Synchronous pancreas and gallbladder cancer with concomitant alopecia totalis.

A 55-year-old female presented with history of pain in the right hypochondrium along with complete loss of facial and scalp hair over last two months. On evaluation, she was found to have locally advanced, synchronous malignancies of the gallbladder and head of the pancreas. Synchronous malignancy of gallbladder and pancreas is in itself very rare and less than 10 such cases have been reported in the world literature. Alopecia totalis has been classically associated with various autoimmune disorders. However, alopecia totalis as a presenting feature of any abdominal malignancy has never been reported in the medical literature. The present report describes a rare association of synchronous pancreatobiliary malignancies with strange clinical presentation.

Primary malignant melanoma of the gall bladder masquerading as xanthogranulomatous cholecystitis.

Malignant melanoma of the gall bladder is rare. Most cases are metastatic and primary gall bladder melanoma is even more rare. We report a case of primary malignant melanoma of the gall bladder which illustrates the diagnostic challenge posed by this condition. Histopathology and immunohistochemistry play a pivotal role in making a diagnosis and ruling out conditions which mimic it such as xanthogranulomatous cholecystitis and other relatively common epithelial malignancies. We tested for prognostic and predictive markers including BRAF and PD-L1 and immunohistochemistry showed positive staining for BRAF. The tumour cells expressed HMB-45 and were negative for cytokeratin and CD68, favouring a diagnosis of malignant melanoma and excluding the possibility of xanthogranulomatous cholecystitis and carcinoma. On follow-up at 3 months there was no evidence of recurrence of metastasis.

Heterodimerization of cholecystokinin 1 and cholecystokinin 2 receptors in gallbladder cancer: a new mechanism for carcinogenesis.

PURPOSE: Cholecystokinin is present in abundance in gallbladder tissue and mediates function through two structurally related receptors, CCK1R and CCK2R. Heterodimerization of these receptors is known to impact cell growth in vitro. However, the significance of these heterodimers in gallbladder carcinogenesis is relatively unknown. METHODS: Therefore, we evaluated the expression and the dimerization status of CCK1 and CCK2 receptors in human gallbladder carcinoma cell line (GBC-SD) and resected gallbladder tissue from normal (n = 10), cholelithiasis (n = 25) and gallbladder cancer (n = 25) by immunofluorescence/immunohistochemistry and western blot. The dimerization status of CCK1R and CCK2R was evaluated by co-immunoprecipitation. To understand the effect of heterodimerization of these receptors on growth-related signaling pathways, the expression of p-AKT, rictor, raptor and p-ERK was evaluated by western blot. RESULTS: We demonstrated the expression and heterodimerization of CCK1 and CCK2 receptor in GBC-SD gall bladder carcinoma cell line. Knockdown of CCK1R and CCK2R in the cell line led to significant reduction in p-AKT (P = 0.005; P = 0.0001) and rictor (P < 0.001; P < 0.001) levels. In tissue samples, significantly higher expression of CCK1R and CCK2R was observed in gallbladder cancer when compared to other groups both by immunohistochemistry (P = 0.008 and P = 0.013) and western blot (P = 0.009 and P = 0.003). An increase in heterodimer formation of CCK1R with CCK2R was observed in gallbladder cancer when compared to normal and cholelithiasis tissues. No significant difference in the expression of p-AKT and p-ERK was observed between the three groups. CONCLUSION: Our results provide the first evidence of heterodimerization of CCK1R and CCK2R in gallbladder tissue, and its association with development of gallbladder cancer. This finding has potential clinical and therapeutic significance.

Natural Orifice Transanal Endoscopic Rectopexy for Complete Rectal Prolapse: Prospective Evolution of a New Technique and Short-term Outcomes.

