Biomedical subjects
Publications and source records attributed to C Ramos.
Prenatal diagnosis of sex differentiation disorders is extremely rare and is estimated in 1/2500 analyzed gestations. A group of this disorders are the 46, XX males and its incidence is estimated in 1/20000 male neonates. We report a male XX fetus in which the diagnosis of sex determination was requested at 20 gestation weeks to clarify the real gender of the fetus. Discrepancy between cytogenetic and ultrasonographic was detected.
From Raman spectroscopy, magnetization, and thermal expansion on the system La(2/3)(Ca(1-x)Sr(x))(1/3)MnO3, we have been able to provide a quantitative basis for the heterogeneous electronic model for manganites exhibiting colossal magnetoresistance (CMR). We construct a mean-field model that accounts quantitatively for the measured deviation of T(C)(x) from the T(C) predicted by de Gennes double-exchange in the adiabatic approximation and predicts the occurrence of a first-order transition for a strong coupling regime, in accordance with the experiments. The existence of a temperature interval T(C) < T < T*, where CMR may be found, is discussed in connection with the occurrence of an idealized Griffiths phase.
Choroideremia (CHM) is an X-linked recessive ophthalmic disease characterized by a progressive degeneration of the choroid and the pigmented epithelium of the retina. We present the genetic characterization of a female patient affected with CHM who has been previously studied cytogenetically and showed a balanced translocation between chromosomes X and 4 [46,X,t(X;4)(q21;p16)]. The breakpoint in the X chromosome lies in the locus of CHM gene and for this reason, we have elucidated whether or not CHM was disrupted in the X chromosome involved in the translocation using different techniques. FISH showed that the 3'UTR and the last exons of the CHM were on the der(X) chromosome, and the 5'UTR and first exons of this gene were on the der(4) chromosome. Expression level analysis revealed that the breakpoint in the der(X) was located between exons 8 and 9 of the CHM gene because the expression level decreased from this point onwards. Based on this result the expression level analysis proved to be a valid method to pinpoint the location of breakpoints when the gene being expressed in peripheral blood is disrupted. Our results confirmed that the CHM gene was indeed disrupted in the X chromosome involved in the translocation. Besides, the nonrandom inactivation of the normal X chromosome observed using a methylation-specific polymerase chain reaction (M-PCR) technique explained the CHM in the female patient.
To assess the role of scintigraphy with 111In-DTPA-D-Phe-octreotide (111In-octreotide) in the diagnosis of pituitary adenomas and in the evaluation of post-surgical recurrent or residual tumours, we performed scintigraphy with 111In-DTPA-D-Phe-octreotide (SRS) in 35 patients: 14 patients with confirmed pituitary tumours and 15 with confirmed recurrent tumours. Clinical, biochemical and histological analyses, conventional images (CT/MRI), and follow-up assessments during a period of 1 year to 4 years were recorded in all patients. In the present study, scintigraphy with 111In-octreotide showed positive uptake in 10 out of 14 patients with confirmed pituitary tumour and in 13 out of 15 patients with confirmed recurrent tumour, with an overall sensitivity of 79%. SRS showed better results in growth hormone (GH)- and prolactin (PRL)-secreting tumours (7/8 patients correctly identified) than in other adenomas (3/9). SRS detected recurrence of adenocorticotrophic hormone (ACTH)-secreting tumours (4/5 patients correctly identified) and non-secreting tumours (5/7 patients correctly identified). 111In-octreotide scintigraphy, in combination with other imaging modalities, is useful in the diagnosis and follow-up of pituitary tumours. It allows scar tissue to be differentiated from tumour recurrence after surgical treatment and ensures better selection of patients who will benefit from medical treatment with somatostatin analogues.
