[Cloning, sequencing and expression of the full-length gene encoding paramyosin of Schistosoma japonicum in vivo]

AIM

To clone and sequence the gene encoding paramyosin of S. japonicum (Chinese strain) and to study the expression of the DNA-based vaccine encoding the full-length paramyosin of S. japonicum in vivo.

METHODS

Total RNA was isolated from adult S. japonicum using TRIzol reagent. The full-length cDNA encoding paramyosin of S. japonicum was amplified by RT-PCR and cloned into pGEM-T vector and sequenced by the method of dideoxy-mediated chain-termination. The cDNA encoding paramyosin of S. japonicum was subcloned into the expressive plasmid vector pCDNA/AMP(pCMV-Sjc97), and the recombinants were identified by restriction enzyme digestion and sequencing. The immunofluorescence assay was used to study the expression of Sjc97 in vivo in mice.

RESULTS AND CONCLUSION

The 2.6 kb cDNA encoding the full-length paramyosin of Chinese S. japonicum has been successfully cloned and sequenced for the first time. The full-length sequence of paramyosin of S. japonicum was determined. Comparison of the nucleotide sequence and the deduced amino acid sequence of Sjc97 with that of S. japonicum paramyosin (Philippine strain) (Sjp97), S. japonicum paramyosin(Japanese strain) (Sjj97), S. mansoni (Sm97), B6 and Y6 clone (the partial cDNA encoding paramyosin of Chinese strain) showed that Sjc97 differed from Sjp97 by 16/2,601 nucleotide and 3/866 amino acid substitutions (99.4% on nt-level and 99.7% on aa-level in homology); from Sjj97 by 20/2,601 nucleotide and 2/866 amino acid substitutions (99.2% on nt-level and 99.8% on aa-level in homology); and from B6 by 11/1,329 nucleotide and 1/443 amino acid substitutions (99.0% on nt-level and 99.8% on aa-level in homology); from Y6 by 13/1,329 nucleotide and 1/443 amino acid substitutions (98.9% on nt-level and 99.8% on aa-level in homology); Sjc97 differed from the Sm97 by 2,235/2,601 nucleotide and 34/866 amino acid (91.0% on nt-level and 96.0% on aa-level in homology). The plasmid expression vector encoding the full-length paramyosin of Chinese S. japonicum has been successfully constructed. The pCMV-Sjc97 vaccine could express Sjc97 protein in vivo in mice after intramuscular immunization.

[Observation on the dynamics of specific anti-GST antibodies in rabbits immunized with recombinant 26 kDa GST of Schistosoma japonicum]

AIM

To investigate the dynamics of the anti-GST antibodies in rabbits immunized with recombinant 26 kDa GST of Schistosoma japonicum.

METHODS

The specific antibodies were detected weekly by GST-ELISA in rabbits vaccinated with purified recombinant 26 kDa GST antigen of S. japonicum plus FCA/IFCA; rabbits immunized with 0.85% saline plus FCA/IFCA served as control group.

RESULTS

The specific anti-GST antibodies began to increase at week 4 post-immunization, the mean OD value in rabbits vaccinated with recombinant GST could reach 1.03 +/- 0.46 (adjuvant control group only 0.42 +/- 0.04). The experiment was completed at week 65 post-immunization when the mean OD values for specific anti-GST antibody in immunized rabbits were 0.94 +/- 0.26(0.29 +/- 0.16 in the control group).

CONCLUSION

Strong anti-GST antibody responses could be induced in rabbits vaccinated with recombinant 26 kDa GST of S. japonicum.

[Studies on the features of protective immune response induced by recombinant Sjc26GST of Schistosoma japonicum]

AIM

To compare the differences in the protective immune response induced by reSjc26GST between C57BL/6 and BALB/c mice.

METHODS

Mice were immunized subcutaneously with reSjc26GST emulsified with Freund's adjuvant. The specific antibody isotypes elicited by reSjc26GST, in vitro lymphocyte proliferation and cytokine responses to reSjc26GST were examined.

RESULTS

The level of anti-reSjc26GST IgG was higher in immunized C57BL/6 mice than in BALB/c mice, and examination of the IgG subclasses demonstrated that reSjc26GST-immunized C57BL/6 mice resulted in predominantly IgG1 and IgG2a/IgG2b antibody responses, whereas in BALB/c mice, IgG1 antibody. Cytokine production assays revealed that the quantity of IFN-gamma and IL-2 and IL-5 released from the reSjc26GST-primed splenocytes were significantly higher in C57BL/6 mice than in BALB/c mice. These results showed that the immunization with reSjc26GST in C57BL/6 mice elicited a mixed immune reaction of Th1 and Th2 cell responses as demonstrated by the elevated levels of IgG1, IgG2a/IgG2b and IL-2, IFN-gamma, IL-5, whereas in BALB/c mice, reSjc26GST immunization elicited Th2 response as demonstrated by the elevated levels of IgG1, IL-2 and IFN-gamma.

CONCLUSION

Immunization with reSjc26GST could elicit higher humoral and cellular immune responses in C57BL/6 mice than in BALB/c mice.

[Differences in haemozoin production and pathogenicity between chloroquine-sensitive and chloroquine-resistant strains of Plasmodium berghei]

AIM

To better understand the differences in haemozoin formation and pathogenicity between chloroquine-sensitive(N) and chloroquine-resistant(RC) strains of Plasmodium berghei.

METHODS

IRC mice were grouped as follows: group Xba I (Normal control, NC), group II (control treated with chloroquine alone, CC), group III (mice infected with N strain), group IV (mice infected with RC strain, RC) and group V (mice infected with RC strain and treated with chloroquine, RCC). Morphologic features of the parasites, parasitaemia, histological and ultrastructural changes of livers among the groups were compared.

RESULTS

Severe damages of the hepatic cells of the N group including increased lysosomes and swollen and fused mitochondria were detected. On the contrary, the prominent features in liver section of the RC group were inflammatory cell (notably mononuclear) infiltration and Kupffer cell activation. Numerous trophozoites and schizonts were sequestrated in hepatic sinusoids and less degeneration of parenchymal cells was found except for some swollen and vacuolated mitochondria. Internal food vacuoles containing haemozoin were found in the parasites of the N group, whereas external food vacuoles without haemozoin granules were arranged in foamy appearance within the parasitized cell of the RC group.

CONCLUSION

P. berghei RC strain may modify the mode of ingestion and degradation of hemoglobin in the parasites, resulting in impeding haemozoin formation. The difference in virulence between the N and RC strain of P. berghei is probably attributed to the significant differences in the induction of immune response of the host.

