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Biomedical subjects

R Ravi

Publications and source records attributed to R Ravi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Growing teratoma syndrome.

Growing teratoma syndrome includes patients with enlarging metastatic masses, containing mature teratoma, following chemotherapy for advanced nonseminomatous germ cell tumors. The serum tumor markers in these cases, however, normalize during chemotherapy. Surgery is the treatment of choice and survivals approaching 100% have been achieved in these cases. Three patients with growing teratoma syndrome are described, the metastatic masses being in the retroperitoneum in all cases. Following surgery, all patients are alive without disease with a follow-up of 6-26 months.

Adult↗
PubMed1995

Patterns of MiB-1 staining of brain tumors: microwave-antigen retrieval as a tool in diagnostic pathology.

MiB-1 antibody staining can be carried out on formalin fixed, paraffin embedded tissue only if microwave antigen retrieval is performed. This method was used to identify proliferating cells in archival paraffin sections of 137 cases of human brain tumors. The tumors concerned were astrocytomas (57), glioblastomas (16), oligodendrogliomas (11), mixed gliomas (8), ependymomas (9), subependymoma (2), medulloblastomas (4) and meningiomas (30). For the tumors which were histologically graded (the astrocytomas, oligodendrogliomas and ependymomas), generally the scores of MiB-1 staining were correlated with the tumor grade, although there were exceptions to this rule, for example, a few low grade tumors displayed high MiB-1 counts while some highly malignant brain tumors failed to display any positive staining for MiB-1, despite having high mitotic counts. This phenomenon was probably due to loss of proliferating antigens. In the MiB-1 positive sections, hot spots with a high mitotic activity could be identified with ease and the abnormal morphology of the tumor nuclei and of the atypical mitoses were highlighted by the contrasting intensily brown staining. In addition, the dividing cell type could be easily identified and differences in mitotic behavior of invasive and necrotic parts of tumors could be observed.

Antigens, Nuclear↗
PubMed1994

Integrated approach to the management of patients with advanced germ cell tumors of the testis.

Between 1985 and 1991, 63 patients with disseminated germ cell tumors of the testis were treated with initial cisplatin based combination chemotherapy. Complete response was seen in 38% of patients. Adjunctive surgical resection of residual disease was carried out in 26 patients (41%), including the use of intraoperative radiation therapy in two patients with seminoma. Furthermore, two other patients with seminoma and residual mass underwent retroperitoneal irradiation. Salvage chemotherapy was administered to five patients with progressive disease, and only one of these could be salvaged with adjunctive surgery. A disease-free state was achieved in 75% of patients at a mean follow-up period of 30 months.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Endoscopic neodymium:YAG laser treatment of radiation-induced hemorrhagic cystitis.

Hemorrhagic cystitis is a debilitating complication of radiation therapy for pelvic malignancy. Forty-two such patients with intractable hematuria underwent endoscopic Nd:YAG laser coagulation under local anesthesia between January 1990 and July 1992. The laser power was kept at < or = 30 W and the pulse duration < or = 3 s. Control of bleeding was achieved in 39 patients after one sitting and in 2 patients after two sittings of laser treatment. There were no complications of the procedure and recurrence of bleeding was not seen in any of the patients achieving CR at a mean follow-up period of 14 months. With modifications in the safety guidelines, we recommend laser treatment as the initial procedure of choice in patients with hemorrhagic radiation cystitis.

Adult↗
PubMed1994

Transverse colon conduit urinary diversion in patients treated with very high dose pelvic irradiation.

OBJECTIVE: To study the results of transverse colon conduit urinary diversion in patients receiving very high dose pelvic irradiation (> or = 65 Gy). PATIENTS AND METHODS: Records were reviewed for 30 such patients who underwent transverse colon conduit as a primary form of urinary diversion between January 1986 and June 1992. Most of the conduits were constructed using refluxing ureterocolic anastomoses with stents. RESULTS: There was no operative mortality. Although the procedure was associated with a complication rate of 37% and a re-operation rate of 20%, there were no bowel or urinary anastomotic leaks. The operation could be safely performed on patients with renal failure, with 83% of such patients showing normal or improved serum creatinine levels post-operatively. CONCLUSION: The advantages of transverse colon conduit urinary diversion are the use of non-irradiated bowel and ureters for diversion. We recommend it as a primary form of urinary diversion in these high risk cases.

Adult↗
PubMed1994

Role of radiation therapy in the treatment of carcinoma of the penis.