BACKGROUND: Endoluminal surgery for the management of rectal prolapse remains largely experimental. OBJECTIVE: To evaluate the evolution and short-term outcomes of a new endoluminal technique for the management of complete rectal prolapse. DESIGN: This was a prospective study. SETTINGS: This study was conducted at a single tertiary care teaching center. PATIENTS: A total of 29 patients were included. The first 12 patients underwent the procedure with our initial technique, and the last 17 patients were subjected to the new modified procedure. The follow-up duration was 3 years for the older technique and 26 months for the newer technique. INTERVENTION: This technique involves: 1) ventral "suture" rectopexy: rectum is fixed anteriorly to the anterior abdominal wall using percutaneously placed sutures. 2) Posterior rectum is fixed to the sacral promontory using tackers through a submucosal tunnel. MAIN OUTCOME MEASURES: Safety, recurrence, functional outcomes, morbidity, and mortality were the main outcome measures. RESULTS: There were improvements in constipation and incontinence scores, anal manometric pressures, anorectal angle, anorectal descent, and quality of life postoperatively in both groups. In patients undergoing the modified procedure, there was a significant decrease in duration of surgery (220 ± 48.89 vs 110 ± 12.51 min), shortened hospital stay (4.6 ± 1.71 vs 2.6 ± 0.65 d), decreased recurrence (25% vs 5.8%), and complications (surgical-site infection and retrorectal abscess). LIMITATIONS: Short follow-up, small sample size, and single-center study were the limitations. CONCLUSION: This is a novel endoluminal technique for treating rectal prolapse obviating perirectal dissection, abdominal incisions, or a mesh. This can now be performed under complete endoscopic and fluoroscopic vision. It avoids general anesthesia and therefore can be an alternative for patients with comorbid conditions in whom the standard abdominal procedure may not be well tolerated. Larger randomized multicentric studies with longer follow-ups are warranted. See Video Abstract at http://links.lww.com/DCR/C59. RECTOPEXIA ENDOSCPICA TRANSANAL POR ORIFICIO NATURAL PARA EL PROLAPSO RECTAL COMPLETO EVOLUCIN PROSPECTIVA DE UNA NUEVA TCNICA Y RESULTADOS A CORTO PLAZO: ANTECEDENTES:La cirugía endoluminal para el tratamiento del prolapso rectal ha permanecido en gran parte experimental.OBJETIVO:Este estudio tiene como objetivo evaluar la evolución y los resultados a corto plazo de una nueva técnica endoluminal para el manejo del prolapso rectal completo.DISEÑO:Estudio prospectivo.ÁMBITOS:Único centro docente de tercer nivel de atención.PACIENTES:Se incluyeron un total de 29 pacientes (19 hombres y 10 mujeres) con prolapso rectal completo. Los primeros 12 pacientes fueron sometidos al procedimiento con nuestra técnica anteriormente descrita y los últimos 17 pacientes fueron sometidos al nuevo procedimiento modificado. La duración del seguimiento es de 3 años para la técnica más antigua y de 26 meses para la técnica más nueva.INTERVENCIÓN:Esta técnica implica: A) Rectopexia de "sutura" ventral: el recto se fija anteriormente a la pared abdominal anterior mediante suturas colocadas percutáneamente. B) El recto posterior se fija al promontorio sacro mediante grapas a través de un túnel submucoso.PRINCIPALES MEDIDAS DE RESULTADO:Seguridad, recurrencia, resultados funcionales, morbilidad y mortalidad.RESULTADOS:Hubo mejorías en las puntuaciones de estreñimiento (ODS) e incontinencia (SMIS), presiones manométricas anales (reposo y contracción), ángulo anorrectal, descenso anorrectal y calidad de vida post operatoria en ambos grupos. En los pacientes sometidos al procedimiento modificado hubo una significativa disminución en la duración de la cirugía (220 + 48,89 vs 110 + 12,51 minutos), acortamiento de la estancia hospitalaria (4,6 + 1,71 vs 2,6 + 0,65 días), disminución de la recurrencia (25% vs 5,8%) y complicaciones (infecciónes del sitio quirúrgico y abscesos retrorrectales).LIMITACIONES:Seguimiento corto, tamaño de muestra pequeña, estudio de un solo centro.CONCLUSIÓNES:La rectopexia endoscópica transanal por orificio natural (NOTER) es una novedosa técnica endoluminal para el tratamiento del prolapso rectal que evita la disección perirrectal, las incisiones abdominales o la fijación de una malla. Este procedimiento puede realizar hoy día bajo visión completa endoscópica y fluoroscópica. Evita la anestesia general y, por lo tanto, puede ser una alternativa para pacientes con condiciones comórbidas donde el procedimiento abdominal estándar puede no ser bien tolerado. Se justifican estudios multicéntricos aleatorios más grandes con un seguimiento más prolongado para validar aún más esta nueva técnica. Consulte Video Resumen en http://links.lww.com/DCR/C59. (Traducción-Dr Osvaldo Gauto).

