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Biomedical subjects

M S Mahaley

Publications and source records attributed to M S Mahaley.

At least 37 records · Page 2Linked to original sources
PubMed1988

Specific chromosomal abnormalities in malignant human gliomas.

Karyotypic analysis of 54 malignant human gliomas (5 anaplastic astrocytomas, 43 glioblastoma multiformes, 3 gliosarcomas, 2 giant cell glioblastomas, 1 anaplastic mixed glioma) has demonstrated that 12 tumors contained normal stemlines or only lacked one sex chromosome. The 42 tumors with abnormal karyotypes included 38 tumors which could be completely analyzed. Six of these 38 cases had near-triploid or near-tetraploid stemlines and 32 had near-diploid stemlines. Statistically significant numerical deviations in the near-diploid group were gains of chromosome 7 (26 of 32; P less than 0.001), and losses of chromosome 10 (19 of 32; P less than 0.001). Double minutes occurred in 18 of 32 near diploid tumors. The distribution of structural abnormalities was analyzed statistically by comparing the incidence of breakpoint in each chromosomal arm to the expected value based on chromosomal arm length. This analysis demonstrated that structural abnormalities of 9p and 19q were significant statistically (P less than 0.005 and P = 0.02, respectively). Although chromosome 1, 6p, the centromeric region of chromosome 11, 13q, and 15q were also frequently involved in structural abnormalities, the incidence of these breaks did not reach statistical significance. This demonstration of specific chromosomal abnormalities in near-diploid gliomas provides the basis for the investigation of genes which may be quantitatively or qualitatively altered in these neoplasms.

Adult↗
PubMed1988

Systemic gamma-interferon therapy for recurrent gliomas.

Recombinant gamma-interferon (2 mg/sq m) was administered intravenously twice weekly in 8-week courses to 14 patients with recurrent gliomas. Computerized tomography (CT) evidence of response was seen in only one patient, and stabilization for 12 to 86 weeks was recorded in three. This was a disappointing result, particularly in a series of patients with relatively small initial tumor volumes (less than 50 cu mm on enhanced CT) and Karnofsky functional ratings of 70 or higher. In addition, several instances of toxicity potentially attributable to gamma-interferon were observed.

Acute Kidney Injury↗
PubMed1987

Effect of methylprednisolone on radiotherapy of F344 rats with avian sarcoma virus induced gliomas.

We have examined the impact of methylprednisolone acetate (MPA) on survival of F344 rats that were bearing avian sarcoma virus (ASV)-induced gliomas and that were treated optimally with radiotherapy. Toxicity of MPA (dose range of 0.2-5.0 mg/kg X 7 over 3 weeks) was first established in non-tumor bearing rats as assessed by their relative failure to gain weight. Doses of 2.0 or 5.0 mg/kg X 7 caused animals to be 21.8 or 43.9%, respectively, underweight compared with vehicle controls. In rats bearing ASV-induced gliomas, treatment with 3,000 cGY (nine fractions over a 3-week period) alone or with 0.2 or 1.0 mg MPA/kg (X 6 during the 3-week radiotherapy course) produced a significantly prolonged survival compared with that of untreated, tumor bearing rats. However, MPA did not enhance survival when given concurrently with radiotherapy; indeed, at the higher of these two doses, median survival of tumor-bearers was slightly less than with radiotherapy alone. This trend towards interference with the beneficial effects of radiotherapy was more pronounced with the highest dose of MPA studied, 5.0 mg/kg body weight X 6. These animals had a median survival time that was significantly less than that of tumor-bearers receiving radiotherapy alone, but not significantly different from untreated rats with gliomas. The possible significance of these observations is discussed.

Animals↗
PubMed1987

Complications following transfemoral cerebral angiography for cerebral ischemia. Report of 159 angiograms and correlation with surgical risk.

One hundred fifty-nine transfemoral cerebral angiograms for patients with carotid stenosis who subsequently underwent carotid endarterectomy were reviewed. No patient with an asymptomatic carotid bruit developed cerebrovascular complications during angiography. Patients with transient ischemic attacks (TIAs) had a 4.5% incidence of complications. Patients with stroke in evolution had a complication rate of 7.7%. Patients with completed strokes had no angiographic complications. No complication lasted more than 1 hour; all occurred during angiography or immediately afterwards. Stroke in progress has too high a surgical and angiographic risk to warrant study. Transient ischemic attacks have an acceptable morbidity both surgically and angiographically.

Carotid Artery Diseases↗
PubMed1987

Randomized phase III trial of single versus multiple chemotherapeutic treatment following surgery and during radiotherapy for patients with anaplastic gliomas.

