[Clinical efficacy of entecavir combined with Biejiajian pills and its influence on TCM syndrome scores during the treatment of chronic hepatitis B with hepatic fibrosis and blood stasis syndrome].

Objective: To investigate the clinical efficacy of entecavir combined with Biejiajian pills and its influence on TCM syndrome scores during the treatment of chronic hepatitis B with hepatic fibrosis and blood stasis syndrome by prospective, randomized and controlled study. Methods: Patients with chronic hepatitis B with hepatic fibrosis and blood stasis syndrome were selected as the research subjects and randomly divided into a treatment group and a control group. Entecavir plus Biejiajian pills or entecavir plus a simulant of Biejiajian pills were given for 48 weeks. The changes in liver stiffness measurement (LSM) and TCM syndrome scores before and after treatment were compared between the two groups to analyze the correlation. The data between groups were analyzed by t-test/Wilcoxon rank sum test or χ(2) test. Pearson correlation coefficient was used to analyze the correlation between TCM syndrome scores and LSM values. Results: After 48 weeks of treatment, the LSM values of the two groups were significantly lower than those of the baseline (P < 0.001), liver fibrosis was significantly improved, and the LSM values of the treatment group were lower than those of the control group [(8.67 ± 4.60) kPa and (10.13 ± 4.43) kPa, t = -2.011, P = 0.049]. After 48 weeks of treatment, the TCM syndrome scores of the two groups were significantly reduced compared with the baseline (P < 0.001), and the clinical symptoms were significantly relieved, and the total effective rates of the improvement of the TCM syndrome scores in the two groups were 74.19% and 72.97%, respectively, but the differences between the groups were not statistically significant (χ(2) = 0.013, P = 0.910). Correlation analysis showed that there was no obvious trend between TCM syndrome scores and LSM values. There were no serious adverse reactions associated with the drug during the observation period of this study. Conclusion: Based on antiviral treatment with entecavir, regardless of whether it is combined with the Biejiajian pill, it can effectively reduce the LSM value, improve liver fibrosis, reduce TCM syndrome scores, and alleviate symptoms in patients with chronic hepatitis B with liver fibrosis and blood stasis syndrome. Compared with entecavir alone, the combined Biejia pill has greater efficacy in improving liver fibrosis and a favorable safety profile, meriting its implementation and widespread application.

Characterization and development of 56 EST-SSR markers derived from the transcriptome of Odontobutis potamophila.

Expressed sequence tags (ETSs) are the sources of microsatellite development. In this study, we isolated and characterized microsatellite markers for Odontobutis potamophila by using Illumina RNA-sequencing. We sequenced a large number of ESTs and screened 200 potential microsatellites. Consequently, a total of 56 novel polymorphic microsatellite repeat markers were identified in thirty-two individuals from a wild population area (Jiande, Zhejiang Province, China). The number of alleles per locus varied from two to eight, the observed heterozygosity (HO) ranged from 0.03571 to 0.9375, and the expected heterozygosity (HE) ranged from 0.14326 to 0.81549. The average number of alleles, HO, and HE were 5.0, 0.4467, and 0.5518, respectively. By the calculation, the range of polymorphism information content (PIC) was 0.1177-0.8492. Most of the loci showed moderate or high polymorphism. These newly developed EST-simple sequence repeat (EST-SSR) markers would serve as an efficient tool for analyzing population connectivity and provide sufficient information for genetic diversity research, parentage, and molecular breeding of O. potamophila and other fishes with similar genetic relationship.

[Therapeutic effect of IGF-1R-targeting inhibitor (TAE226) on malignant pleural effusion in nude mice].