Natural Orifice Endosonographic Colposuspension With Rectopexy for Combined Pelvic Organ Prolapse: A Feasibility Study.

BACKGROUND: We describe a natural orifice technique for simultaneous endoluminal lateral suspension of apical vaginal wall and rectal prolapse fixation with ultrasound and fluoroscopic assistance. IMPACT OF INNOVATION: The technique is minimally invasive, can be performed under regional anaesthesia, and avoids laparotomy or use of a mesh in addition to preserving the uterus. TECHNOLOGY MATERIALS AND METHODS: This technique involves suprapubic transvaginal ventral suture colposuspension, fixation of the anterior rectal wall to the undersurface of the anterior abdominal wall and tack fixation of the posterior rectal wall to the underlying sacral promontory through a submucosal tunnel performed endoscopically with fluoroscopic and ultrasound assistance. PRELIMINARY RESULTS: Seven patients with a mean age of 63 years were followed between 3 to 11 months. CONCLUSIONS: This is a novel minimally invasive transluminal procedure that repairs concomitant rectal and vaginal prolapse in the same sitting. FUTURE DIRECTIONS: Improvement in the instrument design and incorporation of endoluminal robotic systems will enhance the technical ease. The study needs validation in larger series of patients with longer follow-up.

Gallbladder perforation: A single-center experience in north India and a step-up approach for management.

BACKGROUND: Spontaneous gallbladder perforation (GBP) is an uncommon diagnosis. This study presented the experience of managing spontaneous GBP over nine years at a large, tertiary care university hospital in north India and investigated the outcomes and treatment strategies. METHODS: A retrospective review of prospectively maintained digital database of consecutive patients was performed. All patients received medical and/or surgical treatment for spontaneous GBP in our department between January 2010 and June 2018. RESULTS: We identified 151 patients (81 females and 70 males) with mean age of 53 years. Most common presenting features were pain (96.7%), fever (54.3%) and jaundice (31.1%). Most common cause was gallbladder stones (84.8%) followed by common bile duct stones (30.5%), xanthogranulomatous cholecystitis (17.9%) and malignancy (11.9%). As per Niemeier classification, 8.6% had type 1 GBP (free perforation in peritoneal cavity), 76.2% had type 2 GBP (localized perforation) and 13.2% had type 3 GBP (cholecysto-enteric fistula). About 60% of the perforations were diagnosed preoperatively. Type 1 was more common in patients with diabetes and also had the worst prognosis. Surgery was performed in 109 patients (72.2%). Seven patients (4.6%) had a postoperative morbidity of Clavien-Dindo III or higher. There were three mortalities in patients who underwent surgery. CONCLUSIONS: High index of suspicion is required for preoperative diagnosis of GBP, especially in types 2 and 3. Laparoscopic cholecystectomy can be difficult in these patients and patients may require open or partial cholecystectomy. Early diagnosis and step-up approach for the treatment of GBP is critical.

Expression of Antimicrobial Peptides and Cytokines in Human Omentum Following Abdominal Surgery.

