Experimental studies of the material properties of the forewing of cicada(Homóptera, Cicàdidae)

Detailed investigations on the structural and mechanical properties of the forewing of the cicada were carried out. Measurement of the structures of the wings showed that the thickness of the membrane of each cell and the diameter of each vein were non-uniform in both the longitudinal and transverse directions, and their means were approximately 12.2 and 133.3 μm,respectively. However, the aspect ratios of the wings and the bodies were quite uniform and were approximately equal to 2.98 and 2.13, respectively. Based on the measured thickness, mass and area of the membranes of the cells,the mean density and the mean area density of the wing were approximately 2.3 g cm-3 and 2.8×10-3 g cm-2,respectively. In addition, the diameters of the veins of the wings, including the diameters of the holes in the vein of the leading edge, were examined. The mechanical properties of the wing were investigated separately by nanoindentation and tensile testing. The results indicated that the mean Young's modulus, hardness and yield stress of the membranes of the wings were approximately 3.7 GPa, 0.2 GPa and 29 MPa, respectively, and the mean Young's modulus and strength of the veins along the direction of the venation of wings were approximately 1.9 GPa and 52 MPa, respectively. Finally, the relevant results were briefly analyzed and discussed, providing a guideline to the biomimetic design of the aerofoil materials of micro air vehicles.

Current status of coronary multislice CT angiography

Multislice computed tomography (MSCT) is an emerging technique which has an enormous potential to improve the current practice of coronary artery imaging. This article reviews the current status of coronary MSCT angiography (MSCTA) with emphasis on the imaging techniques and clinical utilities of 16-slice CTA. Results and experiences gained from coronary MSCTA in the past few years have taught us that accurate diagnosis of coronary artery disease relies on good technical studies and can be achieved by optimizing image parameters including image timing and image reconstruction ECG-trigger delay. Current clinical applications of coronary MSCTA include: quantitative assessment of coronary artery stenosis, characterization of coronary atherosclerotic plaques, and follow-up of coronary artery stent and bypass graft. Furthermore, MSCT has brought an increasing awareness to the amount of radiation used in CT. This has prompted CT researchers and manufacturers to improve various techniques and develop new strategies to reduce radiation dose. It is anticipated that MSCT will become a sensitive and accurate tool for detecting coronary artery disease and monitoring outcomes after treatment for coronary artery disease.

Modified fast marching and level set method for medical image segmentation

In this paper, an interactive segmentation method that combines fast marching and level set method is proposed. Level set segmentation involves solving the energy-based active contour minimization problems by the computation of geodesics or minimal distance curves. First, by selecting the seed point, the fast marching method is used to extract rough boundaries of the interested object. We modified the traditional fast marching method to capture the weak edges by introducing watershed transform. Then, the contour obtained from the fast marching method mentioned above is regarded as an initialization and the level set method is used to finely tune the contour. The algorithm is demonstrated on some medical images: segmentation of knee tissues in CT image and segmentation of brain tissues in MR image. The results show that this method can remove the small regions obtained from fast marching method and converge the desired boundary.

[Clinical observation of misoprostol on induction in late pregnancy]

Eighty late pregnancy women were randomized into two groups. Misoprostol group and oxytocin group. We observed the different effects of misoprostol and oxytocin on induction, the different effects of misoprostol on induction which was given through rectum or through vagina. The results indicate that the rate of successful induction in misoprostol group is higher than that of oxytocin group, the rate of caesarean section in misoprostol group is lower than that of oxytocin group. There was no significant difference in the durations of misoprostol which was given through rectum or through vagina on induction. It is suggested that misoprostol is more effective on induction than that of oxytocin. We can choose misoprostol given through rectum to prompt delivery in conditions such as premature rupture of membranes and vaginitis.

[Relationship between TT virus infection and hepatocellular carcinoma]

OBJECTIVE

To clarify the relationship between TT virus (TTV) infection and the development of hepatocellular carcinoma (HCC).

METHODS

TTV was examined in sera of 112 patients with HCC and 95 patients with chronic liver disease (CLD) without HCC. 30 patients without liver disease were examined as control. TTV DNA was detected by the second generation of TTV PCR primers (NG059, NG061 and NG063) after extraction of DNA from 50 microliters serum. The relationship between TTV infection and clinical features of each group patients was analyzed.

RESULTS

TTV DNA was detected in 17.86% (20/112) of HCC patients, and this prevalence in HCC patients was not significantly higher than that of TTV DNA in CLD patients (15.78%, 15/95). There were no significant differences in age, gender, tumor factors (size, TNM classification and markers) and other hepatitis virus markers between TTV-positive and TTV-negative in HCC and CLD patients, except history of blood transfusion [(80.00% vs 35.87% (P < 0.05) in HCC patients and 73.33% vs 27.50% (P < 0.05) in CLD patients)] and ALT [(93 +/- 27) IU/L vs (68 +/- 31) IU/L (P < 0.05) in HCC patients]. It seemed that TTV did not do any harm to the liver function of patients who infected with HBV or HCV, except for elevating ALT level in such a kind of HCC patients.

CONCLUSION

Although TTV could do harm to the liver function of HCC patients, it does not contribute to the development of HCC from CLD.

Anticancer treatment of endostatin gene therapy by targeting tumor neovasculature in C57/BL mice

Antiangiogenesis strategy has been widely recognized as a viable approach to fight cancer. Considering the high cost and inconvenience of protein therapy of endostatin (ES), which is a potent antiangiogenic protein, we attempted to explore the inhibitory effect of ES gene therapy on tumor growth and metastasis. In this experiment, Lewis lung carcinoma (LLC)-bearing C57/BL mice were used to evaluate the antitumor effect of ES gene therapy and its impairment of tumor neovasculature. The data showed that the ectopic ES in circulation expressed by intramuscular administration of formulated ES-encoding plasmid DNA significantly suppressed primary tumor growth and lung metastasis in LLC-bearing C57/BL mice. Hence, our results demonstrated the inhibitory effect of ES gene therapy on angiogenesis-dependent tumor growth and metastasis.

