Xanthan gum and pectin as beverage stabilizers reduce the digestive enzyme hydrolysis of antioxidant and antihypertensive peptides obtained from a brewery byproduct.

An acidic beverage was formulated with xanthan gum (XG), pectin (P) and brewer spent grain (BSG) peptides with antioxidant and antihypertensive properties. The impact of hydrocolloids levels on peptide bioaccessibility was studied. Peptides were obtained from BSG using Purazyme and Flavourzyme enzymes. BSG peptides were fractionated by ultrafiltration (UF) and four fractions were obtained: F1 (>10 kDa), F2 (10-5 kDa), F3 (1-5 kDa), and F4 (<1 kDa). F3 showed the highest protein purity, ferulic acid content, proportion of amphipathic peptides, and bioactive properties (ABTS+ radical scavenging and ACE-I inhibitory activity). The identified peptides from F3 by tandem mass spectrometry were 138. In silico analysis showed that 26 identified peptides had ABTS+ inhibitory activity, while 59 ones presented good antihypertensive properties. The effect of XG and P levels on bioaccessibility of F3 peptides in the formulated beverages was studied by a central composite experimental design. It was observed that F3 peptides interacted with hydrocolloids by electrostatic forces at pH of formulated beverages. The addition of hydrocolloids to formulation modulated the release of the antioxidant peptides and protected the degradation of ACE-I inhibitory peptides from F3 during simulated gastrointestinal digestion. Finally, the level of hydrocolloids that produced intermediate viscosities in the formulated beverages improved the bioaccessibility of the F3 peptides.

Torque changes of anchorage units in preadolescent patients treated with a digitally designed tooth-borne expander anchored to deciduous vs. permanent molars.

AIM: To compare the effects on permanent or deciduous anchorage dental units in patients treated with a digitally designed palatal expander. METHODS: Inclusion criteria were the following: presence of maxillary transverse deficiency, no previous orthodontic treatment, no extractions, absence of agenesis, congenital pathologies and cranio-maxillofacial malformations. Twenty patients (11 males, 9 females, 11 ± 1.8 years) received a digitally designed and metal printed palatal expander anchored on first permanent molars and 1 activation per day for 30 days (Group 1). Twenty-one patients (12 males, 9 females, 8.6 ± 1.4 years) received a digitally designed and metal printed palatal expander anchored on second deciduous molars and 2 activations per day for 14 days (Group 2). Digital intraoral scans were taken before expansion and after device removal, and torque and the palatal transverse diameter were digitally measured. The FDI notation was used to indicate each tooth CONCLUSION: Less dental torque augmentation was produced in Group 2. RESULTS: Significant intragroup differences over time were found in Group 1 considering the torque of teeth 1.6, 1.4, 1.3, 2.1, 2.4, 2.5, 2.6. Significant differences between groups were found regarding the longitudinal change in torque of teeth 1.5, 2.4 and 2.5. Significant intragroup differences over time were found in both groups considering all transverse diameter parameters. No significant differences were found between groups in the transverse diameter modifications over time. CONCLUSION: Less dental torque augmentation was produced in Group 2.

Prescriptive behavior of non-vitamin K oral anticoagulants in patients affected by atrial fibrillation in general practice.

