Clinical and Genetic Characterization of RDH12-Retinal Dystrophy in a South American Cohort.

PURPOSE: To characterize the largest cohort of individuals with retinol dehydrogenase 12 (RDH12)-retinal dystrophy to date, and the first one from South America. DESIGN: Retrospective multicenter international study. SUBJECTS: Seventy-eight patients (66 families) with an inherited retinal dystrophy and biallelic variants in RDH12. METHODS: Review of clinical notes, ophthalmic images, and molecular diagnosis. MAIN OUTCOME MEASURES: Visual function, retinal imaging, and characteristics were evaluated and correlated. RESULTS: Thirty-seven individuals self-identified as Latino (51%) and 34 as White (47%). Sixty-nine individuals (88%) had Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy. Macular and midperipheral atrophy were seen in all patients from 3 years of age. A novel retinal finding was a hyperautofluorescent ring in 2 young children with LCA. Thirty-nine patients (50%) had subsequent visits, with mean follow-up of 6.8 ± 7.3 (range, 0-29) years. Eight variants (21%) were previously unreported, and the most frequent variant was c.295C>A, p.Leu99Ile, present in 52 alleles of 32 probands. Individuals with LCA homozygous for p.Leu99Ile (31%) had a later age of onset, a slower rate of best-corrected visual acuity decrease, the largest percentage of patients with mild visual impairment, and were predicted to reach legal blindness at an older age than the rest of the cohort. CONCLUSIONS: By describing the largest molecularly confirmed cohort to date, improved understanding of disease progression was possible. Our detailed characterization aims to support research and the development of novel therapies that may have the potential to reduce or prevent vision loss in individuals with RDH12-associated retinal dystrophy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures.

A duplex SYBR Green I-based real-time RT-PCR assay for the simultaneous detection and differentiation of Massachusetts and non-Massachusetts serotypes of infectious bronchitis virus.

Infectious bronchitis is a highly contagious viral disease of poultry caused by infectious bronchitis virus (IBV) and is considered one of the most economically important viral diseases of chickens. Control of IBV has been attempted using live attenuated and inactivated vaccines. Live attenuated vaccines of the Massachusetts (Mass.) serotype are the most commonly used for this purpose. Due to the continuous emergence of new variants of the infectious bronchitis virus, the identification of the type of IBV causing an outbreak in commercial poultry is important in the selection of the appropriate vaccine(s) capable of inducing a protective immune response. The present work was aimed at developing and evaluating a duplex SYBR Green I-based real-time RT-PCR (rRT-PCR) assay for the simultaneous detection and differentiation of Mass. and non-Mass. serotypes of IBV. The duplex rRT-PCR yielded curves of amplification with two specific melting curves (Tm1 = 83 °C ± 0.5 °C and Tm2 = 87 °C ± 0.5 °C) and only one specific melting peak (Tm = 87 °C ± 0.5 °C) when the IBV Mass. serotype and IBV non-Mass. serotype strains were evaluated, respectively. The detection limit of the assay was 8.2 gene copies/µL based on in vitro transcribed RNA and 0.1 EID50/mL. The assay was able to detect all the IBV strains assessed and discriminated well among the IBV Mass. and the IBV non-Mass. serotypes strains. In addition, amplification curves were not obtained with any of the other viruses tested. From the 300 field samples tested, the duplex rRT-PCR yielded a total of 80 samples that were positive for IBV (26.67%), 73 samples identified as the IBV Mass. serotype and seven samples as identified as the IBV non-Mass. serotype. A comparison of the performance of test as assessed with field samples revealed that the duplex rRT-PCR detected a higher number of IBV-positive samples than when conventional RT-PCR or virus isolation tests were used. The duplex rRT-PCR presented here is a useful tool for the rapid identification of outbreaks and for surveillance programmes during IB-suspected cases, particularly in countries with a vaccination control programme.

Dental caries experience in school children and the impact of non-cavitated lesions on the caries index.

