22 results on '"Jayanthi NV"'
Search Results
2. Pre-vertebral surgical emphysema following functional endoscopic sinus surgery.
- Author
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Sanu A, Jayanthi NV, and Mohan AR
- Abstract
Functional endoscopic sinus surgery (FESS) is a widely practiced technique in the UK. This procedure has variable complication rates and can have some serious consequences. We present a case of surgical emphysema of the neck, face and the pre-vertebral space following FESS. Emphysema of the face and neck has been previously reported. However, to our knowledge, emphysema of the pre-vertebral space following FESS has not been documented. Pre-vertebral emphysema following FESS is an unusual and potentially serious complication. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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3. Completely minimally invasive versus hybrid Ivor-Lewis oesophagectomy for oesophageal and gastro-oesophageal junctional cancer: a UK multi-centre comparative study.
- Author
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Patel K, Askari A, Abbassi O, Jayanthi NV, Claydon O, Laycock J, Ramalingam A, Kumar B, Wong J, Aly M, and Jambulingam P
- Subjects
- Anastomotic Leak surgery, Esophagectomy adverse effects, Humans, Length of Stay, Minimally Invasive Surgical Procedures adverse effects, Postoperative Complications epidemiology, Postoperative Complications etiology, Postoperative Complications surgery, Retrospective Studies, Treatment Outcome, United Kingdom epidemiology, Esophageal Neoplasms, Stomach Neoplasms surgery
- Abstract
Background: Limited robust evidence exists comparing outcomes following completely minimally invasive oesophagectomy (CMIO) to hybrid oesophagectomy (HO) in the treatment of resectable oesophageal and gastro-oesophageal junctional (GOJ) cancer. This multi-centre study aims to assess postoperative morbidity between HO and CMIO according to the full Esophagectomy Complications Consensus Group (ECCG) complication platform., Methods: All consecutive patients undergoing an Ivor-Lewis HO or Ivor-Lewis CMIO for cancer between 2016 and 2018 in three UK tertiary centres were included. The primary study outcome was 30-day overall complications, evaluated by the ECCG complication subgroups. Secondary outcomes included survival outcomes and perioperative parameters between the two approaches., Results: Of the 382 patients included, 228 (59.7%) patients had HOs and 154 (40.3%) patients had CMIOs with no inter-group baseline differences. Patients undergoing CMIO experienced less 30-day postoperative complications compared to those under undergoing HO (43.5% vs 57.0%, p = 0.010). ECCG defined pulmonary and infective complications were less frequent in the CMIO group. Anastomotic leak rates and oncological outcomes were similar between the two groups. Independent predictors of 30-day postoperative complications include surgical approach with HO and high ASA grade on multivariable analysis., Conclusions: Ivor-Lewis CMIO demonstrates superior short-term surgical outcomes when compared to Ivor-Lewis HO with no compromise in oncological feasibility. Anastomotic leak rates were equivalent between both groups. A robust randomised controlled trial is required to validate the findings of this study., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2022
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4. Total endoluminal repair of aorto-oesophageal fistula.
- Author
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Vara S, Jayanthi NV, Gadhvi V, and Thapar A
- Subjects
- Angioplasty, Female, Gastrointestinal Hemorrhage etiology, Gastrointestinal Hemorrhage surgery, Hematemesis etiology, Humans, Aortic Diseases diagnostic imaging, Aortic Diseases surgery, Esophageal Fistula diagnostic imaging, Esophageal Fistula surgery
- Abstract
A woman in her 50s presented to the Emergency Department, following massive haematemesis, having swallowed a single tooth denture 3 years previously. Endoscopy initially revealed profuse bleeding at 20cm from the incisors, initially treated with an oesophageal covered stent. Following ongoing haematemesis, a thoracic and abdominal CT angiogram demonstrated an aorto-oesophageal fistula, which was successfully treated with a thoracic endograft and left tube thoracostomy. The patient remains well to 1 year. This is the first case to demonstrate successful use of covered stents in both the aorta to stop exsanguination, as well as the oesophagus to prevent mediastinitis and avoid the need for thoracotomy and hypothermic circulatory arrest in a critically ill patient., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2022
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5. Microvascular grafting to enhance perfusion in colonic long-segment oesophageal reconstruction.