Introduction Omentum can secrete out biological agents like different growth factors, cytokines, and antimicrobial peptides. The aim of our study was to determine the expression of antimicrobial peptides and cytokines in human omentum tissue and its response to intra-abdominal infection. Methodology Omentum tissue was obtained from 60 patients: control (n=20) and cases (n=40). mRNA expression of antimicrobial peptides (LL-37, HBD-1, HBD-2, HNP1-3) and cytokines (TNF- α, IL-8, IL-10, IL1ß) was evaluated using Real-Time PCR. Protein quantification was done by Immunoblotting and ELISA. Results Significantly higher expression of antimicrobial peptides (LL-37, HBD-1, HBD-2, HNP1-3) and cytokines (TNF- α, IL-8, IL-10, IL1ß) was observed in cases as compared to control at both the transcriptional and translational level (p<0.0001). Conclusion Omentum governs a population of antimicrobial peptides with potent immunologic functions. The expression of antimicrobial peptides and cytokines is inducible and increases with the severity of infection. Omentum is thus an immunologically active and adaptable organ but its complete regulatory mechanism is still elusive.

Predictors and Outcomes of Pancreatic Fistula Following Pancreaticoduodenectomy: a Dual Center Experience.

Fistula following leaked pancreatico-enteric anastomosis is a common, potentially lethal complication of pancreaticoduodenectomy (PD). Early assessment and prediction of its occurrence can improve postoperative outcomes. Various perioperative factors were analyzed for its contribution to clinically relevant postoperative pancreatic fistula (crPOPF). Also, the difference in clinical outcomes of patients with and without fistula was studied. Sixty-seven patients undergoing PD for malignancies were analyzed during 3-year period in a dual-institutional study. Various preoperative, intraoperative, and postoperative factors were assessed. The incidence and severity of POPF and its association with the development of other post-PD complications were observed. Patients with and without POPF were divided into groups and compared with univariate and multivariate analyses, to identify significant contributing factors. Clinically relevant POPF was present in 20.9% cases. crPOPF contributed to delayed gastric emptying, albeit insignificant (p = 0.403), but was significantly associated with increased incidence of post-pancreatectomy hemorrhagic (p = 0.005) and infectious complications (p = 0.013). Soft pancreas (p = 0.024), intraoperative blood loss (p = 0.045), blood transfusion (p = 0.024), and fistula risk score (p = 0.001) were significant predictors of crPOPF. First postoperative day (POD1) drain fluid amylase (DFA) values at cut-off of 1336 U/L (AUC = 0.871; p < 0.001) significantly predicted crPOPF with good sensitivity and specificity. POD1 DFA was only factor significant on multivariate analysis (p = 0.014). There was no significant difference in overall survival between groups. crPOPF results in significant post-pancreatectomy hemorrhagic and septic complications, along with increased mortality. It can be accurately predicted by several preoperative and intraoperative factors. POD1 DFA can independently predict crPOPF development.

Missed pancreatic injury in patients undergoing conservative management of blunt abdominal trauma: Causes, sequelae and management.

OBJECTIVES: Pancreas is a less commonly injured organ in blunt abdominal trauma. This study aimed to analyze the management and outcomes of patients in whom the pancreatic injury was missed during the initial evaluation of blunt abdominal trauma. MATERIAL AND METHODS: We retrospectively (2009-2019) analyzed the details and outcome of patients who underwent conservative management of blunt abdominal trauma, where the diagnosis of pancreatic injury was missed for at least 72 hours following trauma. RESULTS: A total of 31 patients with missed pancreatic injury were identified. All patients were hemodynamically stable following trauma and most (21) were initially assessed only by an ultrasound. A delayed diagnosis of pancreatic injury was made at a mean of 28 (4 to 60) days after trauma when patients developed abdominal pain (31), distension (18), fever (10) or vomiting (8). On repeat imaging, 18 (58.1%) patients had high grade pancreatic injuries including complete transection or pancreatic duct injury. Seven (22.5%) patients were managed conservatively, seventeen (54.8%) underwent percutaneous drainage of intra-abdominal collections, seven (22.5%) underwent endoscopic or surgical drainage procedure for symptomatic pseudocyst. Eleven (35.4%) patients needed readmissions to manage recurrent pancreatitis, intra-abdominal abscess and pancreatic fistula. Three patients required pancreatic duct stenting for pancreatic fistula. There was no mortality. CONCLUSION: Pancreatic injury may be missed in patients who remain hemodynamically stable with minimal clinical symptoms after abdominal trauma, especially if screened only by an ultrasound. In our series, there was significant morbidity of missed pancreatic injury.