Structure of dental glass-ionomer cements by confocal fluorescence microscopy and stereomicroscopy

The microstructure of four cements, setting by different mechanisms (acid-base, dual cure, triple cure), was studied. The porosity of unpolymerized materials was detected by stereomicroscopy. After polymerization and storage in water or lactic acid solution, the porosity, filler distribution and gel layer, which was formed at the filler/matrix interface of polymerized materials, were examined by confocal laser microscopy. For this purpose, the specimens were treated with fluorescent dye solution before the test. The results showed that hydrolytic degradation (pH 7) mainly involved the resin matrix, and the acid erosion (pH 3.5) involved the gel layer too. As regards the filler, materials with different setting mechanism released the glass particles in different times. The loss of the filler particles occurred quicker in acid-base setting cements, and slower in triple-cured material.

Molecular dynamics study of aquaporin-1 water channel in a lipid bilayer

The aquaporin-1 water channel was modeled in a palmitoyl-oleoyl-phosphatidyl-choline lipid bilayer, by means of molecular dynamics simulations. Interaction of the protein with the membrane and inter-monomer interactions were analyzed. Structural features of the channel important for its biological function, including the Asn-Pro-Ala (NPA) motifs, and the diffusion of water molecules into the channels, were investigated. Simulations revealed the formation of single file water inside the channels for certain relative positions of the NPA motifs.

[Cloning and phylogenetic analysis of hepatitis-associated TT virus subgenome]

Polymerase chain reaction (PCR) was utilized for the DNA amplification from transfusion transmitted virus (TTV) positive serum samples. Five TTV DNA fragments, overlapped about 90% of the genome, were amplified by long template PCR for the generation of TTV subgenome. Recombinant plasmids were obtained by directly inserting PCR products into pT-Adv vector, and DNA sequence analyses showed they were TTV DNA fragments. By using specific restriction enzymes, five TTV DNA fragments were ligated into a TTV DNA subgenome clone and named as TTV021. TTV021 has been deposited in GenBank database with the accession number AF254410. The results of computer analyses showed that TTV021, 3472 nt long, contains two open reading frames (ORF1, 785 aa; ORF2, 146 aa). Identity alignments between TTV021 and other TTV isolates indicated several high conserved regions existed. Phylogenetic analysis of 356 nt from TTV021 suggested that the isolate has close evolutionary relationship with CHN1 (type 1a), but has far relation with other TTV isolates.

[In vitro cotransfer human multidrug resistance gene (mdr-1) and dihydrofolate reductase gene (DHFR) into human CD(34)(+) progenitor cells to broaden the spectrum of drug resistance]

OBJECTIVE

To explore the feasibility of cotransferring human mdr-1 gene and DHFR gene into human CD(34)(+) progenitor cells to broaden the spectrum of drug resistance and improve the tolerance of myelosuppression following combination chemotherapy.

METHODS

The recombinant retroviral vector pSF-DIM containing mdr-1 and DHFR (L22Y) gene was constructed by introducing IRES sequence into vector FMCF which enable highly efficient gene expression in early hematopoietic cells. The retrovirus titers were raised by repeated supernatant cross infection between the amphotropic and ectropic retroviral packaging cells. Human CD(34)(+) progenitor cells were transduced by supernatant infection. Expression of P-gp was detected by flow cytometry. Integration of the foreign drug resistance gene in CD(34)(+) cells was determined by PCR. Drug resistance was evaluated by CFU-GM assay.

RESULT

Integration of the two foreign drug resistance genes was detected in the CD(34)(+) cells after pSF-DIM transduction. Compared with the untransduced group, the expression of P-gp elevated by 10.98% after gene transduction and the CFU-GM yields were significantly increased at 48 nmol/L of MTX and 10 ng/ml or 12 ng/ml of taxol (P < 0.05).

CONCLUSION

The retroviral vector pSF-DIM can mediate mdr-1 and DHFR gene integration and co-expression in human hematopoietic progenitor cells so as to broaden the spectrum of drug resistance.

[Apoptosis-related genes cloned by improved subtractive hybridization]

OBJECTIVE

To clone apoptosis-related genes induced by all-trans retinoic acid (ATRA) from human breast cancer cell line MCF-7, and to analyze the association between the cloned genes and apoptosis.

METHODS

An apoptotic cell model of MCF-7 cells was constructed with ATRA induction. The apoptosis-related genes were cloned by improved PCR-based subtractive hybridization.

RESULTS

Twelve differentially expressed clones were screened out. After exclusion of false positive clones by reverse dot blotting, 5 clones containing fragments of 0.5-1.5 kb were sequenced. The results of sequencing were compared with BLAST. A novel gene, named apmcf-1, coding for 47 amino acids was identified. This gene was accepted by GenBank, (Accession number: AF141882). The result of reverse dot blotting showed that it was related to apoptosis. The other 4 genes were already known. Three of them were related to apoptosis as previously reported. Two of them, hsp-90 and rb-L3, had little information about their relationship with apoptosis.

CONCLUSION

ATRA-induced tumor cell apoptosis is a complex process with multiple genes involved.

cDNA transfection of amino-terminal fragment of urokinase efficiently inhibits cancer cell invasion and metastasis

Focusing of urokinase-type plasminogen activator (uPA) to the cell surface via binding to its specific receptor (uPAR, CD87) is critical for tumor invasion and metastasis. Consequently, the inhibition of uPA-uPAR interaction on the cell surface might be a promising anti-invasion and anti-metastasis strategy. We examined the effects of cDNA transfection of the human uPA amino-terminal fragment (ATF) on invasion and metastasis of cancer cells. First, a highly metastatic human lung giant-cell carcinoma cell line (PG), used as the target cell for evaluation of this effect, was demonstrated to express both uPA and uPAR. Then, ATF, which contains an intact uPAR binding site but is catalytically inactive, was designed as an antagonist of uPA-uPAR interaction and was transfected into PG cells. [(3)H]-Thymidine incorporation and cell growth curves indicated that expressed ATF did not affect the proliferation of transfected cells. However, analysis by scanning electron microscopy revealed that ATF changed the host cells from the typical invasive phenotype to a noninvasive one. Correspondingly, the modified Boyden chamber test in vitro showed that ATF expression significantly decreased the invasive capacity of transfected cells. Furthermore, in the spontaneous metastasis model, it was confirmed in vivo that expressed ATF remarkably inhibited lung metastasis of implanted ATF-transfected PG cells. In summary, autocrine ATF could act as an antagonist of uPA-uPAR interaction, and ATF cDNA transfection could efficiently inhibit the invasion and metastasis of the cancer cells. Inhibition of uPA-uPAR interaction on the cell surface might be a promising anti-invasion and anti-metastasis strategy.