In 81 patients with anaplastic supratentorial gliomas, single versus multiple chemotherapeutic agents were selected for treatment following surgery and during radiotherapy in a prospective randomized study. Time to treatment failure and survival were not significantly enhanced by multiple agent chemotherapy, as administered in this study.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Phase II diaziquone-based chemotherapy trials in patients with anaplastic supratentorial astrocytic neoplasms.

We treated 103 patients with histologically confirmed anaplastic supratentorial astrocytic neoplasms with either diaziquone (AZQ) and carmustine (BCNU) or AZQ and procarbazine. There were 74 patients with glioblastoma multiforme (GBM) and 29 patients with anaplastic astrocytoma (AA). AZQ plus BCNU produced partial (PR) or unequivocal responses in seven of 32 (21.9%) patients with GBMs and three of ten (30%) patients with AAs. Two patients with GBMs (6.3%) and five patients with AAs (50%) showed stable disease (SD). AZQ plus procarbazine produced PRs or unequivocal responses in five of 42 (11.9%) patients with GBMs and nine of 19 (47.4%) patients with AAs. Eight patients with GBMs (19%) and one patient with an AA (5.2%) showed SD. In addition to histologic diagnosis, only the Karnofsky performance-status (KPS) rating independently influenced response and survival. Differences in response rates between the two regimens were not significant, although estimated median survival after adjusting for performance status was slightly better with AZQ plus BCNU than with AZQ plus procarbazine (P = .031). Neither age nor prior chemotherapy were significant independent risk factors. Toxicity was mild and primarily hematologic. We conclude that these AZQ-based regimens have activity in patients with recurrent anaplastic gliomas, but that they are not clearly superior to other agents in current use. The histologic diagnosis of GBM is associated with a significantly worse prognosis than AA, and we believe that this important distinction must be recognized in phase II as well as phase III trials.

Adolescent↗
PubMed1986

Central neurotoxicity following intracarotid BCNU chemotherapy for malignant gliomas.

Central neurotoxicity is reported in 5 of 16 patients with recently diagnosed anaplastic gliomas, who received intra-arterial BCNU (200 mg/M2/course) and also 2 in a series of 26 patients with recurrent gliomas similarly treated. Neurotoxicity was usually delayed, commencing several weeks following the second or third course. CT scans during central neurotoxicity represented 1 or more of 3 patterns: no change; increased low density area(s); and/or ipsilateral gyral enhancement and punctate calcification in the middle cerebral artery territory. In one clinicopathological correlation, coagulative necrosis of the white matter was observed, identical histologically to those changes recognized as delayed vascular events following radiotherapy. Cautious exploration of the various clinical factors that may contribute to this toxicity seems appropriate, as exploration of the potential benefits of regional chemotherapeutic infusions is undertaken.

Brain Neoplasms↗
PubMed1986

Nalbuphine and droperidol in combination for sedation and prevention of nausea and vomiting during intra-carotid BCNU infusion.

A therapeutic regimen is described for sedative, analgesic, and anti-emetic effect in patients receiving intra-arterial carmustine (BCNU) for malignant gliomas. This regimen consists of nalbuphine, 30 mg, i.v., and droperidol, 2.5 mg, i.v., given immediately prior to intra-carotid BCNU infusion. Droperidol, 2.5 mg, i.v., is then administered on four hour intervals for sixteen hours post-procedure. This combination provided excellent effect in nine patients treated for twelve intra-carotid infusions. None of the nine patients experienced vomiting, one experienced mild nausea several hours post-infusion, and non complained of severe pain or discomfort. Thirteen additional patients received diazepam, 10 mg, P.O., prior to the intra-carotid BCNU infusion, with fentanyl, 100 mcg, i.v., and prochlorperazine, 10 mg, i.m. at the onset of infusion. All thirteen patients suffered from severe nausea, vomiting, and orbital pain. The nalbuphine/droperidol combination is thought to provide a superior alternative to the traditional narcotic/pheonothiazine/benzodiazepine combination for carotid BCNU infusion. This combination has theoretical advantages for the patient with intracranial mass lesions by providing analgesia and sedation with minimal potential for respiratory depression and carbon dioxide retention.

Adult↗
PubMed1986

Chromosomal evolution in malignant human gliomas starts with specific and usually numerical deviations.

