Mannogalactoglucan from mushrooms protects pancreatic islets via restoring UPR and promotes insulin secretion in TIDM mice

Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.

Meiotic nuclear divisions 1 suppresses the proliferation and invasion of pancreatic cancer cells via regulating H2A.X variant histone

Introduction:Among all malignant tumors of the digestive system,pancreatic carcinoma exhibits the highest mortality rate.Currently,prevention and effective treatment are urgent issues that need to be addressed.Methods:The study focused on meiotic nuclear divisions 1(MND1),integrating data from the Gene Expression Profiling Interactive Analysis(GEPIA)database with prognostic survival analysis.Simultaneously,experiments at cellular level were employed to demonstrate the effect of MND1 on the proliferation and migration of PC.The small-molecule inhibitor of MND1 was used to suppress the migration of PC cells by knocking down MND1 using small interfering RNA(siRNA)in Patu-8988 and Panc1 cell lines.Results:The results of Cell Counting Kit-8 indicated that the suppression of MND1 resulted in a decrease in cell proliferation.Wound healing and Transwell assays revealed that MND1 knockdown reduced cell migration and invasion.Flow cytometry revealed that inhibiting MND1 hindered the cell cycle.Furthermore,MND1 could stimulate the proliferation,migration,and invasion of Patu-8988 and Panc1 cells by increasing the expression of MND1.Notably,MND1 had a positive effect on H2AFX expression in PC cells.Elevated MND1 expression suggests the low overall survival rate of individuals diagnosed with PC.Conclusion:These findings suggest that MND1 has the potential to be a gene with the ability to accurately diagnose and treat PC.

Dietary Green Tea Extract and Antioxidants Improve Insulin Secretory Functions of Pancreatic β-Cells in Mild and Severe Experimental Rodent Model of Chronic Pancreatitis

Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas. It is predominantly idiopathic (with an unknown cause) in India and mostly due to alcohol in the West. Diabetes that occur secondary to chronic pancreatitis (T3c Diabetes) is often brittle, and is difficult to attain normoglycemia with conventional treatment requiring multiple doses of insulin. Mild and severe model of CP was induced in mice by repeated intraperitoneal injections of cerulein and L-arginine respectively with an intent to study islet dysfunction and develop therapeutic strategy in animal models of CP. Dietary intervention of epigallocatechin-3-gallate (EGCG) was tested in both the models of CP for its beneficial effects on insulin secretory functions. Pancreata collected upon euthanasia were used to study alterations in the morphology of pancreatic parenchyma and inflammation by staining with H&E and fibrotic changes by Masson’s trichrome and picrosirius staining. Insulin secretory functions of islets were evaluated to test the efficacy of the dietary intervention on β-cell functions. Intraperitoneal glucose tolerance test was performed to monitor the glucose homeostasis before and after the dietary intervention. Both the models resulted in CP with dispersed acini, inflammation and fibrosis. The loss of acini and extent of fibrosis was more in L-arginine model. 2-fold improvement in glucose-stimulated insulin secretory functions of islets was observed with 0.5% EGCG dietary intervention in cerulein model of CP and 1.6-fold in L-arginine model of CP. A further improvement in insulin secretion by 3.2-fold was observed with additional dietary supplements like N-acetyl cysteine, curcumin in combination with EGCG. Our results thus demonstrate and highlight the therapeutic potential of dietary green tea (EGCG) supplementation in reversing islet dysfunction and improving glucose homeostasis in experimental chronic pancreatitis in mice.

Circulating tumor cells as prognostic marker in pancreatic cancer

In this editorial we comment on the article by Zhang et al published in the recent issue of the World Journal of Clinical Oncology.Pancreatic cancer is the fourth most common cause of cancer-related mortality and has the lowest survival rate among all solid cancers.It causes 227000 deaths annually worldwide,and the 5-year survival rate is very low due to early metastasis,which is 4.6%.Cancer survival increases with better knowledge of risk factors and early and accurate diagnosis.Circulating tumor cells(CTCs)are tumor cells that intravasate from the primary tumor or metastasis foci into the peripheral blood circulation system spontan-eously or during surgical operations.Detection of CTC in blood is promising for early diagnosis.In addition,studies have associated high CTC levels with a more advanced stage,and more intensive treatments should be considered in cases with high CTC.In tumors that are considered radiologically resectable,it may be of critical importance in detecting occult metastases and preventing unnecessary surgeries.

