Observations of synaptic efficacy and paired-pulse facilitation in area CA1 of hippocampal slices from coriaria lactone-kindled rats

The changes of population spike(PS)/population excitatory postsynaptic potential (EPSP) slope relationship and paired-pulse facilitation (PPF) were primarily investigated with extracellular recording in stratum pyramidale to stimulation of Schaffer collaterals in CA1 region of hippocampal slices from coriaria lactone (CL)-kindled and control rats. The results were as follows: (1) neither spontaneous nor evoked epileptiform bursts were found in all hippocampal slices from CL-kindled and control rats; (2) the synaptic efficacy, expressed by the ratio of PS/EPSP slope, at low stimulation intensity ranging from 10-30% of its maximum was significantly increased on CL-kindled rats (P less than 0.05); and (3) although PPF was found in all slices, the PPF strength only at stimulation intensity of 10 and 20% of maximum was augmented remarkably in CL-kindled rats (P less than 0.002 and 0.024, respectively). According to the results from our previous work, we suggested that the increment of PS/EPSP slope ratio and PPF strength at low stimulation intensity may result from the potentiation of excitatory synaptic activity or/and the change of intrinsic excitability of pyramidal neurons.

[Review of improving the technology of processing Chinese herbal medicines]

In this paper, the present situation of processing technology for Chinese herbal medicines is expounded in all aspects. Careful processing, overall developing and comprehensive utilization are put forward as improving ways, in the hope of providing a scientific basis for carrying forward the traditional processing techniques for Chinese herbal medicines in producing areas and putting the resources to full and rational use.

[An analysis of heritability of intra-erythrocytic Na+, K+ in 139 twins]

By means of the twin model contributions of shared genes and shared environments for red blood cells Na+ and K+ were analysed by genetic and epidemiologic methods. Determination of zygosity was mainly based on examination of red blood cells system, including ABO blood group, MN blood group, P blood group, Rh blood group and secretor status of saliva, such that the probability a dizygotic pair being identical for all of these indices was less than 0.05. 139 pairs of twin in Nan Kai district Tianjin were investigated containing 74 pairs of monozygotic twins (MZ) and 65 pairs of dizygotic twins(DZ). Several methods of estimating genetic heritability (h2) were used, such as the three methods proposed by Vogel, the Holzinger's method. Levine's method based on model of variance analysis and path analysis. The degrees of compatibility of various h2 were also analysed. The contributions of shared genes, shared environments and twin's own special environments were similar for RBC Na+, h2 = 0.32, C2 = 0.35, u2 = 0.33. The contributions of shared environments were the main cause for RBC K+, C2 = 0.97.

A sequence-dependent 1H-NMR study on the formation of beta-turns in tetrapeptides containing charged residues

The importance of side-chain charge interactions in the formation of beta-turns was studied. Sixteen protected NAc-tetrapeptide amides were studied, namely the variants of DEKS: NEKS, EEKS, DDKS, DQKS, NQKS, DERS, NERS, EERS, DDRS, NDRS, DQRS, and DKES. Three tetrapeptides--NPDM, NSDM, and NDDS--were also studied as they have a high probability of forming beta-turns, based on statistical predictions. The results indicate that a small proportion of type I beta-turn exists in solutions of DEKS and DERS in methanol/water (60/40), while NEKS has an even smaller population of this turn. The other tetrapeptides are present in solution only in the extended conformation. These results clearly show the importance of the salt bridge between the side chains of K2 and E3 or R2 and E3, as well as the importance of the charge on the side chain of the first residue in stabilizing the beta-turn. The relevance of statistical predictions for beta-turns in short peptides is discussed.

[Influence of external conditions of the occurrence of sexual stage in Cordyceps]

Experiments have been carried out on fruiting the dead larva of Napialus hunanensis infected with Cordyceps hawkesii in nature, under alternating temperatures, humidity preservation and adequate illumination. The results show that the occurrence of sexual state from the dead larva can be induced normally by providing suitable external conditions.

