[An experimental study on the treatment of fetal rabbits with intrauterine growth retardation]

OBJECTIVE

To investigate the effect of histocyte activators and vasodilators on the amino acids concentration in fetal rabbits with intrauterine growth retardation (IUGR).

METHODS

The rabbits with IUGR were caused by passive smoking and treated with histocyte activators (adenosine triphosphatase, coenzyme A, cytochrome C, and vasodilators (injectio salviac molfiorrhizae composita, anisodamine). The effects of different remedies on the fetal plasma amino acids' concentration and the fetal development (i.e. birth weight, the weights of fetal liver and fetal brain) were studied.

RESULTS

Both histocyte activators and vasodilators had favorable effects on the improvement of fetal development and the increase of fetal plasma amino acids' concentration. But the action of histocyte activators was stronger than vasodilators.

CONCLUSIONS

The results suggested that vasodilators could improve the uterine-placental flow, and histocyte activators could enhance placental transfer of amino acids. But histocyte activators seem to be better than vasodilators.

[The quantitative and morphological analysis of placenta and brain in rabbits with intrauterine fetal growth retardation]

OBJECTIVE

To observe the changes of quantitative and morphological structure in placenta and fetal brain of rabbits with intrauterine fetal growth retardation (IUGR) resulted from exposure to cigarette smoking.

METHODS

The pure species of 23 pregnant New Zealand rabbits were used and divided into three groups. (1) group A: 9 rabbits were exposed to cigarette smoking everyday in the whole period of pregnancy; (2) group B: 7 rabbits were exposed to cigarette smoking everyday in the late half period of pregnancy; (3) group C: no smoking, as control group. The villus area of placenta, the capillary area in villus and the thickness of granulosa layer in fetal brain were studied by histomorphometric parameter.

RESULTS

It was showed that the placental villus area was decreased significantly in group A than that of the control group. The capillary area in villus of both group A and group B was less than that of the group C. The thickness of granulosa layer in cerebrum and cerebellum of group B is less than that of the control group. Nevertheless, only the thickness of granulosa layer in cerebrum of group B decreased significantly than that of the control group.

CONCLUSIONS

The development of cerebrum in fetal rabbits were influenced significantly by smoking. The development of cerebellum was influenced by smoking mainly in the early half period of pregnancy. It means that the most important time for cerebellum development is the early period of pregnancy and both the early and late half period of pregnancy were important for the cerebrum development.

Horseradish peroxidase permeability across rat nasal mucosa in selective stimulation of substance P innervation with capsaicin

To investigate the physiological role of substance P innervation (SPI) in the nasal mucosa from inhaled irritant macromolecules, SPI in the rat nasal mucosa was selectively stimulated with capsaicin and the degree of horseradish peroxidase (HRP) permeability across the nasal epithelium was evaluated by enzyme immunoassay or by histochemical electron microscopy. The serum level of HRP was reduced significantly in capsaicin-administered rats compared to control rats along the time course with quantitative analysis of the enzyme immunoassay. Control rats showed heavy permeation of HRP across the epithelium, but capsaicin-administered rats showed weak permeation of HRP across the epithelium with histochemical electron microscopy. The epithelial lining and its tight junctions were left intact as judged by electron microscopy. In conclusion, selective stimulation of SPI of the rat nasal mucosa with capsaicin decreased the epithelial absorption permeability to HRP without compromising the epithelial integrity. These findings imply that the physiological role of capsaicin-sensitive SPI in the rat mucosa is to protect the airway from inhaled irritant macromolecules.

Electroosmotic control of chiral separation in capillary zone electrophoresis

The resolution in capillary zone electrophoresis (CZE), with the assumption of diffusion control only, is strongly dependent on the direction and magnitude of electroosmotic flow. In fact, excellent separation resolution will be obtained if the electroosmotic flow is in the opposite direction of the electrophoretic migration. By applying various radial electric potential gradients across the capillary wall, the direct control of the zeta potential and the electroosmotic flow results in a great enhancement of chiral resolution in cyclodextrin-modified CZE. All 12 basic chiral drugs, including (+/-)-ephedrine, (+/-)-pseudoephedrine, (+/-)-norephedrine, (+/-)-epinephrine, (+/-)-norepinephrine, and (+/-)-isoproterenol, are separated and resolved within 22 min of the analysis time. There is no additional band broadening and dispersion introduced by the direct control of electroosmosis with the application of various radial electric potential gradients.