- Author
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Charalabopoulos A, Davakis S, Syllaios A, Jayanthi NV, Conn G, Ahmad F, and Lorenzi B
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- Anastomosis, Surgical, Colon surgery, Esophagogastric Junction, Humans, Perfusion, Retrospective Studies, Esophageal Neoplasms surgery, Esophagectomy
- Abstract
Purpose: Oesophagectomy with long-segment colon reconstruction is the first-line treatment when the stomach is not available. Supercharging of the newly formed conduit can improve vascular function utilizing intraoperative perfusion imaging system, following thoracoscopic oesophagectomy for distal-oesophageal and gastroesophageal junction cancer. The purpose of this study is to examine the safety and efficacy of microvascular augmentation of left colonic interposition following oesophagectomy for oesophageal cancer., Methods: A retrospective analysis of 156 consecutive oesophagectomies between January 2016 and July 2018 was performed. All oesophagectomies involving left colon interposition with microvascular augmentation were included in the study. In all cases, oesophageal mobilization was performed thoracoscopically in prone position and the left colon was used as neo-oesophagus in an isoperistaltic fashion. Conduit perfusion was assessed with the Spy system and neck supercharging was performed using microsurgical technique., Results: A total of n = 5 (3.2%) patients were identified. Two cases had delayed and 3 had immediate reconstruction. The conduit was microsurgically augmented in 3 cases with both venous and arterial anastomoses (supercharging) and in 2 cases with venous anastomosis only (superdrainage). No anastomotic leak was identified. One case developed left recurrent laryngeal nerve palsy with associated aspiration pneumonia., Conclusions: Supercharged colonic interposition is a safe way of oesophageal reconstruction when long-segment interposition graft is needed. In oesophageal cancer and in the absence of a viable stomach with intact gastroepiploic arcade, it should be considered a feasible option with favourable outcomes, when the expertise and facilities are available. Use of intraoperative perfusion imaging reveals improved conduit blood supply post-supercharging., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2021
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6. Three-Dimensional vs Two-Dimensional Completely Minimally Invasive 2-Stage Esophagectomy With Intrathoracic Hand-Sewn Anastomosis for Esophageal Cancer: Comparison of Intra-and Postoperative Outcomes.
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Abbassi O, Patel K, and Jayanthi NV
- Subjects
- Anastomosis, Surgical adverse effects, Esophagectomy adverse effects, Humans, Lymph Nodes, Minimally Invasive Surgical Procedures, Postoperative Complications, Retrospective Studies, Treatment Outcome, Esophageal Neoplasms surgery, Laparoscopy
- Abstract
Background . Completely minimally invasive esophagectomy (CMIE) has been associated with reduced morbidity compared to open esophagectomy in the treatment of esophageal cancer. Three-dimensional (3D) vision can enhance depth perception during minimally invasive surgery when compared to two-dimensional (2D) vision. We aimed to compare outcomes from 2-stage CMIEs when performed in 2D vs 3D. Method . All consecutive 2-stage CMIEs performed for esophageal or gastroesophageal junctional cancer at a single-centre between 2016 and 2018 were identified from a prospectively maintained database. All operations were completed in either 2D or 3D. All esophagogastric anastomoses were hand-sewn thoracoscopically. Intraoperative and postoperative clinical parameters were compared between 2D and 3D CMIE. Results . Overall, 98 patients underwent a 2-stage CMIE, of which 59 (60.2%) were in 2D and 39 (39.8%) in 3D. Median operative blood loss was less in the 3D group compared to the 2D group (283 mls vs 409 mls, P = .016). A higher number of lymph nodes were retrieved from 3D CMIE (30 vs 25, P = .010). The median duration of surgery was 407 minutes (interquartile ranges (IQR): 358-472 minutes) and 426 minutes (IQR: 369-509 minutes) when performed in 2D and 3D, respectively ( P = .162). There were no significant intergroup differences in 30-day postoperative complications, short-term mortality, and hospital stay. Conclusion . We report reduced blood loss and higher lymph node yield when performing 3D CMIE than 2D CMIE. Other intraoperative and postoperative clinical outcomes were similar in both groups. A randomized controlled trial is needed to validate these findings of superior outcomes from CMIE performed in 3D over 2D.
