The histology of needle biopsy specimens of skeletal muscle from the vastus lateralis was quantitatively assessed in a group of adults with growth hormone (GH) deficiency, most of whom had hypopituitarism treated with conventional pituitary hormone replacement. The mean age of the 21 patients (16 males and 5 females) was 39 ± 2 (SEM). Comparisons were made with age-and sex-matched controls following six months double-blind, placebo-controlled treatment with recombinant human GH (rhGH) in the GH-deficient patients. Before treatment, needle muscle biopsies from patients with GH deficiency showed mean type I and II fibre areas of 5,153 ± 273 and 4,828 ± 312 µm² respectively, which did not differ from the controls (4,482 ± 306 and 4,699 ± 310 µm²). Percentages of type I fibres were similar in the two groups (47.2 ± 2.5% in GH deficiency and 45.3 ± 2.2% in controls). No difference in the variability of type I or II fibre areas was demonstrated between the groups. Correlations between the relative contribution to total fibre area by type I fibres (mean fibre area × percent) and maximal oxygen uptake (p = 0.006), and between type II fibres and quadriceps force (p = 0.035) were noted in GH-deficient adults before treatment. Following rhGH treatment, no change was noted in mean fibre areas, variability of fibre areas, or percentage of either fibre type. We conclude that in adults with GH deficiency: (a) no consistent histological evidence of myopathy was seen; (b) qualitatively, the muscle fibres function similarly to normal, and (c) rhGH treatment does not result in any detectable change in fibre areas or proportion.

During the period from March 1 to June 1, 1971, the Lawrence Livermore Laboratory made simultaneous measurements of environmental radiation background at 107 weather stations throughout the United States.Measurements were made using CaF":Dy thermoluminescent dosimeters (TLD-200).Freshly annealed dosimeters were mailed to the stations where they were exposed in the station's instrument shelter. At the end of the exposure period, the dosimeters were returned to Livermore for readout. Light output is proportional to the radiation dose received by the phosphor from the sum of terrestrial and cosmic sources. The cosmic component was estimated from the elevation and geomagnetic latitude of the station, and terrestrial radiation was obtained by difference.Median environmental radiation exposure rate (terrestrial + cosmic) was 9.4 uR/hr with a range from 3.7 to 19.9 pR/hr. The median terrestrial exposure rate was 5.5 pR/hr. Low backgrounds were found in the Hawaiian Islands, Northern Alaska, and Florida. High backgrounds in the Rocky Mountain Work perforated under the auspices of the U. S. Atomic Energy CoiKtission.

Details are presented on the tests that should be performed during the installation of a megavoltage linear accelerator. Also discussed are the dosimetry studies that should be done as part of the operation of the machine. Information in specific radiation monitoring equipment is provided. (AIP)

No abstract

No abstract

No abstract