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Biomedical subjects

A Padmanabhan

Publications and source records attributed to A Padmanabhan.

18 recordsLinked to original sources
PubMed2002

T-level downstaging and complete pathologic response after preoperative chemoradiation for advanced rectal cancer result in decreased recurrence and improved disease-free survival.

PURPOSE: Preoperative chemoradiation therapy is used widely in the treatment of rectal cancer. The predictive value of response to neoadjuvant remains uncertain. We retrospectively evaluated the impact of response to preoperative and, specifically, of T-level downstaging, nodal downstaging, and complete pathologic response after chemoradiation therapy on oncologic outcome of patients with locally advanced rectal cancer. METHODS: There were 88 patients with ultrasound Stage T3/T4 midrectal (n = 37) and low rectal (n = 51) cancers (63 males; mean age 62.6 years). All patients were treated by preoperative 5-fluorouracil-based chemotherapy and pelvic radiation followed by surgical resection in six weeks or longer (56 sphincter-preserving resections). RESULTS: T-level downstaging after neoadjuvant treatment was demonstrated in 36 (41 percent) of 88 patients, and complete pathologic response was observed in 16 (18 percent) of the 88. Of the 42 patients with ultrasound-positive nodes, 27 had no evidence of nodal involvement on pathologic evaluation (64 percent). The overall response rate (T-level downstaging or nodal downstaging) was 51 percent. At a median follow-up of 33 months, 86.4 percent of patients were alive. The overall recurrence rate was 10.2 percent (three patients had local and six had metastatic recurrences). Patients with T-level downstaging and complete pathologic response were characterized by significantly better disease-free survival (P = 0.03, P = 0.04) and better overall survival (P = 0.07, P = 0.08), according to Wilcoxon's test comparing Kaplan-Meier survival curves. None of the patients with complete pathologic response developed recurrence or died during the follow-up period. CONCLUSION: T-level downstaging and complete pathologic response after preoperative chemoradiation therapy followed by definitive surgical resection for advanced rectal cancer resulted in decreased recurrence and improved disease-free survival. Advanced rectal cancers that undergo T-level downstaging and complete pathologic response after chemoradiation therapy may represent subgroups that are characterized by better biologic behavior.

Adenocarcinoma↗
PubMed2001

High prevalence of microcytic anaemia in Omani children: a prospective study.

Iron deficiency is a common cause of microcytic anaemia. However, a high prevalence of haemoglobinopathies in the Arab population makes differential diagnosis difficult. This prospective study of anaemia in children attending a regional hospital in the Sultanate of Oman looked at the prevalence and causes of anaemia in 256 children, 153 in the age group 3-5 years (group A) and 103 in the age group 10-12 years (group B). Of the children studied, 45.1% in group A and 37.9% in group B were anaemic according to WHO criteria. All the anaemic children had low mean corpuscular haemoglobin and 75% showed microcytosis. Serum ferritin levels were normal and glucose-6-phosphate dehydrogenase deficiency did not contribute to the anaemia. The microcytosis and microcytic anaemia in the study population could be attributed to the alpha-thalassaemia trait which is highly prevalent in Oman. The information is of value in any country where there is a significant prevalence of alpha-thalassaemia genes because these can confound the diagnosis of iron deficiency.

Anemia, Iron-Deficiency↗
PubMed1999

Reconstruction of rectovaginal fistula with sphincter disruption by combining rectal mucosal advancement flap and anal sphincteroplasty.

PURPOSE: This study evaluated the effectiveness of combining advancement flap with sphincteroplasty in patients symptomatic with rectovaginal fistula and anal sphincter disruption. METHODS: Twenty patients with rectovaginal fistulas and anal sphincter disruptions after vaginal deliveries underwent combined rectal mucosal advancement flap and anal sphincteroplasty between July 1986 and July 1993. The mean age of the patients was 30 (range, 18-40) years and the mean duration of symptoms was 54.8 weeks (range, 7 weeks to 6 years). In addition to mucosal advancement flap repair, 13 patients underwent two-layer repair of anal sphincters (with reapproximation of the puborectalis in 8 of the patients); 6 patients underwent one-layer overlap repair of anal sphincters (with reapproximation of the puborectalis in 2 of the patients); and 1 patient underwent reapproximation of internal anal sphincter alone because squeeze pressures were adequate, as determined by anal manometry. RESULTS: Postoperatively, vaginal discharge of stool and flatus was eliminated entirely in all 20 patients. Perfect anal continence of stool and flatus was restored in 14 patients (70 percent). Incontinence was improved but not eliminated in six patients (4 incontinent to liquid stool and 2 to flatus), and two patients required perineal pads. Subjectively, 19 patients (95 percent) reported the result as excellent or good. There were no complications. CONCLUSION: The combination of mucosal advancement flap and anal sphincteroplasty is a safe and highly effective procedure for correcting rectovaginal fistula with sphincter disruption after obstetrical injuries.

