THE MICROBIOME AND METABOLIC DISORDERS: THE LINK BETWEEN THE GUT MICROBIOTA AND METABOLIC SYNDROME.

The diverse population of microbes that live in our digestive system, known as the gut microbiota, remains essential for many physiological processes. It plays a role in obtaining energy from food and controls both regional and overall immunity. In addition, changes in the microbiota of the digestive tract are connected to the emergence of an extensive variety of illnesses, such as cancer, gastrointestinal problems, and metabolic disorders. From a metabolic perspective, the gut microbiota can affect processes like lipid accumulation, lipopolysaccharide satisfied, and short-chain fatty acid synthesis, all of which have an effect on food intake, inflammatory reactions, and insulin signaling. Prebiotics, probiotics, specialized anti-diabetic medications, and faecalmicrobiota implantation are a few of the ways that have been discovered to alter the gut microbiota; each has a different influence the human body's metabolism and the emergence of metabolic disorders. These therapies have been reported to be therapeutic strategies for enhancing general wellness and reestablishing a balanced gut flora.

An Anatomical Study of Dry Mandibles to Determine the Important Surgical Reference Points in Ramus Osteotomy - An Evaluative Study.

Introduction: The variable relation and clinical significance of mandibular foramen (MF) and Lingula with inferior alveolar neurovascular bundle (IANB) is important for dental surgeons. Knowing the landmarks on the ramus of the mandible is of paramount importance to perform the surgery without causing damage to the neurovascular bundle. Materials and Methods: This study was conducted on 85 dry adult mandibles of unknown sex and age. The distances were measured from the anatomical reference points (anti-Lingula, Lingula and MF) using digital callipers. Results: The distance from the anti-Lingula to the anterior border of the ramus (A) was significantly longer on the right side (14.91 mm) than on the left side (14.5 mm). There was a significant difference in mean distances between the anti-Lingula and MF of both the sides (P ≤ 0.005). No significant difference was noted in the distances between the Lingula and the Anti-Lingula, observed for the posterior (B, P = 0.75) and the inferior margin of the mandible (D, P = 0.54). However we found correlation of vertical distances of anti-Lingula with Lingula and MF exhibited moderate positive correlation. Discussion: The IANB is prone to damage during mandibular surgery. Using anti-Lingula alone as a reference point is not guaranteed, but it is still an important anatomical landmark for the surgeon to operate.

A pilot study to evaluate the changes in venous blood gas parameters and hypoxia biomarkers in health care workers using different kinds of masks.

Background: The study is aimed to investigate the metabolic alterations and changes in biochemical parameters associated with extended mask. Methods: It was a prospective comparative study conducted on 129 participants comprised of 37 healthy controls and 92 health care workers using different kind of masks like, cloth mask, surgical masks and N95-FFR/PPE. Two samples on day-1 and day-10 were collected for analysis of blood gas parameters, serum hypoxia-inducible factor-α (HIF-α), and erythropoietin (EPO). Results: Oxygen saturation percentage (sO2) of 72.68 (P = 0.033) was significantly low, whereas, Na+ (P = 0.05) and Ca2+ (P < 0.001) were raised in exposed individuals than the healthy controls. The serum HIF-α level of 3.26 ng/mL, was considerable higher in the exposed individuals than controls (P = 0.001). pO2 and sO2 were the lowest and HIF-α and EPO were raised in N95-FFR/PPE of all mask users (P < 0.01). A significant difference was evidenced for pCO2, pH, Na+, Ca2+, and EPO in the exposed group. A positive correlation between the duration of mask use (in hours) with HIF-α (r = 0.247, P = 0.005) and Ca2+ (r = 0.306, P < 0.001) was observed. The major complaints in N95-FFR/PPE users were headache (15.2%) and polydipsia (33.3%). Conclusion: The study findings depicted a significant metabolic alterations in PPE/N95 users which could be due to chronic hypoxic exposure of the tissues.

INVESTIGATING THE EFFECT OF NICOTINE FROM CIGARETTES ON THE GROWTH OF ABDOMINAL AORTIC ANEURYSMS: REVIEW.