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- 2021
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7. Completely Minimally Invasive Esophagectomy Versus Hybrid Esophagectomy for Esophageal and Gastroesophageal Junctional Cancer: Clinical and Short-Term Oncological Outcomes.
- Author
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Patel K, Abbassi O, Tang CB, Lorenzi B, Charalabopoulos A, Kadirkamanathan S, and Jayanthi NV
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- Humans, Minimally Invasive Surgical Procedures, Neoplasm Recurrence, Local, Postoperative Complications, Treatment Outcome, Esophageal Neoplasms surgery, Esophagectomy
- Abstract
Background: Minimally invasive surgery for resectable esophageal and gastroesophageal junctional (GEJ) cancer significantly reduces morbidity when compared with open surgery, as is evident from published landmark trials. Comparison of outcomes between hybrid esophagectomy (HE) and completely minimally invasive esophagectomy (CMIE) remains unclear., Objective: We aimed to ascertain whether CMIE is associated with less postoperative complications compared with HE without oncological compromise., Methods: All consecutive two-stage HEs and CMIEs performed between 2016 and 2018 were included. All procedures were performed with an intrathoracic anastomosis. Primary clinical outcomes were pulmonary infective and overall complications within 30 days of surgery, while primary oncological outcomes included overall survival (OS) and disease-free survival (DFS) at both 6 months and to date. Secondary outcomes included intraoperative variables and postoperative clinical parameters., Results: Overall, 98 patients had CMIEs and 49 patients had HEs. There were no baseline differences between the two groups. Thirty-day postoperative pulmonary infection rates were lower in the CMIE group compared with the HE group (12.2% vs. 28.6%; p = 0.014), and 30-day overall postoperative complication rates were also lower following CMIE (35.7% vs. 59.2%; p = 0.007). OS and DFS were similar between the two groups at 6 months (p = 0.201 and p = 0.109, respectively)., Conclusions: CMIE is associated with less pulmonary infective and overall postoperative complications compared with HE for resectable esophageal and GEJ cancer. No intergroup difference was observed regarding short-term survival and cancer recurrence in patients undergoing CMIE and HE. A randomized controlled trial comparing the two operative approaches is required to validate these findings.
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- 2021
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8. ASO Author Reflections: Superior Postoperative Outcomes from Completely Minimally Invasive Approach Versus Hybrid Approach to Esophagectomy for Esophageal and Gastro-Esophageal Junctional Cancer.
- Author
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Patel K and Jayanthi NV
- Subjects
- Esophagectomy, Humans, Minimally Invasive Surgical Procedures, Treatment Outcome, Esophageal Neoplasms surgery, Stomach Neoplasms surgery
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- 2020
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9. Over-the-scope-clip treatment of gastrobronchial fistula following minimally invasive oesophagectomy: a novel approach.
- Author
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Kordzadeh A, Syllaios A, Davakis S, Lorenzi B, Jayanthi NV, Tang CB, and Charalabopoulos A
- Abstract
Gastrobronchial fistulae (GBF) following minimally invasive oesophagectomy (MIO) is a rare entity, with an estimated incidence of 0.3-1.5% according to the published literature. It could present with persistent cough (Ohno's sign), chest pain, haemoptysis and recurrent pneumonia. Barium swallow examination remains the most sensitive investigation in 78% of the cases; the main stay of management is surgical and in some cases endoscopic (stent insertion). We report a rare case of a GBF 1 month after two-stage MIO for cancer of the gastro-oesophageal junction, which was successfully treated for the first time with an over-the-scope-clip.
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- 2019
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10. Totally minimally invasive two-stage esophagectomy with intrathoracic hand-sewn anastomosis: short-term clinical and oncological outcomes.