Display of positron emission tomography with Cadplan

Recent clinical experience at Peter MacCallum Cancer Institute (PMCI) with the use of unregistered Positron Emission Tomography (PET) images for radiotherapy target marking in the lung suggests that co-registered PET images would be invaluable. PMCI has three radiotherapy treatment planning systems but none of them currently is able to display or co-register PET images with Computed Tomography (CT) images. This paper details the approach taken to display co-registered PET images with the CADPLAN treatment planning system. CT Image files are normally transferred to Cadplan by DICOM transfer, but the Cadplan DICOM server will not receive (has no presentation context for) PET images. The fundamental design of the CADPLAN system envisages display of only a single image dataset, which must be a CT scan for planning reasons. The problem of data transfer is crudely solved by File Transfer Protocol (FTP) over the network. Fortunately the multislice format of the PET image files makes individual transfer manageable. A menu based C program running at the same time as Cadplan is invoked to sample the DICOM PET Image and create multiple Cadplan CART image format files that are co-registered with each existing transverse CT slice. With the Cadplan in contour mode, the program allows the co-registered PET images to be swapped in and out of the image section of the CART files promptly, while keeping the contour information. This allows radiotherapy target volumes to be marked using transverse PET emission images, and effectively circumvents the design constraints prohibiting the display of more than one image set. Contours can be over-laid for review on reconstructed sagittal or coronal views of CT or PET images constructed using the standard Cadplan tools. Co-registration is facilitated by identical positioning with the aid of lasers and FDG loaded fiducial markers on the PET scanner and CT couch. A polyurethane cast fixed with EFFILOCK is used to ensure identical patient orientation on the CT and PET couches. Since both imaging modalities are without significant geometric distortion the co-registration is then simply a translation. PET transmission images can be used for co-registration verification. The practical implementation of display of PET images with CADPLAN has enabled us to begin a trial of 10 patients, the results of which will be reported separately.

[Effects of pressure induced retinal ischemia on ERG in rabbit]

OBJECTIVE

To observe the effects of pressure induced retinal ischemia on electroretinogram(ERG) in rabbit.

METHODS

Retinal ischemia was induced in rabbits by increasing intraocular pressure at 30 mmHg, 60 mmHg, 90 mmHg, 120 mmHg for 45 minutes, and retinal function was monitored by eletroretinography.

RESULTS

There was no difference on ERG before or after the experiment both in 30 mmHg group and control one. In 60 mmHg pressure induced ischemia eyes, the amplitudes of the b-wave and OPs wave reduced significantly. Four hours after reperfusion, they were totally recovered. After an ischemic insult of 90 mmHg or 120 mmHg for 45 minutes, there was no response of ERG. Four hours later, the amplitudes of the b-wave and OPs wave were 66.912 +/- 20.157 and 16.423 +/- 3.965 the former, 38.852 +/- 23.438 and 8.610 +/- 12.090 the latter, respectively.

CONCLUSION

These results suggest that higher intraocular pressure causes more severe retina ischemic damage, and less recovery ability.

[The value of color Doppler imaging ultrasound in diagnosis of orbital diseases]

OBJECTIVE

To study the useful value of color Doppler imaging (CDI) ultrasound in the diagnosis and differential diagnosis of orbital diseases.

METHODS

By using the technique of CDI ultrasound, 288 cases with orbital diseases were examined to show color Doppler flow imaging and pulsed wave Doppler (PWD) spectrum.

RESULTS

Among 288 cases of the orbital diseases, 38 cases of malignant tumors and 23 cases inflammatory pseudotumors showed the signals of blood flow. From CDI ultrasound examination, there were 18 in 23 cases with benign mixed tumors of the lacrimal gland showing artery blood flow and 22 in 28 cases with neurilemoma showing signals of blood flow. No blood flow was obtained in 62 among 74 cases with cavernous hemangioma, in 16 cases of dermoid cysts or epidermoid cysts and 1 case of lipoma. From CDI, rich blood flow was seen in 4 and scarce in 3 cases with meningioma, and in 6 cases of optic nerve gliomas, there were 5 cases without any blood flow signals. Other 2 cases with benign hemangioendothelioma, 2 hemangiopericytoma and 1 neurofibroma showed rich or scarce blood flow signals. Among 29 cases of venous hemangiomas, 16 cases showed venous flow. Three cases with arteriovenous aneurysms showed artery blood flow in the CDI. Fifteen cases with varicosis exhibited a dynamic blood flow changes in the CDI. Six cases with infantile hemangioma, the decreased blood supply was shown in the CDI after treatment. In the thirteen cases with carotid artery cavernous sinus fistula, including 8 cases of internal carotid artery cavernous sinus fistula (CCF) and 5 dural cavernous sinus fistula (DCF), dilated superior ophthalmic vein (SOV) with arterialized blood flow was seen. In the mean time, PWD showed that the SOV of CCF had a higher velocity and a higher flow volume than that of DCF, while its resistance index was lower than that of the DCF. In 1 case with thrombophlebitis, its SOV showed dilated superior ophthalmic vein without blood flow.

CONCLUSIONS

CDI can provide the information of color blood flow in orbital diseases, especially the tumors with rich vascular tissue and orbital vascular diseases. It is important in the diagnosis and differential diagnosis of the orbital diseases in combination with B-mode ultrasound, CT or MRI.

GeneChip analysis after acute spinal cord injury in rat

Spinal cord injury (SCI) leads to induction and/or suppression of several genes, the interplay of which governs the neuronal death and subsequent loss of motor function. Using GeneChip, the present study analyzed changes in the mRNA abundance at 3 and 24 h after SCI in adult rats. SCI was induced at T9 level by the New York University impactor by dropping a 10-g weight from a height of 25 mm. Several transcription factors, immediate early genes, heat-shock proteins, pro-inflammatory genes were up-regulated by 3 h, and persisted at 24 h, after SCI. On the other hand, some neurotransmitter receptors and transporters, ion channels, kinases and structural proteins were down-regulated by 3 h, and persisted at 24 h, after SCI. Several genes that play a role in growth/differentiation, survival and neuroprotection were up-regulated at 24 h after SCI. Using real-time quantitative PCR, the changes observed by GeneChip were confirmed for seven up-regulated (interleukin-6, heat-shock protein-70, heme oxygenase-1, suppressor of cytokine signaling 2, suppressor of cytokine signaling 3, interferon regulatory factor-1, neuropeptide Y), two down-regulated (vesicular GABA transporter and cholecystokinin precursor) and two unchanged (Cu/Zn-superoxide dismutase and phosphatidyl inositol-3-kinase) genes. The present study shows that inflammation, neurotransmitter dysfunction, increased transcription, ionic imbalance and cytoskeletal damage starts as early as 3 h after SCI. In addition to these effects, 24 h after SCI the repair and regeneration process begins in an attempt to stabilize the injured spinal cord.

Synthesis and quantitative structure-activity relationships of fluorine-containing 4,4-dihydroxylmethyl-2-aryliminooxazo(thiazo)lidines as trehalase inhibitors

Five fluorine-containing 4,4-dihydroxylmethyl-2-aryliminooxazolidines and five 4,4-dihydroxylmethyl-2-aryliminothiazolidines were synthesized and evaluated for their inhibitory activity against trehalase in vitro. All these compounds were very readily synthesized compared with the natural trehalase inhibitors. They had moderate inhibitory activity toward trehalase, and showed larvicidal activity and inhibition action to insect flight. The steric parameters and semiempirical quantum parameters of these compounds were acquired by using the molecular modeling method and the PM3-SCF-MO method, respectively. A quantitative structure-activity relationship between half-inhibitory concentrations toward trehalase and the above parameters was established.

