[Interpretation of the pivot test using accelerometers in the orthopedic practice]. / Interpretación de la maniobra de pivote mediante el uso de acelerómetros en pacientes que acuden a consulta ortopédica.

The anterior (A) and posterior (P) cruciate ligaments (CL) of the knee, located inside the joint, connect the femur and the tibia and thus provide stability in the anteroposterior axis of one bone over the other. The anterior cruciate ligament (ACL) may be injured as a result of rotation when practicing a sport involving turning with the foot on the ground. ACL injuries are diagnosed with maneuvers like the Lachman, drawer and pivot. Accelerometers were used to plot the pivot maneuver in patients seeing the orthopedist surgeon using the KT1000 test as gold standard. This case-control descriptive study was approved by the Hospital's Ethics Committee. Results: 92 patients accepted to participate through an informed consent; nine cases were KT1000 positive, and nine age- and gender-matched controls were selected among KT1000 negative patients. KT1000 alterations were greater among females (78%) and in 67% of cases the right leg was affected. Mean KT1000 results were 5.44 mm in cases and 0.66 mm in controls. Accelerometers allowed plotting the pivot maneuver and the resulting charts for cases and controls were similar. Remarkable differences were seen only in one male patient with a 15 mm KT1000, who underwent repair of the left ACL; the maneuver was performed under sedation. We concluded that conscious patients oppose the maneuver, unlike anesthetized patients, and that the use of accelerometers helps document the pivot maneuver which, in turn, helps detect differences between a normal ACL and an injured one.

Removal of groundwater arsenic using a household filter with iron spikes and stainless steel.

Arsenic (As) in groundwater for domestic use poses a worldwide threat to public health, most notably in rural areas. The aims of this study were: first, determine groundwater composition in a mining area in central Mexico (Huautla); second, assess As exposure through human groundwater consumption and; third, develop and test a household filter to obtain drinking water for these rural communities. From the 17th century through the 1990s, mines in the area produced Ag-galena and sphalerite from volcanic rock. Groundwater flooded the mines when they were abandoned due to low silver prices. Local households now use the water to meet domestic needs. Water from the mines was found to have high As content (0.04-0.26 mg L(-1)) and Fe, Mn, Pb and Cd were also above Mexican drinking water standards and WHO guidelines. All the population in the Huautla community was exposed to the metalloid through water used in food preparation. The best As removal was obtained with a filter using oxidized commercial fiber (HCl 2N as oxidant). Concentrations in the effluent were below Mexican drinking water standards (0.025 mg As L(-1) water) during the 105-day (2520 h) filter operation, with a maximum As removal efficiency of 95.4%. The household filter was simple, low-cost and may be very attractive for As removal in rural areas in developing countries.

Functional analysis of splicing mutations in MYO7A and USH2A genes.

Usher syndrome is defined by the association of sensorineural hearing loss, retinitis pigmentosa and variable vestibular dysfunction. Many disease-causative mutations have been identified in MYO7A and USH2A genes, which play a major role in Usher syndrome type I and type II, respectively. The pathogenic nature of mutations that lead to premature stop codons is not questioned; nevertheless, additional studies are needed to verify the pathogenicity of some changes such as those putatively involved in the splice process. Five putative splice-site variants were detected in our cohort of patients: c.2283-1G>T and c.5856G>A in MYO7A and c.1841-2A>G, c.2167+5G>A and c.5298+1G>C in the USH2A gene. In this study, we analyze these changes with bioinformatic tools and investigate the expression of MYO7A and USH2A transcripts through hybrid minigene assays. Our study showed that all five mutations abolished the consensus splice site producing the skipping of involved exons. In addition, for variant c.2167+5G>A, a new donor splice site was observed. Our data reveal the pathogenic nature of the analyzed variants. The fact that splicing mutations led to in-frame or out-of-frame alterations cannot explain phenotypic differences, thus, genotype-phenotype correlations cannot be inferred.

[Genetic counselling in visual and auditory disorders]. / El asesoramiento genético en los déficits visuales y auditivos.