- Author
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Elshaer M, Gravante G, Tang CB, and Jayanthi NV
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- Aged, Anastomosis, Surgical methods, Feasibility Studies, Female, Humans, Length of Stay, Male, Middle Aged, Operative Time, Postoperative Complications etiology, Prone Position, Prospective Studies, Retrospective Studies, Treatment Outcome, Esophageal Neoplasms surgery, Esophagectomy methods, Esophagus surgery, Stomach surgery, Thoracoscopy methods
- Abstract
Several esophageal resection techniques have been reported in literature. The objective of this study is to assess postoperative and oncological outcomes of two-stage minimally invasive esophagectomy (MIE) in a prone position using thoracoscopic hand-sewn anastomosis. Consecutive patients who underwent two-stage MIE in 2016 performed by the senior author were included. This was compared with the preceding cohort of consecutive patients who underwent two-stage hybrid esophagectomy (HE). The primary outcome was 30-day morbidity and mortality. The secondary outcomes were operation duration, length of stay (LOS), total nodes examined (TNE), number of positive nodes (NPN), and resection margin. Overall, 15 patients underwent MIE and 11 patients underwent HE. Respiratory complications occurred in three (20.0%) patients in the MIE group and in five (45.5%) patients in the HE group (P = 0.218). Cardiac complications occurred in two (18.2%) patients, and two other patients (18.2%) experienced anastomotic leak in the HE group. Mean operative duration was 349 ± 41.6 min in MIE and 309 ± 47.8 min in HE (P = 0.040). Median LOS was 10 days (range: 7-70) in MIE and 13 days (range: 10-116) in HE (P = 0.045). Median TNE was 23 (range: 12-36) in MIE and 20 (range: 14-47) in HE (P = 0.775). Longitudinal margin was involved in one patient (9.1%) in HE and no longitudinal margin was involved in the MIE group. Circumferential resection margin was involved in seven patients (46.7%) in MIE and in four patients (36.4%) in HE (P = 0.391). Two-stage MIE using hand-sewn technique is safe and feasible without compromising surgical and oncological outcomes. A multicenter large trial is recommended to confirm these results.
- Published
- 2018
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11. Role of 3D in minimally invasive esophagectomy.
- Author
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Charalabopoulos A, Lorenzi B, Kordzadeh A, Tang CB, Kadirkamanathan S, and Jayanthi NV
- Subjects
- Aged, Anastomosis, Surgical, Cohort Studies, Female, Humans, Imaging, Three-Dimensional, Male, Middle Aged, Pilot Projects, Prone Position, Suture Techniques, Adenocarcinoma surgery, Esophageal Neoplasms surgery, Esophagectomy methods, Esophagogastric Junction, Surgery, Computer-Assisted methods, Thoracoscopy methods
- Abstract
Purpose: Two-stage minimally invasive esophagectomy (MIE) has gained popularity in the surgical treatment of esophageal cancer. MIE's limitation is embedded in the construction of intrathoracic anastomosis. Various anastomotic techniques have been reported; however, the mechanical one remains the most commonly adopted. This pilot study aims to describe an efficient, safe, and reproducible way of performing a hand-sewn intrathoracic esophagogastric anastomosis in conjunction with short-term results using 2D and 3D thoracoscopic approaches., Methods: A total of n = 13 patients (mean age 67.4) underwent MIE for distal esophageal or gastroesophageal junction adenocarcinoma between January and September 2016. Resection was performed in prone position, and the esophagogastric anastomosis was constructed in an end-to-side manner in two layers with barbed knotless suture. A 2D thoracoscopic approach was used in n = 10 patients (77%) and a 3D approach in n = 3 (23%)., Results: n = 8 patients (61.5%) had neo-adjuvant chemotherapy and n = 5 (38.5%) had primary surgery. The mean operating time was 420 min, and the average length of stay was 10 days with no associated mortality. n = 1 (7.7%) developed a radiological leak that did not require an intervention. Thoracoscopic approach with the glasses-based 3D optical system using the angulating-tip 100° camera provided a far superior view for precise lymphadenectomy in combination to an efficient and safe construction of the anastomosis., Conclusion: The barbed knotless suturing technique in MIE is an efficient and safe method of constructing the esophagogastric anastomosis with promising short-term outcomes. A 3D thoracoscopic approach appears to be superior in performing the anastomosis to that of a 2D technique.
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- 2017
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12. Male infertility following inguinal hernia repair: a systematic review and pooled analysis.