OBJECTIVE: To study the therapeutic effect of IGF-1R inhibitor TAE226 on malignant pleural effusion (MPE) in nude mice. METHODS: Human lung carcinoma A549 cells were injected into the pleural cavity of nude mice to establish MPE model. The mice were randomly divided into model group and treatment group, and were orally administered with distilled water and TAE226 (20 mg/kg) in the same volume, respectively. The volume of pleural effusion and tumor weight of the two groups were observed. HE staining was used to reveal the histological changes and enzyme-linked immunosorbent assay (ELISA) was used to detect the IGF-1R protein expression. IGF-1R mRNA level in the tumor tissue was determined by RT-PCR. Microvessel density (MVD) and cell proliferation index (PI) were assessed by immunohistochemical analysis. The protein expression levels of IGF-1R, p-IGF-1R, PI3K and p-PI3K in the tumor tissue were determined by Western blotting. RESULTS: The volumes of pleural effusion were (241.4±89.7) µl and (121.7±78.8) µl in the model and treatment groups, respectively (P<0.05). The tumor weight of treatment group was (316.7±186.3) mg, significantly lower than that of the model group (671.4±281.4) mg (P<0.05). RT-PCR analysis showed that IGF-1R mRNA level was 0.914±0.029 in the treatment group, significantly lower than that of the model group (1.152±0.037, P<0.01). The ELISA data revealed that IGF-1R protein expression level of the model group was significantly higher than that of the treatment group [(41.0±4.7) µg/L vs. (24.0±3.1) µg/L, P<0.01]. Immunohistochemical analysis showed that there were significant differences between MVD and PI in the model and treatment groups [MVD, 34.75±3.49 vs. 22.25±3.63; PI, (75.25±7.15)% vs. (45.75±5.12)%; P<0.01 for both). Western blot data showed that IGF-1R and PI3K protein expression levels were not significantly different between the model and treatment groups (1.03±0.33 vs. 0.98±0.37 and 1.05±0.28 vs. 0.98±0.19), respectively (P>0.05), but p-IGF-1R and p-PI3K protein expression levels had significant differences between the two groups (1.08±0.10 vs. 0.51±0.08 and 1.12±0.09 vs. 0.86±0.09), respectively (P<0.01 for both). CONCLUSIONS: The IGF-1R inhibitor can effectively inhibit the formation of malignant pleural effusion. Its mechanism may be related to the suppression of tumor cell proliferation, invasion and angiogenesis through inhibition of PI3K signaling. TAE226 treatment may be a potential therapeutic regimen of treating malignant pleural effusion.

Functional polymorphisms in microRNA gene and hepatitis B risk among Asian population: a meta-analysis.

Genetic mutations in microRNA gene can alter expression, which may interact to increase the risk of developing various diseases, including hepatitis B. However, published results are inconclusive or ambiguous. The aim of this review and meta-analysis is to more precisely estimate the association between polymorphisms in microRNA genes and hepatitis B risk. A digital search was performed of the MEDLINE EMBASE, CNKI, and CBM databases to identify relevant articles published up to February 18, 2014. Ten case-control studies were included, with a total of 6042 patients with hepatitis B and 6834 healthy controls. Nine single-nucleotide polymorphisms in the miRNA gene were examined, including miR-34b/c [rs4938723 (T>C)], miR-196a-2 [rs11614913 (C>T)], miR-146a [rs2910164 (G>C)], miR-499 [rs3746444 (T>C)], miR-122 [rs3783553 (ins/del)], miR-149 [rs2292832 (C>T)], miR-106b-25 [rs999885 (A>G)], miR-let-7c [rs6147150 (ins/del)], and miR-218 [rs11134527 (A>G)]. The meta-analysis results indicated that the miR-196a-2*T, miR-122*del, miR-106b-25*A, and miR-let-7c*del alleles/carriers increase the risk of hepatitis B among the Asian population. However, the miR-146a, miR- 499, miR-149, miR-218, and miR-34b/c polymorphisms may not be linked with the risk of hepatitis B. Further investigations are warranted to determine the exact associations between microRNA mutations and hepatitis B susceptibility.

Comparison of radiological and clinical features of temporal lobe necrosis in nasopharyngeal carcinoma patients treated with 2D radiotherapy or intensity-modulated radiotherapy.

