Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Enhanced cholinergic transmission promotes recall in honeybees

The involvement of the cholinergic system in learning and memory in honeybees has been well established using olfactory conditioning. We examined the effect of Methyl Parathion (MeP), an acetylcholinesterase inhibitor of the organo-phosphate family, on the learning and recall of visual and olfactory discrimination tasks in honeybees. One of our expectations was to observe the effects induced by both the nicotinic and muscarinic systems, as the blocking of acetylcholinesterase should induce an increase in the activity of both systems. We were also interested in knowing whether the type of tasks could influence the results. The visual tasks involved learning to discriminate the orientation of gratings in a Y-maze; the olfactory task involved learning to discriminate odours in a proboscis extension reflex (PER) paradigm. The results indicate that MeP treatment enhances recall of learned tasks in the visual and olfactory domains, but it does not affect the acquisition phase in either domain. Surprisingly, MeP treatment led to muscarinic-like effects but failed to mimic the nicotinic-like effects already described in relation to learning phases in honeybees. Implications for the role of cholinergic pathways in learning and memory and the nature of their involvement are discussed, and a hypothesis relating to the organisation of the cholinergic system and the relationship between the nicotinic and muscarinic systems in honeybees is proposed. The results are also discussed in terms of their ecotoxicological consequences.

Expression and functional significance of Twist1 in hepatocellular carcinoma: its role in vasculogenic mimicry

The up-regulation and nuclear relocation of epithelial-mesenchymal transition (EMT) regulator Twist1 have been implicated in the tumor invasion and metastasis of human hepatocellular carcinoma (HCC). The term vasculogenic mimicry (VM) refers to the unique capability of aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks. However, the relationship between Twist1 and VM formation is not clear. In this study, we explored HCC as a VM and EMT model in order to investigate the role of Twist1 in VM formation. We first examined the expression of Twist1 in human HCC samples and cell lines and found that Twist1 was frequently overexpressed in the nuclear relocation occurring in VM-positive HCCs (13/18 [72%]). Twist1 nuclear expression was likewise significantly associated with VM formation. Clinicopathological analysis revealed that both VM and Twist1 nuclear expressions present shorter survival durations than those without expression. We consistently demonstrated that an overexpression of Twist1 significantly enhanced cell motility, invasiveness, and VM formation in an HepG2 cell. Conversely, a knockdown of Twist1 by the short hairpin RNA approach remarkably reduced Bel7402 cell migration, invasion, and VM formation. Using chromatin immunoprecipitation, we also showed that Twist1 binds to the vascular endothelial (VE)-cadherin promoter and enhances its activity in a transactivation assay.

CONCLUSION

The results of this study indicate that Twist1 induces HCC cell plasticity in VM cells more through the suppression of E-cadherin expression and the induction of VE-cadherin up-regulation than through the VM pattern in vivo and in a three-dimensional in vitro system. Our findings also demonstrate a novel cogitation in cancer stem-like cell differentiation and that related molecular pathways may be used as novel therapeutic targets for the inhibition of HCC angiogenesis and metastasis.

Changes in lymphocyte subsets in the peripheral blood of patients with active pulmonary tuberculosis

The aim of this study was to determine the percentage of lymphocyte subsets in peripheral blood in patients with active tuberculosis. A total of 21 patients with active tuberculosis and 15 healthy volunteers were included in the study. T-lymphocyte subsets, B-lymphocytes (CD19(+) cells), natural killer (NK) cells and cells positive for costimulatory molecules CD28 and CD152 were evaluated using flow cytometry. Patients with tuberculosis had a significantly decreased percentage of CD3(+) and CD3(+)CD4(+) cells, and a significantly decreased ratio of CD3(+)CD4(+) to CD3(+)CD8(+) cells compared with healthy controls. In contrast, the percentage of B-cells (CD19(+) cells), CD3(+)CD8(+) cells, CD28(+) cells, CD152(+) cells, and subpopulations of CD4(+)CD152(+), CD8(+)CD152(+) and CD8(+)CD28(+) T-cells were all significantly increased compared with healthy controls. There were no statistically significant differences in the percentages of NK cells or CD4(+)CD28(+) cells between patients and controls. These results indicate that patients with active tuberculosis have altered lymphocyte homeostasis.

