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Biomedical subjects

T S Vats

Publications and source records attributed to T S Vats.

At least 19 recordsLinked to original sources
PubMed1995

Psychosocial adjustment and the role of functional status for children with asthma.

This study examined the psychosocial adjustment of children with asthma compared to children with diabetes, with cancer, and healthy children and the role of functional status in psychosocial adjustment. The total sample included 100 children, aged 8-16 years, (mean = 11.5 years), consisting of 48 boys and 52 girls. Children with asthma scored significantly higher on measures of affective adjustment (depression and internalizing behavior), significantly lower on self-esteem, and evidenced significantly greater functional impairment. Children with cancer missed significantly more school days. After controlling for functional status, no significant differences remained in affective adjustment but absences remained significantly higher for the children with cancer.

Adaptation, Psychological↗
PubMed1990

Combination of radiation therapy and intracranial bleomycin in the 9L rat brain tumor model.

The rat 9L brain tumor model was used to investigate the therapeutic potential of a combined modality approach using intracranial Bleomycin and radiation therapy. Bolus Bleomycin was delivered intracranially into the tumor volume via cannula guides; for continuous infusions, osmotic mini-pumps were implanted subcutaneously between the scapulae with flexible tubing to deliver the drug directly into the tumor and brain. Two to six bolus injections of Bleomycin (1 unit/kg each) over 5-11 days produced modest (usually statistically significant, p less than 0.05) increases in the median survival time compared to controls. Continuous infusion of Bleomycin by osmotic pump (10 units/kg over 7 days or 15 units/kg over 14 days) was also effective at significantly increasing median survival times compared to that of controls. Radiation therapy schedules of 10 daily fractions in 12 days (2 weeks) or 10 twice-daily fractions in 5 days produced dose-dependent increases in median survival time. Multiple bolus injections of Bleomycin when combined with fractionated radiation therapy significantly increased the median survival time due to fractionated radiation therapy alone for low doses (40 or 50 Gy). However, at higher radiation doses, the addition of Bleomycin either had no effect on median survival time or actually shortened it. Continuous infusion of Bleomycin by osmotic pump was effective when added to low dose radiation therapy in several experiments, twice for a total radiation dose of 50 Gy and once for radiation therapy of 60 Gy. However, it was also observed (once for 60 Gy and twice for 70 Gy) that the addition of continuous infusion Bleomycin either had no effect or served to decrease the improvement of median survival time obtained by radiation therapy alone. Thus, we conclude that increases in normal tissue toxicity can prevent full attainment of improved therapeutic advantage from the addition of Bleomycin to fractionated radiation therapy in the rat 9L model. These results should be considered when attempts are made to combine radiation therapy and intracranial Bleomycin for the treatment of patients with primary malignant brain tumors.

Animals↗
PubMed1990

A phase I/II study of the use of Fluosol as an adjuvant to radiation therapy in the treatment of primary high-grade brain tumors.

