Preservation of Beta cell function in adult human pancreatic islets for several months in vitro

Summary Islets of Langerhans were isolated from four human kidney donors, aged 16 to 21 years, by the collagenase method described for isolation of rodent islets. So far the human islets have been kept in tissue culture, without attachment, in medium RPMI 1640 supplemented with 10% calf serum for more than 9 months, with preservation of the ability to release insulin in response to glucose stimulation. Replacement of calf serum with serum from normal human subjects did not affect B-cell survival, but resulted in elevated insulin values partly due to lower insulin degrading activity. Thus the described technique presents a valuable tool for studying chronic effects of metabolites and hormones on islet function, as well as for islet storage prior to transplantation into humans.     

Islet separation and islet cell culture in vitro from human embryo pancreas

INTRODUCTlONDiabetesmellitusisthemostc0mmondiseaseanditsdeathrateranksthe8thintheworld.Upt0n0w,itsincidencehasatendencytoincrease[11.Sincedisorderofsugarmetabolismmightresultinmicrovasculardegenerati0nandinjuryofimportanthumanorgans,itwillendangerhumanhealthseri0usly-Inl969,Younszaifirstreportedthemethodthatcoulddecreasediabetessymptomsbyislettissuetransplantation.In1981,ourcountrybegantotreatdiabetestype1bytransplantingculturedislettissues.Inourstudy,wedigestedthepiecesofpancreaswithcol…     

Different digestion enzymes used for human pancreatic islet isolation: A mixed treatment comparison (MTC) meta-analysis

Collagenases are critical reagents determining yield and quality of isolated human pancreatic islets and may affect islet transplantation outcome. Some islet transplantation centers have compared 2 or more collagenase blends; however, the results regarding differences in quantity and quality of islets are conflicting. Thus, for the first time, a mixed treatment comparison (MTC) meta-analysis was carried out to compile data about the effect of different collagenases used for human pancreas digestion on islet yield, purity, viability and stimulation index (SI). Pubmed, Embase and Cochrane libraries were searched. Of 755 articles retrieved, a total of 15 articles fulfilled the eligibility criteria and were included in the MTC meta-analysis. Our results revealed that Vitacyte and Liberase MTF were associated with a small increase in islet yield (islet equivalent number/g pancreas) when compared with Sevac enzyme [standardized mean difference (95% credible interval – CrI) = −2.19 (−4.25 to −0.21) and −2.28 (−4.49 to −0.23), respectively]. However, all other enzyme comparisons did not show any significant difference regarding islet yield. Purity and viability percentages were not significantly different among any of the analyzed digestion enzymes. Interestingly, Vitacyte and Serva NB1 were associated with increased SI when compared with Liberase MTF enzyme [unstandardized weighted mean difference (95% CrI) = −1.69 (−2.87 to −0.51) and −1.07 (−1.79 to −0.39), respectively]. In conclusion, our MTC meta-analysis suggests that the digestion enzymes currently being used for islet isolation works with similar efficiency regarding islet yield, purity and viability; however, Vitacyte and Serva NB1 enzymes seem to be associated with an improved SI as compared with Liberase MTF.     

Different digestion enzymes used for human pancreatic islet isolation: A mixed treatment comparison (MTC) meta-analysis

Collagenases are critical reagents determining yield and quality of isolated human pancreatic islets and may affect islet transplantation outcome. Some islet transplantation centers have compared 2 or more collagenase blends; however, the results regarding differences in quantity and quality of islets are conflicting. Thus, for the first time, a mixed treatment comparison (MTC) meta-analysis was carried out to compile data about the effect of different collagenases used for human pancreas digestion on islet yield, purity, viability and stimulation index (SI). Pubmed, Embase and Cochrane libraries were searched. Of 755 articles retrieved, a total of 15 articles fulfilled the eligibility criteria and were included in the MTC meta-analysis. Our results revealed that Vitacyte and Liberase MTF were associated with a small increase in islet yield (islet equivalent number/g pancreas) when compared with Sevac enzyme [standardized mean difference (95% credible interval – CrI) = ?2.19 (?4.25 to ?0.21) and ?2.28 (?4.49 to ?0.23), respectively]. However, all other enzyme comparisons did not show any significant difference regarding islet yield. Purity and viability percentages were not significantly different among any of the analyzed digestion enzymes. Interestingly, Vitacyte and Serva NB1 were associated with increased SI when compared with Liberase MTF enzyme [unstandardized weighted mean difference (95% CrI) = ?1.69 (?2.87 to ?0.51) and ?1.07 (?1.79 to ?0.39), respectively]. In conclusion, our MTC meta-analysis suggests that the digestion enzymes currently being used for islet isolation works with similar efficiency regarding islet yield, purity and viability; however, Vitacyte and Serva NB1 enzymes seem to be associated with an improved SI as compared with Liberase MTF.     