Human papillomavirus infection in Beijing, People's Republic of China: a population-based study

Background:

No recent data exist on human papillomavirus (HPV) infection in Beijing, People's Republic of China.

Materials and method

We interviewed and examined a representative, randomly selected sample of 5552 sexually active women aged 25–54 years. Cervical cell samples were analysed for HPV DNA by a MY09/11-based PCR assay.

Results:

Human papillomavirus prevalence was 6.7% overall and 4.8% among women without cervical abnormalities. Of the 21 subtypes identified, HPV16 was the commonest type (2.6% overall; 39.1% of HPV-positive women), followed by HPV 58 (1.0%), 33 (0.8%), 43 (0.7%) and 56 (0.7%). High-risk HPV types predominated in all age groups. Human papillomavirus prevalence was highest in young to middle-aged women. Marital status, number of husband's sexual partners, age at sexual debut and nulligravidity were all associated with being HPV positive.

Conclusions:

In our survey, HPV 16, HPV 58 and HPV 33 were the most prevalent HPV types in Beijing, indicating the potential for the prophylactic HPV 16/18 vaccine in China.

[The mechanisms of microenvironments influence on vasculogenic mimicry between intraocular and subcutaneous melanoma]

OBJECTIVE

To investigate the influence of different microenvironments on melanoma vasculogenic mimicry, invasiveness and metastasis behavior.

METHODS

It was an experimental study. Sixty C57BL/6J mice were randomly divided into two groups with 30 mice per group. Melanoma B16 cells were injected into the subretinal space and groin area of mice synchronously. The number of each type of microcirculation pattern was counted. The invasion and metastasis were observed. EphA2, MMP-2 and MMP-9 expression and their mRNA levels were detected by immunohistochemical staining and real time RT-PCR and compared between two groups.

RESULTS

Five invasions and six lung metastases were found in the subretinal group while no invasion and metastasis were found in the groin group. The number of VM channels was significantly higher in subretinal group (t = 4. 188, P = 0.000). However, no significant difference of mosaic vessel and endothelium-dependent vessel was observed between two groups (t = 1.473, 1.805; P = 0.146, 0.076, respectively). EphA2, MMP-2 and MMP-9 expression was significantly higher in the subretinal group (data not shown). The mRNA levels of EphA2, MMP-2 and MMP-9 were rather higher in the subretinal tumor (t = 3.642, 8.109, 9.357; P = 0.002, 0.001 and 0.001, respectively). There was a positive association in melanoma cells of the VM between expression of EphA2 (r = 0.412, P = 0.021) but no statistically significant correlation between VM and MMP-2 (P > 0.05), nor between VM and MMP-9.

CONCLUSIONS

Different microenvironments affect invasiveness and blood supply patterns of melanoma. Melanoma cells in intraocular microenvironment increased EphA2 expression which induced the formation of VM channels. Moreover, the expression of MMP-2 and MMP-9 in tumor tissue increased to enhance the invasiveness and metastasis behavior.

[Correlation between expressions of matrix metalloproteinase-2 & 9 and vasculogenic mimicry in gastrointestinal stromal tumors]

OBJECTIVE

To study the correlation between the expression of matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF) and vasculogenic mimicry (VM) in gastrointestinal stromal tumors (GIST).

METHODS

The immunohistochemical staining indices (SI) of MMP-2, MMP-9, VEGF were assessed on specimens of 84 human cases with GIST (21 VM-positive cases). Gelatin zymography analysis of the activity of MMP-2 and MMP-9 activities were performed on another 42 human cases of GIST with fresh tissue (22 VM-positive cases).

