326 research outputs found
Comparing the retinal structures and functions in two species of gulls (Larus delawarensis and Larus modestus) with significant nocturnal behaviours
AbstractRing-billed gulls (Larus delawarensis) and gray gulls (Larus modestus) are two species active both by day and night. We have investigated the retinal adaptations that allow the diurnal and nocturnal behaviours of these two species. Electroretinograms and histological analyses show that both species have a duplex retina in which cones outnumber rods, but the number of rods appears sufficient to provide vision at night. Their retinas respond over the same scotopic dynamic range of 3.4logcdm−2, which encompasses all of the light levels occurring at night in their photic environment. The amplitudes of the scotopic saturated a- and b-wave responses as well as the photopic saturated b-wave response and the photopic sensitivity parameter S are however higher in ring-billed gulls than in gray gulls. Moreover, the process of dark adaptation is about 30min faster in gray gulls than in ring-billed gulls. Our results suggest that both species have acquired in the course of their evolution functional adaptations that can be related to their specific photic environment
Mutations in SRY and WT1 genes required for gonadal development are not responsible for XY partial gonadal dysgenesis
The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.172
The novel p.E89K mutation in the SRY gene inhibits DNA binding and causes the 46,XY disorder of sex development
An Illustrative Case Of Léri-weill Dyschondrosteosis
We report on a girl presenting Léri-Weill dyschondrosteosis (LWD) due to deletion of the SHOX gene. Her family included individuals with short stature alone or with both short stature and mesomelia or Madelung's deformity. The deletion was demonstrated through detection of hemizygosity for microsatellite markdrs SHOX-CA repeat, DXYS10092, DXYS10093 and DXYS10091 localized around the SHOX gene, with retention of paternal alleles in the proband and three of her sisters who had short stature as the only clinical feature. Hemizygosity for these loci was also observed in their mother, who had short stature too. The deletion in the proband was however larger, including locus DXY 10083. The proband's only sister with normal height did not carry the deletion. Family history suggests transmission of the deletion from the proband's maternal great-grandfather to her grandfather via the Y chromosome, and from the grandfather to the proband's mother via the X chromosome after crossing-over in the pseudoautosomal region proximal to the SHOX gene. Copyright © 2008, Sociedade Brasileira de Genética.314839842Belin, V., Cusin, V., Viot, G., Girlich, D., Toutain, A., Moncla, A., Vekemans, M., Cormier-Daire, V., SHOX mutations in dyschondrosteosis (Léri-Weill syndrome) (1998) Nat Genet, 19, pp. 67-69Benito-Sanz, S., del Blanco, D.G., Aza-Carmona, M., Magano, L.F., Lapunzina, P., Argente, J., Campos-Barros, A., Heath, K.E., PAR1 deletions downstream of SHOX are the most frequent defect in a Spanish cohort of Léri-Weill dyschondrosteosis (LWD) probands (2006) Hum Mutat, 27, p. 1062Benito-Sanz, S., del Blanco, D.G., Huber, C., Thomas, N.S., Aza-Carmona, M., Bunyan, B., Maloney, V., Campos-Barros, A., Characterization of SHOX deletions in Léri-Weill dyschondrosteosis (LWD) reveals genetic heterogeneity and no recombination hotspots (2006) Am J Hum Genet, 79, pp. 409-412Benito-Sanz, S., Thomas, N.S., Huber, C., Gorbenko del Blanco, D., Aza-Carmona, M., Crolla, J.A., Maloney, V., Campos-Barros, A., A novel class of pseudoautosomal region 1 deletions downstream of SHOX Is associated with Léri-Weill dyschondrosteosis (2005) Am J Hum Genet, 77, pp. 533-544Clement-Jones, M., Schiller, S., Rao, E., Blaschke, R.J., Zuniga, A., Zeller, R., Robson, S.C., Strachan, T., The short stature homeobox gene SHOX is involved in skeletal abnormalities in Turner