Role of nutrient-driven O-GlcNAc-post-translational modification in pancreatic exocrine and endocrine islet development.

Although the developing pancreas is exquisitely sensitive to nutrient supply in utero, it is not entirely clear how nutrient-driven post-translational modification of proteins impacts the pancreas during development. We hypothesized that the nutrient-sensing enzyme O-GlcNAc transferase (Ogt), which catalyzes an O-GlcNAc-modification onto key target proteins, integrates nutrient-signaling networks to regulate cell survival and development. In this study, we investigated the heretofore unknown role of Ogt in exocrine and endocrine islet development. By genetic manipulation in vivo and by using morphometric and molecular analyses, such as immunofluorescence imaging and single cell RNA sequencing, we show the first evidence that Ogt regulates pancreas development. Genetic deletion of Ogt in the pancreatic epithelium (OgtKOPanc) causes pancreatic hypoplasia, in part by increased apoptosis and reduced levels of of Pdx1 protein. Transcriptomic analysis of single cell and bulk RNA sequencing uncovered cell-type heterogeneity and predicted upstream regulator proteins that mediate cell survival, including Pdx1, Ptf1a and p53, which are putative Ogt targets. In conclusion, these findings underscore the requirement of O-GlcNAcylation during pancreas development and show that Ogt is essential for pancreatic progenitor survival, providing a novel mechanistic link between nutrients and pancreas development.

Early vs late drain removal after pancreatic resection-a systematic review and meta-analysis.

BACKGROUND: Reducing clinically relevant post-operative pancreatic fistula (CR-POPF) incidence after pancreatic resections has been a topic of great academic interest. Optimizing post-operative drain management is a potential strategy in reducing this major complication. METHODS: Studies involving pancreatic resections, including both pancreaticoduodenectomy (PD) and distal pancreatic resections (DP), with intra-operative drain placement were screened. Early drain removal was defined as removal before or on the 3rd post-operative day (POD) while late drain removal was defined as after the 3rd POD. The primary outcome was CR-POPF, International Study Group of Pancreatic Surgery (ISGPS) Grade B and above. Secondary outcomes were all complications, severe complications, post-operative haemorrhage, intra-abdominal infections, delayed gastric emptying, reoperation, length of stay, readmission, and mortality. RESULTS: Nine studies met the inclusion criteria and were included for analysis. The studies had a total of 8574 patients, comprising 1946 in the early removal group and 6628 in the late removal group. Early drain removal was associated with a significantly lower risk of CR-POPF (OR: 0.24, p < 0.01). Significant reduction in risk of post-operative haemorrhage (OR: 0.55, p < 0.01), intra-abdominal infection (OR: 0.35, p < 0.01), re-admission (OR: 0.63, p < 0.01), re-operation (OR: 0.70, p = 0.03), presence of any complications (OR: 0.46, p < 0.01), and reduced length of stay (SMD: -0.75, p < 0.01) in the early removal group was also observed. CONCLUSION: Early drain removal is associated with significant reductions in incidence of CR-POPF and other post-operative complications. Further prospective randomised trials in this area are recommended to validate these findings.

Synaptotagmin-7 enhances calcium-sensing of chromaffin cell granules and slows discharge of granule cargos.

Synaptotagmin-7 (Syt-7) is one of two major calcium sensors for exocytosis in adrenal chromaffin cells, the other being synaptotagmin-1 (Syt-1). Despite a broad appreciation for the importance of Syt-7, questions remain as to its localization, function in mediating discharge of dense core granule cargos, and role in triggering release in response to physiological stimulation. These questions were addressed using two distinct experimental preparations-mouse chromaffin cells lacking endogenous Syt-7 (KO cells) and a reconstituted system employing cell-derived granules expressing either Syt-7 or Syt-1. First, using immunofluorescence imaging and subcellular fractionation, it is shown that Syt-7 is widely distributed in organelles, including dense core granules. Total internal reflection fluorescence (TIRF) imaging demonstrates that the kinetics and probability of granule fusion in Syt-7 KO cells stimulated by a native secretagogue, acetylcholine, are markedly lower than in WT cells. When fusion is observed, fluorescent cargo proteins are discharged more rapidly when only Syt-1 is available to facilitate release. To determine the extent to which the aforementioned results are attributable purely to Syt-7, granules expressing only Syt-7 or Syt-1 were triggered to fuse on planar supported bilayers bearing plasma membrane SNARE proteins. Here, as in cells, Syt-7 confers substantially greater calcium sensitivity to granule fusion than Syt-1 and slows the rate at which cargos are released. Overall, this study demonstrates that by virtue of its high affinity for calcium and effects on fusion pore expansion, Syt-7 plays a central role in regulating secretory output from adrenal chromaffin cells.