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Kordzadeh A, Liu MO, and Jayanthi NV
- Subjects
- Azoospermia etiology, Herniorrhaphy methods, Humans, Laparoscopy, Male, Sperm Motility, Hernia, Inguinal surgery, Herniorrhaphy adverse effects, Infertility, Male etiology, Surgical Mesh adverse effects
- Abstract
Introduction: The aim of this systematic review is to establish the clinical impact of open (mesh and/or without mesh) and laparoscopic hernia repair (transabdominal pre-peritoneal (TAP) and/or totally extra-peritoneal (TEP)) on male fertility. The incidence of male infertility following various types of inguinal hernia repair is currently unknown. The lack of high-quality evidence has led to various speculations, suggestions and reliance on anecdotal experience in the clinical practice., Methods: An electronic search of the literature in Medline, Scopus, Embase and Cochrane library from 1966 to October 2015 according to PRISMA checklist was conducted. Quality assessment of articles was conducted using the Oxford Critical Appraisal Skills Programme (CASP) and their recommendation for practice was examined through National Institute for Health and Care Excellence (NICE). This resulted in ten studies (n = 10), comprising 35,740 patients., Results: Sperm motility could be affected following any type and/or technique of inguinal hernia repair but this is limited to the immediate postoperative period (≤48 h). Obstructive azoospermia was noted in 0.03% of open and 2.5% of bilateral laparoscopic (TAP) hernia repair with mesh. Male infertility was detected in 0.8% of the open hernia repair (mesh) with no correlation to the type of mesh (lightweight vs. heavyweight)., Conclusion: Inguinal hernia repair without mesh has no impact on male fertility and obstructive azoospermia. However, the use of mesh in bilateral open and/or laparoscopic repair may require the inclusion of male infertility as the part of informed consent in individuals that have not completed their family or currently under investigations.
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- 2017
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13. Gastric electrical stimulation for treatment of clinically severe gastroparesis.
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Jayanthi NV, Dexter SP, and Sarela AI
- Abstract
Background: Severe, drug-resistant gastroparesis is a debilitating condition. Several, but not all, patients can get significant relief from nausea and vomiting by gastric electrical stimulation (GES). A trial of temporary, endoscopically delivered GES may be of predictive value to select patients for laparoscopic-implantation of a permanent GES device., Materials and Methods: We conducted a clinical audit of consecutive gastroparesis patients, who had been selected for GES, from May 2008 to January 2012. Delayed gastric emptying was diagnosed by scintigraphy of ≥50% global improvement in symptom-severity and well-being was a good response., Results: There were 71 patients (51 women, 72%) with a median age of 42 years (range: 14-69). The aetiology of gastroparesis was idiopathic (43 patients, 61%), diabetes (15, 21%), or post-surgical (anti-reflux surgery, 6 patients; Roux-en-Y gastric bypass, 3; subtotal gastrectomy, 1; cardiomyotomy, 1; other gastric surgery, 2) (18%). At presentation, oral nutrition was supplemented by naso-jejunal tube feeding in 7 patients, surgical jejunostomy in 8, or parenterally in 1 (total 16 patients; 22%). Previous intervention included endoscopic injection of botulinum toxin (botox) into the pylorus in 16 patients (22%), pyloroplasty in 2, distal gastrectomy in 1, and gastrojejunostomy in 1. It was decided to directly proceed with permanent GES in 4 patients. Of the remaining, 51 patients have currently completed a trial of temporary stimulation and 39 (77%) had a good response and were selected for permanent GES, which has been completed in 35 patients. Outcome data are currently available for 31 patients (idiopathic, 21 patients; diabetes, 3; post-surgical, 7) with a median follow-up period of 10 months (1-28); 22 patients (71%) had a good response to permanent GES, these included 14 (68%) with idiopathic, 5 (71%) with post-surgical, and remaining 3 with diabetic gastroparesis., Conclusions: Overall, 71% of well-selected patients with intractable gastroparesis had good response to permanent GES at follow-up of up to 2 years.
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- 2013
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14. Laparoscopic repair of perforated peptic ulcer-technical tip.
