Implementation of an international medical student pen-pal club:survey outcomes of perceptions in cultural competency and global health

Background:Pen-pal clubs(PPC)are used worldwide for students to learn about different cultures and other skillsets without the need for travel.Many medical students are interested in global health opportunities abroad but costs,scheduling,and other barriers allow few to participate in such experiences.It is important that medical students have nuanced global medical perspectives and can contribute to the global medical community.Objective:The purpose of this study is to demonstrate that an international medical student PPC improves medical students'perspectives of cultural competency and global health engagement.Methods:In 2021,a novel medical student PPC was established that began between an American and Japanese medical school.Following a shareholders meeting,it was decided that the number of medical schools involved globally be expanded through previous institutional affiliations and online presences.In total,the club connected 50 American medical students and 52 medical students from 17 high-and middle-income countries.The primary form of communication was online;pen-pals were encouraged to communicate monthly using provided topics,although frequency and way of communication was their discretion.In February 2022,American PPC members were emailed a qualitative survey to assess the PPC's impact.Results:The survey was completed by 42%of American PPC members,95%of which were 22-26 years.Participants were preclinical medical students,60%whom were female and the majority either white(47%)or Asian(43%).Overall,the PPC positively influenced American medical students'perception of global medicine,medical education,and their cultural competency after joining the PPC compared to prior(P=0.004).Conclusion:PPCs encourage medical students to think from a global perspective and foster open-mindedness within varying social and cultural contexts.Having a global communication platform for students during medical school education may be an additional way to train aspiring global leaders.

Long-term outcome in patients with obscure gastrointestinal bleeding after negative capsule endoscopy

AIM:To investigate long-term outcome in obscure gastrointestinal bleeding(OGIB) after negative capsule endoscopy(CE) and identify risk factors for rebleeding.METHODS:A total of 113 consecutive patients underwent CE for OGIB from May 2003 to June 2010 at Seoul National University Hospital.Ninety-five patients(84.1%) with a subsequent follow-up after CE of at least 6 mo were enrolled in this study.Follow-up data were obtained from the patients' medical records.The CE images were reviewed by two board-certified gastroenterologists and consensus diagnosis was used in all cases.The primary outcome measure was the detection of rebleeding after CE,and factors associated with rebleeding were evaluated using multivariate analysis.RESULTS:Of the 95 enrolled patients(median age 61 years,range 17-85 years),62 patients(65.3%) were male.The median duration of follow-up was 23.7 mo(range 6.0-89.4 mo).Seventy-three patients(76.8%) underwent CE for obscure-overt bleeding.Complete examination of the small bowel was achieved in 77 cases(81.1%).Significant lesions were found in 38 patients(40.0%).The overall rebleeding rate was 28.4%.The rebleeding rate was higher in patients with positive CE(36.8%) than in those with negative CE(22.8%).However,there was no significant difference in cumulative rebleeding rates between the two groups(log rank test;P = 0.205).Anticoagulation after CE examination was an independent risk factor for rebleeding(hazard ratio,5.019;95%CI,1.560-16.145;P = 0.007),regardless of CE results.CONCLUSION:Patients with OGIB and negative CE have a potential risk of rebleeding.Therefore,close observation is required and alternative modalities should be considered in suspicious cases.

Histologic characteristics of gastric polyps in Korea: Emphasis on discrepancy between endoscopic forceps biopsy and endoscopic mucosal resection specimen

AIM： To investigate histological characteristics of gastric polyps in the Korean population. METHODS： We reviewed endoscopic photographs and medical records of patients with gastric polyps who underwent endoscopic mucosal resection from April 1996 through February 2003. RESULTS： A total of 85 gastric polyps from 74 patients were reviewed, Male-to-female ratio was 1：1,96, Mean age was 59.9 =1：10,8 years. Multiple polyps were observed in 10,8%, Gastric polyps occurred most frequently in the antrum （58.8%）, Pathological results on resected specimens were as follows： tubular adenoma 45.9%, hyperplastic polyp 31.8%, inflammatory polyp 9.4%, hamartoma 3.5%, fundic gland polyp 2.4%, tubulovillous adenoma 2.4%, adenocarcinoma 2.4%, dysplasia 1.1%, and mucosal pseudolipomatosis 1.1%. Discrepancy rate between endoscopic biopsy and pathology of resected specimens was 27.1%. There was no relationship between the size of the polyp and concordance rate. CONCLUSION： There is considerable discrepancy in histologic findings between endoscopic forceps biopsy and resected specimens. Approaches to review of the histology of an entire polyp should be performed, especially when an adenoma is suspected.