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and in recent years the pharmacological approach has been strongly implemented; in Italy, the prescription of the non-vitamin K oral anticoagulants (NOAC) was also extended to General Practitioners (GPs) since 2020. The aim of the present study was to investigate the GPs prescribing behaviour of NOACs. An observational study was performed by using the computerized medical record of 14 GPs in Sicily: patients affected by AF were selected and stratified according to the prescribed antithrombotic drugs. Patients were considered inadequately managed if antithrombotic treatment was not adherent to recent ESC guidelines. A total of 467 (2.7 %) patients were affected by AF, 276 (59.1 %) were treated with an oral anticoagulant (OAC) regardless the high stroke risk (OR 1.64; 95 %CI 0.74-3.62; p = 0.226). The NOAC users were 236 patients as follow: Rivaroxaban 33.5 %, Apixaban 33,1 %, Dabigatran 17,4 %, Edoxaban 16.1 %. In 7 patients an inappropriate NOAC treatment was observed. Among Vitamin-K antagonist users, 25.0 % were considered inappropriate. Patients not treated with OAC were 191, of them 81.7 % were at high stroke risk and did not receive any OAC despite the indication to treat. In addition, the probability to be not properly managed significantly increased in older and in patients with atherosclerosis. Conversely, patients with at least one reported cardiology counselling significantly reduced the likelihood to be not properly managed (OR 0.38, 95 %CI 0.25-0.58; p 0.01). Our results suggest the need to optimize the management of real-life AF patients by improving prescribing adherence to ESC guidelines.

Predicting response to cancer immunotherapy using noninvasive radiomic biomarkers.

INTRODUCTION: Immunotherapy is regarded as one of the major breakthroughs in cancer treatment. Despite its success, only a subset of patients responds-urging the quest for predictive biomarkers. We hypothesize that artificial intelligence (AI) algorithms can automatically quantify radiographic characteristics that are related to and may therefore act as noninvasive radiomic biomarkers for immunotherapy response. PATIENTS AND METHODS: In this study, we analyzed 1055 primary and metastatic lesions from 203 patients with advanced melanoma and non-small-cell lung cancer (NSCLC) undergoing anti-PD1 therapy. We carried out an AI-based characterization of each lesion on the pretreatment contrast-enhanced CT imaging data to develop and validate a noninvasive machine learning biomarker capable of distinguishing between immunotherapy responding and nonresponding. To define the biological basis of the radiographic biomarker, we carried out gene set enrichment analysis in an independent dataset of 262 NSCLC patients. RESULTS: The biomarker reached significant performance on NSCLC lesions (up to 0.83 AUC, P < 0.001) and borderline significant for melanoma lymph nodes (0.64 AUC, P = 0.05). Combining these lesion-wide predictions on a patient level, immunotherapy response could be predicted with an AUC of up to 0.76 for both cancer types (P < 0.001), resulting in a 1-year survival difference of 24% (P = 0.02). We found highly significant associations with pathways involved in mitosis, indicating a relationship between increased proliferative potential and preferential response to immunotherapy. CONCLUSIONS: These results indicate that radiographic characteristics of lesions on standard-of-care imaging may function as noninvasive biomarkers for response to immunotherapy, and may show utility for improved patient stratification in both neoadjuvant and palliative settings.

Parboiling of sorghum grains as a strategy to improve endosperm yield and mineral content of refined flours.

The aims were (i) to optimize the parboiling/decorticating process by assessing the effects of parboiling soaking temperature (60-80 ℃) and pearling time (4-6 min and 5.5-9.5 min for red and white sorghum) on endosperm yield and ash content, to obtain pregelatinized refined flours from parboiling sorghum (RF-PS) and (ii) to evaluate the final content of selected nutrients in RF-PS obtained in these optimal conditions. Endosperm yield decreased with the increase of pearling time, and a maximum around 70 ℃ soaking temperature was observed. Ash content decreased with increasing soaking temperature and pearling time. The optimal conditions of soaking temperature-pearling time were 73.3 ℃-4.8 min for red sorghum and 67.9 ℃-8.6 min for white sorghum, considering maximum endosperm yield and ash content lower than 0.65 g/100 g. In RF-PS obtained under optimal conditions, protein, lipid, Cu, and free polyphenols were higher in red sorghum than white sorghum (10.16 ± 0.62 vs. 9.42 ± 0.61 g/100 g, 0.89 ± 0.16 vs. 0.62 ± 0.11 g/100 g, 2.08 ± 0.21 vs. 1.88 ± 0.20 mg/kg, 79.51 ± 14.51 vs. 63.82 ± 4.33 mg/100 g). Fe, Zn, Ca, and Na were higher in white sorghum than red sorghum (20.61 ± 2.92 vs. 17.56 ± 0.98 mg/kg, 11.94 ± 0.84 vs. 9.58 ± 1.65 mg/kg, 87.45 ± 12.91 vs. 75.31 ± 12.57 mg/kg, 129.62 ± 9.03 vs. 102.69 ± 28.34 mg/kg). No difference was observed in the contents of ash, Mg, and K. It was possible to improve endosperm yield using a parboiling process prior to decortication. In addition, this process contributes to increase the mineral content in RF-PS.