Syntheses and activities as trehalase inhibitors of N-arylglycosylamines derived from fluorinated anilines

Twelve N-arylglycosylamines were prepared in a one-pot reaction by treatment of D-glucose, D-galactose, D-mannose or D-xylose with fluorinated anilines in the presence of small amount of hydrochloric acid. The inhibitory activity against porcine trehalase and the fungicidal activity of the title compounds toward Rhizoctonia solani have been tested.

[Study on different responses of rats' small intestine mucous membrane and bladder transitional epithelium in the same carcinogenic urine environment]

OBJECTIVE

To preliminarily verify the tentative idea of replacement of bladder transitional epithelium with small intestine mucous membrane to prevent recurrence of carcinoma of bladder.

METHODS

A certain segment of small intestine was transplanted to the urinary bladder of the same body in 17 rats. Then N-butyl-N-(4-hydroxy-butyl) nitrosamine (BBN) was used to induce carcinoma of bladder. BBN was used to 11 control rats that did not undergo operation.

RESULTS

Bladder carcinoma failed to be found in the transplanted small intestine mucous membrane in all experimental rats except one. After stimulation of BBN, carcinoma of urinary bladder occurred in all rats' bladder transitional epithelium.

CONCLUSION

1) The carcinogenic substances in the urine of rats suffering from BBN-induced bladder carcinoma are carcinogenic only to bladder transitional epithelium and have no effect on small intestine epithelium. 2) Bladder transitional epithelium may be more sensitive to the urine carcinogenic substances and easier to be cancerized than small intestine epithelium. 3) The tentative idea of substitution of small intestine mucous membrane for bladder transitional epithelium to prevent the recurrence of bladder carcinoma is worth further studying.

[Projections of 5-HTergic fibers to the spinal phrenic nucleus and medullary phrenic premotor neurons in the cat]

Experiments were performed on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into the spinal phrenic nucleus. The brainstem sections were double processed for HRP histochemical staining with TMB-DAB method and 5-HT immunohistochemical staining with anti-5-HT primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-5-HT double-labeled neurons were observed mainly in the nucleus raphe pallidus. A few double-labeled neurons were also observed in nucleus raphe obscurus and nucleus raphe magnus. 5-HT immunopositive terminal fibers were observed in the vicinity of HRP single-labeled neurons (phrenic premotor neurons) located in the nucleus ambiguus and ventrolateral solitary tract nucleus. The results indicate that the 5-HTergic neurons in the nucleus raphe pallidus send axonal projections to the phrenic nucleus, and that the brainstem phrenic premotor neurons also receive 5-HTergic axonal projections.

Afferent projection to the retrotrapezoid nucleus from respiratory related structures in the brainstem of rabbit--a retrograde CB-HRP tracing study

Experiments were performed on 10 adult rabbits. After microinjection of cholera toxin B-subunit conjugated horseradish peroxidase (CB-HRP) into the retrotrapezoid nucleus (RTN), retrogradely labeled neurons were mainly observed in the Kölliker-Fuse nucleus (KF), the medial parabrachial nucleus (PBM) and the lateral parabrachial nucleus (PBL). A few labeled neurons were also observed in the ventrolateral solitary tract nucleus, the ambiguus and retroambiguus nuclei, and the ventromedial area of retrofacial nucleus. Labeled terminal fibers were mainly observed in the retrofacial nucleus, the ambiguus and retroambiguus nuclei, the ventrolateral area of solitary tract nucleus, and the PBL-PBM-KF. The above results show that the RTN has axonal connections with the pontine and medullary respiratory related structures.

[Cloning and nucleotide sequencing of full length L segment cDNA of Hantavirus strain A9]

OBJECTIVE

Cloning and nucleotide sequencing of full length cDNA sequence of L segment of Hantavirus strain A9.

METHODS

The L segment cDNA of Hantavirus strain A9 was amplified by RT-PCR. PCR products were cloned and sequenced. Full length cDNA clone of the L segment was obtained by subcloning.

RESULTS

The L segment of strain A9 was 6 533 nucleotides in length and encoded a putative L polymerase that was 2 151 amino acids in length. Analysis of nucleotide and deduced amino acid sequences of the L segment of strain A9 showed a close relationship with the other Hantaviruses most notably the 76-118, Cl-1 and Cl-2 strains, with which they shared a 83.8% nucleotide identity. More distant similarity could also be seen with other Hantaviruses. Sequence comparison performed among the RNA-dependent RNA polymerases of 27 negative stranded RNA viruses revealed that the same existence of six conserved regions and several strictly conserved residues located at the deduced amino acid sequence of A9 L segment.

CONCLUSIONS

The nucleotide sequence of L segment of strain A9 was similar to other Hantavirus L segments. Deduced amino acid sequence of A9 L segment shares 6 conserved regions with other RNA virus RNA polymerase. The conserved residues in these polymerases and their possible functions in light of the available structural information have been discussed.

[The effect of Paeonol on erythrocyte deformability determined by micropipette aspiration technique]

OBJECTIVE

The effect of Paeonol (PAE) on erythorcyet(RBC) deformability was studied in order to provide experimental data for the application in clinic and the evaluation in pharmacological action.

METHODS

Micropipette Aspiration Technique was used to determine the RBC deformation length. The method of calculation was also simplified and a new apparent deformation Index(ADI) was defined.

RESULTS

PAE could increase the ADImin and ADImax and decrease Tmax significantly.

CONCLUSION

PAE has the effect of deformational ability on RBC. Micropipette aspiration technique is a feasible method for determining the effect of traditional Chinese medicine on erythrocyte deformability.

[Mortality study of major non-communicable diseases in Shanghai, from 1951 to 1998]

OBJECTIVE

To study the transition of major non-communicable diseases (NCDs) in Shanghai.

METHODS

Demographic and mortality data since early 1950s in Shanghai was used. Linear regression model was employed to evaluate the mortality trends of diseases.

RESULTS

During the past five decades, age-adjusted mortality had been gradually decreasing, with leading cause of deaths shifting from infectious diseases to NCDs. In 1998, the average life expectancy reached 77.03, and the three leading causes of deaths, i.e. tumor, cardio-vascular diseases and respiratory diseases, accounted for 75% of all deaths. The crude mortality of major NCDs increased consistently. However, the age-adjusted mortality trends of major NCDs decreased during the past two decades after a 30-year's increase. Turnover took place in the late 1970s for tumors, for coronary heart in late 1980s diseases and in the early 1990s for strokes. For malignant tumors, the age-adjusted mortality of breast cancer, cancer of colon and rectum did not significantly decrease in the past two decades.

