[Isolation of extracellular micro-vesicles from cell culture medium: comparative evaluation of methods]. / Sravnitel'nyi analiz metodov vydeleniia vnekletochnykh mikrovezikul iz kul'tural'noi sredy.

Extracellular vesicles (EV) are secreted by cells of multicellular organisms. EV mediate specific mode of intercellular communication by "horizontal" exchange of substances and information. This phenomenon seems to have an essential biological significance and became a subject of intensive research. Biogenesis, structural and functional features of the EV is being commonly studies in in vitro condition. Several methods of EV isolation from cell culture medium are established, however selection of method might influence on obtained results. The choice of the optimal method depends usually from the amount of medium and the aims of the research while is still challenging issue. We performed a comparative analysis of four different methods of EV isolation from cell culture medium: differential ultracentrifugation, ultracentrifugation with a 30% sucrose/D2O "cushion", precipitation with plant proteins and immune-affinity capturing. EV isolated by different approaches were compared in terms of following parameters: size, concentration, morphology of EV, contamination by non-vesicular particles, content of exosomal tetraspanins on the EV surface, content of total proteins, RNA, and several glioma-associated miRNAs. Applied methods included nano-patricle tracking analysis (NTA), dynamic light scattering (DLS), cryo-electron microscopy, flow cytometry and RT-qPCR. On the base of obtained results, we developed practical recommendations that may help researchers to make a best choice of EV isolation method.

A 5-bp deletion in ELOVL4 is associated with two related forms of autosomal dominant macular dystrophy.

Stargardt-like macular dystrophy (STGD3, MIM 600110) and autosomal dominant macular dystrophy (adMD) are inherited forms of macular degeneration characterized by decreased visual acuity, macular atrophy and extensive fundus flecks. Genetic mapping data suggest that mutations in a single gene may be responsible for both conditions, already known to bear clinical resemblance. Here we limit the minimum genetic region for STGD3 and adMD to a 0.6-cM interval by recombination breakpoint mapping and identify a single 5-bp deletion within the protein-coding region of a new retinal photoreceptor-specific gene, ELOVL4, in all affected members of STGD3 and adMD families. Bioinformatic analysis of ELOVL4 revealed that it has homology to a group of yeast proteins that function in the biosynthesis of very long chain fatty acids. Our results are therefore the first to implicate the biosynthesis of fatty acids in the pathogenesis of inherited macular degeneration.

A new locus for dominant drusen and macular degeneration maps to chromosome 6q14.

PURPOSE: To report the localization of a gene causing drusen and macular degeneration in a previously undescribed North American family. METHODS: Genetic mapping studies were performed using linkage analysis in a single family with drusen and atrophic macular degeneration. RESULTS: The clinical manifestations in this family ranged from fine macular drusen in asymptomatic middle-aged individuals to atrophic macular lesions in two children and two elderly patients. We mapped the gene to chromosome 6q14 between markers D6S2258 and D6S1644. CONCLUSIONS: In a family with autosomal dominant drusen and atrophic macular degeneration, the gene maps to a 3.2-cM region on chromosome 6q14. This locus appears to be distinct from, but adjacent to, the loci for cone-rod dystrophy 7 (CORD7) and North Carolina macular dystrophy (MCDR1). Future identification of the gene responsible for the disease in this family will provide a better understanding of macular degeneration.

A novel mutation in the ABCR gene in four patients with autosomal recessive Stargardt disease.