OBJECTIVE: To study the effectiveness of radiation therapy (RT) for the primary tumour and for groin node and distant metastases in patients with squamous cell carcinoma of the penis. SUBJECTS AND METHODS: Between January 1959 and June 1988, 156 patients with negative lymph nodes in the groin underwent RT of the primary tumour. RT was also administered to 120 patients with lymph node involvement in the groin and to nine with distant metastases. RESULTS: Local control of the primary tumour was achieved in 65% of patients with RT alone and in another 33% with salvage surgery. Lymph node recurrence in the groin was seen in 11% of patients and the corrected 5-year disease-free survival was 87%. Pre-operative inguinal RT was useful in patients with mobile lymph nodes > or = 4 cm in size in the groin, with only 8% of such lymphadenectomy specimens showing perinodal infiltration and only 3% of such patients having post-operative groin recurrences. Pelvic and/or para-aortic RT was ineffective in patients with pelvic node metastases. Palliative RT resulted in amelioration of symptoms in 56% of patients with fixed lymph nodes in the groin, all five patients with painful bony metastases and one of two patients with cord compression and paraplegia. CONCLUSION: Radiation therapy is ideal for patients with T1 and T2 primary cancers of the penis. Pre-operative RT is useful for patients with mobile lymph nodes > or = 4 cm in size in the groin. RT provides effective palliation in patients with advanced regional disease and/or distant metastases.

Brachytherapy↗
PubMed1994

Identification of A1 adenosine receptors in rat cochlea coupled to inhibition of adenylyl cyclase.

A1 adenosine receptors (A1ARs) are found in a number of tissues in the body where their physiological roles have been identified. In the cochlea, neither the existence of these receptors nor a physiological role of adenosine has been described previously. Membranes prepared from rat cochlea demonstrated high affinity and saturable binding to N6-2-(4-amino-3-[125I]iodophenyl)ethyladenosine ([125I]APNEA), an A1AR agonist, with maximum binding capacity and dissociation constant values being 40.5 +/- 0.5 fmol/mg protein and 1.28 +/- 0.03 nM, respectively. Adenosine analogues competed for [125I]APNEA binding sites with a rank order of potency characteristic of these sites being the A1AR. The [125I]APNEA binding was significantly reduced by pertussis toxin, indicating coupling of these receptors with the Gi and/or Go proteins in cochlear membranes. Photoaffinity labeling of the receptor protein with the A1AR agonist N6-2-(4-azido-3[125I]iodophenyl)ethyladenosine showed specific labeling of a 36-kDa receptor protein. Activation of the A1AR with R-phenylisopropyladenosine (R-PIA) led to inhibition of forskolin-stimulated adenylyl cyclase activity. Amplification of reverse-transcribed RNA derived from cochlear tissue by polymerase chain reaction (using primers for the bovine A1AR) yielded a 770-bp product that hybridized to an A1AR cDNA probe on Southern blots. These data indicate the presence of an inhibitory receptor in the peripheral auditory system, which may play an important role in modulating auditory functions.

Adenylyl Cyclase Inhibitors↗
PubMed1994

Incidentally detected renal cell carcinoma in patients with other cancers.

Widespread imaging of the kidneys as part of an abdominal or abdominopelvic evaluation of other diseases has led to a marked increase in the incidence of serendipitous renal cell carcinoma. These tumors are generally small, of low pathological stage, and carry a better prognosis than symptomatic cancers. This may merely be due to their earlier detection than the usual renal cell carcinoma. The malignant potential of these tumors, however, might still be high. We report 2 cases of incidentally detected renal tumors in patients with other cancers.

Adenocarcinoma, Clear Cell↗
PubMed1993

Second primary bladder cancer following pelvic irradiation for other malignancies.

Between 1985 and 1990, five cases of radiation-induced bladder cancer were treated at our center. The first primary neoplasm was uterine cervical cancer in three patients, uterine endometrial cancer in one patient, and Hodgkin's disease in one patient. Additional treatment for the primary neoplasm included panhysterectomy for the patient with endometrial cancer and cyclophosphamide-based combination chemotherapy for the patient with Hodgkin's disease. The mean age at development of bladder cancer was 60.4 years, and the average time interval between irradiation and development of bladder cancer was 14.6 years. All the bladder cancers were invasive. The treatment modalities included anterior pelvic exenteration in one patient, partial cystectomy in one patient, reirradiation in two patients, including the use of intraoperative electron therapy in one patient, and TUR plus endoscopic Nd:YAG laser treatment in one patient. Four patients are alive without disease at a mean follow-up period of 15 months from the diagnosis of bladder cancer.