The main objective of this study was to evaluate the safety and efficacy of a perfluorochemical emulsion, Fluosol, with short-term high inspired oxygen tension as an adjuvant to radiation therapy in the treatment of high-grade tumors of the brain. Radiation was delivered to the whole brain at 1.8 Gy per daily treatment for 5 weeks to a total dose of 45 Gy. The radiation portals were then reduced in size to encompass the known volume of tumor, as determined by the presurgical contrast-enhancing ring on computed tomography (CT), plus a 3-cm margin. An additional 10 treatments of 2 Gy each were given to the smaller volume, to bring the total tumor dose to 65 Gy in 7 weeks. This report describes the experience of the first 18 patients treated at the University of Kansas Medical Center on this study, whose median follow-up time from the date of surgery is 77 weeks (62-115 w). Immediately following Fluosol administration on a Monday, patients breathed 100% oxygen for at least 45 minutes prior to and throughout their radiation treatment. On each subsequent day of the weeks in which they received Fluosol, patients breathed 100% oxygen. Hematology and blood chemistries were also drawn prior to Fluosol treatment each Friday during treatment and at the 2-week, 3-month, and 6-month follow-up visits. The median age of the patients was 45 years (16-72); 13 patients were male and 15 carried the diagnosis of glioblastoma multiforme (3 had anaplastic astrocytoma). Two thirds of the patients had an initial allergic reaction to the Fluosol consisting of back pain, shortness of breath, and flushing, but all responded to 50-100 mg of Benadryl. During radiation therapy, all patients developed scalp erythema and complete alopecia by the end of 3 weeks, but no patient required a treatment rest. The serum levels of SGOT, SGPT, and alkaline phosphatase were examined before and throughout the Fluosol treatment and, by week 5, 11/18 of the patients had increased values of all three enzymes above the upper range of normal. These increases persisted through the end of treatment, but most values returned to essentially normal by the 3-month follow-up visit. We conclude that Fluosol, given in the manner described above, appears to be associated with minimal significant side effects and no changes could be detected in the white matter of any of the patients at the time of their magnetic resonance imaging study at 6 months follow-up.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Potentiation of rat brain tumor therapy by fluosol and carbogen.

We have been using the 9L rat brain tumor model to investigate the effect of the combination of a perfluorochemical emulsion, Fluosol-DA 20%, and carbogen breathing on the therapy of brain tumors. The combination of Fluosol, carbogen breathing, and carmustine (BCNU) was more effective at prolonging survival than was BCNU alone. This difference was small but significant (P less than 0.25). neither Fluosol without carbogen nor carbogen without Fluosol significantly altered the effect of BCNU. Fluosol and carbogen alone did not affect the survival of tumor-burdened rats. Fluosol and carbogen breathing did not alter the effect of single doses of radiation on these tumors. This result supports the hypothesis that 9L brain tumors contain few, if any, critical hypoxic cells. However, these tumors may contain cells which are oxygen deficient but not radiobiologically hypoxic. The Fluosol-carbogen combination may be changing the intratumor environment in such a way that the metabolism or activity of BCNU is altered.

Animals↗
PubMed1988

Effect of spirogermanium and radiation therapy on the 9L rat brain tumor model.

Spirogermanium (SPG) was investigated in the 9L rat brain tumor model in vivo and in vitro. Used at a single ip dose of 50 or 60 mg/kg or at 5 daily doses of 10 mg/kg, SPG was ineffective in prolonging survival of rats burdened with the intracerebrally implanted tumor, i.e., the median survival time (MST) was the same as that for the controls. Only a schedule of 3 X 20 mg SPG/kg every other day improved the MST compared with controls. Single-dose (20-Gy) radiation therapy (RT, cesium-137 whole-head irradiation) did prolong survival. However, when single-dose SPG was combined with RT (1 hr or 1 day before, or 1 hr after RT), the survival response was worse than after RT alone. When the daily SPG was combined with daily RT (5 doses of 6 Gy), survival was no better than after daily RT alone. In vitro, SPG produces a concentration-dependent, exponential decrease in cell survival as measured by colony formation assay. When combined with radiation, there is an additive effect on cell lethality. Aside from the possibility that SPG does not penetrate the rat brain tumor itself, we have no explanation why SPG shows some activity against human brain tumors and is cytotoxic against 9L cells in vitro, yet is both ineffective by itself and fails to potentiate RT in the 9L rat brain tumor model.

Animals↗
PubMed1986

Intraperitoneal bleomycin for ventriculoperitoneal spread of a hypothalamic astrocytoma.