Distal femoral hemiepiphysiodesis using screw and non-absorbable filament for the treatment of idiopathic genu valgum. Preliminary results of 12 knees.

INTRODUCTION: Different techniques for gradual correction of angular deformities of lower limbs exist. Screws and nonabsorbable filament has been described as an effective alternative for transitory hemiepiphysiodesis in New Zealand rabbits. HYPOTHESIS: Hemiepiphysiodesis using screws and non-absorbable filament is effective in pediatric population, for correction of genu valgum. METHODS: Retrospective evaluation, 12 knees in 6 patients younger than 15 years (3 female), operated because of genu valgum. An anchoring system with two 4.0mm cancellous screw with metal washer joined by FiberWire #2.0 filament. Initial and final intermalleolar distance (IMD) and mechanical lateral distal femoral angle were compared, recording complications. Mann-Whitney test was used for statistics, with significance value <0.05. RESULTS: All patients achieved the expected correction. IMD and mLDFA were significatively improved. Only one patient presents a minor perioperative complication. DISCUSSION: Lateral distal femoral hemiepiphysiodesis with screws and nonabsorbable filament resulted to be an effective alternative for genu valgum gradual correction in pediatric population. This is the first article that proposes this model, as an efficient and simple alternative for the treatment of genu valgum in pediatric patients. LEVEL OF EVIDENCE: Retrospective study, Level IV.

Nutritional improvement of corn pasta-like product with broad bean (Vicia faba) and quinoa (Chenopodium quinoa).

In this study, the nutritional quality of pasta-like product (spaghetti-type), made with corn (Zea mays) flour enriched with 30% broad bean (Vicia faba) flour and 20% of quinoa (Chenopodium quinoa) flour, was determined. Proximate chemical composition and iron, zinc and dietary fiber were determined. A biological assay was performed to assess the protein value using net protein utilization (NPU), true digestibility (TD) and protein digestibility-corrected amino acid score (PDCAAS). Iron and zinc availability were estimated by measuring dialyzable mineral fraction (%Da) resulting from in vitro gastrointestinal digestion. Nutritionally improved, gluten-free spaghetti (NIS) showed significantly increased NPU and decreased TD compared with a non-enriched control sample. One NIS-portion supplied 10-20% of recommended fiber daily intake. Addition of quinoa flour had a positive effect on the FeDa% as did broad bean flour on ZnDa%. EDTA increased Fe- and ZnDa% in all NIS-products, but it also impaired sensorial quality.

Germination and extrusion as combined processes for reducing phytates and increasing phenolics content and antioxidant capacity of Oryza sativa L. whole grain flours.

Whole rice (WR) products with low phytic acid (PA) content and enhanced bio-functional components were obtained by the combination of germination and extrusion processes. Germination conditions (24 h - 35 °C), with a previous soaking process (24 h - 20 °C), were chosen according to the remnant PA content and germination rate. Specific mechanical energy consumption, expansion, sensorial and mechanical hardness, specific volume, solubility, water absorption, free phenolic content (FPC) and antioxidant capacity were evaluated. Results indicated that 175 °C and 14 g 100 g(-1) of moisture were the most appropriate conditions to obtain expanded products and precooked flours based on germinated WR. Selected extruded product presented less PA content (821.6 9 ± 10.3 versus 695.2 0 ± 1.6 mg 100 g(-1)) and higher Fe bio-accessibility, FPC (45.2 9 ± 1.61 versus 66.3 5 ± 3.35 mg GAE g(-1)) and antioxidant capacity compared with WR (34.9 5 ± 0.8 versus 54.6 3 ± 1.6 µmol trolox g(-1)). Combining germination-extrusion processes could be a strategy to obtain expanded products or precooked flours based on WR with enhanced health benefits.

