Diabetic nephropathy: glomerular filtration rate and estimated creatinine clearance

OBJECTIVE: To assess in diabetic nephropathy, the accuracy of estimated creatinine clearance (calculated with the Cockroft Gault formula) and the clearance of the Tc99m-DTPA, to measure the glomerular filtration rate (GFR). PATIENTS AND METHODS: We analysed the GFR measure by Tc99m-DTPA method and the estimated by the Cockroft Gault formula, in 21 subjects with type 1 or type 2 diabetes. RESULTS: There was a strong positive correlation between the two methods but the Cockroft Gault formula underestimated the GFR. CONCLUSIONS: The formula gives a accurate estimates of GFR, when GFR is <100 ml/min/1,73 m2. Beside the underestimation, the formula could be used in the management of diabetic nephropathy because the repeated isotope assessments of renal function are impracticable

An overview of lignin pathways of valorization: from isolation to refining and conversion into value‑added products

ABSTRACT: The increasing demand for greener and sustainable alternatives to fossil-derived fuels, chemicals, and materials has attracted huge attention to lignin, the largest renewable source of aromatic building blocks on earth. This natural polymer accounts for 15 to 40% of all lignocellulosic biomass. As such, in the pulp and paper industries, for example, huge amounts of lignin are produced worldwide. However, most applications for these lignins are of low value, such as their burning for energy. Furthermore, with the introduction of second-generation ethanol biorefineries, the overall lignin production increased. To attain a circular bio-based economy, all side-streams of lignocellulosic biomass and, particularly, lignin should be valorized to as high of a value as possible. Lignin's rich structure has allowed achieving various high-value products over the years, not only in the production of biofuels but also regarding chemicals and materials. The present paper addresses a broad vision of the several stages of lignin valorization, from the isolation of lignin through pre-treatments of lignocellulosic biomass and the current industrial lignin production to fractionation methodologies that provide homogeneous lignins more adequate for valorization and the conversion of lignin into value-added products via chemical and biological routes.info:eu-repo/semantics/publishedVersio

Prebiotic xylo-oligosaccharides as high-value co-products on an integrated biorefinery approach from lignocellulosic feedstock

The present work proposes the production of prebiotic xylo-oligosaccharides (XOS) as high-value co-products of the Lignocellulose Feedstock Biorefinery concept, foreseeing potential applications on food, feed and nutraceutical industries. Autohydrolysis was used to selectively solubilise the hemicellulosic fraction of several xylan-rich, widely available, agricultural, agro-industrial and forestry by-products: corn cobs, brewery’s spent grain and Eucalyptus wood chips. The soluble hemicellulose-rich and the solid cellulose- and lignin-rich fractions were separated, and the crude XOS-rich hydrolysates were further purified by gel filtration chromatography. Selected fractions of purified XOS within the desired ranges of polymerization degree were characterised and their prebiotic potential was investigated in in vitro fermentations by bifidobacteria, lactobacilli and intestinal inocula. Parameters such as bacterial growth and XOS consumption were evaluated and compared with commercially available xylo-oligosaccharides. The differences observed were considered of relevance for the formulation of symbiotic preparations and the future design of targeted, tailor-made prebiotic xylo-oligosaccharides

Diabetes in the elderly: our reality

AIM: To evaluate the impact of the aging of our population in the growing of diabetes prevalence, among patients treated inward at our department. MATERIAL AND METHODS: The clinical files of 242 diabetics older than eighty years, treated between 1999 and 2002 were studied retrospectively. Demographic (sex, age, year of first contact), clinical (causes of admission, co-morbidities, duration of diabetes, previous hypoglycaemic treatment, duration of hospitalisation and evolution) and biochemical (glycaemia, HbA1c, lipaemia and C-peptide) data were recorded. RESULTS: A progressive rising in the number of aged patients was found during this period (seven in 1999 to 55 in 2002), with a large proportion of women (73%). The more frequent causes of in-hospital treatment were hyperglycaemia (20.6%) and feet ulcers (septic or necrotic) (16.5%). In nearly 42% of the cohort an acute infection was found. Diabetes was unknown in 13% of cases and less than ten years of duration in 38%. In this cohort most of the patients (77%) were treated with oral hypoglycaemic drugs, mostly sulfonylureas. HbA1c mean value was 10.4 +/- 2.2%; C -peptide was measured in a subset of cases (n=79), suggesting deficient insulin secretion in 18% of them. The global mean duration of hospitalisation was eleven days. Nineteen patients (8%) died during the hospitalization. CONCLUSIONS: In this study, we concluded that diabetes in people older than 75 years, is being progressively more often diagnosed. The general metabolic control was bad (HbA1c mean value--10.4 +/- 2.2%), with a significant number of patients presenting a deficient C-peptide secretion, worsened by frequent coexisting infections. So, a strengthened clinical care, directed to a careful diagnosis and treatment, may effectively contribute to a better prognosis and quality of life of aged diabetic patients

Autoimmune hypophysitis or lymphocytic hypophysitis

This entity, due to the pituitary lymphoplasmacytic infiltrate, was described for the first time in 1962. The clinical suspicion relies on a rapidly progressing hypopituitarism, particularly with adrenal involvement, affecting women in the peripartum period or patients with previously recognized autoimmune disease. Diabetes insipidus is also often reported. A sellar mass is found in 80% of cases. The diagnosis is confirmed by histology, due to the absence of a specific serological test. The endocrine deficiencies are frequently definitive. Corticotherapy is usually effective in reducing neurological symptoms due to pituitary enlargement, and frequently allows to avoid surgery. The disease-related deaths were due to acute adrenal insufficiency or ineffectively treated hypopituitarism. We are reporting a clinical case of probable lymphocytic hypophysitis in the early post partum of a woman with depression and Graves disease. She has hyperprolactinemia and ACTH deficiency, without pituitary changes in the magnetic resonance imaging. She was treated and her depression and hyperthyroidism were relieved. Hyperprolactinemia recovered spontaneously but she still needs glucocorticoid substitution