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Jayanthi NV
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- Adult, Aged, Aged, 80 and over, Female, Humans, Length of Stay, Male, Middle Aged, Suture Techniques, Duodenal Ulcer surgery, Laparoscopy methods, Peptic Ulcer Perforation surgery, Stomach Ulcer surgery
- Abstract
Increasing number of gastrointestinal emergencies are managed laparoscopically. Laparoscopic repair of a perforated peptic ulcer remains contentious. Fashioning an omental patch is a crucial and an essential part of this repair, whether it is performed open or laparoscopically. This article describes a technique to fashion an adequate omental patch over the perforated peptic ulcer.
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- 2013
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15. Laparoscopic repair of perforated peptic ulcer.
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Jayanthi NV
- Subjects
- Humans, Duodenal Ulcer complications, Laparoscopy methods, Peptic Ulcer Perforation surgery, Stomach Ulcer complications
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- 2011
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16. Emergence of secondary resistance to imatinib in recurrent gastric GIST.
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Jayanthi NV
- Subjects
- Benzamides, Drug Resistance, Neoplasm, Humans, Imatinib Mesylate, Antineoplastic Agents therapeutic use, Gastrointestinal Stromal Tumors drug therapy, Neoplasm Recurrence, Local drug therapy, Piperazines therapeutic use, Pyrimidines therapeutic use, Stomach Neoplasms drug therapy
- Published
- 2010
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17. Patients' attitudes towards "do not attempt resuscitation" status.
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Gorton AJ, Jayanthi NV, Lepping P, and Scriven MW
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- Adult, Aged, Female, Hospitals, District, Humans, Informed Consent ethics, Male, Middle Aged, Prospective Studies, Resuscitation Orders legislation & jurisprudence, Resuscitation Orders psychology, Surveys and Questionnaires, Wales, Attitude to Health, Decision Making ethics, Heart Arrest therapy, Resuscitation Orders ethics
- Abstract
Introduction: The decision of "do not attempt resuscitation" (DNAR) in the event of cardiopulmonary arrest is usually made when the patients are critically ill and cannot make an informed choice. Although, various professional bodies have published guidelines, little is know about the patients' own views regarding DNAR discussion., Aim: The aim of this study was to determine patients' attitudes regarding discussing DNAR before they are critically ill., Methods: A prospective study was performed in a general out patients department. A questionnaire was distributed to consecutive outpatients along with an explanatory leaflet in the adult outpatient clinic., Results: 364 patients completed the questionnaire (response rate 77%). 90% of respondents wanted all patients to be asked regarding DNAR decision at some point during a hospital admission. The majority would not find a DNAR discussion distressing. Only 10% would find it upsetting, however, 48% of these still wanted a discussion. 37% of respondents wanted to discuss DNAR decisions on admission; 32% in outpatients; 17% at consent for surgery, 14% when they are critically ill. 87% of respondents would not object to their relatives being involved in making decisions about their resuscitation status. However, only 12% of the subjects in the study had been involved in discussing the resuscitation status of a relative and 21% would not be comfortable to discuss a relative's resuscitation status. Although 33% of patients preferred their resuscitation status to simply be documented within their clinical notes, 77% wanted it to be more easily accessible., Conclusions: This study suggests that contrary to current practice most patients want to discuss their DNAR status prior to becoming critically ill. This includes half of the small number that find it distressing to discuss. Although most patients are comfortable with relatives being involved in discussing DNAR, a significant proportion do not want their relatives to be asked. Furthermore, once a decision has been made, the majority of patients want it to be more accessible than current practice allows.
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- 2008
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18. The competency of foregut mesenchyme in islet mesenchyme-to-epithelial transition during embryonic development.
