Biomedical subjects

Sandeep Singh

Publications and source records attributed to Sandeep Singh.

35 records · Page 2Linked to original sources

PubMed2004

The accuracy of endoscopic ultrasound for restaging esophageal carcinoma after chemoradiation therapy.

BACKGROUND: Endoscopic ultrasound (EUS) is an accurate staging modality for esophageal malignancy. Studies have determined that EUS does not retain this accuracy after chemoradiation and that it should not be used as a restaging tool for esophageal carcinoma. In this study, the authors examined their experience with esophageal carcinoma and restaging after neoadjuvant therapy with EUS. METHODS: A retrospective chart review was conducted that included 83 patients with locoregional esophageal adenocarcinoma who were treated with chemoradiation under protocol. All patients underwent surgical resection. EUS was performed for restaging, and the results were compared with findings at surgical pathology using the TNM classification system. RESULTS: All 83 patients identified underwent surgery. There were 77 males, and the mean patient age was 59 years. At restaging, the tumor status (T classification) was assessed correctly by EUS in 22 of 83 patients (29%). The sensitivity of EUS for the individual T classifications were 0% for T0 tumors, 19% for T1 tumors, 27% for T2 tumors, 52% for T3 tumors, and 0% for T4 tumors. In 19 of 83 patients, the tumor classification was correct, whereas 42 of 83 patients were over classified, and 15 of 83 patients were under classified when the EUS results were compared with the surgical pathology results. The lymph node status (N classification) was assessed correctly by EUS in 41 of 83 patients. The sensitivity of EUS for N classification was 48% for N0 disease and 52% for N1 disease. Twenty-two patients were restaged with residual disease according to the EUS results but had no evidence of residual tumor or lymph node involvement according to the surgical pathology results. CONCLUSIONS: EUS did not retain its usefulness as a restaging modality after neoadjuvant chemoradiation for esophageal adenocarcinoma when the standard TNM classification system was used.

Adenocarcinoma↗

PubMed2004

Carboplatin induces apoptotic cell death through downregulation of constitutively active nuclear factor-kappaB in human HPV-18 E6-positive HEp-2 cells.

Because the role of nuclear factor kappaB (NF-kappaB) is in cellular growth control and neoplasia, we explored the status of NF-kappaB and investigated its role in survival of human HPV-18 E6-positive HEp-2 cells. We observed accumulation of p65 in the nucleus. Moreover, without any external stimulus constitutive NF-kappaB DNA binding and transactivation activity were detected in HEp-2 cells. Treatment with NF-kappaB inhibitor curcumin (diferuloylmethane) and transient transfection of the mutant form of IkappaBalpha, IkappaBalpha super repressor (IkappaBalpha-SR), suppressed constitutive NF-kappaB activity as well as proliferation, suggesting that constitutive NF-kappaB activity is required for the survival of HEp-2 cells. Carboplatin treatment downregulated constitutive NF-kappaB activity and prevented nuclear retention of p65. Further, carboplatin also suppressed the constitutive IkappaBalpha phosphorylation leading to stabilization of IkappaBalpha protein in the cells. Carboplatin inhibited NF-kappaB binding to its response element present in Bcl-2 promoter resulting in downregulation of antiapoptotic Bcl-2 protein. Thus, our results for the first time indicate that constitutive NF-kappaB has a significant role in the survival of HPV-18 E6-positive HEp-2 cells. Moreover, inactivation of NF-kappaB is one of the mechanisms underlying the induction of carboplatin-mediated apoptosis in HPV-18 E6-positive cancer cells.

Antineoplastic Agents↗

PubMed2003

Isolated dorsal dislocation of the intermediate cunieform: a case report and review of the literature.

We present one very rare case of patient with an isolated dorsal dislocation of the middle cuneiform (closed injury) sustained after a fall. He was treated surgically through a dorsal approach and fixation with K-wires after manual reduction was unsuccessful. A cast was applied for a total of 6 weeks followed by active range-of-motion exercises. At the 18-month follow-up, he was asymptomatic.

Bone Wires↗

PubMed2003

Unusually large solitary unicameral bone cyst: case report.

A 15-year-old boy presented with complaints of pain and swelling of the right leg. Radiography revealed a large lytic lesion involving the proximal half of the tibia. The patient was taken to surgery, where the cavity was curetted and packed with allogeneic bone graft. Tissue was sent for histopathological evaluation. The patient was kept in an above-knee cast for 4 months, after which partial weight-bearing was allowed. The histopathological diagnosis was a unicameral bone cyst. A radiograph at 1 year showed incorporation of the graft, but a small part of the cavity was still visible and there was a persistent discharge. The patient was again subjected to allogeneic bone grafting in the remaining cavity. At 3.5 years of follow-up now, the patient is walking unsupported, there is no pain, and the radiograph shows complete obliteration of the cavity. Unicameral bone cysts are usually a few centimeters in size. To the best of our knowledge, a unicameral bone cyst of such a large size has never been reported in the literature.