Giant stentolith: A rare complication of long-dwelling biliary endoprosthesis.

Endoscopic biliary stenting is performed for various indications in routine clinical practice. Plastic stents are indicated primarily for short-term biliary decompression and require removal or exchange after 12-16 weeks. However, patients who become asymptomatic after the procedure may not return for scheduled stent removal and subsequently present with severe complications. We herein present the case of a 57-year-old female who underwent biliary stenting after the endoscopic clearance of bile duct stones. Her symptoms resolved after the intervention, but she was lost to follow-up with the stent remaining in situ. Four years later, she presented with pain in the right hypochondrium and experienced recurrent episodes of cholangitis. Magnetic resonance cholangiopancreatography revealed a retained plastic stent in the proximal bile duct with a large stone cast around the stent-a stentolith. Owing to the large stone size and proximal migration of the retained biliary stent, the patient required open surgical exploration for stentolith removal. Patients with forgotten biliary stents presenting with serious complications are not uncommon in India. Unaware of the complications of long-dwelling biliary stents, patients ignore the advice for the timely removal of biliary stents. Detailed patient counselling, education and documentation are essential to avoid this condition.

Complex Obstetric Perineal Injury Reconstruction Using Antropyloric Valve Transposition.

Despite significant advancements in the field of medicine, management of complex obstetric perineal injuries remains a challenge. Although several surgical techniques have been described, no techniques have provided satisfactory long-term results. Recently, a perineal transposed antropyloric valve has been used for anorectal reconstruction in patients with damaged or excised anal sphincters. We describe this technique in the case of complex obstetric perineal trauma with extensive tissue loss, presenting with end stage fecal incontinence. The functional outcome after this procedure was evaluated. The patient tolerated the surgery well, and there were no procedure-related upper gastrointestinal disturbances. Short-term functional outcomes were encouraging. At the 36-month follow-up, the patient's neoanal resting and squeeze pressures were 50 and 70 mmHg, respectively. The postoperative St. Mark's incontinence score was 7. Perineal antropyloric valve transposition is feasible and can be successfully applied in the management of end-stage fecal incontinence associated with complex obstetric perineal injury.

Corrosive Esophageal Strictures: From Dilatation to Replacement: A Retrospective Cohort Study.

Endoscopic dilatation is the recommended primary therapy for chronic corrosive esophageal strictures (ES), and surgery is reserved for failed dilatation. Through this study, we intend to analyze the efficacy and long-term outcomes of both endoscopic and surgical interventions in corrosive ES. A retrospective cohort analysis of patients with chronic corrosive ES, managed with endoscopic or surgical procedures at a tertiary teaching institute in North India from December 2009 to December 2016, was performed from a prospectively maintained database. The primary outcome measure was the absence of dysphagia following dilatation or surgery. During the study period, 64 patients with ES underwent surgical or endoscopic treatment. Associated gastric strictures and pharyngeal strictures were present in 39 (60%) and 22 patients (28.9%), respectively. The mean age was 28.8 years and mean BMI was 14.2 kg/m2. Acid was the most common corrosive substance. Endoscopic dilatation using Savary-Gilliard (SG) dilators was successful in achieving persistent symptom relief in 46 patients (71.8%) after a total of 358 sessions (mean number of dilatations were 5.2 ± 1.2) of dilatations over 2 years. The dilatation therapy failed in 18 patients (28.1%) including technical failures (15.6%), perforations (3.1%), refractory stricture (1.5%) and recurrent strictures (7.8%). Increasing stricture length (more than 6 cm) was associated with poor outcome of endoscopic dilatation (p < 0.001). Only eleven patients (17%) required esophageal replacement (resection: 0, bypass: 11) for failed dilatations including seven gastric pull-ups and four pharyngo-coloplasty. The stricture rate after surgery was 36.3% (4/11). The median follows up was 32 months. Endoscopic dilatation of corrosive ES is safe and effective therapy and should be the first-line therapy for these patients and surgery should be considered only in patients who have unsuccessful outcome following dilatation therapy.

Simulation of Brain Response to Noncontact Impacts Using Coupled Eulerian-Lagrangian Method.