BACKGROUND: To compare the imaging and clinical features of temporal lobe necrosis (TLN) in nasopharyngeal carcinoma (NPC) patients treated with two-dimensional radiotherapy (2D-RT) or those with intensity-modulated radiotherapy (IMRT). METHODS: We retrospectively analysed NPC patients who underwent 2D-RT (72 patients, 128 temporal lobes) or IMRT (36 patients, 50 lobes) and developed radiation-induced, MRI-confirmed TLN. RESULTS: White-matter lesions (WMLs), contrast-enhanced lesions, cysts and local mass effects were present in 128 out of 128 vs 48 out of 50 (P=0.078), 123 out of 128 vs 47 out of 50 (P=0.688), 10 out of 128 vs 1 out of 50 (P=0.185) and 57 out of 128 vs 13 out of 50 (P=0.023) temporal lobes, respectively, in the 2D-RT and IMRT groups. The WMLs were more extensive in the 2D-RT group (P<0.001). The maximum diameter of contrast-enhanced lesions was greater in the 2D-RT group (P<0.001), and these lesions tended to extend far away from the nasopharynx. The WMLs and enhancement had no impact on cyst development (both P=1). Local mass effects were always accompanied with contrast-enhanced lesions (P=0.024) but were not correlated with WMLs or cysts (P=0.523 and 0.341, respectively). There were no between-group differences in clinical features (all P-values>0.05), whereas the difference in the incidence of severe debility was of marginal significance (18.1% vs 5.6%, P=0.077). CONCLUSIONS: The IMRT-induced TLN was less extensive and milder than 2D-RT-induced TLN, but both had similar clinical features.

Prognostic value of magnetic resonance imaging-detected cranial nerve invasion in nasopharyngeal carcinoma.

BACKGROUND: We previously reported that magnetic resonance imaging evidence of cranial nerve invasion was an unfavourable prognostic factor in nasopharyngeal carcinoma. However, the prognostic value of this evidence in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy remains unknown. METHODS: We retrospectively analysed 749 nasopharyngeal carcinoma patients who underwent intensity-modulated radiotherapy. RESULTS: Cranial nerve invasion was observed in 299 (39.9%) patients with T3-4 disease. In T3-4 nasopharyngeal carcinoma, magnetic resonance imaging-detected cranial nerve invasion was associated with inferior 5-year overall survival, distant metastasis-free survival, and locoregional relapse-free survival (P=0.002, 0.003, and 0.012, respectively). Multivariate analyses confirmed that cranial nerve invasion was an independent prognostic factor for distant metastasis-free survival (hazard ratio, 1.927; P=0.019) and locoregional relapse-free survival (hazard ratio, 2.605; P=0.032). Furthermore, the receiver-operating characteristic curves verified that the predictive validity of T classifications was significantly improved when combined with magnetic resonance imaging-detected cranial nerve invasion in terms of death, distant metastasis, and locoregional recurrence (P=0.015, 0.021 and 0.008, respectively). CONCLUSIONS: Magnetic resonance imaging-detected cranial nerve invasion is an independent adverse prognostic factor in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy.

Evidence for monophyly and arthropod affinity of cambrian giant predators.

The Chinese Early Cambrian Chengjiang fauna includes three different anomalocaridids, a globally spread, extinct marine group including the largest known Cambrian animals. Anomalocaridids were active predators, and their presence implies that a complex ecosystem appeared abruptly in the earliest Phanerozoic. Complete specimens display several sets of characters shared only with some other exclusively Cambrian forms. This evidence indicates that anomalocaridids, Opabinia, and Kerygmachela form a monophyletic clade. Certain features indicate arthropod affinities of the lade, and for this group an unnamed (sub)phylum-level taxon within an arthropod (super)phylum is proposed.

Head segmentation in early cambrian fuxianhuia: implications for arthropod evolution.