CYP2D6 genetic polymorphisms are associated with susceptibility to pituitary tumors

Several polymorphisms of drug-metabolizing enzymes have been implicated in the susceptibility to tumor development. The role of the CYP2D6, GSTM1 and GSTT1 genes has been extensively studied, with alleles conferring different metabolic efficiencies and tumor risk. We studied the relationship between the main polymorphisms of these genes and the susceptibility to develop pituitary tumors, by performing a case-control study comprising 235 patients and 256 controls which were genotyped by means of PCR-RFLP based assays. Frequencies of the CYP2D6*1 and of the poor metabolizer allele CYP2D6*4, were determined along with the frequencies of the GSTM1 and GSTT1 null genotypes. CYP2D6 genotype frequencies were similar in patients and controls (p=0.087). CYP2D6*1 and CYP2D6*4 allele frequencies were 83.8%, 16.2% in cases and 78.3%, 21.7% in controls, showing a significant difference between the two groups (p=0.012). There were no significant differences between the frequencies of the GSTM1 and GSTT1 null genotypes in both groups. No association was found between histological type and any of the studied polymorphisms. Our data suggest an association of the CYP2D6*1 allele and the susceptibility to pituitary adenomas, which could be due to an increased metabolism of unidentified procarcinogens or to linkage disequilibrium with another gene involved in pituitary tumorigenesis

Physicochemical characterization of psyllium fiber

Psyllium is the common name used for several members of the plant genus Plantago, whose seeds are commercially used for mucilage production. Owing to its considerable fiber amount it has been used as dietary fiber supplement. Psyllium has a strong gelling ability, even at low temperature, enabling its use as a gelling agent in the food industry. This work is part of a project to developing jellies enriched with fiber, honey and propolis, aiming to increase these products intake, with evident health benefits. The chemical characterization of psyllium was performed, with the following results (in dry matter): total ash 2.5%, fat content 3.4% and total protein 1.4%. After qualitative acid hydrolysis polymeric sugars were quantified (in dry matter): glucan 7.3%, xylan 61.1% and arabinan 22.9%. This means that total fiber content is about 90%, being soluble fiber predominant, and allows classifying psyllium hemicellulose as an arabinoxylan. Psyllium functional properties were evaluated by water-binding capacity and swelling determination: 27.1 g/g and 36.9 ml/g, respectively. These properties are important in the food industry, but under certain circumstances may limit the food type that can be enriched with this fiber. An important part of the research consisted on the characterization of gels viscoelastic behavior and texture, which were prepared with different psyllium particle dimension (raw and ground) and concentration (2.0%, 2.5% and 3.0%). The Response Surface Methodology was used to study the effect of process conditions (time and temperature) on texture and color characteristics of gels. Texture properties of gels were evaluated by Texture Profile Analysis. Gels dynamic behaviour was studied by a sequence of oscillatory measurements of temperature, time and frequency sweeps. Psyllium gelling properties were improved with the reduction of the fiber particle dimension. Gels revealed potential viscoelastic properties that might be interesting in the industrial purpose of honey jelly production

Genetic polymorphism of CYP2D6 influences susceptibility to papillary thyroid cancer

OBJECTIVE: Xenobiotic-metabolizing enzymes are widely polymorphic and confer interindividual variation in the ability to detoxify carcinogens or to activate pro-carcinogens. A common polymorphism of cytochrome P450 2D6 (CYP2D6) results in lack of enzyme activity and has been associated with an altered susceptibility to several cancers. The aim of this study was to investigate the association between the CYP2D6 poor metaboliser genotype and the risk of papillary thyroid cancer (PTC). DESIGN: Retrospective case-control study. PATIENTS: One hundred and eighty-seven patients with PTC and 256 controls. MEASUREMENTS: Genotyping was performed by PCR and restriction enzyme analysis to detect the presence of the common CYP2D6*4 poor metaboliser allele. RESULTS: The frequency of individuals with the homozygous poor metaboliser genotype was lower in the patient group [1.6 vs. 5.5%, P = 0.037, OR = 0.28 (95% CI 0.09-0.93)]. The CYP2D6*4 allele frequency was also lower in the patient group [13.4 vs. 21.7%, P = 0.002, OR = 0.56 (95% CI 0.39-0.80)]. CONCLUSIONS: The results suggest that the poor metaboliser genotype is associated with a protective effect against PTC. This could be explained by a possible role of CYP2D6 on the metabolic activation of putative environmental chemical thyroid carcinogens or by linkage to another cancer-causing gene. Further research may allow the identification of metabolic risk factors and contribute towards understanding the molecular mechanisms involved in thyroid carcinogenesis

Anaplastic thyroid tumor: retrospective analysis of 12 cases

Anaplastic thyroid tumor is a rare tumor and constitutes 5 to 10% of thyroid carcinomas. Is one of the most aggressive solid tumors and the prognosis is always fatal with a mean survival of 3 to 7 months. The current therapeutics are scarce and inefficacious. A retrospective analysis was performed in 12 clinical cases of anaplastic thyroid tumor observed at the Department of Endocrinology, Diabetes and Metabolism of the University Hospital of Coimbra. We analysed data relative to sex, previous thyroid pathology, clinical signs and symptoms, date of diagnosis, treatment and outcome. In this series, the anaplastic thyroid carcinoma showed to be a highly malignant tumor with a mortality rate of 100% with a survival after the diagnosis between 15 days and 9 months