Comparison of the diagnostic yield of rapid versus non-rapid onsite evaluation in endoscopic ultrasound-guided fine-needle aspiration cytology of solid pancreatic lesions.

Background: The role of rapid on-site evaluation (ROSE) for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions is debatable. In this study, we aimed to compare the diagnostic yield of ROSE vs. non-ROSE in solid pancreatic lesions. Methods: This retrospective single-center study included patients undergoing EUS-FNA of solid pancreatic lesions from 2019-2021. Patients with cystic lesions, those undergoing fine-needle core biopsy, those undergoing repeat procedures, and patients with non-diagnostic smears with less than 6-month follow up were excluded. The diagnostic yield, need for repeat procedures and number of passes required with and without ROSE were analyzed in these patients. Results: Of the 111 patients included, 56 underwent ROSE. The majority of lesions were malignant in both groups (79.6% ROSE vs. 75% non-ROSE). The diagnostic yield was 96.4% in the ROSE group and 94.5% in the non-ROSE group. Repeat samples were needed in 1 ROSE and 2 non-ROSE patients. The median number of passes made was significantly fewer in the ROSE group (3.5, interquartile range - 3,4) compared with the non-ROSE group (4, interquartile range - 3,5) P=0.01. However, the frequency of procedure-related complications was similar in both groups. Conclusion: The utilization of ROSE during EUS-FNA of solid pancreatic lesions does not affect the diagnostic yield or the need for repeat samples, but reduces the number of passes needed for acquiring samples.

Bile Culture May Guide Antibiotic Stewardship in Acute Bacterial Cholangitis.

BACKGROUND: Bile cultures are often sent with blood cultures in patients with acute bacterial cholangitis. AIMS: To assess the yield of blood and bile cultures in patients with cholangitis and the clinical utility of bile cultures in guiding therapy. METHODS: All patients diagnosed with cholangitis, based on the Tokyo 2013/2018 guidelines were recruited retrospectively over ten years. The clinical and investigation details were recorded. The results of bile and blood cultures including antibiotic sensitivity patterns were noted. The concordance of microorganisms grown in blood and bile cultures and their sensitivity pattern were assessed. RESULTS: A total of 1063 patients with cholangitis were included. Their mean age was 52.7 ± 14 years and 65.4% were males. Blood cultures were positive in 372 (35%) patients. Bile culture was performed in 384 patients with 84.4% being positive, which was significantly higher than the yield of blood culture (p < 0.001). Polymicrobial growth was more in bile (59.3%) than in blood cultures (13.5%, p < 0.001). E.coli, Klebsiella, Enterococcus and Pseudomonas were the four most common organisms isolated from both blood and bile. Extended spectrum betalactamase producing organisms were isolated in 57.7% and 58.8% of positive blood and bile cultures, respectively. Among 127 patients with both blood and bile cultures positive, complete or partial concordance of organisms was noted in about 90%. CONCLUSION: Bile and blood cultures have a similar microbial profile in most patients with cholangitis. As bile cultures have a significantly higher yield than blood cultures, they could effectively guide antimicrobial therapy, especially in those with negative blood cultures.

The Fifth Residue of the Coat Protein of Turnip Mosaic Virus Is Responsible for Long-Distance Movement in a Local-Lesion Host and Aphid Transmissibility in a Systemic Host.

