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.

Structural, magnetic, electric and electrochemical studies on zinc doped magnesium ferrite nano particles - Sol-gel method

The sol-gel process was used to prepare zinc doped magnesium ferrite (Mg1-xZnxFe2O4) nanopowders obtained from the nitrates of magnesium, zinc and ferrous is precursor materials, maintain the pH value which were then studied for sensing purposes. The crystallite size and phase of the ferrite samples studied by X-ray diffraction (XRD) revealed a pure spinel phase (Mg1-xZnxFe2O4) with a cubic spinel structure and higher crystallite size and etc. The functional groups with possible stretching analysis were taken from Fourier transform infrared spectroscopy (FTIR). The surface features and morphology and the purity of the samples were analysed through a Scanning electron microscope (SEM) and energy dispersive X-ray (EDAX) spectrum respectively. Through the vibrating sample magnetometer (VSM), the magnetic behaviour was studied from relevant parameters such as saturation magnetization (Ms), coercivity (Hc) and retentivity (Mr). The larger Ms in 0.8 has ferromagnetic nature were observed. The dielectric constants (ε'& ε''), dielectric loss (tan δ) with AC conductivity (σAC) determined through the LCR metre, and electrochemical behaviour of the samples were found through cyclic voltametery. The possible polarizations at lower and higher frequencies are studied The obtained data are extensively examined and understood.

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.

Comparing 90-Day Post-Operative Mortality after Neoadjuvant Proton-Based vs. Photon-Based Chemoradiotherapy for Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Standard of treatment for locally advanced esophageal cancer consists of chemoradiotherapy (CRT) followed by surgery. Evidence suggests that proton beam therapy (PBT) results in lower toxicity and fewer post-operative complications compared to photon-based radiotherapy (RT). Mortality in the first 90 days after surgery is a rare event occurring in 2-8% of patients, with higher reported rates (of up to 17%) in older patients. This 90-day mortality (90DM) rate is an important measure of post-operative (non-oncologic) mortality as a proxy of quality of care. We hypothesize that PBT could reduce the incidence of 90DM compared to photon-based RT.

MATERIALS/METHODS

From a single-center retrospectively acquired database patients with esophageal cancer treated with neoadjuvant CRT and esophagectomy in 1998-2022 were selected. Univariable logistic regression analyses were used to study the associations of RT modality and other patient- and treatment-related characteristics with 90DM. Subsequently, 3 separate methods were applied to adjust for confounding bias. These included multivariable logistic regression, 1:1 nearest-neighbor propensity score matching (PSM), and inverse probability of treatment weighting (IPTW). Finally, stratified analyses for patient groups aged ≥67 vs. <67 years were performed.

RESULTS

A total of 894 eligible patients were included (PBT, n = 202; photon-based RT, n = 692). PBT patients had a significantly higher age, better performance score, and a higher number of comorbidities. The 90DM rate was 5 (2.5%) in the PBT group and 29 (4.2%) in the photon-based RT group (p = 0.262). Significant univariable predictors of 90DM included higher age and tumor location. After multivariable adjustment, PBT vs. photon therapy was not significantly associated with 90DM (OR 0.49, 95% CI 0.18-1.31). The 90DM rates in the PSM cohort (n = 181 vs. n = 181) were 2.8% for PBT and 3.3% for photon-based RT (p = 0.379). The 90DM rates in the IPTW cohort were 2.8% for PBT and 4.1% for photon-based RT (p = 0.427). In the full cohort, stratified analysis for age groups revealed that in patients aged ≥67 years, PBT was associated with a decreased risk of 90DM compared to photon-based RT (1.3% vs. 8.8%; p = 0.046), which was not the case in patients aged <67 years. In the PSM cohort, a comparable (but non-significant) difference was observed in favor of PBT in patients aged ≥67 years (i.e., 1.5% vs. 7.5%; p = 0.099). Within-group analyses in the original cohort demonstrated that a higher age significantly increased the risk of 90DM within the photon-based RT group (8.8% vs. 2.7% for age ≥67 vs. <67 years; p = 0.001), but not within the PBT group (1.3% vs. 3.2%; p = 0.398).