PURPOSE: To identify additional mutations in the ABCR gene and describe the clinical features of four affected siblings with autosomal recessive Stargardt disease. METHODS: A cohort of eight siblings was identified for study. Four of these individuals were diagnosed with Stargardt disease based on clinical evaluation and fluorescein angiography. Blood samples were obtained from seven of eight siblings, including all those affected. All 50 exons of the ABCR gene were analyzed by single-stranded confirmation polymorphism analysis, followed by direct sequencing of observed variants, to identify mutations in the ABCR gene. RESULTS: We identified a previously unreported kindred of eight siblings, four of whom had mutations in both of their ABCR alleles. A previously described G-to-C transversion of nucleotide 2588, predicting a Gly863Ala amino acid substitution, and a novel G-to-A transition of nucleotide 161, resulting in a Cys54Tyr substitution, were identified. These mutations co-segregated with the affected members of this family. Three of the siblings demonstrated clinical features characteristic of classic Stargardt disease, with bilateral regions of macular atrophy associated with yellow-white "flavimaculatus" flecks in the posterior pole at the level of the retinal pigment epithelium. The fourth affected sibling showed features of early Stargardt disease, with a beaten-bronze appearance to both maculas, as well as perimacular flecks. In all four affected patients, fluorescein angiography showed a characteristic peripheral dark choroid. CONCLUSIONS: We have identified both a previously described and a novel mutation in the ABCR gene in four patients with autosomal recessive Stargardt disease. In-depth knowledge of the ABCR mutation spectrum in patients with Stargardt disease will provide for more efficient screening and may provide potential therapies for Stargardt disease and other retinal diseases.

The ABCR gene in recessive and dominant Stargardt diseases: a genetic pathway in macular degeneration.

Stargardt disease (STGD) is a juvenile-onset macular dystrophy and can be inherited in an autosomal recessive or in an autosomal dominant manner. Genes involved in dominant STDG have been mapped to human chromosomes 13q (STGD2) and 6q (STGD3). Here, we identify a new kindred with dominant STGD and demonstrate genetic linkage to the STGD3 locus. Because of a more severe macular degeneration phenotype of one of the patients in this family, the gene responsible for the recessive STGD1, ABCR, was analyzed for sequence variants in all family members. One allele of the ABCR gene was shown to carry a stop codon-generating mutation (R152X) in three family members, including the one patient who had inherited also the dominant gene. A grandparent of that patient with the same ABCR mutation developed age-related macular degeneration (AMD), consistent with our earlier observation that some variants in the ABCR gene may increase susceptibility to AMD in the heterozygous state. Based on these results, we propose that there is a common genetic pathway in macular degeneration that includes genes for both recessive and dominant STGD.

Clinical and genetic studies of an autosomal dominant cone-rod dystrophy with features of Stargardt disease.

Cone-rod dystrophy (CORD) and Stargardt disease (STGD) are two hereditary retinal dystrophies with similarities to age-related macular degeneration. Cone-rod dystrophies are a group of degenerative disorders resulting in decreased visual acuity and color vision, attenuated electroretinographic (ERG) responses, and atrophic macular lesions. Autosomal dominant, autosomal recessive, and X-linked forms of cone-rod dystrophy have been reported. Stargardt disease is characterized by reduced visual acuity, atrophic macular changes, prominent 'flavimaculatus flecks' in the pigment epithelium of the posterior retina, and a virtually pathognomic 'dark choroid' pattern on fluorescein angiography. Stargardt disease is classically inherited as an autosomal recessive trait, although numerous families have been described in which features of Stargardt disease are transmitted in an autosomal dominant manner. We have identified a new kindred with autosomal dominant cone-rod dystrophy with features of Stargardt-like disease. Detailed clinical evaluation, genotype analysis, and linkage analysis were performed. Fluorescein angiography revealed a 'dark choroid' pattern in three affected subjects. Electroretinography disclosed markedly reduced scotopic and photopic responses in three affected individuals. Genetic analysis revealed linkage to known loci for cone-rod dystrophy (CORD7) and Stargardt-like disease (STGD3) on chromosome 6q14. A peak lod score of 3.3 was obtained with the marker D6S280 at straight theta =0.010. A physical map was constructed by screening a YAC library with short tandem repeat markers in the region. Screening of a candidate gene, the rho1 subunit of the GABA receptor, failed to reveal any mutations.

A new locus for autosomal dominant stargardt-like disease maps to chromosome 4.