Five restriction fragment length polymorphisms of the APOA1-C3 gene and their influence on lipids and apolipoproteins in healthy Chinese

The distribution of five restriction fragment length polymorphisms (RFLPs) of the APOA1-C3 gene cluster and their influence on serum lipids and apolipoprotein levels was investigated in 151 healthy Chinese of both sexes. The frequencies of the rare alleles at ApaI, BanI, XmnI (A1) and SstI (C3) sites were significantly different in the Chinese when compared to Caucasians as follows: ApaI: 0.25 vs. 0.42 (p < 0.02); BanI: 0.33 vs. 0.16 (p < 0.01); XmnI: X2, 0.30 vs. 0.14, and X3, 0.08 vs 0.05 (p = 0.001); SstI (C3): 0.23 vs. 0.12 (p = 0.011). The frequency of P2 (PstI) at 0.04 was similar to that in Caucasians (0.07). The distribution of the genotypes of all the RFLPs was in Hardy-Weinberg equilibrium in this population. A significant association of the SstI polymorphism of the C3 region with the serum high-density lipoprotein (HDL)-cholesterol level was observed in both men and women, the rarer allele (S2) being associated with higher levels (p < 0.05). 5.8% of the sample variance of the HDL-cholesterol level in this sample could be explained by the SstI polymorphism of the C3 region (F = 6.07, p = 0.003). The association of the SstI locus with serum HDL-cholesterol was stronger in males than in females (R2 = 13.8 and 6.7%, respectively). There was a similar trend of association of the serum apolipoprotein A-I level with the SstI polymorphism, though it did not reach statistical significance. There was no association between the levels of any of the lipid and apolipoproteins studied with RFLPs of the APOA1 gene.

Racial variation of factor VII activity and antigen levels and their correlates in healthy Chinese and Indians at low and high risk for coronary artery disease

Plasma factor VII activity (FVIIc) is one of the independent risk factors of coronary artery disease (CAD) and is controlled by both genetic and environmental factors. South Asians including Indians have one of the highest prevalence and mortality rates from CAD while the Chinese have a much lower risk. Generally accepted risk factors cannot explain the high mortality from CAD in Indians. We examined two hundred and seventy seven Chinese (124 m, 153 f); and 216 healthy Indian (150 m, 66 f) adults for serum lipids; plasma FVIIc and FVIIag levels in order to examine racial variations of these and their correlates in these two populations. Both Indian men and women had significantly higher FVIIc levels (12% and 11%, respectively) than the Chinese even after adjustments of age, BMI and lipids (P < 0.01). In contrast, Indians had significantly lower plasma FVIIag levels than Chinese (8% and 9%, respectively in men and women; P < 0.01). Multiple linear regression analysis shows a strong correlation of FVIIc with serum triglycerides accounting for 4-8% of the total variability of FVIIc in different groups. Further, there was a stronger correlation between FVIIc and FVIIag in Indians than that in the Chinese (0.43 vs. 25) suggesting a greater activation resulting in higher FVIIc in Indians inspite of lower FVIIag levels. The higher FVIIc and stronger activation by triglycerides observed in this study partly explain the higher risk of CAD in Indians.

Association of factor VII genotype with plasma factor VII activity and antigen levels in healthy Indian adults and interaction with triglycerides

Plasma factor VII activity (factor VIIc) is one of the independent risk factors for coronary artery disease and is controlled by both genetic and environmental factors. Several studies in healthy Caucasian subjects have revealed an association of a common genetic polymorphism at residue 353 (Arg-->Gln) of the factor VII gene with plasma factor VIIc. We have investigated the influence of this polymorphism (factor VII Arg/Gln353) on fasting plasma factor VIIc and antigen (factor VIIag) levels and its interaction with triglyceride levels in 185 healthy Dravidian Indians of both sexes (128 men, 57 women). The frequency of Gln353 has been found to be significantly higher in Dravidian Indians (0.29; confidence interval, 0.27 to 0.30) than in Caucasians (0.10). The distribution of factor VII Arg/Gln353 genotypes was at Hardy-Weinberg equilibrium. The carriers of the Gln353 allele had significantly lower plasma factor VIIc and factor VIIag in men (P < .05). The factor VII Arg/Gln353 polymorphism explained 13% and 11% of the total variance of plasma factor VIIc and factor VIIag, respectively, in men (P < .001) and 6% and 9% in women (P > .1). The genotype-specific correlation of factor VIIc and factor VIIag with triglyceride levels was stronger in carriers of the Gln353 allele (r = .38 and .41; P < .001) than in Arg353 homozygotes (r = .09 and .27; P = .19 and .005, respectively).

