Dielectric properties of R2O−SiO2 glasses prepared via sol-gel

Gels from R₂O−SiO₂ (R=potassium, sodium and lithium) systems with a maximum alkaline content of 5 mol % were prepared. The conductivity and the alkaline ion incorporation degree as a function of temperature were studied by a.c. impedance spectroscopy and dielectric relaxation measurements. At low temperature (20 to 200°C) the major contribution to the total electric conductivity is due to water conducting species (mainly protons) which are adsorbed inside the gels. From 450°C gels start to behave as conventional glasses. The total electric conductivity and activation energy values for conduction at those high temperatures are of the same order as those for glasses prepared by direct melting.     

Prevalence of Down's syndrome in Asturias, 1987-1993. Members of the Work Group of the RCDA

OBJECTIVE: To determine the frequency of Down Syndrome (DS) in Asturias and the prenatal diagnosis impact on the birth prevalence of this chromosomal anomaly. METHODS: The analysed data came from the Registry of Congenital Defects of Asturias (1990-1993) and from a retrospective study conducted by the same working group (1987-1989). The total prevalence rates and the prevalence at birth were calculated. RESULTS: Out of 55,601 births, DS was recorded in 83 cases: 69 livebirths, two fetal deaths and 12 induced abortions following prenatal diagnosis, giving a total prevalence rate of 14.9 per 10,000 and a birth prevalence of 12.8. The proportion of induced abortions was 15 per cent in this period; the proportion of cases in the high risk maternal age group (35 years and over) was around 50% of the total. The proportion of induced abortions was 15 per cent in this period. CONCLUSIONS: The frequency of DS in Asturias is comparable to the other populations. Prenatal diagnosis had little impact on the birth prevalence figures. These results may help us draw up prevention and prenatal diagnosis policies for these defects in Asturias when giving the frequency of this health problem.     

Differential expression of CD44v6 in adenocarcinoma of the pancreas: an immunohistochemical study

Alternative splicing gives rise to numerous CD44 isoforms, some of which seem to have a role in tumour metastasis. Specifically, a variant form of CD44 with sequences encoded by exon v6 (CD44v6) confers metastatic potential when transfected into a nonmetastasizing cell line of rat pancreatic adenocarcinoma. This study has investigated standard CD44 (CD44s) and CD44v6 expression immunohistochemically in 6 samples of normal pancreatic tissue, 4 of tissue affected by chronic pancreatitis, and 24 of tissue from metastasizing and nonmetastasizing pancreatic adenocarcinomas. In addition, 18 samples from lymph node or visceral metastases were included in the study. CD44s was expressed in nonneoplastic tissue and in tissue from pancreatic adenocarcinomas. In contrast, CD44v6 was not detected in any of the normal tissue or chronic pancreatitis specimens, whereas 54% of pancreatic adenocarcinomas and 55% of metastases expressed this variant exon. Although it is not clear whether CD44 isoforms containing exon v6 play a part in malignant progression in the human exocrine pancreas, it seems plausible that the expression of multiple isoforms containing this and other variant exon confers a selective advantage on pancreatic adenocarcinoma.     

Dry eye in Waldenstr?m's macroglobulinemia. Improvement after systemic chemotherapy

Waldenstr?m's macroglobulinemia is an uncommon cause of dry eye. We describe a case of dry eye associated with Waldenstr?m's macroglobulinemia that responded poorly to substitutive topical treatment but improved spectacularly in response to systemic chemotherapy. As far as we know, no similar case has been reported.     

Infiltrating transitional carcinoma of the bladder. (1st part). Preoperative or neoadjuvant chemotherapy. Our experience with 38 patients followed-up for a prolonged period

Analysis of the evolution of 37 patients treated with neoadjuvant chemotherapy + radical cystectomy and bilateral lymphadenectomy. Patients were followed until death, and survivors between 43 and 68 months. Twenty-six patients died. Twenty of them within 24 months after treatment and 6 after 2 years. Five did not undergo surgery due to fast tumour progression during the interval scheduled for cytostatics administration. Bladder removal was rejected in 5 cases after a significant loco-regional progression was shown by laparotomy. Initially, bladder was preserved in 12 patients after TUR + chemotherapy, and in 8 patients when cCR was observed: 1 died due to a disease unrelated cause. 1 was lost after 16 months with no evidence of vesical cancer or metastasis. 3 presented distant dissemination. 3 are alive and have no evidence of tumour. 1 pCR died of metastasis. 1 cPR required radical cystectomy and died of metastasis. Of the 2 cases defined as sCR, one had to undergo radical cystectomy and remains disease-free while the other one died of metastasis. Radical cystectomy was performed in 15 cases. Three remain tumour-free, 2 were lost. to follow-up and 10 died (3 for disease-unrelated causes and 7 as a consequence of their condition). Nodes affectation were present in 54%. Metastasis was found in 57.3% and 17.3% had local relapse. The pre-operative chemotherapy regime examined has not contributed to prolong the metastasis-free interval in the group of patients studied.     

Biologic value of the protein concentrate of Atripex lampa and its value as a complement to wheat flour

The Atriplex lampa, chenopodiáceae, is a very abundant bush in the arid and semiarid regions of our Province. This work was undertaken to characterize from the chemical point of view, both the fresh leaves and the protein concentrate (PC) obtained from them. A second purpose was to determine the biological value of the protein, and to evaluate its capacity as a complement to wheat flour (WF). Through this study, the leaf was shown to have a high content of ashes, sodium, potassium and silica, what accounts for its low palatability. The PC obtained has a protein concentration of 59.37 g/100 g and its biological value is limited by the sulfur amino acids, with a chemical score of 85.70. Since the protein is poorly utilized, this results in a relatively low value of its net protein utilization (NPU), a fact which may be attributed to its low true digestibility. The studies on the complementary effects of PC on WF were made at three levels, i.e., 30, 50 and 60%, respectively. The results revealed that the best complementation, measured by the nitrogen utilization, happened to be when 50% of the protein contribution was provided by the A. lampa protein concentrate.     

Is an intestinal permeability test a valid marker for slight dietary transgressions in adolescents with coeliac disease?

Adolescents with coeliac disease often fail to adhere to a strict gluten free diet. The effectiveness of intestinal permeability to sugars as a marker of slight dietary transgressions by such adolescents was assessed. Severe dietary transgressions were excluded from the study. Subjects were divided into two groups according to whether they committed slight dietary transgressions or adhered to a strict gluten free diet. A reference group of preadolescents with coeliac disease was also included in the study. Intestinal permeability and antigliadin antibody tests were performed on all patients. The diagnostic marker of intestinal permeability was excellent in the reference group. Neither the intestinal permeability test nor antigliadin antibody tests, however, succeeded in discriminating between the two groups of adolescents considered in this study. In conclusion the intestinal permeability test is not a valid marker for slight dietary transgression in such patients.