Increased urinary excretion of zinc and copper by mercuric chloride injection in rats

The effects of HgCl2 on urinary excretion of Zn, Cu and metallothionein at different time intervals were observed in male Wistar rats. The rats were given a daily intraperitoneal injection of 203HgCl2 (0.5 or 1.0 mg Hg kg-1) for 2 days. 203Hg, Zn, Cu and metallothionein in urine, kidney and liver were analyzed. Significant increases in urinary Zn and Cu concentrations were found in HgCl2-dosed groups. Elevated urinary Zn and Cu concentrations were accompanied by an increased metallothionein excretion in urine at different time periods. Zn concentration in urine remained elevated during the entire observation period of 7 days. There were also increased concentrations of Cu and Zn in the renal cortex in one of the two exposed groups. The results indicate that urinary Cu and Zn are related to the manifestation of renal toxicity and/or the synthesis of metallothionein in kidney induced by mercury.

[EEG studies in female adolescent delinquents. Quantitative and visual analysis]

Quantitative analysis and visual interpretation on spontaneous brain electrical activity were both undertaken in 41 female adolescents and 55 normal controls. Delinquent group had higher abnormal rate of electrical encephalogram (EEG) than normal group. Spectral power analysis showed that the power of fast activity was increased in central region and the power of all bands (1-30 Hz) was generally decreased in occipital region in delinquents. It indicates that synchronization of EEG in female delinquents may be weak. The results of multi-variate discrimination analysis suggest the possibility of discriminating two groups with quantitative EEG data.

Two optical methods for simultaneous measurement of particle size, velocity, and refractive index

Two optical methods that were developed for recognizing the composition of moving spherical particles as well as measuring their sizes and velocities are described here. Both methods are meant for characterizing single particles with a high spatial and temporal resolution. One method is an extension of the phase-Doppler technique, whereas the other is a newly developed method that utilizes cylindrical waves of laser light to illuminate the particles. The principles of both methods are described, and some experimental data are presented to demonstrate the feasibility of the theoretical concepts.

Adenovirus E1A activation domain binds the basic repeat in the TATA box transcription factor

The adenovirus large E1A protein is a potent activator of transcription. We use several different experimental approaches to demonstrate that the large E1A protein binds specifically and stably to the TATA box-binding factor (TFIID), the general polymerase II transcription factor that initiates assembly of transcription complexes. Sedimentation velocity centrifugation revealed that TFIID and E1A form a heterodimer in vitro. We demonstrate that the activation domain of E1A (conserved region 3) binds to TFIID. E1A interacts with a 51 residue region from the conserved C-terminal domain of TFIID that includes a repeat of basic residues between the homologous direct repeats of TFIID. Analysis of TFIID binding by various E1A mutants indicates that TFIID binding is necessary, although not sufficient, for E1A transactivation.

[Quantitative EEG analysis and the value for differential diagnosis on depression: I. Spectral power and coherence analysis]

Spectral power and coherence analysis were taken on 47 depressive patients and 43 normal controls. Depressive patients showed abnormal brain activity mostly in frontal-central regions. The endogenous and manic-depressive groups mainly presented higher power of slow activity and predominant in right hemisphere, while the non-endogenous and other groups presented higher power mainly in the fast bands. Coherence analysis showed that the coherence of EEG between homogenous points of two hemispheres was decreased in depressed patients.

[Quantitative EEG analysis and the value for differential diagnosis on depression: II. Multivariate regression and discriminate analysis]

Multivariate regression and discriminate analyses were carried out based on the EEG power variables and some related clinical materials from 47 depressed patients and 43 normal controls. The results of regression analysis showed that the severity and duration of depression were associated with EEG slow activity, while the age of first episode and age of the patients were associated with EEG fast activity. Discriminate analysis clearly demonstrates the possible utility of EEG data in the differential diagnosis of depression.

[Efficiency evaluation of combined intervention measures with improving drinking water first to prevent infantile acute diarrhea]

The paper analysed factors of acute diarrhea in children under five by Mantel-Haenszel stratification and Logistic regression. The total person-years of observation were 1332. The results showed that the combined risk factors which caused diarrhea were drinking the pond water and failure to wash hands before eating and so on. The combined intervention Measures, especially improvement of drinking water had effectively decreased the incidence rate of infantile acute diarrhea through the observation in the past two years.