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Biomedical subjects

S Kramer

Publications and source records attributed to S Kramer.

At least 163 records · Page 9Linked to original sources
PubMed1981

Combined pre- and postoperative adjuvant radiotherapy for bladder cancer: results of RTOG/Jefferson Study.

This paper presents the results of adjuvant "sandwich" radiotherapy for bladder cancer in 65 patients treated in a Radiation Therapy Oncology Group (RTOG) phase II study and at Thomas Jefferson University Hospital. In this approach of adjuvant therapy, patients with clinical stages B or C bladder cancer were given low dose preoperative irradiation (500 rads) to the whole pelvis on the day before or on the day of surgery. Following cystectomy, patients were pathologically staged. Those with high grade (III or IV) stage B1 tumors or stages B2 or C were given 4500 rads in five weeks postoperative radiation. Thirty-four of these 65 patients were entered in the RTOG protocol and 31 in the Jefferson Study. TWenty patients had early lesions (stage 0, A or B1, grade I-II) and did not receive postoperative irradiation. Six patients had stage D cancer and were given palliative therapy. Of 39 patients eligible for postoperative irradiation, 29 received the full course of pre- and postoperative irradiation. Ten patients did not receive treatment. Follow-up ranged from six months to three years with a median of 18 months. Treatment was extremely well tolerated. Incidence of major complications was 6% (4/65). Local control of disease was excellent, with no failures in pelvis response. Actuarial survival at three years is 78%. At this preliminary analysis, these survival results appear to be better than those obtained with other approaches using preoperative irradiation and surgery.

Clinical Trials as Topic↗
PubMed1981

Neurotoxicity of folates: implications for vitamin B12 deficiency and Huntington's chorea.

Recent work has shown that several folates interact with excitatory kainic acid receptors in the mammalian brain and appear to have agonist activity at these receptors. Since kainic acid is a potent neurotoxin it is possible that folates share this toxicity and that high levels of folates result in neuronal damage. Levels of methyltetrahydrofolate are markedly elevated in vitamin B12 deficiency, a disease associated with neuronal destruction. We propose that this destruction occurs as a result of a neurotoxic action of methyltetrahydrofolate. Injection of kainic acid into the basal ganglia of experimental animals produces a pattern of damage similar to that found in patients dying of Huntington's chorea. It is possible that the underlying defect in this disease resides in the pathways of folate metabolism such that a neurotoxic excess of folates accumulates in the central nervous system. Such a disease process might be arrested by antifolate drugs.

Animals↗
PubMed1980

Postirradiation sarcoma of the head and neck: a report of three late sarcomas following therapeutic irradiation for primary malignancies of the paranasal sinus, nasal cavity, and larynx.

Sarcoma of the head and neck region following irradiation for primary malignancy other than retinoblastoma has rarely been reported. Three cases of postirradiation sarcoma arising in the head and neck region following definitive radiotherapy for primary malignancies of the nasal cavity, paranasal sinuses, and larynx are presented. The intervals from initial radiation to diagnosis of sarcoma were 10 years, 10 1/2 years, and 12 1/2 years, respectively. The dosage ranged from 6000--6400 rads using conventional fractionation (1750--1811 ret) on a 60Cobalt teletherapy unit. Methotrexate (25 mg I. V. every three days for seven doses) was utilized during the initial course of radiation in two of the three patients. The cases conform well to established criteria for the diagnosis of radiation-induced sarcoma. Postirradiation sarcoma of the head and neck region is a remote hazard that must be weighed against the benefits of curative radiation therapy, particularly when treating in the presence of bone disease or when treating retinoblastoma or benign lesions.

Adult↗
PubMed1980

The effect of delta-aminolevulinic acid on the synthesis and metabolism of GABA in rabbit brain homogenates.

The porphyrin precursor delta-aminolevulinic acid (delta-ALA) is a structural analogue of the putative amino acid neurotransmitter, gamma-aminobutyric acid (GABA). This study has demonstrated that delta-ALA has no effect on glutamate decarboxylase activity and only a small inhibitory effect of GABA aminotransferase activity. This would suggest that if accumulation of delta-ALA is related to development of the acute attack of porphyria, it is not via an effect on GABA synthesis and metabolism.

Animals↗
PubMed1980

Randomized preoperative and postoperative radiation therapy for patients with carcinoma of the head and neck: preliminary report.

Two hundred and ninety-eight patients with squamous cell carcinoma of the oral cavity, oropharynx, supraglottic larynx, hypopharynx or maxillary sinus have been randomized for preoperative radiation therapy and surgery vs. surgery and postoperative radiation therapy plus, in the case of patients with lesions of the oral cavity and oropharynx, radical radiation therapy. Data have been analyzed on 243 patients in this interim report. The differences between the three groups with respect to local control and survival are not statistically significant at this time. Additional accrual and continued follow-up are necessary to make definite treatment comparisons.

Carcinoma, Squamous Cell↗
PubMed1980

Adjuvant "sandwich" radiation therapy for bladder cancer.

Preliminary results of a study using a new concept of adjuvant "sandwich" radiotherapy in bladder cancer are presented. In this approach low-dose preoperative irradiation (500 rads) is delivered prior to cystectomy, and then on the basis of histopathologic staging patients with superficial tumors (Stage A and B) are followed with no further treatment; patients with deeply invasive tumors (Stage B, Grade III or IV, B2 or C) are treated with high-dose postoperative irradiation (4,500 rads in five weeks); and patients with advanced or metastatic disease (Stage D) are treated palliatively. Eighteen patients were treated with this approach, and all patients have been followed for at least one year. Sixteen (89 per cent) are alive with no evidence of tumor. One patient died of distant metastasis, and 1 patient died of peritonitis without evidence of disease. Since recurrence is known to develop in 50 per cent of patients within the first year after treatment, the low rate of failure obtained using this approach of adjuvant "sandwich" radiotherapy with a minimum follow-up of one year appears to be promising. This approach ideally balances the risk versus benefit ratio of adjuvant therapy sparing patients with superficial tumors from unnecessary treatment while treating patients with more advanced disease aggressively.

Follow-Up Studies↗