syndrome (2000) Hum Mol Genet, 9, pp. 695-702Ellison, J.W., Wardak, Z., Young, M.F., Gehron Robey, P., Laig-Webster, M., Chiong, W., PHOG, a candidate gene for involvement in the short stature of Turner syndrome (1997) Hum Mol Genet, 6, pp. 1341-1347Filatov, D.A., Gerrard, D.T., High mutation rates in human and ape pseudoautosomal genes (2003) Gene, 317, pp. 67-77Fukami, M., Kato, F., Tajima, T., Yokoya, S., Ogata, T., Transactivation function of an approximately 800-bp evolutionarily conserved sequence at the SHOX 3′ region: Implication for the downstream enhancer (2006) Am J Hum Genet, 78, pp. 167-170Henry, A., Thorburn, M.J., Madelung's deformity. A clinical and cytogenetic study (1967) J Bone Joint Surg, 49 B, pp. 66-73Jorge, A.A., Souza, S.C., Nishi, M.Y., Billerbeck, A.E., Liborio, D.C., Kim, C.A., Arnhold, I.J., Mendonca, B.B., SHOX mutations in idiopathic short stature and Leri-Weill dyschondrosteosis: Frequency and phenotypic variability (2007) Clin Endocrinol, 66, pp. 130-135Lien, S., Szyda, J., Schechinger, B., Rappold, G., Arnheim, N., Evidence for heterogeneity in recombination in the human pseudoautosomal region: High resolution analysis by sperm typing and radiation-hybrid mapping (2000) Am J Hum Genet, 66, pp. 557-566Rao, E., Weiss, B., Fukami, M., Rump, A., Niesler, B., Mertz, A., Muroya, K., Winkelmann, M., Pseudoautosomal deletions encompassing a novel homeobox gene cause growth failure in idiopathic short stature and Turner syndrome (1997) Nat Genet, 16, pp. 54-63Rappold, G., Blum, W.F., Shavrikova, E.P., Crowe, B.J., Roeth, R., Quigley, C.A., Ross, J.L., Niesler, B., Genotypes and phenotypes in children with short stature: Clinical indicators of SHOX haploinsufficiency (2007) J Med Genet, 44, pp. 306-313Rappold, G.A., Fukami, M., Niesler, B., Schiller, S., Zumkeller, W., Bettendorf, M., Heinrich, U., Onigata, K., Deletions of the homeobox gene SHOX(short stature homeobox) are an important cause of growth failure in children with short stature (2002) J Clin Endocrinol Metab, 87, pp. 1402-1406Schneider, K.U., Sabherwal, N., Jantz, K., Röth, R., Muncke, N., Blum, W.F., Cutler Jr, G.B., Rappold, G., Identification of major raombinant hotspot in patients with short stature and SHOX deficiency (2005) Am J Hum Genet, 77, pp. 89-96Shears, D.J., Vassal, H.J., Goodman, F.R., Palmer, R.W., Reardon, W., Superti-Furga, A., Scambler, P.J., Winter, R.M., Mutation and deletion of the pseudoautosomal gene SHOX cause Léri-Weill dyschondrosteosis (1998) Nat Genet, 19, pp. 70-72Zebala, L.P., Manske, P.R., Goldfarb, C.A., (200't) Madelung's deformity: A spectrum of presentation.. The J Hand Surg, 32 A, pp. 1393-1401Zinn, A.R., Ramos, P., Ross, J., (1006) A second recombination hotspot associated with SHOX deletions Am J Hum Genet, 78, pp. 523-52
Morphometry And Histology Of Gonads From 13 Children With Dysgenetic Male Pseudohermaphroditism
Background. - Dysgenetic male pseudohermaphroditism (DMP) is a sexual differentiation disorder characterized by bilateral dysgenetic testes, persistent müllerian structures, and cryptorchidism in individuals with a 46,XY karyotype. However, the histologic criteria for the diagnosis of DMP are poorly established. Objective. - To determine gonadal histology in children with DMP. Patients and Methods. - Between 1996 and 1998, 13 patients with DMP were evaluated on our service. The clinical diagnosis of DMP was based on a 46,XY karyotype, sex ambiguity, high levels of follicle-stimulating hormone and low levels Of antimüllerian hormone, a decreased testosterone response to human chorionic gonadotropin stimulation without accumulation of testosterone precursors, and the presence of müllerian structures. Molecular sequencing the HMGbox region of the SRY gene did not reveal any mutations. Biopsies were performed for 22 of 26 gonads (patient age at the time of biopsy, 16 months to 10 years). Conventional microscopy was used to evaluate mean tubular diameter, tubular