RESULTS

The staining indices (SI) of MMP-2 and MMP-9 were higher in the VM-positive group (4.10 +/- 2.05 and 3.43 +/- 1.89 respectively) than in the VM-negative group (2.98 +/- 1.97 and 2.38 +/- 1.84 respectively, both P < 0.05); there was no statistic difference in the SI of VEGF between VM-positive and VM-negative group. Gelatin zymography analysis showed that the activity of MMP-2 and MMP-9 were significantly higher in the VM-positive group (3.62 +/- 3.95 and 4.77 +/- 5.29 respectively) than in the VM-negative group (1.26 +/- 1.21 and 2.11 +/- 1.54 respectively, both P < 0.05).

CONCLUSION

The expression of MMP-2 and MMP-9 correlates with VM formation in GIST.

[Diagnostic value of SYT-SSX fusion gene detection by fluorescence in-situ hybridization for synovial sarcoma]

OBJECTIVE

To establish a method of SYT-SSX fusion gene detection by FISH and to explore its diagnostic value for synovial sarcoma.

METHODS

The presence of SYT-SSX fusion gene was determined by FISH using a tissue microarray containing 62 known synovial sarcomas, 60 non-synovial sarcomas and 133 equivocal synovial sarcomas. FISH results were compared with those of RT-PCR published previously.

RESULTS

Overall, 96.9% (247/255) of the cases were successfully analyzed by FISH. The sensitivity of FISH for known synovial sarcomas was 96.7% (58/60), and the specificity for the non-synovial sarcoma was 100% (59/59). Moreover, SYT-SSX gene fusion was detected in 78.1% (100/128) of the equivocal synovial sarcomas. The concordance rate between FISH and RT-PCR was 83.6% (102/122) in those equivocal synovial sarcomas, and overall 79.7% (106/133) of these cases were confirmed as synovial sarcomas either by RT-PCR or by FISH.

CONCLUSIONS

The sensitivity and specificity of FISH detection of SYT-SSX fusion gene are high. FISH and RT-PCR are complementary to each other in the confirmation of synovial sarcomas, particularly those questionable cases.

Functional significance of VEGF-a in human ovarian carcinoma: role in vasculogenic mimicry

Ovarian cancer is a silent killer, and shows early extensive tumor invasion and peritoneal metastasis. The microcirculation of most tumors includes cooperation of pre-existing vessels, intussusceptive microvascular growth, postnatal vasculogenesis, glomeruloid angiogenesis and vasculogenic mimicry (VM). VM is critical for a tumor blood supply and is asscociated with aggressive features and metastasis. Our studies highlight the plasticity of aggressive human ovarian carcinoma cells and call into question the underlying significance of their ability to form VM in vitro induced by VEGF-a. These studies also show their clinicalpathological features of the cancers with human Paraffin-embedded tumor tissue samples. Results show that the process: VEGF-a-->EphA2-->MMPs-->VM is the main pathway for VM formation and VEGF-a appears to play an important role in the formation of VM based on our in vitro assays and clinical immunohistochemical analyses. VM-targeting strategies for ovarian cancer include anti-VEGF-a treatment, knocking down the EphA2 gene and using antibodies against human MMPs if the tumor is VM positive. This strategy may be of significant value in laying the foundation for a more explicit anti-tumor angiogenesis therapy.

[The influence of different microenvironments on melanoma invasiveness and microcirculation patterns]

OBJECTIVE

To investigate the influence of different microenvironments on tumor microcirculation patterns and invasive capability.

METHODS

Melanoma B16 cells were injected into the peritoneal cavity and skeletal muscle of C57 mice synchronously. CK18 expression in melanoma was assessed to distinguish the malignant phenotype of tumors in the peritoneal cavity from that in the skeletal muscle. HIF-1alpha, MMP-2 and MMP-9 protein and mRNA expression were compared in the two microenvironments. Cells positive for each immunohistochemical stain and the vessels representative of each type of microcirculation pattern were evaluated in two microenvironments.