Separating aneurysmal arterial disease from atherosclerosis and further occlusive artery conditions, it is a vascular degenerative disorder. Within the vascular tree, there is a regionalization of the propensity to produce aneurysms and the different locations result in different clinical processes. As the predominant risk factor for ubrenal abdominal aortic aneurysm (AAA), smoking is one of the most common manifestations of aneurysmal illness. For AAA compared to atherosclerosis, smoking is a far bigger risk factor. Along with contributing to the pathophysiology of AAA, smoking raises the likelihood that established AAA will rupture as well as its rate of expansion. The development of improved models for animals that are reliant on smoke or smoke constituents is helping to determine the mechanistic connection between AAA and smoking. According to the processes, there are long-lasting changes in the function of inflammatory and vascular smooth muscle cells. Focused on AAA, this review looks at the medical, epidemiology and mechanical evidence that links smoking to aneurysms.

Histopathologist and clinician interface in diagnosis and management of autoimmune hepatitis.

Diagnosis of AIH is based on a combination of clinical, laboratory and histological information. It has been formalised by diagnostic scoring systems, to which liver biopsy contributes substantially. Diagnostic biopsy is thus, desirable in nearly all patients. An adequate biopsy size, provision by clinicians of adequate information to histopathologists and active discussion at regular meetings are all important for accurate histological diagnosis. Recently, the specificity of some features previously thought to suggest AIH has been questioned, and new recommendations for histological diagnosis have been proposed, although not yet validated. The histology of acutely presenting AIH and that of severe or fulminant AIH include some characteristic features. Primary biliary cholangitis, primary sclerosing cholangitis and non-alcoholic fatty liver disease may co-exist with AIH on biopsy. Liver biopsy also enables grading of severity of inflammation and staging of fibrosis. Presence of cirrhosis is a poor prognostic marker. Repeat liver biopsy after achieving biochemical remission, although not performed routinely, enables assessment of (a) histological remission, a favourable prognostic indicator and (b) fibrosis progression. It can thus help determine further management.

A study of apolipoprotein A1(ApoA1) and interleukin-10(IL-10) in diabetes with foot ulcers.

Background: The high morbidity, mortality and associated economic burden have entailed to identifying early biomarker of diabetic foot ulcers (DFU). Pro-inflammatory and anti-inflammatory molecules play a role in the chronic inflammation associated with diabetic foot ulcers (DFU). Aim: This study aims to find the association between ApoA1, IL-10, TNF-α and diabetic foot ulcers, and whether their levels can assess the severity of the disease. Method: Two groups, diabetic mellitus without foot ulcers and diabetes with foot ulcers were recruited for the study. Detailed clinical history was obtained and blood was collected to measure TNF-α , IL-10 and Apo A1. The association between variables was analysed using Pearson correlation test. ROC analysis was used to identify cut-off values of ApoA1, IL-10 and TNF-α in diabetes patients with foot ulcers. Results: The presence of pro-inflammatory parameter, TNF-α , was higher and anti-inflammatory biomarkers, HDL, ApoA1 and IL-10 were lower in patients of DFU than those without foot ulcers (p < 0.001). Increasing age, smoking, retinopathy, eGFR and inflammatory biomarkers like low levels of ApoA1 (p < 0.005) and IL-10 (p < 0.001) significantly contributed to the development of diabetic foot ulcers. ROC curve identified the cut-off for ApoA1 and IL-10 as 89.82mg/dL and 78.80pg/mL respectively. Conclusion: In the light of this study, ApoA1 has the potential to predict DFU. The finding proposes IL-10 (b = -0.37, p < 0.001) could be considered in stratifying DFU as per its severity.

Transnasal Flexible Laryngoscopy Using Different Topical Preparations and Methods of Application-A Randomized Study.