Proton pump inhibitors as a risk factor for recurrence of Clostridium-difficile-associated diarrhea

AIM:To investigate the risk factors for Clostridiumdifficile-associated diarrhea(CDAD)recurrence,and its relationship with proton pump inhibitors(PPIs). METHODS:Retrospective data of 125 consecutive hospitalized patients diagnosed with CDAD between January 2006 and December 2007 were collected by medical chart review.Collected data included patient characteristics at baseline,underlying medical disease, antibiotic history before receiving a diagnosis of CDAD, duration of hospital stay,severity of CDAD,concurrenttreatment with PPIs,laboratory parameters,response to CDAD therapy,and recurrence of disease within 90 d of successful treatment.Various clinical and laboratory parameters were compared in patients in whom CDAD did or did not recur. RESULTS:Of the 125 patients(mean age,67.6± 13.9 years)that developed CDAD,98(78.4%)did not experience recurrence(non-recurrent group)and 27 (21.6%)experienced one or more recurrences(recurrent group).Prior to the development of CDAD,96% of the 125 patients were prescribed antibiotics,and 56(44.8%)of the patients received PPIs.Age older than 65 years(P=0.021),feeding via nasogastric tube(NGT)(P=0.045),low serum albumin level(P =0.025),and concurrent use of PPIs(P=0.014) were found to be risk factors for CDAD recurrence by univariate analysis.However,sex,length of hospital stay,duration and type of antibiotics used,severity of disease,leukocyte count and C-reactive protein(CRP) were not associated with risk of CDAD recurrence.On multivariate analysis,the important risk factors were advanced age(>65 years,adjusted OR:1.32,95% CI:1.12-3.87,P=0.031),low serum albumin level(< 2.5 g/dL,adjusted OR:1.85,95%CI:1.35-4.91,P= 0.028),and concurrent use of PPIs(adjusted OR:3.48, 95%CI:1.64-7.69,P=0.016). CONCLUSION:Advanced age,serum albumin level< 2.5 g/dL,and concomitant use of PPIs were found to be significant risk factors for CDAD recurrence.

Clinical and endoscopic characteristics of drug-induced esophagitis

AIM: To investigate clinical, endoscopic and pathological characteristics of drug-induced esophagitis.

Clinical significance of CT-defined minimal ascites in patients with gastric cancer

AIM： To study the clinical significance of minimal ascites, which was only defined by the CT and whose nature was not determined preoperatively, in the relationship with the peritoneal carcinomatosis. METHODS： The medical records and the dynamic CT films of 118 patients with gastric cancer were reviewed. Factors associated with peritoneal carcinomatosis were analyzed in 40 patients who had CT-defined ascites of which the nature was surgically confirmed, RESULTS： Only 12.5-25% of the CT-defined minimal ascites, whose volume was estimated to be less than 50 mL, were associated with peritoneal carcinomatosis. When the estimated CT-defined ascitic volume was 50 mL or more, peritoneal carclnomatosis was identified in 75-100%. When CT-defined lymph node enlargements were not found beyond the regional gastric area, perigastric invasions were not suspected, and the size of tumor was less than 3 cm, peritoneal carcinomatosis seemed significantly less accompanied at the univariate analysis. However, except for the minimal volume of CT- defined ascites in comparison with the mild or more, other factors were not confirmed multivariately. CONCLUSION： In the patients with gastric cancer, CT- defined minimal ascites alone is rarely associated with peritoneal carcinomatosis, if it does not accompany other signs suggestive of malignant seeding. Therefore, consideration of active curative resection should not be hesitated, if CT-defined minimal ascites is the only delusive sign.

