Photoreceptor spectral tuning by colorful, multilayered facet lenses in long-legged fly eyes (Dolichopodidae).

The facet lenses of the compound eyes of long-legged flies (Dolichopodidae) feature a striking, interlaced coloration pattern, existing of alternating rows of green-yellow and orange-red reflecting facets, due to dielectric multilayers located distally in the facet lenses (Bernard and Miller. Invest Ophthalmol 7:416-434 (1968). We investigated this phenomenon in the dolichopodid Dolichopus nitidus by applying microspectrophotometry, electron microscopy and optical modeling. The measured narrow-band reflectance spectra, peaking at ~540 and ~590 nm with bandwidth ~105 nm, are well explained by a refractive index oscillating sinusoidally in six periods around a mean value of about 1.44 with amplitude 0.6. The facet lens reflectance spectra are associated with a spectrally restricted, reduced transmittance, which causes modified spectral sensitivities of the underlying photoreceptors. Based on the modeling and electroretinography of the dolichopodid Condylostylus japonicus we conjecture that the green and orange facets narrow the spectral bandwidths of blue and green central photoreceptors, respectively, thus possibly improving color and/or polarization vision.

The occurrence of primary nocturnal enuresis and associated factors in 5-year-old outpatients in Slovenia.

AIM: To determine the occurrence of primary nocturnal enuresis in 5-year-old outpatients in Slovenia and the possible correlations with different factors. METHODS: The epidemiological study was conducted in Slovenia between 2005 and 2007. A special questionnaire was distributed randomly among the parents of 1846 5-year olds in children's outpatient clinics in all regions of Slovenia. RESULTS: The response rate was on average 71.0%, which means that 7% of all Slovenian 5-year olds were included in the study. The occurrence of primary nocturnal enuresis was 8.7% and was higher in families with many siblings (chi(2) test, p < 0.01). The boy:girl ratio was 1.4 (Student t-test, p = 0.024). Parents were found to be more disturbed by the problem than their children (chi(2) test, p < 0.01). The maternal and paternal education levels of children with primary nocturnal enuresis did not differ from the Slovenian adult population (chi(2) test, p > 0,05). CONCLUSION: The occurrence of primary nocturnal enuresis in 5-year-old outpatients in Slovenia is comparable with data from other countries. Primary nocturnal enuresis is more frequent in boys than in girls, with higher occurrence in families with more siblings, and parents are more disturbed by the problem than their children.

Atypical haemolytic uremic syndrome complicated by microangiopathic antiphospholipid-associated syndrome.

A 4-year-old boy with an atypical course of haemolytic uremic syndrome (HUS), who developed microangiopathic antiphospholipid-associated syndrome (MAPS) with signs of multiple organ failure during the course of his disease, is reported. Early and aggressive treatment with intravenous gammaglobulin, pulse methylprednisolone and plasmapheresis resulted in an excellent clinical recovery. Our patient showed a concomitant presence of multiple factors that could precipitate atypical HUS, including positive antiphospholipid antibodies, decreased level of factor H and positive anti-ADAMTS-13 antibodies. We suggest that, along with infections, autoimmune conditions or defined genetic abnormalities of complement regulatory genes, MAPS should be considered among the pathogenic mechanisms in patients with atypical HUS.

Sixteen novel mutations identified in COL4A3, COL4A4, and COL4A5 genes in Slovenian families with Alport syndrome and benign familial hematuria.

Alport syndrome (ATS) and benign familial hematuria (BFH) are type IV collagen inherited disorders. Mutations in COL4A5 are generally believed to cause X-linked ATS, whereas mutations in COL4A3 and COL4A4 genes can be associated with the autosomal-recessive and -dominant type of ATS or BFH. In view of the wide spectrum of phenotypes, an exact diagnosis is sometimes difficult to achieve. This study involved screening each exon with boundary intronic sequences of COL4A3, COL4A4, and COL4A5 genes by optimized polymerase chain reaction-single-stranded conformational polymorphism analysis in 17 families with ATS and in 40 families diagnosed as having BFH. Twelve different mutations were found in the COL4A5 gene in ATS patients, comprising nine missense mutations, a splice site mutation, a mutation causing frameshift, and a nonsense mutation. One of the missense mutations (p.G624D) was present not only in one family with ATS but also in five families with suspected BFH. Three heterozygous mutations in the COL4A3 gene (two missense and one frameshift) and four heterozygous mutations in COL4A4 (two splice site, one in-frame deletion, and one missense) were identified in patients with BFH. Sixteen mutations are to the best of our knowledge new and private.

Chlamydial infection of the urinary tract in children and adolescents with hematuria.

Urogenital infection with Chlamydia trachomatis in adults and adolescents is a common sexually transmitted disease. The purpose of this study was to investigate whether isolated microhematuria in children and adolescents is associated with Chlamydia trachomatis infection of the urinary tract. The study group included 37 children and adolescents with isolated nonglomerular microhematuria. Urethral smears for the isolation of Chlamydia trachomatis in cell culture were taken at the time of cystourethroscopy from all patients. Polymerase chain reaction (PCR) for the detection of chlamydial DNA in urine was carried out in 25 of 37 (68%) patients and direct immunofluorescence (DIF) of urine in 16 of 37 (43%) patients. The control group included 33 children and adolescents without hematuria; PCR and DIF of urine were carried out in all controls. Chlamydia trachomatis infection of the urinary tract was confirmed in 8 of 37 (22%) patients in the study group, and in none in the control group (0 of 33, P<0.001). Further studies of larger groups of patients should be conducted, before recommending testing for Chlamydia trachomatis infection of the urinary tract in children and adolescents with unexplained microhematuria.

A follow-up study of vesico-ureteric reflux and renal scars in asymptomatic siblings of children with reflux.

The objectives of this study were to follow up children with vesico-ureteric reflux (VUR) and renal scars, to evaluate kidney growth and to determine the incidence of urinary tract infection (UTI) and elevated blood pressure in 40 asymptomatic siblings of children with VUR, in whom VUR had been detected at an early age, and to gather additional data which could help to evaluate the need for screening for VUR in asymptomatic siblings. During the follow-up period of 3-7 years, two children (5%) had UTI; 66% of VUR grade 1 and 2 disappeared. The progression of scars was only detected in two of nine children with renal scars on the initial study, both of whom had high-grade VUR. Renal ultrasound was normal in all siblings and none developed hypertension. The results indicate that low-grade sterile VUR may not play a major role in renal scarring, but this may not be the case with high-grade sterile VUR. Considering the correlations among VUR, UTI and reflux nephropathy, routine screening for VUR at an early age in asymptomatic siblings of children with VUR seems to be justified to identify those at the greatest risk of subsequent renal damage.