Adolescent↗

PubMed2003

Self- and balloon-expandable stent implantation for severe native coarctation of aorta in adults.

BACKGROUND: Balloon angioplasty for native coarctation of the aorta (CoA) in adults, though promising, is sometimes limited by significant residual gradient (>20 mm Hg). Few studies available have reported on use of balloon-expandable stents in such a situation. We evaluated the use of self- and balloon-expandable stents in patients with suboptimal response to balloon angioplasty (BA). METHODS: Twenty-one hypertensive patients (age, 18 to 61 years; mean, 28.6 +/- 11.2 years) with native CoA and in whom results of BA were suboptimal (ie, residual peak systolic gradient [PSG] >20 mm Hg) underwent stent implantation. Balloon-expandable Palmaz stents were implanted in 5 patients (group A) and self-expandable nitinol aortic stents in the remaining 16 patients (group B). RESULTS: In group A, PSG decreased from 62.8 +/- 10.6 (53 to 80) mm Hg to 28.1 +/- 6.3 (22 to 39) mm Hg after BA. Systolic gradient further decreased to 8.3 +/- 3.9 (2 to 16) mm Hg (P <.001) after implantation of the balloon-expandable Palmaz stent. In group B, PSG decreased from 70.2 +/- 24.6 (40 to 110) mm Hg to 28.4 +/- 9.8 (22 to 42) mm Hg after BA and further reduced to 9.0 +/- 5.5 (4 to 16) mm Hg (P <.001). One of these patients had a nitinol self-expandable stent implanted after a Palmaz stent embolized immediately after deployment. Nitinol stents were easier to deploy and conformed better to aortic anatomy compared with balloon-expandable stents. In group A, the diameter of the coarcted segment increased from 3.8 +/- 0.8 mm to 13.3 +/- 0.8 mm (P <.001) after stent implantation and in group B it increased from 4.5 +/- 1.1 mm to 14.1 +/- 2.1 mm (P <.001). There was no significant difference between the two groups in the PSG and diameter of the coarcted segment before and after stent implantation. With the exception of one case, in which a Palmaz stent embolized, there was no other complication in our series. On follow-up of 12 to 71 months (mean, 40.7 +/- 5.8 months) all the implanted stents remained in their original position and none showed evidence of fracture. Improvement in hypertension was seen in 20 of 21(95.2%) of the patients. On recatheterization and angiography 1.2 +/- 0.6 years after implantation in 19 patients, one patient showed an increase in PSG to 27 mm Hg across the nitinol stent and underwent successful redilation. No increase in gradient was seen in other patients. Beneficial late remodeling was seen in 10 of 14(71.4%) of patients restudied after implantation of self-expandable stent. None of the patients showed aneurysm formation. CONCLUSIONS: Stent implantation is safe and effective in improving suboptimal results after BA for CoA. Self-expandable stents were easier to implant, adapted better to the wall of the aorta, and in most patients had similar efficacy in reducing coarctation as balloon-expandable stents.

Adult↗

PubMed2003

Multifocal skeletal tuberculosis in children: a retrospective study of 18 cases.

Multifocal skeletal tuberculosis is an uncommonly reported entity, Unanimity on terminology is lacking in the literature. The article presents a series of 18 such patients encountered in our institution. All the patients were below 15 y of age. Male to female ratio was 13:5. Most of the cases presented with swellings, discharging sinuses and/or ulcers. Appendicular involvement was seen in 17 of these cases. All the cases were diagnosed histopathologically as tuberculosis. All the cases were treated with multi-drug anti-tubercular therapy with additional procedures such as incision and drainage or sinus tract curettage performed in 9 of the patients. All the lesions healed. Their clinical behaviour, result and outcome are analysed with available international literature.

Adolescent↗

PubMed2003

Multivessel off-pump coronary artery bypass: analysis of 4953 cases.

