[TNT-degrading enzyme of Citrobacter freundii and its regulation by carbon and nitrogen source]

It was detected that both NAD(P)H-linked reductase (TNT-Red) and NAD(P)+-linked TNT dehydrogenase (TNT-Deh) were present in TNT-degrading enzymes of Citrobacter freundii simultaneously. The time course of formation for the enzymes and the actions of coenzymes in enzymatic reaction of TNT have been studied. The effects of varied carbon and nitrogen sources on the regulation of the enzymes were different clearly. When the concentration of NH4Cl or urea in culture medium was more than 0.1 mol/L, the formation of both TNT reductase and TNT dehydrogenase was promoted. However, the formation of these enzymes was inhibited by KNO3 in culture. The production of both reductase and dehydrogenase was promoted by glucose. The sodium citrate was able to help the formation of the TNT dehydrogenase. The activity of the TNT reductase was increased when the concentration of sodium citrate was less than 0.5%, but when it was more than 0.5%, the activity of this enzyme was decreased rapidly.

[Study on follicle growth, ovulation and morphological changes of endometrium by ultrasonic and biochemical measurements]

Daily growth of the follicles before ovulation and the changes of the endometrium after ovulation were recorded in 16 spontaneous menstrual cycles by the ultrasonic and biochemical measurements. The mean diameter of the dominant follicle was 20 mm before ovulation, the mean volume 3.0 ml, and the growth rate of the follicles 1-3 mm/24 h. Ovulation occurred within 24 h of the luteinizing hormone peak and within 48 hours of the blood estrogen peak. The fact that the blood progesterone levels were higher on the day of the LH peak indicated that luteinization of the dominant follicles had already occurred prior to ovulation. Sonographic criteria of the endometrical tissue were obtained after the serial observation. According to the different sonographic appearances, the secretory phase of the endometrial tissue was divided into the early secretory phase, the middle secretory phase and the late secretory phase. The sonographic characterization of the endometrial tissue in the different phases as well as the thickness of the endometrium during the cycles were described. The clinical usefulness of the criteria of the different phases was to evaluate the subsequent luteal function, and facilitate the clinical management of the infertile women. The study confirms that ultrasound can provide a reliable measure in monitoring the follicular growth and ovulation, and observing the morphological changes of the endometrial tissue during the secretory phase. Thus the in vivo differentiation of the endometrial tissue during the secretory phase could be studied non-invasively by means of the ultrasound tissue characterization.

Observations of Langerhans' cells in leprosy using monoclonal antibody OKT6

Changes in the Langerhans' cells (LC) in seven cases of leprosy were observed using the monoclonal antibody OKT6. In the epidermis of the lesions of most of the leprosy cases, the processes of LC were reduced or diminished. Some LC were disintegrated. In two BT cases in the upgrading (type 1) reactional stage, either increased numbers and aggregation of OKT6-positive cells in clusters or their disintegration was seen in different areas of the epidermis.

Nuclear pore complex in spermatogenesis of Beijing domestic duck. Electron microscope observation of freeze-etching

The nuclear pore complex in spermatogenesis of Beijing domestic duck has been studied by means of electron microscopic observation of freeze-etching. The structure of the pore observed proves to be in accord with the model of the nuclear pore complex proposed respectively by Franke (1970) and Roberts et al. (1970). But its central granule may be present (1-3 granules) or absent. The granules are considered to be material in transit. The size and frequency of the pore vary with different types of reproductive cells, which is believed to be related to the cells' function. The pores concentrate on the side of nucleus near Golgi zone in primary spermatocyte and near the proacrosome of spermatid, and this shows the functional variety of parts in the nucleus.