[Experimental study of anti-metastasis effect of urokinase amino-terminal fragment gene on human breast cancer cells]

OBJECTIVE

To explore the suppressive effects of urokinase amino-terminal fragment (ATF) gene on metastatic potential of human breast cancer cell line MCF-7.

METHODS

A pcDNA3-ATF plasmid containing ATF cDNA under CMV promotor/enhancer control was constructed and transfected into MCF-7 cells by lipofectin. The expression of of uPA/uPAR and ATF in MCF-7 cells were analyzed by RT-PCR and Western blot. The effect of ATF expression on invasiveness in vitro, tumorigenesis and metastasis in vivo of MCF-7 cell was investigated.

RESULTS

MCF-7 cells displayed an overexpression of uPA/uPAR. Expression of ATF was detected after ATF gene-transfection. The invasive capacity of ATF gene-transfected MCF-7 cells was decreased significantly. Although the tumorigenesis was not affected, the in vivo metastasis of ATF gene-transfected MCF-7 cells was remarkably inhibited.

CONCLUSION

Suppression of invasiveness and metastasis of ATF-transfected MCF-7 cells is perhaps due to a competitive inhibition of interaction with endogenous uPA/uPAR.

[Study on the epidemiological feature and control measure for rabies from 1990 to 2000 in Jiangsu province]

OBJECTIVE

To analyze the epidemiological feature of rabies and explore the risk factors in Jiangsu for the control of rabies.

METHODS

Data on rabies in Jiangsu from Jan. 1990 to Sep. 2000, and on case studies as well as surveillance from 1998 to 2000, were collected. Circular distribution statistics and Chi-square test were used.

RESULTS

The number of rabies had been decreasing since 1990 yearly, but increased in the last two years. The new cases of rabies tended to focus in the area of Nantong, Yanchen and Taizhou city. There were about 80% of cases in the above areas. Dogs were the main hosts (93.22%). Ninety-four point nine two percent of the persons were affected through dog bites with major wounded part as thoracic limbs (46.27%). Rates of severe bites, being wounded close to the central nervous system and more than 1 wound per cases were significantly higher than that in the population under surveillance. The antibody conversion rate was 86.28% after immunization in the surveillance population. The immunization rate was 58.20% among dogs.

CONCLUSION

Severe deep bites, wounded part close to the central nervous system and more than 1 wound per case were the risk factors in patients with rabies. Maltreatment and low immunization rate were important risk factors as well.

[Homogeneity study on the Streptococcus suis isolated from human and swine]

OBJECTIVE

To identify S. suis and to evaluate the homogeneity of isolates of S. suis from human and swine.

METHODS

Culture, morphology, API biochemical tests and serum coagulate tests were used. All the 7 strains of streptococcus were confirmed to be S. suis serotype 2. Two strains and 1 strain were isolated from blood and cerebrospinal fluid (CSF) of patients, respectively, while the other 4 strains were obtained from the infected swine or their corpses. Seven strains of S. suis serotype 2 and reference strain SS2 were analyzed by randomly amplified polymorphic DNA analysis with six primers and Rep PCR with four primers and thalli fatty acid profile analysis. Cluster and principal compound analysis of results were performed with RAPD, Phylip and Treeview software.

RESULTS

By analysis on RAPD patterns, a close relationship among 7 strains of S. suis serotype 2 and reference strain SS2 was discovered. Human-born strains and swine-born strains exhibit similar RAPD patterns. There was a same clonal relationship between strains originated from the blood and CFS of the patients. These results were confirmed by thalli fatty acid profile to have genotypic and phenotypic identity.

CONCLUSION

Homogeneity exists among the 7 strains and reference strain SS2.

[Cloning of mouse endostatin and primary analysis on its biological activity]

The mouse endostatin cDNA was cloned by the total RNA of Chinese Kunming mouse liver as template with RT-PCR. The results of sequencing showed one base pair difference. The ctg was replaced by gtg(L22545 in GenBank) at position 278 base pair, causing the encoded amino acid from reported Val to Leu in this experiment. This new endostatin cDNA was registered in GenBank with an accession number of AF257775. The recombinant eukaryotic expression plasmid pSecTag2-ES was then constructed and transfected into COS-7 cells for transient expression. The results of testing by Western blotting showed an expression fragment in supernatants of pSecTag2-ES transfected COS-7 cells at 48 and 72 hours of transfection. Cultured HUVECs were used to detect the biological effect of supernatants in pSecTag2-ES transfected COS-7 after 48 hours of transfection. 3H incorporation assay showed an obvious inhibition of endothelial cell prolifetation. The results demonstrated primary that the cloned endostatin cDNA had biological activity.

Improved PCR-based subtractive hybridization strategy for cloning differentially expressed genes

An improved PCR-based subtractive hybridization strategy was used to clone apoptosis-related genes induced by all-trans retinoic acid (ATRA) from human promyelocytic leukemia cell line HL-60 cells. The protocol used the cap-finder method, long-distance PCR, streptavidin magnetic bead-mediated subtraction and spin column chromatography. Twenty-seven clones related to apoptosis were identified by reverse dot blot assay. Seventeen were known genes, of which seven have been reported to be apoptosis related. The remaining 10 were unknown genes, five of which were sequenced and named apr-1 to apr-5. apr-1, apr-2, apr-3 and TNF were reidentified by reverse dot blot, and it is suggested that they might be related to apoptosis. The results suggest that this strategy might be efficient for large-scale cloning of differentially expressed genes in target cells.

[Studies on human streptococcal infectious syndrome caused by infected pigs]

OBJECTIVES

To demonstrate the clinical manifestations of S. suis infectious syndrome; to study the characteristics of causative organism and its source.

