Cytogenetic relationships, polyploid origin and taxonomic issues in Paspalum species: inter- and intraspecific hybrids between a sexual synthetic autotetraploid and five wild apomictic tetraploid species.

Paspalum is a noteworthy grass genus due to the forage quality of most species, with approximately 330 species, and the high proportion of those that reproduce via apomixis. Harnessing apomictic reproduction and widening knowledge about the cytogenetic relationships among species are essential tools for plant breeding. We conducted cytogenetic analyses of inter- and intraspecific hybridisations involving a sexual, colchicine-induced autotetraploid plant of P. plicatulum Michx. and five indigenous apomictic tetraploid (2n = 40) species: P. compressifolium Swallen, P. lenticulare Kunth, two accessions of P. nicorae Parodi, P. rojasii Hack. and two accessions of P. plicatulum. Fertility of the hybrids was investigated and their reproductive system was analysed considering the relative embryo:endosperm DNA content from flow cytometry. Morphological, nomenclatural and taxonomic issues were also analysed. Cytogenetic analysis suggested that all indigenous tetraploid accessions of five apomictic species are autotetraploid or segmental allotetraploid. If segmental allotetraploids, they probably originated through autoploidy followed by diploidisation processes. Autosyndetic male chromosome pairing observed in all hybrid families supported this assertion. Allosyndetic chromosome associations were also observed in all hybrid families. In the hybrids, the proportion of male parent chromosomes involved in allosyndesis per pollen mother cell varied from 5.5% to 35.0% and the maximum was between 25% and 60%. The apomictic condition of the indigenous male parents segregated in the hybrids. These results confirm a strong association between autoploidy and apomixis in Paspalum, and the existence of cytogenetic relationships between different species of the Plicatula group. Allosyndetic chromosome pairing and seed fertility of the hybrids suggest the feasibility of gene transfer among species.

Reproductive biology of the native forage grass Trichloris crinita (Poaceae, Chloridoideae).

Trichloris crinita is a perennial forage grass species native to arid regions of the American continent. Due to its extensive area of distribution, good forage quality and resistance to drought and grazing, this species is widely utilised as forage and for revegetation purposes in environments with low water availability. Despite its importance, genetic improvement of T. crinita has been very limited, partly as consequence of the lack of knowledge on its mode of reproduction. In the present work, we studied the reproductive biology of T. crinita by means of embryological analyses, flow cytometric seed screen (FCSS), self-compatibility tests and progeny testing with morphological and molecular markers. Cytological analyses revealed embryo sacs with eight nuclei and of Polygonum type for all T. crinita accessions analysed. FCSS histograms exhibited two clear peaks corresponding to 2C and 3C DNA content, indicating embryo sacs of sexual origin. Controlled pollination experiments designed to evaluate seed set (%) demonstrated that T. crinita is self-compatible, whereas results from morphological and simple sequence repeat (SSR) marker analysis of progeny revealed lack of outcrossing. Together, these results indicate that T. crinita reproduces sexually. It is a self-compatible and autogamous species. It is expected that these data will have a positive impact in the genetics and breeding of this species, and therefore contribute to its proper utilisation in arid regions.

Carcinoma de Células escamosas de vulva. Presentación de 28 pacientes / Squamous cell carcinoma of the vulva. Experience in 28 patients

Introducción. El carcinoma de células escamosas de la vulva constituye el 1 al 4 % de los tumores en la mujer, y ocupa el cuarto lugar de las neoplasias del tracto genital femenino. Objetivos. Determinar la incidencia de carcinoma epidermoide de vulva, e identificar el grado de invasión. Material y métodos. Se realizó un estudio retrospectivo, observacional de las pacientes atendidas en el consultorio de patología vulvar durante 4 años y 8 meses. Se estudiaron 28 mujeres con diagnóstico clínico e histopatológico de carcinoma de células escamosas. Resultados. Del total de pacientes evaluadas en el consultorio, 6,17% (28) presentó carcinoma de células escamosas. La edad promedio fue de 62,5 años. De las 28 pacientes, el 64,28% (18) presentó carcinoma de células escamosas invasor y el 35,7% (10) VIN, cuatro desarrollados a partir de liquen escleroso, tres con displasia epitelial (VIN diferenciado) y tres con diagnóstico de papulosis bowenoide (VIN usual). Todas las pacientes refirieron como signo predominante prurito y el tabaquismo se detectó en el 60% de los casos. Conclusiones. Se presentan 28 casos de carcinoma epidermoide vulvar: el 64,2 % fue invasor y el 35,7% neoplasia intraepitelial (VIN). De ésta el 70% correspondió a VIN diferenciado y el 30% restante a VIN usual. Esta casuística nos ha permitido conocer la incidencia de neoplasia epitelial vulvar en nuestro medio además de poder diferenciar los grados de invasión y factores patogénicos.

