[The risk of incident gastric cancer for populations with different precancerous gastric lesions: a prospective follow-up study]

Objective: To provide evidence for optimizing the screening strategy for gastric cancer (GC), we evaluated the risk of incident GC for individuals with different precancerous gastric lesions in a prospective cohort study. Methods: Based on the National Upper Gastrointestinal Cancer Early Detection Program launched in Linqu, Shandong, a high-risk area of gastric cancer in China, we included a total of 14 087 subjects diagnosed with different gastric lesions stages by endoscopic screening from 2012 to 2018. Study subjects were prospectively followed up until December 31, 2019. The incidence of GC during the follow-up was ascertained by repeated endoscopic examinations, cancer, death registry reports, and active follow-up of study subjects and was confirmed by reviewing medical records extracted from the hospital information management system. The Poisson regression model was applied to calculate the relative risk (RR) and 95%CI for GC occurrence among subjects with different gastric lesions. Results: Among 14 087 subjects with different gastric lesions as determined by their first endoscopic examination in 2012-2018, 7 608 (54.00%) had a global diagnosis of superficial gastritis (SG), 2 848 (20.22%) had chronic atrophic gastritis (CAG), 3 103 (22.03%) had intestinal metaplasia (IM), and 520 (3.69%) had low-grade intestinal neoplasia (LGIN). During the follow-up, 109 subjects were diagnosed with GC, including 63 with high-grade intestinal neoplasia (HGIN) and 46 with invasive GC. Compared to subjects having normal gastric mucosa or SG, those with CAG (RR=3.85, 95%CI: 2.04-7.28), IM (RR=5.18, 95%CI: 2.79-9.60), and LGIN (RR=19.08, 95%CI: 9.97-36.53) had significantly increased risk of progression to GC. Individuals with these gastric lesions had an elevated risk of developing HGIN and invasive GC. For subjects with LGIN, the RR was 22.96 (95%CI: 9.71-54.27) for developing HGIN and 14.64 (95%CI: 5.37-39.93) for developing invasive GC. Subgroup analyses found that all age group subjects with LGIN diagnosed during the initial endoscopic examination had a significantly increased risk of developing the GC. Conclusions: Our large-scale prospective study on a high-risk area of GC showed that most residents aged 40-69 years had gastric lesions of different stages. Subjects with more advanced gastric lesions had a significantly increased risk of progression to GC.

Discovery of 2H-chromone-4-one based sulfonamide derivatives as potent retinoic acid receptor-related orphan receptor γt inverse agonists

Retinoic acid receptor related orphan receptor γt (RORγt), identified as the essential functional regulator of IL-17 producing Th17 cells, is an attractive drug target for treating autoimmune diseases. Starting from the reported GSK2981278 (Phase II), we structurally modified and synthesized a series of 2H-chromone-4-one based sulfonamide derivatives as novel RORγt inverse agonists, which significantly improved their human metabolic stabilities while maintaining a potent RORγt inverse agonist profile. Efforts in reducing the lipophilicity and improving the LLE values led to the discovery of c9, which demonstrated potent RORγt inverse agonistic activity and consistent metabolic stability. During in vivo studies, oral administration of compound c9 exhibited a robust and dose-dependent inhibition of IL-17A cytokine expression and significantly lessened the skin inflammatory symptoms in the mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that c9 can suitably occupy the active pocket, and the introduction of the morpholine pyridine group can interact with Leu396, His479, and Cys393. Thus, compound c9 was selected as a preclinical compound for treating Th17-driven autoimmune diseases.

[Value of PET/MRI in the diagnosis of malignant pleural effusion in comparison with PET/CT]

Objective: To investigate the diagnostic value of PET/MRI for malignant pleural effusion (MPE), and compare its diagnostic difference with PET/CT. Methods: The data of 57 patients with suspected MPE admitted into Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from October 2017 to January 2020 was analyzed. A total of 53 patients were included in the prospective study, and the whole body PET/CT and thoracic PET/MRI were performed on them respectively. Two physicians used a blind method to evaluate the morphological features of PET/CT and PET/MRI images, delineate the region of interest (ROI), obtain the maximum standard uptake value (SUVmax) of the ROI in the PET/CT and PET/MRI images. The target-to-background ratio (TBR) of the lesion was calculated. The diffusion-weighted imaging (DWI) characteristics of the pleura in PET/MRI images were analyzed. Taking pathological diagnosis as the gold standard, the diagnostic effect of PET/CT and PET/MRI on MPE were evaluated. Results: The 53 patients who were finally included were (62.8±1.7) years old, consisting of 31 males. Pathological results showed that 41 cases were MPE and 12 cases were benign pleural effusion (BPE). There were no statistical differences in age, gender and smoking history between the two groups (P>0.05). Bland-Altman analysis showed that the SUVmax of pleural lesions by PET/MRI was higher than that by PET/CT (6.4±0.6 vs 5.3±0.5, P<0.001). The TBR of PET/MRI was higher than that of PET/CT (2.2±0.2 vs 1.8±0.2, P<0.001). The sensitivity, specificity, and accuracy of PET/MRI in the diagnosis of MPE by combining imaging features such as SUVmax and DWI of pleural lesions were 75.6%, 100%, and 81.1%, respectively. The sensitivity, specificity, and accuracy of PET/CT combined with SUVmax and imaging features of pleural lesions in the diagnosis of MPE were 85.4%, 83.3%, and 77.4%, respectively. There was no statistically significant difference between PET/MRI and PET/CT in the area under the curve (AUC) for diagnosing MPE (0.934 vs 0.873, P>0.05). Conclusions: PET/MRI and PET/CT have the equivalent diagnostic efficiency for MPE. However, PET/MRI shows higher SUVmax and TBR for pleural lesions, and has specific pleural DWI imaging characteristics, which is worthy of further clinical research.

[Imported falciparum malaria in Suzhou City: a report of two cases in 2019]

The demographic features, epidemiology, diagnosis and treatment of two cases with falciparum malaria imported into Suzhou City in 2019 were reported. These findings indicate a risk of imported malaria in visitors besides high prevalence in migrant labors, and much attention should be paid to children that are at a high risk of infections.