Thread shape factor: evaluation of three different orthodontic miniscrews stability.

The thread shape factor (TSF) to evaluate the relationships between geometrical characteristics and mechanical properties of the temporary anchorage devices (TADs) has recently been introduced. This in vitro experimental study evaluated in 30 different tests with three TADs: ORTHOImplant (1.8 mm diameter and 10 mm length; 3M Unitek), Tomas (1.6 mm diameter and 10 mm length; Dentaurum), and Orthoeasy (1.7 mm diameter and 10 mm length; Forestadent). Scanning electron microscopy images were acquired for each TAD to measure the TSF; afterwards, the maximum insertion torque (MIT) was evaluated and thereafter pull-out tests on two differently designed organic bone analogs were carried out using a testing machine with a crosshead speed of 2 mm/minute being applied. One-way analysis of variance with group as factor was performed. Post hoc multiple comparisons Bonferroni test was used. Rank-transformed data were used when asymmetry of data was shown. To assess correlation between characteristics, load, and MIT, Spearman's rank correlation coefficient was used. A P-value of 0.05 was considered statistically significant. Significant direct correlations were found between TSF and depth and both load and MIT. Particularly, a correlation of 0.90 (P < 0.001) was found between depth and MIT for 2.2 mm cortical thickness. The authors conclude that MIT and maximum load values of pull-out test are statistically related to depth of the thread of the screw and to TSF.

Prospective study of the burden of acute gastroenteritis and rotavirus gastroenteritis in children less than 5 years of age, in Padova, Italy.

BACKGROUND: Data on the burden of rotavirus gastroenteritis in Europe are needed to help understand the potential impact of introducing new rotavirus vaccines. MATERIALS AND METHODS: As part of prospective observational study (Rotavirus gastroenteritis Epidemiology and Viral types in Europe Accounting for Losses in Public Health and Society Study, REVEAL) conducted in 2004--2005 in seven European countries, we studied, the characteristics of acute gastroenteritis and rotavirus gastroenteritis in children less than 5 years in primary care, emergency room and hospital settings (Padova, Italy). RESULTS: A total of 757 children with acute gastroenteritis were included and enzyme-linked immunoabsorbent assay (ELISA) results were available for 725 cases. The overall estimated annual incidence for rotavirus gastroenteritis was 4.7%. Overall, rotavirus gastroenteritis was estimated to account for 43.6% of acute gastroenteritis cases. Among children with acute gastroenteritis (AGE) aged 6-23 months, 61.2% were rotavirus positive. Rotavirus gastroenteritis (RVGE) was responsible for 68.8% of hospitalizations, 61% of emergency consultations, and 33% of primary care consultations. The most prevalent serotype was G9 (84.4%) followed by G1 (11.8%). The relative risk for rotavirus gastroenteritis of being referred to hospital after an initial consultation in primary care was 3.37 (95% CI: 1.77-6.43) and 3.38 (95% CI: 2.28-5.01) for emergency room referral. Children with rotavirus gastroenteritis generally had more severe disease than children with rotavirus-negative gastroenteritis. CONCLUSION: Rotavirus accounts for a significant proportion of acute gastroenteritis cases in children less than 5 years in Italy, many of whom require frequent primary care consultations, or care in emergency room or hospital settings.