CONCLUSION

Post-operative 90DM after esophagectomy for cancer was not significantly different between PBT and photon-based neoadjuvant CRT. However, among older patients we observed a signal that PBT may reduce the risk of 90DM. Higher age increased the risk of 90DM in patients who underwent photon-based RT, but not in patients who underwent PBT.

Outcomes and complications of Titanium elastic nailing for forearm bones fracture in children: our experience in a district general hospital in the United Kingdom

Intramedullary Titanium elastic nailing (TENS) is successfully used for irreducible and displaced forearm bone fractures in children. The purpose of this study was to report the potential complications and functional outcomes associated with paediatric forearm fractures treated with TENS nails. We retrospectively reviewed 65 children with displaced forearm bone fractures treated by TENS nailing with a mean follow-up of 5.84 months (4-12). Data detailing patient demographics, fracture characteristics, associated fractures, injury surgery interval, grade of the operating surgeon, methods of fixation, time to union, the timing of removal of the nail, and complications were collected and analysed. The mean age in our study was 9.13 years. 92% had fractures of both radius and ulna, 83.3% had fixation of both bones, and 16.7% had single bone fixation only. Open reduction was required in 38.5% of cases. The average time to fracture union was 10.34 weeks (6-20). The average time of implant removal was 20.12 weeks (9-32). We observed an overall complication rate of 41.5%. We noted a higher (56% vs 32.5%, p=0.059) complication rate in open reduction cases. According to the Price criteria, we had excellent to good results in over 98% of patients despite a slightly higher complication rate. Titanium elastic nailing is a safe, reliable method of internal fixation for irreducible or unstable fractures of both bones of the forearm in children. Open reduction of fracture was associated with higher complications. Despite higher overall complications, we noted excellent functional results in most cases.

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.

Total knee replacement survivorship by Design Philosophy: are we ignoring medial pivot design? Analysis based on the UK National Joint Registry

The UK National Joint Registry(NJR) has not reported total knee replacement (TKR) survivorship based on design phi- losophy alone, unlike its international counterparts. We report outcomes of implant survivorship based on design phi- losophy using data from NJR's 2020 annual report. All TKR implants with an identifiable design philosophy from NJR data were included. Cumulative revision data for cruciate-retaining(CR), posterior stabilised(PS), mobile-bearing(MB) design philosophies was derived from merged NJR data. Cumulative revision data for individual brands of implants with the medial pivot (MP) philosophy were used to calculate overall survivorship for this design philosophy. The all-cause revision was used as the endpoint and calculated to 15 years follow-up with Kaplan-Meier curves. 1,144,384 TKRs were included. CR is the most popular design philosophy (67.4%), followed by PS(23.1%), MB (6.9%) and least commonly MP (2.6%). MP and CR implants showed the best survivorship (95.7% and 95.6% respectively) at 15 years which is statistically significant at, and beyond, 10 years. Observed survivorship was lower at all time points with the PS and MB implants (94.5% for both designs at 15 years). While all design philosophies considered in this study survive well, CR and MP designs offer statistically superior survivorship at and beyond 10 years. MP design performs better than CR beyond 13 years yet, remain the least popular design philosophy used. Publishing data based on knee arthroplasty design phi- losophy would help surgeons when making decisions on implant choice.

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.

Heterogeneity of management practices surrounding operable gallbladder cancer - results of the OMEGA-S international HPB surgical survey

BACKGROUND

Gallbladder cancer (GBC) is an aggressive, uncommon malignancy, with variation in operative approaches adopted across centres and few large-scale studies to guide practice. We aimed to identify the extent of heterogeneity in GBC internationally to better inform the need for future multicentre studies.

METHODS

A 34-question online survey was disseminated to members of the European-African Hepatopancreatobiliary Association (EAHPBA), American Hepatopancreatobiliary Association (AHPBA) and Asia-Pacific Hepatopancreatobiliary Association (A-PHPBA) regarding practices around diagnostic workup, operative approach, utilization of neoadjuvant and adjuvant therapies and surveillance strategies.

RESULTS

Two hundred and three surgeons responded from 51 countries. High liver resection volume units (>50 resections/year) organised HPB multidisciplinary team discussion of GBCs more commonly than those with low volumes (p < 0.0001). Management practices exhibited areas of heterogeneity, particularly around operative extent. Contrary to consensus guidelines, anatomical liver resections were favoured over non-anatomical resections for T3 tumours and above, lymphadenectomy extent was lower than recommended, and a minority of respondents still routinely excised the common bile duct or port sites.