Our previous karyotypic studies of malignant human gliomas have demonstrated that their most consistent early or primary gross changes include gains of #7, losses of #10, #22, and the gonosomes, and the presence of double minutes. Karyotypes of 15 additional malignant human gliomas reported here have confirmed these observations and, by enlarging our series, we can now show that in addition to double minutes, certain other gross structural abnormalities also are clearly associated with the early evolution of this type of tumor. The most prevalent deviations are deletions and translocations involving 9p. Other chromosomes commonly involved in rearrangements are #1, #6, and #13, and less frequently #7, #11, and #16.

Adult↗
PubMed1986

Efficacy of vincristine and cyclophosphamide in the therapy of recurrent medulloblastoma.

We conducted a Phase II study of combination therapy with vincristine and cyclophosphamide in the treatment of patients with recurrent or metastatic medulloblastoma. Fourteen patients were treated with vincristine 2 mg/m2 (2.0-mg maximal dose) by intravenous bolus on Day 1 and cyclophosphamide 1 g/m2 by intravenous infusion on Days 1 and 2, with cycles repeated every 4 weeks. All 4 patients with extraneural disease (biopsy-proven bony metastases) responded (duration of responses 2+, 6+, 8, and 16+ months) and 4 of 8 evaluable patients with neuraxis disease responded (duration of response 2, 2+, 2+, and 21+ months). Toxicity was limited to neutropenia without any episodes of infection. These therapeutic results compare favorably with other reports of therapy for recurrent medulloblastoma and support the inclusion of vincristine and cyclophosphamide in randomized adjuvant therapy trials of patients with medulloblastoma.

Adolescent↗
PubMed1986

Recognition of special qualifications in neurological surgery.

In recent years, one-half of the 23 recognized specialty boards in medicine have begun formally to recognize subspecialization with some type of certification process. One such board, the American Board of Internal Medicine, examines and certifies in 11 subspecialty areas while the American Board of Pathology does so in nine, the American Board of Pediatrics in eight, the American Board of Obstetrics and Gynecology in four, and the American Board of General Surgery in three. Arguments for and against similar recognition of subspecialization within neurosurgery are reviewed. The present position of other specialties and their boards regarding this sensitive issue is summarized, as well as their certification structure. The various pathways available to certifying boards for recognition of subspecialization are also presented. The American Board of Neurological Surgery (ABNS) has approved a subspecialty certificate called a "certificate of Special Qualification in Critical Care Medicine." This is a subspecialty that is longitudinally oriented, touching on a number of other specialties in addition to neurosurgery, and thus differs from a vertical subspecialty such as Pediatric Neurosurgery or Cerebrovascular Neurosurgery. The background for development of such a certificate and the current requirements for obtaining it are reviewed. At the present time, the ABNS opposes the possible fragmentation of neurosurgery by offering certification in multiple subspecialty areas. Nonetheless, the current trend in medicine as a whole is in the direction of such subspecialization and its formal recognition. Increasing numbers of neurosurgeons tend to concentrate all or a good deal of their professional efforts in a specific area. Thus, organized neurosurgery must continue to consider methods for subspecialty recognition.

Certification↗
PubMed1985

Complications following carotid endarterectomy for all indications: report of 192 operations.

The complications (stroke, myocardial infarction, and death) with 192 endarterectomies performed on 162 patients were evaluated and categorized according to the presenting syndrome: asymptomatic bruit, transient ischemic attack, stroke, stroke in progress, and posterior fossa ischemia. Each group's complication rate was then evaluated over several postoperative periods (0.5 hour to 30 days) and compared with rates in comparable studies. Overall mortality for the entire series was 0.5%. This study points out the need to separate patients having undergone endarterectomy into presenting groups before comparing with other studies having similar postoperative observations.

Carotid Artery Diseases↗
PubMed1985

Immunobiology of primary intracranial tumors. Part 10: Therapeutic efficacy of interferon in the treatment of recurrent gliomas.

Human lymphoblastoid alpha-interferon was administered intravenously or intramuscularly to 19 patients with recurrent gliomas. Each patient had previously undergone surgery and radiation therapy. The treatment course consisted of 8 weeks of therapy with an escalating daily dosage and number of days of treatment per week to a total dose of 900 X 10(6) U/sq m. Response to treatment was determined by serial computerized tomography (CT) scans. Seven of the 17 evaluable patients were determined to be treatment responders at 12 weeks (1 month after completion of treatment), and the other 10 patients exhibited tumor progression during this period. Median survival time was 511 days for the responders versus 147 days for the non-responding patients. Interferon appears to be efficacious in the treatment of recurrent anaplastic gliomas as defined by CT brain scan responses following therapy.

Adult↗