RESULTS

CK18 and HIF-1alpha expression in melanoma were significantly higher in the skeletal muscle than in the peritoneal cavity (t = 8.142, t = 3.645, P < 0.05). Compared with the peritoneal cavity, melanoma cells in the skeletal muscle overexpressed MMP-2 and MMP-9 (t = 4.916, t = 7.782, P < 0.05). Real time-PCR results also showed that MMP-2 and MMP-9 mRNA levels in melanoma were higher in the skeletal muscle than in the peritoneal cavity (t = 36.814, t = 26.025, P < 0.05). Vasculogenic mimicry channels and endothelium-dependent vessels were the major microcirculation patterns in the skeletal muscle and in the peritoneal cavity respectively.

CONCLUSIONS

Different microenvironments affect invasiveness and blood supply patterns of melanoma. Different microenvironment induced tumor cell secretion of more invasion-related proteins and affect invasiveness and blood supply patterns of melanoma.

[Expression of FasL and apoptosis in pulmonary tissue of rats exposed to silica at different time]

OBJECTIVE

To investigate the change of the expression of the FasL receptor and apoptosis in the pathology of silicosis of the rats exposed to silica and their roles.

METHODS

Ninety-six wistar rats were randomizedly divided into the control group and the experimental group. The silicotic animal model was established by the direct tracheal instillation of silica into rat lungs surgically. The control rats underwent directly tracheal instillation of saline into lungs surgically. Eight rats from each group were sacrificed at different days. The expression of FasL receptor in the tissue of the model rats was detected by tissuechip microarray and immunohistochemistry and the cell apoptosis induced by silica was determined by TdT-mediated dUTP nick end-labeling method. The integral optical density of positive cells were quantitatively analyzed using Image-Pro Plus Version 4.5 for windows.

RESULTS

The expression of FasL in the lung tissue of the model rats on the 7th, the 14th, the 21st, and the 28th day was significantly higher than that in the control group (P < 0.05), and peaked at the 14th day after exposure to silica. Apoptotic cells in the lung tissue of the model rats on the 1st, the 3rd, the 7th, the 14th, the 21st, and the 28th day were significantly more than those in the control group, and peaked at the 7th and the 14th day after exposure to silica.

CONCLUSION

Silica can lead to apoptosis in lung tissues. FasL is expressed in all kinds of cells in the pulmonary tissues of the rats exposed to silica and leads to apoptosis. From the 7th day to 14th day, inflammatory cells dominate in apoptotic cells.

An effective indirect fluorescent antibody test for diagnosis of intestinal acariasis

Adult mites' bodies of Dermatophagoides farinae were used as antigen in an indirect fluorescent antibody test (IFAT) to detect mite-specific IgG in sera of 48 patients with intestinal acariasis based on stool examination. Antibody titers with positive reaction ranged from 1:4 to 1:512 in 48 patients with intestinal acariasis. If antibody titers > or = 1:16 is regarded as being positive, the positive rate of patients detected with IFAT was 92%.

Effect of FLIP small interfering RNA on apoptosis of colorectal cancer cells

AIM: To investigate the promotion effect of small interfering RNA of FADD-like IL-1β converting enzyme inhibitory protein (FLIP) on the cell apoptosis in colorectal cancer.

METHODS: Human colorectal cancer cell line HT-29 was cultured in vitro and transfected with two siRNAs (different loci) of FLIP by electroporation technique. The level of FLIP mRNA expression before and after interfering was detected by semi-quantitative polymerase chain reaction (PCR). The specificity and time effect for interference and the interfering effect between the two siRNAs were compared. Then the cells were treated with agonistic anti-Fas antibody to induce apoptosis. The apoptosis before and after interfering was determined by Annexin V and DNA degration.

RESULTS: The level of FLIP mRNA in HT-29 cells was inhibited by the specific siRNAs. The decrease of FLIP mRNA expression began to appear 24 hours after transfection. And the most apparent interfering efficiency was 65.02% 48 hours after transfection, which was markedly higher than that in the cells transfected with the control siRNAs. Both siRNAs (siRNA-F1 and siRNA-F2) from different loci had interfering effect on FLIP mRNA expression, but there was no significant difference between them. Compared with those in non-transfected cells (1.76%), the apoptotic rates were significantly higher in siRNA transfected cells (29.50%) after treated with agonistic anti-Fas antibody.