METHODS

25 cases of unknown causes of food poisoning were identified in the central area of Jiangsu province, China in July 1998. Biological specimens was collected in some patients, and the causative organism was isolated using a number of different culture medium. Isolated organisms were identified by serum antibody tests, API biochemical tests, drug sensitivity tests and animal model experiments. The human born strains and the pig born strains were compared by RAPD technique. Epidemiological methods were applied to trace the source of causative organisms.

RESULTS

Cases were clinically categorized into two types: Streptococcal toxic shock syndrome (STSS) and streptococcal meningitis syndrome (SMS). Three strains of streptococci were isolated respectively from the blood and cerebrospinal fluid of 6 cases. All these 6 strains were confirmed to be S. suis type 2 by culture characteristics, morphology, biochemical characteristics, serum antibody tests and fatty acid profile analysis. Animal model experiment showed that these strains were sensitive to rabbits and pigs, but not to rats. RAPD fingerprint test revealed an identity between human born and pig born strains.

CONCLUSIONS

The aetiological agent of these human cases was S. suis type 2. Human cases were contracted by direct contact with the infected pigs or the corpse of infected pigs.

[The expression and mechanism study of BMP in pleomorphic adenoma]

OBJECTIVE

One important pathological character of pleomorphic adenomas is that there is chorndriod component in the epithelial tumors. It is well known that bone morphogenetic protein (BMPs) plays important roles in the morphogenesis of hard tissue by inducing mesenchymal cells to differentiate into osteoblasts and chondroblasts in vivo. So we examined the expression of BMP and BMP2 mRNA in pleomorphic adenomas to study the pathological mechanism of chorndriod tissue formation.

METHODS

Using ABC immunohistochemistry method, 6 specimens of pleomorphic adenomas were examined with BMP antibody. Reverse transcriptase-polymerase chain reaction (RT-PCR) methods were developed for detecting BMP2 mRNA expression with special primers used to amplify the BMP2 cDNA mature domain fragment. The total RNA was extracted from frozen 6 specimens of pleomorphic adenoma and then reversed to cDNA by reverse transcription using AMV reverse transcriptase. PCR conditions were 94 degrees C for 20 seconds, 60 degrees C for 30 seconds, and 72 degrees C for 1 minute, 40 cycles, followed by extension for 30 minute at 72 degrees C. The reaction products were analyzed by electrophoresis.

RESULTS

BMP expression could be found in all of the specimens of pleomorphic adenoma examined by immunohistochemistry method. BMP2 RT-PCR product was detected in only 5 specimens that showed BMP2 mRNA existed in 5 specimens.

CONCLUSION

These results may be helpful to study the mechanism of pleomorphic adenoma. It is speculated that BMP secreted by tumor cells may play important roles in origin of osteoid tissue in pleomorphic adenoma by inducing neoplastic myoepithelial cells to differentiate to chondrocytes.

[Prospective study on the correlation factors of fetal macrosomia]

The increase of body weight in pregnancy women, 50 g oral glucose challenge test (50 g GCT), pregnant women and umbilicus vein blood insulin (INS), growth hormone (GH), glucose and neonate weight were measured in 110 pregnant women and their neonates were measured to explore the correlation factors of fetal macrosomia. The incidence of macrosomia was higher in pregnant women whose increased weight > or = 15 kg than those < 15 kg. 50 g GCT plasma glucose showed positive correlation with neonatal weight. Which was higher in the group of the fetal macrosomia than of the normal neonates. The results suggest that both the increasing weight of the pregnant women and the 50 g GCT are related parameters to predict fetal macrosomia. To prevent fetal macrosomia the diet should be limited in those who have had a high increasing body weight in pregnancy and appropriate intervention is required to those whose 50 g GCT are positive.

[The inhibition of prourokinase gene transfer on deposition of platelets on rabbit carotid artery intima]

OBJECTIVE

To observe the expression of pro-urokinase (proUK) gene in rabbit carotid artery transfected with replication-deficient adenovirus vector containing proUK gene (Ad/prouk) and the deposition of platelet on the same injured vessel.

METHODS

Ad/proUK (Ad/proUK, 3 x 10(10) pfu/ml) was injected into the right carotid artery locally. Wild type adenovirus (Ad) was locally injected into the left carotid artery as self-control. The expression of proUK gene was investigated by immunohistochemistry assay. After injury of the gene-transfected vessel by electric stimulation, the deposition of (111) In-labeled platelet was quantitatively observed. The thrombosis was observed with HE-stained vessel section.

RESULTS

There were lots of proUK granules in the endothelium of Ad/proUK gene-transfected vessel. The differences in (111) In-platelets deposition per gram dry weight vessel segment were significant between Ad/proUK and Ad transfected control vessels [(4.60 +/- 0.93) x 10(7)/g vs control (27.95 +/- 4.93) x 10(7)/g, P < 0.01)]. The HE-stained vessel section showed that there were only small thrombi in proUK gene-transfected vessel but massive thrombi almost blocked up the whole vessel in control vessel.

CONCLUSION

The proUK gene-transfected vessel can obviously inhibit (111) In-labeled platelet deposition on injured vessel and thus thrombosis.

Blood flow distribution in sorbent beds: analysis of a new sorbent device for hemoperfusion

A new polymer-based sorbent cartridge has been recently developed for enhancing middle molecule removal during hemodialysis. The cartridge (Betasorb, Renaltech, New York, USA) has been designed to be placed in series with the dialyzer in the blood circuit. It is therefore important to evaluate the distribution of flow into the blood compartment of the device in order to assess if the surface of the sorbent is utilized to the best. For this purpose, a special imaging technique was utilized. Cartridges were analyzed during a simulated in vitro circulation at 250 and 350 ml/min of blood flow and 25% and 40% hematocrit. Cartridges were placed in vertical position and a cross longitudinal section 1 cm thick was analyzed in sequence by a helical scanner. Dye was injected into the arterial inlet and the progressive distribution was evaluated by sequential densitometrical measures carried out automatically by the machine. The sequential images analyzed by the scanner demonstrated excellent distribution of the flow in the blood compartment with minimal difference between the central and the peripheral regions of the compartment. In particular the following flow velocity pattern could be observed under the different experimental conditions tested. We may conclude that the cartridge design is adequate and no channelling effects could be detected in the blood compartment. The flow distribution is slightly affected by changes in flow rate and hematocrit showing an optimal utilization of the available surface for molecule adsorption.