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We have analyzed Msx1 expression in the mature mouse brain using in situ hybridization and beta-galactosidase activity in Msx1(nLacZ) mice. The study revealed that Msx1 is strongly expressed in the circumventricular organs, such as the subcommissural organ and choroid plexus, and in some epithelia, such as that of the dorsal, but not the ventral part of the third ventricle. Immunohistochemical analysis revealed that the Msx1-expressing cells of the hippocampus and fimbria are astrocytes, oligodendrocytes or immature oligodendrocytes. In contrast, no co-expression was detected in these structures using several neuronal markers. These results were confirmed, using transmission electron microscopy, by the presence of 5-bromo-3-indolyl-beta-D-galactopyranosideprecipitates in astrocytes and oligodendrocytes in both sites. Moreover, using an anti-glial fibrillary acidic protein antibody (GFAP), our study reveals two populations of astrocytes in the adult hippocampus and other areas, such as the fimbria, namely Msx1+/GFAP+ and Msx1-/GFAP+. Beta-galactosidase activity was also observed in endothelial cells of hippocampal fissure blood vessels. We also observed co-localization of polysialic acid neural cell adhesion molecule, a marker of the polysialylated form of the neural cell adhesion molecule, in Msx1-expressing cells in the fimbria. These cells may be precursors of glial cells and originate from the epithelium of the fimbria. The present study indicates, in the mature mouse brain, that Msx1 may be linked to secretory activity in circumventricular organs, and to glial proliferation and differentiation in the hippocampus and fimbria, and presumably also in other cerebral areas. We suggest that Msx1 could be associated with brain homeostasis and blood-brain barrier function.
The sinus venosus of fish is the most caudal chamber of the heart. It is often reduced in teleosts but well developed in elasmobranchs. The sinus venosus of the dogfish (Scyliorhinus canicula) is vital, since it harbours key elements such as a little known neuroendocrine system and the nodal tissue. However, the study of its structure is still incomplete. We examined the endocardium, epicardium and subepicardium of the sinus venosus in mature dogfishes. The wall is 100-250 microm thick and comprises three main layers. Large bundles of myocardial cells occupy the middle layer. The endothelial ensheathing is composed of thin endocardial cells with prominent nuclei towards the lumen, whose cytoplasm contains numerous dense bodies and moderately dense bodies, 150-800 nm in diameter and large vacuoles. The possible functions of these organelles are discussed. The outermost layer is made of a robust sheet of cuboidal epicardial cells separated from the subepicardium by a conspicuous basal lamina. Numerous microvilli towards the pericardial cavity and elliptical vesicles are located in the apex of epicardial cells. A thick layer richly endowed with dense bundles of collagen fibres forms the subepicardial space. This structure should be contrasted with the venous return mechanism of elasmobranchs.
Msx1 is a regulatory gene involved in epithelio-mesenchymal interactions in limb formation and organogenesis. In the embryonic CNS, the Msx1 gene is expressed along the dorsal midline. Msx1 mutant mice have been obtained by insertion of the nlacZ gene in the Msx1 homeodomain. The most important features of homozygous mutants that we observed were the absence or malformation of the posterior commissure (PC) and of the subcommissural organ (SCO), the collapse of the cerebral aqueduct, and the development of hydrocephalus. Heterozygous mutants developed abnormal PC and reduced SCO, as revealed by specific antibodies against SCO secretory glycoproteins. About one third of the heterozygous mutants also showed hydrocephalus. Other defects displayed by homozygous mutants were ependymal denudation, subventricular cavitations and edema, and underdevelopment of the pineal gland and subfornical organ. Some homozygous mutants developed both SCO and PC, probably as a consequence of genetic redundancy with Msx2. However, these mutants did not show SCO-immunoreactive glycoproteins and displayed obstructive hydrocephalus. This suggests that Msx1 is necessary for the synthesis of SCO glycoproteins, which would then be required for the maintenance of an open aqueduct.
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The discovery of fetal DNA in maternal plasma from early pregnancies has led to new opportunities for clinical application. In the last few years there have been numerous reported applications, mainly fetal gender and RhD genotyping. The prenatal diagnosis of some inherited genetic diseases such as Huntington disease is also very frequently required in the prenatal diagnosis routine. We have successfully diagnosed, with a non-invasive procedure, an unaffected HD fetus at the 13th week of gestation using fetal DNA from maternal plasma and the quantitative fluorescent PCR method, which is one of the most sensitive ways to detect fetal DNA in maternal plasma at such an early time of gestation.