Adenocarcinoma↗
PubMed1993

Intravesical formalin for hemorrhagic cystitis following irradiation of cancer of the cervix.

OBJECTIVE: To determine the effectiveness of intravesical formalin instillation in hemorrhagic cystitis following irradiation of cancer of the cervix. METHOD: Records were reviewed for 35 patients with hemorrhagic radiation cystitis who underwent treatment with 1% (n = 22), 2% (n = 10), and 4% formalin (n = 4), using Fair's technique. RESULT: Complete response was seen in 31 patients (89%) and partial response in 3 patients (8%) after a single instillation. Minor complications were seen in 19 patients (54%). Major complications occurred in 11 patients (31%), with 5 cases requiring subsequent urinary diversion. One patient died of persistent bleeding and probable formalin toxicity. Hematuria recurred in 7 patients achieving complete response at a mean period of 8 months after treatment. A 1% solution was as effective in controlling hematuria as higher concentrations and was associated with significantly less morbidity. CONCLUSION: Intravesical instillation of 1% formalin is an effective treatment for intractable hematuria secondary to radiation cystitis.

Administration, Intravesical↗
PubMed1993

Correlation between the extent of nodal involvement and survival following groin dissection for carcinoma of the penis.

Between 1962 and 1986, 208 inguinal and 143 ilio-inguinal lymphadenectomies were performed on 201 patients with carcinoma of the penis. The crude 5-year survival rate was 95% for patients with negative nodes, 76% when only inguinal nodes were positive, and 0% when the pelvic nodes were positive. The adverse prognostic factors were (1) involvement of > 3 inguinal nodes, (2) perinodal infiltration in the inguinal area, and (3) pelvic node involvement.

Groin↗
PubMed1993

Morbidity following groin dissection for penile carcinoma.

From 1962 to 1990, 231 inguinal and 174 ilio-inguinal lymphadenectomies were performed on 234 patients with penile carcinoma. The morbidity of inguinal lymphadenectomy included wound infection in 18%, skin edge necrosis in 61%, seroma formation in 5% of dissections, and lymphoedema in 25% of limbs. The morbidity of ilio-inguinal lymphadenectomy included wound infection in 14%, skin edge necrosis in 64%, seroma formation in 9% of dissections, and lymphoedema in 29% of limbs. Pre-operative radiation to the groin significantly increased the healing complications. The routine use of a myocutaneous flap for primary reconstruction of the groin following ilio-inguinal lymphadenectomy resulted in 100% primary wound healing and significantly reduced the post-operative hospital stay to a mean of 10 days.

Humans↗
PubMed1993

Primary angiosarcoma of the urinary bladder.

Angiosarcoma of the urinary bladder is an extremely rare neoplasm with only 5 cases having been reported in literature so far. The etiologic factors implicated in visceral angiosarcoma are exposure to thorium dioxide, arsenic, polyvinyl chloride, irradiation, chemotherapy and the presence of retained foreign body material. The histologic picture is characterised by irregular vascular channels showing anastomoses and lined by atypical endothelial cells. The prognosis of this neoplasm is uniformly poor. Herein we report a case of primary angiosarcoma of the bladder in a man who had no prior exposure to any of the etiologic factors and is disease free 8 months after treatment with partial cystectomy and adjuvant postoperative pelvic irradiation.

Hemangiosarcoma↗
PubMed1993

Prophylactic lymphadenectomy vs observation vs inguinal biopsy in node-negative patients with invasive carcinoma of the penis.

From 1962 to 1984, 423 patients with invasive penile cancer and negative groin nodes were subjected to prophylactic lymphadenectomies (n113), observations (n258) or inguinal biopsies (n52) in a non-randomised fashion. The numbers of patients with T2, T3 and T4 lesions were similar in the three groups. The overall five-year disease-free survivals were 94, 93 and 85%, respectively. All groin recurrences in the observation group occurred within 18 months of the surgery for the primary tumor. The five-year disease-free survivals of node-positive patients in the lymphadenectomy and observation groups were 100 and 76%, respectively; three patients in the latter group had refused surgical treatment when their adenopathy was mobile. Morbidity from the prophylactic lymphadenectomies included wound breakdown in 61%, wound infection in 18% and lymphedema in 25% of patients. We feel that neither prophylactic lymphadenectomy nor inguinal biopsy are justified in these patients. Close observation of the groin nodal status would be appropriate.

Adult↗