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Data are presented on the 226Ra content of various food samples collected from Bombay city and high background areas of Kerala State in India. The experimental technique consisted in measuring the activity of the gaseous daughter product 222Rn in a ZnS-coated α-scintillation counter. Comparison of data for the samples of these two areas, having wide differences in their background radiation level, shows that the Kerala samples have a 226Ra/g ash content which is, on an average, a factor of five to ten times higher. An exception is the coconut sample which is grown profusely in Kerala State; this does not show a higher concentration of 226Ra in spite of the higher availability of 226Ra in the Kerala State soil.From a tentative model formed for the food habits of the people of these two regions, their 226Ra burden has been estimated. The determination of 226Ra in bones and other organs of the human body indicates that a man from high background areas of Kerala State contains about ten times more of this radioisotope than a Bombay citizen. A value of 0·85 × 10−14g Ra/g ash of bone was found from direct measurements of a single subject from Bombay.

A simplified whole-body counter designated as “shielded chair” has been developed for routine monitoring of occupational subjects of Bhabha Atomic Research Center. It incorporates a mild steel shielded chair weighing about 3 tons and a NaI(TL) crystal detector of 4 in. dia. 3 in. thick shielded with 1.5 in. thick Pb. The crystal assembly weighing about 550 lbs. is mounted on a plate hinged to the side of the shielded chair frame. Data is presented on its background and compared to that in the iron-room. Variations in the response for a point source of 137Cs moving inside the phantom are depicted graphically. Sensitivities for various radionuclides for both integral counting above 50 keV and the photopeak region are given. A system of integral counting with a single adjustment on the upper ceiling in counts per minute has been devised which takes care of almost all of the gamma emitting radionuclides in quantities in excess of the cumulative half yearly intake for occupational exposures to maximum permissible concentration in air or water as recommended by ICRP. This would suffice for a quick routine monitoring of occupational workers and it simplifies the electronic circuitry and its associated maintenance problems. The sensitivity of the system is sufficient to detect easily the potassium and 137Cs content of a normal subject.

Experimental data on the response of the two-crystal scanning geometry for wholebody counting was obtained with a 137Cs point source moving inside the phantom. The phantom was made out of “Hardboard” sheets which had shape and other parameters approaching to that of the human body. Similar data was also obtained for the multicrystal geometry and it was found that the two-crystal scanning geometry gave far less deviations for different locations of the source inside the phantom. It was also found that, with extra counting time on the head side in the scanning geometry, improvement in response was obtained for the source movement along the middle and from middle to side of the phantom only, whereas for all other patterns of source movement there is no improvement in the response over that obtained with the uniform speed. The deviations in the counting efficiency for the scanning geometry were on the lower side compared to the computed and experimental values reported by Naversten for a simplified phantom of water and Masonite and of 20 cm thickness.

A study was undertaken to estimate the actual concentration of gamma-active isotopes in vegetables, tea. tobacco, powdered milk, wheat, rice, fish, etc., which are available in Bombay, India. A large-size NaI(Tl) crystal scintillator and a thirty-channel pulse-height analyser were used to identify and to estimate the concentration of the radioisotopes. The studies were carried out over a period of about 15 months which is broadly divided as (1) the year following the stoppage of nuclear weapon tests (in October 1958), (2) the month before the French atomic weapon test in Sahara desert on February 13, 1960, and (3) the month after this test. In addition to the presence of natural radioactivity of K40, fission product activities such as Zr95-Nb95, Ru103I131, Cs137, Ba140-La140Ce141and Ce144were noticed, but in varying amounts in different materials. The very high activities of Zr95-Nb95and Ce144in tea were found to be chemically bound in its leaves preventing this uptake by human beings. The presence of Zr95-Nb95in carrots suggests its preferential pick up through the roots. The radioisotope Zn65was detected in fish and prawns. The analysis of certain vegetables during the month following the French test clearly indicated the presence of short-lived fission products which should have originated in the test. The degree of contamination is found to depend upon the total surface offered to the fallout and its roughness to hold the activity.

The hepatic microsomal parahydroxylation of aniline is measured by the determination of its product p-aminophenol (pAP). The pAP formed in incubation mixtures is assayed either after ether extraction or after trichloroacetic acid (TCA) precipitation. The TCA-precipitation method is simpler and less time-consuming than the ether-extraction method, but it has been found that the apparent recovery of pAP was lower in TCA supernatants than with the ether-extraction method. In the present work, it was found that the recovery of pAP by the TCA-precipitation method depended on the nature of NADPH-generating system used in the incubation mixture. When “soluble fraction” was used as a source of glucose-6-phosphate dehydrogenase for the reduction of NADP to NADPH, the recovery of pAP using the TCA-precipitation method was less than that with the ether-extraction method. But when “soluble fraction” was replaced by yeast glucose-6-phosphate dehydrogenase or by chemically prepared NADPH, the recovery of pAP was approximately equal with both the methods. Lowered recovery of pAP when added to the soluble fraction or its dialyzate might be due to the presence of sulfhydryl reacting groups. The addition of mercuric chloride to the soluble fraction dialyzate resulted in almost “full” recovery of pAP by the TCA-precipitation method, i.e., the apparent loss of pAP was prevented.

Superficial soft-tissue masses arising from skin appendages, metastasis, and inflammatory lesions have been widely reported. However, nerve-related superficial mass-like lesions other than peripheral nerve sheath tumors are less commonly described. High resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss the entire spectrum of these lesions and also outline a systemic diagnostic approach.

BackgroundThe prevalence of osteoarthritis of the atlanto-odontoid joint has been reported by radiology, autopsy, and conventional computed tomography (CT), but the prevalence has not yet been assessed by multidetector computed tomography (MDCT).PurposeTo reveal the prevalence of osteoarthritis of the atlanto-odontoid joint and to analyze the inter-relationships among gender, age, and osteoarthritis with MDCT in adults.Material and MethodsFirst, a series of 700 selected domestic patients aged >18 years undergoing an upper cervical MDCT scan were divided equally into seven age groups. Second, using the postprocessing technique of multiplanar reconstruction, osteoarthritis of the atlanto-odontoid joint was viewed from any direction and classified into four grades, which were normal, mild, moderate, and severe. Lastly, the incidence of the different grades of osteoarthritis was assessed, and the reproducibility was tested.ResultsThere was no significant difference between gender and osteoarthritis of atlanto-odontoid joint (P > 0.05). The rate of osteoarthritis was 16% in the age group 18–25 years, 23% in the age group 25–30 years, 33% in the age group 30–40 years, 54% in the age group 40–50 years, 70% in the age group 50–60 years, 87% in the age group 60–70 years, and 93% in the age group >70 years. Mild osteoarthritis appeared at the earliest at age 19.6 years, moderate osteoarthritis in at earliest at age 24.2 years, and severe osteoarthritis at the earliest at age 48.5 years. The inter-observer reliability was excellent (k = 0.86).ConclusionOsteoarthritis of the atlanto-odontoid joint could be detected by MDCT in a young adult. It increased rapidly with increasing age on MDCT.