PURPOSE: Inherited retinal dystrophies and hearing loss disorders have a broad clinical and genetic heterogeneity. Over the last decade there have been major advances in our understanding of the molecular pathology of these diseases; currently over 200 genes and loci are known to be involved in retinal disorders, and over 60 genes/loci are causative for hearing impairment. METHODS: Genetic testing is crucial for confirming the diagnosis at a molecular level. It also allows a more precise prognosis to be made of the future clinical evolution, as well as an accurate genetic and reproductive counselling, and raises the possibility of creating genetically homogeneous groups of patients for future clinical trials. RESULTS: The high number of genes responsible for these disorders makes molecular testing overwhelming in terms of cost, time and technical effectiveness, and no centre offers testing of all known genes. Several diagnostic tools have emerged recently to circumvent this problem. CONCLUSIONS: In this report, we review the vast genetic heterogeneity of retinal dystrophies and hypoacusis, recent advances in gene discovery, the different DNA-based microarray technologies available for molecular testing, their benefits and limitations, and novel therapeutic approaches.

El asesoramiento genético en los déficits visuales y auditivos / Genetic counselling in visual and auditory disorders

Objetivo: Las enfermedades hereditarias que afectana la retina y la audición presentan una ampliaheterogeneidad clínica y genética. Durante la pasadadécada se han producido importantes avances en elconocimiento de la patogenia molecular de estasenfermedades y, actualmente, más de 200 genes yloci están implicados en enfermedades de la retina ymás de 60 son responsables de pérdida de audición.Método: El estudio genético molecular es crucialpara confirmar el diagnóstico clínico, permite, en ocasiones,conocer el pronóstico de la enfermedad, unconsejo genético y reproductivo adecuado y permitela posibilidad de crear grupos de pacientes genéticamentehomogéneos para futuros ensayos clínicos.Resultados: El elevado número de genes implicadoshace que el diagnóstico molecular no sea factibleen términos de coste, tiempo y esfuerzo técnicoy no existe ningún centro que oferte el análisis detodos los genes conocidos. Recientemente, se handesarrollado varias herramientas diagnósticas dirigidasa paliar este problema. Conclusiones: En este trabajo se ha revisado laamplia heterogeneidad genética de las distrofiasretinianas y la hipoacusia, los recientes descubrimientosde nuevos genes, las distintas herramientasdiagnósticas basadas en microchips de ADN, susventajas y limitaciones y los nuevos avances en buscade una terapia

Purpose: Inherited retinal dystrophies and hearingloss disorders have a broad clinical and geneticheterogeneity. Over the last decade there have beenmajor advances in our understanding of the molecularpathology of these diseases; currently over 200genes and loci are known to be involved in retinaldisorders, and over 60 genes/loci are causative forhearing impairment.Methods: Genetic testing is crucial for confirmingthe diagnosis at a molecular level. It also allows amore precise prognosis to be made of the future clinicalevolution, as well as an accurate genetic andreproductive counselling, and raises the possibilityof creating genetically homogeneous groups ofpatients for future clinical trials.Results: The high number of genes responsible forthese disorders makes molecular testing overwhelmingin terms of cost, time and technical effectiveness,and no centre offers testing of all knowngenes. Several diagnostic tools have emergedrecently to circumvent this problem. Conclusions: In this report, we review the vastgenetic heterogeneity of retinal dystrophies andhypoacusis, recent advances in gene discovery, thedifferent DNA-based microarray technologies availablefor molecular testing, their benefits and limitations, and novel therapeutic approaches

Identification of 14 novel mutations in the long isoform of USH2A in Spanish patients with Usher syndrome type II.

Mutations in USH2A gene have been shown to be responsible for Usher syndrome type II, an autosomal recessive disorder characterised by hearing loss and retinitis pigmentosa. USH2A was firstly described as consisting of 21 exons, but 52 novel exons at the 3' end of the gene were recently identified. In this report, a mutation analysis of the new 52 exons of USH2A gene was carried out in 32 unrelated patients in which both disease-causing mutations could not be found after the screening of the first 21 exons of the USH2A gene. On analysing the new 52 exons, fourteen novel mutations were identified in 14 out of the 32 cases studied, including 7 missense, 5 frameshift, 1 duplication and a putative splice-site mutation.