CONCLUSION: Small interfering RNA of FLIP can markedly decrease the expression of FLIP mRNA and sensitize the Fas-mediated apoptosis of colorectal cancer cell line HT-29. The RNA interfering technique targeted on FLIP may provide a new method in the gene therapy of colorectal cancer.

Sulindac induces apoptosis and protects against colon carcinoma in mice

AIM: To study the effect of sulindac on colon cancer induction in mice.

METHODS: The chemo-preventive action of 80 ppm sulindac fed during initiation and post-initiation and 100 ppm sulindac fed during progressive stages of induction of colon carcinogenesis in mice was investigated using 1,2-dimethylhydrazine (DMH). Using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique and PCNA immunohistochemical staining, we observed the apoptotic and proliferative cell density changes at different carcinogenic stages and the effect of sulindac on these two phenomena.

RESULTS: Dietary sulindac significantly inhibited the incidence of colonic neoplasmas in mice. Compared with the control group, feeding sulindac during initiation and post-initiation stages inhibited the incidence by 46.7-50.4%, and feeding sulindac during progressive stages inhibited the incidence by 41.1%. Animals that were fed sulindac showed less serious pathological changes than those that were fed the control diet (P<0.01, H = 33.35). There was no difference in the density of proliferating cells among those groups which were or were not fed sulindac. In the same period, feeding sulindac resulted in a higher density of apoptotic cells than feeding control diet.

CONCLUSION: Sulindac has an anti-carcinogenic function in mice. Its effect on preventing colon carcinogenesis is better than its effect on treating established tumors. By inducing apoptosis, sulindac inhibited the development of colon cancer and delayed canceration. Sulindac has no effect on proliferation. The anti-carcinogenic properties of sulindac are most effective in the moderate and severe stages of dysplasia and canceration.

Alterations of liver temperature during hepatic fibrosis

AIM: To investigate the alterations of liver temperature during hepatic fibrosis in rats induced by CCl₄.

METHODS: Liver fibrosis was induced in rats after administration of CCl₄ twice a week for 8 weeks. The rat liver temperature in 2-, 4-, 6- and 8- wk models and control group rat was detected by computer-assisted infrared thermorgraphic technology. To observe the histological change, the liver tissue microarray in every group of animals was stained by hematoxylin and eosin. Sirius red stain and polarization microscopy method was used for I and III collagen expression. Immunohistochemistry was used for detection of laminin to outline the formation of basement membrane on hepatic sinusoids.

RESULTS: The average infrared images temperature of hepatic fibrosis in rats induced by CCl₄ changed with the time of the model made. In 2-wk model group, the infrared image temperature of right liver lobe was 28.6±1.1 ℃, compared with 2-wk control group (P <0.05, t = -2.518). The temperature of 4-wk model group was 27.2±1.0 ℃. In 6-wk model group, the temperature was 30.1±1.2 ℃, compared with 6 wk control group (P <0.05, t = 3.773). The temperature of 8-wk model group was 27.4±1.0 ℃, compared with 8 wk control group (P <0.01, t = 4.998). The histological changes of liver tissue were inflammation and hepatocytic degeneration and necrosis in 2-wk model group. There was a significant increase of extracellular matrix among the necrostic hepatocytes in 4-wk model group. In 6-wk model group liver tissue showed the numbers of necrostic hepatocytes increased significantly and the septa formed around central vein and portal area. In 8 wk model group, there were wide septa expansions from the portal area to the central venous and pseudo-nodular formation. Sirius red and immunohistochemical stains showed collagen types I, III and laminin expression in liver tissues increased gradually in 2-, 4-, 6-, 8- wk model group. Collagen type III was the main collagen in 2- and 4-wk model groups. Collagen type I was the main collagen in 6- and 8-wk model groups.