HC-Pro and coat protein (CP) genes of a potyvirus facilitate cell-to-cell movement and are involved in the systemic movement of the viruses. The interaction between HC-Pro and CP is mandatory for aphid transmission. Two turnip mosaic virus (TuMV) isolates, RC4 and YC5, were collected from calla lily plants in Taiwan. The virus derived from the infectious clone pYC5 cannot move systemically in Chenopodium quinoa plants and loses aphid transmissibility in Nicotiana benthamiana plants, like the initially isolated virus. Sequence analysis revealed that two amino acids, P5 and A206, of YC5 CP uniquely differ from RC4 and other TuMV strains. Recombination assay and site-directed mutagenesis revealed that the fifth residue of leucine (L) at the N-terminal region of the CP (TuMV-RC4), rather than proline (P) (TuMV-YC5), is critical to permit the systemic spread in C. quinoa plants. Moreover, the single substitution mutant YC5-CPP5L became aphid transmissible, similar to RC4. Fluorescence microscopy revealed that YC5-GFP was restricted in the petioles of inoculated leaves, whereas YC5-CPP5L-GFP translocated through the petioles of inoculated leaves, the main stem, and the petioles of the upper uninoculated leaves of C. quinoa plants. In addition, YC5-GUS was blocked at the basal part of the petiole connecting to the main stem of the inoculated C. quinoa plants, whereas YC5-CPP5L-GFP translocated to the upper leaves. Thus, a single amino acid, the residue L5 at the N-terminal region right before the 6DAG8 motif, is critical for the systemic translocation ability of TuMV in a local lesion host and for aphid transmissibility in a systemic host.

Pregnancy Outcomes in Patients with Early-Onset Idiopathic Chronic Pancreatitis.

BACKGROUND: Early-onset idiopathic chronic pancreatitis (EOICP) is a disease that affects young individuals. Data on pregnancy outcomes in EOICP are limited. AIM: To assess the pregnancy outcomes in patients with EOICP and the effect of pregnancy on the course of EOICP. METHODS: Patients with EOICP with disease onset before their pregnancy were recruited. Data regarding demographic variables, disease duration, pregnancy outcomes, and course of illness were noted. RESULTS: 50 patients were included in the study contributing to a total of 86 pregnancies. The mean age of onset of symptoms and at the time of delivery was 17.95 (5.71) and 23.44 (4.28) years, respectively. Gestational diabetes (GD) and gestational hypertension (GH) noted in one (1.5%) each. 3 (4.5%) pregnancies were preterm. 19 (22.1%) pregnancies did not have successful outcomes (7 (8.1%) were induced abortions). 12 (15.2%) pregnancies had spontaneous pregnancy losses. 8 (10.1%) were spontaneous abortions and 4 (5.1%) were stillbirths. Of 67 successful pregnancies, 33 (49.3%) pregnancies were delivered by LSCS. Compared to average rates of LSCS in India, this was significantly higher (21.5% vs 49.3%-p ≤ 0.001). The average birth weight was 2.87 (0.48) kg. There was one (1.5%) neonatal death. Compared to the published Indian data, there was no significant difference in the incidence of spontaneous pregnancy losses, GD, GH, preterm labor, and birth weight. Pancreatic pain was reported by 21 (42%) women in total 27 (31.4%) pregnancies. There was no difference in maternal or fetal outcomes between pregnancies with or without pancreatic pain. There were no pancreatitis-related complications reported during the pregnancies. CONCLUSION: The present study shows that mothers affected with EOICP have pregnancy outcomes similar to healthy women in India.

Low Serum Hepcidin Levels in Patients with Ulcerative Colitis - Implications for Treatment of Co-existent Iron-Deficiency Anemia.

Ulcerative colitis (UC) is often associated with anemia. Hepcidin, the central regulator of iron homeostasis, is known to be induced by inflammation and suppressed by anemia. It is not clear how hepcidin is affected in those with UC, when both inflammation and anemia may co-exist.Such knowledge may hold implications for treatment. Hematological and iron-related parameters, C-reactive protein (CRP), growth differentiation factor 15 (GDF-15) and erythroferrone (ERFE) (erythroid regulators of hepcidin) levels were estimated in blood from those with UC and in control subjects. Values for hematological and iron-related parameters showed evidence of iron-deficiency and resultant anemia, in patients with UC. The presence of UC was significantly associated with inflammation. Serum levels of ERFE, but not of GDF-15, were significantly higher in patients with UC than in control patients, while hepcidin levels were significantly lower. Serum hepcidin concentrations in patients with UC correlated positively with serum iron, ferritin and GDF-15, and negatively with serum ERFE. The iron status and serum hepcidin levels in UC patients with co-existent anemia were significantly lower and serum ERFE values significantly higher than in those with UC without anemia. The effect of anemia on hepcidin predominated over that of inflammation in patients with UC, resulting in suppressed hepcidin levels. This effect is possibly mediated through erythroferrone. We suggest that a serum hepcidin-guided approach may be useful to guide use of oral iron supplements to treat co-existent iron-deficiency anemia in patients with UC and other chronic inflammatory diseases.