Mutation profile of the MYO7A gene in Spanish patients with Usher syndrome type I.

Usher syndrome type I is the most severe form of Usher syndrome. It is an autosomal recessive disorder characterized by profound congenital sensorineural deafness, retinitis pigmentosa, and vestibular abnormalities. Mutations in the myosin VIIA gene (MYO7A) are responsible for Usher syndrome type 1B (USH1B). This gene is thought to bear greatest responsibility for USH1 and, depending on the study, has been reported to account for between 24% and 59% of USH1 cases. In this report a mutation screening of the MYO7A gene was carried out in a series of 48 unrelated USH1 families using single strand conformation polymorphism analysis (SSCP) and direct sequencing of those fragments showed an abnormal electrophoretic pattern. Twenty-five mutations were identified in 23 out of the 48 families studied (47.9%). Twelve of these mutations were novel, including five missense mutations, three premature stop codons, three frameshift, and one putative splice-site mutation. Based on our results we can conclude there is an absence of hot spot mutations in the MYO7A gene and that this gene plays a major role in Usher syndrome.

[Molecular genetic study of Usher syndrome in Spain]. / Estudio genético molecular del síndrome de Usher en España.

Usher syndrome (USH) associates deafness and retinitis pigmentosa (RP). It is a disease both clinically and genetically heterogeneous. It is inherited as an autosomal recessive trait and its prevalence makes it the most frequent association of hearing loss and RP. Clinically Usher syndrome is divided into type I (USH1), II (USH2) and III (USH3), according to the severity of hearing loss, age of onset of RP and the existence or not of vestibular dysfunction. There are at least 7 different localizations for USH1 and 5 genes have been identified. For USH2, 3 loci and 2 genes have been reported and USH3 is due to Clarin-1 gene. Our aim is to perform a clinical and genetic characterization of all Usher syndrome patients in Spain.

Estudio genético molecular del síndrome de Usher en España / Molecular genetic study of Usher syndrome in Spain

El síndrome de Usher (USH) asocia sordera y retinosis pigmentaria (RP). Es una enfermedad heterogénea tanto clínica como genéticamente. Su modo de transmisión es autosómico recesivo y su prevalencia la convierte en la asociación de sordera y ceguera de origen genético más frecuente. Clínicamente, el síndrome de Usher se divide en los tipos I (USH1), II (USH2) y III (USH3) en función de la gravedad de la sordera, la edad de aparición de la RP y la presencia o no de disfunción vestibular. Existen al menos 7 localizaciones distintas para el USH1 y se han aislado 5 genes responsables de la enfermedad. Respecto al USH2 se han localizado 3 loci y se han aislado dos genes. El USH3 está causado por el gen clarina-1. Nuestro objetivo es la caracterización clínica y genética de los pacientes con síndrome de Usher en España mediante la búsqueda de mutaciones en los genes implicados en la enfermedad y la correlación con el fenotipo

Usher syndrome (USH) associates deafness and retinitis pigmentosa (RP). It is a disease both clinically and genetically heterogeneous. It is inherited as an autosomal recessive trait and its prevalence makes it the most frequent association of hearing loss and RP. Clinically Usher syndrome is divided into type I (USH1), II (USH2) and III (USH3), according to the severity of hearing loss, age of onset of RP and the existence or not of vestibular dysfunction. There are at least 7 different localizations for USH1 and 5 genes have been identified. For USH2, 3 loci and 2 genes have been reported and USH3 is due to Clarin-1 gene. Our aim is to perform a clinical and genetic characterization of all Usher syndrome patients in Spain

Mutation screening of USH3 gene (clarin-1) in Spanish patients with Usher syndrome: low prevalence and phenotypic variability.