A pediatric patient is presented in whom malignant ascites developed after ventriculoperitoneal shunt placement for a suprasellar astrocytoma. Paracentesis followed by intraperitoneal bleomycin resulted in decreased fluid re-accumulation with minimal side effects. A review of the literature shows that intracavitary chemotherapy, including bleomycin, can result in safe, effective relief of malignant effusion associated with adult tumors. We have demonstrated that such treatment is also applicable to the pediatric population. In this case, the effectiveness of intracavitary bleomycin may be related to its direct action against brain glioma cells. The need for effective treatment of malignant effusions in pediatric patients is growing because of their increased survival time with tumor. We propose that intracavitary bleomycin may provide relief from this potential complication of childhood solid tumors.

Astrocytoma↗
PubMed1985

Mitoxantrone in refractory acute leukemia in children: a phase I study.

Nine children with acute non-lymphocytic leukemia (ANLL), ages 16 months to 16 years (median 7 years), and 15 children with acute lymphocytic leukemia (ALL), ages 10 months to 18 years (median 5 years), were treated with 5-day courses of mitoxantrone (Novantrone; dihydroxyanthracenedione) as induction therapy. All the children had leukemia which was resistant to conventional therapy and all but one patient had received anthracycline therapy prior to the initiation of this trial. Three patients (two with ANLL, one with ALL) received the drug at a dose of 6 mg/m2/day i.v. for 5 days. Both patients with ANLL achieved partial remissions (PR) (105 and 87 days duration). The child with ALL failed to respond to two courses of the drug, and died of progressive disease 45 days after the institution of therapy. Twenty-one patients (14 with ALL, seven with ANLL) were treated with 8 mg/m2/day i.v. mitoxantrone for 5 days. There were three early deaths (all ALL) which were not felt to be secondary to drug toxicity. Four of the 18 children achieved complete remission (CR) (one ANLL - 35 days; three ALL - 39, 31 and 13 days). One child with ANLL achieved a PR (13 days) and one child with ALL showed improvement in his bone marrow status. Twelve children failed to respond to this therapy. Dose-limiting toxicity was not seen among the patients who received 6 mg/m2/day for 5 days. There were five patients who had mucositis and one patient who had nausea and vomiting among those patients who received 8 mg/m2/day for 5 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1984

Management of children with isolated testicular leukemia.

Since 1975, nine children with testicular leukemia were treated at the University of Kansas Medical Center on a standard protocol. Six patients presented with overt testicular leukemia and three patients had microscopic testicular leukemia detected on a biopsy done after 3 years of continuous complete remission. All patients had an M1 bone marrow at the time of testicular relapse and one patient had a concomitant central nervous system (CNS) relapse. Therapy consisted of testicular irradiation, CNS chemoprophylaxis, and systemic reinduction chemotherapy. Systemic maintenance therapy after the testicular relapse consisted of 6-mercaptopurine and methotrexate with vincristine/prednisone pulses administered in the same basic dose and schedule as the patient's original maintenance regimen. These nine patients had a mean duration of first remission of 33 months and a mean duration of second remission of 45+ months. Four patients have relapsed (two bone marrow, one CNS, one CNS + bone marrow), but five patients remain in their second complete remission for 33+ to 94+ months from the time of testicular relapse. These results demonstrate that, in some children, testicular leukemia represents a site of temporary drug resistance and long-term second remissions can be obtained (once local disease is controlled) by using the initial maintenance chemotherapy regimen.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Development of normal tissue damage in the rat subsequent to thoracic irradiation and prior treatment with cancer chemotherapeutic agents.

