RNA metabolism of the normal and the copper treated human endometrium

Ribonucleic acid (RNA) metabolism of the normal and copper-treated ( Cu-T200 IUD) human endometrium was investigated. The relative concentration of total, messenger, ribosomal and transfer RNA was measured in normal and Cu-treated endometrium using the technique of affinity chromatography in polysepharose. The transition from the proli ferative to the secretory endometrium in normal women was accompanied by significant increases (p less than .05) in total RNA, messenger RNA and in ribosomal RNA. The relative proportions of bound and free messenger RNA were also modified by endometrial maturation changing from 70% bound messenger RNA in the proliferative to 83% in the secretory phase. Cu-T200 Cu release appeared to particularly affect RNA metabolism in the secretory phase. During the proliferative phase only the concentration of transfer RNA and the proportion of bound to free messenger RNA were modified by the Cu-T200. The Cu-T200 induced significant decreases (p less than .01 and p less than .05) in all RNA parameters, with the exception of the RNA/deoxyribonucleic acid ratio.     

An axial-emission self-modulating ion gauge

An axial-emission self-modulating ultra-high vacuum ion gauge (AESMG) based on developments of the axial-emission ion gauge (AEG) is described. The self-modulation technique used in AESMG operates by means of changing the potential of the collector. The AESMG has some advantages such as rather high sensitivity, simplicity of structure and the modulating coefficient of soft X-ray photocurrent is almost equal to unity. The limiting measurable pressure of AESMG is about 2 × 10^?12 torr.     

Messenger RNA synthesis, transport, and storage in silkmoth ovarian follicles

The effect on liver microsomal enzyme activity of three steroid contraceptive drug (SCD) combinations was compared in rats, mice and guinea-pigs. Lynestrenol plus mestranol, norethisterone plus mestranol and norethynodrel plus mestranol were given orally for 4 consecutive days (acute treatment) or 30 days (chronic treatment) at various doses eliciting an experimentally controlled antifertility activity which varied in its extent. In rats and mice all the combined treatments (with the exception of norethynodrel plus mestranol in mice) were active as inducers of liver microsomal enzymes. This induction seems to be mediated mainly by the progestogenic compounds. Oestrogens showed a very poor effect bordering on significance only in a few cases. No effect on liver microsomal protein or cytochrome P 450 concentration was obtained after treatment with doses capable of increasing the microsomal enzyme activity. The activity of the liver microsomal enzymes did not appear to be reduced immediately (2 h) after the last administration of the SCD given during 4 or 30 days. Contraceptive treatments at doses capable of eliciting complete antifertility activity were inactive on liver microsomal enzyme activity in guinea-pigs.     

A Note on Heuristic Methods in Optimal System Reliability

Many optimization techniques have been used to solve redundancy allocation problems, most of which result in noninteger solutions. A few, including dynamic programming and integer programming, as well as a host of heuristic methods give integer solutions. This note critically reviews six promising heuristic approaches. The advantages and disadvantages of each of the approaches are discussed. An extended approach is presented which incorporates some of the ideas of the previous methods for solving a general non series-parallel system. The extended approach appears to be quite efficient and is general. The simplicity and efficiency of the approach will lend itself to solving large practical problems.     

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.     

Multiple layers of basement membrane around myelinated and unmyelinated fibers in cellular blue nevus

Concentric multiple layers of basement membranes around Schwann cells in cellular blue nevus are reported.     

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.