Effects of dietary inclusion of Lactobacillus and inulin on growth performance, gut microbiota, nutrient utilization, and immune parameters in broilers

The effects of dietary Lactobacillus (BCRC 16092) and inulin on growth performance, intestinal microflora, mineral utilization, and tissue mineral contents were evaluated in broilers. The experiment was conducted using 1,152 one-day-old broilers randomly distributed to 9 treatments in a factorial arrangement (3 × 3) using 3 levels of inulin (0, 1, and 2%) and 3 levels of Lactobacillus addition (108, 109, and 1010 CFU/kg). Broilers (1 D of age; 8 replicates per treatments and 16 broilers per replicate) with an initial body weight of 48.36 ± 0.21g were evaluated for 42 D. A 4-D mineral digestibility trial was conducted during the final week of the experiment. The results showed that Lactobacillus supplementation can increase average daily gain and nutrient digestibility and improve feed/gain in broilers (P < 0.05). Moreover, Lactobacillus and inulin supplementation increased the numbers of Lactobacillus and Bifidobacteria, increased serum concentration of IgG and IgA, and decreased the numbers of Escherichia coli and pH in ileum and cecum. The present study demonstrated Lactobacillus and inulin fed to broilers has a positive effect on gut microbiota, growth and nutrient utilization, immune system, and mineral metabolism.

[Molecular mechanisms of resistance to phosphatidyl inositol 3-kinase inhibitors in triple-negative breast cancer cells]

OBJECTIVE

To explore the molecular mechanisms of resistance to phosphatidyl inositol 3-kinase (PI3K) inhibitors in triple-negative breast cancer (TNBC) cells.

METHODS

HCC70 cells (TNBC) were transfected with siFZD7, siWANT5B or siGSK3 using lipofectamine 2000 transfection reagent. The expression levels of key proteins of WNT/β-catenin and PI3K/AKT/mTOR pathways were determined by Western blot analysis. After HCC70, MCF-7 (ER-positive) and SK-BR3 (HER2-positive) cells were treated with PI3K/AKT/mTOR inhibitors, the inhibition rates of cell proliferation were measured by MTT assay, and half maximal inhibitory concentrations (IC50) were calculated. The altered activities of WNT/β-catenin and PI3K/AKT/mTOR proteins were detected by Western blot and luciferase report gene assay, respectively. The nuclear translocation of β-catenin protein was examined by immunofluorescence assay. Xenograft nude mouse model was used to evaluate the tumorigenicity of breast cancer cells treated with BKM120 in vivo. The expression levels of p-LRP6, p-4EBP1 and β-catenin proteins in the tumor tissues were determined by immunohistochemical staining.

RESULTS

The expression levels of FZD7, WANT5B and GSK3 proteins were significantly reduced in the HCC70 cells transfected with the target siRNAs. Meanwhile, the activity of WNT/β-catenin was enhanced and PI3K/AKT/mTOR pathway was inhibited. PI3K/AKT/mTOR inhibitors suppressed MCF-7 and SK-BR3 cell proliferation. The IC50 of GDC-094, BKM120, XL147, perifosine, everolimus, and BEZ235 in MCF-7 cells were 0.46 mmol/L, 1.44 mmol/L, 4.34 mmol/L, 11.35 μmol/L, 53.71 μmol/L and 12.87 μmol/L respectively, and 0.63 mmol/L, 0.58 mmol/L, 3.74 mmol/L, 13.22 μmol/L, 60.00 μmol/L and 11.38 μmol/L in the SK-BR3 cells, respectively. The results of luciferase report gene assay showed that the luciferase activities in HCC70, MCF-7 and SK-BR3 cells treated with BKM120 were 1.75±0.05, 1.13±0.02 and 0.43±0.01, respectively. The luciferase activities in HCC70 and SK-BR3 cells were significantly different from that of the control cells (1.00±0.02, P<0.05). The immunohistochemical analysis showed that BKM120 inhibited mTOR activity, and the enhanced WNT/β-catenin activity reversed the phenotype of inhibitory mTOR induced by BKM120. BKM120 suppressed the tumorigenic ability of MCF-7 and SK-BR3 cells in vivo, but had no effect on cultured HCC70 cells. The immunohistochemical analysis showed nuclear translocation of β-catenin protein and increased expression level of p-LRP-6 protein in transplanted tumor tissues from HCC70 cells treated with BKM120, increased the level of p-LRP-6 protein, and no changes of p-4EBP1 protein expression. However, no nuclear translocation of β-catenin protein and no decrease of p-LRP6 and p-4EBP1 protein levels in the transplanted tumor tissue of MCF-7 cells after treatment with BKM120.

CONCLUSIONS

The triple-negative breast cancer HCC70 cells have drugs-resistance to PI3K inhibitors. The WNT/β-catenin signaling pathway may regulate the PI3K/AKT/mTOR pathway, therefore, inducing the drug-resistance of TNBC cells to PI3K inhibitors.

Haematopoiesis in molluscs: A review of haemocyte development and function in gastropods, cephalopods and bivalves

Haematopoiesis is a process that is responsible for generating sufficient numbers of blood cells in the circulation and in tissues. It is central to maintenance of homeostasis within an animal, and is critical for defense against infection. While haematopoiesis is common to all animals possessing a circulatory system, the specific mechanisms and ultimate products of haematopoietic events vary greatly. Our understanding of this process in non-vertebrate organisms is primarily derived from those species that serve as developmental and immunological models, with sparse investigations having been carried out in other organisms spanning the metazoa. As research into the regulation of immune and blood cell development advances, we have begun to gain insight into haematopoietic events in a wider array of animals, including the molluscs. What began in the early 1900's as observational studies on the morphological characteristics of circulating immune cells has now advanced to mechanistic investigations of the cytokines, growth factors, receptors, signalling pathways, and patterns of gene expression that regulate molluscan haemocyte development. Emerging is a picture of an incredible diversity of developmental processes and outcomes that parallels the biological diversity observed within the different classes of the phylum Mollusca. However, our understanding of haematopoiesis in molluscs stems primarily from the three most-studied classes, the Gastropoda, Cephalopoda and Bivalvia. While these represent perhaps the molluscs of greatest economic and medical importance, the fact that our information is limited to only 3 of the 9 extant classes in the phylum highlights the need for further investigation in this area. In this review, we summarize the existing literature that defines haematopoiesis and its products in gastropods, cephalopods and bivalves.