Fetal undernutrition, placental insufficiency, and pancreatic ß-cell development programming in utero.

The prevalence of obesity and type 2 (T2D) diabetes is a major health concern in the United States and around the world. T2D is a complex disease characterized by pancreatic ß-cell failure in association with obesity and insulin resistance in peripheral tissues. Although several genes associated with T2D have been identified, it is speculated that genetic variants account for only <10% of the risk for this disease. A strong body of data from both human epidemiological and animal studies shows that fetal nutrient factors in utero confer significant susceptibility to T2D. Numerous studies done in animals have shown that suboptimal maternal environment or placental insufficiency causes intrauterine growth restriction (IUGR) in the fetus, a critical factor known to predispose offspring to obesity and T2D, in part by causing permanent consequences in total functional ß-cell mass. This review will focus on the potential contribution of the placenta in fetal programming of obesity and TD and its likely impact on pancreatic ß-cell development and growth.

Reduced uterine perfusion pressure causes loss of pancreatic ß-cell area but normal function in fetal rat offspring.

Maternal hypertension during pregnancy is a major risk factor for intrauterine growth restriction (IUGR), which increases susceptibility to cardiovascular and metabolic disease in adulthood through unclear mechanisms. The aim of this study was to characterize the pancreatic ß-cell area and function in the fetal rat offspring of a reduced uterine perfusion pressure (RUPP) model of gestational hypertension. At embryonic day 19.5, RUPP dams exhibited lower body weight, elevated mean blood pressure, reduced litter size, and higher blood glucose compared with sham-operated controls. In RUPP placental lysates, a nonsignificant change in mammalian target of rapamycin (mTOR) activity markers, phosphorylated S6 at serine 240, and phosphorylated AKT (at S473) was observed. RUPP offspring showed significantly reduced ß-cell-to-pancreas area and increased ß-cell death but normal insulin levels in serum. Isolated islets had normal insulin content and secretory function in response to glucose and palmitate. Fetal pancreatic lysates showed a tendency for reduced insulin levels, with a significant reduction in total mTOR protein with RUPP surgery. In addition, its downstream complex 2 targets phosphorylation of AKT at S473, and pAKT at Thr308 tended to be reduced in the fetal RUPP pancreas. Altogether, these data show that RUPP offspring demonstrated increased ß-cell death, reduced ß-cell area, and altered nutrient-sensor mTOR protein level in the pancreas. This could represent a mechanistic foundation in IUGR offspring's risk for enhanced susceptibility to type 2 diabetes and other metabolic vulnerabilities seen in adulthood.

Differentially Expressed MicroRNA-483 Confers Distinct Functions in Pancreatic ß- and α-Cells.

Insulin secreted from pancreatic ß-cells and glucagon secreted from pancreatic α-cells are the two major hormones working in the pancreas in an opposing manner to regulate and maintain a normal glucose homeostasis. How microRNAs (miRNAs), a population of non-coding RNAs so far demonstrated to be differentially expressed in various types of cells, regulate gene expression in pancreatic ß-cells and its closely associated α-cells is not completely clear. In this study, miRNA profiling was performed and compared between pancreatic ß-cells and their partner α-cells. One novel miRNA, miR-483, was identified for its highly differential expression in pancreatic ß-cells when compared to its expression in α-cells. Overexpression of miR-483 in ß-cells increased insulin transcription and secretion by targeting SOCS3, a member of suppressor of cytokine signaling family. In contrast, overexpression of miR-483 decreased glucagon transcription and secretion in α-cells. Moreover, overexpressed miR-483 protected against proinflammatory cytokine-induced apoptosis in ß-cells. This correlates with a higher expression level of miR-483 and the expanded ß-cell mass observed in the islets of prediabetic db/db mice. Together, our data suggest that miR-483 has opposite effects in α- and ß-cells by targeting SOCS3, and the imbalance of miR-483 and its targets may play a crucial role in diabetes pathogenesis.