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Teague WJ, Rowan-Hull AM, Jayanthi NV, and Johnson PR
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- Animals, Chick Embryo, Quail embryology, Epithelium embryology, Islets of Langerhans embryology, Mesoderm
- Abstract
Background/purpose: Potential for curative stem-cell treatments of juvenile-onset diabetes has focussed research into pancreatic islet development. Islets were previously thought to originate solely from embryonic pancreatic epithelium, but we have demonstrated that islets can originate from mesenchyme, that is, islet mesenchyme-to-epithelial transition. The aim of this study was to establish the competence of foregut mesenchyme during mesenchymal islet development., Methods: Embryonic chick pancreatic epithelium of gestational stage Hamburger-Hamilton (HH) 22 (J Morphol. 1951;88:49-92) was combined with quail stomach mesenchyme of increasing gestation (stage HH22 [n = 6], HH26 [n = 6], HH28 [n = 4], or HH31 [n = 6]). Recombinants were cultured and analysed by immunocytochemistry for coexpression of insulin and quail-specific antigen to determine the embryonic origin of islets., Results: Recombinants constructed using stage HH22 mesenchyme yielded 34 islets, of which 35% were mesenchymal. However, when recombinants were constructed using stage HH26 mesenchyme, 24% of 25 islets were mesenchymal. When using mesenchyme, 13% of 15 islets were mesenchymal. All islets (n = 35) in recombinants constructed using stage HH31 mesenchyme were epithelial derived. Islet mesenchyme-to-epithelial transition diminished significantly with increasing mesenchymal gestational stage (P = .002)., Conclusions: These data show foregut mesenchyme is competent to form islets between stages HH22 and HH28. Developmental competence of foregut mesenchyme in islet mesenchyme-to-epithelial transition diminishes as gestation increases. This may have important implications for identifying stem cells to treat juvenile-onset diabetes.
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- 2006
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19. The effect of IV cannula length on the rate of infusion.
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Jayanthi NV and Dabke HV
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- Blood Flow Velocity, Blood Viscosity, Equipment Design, Fluid Therapy, Hemorheology, Humans, Infusions, Intravenous methods, Shock therapy, Time Factors, Catheters, Indwelling, Infusions, Intravenous instrumentation
- Abstract
According to the Hagen-Poiseuille's law, rate of laminar flow through a tubular structure varies directly with fourth power of its radius and inversely with its length. Although it is well recognised that faster infusion rates can be achieved with wider-bore IV cannulae, the effect of length on flow rates is less well known. In the current in vitro study, we assessed the effect of length of an IV cannula on the rate of flow of infusion. Mathematical calculations performed using Hagen-Poiseuille's law predicted an increase of 40% in flow rates when the IV cannulae were shortened by 13mm. However, when the flow rates of the shortened cannulae were measured in vitro an increase of only 4-18% was observed. Although the increase in flow rates was statistically significant, it may not be sufficient to be significant in clinical practice. Turbulence resulting from design characteristics of the infusion system is responsible for the measured flow rates to be lower than that predicted by mathematical calculations.
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- 2006
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20. The importance of pancreatic embryonic epithelium for mesenchyme-to-epithelial transition during islet development.
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Jayanthi NV, Rowan-Hull AM, Teague WJ, and Johnson PR
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- Animals, Cattle, Cell Culture Techniques methods, Cell Differentiation, Chick Embryo, Coturnix, Insulin metabolism, Insulin Secretion, Mesoderm cytology, Pancreas cytology, Embryo, Nonmammalian physiology, Epithelial Cells cytology, Islets of Langerhans cytology, Islets of Langerhans embryology, Pancreas embryology
- Abstract
Stem or progenitor cells are a promising potential alternative source of pancreatic islets for transplantation in the treatment of juvenile-onset diabetes. However, to derive islets from such cells, it is important to elucidate the mechanisms of normal pancreatic development. Previous work in our laboratory has shown that, contrary to previous thinking, pancreatic mesenchyme when combined with pancreatic epithelium can contribute cells to islets. However, the signals and role of individual tissues involved in this mesenchyme-to-epithelial transition (MET) have yet to be elucidated. The aim of this study was to investigate whether MET can occur in the absence of pancreatic epithelium. Chick and quail eggs were incubated for 4 days and the dorsal pancreatic buds and stomach rudiments were microdissected. Mesenchyme and epithelium of the organ rudiments were separated after collagenase treatment. Separated pancreatic mesenchyme were cultured alone and in combination with stomach (nonpancreatic). After 7 days of culture, the specimens were analysed using immunohistochemistry for quail-specific nucleolar antigen (QCPN), insulin, and islet precursor cell marker (ISL-1). Pancreatic mesenchyme when cultured in the absence of epithelium did not differentiate into islets, but differentiated into fibroblast-like cells. When pancreatic mesenchyme were cultured in combination with stomach epithelium, there was no evidence of mesenchymally derived islets. We have demonstrated that pancreatic mesenchyme require pancreatic epithelium to differentiate into islet cells. These findings further increase our understanding of normal pancreatic islet development and may help to elucidate the molecular mechanisms of MET in islet development.