BACKGROUND: To avoid the harmful effects of cardiopulmonary bypass (CPB), cardiac surgeons are using off-pump coronary artery bypass (OPCAB) as an effective alternative to conventional coronary artery bypass grafting (CABG). In the present study, we analyze our results with OPCAB in patients with multivessel coronary artery disease and compare them with those achieved in patients who underwent operations on CPB. METHODS: Between January 1997 and April 2002, 4953 patients underwent CABG without CPB (OPCAB group). These patients were compared with 7133 patients who underwent conventional on-pump CABG (CCAB group) during the same period. All patients were operated on through a median sternotomy. The Octopus was used as the mechanical stabilizer, and intracoronary shunts were used in most patients. Transesophageal echocardiography was used in all patients, and epiaortic scanning was used in selected patients. RESULTS: The mean patient age was 59 +/- 8.9 years in the OPCAB group and 57.4 +/- 8.9 years in the CCAB group (P <.001). There were more women in the OPCAB group (11.7% versus 10.4%; P =.023), and 2.8% of the patients required conversion to CPB. The mean numbers of grafts were 3.0 +/- 0.7 and 3.2 +/- 0.8 in the OPCAB and the CCAB groups, respectively (P <.001). More patients in the CCAB group received grafts to the circumflex territory. Intubation times (19 +/- 4 hours versus 25 +/- 6 hours; P <.001), blood losses (350 +/- 41 mL versus 598 +/- 74 mL; P <.001), requirements for blood and blood products (30.8% versus 45.3%; P <.001), the frequency of reopening for bleeding (0.6% versus 2.8%; P <.001), requirements for postoperative intra-aortic balloon pump (1.3% versus 2.6%; P <.001), the frequency of atrial fibrillation OPCAB group. The mortality rate was 0.97% and 1.86% in the OPCAB and the CCAB groups, respectively (P <.001). Intensive care unit stays (23 +/- 6 hours versus 34 +/- 8 hours; P <.001) and hospital stays (5 +/- 2 days versus 8 +/- 3 days; P <.001) were significantly shorter in the OPCAB group. CONCLUSION: OPCAB is a safe and effective procedure for patients with multivessel coronary artery disease and is associated with reduced morbidity and mortality. However, large randomized studies with long-term follow-up may show the real benefits of OPCAB compared with CABG on CPB.

Aged↗

PubMed2002

Percutaneous transvenous mitral commissurotomy: immediate and long-term follow-up results.

Percutaneous transvenous mitral commissurotomy has emerged as an effective nonsurgical technique for the treatment of patients with symptomatic mitral stenosis. This report highlights the immediate and long-term follow-up results of this procedure in an unselected cohort of patients with rheumatic mitral stenosis from a single center. It was performed in a total of 4,850 patients using double balloon in 320 (6.6%), flow-guided Inoue balloon technique in 4,374 (90.2%), and metallic valvulotome in 156 (3.2%) patients. Their age range was 6.5-72 years (mean, 27.2 +/- 11.2 years) and 1,552 (32%) patients were under 20 years of age. Atrial fibrillation was present in 702 (14.5%) patients. No patient was rejected on the basis of echocardiographic score using the Wilkins criteria. Echocardiographic score of > or = 8 was present in 1,632 (33.6%) patients, of which 103 (2.1%) had densely calcified (Wilkins score 4+) valve. A detailed clinical and echocardiographic (two-dimensional, continuous-wave Doppler and color-flow imaging) assessment was done at every 3 months for the first year and at 6-month interval thereafter. The procedure was technically successful in 4,838 (99.8%) patients but optimal result was achieved in 4,408 (90.9%) patients with an increase in mitral valve area (MVA) from 0.7 +/- 0.2 to 1.9 +/- 0.3 cm(2) (P < 0.001) and a reduction in mean transmitral gradient from 29.5 +/- 7.0 to 5.9 +/- 2.1 mm Hg (P < 0.001). The mean left atrial pressure decreased from 32.1 +/- 9.8 to 13.1 +/- 6.2 mm Hg (P < 0.001). Although there was no statistically significant difference in the MVA achieved between de novo and restenosed valves (1.9 +/- 0.3 and 1.8 +/- 0.2 cm(2), respectively; P > 0.05), or between noncalcific and calcific valves (2.0 +/- 0.3 and 1.8 +/- 0.2 cm(2), respectively; P > 0.05), on the whole MVA obtained after percutaneous transvenous mitral commissurotomy was less in restenosed and calcific valves. Ten (0.20%) patients had cardiac tamponade during the procedure. Mitral regurgitation appeared or worsened in 2,038 (42%) patients, of which 68 (1.4%) developed severe mitral regurgitation. Urgent mitral valve replacement was carried out in 52 (1.1%) of these patients. Data of 3,500 patients followed over a period of 94 +/- 41 months (range, 12-166 months) revealed MVA of 1.7 +/- 0.3 cm(2). Elective mitral valve replacement was done in 34 (0.97%) patients. Mitral restenosis was seen in 168 (4.8%) patients, of which 133 (3.8%) were having recurrence of class III or more symptoms. Thus, percutaneous transvenous mitral commissurotomy is an effective and safe procedure with gratifying results in high percentage of patients. The benefits are sustained in a majority of these patients on long-term follow-up. It should be considered as the treatment of choice in patients with rheumatic mitral stenosis of all age groups.