An analysis of the role of collagenase and protease in the enzymatic dissociation of the rat pancreas for islet isolation

Summary Crude Clostridium histolyticum collagenase is widely used for the enzymatic degradation of pancreatic extracellular matrix in order to isolate the islets of Langerhans. The variable enzymatic composition of crude collagenases is a critical issue which contributes to the poor reproducibility of islet isolation procedures. In this study, the separate contributions of collagenase and protease to the islet isolation process were analysed by testing various combinations of purified collagenase and purified protease in rat pancreas dissociations under conditions which eliminated all other proteolytic activity. Under these conditions, complete tissue dissociation by purified collagenase required 99±10 min, whereas increasing amounts of protease progressively reduced this time to a minimum of 36±1 min. Histochemical analysis of the dissociation process showed that protease enhanced the degradation of all four major components of the extracellular matrix: collagen was degraded more completely, while proteoglycans, glycoproteins and elastin were degraded at a higher rate. Pancreas dissociation under the present, strictly controlled conditions resulted in a high yield of viable islets: 4.2–5.0 l islet tissue volume (3,300–3,800 islets) were isolated per g pancreas in the presence of a high or low protease concentration, respectively. Prolonged dissociation in the presence of protease resulted in a dramatic decrease in islet yield which correlated with the observation that the enzyme accelerated islet disintegration. It is concluded that the collagenase-induced dissociation of the extracellular matrix is facilitated by protease. Our study shows that high yields of viable islets can be obtained under controlled enzymatic conditions, provided that the exposure of islets to protease is limited.     

The role of extracellular matrix components in angiogenesis and fibrosis: Possible implication for Systemic Sclerosis

Abstract

Extracellular matrix (ECM) plays a crucial role in the regulation of both physiological and pathological angiogenesis. ECM homeostasis and function is ensuring by the tightly regulation of the different ECM components including, collagens, proteoglycans and a variety of different glycoproteins. An altered expression of the above ECM molecules as well as an imbalance between the action of matrix remodeling enzymes and their tissue inhibitors is known to be responsible for impaired angiogenesis and fibrosis. Systemic Sclerosis (SSc) is an autoimmune disease characterized by micro-angiopathy, failure of reparative angiogenesis, and excessive fibrosis of the skin and various internal organs, dues to an increased production of ECM. A comprehensive search through Medline/PubMed and Scopus was performed for English-language original papers, using the keywords related to ECM components and SSc. This review will analyze the role played by ECM components in the deregulation of angiogenic mechanisms and in the persistence of a pro-fibrotic phenotype, during SSc. A better knowledge of these processes might provide information about molecules, which could be considered targets for future pro-angiogenic and/or anti-fibrotic therapies.     

Expression of glomerular extracellular matrix components in human diabetic nephropathy: decrease of heparan sulphate in the glomerular basement membrane

Summary Diabetic nephropathy is characterized by albuminuria which proceeds to overt proteinuria. The highly negatively stained HS side chain of heparan sulphate proteoglycan (HSPG) is a major determinant of the charge-dependent permeability of the GBM. We set out to study the presence of HS and HSPG in the GBM of patients with diabetic nephropathy using newly developed monoclonal antibodies, and to compare HSPG expression to the expression of other previously investigated glomerular extracellular matrix compounds. Immunohistochemically, glomerular extracellular matrix components were analysed in 14 renal biopsies of patients with diabetic nephropathy and compared with those of normal control subjects. Monoclonal antibodies used were: JM403 against the HS side chain of GBM HSPG and JM72 against the HSPG-core protein. Also, a polyclonal antiserum (B31) against human GBM-HSPG-core protein was used. Additionally, antibodies were used against collagen types I, III, IV and against 1(IV)NC, 3(IV)NC and fibronectin. Staining was scored for intensity and for staining pattern by four independent observers who had no previous knowledge of the sample origin. No glomerular staining was seen for collagen type I. Collagen type III was present in some diabetic nodules. Anti-collagen type IV showed a decreased GBM staining in patients with diabetic nephropathy (p = 0.04). With anti-1(IV)NC no changes in GBM staining intensity were observed; with anti-3(IV)NC brilliant GBM staining was seen in both groups. Increased mesangial staining (p = 0.003) was seen with anti-collagen type IV in biopsies with nodular lesions. No differences were observed for fibronectin although it was abundantly present in the mesangial area of biopsies from patients with diabetic nephropathy. In biopsies with mesangial expansion and in biopsies with diabetic nodules, we observed a decreased GBM (p = 0.001) HS side chain staining (JM403) without changes in HSPG-core protein staining (JM72,B31). The HS staining pattern regularly changed from a linear to a more granular and irregular pattern. In patients with a creatinine clearance of more than 15 ml/min, the intensity of GBM HS staining showed an inverse correlation with the rate of proteinuria (r = -0.85, p = 0.004), suggesting a functional relationship. The decreased HS staining in the GBM may reflect the potentially disrupted charge barrier in diabetic nephropathy.Abbreviations HS Heparan sulphate - GBM glomerular basement membrane - HSPG heparan sulphate proteoglycan - NC noncollagenous globular domain - IDDM insulin-dependent diabetes mellitus - NIDDM non-insulin-dependent diabetes mellitus     