Nuclear Mutation Inhibits Expression of the Chloroplast Gene That Encodes the Large Subunit of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase

Chlamydomonas reinhardtii mutant 76-5EN was recovered as a light-sensitive, acetate-requiring strain that failed to complement a chloroplast structural gene mutant of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39). Further genetic analysis revealed that the new mutation was inherited in a mendelian pattern, indicating that it resides within the nucleus. The 76-5EN mutant lacks Rubisco holoenzyme but has wild-type levels of whole-chain electron transport activity and chlorophyll. During a 1-min pulse labeling with 35SO42-, little or no Rubisco large-subunit synthesis occurred in the mutant. Nuclear-encoded small subunits were synthesized to a normal level and were subsequently degraded. When analyzed by northern hybridization, the 76-5EN mutant was found to have a decreased level of large-subunit mRNA. Large-subunit mRNA synthesis also appeared to be reduced during a 10-min pulse labeling with [32P]orthophosphate, but the labeled mRNA was stable during a 1-h chase. These results indicate that a nuclear gene mutation specifically disrupts the accumulation of large-subunit mRNA within the chloroplast. A deeper understanding of the nature of the 76-5EN gene may be useful for manipulating the expression of the agronomically important Rubisco enzyme.

Effects of thyroid hormone on the calcium current and isoprenaline-induced background current in rabbit ventricular myocytes

The majority of previous studies have been performed to explain the effects of thyroid hormone on the heart in chronic hyperthyroidism that was usually induced by eight to 10 daily injections of thyroid hormones. However, it is unclear whether or not the electrophysiological effects result from the chronic manifestations of hyperthyroidism and whether thyroid hormone acts directly or indirectly on cardiac myocytes to alter cardiac electrophysiological properties. In order to examine the acute term electrophysiological effects of thyroid hormone applied in vitro and the mechanisms responsible for some of these effects, we investigated the modulatory effects of thyroid hormone on the calcium current and isoprenaline-induced background current in L-triiodothyronine-treated ventricular myocytes of the rabbit. The major findings were as follows. Over 5 h (range, 5-24 h) after treatment of L-triiodothyronine (1 microM) in vitro, the calcium current was increased significantly. Isoprenaline (1 microM) and cyclic AMP (100 microM) caused an increase in the calcium current in both euthyroid and hyperthyroid myocytes. The hyperthyroid myocytes were more sensitive to the effect of beta-adrenergic stimulation on the calcium current and isoprenaline-activated background current. In euthyroid myocytes, acetylcholine (1 microM) produced no or little changes in the amplitude of the calcium current. In hyperthyroid myocytes, acetylcholine markedly reduced the calcium current, however, acetylcholine was ineffective in the presence of sufficient intracellular cyclic AMP (100 microM). Our results suggest that thyroid hormone can affect the cardiac myocytes directly. Furthermore, our results demonstrate that thyroid hormone affects the calcium current and isoprenaline-activated background current. These electrophysiological changes may explain, at least in part, the occurrence of positive inotropy and cardiac arrhythmias that is associated with hyperthyroidism.

Reliability of seizure classification using a semistructured interview

Methods for standardized classification of epileptic seizures are important for both clinical practice and epidemiologic research. In this study, we developed a strategy for standardized classification using a semistructured telephone interview and operational diagnostic criteria. We interviewed 1,957 adults with epilepsy ascertained from voluntary organizations. To confirm and expand the seizure history, we also interviewed a first-degree relative for 67% of subjects and obtained medical records for 59%. Three lay reviewers used all available information to classify seizures. To assess reliability, each reviewer classified a sample of subjects assigned to the others. In addition, an expert physician classified a sample of subjects assigned to two of the reviewers. Agreement was "moderate-substantial" for generalized-onset seizures, both for the comparisons between pairs of lay reviewers and for the neurologist versus lay reviewers. Agreement was "substantial-almost perfect" for partial-onset seizures, both for pairs of lay reviewers and for the neurologist versus lay reviewers. These results suggest that seizures can be reliably classified by lay reviewers, using operational criteria applied to symptoms ascertained in a semistructured telephone interview.