[Expression, purification and identification of human IFN-alpha 2 b/HBV Pre S2 fusion protein]

OBJECTIVE

To express a fusion protein of human interferon-a2b and HBV Pre S2 in E.coli for the purpose of investigating anti-HBV immunomodulatory protein.

METHODS

Human interferon-a2b and HBV Pre S2 encoding genes were amplified from plasmid templates through PCR, then fused and cloned into plasmid pBV220 through engineering technique to generate expression plasmid pBV-IFN-Pre S2. The plasmid was transfected into E. coli to produce fusion protein. RP-HPLC and ion-exchange chromatography were employed to purify fusion protein.

RESULTS

27 kDa fusion protein was expressed up to 15% of total bacterial protein in E. coli. After purification, the purity of fusion protein reached 95% of total protein. Anti-viral assay showed that IFN-Pre S2 protein induced a VSV-resistant activity of 1.25 x 10(8) lU/mg protein in Wish cell line, similar to the bioactivity of original recombinant human IFN-alpha 2b. ELISA data showed that IFN-Pre S2 protein had antigenicities of both human IFN-alpha 2b and HBV Pre S2. In addition, fusion protein showed the feature of binding to polymeric human serum albumin (PHSA).

CONCLUSIONS

The bifunctional fusion protein was efficiently expressed in E. coli. The work provided initial evidence for studying PHSA-receptor-targeting IFN-alpha 2b,which might have potential application for the treatment of HBV infection.

[Distribution and transferring of carbon in kast soil system of peak forest depression in humid subtropical region]

Taking Guilin Yaji Karst Experiment Site as an exemple and with the methods of field monitoring and laboratory analysis, this paper studied the distribution and transferring of carbon in the karst soil system of peak forest depression in the humid subtropical region of China. The carbon pools in biomass, litters and soil organic matter(SOM) and their mobility as expressed by oxidizability and decomposition rate of SOM, the concentration of soil CO2 and the emission rate of CO2 from soil were investigated. The mobile carbon pool in the system supplied a rich source of CO2, which drived the karst process. When active karst process happened in Spring and Summer, over 60% of carbon in the output water was derived from soil CO2, as traced by delta 13 C distribution in the system. Therefore, owing to the carbon transfer in the pathway of air-plant-soil-water, karst process took place rather under soil-rock-water interface than under air-rock-water interface. Thus, the epigenetic karst process was driven and accelerated by soil as an interface of carbon environmental geochemistry.

[Functional and structural analysis of a prokaryotic enhancer-like element in Escherichia coli MC1061 strain]

Cat and lacZ genes were used as reporter gene and three prokaryotic enhancer-like element (MC2, MC8 and MC9) were identified in the genomic DNA of MC1061 strain. All three fragments can improve the expression of lacZ gene by 2-5 times with the orientation independence. The results of in vivo transcription and Dot blot hybridization assays suggested that MC8 regulated the expression of lacZ at transcription level. Stepwise deletion expreriments showed the functional domain of MC8 located at 450-950 bp, and in regions 450-600 bp and 840-950 bp contain at least one functional loci. Sequence data indicated three are 3 A + T rich sections in MC8, 2 of them are in the functional loci.

Sequence analysis of a rice BAC covering the syntenous barley Rpg1 region

In the course of map-based cloning of the barley stem rust resistance gene Rpg1, we identified a rice bacterial artificial chromosome (BAC) containing the Rpg1 flanking markers. Based on the excellent gene order colinearity between barley and rice in this region, we expected that this rice BAC would contain the barley Rpg1 homologue. In order to identify the putative rice homologue, we sequenced ca. 35 kb of the rice BAC at random and then an additional 33 kb of contiguous sequence between the two most closely spaced Rpg1 flanking markers. Sequence analysis revealed a total of 15 putative genes, 5 within the 33-kb contiguous region. A rice Rpg1 homologue was not identified, although a gene encoding a hypothetical polypeptide with similarity to a membrane protein could not be eliminated as a candidate. Surprisingly, four of the genes identified in the 33-kb contiguous rice sequence showed a high degree of similarity with genes on Arabidopsis chromosome 4. The genome regions harboring these genes showed some relatedness, but many rearrangements were also evident. These data suggest that some genes have remained linked even over the long evolutionary separation of Arabidopsis and rice, as has also been reported for mammals and invertebrates.