Altered expression of extracellular matrix molecules and their receptors in chronic pancreatitis and pancreatic adenocarcinoma in comparison with normal pancreas

Summary The aim of this study was to elucidate the expression and distribution patterns of both integrins and extracellular matrix (ECM) molecules in chronic pancreatitis (CP) and pancreatic adenocarcinoma (PC) compared with normal pancreas (NP). Expression of nine α-subunits (α2-α6, αv, αl, αm, and αx), four β-subunits (β1, β3-β5), and four ECM molecules (type IV collagen, laminin, fibronectin, and vitronectin) was investigated immunohistochemically. In CP, all integrins except αv showed nearly the same staining patterns compared with NP. Some acinar cells in CP expressed αv. Whereas α2, α3, and α6 expression was stronger and diffuse, no α5 expression was seen in PC. Basement membrane (BM) showed continuous staining in CP, whereas it showed discontinuous/absent staining in PC with antitype IV collagen, laminin, and vitronectin antibodies. Some carcinoma cells showed reverse correlation between α2, α3, and α6 expression and type IV collagen and laminin expression. Fibronectin showed diffuse stromal expression in CP and PC. Some acinar cells or duct cells in CP carcinoma cells in PC showed intracellular VN expression. These results suggest that these integrins and ECM molecules are involved in inflammatory and malignant processes in pancreas.     

Insulin release from human pancreatic islets in vitro

Summary Islets of Langerhans were isolated by collagenase digestion from the pancreas of a 39 year-old female renal transplant donor. The islets were subjected to three consecutive periods of tissue culture, after each of which they were incubated in vitro with various agents whose effects on insulin release from islets of laboratory animals have previously been established. After the first culture period, the basal insulin secretion rate of 5.2 U/islet/h seen with 2 mmol/l glucose was increased approx. 5-fold on raising the glucose concentration to 20 mmol/l. The islets retained the insulin-secretory response to 20 mmol/l glucose throughout the period of study. Insulin secretion was also stimulated by mannose, leucine, -ketoisocaproate, dihydroxyacetone and 3-hydroxybutyrate, but not by fructose or N-acetyl-glucosamine. Fructose however increased insulin release in the presence of 4 mmol/l glucose. Caffeine elicited insulin release in the absence of glucose and enhanced insulin release in response to 10 mmol/l glucose. Glucose-stimulated insulin release was inhibited by trifluoperazine (25 mol/l).     

Efficacy and safety of gemcitabine-capecitabine combination therapy for pancreatic cancer: A systematic review and meta-analysis of randomized controlled trials

Background:Recent randomized controlled trials revealed the combination of gemcitabine and capecitabine (GemCap) regime shows promising efficacy in pancreatic cancer patients. Here, we conducted a meta-analysis to compare the efficacy and safety of gemcitabine (Gem) with GemCap for pancreatic cancer.Methods:The database of MEDLINE (PubMed), EMBASE, Cochrane Central Controster of Controlled Trials, Web of Science was searched for relevant randomized controlled trials before 8 April, 2020. The outcomes were overall survival (OS), 12-month survival rate, progress free survival (PFS), partial response rate (PRR), objective response rate (ORR), and Grade 3/4 toxicities.Results:Five randomized controlled trials involving 1879 patients were included in this study. The results showed that GemCap significantly improves the OS (hazard ratio = 1.15, 95% CI: 1.037-1.276, P = .008), PFS (hazard ratio = 1.211, 95% CI 1.09-1.344, P = 0), PRR (relative risk (RR) = 0.649, 95% CI 0.488-0.862, P = .003), ORR (RR = 0.605, 95% CI 0.458-0.799, P = 0), and the overall toxicity (RR = 0.708, 95% CI 0.620-0.808, P = .000) compared to Gem alone. However, no significant difference was found in 12-month survival.Conclusions:Despite a higher incidence of Grade 3/4 toxicity, GemCap was associated with better outcomes of OS, PFS, PRR, ORR, as compared with Gem, which is likely to become a promising therapy for pancreatic cancer.     