Orientation-dependent nanostructure arrays based on anisotropic silicon wet-etching for repeatable surface-enhanced Raman scattering

Repeatable fabrication of sensitive plasmonic substrates through a simple procedure has become a major challenge for SERS-based sensing and imaging. Herein, a new class of high-performance SERS substrates, including pyramid, ridged-hexagon, and quasi-triangle nanostructures, is successfully fabricated based on the nanosphere lithography technique and anisotropic wet etching. Using the wafer-scale Cr-hole array as the etching mask, cavity-templates of various configurations are fabricated by the orientation-dependent wet etching technique, from where the nanostructure arrays are finally peeled-off. The anisotropic wet etching on (100), (110), and (111) silicon wafers has been systematically studied at the nanoscale revealing the formation mechanism of these cavity-templates. The peeled-off nanostructure arrays provide high-density tips and/or gaps (about 2.5 × 10(7) mm(-2)) and thus facilitate the generation of "hot spots". The distribution of the electromagnetic field is visualized by the finite difference time domain calculation. And the calculation results are validated by SERS characterization. The SERS enhancement factors of these substrates are in the order of 10(6)-10(7), with the maximum enhancement factor of 1.32 × 10(7) yielded by the ridged-hexagon arrays. The proposed nanostructure arrays present excellent homogeneity and reproducibility (with the largest relative standard deviation of 16.43%) for the reason that the SERS-active substrates are peeled-off from an identical template. The cost-effective fabrication, high sensitivity, good homogeneity and well-performed reproducibility demonstrate that these orientation-dependent NSs are good candidates for SERS-based in vitro and in situ detection and biosensing.

Copper bioavailability, blood parameters, and nutrient balance in mink

A 3 × 3 + 1 factorial experiment was conducted based on a completely randomized design to evaluate the effects of different sources of copper on plasma metabolites, nutrient digestibility, relative copper bioavailability, and retention of some minerals in male mink. Animals in the control group were fed a basal diet, which mainly consisted of corn, fish meal, meat and bone meal, and soybean oil, with no copper supplementation. Mink in the other 9 treatments were fed the basal diet supplemented with Cu from reagent-grade copper sulfate (CuSO4), tribasic copper chloride (TBCC), or copper methionine (CuMet). Copper concentrations of the experimental diets were 50, 100, and 150 mg Cu/kg DM. Blood samples were collected via the toe clip at the end of study (d 42) to determine blood hematology and blood metabolites. A metabolism trial of 4 d was conducted during the last week of experimental feeding. There was a linear (P < 0.01) effect of dose of Cu on plasma Cu concentrations, ceruloplasmin concentration, and Cu-Zn superoxide dismutase activity. A linear response to Cu dose was noted for fat (P < 0.05) digestibility. Supplemental dose of Cu linearly increased (P < 0.05) liver Cu and decreased (P < 0.05) liver Zn level but did not alter liver Fe. The concentration of liver Cu of the mink fed with TBCC and CuMet diets was greater (P < 0.05) than that fed CuSO4. Compared with CuSO4 (100%), relative bioavailability values of TBCC were 104 and 104%, based on serum ceruloplasmin and liver copper, respectively, and relative bioavailability values of CuMet were 130 and 111%. CuMet and TBCC are more bioavailable than CuSO4. In conclusion, the relative bioavailability of CuMet obtained in this study was greater than that of CuSO4 and TBCC. Dose of Cu had an important effect on the regulating ceruloplasmin concentration, Cu-Zn superoxide dismutase activity, and the digestion of dietary fat in mink.

Synergistic mechanisms of retigeric acid B and azoles against Candida albicans

AIMS

To clarify the underlying synergistic antifungal mechanisms of retigeric acid B (RAB) in combination with azoles against Candida albicans.

METHODS AND RESULTS

Increased accumulation of rhodamine 123 in C. albicans was measured by both spectrophotometric method and flow cytometry. The inhibitory properties to the drug efflux of C. albicans were determined spectrophotometrically. The decreased cellular ergosterol synthesis was measured using its unique spectrophotometric absorbance profile, and the downregulation expression levels of CDR1 and ERG11 were detected by real-time reverse transcription polymerase chain reaction. Transmission electron microscopy investigation found the wrinkled cell membrane and the impaired cell wall.

CONCLUSIONS

RAB synergizes the antifungal effect of azoles against C. albicans by inhibiting efflux pump activity, targeting the ergosterol biosynthesis pathway and increasing the fluidity for the resulted ergosterol depletion.

SIGNIFICANCE AND IMPACT OF THE STUDY

Investigating the mechanism of the synergy between RAB and azoles against C. albicans will help us to uncover the antifungal roles of this lichen-derived triterpene acid and find its possible clinical applications in overcoming fungal resistance.

Sulfated polysaccharides and immune response: promoter or inhibitor?

Sulfated polysaccharides, which frequently connect to core protein, are expressed not only on cell surface but also throughout the extracellular matrix. Besides providing structural integrity of cells, sulfated polysaccharides interact with a variety of sulfated polysaccharides-binding proteins, such as growth factors, cytokines, chemokines and proteases. Sulfated polysaccharides play two-edged roles, inhibitor and promoter, in immune response. Some sulfated polysaccharides act as the immunosuppressor by blocking inflammatory signal transduction induced by proinflammatory cytokines, suppressing the activation of complement and inhibiting the process that leukocytes adhere to and pass through endothelium. On the contrary, the interaction between immune cells and sulfated polysaccharides produced by bacteria, endothelial cells and immune cells initiate the occurrence of immune response. It promotes the processes of recognizing and arresting antigen, migrating transendothelium, moving into and out of immune organ and enhancing the proliferation of lymphocyte. The structure of sulfated polysaccharides, such as molecular weight and sulfated sites heterogeneity, especially the degree of disaccharide sulfation, position of the sulfate moiety and organization of sulfated domains, may play critical role in their controversial effects. As a consequence, the interaction between sulfated polysaccharides and sulfated polysaccharide-binding proteins may be changed by modifying the structure of sulfated polysaccharides chains. The administration of drug targeting sulfated polysaccharide-protein interaction may be useful in treating inflammatory related diseases.