Membrane lipids couple synaptotagmin to SNARE-mediated granule fusion in insulin-secreting cells.

Insulin secretion depends on the Ca2+-regulated fusion of granules with the plasma membrane. A recent model of Ca2+-triggered exocytosis in secretory cells proposes that lipids in the plasma membrane couple the calcium sensor Syt1 to the membrane fusion machinery (Kiessling et al., 2018). Specifically, Ca2+-mediated binding of Syt1's C2 domains to the cell membrane shifts the membrane-anchored SNARE syntaxin-1a to a more fusogenic conformation, straightening its juxtamembrane linker. To test this model in live cells and extend it to insulin secretion, we enriched INS1 cells with a panel of lipids with different acyl chain compositions. Fluorescence lifetime measurements demonstrate that cells with more disordered membranes show an increase in fusion efficiency, and vice versa. Experiments with granules purified from INS1 cells and recombinant SNARE proteins reconstituted in supported membranes confirmed that lipid acyl chain composition determines SNARE conformation and that lipid disordering correlates with increased fusion. Addition of Syt1's C2AB domains significantly decreased lipid order in target membranes and increased SNARE-mediated fusion probability. Strikingly, Syt's action on both fusion and lipid order could be partially bypassed by artificially increasing unsaturated phosphatidylserines in the target membrane. Thus, plasma membrane lipids actively participate in coupling Ca2+/synaptotagmin-sensing to the SNARE fusion machinery in cells.

MicroRNA-30d induces insulin transcription factor MafA and insulin production by targeting mitogen-activated protein 4 kinase 4 (MAP4K4) in pancreatic ß-cells.

MicroRNAs (miRNAs) represent small noncoding RNAs that play a role in many diseases, including diabetes. miRNAs target genes important for pancreas development, ß-cell proliferation, insulin secretion, and exocytosis. Previously, we documented that microRNA-30d (miR-30d), one of miRNAs up-regulated by glucose, induces insulin gene expression in pancreatic ß-cells. Here, we found that the induction of insulin production by overexpression of miR-30d is associated with increased expression of MafA, a ß-cell-specific transcription factor. Of interest, overexpression of miR-30d prevented the reduction in both MafA and insulin receptor substrate 2 (IRS2) with TNF-α exposure. Moreover, we identified that mitogen-activated protein 4 kinase 4 (MAP4K4), a TNF-α-activated kinase, is a direct target of miR-30d. Overexpression of miR-30d protected ß-cells against TNF-α suppression on both insulin transcription and insulin secretion through the down-regulation of MAP4K4 by the miR-30d. A decrease of miR-30d expression was observed in the islets of diabetic db/db mice, in which MAP4K4 expression level was elevated. Our data support the notion that miR-30d plays multiple roles in activating insulin transcription and protecting ß-cell functions from impaired by proinflammatory cytokines and underscore the concept that miR-30d may represent a novel pharmacological target for diabetes intervention.

MicroRNAs as pharmacological targets in diabetes.

Diabetes is characterized by high levels of blood glucose due to either the loss of insulin-producing beta-cells in the pancreas, leading to a deficiency of insulin in type 1 diabetes, or due to increased insulin resistance, leading to reduced insulin sensitivity and productivity in type 2 diabetes. There is an increasing need for new options to treat diabetes, especially type 2 diabetes at its early stages due to an ineffective control of its development in patients. Recently, a novel class of small noncoding RNAs, termed microRNAs (miRNAs), is found to play a key role as important transcriptional and posttranscriptional inhibitors of gene expression in fine-tuning the target messenger RNAs (mRNAs). miRNAs are implicated in the pathogenesis of diabetes and have become an intriguing target for therapeutic intervention. This review focuses on the dysregulated miRNAs discovered in various diabetic models and addresses the potential for miRNAs to be therapeutic targets in the treatment of diabetes.

Impact of placental mTOR deficiency on peripheral insulin signaling in adult mice offspring.