[Effects of local vibration on the levels of plasma endothelin and nitric oxide in rabbits]

In order to explore the effects of local vibration on plasma endothelin(ET) and nitric oxide (NO) and the relations with vibration-induced vascular impairment(VVI), plasma ET and NO levels of rabbits were measured after exposure to different vibration power and different exposure period. The results showed an increasing tendency in plasma ET levels, and a decreasing tendency in plasma NO levels in experiment groups, while lasting vibration exposure and enhancing vibration power. It suggested that local vibration could result in the increasing of plasma ET level and decreasing of plasma NO level, which might be one of the mechanisms of vibration-induced vascular impairment.

Estimation of body fluid changes during peritoneal dialysis by segmental bioimpedance analysis

Estimation of body fluid changes during peritoneal dialysis by segmental bioimpedance analysis.

BACKGROUND

Commonly used bioimpedance analysis (BIA) is insensitive to changes in peritoneal fluid volume. The purpose of this study was to show, to our knowledge for the first time, that a new segmental approach accurately measures extracellular fluid changes during peritoneal dialysis (PD).

METHODS

Fourteen stable PD patients were studied during a standard exchange with fluids of known conductivity. Bioimpedance was continuously measured in the arm, trunk, and leg and from wrist to ankle. Volume changes were calculated using both a newly developed sum of segmental BIA (SBIA) and current wrist-to-ankle BIA (WBIA) and were compared with actual volume changes measured gravimetrically.

RESULTS

When 2.19 +/- 0.48 L were removed from the peritoneal cavity during draining, 95.2 +/- 13.8% of this volume was detected by SBIA compared with only 12.5 +/- 24. 3% detected by WBIA. When 2.11 +/- 0.20 L of fresh dialysate was infused into the peritoneal cavity during filling, 91.1 +/- 19.6% of this volume was detected by SBIA compared with only 8.8 +/- 21.1% detected by WBIA.

CONCLUSION

The good agreement between measured and calculated data using SBIA was due to: (a) improved placement of electrodes, (b) estimation of trunk extracellular volume based on a new algorithm, and (c) consideration of changes in dialysate conductivity. Correct estimation of fluid volume in the trunk is a prerequisite for applications in which direct analysis of fluid changes cannot be performed such as with peritoneal equilibration tests and continuous flow PD.

[Application of IL-1 beta and 8 mRNA and some other indices in monitoring the activity of ulcerative colitis]

OBJECTIVE

To evaluate the monitoring action of the expression of IL-1 beta, IL-8 mRNA, myeloperoxidase (MPO) and superoxide dismutase (SOD) activity in the active ulcerative celitis (UC).

METHODS

Twenty active UC patients, 23 inactive UC patients; and 14 non-UC inflammation patients were selected. Twelve patients who complained of flatulence, abdominal pain and constipation receiving endoscopic examination were used as control. MPO and SOD activity, IL-1 beta and IL-8 mRNA expression (hybridization in situ) were determined on the endoscopic biopsy specimens of all patients. In 20 active UC patients, 14 patients received endoscopic examination and 4 indices detection were done once again after 2 months' treatment with prednisone and SASP.

RESULTS

Mucosal MPO activities of active UC patients, inactive UC patients, and non-UC inflammation patients are higher than those of control patients, (19.37 +/- 0.54, 11.59 +/- 1.41, and 12.97 +/- 0.49) U/g tissue vs (9.49 +/- 0.51) U/g tissue (P < 0.01). SOD activities are lower than that of control patients, (5.03 +/- 07,7. 7.66 +/- 0.79, and 6.98 +/- 0.61) U/mg protein vs (8.82 +/- 0.58) U/mg protein (P < 0.05). Mucosal MPO activity of active UC patients is also higher than that of inactive and non-UC inflammation patients (P < 0.01); while SOD activity is lower than them (P < 0.01). After 2 months' medical treatment, MPO activity of 14 active UC patients decreased, (12.61 +/- 0.74) U/g tissue vs (19.31 +/- 0.44) U/g tissue (P < 0.01), while SOD activity elevated (7.44 +/- 0.55) U/mg protein vs (5.10 +/- 1.05) U/mg protein (P < 0.05), compared with that of before treatment. Positive expression of IL-1 beta mRNA appeared in the epithelial and inflammatory cells of all active UC patients, 9 inactive UC patients, and 7 non-UC inflammation patients. While expression of IL-8 mRNA only appeared positively in all active UC patients. In 14 active UC patients, there were no detection of interleukin mRNA expression after 2 months' treatment.

CONCLUSIONS

Mucosal MPO, SOD, IL-1 beta, and IL-8 mRNA could be used as 4 indices monitoring the activity of UC. And IL-1 beta mRNA is also helpful to supervise early or late UC activity.

[Surveillance of hemorrhagic fever with renal syndrome and studies on its predictive indices in Jiangsu Province]

OBJECTIVE

To study its predictive significance of the direct use of surveillance data of hemorrhagic fever with renal syndrome (HFRS) collected in Jiangsu province, and find an indicator of choice for qualitative prediction.

METHODS

A correlation analysis between the HFRS incidence rate and surveillance data collected in the past 12 years since 1986 was applied.

RESULTS

There was significant relationship between HFRS incidence rate and indoor density of rattus norvegicus (Rn), proportions of mixed species of rats and Rn with HFRS virus, indices of mixed species of rats and Rn with virus in the spring Relationship between HFRS incidence rate and densities of outdoor mixed species of rats and Apodemus agrarius (Aa), and proportions of mixed species and Aa with virus was all significant in autumn and winter. And, there was significant relationship between HFRS incidence rate during the whole year and annual average density of rats, proportion of rats with virus, index of rats with virus. There was no significant relationship between HFRS incidence rate and human inapparent infection rate. The coefficients of correlation between HFRS incidence rate in the spring and indices of indoor mixed species of rats and Rn with virus were 0.8637 and 0.8295, respectively (P < 0.001). And, those between HFRS incidence rate and indices of outdoor mixed species of rats and Aa were 0.7089 and 0. 7258 in the autumn and winter, respectively (P < 0.01). The coefficients of correlation between HFRS incidence rate in the next spring and indices of outdoor mixed species and Aa with virus in the autumn were 0.7118 and 0.7113, respectively (P < 0.01). The coefficient of correlation between HFRS incidence rate during the whole year and annual average index of rats with virus was 0.9207 (P < 0.001).

