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Biomedical subjects

M L Kohn

Publications and source records attributed to M L Kohn.

8 recordsLinked to original sources

High-dose-rate intraluminal brachytherapy in the treatment of endobronchial malignancy. Work in progress.

Remote afterloading high-dose-rate brachytherapy (RAHDRB) was used endobronchially for the management of malignant airway obstruction in 82 patients, 72 of whom had primary disease in the lung. Treatment was palliative (n = 58) or definitive (n = 24). The extent of airway compromise was determined at bronchoscopy and with symptoms of hemoptysis, dyspnea, or cough or with radiographic evidence of atelectasis. RAHDRB doses were 1,000-4,700 cGy in one to five fractions. External beam radiation was used in previously unirradiated patients. A substantial reduction ,N airway disease and an improvement in symptoms were seen in 82% of patients. Obstruction scores showed an overall 74% improvement. Complications occurred in only 10 patients (two of whom died). Median survival was short (palliative group, 5 months; definitive group, 12 months); however, symptoms remained palliated in 62 patients (76%) until death or the last follow-up examination. RAHDRB is effective and can be applied with equal success in all patients with malignant airway obstruction, even those whose disease has recurred after external beam irradiation.

Aged

Nucletron MicroSelectron calibration and radiation survey.

The calibration of a Nucletron MicroSelectron High Dose Rate Remote Afterloader unit and the radiation survey around the facility is discussed. The radiation survey of the facility indicates that the use of an existing linear accelerator vault will provide adequate shielding. The methodologies for performing source calibration are presented.

Brachytherapy

Filters for radiation reduction: a comparison.

Aluminum, yttrium, copper, and R-filters were evaluated with respect to effective beam energy, entrance radiation exposure to the skin, x-ray tube loading, and the quality of resultant radiographs. Since all filters yielded acceptable radiographs, a figure of merit was developed to determine which filter delivered the lowest entrance radiation exposure for the lowest increase in x-ray tube loading. The figure of merit indicated that the best results were obtained with the 0.1-mm Cu filter with 2 mm Al at 60-105 kVp and with the 0.2-mm Cu filter with 2 mm Al at 105-120 kVp. Cu filters produced radiographs with quality comparable to that of R- or Y filters. Cu filters are inexpensive alternatives to rare-earth filters and yielded a reduction in radiation exposure with less x-ray tube loading.

Aluminum

The interaction of social class and other factors in the etiology of schizophrenia.

Epidemiological evidence clearly indicates an especially high rate of schizophrenia at the lowest social class levels of urban populations. The author suggests that this relationship between class and schizophrenia exists because the conditions of life experienced by people of lower social class position foster conceptions of social reality that are so limited and rigid as to impair their ability to deal resourcefully with the problematic and the stressful. Such impairment does not in itself result in schizophrenia; however, in conjunction with genetic vulnerability and great stress, it could be disabling.

Humans