BACKGROUND: Transbronchial needle aspiration (TBNA) is a bronchoscopic technique whose usefulness in diagnosing endobronchial lesions has not yet been clearly established. OBJECTIVE: We aimed to determine whether the diagnostic yield of fiberoptic bronchoscopy could be increased, without a negative impact on diagnostic costs, if TBNA were used in combination with conventional diagnostic techniques (bronchial washings and bronchial brushings and forceps biopsy). PATIENTS AND METHODS: The cases of 130 patients diagnosed with bronchogenic carcinoma with endoscopically visible lesions were analyzed retrospectively. All had undergone conventional diagnostic procedures; TBNA was also performed if the bronchoscopist considered it was indicated. The final cost was calculated in euros for each diagnosis as the sum of the cost of the procedures needed to reach the diagnosis, including both endoscopic procedures and others (transthoracic needle aspiration, lymph node biopsy). Diagnostic yield and costs in cases diagnosed using only conventional techniques were compared to the yield and costs in cases in which both conventional techniques and TBNA were used. RESULTS: TBNA was performed in 49 patients and provided the diagnosis in 85.7%. Conventional techniques led to cytological and histological diagnosis in 80.2% of the cases, and the combination of conventional techniques and TBNA gave a diagnosis in 89.7% (P=.01). Significant differences were observed in extrinsic compression (conventional 37.5%; conventional+TBNA 100%; P=.01), submucosal infiltration (conventional 54.6%; conventional+TBNA 85%; P=.03), and exophytic mass with necrosis (conventional 80%; conventional+TBNA 100%; P=.01). The mean (SD) cost of diagnosis was euros 381.60 (euros 156.53) using conventional techniques and euros 413.25 (euros 112.91) for conventional techniques in combination with TBNA. By adding TBNA, costs decreased for diagnoses of submucosal infiltration, exophytic mass with necrosis and extrinsic compression, although the saving was significant only for extrinsic compression. CONCLUSION: The diagnostic yield of TBNA is high for endoscopically visible bronchial anomalies suggesting neoplasm, particularly when the lesion is due to extrinsic compression, submucosal infiltration, or exophytic mass with necrosis.
Nowadays, the chemoradiotherapeutic protocols for Hodgkin's disease (HD) achieve high curability rates. Hemato-oncologists focus on both avoiding medical and psychological sequelae of the treatment and returning patients to a normal life. The quality of life and psychological well-being of Spanish patients who are long-term survivors of HD were studied and compared to the results obtained from healthy controls. Questionnaires on quality of life [European Organization for Research and Treatment of Cancer (EORTC) QLQ30] and psychological status [hospital anxiety and depression (HAD) scale] were mailed to HD patients without active disease and free of second malignancies and were also given to healthy controls. Of 67 selected patients (68.6%), 46 were included in this study. The median follow-up for these 46 patients was of 7.6 years (0.8-22.1) after being diagnosed. Although there were no differences between patients and controls with regard to their global state of health and quality of life (72.9+/-22.7 vs 79.3+/-18.7; p=0.22), patients presented a lower physical function (88.2+/-18.1 vs 96.5+/-9.7; p=0.05) and a worse social operation scale (81.5+/-25.4 vs 96.3+/-13.1; p= 0.0015) together with higher symptoms of dyspnea (8.6+/-14.7 vs 0+/-0; p=0.03) and higher economic difficulties (23.1+/-38.3 vs 0.7+/-4.9; p=0.017) when compared with healthy controls. However, we did not find differences in the scores and the proportion of cases of anxiety and depression between the two groups. The quality of life questionnaire disclosed differences between patients and controls in some functional and symptomatic scales. These differences can be read as a consequence of either the disease itself or the treatment received. However, the results of this controlled pilot study should be confirmed in a larger series of Spanish HD survivors. In the future, these results could be a reference when new therapeutic protocols are designed to reduce the impact on the quality of life of the patients. Socioeconomic support to the patients should also be provided in order to improve their medical care.
The effect of ascorbic acid, light, and storage on the stability of the pigments beta-carotene and capsanthin in red pepper (Capsicum annuum) powder has been elucidated by determining the amount of pigment in samples treated by various concentrations of ascorbic acid. Determination of pigment concentration has been performed after different storage times using high-performance liquid chromatography. The dependence of the concentration of pigments on the concentration of ascorbic acid, presence of light and the storage time has been assessed by stepwise regression analysis. The concentration of pigments decreased at longer storage time and increased at higher concentration of ascorbic acid, beta-carotene being more sensitive towards storage time and concentration of ascorbic acid than capsanthin. Interaction between the effects of light and storage time, and light and concentration of ascorbic acid has been established.