Adolescent↗
PubMed1993

Expression of Chinese hamster cAMP-dependent protein kinase in Escherichia coli results in growth inhibition of bacterial cells: a model system for the rapid screening of mutant type I regulatory subunits.

The regulatory and catalytic subunits of cAMP-dependent protein kinase (PKA) were coexpressed within the same bacterial cell using a polycistronic bacterial T7 expression vector encoding Chinese hamster cDNAs for the type I regulatory (RI) and catalytic alpha (C alpha) subunits of PKA. Basal expression of active RI/C alpha holoenzyme in the BL21(DE3) strain of Escherichia coli caused severe growth inhibition resulting in extremely small colony size. Several lines of evidence demonstrate that this growth inhibition requires active PKA subunits and cAMP: (i) this phenotype is dependent on cAMP since it is not seen in a strain lacking adenylyl cyclase activity, but the growth rate of these transformants is slower when exogenous cAMP is added; (ii) normal growth occurs when wild-type RI cDNA is replaced by a mutant RI cDNA encoding a RI protein with reduced cAMP binding; and (iii) the growth-inhibited phenotype of the transformed BL21(DE3) cells requires soluble, active C alpha protein. Holoenzyme expressed in bacteria is activated by cAMP, which stimulates phosphorylation of an endogenous 50-kDa protein that is missing in four host mutants selected for normal growth after transformation with PKA holoenzyme. A mutant RI cDNA library was generated by PCR random mutagenesis and screened by polycistronic expression in BL21(DE3) cells. The RI cDNA sequence from one revertant has base-pair substitutions creating two amino acid substitutions within the cAMP binding sites. The coexpression of the RI/C alpha subunits in BL21(DE3) bacterial cells provides a system for rapidly selecting mutations in the RI subunits of PKA.

Animals↗
PubMed1991

Abdominal colon and rectal operations in the elderly.

Sixty-seven abdominal operations for colon and rectal disorders were performed on 56 patients 80 years of age or older from January 1, 1984 to June 30, 1989. Nine patients required multiple operations. Sixty-two procedures (92 percent) were performed on patients in their ninth decade; two operations were performed on patients 95 years of age or older. Forty-five patients (80 percent) were operated upon for carcinoma. Operations included segmental colectomy (33 patients), low anterior resection (12 patients), total abdominal colectomy (3 patients) and abdominoperineal resection (2 patients). Forty patients were classified as ASA Class III; the majority were monitored in the surgical intensive care unit for a mean of 2.84 days. Thirty patients were monitored with arterial catheters and 21 with central invasive monitoring. Operative mortality was 7 percent (4 patients). Two patients died from diffuse carcinomatosis; one patient had a fatal myocardial infarction. The final death occurred from multisystem organ failure following anastomotic dehiscence. Twenty-seven operations were performed without postoperative complications; 18 operations were followed by a single minor complication. The average hospital stay was 18.96 days. All patients were admitted from home. Thirty-three returned home postoperatively; 16 were discharged to an extended care facility. In conclusion, elderly patients with colon and rectal disorders can be operated upon with acceptable morbidity and mortality. Age alone should not interdict surgical therapy.

Abdomen↗
PubMed1991

Squamous-cell carcinoma of the anal canal: management with combined chemo-radiation therapy.