The arthropod Fuxianhuia from the Chengjiang fauna displays primitive aspects of cephalic segmentation and trunk limb morphology that indicate a basal position within Euarthropoda. The cephalon consists of an eye-bearing sclerite that articulates with a head shield bearing antennules and subchelate appendages. Eye stalks, antennules, and subchelate appendages are proto-, deuto-, and tritocerebral limbs and organs, respectovely. The anterior position of the eye-bearing sclerite parallels the embryonic origin of arthropod eye lobes. The head of Fuxianhuia includes the acron and one somite and is regarded as a protocephalon. The definitive head of arthropods may have fused separate eye-bearing and appendage-bearing sclerites.

The co-transplantation of human bone marrow stromal cells and embryo olfactory ensheathing cells as a new approach to treat spinal cord injury in a rat model.

BACKGROUND: Both bone marrow stromal cells (BMSC) and olfactory ensheathing cells (OEC) have been demonstrated experimentally as promising for therapy of spinal cord injury (SCI). However, clinical use may be constrained by the margin neuronal differentiation capacity of BMSC as well as the limited number of isolatable OEC. This study therefore tested the efficacy of co-grafting human BMSC and OEC in treating thoracic SCI. METHODS: Rat SCI models were created with cushion forces. OEC were labeled with Hoechst 33342 and BMSC with BrdU or GFP. BMSC, OEC and BMSC plus OEC were injected into the injured sites of rat spinal cords. Histologic, electrophysiologic and functional approaches were applied to assess the effects of transplantation of these cell types. RESULTS: Behavioral evaluation showed an improvement in animals with all cell-based treatments. The co-graft led to significantly higher gait scaling. The latency of transcranial magnetic motor-evoked potential (tcMMEP) responses was also better restored in the co-graft group. Larger numbers and sizes of axon bundles through the transitional zone between the normal and injured regions were observed in the co-graft animals in comparison with all other animals. Transplanted bone marrow stromal cells were identified as neurofilament-positive in the co-grafted animals although the number of glial fibrillary acidic protein-positive cells remained the same in all groups. DISCUSSION: Taken together, our results suggest that the combined use of BMSC and OEC may provide an improved approach for the treatment of SCI.

Extracellular matrix stability of primary mammalian chondrocytes and intervertebral disc cells cultured in alginate-based microbead hydrogels.

Three-dimensional alginate constructs are widely used as carrier systems for transplantable cells. In the present study, we evaluated the chondrogenic matrix stability of primary rat chondrocytes and intervertebral disc (IVD) cells cultured in three different alginate-based microbead matrices to determine the influence of microenvironment on the cellular and metabolic behaviors of chondrogenic cells confined in alginate microbeads. Cells entrapped in calcium, strontium, or barium ion gelled microbeads were monitored with the live/dead dual fluorescent cell viability assay kit and the 1,9-dimethylmethylene blue (DMB) assay designed to evaluate sulfated glycosaminoglycan (s-GAG) production. Expression of chondrogenic extracellular matrix (ECM) synthesis was further evaluated by semiquantitative RT-PCR of sox9, type II collagen, and aggrecan mRNAs. Results indicate that Ca and Sr alginate maintained significantly higher population of living cells compared to Ba alginate (p < 0.05). Production of s-GAG was similarly higher in Ca and Sr alginate microbead cultures compared to Ba alginate microbeads. Although there was no significant difference between strontium and calcium up to day 14 of culture, Sr alginate showed remarkably improved cellular and metabolic activities on long-term cultures, with chondrocytes expressing as much as 31% and 44% greater s-GAG compared to calcium and barium constructs, respectively, while IVD cells expressed 63% and 74% greater s-GAG compared to calcium and barium constructs, respectively, on day 28. These findings indicate that Sr alginate represent a significant improvement over Ca- and Ba alginate microbeads for the maintenance of chondrogenic phenotype of primary chondrocytes and IVD cells.

Family-based association studies of CAPON and schizophrenia in the Chinese Han population.