Programmed cell death 1 inhibitor sintilimab plus concurrent chemoradiotherapy for locally advanced pancreatic adenocarcinoma

BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the tumor has grown significantly but has not yet spread to distant organs,presents unique challenges in treatment.This article aims to discuss the current strategies,challenges,and future directions in the management of locally advanced pancreatic adenocarcinoma(LAPC).AIM To investigate the feasibility and efficacy of programmed cell death 1(PD-1)inhibitor sintilimab plus concurrent chemoradiotherapy for LAPC.METHODS Eligible patients had LAPC,an Eastern cooperative oncology group performance status of 0 or 1,adequate organ and marrow functions,and no prior anticancer therapy.In the observation group,participants received intravenous sintilimab 200 mg once every 3 wk,and received concurrent chemoradiotherapy(concurrent conventional fractionated radiotherapy with doses planning target volume 50.4 Gy and gross tumor volume 60 Gy in 28 fractions and oral S-140 mg/m2 twice daily on days 1-14 of a 21-d cycle and intravenous gemcitabine 1000 mg/m2 on days 1 and 8 of a 21-d cycle for eight cycles until disease progression,death,or unacceptable toxicity).In the control group,participants only received concurrent chemoradiotherapy.From April 2020 to November 2021,64 participants were finally enrolled with 34 in the observation group and 30 in the control group.RESULTS Thirty-four patients completed the scheduled course of chemoradiotherapy,while 32(94.1%)received sintilimab plus concurrent chemoradiotherapy with 2 patients discontinuing sintilimab in the observation group.Thirty patients completed the scheduled course of chemoradiotherapy in the control group.Based on the Response Evaluation Criteria in Solid Tumors guidelines,the analysis of the observation group revealed that a partial response was observed in 11 patients(32.4%),stable disease was evident in 19 patients(55.9%),and 4 patients(11.8%)experienced progressive disease;a partial response was observed in 6(20.0%)patients,stable disease in 18(60%),and progressive disease in 6(20%)in the control group.The major toxic effects were leukopenia and nausea.The incidence of severe adverse events(AEs)(grade 3 or 4)was 26.5%(9/34)in the observation group and 23.3%(7/30)in the control group.There were no treatment-related deaths.The observation group demonstrated a significantly longer median overall survival(22.1 mo compared to 15.8 mo)(P<0.05)and progression-free survival(12.2 mo vs 10.1 mo)(P<0.05)in comparison to the control group.The occurrence of severe AEs did not exhibit a statistically significant difference between the observation group and the control group(P>0.05).CONCLUSION Sintilimab plus concurrent chemoradiotherapy was effective and safe for LAPC patients,and warrants further investigation.

The Effect of Tuberculosis Infection on Pancreatic Beta-Cell Function in Patients with Type 2 Diabetes Mellitus

Objective: The aim of this study is to investigate how individuals with type 2 diabetes mellitus’ pancreatic β-cell function index and insulin resistance index are affected by tuberculosis infection. Methods: The study group consisted of 89 patients with type 2 diabetes mellitus and tuberculosis infection who were admitted to Jingzhou Chest Hospital between March 2019 and March 2021. Gender and duration of diabetes were matching conditions. The control group was made up of 89 patients with type 2 diabetes who were admitted to Jingzhou Central Hospital’s endocrinology department during the same period. The two patient groups provided general information such as gender, age, length of diabetes, and blood biochemical indexes such as glycosylated hemoglobin (HbA1c), fasting glucose (FPG), and fasting C-peptide (FC-P). The HOMA calculator was used to calculate the HOMA-β and the HOMA-IR, and intergroup comparisons and correlation analyses were carried out. Results: Regarding gender, age, disease duration, FC-P, and HbA1c, the differences between the two groups were not statistically significant (P > 0.05). However, BMI, FPG, HOMA-β, and HOMA-IR showed statistically significant differences (P < 0.05). In comparison to the control group, the study group’s HOMA-β was lower and its HOMA-IR was greater. According to Spearman’s correlation analysis, HOMA-β had a negative association (P th FPG, HbA1c, and the length of the disease, and a positive correlation with BMI and FC-P. A positive correlation was found between HOMA-IR and BMI, FPG, and FC-P (P < 0.01), as well as a correlation with the length of the disease (P > 0.05) and HbA1c. Conclusions: In type 2 diabetes mellitus combined with tuberculosis infection, the patients had higher FPG levels and lower FC-P levels, the secretory function of pancreatic β-cells was more severely impaired, and insulin resistance was more obvious.