CONCLUSION

The increase of crude mortality of major NCDs was mainly due to the trend of aging in Shanghai. It is suggested that the risk factors of major NCDs had decreased to some extent but the behavior and dietary related risk factors remained serious.

[Investigation on the mechanics of adhesion to the selective extracellular matrix coated surfaces of lung cancer cells]

The adhesion properties of tumor cells with extracellular matrix(ECM) are closely associated with their invasion and metastasis. Our work reported here was intended reveal the relevant biomechanical and biorheological manifestations of human lung cancer. Using micropipette aspiration technique, we investigated quantitatively the adhesive mechanics properties of high metastatic human giant cell carcinoma(PG) cells as well as low metastatic adenocarcinoma(PAa) cells of lung based on cell culture in vitro. The results showed that the adhesion forces of PAa and PG cells to collagen IV were significantly higher than those to glass surfaces, but at the lower concentrations(1.00 microgram/ml and 2.00 micrograms/ml) of collagen IV, the amplitude for the increase of adhesion forces of PG cells were less than the amplitude for that of PAa cells, and most of the adhesion force values of PAa cells to the coated surfaces of incorporation of laminin along with 2 micrograms/ml collagen IV were significantly greater than those of PG cells. At the lower concentrations(0.625 microgram/ml for PAa cells, and 0.625 microgram/ml, 1.25 micrograms/ml for PG cells) of laminin tested, the adhesion force values of PAa and PG cells all decreased, but the amplitude and level for the decreased values of adhesion forces of PG cells were greater than those for the PAa cells. In conclusion, the adhesive and proteolytic behaviour of cancer cells to extracellular matrix might be mediated mainly by tumor cell membrane receptors such as integrin receptors and laminin receptors, it might affect the biological characteristics and the metastasis of the tumor cells. The results may benefit to explain some questions in biomechanical views about how the highly metastatic PG cells are prone to migration and invasion.

N'-tert-Butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N-aroylhydrazines, a novel nonsteroidal ecdysone agonist: syntheses, insecticidal activity, conformational, and crystal structure analysis

Seventeen N'-tert-butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N-aroylhydrazines were synthesized, and their insecticidal activities against armyworm (Leucania separata (Walker)) were tested. The conformation and structure of compound 1b was studied by 1H NMR spectroscopy and X-ray crystallography. The crystal structure belongs to the orthorhombic system and the N—N bond adopts a gauche conformation, which was assumed to be the active conformation, with a dihedral angle of 69.9°.Key words: N'-tert-butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N-aroylhydrazine, syntheses, insecticidal activity, conformation, crystal structure.

Investigation on the rheological properties of hepatocellular carcinoma cells and their relevance to cytoskeleton structure

OBJECTIVE

To investigate the relevance of the rheological properties, i.e., viscoelasticities and adhesion to basement membrane components coated surface, of both hepatocytes and hepatocellular carcinoma (HCC) cells to the cytoskeleton structure.

METHODS

Micropipette aspiration technique was adopted to measure viscoelastic coefficients and adhesion forces to 2 microg/ml collagen IV/1.25 microg/ml laminin coated surface of the cells. Two kinds of cytoskeleton perturbing agents, colchicine and cytochalasin D, were used to treat both HCC cells and hepatocytes and the effects of these treatments on cell viscoelastic coefficients and cell adhesion forces were investigated.

RESULTS

Upon treatment of cells with colchicine in a concentration range of 1 to 60 mg/L, the elastic coefficients, especially the first elastic coefficient K1, and adhesion forces of hepatocytes generally tended to increase or increased significantly while, in contrast, viscoelastic coefficients and adhesion forces of HCC cells decreased obviously. Upon treatment of cells with cytochalasin D in a concentration range of 0.25-5.00 mg/L, viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with a larger magnitude for the decrease in elastic coefficients and adhesion forces of HCC cells than for those of hepatocytes. Adhesion forces of hepatocytes and HCC cells onto collagen IV/laminin coated surface varied similarly as viscoelastic coefficients under the action of the cytoskeleton perturbing agents. A significant positive correlation existed between changes of HCC cell adhesion forces on collagen IV/laminin coated surfaces and those of cell elastic coefficients (P<0.01).

CONCLUSIONS

The effects of cochicine and cytochalasin D on rheological properties of HCC cells differed significantly either in ways or extents from those on rheological properties of hepatocytes. These results might reflect the difference in the state of cytoskeleton structure and function among these two kinds of cells.

[Change of prolactin in SD rats with experimental autoimmune thyroiditis]

OBJECTIVE

To verify the effect of prolactin (PRL) on the development and progression of experimental autoimmune thyroiditis (EAT) in SD rats and the inhibitive effect of bromocriptine (BRC) on the development of EAT.

METHODS

SD rats were injected with BRC to inhibit the development of EAT and the change of PRL were observed.

RESULTS

High level of serum PRL was found in the EAT rats [(8.70 +/- 0.42) microg/L, P < 0.01 vs. control (6.46 +/- 0.67) microg/L], and there was also high levels of thyroid autoantibodies (thyroglobulin antibody, thyroid peroxidase antibody). However, in rats receiving BRC, the levels of thyroid autoantibodies decreased as the PRL level declined (5.30 +/- 0.81) microg/L and the thyroid lesions were mild.

CONCLUSION

Hyperprolactinemia plays a role in the development of EAT and control of the hyperprolactinemia with BRC may afford therapeutic benefit.

Synthesis and quantitative structure-activity relationships of new 2,5-disubstituted-1,3,4-oxadiazoles

Fourteen new 2,5-disubstituted-1,3,4-oxadiazoles, namely (i) six 2-[2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropyl]-5-substituted-1,3,4-oxadiazoles and (ii) eight 2-substituted-phenoxymethyl-5-substituted-aryl-1,3,4-oxadiazoles, were synthesized and evaluated for their insect growth regulatory activity against second-instar larvae of armyworm (Pseudaletia separata Walker). Two of these compounds (7 and 8) showed good insecticidal activities, with LC(50) values of 14.33 and 15.85 microg/mL, respectively. Steric parameters (e.g., the molecular length d and the ratio of the nonpolar surface area and polar surface area V(1)/V(2)) and semiempirical quantum parameters (e.g., the molecular total energy E(t) and the lowest unoccupied molecular orbital energy E(LUMO) and so on) of these compounds, as well as those of six other 2,5-disubstituted-1,3,4-oxadiazoles reported, were acquired by the molecular modeling method and the PM3-SCF-MO method, respectively. With the help of the synthons' activity contribution method based on the Free-Wilson approach in its Fujita-Ban variant, quantitative structure-activity relationships were studied by regressing half-lethal concentrations against the above parameters.

[Monitor visual function with flash visual evoked potential during orbital surgery]

OBJECTIVE

To evaluate the feasibility and reliability of monitoring visual function with flash visual evoked potential (FVEP) during orbital surgery.