New strategy of antiangiogenic therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumor, and tumor progression and prognosis is associated with angiogenesis. Extracellular matrix remodeling and inflammation play important roles in hepatocarcinogenesis. Some ingredients of extracellular matrix such as endostatin and sulfated polysaccharide, some immunomodulatory agents and cox-2 inhibitor suppress the angiogenesis of HCC. Because vasculogenic mimicry is associated with high tumor grade, some differentiation agents are used to inhibit antiagiogenesis. Besides suppressing the proliferation directly, somatostatin inhibits angiogenesis to suppress growth indirectly. Copper chelator prevents copper from functioning as a cofactor in angiogenesis. The renin-angiotensin system is frequently activated in patients with chronic liver diseases. Perindopril, an angiotensin converting enzyme inhibitor, inhibits angiogenesis by reducing vascular endothelial growth factor (VEGF) production. Kinase inhibitors of VEGF and epidermal growth factor receptors are expected to be of benefit for some patients. Following transarterial embolisation and/or resection, antiangiogenic therapy could prevent the recurring and metastasis. Hypoxia enhances the proliferation, suppresses the differentiation and apoptosis, and induces multidrug resistance of HCC. Because antiangiogenic therapies induce hypoxia, it should be borne in mind the side affects of antiangiogenic therapy. Because long-acting antiangiogenent are needed to control cancer, it needs more clinical studies to confirm the drug resistance of antiangiogenetic therapy.

Effects of sulfated polysaccharides on tumour biology

Sulfated polysaccharides can act not only as anticoagulants but also as tumour inhibitors. Recent studies suggest that sulfated polysaccharides could affect tumour cells directly. Sulfated polysaccharides could inhibit the metastasis and proliferation of tumour cells by binding to growth factors and cell adhesion molecules. Moreover, sulfated polysaccharides could inhibit heparanase, which cleaves heparan sulfate chains of heparan sulfate proteoglycans and cause release of growth factors sequestered by heparan sulfate chains. Some sulfated polysaccharides can induce apoptosis and differentiation of tumour cells, but the mechanism is uncertain. In addition, sulfated polysaccharides can enhance the innate and adaptive immune response for tumour cells. Thus, the anti-tumour mechanism of sulfated polysaccharides can be explained, at least partly, through the effects on tumour biology directly.

Cell-matrix talks: effects on differentiation of hepatocellular carcinoma

Different event is a process that is dependent on stimulation of extracellular signals, signal transduction and gene express. Malignant transformation of hepatocytes may occur in cirrhosis, which is the result of extracellular matrix (ECM) remodeling. ECM could affect and maintain the differentiated phenotype of hepatocytes by regulating liver transcription factors. Moreover, ECM remodeling is correlated with dedifferentiation of hepatocellular carcinoma (HCC). Integrin-matrix adhesion system and E-cadherin/catenin adhesion complex mediate the cell-matrix interaction through focal adhesion kinase, extracellular-signal-regulated kinases and beta catenin/Wnt pathway. The different event of HCC compared with the reversion of abnormal cell-matrix interaction. New drugs that are power for regulating cell-matrix interaction may represent a novel therapeutic strategy for HCC.

Sulfated oligosaccharides and tumor: promoter or inhibitor?

The topic about the role of sulfated oligosaccharides in carcinogenesis and progression of tumor remains controversial. The present review aims to evaluate the role of sulfated oligosaccharides in carcinogenesis and progression of tumor. The modification of sulfated oligosaccharides, especially chondroitin sulfate and heparan sulfate, is an important event in carcinogenesis and is correlated with the degree of differentiation. Enhance of chondroitin sulphate may promote carcinogenesis, while enhance of heparin sulphate may promote metastasis. Resistance of antiproliferation activity of sulfated oligosaccharides may contribute to the aberrant behavior of the cancer cell. Some researches supported that sulfated proteoglycan on the cell surface may enhance metastasis; while some soluble sulfated oligosaccharides could suppress metastasis. Thus, sulfated oligosaccharides play double roles, promoter or inhibitor, in carcinogenesis and tumor progression. Four topics about the correlation between sulfated oligosaccharides and carcinogensis and progression are very interesting and must be identified: whether the modified sulfated oligosaccharides have a different effect from the unmodified sulfated oligosaccharides; whether different sulfate oligosaccharides have the different action; whether the function of sulfated proteoglycan on the cell surface is different from that of soluble sulfated oligosaccharides; whether the function of sulfated oligosaccharides in primary tumor is different from that in metastasis tumor. Further data on the long-term safety of sulfate oligosaccharides for cancer patients are therefore required to allow overall risk-benefit assessments.

Surface and bulk interchange energy in binary mixtures of chain molecules

The interchange (interaction) parameter, controlling the phase behaviour of a binary mixture, is determined for the bulk and the surface of binary mixtures of different types of chain molecules, using surface tensiometry and a mean-field theory. For all mixtures and concentrations studied an identical behaviour is observed at the surface, depending only on the square of the reduced chain length mismatch delta n/n, where delta n and dealta n are the difference in and average of the number of carbons of the two components.

Antimicrobial susceptibility of Neisseria gonorrhoeae strains isolated in Guangzhou, China, 1996-2001

OBJECTIVE

To investigate the in vitro antimicrobial susceptibility and resistant trends of Neisseria gonorrhoeae strains isolated in Guangzhou, from 1996 to 2001.

METHODS

The agar dilution method was used to determine the minimum inhibitory concentrations (MICs) to four antimicrobials, penicillin G, ciprofloxacin, ceftriaxone, and spectinomycin. The resistance of all strains to four antibiotics was interpreted according to criteria used in the project of surveillance of gonococcal antibiotic susceptibility in the WHO Western Pacific Region. Penicillinase producing N gonorrhoeae (PPNG) was analysed by the paper acidometric method.