Metastatic pancreatic and lung cancer patient in complete remission following immunotherapy: A case report and review of literature

BACKGROUND Metastatic pancreatic ductal adenocarcinoma(PDAC)is a lethal malignancy with dispiriting survival data.Immunotherapy is a promising approach to many cancer types,but achieves poor outcomes in advanced PDAC due to its immunosuppressive tumor microenvironment.We describe a case of metastatic PDAC effectively treated with pembrolizumab.CASE SUMMARY We report the case of a 67-year-old woman with unresectable locally advanced PDAC,treated with gemcitabine plus nab-paclitaxel followed by radiotherapy plus capecitabine.At nine months,pancreatic tumor progression was observed at the level of the hepatic hilum with the appearance of a new pulmonary nodule suggestive of a second primary,confirmed by left lung biopsy.Systemic immunotherapy was then initiated with pembrolizumab,an immune checkpoint inhibitor targeting programmed cell death protein-1 that covers the two tumor types.The patient showed a complete metabolic response that was maintained throughout the treatment.The patient continues to be disease-free at 5.6 years since the start of immunotherapy.CONCLUSION These results suggest that the administration of pembrolizumab after chemoradiotherapy has a beneficial effect in patients with metastatic PDAC.To our knowledge,this is the first reported case of a patient with metastatic PDAC and metastatic lung cancer showing such a long-lasting complete response after pembrolizumab treatment without curative surgery.Further studies are required to determine biomarkers that identify PDAC patients most likely to benefit from this immunotherapy.

T cells in pancreatic cancer stroma:Tryptophan metabolism plays an important role in immunoregulation

Several studies have shown that the immune system is highly regulated by tryptophan metabolism,which serves as an immunomodulatory factor.The indoleamine 2,3-dioxygenase 1(IDO1),as an intracellular enzyme that participates in metabolism of the essential amino acid tryptophan in the kynurenine pathway,is an independent prognostic marker for pancreatic cancer(PC).First,overexpression of IDO1 inhibits the maturation of dendritic cells and T-cell proliferation in the liver and spleen.Second,the high expression of kynurenine induces and activates the aryl hydrocarbon receptor,resulting in upregulated programmed cell death protein 1 expression.Third,the induction of IDO1 can lead to loss of the T helper 17 cell/regulatory T cell balance,mediated by the proximal tryptophan catabolite from IDO metabolism.In our study,we found that overexpression of IDO1 upregulated CD8+T cells and reduced natural killer T cells in pancreatic carcinoma in mice.Hence,it may be essential to pay more attention to tryptophan metabolism in patients,especially those who are tolerant to immunotherapy for PC.

Clinical implications and perspectives of portal venous circulating tumor cells in pancreatic cancer

Despite recent improvements in the diagnosis and treatment of pancreatic cancer(PC),clinical outcomes remain dismal.Moreover,there are no effective prognostic or predictive biomarkers or options beyond carbohydrate antigen 19-9 for personalized and precise treatment.Circulating tumor cells(CTCs),as a member of the liquid biopsy family,could be a promising biomarker;however,the rarity of CTCs in peripheral venous blood limits their clinical use.Because the first venous drainage of PC is portal circulation,the portal vein can be a more suitable location for the detection of CTCs.Endoscopic ultrasound-guided portal venous sampling of CTCs is both feasible and safe.Several studies have suggested that the detection rate and number of CTCs may be higher in the portal blood than in the peripheral blood.CTC counts in the portal blood are highly associated with hepatic metastasis,recurrence after surgery,and survival.The phenotypic and genotypic properties measured in the captured portal CTCs can help us to understand tumor heterogeneity and predict the prognosis of PC.Small sample sizes and heterogeneous CTC detection methods limit the studies to date.Therefore,a large number of prospective studies are needed to corroborate portal CTCs as a valid biomarker in PC.