fertility index, and number of Sertoli cells per tubular profile. Results. - All 26 gonads were located outside of the labioscrotal folds. Their histologic features varied from only a reduction in tubular size to features of a streak gonad. Five of the 22 gonads grossly resembled a streak gonad. The mean tubular diameter was severely reduced (>30% reduction relative to the normal tubular diameter for the patient's age) in 4 gonads, markedly reduced (10%-30%) in 11 gonads, slightly reduced (<10%) in one gonad, and normal in one gonad. The tubular fertililty index, expressed as the percentage of tubular profiles containing germ cells, was severely reduced (<30% of normal values) in 9 gonads, markedly reduced (50%-30%) in 2 gonads, and normal in 6 gonads. The number of Sertoli cells per tubular profile was elevated in 16 gonads and normal in one gonad. Thin tubules surrounded by fibrous tissue were occasionally observed. Conclusion. - The histologic findings confirmed the clinical diagnosis of DMP in every patient in the present series. However, gonadal histology was variable, and careful morphometric evaluation may be necessary to establish the diagnosis.1255652656Robboy, S.J., Miller, T., Donahoe, P.K., Dysgenesis of testicular and streak gonads in the syndrome of mixed gonadal dysgenesis: Perspective derived from clinicopathologic analysis of twenty-one cases (1982) Hum Pathol, 13, pp. 700-716Troche, V., Hernandez, E., Neoplasia arising in dysgenetic gonads (1986) Obstet Gynecol Surv, 41, pp. 74-79Krasna, I.H., Lee, M.L., Smilow, P., Sciorra, L., Eierman, L., Risk of malignancy in bilateral streak gonads: The role of the Y chromosome (1992) J Pediatr Surg, 27, pp. 1376-1380Rohatgi, M., Gupta, D.K., Menon, P.S., Verma, I.C., Mathur, M., Mixed gonadal dysgenesis and dysgenetic male pseudohermaphroditism - A critical analysis (1992) Indian J Pediatr, 59, pp. 487-500Rey, R.A., Belville, C., Nhou-Fékété, C., Evaluation of gonadal function in 107 intersex patients by means of serum antimüllerian hormone measurement (1999) J Clin Endocrinol Metab, 84, pp. 627-631Stuchi-Perez, E.G., Lukas-Croisier, C., Castro, M., Evaluation of the tubular and interstitial functions of the testis in 46,XY patients with ambiguous genitalia (2000) J Pediatr Endocrinol Metab, 13, pp. 605-612Chang, H.J., Clark, R.D., Bachman, H., The phenotype of 45,X/46,XY mosaicism: An analysis of 92 prenatally diagnosed cases (1990) Am J Hum Genet, 46, pp. 156-167Rajfer, J., Walsh, P.C., Mixed gonadal dysgenesis: Dysgenetic male pseudoher-maphroditism (1981) The Intersex Child: Pediatric and Adolescent Endocrinology, pp. 103-115. , Josso N, ed. Basel, Switzerland: S. KargerBorer, J.G., Nitti, V.W., Glassberg, K.I., Mixed gonadal dysgenesis and dysgenetic male pseudohermaphroditism (1995) J Urol, 153, pp. 1267-1273Donahoe, P.K., Crawford, J.D., Hendren, W.H., Mixed gonadal dysgenesis: Pathogenesis and management (1979) J Pediatr Surg, 14, pp. 287-300Pelletier, J., Bruening, W., Kashtan, C.E., Germline mutations in the Wilms' tumor supressor gene are associated with abnormal urogenital development in Denys-Drash syndrome (1991) Cell, 67, pp. 437-1147Carré-Éusebe, D., Imbeaud, S., Harbison, M., New, M.I., Josso, N., Picard, J.Y., Variants of the anti-Müllerian hormone gene in a compound heterozygote with the persistent Müllerian duct syndrome and his family (1992) Hum Genet, 90, pp. 389-394Nistal, M., Paniagua, R., Non-neoplastic diseases of the testis (1996) Urologic Surgical Pathology, pp. 458-565. , Bostiwick DG, Eble JN, eds. St Louis, Mo: MosbyLennox, B., Ahmad, K.M., Mack, W.S., A method for determining the relative total length of the tubules in the testis (1970) J Pathol, 102, pp. 229-238Jimenez, R., Sanchez, A., Burgos, M., Dias De La Guardia, R.C., Puzzling out the genetics of mammalian sex determination (1996) Trends Genet, 12, pp. 164-166Müller, J., Skakkebaek, N.F., Quantification of germ cells and seminiferous tubules by