RESULTS

793 consecutive N gonorrhoeae isolates collected in Guangzhou were studied from 1996 to 2001. A total of 55 strains of PPNG were identified and the prevalence rapidly spread from 2% to 21.8%. Of the four antibiotics examined, ceftriaxone and spectinomycin appeared to be the most effective agents although two spectinomycin resistant strains were isolated in 1996. Their MIC(50), MIC(90), and geometric mean MIC (MICmean) were all between the sensitive ranges of the interpretative criteria and remained stable over the years. However, resistance increased continuously to penicillin G and dramatically to ciprofloxacin. In 1996-2001, MIC(50), MIC(90), and MICmean of penicillin G increased from 1 micro g/ml to 2 micro g/ml, 4 micro g/ml to 32 micro g/ml, and 0.68 micro g/ml to 2.35 micro g/ml, respectively; those of ciprofloxacin steeply increased from 0.12 micro g/ml to 4 micro g/ml, 2 micro g/ml to 32 micro g/ml, and 0.14 micro g/ml to 2.62 micro g/ml in 1996-9, respectively, and then declined slightly in 2000-1. The prevalence of resistant isolates spread from 57.2% to 81.8% for penicillin G and from 17.6% to 72.7% for ciprofloxacin over the 6 years.

CONCLUSION

Resistance to penicillin and ciprofloxacin increased greatly during 1996-2001. Ceftriaxone and spectinomycin should be used as the first line agents in treating gonorrhoea. It is of great importance to continuously survey the susceptibilities of N gonorrhoeae to antibiotics in controlling the spread of gonococcal infections.

Surface freezing in binary mixtures of chain molecules. I. Alkane mixtures

X-ray surface scattering and surface tension measurements are used to study surface freezing in molten mixtures of alkanes. These binary mixtures consist of protonated and deuterated alkanes, as well as of alkanes of different lengths. As for pure alkanes, a crystalline monolayer is formed at the surface a few degrees above the bulk freezing temperature. The structure of the monolayer has been determined on an angstrom scale. A simple theoretical approach is used to account for the thermodynamical observations at the surface and in the bulk. The model is based on a competition between entropic mixing and a repulsive interaction due to chain-length mismatch. The surface and bulk liquid phases are treated as ideal mixtures, while the solid phases are treated as regular mixtures. The theory is found to account well for all the mixtures studied, both hydrogenated-hydrogenated and hydrogenated-deuterated. The repulsive interaction and its dependence on the chain lengths of the components are determined from fits to the measured data.

Miniaturization of capillary isoelectric focusing

Miniaturization of whole-column imaging capillary isoelectric focusing (CIEF) is discussed. A 1.2 cm capillary was used as a separation column for CIEF. The experimental results for the analysis of two pI markers and the protein myoglobin showed that good CIEF separation results could be obtained. Secondly, a light-emitting diode (LED) was used as the light source for the whole-column absorbance imaging detection. The focusing of both the pI markers and myoglobin were observed with the LED light source. The whole-column imaging CIEF instrument was simplified and miniaturized by the use of the LED. Further developments are also discussed.

Dynamic realization of transport phenomenon in finite system

Exploring the Fokker-Planck or Langevin type transport equation from the underlying dynamics, we study by exploiting the numerical simulations whether or not one may expect dissipative motions in a Hamilton system with finite degrees of freedom without introducing any statistical concept. It will be shown that the macro-level transport phenomenon in a finite system can be dynamically established from the underlying Hamilton system, and the nonlinear coupling between two subsystems is decisive for generating the transport phenomenon.

The effect of mutation at valine-45 on the stability and redox potentials of trypsin-cleaved cytochrome b5

In an attempt to elucidate the determinants of redox potential and protein stability in cytochrome b5, three mutants at a highly conserved residue Val45, which is a member of heme hydrophobic pocket residues have been characterized. The V45Y mutant was designed to introduce a bulkier residue and a hydroxyl group to the heme pocket. The mutants V45H and V45E were constructed to test the effect of positive and negative charge on the stability and redox potential of proteins. The influence of these mutants on the protein stability towards thermal, urea, acid, ethanol and on the redox potential were studied. It is concluded that the decrease of hydrophobic free energy and the larger volume of the tyrosine make the phenylhydroxyl group of tyrosine still sitting inside the hydrophobic pocket, while the side chain of the mutant V45E and V45H shift away from the heme pocket. The redox potentials of mutants V45Y, V45H, V45E and wild-type of cytochrome b5 are -35 mV, 8 mV, -26 mV and -3 mV, respectively. The bigger change of the V45Y on redox potential is due to the close contact between the hydroxyl group and the heme, while the changes of the V45E and V45H result from the alteration of charge density and distribution around the heme. Different relative stability of these mutants towards heat have been observed with the order: WT > V45Y-V45H > V45E being both in the oxidized and reduced state. The relative stability induced by addition of urea decreases in the order: WT > V45Y > V45H > V45E. These results suggest that the difference in the hydrophobic free energy is a major factor contributing to the stability of the Val45 mutants. Also the loose of the helix III in the mutant V45E makes it more unstable. These results indicate that residue Val45 plays an important role in the stability and redox potential of the protein.

Role of nitric oxide in vascular hyper-responsiveness to norepinephrine in hypertensive Dahl rats

OBJECTIVE

To determine whether the abnormal vascular responses observed in salt-sensitive hypertension are caused by an impairment in vascular nitric oxide function.

DESIGN

Isometric tension was measured in aortic rings isolated from Dahl salt-sensitive and salt-resistant rats fed a regular-salt (0.4% NaCl) or a high-salt (8% NaCl) diet, with and without inhibition of endogenous nitric oxide synthesis.

METHODS AND RESULTS

Systolic arterial pressure, measured weekly by the tail-cuff method, increased markedly in DS rats with a high-salt diet but did not increase in the other groups. In aortic rings, norepinephrine evoked dose-dependent contractions which were significantly increased in rings from DS rats with a high-salt diet Pretreatment with Nomega-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, increased the norepinephrine-induced contraction in all groups and abolished differences in contractile responses between high-salt DS rats and the other groups. Acetylcholine induced endothelium-dependent relaxation, which was significantly depressed in high-salt DS rats. L-NAME attenuated the acetylcholine-induced relaxation in all groups and abolished the difference in relaxation response between high-salt DS rats and the other groups. Sodium nitroprusside-induced relaxation was significantly depressed in high-salt DS rats.

CONCLUSIONS

Vascular hypercontractile responses to norepinephrine in DS hypertensive rats can, in part, be explained by an impairment in endothelial nitric oxide production.