Twenty patients with squamous-cell carcinoma of the anal canal received combined chemo-radiation therapy as their primary treatment. There were 18 women and two men with a mean age of 63 years (range, 34-91 years). The mean follow-up was 34 months (range, 6-62 months). Anal margin cancers and adenocarcinomas were excluded. Fourteen of 20 patients treated had a complete response. There were six local failures: three with residual disease at the end of treatment and three with recurrent disease at a later date. Of the three with residual disease, one underwent abdominoperineal resection and two received salvage therapy (one with chemo-radiation and one with radiation alone). All three patients with recurrent disease were treated with abdominoperineal resection. All six were disease free at the end of the study. Of the 14 patients with complete local response, one presented with liver metastases 19 months later. Sixteen patients (80 percent) were alive at the end of the study, and 19 patients (95 percent) had no evidence of disease. These data add support for salvage therapy in the treatment of patients with residual disease following initial chemo-radiation therapy. Salvage options for patients with squamous-cell carcinoma of the anus who fail the Nigro protocol will be discussed.

Adult↗
PubMed1991

Surgical treatment of low rectovaginal fistulas.

Forty women with low rectovaginal fistulas were operated upon over a 9-year period. The etiology of the fistula in the majority was obstetric. Nine women had prior attempts to repair the fistula. All 40 women were managed with endorectal advancement flap with the addition of sphincteroplasty or perineal body reconstruction in 15 patients and rectocele repair in six patients. Postoperative complications included urinary difficulties (two patients) and wound complications (three patients). There were two recurrences. All women treated with sphincteroplasty or perineal body reconstruction were continent. Seven women complained of varying degrees of incontinence postoperatively; none had undergone sphincter or perineal body reconstruction. Endorectal advancement flap is a safe and effective operation for women with rectovaginal fistulas. Concomitant sphincteroplasty or perineal body reconstruction should be performed in women with historical, physical, or manometric evidence of incontinence.

Adult↗
PubMed1989

Radiotherapy alone and chemoradiation for nonmetastatic esophageal carcinoma. A critical review of chemoradiation.

Sixty-five patients with nonmetastatic (Stages I, II, and III) esophageal cancer (EC) were treated with radiotherapy (RT) alone (56.00 to 61.00 Gy in 6 to 7 weeks) or synchronous combinations of radiotherapy and chemotherapy (RT-CT). RT-CT consisted of 41.40 to 50.40 Gy in 4.5 to 8 weeks with continuous infusion 5-fluorouracil 5-FU (1000 mg/m2/d for 4 days in weeks 1, 4, and 8), mitomycin C (10 mg/m2 intravenously [IV] in weeks 1 and 8), cisplatin (75 mg/m2 IV in week 4). Maintenance CT consisted of methotrexate (200 mg/m2 IV), leucovorin (10 mg/m2 orally every 6 hours for 5 doses), and 5-FU (600 mg/m2 IV) in weeks 10, 12, and 14. Thirty-five patients treated by RT alone (Group A) were comparable in terms of age, sex, AJC staging, histologic condition, and location of primary with 30 patients treated by RT-CT (Group B). In Group A (range, 2- to 144+ months), two patients (42 and 144 months) are alive and well. In Group B (range, 2- to 59+ months), 12 patients (7 to 59 months) are alive and well. Median survival in Group A is 8 months, compared with 15 months for patients achieving a complete response (CR) in Group B. Patients in Group B achieved a 77% CR rate by endoscopy-biopsy, whereas 30% of the patients in Group A achieved a CR (P = 0.0001). The recurrence rates at the primary site/regional nodes were 77% and 27% in Groups A and B, respectively (P = 0.0001). The incidences of distant metastases were 29% and 20%, respectively (P = 0.423). In Group A, the 1-year and 2-year cumulative survival rates were 27% and 13%, respectively. In Group B, the cumulative survival rates were 53% at 1 year and 29% at 2 years (P = 0.023). Aside from reversible myelotoxicity, the incidences of pulmonary fibrosis, esophagitis, and fistulae formation were less frequent in the combined technique treatment group. A compilation of reported chemoradiation protocols for EC indicates consistently improved 1-year and 2-year survival rates, compared with surgical and RT series. The key to further improvement in the treatment of EC appears to lie in increasing the biologic response (RT fractionation and endocavitary RT) and optimal use of multiple effective CT agents with nonadditive toxicities.

Adenocarcinoma↗
PubMed1987

Preliminary results of concomitant radiotherapy and chemotherapy in advanced cervical carcinoma.