CONCLUSION: The liver temperature changes regularly with hepatic tissue pathology in course of rat hepatic fibrosis induced by CCl₄.

Differential gene and protein expression in primary breast malignancies and their lymph node metastases as revealed by combined cDNA microarray and tissue microarray analysis

BACKGROUND

Metastatic disease is a major adverse prognostic factor in breast carcinoma. Lymph node metastases often represent the first step in the metastatic process.

METHODS

To gain insight into the molecular events that underlie breast carcinoma metastasis, the authors compared gene expression profiles, obtained by cDNA microarray analysis, of nine matched primary tumors and metastases after screening for enrichment of tumor cells. Statistical analysis identified genes that are expressed at elevated or decreased levels in metastases relative to the corresponding primary tumors. Multidimensional scaling analysis indicated that in terms of expression levels, primary tumors were tightly clustered, whereas metastases exhibited a greater spread; this finding points to the more heterogeneous nature of metastases. Among the differentially expressed entities were the invasion- and tissue modeling-related genes IGFBP5, fibronectin, and MMP2; the cell cycle regulatory gene cyclin D1; other genes, such as enolase 2; and an expressed sequence tag similar to angiopoietin 1. To validate and extend these initial findings, the authors constructed a tissue microarray consisting of 100 primary malignancies paired with their lymph node metastases. Antibodies for the IGFBP-5, fibronectin, MMP-2, cyclin D1, and MDM-2 proteins were used to stain tissue array sections.

RESULTS

Consistent with microarray data, statistically significant overexpression of IGFBP-5, down-regulation of cyclin D1, and unchanged MDM-2 levels were observed in metastatic tumor cells. Nonetheless, although fibronectin and MMP2 mRNA expression levels were decreased in many metastasis specimens, expression levels of the corresponding proteins in the extracellular matrix were elevated in most metastases. Decreased expression of fibronectin and MMP2 in lymph node metastases was further confirmed by real-time polymerase chain reaction assays performed on five additional specimen pairs.

CONCLUSIONS

The results of the current study suggest that extracellular matrix protein expression and nuclear gene expression are associated via a negative-feedback regulatory mechanism. Therefore, gene expression profiling and tissue array validation should be combined to elucidate molecular events associated with the metastatic process.

[Relationship between endotoxemia and APACHE-III scoring and integrated therapy of Chinese and Western medicine]

OBJECTIVE

To explore the relationship between endotoxemia and the severity of disease condition and therapeutic effect.

METHODS

According to randomized controlled principle, the 153 acute infectious patients were divided into simple antibiotics treated group and antibiotics plus Chinese drugs combined treated group, and patients in each group were subdivided into 3 types according to acute physiology and chronic health evaluation (APACHE-III) scoring: type A (APACHE-III scoring < or = 20 points), type B (APACHE-III scoring 21-40 points) and type C (APACHE-III scoring > 40 points). The 77 cases in the simple treated group were 40 males and 37 females, aging 18-76 years, mean 46.5 +/- 27.5 years, 41 cases of type A, 28 of type B and 8 of type C, treatment course 10-14 days, mean 11.5 +/- 2.5 days. The 76 cases in the combined treated group were 39 males and 37 females, aging 18-70 years, mean 44.5 +/- 25.5 years, 37 of type A, 30 of type B and 9 of type C, treatment course 10-14 days, mean 10.5 +/- 2.5 days. Limulus test was used to determine the endotoxin content in peripheral blood of patients, and further analysis on the relationship between endotoxemia and APACHE-III scoring was conducted.

RESULTS

Acute severe infectious patients whose APACHE-III scoring > 20 points occurred endotoxemia (P < 0.05), and the condition of disease was positively related to the APACHE-III scoring (r = 0.718, P < 0.05). Chinese drugs plus antibiotics can obviously alleviate endotoxemia (P < 0.05) and improve the prognosis of patients.