Introduction. The squamous cell carcinoma of the vulva constitutesbetween 1 and 4% of cancers affecting women, occupying fourthplace among neoplasias of the female genital tract.Objetives. To determine the incidence of squamous cell carcinomaof the vulva and identify grade of invasion.Material and methods. An observational retrospective study wasconducted, in which 28 patients were studied with clinical and pathologicaldiagnosis of squamous cell carcinoma of the vulva.Results. Of the total genital carcinomas in our hospital, the vulvarcarcinomas accounted for 6.17% of the genital tract tumours. Of the28 patients included in the study, 18 invasive carcinomas (64.28%)were detected and 10 vulvar intraepidermal neoplasia (VIN 35.7%).The average age of incidence was 62.5 years. The predominantsymptom was pruritus, and the most significant signs were tumour.In the 10 patients that were diagnosed with VIN, 4 developed froma lichen sclerosus, 3 from epithelial dysplasia and 3 with papulosisbowenoide. 60% of patients were smokers.Conclusions. 28 cases of epidermoide carcinoma of the vulva werestudied resulting in 64.2% invasive and 35.7% VIN. Of the latter, 70%corresponded to differentiated VIN and 30% usual VIN. This casuistryhas permitted us to observe the incidence of squamous cell carcinomain our region, and allowed us to differentiate the grades of invasionand pathogenic factors (Dermatol Argent 2009;15(5):344-349).

Eritrodermia en 3160 pacientes internados en clínica médica / Erythroderma in 3160 in-patients at clinical department

La eritrodermia es una enfermedad inflamatoria cutánea generalizada. Generalmente se presenta en la edad media de la vida y en la mayoría de los casos es debida a exacerbación de dermatosis preexistentes. Puede asociarse a manifestaciones sistémicas como poliadenopatías, hepatomegalia, eritrosedimentación acelerada, leucocitosis y/o eosinofilia, entre otros. Con el fin de conocer la incidencia y la etiología de esta patología en nuestro hospital realizamos un estudio retrospectivo y observacional sobre 3160 historias clínicas de pacientes internados en el servicio de clínica médica. Detectamos 25 casos de eritrodermia lo cual implica una incidencia del 0.79%. La edad media de presentación fue 48 años. La etiología más frecuente fue la secundaria a medicamentos, siendo los β lactámicos los más involucrados. La alteración sistémica mayormente observada fue la eosinofilia (62%). El comienzo de la enfermedad en la mayoría de los casos fue agudo.

Erythroderma is an inflammatory and generalized skin disorder (more than 90% of the body surface area) accompanied by a variably degree of scaling. Often affects middle ages of life and it is usually caused by the exacerbation of a preexisting dermatoses. It could be associated to systemic manifestations like lymphadenopathy, liver enlargement, leukocytosis and elevated erythrocyte sedimentation. The aim of this study was to determinate the incidence and also the etiology of this pathology in our environment. We made a retrospective and observable study based on the research of 3160 clinic stories of patients that were in the hospital at the Clinical Department. We found that 25 patients were diagnosed with erithroderma (incidence 0.79%). The mean age at diagnosis was 48 years. The most common causative factor was drug reactions been the β lactams the most involved drug. Eosinophilia was the most important systemic manifestation (62%). The onset of erithroderma was usually abrupt and florid.