BACKGROUND: The field of laryngology has grown exponentially since the advent of the transnasal flexible laryngoscopy. Flexible laryngoscopy when performed skillfully using the proper technique, facilitates a good view of the hidden areas of the larynx. OBJECTIVE: To compare the effectiveness of the topical agents in providing a more comfortable experience for the patient, allowing the practitioner to advance the endoscope with less friction, pain and discomfort for the patient using 10% lidocaine spray, 2% lidocaine gel, 4% lidocaine with xylometazoline (1:1) soaked pledgets, or aqueous gel. MATERIALS AND METHODS: A prospective randomized single-blinded clinical trial was conducted in a tertiary care teaching hospital in South India where 376 patients were recruited and allocated into four groups based on the topical preparation used. Following endoscopy, each subject filled a questionnaire grading their experience on a visual analogue scale. The clinician also then answered a questionnaire on aspects of the endoscopy performed. RESULTS: The pain score and the ease of performing the procedure among the different groups were comparable. Those in the 10% lidocaine arm experienced significant burning sensation (P = 0.0001). The other variables such as throat pain (P = 0.783), gag reflex (P = 0.318), unpleasant taste (P = 0.092), globus (P = 0.190), swallowing difficulty after the procedure (P = 0.273), difficulty in breathing (P = 0.744) and willingness to have a repeat procedure (P = 0.883) were also comparable. CONCLUSION: Aqueous gel can be used topically during a flexible nasopharyngolaryngoscopy instead of an anesthetic agent alone or one combined with a nasal decongestant.

Length of Barrett's esophagus in the presence of low-grade dysplasia, high-grade dysplasia, and adenocarcinoma.

INTRODUCTION: The identification and follow-up of ultra-short Barrett's esophagus (BE) is controversial. BE surveillance guidelines emphasize mainly on long-segment BE. However, in practice a substantial proportion of esophageal adenocarcinoma (EAC) are found close to the gastro-esophageal junction (GEJ). Our study aims to chart the length of BE when low-grade dysplasia (LGD), high-grade dysplasia (HGD) and EAC arise in BE. METHODS: Endoscopic findings from all cases with a diagnosis of LGD and HGD in BE between June 2014 and June 2019, and 100 consecutive cases of EAC diagnosed between June 2018 and August 2019, were reviewed. Additionally, 438 consecutive gastroscopies were reviewed to identify 100 cases of non-dysplastic BE. RESULTS: 99 cases of LGD and 61 cases of HGD were reviewed. LGD and HGD when diagnosed, was located in BE ≤ 1 cm in 20% and 18% cases, respectively. LGD and HGD when diagnosed, was located in BE ≤ 3 cm in 48.5% and 40.9% cases, respectively. LGD and HGD when diagnosed in BE ≤ 3 cm was found at index endoscopy in 67% and 42% cases, respectively. Of the 100 cases of EAC, only 23 had concurrent visible BE, with BE higher than the level of EAC in seven. EAC when found, had its proximal extent ≤ 1 cm from GEJ in 22% and ≤ 3 cm from GEJ in 40% cases. Of the 100 non-dysplastic BE, 53% were ≤ 1 cm and 78% were ≤ 3 cm long. CONCLUSION: Almost 20% of all dysplasia in BE occurs in BE < 1 cm. Over 40% occurs in BE < 3 cm. Similarly, 20% of EAC occurs within 1 cm of GEJ and 40% occur within 3 cm. A majority of dysplasia diagnosed within 3 cm of the GEJ is found on index endoscopy. We propose that all lengths of columnar lined epithelium above the GEJ are recognized as BE and subjected to a thorough biopsy protocol.

Assisted reproductive technologies induce temporally specific placental defects and the preeclampsia risk marker sFLT1 in mouse.

Although widely used, assisted reproductive technologies (ARTs) are associated with adverse perinatal outcomes. To elucidate their underlying causes, we have conducted a longitudinal analysis of placental development and fetal growth using a mouse model to investigate the effects of individual ART procedures: hormone stimulation, in vitro fertilization (IVF), embryo culture and embryo transfer. We demonstrate that transfer of blastocysts naturally conceived without hormone stimulation and developed in vivo prior to transfer can impair early placentation and fetal growth, but this effect normalizes by term. In contrast, embryos cultured in vitro before transfer do not exhibit this compensation but rather display placental overgrowth, reduced fetal weight, reduced placental DNA methylation and increased levels of sFLT1, an anti-angiogenic protein implicated in causing the maternal symptoms of preeclampsia in humans. Increases in sFLT1 observed in this study suggest that IVF procedures could increase the risk for preeclampsia. Moreover, our results indicate that embryo culture is the major factor contributing to most placental abnormalities and should therefore be targeted for optimization.

A comparison of outcomes for standard and multiplex partial nephrectomy in a solitary kidney: The National Cancer Institute experience.