CONCLUSION

Endotoxemia can serve as a referential parameter for predicting the severity of disease. Integrated therapy of Chinese and western medicine in treating bacterial infection revealed better results than that of antibiotics solely.

[Determination of 4-chloro-3,5-dimethyl phenol in antiseptics and synthetic products by scanning thin-layer chromatography]

A new method of scanning thin-layer chromatography was established for the quantitative determination of the 4-chloro-3,5-dimethyl phenol by developing with 40% benzene in trichloromethane on GF254 silica gel plate. The results showed that the linear dynamic range of 4-chloro-3, 5-dimethyl phenol was 0.1858 g/L-7.4320 g/L in which the relative peak area obeyed the Lambert-Beer's law with a correlation coefficient of 0.9994 and recoveries of 98.31%-100.1%. The method is simple, rapid, sensitive and reproducible.

Effect of p58GTA on beta-1,4-galactosyltransferase 1 activity and cell-cycle in human hepatocarcinoma cells

Beta-1,4-galactosyltransferase 1 (beta1,4-GT 1) is the key enzyme transferring galactose to the terminal N-acetylglucosamine (GlcNAc) forming Galbeta3-->4GlcNAc structure in the Golgi apparatus. In addition, it also serves as a cell adhesion molecule by recognizing and binding to terminal GlcNAc of glycoconjugates on the adjacent cell surface and matrix through a subpopulation of the enzyme distributed on the cell surface. Transient expression of the p58GTA protein kinase, which belongs to the p34cdc2-related supergene family, could enhance beta1,4-GT 1 total activity in COS cells. In this study, the p58GTA interaction with beta1,4-GT 1 was confirmed using an in vitro assay with the TNT Coupled Reticulocyte Lysate System. An expression vector containing p58GTA was stably transfected into 7721 cells, a human hepatocarcinoma cell line, expression was confirmed by Northern and Western blot analyses. The cells transfected with p58GTA (p58GTA/7721) contained 1.9 times higher total beta1,4-GT 1 activity and 2.6 times higher cell-surface beta1,4-GT 1 activity than the mock transfected cells (pcDNA3/7721). However, Ricinus communis agglutinin-I lectin blot analysis revealed that the enhanced beta1,4-GT1 activity did not increase the Galbetal-->4GlcNAc groups on most of the membrane proteins in p58GTA/7721 cells. By flow cytometry analysis, it was found that the p58GTA/7721 cells were G2/M phase arrested, compared with the pcDNA3/7721 cells. These results suggest that the p58GTA stable transfection into human hepatocarcinoma cells could enhance the two beta1,4-GT1 subcellular pool activities independently and change its cell-cycle without modifying the beta-1,4-linked galactose residues on most membrane proteins.

[Study on diagnosis and treatment of infections multiple organ dysfunction syndrome by integrated traditional Chinese and Western medicine]

OBJECTIVE

To explore the diagnostic and therapeutic approach of integrated traditional Chinese and western medicine (TCM-WM) on infectious multiple organ dysfunction syndrome/multiple system and organ failure (MODS/MSOF) for elevating the successful rate of rescuing the patients.

METHODS

Diagnosis with western medicine and Syndrome Differentiation of TCM in 225 in-patients of acute infectious disease complicated with MODS/MSOF were conducted, and TCM treatment, based on western medical comprehensive treatment, was given to observe the effect and explore the mechanism of the TCM-WM therapy.

RESULTS

Up to the end of 1998, 161 cases of the 225 cases were successfully cured and 64 died, the mortality being 28.4%. Among them, 58 out of 140 cases of MSOF died, the mortality was accounted for 41.4%. In 106 cases conformed to the diagnostic criteria of MSOF proposed by Professor Knaus WA, USA, 52 cases were cured successfully and 54 died, the mortality being 50.9%.