Finite element (FE) method has been widely used for gaining insights into the mechanical response of brain tissue during impacts. In this study, a coupled Eulerian-Lagrangian (CEL) formulation is implemented in impact simulations of a head system to overcome the mesh distortion difficulties due to large deformation in the cerebrospinal fluid (CSF) region and provide a biofidelic model of the interaction between the brain and skull. The head system used in our FE model is constructed from the transverse section of the human brain, with CSF modeled by Eulerian elements. Spring connectors are applied to represent the pia-arachnoid connection between the brain and skull. Validations of the CEL formulation and the FE model are performed using the experimental results. The dynamic response of brain tissue under noncontact impacts and the brain regions susceptible to injury are evaluated based on the intracranial pressure (ICP), maximum principal strain (MPS), and von Mises stress. While tracking the critical MPS location on the brain, higher likelihood of contrecoup injury than coup injury is found when sudden brain-skull motion takes place. The accumulation effect of CSF in the ventricle system, under large relative brain-skull motion, is also identified. The FE results show that adding relative angular velocities, to the translational impact model, not only causes a diffuse high strain area, but also cause the temporal lobes to be susceptible to cerebral contusions since the protecting CSF is prone to be squeezed away at the temporal sites due to the head rotations.

Vitamin D Receptor and Role of Vitamin D Supplementation in Advanced Gallbladder Cancer: A Prospective Study from Northern India.

BACKGROUND: The proposed role of Vitamin D Receptor (VDR) in various cancers underscores the importance of vitamin D compounds as a novel therapeutic agent in the prevention of occurrence and progression of cancer. Vitamin D Receptor (VDR) expression in gallbladder cancer (GBC) has not been widely analyzed yet. In the present study, an attempt has been made to study VDR expression and the role of vitamin D supplementation during palliative chemotherapy in advanced GBC. METHODS: Expression of VDR was analyzed in benign cholecystectomy specimens (n=11), and GBC specimens (n=32). Thirty patients with advanced GBC were subjected to palliative chemotherapy. Out of them, 19 patients were supplemented with Vitamin D and 11 patients were not. Effect of vitamin D supplementation on the change in vitamin D scores and improvement in quality of life (QOL) were assessed by EORTC QLQ c30 version 3.0. and the difference in outcome between the two groups were studied. RESULTS: Mean intensity, staining and immunoreactivity scores signifying VDR expression were decreased in the studied population of GBC when compared to benign disease. In palliative setting, vitamin D supplementation significantly improved the quality of life. However, the effect on disease- specific survival, although present, was not statistically significant. CONCLUSION: VDR expression downregulation is associated with increasing malignant process. Vitamin D may act as sensitizers for tumor cell death besides downplaying potential harmful effects of palliative chemotherapy thus reducing the associated morbidity. This study assumes importance as the first clinical study reporting VDR expression in GBC tissue and the possible role of vitamin D supplementation in patients with advanced disease.

Antibacterial spectrum of human omentum and differential expression of beta defensins.

BACKGROUND: Human ß defensins (hBD1 and hBD2) are cationic, cysteine-rich peptides and form an integral part of the mammalian innate immune system. hBD1 is constitutively expressed in epithelial cells, whereas hBD2 increases in response to bacterial infection. Human omentum is known for its anti-inflammatory properties and also possesses an antibacterial activity of its own. We hypothesized that antimicrobial peptides, ß defensins, may govern host defense mechanism in the microbe-rich environment of the peritoneal cavity. Therefore, we analyzed the expression of hBD1 and hBD2 in omentum tissue in vivo and also studied the antibacterial activity of omentum against common pathogens. METHODOLOGY: Omentum tissues were obtained from 30 patients (15 cases and 15 controls). Real-time polymerase chain reaction (PCR) was used to evaluate the mRNA expression of hBD1 and hBD2. Protein quantification was done using Western blotting technique. Antibacterial susceptibility was performed to check the antibacterial activity of omentum. RESULT: Significantly higher expression of hBD2 was observed in cases compared to controls at both the transcriptional and translational levels. In comparison with an array of antibiotics, activated omentum also showed antibacterial property even at lower concentration of its extract. CONCLUSION: Omentum directly responds to bacterial infection, which may be due to differential expression of hBD1 and hBD2 in human omental tissue. These peptides (hBD1 and hBD2) may be an ideal candidate for novel antibiotic class with a broad-spectrum activity.