Suboptimal in utero environments such as poor maternal nutrition and gestational diabetes can impact fetal birth weight and the metabolic health trajectory of the adult offspring. Fetal growth is associated with alterations in placental mechanistic target of rapamycin (mTOR) signaling; it is reduced in fetal growth restriction and increased in fetal overgrowth. We previously reported that when metabolically challenged by a high-fat diet, placental mTORKO (mTORKOpl) adult female offspring develop obesity and insulin resistance, whereas placental TSC2KO (TSC2KOpl) female offspring are protected from diet-induced obesity and maintain proper glucose homeostasis. In the present study, we sought to investigate whether reducing or increasing placental mTOR signaling in utero alters the programming of adult offspring metabolic tissues preceding a metabolic challenge. Adult male and female mTORKOpl, TSC2KOpl, and respective controls on a normal chow diet were subjected to an acute intraperitoneal insulin injection. Upon insulin stimulation, insulin signaling via phosphorylation of Akt and nutrient sensing via phosphorylation of mTOR target ribosomal S6 were evaluated in the offspring liver, white adipose tissue, and skeletal muscle. Among tested tissues, we observed significant changes only in the liver signaling. In the male mTORKOpl adult offspring liver, insulin-stimulated phospho-Akt was enhanced compared to littermate controls. Basal phospho-S6 level was increased in the mTORKOpl female offspring liver compared to littermate controls and did not increase further in response to insulin. RNA sequencing of offspring liver identified placental mTORC1 programming-mediated differentially expressed genes. The expression of major urinary protein 1 (Mup1) was differentially altered in female mTORKOpl and TSC2KOpl offspring livers and we show that MUP1 level is dependent on overnutrition and fasting status. In summary, deletion of placental mTOR nutrient sensing in utero programs hepatic response to insulin action in a sexually dimorphic manner. Additionally, we highlight a possible role for hepatic and circulating MUP1 in glucose homeostasis that warrants further investigation.

PACAP and acetylcholine cause distinct Ca2+ signals and secretory responses in chromaffin cells.

The adrenomedullary chromaffin cell transduces chemical messages into outputs that regulate end organ function throughout the periphery. At least two important neurotransmitters are released by innervating preganglionic neurons to stimulate exocytosis in the chromaffin cell-acetylcholine (ACh) and pituitary adenylate cyclase activating polypeptide (PACAP). Although PACAP is widely acknowledged as an important secretagogue in this system, the pathway coupling PACAP stimulation to chromaffin cell secretion is poorly understood. The goal of this study is to address this knowledge gap. Here, it is shown that PACAP activates a Gαs-coupled pathway that must signal through phospholipase C ε (PLCε) to drive Ca2+ entry and exocytosis. PACAP stimulation causes a complex pattern of Ca2+ signals in chromaffin cells, leading to a sustained secretory response that is kinetically distinct from the form stimulated by ACh. Exocytosis caused by PACAP is associated with slower release of peptide cargo than exocytosis stimulated by ACh. Importantly, only the secretory response to PACAP, not ACh, is eliminated in cells lacking PLCε expression. The data show that ACh and PACAP, acting through distinct signaling pathways, enable nuanced and variable secretory outputs from chromaffin cells.

Placental Insulin Receptor Transiently Regulates Glucose Homeostasis in the Adult Mouse Offspring of Multiparous Dams.

In pregnancies complicated by maternal obesity and gestational diabetes mellitus, there is strong evidence to suggest that the insulin signaling pathway in the placenta may be impaired. This may have potential effects on the programming of the metabolic health in the offspring; however, a direct link between the placental insulin signaling pathway and the offspring health remains unknown. Here, we aimed to understand whether specific placental loss of the insulin receptor (InsR) has a lasting effect on the offspring health in mice. Obesity and glucose homeostasis were assessed in the adult mouse offspring on a normal chow diet (NCD) followed by a high-fat diet (HFD) challenge. Compared to their littermate controls, InsR KOplacenta offspring were born with normal body weight and pancreatic ß-cell mass. Adult InsR KOplacenta mice exhibited normal glucose homeostasis on an NCD. Interestingly, under a HFD challenge, adult male InsR KOplacenta offspring demonstrated lower body weight and a mildly improved glucose homeostasis associated with parity. Together, our data show that placenta-specific insulin receptor deletion does not adversely affect offspring glucose homeostasis during adulthood. Rather, there may potentially be a mild and transient protective effect in the mouse offspring of multiparous dams under the condition of a diet-induced obesogenic challenge.