CONCLUSION

Our findings suggest some similarities in the management of GBC internationally, but also specific areas of practice which differed from published guidelines. Transcontinental collaborative studies on GBC are necessary to establish evidence-based practice to minimise variation and optimise outcomes.

Phthalate migration and its effects on poly(vinyl chloride)-based footwear: pathways, influence of environmental conditions, and the possibility of human exposure

The study of phthalate migration in footwear is important from an environmental viewpoint and the consumer health perspective as it remains in direct contact with the user for a long time. In this research article, the migration of phthalate, specifically di-(2-ethylhexyl) phthalate (DEHP), from the poly(vinyl chloride) (PVC) shoe sole to the attached leather insole has been studied for six months under different environmental conditions. After one month, the DEHP concentration in the PVC sole decreased by 45-58%, and that in the leather insole increased from 0.35 mg g^-1 to 38-58 mg g^-1. After six months, about 90% of the DEHP has been lost from the PVC sole, and that in the leather insole reached close to its initial value (value before the experiment). The migration rate depends on the environmental conditions and the presence of phthalate soluble solvents in the sole-adhesive-insole system of the footwear. The influence of DEHP migration on the physicochemical characteristics of the PVC sole and leather insole has been studied by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), thermo-gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The migration and emission pathways of DEHP, the influence of environmental conditions, and the possibility of human exposure to phthalate through footwear are discussed.

Computational Fluid Dynamics Simulation on Thermal Performance of Al/Al2O3/SWCNT Nanocoolants for Turning Operations

The objective of this study is to numerically investigate the thermal performance of cutting fluids dispersed with nanoparticles for effective heat removal during turning operations. The simulations are performed using Ansys Fluent software, and the problem is modelled as a three-dimensional turbulent incompressible single-phase flow. The computational domain consists of a heated cutting tool and work piece, and nanocoolants are sprayed from a nozzle located above the machining zone. The nanocoolants are prepared by mixing mineral oil with nanoparticles of Al₂O₃ (Aluminium Oxide), Al (Aluminium) and SWCNT (Single Walled Carbon Nanotube). The heat transfer performances of different nanocoolants are compared by varying the nanoparticle volume fraction (φ) and coolant velocity (U_c) in the range of 2% ≤ φ ≤ 8% and 1 m/s ≤ U_c ≤ 15 m/s, respectively. The results indicated a drastic drop in the cutting tool temperature with an increase in the volume fraction of dispersed nanoparticles and coolant velocity. The increase in volume fraction decreases the average cutting tool temperature by 25.65% and also enhances the average heat transfer rate by 25.43%. It is additionally observed that SWCNT nanocoolants exhibited a superior thermal performance and heat removal rate compared with Al and Al₂O₃ nanocoolants. The analysed numerical results are validated and are in good accordance with the benchmark results validated from literature.

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 β-cells is unexplored. In this study, we identified the role of OGT in mitochondrial function in β-cells. Constitutive deletion of OGT (βOGTKO) or inducible ablation in mature β-cells (iβOGTKO) causes distinct effects on mitochondrial morphology and function. Islets from βOGTKO, but not iβOGTKO, 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 βOGTKO mice. We identified altered islet proteome between βOGTKO and iβOGTKO mice. Pancreatic and duodenal homeobox 1 (Pdx1) was reduced in in βOGTKO islets. Pdx1 overexpression increased insulin content and improved mitochondrial morphology and function in βOGTKO islets. These data underscore the essential role of OGT in regulating β-cell mitochondrial morphology and bioenergetics. In conclusion, OGT couples nutrient signal and mitochondrial function to promote normal β-cell physiology.

Validation of Tokyo Guidelines 2007 and Tokyo Guidelines 2013/2018 Criteria for Acute Cholangitis and Predictors of In-Hospital Mortality

BACKGROUND

Acute cholangitis (AC) is a common emergency with a significant mortality risk. The Tokyo Guidelines (TG) provide recommendations for diagnosis, severity stratification, and management of AC. However, validation of the TG remains poor. This study aims to validate TG07, TG13, and TG18 criteria and identify predictors of in-hospital mortality in patients with AC.