Diabetes in pregnancy outcomes: A systematic review and proposed codification of definitions

Rising rates of diabetes in pregnancy have led to an escalation in research in this area. As in any area of clinical research, definitions of outcomes vary from study to study, making it difficult to compare research findings and draw conclusions. Our aim was to compile and create a repository of definitions, which could then be used universally. A systematic review of the literature was performed on published and ongoing randomized controlled trials in the area of diabetes in pregnancy between 01 Jan 2000 and 01 Jun 2012. Other sources included the World Health Organization and Academic Society Statements. The advice of experts was sought when appropriate definitions were lacking. Among the published randomized controlled trials on diabetes and pregnancy, 171 abstracts were retrieved, 64 full texts were reviewed and 53 were included. Among the ongoing randomized controlled trials published in ClinicalTrials.gov, 90 protocols were retrieved and 25 were finally included. The definitions from these were assembled and the final maternal definitions and foetal definitions were agreed upon by consensus. It is our hope that the definitions we have provided (i) will be widely used in the reporting of future studies in the area of diabetes in pregnancy, that they will (ii) facilitate future systematic reviews and formal meta analyses and (iii) ultimately improve outcomes for mothers and babies. Copyright © 2015 John Wiley & Sons, Ltd.     

Amelogenin,an extracellular matrix protein,in the treatment of venous leg ulcers and other hard-to-heal wounds: Experimental and clinical evidence

Amelogenins are extracellular matrix proteins that, under physiological conditions, self-assemble into globular aggregates up to micron-sizes. Studies with periodontal fibroblasts indicate that attachment to these structures increases the endogenous secretion of multiple growth factors and cell proliferation. Pre-clinical and clinical studies indicate that cutaneous wounds benefit from treatment with amelogenins. A randomized controlled trial (RCT) involving patients with hard-to-heal venous leg ulcers (VLUs) (ie, ulcers with a surface area ≥10 cm² and duration of ≥6 months) showed that the application of amelogenin (Xelma^®, Molnlycke Health Care, Gothenburg, Sweden) as an adjunct treatment to compression results in significant reduction in ulcer size, improvement in the state of ulcers, reduced pain, and a larger proportion of ulcers with low levels of exudate, compared with treatment with compression alone. Amelogenin therapy was also shown to be safe to use in that there were no significant differences in adverse events noted between patients treated with amelogenin plus compression and those treated with compression alone. Case study evaluations indicate that the benefits of amelogenin therapy demonstrated in the RCT are being repeated in “real life” situations and that amelogenin therapy may also have a role to play in the treatment of other wound types such as diabetic foot ulcers.     

Effect of antidepressants in pregnancy outcomes: A protocol for systematic review and meta-analysis

Background:Depression is much more common in women pre their pregnancies with antidepressants use less common which is caused by when many patients opt to discontinue with the use due to its side effects it causes. But whether depression is treated by antidepressants or not this has the same negative pregnancy outcomes on both the mother and the unborn and even born child from these mothers.Methods:Information will be retrieved for this systematic review and meta-analysis study on antidepressants use pregnancy outcomes from PubMed and Google scholar search engines using search medical subjects headings on PubMed and the PICOS framework as the determinant of the research question. All returned articles searched will be stored to Zotero.org and the software RevMan will be used to analyze data.Ethics and dissemination:The review and meta-analysis will not require ethical approval and the findings will be published in peer-reviewed journals and presented at local and international conferences. In addition, findings from this study will assist in assessing health related risk outcomes of antidepressants during- and postpregnancy on both the fetal and mother either when used pre- and during-pregnancy.Systematic review registration:International prospective Register of Systematic Reviews (PROSERO) number: CRD42021232111.     

Screening/surveillance programs for pancreatic cancer in familial high-risk individuals: A systematic review and proportion meta-analysis of screening results

Background/Objectives

Screening/surveillance programs for pancreatic cancer (PC) in familial high-risk individuals (FPC-HRI) have been widely reported, but their merits remain unclear. The data reported so far are heterogeneous—especially in terms of screening yield. We performed a systematic review and meta-analysis of currently available data coming from screening/surveillance programs to evaluate the proportion of screening goal achievement (SGA), overall surgery and unnecessary surgery.