Rapid selection of potyviral cross-protection effective mutants from the local lesion host after nitrous acid mutagenesis.

Zucchini yellow mosaic virus (ZYMV) seriously damages cucurbits worldwide. Control of ZYMV by cross-protection has been practised for decades, but selecting useful mild viruses is time-consuming and laborious. Most attenuated potyviruses used for cross-protection do not induce hypersensitive reaction (HR) in Chenopodium quinoa, a local lesion host Chenopodium quinoa. Here, severe ZYMV TW-TN3 tagged with green fluorescent protein (GFP), designated ZG, was used for nitrous acid mutagenesis. From three trials, 11 mutants were identified from fluorescent spots without HR in inoculated C. quinoa leaves. Five mutants caused attenuated symptoms in squash plants. The genomic sequences of these five mutants revealed that most of the nonsynonymous changes were located in the HC-Pro gene. The replacement of individual mutated HC-Pros in the ZG backbone and an RNA silencing suppression (RSS) assay indicated that each mutated HC-Pro is defective in RSS function and responsible for reduced virulence. Four mutants provided high degrees of protection (84%-100%) against severe virus TW-TN3 in zucchini squash plants, with ZG 4-10 being selected for removal of the GFP tag. After removal of the GFP gene, Z 4-10 induced symptoms similar to ZG 4-10 and still provided 100% protection against TW-TN3 in squash, thus is considered not a genetically engineered mutant. Therefore, using a GFP reporter to select non-HR mutants of ZYMV from C. quinoa leaves is an efficient way to obtain beneficial mild viruses for cross-protection. This novel approach is being applied to other potyviruses.

Generation of Attenuated Passiflora Mottle Virus Through Modification of the Helper Component Protease for Cross Protection.

Passiflora mottle virus (PaMoV), an aphid-borne potyvirus, is the primary causal virus of devastating passionfruit woodiness disease in Vietnam. Here we generated a nonpathogenic, attenuated PaMoV strain for disease control by cross protection. A full-length genomic cDNA of PaMoV strain DN4 from Vietnam was constructed to generate an infectious clone. The green fluorescent protein was tagged at the N-terminal region of the coat protein gene to monitor in planta the severe PaMoV-DN4. Two amino acids within the conserved motifs of helper component protease (HC-Pro) of PaMoV-DN4 were mutated individually or in combination as K53E or/and R181I. Mutants PaMoV-E53 and PaMoV-I181 induced local lesions in Chenopodium quinoa plants, while PaMoV-E53I181 caused infection without apparent symptoms. In passionfruit (Passiflora edulis) plants, PaMoV-E53 elicited severe leaf mosaic and PaMoV-I181 induced leaf mottling, while PaMoV-E53I181 caused transient mottling followed by symptomless recovery. PaMoV-E53I181 was stable after six serial passages in yellow passionfruit (Passiflora edulis f. flavicarpa) plants. Its temporal accumulation levels were lower than those of the wild type, with a zigzag accumulation pattern, typical of a beneficial protective virus. An RNA silencing suppression (RSS) assay revealed that all three mutated HC-Pros are defective in RSS. Triplicated cross-protection experiments with a total of 45 plants showed that the attenuated mutant PaMoV-E53I181 provided a high protection rate (91%) against the homologous wild-type virus in passionfruit plants. This work revealed that PaMoV-E53I181 can be used as a protective virus to control PaMoV by cross protection.

Concurrent Control of Two Aphid-Borne Potyviruses in Cucurbits by Two-in-One Vaccine.