CONCLUSION

TCM-WM treatment could elevate the therapeutic effect in treating MODS, the mechanism might be through improving the hemodynamic and hemorrheologic condition of patients to relieve nail-fold microcirculation disorder; influencing the levels of cytokine and inflammatory mediator, so as to alleviate the systemic inflammatory reaction, it might also abate the inhibited condition of gastro-intestinal motility, alleviate the intestinal flora imbalance, prevent intestinal bacteria and endotoxin malposition, and protect cells from peroxidation.

How honeybees make grazing landings on flat surfaces

Freely flying bees were filmed as they landed on a flat, horizontal surface, to investigate the underlying visuomotor control strategies. The results reveal that (1) landing bees approach the surface at a relatively shallow descent angle; (2) they tend to hold the angular velocity of the image of the surface constant as they approach it; and (3) the instantaneous speed of descent is proportional to the instantaneous forward speed. These characteristics reflect a surprisingly simple and effective strategy for achieving a smooth landing, by which the forward and descent speeds are automatically reduced as the surface is approached and are both close to zero at touchdown. No explicit knowledge of flight speed or height above the ground is necessary. A model of the control scheme is developed and its predictions are verified. It is also shown that, during landing, the bee decelerates continuously and in such a way as to keep the projected time to touchdown constant as the surface is approached. The feasibility of this landing strategy is demonstrated by implementation in a robotic gantry equipped with vision.

Effect of suppression of TGF-beta1 expression on cell-cycle and gene expression of beta-1,4-galactosyltransferase 1 in human hepatocarcinoma cells

beta-1,4-galactosyltransferase 1 (beta1,4-GT 1) is localized both in the Golgi complex where it catalyzes the transfer of galactose from UDP-galactose to terminal N-acetylglucosamine forming Galbeta1 --> 4GlcNAc structure, and on the cell surface where it serves as an adhesion molecule. It has previously been reported that the expression of beta1,4-GT 1 was cell-cycle-specific, regulated by cell growth. Transforming growth factor-beta1 (TGF-beta1) could regulate cell G1/S phase transition and modulate cell growth in many types of cells. In this study, we introduced the antisense-TGF-beta1 into SMMC-7721 cell, a human hepatocarcinoma cell line, for blocking its intrinsic TGF-beta1 expression, and changing its cell-cycle, and then analyzed the gene expression of beta1,4-GT 1 together with the beta1,4-GT activity. The result showed that the antisense-TGF-beta1 transfected SMMC-7721 cells (AST/7721) were growth enhanced, with more cells in S phase and less cells in G2/M phase compared with the mock transfected cells (pcDNA3/7721). At the same time, it was found that the gene expression of beta1,4-GT 1 in AST/7721 was decreased to one fifth that of pcDNA3/7721, and the cell surface beta1,4-GT activity was reduced to one fifth of the control, while the total activity of beta1,4-GT was decreased to one half that of the control. The results indicate that suppression of TGF-beta1 expression resulted in change of cell-cycle together with the decreased gene expression of beta1,4-GT 1 and beta1,4-GT activity in human hepatocarcinoma cells.

Structures and magnetism of two novel heptanuclear lanthanide-centered trigonal prismatic clusters: [LnCu6(mu 3-OH)3(HL)2(L)4](ClO4)2.25H2O (Ln = La, Tb; H2L = iminodiacetic acid)

The new heteronuclear iminodiacetic acid (H2L) complexes [LnCu6(mu 3-OH)3(HL)2(L)4](ClO4)(2).25H2O with Ln = La (1) and Tb (2) have been prepared in aqueous solution and characterized by single-crystal X-ray diffraction to be isomorphous (crystallographic data for 1 and 2: hexagonal, P63/m; a = b = 12.6425(14) A, c = 24.541(5) A, Z = 2 (1); a = b = 12.5802(9) A, c = 24.285(4) A, Z = 2 (2)). Ln3+ was found to be located in the center of the trigonal prismatic cage formed by six Cu2+ ions, with a tricapped trigonal prismatic coordination environment of nine O atoms. The magnetic properties of complexes 1 and 2 have been studied. The results indicate the presence of ferromagnetic couplings between Tb3+ and Cu2+ in compound 2.