METHODS

This is a retrospective audit of patients with a discharge diagnosis of AC in the year 2016. Demographic, clinical, investigation, management and mortality data were documented. We performed a multinomial logistic regression analysis with stepwise variable selection to identify severity predictors for in-hospital mortality.

RESULTS

Two hundred sixty-two patients with a median age of 75.9 years (IQR 64.8-82.8) years were included for analysis. TG13/TG18 diagnostic criteria were more sensitive than TG07 diagnostic criteria (85.1 vs. 75.2%; p < 0.006). The majority of the patients (n = 178; 67.9%) presented with abdominal pain, pyrexia (n = 156; 59.5%), and vomiting (n = 123; 46.9%). Blood cultures were positive in 95 (36.3%) patients, and 79 (83.2%) patients had monomicrobial growth. The 30-day, 90-day, and in-hospital mortality numbers were 3 (1.1%), 11 (4.2%), and 15 (5.7%), respectively. In multivariate analysis, type 2 diabetes mellitus (OR = 12.531; 95% CI 0.354-116.015; p = 0.026), systolic blood pressure <100 mm Hg (OR = 10.108; 95% CI 1.094-93.395; p = 0.041), Glasgow coma score <15 (OR = 38.16; 95% CI 1.804-807.191; p = 0.019), and malignancy (OR = 14.135; 95% CI 1.017-196.394; p = 0.049) predicted in-hospital mortality.

CONCLUSION

TG13/18 diagnostic criteria are more sensitive than TG07 diagnostic criteria. Type 2 diabetes mellitus, systolic blood pressure <100 mm Hg, Glasgow coma score <15, and malignant etiology predict in-hospital mortality in patients with AC. These predictors could be considered in acute stratification and treatment of patients with AC.

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.

Placental mTOR complex 1 regulates fetal programming of obesity and insulin resistance in mice

Fetal growth restriction, or low birth weight, is a strong determinant for eventual obesity and type 2 diabetes. Clinical studies suggest placental mechanistic target of rapamycin (mTOR) signaling regulates fetal birth weight and the metabolic health trajectory of the offspring. In the current study, we used a genetic model with loss of placental mTOR function (mTOR-KO^Placenta) to test the direct role of mTOR signaling on birth weight and metabolic health in the adult offspring. mTOR-KO^Placenta animals displayed reduced placental area and total weight, as well as fetal body weight at embryonic day (E) 17.5. Birth weight and serum insulin levels were reduced; however, β cell mass was normal in mTOR-KO^Placenta newborns. Adult mTOR-KO^Placenta offspring, under a metabolic high-fat challenge, displayed exacerbated obesity and metabolic dysfunction compared with littermate controls. Subsequently, we tested whether enhancing placental mTOR complex 1 (mTORC1) signaling, via genetic ablation of TSC2, in utero would improve glucose homeostasis in the offspring. Indeed, increased placental mTORC1 conferred protection from diet-induced obesity in the offspring. In conclusion, placental mTORC1 serves as a mechanistic link between placental function and programming of obesity and insulin resistance in the adult offspring.

Islet O-GlcNAcylation Is Required for Lipid Potentiation of Insulin Secretion through SERCA2

During early obesity, pancreatic β cells compensate for increased metabolic demand through a transient phase of insulin hypersecretion that stabilizes blood glucose and forestalls diabetic progression. We find evidence that β cell O-GlcNAcylation, a nutrient-responsive post-translational protein modification regulated by O-GlcNAc transferase (OGT), is critical for coupling hyperlipidemia to β cell functional adaptation during this compensatory prediabetic phase. In mice, islet O-GlcNAcylation rises and falls in tandem with the timeline of secretory potentiation during high-fat feeding while genetic models of β-cell-specific OGT loss abolish hyperinsulinemic responses to lipids, in vivo and in vitro. We identify the endoplasmic reticulum (ER) Ca²⁺ ATPase SERCA2 as a β cell O-GlcNAcylated protein in mice and humans that is able to rescue palmitate-stimulated insulin secretion through pharmacological activation. This study reveals an important physiological role for β cell O-GlcNAcylation in sensing and responding to obesity, with therapeutic implications for managing the relationship between type 2 diabetes and its most common risk factor.