Discrepancies between primary physician practice and treatment guidelines for Helicobacterpylori infection in Korea

AIM： To evaluate the attitude of primary care physicians in the diagnosis and treatment of Helicobacter pylori （fl pylori） infection. METHODS： Primary care physicians in the Seoul metropolitan area answered self-administered questionnaire from January to March 2003. RESULTS： One hundred and eight doctors responded to the questionnaire. The most frequent reasons for testing H pylori infection were gastric and duodenal ulcers （93.5% and 88.9%, respectively）. For patients with Hplori positive dyspepsia, 28.7% of doctors always tried to eradicate the worm and 34.4% treated selectively. A large proportion （28.7%） of primary care physicians treated H pylori on a patient＇s request basis. Only 9.3% of primary care physicians always conducted follow-up testing after treating H pylori infection. When H pylori was not cleared by the first treatment, 40.7% of doctors reused the same regimen, 16.7% changed to another triple regimen and 25% to a quadruple regimen. CONCLUSION： It has been well documented that the issuance of guidelines alone has little impact on practice. Communication between primary care physicians and gastroenterologists in the form of continuous medical education is required.

Role of ascites adenosine deaminase in differentiating between tuberculous peritonitis and peritoneal carcinomatosis

AIM： To investigate the usefulness of tumor markers and adenosine deaminase in differentiating between tuberculous peritonitis （TBP） and peritoneal carcinoma- tosis （PC）. METHODS： A retrospective analysis of data was per- formed on consecutive patients who underwent perito- neoscopic and abdominal computed tomography （CT） evaluations. Among 75 patients at the Seoul National University Hospital from January 2000 to June 2010 who underwent both tests, 27 patients （36.0%） and 25 patients （33.3%） were diagnosed with TBP and PC, re- spectively. Diagnosis was confirmed by peritoneoscopic biopsy. RESULTS： Serum c-reactive protein （7.88：1：6.62 mg/ dL vs 3.12 ＋ 2.69 mg/dL, P = 0.01）, ascites adenos- ine deaminase （66.76：1：32.09 IU/L vs 13.89 ：l： 8.95 IU/L, P 〈 0.01）, ascites lymphocyte proportion （67.77 ：1： 23.41% vs 48.36 ＋ 18.78%, P 〈 0.01）, and serum- ascites albumin gradient （0.72 ＋ 0.49 g/dL vs 1.05 ＋ 0.50 g/dL, P = 0.03） were significantly different be- tween the two groups. Among tumor markers, serum and ascites carcinoembryonic antigen, serum carbohy- drate antigen 19-9 showed significant difference be- tween two groups. Abdominal CT examinations showed that smooth involvement of the parietal peritoneum was more common in the TBP group （77.8% vs 40.7%） whereas nodular involvement was more common in the PC group （14.8% vs 40.7%, P = 0.04）. From receiver operating characteristic （ROC） curves ascites adeno- sines deaminase （ADA） showed better discriminative capability than tumor markers. An ADA cut-off level of 21 IU/L was found to yield the best results of differ- ential diagnosis; sensitivity, specificity, positive predic- tive value, and negative predictive value were 92.0%, 85.0%, 88.5% and 89.5%, respectively. CONCLUSION： Besides clinical and radiologic findings, ascitic fluid ADA measurement is helpful in the differen- tial diagnosis of TBP and PC.

Restraint stress induces and exacerbates intestinal inflammation in interleukin-10 deficient mice

AIM:To investigate the effects of restraint stress on chronic colitis in interleukin(IL)-10 deficient(IL-10^(-/-))mice.METHODS:The first experiment compared the effect of restraint stress on the development of intestinal inflammation in wild-type and IL-10^(-/-) mice.Both wildtype and IL-10^(-/-) mice were physically restrained in a well-ventilated,50 cm3 conical polypropylene tube for2 h per day for three consecutive days.The second experiment was performed to assess the effect of restraint stress on exacerbation of colitis induced by piroxicam in IL-10^(-/-) mice.The IL-10^(-/-) mice were exposed to restraint stress for 2 h per day for 3consecutive days,and then treated with piroxicam for4 d at a dose of 200 ppm administered in the rodent chow.RESULTS:In the first experiment,none of the wildtype mice with or without restraint stress showed clinical and histopathological abnormality in the gut.However,IL-10^(-/-) mice exposed to restraint stress exhibited histologically significant intestinal inflammation as compared to those without restraint stress.In the second experiment,restraint stress significantly reduced body weight and increased the severity of intestinal inflammation assessed by histopathologic grading in IL-10^(-/-) mice.Colonic IL12p40 mRNA expression was strongly increased in mice exposed to restraint stress.CONCLUSION:This novel animal model could be useful in future study of psychological stress in the pathogenesis of inflammatory bowel disease.