METHOD

The visual function of 82 cases was monitored during orbital surgery with FVEP. Of these cases, the intraoperative and postoperative visual functions (IOVF and POVF) were compared.

RESULTS

Sixty-nine cases were successfully monitored. Sixty-seven cases obtained the accordance of IOVF and POVF, and there were false positive in 1 case and false negative in 1 case.

CONCLUSION

Intraoperative monitoring of visual function with FVEP can show the surgical injury of the optic nerve and unsuitable procedures, and decrease the surgical blind rate.

[Assay and L1 gene sequence analysis of human papillomavirus type 6 and 11 in condylomata acuminata]

OBJECTIVE

To determinate the prevalence of HPV type 6, 11 in condylomata acuminata, and analyze the sequence of L1 gene and its deduced L1 protein.

METHODS

PCR was used to amplify DNA sequences between E6 and E7 of HPV type 6 and 11. The PCR products were identified by the fragment length cleaved with restriction enzyme RsaI. L1 genes were amplified with high fidelity Taq, and cloned DNA sequences were detected by the dideoxynucleotide method.

RESULTS

In 34 examples of condylomata acuminata, HPV11 was found in 25 examples (73.5%), HPV6 in 15(44.1%), including HPV6 + HPV11 in 6(17.6%). In comparison with the prototypes there were 7-8 point mutations in HPV11 L1 gene and 3 in HPV6L1 gene. L1 encoded protein changes showed up only in 1-3 amino acids in the former cases.

CONCLUSION

Most of patients tested with condylomata acuminata are mainly infected by HPV11, the rest of them by HPV6 or by co-infection of two mixex types. Sequence analysis of L1 genes indicated that mutations were found in both HPV6 and 11, whereas deduced amino acid mutations in L1 protein were limited in HPV11 only.

The preparation and characterization of an immobilized l-glutamic decarboxylase and its application for determination of l-glutamic acid

This paper is to study the preparation and characterization of an immobilized L-glutamic decarboxylase (GDC) and develop a sensitive method for the determination of L-glutamate using a new biosensor, which consists of an enzyme column reactor of GDC immobilized on a novel ion exchange resin (carboxymethyl-copolymer of allyl dextran and N.N'-methylene-bisacrylamide CM-CADB) and ion analyzer coupled with a CO(2) electrode. The conditions for the enzyme immobilization were optimized by the parameters: buffer composition and concentration, adsorption equilibration time, amount of enzyme, temperature, ionic strength and pH. The dynamic response of Na(2)HPO(4)-citric acid buffer system selected is much better than that of the others, 0.10 M HAc-0.10 M NaAc and 0.10 M sodium citrate-0.10 M citric acid. The initial rate of the enzyme reaction v(0) in this buffer system is 1.76 mol. l(-1) min(-1), moreover, the rate of the enzyme reaction appears linear in the first 4 min. The optimum adsorption equilibrium time is around 6 h. The amount of enzyme adsorbed on CM-CADB resin affects the response to substrate L-glutamic acid, the widest range of linearity is obtained with over 30 mg (GDC)/g(resin). The GDC activity immobilized on CM-CADB reaches a maximum when the immobilization temperature was kept around 40 degrees C. pH was kept at 4.4 when measuring the activity of the immobilized GDC. No variation of the activity of immobilized GDC is observed when the capacity is over 2.5 meq/g.(CM-CADB resin). The properties of the immobilized enzyme on CM-CADB were characterized. No significant improvement can be achieved when the substrate concentration exceeds 12.00 mmol/l, where the activity of immobilized GDC is equal to 1.58 mmol/l.min.g. The optimum pH is found to be 5.2, which changes 0.2 unit, comparing with that of the free GDC (5.0). The optimum temperature is found to be around 48 degrees C, which is lower than that of free GDC (55 degrees C). The critical temperature of the free GDC and the immobilized GDC is approximately 50 degrees C and 45 degrees C, respectively. The half-life of the activity is 127 days when the immobilized enzyme was stored in the cold (4 degrees C). An immobilized GDC enzyme column reactor matched with a flow injection system-ion analyzer coupled with CO(2) electrode-data collection system made up the original form of the apparatus of biosensor for determining of L-glutamic acid. The determination conditions are that the buffer solution is 0.10 M Na(2)HPO(4)-0.05 M citric acid at pH 4.4 and t = 37 degrees C. The limit of detection is 1.0 x 10(-)(5) M. The linearity response is in the range of 5 x 10 (-2) - 5 x 10 (-5) M. The equation of linear regression of the calibration curve is y = 43.3x + 181.6 (y is the milli-volt of electrical potential response, x is the logarithm of the concentration of the substrate of L-glutamic acid). The correlation coefficient equals 0.99. The coefficient of variation equals 2.7%.

Changes in cardiovascular risk factors in different socioeconomic groups: seven year trends in a Chinese urban population

STUDY OBJECTIVE

To analyse trends in socioeconomic differences in cardiovascular disease risk factors among an urban Chinese population using educational attainment as the socioeconomic indicator.

DESIGN

Population surveys with randomly selected independent samples were carried out in 1989 and in 1996. Educational attainment, blood pressure, body mass index, cigarette smoking and lack of leisure time physical activity were determined.

SETTING

Urban areas of the city of Tianjin, China.

PARTICIPANTS

A total of 14 275 respondents aged 25-64 years.

MAIN RESULTS

Diastolic blood pressure increased and the proportion of people without leisure time physical activity decreased in both sexes during the study period. The prevalence of smoking and the number of cigarettes smoked daily increased significantly among men. Smoking decreased in the least educated men and increased in those who had studied at least to college level. Body mass index decreased across all educational strata in women, but blood pressure increased in women with at least college level education.

CONCLUSIONS

These data reveal a different picture in trends in the association of education and cardiovascular risk factors from those depicted in developed countries. This highlights the need for an effective intervention programme in the study population.

[The effect of vinblastine on the viscoelastic properties of lung cancer cells]

BACKGROUND

To explore the effect of vinblastine on the viscoelastic properties of highmetastatic human giant cell carcinoma cells ( PC) and low metastatic adenocarcinoma cells (PAa) of the lung and its biomechanical mechanisms.

METHODS

The viscoelastic properties of PG and PAa cells and their changes after treated with vinblastine (VCR, 0. 10-2. 00Lg/ml) were detected by micropipette aspiration technique. Viscoelasticity was analyzed by the special three-element standard linear solid model.

RESULTS

Before treated with VCR, the elastic coefficients K1 and K2 as well as viscous coefficient L of PAa were significantly higher than those of PG cells. The values of K1, K2 and L of PAa cells decreased along with the increase of VCR concentration. However, the viscoelastic coefficient values in PG cells decreased when the VCR concentration was lower than 1. 00Lg/ml and then turned to increase as concentration of VCR went on increasing. The microtubules and microfilaments were sparse random in the PAa cells and diminished in PG cells. After treated with VCR, they were cut down seriously in PAa cells, and manifestations of mitotic arrest of cell cycle increased unusually in PG cells.