Effects of sodium hyaluronate on experimental osteoarthritis in rabbit knee joints

The aim of this study was to examine the effects of intraarticular administration of hyaluronan (HA) on cartilage degradation. Using a partial menisectomy model of osteoarthritis (OA) in the rabbit knee, the authors investigated the catabolic and anabolic changes induced by intraarticular injection of HA. To analyze anabolic changes, the authors assessed cell proliferation by measuring [3H] thymidine uptake, and proteoglycan biosynthesis by noting [35S] sulfate incorporation. For catabolic changes, messenger ribonucleic acid (mRNA) expression of interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in cartilage and synovium were detected with reverse transcriptase polymerase chain reaction (RT-PCR). Of significance for blocking the development of early OA in chondrocytes was the finding that total proteoglycan synthesis in the HA treatment group was significantly higher than in the controls. At the mRNA level in cartilage and synovium, HA inhibited MMP-3 and TIMP-1 production in the same way in the HA treatment group, while not affecting MMP-1 production. Thus it can be concluded that HA affects cartilage catabolism and anabolism to prevent the progress of OA.

Different frequencies of p53 codon-249 hot-spot mutations in hepatocellular carcinomas in Jiang-su province of China

Environmental carcinogens often induce specific mutations in the p53 gene, apparent in tumors. The relation between aflatoxin B1 (AFB1 )-related hepatocellular carcinomas (HCCs) and hot spot at codon 249 of the p53 gene has received a great deal of attention, but its significance is still controversial. To clarify this problem, we analyzed the p53-mutational status of HCCs in Jiang-su province in China, where AFB1 contamination of the staple food significantly differs between the northern and southern parts (prominent only in the latter), while other conditions are quite similar. Background liver status and mutations in exons 5 to 8 of p53 in a total of 31 cases were divided approximately equally between the 2 areas. In all, 15 tumors exhibited a total of 17 mutations in the p53 gene; 9 cases from the southern part of the province had the hot-spot mutation at codon 249 (9/16, 56%), but only one case from the northern part (1/15, 8%). These results suggest that AFB1 contamination may correlate with codon-249 mutations in HCC.

Different frequencies of p53 codon-249 hot-spot mutations in hepatocellular carcinomas in Jiang-su province of China

Environmental carcinogens often induce specific mutations in the p53 gene, apparent in tumors. The relation between aflatoxin B1 (AFB1 )-related hepatocellular carcinomas (HCCs) and hot spot at codon 249 of the p53 gene has received a great deal of attention, but its significance is still controversial. To clarify this problem, we analyzed the p53-mutational status of HCCs in Jiang-su province in China, where AFB1 contamination of the staple food significantly differs between the northern and southern parts (prominent only in the latter), while other conditions are quite similar. Background liver status and mutations in exons 5 to 8 of p53 in a total of 31 cases were divided approximately equally between the 2 areas. In all, 15 tumors exhibited a total of 17 mutations in the p53 gene; 9 cases from the southern part of the province had the hot-spot mutation at codon 249 (9/16, 56%), but only one case from the northern part (1/15, 8%). These results suggest that AFB1 contamination may correlate with codon-249 mutations in HCC.

Application of capillary nongel sieving electrophoresis for gene analysis

Capillary electrophoresis (CE) has proved to be a strong tool for DNA analysis and has found abundant applications in the fields of restriction fragment sizing, mutation screening, polymerase chain reaction (PCR) product characterizing and forensic identifying. CE may be the main alternative to slab gel electrophoresis. Capillary nongel electrophoresis is the most favorable mode when aiming for this purpose because of its advantages of long lifetime, easy operation, good reproducibility, and low expense. In this paper, a new kind of sieving matrix, with mannitol as the additive for capillary electrophoresis, as well as related methods and their application for gene analysis were reported. Nine DNA fragments amplified by multiplex PCR from a normal dystrophin gene were well separated by this system. Three different deletions were found in Duchenne muscular dystrophy (DMD) patients. Three to four copies of the sex-determination region of the Y chromosome (SRY) gene, as well as the phenylalanine hydroxylase (PAH) gene, could be detected in mixed samples. The frequencies of short tandem repeats (STR) in PAH genes was analyzed in 61 normal Chinese individuals and 6 phenylketonuria families. One case of prenatal gene diagnosis was performed. By using this matrix, CE coupled with reverse transcription PCR (RT-PCR), the analysis of the alternative splicing expression pattern of the fragile X mental retardation 1 (FMR1) gene in adult lung tissue was achieved.

[The role of breathing control disorder in the development of carbon dioxide retention in patients with obesity hypoventilation syndrome]

OBJECTIVE

To define the role of breathing control in the pathogenesis of carbon dioxide (CO(2)) retention in patients with obesity hypoventilation syndrome.