OBJECTIVES: To study the short and intermediate surgical, renal functional, and oncologic outcomes of multiplex partial nephrectomy (mPN) and standard partial nephrectomy (sPN) in the setting of a solitary kidney. PATIENTS AND METHODS: Review of a prospectively maintained database of patients undergoing solitary kidney partial nephrectomy at our institution was performed. Patients were stratified into 2 cohorts: mPN-where 3 or more renal tumors were resected and sPN-where 1 or 2 tumors were resected. Perioperative, renal functional, and oncological outcomes were compared. RESULTS: Ninety-three patients with a solitary kidney underwent a total of 121 surgical procedures; 43 (35.5%) were sPN and 78 (64.4%) were mPN. The total and major (Clavien Grade III and IV) complication rates between sPN and mPN were similar (57.1% vs. 70.1%, P = 0.2; 31.0% vs. 35.1%, P = 0.3). At 12 months post-op, the percentage of patients with eGFR > 45 was similar in each group (sPN 87.0%, mPN 73.7%; P = 0.2), and long-term hemodialysis rates were 4.7% and 6.4%, respectively. Completion nephrectomy was performed in 2.3% of sPN and 2.6% of mPN. At a median follow-up of 40.1 months, the metastasis rate was 8.6% in the sPN group and 4.1% in the mPN group (P = 0.4). CONCLUSIONS: Partial nephrectomy in the setting of a solitary kidney can effectively preserve renal function. The renal functional and oncologic outcomes were similar in sPN and mPN, with low hemodialysis rates and complication rates within the expected range of these operations. Three or more tumors in a solitary kidney should not be a contraindication for nephron sparing surgery.

Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice.

Basophils are evolutionarily conserved in vertebrates, despite their small numbers and short life span, suggesting that they have beneficial roles in maintaining health. However, these roles are not fully defined. Here we demonstrate that basophil-deficient mice exhibit reduced bacterial clearance and increased morbidity and mortality in the cecal ligation and puncture (CLP) model of sepsis. Among the several proinflammatory mediators that we measured, tumor necrosis factor (TNF) was the only cytokine that was significantly reduced in basophil-deficient mice after CLP. In accordance with that observation, we found that mice with genetic ablation of Tnf in basophils exhibited reduced systemic concentrations of TNF during endotoxemia. Moreover, after CLP, mice whose basophils could not produce TNF, exhibited reduced neutrophil and macrophage TNF production and effector functions, reduced bacterial clearance, and increased mortality. Taken together, our results show that basophils can enhance the innate immune response to bacterial infection and help prevent sepsis.

Distinct Mechanoresponsive Luminescence, Thermochromism, Vapochromism, and Chlorine Gas Sensing by a Solid-State Organic Emitter.

In this study, we report a synthetically simple donor-acceptor (D-A)-type organic solid-state emitter 1 that displays unique fluorescence switching under mechanical stimuli. Orange and yellow emissive crystals of 1 (1O, 1Y) exhibit an unusual "back and forth" fluorescence response to mechanical force. Gentle crushing (mild pressure) of the orange or yellow emissive crystal results in hypsochromic shift to cyan emissive fragments (λem = 498-501 nm) with a large wavelength shift Δλem = -71 to -96 nm, while further grinding results in bathochromic swing to green emissive powder λem = 540-550 nm, Δλem = +40 to 58 nm. Single-crystal X-ray diffraction study reveals that molecules are packed by weak interactions, such as C-H···π, C-H···N, and C-H···F, which facilitate intermolecular charge transfer in the crystal. With the aid of structural, spectroscopic, and morphological studies, we established the interplay between intermolecular and intramolecular charge-transfer interaction that is responsible for this elusive mechanochromic luminescence. Moreover, we have also demonstrated the application of this organic material for chlorine gas sensing in solid state.

Antioxidant, functional properties and amino acid composition of pepsin-derived protein hydrolysates from whole tilapia waste as influenced by pre-processing ice storage.