Usher syndrome type III is an autosomal recessive disorder clinically characterized by the association of retinitis pigmentosa (RP), variable presence of vestibular dysfunction and progressive hearing loss, being the progression of the hearing impairment the critical parameter classically used to distinguish this form from Usher syndrome type I and Usher syndrome type II. Usher syndrome type III clinical subtype is the rarest form of Usher syndrome in Spain, accounting only for 6% of all Usher syndrome Spanish cases. The gene responsible for Usher syndrome type III is named clarin-1 and it is thought to be involved in hair cell and photoreceptor cell synapses. Here, we report a screening for mutations in clarin-1 gene among our series of Usher syndrome Spanish patients. Clarin-1 has been found to be responsible for the disease in only two families: the first one is a previously reported family homozygous for Y63X mutation and the second one, described here, is homozygous for C40G. This accounts for 1.7% of Usher syndrome Spanish families. It is noticeable that, whereas C40G family is clinically compatible with Usher syndrome type III due to the progression of the hearing loss, Y63X family could be diagnosed as Usher syndrome type I because the hearing impairment is profound and stable. Thus, we consider that the progression of hearing loss is not the definitive key parameter to distinguish Usher syndrome type III from Usher syndrome type I and Usher syndrome type II.

A possible association between the CCK-AR gene and persistent auditory hallucinations in schizophrenia.

Recent studies have suggested that DNA variations in the CCK-AR gene might predispose individuals to schizophrenia and particularly to auditory hallucinations (AH). The aim of this study is to assess the association between AH, using a specific scale for AH in schizophrenia (PSYRATS), and the CCK-AR polymorphism at 779 in a Spanish sample. A total of 105 DSM-IV schizophrenic patients with AH and 93 unrelated controls were studied. Twenty-two patients were considered as persistent auditory hallucinators, which showed similar clinical and demographic characteristic than patients with episodic AH, but with the exception of the PSYRATS values. The persistent AH group showed an excess of the A1 allele when was compared with episodic or control groups. Our data support the possible role of the CCK-AR gene in the development of persistent AH in schizophrenic patients.

[Early diagnosis of retinoblastoma: usefulness of searching for RB1 gene mutations]. / Diagnóstico temprano del retinoblastoma: importancia de la búsqueda de mutaciones en el gen RB1.

BACKGROUND: Retinoblastoma, the intraocular malignancy most common in children,occurs in both familial and sporadic (bilateral or unilateral). Hereditary predisposition is caused by a germ-line mutation while non-hereditary is due to two somatic mutations in a retinal cell. This work was carried out in order to analyse genetically, the high number of families with some affected member and to go deep into the molecular mechanisms responsible of this pathology. PATIENTS AND METHOD: 59 families with one or more affected members were analysed. Cytogenetics and with polymorphic markers studies were carried out and a search for mutations was performed in DNA from white cells and from available tumoral tissue. RESULTS: In four of the 5 familial cases, the responsible mutation was established,the same as in 9 of the 13 bilateral sporadic. In the 7% of the unilateral sporadic cases, mutation was found in leucocytary DNA. Lost of heterozygosity as a second mutational event was mainly due to mitotic recombination. CONCLUSIONS: Among the mutations of our series, a higher frequency of punctual mutations,responsible of the first mutational event, was observed at constitutional level. Lost of heterozygosity was the mechanism observed in the majority of the tumours.

1,5-Dimethyl-4-phenylimidazolidin-2-one-derived iminic glycinimides: useful new reagents for practical asymmetric synthesis of alpha-amino acids.

New 1,5-dimethyl-4-phenylimidazolidin-2-one-derived acyclic chiral iminic glycine reagents have been prepared and diastereoselectively alkylated with activated alkyl halides and electrophilic olefins in the presence of lithium chloride under (a) strong bases (LHMDS, KOBu(t)) and low temperature (-78 degrees C) conditions, (b) solid-liquid phase-transfer catalysis reaction (LiOH, TBAB, -20 degrees C) conditions, and (c) in the presence of organic bases (DBU, BEMP, TMG, -20 degrees C). In the case of dielectrophiles C- and N-alkylation takes place to afford heterocyclic derivatives. Hydrolysis of alkylated products has been carried out (a) in two-step procedures with LiOOH or LiOH followed by acidic hydrolysis or Dowex purification, (b) in one single-step under refluxing water to give the corresponding alpha-amino acid, (c) in the presence of DBU in methanol to provide N-protected alpha-amino acids methyl esters, or (d) by a protection-hydrolysis procedure to afford N-Boc-protected alpha-amino acids. The chiral imidazolidinone has generally been recovered in good yield. This methodology has been shown to be useful for the synthesis of acyclic and heterocyclic (S)- and (R)-alpha-amino acids.