METHODS

10 obese obstructive sleep apnea syndrome (OSAS) patients were studied. They were separated according to their waking arterial partial pressure of CO(2) (PaCO(2)), 5 being eucapnic and 5 hypercapnic. Both groups had similar body mass index, apnea hypopnea index and normal lung function. The hypoxic (Delta P(0.1)/Delta SaO(2), Delta V(E)/Delta SaO(2)) and the hypercapnic response (Delta P(0.1)/Delta PaCO(2), Delta V(E)/Delta PaCO(2)) were tested before and during continuous positive airway pressure (CPAP) treatment (at 2, 4, 6 weeks).

RESULTS

Compared with the eucapnic patients, all the hypercapnic patients had lower Delta P(0.1)/Delta SaO(2) [(-0.04 +/- 0.02) cmH(2)O% vs (-0.14 +/- 0.03) cmH(2)O%], Delta V(E)/Delta SaO(2) [(-0.17 +/- 0.04) L x min(-1)% vs (-0.34 +/- 0.04) L x min(-1)%], Delta P(0.1)/Delta PaCO(2) [(0.23 +/- 0.1) cmH(2)O/mm Hg vs (0.49 +/- 0.1) cmH(2)O/mm Hg], Delta V(E)/Delta PaCO(2) [(1.32 +/- 0.7) L x min(-1) x mm Hg(-1) vs (2.18 +/- 0.81) L x min(-1) x mm Hg(-1)] and the Delta P(0.1)/Delta SaO(2), Delta V(E)/Delta SaO(2) were also lower than the normal value. After treatment with CPAP, the hypercapnic and the hypoxic response of the hypercapnic patients increased gradually, at about 4 approximately 6 week, both of them increased to the normal range, PaCO(2) showed a complete return to eucapnia, their weight were unchanged.

CONCLUSION

The depressed breathing control play an important role in the development of CO(2) retention in OSAS patients, and the disorder in breathing control may be secondary to hypoxia, hypercapnia and sleep disorder related to the OSAS.

[Utility of nocturnal oximetry for case finding in patients with suspected sleep apnea syndrome]

OBJECTIVE

Pulse oximeter is a useful screening device for SAS. We studied whether measurement of SaO2 could identify patients with SAS and evaluate the severity of SAS.

METHODS

174 snorers were assessed clinically and then underwent formal PSG and oximetry test at the same time. From the oximetry data, the percentage of time spent at SaO2 below 90% (SIT90%), waking SaO2(H SaO2%), the lowest SaO2(L SaO2%) during sleep, the mean SaO2(M SaO2%) and the number of oxygen desaturation > or = 4% per hour (DI4) were calculated. We also divided 100 cases among them into four groups by AHI, which were G0(AHI < 5), G1(AHI 5-19), G2(AHI 20-39), G3(AHI > or = 40), and evaluated whether the SIT90, ISaO2, MSaO2 and DI4 are different among the four groups.

RESULTS

There was an statistically significant correlation (r = 0.91 P < 0.001) between DI4 and AHI. DI4 > or = 5 per hour identified patients with AHI > 5 with a sensitivity of 94%; DI4 > or = 15 per hour identified patients with AHI > 5 with a specificity of 98%, and for patients with AHI > or = 20, the sensitivity was 100%. The SIT90 and DI4 were significantly different among the four groups (P < 0.01).

CONCLUSIONS

Oximetry with DI4 < 5 practically excludes clinically significant SAS, and DI4 > or = 15 identified almost all of them. SIT90 and DI4 could be used as parameters in evaluating the severity of SAS.

Pteridine analysis in urine by capillary electrophoresis using laser-induced fluorescence detection

Pteridines are a class of compounds excreted in urine, the levels of which are found to elevate significantly in tumor-related diseases. For the first time, we have developed a method, based on high-performance capillary electrophoresis (HPCE) and laser-induced fluorescence (LIF) detection, to monitor the pteridine levels in urine. HPCE provides better separation than high-performance liquid chromatography and the LIF detector enables us to detect minute amounts of pteridines in body fluid. Eight different pteridine derivatives were well separated in 0.1 M Tris-0.1 M borate-2 mM EDTA buffer (pH 8.75) using a 60-cm fused-silica capillary (50-micron i.d., 35-cm effective length), six of which were detected and characterized in urine samples from normal persons and different cancer patients. The detection limits of these pteridines are under 1 x 10(-10) M. The levels of neopterin, pterine, xanthopterin, and pterin-6-carboxylic acid were found to be significantly elevated in urine excreted by cancer patents, while the level of isoxanthopterin dropped in these patients. No significant change of biopterin level was found between healthy individuals and cancer patients. This method can be used in clinical laboratories either for cancer monitoring or for precancer screening.