CONCLUSION

The index of rats with virus was an indicator of choice for qualitative prediction of HFRS, and the density of rats may be the secondary choice.

Sum of segmental bioimpedance analysis during ultrafiltration and hemodialysis reduces sensitivity to changes in body position

BACKGROUND

Bioimpedance, a noninvasive technique to analyze body composition, has attracted interest in determining body hydration in hemodialysis patients. However, the so-called whole-body (wrist-to-ankle) bioimpedance analysis (WBIA) is sensitive to changes in regional fluid distribution and tends to underestimate fluid changes during ultrafiltration in hemodialysis patients. The aim of this study was to show that volume changes calculated from a new approach, that is, segmental bioimpedance analysis (SBIA), are not affected by changes in body position.

METHODS

Ten male patients (age 44 +/- 8 years, target weight 70.8 +/- 10 kg) were studied during their regular hemodialysis treatment while maintaining either a sitting or a supine body position throughout the study. Extracellular volume was calculated from extracellular resistance obtained from bioimpedance data measured for a range of frequencies (5 to 500 kHz) using the Xitron BIS4000B analyzer. Wrist-to-ankle measurements were compared with segmental arm, trunk, and leg measurements.

RESULTS

Changes in extracellular volume estimated from wrist-to-ankle measurements only reached 80 +/- 13% and 65 +/- 17% of the actual change in body mass during sitting and supine dialysis treatments, respectively. However, when segmental measurements were analyzed, the calculated change in extracellular volume was 101 +/- 6% and 100 +/- 3% of the actual change in body mass during the sitting and supine treatments, respectively.

CONCLUSIONS

SBIA properly identifies regional fluid changes and provides an appropriate measure of fluid changes caused by ultrafiltration and hemodialysis. The volume estimation based on the sum of segmental bioimpedance measurements is independent of body position, which is a prerequisite for applications in everyday practice.

[Clinical obeservation of improved passing peritoneum extraperitoneal cesarean sectron]

One hundred and fifty puerperas who had indications for cesarean section and factors associated with intrauterine infection were random divided into three groups and adopted three different operative proccdures which were improved passing peritoneum extraperitoneal, extraperitoneal and low segement cesarean section respectively. Three were 50 puerperas in each group, seven paremeters were observed during and after operation. The results showed that the mean times of three groups from cutting skin to fetal head delivered were 19.5, 22.6 and 19.9 minutes respectively (P < 0.05), the mean operative times were 58.04, 68.2 and 72.0 minutes in proper urder (P < 0.01). Gastrointestinal function recovery mean times were 26.6, 26.0 and 47.9 hours (P < 0.01) in sequence. Postoperative morhidity rates were 10%, 12% and 24% (P < 0.01) in order. Postoperative comlicatins were 0%, 26% and 6% (P < 0.01). There were no significant difference both in newborn one minute Apgar grading and blood loss volume during the operation in three groups. Improved passing peritoneun extraperitoneal cesarean section is a simple, convenient, safe and practical oprative method. It is especially applied to those cases who have a bad form of uterine hypomere and factors of intrauterine infection.

The clinical application of computerized three-dimensional mimic operation for maxillofacial bone tumor

Facial bone, as the frame to support maxillofacial region and with several sinuses and cavities, is structurally complicated and the maxillofacial tumors, benign or malignant, in this region usually grows into the deep tissues, sinus-cavities and orbit and destroys the bone. In this study, the maxillofacial tumors were subjected to a mimic operation on a computer following CT scanning and 3-dimensional reconstruction. The data similar to those of real operation were obtained, which could be used for developing operative plans. As compared with data on the basis of conditions in the real operation, computerized mimic operation reflected the real conditions during operation. Computerized mimic operation is valuable for the preoperative planning and the prediction of probable intraoperative events.

[Effects of aprotinin on heparinized whole blood activated clotting time and whole blood prothrombin time]

When aprotinin is used during cardiopulmonary bypass, there is a prolongation of the activated clotting time (ACT), which is used to monitor heparinization. The aim of this study was to observe the effects of aprotinin and heparin on whole blood ACT and whole blood prothrombin time (BPT). The results showed that when kaolin was used as the contact activator, the intrinsic clotting system was also inhibited by aprotinin, the observed ACTs with various dose aprotinin and concomitant heparin were significantly prolonged (Q = 0.757, P < 0.01). There was a dose-dependent prolongation of BPT by heparin (r = 0.985, P < 0.01). However, the heparin-mediated prolongation of BPT was not enhanced by aprotinin. The authors conclude that aprotinin prolongs heparinized whole blood activated clotting time but was not whole blood prothrombin time.

[The effect of interleukin-1 beta interleukin-8 in the pathogenesis of experimental colitis and evaluation of interleukin-1 receptor antagonist therapy]

OBJECTIVE

To study the effect of interleukin-1 beta and interleukin-8 in the pathogenesis of colitis and evaluate the therapeutic effect of interleukin-1 receptor antagonist(IL-1ra).

METHODS

A rat model of chronic experimental colitis was induced by administration of trinitrobenzenesulfonic acid (TNBS, 30 mg) in 50% ethanol 0.25 ml. IL-1ra was then administered intravenously with a dosage of 7 mg/kg at different times. Hydrocortisone (3 mg) i.v. administration was served as control. Tissue expression of IL-1 beta mRNA and IL-8 mRNA was then studied by in situ hybridization before and after IL-1ra administration. Histological examination and tissue myeloperoxidase (MPO) and superoxide dismutase (SOD) activities detection were also made to assess the severity of colitis.