Regional differences in islet amyloid deposition in the residual pancreas with new-onset diabetes secondary to pancreatic ductal adenocarcinoma

BACKGROUND Islet amyloid deposition and reducedβ-cell mass are pathological hallmarks in type 2 diabetes mellitus subjects.To date,the pathological features of the islets in diabetes secondary to pancreatic ductal adenocarcinoma(PDAC)have not been specifically addressed.AIM To provide further insight into the relationship between islet amyloid deposition of the residual pancreas in PDAC patients and to explore whether regional differences(proximal vs distal residual pancreas)are associated with islet amyloid deposition.METHODS We retrospectively collected clinical information and pancreatic tissue removed from tumors of 45 PDAC patients,including 14 patients with normal glucose tolerance(NGT),16 patients with prediabetes and 15 new-onset diabetes(NOD)patients diagnosed before surgery by an oral glucose tolerance test at West China Hospital from July 2017 to June 2020.Pancreatic volume was calculated by multiplying the estimated area of pancreatic tissue on each image slice by the interval between slices based on abdominal computer tomography scans.Several sections of paraffin-embedded pancreas specimens from both the proximal and/or distal regions remote from the tumor were stained as follows:(1)Hematoxylin and eosin for general histological appearance;(2)hematoxylin and insulin for the determination of fractionalβ-cell area(immunohistochemistry);and(3)quadruple insulin,glucagon,thioflavin T and DAPI staining for the determination ofβ-cell area,α-cell area and amyloid deposits.RESULTS Screening for pancreatic histologic features revealed that duct obstruction with islet amyloid deposition,fibrosis and marked acinar atrophy were robust in the distal pancreatic regions but much less robust in the proximal regions,especially in the prediabetes and NOD groups.Consistent with this finding,the remnant pancreatic volume was markedly decreased in the NOD group by nearly one-half compared with that in the NGT group(37.35±12.16 cm^(3) vs 69.79±18.17 cm^(3),P<0.001).As expected,islets that stained positive for amyloid(islet amyloid density)were found in the majority of PDAC cases.The proportion of amyloid/islet area(severity of amyloid deposition)was significantly higher in both prediabetes and NOD patients than in NGT patients(P=0.002;P<0.0001,respectively).We further examined the regional differences in islet amyloid deposits.Islet amyloid deposit density was robustly increased by approximately 8-fold in the distal regions compared with that in the proximal regions in the prediabetes and NOD groups(3.98%±3.39%vs 0.50%±0.72%,P=0.01;12.03%vs 1.51%,P=0.001,respectively).CONCLUSION In conclusion,these findings suggest that robust alterations of the distal pancreas due to tumors can disturb islet function and structure with islet amyloid formation,which may be associated with the pathogenesis of NOD secondary to PDAC.

Rare ROS1-CENPW gene in pancreatic acinar cell carcinoma and the effect of crizotinib plus AG chemotherapy:A case report

BACKGROUND This is the first report of an ROS1-CENPW fusion gene in pancreatic malignancies.CASE SUMMARY A 77-year-old woman with a pancreatic tumor and multiple liver metastases was admitted to our hospital.Genetic testing revealed the presence of the ROS1-CENPW fusion gene,a rare fusion gene that has not been previously reported in the field of pancreatic cancer.The patient received crizotinib plus AG(albumin paclitaxel plus gemcitabine)chemotherapy.After treatment,the patient’s condition stabilized,and her prognosis was good.CONCLUSION The ROS1-CENPW gene treatment regimen used in this case is an excellent treatment option that provides new hope for patients with advanced pancreatic cancer and similar genetic mutations.To date,owing to the rarity of the ROS1-CENPW fusion gene,our team has encountered only a single case.Therefore,the efficacy of crizotinib plus AG chemotherapy in patients with pancreatic acinar cell carcinoma harboring the ROS1-CENPW fusion gene requires further validation.

WJSC 6^(th) Anniversary Special Issues(2):Mesenchymal stem cells Mesenchymal stem cells help pancreatic islet transplantation to control type 1 diabetes

Islet cell transplantation has therapeutic potential to treat type 1 diabetes,which is characterized by autoimmune destruction of insulin-producing pancreatic isletβcells.It represents a minimal invasive approach forβcell replacement,but long-term blood control is still largely unachievable.This phenomenon can be attributed to the lack of islet vasculature and hypoxic environment in the immediate post-transplantation period that contributes to the acute loss of islets by ischemia.Moreover,graft failures continue to occur because of immunological rejection,despite the use of potent immunosuppressive agents.Mesenchymal stem cells(MSCs)have the potential to enhance islet transplantation by suppressing inflammatory damage and immune mediated rejection.In this review we discuss the impact of MSCs on islet transplantation and focus on the potential role of MSCs in protecting islet grafts from early graft failure and from autoimmune attack.