The application of attenuated viruses has been widely practiced for protecting crops from infection by related severe strains of the same species. Papaya ringspot virus W-type (PRSV W) and zucchini yellow mosaic virus (ZYMV) devastate cucurbits worldwide. However, the prevailing of these two viruses in cucurbits cannot be prevented by a single protective virus. In this study, we disclosed that co-infection of horn melon plants by two mild strains, PRSV P-type (PRSV P) HA5-1 and ZYMV-ZAC (a previously developed mild mutant of ZYMV) confers concurrent protection against PRSV P and ZYMV. Consequently, mild mutants of PRSV W were created by site-directed mutagenesis through modifications of the pathogenicity motifs FRNK and PD in helper component-protease (HC-Pro). A stable PRSV W mutant WAC (PRSV-WAC) with R181I and D397N mutations in HC-Pro was generated, inducing mild mottling, followed by symptomless recovery in cucurbits. Horn melon plants pre-infected by PRSV-WAC and ZYMV-ZAC showed no apparent interference on viral accumulation with no synergistic effects on symptoms. An agroinfiltration assay of mixed HC-Pros of WACHC-Pro + ZACHC-Pro revealed no additive effect of RNA silencing suppression. PRSV-WAC or ZYMV-ZAC alone only antagonized a severe strain of homologous virus, while co-infection with these two mild strains provided complete protection against both PRSV W and ZYMV. Similar results were reproduced in muskmelon and watermelon plants, indicating the feasibility of a two-in-one vaccine for concurrent control of PRSV W and ZYMV in cucurbits.

Generation of Attenuated Mutants of East Asian Passiflora Virus for Disease Management by Cross Protection.

East Asian passiflora virus (EAPV) seriously affects passionfruit production in Taiwan and Vietnam. In this study, an infectious clone of the EAPV Taiwan strain (EAPV-TW) was constructed, and EAPV-TWnss, with an nss tag attached to its helper component-protease (HC-Pro), was generated for monitoring the virus. Four conserved motifs of EAPV-TW HC-Pro were manipulated to create single mutations of F8I (simplified as I8), R181I (I181), F206L (L206), and E397N (N397) and double mutations of I8I181, I8L206, I8N397, I181L206, I181N397, and L206N397. Four mutants, EAPV I8I181, I8N397, I181L206, and I181N397, infected Nicotiana benthamiana and yellow passionfruit plants without conspicuous symptoms. Mutants EAPV I181N397 and I8N397 were stable after six passages in yellow passionfruit plants and expressed a zigzag pattern of accumulation dynamic, typical of beneficial protective viruses. An agroinfiltration assay indicated that the RNA silencing suppression capabilities of the four double mutated HC-Pros are significantly reduced. Mutant EAPV I181N397 accumulated the highest level of the small interfering RNA at 10 days postinoculation (dpi) in N. benthamiana plants, then dropped to background levels after 15 dpi. In both N. benthamiana and yellow passionfruit plants, EAPV I181N397 conferred complete cross protection (100%) against severe EAPV-TWnss, as defined by no severe symptoms and absence of the challenge virus, checked by Western blotting and reverse transcription PCR. Mutant EAPV I8N397 provided high degrees of complete protection against EAPV-TWnss in yellow passionfruit plants (90%) but not in N. benthamiana plants (0%). Both mutants showed complete protection (100%) against the Vietnam severe strain EAPV-GL1 in passionfruit plants. Thus, the mutants EAPV I181N397 and I8N397 have excellent potential for controlling EAPV in Taiwan and Vietnam. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Modification of Papaya Ringspot Virus HC-Pro to Generate Effective Attenuated Mutants for Overcoming the Problem of Strain-Specific Cross Protection.