TissueGrinder, a novel technology for rapid generation of patient-derived single cell suspensions from solid tumors by mechanical tissue dissociation.

Introduction: Recent advances hold promise of making personalized medicine a step closer to implementation in clinical settings. However, traditional sample preparation methods are not robust and reproducible. In this study, the TissueGrinder, a novel mechanical semi-automated benchtop device, which can isolate cells from tissue in a very fast and enzyme-free way is tested for cell isolation from surgically resected tumor tissues. Methods: Thirty-three surgically resected tumor tissues from various but mainly pancreatic, liver or colorectal origins were processed by both novel TissueGrinder and explant method. An optimized processing program for tumors from pancreatic, liver or colorectal cancer was developed. The viability and morphological characteristics of the isolated cells were evaluated microscopically. Expression of pancreatic cancer markers was evaluated in cells isolated from pancreatic tumors. Finally, the effect of mechanical stress on the cells was evaluated by assessing apoptosis markers via western blotting. Results: TissueGinder was more efficient in isolating cells from tumor tissue with a success rate of 75% when compared to explant method 45% in terms of cell outgrowth six weeks after processing. Cells isolated with TissueGinder had a higher abundance and were more heterogeneous in composition as compared to explant method. Mechanical processing of the cells with TissueGrinder does not lead to apoptosis but causes slight stress to the cells. Discussion: Our results show that TissueGrinder can process solid tumor tissues more rapidly and efficiently and with higher success rate compared to the conventionally used explant method. The results of the study suggest that the TissueGrinder might be a suitable method for obtaining cells, which is important for its application in individualized therapy. Due to the great variance in different tumor entities and the associated individual tissue characteristics, a further development of the dissociation protocol for other types of tumors and normal tissue will be targeted.

Transgenic overexpression of microRNA-30d in pancreatic beta-cells progressively regulates beta-cell function and identity.

Abnormal microRNA functions are closely associated with pancreatic ß-cell loss and dysfunction in type 2 diabetes. Dysregulation of miR-30d has been reported in the individuals with diabetes. To study how miR-30d affects pancreatic ß-cell functions, we generated two transgenic mouse lines that specifically overexpressed miR-30d in ß-cells at distinct low and high levels. Transgenic overexpressed miR-30d systemically affected ß-cell function. Elevated miR-30d at low-level (TgL, 2-fold) had mild effects on signaling pathways and displayed no significant changes to metabolic homeostasis. In contrast, transgenic mice with high-level of miR-30d expression (TgH, 12-fold) exhibited significant diet-induced hyperglycemia and ß-cell dysfunction. In addition, loss of ß-cell identity was invariably accompanied with increased insulin/glucagon-double positive bihormonal cells and excess plasma glucagon levels. The transcriptomic analysis revealed that miR-30d overexpression inhibited ß-cell-enriched gene expression and induced α-cell-enriched gene expression. These findings implicate that an appropriate miR-30d level is essential in maintaining normal ß-cell identity and function.

Robotic versus laparoscopic ventral hernia repair: a systematic review and meta-analysis of randomised controlled trials and propensity score matched studies.

PURPOSE: There has not been a consensus on the superiority of a surgical approach for minimally invasive ventral hernia repair. This systematic review and meta-analysis (SRMA) aims to compare clinical, and patient-reported outcomes of robotic-assisted ventral hernia repair (rVHR) to traditional endo-laparoscopic ventral hernia repair (lapVHR). METHODS: We searched PubMed, EMBASE, Cochrane and Scopus from inception to 16th March 2021. We selected randomised controlled trials and propensity score matched studies comparing rVHR to lapVHR. A meta-analysis was done for the outcomes of operative time, length of hospital stay, open conversion, recurrence, surgical site occurrence and cost. RESULTS: A total of 5 studies (3732 patients) were included in the qualitative and quantitative synthesis. Significantly shorter operative times were reported with the lapVHR as compared to rVHR (weighted mean difference (WMD): 62.52, 95% CI: 50.84-74.19). There was also significantly less rates of open conversion with rVHR as compared to lapVHR (WMD: 0.22, 95% CI: 0.09-0.54). No significant differences in patient-reported outcomes that was discernible from the two papers that reported them. CONCLUSION: Overall, rVHR is comparable to lapVHR with longer operative times but less open conversion. It is, therefore, important to have proper patient selection to maximise the utility of rVHR.