A Study on Enhancing Pancreatic Islet Function in Type 2 Diabetes and Coronary Heart Disease Patients with Liraglutide and Metformin Combination Therapy

Objective:To investigate the impact of combining liraglutide with metformin on the enhancement of pancreatic islet function in patients with type 2 diabetes and coronary heart disease.Methods:60 patients with type 2 diabetes and coronary heart disease admitted from February 2022 to August 2023 were selected as research subjects.They were randomly assigned to either control or treatment groups,with 30 patients in each.The control group received metformin alone,while the treatment group received liraglutide in combination with metformin.Various indicators,including blood sugar levels,pancreatic islet function,and cardiac function between the two groups were compared.Results:The results of FPG,2hPG,HbA1c,HOMA-IR,NT-proBNP,and LVEDD in the treatment group were lower than those in the control group,whereas the values of FINS,HOMA-β,E/A,and LVEF in the treatment group were higher than those in the control group(P<0.05).Conclusion:The use of liraglutide in combination with metformin significantly benefits patients with type 2 diabetes and coronary heart disease.It leads to improved pancreatic islet function,better blood sugar control,and enhanced cardiac function.This combination therapy is recommended for clinical adoption.

Isolation, Culture and Induced Differentiation of Fetal Porcine Islet Derived Pancreatic Stem Cell

To isolate and culture the porcine pancreatic stem cells and investigate their function, the fetal porcine pancreatic stem cells were isolated by the method of suspending plus adhering culture. The isolated cells were then identified by immunohistochemical staining, and their culture viability measured through the MTT method in vitro. This induced them to differentiate into endocrine cells and detect their function. The isolated IPSCS did not express nestin, but expressed CK-19, a marker of ductal epithelia cells and ct-actin, a smooth muscle marker, demonstrating the growth characteristics of ES-like cells, and strong proliferative ability, after 18 passages. They could excrete insulin, and showed ultrastructure changes after being induced. Porcine pancreatic stem cells can be isolated by this method, induced to form islet-like clusters, and can secret insulin.

Differentiation of fetal pancreatic stem cells into neuron-like and islet-like cells in vitro

Pancreatic stem cells were isolated and cultured from aborted human fetal pancreases of gestational age 14-20 weeks. They were seeded at a density of 1 × 104 in serum-free media for differentiation into neuron-like cells, expressing β-tubulin III and glial fibrillary acidic protein. These neuron-like cells displayed a synapse-like morphology and appeared to form a neuronal network. Pancreatic stem cells were also seeded at a density of 1 × 105 for differentiation into islet-like cells, expressing insulin and glucagon, with an islet-like morphology. These cells had glucose-stimulated secretion of human insulin and C-peptide. Results suggest that pancreatic stem cells can be differentiated into neuron-like and islet-like cells.

Expression of stem cell markers CK-19 and PDX-1mRNA in pancreatic islet samples of different purity from rats

BACKGROUND: Islet stem cells are more or less retained in the procedure of islet isolation and purification, and are transplanted together with islet grafts. Keratoprotein (CK-19) and pancreatic duodenal hox gene 1 (PDX-1) are markers of stem cells. This study was undertaken to examine the expression of these markers in pancreatic islet samples of different purity from rats. METHODS: A total of 30 male Sprague-Dawley rats were randomly assigned to 3 groups to undergo perfusion with V-type collagenase via the pancreatic duct, then the pancreas was excised, diced, shaken, digested and centrifuged to obtain islet sediments. The sediment from group A was not purified, while that from group B was purified with 25% Ficoll-400 and that from group C with 25% and 11% Ficoll-400. RNA was extracted from the different islet samples for reverse transcriptase-polymerase chain reaction (RT-PCR). The expression of the pancreatic stem cell markers CK-19 and PDX-1 was assessed. RESULTS: The purity of islets in samples was (43.6 +/- 6.29)% in group A; (65.3 +/- 4.40)% in group B; and (77.6 +/- 6.36)% in group C (P<0.05). The expression of CK-19 and PDX-1 mRNA was significantly higher in group A than in groups B and C, but group C showed the lowest level of expression. CONCLUSION: The expression of CK-19 and PDX-1 mRNA in islet samples of different purity suggests the presence of stem cells in all islet samples.