microRNA-483 Protects Pancreatic β-Cells by Targeting ALDH1A3

Pancreatic β-cell dysfunction is central to the development and progression of type 2 diabetes. Dysregulation of microRNAs (miRNAs) has been associated with pancreatic islet dysfunction in type 2 diabetes. Previous study has shown that miR-483 is expressed relatively higher in β-cells than in α-cells. To explore the physiological function of miR-483, we generated a β-cell-specific knockout mouse model of miR-483. Loss of miR-483 enhances high-fat diet-induced hyperglycemia and glucose intolerance by the attenuation of diet-induced insulin release. Intriguingly, mice with miR-483 deletion exhibited loss of β-cell features, as indicated by elevated expression of aldehyde dehydrogenase family 1, subfamily A3 (Aldh1a3), a marker of β-cell dedifferentiation. Moreover, Aldh1a3 was validated as a direct target of miR-483 and overexpression of miR-483 repressed Aldh1a3 expression. Genetic ablation of miR-483 also induced alterations in blood lipid profile. Collectively, these data suggest that miR-483 is critical in protecting β-cell function by repressing the β-cell disallowed gene Aldh1a3. The dysregulated miR-483 may impair insulin secretion and initiate β-cell dedifferentiation during the development of type 2 diabetes.

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 β-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 β-cell function and glucose homeostasis by genetically ablating eIF4G1 specifically in β-cells in vivo (βeIF4G1 knockout [KO]). Adult male and female βeIF4G1KO mice displayed glucose intolerance but normal insulin sensitivity. β-Cell mass was normal under steady state and under metabolic stress by diet-induced obesity, but we observed increases in proliferation and apoptosis in β-cells of βeIF4G1KO. 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 β-cells or intact islets of βeIF4G1KO 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 β-cell function.

Short communication: Molecular markers for epithelial cells across gastrointestinal tissues and fecal RNA in preweaning dairy calves

The objective of this study was to compare the transcription of gene markers for gastrointestinal (GI) epithelial cells, including fatty acid binding protein 2 (FABP2) and cytokeratin 8 (KRT8), and tight junction complex genes (TJP1, CLDN1, CLDN4) in fecal RNA against several GI tract tissue sections in dairy calves. Eight healthy Jersey calves were euthanized at 5 wk of age, and postmortem samples were collected from rumen, duodenum, jejunum, ileum, large intestine, cecum, and feces for total RNA isolation. Tissues and fecal samples were immediately frozen in liquid nitrogen until RNA isolation. A real-time quantitative PCR analysis was performed using a single standard curve composited of equal amounts of all samples, including cDNA from fecal and GI tract tissues. The mRNA expression of the tight junctions TJP1, CLDN1, and CLDN4 was greater in fecal RNA compared with lower GI tract tissues (i.e., duodenum, jejunum, ileum, large intestine, and cecum). Similar to fecal RNA, rumen tissue had greater expression of tight junctions CLDN1 and CLDN4 than lower GI tract tissues. Similarly, rumen tissue had greater expression of TPJ1 than all lower GI tract tissues except duodenum. The expression of TJP1 and CLDN4 was greater in fecal RNA than in rumen tissue; in contrast, CLDN1 mRNA expression was greater in rumen tissue than in the fecal RNA. The expression of FABP2 was greater in duodenum in comparison to all tissue except ileum. The mRNA expression of FABP2 in fecal samples was similar to jejunum and ileum. The expression of KRT8 in fecal samples was similar to duodenum, large intestine, and cecum. The fecal RNA had a greater expression of KRT8 in comparison to jejunum and ileum. The rumen tissue had the lowest mRNA expression of KRT8. The expression levels of FABP2, KRT8, and tight junction genes observed in fecal transcripts suggest that a considerable amount of RNA derived from GI tract epithelial cells can be detected in fecal RNA, which is in agreement with previous data in neonatal dairy calves and other biological models including humans, rodents, and primates. The greater expression of tight junctions in fecal RNA in comparison to sections of the low GI remains to be understood, and due to the importance of tight junctions in GI physiology, further clarification of this effect is warranted. The similarities in mRNA expression of FABP2 and KRT8 between fecal RNA and intestinal sections add up to the accumulating evidence that fecal RNA can be used to investigate molecular alterations in the GI tract of neonatal dairy calves. Further research in this area should include high-throughput transcriptomic analysis via RNA-seq to uncover novel molecular markers for specific sections of the GI tract of neonates.