RESULTS

An acute inflammation with ulcers, neutrophil infiltration and crypt abscess developed that evolved into a chronic inflammation with abundant fibrous connective tissue hypertrophy at 21 days. And it then recurs only after 10 mg TNBS administration. Activities of MPO and SOD correlated with severity of inflammation. Expression of IL-1 beta mRNA was detected in macrophages in lamina propria and submucosa during the whole period of inflammation. It could be also present in epithelial cells in the 3rd day of colitis. While IL-8 mRNA expression appeared at the 3rd day, and disappeared at 21th day when colitis turned into chronic. After IL-1ra administration, the expression of these two interleukins could not be detected, accompanied with alleviation of histological manifestation, decrease of MPO activity and elevation of SOD activity.

CONCLUSIONS

IL-1 beta and IL-8 were involved in the pathogenesis of colitis. IL-1ra has preventive and therapeutic effect to colitis.

LIGHT, a novel ligand for lymphotoxin beta receptor and TR2/HVEM induces apoptosis and suppresses in vivo tumor formation via gene transfer

LIGHT is a new member of tumor necrosis factor (TNF) cytokine family derived from an activated T cell cDNA library. LIGHT mRNA is highly expressed in splenocytes, activated PBL, CD8(+) tumor infiltrating lymphocytes, granulocytes, and monocytes but not in the thymus and the tumor cells examined. Introduction of LIGHT cDNA into MDA-MB-231 human breast carcinoma caused complete tumor suppression in vivo. Histological examination showed marked neutrophil infiltration and necrosis in LIGHT expressing but not in the parental or the Neo-transfected MDA-MB-231 tumors. Interferon gamma (IFNgamma) dramatically enhances LIGHT-mediated apoptosis. LIGHT protein triggers apoptosis of various tumor cells expressing both lymphotoxin beta receptor (LTbetaR) and TR2/HVEM receptors, and its cytotoxicity can be blocked specifically by addition of a LTbetaR-Fc or a TR2/HVEM-Fc fusion protein. However, LIGHT was not cytolytic to the tumor cells that express only the LTbetaR or the TR2/HVEM or hematopoietic cells examined that express only the TR2/HVEM, such as PBL, Jurkat cells, or CD8(+) TIL cells. In contrast, treatment of the activated PBL with LIGHT resulted in release of IFNgamma. Our data suggest that LIGHT triggers distinct biological responses based on the expression patterns of its receptors on the target cells. Thus, LIGHT may play a role in the immune modulation and have a potential value in cancer therapy.

A viral gene that activates lytic cycle expression of Kaposi's sarcoma-associated herpesvirus

Herpesviruses exist in two states, latency and a lytic productive cycle. Here we identify an immediate-early gene encoded by Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus eight (HHV8) that activates lytic cycle gene expression from the latent viral genome. The gene is a homologue of Rta, a transcriptional activator encoded by Epstein-Barr virus (EBV). KSHV/Rta activated KSHV early lytic genes, including virus-encoded interleukin 6 and polyadenylated nuclear RNA, and a late gene, small viral capsid antigen. In cells dually infected with Epstein-Barr virus and KSHV, each Rta activated only autologous lytic cycle genes. Expression of viral cytokines under control of the KSHV/Rta gene is likely to contribute to the pathogenesis of KSHV-associated diseases.

Validation of changes in extracellular volume measured during hemodialysis using a segmental bioimpedance technique

Sum of segmental bioimpedance analysis (BIAs) has recently been introduced as a more accurate estimation of extracellular volume (ECV). The current study was designed to compare the changes in ECV estimated by whole body bioimpedance (BIA(W)) and BIAs and to determine whether BIAs could be used to accurately estimate changes in ECV compared with the ultrafiltration volume (UFV) as measured by the dialysis machine. Ten men (age, 49 +/- 10 years; dry weight, 78 +/- 13 kg) were studied during hemodialysis (HD). A multifrequency bioimpedance analyzer (BIS4000B; Xitron Technologies, San Diego, CA) and a digital switch developed by the authors were used to automatically collect data from three body segments (arm, trunk, and leg) and the whole body using the stated technique. There was a significant difference in delta ECV(W) and UFV at the end of the treatment (2.75 +/- 0.74 L vs 3.95 +/- 0.73 L, p < 0.05) because fluid removal from the trunk has almost no effect on whole body resistance. However, delta ECVs was not significantly different from UFV (3.76 +/- 0.65 L vs 3.95 +/- 0.73 L, p = NS). BIAs is a more accurate approach to monitor changes in ECV during HD than is BIA(W) because changes in local resistance can be allocated to segments with uniform geometry and resistivity. This is a prerequisite for future studies on dynamics of regional fluid distribution during hemodialysis.

[The establishment of TNBS-induced experimental colitis]

OBJECTIVE

To explore the pathogenesis of inflammatory bowel disease (IBD) and to establish some indices monitoring the activity and severity of IBD.

METHODS

A rat model of experimental colitis was induced by administration of the hapten 2, 4, 6-trinitrobenzenesulfonic acid (TNBS, 30 mg) in 50% ethanol 0.25 ml as the "barrier breaker". And it then recurs only after 10 mg TNBS administration. Inflammation was assessed by gross appearance using a grading scale and by histology. Myeloperoxidase(MPO) and superioxide dismutase(SOD) activities were also measured to evaluate the severity of inflammation.

RESULTS

An acute inflammation with ulcers and neutrophil infiltration developed that evolved into a chronic inflammation with luminol narrowing and abundant fibrous connective tissue hypertrophy at 21 days. Crypt abcess were observed in some rats killed in 1 week. MPO activity was significantly elevated, while SOD decreased, in mucosa from all treated groups at all time intervals when macroscopic and microscopic mucosal injury was evident.

CONCLUSIONS

These results indicate that this model affords an opportunity to study the pathogenesis of colonic inflammatory disease and may be used to evaluate new treatments potentially applicable to IBD in humans. In addition, MPO and SOD activities could be regarded as two markers which may evaluate the severity of colonic inflammation.