Composición y aporte potencial de hierro, calcio y zinc de panes y fideos elaborados con harinas de trigo y amaranto / Composition and potential contribution of iron, calcium and zinc of bread and pasta made with wheat and amaranth flours]

Amaranth, a traditional american crop that is nowadays given renewed importance, has good food potential value. The minerals contributed by the grain are quantitatively important. However, as the flour is obtained by total grinding of the grain, this process leads to the presence of anti-nutritional components, such as fitates, and therefore, the evaluation of the actual availability of the minerals of nutritional interest becomes necessary. The process of bread fermentation, plus the addition of fitases and enhancers of mineral availability such as citric and ascorbic acid, might improve mineral bioavailability. The objective of this work was to assess protein, ash, lipids and total dietary fiber content and evaluate the concentration and dialyzability of Fe, Zn and Ca (as mineral bioavailability indicator) in bread and pasta 100% wheat, and bread and pasta obtained by replacing 20% wheat flour (WF) with whole amaranth flour (WAF). Ascorbic acid (AA), citric acid (CA) and fitase were used as mineral bioavailability enhancers. The potential contribution of each mineral (PC) was calculated as each mineral concentration times its dialyzability. In 80:20 bread an increase of total dietary fiber and minerals, compared to 100% wheat products was observed. A maximum FePC in 80:20 bread was obtained with CA and fitase (0.55mg%). In pasta, the maximum effect was observed with CA (0.07 mg%). The CaPC was maximum in 80:20 pasta with CA (16.72 mg%). The greatest ZnPC was found in 80:20 bread with CA and fitase (0.40 mg%). The introduction of the WAF in fermented baked products with addition of CA and fitase allows to obtain nutritional advantages.

El amaranto es un cultivo americano autóctono actualmente revalorizado por su elevado potencial alimentario. Los minerales aportados por el grano son cuantitativamente importantes. Sin embargo, la presencia de fitatos en los tegumentos externos del grano hace necesaria la evaluación de la biodisponibilidad de los minerales de interés nutricional pues la harina se obtiene por molienda integral. El proceso de fermentación del pan, sumado al agregado de fitasas y promotores de la dializabilidad mineral, podría mejorar la biodisponibilidad mineral. El objetivo del trabajo fue establecer el porcentaje de proteínas, cenizas, lípidos, fibra dietaria total (FDT), Fe, Zn y Ca y estudiar la dializabilidad de esos minerales - como indicadora de su biodisponibilidad - en panes y fideos elaborados con 100% harina de trigo (HT) y con 20% de reemplazo de HT por harina integral de amaranto (HIA). Como promotores de la biodisponibilidad mineral se utilizaron ácidos ascórbico (AA) y cítrico (AC) y fitasa. Se estableció el aporte potencial (AP) de cada mineral como el producto de su concentración y dializabilidad. En los panes 80:20 se observó un incremento sustancial del contenido de FDT y minerales. El máximo APFe se obtuvo en panes 80:20 con AC y fitasa (0,55 mg%). En fideos, el máximo efecto se observó con AC (0,07 mg%). El APCa fue máximo en fideos 80:20 con AC (16,72 mg%). El mayor APZn se evidenció en pan 80:20 con AC y fitasa (0,40 mg%). La introducción de la HIA en productos panificados fermentados con adición de AC y fitasas permite obtener ventajas nutricionales.

Effect of the extrusion on functional properties and mineral dialyzability from Phaseolus vulgaris bean flour.

The effects of extrusion conditions on cooking degree, flour dispersion viscosity and mineral potential availability of extruded bean flour were studied. Phaseolus vulgaris beans of the agronomic cultivar "Flor de mayo" were ground and dehulled to obtain grits and then extruded at different temperatures (140, 160 and 180 degrees C) and moisture contents (17, 20 and 23%), according to a bifactorial experimental design. Degree of cooking was estimated by water solubility (WS) and specific mechanical energy (SME). The effect of variables on WS and SME were analysed by surface response methodology. Flour dispersion viscosity and mineral availability (estimated by in vitro dialyzability), were also evaluated on selected samples. Results showed that, within the ranges of the variables used for this study, only the effect of temperature was significant on the degree of cooking. No direct correlation was observed between water solubility and SME, although a maximum value of WS corresponded to a range of SME values of 400-500 J/g was observed. Dispersion viscosity decreases as WS increases, so if high calorie density is desired, for instance in order to produce a cream soup formula, bean grits should be extruded at high temperature and as low moisture as possible, in our case 180 degrees C and 17% moisture. On the other hand, the effects of extrusion variables on iron and zinc dialyzability were not much affected.