The effect of combined modalities (radiotherapy-chemotherapy) on the development of long-term normal tissue damage was investigated in rats. Animals received single I.P. injections of Hank's balanced saline solution, adriamycin (ADR, 1.0 mg/kg), bleomycin (BLM, 10 units/kg), or dihydroxyanthraquinone (DHAQ, 3.0 mg/kg); and/or irradiation of the chest with 25 MV x-rays (12 Gy) at 0, 43, 93, or 199 days after drug treatment. Only animals treated with DHAQ displayed appreciable toxicity, with more animals dying at less than 200 days when radiation was added at 0 or 43 days. Although animals treated with BLM or radiation exhibited evidence of lung damage (histologically by 199 days and radiographically by 300 days), their survival was not compromised. The simultaneous administration of x-ray and BLM produced enhanced effects as compared to either agent alone. These results demonstrate an enhancement of normal tissue damage by combined treatment with radiation and chemotherapeutic agents, not only for acute toxicity but also for long-term effects. This damage was ultimately expressed as alteration of lung structure (histologically and radiographically) in the case of BLM, and as animal lethality in the case of DHAQ. In addition, there was a reduction in the degree of enhancement observed as a function of the separation in time between treatment with chemotherapeutic agents and subsequent irradiation. These factors should be considered when combined modality therapy is used for treatment of cancer in the thoracic region.

Animals↗
PubMed1984

Angiotensin-I-converting enzyme in cancer patients.

Serum levels of angiotensin-I-converting enzyme (ACE) were assayed before, during, and after radiation therapy in 209 patients receiving treatment for neoplastic disease. Daily fluctuations in the measured ACE levels were minimized by comparing all patient values to that of a simultaneously run sample from a standard source of serum obtained by pooling sera from young, healthy volunteers. Most of the patients tested presented with a normal to low ACE level, with the mean value for all patients being 70% of the standard value. More patients with primary lung cancer displayed values that were low (107 of 120) than did patients with disease outside the lung (44 of 78), this difference being statistically significant at p less than 0.001. In addition, more patients with lung cancer had values less than 70% of the standard than did patients with disease outside the lungs. These initial results suggest that monitoring of serum ACE levels may be useful in the management of patients with malignant disease in the lung.

Female↗
PubMed1983

Bleomycin and brain tumors. A review.

A logical inference from the recent reports indicating that malignant brain tumors are composed of a heterogeneous cell population is that combination chemotherapy will be required for effective brain tumor control. For several years we have been investigating the use of Bleomycin as an agent to be used in conjunction with radiation therapy and a nitrosourea compound. Since systemically administered Bleomycin does not cross the blood-brain-barrier and has significant toxicity when used parenterally in high doses, we have studied the use of smaller doses of Bleomycin injected directly into the brain tumor cavity. Such an intracerebral dose was more effective in prolonging survival of rats burdened with experimental 9L gliosarcomas than an intravenous dose that is 25 times as great. The combination of intracerebrally administered Bleomycin and radiation therapy was more effective than either modality alone. Furthermore, the combination of Bleomycin delivered intracerebrally and BCNU given systemically was more effective than either agent used alone. Finally, in a Phase I clinical of Bleomycin given via an Ommaya reservoir to eight patients with recurrent malignant brain tumors, we have demonstrated that individual doses of up to 7.5 units and cumulative doses of up to 255 units can be administered without significant toxicity.

Adult↗
PubMed1981

Vindesine and prednisone for remission induction in children with acute lymphocytic leukemia.

Vinca alkaloids are effective anticancer agents. Vindesine is a recent vinca alkaloid derivative with anti-tumor effects shown in in vitro systems and in patients with acute lymphocytic leukemia (ALL). The present study was designed to investigate the therapeutic effectiveness and toxicity of vindesine in combination with prednisone for remission induction in late stage ALL in children. Sixteen children with late-stage ALL were treated with vindesine 4.0 mg/m2/week intravenously and prednisone 60 mg/m2/day orally in four divided doses for minimum of three weeks. Thirteen children were evaluable. Of these patients, four had complete remission and four had partial response. Toxicity was well tolerated and consisted of bone pain, paresthesias, loss of deep tendon reflexes, leukopenia, and thrombocytopenia primarily. Abnormal liver function tests and fever were also noted in some patients. All patients had received vincristine and prednisone prior to vindesine prednisone combination. All patients had been resistant to vincristine prednisone combination prior to vindesine prednisone treatment. This study suggests effectiveness of vindesine in late stage ALL and lack of cross-resistance of vindesine and vincristine.

Adolescent↗