Theodore Fields

Neutron activation studies of biological fluids: Manganese and copper☆

A detailed description of a procedure is presented for estimation of non-dialyzable manganese and copper in biological fluids by neutron activation. A 1-ml sample of serum or cerebrospinal fluid is serially dialyzed against 10-ml aliquots of ammonium barbituric acid buffer, pH 7.35, in a period of less than 3 hr. The dialyzed samples are then irradiated and analyzed for manganese and copper by γ-ray spectroscopy. Analysis of sera obtained from 30 adult, apparently healthy male subjects, revealed concentration of non-dialyzable manganese as 1,3 ± 0.2 μg% and that of copper 164 ± 41 μg%. Bloods collected from eight hospitalized male subjects with clinical diagnosis of myocardial infarction revealed serum manganese elevations over those of normal male levels. These manganese elevations apparently were not related to elevations of sera transaminase concentrations. Cerebrospinal fluid analysis of 12 hospitalized male subjects without known organic disease of central nervous system and with normal cerebrospinal fluid protein revealed the following non-dialyzable concentrations: manganese 0.4 ± 0.12 μg% and copper 27.8 ± 16.1 μg%.

Autoradiographic localization of P32 phosphate in metastatic carcinoma of the breast to bone.

The use of P32-labeled phosphate as palliative therapy in carcinoma of the breast, metastatic to bone, has had widespread trial. Clinical observation has suggested that relief of symptoms from the metastic tumors occurs in bones lesions. To confirm the site of P32 localization, sections of human bone containing lesions recently with treated P32 were examined autoradiographically. Phosphorus32 activity as determined by this technique and microscopic localization of radionecrosis was confined to the periphery of the lesions. X-ray shadowgraphs confirmed this observation, the areas of P32 concentration coinciding with areas of new bone trabeculae. Gross examination showed hemorrhagic changes in the bone at the sites described. The tumor tissue showed little gross change. Serial determination of alkaline phosphatase activity in the patient shows a marked sensitivity to P32 therapy and appears to be a better criterion than the white blood count for controlling dosage. Preliminary conclusions from these observations would suggest that P32 phosphate therapy of metastatic carcinoma of the breast to bone is dependent upon localization in regenerating bone surrounding the lesion. Therapeutic effect may be produced by decreasing the intraosseous pressure of regenerating bone, and may secondarily affect the lesion by surrounding it with a shell of radioactivity.

New simple radiation scanning system.

This laboratory has been concerned with the development of a simplified system of scanning a radiation site with a scintillation counter. We have designed a complete single-packaged unit, approximately 3 inches in diameter by 12 inches in length, containing the entire detector, amplifier, and indicating device. The instrument (Fig. 1) contains a 1/4-inch O.D. × 2-inch NaI (Tl) crystal and DuMont 6467 photomultiplier powered by a transistorized high voltage power pack (1½ 1½ × 1½ inches). The output of the photomultiplier is fed through a two-stage transistor impedance matching amplifier to an Amperex 6977 subminiature indicator triode biased negatively to zero light output. The light pulse from the triode is fed by light pipe (or lens) to Polaroid 400 film. Typical rated light output of the triode is 3 to 4 foot lamberts. Preliminary experiments with a lO-microcurie J131 source, 4 inches distance, gave positive pulses of 1 to 2 volts. The permissible scanning rate for these early tests was 3 inches per se...