[Mechanism of injury of intestine, liver and lung in acute cholangitis of severe type model and the protective effect of huoxue qingjieling]

Lung capillary permeability was measured with 125I labelled bovine serum albumin, the progression of hepato-cellular injury was quantitatively assessed using atriphenyltetrazolium chloride assay, injury of small intestinal mucosa was determined by the changes of diamine oxidase (DAO) level, content of oxygen free radicals (OFR) was measured by electron spin resonance spectrometer and levels of phospholipase A2(PLA2) of intestine, hepatocellular viability were observed by bioassay methods respectively. The results showed that function of lung, liver and intestine was seriously injuried in ACST rats. These injuries demonstrated by increase of capillary permeability and decrease of hepatocellular viability as well as DAO in intestinal mucosa (P < 0.01) in comparing with control, while the levels of OFR and PLA2 in the above-mentioned 3 organs were elevated simultaneously (P < 0.01). As for the comparison of efficacy of different treatment, Huoxue Qingjieling was the best one, the bile duct decompression or ampicillin showed little benefit on injury protection even aggravated in some tissues, they displayed a close relationship with their influence on the OFR and PLA2. Besides, the levels of OFR or PLA2 in various tissues were different from each other, therefore, the serum levels of OFR or PLA2 can not reflect the real levels occurred in organ or tissue level.

Separation and determination of some stereoisomers by capillary gel electrophoresis with cyclodextrin incorporated in polyacrylamide gel

Capillary gel electrophoresis (CGE) was successfully applied to the separation of optically active isomers and position isomers by incorporating a suitable cyclodextrin chiral selector in polyacrylamide gel. A commercially available ss-cyclodextrin (ss-CD) was used for enantioselectivity towards o-, m- and p-nitrobenzoic acid, o-, m- and p-hydroxybenzoic acid, o-, m- and p-toluic acid and the optical isomers of dansyl-D,L-leucine and R,S-1,1'-binaphthyl-2,2-dihydrogenphosphate. Especially the effect of organic solvents, such as acetonitrile, methanol, dimethylsulphoxide and others were examined in detail. The resolution varied to some extent with the addition of the organic solvent to the polyacrylamide gel and the running buffer solution. The possible mechanism has also been discussed. In addition, quantitative aspects of the separation of stereoisomers using CGE have been studied, showing that both the resolution and accuracy of the determinations were affected by the ratio of the enantiomers.

Fluorescence imaging detection for capillary isoelectric focusing

A simple laser-induced fluorescence (LIF) imaging detector and an ultrasensitive LIF imaging detector are described for capillary isoelectric focusing (CIEF). An argon ion laser beam of 496.5 nm is used as excitation source. In the simple LIF imaging detector, the excitation beam is directed into a capillary column by an optic fiber array. In the ultrasensitive LIF imaging detector, the laser beam is first expanded, then is focused into the 4.5 cm long capillary column by a cylindrical lens. Fluorescence emission is detected by a charge-coupled device (CCD) camera. The feasibility and performance of the LIF imaging detector system for CIEF are first verified with a naturally fluorescent protein, b-phycoerythrin. Then, the ultrasensitive LIF imaging system is used as a detector for CIEF of proteins labeled with fluorescein isothiocyanate (FITC). Three FITC-labeled proteins (i) alpha-D-galatosylated FITC-albumin, (ii) insulin-FITC, and (iii) casein-FITC, are used as model samples. Fluorescence images of the model samples are measured during the CIEF process. The focusing of the protein samples is complete in about 1.5 min. The ultrasensitive detector's detection limits for the FITC-labeled proteins are at the level of 10(-10) M, and the mass detection limits are about 4.5 x 10(-17) mole, even though only 10% of the fluorescence emission is collected. Therefore, the method is capable of separating and detecting 10(-11) M or amole (10(-18) mole) level protein samples with a band-pass filter more specific to the fluorescence light.(ABSTRACT TRUNCATED AT 250 WORDS)

Termination of early pregnancy by two regimens of mifepristone with misoprostol and mifepristone with PG05--a multicentre randomized clinical trial in China

A multicentre randomized open clinical trial was conducted to compare the efficacy and side effects of two regimens of mifepristone with misoprostol, and mifepristone with PG05 for termination of early pregnancy (amenorrhoea < = 49 days). Six-hundred women in early pregnancy, who requested medical abortion were randomly allocated into 3 groups. In group 1 (n = 301), an initial dose of mifepristone 50 mg was given, followed by 25 mg every 12 hours up to a total dose of 150 mg mifepristone, plus a single oral dose of misoprostol 600 micrograms in the morning of the third day. In group 2 (n = 150), the same regimen of mifepristone was given, but dl-15-methyl PGF2 alpha (PG05) 1 mg vaginal suppository was inserted on the third day. In group 3 (n = 149), a single dose of mifepristone 200 mg was given and misoprostol 600 micrograms was used as in group 1. The complete abortion rate were 94.4%, 97.3%, and 94.6% for group 1, 2 and 3, respectively. 3.0, 2.0 and 2.7% of women had incomplete abortion, and 1.7, 0.7 and 2.0% of women in the 3 groups were treatment failures; in the remaining 1% in group 1 and 0.7% in group 3, treatment outcome could not be determined. There were no significant differences among the 3 groups. Lower abdominal pain was the main complaint which was reported by 82% of the subjects after PGs administration. The incidence of diarrhoea in PG05 group (38.7%) was significantly higher than that in the other two groups (21.6 and 20.1%) (P < 0.001), and so was vomiting. It was concluded that misoprostol, as an orally effective prostaglandin, in combination with mifepristone for induced abortion of early pregnancy was as effective as PG05 vaginal suppository. Besides, it has advantages of convenience of use, less side effects, easy storage and transfer, and low cost.