UNLABELLED: The purpose of this study was to evaluate the current status of dental caries in 11 to 13 year-old schoolchildren residing in Sucre Municipality, Miranda State, and the impact of the non-cavitated lesion on the caries index. Twelve elementary schools were included in this study and a sample of 1484 children was examined using artificial light, a #5 mirror and a #23 probe. The criteria followed were those proposed by Radike (1972) as modified by Acevedo et al. (2005) in order to include initial non-cavitated caries lesions. Teeth were cleaned and dried for 5 seconds with a triple syringe. Caries prevalence was 94.07% and the average DMFS index for the total sample was 4.35 +/- 4.21. This increased significantly to 6.45 +/- 5.01, when the initial caries lesions were included (p < 0.05). According to gender, DMFS was higher in the female population (4.51 +/- 4.45) than in males (4.21 +/- 3.97), but the difference was not statistically different (p > 0.05). The same pattern was observed, when the initial caries lesions were added. The new mean DMFS was 6.67 +/- 5.15 and 6.26 +/- 4.88 for females and males, respectively. Non-cavitated lesions represent 33% of the total caries lesions recorded. CONCLUSION: These results show that (i) dental caries prevalence in this population remains high and (ii) initial lesions contribute significantly to the DMFS index.

Frequency and distribution of Mutans Streptococci in dental plaque from caries-free and caries-affected Venezuelan children.

Mutans Streptococci, in particular S. mutans and S. sobrinus, are generally considered to be the prime etiological bacteria of human dental caries. The aim of this study was to determine the frequency of mutans streptococci in dental plaque in three groups of caries-free and caries-affected Venezuelan children aged 2-6, 7-12, 13-19 years, and their possible association with dental caries. The frequency of mutans streptococci was determined in samples of pooled dental plaque collected from all detectable sources of 30 (62.5%) caries-affected and 18 (37.5%) caries-free children. The samples were collected from all available tooth sites using a Hollenbak probe and immediately suspended in Ringer's solution, serially diluted and cultured in Mitis Salivarius (MS) agar for total streptococci determination and Mitis Salivarius Bacitracin (MSB) for isolation of mutans streptococci. The bacterial identification procedure was done using the API Rapid Strep System. The criteria used to determine dmft and DMFT was established by Klein and Palmer (1941). Mean dmft and DMFT were 6.4 +/- 3.2 and 4.4 +/- 2.9, respectively. Ten (33%) out of 30 caries-affected children harbored mutans streptococci. The species most frequently found were S. mutans (20%), S. sobrinus (10%) and S. rattus (3.3%). Meanwhile, in the caries-free group only 6 out of 18 children (33%) harbored mutans streptococci, specifically S. mutans and S. sobrinus, both at 17%, with no significant difference between the two groups. These results indicate that the percentage of children that harbored mutans streptococci was similar in both groups, suggesting that other acidogenic species may be responsible for caries development.

Impact of RNA Degradation on Viral Diagnosis: An Understated but Essential Step for the Successful Establishment of a Diagnosis Network.

The current global conditions, which include intensive globalization, climate changes, and viral evolution among other factors, have led to an increased emergence of viruses and new viral diseases; RNA viruses are key drivers of this evolution. Laboratory networks that are linked to central reference laboratories are required to conduct both active and passive environmental surveillance of this complicated global viral environment. These tasks require a continuous exchange of strains or field samples between different diagnostic laboratories. The shipment of these samples on dry ice represents both a biological hazard and a general health risk. Moreover, the requirement to ship on dry ice could be hampered by high costs, particularly in underdeveloped countries or regions located far from each other. To solve these issues, the shipment of RNA isolated from viral suspensions or directly from field samples could be a useful way to share viral genetic material. However, extracted RNA stored in aqueous solutions, even at -70 °C, is highly prone to degradation. The current study evaluated different RNA storage conditions for safety and feasibility for future use in molecular diagnostics. The in vitro RNA-transcripts obtained from an inactivated highly pathogenic avian influenza (HPAI) H5N1 virus was used as a model. The role of secondary structures in the protection of the RNA was also explored. Of the conditions evaluated, the dry pellet matrix was best able to protect viral RNA under extreme storage conditions. This method is safe, cost-effective and assures the integrity of RNA samples for reliable molecular diagnosis. This study aligns with the globally significant "Global One Health" paradigm, especially with respect to the diagnosis of emerging diseases that require confirmation by reference laboratories.