stereological examination of testicles from 50 boys who suffered from sudden death (1983) Int J Androl, 6, pp. 143-156Cortes, D., Müller, J., Skakkebaek, N.E., Proliferation of Sertoli cells during development of the human testis assessed by stereological methods (1987) Int J Androl, 10, pp. 589-596Nistal, M., Abaurrea, M.A., Paniagua, R., Morphological and histometric study on the human Sertoli cell from birth to the onset of puberty (1982) J Anat, 14, pp. 351-363Van Niekerk, W.A., Retief, A.E., The gonads of human true hermaphrodites (1981) Hum Genet, 58, pp. 117-122Guerra Jr., G., De Mello, M.P., Assumpção, J.G., True hermaphrodites in the southeastern region of Brazil: A different cytogenetic and gonadal profile (1998) J Pediatr Endocrinol Metab, 11, pp. 519-524Quigley, C.A., De Bellis, A., Marschke, K.B., El-Awady, M.K., Wilson, E.M., French, F.S., Androgen receptor defects: Historical, clinical and molecular perspectives (1995) Endocr Rev, 16, pp. 271-32
New insights into the morphology, reproduction and distribution of the large-tuberculate octopus Graneledone macrotyla from the Patagonian slope
The new information reported in this paper is based on 11 specimens of the large-tuberculate octopus Graneledone macrotyla. These specimens were caught in bottom trawl surveys ATLANTIS 2009 and 2010 carried out on the Patagonian slope off the Argentinean Economic Exclusive Zone between 24 February and 1 April 2009 and from 9 March to 5 April 2010 respectively. A new diagnosis and a complete description of the species are provided. This is the first time that stylets, beaks and spermatophores are described. This is also the first time in which mature females have been studied and the female genitalia described. Like other eledonid octopods, G. macrotyla does not have spermathecae in the oviducal glands. The presence of fertilized eggs inside the ovary suggests that fertilization takes place within the ovary. The simultaneous occurrence of oocyte cohorts at different oogenic stages suggests that the species is a multiple spawner. G. macrotyla inhabits shallower waters on the Patagonian slope (475-921 m) than in the subantartic area (1647-2044 m). From a biogeographical point of view, our data show that G. macrotyla inhabits the plume of cold subantarctic waters, which is pushed far north into the southwestern Atlantic by the Falkland (Malvinas) Current.Nueva información sobre la morfología, reproducción y distribución del pulpo megatuberculado Graneledone macrotyla del talud continental Patagónico. – La novedosa información que se proporciona en este trabajo se basa en 11 ejemplares del pulpo megatuberculado Graneledone macrotyla. Esos ejemplares se capturaron en las campañas de prospección ATLANTIS 2009 y 2010, realizadas con arte de arrastre bentónico en el talud patagónico por fuera de la Zona Económica Exclusiva de Argentina, entre el 24 de febrero y el 1 de abril de 2009 y desde el 9 de marzo hasta el 5 de abril de 2010, respectivamente. Se ofrece una nueva diagnosis y una descripción completa de la especie. Esta es la primera vez en que se describen los estiletes, picos y espermatóforos. También es totalmente novedoso el estudio de hembras maduras, lo que ha permitido la descripción de su órgano genital. Como ocurre en otros pulpos de la subfamilia Eledoninae, G. macrotyla carece de espermatecas en las glándulas oviductales. La presencia de huevos fecundados en el ovario sugiere que la fecundación acontece dentro de este órgano. La presencia simultánea de varias cohortes de ovocitos de diferente tamaño sugiere que se trata de una especie cuya freza es múltiple. G. macrotyla vive en aguas más someras del talud patagónico (475-921 m) que en la región subantártica (1647-2044 m). Estos datos muestran que G. macrotyla vive en la pluma de aguas subantárticas, que transportan agua fría hacia el norte del Atlántico sudoccidental a través de la corriente de Malvinas (Falkland)