Cross protection application of HA5-1, an attenuated mutant of papaya ringspot virus (PRSV) HA strain from Hawaii, was withdrawn from Taiwan due to the narrow geographic strain specificity of HA5-1. Here, to overcome this problem, we created attenuated mutants of PRSV YK, a dominant severe strain from Taiwan, by mutating helper component protease (HC-Pro) at F7, R181, F206, and D397 residues critical for potyviral pathogenicity. PRSV YK HC-Pro R181I, F206L, and D397N single-mutant viruses induced mild symptoms, but their adverse effects on growth of papaya plants disqualified them as useful protective viruses. However, F7I single-mutant and F7I + F206L double-mutant viruses displayed mild symptoms followed by recovery, and they showed a zigzag pattern of accumulation in papaya plants, indicating their potential to trigger RNA silencing and retain partial antagonistic suppression of host defense. Although F7I + R181I and F7I + D397N double-mutant viruses caused symptomless infection, they accumulated barely above mock level and, thus, were not qualified as proper protective viruses. RNA silencing suppression (RSS) analysis by agroinfiltration in Nicotiana benthamiana plants revealed that the HC-Pro F7I and F7I + F206L mutant proteins were weaker in RSS ability than the wild-type protein. Under greenhouse conditions, F7I and F7I + F206L mutant viruses were genetically stable but not aphid transmissible. Compared with the HA5-1 mutant's low degree (10%) of protection to papaya plants, the F7I and F7I + F206L mutants provided complete (100%) protection to papaya and horn melon plants against strain YK. Thus, F7I and F7I + F206L mutants solve the problem of strain-specific protection and have great potential for control of PRSV in Taiwan.

Common polymorphisms of protein tyrosine phosphate non-receptor type 2 gene are not associated with risk of Crohn's disease in Indian.

BACKGROUND: Multiple genetic risk factors for Crohn's disease (CD) have been identified. However, these observations are not consistent across different populations. The protein tyrosine phosphate non-receptor type 2 (PTPN2) gene plays a role in various aspects of host defense including epithelial barrier function, autophagy, and innate and adaptive immune response. Two common polymorphisms in the PTPN2 gene (rs2542151 and rs7234029) have been associated with risk of CD in Western countries. AIM: To evaluate the association of PTPN2 gene polymorphisms with risk of CD in Indian population. METHODS: We conducted a prospective case-control study. Patients with CD were recruited, and their clinical and investigation details were noted. Controls were patients without organic gastrointestinal disease or other comorbid illnesses. Two common polymorphisms in the PTPN2 gene (rs2542151 and rs7234029) were assessed. DNA was extracted from peripheral blood samples of cases and controls and target DNA was amplified using specific sets of primers. The amplified fragments were digested with restriction enzymes and the presence of polymorphism was detected by restriction fragment length polymorphism. The frequency of alleles was determined. The frequencies of genotypes and alleles were compared between cases and controls to look for significant differences. RESULTS: A total of 108 patients with CD (mean age 37.5 ± 12.7 years, females 42.6%) and 100 controls (mean age 39.9 ± 13.5 years, females 37%) were recruited. For the single nucleotide polymorphism (SNP) rs7234029, the overall frequency of G variant genotype (AG or GG) was noted to be significantly lower in the cases compared to controls (35.2% vs 50%, P = 0.05). For the SNP rs2542151, the overall frequency of G variant genotype (GT or GG) was noted to be similar in cases compared to controls (43.6% vs 47%, P = 0.73). There were no significant differences in minor allele (G) frequency for both polymorphisms between the cases and controls. Both the SNPs had no significant association with age of onset of illness, gender, disease location, disease behaviour, perianal disease, or extraintestinal manifestations of CD. CONCLUSION: Unlike observation form the West, polymorphisms in the PTPN2 gene (rs7234029 and rs2542151) are not associated with an increased risk of developing CD in Indian patients.

Modification of the N-terminal FWKG-αH1 element of potyviral HC-Pro affects its multiple functions and generates effective attenuated mutants for cross-protection.