Although there is evidence pointing to CAPON as a susceptible gene for schizophrenia, the results of independent association studies have so far been inconsistent. A recent case-control study by Zheng et al. supported CAPON as a susceptible site for the disease in the Chinese Han population. In their study both the single polymorphism (rs348624) and individual haplotypes showed significant association with schizophrenia. Our study further investigates this relationship this time using a family-based association. We selected 5 SNPs including rs348624 and performed a Transmission Disequilibrium Test (TDT) in 319 Chinese Han trios. Our results identified no single marker nor haplotype associated with schizophrenia, which did not suggest that CAPON was a susceptible site in the Chinese Han population, or it appeared unlikely that the CAPON played a major role in the aetiology of schizophrenia. Since there is consistent evidence pointing to 1q21-22 as a positional candidate region for schizophrenia, we suggest that further research should focus on other genes located in this region.

MiR-136 triggers apoptosis in human gastric cancer cells by targeting AEG-1 and BCL2.

OBJECTIVE: Gastric cancer is the second most prevalent cancer across the globe and accounts for about 10% of new cancer cases. It is one among the leading causes of cancer-related deaths around the world. Recently, microRNAs have been identified as important therapeutic targets for the treatment of several cancers owing to their potential to target multiple genes and hinder several biological processes such as proliferation and apoptosis. In the current study, we investigated the potential of miR-136 as therapeutic target for gastric cancer. MATERIALS AND METHODS: Total RNA was isolated by RNeasy RNA isolation kit and cDNA was prepared byRevertAid cDNA synthesis kit. The transcript analysis was carried out by quantitative RT-PCR. The transfection of miR-136 mimics or plasmids was carried out by using the Lipofectamine 2000 reagent. Apoptosis was detected by DAPI and acridine orange/ethidium bromide (AO/EB) staining. Protein expression was examined by Western blotting. RESULTS: The results indicated that the expression of miR-136 is significantly downregulated in gastric cancer cells. Transfection and subsequent overexpression of miR-136 in gastric cancer cells significantly promoted apoptosis as evident from DAPI and OA staining. In silico analysis revealed AEG-1 and BCL2 to be the potential targets of miR-136. Therefore, the expression of AEG-1 and BCL2 was determined in untreated control, cisplatin treated control and miR-136 transfected AGS gastric cancer cells. The results revealed that overexpression of miR-136 expression causes significant downregulation of AEG-1 and BCL2 protein expression. CONCLUSIONS: Taken together, we conclude that miR-136 promotes apoptosis in gastric cancer cells by targeting AEG-1 and BCL2. Therefore, miR-136 may prove as a potential therapeutic target for the treatment of gastric cancer.

DNMT3A-mediated down-regulation of microRNA-105 promotes gastric cancer cell proliferation.

OBJECTIVE: It has been well-established that microRNAs (miRNAs), a class of short non-coding RNA molecules, play an important role in the development of gastric cancer. In the present study, we focused on miR-105, a novel miRNA not previously linked to gastric cancer. PATIENTS AND METHODS: 36 paired surgically resected gastric cancer tissues and matched adjacent normal tissues were used to detect the expression of miR-105. AGS cells were used to overexpress or silence of miR-105 and to determine its effect on several tumorigenic properties. A cell proliferation enzyme-linked immunosorbent assay was used to analyze the incorporation of BrdU during DNA synthesis of AGS cells. Total cDNA from AGS cells was used to amplify the 3'-UTR of YY1 by PCR and luciferase activity was determined using the Dual-Luciferase Reporter Assay System RESULTS: We found that expression of miR-105 was reduced in gastric cancer tissues, compared with adjacent normal tissues, due to hypermethylation at its promoter region. Overexpression of miR-105 suppressed, whereas its inhibition promoted cell viability and proliferation. We further identified Yin Yang 1 (YY1) as a direct target of miR-105, by which miR-105 exerted its anti-proliferative role. Moreover, we found that DNMT3A was responsible for the down-regulation of miR-105 in gastric cancer cells. CONCLUSIONS: Our data demonstrate that miR-105 inhibits gastric cancer cell proliferation and progression, which might provide a therapeutical target for cancer therapy.