Fatty liver is an independent risk factor for gallbladder polyps

BACKGROUND Gallbladder polyps(GBPs)are known to be associated with obesity and metabolic diseases.However,to date,the relationship between GBPs and abnormal body fat distribution,such as fatty liver,visceral obesity,or sarcopenia,has not yet been established.AIM To evaluate whether GBPs are associated with fatty liver,visceral obesity,or sarcopenia.METHODS We retrospectively reviewed the medical records of subjects who underwent various laboratory tests,body composition measurement with a non-invasive body composition analyzer,and abdominal ultrasonography during health checkups.A total of 1405 subjects with GBPs were compared with 2810 age-and sex-matched controls.RESULTS The mean age of the subjects was 46.8±11.7 years,and 63.8%were male.According to multiple logistic regression analysis,the presence of fatty liver[odds ratio(OR)1.413;95%confidence interval(CI)1.218-1.638;P<0.001]was an independent risk factor for GBP,together with low levels of alanine aminotransferase(OR 0.993;95%CI 0.989-0.996;P<0.001).Additionally,fatty liver showed both independent(OR 1.629;95%CI,1.335-1.988;P<0.001)and dosedependent(moderate to severe fatty liver;OR 2.137;95%CI,1.662-2.749;P<0.001)relationship with large GBPs(≥5 mm).The presence of sarcopenia and high visceral fat area were not significantly associated with GBPs.CONCLUSION Fatty liver was found to be closely associated with GBPs irrespective of sarcopenia and visceral obesity.

Comparison between uncovered and covered self-expandable metal stent placement in malignant duodenal obstruction

AIM:To compare the clinical outcomes of uncovered and covered self-expandable metal stent placements in patients with malignant duodenal obstruction.METHODS:A total of 67 patients were retrospectivelyenrolled from January 2003 to June 2013.All patients had symptomatic obstruction characterized by nausea,vomiting,reduced oral intake,and weight loss.The exclusion criteria included asymptomatic duodenal obstruction,perforation or peritonitis,concomitant small bowel obstruction,or duodenal obstruction caused by benign strictures.The technical and clinical success rate,complication rate,and stent patency were compared according to the placement of uncovered(n = 38) or covered(n = 29) stents.RESULTS:The technical and clinical success rates did not differ between the uncovered and covered stent groups(100% vs 96.6% and 89.5% vs 82.8%).There were no differences in the overall complication rates between the uncovered and covered stent groups(31.6% vs 41.4%).However,stent migration occurred more frequently with covered than uncovered stents [20.7%(6/29) vs 0%(0/38),P < 0.05].Moreover,the overall cumulative median duration of stent patency was longer in uncovered than in covered stents [251 d(95%CI:149.8 d-352.2 d) vs 139 d(95%CI:45.5 d-232.5 d),P < 0.05 by log-rank test] The overall cumulative median survival period was not different between the uncovered stent(70 d) and covered stent groups(60 d).CONCLUSION:Uncovered stents may be preferable in malignant duodenal obstruction because of their greater resistance to stent migration and longer stent patency than covered stents.