Prevalence of 2314delG mutation in Spanish patients with Usher syndrome type II (USH2).

The Usher syndrome (USH) is a group of autosomal recessive diseases characterized by congenital sensorineural hearing loss and retinitis pigmentosa. Three clinically distinct forms of Usher syndrome have so far been recognized and can be distinguished from one another by assessing auditory and vestibular function. Usher syndrome type II (USH2) patients have congenital moderate-to-severe nonprogressive hearing loss, retinitis pigmentosa, and normal vestibular function. Genetic linkage studies have revealed genetic heterogeneity among the three types of USH, with the majority of USH2 families showing linkage to the USH2A locus in 1q41. The USH2A gene (MIM 276901) has been identified: three mutations, 2314delG, 2913delG, and 4353-54delC, were initially reported in USH2A patients, the most frequent of which is the 2314delG mutation. It has been reported that this mutation can give rise to typical and atypical USH2 phenotypes. USH2 cases represent 62% of all USH cases in the Spanish population, and 95% of these cases have provided evidence of linkage to the USH2A locus. In the present study, the three reported mutations were analyzed in 59 Spanish families with a diagnosis of USH type II. The 2314delG was the only mutation identified in our population: it was detected in 25% of families and 16% of USH2 chromosomes analyzed. This study attempts to estimate the prevalence of this common mutation in a homogeneous Spanish population.

Oxime Palladacycles: Stable and Efficient Catalysts for Carbon-Carbon Coupling Reactions.

Oxime palladacycles are thermally stable complexes not sensitive to air or moisture, easily prepared from very cheap materials, which can be used as versatile and very efficient catalysts for different carbon-carbon bond-forming reactions.

New chiral didehydroamino acid derivatives from a cyclic glycine template with 3,6-dihydro-2H-1,4-oxazin-2-one structure: applications to the asymmetric synthesis of nonproteinogenic alpha-amino acids.

New chiral (Z)-alpha,beta-didehydroamino acid (DDAA) derivatives with 3,5-dihydro-2H-1,4-oxazin-2-one structure 11a-f have been stereoselectively prepared after condensation of chiral glycine equivalent 7 with aldehydes in the presence of K(2)CO(3) under mild solid-liquid phase-transfer catalysis reaction conditions. These new systems have been used in diastereoselective cyclopropanation reactions using Corey's ylide for the asymmetric synthesis of 1-aminocyclopropane-1-carboxylic acids (ACCs) such as allo-corononamic and allo-norcoronamic acids. The hydrogenation reaction of these systems at ambient pressure in the presence of formaldehyde affords saturated oxazinones and N-methylated oxazinones which have been transformed into the N-methyl-alpha-amino acids (N-MAAs) (S)-2-(methylamino)butanoic acid and (S)-N-methylleucine. In addition, the parent alpha, beta-didehydroalanine derivative 11g has been prepared by a direct aminomethylation-elimination sequence from 7 and Eschenmoser's salt and has been used in Diels-Alder cycloaddition with endo selectivity for the synthesis of the enantiomerically pure bicyclic alpha-amino acids (-)-2-aminobicyclo[2.2.1]heptane-2-carboxylic and (-)-2-aminobicyclo[2.2.2]octane-2-carboxylic acids.

Identification of three novel mutations in the MYO7A gene

Three new mutations in the myosin VIIA gene involved in the pathogenesis of Usher syndrome type Ib are reported. These mutations are K1080X in exon 25, E1170K in exon 28, and Y1719C in exon 37. It is presumed that these mutations are involved in the Usher syndrome Ib phenotype. Hum Mutat 14:181, 1999. Copyright 1999 Wiley-Liss, Inc.