Downregulation of cAMP-dependent protein kinase inhibitor gamma is required for BMP-2-induced osteoblastic differentiation.

Osteoblasts, normally derived from undifferentiated mesenchymal precursor cells, acquire their characteristic phenotypes when induced by various regulatory factors, one of which is bone morphogenetic protein-2 (BMP-2). Our recent studies suggest that expression of cAMP-dependent protein kinase (PKA) inhibitor G (PKIG) is down-regulated as human mesenchymal stromal cells (MSCs) undergo BMP-2-induced osteoblastic differentiation. This raises our hypothesis that the PKA pathway is involved in osteogenesis. In this report, we demonstrated that PKIG in human MSCs and its murine homologue PKA inhibitor gamma (PKIgamma) in murine pre-myoblast C2C12 cells were down-regulated when these cells were treated with BMP-2. On the contrary, the PKA activity of C2C12 cells was increased upon BMP-2 treatment. Overexpression of PKIgamma in C2C12 cells was shown to repress mRNA expression of early osteoblastic markers osterix and type I collagen while inhibiting the PKA activity. This correlated with decreased alkaline phosphatase (ALP) activities. Furthermore, inhibition of the PKA activity using its specific inhibitor KT5720 was found to have the similar effect, whereas 8-Br-cAMP, a specific PKA activator, accelerated BMP-2-induced ALP activities. Finally, this study showed that BMP-2 treatment promoted activities of transcription regulatory elements including cAMP response element (CRE) and activating protein-1 (AP1). This effect of BMP-2 was diminished in PKIgamma-overexpressed C2C12 cells. Taken together, our results indicate that the activation of the PKA pathway may be one of key BMP-2-activated signaling events that lead to osteogenesis and that downregulation of PKIgamma may be prerequisite for the PKA activation during the osteoblastic differentiation of precursor cells.

A semi-analytical expression for the concentration distribution of substrate molecules in fast, enzyme-catalysed reaction systems.

A semi-analytical expression for the concentration distribution of the substrate molecules in fast enzyme-catalysed reaction system is presented. On this basis, the physical pictures of the reactions are discussed.

Caenorhabditis elegans ZC376.5 encodes a tRNA (m2/2G(26))dimethyltransferance in which (246)arginine is important for the enzyme activity.

It has been estimated that eukaryotes carry more than 50 genes for tRNA modifying enzymes. Of the few so far identified most come from yeast, a lower eukaryote. In Saccharomyces cerevisiae, the TRM1 gene is a nuclear gene encoding the tRNA(m2/ 2G(26))dimethyltransferase, which catalyses the formation of the N2, N2-dimethylguanosine at position 26 in tRNA. We have isolated and characterized the corresponding gene ZC376.5 in Caenorhabditis elegans. Via RTPCR the cDNA sequence of the full length ZC376.5 has now been cloned, expressed in Escherichia coli and demonstrated to encode a tRNA(m2/2G(26))dimethyltransferase that produces dimethyl-G26 in vivo and in vitro with tRNA from yeast and bacteria as substrates. This is the first example of a complete gene sequence coding for a tRNA modifying enzyme from a multicellular organism. A point mutation in exon IV in the C. elegans genome sequence coding for the tRNA(m2/2G(26))methyltransferase that substituted arginine246 for glycine eliminated the modification activity. Exchanging the corresponding lysine residue in the yeast Trm1p for alanine caused a severe loss of activity, indicating that the identity of the amino acid at this position is important for enzyme activity.

The carcinoembryonic antigen (CEA) gene family in non-human primates.