Formulation and sensory evaluation of Prosopis alba (Algarrobo) pulp cookies with increased iron and calcium dialyzabilities.

Prosopis alba (algarrobo) is an important indigenous specie, which fruits are used as food and feed since ancient times. Cookies containing algarrobo pulp (AP) with increased iron and calcium availabilities were formulated and sensory evaluated. AP is preferred as food ingredient because of its high sugar content and pleasant flavour. Formulated cookies mean proximal composition was 8.9 g/100 g protein, 7.2 g/100 g dietary fiber, 25 g/100 g total sugar, and 18.5 g/100 g crude fat with iron and calcium contents 30 ppm and 340 ppm, respectively. Ascorbic (AA) and citric (CA) acids at different mM acid: mM Fe were added in order to increase mineral availabilities being evaluated by an in vitro method. Those ratios were 5:1 and 10:1 for AA:Fe whereas for CA:Fe were 50:1 and 100:1 and combinations of them. After chosen the best AA:Fe and CA:Fe ratios (5:1 and 50:1, respectively), sensory evaluation with trained sensory panel and a consumer acceptability test with one hundred and seventy untrained judges were carried out. Acceptability test showed that 77.65% of the people (< 25 years old 41.76%, 25-50 years old 20.00% and > 50 years old 15.89%) tasting final formulated cookies indicated that they "like very much" or "moderately like" and there were not consumers rejecting them.

[Celiac disease; a world in exploration]. / La celiachia: un mondo in esplorazione.

Celiac disease (CD) or gluten-sensitive enteropathy is an autoimmune disorder triggered by gluten ingestion in genetically predisposed subjects. The presence of gluten in these patients leads to a self-perpetuating mucosal damage, while the elimination of gluten results in a full mucosal recovery. The prevalence of CD in the general population is between 0.3% and 1%. The clinical manifestation of CD is variable; in addition to the classical gastrointestinal form a variety of other clinical manifestation of the disease have been described, including atypical and asymptomatic form. The diagnosis of CD is still based on the small intestinal biopsy findings, but can be suspected using serological testing, e.g. the antigliadin antibody (AGA), the antiendomysial antibody (EMA) and the anti-tissue transglutaminase antibody (tTG). The keystone treatment of CD patients is a life-long gluten-free diet.

Early effects of gliadin on enterocyte intracellular signalling involved in intestinal barrier function.

BACKGROUND AND AIMS: Despite the progress made in understanding the immunological aspects of the pathogenesis of coeliac disease (CD), the early steps that allow gliadin to cross the intestinal barrier are still largely unknown. The aim of this study was to establish whether gliadin activates a zonulin dependent enterocyte intracellular signalling pathway(s) leading to increased intestinal permeability. METHODS: The effect of gliadin on the enterocyte actin cytoskeleton was studied on rat intestinal epithelial (IEC-6) cell cultures by fluorescence microscopy and spectrofluorimetry. Zonulin concentration was measured on cell culture supernatants by enzyme linked immunosorbent assay. Transepithelial intestinal resistance (Rt) was measured on ex vivo intestinal tissues mounted in Ussing chambers. RESULTS: Incubation of cells with gliadin led to a reversible protein kinase C (PKC) mediated actin polymerisation temporarily coincident with zonulin release. A significant reduction in Rt was observed after gliadin addition on rabbit intestinal mucosa mounted in Ussing chambers. Pretreatment with the zonulin inhibitor FZI/0 abolished the gliadin induced actin polymerisation and Rt reduction but not zonulin release. CONCLUSIONS: Gliadin induces zonulin release in intestinal epithelial cells in vitro. Activation of the zonulin pathway by PKC mediated cytoskeleton reorganisation and tight junction opening leads to a rapid increase in intestinal permeability.