Ten patients with advanced and previously untreated squamous cell carcinoma of the cervix were treated with a synchronous course of radiotherapy (RT) and chemotherapy (CT). RT consisted of 3600 to 4500 cGy external pelvic treatments on a 6-MeV linear accelerator followed by two intracavitary applications administering a total of 4000 mg hr of radium equivalent cesium. CT consisted of a course of mitomycin C (10 mg/m2 iv bolus) and 5-fluorouracil (5FU; 1000 mg/m2/24 hr for 96 hr) during the second week of external RT and another course of cis-platinum (CDDP; 75 mg/m2, 1-6 hr infusion) and 5FU (1000 mg/m2/24 hr for 96 hr) during the first intracavitary cesium application. Toxicity was acceptable and complete clinical response was obtained in all patients at the end of the regimen. Nine patients are alive (eight without disease) 6 to 37 months following initiation of treatment (median 20 months). One patient has developed lumbar spine bone metastases and another died of local and pulmonary disease at 28 months. This combination of 5FU/mitomycin C/CDDP and RT appears to be a practical, well-tolerated, and highly effective regimen for advanced cervical carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Clear cell myeloma.

We report a case of clear cell myeloma misinterpreted at initial biopsy as liposarcoma. The patient had lytic skeletal lesions and monoclonal IgA, kappa, serum immunoglobulin. The tumor cells contained cytoplasmic vacuoles that produced a clear histologic appearance. The light-microscopic and ultrastructural findings are compared with those of other cases of lymphoplasmacytic disorders with prominent cytoplasmic inclusions.

Aged↗
PubMed1983

Malignant hemangiopericytoma of the gallbladder.

A rare case of malignant hemangiopericytoma in the gallbladder is described perhaps for the first time in the literature. Areas of necrosis, mitotic activity within the tumor, and the presence of metastases in the regional lymph nodes and right ovary suggest an aggressive behavior of the tumor and poor prognosis.

Adult↗
PubMed1983

Extraskeletal Ewings sarcoma.

A case of Ewings sarcoma arising in the soft tissue of the thumb is described. This appears to be the first case of digital extraskeletal Ewings sarcoma. The soft tissue location, the primary rather than metastatic nature, and the tumor type in this case were well documented.

Adenocarcinoma↗
PubMed1983

Pancoast syndrome caused by extramedullary plasmacytoma.

A 61-year-old patient had the clinical findings of Pancoast syndrome with shoulder pain, weakness and atrophy of band muscles, and an opacified area in the apical lung field. Unlike most cases with Pancoast syndrome in which the tumors are primary carcinomas of the lung, the present case was shown to have a plasmacytoma involving the apical parietal pleura and the adjacent chest wall. The need for histologic diagnosis before treating patients with Pancoast syndrome is emphasized.

Humans↗
PubMed1980

Role of endoscopy in upper gastrointestinal bleeding in patients with malignancy.

A retrospective review of upper gastrointestinal bleeding in 55 patients with malignant disease is presented here. Major causative factors seem to be superficial gastritis and gastric erosions. With aggressive endoscopy, a diagnostic accuracy of 90 percent has been achieved. However, having the exact diagnosis too often has little significance on the final outcome of these critically ill patients, unless therapy directed against bleeding can provide time for effective antineoplastic treatment. With the better understanding of the pathology of the superficial gastric erosions, a better program of management can be evolved.

Adult↗
PubMedDate not supplied

Thymoma: a pathological study of 50 cases.

BACKGROUND: A combination of epithelial cells and lymphocytes results in a varied histomorphology of thymomas and consequent varied classification systems. AIM: To correlate the Marino and Muller-Hermelink (MMH) classification with the invasive behaviour of thymomas. SETTING AND DESIGN: Retrospective analysis. MATERIALS AND METHOD: Thymomas encountered in the past 21 years were re-classified with the MMH classification and correlated with Masaoka's staging and clinical presentation. RESULTS: The thymomas formed 91% of the primary thymic epithelial tumours. Predominantly cortical thymomas (n=21) and cortical thymomas (n=22) were the common subtypes and 60% and 77% of these, respectively, were in stages II or III. Cystic change, necrosis or haemorrhage played no role in predicting invasive behaviour. Cortical epithelium correlated well with the presence of para-thymic syndromes, especially myasthenia gravis. CONCLUSION: MMH classification is easy to apply. Cortical thymomas in stage I should be followed up for possible recurrence.

Adolescent↗