CONCLUSIONS

The cytoskeleton structure component changes are related to the viscoelasticity of the tumor cells. The anti-neoplasm actions of cytoskeleton interferents such as VCR might be realized by mainly regulating the message of tumor cells growth and differentiation.

[Synthesis and DNA binding studies of Ruthenium complexes by spectra]

New Complexes Ru(bpy)2dppx2+ were synthesized. The binding of Ru(bpy)2dppx2+ to calf thymus DNA has been investigated by using electronic absorption and fluorescence spectra. The intercalation mode was proved to exist. The DNA leads to a dramatic enhancement of the photoluminescence of the drug at 599 nm (lambda ex = 471 nm) and absorption hypochromic effect and red shift. It was obvious that Ruthenium complexes may be used at a good DNA probe.

Protective immunity induced by the full-length cDNA encoding paramyosin of Chinese Schistosoma japonicum

The full-length cDNA encoding paramyosin of Chinese S. japonicum (Sjc97) has been cloned and sequenced for the first time. The homology of the nucleotide sequence of paramyosin and the deduced amino acid sequence between Chinese, Philippine, Japanese strains and S. mansoni (Sm97) were 99.7, 99.8 and 96% at amino acid level, respectively; 99.4, 99.2 and 91% at nucleotide level, respectively. The immunogenicity and protective efficacy of a DNA vaccine encoding Sjc97 was evaluated in C57BL/6 mice. Mice immunized intramuscularly with pCMV-Sjc97 resulted in predominantly IgG2a and IgG2b immune responses, and immune sera were able to mediate antibody-dependent macrophage mediated cytotoxicity in vitro. Cytokine profiles in immunized C57BL/6 mice demonstrated Th1 bias, with IFN-gamma and IL-2 production and lack of IL-4 and IL-5. Immunization with pCMV-Sjc97 conferred a significant level of protection against cercariae in C57BL/6 mice. These results demonstrate that the nucleic acid encoding Sjc97 was able to induce a Th1 type immune response and confer protective efficacy in C57BL/6 mice when administrated via the intramuscular route.

[Point mutations of N-ras oncogene and abnormal expression of rasp21, p53 proteins in orbital rhabdomyosarcoma]

OBJECTIVE

The point mutations of N-ras oncogene and the abnormal expression of rasp21 and p53 proteins in orbital rhabdomyosarcoma (RMS) were analyzed in order to explore the role of oncogene mutations in the pathogenesis of orbital RMS and its relation to patients' prognosis.

METHOD

21 human orbital RMS tissues were analyzed by dot-blot hybridization and immunohistochemistry using synthetic specific oligonucleotide probes and mutant rasp21, p53 monoclonal antibodies.

RESULTS

The second base mutation of codon 12 of the N-ras oncogene was found in 4 patients. The third base mutation of codon 61 was found in 5 patients. The mutant rate was 33.3%. By immunohistochemistry analysis, the overexpression of rasp21 and p53 protein level was found in 42.9% and 76.2% respectively. The prognosis of patients with overexpression of ras p21, p53 was worse than that of normal expression (P < 0.01).

CONCLUSION

The mutants of ras and p53 oncogene play important roles in the pathogenesis of orbital RMS, and the abnormal expression of their protein products is related to patients' prognosis.

[A study on methods to measure the social burden of disease and their significance]

OBJECTIVE

To explore the effects of social burden of disease (BOD) on the total BOD.

METHODS

With stroke as an example, BOD was measured using the index, disability adjusted life years (DALY), and partial social BOD was measured using another index, time lost for nursing care of hospitalized patients.

RESULTS

The burden of stroke was 11.70 DALYs per thousand in men and 9.38 in women, respectively, and the burden for caring of patients with stroke during hospitalization accounted for 2.2% and 2.8% of the total BOD for men and women, respectively.

CONCLUSION

Effects of social BOD should be taken into consideration in measurement of total BOD.

TNF-alpha gene expression in macrophages: regulation by NF-kappa B is independent of c-Jun or C/EBP beta

The interaction of transcription factors is critical in the regulation of gene expression. This study characterized the mechanism by which NF-kappa B family members interact to regulate the human TNF-alpha gene. A 120-bp TNF-alpha promoter-reporter, possessing binding sites for NF-kappa B (kappa B3), C/EBP beta (CCAAT/enhancer binding protein beta), and c-Jun, was activated by cotransfection of plasmids expressing the wild-type version of each of these transcription factors. Employing adenoviral vectors, dominant-negative versions of NF-kappa B p65, and c-Jun, but not C/EBP beta, suppressed (p < 0.05-0.001) LPS-induced TNF-alpha secretion in primary human macrophages. Following LPS stimulation, NF-kappa B p50/p65 heterodimers bound to the kappa B3 site and c-Jun to the -103 AP-1 site of the TNF-alpha promoter. By transient transfection, NF-kappa B p65 and p50 synergistically activated the TNF-alpha promoter. In contrast, no synergy was observed between NF-kappa B p65, with or without NF-kappa B p50, and c-Jun or C/EBP beta, even in the presence of the coactivator p300. The contribution of the upstream kappa B binding sites was also examined. Following LPS stimulation, the kappa B1 site bound both NF-kappa B p50/p65 heterodimers and p50 homodimers. The binding by NF-kappa B p50 homodimers to the kappa B1, but not to the kappa 3, site contributed to the inability of macrophages to respond to a second LPS challenge. In summary, adjacent kappa B3 and AP-1 sites in the human TNF-alpha promoter contribute independently to LPS-induced activation. Although both the kappa B1 and kappa B3 sites bound transcriptionally active NF-kappa B p50/p65 heterodimers, only the kappa B1 site contributed to down-regulation by NF-kappa B p50 homodimers.

GABAergic neurons in Kölliker-Fuse nucleus and Bötzinger complex with axons projecting to phrenic nucleus

Experiments were made on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into phrenic nucleus. The brainstem sections were doubly processed for HRP histochemical staining with the TMB-Co-DAB method, and GABA immunohistochemical staining with anti-GABA primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-FITC double-labeled neurons were observed in the pontine Kölliker-Fuse nucleus and areas around the retrofacial nucleus (Bötzinger complex). Double-labeled neurons were also observed in the raphe nucleus, the lateral paragigantocellular nucleus, and the vestibular nucleus. The results show that brainstem GABAergic neurons in these structures, especially those in the Kölliker-Fuse nucleus and the B?t.C, send axonal projections to the phrenic nucleus.

[Cardiac allograft arteriosclerosis and myocardial necrosis]

OBJECTIVE

To study the development of myocardial necrosis, fibrosis, and arteriosclerosis in cardiac allograft in order to provide a theoretical basis for the prevention and treatment of anti-rejection.