Mechanisms involved in the beta-cell mass increase induced by chronic sucrose feeding to normal rats.

The aim of the present study was to clarify the mechanisms by which a sucrose-rich diet (SRD) produces an increase in the pancreatic beta-cell mass in the rat. Normal Wistar rats were fed for 30 weeks either an SRD (SRD rats; 63% wt/wt), or the same diet but with starch instead of sucrose in the same proportion (CD rats). We studied body weight, serum glucose and triacylglycerol levels, endocrine tissue and beta-cell mass, beta-cell replication rate (proliferating cell nuclear antigen; PCNA), islet neogenesis (cytokeratin immunostaining) and beta-cell apoptosis (propidium iodide). Body weight (g) recorded in the SRD rats was significantly (P<0.05) larger than that of the CD group (556.0+/-8.3 vs 470.0+/-13.1). Both serum glucose and triacylglycerol levels (mmol/l) were also significantly higher (P<0.05) in SRD than in CD rats (serum glucose, 8.11+/-0.14 vs 6.62+/-0.17; triacylglycerol, 1.57+/-0.18 vs 0.47+/-0.04). The number of pancreatic islets per unit area increased significantly (P<0.05) in SRD rats (3.29+/-0.1 vs 2.01+/-0.2). A significant increment (2.6 times) in the mass of endocrine tissue was detected in SRD animals, mainly due to an increase in the beta-cell mass (P=0.0025). The islet cell replication rate, measured as the percentage of PCNA-labelled beta cells increased 6.8 times in SRD rats (P<0.03). The number of apoptotic cells in the endocrine pancreas decreased significantly (three times) in the SRD animals (P=0.03). The cytokeratin-positive area did not show significant differences between CD and SRD rats. The increase of beta-cell mass induced by SRD was accomplished by an enhanced replication of beta cells together with a decrease in the rate of beta-cell apoptosis, without any evident participation of islet neogenesis. This pancreatic reaction was unable to maintain serum glucose levels of these rats at the level measured in CD animals.

Mecanismo de producción del aumento de la masa de células B inducido por la administración crónica de sacarosa a ratas normales / Mechanisms producing an increase in B-cell mass induced by the chronic administration of sucrose to normal rats

El objetivo del presente trabajo fue clarificar los mecanismos mediante los cuales una dieta rica en sacarosa produce, en el páncreas de la rata, un aumento de la masa celular B. Se utilizaron ratas Wistar normales, alimentadas durante 30 semanas con una dieta rica en sacarosa (DRS; 63 por ciento o bien con una dieta similar en la que la sacarosa se reemplazó por la misma proporción de almidón (DC). Se estudió el peso corporal, los niveles séricos de glucosa y triacilglicerol, el tejido endocrino, la masa celular B, el grado de replicación de las células B (antígeno de proliferación nuclear celular, PCNA), la neogénesis insular (inmunomarcación de citoqueratina, CK) y la apoptosis de células B (yoduro de propidio). El peso corporal de las ratas DRS fue significativamente mayor (p<0,05) que el registrado en el grupo DC (556,0ñ8,3 vs 470,0ñ13,1). Tanto los niveles séricos de glucosa como los de triacilglicerol (mmol/L) fueron significativamente mayores (p<0,05) en las ratas DRS que en las DC: Glucemia 8,11 ñ 0,14 vs 6,62 ñ 0,17; triacilglicerol 1,57 ñ 0,18 vs 0,47 ñ 0,04. El número de islotes pancreáticos por unidad de área aumentó significativamente (p<0,05) en las ratas DRS (3,29 ñ 0,1 vs 2,01 ñ 0,2). Además, se detectó un incremento significativo (2,6 veces) en la masa de tejido endocrino de los animales DRS, principalmente debido a un aumento en la masa celular B (p=0,0025. El porcentaje de células B insulares en replicación (PCNA positivas) aumentó 6,8 veces en las ratas DRS (p<0,03). El número de células apoptóticas del páncreas endocrino disminuyó significativamente en el grupo DRS (3 veces, p=0,03). No hubo diferencias significativas en el área positiva para CK entre los animales DRS y DC. El aumento de la masa celular B inducido por la DRS se correspondió con un aumento en la replicación de las células B, junto con una disminución en la proporción de dichas células en apoptosis. No hubo evidencias de neogénesisen los islotes. Dichos cambios pancreáticos no pudieron mantener la glucemia de estos animales en valores semejantes a los obtenidos en las ratas DC. Estos resultados muestran que en este modelo de manipulación alimentaria, aunque el aumento de replicación de las células B y la disminución de la apoptosis jugarían un rol importante, la neogénesis insular constituiría el mecanismo compensador decisivo en la adaptación a la mayor demanda de insulina