Carcinoembryonic antigen (CEA) is a tumor marker of wide clinical use though its function remains unknown. The CEA counterpart and some related macromolecules cannot be demonstrated in mice, thus prohibiting studies of CEA function by gene disruption strategies. In an attempt to find a relevant animal model for functional studies of CEA we have investigated the occurrence of CEA subgroup members in baboon and African green monkey at the genomic and mRNA levels. The investigation was focused on the characteristic immunoglobulin-variable region-like (IgV-like) N-terminal domain of the family members. Based on N-domain sequences 3 and 4 different CEA subgroup genes, respectively, were identified. One sequence in each monkey species corresponded to human CEACAM8, while it was not possible to assign an obvious human counterpart for the other N-domain sequences. However, studies of cDNAs from African green monkey COS-1 cells identified one of the sequences as CEACAM1. Expression of CEACAM1 mRNA and protein was upregulated by IFNgamma as has previously been demonstrated for human CEACAM1. Presence of GPI-linked CEA subgroup members in African green monkey was suggested by sequencing. Both monkey species would thus seem suitable for functional studies of selected CEA subgroup members.

Highly specific monoclonal antibody demonstrates that pregnancy-specific glycoprotein (PSG) is limited to syncytiotrophoblast in human early and term placenta.

Pregnancy specific glycoproteins (PSG) in humans constitute a family of 11 closely related glycoproteins (PSG1-8, PSG11-13) of unknown function(s), which are produced in large amounts by the placenta. As a step toward understanding the biology of PSG, specific monoclonal antibodies (mAbs) against PSG were developed and used to investigate the ultrastructural localization of PSG in the early and term placenta and in first trimester decidua. One mAb, BAP-3, was found to react with all six individually expressed PSGs representing five alternatively spliced forms, but not with any of the seven expressed members of the carcinoembryonic antigen (CEA) subfamily. The BAP-3 epitope is located in the PSG B2 domain. Using the BAP-3 mAb, PSGs were found to be expressed exclusively by the syncytiotrophoblast of first trimester and term villi. The intensity of the staining was much higher in early than in term placenta. All three main cellular compartments involved in the biosynthesis pathway of secreted proteins, i.e. rough endoplasmic reticulum, the Golgi complex and secretory vesicles, were stained for PSG. A second PSG-reactive mAb, BAP-1, also stained the apical plasma membrane of some glandular epithelial cells in first trimester decidua in addition to syncytiotrophoblast. This staining was most likely due to cross-reactivity with biliary glycoprotein (BGP).

Diffusion-controlled reactions of enzymes. An approximate analytic solution of Chou's model.

Based on Chou's model, a criterion was derived, by which one can judge whether or not the physical picture of the critical spherical shell described by Chou for an enzyme-substrate fast reaction system can emerge. Furthermore, for those reaction systems with such a physical picture, an approximate analytical solution was presented, which can be easily handled to calculate the upper limit of the diffusion-controlled reaction and the corresponding concentration distribution of substrate molecules on the surface of the major protein outside the active site. The results thus obtained are in good agreement with those computed by Chou et al. through the approach of numerical solution. Furthermore, the physical significance of the criterion and its relation to the critical spherical shell are substantiated during the process of derivation, which is very helpful for gaining an insight into this kind of biomolecular system with surprisingly high reaction rates.

Behavior of lanthanides in countercurrent chromatography using dihexyl-N,N-diethylcarbamoyl methylene phosphonate as stationary phase.

Counter-current chromatography is a real liquid-liquid chromatography. The retention volume of the solute can be calculated from the batch distribution ratio in organic separations. In the separations of metal ion, there are several complex and dissociation reactions involved in the two phases, and the retention volume cannot be always predicted from the batch distribution ratio. A mass transfer model is proposed in this paper and an expression of V(R) is derived. The retention volume of metal ion is determined not only by the batch distribution ratio but also by the mechanism of the extraction reaction. When 25% dihexyl-N,N-diethylcarbamoyl methylenephosphonate in cyclohexane is used as stationary phase and 2.91 mol/l HNO3 as mobile phase, the dynamic distribution ratios obtained from the chromatogram are not equal to but proportional to the batch distribution coefficients. These results are in agreement with the theoretical expression.