In recent years, hygienic handling of fishery waste is demanded owing to the fact that the fishery waste is an ideal raw material for the preparation of bioactive compounds. In the present study, the effect of pre-processing storage (at 4 ± 2 °C) of whole tilapia waste (WTW) on the properties of its protein hydrolysate derived using pepsin was evaluated. Fish protein hydrolysates (FPH) were prepared from 0, 24 and 48 h old ice stored WTW and designated as FPH-0, FPH-1, and FPH-2, respectively. Total amino acids, total essential amino acids and total hydrophobic amino acids of FPH samples increased with the storage period of raw material (WTW). Antioxidant activities such as DPPH (2, 2 diphynyl-1-picrylhydrazyl) free radical scavenging activity and ferric reducing power of FPH samples were dose dependent. FPH-0 had better antioxidant properties including linoleic acid peroxidation inhibition activity than FPH-1 and FPH-2. The DNA nicking assay revealed the protective effect of FPH preparations against Fenton's reaction mediated oxidative damage. FPH-2 had better emulsifying properties and foaming stability whereas the FPH-0 had relatively good foaming capacity. SDS-PAGE indicated the presence of peptides ranging from 116 to < 14.4 kDa in FPH-0 and less than 18 kDa in FPH-1 and FPH-2. The present study, clearly demonstrated that whole tilapia waste can effectively be converted to FPH and could be a potential ingredient in functional food and as a rich source of high-quality protein in animal feed formulations.

Long-Term Prognostic Significance of Persisting Histological Activity Despite Biochemical Remission in Autoimmune Hepatitis.

OBJECTIVES: Biochemical remission is widely considered a satisfactory treatment end point in autoimmune hepatitis (AIH). The significance of persisting histological activity despite biochemical remission is unknown. We aimed to assess the frequency and prognostic significance of persisting histological inflammation in patients with AIH who had achieved biochemical remission with treatment. METHODS: We studied 120 patients (median age at diagnosis 57 years; 81% female) with AIH by International Criteria (59% definite), who received immunosuppressive treatment and underwent a follow-up liver biopsy after at least 6 months of sustained biochemical remission (defined as normal serum ALT and globulin). RESULTS: Fifty-five patients (46%) had persisting histological activity (Ishak histological activity index (HAI) ≥4). These patients had higher serum ALT (24 vs. 18 IU/l, P=0.003) and AST (27 vs. 23 IU/l, P=0.03) at the time of follow-up biopsy, compared with patients who achieved histological remission (HAI ≤3). They had less frequent regression of fibrosis on follow-up biopsy compared with those achieving histological remission (32 vs. 60%, P=0.004) and had excess mortality (standardized mortality ratio 1.4 vs. 0.7, P<0.05). The excess mortality was due to liver disease. On multivariate analysis, persisting histological activity was independently associated with all-cause death/transplantation (HR 3.1 (95% CI 1.2-8.1); P=0.02); an association with liver-related death/transplantation fell short of significance (HR 9.7 (95% CI 0.84-111.6; P=0.07). CONCLUSIONS: Persisting histological activity, despite biochemical remission, is frequent in patients with treated AIH and is associated with lower rates of fibrosis regression and reduced long-term survival.

A defined synthetic substrate for serum-free culture of human stem cell derived cardiomyocytes with improved functional maturity identified using combinatorial materials microarrays.

Cardiomyocytes from human stem cells have applications in regenerative medicine and can provide models for heart disease and toxicity screening. Soluble components of the culture system such as growth factors within serum and insoluble components such as the substrate on which cells adhere to are important variables controlling the biological activity of cells. Using a combinatorial materials approach we develop a synthetic, chemically defined cellular niche for the support of functional cardiomyocytes derived from human embryonic stem cells (hESC-CMs) in a serum-free fully defined culture system. Almost 700 polymers were synthesized and evaluated for their utility as growth substrates. From this group, 20 polymers were identified that supported cardiomyocyte adhesion and spreading. The most promising 3 polymers were scaled up for extended culture of hESC-CMs for 15 days and were characterized using patch clamp electrophysiology and myofibril analysis to find that functional and structural phenotype was maintained on these synthetic substrates without the need for coating with extracellular matrix protein. In addition, we found that hESC-CMs cultured on a co-polymer of isobornyl methacrylate and tert-butylamino-ethyl methacrylate exhibited significantly longer sarcomeres relative to gelatin control. The potential utility of increased structural integrity was demonstrated in an in vitro toxicity assay that found an increase in detection sensitivity of myofibril disruption by the anti-cancer drug doxorubicin at a concentration of 0.05 µM in cardiomyocytes cultured on the co-polymer compared to 0.5 µM on gelatin. The chemical moieties identified in this large-scale screen provide chemically defined conditions for the culture and manipulation of hESC-CMs, as well as a framework for the rational design of superior biomaterials.

