Determination of added blood in ground beef

Blood added to ground beef is estimated from hemoglobin extracted with water. Since myoglobin is co-extracted with the hemoglobin, the 2 heme pigments are separated in one portion of the extract by precipitating the hemoglobin in an 85% (NH4)2SO4 solution. The myoglobin remaining in solution is used as the reference solution for determining the hemoglobin in another portion of the extract containing both pigments. The hemoglobin is converted to cyanomethemoglobin and quantitated by its absorbance at 422 nm.     

Active giant cell arteritis with cerebral involvement. Findings following four years of corticosteroid therapy

A patient had continued active giant cell arteritis proved on biopsy four years after the initial diagnosis of temporal arteritis. The patient had had erythrocyte sedimentation rates within the normal range and had been receiving corticosteroids without interruption for four years. Central nervous system symptoms occurred three and four years after the initial diagnosis.     

Secretion of parathyroid hormone by abnormal human parathyroid glands in vitro

Radiation survival curves for Lewis lung tumours in the lungs ranging in size from 0-5 to 20 mm3 have been obtained, and a size-dependent variation in hypoxic fraction was found. Cell-survival studies following treatment of various sizes of s.c. tumours indicated that the effects of 60Co gamma-rays and the chemotherapeutic agents 1,3-bas(2-chloroethyl)-1-nitrosourea (BCNU) and cyclophosphamide are all size-dependent. Large pulmonary nodules which had regressed but had not been cured by cyclophosphamide regrew with a radiosensitivity that was characteristic of previously untreated tumours. The results give additional experimental support to the clinical interest in early adjuvant therapy of micrometastases, and sequential combined modality therapy for larger tumours.     

Diazepam treatment of socially isolated monkeys

Four rhesus monkeys were reared for the first eight months of life in total social isolation. One animal died during this period; the three remaining subjects were treated with diazepam in an isolation chamber, in their home cages, and in a playroom testing situation. Diazepam significantly decreased the self-disturbance behaviors of two subjects, and there was even the appearance of some social behaviors, although they were limited and not of the same quality as in nonisolated subjects. The authors discuss the implications of the data for understanding the significance of the social isolation syndrome in monkeys as a model for human psychoses.     

Effect of hyperbaric oxygen exposure on pulmonary clearance of 5-hydroxytryptamine

Clearance of 5-hydroxytryptamine (5-HT) by the lungs of normal and vitamin E-deficient rats was evaluated following a 60-min exposure to 100% oxygen (O2) at 4 ATA (HBO). After exposure, lungs were isolated, ventilated, and perfused, with a recirculating system used for measurement of 5-HT clearance. Control lungs were obtained from rats exposed to air at 1 ATA. In control normal rats, fractional clearance of 5-HT was 0.78+/-0.03 (mean+/-SE). Following HBO 5-HT clearance was 0.55+/-0.04 (P less than 0.01). In control vitamin E-deficient rats. 5-HT clearance was 0.85+/-0.05 and was decreased to 0.46+/-0.03 (P less than 0.001) following HBO. To evaluate the effect of recovery time after HBO on 5-HT clearance, separate groups of rats were killed at varying intervals post-HBO. In normal rats, 5-HT clearance had returned to control levels by 3-4 after HBO; in vitamin E-deficient rats, clearance remained unchanged 4 h after HBO and was only 74% (P less than 0.001) of control values 24 h post-HBO. These results indicate that depression of pulmonary 5-HT clearance occurs in rats due to hyperoxia and is potentiated by vitamin E deficiency. This represents a reversible alteration of lung function which requires vitamin E for complete recovery.