Dynamics of segmental extracellular volumes during changes in body position by bioimpedance analysis

Extracellular volume (ECV) of arms, trunk, and legs determined from segmental bioimpedance data in 11 healthy men (31.6 +/- 7 yr) obtained at the end of a 30-min equilibration phase in the supine body position was compared with ECV determined from whole body measurements (ECVWB). ECV was calculated from extracellular resistance (RECV) identified from the bioimpedance spectrum for a range of 10 frequencies. Whole body RECV (527.6 +/- 55.6 Omega) was equal to the sum of RECV in the arms, trunk, and legs (241.6 +/- 36. 3, 49.2 +/- 5.1, and 236.3 +/- 25.5 Omega, respectively). The sum of equilibrated ECV in arms (1.31 +/- 0.25 liters), trunk (10.08 +/- 1.65 liters), and legs (2.80 +/- 0.82 liters) was smaller than ECVWB (20.90 +/- 2.59 liters). In six subjects who changed from a standing to a supine body position, ECV decreased in arms (-2.59 +/- 2.51%, P = NS) and legs (-10.96 +/- 3.02%, P < 0.05) but increased in the trunk (+4.2 +/- 3.2%, P < 0.05). ECVWB also decreased (-4.98 +/- 1. 41%, P < 0.05). However, the sum of segmental extracellular volumes remained unchanged (-0.06 +/- 0.07%, P = NS). The sum of segmental ECVs is not sensitive to changes in body position, which otherwise interferes with the estimation of ECV in bioimpedance analysis when ECVWB is used.

Simple high-performance liquid chromatographic determination of the protease inhibitor indinavir in human plasma

Indinavir is a member of a class of protease inhibitors that actively prevent the acquired immunodeficiency syndrome virion from maturing. A high-performance liquid chromatographic (HPLC) assay was developed and validated for the determination of indinavir in human plasma. Indinavir and the internal standard were isolated from the plasma by ether extraction. The residue after evaporation of ether was reconstituted with buffer and injected onto a C4 reversed-phase column eluted isocratically with a mobile phase consisting of 35:65 (v/v) of acetonitrile and buffer. A wavelength of 210 nm was found to be optimum for detection. The calibration range of this assay was from 10 to 5000 ng/ml and coefficients of variation for the assay ranged from 4.6% to 11.0% for three different drug concentrations and the limit of quantitation was 10 ng/ml. During the validation, short-term stability of the drug in plasma, stability during heat deactivation and on repeated freezing and thawing of plasma was evaluated. The overall recovery of indinavir by the ether extraction method was 91.4%. This HPLC assay was found to be a simple and reproducible method for monitoring indinavir levels in human plasma obtained during clinical trials of the drug.

[A multiexponential model in cavity ring-down absorption spectroscopy]

A multiexponential model of cavity ring-down absorption spectroscopy is established for taking into account the laser linewidth effects. It is demonstrated that by fitting the logarithmic ring-down function to a truncated polynomial, absorption coefficent can be extracted from coefficients of the first as well as higher order terms of the fitted polynomial. The new fit model results in higher accuracy and broader dynamic range than the previous single exponential model.

[Studies on arachidonic acid production by Mortierella]

The effects of the incubation temperature, initial pH of the medium, carbon source and nitrogen source on the production of arachidonic acid by Mortierella sp. M10 were studied. Thought orthogonal experiments, the optimum culture medium was obtained (g/L): glucose, 100; yeast extract, 10; KNO3, 4.0; KH2PO4, 2.0; CaCl2.2H2O, 0.1; MgSO4.7H2O, 0.5; FeCl3.6H2O, 0.015; ZnSO4.7H2O, 0.0075; CuSO4.5H2O, 0.0005. Under the optimum culture conditions, the dry cell weight and arachidonic acid was 33.51 g/L and 0.827 g/L, respectively. The flask culture process was analysed.

Ribozyme-mediated high resistance against potato spindle tuber viroid in transgenic potatoes

A hammerhead ribozyme [R(-)] targeting the minus strand RNA of potato spindle tuber viroid (PSTVd) and a mutated nonfunctional ribozyme [mR(-)] were designed, cloned, and transcribed. As predicted, both monomer and dimer transcripts of the active R(-) ribozyme gene could cleave the PSTVd minus strand dimer RNA into three fragments of 77, 338, and 359 bases in vitro at 25 and 50 degrees C. The tandem dimer genes of R(-) and mR(-) were subcloned separately into the plant expression vector pROK2. Transgenic potato plants (cultivar Desirée) were generated by Agrobacterium tumefaciens-mediated transformation. Twenty-three of 34 independent transgenic plant lines expressing the active ribozyme R(-) resulted in having high levels of resistance to PSTVd, being free of PSTVd accumulation after challenge inoculation with PSTVd, but the remaining lines showed weaker levels of resistance to PSTVd with low levels of PSTVd accumulation. In contrast, 59 of 60 independent transgenic lines expressing the mutated ribozyme mR(-) were susceptible to PSTVd inoculation and had levels of PSTVd accumulation similar to that of the control plants transformed with the empty vector. The resistance against PSTVd replication was stably inherited to the vegetative progenies.

[Expression of green fluorescent protein with baculovirus vector in insect cells]

The green fluorescent protein (GFP) gene was subcloned into the transfer vector pVLneo downstream of the polyhedrin gene (ocu) promoter. Insect cells were cotransfected with recombinant plasmid and Autographa californica Nuclear Polyhedrosis Virus (AcNPV) DNA. In the presence of G418, the recombinant virus containing GFP gene was purified. The GFP expressed in insect cells with a Mw of 30 kDa is observable by strong green light under a fluorescent microscope. Excitation and emission spectra of the GFP were 395 nm and 509 nm respectively. Integration of GFP gene on AcNPV genome was identified directly by Southern blot which gave strong hybridization signal between GFP cDNA probe and 1 kb EcoRI fragment of recombinant virus.

Study on enzyme electrode biosensor of choline

Choline oxidase was immobilized at a hydrogen peroxide electrode and the enzyme electrode was used for the amperometric determination of choline. The linear range is 0-200 mg/L with a response time of 40 seconds and a 25-microliter sample injection. The relative standard deviation (RSD) is less than 1.5% in 20 assays. The enzyme membrane can be used continuously at 25 degrees C for 60 days. The recovery rate of this method is 100.3-102.3%.