Enhancement of mRNA expression of tissue-type plasminogen activator by L-threo-3,4-dihydroxyphenylserine in association with ocular dominance plasticity.

Tissue-type plasminogen activator (tPA) plays important roles in the regulation of synaptic plasticity in the hippocampus and cerebellum. We found that the expression of tPA mRNA in the visual cortex was increased significantly by the peripheral administration of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS; 100 mg/kg, i.p.), which we had previously shown to have a promotive effect on ocular dominance (OD) plasticity. When plasminogen activator inhibitor-1 (PAI-1; 100 muM in an osmotic minipump) was infused into the kitten visual cortex, OD plasticity was suppressed; i.e. a significantly large number of binocular cells was recorded in the PAI-1 infused cortex following monocular deprivation. These results, therefore, suggest that the PA system is involved in the promotive effect of L-threo-DOPS in OD plasticity.

Vitamin D receptor alleles, bone mineral density and turnover in premenopausal Japanese women.

Recent studies have shown that genetic effects on bone mineral density (BMD) and bone turnover are related to allelic variation in the vitamin D receptor (VDR) gene. We examined allelic influences of the VDR gene on bone turnover and density in 202 normal healthy premenopausal Japanese women (age 30.1 +/- 1.2, mean +/- SEM). The VDR effect on BMD and turnover is similar to that observed in Caucasian women; however, there are major differences in allele frequency. The B allele by BsmI restriction fragment length polymorphisms (RFLPs), associated with low BMD and high bone turnover, is found in only 12% of Japanese women (1.4% homozygote BB), compared with 41% of Caucasians (16.7% homozygote BB). In comparing the two most frequent genotypes, Bb heterozygotes (21.5%) and bb homozygotes (77.1%), BMD is 5.3% lower in Bb heterozygotes, and levels of bone formation markers including osteocalcin and bone-specific alkaline phosphatase are 20-32% higher with lower serum calcium (2.30 +/- 0.02 vs 2.35 +/- 0.01 mmol/l) and higher 1,25-dihydroxyvitamin D (95 +/- 4.8 vs. 76 +/- 3.8 pmol/l). Further discrimination of the genotype was achieved using two additional RFLPs (ApaI, A and TaqI, T); the lumbar spine BMD of the common genotype BbAATt was 9.3% (0.94 SD) lower than in the bbaaTT genotype in premenopausal Japanese women. These data confirm that VDR RFLPs affect bone mineral metabolism regardless of racial differences. Moreover, the VDR genotypes based on haplotype analysis should yield useful insights into the potential prevention of osteoporosis.

A new data analyzing tocodynamometer and its suitability for clinical application.

Actual intrauterine pressure (IUP) was measured continuously by the extraamniotic method for the monitoring of uterine contractions (UC) throughout the entire course of labor. As a result, it was found by using a PDP 11/60 minicomputer that the wave of intrauterine pressure levels includes signals below a frequency of 0.05 Hz and that a period of 10 minutes is suitable for averaging the levels of parameters of IUP which makes it possible to evaluate the average expulsive activity. A new data analyzing tocodynamometer with a digital low pass filter was developed based on the data mentioned above, and the average values for maximum active pressure, the UC area and UC interval were computed simultaneously. The data for these factors were digitally displayed and printed on recording paper at every UC time. These values were clinically useful for drawing the partograms and were available to use in trying to express the expulsive activity in simple "labor index" terms.

[Studies on the tocogram with bearing-down efforts during labor--analysis of the waveform and its clinical significance].

Together with a recording of external tocogram (Ex. toc.), intra-uterine pressure (IUP) and pressure between fetus and birth canal (PFB) were measured simultaneously and continuously, in 77 women during labor who were showing uterine contraction (UC) with bearing-down efforts (BDE). UC curves with BDE were analyzed to detect characteristic features and the sequence of their change in the second stage of labor. The following results were obtained. IUP curves were able to be classified into three types (Type A, B and C) according to the characteristics of the BDE waveform. This means of categorization was also able to be applied to the waveforms of PFB and Ex. toc., because those two pressure curves were essentially the same as that of IUP. Most of the type A contractions were observed early in the second stage of labor, and type B and C made their appearance successively. During the period of labor, from the first appearance of BDE on UC until the termination of the delivery, the mean frequency of UC with BDE was estimated to be 43 times in premiparae (Type A 5.8, Type B 19.7 and Type C 15.5 times) and 13 times in multiparae (Type A 2.0, Type B 2.7 and Type C 7.6 times). 3) Clinical significance from the point of view of parameters was as follows. The peak pressure of IUP increased slightly as labor progressed and the mean levels were 14.4kPa in Type A, 17.7kPa in Type B and 23.5kPa in Type C, respectively. PFB peak pressure, however, remained close to 50kPa in all cases irrespective of the type of curve. The mean BDE pressure was about a half the mean peak pressure for IUP and PFB respectively. The ratio of the levels of peak pressure of PFB and IUP (PFB/IUP ratio) were found to be approximately from 2.04 to 3.12. By a power spectrum analysis, the maximum levels of power in Type B curves were found at both 0.01 Hz and 0.2 Hz. The differential calculus curves estimated from IUP with BDE were able to be divided into three types, and the maximum value in Type B curves of IUP was 12.8kPa/sec. The IUP levels were plotted against those of PFB estimated from UC curves and the curve obtained indicated a straight line relationship. The levels of PFB were consistently two or three times higher than those of IUP.(ABSTRACT TRUNCATED AT 400 WORDS)

[Pressures on the human fetus during labor - intrauterine and on the fetal head (author's transl)].

During labor, the body surface of the fetus is subjected to strong pressure exerted by uterine contractions. In 40 cases, intrauterine pressure (IUP) which acts on the fetal body in the uterine cavity and pressure between the presenting part of the fetus and birth canal (PFB) which acts on the part of the fetus engaged in the birth canal were measured to determine the difference in pressure depending on the parts of the fetal body and their changes during the progress of labor. 1) Both peak IUP and PFB values increased gradually in the first stage of labor, and they became double in the period of labor with bearing-down efforts. 2) Since the peak value of PFB was 2.2 to 3.5 times higher than that of IUP, the part of the fetus engaged in the birth canal should always be subjected to 2.2 to 3.5 times more pressure than the intrauterine part of the fetal body. 3) Manual procedures such a vacuum extraction and Krysteller's compression on the uterine fundus increased the peak value of PFB markedly. The objective measurement of the pressure which acts on the fetal head during labor can be considered to contribute to the prevention of cerebral damage and fetal hypoxia.