METHODS

The recipient was pretreated with inoculation of donor splenocytes (SPC) followed by cyclophosphamide (CP). Heterotopic cervical heart transplantation was performed. The allografts stained with Hematoxylin and eosin (HE), Masson and Van Gieson were studied about inflammatory cell infiltration, myocardial necrosis, fibrosis and arteriosclerosis.

RESULTS

Preconditioning with SPC followed by CP prolonged the survival time of cardiac allograft. Inflammatory cell infiltration, myocardial necrosis, fibrosis, and arteriosclerosis in cardiac allograft were significantly decreased.

CONCLUSIONS

The development of acute cardiac allograft rejection originated from the epicardial area to the intimal area of the heart in rat. The infiltration of collagenous fiber in the coronary arteries is one of the major causes of concentric stenosis. The pretreatment of SPC followed by CP can prevent and relieve the rejection.

Changes in Ca(2+) cycling proteins underlie cardiac action potential prolongation in a pressure-overloaded guinea pig model with cardiac hypertrophy and failure

Ventricular arrhythmias are common in both cardiac hypertrophy and failure; cardiac failure in particular is associated with a significant increase in the risk of sudden cardiac death. We studied the electrophysiologic changes in a guinea pig model with aortic banding resulting in cardiac hypertrophy at 4 weeks and progressing to cardiac failure at 8 weeks using whole-cell patch-clamp and biochemical techniques. Action potential durations (APDs) were significantly prolonged in banded animals at 4 and 8 weeks compared with age-matched sham-operated animals. APDs at 50% and 90% repolarization (APD(50) and APD(90) in ms) were the following: 4 week, banded, 208+/-51 and 248+/-49 (n = 15); 4 week, sham, 189+/-68 and 213+/-69 (n = 16); 8 week, banded, 197+/-40 and 226+/-40 (n = 21); and 8 week, sham, 156+/-42 and 189+/-45 (n = 22), respectively; P<0.05 comparing banded versus sham-operated animals. We observed no significant differences in the K(+) currents between the 2 groups of animals at 4 and 8 weeks. However, banded animals exhibited a significant increase in Na(+) and Na(+)-Ca(2+) exchange current densities compared with controls. Furthermore, we have found a significant attenuation in the Ca(2+)-dependent inactivation of the L-type Ca(2+) current in the banded compared with sham-operated animals, likely as a result of the significant downregulation of the sarcoplasmic reticulum Ca(2+) ATPase, which has been documented previously in the heart failure animals. Our data provide an alternate mechanism for APD prolongation in cardiac hypertrophy and failure and support the notion that there is close interaction between Ca(2+) handling and action potential profile.

Comparison of three treatment options for single brain metastasis from lung cancer

Whole brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and the combination of both treatment methods were used for the management of single brain metastasis from lung cancer. The purpose of this study is to compare these three different treatment options in terms of local response, survival, and quality of life. From June 1995 to July 1998, 70 lung cancer patients with new diagnosed single brain metastasis were treated with either WBRT alone (n = 29), or SRS alone (n = 23), or the combination of both methods (n = 18). Multiple endpoints, including survival, freedom from local progression (FFLP), freedom from new brain metastasis (FFNBM), local control, Karnofsky performance status (KPS), and causes of death, were measured from the date of treatment completion and compared using univariate and multivariate analyses. For patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, the median survivals were 5.7, 9.3, and 10.6 months, the median FFLP were 4.0, 6.9, and 8.6 months, the median FFNBM were 4.1, 6.7, and 8.6 months, and the local response rates were 55.6, 87.0, and 88.9%, respectively. Four of the 29 patients treated with WBRT-alone continued with progression of disease. The post treatment KPS showed improvement in 41.4, 82.6, and 88.9% of patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. The progression of new and/or recurred metastatic brain tumor as the cause of death accounted for 51.7%, 50. 0%, and 28.3% of the patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. Univariate analyses showed that the significant differences among the three treatment arms were observed based on all of the above mentioned endpoints. However, the comparison between SRS-alone and SRS+WBRT groups indicated that adding WBRT only improves FFNBM (P = 0.0392). Cox regression analyses revealed no significant difference in both of the KPS (P = 0.1082) and causes of death (P = 0.081) among the three arms. Both SRS alone and SRS+WBRT seem better in prolonging life and improving quality of life than WBRT alone for patients with single brain metastasis from lung cancer. But the combined therapy did not show significant advantage over SRS alone in improving survival, enhancing local control, and quality of life except for a more favorable FFNBM. Further investigation via a randomized trial is needed to access the value of adding WBRT to SRS in the management of this group of patients. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 37-45 (2000).

Associations between socioeconomic status and cardiovascular risk factors in an urban population in China

INTRODUCTION

In developed countries socioeconomic status has been proven to be an important factor in the progression of cardiovascular disease. The present article reports the results of a cross-sectional assessment to investigate the association between socioeconomic status and cardiovascular risk factors in a Chinese urban population.

METHODS

In 1996, a behavioural risk factor survey was carried out in Tianjin, the third largest city in China. A sample of 4000 people aged 15-69 years, stratified by sex and 10-year age groups, was drawn randomly from urban areas of the city. The present study covers respondents aged 25-69 years (1615 men and 1592 women). Four socioeconomic indicators (education, occupation, income, and marital status), blood pressure, body mass index, and cigarette smoking were determined in the survey.

RESULTS

Educational level seemed to be the most important measure of the four socioeconomic indicators in relation to the cardiovascular risk factors in the study population. People with lower socioeconomic status had higher levels of cardiovascular risk factors. The association between socioeconomic status and cardiovascular risk factors was more consistent among women than men.

DISCUSSION

Our findings do not seem to differ from those observed in developed countries.

Effects of oxidative damage of membrane protein thiol groups on erythrocyte membrane viscoelasticities

In three oxidative damaging systems: the diamide-mercaptoethanol redox modification system (DM), the pyrogallol oxygen free radicals system (PG) and the hypoxanthine-xanthine oxidase oxygen free radical system (HXO), the effect of erythrocyte membrane oxidative damage on membrane viscoelasticities was investigated with micropipette aspiration method. The experimental results indicated that erythrocyte membrane oxidative damage has a great influence upon the membrane mechanical properties. The oxidative damage led to decrease of contents of membrane protein thiol radical. The scanning of SDS-PAGE presented that membrane proteins form the higher molecular weight component (HMP) by the cross-linking of membrane protein thiol radicals that might hinder the conformational change of membrane protein. This might be the reason for the increased membrane elastic modulus and viscous coefficient upon treating erythrocytes with the oxidative damaging systems. A significant negative logarithm regression relation was found between the membrane elastic modulus, mu, or viscoefficient, eta, and the contents of membrane protein thiol radicals. These experimental results suggested that thiol radicals oxidative damage reaction due to the superoxides anions (*O2-) may be an important molecular mechanism inducing changes of membrane viscoelasticities or whole cell deformability of erythrocyte under physiological and pathological oxidative stress.

