation, and Bioinformatics

Cyanobacteria are collectively a globally important monophyletic phylum of bacteria. They have attracted a lot of attention, not only because they are rich sources of natural bioactive products, including toxic substances, but also because they play an important role in global nitrogen and carbon cycles, and are capable of maintaining versatile environmental niche adaptations. A vast number of cyanobacterial genomes have become available due to fast development of sequencing technologies, but effort is still needed to comprehensively understand the molecular basis of their diversity. Here, we introduce a basic pipeline for the cyanobacterial genome sequencing project that can be employed to complete the whole cyanobacterial genome. The pipeline includes DNA extraction from the cyanobacterial culture of interest, hybrid genome sequencing, and genome assembly and annotation. At the end of the chapter, we briefly introduce genome mining tools and one successful genome mining example from our laboratory. This chapter provides general guidance regarding the sequencing project and thus includes several references for alternative methods and tools so that the reader can easily modify the pipeline according to the needs of the laboratory.