Stargardt disease (STGD) is the most common hereditary macular dystrophy and is characterized by decreased central vision, atrophy of the macula and underlying retinal-pigment epithelium, and frequent presence of prominent flecks in the posterior pole of the retina. STGD is most commonly inherited as an autosomal recessive trait, but many families have been described in which features of the disease are transmitted in an autosomal dominant manner. A recessive locus has been identified on chromosome 1p (STGD1), and dominant loci have been mapped to both chromosome 13q (STGD2) and chromosome 6q (STGD3). In this study, we describe a kindred with an autosomal dominant Stargardt-like phenotype. A genomewide search demonstrated linkage to a locus on chromosome 4p, with a maximum LOD score of 5.12 at a recombination fraction of.00, for marker D4S403. Analysis of extended haplotypes localized the disease gene to an approximately 12-cM interval between loci D4S1582 and D4S2397. Therefore, this kindred establishes a new dominant Stargardt-like locus, STGD4.

Expression of PrP mRNA is regulated by a fragment of MRP8 in human fibroblasts.

Prion protein (PrPc) is expressed in many tissues, both in human and animals. The scrapie isoform of PrPc has been shown to cause neurodegeneration. In other studies it has been demonstrated that overexpression of the PrP gene can result in nonneuronal tissue degradation. Little is known, however, about the normal function of PrPc and prion protein gene regulation. Using cultured periodontal ligament cells as an experimental model, we have demonstrated the stimulation of PrP mRNA expression by MRP8 (migration inhibitory factor-related protein). Additionally, we have shown that PDGF has an opposite effect acting as a suppresser. We propose that a correlation exists between PrPc mRNA expression and cell growth arrest and differentiation.

[Periodontal tissue status in shortening of the interalveolar distance]. / Sostoianie tkanei parodonta pri ukorochenii mezhal'veoliarnogo rasstoianiia.

A total of 186 patients aged 40 to 65 with short interalveolar distance were treated. 65.5% of them developed pathological changes in the marginal periodontal tissues (inflammation, periodontal and osseous pouches, resorption of bone tissue of the maxillary alveolar process). Patients with involvement of the marginal periodontal tissue were treated by therapeutic, surgical, and orthodontic methods. Good results were attained in 95.1% of patients.

[The characteristics of the design and use of metal-ceramic dentures in pathological abrasion of the hard dental tissues]. / Osobennosti konstruirovaniia i primeneniia metallokeramicheskikh protezov pri patologicheskoi stiraemosti tverdykh tkanei zubov.

A total of 416 patients aged 40 to 60 suffering from abnormal teeth abrasion were fitted with cermet dentures. Orthodontic treatment was preceded by therapeutic and surgical preparation of the teeth and periodontium and by functional and adaptation rearrangement of the maxillodental system, if indicated. Remote results were assessed after 2 to 12 years. Due to such preparation good results were attained in 95.9% patients. Complications were observed in only 4.1%: exacerbation of periodontitis, ceramic facing chipping off, insertion of abutment teeth, and functional overload of the periodontium.

[The late results of using metal ceramic dentures]. / Otdalennye rezul'taty primeneniia metallokeramicheskikh protezov.

A total of 258 patients aged 29 to 59 wearing cermet dentures for 3 to 10 years were examined. Complications, such as ceramic fracture, inflammatory changes in the gingiva, functional overexercise of the periodontium, failure of cement fixation of the crown, apical periodontitis, occurred in 32 (12.4%) patients. The causes of these complications were analyzed and measures to prevent them developed. 284 patients aged 28 to 60 were fitted with cermet dentures after therapeutic and orthodontic preparation, with all prophylactic measures being adhered to; the results were followed up for 3 to 10 years. The incidence of complications reduced almost four-fold: they were observed in but 3.5% of patients.

[The efficacy of using metal ceramic dentures fixed on pulpectomized teeth]. / Effektivnost' primeneniia metallokeramicheskikh protezov, ukreplennykh na depul'pirovannykh zubov.

A total of 432 patients aged 34 to 60 were examined, 226 of them aged 31 to 59 were admitted for treatment. Out of 1980 examined cermet crowns fixed on depulped teeth complications were detected round 412 (20.88%). Inflammations of the gingiva were found near 218 crowns, apical chronic periodontitis in 98 cases, functional over-exercise of the periodontium in 61, ceramic fracture in 18, failure of cement fixation in 17 cases. When all prophylactic measures are taken, apical periodontitis was properly treated, and dental channels filled during pulp removal, if indicated, complications develop almost three times less frequently, occurring in 7.4% of cases.