Urinary fluoride excretion in children aged 3 to 5 years exposed to fluoridated salt at 60 to 90 mgF/Kg in two Venezuelan cities. A pilot study.

The aim of the present work was to obtain information on the total urinary fluoride concentration and excretion of Venezuelan children at the age of 3 to 5 years, as part of a program to monitor fluoride ingestion. A 24 hour urine sample was collected from each of 63 children, between 3 and 5 years of age and analyzed for (i) total urinary volume (ml), (ii) urinary flow rate (ml/h), (iii) fluoride concentration (ppm) and (iv)fluoride excretion rate (microg/h). The group comprised 32 boys and 31 girls who resided in two different communities, 32 in Caracas, DC and 31 in San Juan de los Morros, Guarico state. Fluoride analyses were done with an ion-specific electrode. Age and gender did not affect total urine volume, urinary flow rate, or urinary fluoride concentration and excretion rate. The children from San Juan de los Morros had a significantly higher total urinary volume (426.45 +/- 36.31 ml) and flow rate (17.09 +/- 1.57ml/h) than children from Caracas (297.06 +/- 23.59 ml and 12.40 +/- 0.98, respectively) (p=0.0039). Significant differences were also observed when the urinary fluoride excretion rate of the two communities was compared. Mean urinary fluoride concentrations did not differ significantly (p < 0.05) between the two communities. These values were 0.67 +/- 0.40, 0.57 +/- 0.34, 0.76 +/- 0.27 ppmF in the 3, 4 and 5 year-old children of Caracas and 0.69 +/- 0.33, 0.65 +/- 0.20, 0.63 +/- 0.36 mgF in San Juan de los Morros children. The results showed low urinary fluoride concentration and excretion, indicating that children residing in the evaluated communities are receiving fluoride below the recommended optimal range.

First evidence of the emergence of novel putative infectious bronchitis virus genotypes in Cuba.

The emergence of new infectious bronchitis virus (IBV) genotypes or serotypes along with the poor cross-protection observed among IBV serotypes have complicated the avian infectious bronchitis (IB) control programs in different geographic regions. In Cuba, the lack of genetic information regarding IBV and the increasing epidemiological importance of this virus in Cuban chicken flocks demand further characterization of IBV isolates. In the present work, studies of genetic diversity and phylogenetic relationships among recent IBV isolates from Cuban chicken flocks showing respiratory disorders were performed. Two putative genotypes genetically different to the Massachusetts genotype H120 strain used in the Cuban vaccination program were found in the flocks assessed. In addition, a potential nephropathogenic IBV isolate was found by first time in Cuba.

Estudio basal de Prevalencia de Caries y Fluorosis Dental en Niños Escolarizados. Venezuela 1997: Informe Final / Basal Study of caries prevalence and dental fluorose in Scholastic Children: Venezuela 1997: Final Report

El objetivo del estudio fue determinar la prevalencia de la enfermedad cariosa y de fluorosis dental, necesarias para la implementación del Programa Nacional de Fluoración de la Sal de Consumo en Venezuela. Los hallazgos sobre Fluorosis dental a nivel nacional revelaron que el 15 por ciento de la muestra estudida tenía signos de alteración, correspondiendo apenas el 0.6 por ciento a las categorias moderada y severa; Las clasificaciones menos severas (dudosa a leve) representaron el 14.4 por ciento de los casos. La distribución de la prevalencia de fluorosis en los grupos etáreos osciló entre el 20 por ciento a los 8 años y 9.3 a los 15. Se destaca que los estractos de mayor edad estuvieron por debajo del porcentaje nacional.