Bile duct injury: to err is human; to refer is divine.

A 42-year-old woman sustained complete transection of common hepatic duct during routine laparoscopic cholecystectomy. The surgery was being performed at a rural setting, and the injury was identified intraoperatively. The surgeon sought the opinion of an expert biliary surgeon via telephone and discussed the possibility of an immediate end-to-end bile duct repair. Since he lacked the experience of doing biliary-enteric anastomosis, he was advised to place a subhepatic drain and transfer the patient to the hepatobiliary centre for definitive surgery. At the referral centre, the patient was evaluated and planned an immediate biliary repair. On exploration, she was found to have a major type, Strasberg E5 injury. The transected ducts were small in calibre and required double Roux-en-Y hepaticojejunostomy over transanastomotic stents. The postoperative recovery was uneventful. Transanastomotic stents were removed after 6 months, and the patient remained perfectly well at a follow-up of 1 year.

Simulation-driven Selection of Electrode Materials Based on Mechanical Performance for Lithium-Ion Battery.

Experimental and numerical studies have shown that mechanical loading associated with lithiation/delithiation may limit the useful life of battery electrode materials. The paper presents an approach to parameterize and compare electrode material performance based on mechanical stability. A mathematical model was developed to determine particle deformation and stress fields based upon an elastic-perfectly plastic constitutive response. Mechanical deformation was computed by combining the stress equilibrium equations with the electrochemical diffusion of lithium ions into the electrode particle. The result provided a time developing stress field which shifts from purely elastic to partially plastic deformation as the lithium-ion diffuses into the particle. The model was used to derive five merit indices that parameterize mechanical stability of electrode materials. The merit indices were used to analyze the mechanical stability for the six candidate electrode materials-three for anode materials and three for the cathode material. Finally, the paper suggests ways to improve the mechanical performance of electrode materials and identifies mechanical properties that need to be considered for selection and optimal design of electrode materials.

Significance of methylation status of MASPIN gene and its protein expression in prognosis of gallbladder cancer.

AIM: We investigated prognostic significance of methylation status of MASPIN gene and its protein expression in normal subjects, cholelithiasis and gallbladder cancer (GBC) patients. METHODS: MASPIN protein expression and its promoter methylation in gallbladder tissue of cholelithiasis (n = 36), GBC (n = 46) and controls (n = 25) were investigated. Clinicopathological parameters and prognosis of patients with GBC were correlated with protein expression of MASPIN. Survival analysis of GBC patients was performed using Kaplan-Meier method. RESULTS: Significant increased (P < 0.0001) protein expression of MASPIN was observed in GBC as compared to cholelithiasis, whereas negligible expression was found in normal tissues. Methylation-specific PCR revealed statistical significant (P = 0.005) difference in methylation status of MASPIN promoter between gallstone and GBC patients. Significant association was observed between methylation profile with protein expression of MASPIN (P = 0.004), stage (P = 0.011) and cellular differentiation (P = 0.012) for GBC. Also, significant (P = 0.004) difference in survival was observed for malignant patients having demethylated MASPIN promoter. Further significant negative correlation (Pearson's coefficient [r] = -0.617; P < 0.0001) was observed between MASPIN expression and survival of cancer patients after surgery. Overall survival was significantly shorter (P ≤ 0.0001; hazard ratio [HR] for death = 2.84; 95% confidence interval [CI], 0.09865-0.3683) in patients of GBC with MASPIN expression ≥169.56 pg/mg (median survival; 10 months) with compared to those with expression <169.56 pg/mg (median survival; 16 months). CONCLUSION: Overexpression of MASPIN protein may play an important role in malignant progression and is correlated with a poor prognosis. Also MASPIN DNA methylation can be used as a novel therapeutic target for treating GBC.