[Effects of dachengqi decoction on gut hormones and intestinal movement after cholecystectomy]

In order to elucidate the mechanism of postoperative intestinal dysfunction and the effects of Dachengqui Decoction (DCQD) on it, somatostatin (SS), gastrin (GAS), vasoactive intestinal polypeptide (VIP), substance P (SP), motilin (MOT) and atrial natriuretic peptide (ANP) were determined, frequency and spectrum of peristaltic sound were simultaneously analyzed in 31 subjects undergoing cholecystectomy, the value of pre-, post-operation and post-medication were compared. Plasma SS and MOT decreased postoperatively (P < 0.05), DCQD elevated SS and MOT to higher level than preoperation, VIP, SP increased for half fold (P < 0.05). Gurgling sound diminished after operation, whereas DCQD normalized it. Peak frequency (Fmax) of gurgling ranging from 234.4 to 468.2 Hz preoperatively, mean frequency (FA) was 341.8 +/- 30.9 Hz postoperatively. FA reduced to 322.3 +/- 79.4, DCQD elevated it to 374.2 +/- 57.1 Hz. The result suggested that intestinal motility was disturbed after cholecystectomy, bowel was in dystonic status, accompanying with decreased plasma MOT, DCQD promoted intestinal peristalsis and enhanced it's tonus. The influence of gut peptides might be one of the important pathway that DCQD works.

[Long-term clinical observation on VCu200 intrauterine devices]

A comparative study was carried out in 350 women using VCu200 intrauterine devices (IUD) and 350 women using stainless steel ring (SSR) IUD for 5-18 years. The endometrial changes and shapes of IUD were studied. The results showed that the pregnancy rate was significantly lower in VCu200 group after 5 years of insertion. In spite of the oxidation, erosion or breakage of the copper wire, calcium deposit of even deformation of the IUD, they were not associated with an increased incidence of endometrial carcinoma and pelvic inflammatory disease. It is suggested that VCu200 IUD need not to be removed if the IUD keeps normal shape and the copper wire remains intact by X ray examination.

[Effects of Tripterygiitotorum in the treatment of insulin dependent diabetes mellitus with islet transplantation]

The therapeutical efficacy of islet transplantation in treating insulin-dependent diabetes mellitus (IDDM) patients is marked for a short time and the long-term efficacy is unsatisfactory. So 30 IDDM patients given tripterygiitotorum (T II) were compared with 24 IDDM patients without using any immunosuppressive agents after islet transplantation.

RESULTS

prior to transplantation both the numbers of T lymphocyte subpopulations such as CD2, CD4, CD8 and the concentrations of C-peptide in all IDDM patients were lowered; after transplantation the numbers of CD2, CD4 were significantly elevated (P < 0.01), the ratio of CD4/CD8 in control group was higher than that in TII group (P < 0.01), while the concentration of C-peptide were greatly increased (normal: 2.24 +/- 0.34; before transplantation: 0.21 +/- 0.01; 15 days after transplantation: 3.24 +/- 1.2 ng/ml). The peak value of C-peptide in TII group began decreasing half a year after transplantation and it gradually dropped to the baseline level. The dose of insulin all were significantly reduced, and 3 patients stopped altogether. Half a year after transplantation TII group remained stable for the requirement of insulin, whereas the control group gradually increased the dose of insulin. (1) Islet transplantation could adjust the immunological disorder in IDDM patients, increase the numbers of T lymphocyte subset such as CD2, CD4, CD8 while the chronic immuno-rejective response occurred. (2) T II inhibited both the numbers and function of T lymphocyte subpopulation and normalized the ratio of CD4/CD8. (3) TII prolonged the survival time of grafts in IDDM patients and suppressed immunological rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental study on the occlusion of arterial blood flow by the implantation of nitinol alloy stents

To evaluate the occlusion of arteries, 6 conic intravascular endoprosthetic stents of titanium-nickel alloy were implanted transluminally to the right external iliac arteries in 2 normal dogs and 4 normal pigs. The stent was characterized by ductility below 313 K (40 degrees C) and restoration memory-shape between 313-319 K. The diameter of the large end of conic stent was 4.0 mm (dog) and 4.5 mm(pig). The topographic anatomy showed that the external iliac artery was near complete occlusion, with a very small residual lumen (about 1 mm in diameter) in dogs at 6 months, with complete occlusion in pigs at 8 months. The histopathological examination indicated that the arterial intima of the upper branch from the stented site was smooth, and that neither inflammatory cell infiltration nor foreign giant cell reaction was found. The newly formed granulation tissue inside the stent came from emboli organization. These results suggest that the shape-memory alloy stent has good biocompatibility and the conic intravascular endoprosthetic stent might completely occlude arterial blood flow.

Surface Tension Measurements of Surface Freezing in Liquid Normal Alkanes

Surface tension measurements reveal surface freezing in liquid n-alkanes. A solid monolayer of molecules is found to exist up to 30 degrees C above the bulk freezing point. This surface phase exists only for carbon numbers 14 n </= 50. The measured carbon number and temperature dependence of the surface tension is interpreted within a simple thermodynamical model based on known bulk latent heat data and surface energy considerations. The vanishing of the surface phase for n </= 14 is a possible transition from surface freezing to surface melting behavior.

[Lipopolysaccharide-induced cellular immunity response and effect of herbal purgation method in intra-abdominal infection]

The alterations of cytokines (TNF,PGE2), plasma lipopolysaccharide and their prognostic influences in 58 patients with intra-abdominal infection were observed with ELISA and RIA. The effect on physiopathologic process with herbal purgation method was explored. The results showed that as the level of plasma LPS raised the serum TNF, plasma PGE2 elevated obviously and the cellular immunity inhibited elevated in treatment and control groups. There was a linear positive correlation between the plasma LPS and the serum TNF in control group. Between the plasma PGE2 and CD4 lymphocytes of peripheral blood, it existed a linear negative correlation in treatment group. After two treatment courses, the recovery of abnormal indexes in treatment group was earlier than that in control group accompanied by escalation of lessened toxicity rate of LPS, more rapid in reducing the level and detectable rate of serum TNF, and the lowering of complication rate successively and the inhibition of cellular immunity tended to be relieved in treatment group.