Spiral CT localization of pancreatic function-ing islet cell tumors

BACKGROUND: Surgeons are always concerned about the localization of pancreatic functioning islet cell tumor. If the tumor is accurately localized before operation, resection of the pancreatic body and tail without intention can be avoided. The purpose of this study was to evaluate spiral CT localization of pancreatic functioning islet cell tumors and CT techniques. METHODS: CT manifestations in 6 patients with clinically and pathologically proved pancreatic functioning islet cell tumors ware analyzed retrospectively. RESULTS: In 4 patients with insulinomas and 2 patients with glucagonomas, 5 were localized accurately by CT be- fore surgery and 1 was detected retrospectively. The en- hancement of tumors was greater than that of normal pan- creas in arterial phase and pancreatic parenchymal phase. Four patients showed mild high-density and 2, iso-density in the portal venous phase. CONCLUSION: Spiral CT multi-phase enhanced scan with 1.5 ml/kg contrast agent and 2-5 mm slice width can loca- lize functioning islet cell tumors accurately.

Progressive <I>β</i>Cell Failure in Type 2 Diabetes Mellitus: Microvascular Pancreatic Isletopathy?

Background: UKPDS suggested relentless deterioration of β cell function as a part of natural course of type 2 diabetes mellitus. However, the course was apparently not universal since many patients maintained glycemic goal (HbA1c β cell failure occurred around the same time as the time of onset of microvascular complications. Finally, the exact mechanism of progressive β cell failure remains to be defined. It is plausible that β cell failure may be due to fibrosis of pancreatic islets secondary to microangiopathy since no organ or tissue is exempt from this complication. Objective: To assess epidemiologic correlation between presence of b cell failure and microvascular complications by determining the prevalence of β cell failure in subjects with type 2 diabetes with increasing number of known microvascular complications. Methods: 650 Subjects with ages 40-75 years and duration of DM 4-23 years were divided into 4 groups according to number of microvascular complications, e.g. retinopathy, nephropathy, and neuropathy. β cell failure (β -?ve ) is defined as HbA1c > 7.0% with any therapy or HbA1c β cell function is deemed “preserved” (β + ve) with HbA1c b cell failure progressively rose with increasing number of microvascular complications from 0 to 2 with no further significant rise with 3 complications whereas subjects with preserved β cell function declined with increasing number of microvascular complications (p β cell failure (p β cell failure/β cell preserved with increasing number of microvascular complications as well as the greater duration of Diabetes. However, a significantly (p β cell failure persisted for rising number of microvascular complications even after eliminating the influence of age and duration of diabetes. Conclusion: β cell failure may be a manifestation of microvascular pancreatic isletopathy similar to other microvascular complications.

Antioxidant activity of chito-oligosaccharides on pancreatic islet cells in streptozotocin-induced diabetes in rats

AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.

Antidiabetic effects of chitooligosaccharides on pancreatic islet cells in streptozotocin-induced diabetic rats

AIM: To investigate the effect of chitooligosaccharides on proliferation of pancreatic islet cells, release of insulin and 2 h plasma glucose in streptozotocin-induced diabetic rats.METHODS: In vitro, the effect of chitooligosaccharides on proliferation of pancreatic islet cells and release of insulin was detected with optical microscopy, colorimetric assay, and radioimmunoassay respectively. In vivo, the general clinical symptoms, 2 h plasma glucose, urine glucose, oral glucose tolerance were examined after sixty days of feeding study to determine the effect of chitooligosaccharides in streptozotocin-induced diabetic rats. RESULTS: Chitooligosaccharides could effectively accelerate the proliferation of pancreatic islet cells. Chitooligosaccharides (100 mg/L) had direct and prominent effect on pancreastic β cells and insulin release from islet cells. All concentrations of chitooligosaccharides could improve the general clinical symptoms of diabetic rats, decrease the 2 h plasma glucose and urine glucose, and normalize the disorders of glucose tolerance.CONCLUSION: Chitooligosaccharides possess various biological activities and can be used in the treatment of diabetes mellitus.