Contrasting analytical and data-driven frameworks for radiogenomic modeling of normal tissue toxicities in prostate cancer.

BACKGROUND AND PURPOSE: We explore analytical and data-driven approaches to investigate the integration of genetic variations (single nucleotide polymorphisms [SNPs] and copy number variations [CNVs]) with dosimetric and clinical variables in modeling radiation-induced rectal bleeding (RB) and erectile dysfunction (ED) in prostate cancer patients. MATERIALS AND METHODS: Sixty-two patients who underwent curative hypofractionated radiotherapy (66 Gy in 22 fractions) between 2002 and 2010 were retrospectively genotyped for CNV and SNP rs5489 in the xrcc1 DNA repair gene. Fifty-four patients had full dosimetric profiles. Two parallel modeling approaches were compared to assess the risk of severe RB (Grade⩾3) and ED (Grade⩾1); Maximum likelihood estimated generalized Lyman-Kutcher-Burman (LKB) and logistic regression. Statistical resampling based on cross-validation was used to evaluate model predictive power and generalizability to unseen data. RESULTS: Integration of biological variables xrcc1 CNV and SNP improved the fit of the RB and ED analytical and data-driven models. Cross-validation of the generalized LKB models yielded increases in classification performance of 27.4% for RB and 14.6% for ED when xrcc1 CNV and SNP were included, respectively. Biological variables added to logistic regression modeling improved classification performance over standard dosimetric models by 33.5% for RB and 21.2% for ED models. CONCLUSION: As a proof-of-concept, we demonstrated that the combination of genetic and dosimetric variables can provide significant improvement in NTCP prediction using analytical and data-driven approaches. The improvement in prediction performance was more pronounced in the data driven approaches. Moreover, we have shown that CNVs, in addition to SNPs, may be useful structural genetic variants in predicting radiation toxicities.

Lumbarisation of the first sacral vertebra a rare form of lumbosacral transitional vertebra / Lumbarización de la primera vertebra sacra: rara forma de una vertebra de transición lumbosacral

In the lumbosacral region, anatomical variations occur with changes in the number of sacral vertebra either by deletion of first sacral vertebra or by the union of fifth lumbar or first coccygeal vertebra with sacrum. Lumbasacral transitional vertebrae (LSTV) is the most common congenital anomalies of the lumbosacral region. It most commonly involves the fifth lumbar vertebra showing signs of fusion to the sacrum known as sacralisation or the first sacral vertebra shows signs of transition to a lumbar configuration commonly known as lumbarisation. Complete transition can result in numerical abnormalities of the lumbar and sacral vertebral segments. Lumbarisation of first sacral vertebra is seen with a very low incidence of 2%. Knowledge of presence of such vertebral variation will be helpful for the clinicians to diagnose and treat patients with low back pain. Although sacralisation of fifth lumbar vertebrae is most commonly seen when compared to lumbarisation of first sacral vertebrae, we report here a case of lumbarisation of first sacral vertebrae for its rarity among the LSTV and clinical implications.

En la región lumbosacra, las variaciones anatómicas se basan en cambios en el número de las vértebras sacras, ya sea por ausencia de la primera vértebra sacra o por unión de la quinta lumbar o primera vértebra caudal con el sacro. Las vértebras de transición lumbasacra (VTLS) son las anomalías congénitas más frecuentes de la región lumbosacra. La VTLS más común se produce a nivel de la quinta vértebra lumbar, con signos de fusión al sacro, proceso conocido como sacralización; mientras que la primera vértebra sacra también puede mostrar signos de transición a una configuración lumbar. A esto último se lo denomina lumbarización. La transición completa puede provocar anomalías numéricas a nivel de los segmentos vertebrales lumbares y sacros. La lumbarización de la primera vértebra sacra se observa con una incidencia muy baja, de solo 2%. El conocimiento de la presencia de dicha variación vertebral será de utilidad para los médicos al momento de diagnosticar y tratar a los pacientes con dolor en la parte baja de la espalda. Aunque la sacralización de la quinta vértebra lumbar se produce más frecuentemente en comparación con la lumbarización de la primera vértebra sacra, se presenta aquí un caso de lumbarización de la primera vértebra sacra, rara entre las VTLS, y con implicaciones clínicas.