Adolescent↗

PubMed2002

Estimation of the rate of osteogenesis by tetracycline double labeling in intertrochanteric fractures of the femur in different age groups and its correlation with radiological grading of osteoporosis.

Our aim was to estimate the rate of osteogenesis by using tetracycline double labeling and to correlate it with the radiological grading of osteoporosis in patients of intertrochanteric fracture of the femur in different age groups. Thirty-two cases of intertrochanteric fracture of the femur of either sex, without any associated osteopenic conditions, who were admitted for surgery constituted the clinical material. The cases were divided into three age groups: group I, <45 years; group II, 45-60 years; and group III, >60 years. Osteoporosis was graded in all groups on plain X-rays by Singh's index (SI) and metacarpal index (MI). The patients were labeled with a single large dose (1.5 g) of tetracycline orally on day 1 and day 8. An iliac crest bone biopsy specimen was obtained from each of the patients during surgical intervention. Thin undecalcified sections were made by the hand grinding technique. The sections were studied under UV light for presence of fluorescence, and rate of osteogenesis (mineral appositional rate, MAR) was calculated for each of the groups. Only 7 patients were found to have radiological osteoporosis (by Singh's index). The average MI and MAR were found to be 46.5% and 1.48 microm/day, respectively. The single-dose labeling schedule has shown good fluorescent bands, comparable to the conventional dose schedule. No correlation was found between Singh's index and metacarpal index in group I and III, whereas in group II it was significant. There is no significant correlation between the rate of new bone formation and the radiological grading of osteoporosis.

Adult↗

PubMed2002

Stents in the small intestine.

Stents represent an exciting development in the field of gastroenterology. Their use to maintain luminal patency in the pancreatobiliary system has been well established. Stents have also found a place in maintaining the patency of the esophagus. Recent developments have led to an increasing role for their use to decompress both the small and large intestine. In the small intestine they are often placed to palliate proximal obstruction in the duodenum or the very proximal jejunum resulting from various malignancies. Self-expandable metal stents are an attractive alternative to surgery, especially in patients with compromised performance status, and can be done safely as outpatient procedures. However, one should be aware of the associated risks and complications. With a proper understanding of the principles involved in stent placement one can safely undertake this procedure.

Biopsy, Needle↗

PubMed2002

Off-pump multivessel coronary artery surgery in high-risk patients.

BACKGROUND: Coronary artery bypass surgery on cardiopulmonary bypass is associated with significant morbidity and mortality, which may be more marked in high-risk patients. We evaluated our results of off-pump coronary artery bypass (OPCAB) in high-risk patients with multivessel coronary artery disease and compared them with results in similar patients who underwent operation on cardiopulmonary bypass. METHODS: A total of 1,075 patients who underwent OPCAB between October 1996 and June 2001 and who had one or more of the following risk factors were included in the study: poor left ventricular function (EF < or = 30%), advanced age (> 70 years), left main stenosis, acute myocardial infarction, and redo coronary artery surgery. These patients were compared with 2,312 similar patients who underwent coronary artery bypass grafting on cardiopulmonary bypass during the same period. Preoperative risk factors, intraoperative variables, and postoperative results were analyzed and compared between two groups. RESULTS: The average number of grafts was 3.0 +/- 0.4 and 3.2 +/- 0.3 in the off-pump (OPCAB) and on-pump (CCAB) groups, respectively. Hospital mortality was 3.2% and 4.5% in OPCAB and CCAB groups respectively (p = 0.109). Perioperative myocardial infarction, requirement of inotropic agents, stroke, and renal dysfunction were comparable in two groups. Intubation time (19 +/- 5 vs 24 +/- 6 hours, p < 0.001), mean blood loss (362 +/- 53 vs 580 +/- 66 mL, p < 0.001), atrial fibrillation (14.3 vs 19.7%, p < 0.001), and prolonged ventilation (4.6 vs 7.6%, p = 0.002) were less in OPCAB group. Intensive care unit stay (20 +/- 8 hours) and hospital stay (6 +/- 3 days) were significantly less in the OPCAB group (p < 0.001). CONCLUSIONS: Off-pump coronary artery surgery can be safely performed in high-risk patients with multivessel coronary artery disease. Operative mortality is comparable to that associated with on-pump surgery, and avoidance of cardiopulmonary bypass is associated with reduced postoperative morbidity in these patients.

Age Factors↗

PubMedDate not supplied