Translational Factor eIF4G1 Regulates Glucose Homeostasis and Pancreatic β-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 both humans and mice. In the present study, we tested the hypothesis that eIF4G1 is critical for β-cell function and glucose homeostasis by genetically ablating eIF4G1 specifically in β-cells in vivo (βeIF4G1KO). Adult male and female βeIF4G1KO mice displayed glucose intolerance but normal insulin sensitivity. β-cell mass was normal under steady state and under metabolic stress by diet-induced obesity, but we observed increases in both proliferation and apoptosis in β-cells of βeIF4G1KO. 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 β-cells or intact islets of βeIF4G1KO 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 β-cell function.

Analysis of perioperative outcomes following laparoscopic repeat liver resection compared to laparoscopic primary liver resection based on a single surgeon's experience: A 1:2 propensity score-matched study

BACKGROUND

We report a single surgeon experience with laparoscopic repeat liver resection (LRLR), and analyse short-term outcomes relative to laparoscopic primary liver resection (LPLR).

METHODS

Two-hundred and twenty-two laparoscopic liver resections were performed from 2012 to 2019 of which 33 were LRLR. 1:2 propensity-score matching was done to compare 32 LRLR with 64 LPLR cohort. We further analyzed the first 16 LRLR cases compared to the subsequent 17 cases.

RESULTS

32 LRLR cases were matched to 64 LPLR cases. Apart from a higher frequency of Pringle maneuver in the LPLR cohort (p = 0.006), there were no differences in other perioperative outcomes. There were more posterosuperior located tumours (75.0% vs 17.6%, p = 0.003) and higher median difficulty score (8.50 vs 5.00, p = 0.025) in the initial 16 LRLR cases compared to the next 17. The earlier group had higher median blood loss (250.00 ml vs 50.00 ml, p = 0.012), but other outcomes were similar.

CONCLUSION

LRLR may be safely performed in selected patients with no difference in key perioperative outcomes compared to LPLR.

Medium term results following heart transplantation for end stage heart failure: A single center experience of 257 patients

OBJECTIVE

End stage heart failure is a lethal disease with a dismal 5 year survival. Heart transplantation has proven to be a highly effective modality of treatment in appropriately selected group of such patients. This is a retrospective analysis of medium term outcomes of heart transplantation in the setting of a private health facility in India. The objective of this study was two fold.

METHODS

The outcome of 257 heart transplants done at a single centre from October 2012 to October 2019 was analyzed. Patients with combined Heart and lung transplants and those whose complete medical records were unavailable were excluded from the study. Survival was tracked at 60 days, 90 days, one year and beyond for a maximum of 7 years. Preoperative patient risk profiles were characterized on the basis of INTERMACS category.

RESULTS

There were 176 male and 81 female patients. The age range was from 8 months to 78 years with a mean of 32.9 years. Survival at 2 months was 87%, at 90 days was 83%, at one year was 81%, 2 years was 75%, at 3 years was 72% and at 5 years and beyond was 62% for the whole series. Strong predictors of 90 day mortality included INTERMACS category (odd's ratio 0.289, p = 0.000) and creatinine more than 1.5 mg/dl (odd's ratio 2.48, p = 0.056). Recipient pulmonary vascular resistance and donor organ ischemic times were not found to be statistically significant factors affecting outcome. Medium term survival was influenced by INTERMACS category (Hazard ratio > 3 for INTERMACS category 1 compared to INTERMACS 4 or 5, p < 0.0001) and creatinine > 1.5 mg/dl (Hazard ratio 2.15, p = 0.003). This effect of creatinine was related to the age of the recipient. Hazard ratio 1.4, p = 0.524 if age <30 and Hazard ratio 4.78, p = 0.006, if age was >50.

CONCLUSION

Satisfactory medium term outcome is possible after heart transplantation even in resource constrained environment of a developing country.

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.