OGT Regulates Mitochondrial Biogenesis and Function via Diabetes Susceptibility Gene Pdx1.

O-GlcNAc transferase (OGT), a nutrient sensor sensitive to glucose flux, is highly expressed in the pancreas. However, the role of OGT in the mitochondria of ß-cells is unexplored. In this study, we identified the role of OGT in mitochondrial function in ß-cells. Constitutive deletion of OGT (ßOGTKO) or inducible ablation in mature ß-cells (ißOGTKO) causes distinct effects on mitochondrial morphology and function. Islets from ßOGTKO, but not ißOGTKO, mice display swollen mitochondria, reduced glucose-stimulated oxygen consumption rate, ATP production, and glycolysis. Alleviating endoplasmic reticulum stress by genetic deletion of Chop did not rescue the mitochondrial dysfunction in ßOGTKO mice. We identified altered islet proteome between ßOGTKO and ißOGTKO mice. Pancreatic and duodenal homeobox 1 (Pdx1) was reduced in in ßOGTKO islets. Pdx1 overexpression increased insulin content and improved mitochondrial morphology and function in ßOGTKO islets. These data underscore the essential role of OGT in regulating ß-cell mitochondrial morphology and bioenergetics. In conclusion, OGT couples nutrient signal and mitochondrial function to promote normal ß-cell physiology.

Validation of TG07 and TG13/TG18 criteria for acute cholangitis and predictors of in-hospital mortality in patients over 80 years old.

Aim of the study: This study aims to validate Tokyo guidelines (TG) TG07/TG13/TG18 criteria and identify predictors of in-hospital mortality in acute cholangitis (AC) patients over 80 years old. Material and methods: This is a retrospective audit of AC patients from January 2009 to December 2016. Demographic, clinical, investigation, management, and mortality data were studied. Multinomial logistic regression analysis with stepwise variable selection identified predictors for in-hospital mortality. Results: Three hundred and eighty-eight patients were treated for AC. One hundred and sixty-two (41.8%) patients were male. 230 (59.3%) patients had a history of biliary disease, 161 (41.5%) patients had type 2 diabetes mellitus (T2DM), and 98 (25.3%) patients had ischaemic heart disease (IHD). Abdominal pain (n = 226, 58.2%), pyrexia (n = 247, 63.7%), and vomiting (n = 159, 41.0%) were the common presenting symptoms. 191 (49.2%) patients had abdominal tenderness. Positive blood cultures were recorded in patients 158 (40.7%) patients. Escherichia coli was the most commonly identified organism (n = 117, 30.2%). 77 (19.8%), 188 (48.5%) and 123 (31.7%) patients were graded with mild, moderate, and severe AC, respectively. 30-day, 90-day, and in-hospital mortality were 9 (2.3%), 19 (4.9%) and 38 (9.8%), respectively. On multivariate analysis, systolic blood pressure ≤ 100 mmHg (OR = 3.817, 95% CI: 1.365-10.761, p = 0.011), hypoalbuminaemia < 28 gm/l (OR = 6.052, 95% CI: 2.635-13.904, p < 0.001), serum creatinine ≥ 176.8 (OR = 2.787, 95% CI: 1.146-6.778, p = 0.024) and international normalized ratio (INR) > 1.5 (OR = 3.247, 95% CI: 1.234-8.544, p = 0.017) were independent predictors of in-hospital mortality. Conclusions: Hypotension, hypoalbuminaemia, elevated creatinine, and elevated INR predict in-hospital mortality in AC patients over 80 years old.

Elderly patients (≥ 80 years) with acute calculous cholangitis have similar outcomes as non-elderly patients (< 80 years): Propensity score-matched analysis.

