Manuel Nistal

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A case is presented of an infertile male whose spermatozoa showed low mobility, a high percentage of irregular large heads and a variable number of tails (between 0 and 4). In the spermatozoa with several tails each axoneme, surrounded by its own outer fibres and mitochondrial sheath, arose from its own basal plate. Throughout the middle piece of every(More)
The oncogene BRAF(V600E) is the most frequent genetic event in papillary thyroid carcinoma (PTC) but its prognostic impact still remains to be elucidated. We evaluated a representative series of 67 individuals with PTC who underwent total thyroidectomy. BRAF-positive tumours correlated with early recurrences (32% vs 7.6%; P=0.02) during a median(More)
Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHS-R), has been primarily linked to the central neuroendocrine regulation of GH secretion and food intake, although additional peripheral actions of ghrelin have also been reported. In this context, the expression of ghrelin and its cognate receptor has been recently demonstrated in rat(More)
Pluripotent cells can be isolated from the mammalian inner cell mass (ICM) of the embryo at the blastocyst stage, and maintained in culture as undifferentiated, embryonic stem cells (ES). These cells are an important model of mammalian development in vitro and are the focus of a great deal of research for their use in Cell Therapy. In vivo, shortly after(More)
The distribution of the androgen receptor (AR) in archival human testes was determined immunocytochemically using an affinity-purified peptide-specific rabbit antibody, PG21, and employing a modified biotin-streptavidin-immunoperoxidase method that incorporated a biotin amplification step. In combination with microwave epitope retrieval, the biotin(More)
The activating mutation BRAF(V600E) is a frequent genetic event in papillary thyroid carcinomas (PTC) that predicts a poor prognosis, leading to loss of sodium/iodide symporter (NIS) expression and subsequent radioiodide-refractory metastatic disease. The molecular basis of such an aggressive behavior induced by BRAF remains unclear. Here, we show a(More)
The ultrastructural study of testicular biopsies from 87 adult men revealed mitosis in two mature Leydig cells, each from a different man. The men showed normal hormone levels and had received no previous chemotherapy or hormone treatment, nor had they been exposed to known toxic agents. The presence of mitotic Leydig cells suggests that differentiated(More)
The testes of two premature newborns and a 9-year-old boy with cystic dysplasia were studied by light and electron microscopy. The histologic pattern of the three cases was similar, differing principally in the extension of the characteristic lesion. This consisted of multiple, anastomosing, irregular cystic spaces of varying sizes and shapes, separated by(More)
Five cases of large cell calcifying Sertoli cell tumour of the testis not associated with complex dysplastic syndromes are reported. The age of the patients ranged from 13 to 34 years and all the tumours were histologically similar, having large, isomorphic, non-mitotic, eosinophilic Sertoli cells with foci of calcification. Flow cytometry demonstrated the(More)
Cdc42, a member of Rho GTPases family, is involved in the regulation of several cellular functions, such as rearrangement of actin cytoskeleton, membrane trafficking, cell-cycle progression, and transcriptional regulation. Aberrant expression or activity of Cdc42 has been reported in several tumours. Here, the specific role of Cdc42 in development and(More)