[Studies on the toxicity of a new synthetic drug SC1001-aminum]

SC1001A is a new sedative, hypnotic and anti-epileptic drug. Screening for possible mutagenicity of the agent consisted of a battery scheme of short-term mutagenic tests with different hereditary detecting end points. Three assays were with in the scheme: Ames test (for detecting gene mutation in vitro), micronucleus test (for detecting chromosomal aberration in vivo) and CHL (Chinese hamster lung cell line) test (for detecting chromosomal aberration in vitro). In addition, a routine teratogenicity study on SC1001A was carried out in mice. They were given daily at 3-dose levels (exposed to up to 33% of the LD50 by gastric incubation from the 6th through the 15th day of gestation. SC1001A gave uniformly negative results in all three mutagenic assay systems. Results of the teratogenic experiment showed that only the pregnant rate in bred mice in the moderate dose group and the mean maternal body weight gain of the dams during gestation in the low dose group were significantly lower than those in the corresponding control group. A clear dose-response relationship was not demonstrated. All dose levels of SC1001A used caused no adverse effects on the number of survival fetuses per litter, growth or development of the fetal mice. No malformations in the external appearance, of the internal organs and of the skeletal systems in fetal mice were observed. The above-mentioned results indicated that SC1001A induced neither gene mutation nor chromosomal damage both in vitro and in vivo. There was no evidence of teratogenesis. Therefore, it is estimated that SC1001A is probably comparatively safe as a pharmaceutical product for human beings in usual dosage.

Regulation of luteinizing hormone secretion in prepubertal heifers fed an energy-deficient diet

The effects of feeding a diet restricted in energy on the endocrine mechanisms regulating LH secretion in prepubertal heifers were examined. On Day 0, thirty heifers were assigned to be either ovariectomized (OVX; n = 10), ovariectomized and administered an estradiol implant (OVXE; n = 10), or to remain ovary-intact (INT, n = 10). Five heifers each were then assigned to be fed either a control (C) or a two-phase, low-to-high energy (L), dietary treatment. The C diet was formulated to support weight gains of 1.1 kg/day throughout the experiment (Day 0-197). Heifers receiving the L treatment were provided a diet restricted in energy (33% of C diet) from Day 0-127 followed by a diet similar to that fed to heifers receiving the C treatment from Day 128-197. Secretion of LH increased rapidly following ovariectomy in C-OVX and L-OVX heifers. During the period of energy restriction, LH pulse frequency was reduced, and mean LH concentration, pulse amplitude, and pituitary response to LHRH were greater in L-OVX than in C-OVX heifers. In L-OVXE and L-INT heifers, secretion of LH was low and unchanged during the period of dietary energy restriction. In contemporaneous treatment groups fed the C diet (C-OVXE and C-INT), frequency of LH pulses increased gradually during this period and C-INT heifers attained puberty on Day 121 +/- 18. Upon switching heifers in the L-OVX, L-OVXE, and L-INT treatments to the C diet, all characteristics of LH secretion changed markedly within 14 days to levels similar to those detected in the C treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cloprostenol sodium and clenbuterol HCl on reproductive performance in postparium anestrous cows

Two experiments were conducted to study effects of cloprostenol sodium (cloprostenol) and clenbuterol HCl (clenbuterol) during postpartum anestrus on subsequent reproductive performance in cows. In Experiment I, 96 cows received either 0.5 mg cloprostenol (PGF, n = 25), 364 mg clenbuterol (CLEN, n = 24), 0.5 mg cloprostenol and 364 mg clenbuterol (CLEN+PGF, n = 21) or no treatment (Control, n = 26) on Day 20 post partum. Treatments failed to influence postpartum interval, pregnancy rate or the incidence of short estrous cycles preceding the first normal estrous cycle. In Experiment II, anestrous cows were administered cloprostenol (0.5 mg) on either Day 20 (PGF20, n = 27) or Day 35 post partum (PGF35, n = 25), or served as untreated controls (Control, n = 26). Neither postpartum interval nor pregnancy rate were affected by cloprostenol treatment. In conclusion, treatment of postpartum cows with PGF did not alter the resumption of normal estrous cycles following parturition.

[An epidemiological survey of gallstones with gray-scale ultrasound]

Gray-scale real-time ultrasound has been employed to investigate gallstone with a positive result of 553 cases out of 15,856 healthy subjects in city and countryside, the incidence being 34.88%. The feature of incidence is as follows: 1. The incidence of the simple gallbladder stone is more common than that of the other sites (male is about 81.15%, female is about 87.29%); 2. The incidence of gallstones of city residents is higher than that of the country people with significant difference statistically (P less than 0.01); 3. The incidence of gallstone in female city residents is higher than male, about 2.5:1, which shows significant difference. (P less than 0.01); 4. The incidence of gallstones in female city residents is higher than in countryside (P less than 0.01); 5. There is no significant difference in the incidence of gallstone between male and female in the countryside (P greater than 0.05); 6. There is no significant difference in the incidence of gallstones between city male and the male in the countryside (P greater than 0.05); 7. Either in the city or in the countryside, it has been shown that there is a tendency of increasing incidence of gallstone with age in both sexes (P less than 0.01). The relationship between the gallstone and the clinical symptoms has been discussed in this paper.

Optical characterization of thin films by guided waves

The study of guided waves in a thin layer allows a precise characterization of refractive index and thickness. Optical anisotropy can also be measured. We show how this technique can be applied to the characterization of a multilayer structure.

Surface optical coatings by ion assisted deposition techniques: study of uniformity

Uniformity of layers produced by IAD strongly depends on the characteristics of the ion beam: optical characterization is made by guided wave measurements. The thickness and refractive index including anisotropy must be considered separately to interpret the measured uniformity.

The central projections of the great auricular nerve primary afferent fibers--an HRP transganglionic tracing method

A study of the central distribution of the primary afferent fibers of the great auricular nerve (GAN) was made in 18 rabbits by means of transganglionic transport of horseradish peroxidase (HRP). HRP applied to the cut central end of the GAN was detected ipsilaterally in the dorsal root ganglion cells (segments C2-C3) and the superior cervical ganglion cells. The transganglionically labeled fibers were seen in the dorsal column of the upper 4 cervical segments and in the cranial nerve nuclei of the medulla oblongata. The afferent projections were rather strong in the regions of laminae I-V of C2, the caudal subnucleus of the nucleus of the spinal tract of the trigeminal nerve (NVSpc), the solitary nucleus (SN), the medial and lateral cuneate nuclei, etc. The results showed that the primary afferent impulses of the GAN and the peripheral nerves which supply the head, face, trunk and viscera might converge on the upper cervical cord, the NVSpc and the SN, and play a certain role of modulation on the transmission of somaticovisceral sensations, especially pain.