Effect of gastric acid suppressants and prokinetics on peritoneal dialysis-related peritonitis

AIM: To investigate the effect of gastric acid suppressants and prokinetics on peritonitis development in peritoneal dialysis(PD) patients.METHODS: This was a single-center, retrospective study. The medical records of 398 PD patients were collected from January 2000 to September 2012 and analyzed to compare patients with at least one episode of peritonitis(peritonitis group, group A) to patients who never had peritonitis(no peritonitis group, group B). All peritonitis episodes were analyzed to compare peritonitis caused by enteric organisms and peritonitis caused by non-enteric organisms.RESULTS: Among the 120 patients who met the inclusion criteria, 61 patients had at least one episode ofperitonitis and 59 patients never experienced peritonitis. Twenty-four of 61 patients(39.3%) in group A and 15 of 59 patients(25.4%) in group B used gastric acid suppressants. Only the use of H2-blocker(H2B) was associated with an increased risk of PD-related peritonitis; the use of proton pump inhibitors, other antacids, and prokinetics was not found to be a significant risk factor for PD-related peritonitis. A total of 81 episodes of peritonitis were divided into enteric peritonitis(EP) or non-enteric peritonitis, depending on the causative organism, and gastric acid suppressants and prokinetics did not increase the risk of EP in PD patients.CONCLUSION: The use of H2B showed a trend for an increased risk of overall PD-related peritonitis, although further studies are required to clarify the effects of drugs on PD-related peritonitis.

Pediatric schwannoma of the tongue:A case report and review of literature

BACKGROUND Neurogenic tumors account for about ten percent of all tumors of childhood,and benign tumor originating from Schwann cells is rare in peripheral nerves.Schwannoma of the tongue is quite rare in children.CASE SUMMARY We present the case of an 8-year-old male with schwannoma in the anterolateral tongue.The mass was slow-growing for one year with no pain and discomfort.He underwent transoral mass excision under general anesthesia.Gross examination revealed a smooth surfaced,17 mm×14 mm×7 mm sized,encapsulated nodule with a clear resection margin.Schwannoma of the tongue was confirmed by the pathological exam.He reported no motor or sensory change,such as dysgeusia or paresthesia,or phonation difficulty during postoperative 12 mo follow-up.CONCLUSION Schwannoma of the tongue is a rare benign neoplasm in childhood.If a painless firm mass is encountered in the tongue of a child,solid tumors like schwannoma should be considered in the differential diagnosis.

Double tailgut cysts (presacral and precoccygeal hamartomas) with CA 19-9 elevation

Tailgut cyst, also called retrorectal hamartoma, is a rare congenital lesion and is usually located anterior to the sacrum and posterior to the rectum. We report a case of double tailgut cyst (presacral and precoccygeal hamartoma). A 62-year- old female visited the hospital complaining of anal pain and pressure in the perianal area for one month. Digital rectal examination revealed a round mass with hard consistency in the lateral and posterior part of rectum 5 cm from the anal verge. Pelvic magnetic resonance imaging showed two cystic and solid presacral masses (lateral and posterior part of rectum) compressing the rectum. The patient underwent surgical resection for pathologic diagnosis. At operation, two masses were located in the left presacral space without invasion to adjacent organs and soft tissue. Pathologic examination revealed double tailgut cysts without malignant transformation. A differential diagnosis of perirectal cystic hamartoma includes epidermal cysts, cystic teratomas, dermoid cysts, anal gland cysts, sarcoma and rectal duplications. Regional inflammatory process frequently complicates this lesion and perirectal fistula can develop. Tailgut cyst also has a malignancy potential, with development of adenocarcinomas. To establish a definite diagnosis and prevent complication, complete surgical resection is recommended.

3D-printed versatile biliary stents with nanoengineered surface for anti-hyperplasia and antibiofilm formation

Biliary strictures are characterized by the narrowing of the bile duct lumen,usually caused by surgical biliary injury,cancer,inflammation,and scarring from gallstones.Endoscopic stent placement is a well-established method for the management of biliary strictures.However,maintaining optimal mechanical properties of stents and designing surfaces that can prevent stent-induced tissue hyperplasia and biofilm formation are challenges in the fabrication of biodegradable biliary stents(BBSs)for customized treatment.This study proposes a novel approach to fabricating functionalized polymer BBSs with nanoengineered surfaces using 3D printing.The 3D printed stents,fabricated from bioactive silica poly(ε-carprolactone)(PCL)via a sol-gel method,exhibited tunable mechanical properties suitable for supporting the bile duct while ensuring biocompatibility.Furthermore,a nanoengineered surface layer was successfully created on a sirolimus(SRL)-coated functionalized PCL(fPCL)stent using Zn ion sputtering-based plasma immersion ion implantation(S-PIII)treatment to enhance the performance of the stent.The nanoengineered surface of the SRL-coated fPCL stent effectively reduced bacterial responses and remarkably inhibited fibroblast proliferation and initial burst release of SRL in vitro systems.The physicochemical properties and biological behaviors,including in vitro biocompatibility and in vivo therapeutic efficacy in the rabbit bile duct,of the Zn-SRL@fPCL stent demonstrated its potential as a versatile platform for clinical applications in bile duct tissue engineering.