Mecanismo de producción del aumento de la masa de células B inducido por la administración crónica de sacarosa a ratas normales / Mechanisms producing an increase in B-cell mass induced by the chronic administration of sucrose to normal rats

El objetivo del presente trabajo fue clarificar los mecanismos mediante los cuales una dieta rica en sacarosa produce, en el páncreas de la rata, un aumento de la masa celular B. Se utilizaron ratas Wistar normales, alimentadas durante 30 semanas con una dieta rica en sacarosa (DRS; 63 por ciento o bien con una dieta similar en la que la sacarosa se reemplazó por la misma proporción de almidón (DC). Se estudió el peso corporal, los niveles séricos de glucosa y triacilglicerol, el tejido endocrino, la masa celular B, el grado de replicación de las células B (antígeno de proliferación nuclear celular, PCNA), la neogénesis insular (inmunomarcación de citoqueratina, CK) y la apoptosis de células B (yoduro de propidio). El peso corporal de las ratas DRS fue significativamente mayor (p<0,05) que el registrado en el grupo DC (556,0ñ8,3 vs 470,0ñ13,1). Tanto los niveles séricos de glucosa como los de triacilglicerol (mmol/L) fueron significativamente mayores (p<0,05) en las ratas DRS que en las DC: Glucemia 8,11 ñ 0,14 vs 6,62 ñ 0,17; triacilglicerol 1,57 ñ 0,18 vs 0,47 ñ 0,04. El número de islotes pancreáticos por unidad de área aumentó significativamente (p<0,05) en las ratas DRS (3,29 ñ 0,1 vs 2,01 ñ 0,2). Además, se detectó un incremento significativo (2,6 veces) en la masa de tejido endocrino de los animales DRS, principalmente debido a un aumento en la masa celular B (p=0,0025. El porcentaje de células B insulares en replicación (PCNA positivas) aumentó 6,8 veces en las ratas DRS (p<0,03). El número de células apoptóticas del páncreas endocrino disminuyó significativamente en el grupo DRS (3 veces, p=0,03). No hubo diferencias significativas en el área positiva para CK entre los animales DRS y DC. El aumento de la masa celular B inducido por la DRS se correspondió con un aumento en la replicación de las células B, junto con una disminución en la proporción de dichas células en apoptosis. No hubo evidencias de neogénesisen los islotes. Dichos cambios pancreáticos no pudieron mantener la glucemia de estos animales en valores semejantes a los obtenidos en las ratas DC. Estos resultados muestran que en este modelo de manipulación alimentaria, aunque el aumento de replicación de las células B y la disminución de la apoptosis jugarían un rol importante, la neogénesis insular constituiría el mecanismo compensador decisivo en la adaptación a la mayor demanda de insulina (AU)