[Immune function and abdominal surgery in blood stasis syndrome in patients with gastrointestinal diseases]

52 Patients with Blood Stasis Syndrome (BSS) in abdominal surgical diseases were divided into 3 types according to their symptoms, signs and natures of diseases. Peripheral blood T lymphocyte subsets of these BSS patients and 12 healthy persons were studied with Flow Cytometry and monoclonal antibodies. The immunoglobulins and complements of these cases were also studied. There were no difference in T cell subsets, immunoglobulins and complements between Qizhi-BSS group and normal control. The Shire-BSS group showed that CD8 cell, IgG, IgM, and C1, C3c were increased. These results showed that the immune response increased in this type of BSS patients. In the Qixu-BSS group, the CD3 was nearly normal, and the CD4+, CD4+/CD8+ ratio, and CD16+ were statistically decreased. However, the CD8+ cells markedly increased, the IgG, IgM and IgD were also lowered significantly in this type. The marked morphologic abnormal changes in ultrastructures of T lymphocyte were found in 6 patients with Qixu-BSS group. These results showed that the Qixu type of Blood Stasis Syndrome patients were in the immuno-suppressive status.

[Determination of partially cellular and local immune function in patients with spleen deficiency syndrome]

The immune function status as reflected by the peripheral blood OKT system T cell subset classification and the lymphocyte in vitro interleukin 2 (IL2) secretory function were determined in 30 patients with Spleen deficiency syndrome and 20 normal subjects in this study. Experimental results decreased cellular immune function and disturbance of immune regulatory mechanism in the patients. Its manifestations were decreased number of total T lymphocytes and helper T cells (Th), relatively increased suppressor T cells (Ts), abnormal rate of Th to Ts, no marked change of IL2 secretory function of T cell in vitro, increased SIgA level before stimulating with acid but marked decreased SIgA level after stimulating. All these suggest the compensatory stage of local immune function.

Sigma compounds derived from phencyclidine: identification of PRE-084, a new, selective sigma ligand

A series of compounds derived from phencyclidine (PCP) was examined in the sigma receptor and PCP receptor binding assays. The derivatives included compounds containing methylene, ethylene or carboxyl ethylene insertion between the cycloalkyl ring and the amine group of PCP. Various phenyl substitutions, cycloalkyl rings and amines of these derivatives were also examined. The methylene and ethylene insertions decreased the compounds' potencies at PCP receptors, whereas they increased the potencies at sigma receptors. The carboxyl ethylene insertion produced compounds with negligible potencies at PCP receptors while possessing high potencies for sigma receptors. One derivative (PRE-084; 2-(4-morpholino)ethyl 1-phenylcyclohexane-1-carboxylate hydrochloride) had an IC50 of 44 nM in the sigma receptor assay, an IC50 of more than 100,000 nM for PCP receptors and an IC50 higher than 10,000 nM in a variety of other receptor systems. In general, compounds with hydroxy-substituted phenyl groups tended to have decreased potency at sigma receptors, whereas methylphenyl and chlorophenyl substitutions increased potencies. Reduction of cycloalkyl ring size decreased potencies for sigma receptors and quaternized amine groups invariably lowered the compound's potencies. Conformational analysis indicated that PRE-084 fitted onto a pharmacophore model for the sigma ligands. The study describes a new, highly selective ligand for the sigma receptor. The results of this study also confirm distinctly different structural requirements for binding to sigma and PCP receptors and provide a new structural consideration for synthesizing sigma-selective compounds.

Assessing fluoroscopic contrast resolution: a practical and quantitative test tool

Fluoroscopic contrast resolution is commonly determined at a specified kVp by imaging a test object comprised of targets where contrast decreases gradually and sequentially. Threshold contrast or contrast resolution is the contrast of the lowest contrast target that can be perceived. This approach suffers from two problems. First, test object contrast is specified at a x-ray tube voltage that is not always obtainable in practice. Second, the small change in contrast between adjacent targets contributes to observer variability making consistent and reproducible contrast threshold determinations difficult. Described is a contrast resolution test tool that eliminates or reduces these problems. The novel target arrangement allows one to quickly and easily specify the contrast resolution of a fluoroscopic imaging chain to a precision approximately equal to 0.5%. Tables of target contrast versus x-ray tube potential are developed that permit one to employ the test object for contrast resolution determination over the normal range of tube potentials encountered on clinical units.

Molybdenum target x-ray spectra: a semiempirical model

A semiempirical model for generating molybdenum target x-ray spectra is presented. The model is an extension of a previous model developed by the authors for tungsten and takes into account the depth of production for both bremsstrahlung and characteristic x-ray photons. As in the previous work, the optimal model parameters were determined using nonlinear least-squares fits to experimental data. Good agreement between the two was obtained. By varying target angle, off-axis angle, and filtration in the model in accordance with the x-ray tube and geometry of interest, results consistent with tabulated spectra for different conditions have been obtained.

Electrophysiological and binding studies on intact NCB-20 cells suggest presence of a low affinity sigma receptor

Whole cell voltage clamp studies were performed on NCB-20 cells to examine physiological responses to drugs possessing affinities for sigma receptors. Those drugs [haloperidol, alpha-(4-fluoro-phenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazinebutano l (BMY-14802), pentazocine, N-allylnormetazocine (SKF-10047), 3-(3-hydroxyphenyl)-N-(1-propyl)piperidine (3-PPP), phencyclidine, 1-[1-(2-thienyl)cyclohexyl]piperidine (TCP), (+)-5-methyl-10,11-dihydro-5H-dibenzo-[a,d]cyclohepten-5,10-imine maleate (MK-801)] caused an apparent inward current, which was due to blockade of a tonic, outward potassium current. The rank order of drug potencies in producing this effect generally resembled the rank orders of sigma-receptor affinities for the drugs, except that a reverse stereoselectivity was observed for several drugs. [3H](+)-SKF-10047 labeled two sites in intact NCB-20 cells (Kd = 49 nM, Bmax = 1.0 pmol/mg protein and Kd = 9.6 microM, Bmax = 69 pmol/mg protein). The high affinity site was similar pharmacologically to the sigma receptor assayed in membrane fragments from NCB-20 cells. However, the low affinity site showed a slightly different profile, highlighted by a reverse stereoselectivity. The rank order of drug potencies was as follows at the low affinity site: haloperidol greater than BMY-14802 greater than (-)-pentazocine greater than (+)-pentazocine greater than (-)-SKF-10047 greater than (-)-3-PPP greater than (+)-SKF-10047 greater than (+)-3-PPP greater than phencyclidine greater than TCP greater than MK-801.(ABSTRACT TRUNCATED AT 250 WORDS)