Bone-targeted lipoplex-loaded three-dimensional bioprinting bilayer scaffold enhanced bone regeneration

Clinical bone-morphogenetic protein 2(BMP2)treatment for bone regeneration,often resulting in complications like soft tissue inflammation and ectopic ossification due to high dosages and non-specific delivery systems,necessitates research into improved biomaterials for better BMP2 stability and retention.To tackle this challenge,we introduced a groundbreaking bone-targeted,lipoplex-loaded,three-dimensional bioprinted bilayer scaffold,termed the polycaprolactone-bioink-nanoparticle(PBN)scaffold,aimed at boosting bone regeneration.We encapsulated BMP2 within the fibroin nanoparticle based lipoplex(Fibroplex)and functionalized it with DSS6 for bone tissue-specific targeting.3D printing technology enables customized,porous PCL scaffolds for bone healing and soft tissue growth,with a two-step bioprinting process creating a cellular lattice structure and a bioink grid using gelatin-alginate hydrogel and DSS6-Fibroplex,shown to support effective nutrient exchange and cell growth at specific pore sizes.The PBN scaffold is predicted through in silico analysis to exhibit biased BMP2 release between bone and soft tissue,a finding validated by in vitro osteogenic differentiation assays.The PBN scaffold was evaluated for critical calvarial defects,focusing on sustained BMP2 delivery,prevention of soft tissue cell infiltration and controlled fiber membrane pore size in vivo.The PBN scaffold demonstrated a more than eight times longer BMP2 release time than that of the collagen sponge,promoting osteogenic differentiation and bone regeneration in a calvarial defect animal.Our findings suggest that the PBN scaffold enhanced the local concentration of BMP2 in bone defects through sustained release and improved the spatial arrangement of bone formation,thereby reducing the risk of heterotopic ossification.

Dually-functionalized Ni-rich layered oxides for high-capacity lithium-ion batteries

Layered lithium nickel-cobalt-manganese oxides(NCM)have been highlighted as advanced cathode materials for lithium-ion batteries(LIBs);however,their low interfacial stability must be overcome to ensure stable cycling performance of the cell.In this work,we propose a one-step surface modification method that uses a task-specific precursor,N,N,N,N-tetraethylsulfamide(NTESA),to improve interfacial stability of Ni-rich NCM cathode materials.The unstable surface properties of Ni-rich NCM cathode material are improved by embedding an artificial cathode-electrolyte interphase(CEI)layer on the cathode surface by heat treatment of the Ni-rich NCM cathode material with an NTESA precursor at low temperature.Our material analyses indicate that this approach allows the formation of amine-and sulfone-functionalized CEI layers on the surface of Ni-rich NCM cathode material without changing the layered structure of the cathode material.NTESA-functionalized Ni-rich NCM cathode materials exhibit improved cycling retention after 100 cycles:for example,a cell cycled with a 3.0 NTESA-modified NCM811 cathode presents the highest retention ratio of 88.3%,whereas a cell cycled with a non-functionalized NCM811 cathode suffers from rapid fading of the cycling performance(68.4%).Our additional SEM,XPS,and EIS analyses indicate that electrolyte decomposition is suppressed during electrochemical cycling,thereby leading to smaller increases in the internal resistances.ICP-MS analyses of the cycled anodes also indicate that the NTESA-based artificial CEI layer inhibits the dissolution of transition metal components from the Ni-rich NCM cathode materials,thereby contributing to an improved overall electrochemical performance of the cell.