[Stress-adaptation of bone]

Loading mechanotransduction sensors on the membrane of bone cells or osteoblasts can improve bone mechanisms and influence second messages, growth factors, bone matrix and oncogenes. The response of bone to stree is preportion to the magmititude of the stress. Stress-adaptation of bone is related with the magnititude, perporties, frequency time of stress.

PKC translocation without changes in Galphaq and PLC-beta protein abundance in cardiac hypertrophy and failure

Activation of protein kinase C (PKC) has been implicated as playing a key role in the pathogenesis of cardiac hypertrophy. This study investigates the response of several signal transduction proteins responsible for PKC activation during the transition from compensated pressure-overload hypertrophy (POH) to congestive heart failure (CHF). Pressure overload was produced on male, adult, Hartley strain guinea pigs using a ligature around the descending thoracic aorta. Sham-operated controls, POH, and CHF groups were identified based on left ventricular hypertrophy, pulmonary congestion, and isolated heart Langendorff mechanics. Quantitative immunoblotting revealed phospholipase C (PLC)-betaI and Galphaq were unchanged during POH and CHF, as were RGS2, RGS3, and RGS4 (regulators of G protein signaling, which are activators of intrinsic GTPase activity). Translocation of PKC-alpha, -epsilon, and -gamma from cytosolic to membranous fractions were significantly increased during POH and CHF. Cytosolic PKC activity was also elevated during POH. We conclude that differential PKC activation may be mediated by increases in Galphaq and PLC-betaI activity rather than upregulation of expression.

[Preliminary study on the immune response in C57BL/6 mice vaccinated by nucleic acid encoding paramyosin of Chinese S. japonicum]

OBJECTIVE

To study the characteristics of immune response in C57 BL/6 mice by nucleic acid encoding full-length paramyosin of Chinese S. japonicum.

METHODS

Total RNA was isolated from adult Chinese S. japonicum using TRIzol reagent. The full-length cDNA encoding paramyosin of Chinese S. japonicum was amplified by RT-PCR and cloned into expression vector pcDNA/Amp (pCMV-SjC97), which was intramuscularly injected into C57 BL/6 mice. The mice were vaccinated with DNA the three-week interval for a total of three inoculations. The specific anti-SjC97 IgM, IgG and IgE antibodies and IgG subclasses were determined by ELISA test.

RESULTS

The pCMV-SjC97 vaccine induced specific anti-SjC97 IgM and IgG antibodies. The antibody response correlated well with the administered amount of pCMV-SjC97. The IgG subclasses, predominantly IgG2a and IgG2b, were observed in the mice vaccinated with pCMV-SjC97, but no IgG1 and IgG3 responses were seen.

CONCLUSION

The strong immune response, especially Th1 type, can be induced in the mice with pCMV-SjC97 vaccine.

[Cloning and expressing of human papillomavirus 16 E7C subgene]

OBJECTIVE

To develop vaccine against HPV16 is the hotspot in this field, this study was to pave the rudiment for this purpose.

METHODS

E7C subgene (encoding aa39 to aa98) was amplified by PCR, and then cloned into pLNCX plasmid.

RESULTS

The recombinant pLNCE7C was obtained and identified by gel analysis of the restricted-endonuclease-digested fragments. It was shown that pLNCE7C was expressed in transfected B16 cells. The expression product was identified in the positive cells by Southern blotting and immunohistochemistry method. It was localized mainly in cytoplasm of B16 cells.

CONCLUSIONS

The plasmid pLNCE7C containing subgene of HPV16E7C not only remains the antigenesis of E7 gene but also eliminates the transforming activity of it. Meanwhile the expression of pLNCE7C is quite good. Therefore the plasmid pLNCE7C is suitable to develop DNA vaccine against HPV16.

Changes in blood pressure, body mass index, and salt consumption in a Chinese population

BACKGROUND

The prevalence of hypertension among the population of Tianjin is one of the highest in China. We attempted to assess the changes in blood pressure, body mass index, and salt consumption in Tianjin from 1989 to 1996.

METHODS

Two independent cross-sectional population surveys with the representative samples of 14,046 persons in 1989 and 2,000 persons in 1996 were carried out in Tianjin. A salt surveillance system was established with four salt consumption surveys (in 1992, 1993, 1994, and 1996) to estimate the changes in salt consumption at the household level.

RESULTS

From 1989 to 1996, the prevalence of hypertension and obesity decreased among people aged 45-64 years in both genders. Mean systolic blood pressure decreased significantly in women and leveled off in men. Diastolic blood pressure increased significantly. Body mass index remained unchanged. The unfavorable trends were mainly attributable to the negative changes in younger people (15-34 years) in both genders. There were no changes in salt consumption between 1992 and 1996 at the house level.

CONCLUSIONS

There was a favorable development in prevalence of hypertension and obesity among individuals in the age group of 45-64 years in the study population. Health education needs to pay more attention to young people.

[Investigation on the adhesive properties of different cycle hepatoma cells]

OBJECTIVE

To study the adhesive forces of HTC cells on different concentration of artificial basement membrane (collagen IV coated)and synchronous G1&S phase HTC cells on a certain concentration of artificial basement membrane.

METHODS

The adhesive forces of HTC cells were investigated by micropipette aspiration technique. The synchronous G1 and S phase cells were achieved through thymine-2-desoryriboside and cochicine sequential blockage method and double thymine-2-desoryriboside blockage method respectively.

RESULTS

HTC cells with 72.10% of G1 phase and 98.94% of S phase were achieved through thymine-2-desoryriboside and cochicine sequential blockage method and double thymine-2-desoryriboside blockage method respectively. The adhesive force of HTC cells on artificial basement membrane was in direct proportion to the concentration of collagen IV. G1 phase HTC cells had higher adhesive forces than S phase cells.

CONCLUSION

These studies suggested that the increase of basement membrane might be conducive to the chemotactic motion and adhesion of tumor cells; G1 phase cells were more capable of adhering to and getting through basement membrane than S phase cells, and reflected the differences of receptors between G1 phase cells and S phase cells.

[Identification of mutations in the human EXT1 and EXT2 genes]

OBJECTIVE

To investigate further the genetic basis of hereditary multiple exostoses (EXT) and provide useful information for gene diagnosis of the disease.

METHODS

Polymerase chain reaction-single strand conformation polymorphism was used to examine the entire coding regions of EXT(1) gene on chromosome 8 and EXT(2) gene on chromosome 11 for mutation in thirty EXT families. Mutations were further identified by sequencing.

RESULTS

Two frameshift mutations were identified in two unrelated EXT families. One was the deletion of one base(T) in exon 6 of the EXT(1) gene, and the other was the deletion of four bases (tgtt) in exon 2 of the EXT(2) gene. Both of the mutations resulted in a frameshift and premature termination of translation.

CONCLUSION

EXT is a genetically heterogeneous bone disorder caused by the mutation of EXT tumor suppressor gene. These results could be directly applied in the genetic counseling and prenatal genetic diagnosis of EXT.