Control of plant viruses by cross-protection is limited by the availability of effective protective strains. Incorporation of an NIa-protease processing site in the extreme N-terminal region of the helper component protease (HC-Pro) of turnip mosaic virus (TuMV) resulted in a mutant virus TuHND I that induced highly attenuated symptoms. Recombination analysis verified that two variations, F7I mutation and amino acid 7-upstream-deletion, in HC-Pro co-determined TuHND I attenuation. TuHND I provided complete protection to Nicotiana benthamiana and Brassica campestris subsp. chinensis plants against infection by the severe parental strain. Aphid transmission tests revealed that TuHND I was not aphid-transmissible. An RNA silencing suppression (RSS) assay by agroinfiltration suggested the RSS-defective nature of the mutant HC-Pro. In the context (amino acids 3-17) encompassing the two variations of HC-Pro, we uncovered an FWKG-α-helix 1 (αH1) element that influenced the functions of aphid transmission and RSS, whose motifs were located far downstream. We further demonstrated that HC-Pro F7 was a critical residue on αH1 for HC-Pro functions and that reinstating αH1 in the RSS-defective HC-Pro of TuHND I restored the protein's RSS function. Yeast two-hybrid and bimolecular fluorescence complementation assays indicated the FWKG-αH1 element as an integral part of the HC-Pro self-interaction domain. The possibility of regulation of the mechanistically independent functions of RSS and aphid transmission by the FWKG-αH1 element is discussed. Extension of TuMV HC-Pro FWKG-αH1 variations to another potyvirus, zucchini yellow mosaic virus, also generated nonaphid-transmissible cross-protective mutant viruses. Hence, the modification of the FWKG-αH1 element can generate effective attenuated viruses for the control of potyviruses by cross-protection.

Comparison of primary follicular lymphoma of gastrointestinal tract and secondary involvement: A study from South India.

Primary follicular lymphoma of the gut (PFL-GI) is a rare entity. This study aims to compare the clinicopathologic features of PFL-GI with cases of gastrointestinal involvement by disseminated nodal follicular lymphoma. This is a retrospective study with 6 cases of primary follicular lymphoma and 8 cases of secondary involvement of the gut, over a period of 9 years. The slides and blocks were retrieved and reviewed. Clinical data was obtained from hospital records. Clinicopathologic features were compared. PFL-GI cases had a slightly higher median age group (p value 0.23) and no gender predilection when compared to cases with secondary involvement which showed a female preponderance. Para-aortic lymphadenopathy was seen in all secondary cases whereas none of the primary cases showed significant lymphadenopathy. The only microscopic feature that was different was the presence of hollowed out pattern of immunostaining for follicular dendritic cells seen in all cases of PFL-GI but in none of the secondary cases.

Clinical profile of hereditary angioedema from a tertiary care centre in India.

INTRODUCTION: Hereditary angioedema (HAE) is a clinical condition which could be fatal if not identified and managed appropriately. Knowledge of this condition is mostly confined to individual case reports and literature reviews in India. In this retrospective study we describe HAE cases which presented to a tertiary care centre in India over a period of three and half years. MATERIALS AND METHODS: Clinical case records of forty-two HAE patients diagnosed based on clinical and laboratory features were accessed after due approval from the Ethics committee. C1 esterase inhibitor (C1 INH) and C4 levels were measured using nephelometry. All relevant data was entered into Microsoft EXCEL worksheet and analysed using simple statistical tools. RESULTS: Among the 42 patients diagnosed as having HAE, 37 had low C1INH levels and were diagnosed to have type 1 HAE. The remaining 5 had normal C1 INH levels and were considered probable HAE based on family history and response to HAE specific treatment. The median age of onset of symptoms was 15 years (range 5-49) and median age at diagnosis, 27.5 years (range 5-55). The median delay in diagnosis was 10 years (range 1-27 years). Family history of HAE was observed in 52.6% and 29% reported deaths in the family with HAE like disease. Low dose androgens or tranexamic acid or both were prescribed in 64.2% of the patients. Orofacial edema was the commonest clinical presentation (76%) followed by edema of the extremities (38%), GI tract symptoms (19%) and genital involvement (11.9%). CONCLUSION: Many cases of HAE may be going undetected in India. There is a need for clinical awareness and laboratory means to accurately identify and administer appropriate treatment.