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- 2005
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21. Foregut mesenchyme contributes cells to pancreatic acini during embryonic development in a chick-quail chimera model.
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Teague WJ, Jayanthi NV, Lear PV, and Johnson PR
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- Animals, Cell Differentiation, Chick Embryo, Epithelium embryology, Epithelium ultrastructure, Immunohistochemistry, Islets of Langerhans ultrastructure, Microscopy, Fluorescence, Pancreas, Exocrine ultrastructure, Quail, Tissue Culture Techniques, Chimera, Islets of Langerhans embryology, Mesoderm ultrastructure, Models, Biological, Pancreas, Exocrine embryology
- Abstract
To understand causes of developmental abnormalities of the pancreas, it is essential to understand its normal embryonic development. Current understanding of the development of pancreatic exocrine tissue is that it develops solely from embryonic epithelium, while the role of the surrounding mesenchyme is to signal to this epithelium and form connective tissue. Recent work in our laboratory has shown that pancreatic bud mesenchyme can contribute cells to islets during embryonic development. However, no published studies have investigated in detail whether mesenchyme contributes cells to the exocrine structures of the pancreas. The aim of this study was to investigate whether cells from foregut mesenchyme can contribute to pancreatic acini during embryonic development. Chick-quail chimera recombinant organs were constructed using pancreatic epithelium and mesenchyme from either the pancreas (n=12) or stomach (n=25). These were cultured for 7 days in 3-D collagen gels. The resulting specimens were analysed using morphological criteria and fluorescent immunocytochemistry against pancreatic amylase, insulin, and the quail-specific nucleolar antigen QCPN. Two independent observers determined the origins of acini as either solely epithelial, solely mesenchymal, or of mixed origin. Results are expressed as percentages of total acini identified in each group. Statistical analysis was performed using chi(2) tests (P<0.01 was considered statistically significant). Recombinations of pancreatic epithelium and pancreatic mesenchyme yielded 11 acini, of which 45% were derived from epithelium only, 45% from mesenchyme only, and 10% of mixed origin. Recombinations of pancreatic epithelium and stomach mesenchyme yielded 78 acini, of which 40% were derived from epithelium only, 32% from mesenchyme only, and 28% of mixed origin. When acini with any mesenchymal cellular contribution were considered as a group, there was no significant difference between stomach and pancreatic mesenchymal contribution (P=0.72). This is the first study to demonstrate the cellular contribution of mesenchyme to pancreatic exocrine structures. Our data show that mesenchyme contributes cells to pancreatic acini during development in this model and that mesenchyme derived from stomach and pancreatic sources are both able to form acini.
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- 2005
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22. Foregut Mesenchyme Contributes Cells to Islets during Pancreatic Development in a 3-Dimensional Avian Model.
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Lear PV, Jayanthi NV, Teague WJ, and Johnson PR
- Abstract
Current interest in the potential use of pancreatic stem-cells in the treatment of insulin dependent diabetes mellitus has led to increased research into normal pancreatic development. Pancreatic organogenesis involves branching morphogenesis of undifferentiated epithelium within surrounding mesenchyme. Current understanding is that the pancreatic islets develop exclusively from the epithelium of the embryonic buds. However, a cellular contribution to islets by mesenchyme has not been conclusively excluded. We present evidence that the mesenchyme of both the dorsal pancreatic bud and stomach rudiment make a substantial contribution of cells to islets during development in a three-dimensional avian model. These data suggest that mesenchyme can be a source not only of signals but also of cells for the definitive epithelia, making pancreatic organogenesis more akin to that of the kidney than to other endodermal organs. This raises the possibility for the use of mesenchymal cells as stem-or progenitor-cells for islet transplantation.
- Published
- 2004
- Full Text
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