Postextubation pulmonary edema: A case series and review
SummaryWe report a series of patients with postextubation pulmonary edema who had no obvious risk factors for the development of this syndrome.MethodsPatients identified by the pulmonary consultation service at an academic medical center were reviewed.ResultsFourteen cases were collected and analyzed. The average age was 34.5 years; 12 patients were male. The average BMI was 25.5. None had documented previous lung disease. Most operations were scheduled as outpatient procedures, and the type of surgery ranged from an incision and drainage of a bite wound to an open reduction- internal fixation of the radius. None of the patients had upper airway surgery. The length of surgeries ranged from 27 to 335min. Laryngospasm was the most commonly identified obstructing event postextubation. Treatment involved airway support when needed, supplemental oxygen, and diuretics.ConclusionsIt would appear that all patients, especially young men, are at risk for the development of this syndrome and that the pathogenesis remains uncertain in many cases
Dipolar repulsion in alpha-halocarbonyl compounds revisited
The concept of dipolar repulsion has been widely used to explain several phenomena in organic chemistry, including the conformational preferences of carbonyl compounds. This model, in which atoms and bonds are viewed as point charges and dipole moment vectors, respectively, is however oversimplified. To provide a causal model rooted in quantitative molecular orbital theory, we have analyzed the rotational isomerism of haloacetaldehydes OHC-CH2X (X = F, Cl, Br, I), using relativistic density functional theory. We have found that the overall trend in the rotational energy profiles is set by the combined effects of Pauli repulsion (introducing a barrier around gauche that separates minima at syn and anti), orbital interactions (which can pull the anti minimum towards anticlinal to maximize hyperconjugation), and electrostatic interactions. Only for X = F, not for X = Cl-I, electrostatic interactions push the preference from syn to anti. Our bonding analyses show how this trend is related to the compact nature of F versus the more diffuse nature of the heavier halogens.Theoretical Chemistr
Role of oxidative stress in chronic otitis media with effusion in children
Chronic otitis media with effusion (OME) is a common pathologic condition characterized by nonpurulent fluid in the middle ear (ME) that leads to moderate conductive hearing loss and flat tympanogram. During OME inflammatory cells generate large amounts of superoxide radicals to improve bactericidal activity. Overproduction of oxygen-derived free radicals induces oxidative damage in humans. Glutathione (GSH) is one of the major components of the antioxidant system that protects cells from oxidative stress. The aim of the study was to evaluate oxidative stress in chronic OME by investigation of ME fluids collected during myringotomy. During myringotomy, fluid was collected from the ME to evaluate lipid peroxide levels in the effusion. Immunohistochemical study was also performed to assess the anatomical features of tympanic membrane. Fifty-nine children with ME effusion without any resolution after repeated medical treatments were enrolled in the study. No morphological significant changes were observed. Lipid peroxide levels in all samples were high (mean 11.5 nmole/million cells), similar to the values found in other chronic diseases. GSH might be employed during surgery while applying ventilation tubes and after surgery to prevent oxidative stress. The high oxidant levels in chronic OME observed in our research and the improvement seen in children after antioxidant treatment suggest that oxygen-derived free radicals play an important role in chronic OME.
Nonparametric stochastic modeling of linear systems with prescribed variance of several natural frequencies
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