BACKGROUND: Acute cholangitis (AC) is a disease spectrum with varying extent of severity. Age ≥ 75 years forms part of the criteria for moderate (Grade II) severity in both the Tokyo Guidelines (TG13 and TG18). Aging is associated with reduced physiological reserves, frailty, and sarcopenia. However, there is evidence that age itself is not the determinant of inferior outcomes in elective and emergency biliary diseases. There is a paucity of reports comparing clinical outcomes amongst elderly patients vs non-elderly patients with AC. AIM: To investigate the effect of age (≥ 80 years) on AC's morbidity and mortality using propensity score matching (PSM). METHODS: This is a single-center retrospective cohort study of all patients diagnosed with calculous AC (January 2016 to December 2016) and ≥ 80 years old (January 2012 to December 2016) at a tertiary university-affiliated teaching hospital. Inclusion criteria were patients who were treated for suspected or confirmed AC secondary to biliary stones. Patients with AC on a background of hepatobiliary malignancy, indwelling permanent metallic biliary stents, or concomitant pancreatitis were excluded. Elderly patients were defined as ≥ 80 years old in our study. A 1:1 PSM analysis was performed to reduce selection bias and address confounding factors. Study variables include comorbidities, vital parameters, laboratory and radiological investigations, and type of biliary decompression, including the time for endoscopic retrograde cholangiopancreatography (ERCP). Primary outcomes include in-hospital mortality, 30-d and 90-d mortality. Length of hospital stay (LOS) was the secondary outcome. RESULTS: Four hundred fifty-seven patients with AC were included in this study (318 elderly, 139 non-elderly). PSM analysis resulted in a total of 224 patients (112 elderly, 112 non-elderly). The adoption of ERCP between elderly and non-elderly was similar in both the unmatched (elderly 64.8%, non-elderly 61.9%, P = 0.551) and matched cohorts (elderly 68.8% and non-elderly 58%, P = 0.096). The overall in-hospital mortality, 30-d mortality and 90-d mortality was 4.6%, 7.4% and 8.5% respectively, with no statistically significant differences between the elderly and non-elderly in both the unmatched and matched cohorts. LOS was longer in the unmatched cohort [elderly 8 d, interquartile range (IQR) 6-13, vs non-elderly 8 d, IQR 5-11, P = 0.040], but was comparable in the matched cohort (elderly 7.5 d, IQR 5-11, vs non-elderly 8 d, IQR 5-11, P = 0.982). Subgroup analysis of patients who underwent ERCP demonstrated the majority of the patients (n = 159/292, 54.5%) had delayed ERCP (> 72 h from presentation). There was no significant difference in LOS, 30-d mortality, 90-d mortality, and in-hospital mortality in patients who had delayed ERCP in both the unmatched and matched cohort (matched cohort: in-hospital mortality [n = 1/42 (2.4%) vs 1/26 (3.8%), P = 0.728], 30-d mortality [n = 2/42 (4.8%) vs 2/26 (7.7%), P = 0.618], 90-d mortality [n = 2/42 (4.8%) vs 2/26 (7.7%), P = 0.618], and LOS (median 8.5 d, IQR 6-11.3, vs 8.5 d, IQR 6-15.3, P = 0.929). CONCLUSION: Mortality is indifferent in the elderly (≥ 80 years old) and non-elderly patients (< 80 years old) with AC.

Translational Factor eIF4G1 Regulates Glucose Homeostasis and Pancreatic ß-Cell Function.

Protein translation is essential for cell physiology, and dysregulation of this process has been linked to aging-related diseases such as type 2 diabetes. Reduced protein level of a requisite scaffolding protein of the initiation complex, eIF4G1, downstream of nutrients and insulin signaling is associated with diabetes in humans and mice. In the current study, we tested the hypothesis that eIF4G1 is critical for ß-cell function and glucose homeostasis by genetically ablating eIF4G1 specifically in ß-cells in vivo (ßeIF4G1 knockout [KO]). Adult male and female ßeIF4G1KO mice displayed glucose intolerance but normal insulin sensitivity. ß-Cell mass was normal under steady state and under metabolic stress by diet-induced obesity, but we observed increases in proliferation and apoptosis in ß-cells of ßeIF4G1KO. We uncovered deficits in insulin secretion, partly due to reduced mitochondrial oxygen consumption rate, glucose-stimulated Ca2+ flux, and reduced insulin content associated with loss of eIF4E, the mRNA 5' cap-binding protein of the initiation complex and binding partner of eIF4G1. Genetic reconstitution of eIF4E in single ß-cells or intact islets of ßeIF4G1KO mice recovers insulin content, implicating an unexplored role for eIF4G1/eIF4E in insulin biosynthesis. Altogether these data demonstrate an essential role for the translational factor eIF4G1 on glucose homeostasis and ß-cell function.