Prevalence of past hepatitis A infection among Crohn's patients and controls - An examination of the 'hygiene hypothesis', and the need for hepatitis A vaccination.

Our study aimed to determine the prevalence of prior exposure to hepatitis A virus in Crohn's disease patients, whose IgG antibody levels against hepatitis A virus were compared with age and sex-matched controls. All of the 41 cases with Crohn's disease and 43 controls included in the study tested positive for IgG anti-hepatitis A virus antibody, with titres (38.8 IU/ml, 22-63.9; median, IQR) similar to those in controls (40.7 IU/ml, 17.3-66.7; p = 0.75). Environmental sanitation remains poor in India, despite reasonable economic gains as reflected by universal exposure to hepatitis A virus infection. Vaccination against hepatitis A may not be important in patients attending inflammatory bowel disease clinic, owing to natural immunity provided by prior infection. The observed rise in inflammatory bowel disease incidence seems to be increasing despite persistently poor environmental hygiene.

Self-expanding metal stent in esophageal perforations and anastomotic leaks.

BACKGROUND AND AIMS: Placement of self-expanding metal stents (SEMS) has emerged as a minimally invasive treatment option for esophageal perforation and leaks. The aim of our study was to assess the role of SEMS for the management of benign esophageal diseases such as perforations and anastomotic leaks. METHODS: All patients (n = 26) who underwent SEMS placement for esophageal perforation and anastomotic leaks between May 2012 and February 2019 were included. Data were analyzed in relation to the indications, type of stent used, complications, and outcomes. RESULTS: Indications for stent placement included anastomotic leaks 65% (n = 17) and perforations 35% (n = 9). Fully covered SEMS (FCSEMS) was placed in 25 patients, and in 1, partially covered SEMS (PCSEMS) was placed. Stent placement was successful in all the patients (n = 26). Four patients did not report for follow-up after stenting. Among the patients on follow-up, 91% (20/22) had healing of the mucosal defect. Stent-related complications were seen in 5 (23%) patients and included stent migration [3], reactive hyperplasia [1] and stricture [1]. CONCLUSION: Covered stent placement for a duration of 8 weeks is technically safe and clinically effective as a first-line procedure for bridging and healing benign esophageal perforation and leaks.

A Conserved Helix in the C-Terminal Region of Watermelon Silver Mottle Virus Nonstructural Protein S Is Imperative For Protein Stability Affecting Self-Interaction, RNA Silencing Suppression, and Pathogenicity.

In orthotospovirus, the nonstructural protein S (NSs) is the RNA-silencing suppressor (RSS) and pathogenicity determinant. Here, we demonstrate that a putative α-helix, designated H8, spanning amino acids 338 to 369 of the C-terminal region of the NSs protein, is crucial for self-interaction of watermelon silver mottle virus NSs protein and that the H8 affects RSS function. Co-immunoprecipitation, yeast two-hybrid, and bimolecular fluorescence complementation analyses revealed that the triple point mutation (TPM) of H8 amino acids Y338A, H350A, and F353A resulted in NSs protein self-interaction dysfunction. Transient expression of H8-deleted (ΔH8) and TPM NSs proteins in Nicotiana benthamiana plants by agroinfitration indicated that these proteins have weaker RSS activity and are far less stable than wild-type (WT) NSs. However, an electrophoretic mobility assay revealed that small interfering RNA (siRNA) binding ability of TPM NSs protein is not compromised. The pathogenicity assay of WT NSs protein expressed by the attenuated turnip mosaic virus vector restored severe symptoms in recombinant-infected N. benthamiana plants but not for ΔH8 or TPM proteins. Taken together, we conclude that the H8 helix in the C-terminal region of NSs protein is crucial for stabilizing NSs protein through self-interaction to maintain normal functions of RSS and pathogenicity, but not for NSs-siRNA binding activity.