Antiaging effect of dietary chitosan supplementation on glutathione-dependent antioxidant system in young and aged rats.

Aging has been defined as the changes that occur in living organisms with the passage of time that lead to functional impairment and ultimately to death. Free radical-induced oxidative damage has long been thought to be the most important consequence of the aging process. In the present study, an attempt has been made to study the salubrious effects of dietary supplementation of chitosan on glutathione-dependent antioxidant defense system in young and aged rats. The dietary supplementation of chitosan significantly reduced the age-associated dyslipidemic abnormalities noted in the levels of total cholesterol, HDL-cholesterol, and LDL-cholesterol in plasma and heart tissue. Its administration significantly (P < 0.05) attenuated the oxidative stress in the heart tissue of aged rats through the counteraction of free radical formation by maintaining the enzymatic [glutathione peroxidase (GPx) and glutathione reductase (GR)] and non-enzymatic [reduced glutathione (GSH)] status at levels comparable to that of normal young rats. Our results conclude that dietary intake of chitosan restores the depleted myocardial antioxidant status and suggest that it could be an effective therapeutic agent in treatment of age-associated disorders where hypercholesterolemia and oxidative stress are the major causative factors.

Learning approaches of undergraduate medical students to physiology in a non-PBL- and partially PBL-oriented curriculum.

Melaka Manipal Medical College (Manipal Campus; Manipal, Karnataka, India) conducts the Bachelor of Medicine and Bachelor of Surgery program, for which the admission intakes are during the months of March and September. The present study was undertaken to study the differences in learning approaches to physiology of undergraduate medical students in a partially problem-based learning (PBL)- and non-PBL-oriented curriculum. PBL was introduced as a curricular reform for the September 2006 batch of students (partially PBL group), whereas it was not incorporated for the March 2006 batch of students (non-PBL group). Learning approaches to physiology of both groups of students were compared using the short inventory of approaches to learning. Mean scores for deep and strategic approaches were found to be significantly higher for the partially PBL group compared with the non-PBL group. The results of the present study support the earlier observation that PBL promotes a deep approach to learning.

Effect of tetracycline on pancreas and liver function of adult male albino rats.

The effect of tetracycline, at two doses of 50 and 200 mg kg(-1) daily, was studied on pancreatic and liver tissue function for 14 and 21 days in adult male albino rats. For pancreatic function the parameters studied were content of amylase and lipase in pancreas, serum amylase and lipase, serum glucose and faecal fat excretion. For liver function, liver specific enzymes in serum, namely alanine amino transaminase, aspartate amino transaminase and lactate dehydrogenase were estimated. In addition, total lipid, antiperoxidative enzymes and lipid peroxidation were measured in pancreas and liver. The content of amylase and lipase in pancreas showed a small but significant decrease in the rats given 50 mg kg(-1) for 21 days and the decrease was much more significant in those receiving the 200 mg kg(-1) dose. In pancreas free radical levels show a significant increase and reduced glutathione shows a substantial decrease at the 50 mg kg(-1) level and a significant change in these parameters was observed at the 200 mg kg(-1) dose. Antioxidant enzymes, superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, showed a small but significant decrease in the pancreas of the rats treated with 50 mg kg(-1) tetracycline. A significant decrease in the antioxidant enzymes level was observed at the 200 mg kg(-1) dose. In the liver, free radical levels and reduced glutathione were within the normal range at the 50 mg kg(-1) level and significant changes were observed at 200 mg kg(-1). The antioxidant status was unaffected in liver after treatment with tetracycline at the 50 mg kg(-1) level and a significant decrease was observed at the higher dose. Our results reveal the safe nature of tetracycline with respect to the liver at the lower dose tested, whereas, both the higher and lower doses seem to have detrimental effect on the pancreas as revealed by the rise in free radical levels and decrease in the antioxidant enzyme levels.