Experience with the rectus abdominis myocutaneous flap with vascularized hard tissue for immediate orbitofacial reconstruction

For a considerable tissue defect of the orbitofacial region after skull base or head and neck tumor en bloc extirpation, we have developed the "flying buttress" technique using the vascularized hard tissue rather than the multi-stage operative method using bone graft or alloplastic materials. The procedure reconstructs the inferior orbital rim and the zygomatic prominence--flying buttresses bridging transversely in a missing face--with free flap coverage, simultaneously in the primary surgery so that the bony structure is maintained for years and ptosis of a large flap is minimized. We prefer to use the rectus abdominis myocutaneous flap for tissue restoration and two types of vascularized hard tissue: the costal cartilages combined with the flap and the temporalis muscle-pedicled calvarial bone. Representative cases are illustrated and the technique is detailed.

[Application of capillary non-gel sieving electrophoresis to the analysis of short tandem repeat in phenylalanine hydroxylase gene and gene diagnosis of phenylketonuria]

OBJECTIVE

To establish a sensitive, accurate and reliable method for analysis of short tandem repeat (STR) markers for gene diagnosis, capillary electrophoresis (CE) was used for analysis of a polymorphic tetranucleotide (TCTA)n in intron 3 of the phenylalanine hydroxylase (PAH) gene.

METHODS

Capillary non-gel sieving electrophoresis (CNGSE) system was used to analyze PCR products of PAH STR among 61 normal Chinese individuals and 6 phenylketonuria (PKU) families.

RESULTS

The PCR fragments that differ 4 bp from each other were well separated by CNGSE. Ten alleles were identified, with a continuous distribution from 224 bp to 260 bp. The largest allele (260 bp) was first detected in Chinese population. The alleles frequencies were calculated and PIC is 0.738. The genotypes of PAH STR of total 80 Chinese people were also analyzed and the heterozygosity is 75%. We used this procedure to PAH gene linkage analysis in 6 PKU families, in which pathogenic gene could be affirmed in 3 families, including one case of prenatal diagnosis.

CONCLUSIONS

In comparison with denaturing polyacrylamide gel electrophoresis, CE is an accurate, rapid, automatic and with high resolution analytical tool. CE in combination with PCR is a hopeful technique and might be widely used for gene diagnosis of genetic diseases in the future.

[Influence of mannitol additive on DNA separation by capillary non-gel sieving electrophoresis]

Polymer solutions with high concentration were employed as sieving buffer in order to obtain satisfactory separation of smaller DNA fragments with length of less than 1,000 base pairs. The concentrated polymer solution had very high viscosity, which was difficult to be pumped into or out of the capillary. Mannitol additive can enhance the sieving ability of hydroxy-propylmethylcellulose (HPMC) solution in a Tris-Borate-EDTA background electrolyte. With the existence of mannitol, good separation of PGEM-3Zf(+)/Hae III was able to be obtained in a less concentrated HPMC solution with relatively low viscosity. The optimum mass concentration of mannitol was investigated and it was found that 60 g/L mannitol could give the best results. Mannitol chain could be formed through hydrogen bond among mannitol, HPMC and borate. This kind of mannitol chain shaped the network and decreased the pore size, so the separation was greatly enhanced.

[Breathing control of patients with obstructive sleep apnea syndrome (OSAS) during sleep]

OBJECTIVE

It is assumed that reduced ventilatory control function during sleep may be one of the mechanisms resulting in obstructive sleep apnea syndrome (OSAS), but the breathing drive has never been measured in patients with OSAS during sleep.

METHOD

P0.1, delta P0.1/delta SaO2, delta VE/delta SaO2, delta P0.1/delta PaCO2 and delta VE/delta PaCO2 in sixteen patients with severe OSAS were measured via nasopharyngeal tubes connected with nasal mask to maintain upper airway patent, during wake and NREM I + II, NREM III + IV, REM sleep stages, and the same parameters in eleven normal subjects, non-snorers were also measured, by nasal mask as control.

RESULT

(1) During wake: P0.1 in all the OSAS patients was remarkably higher than that of the normal subjects (P < 0.05), but there was no difference in delta VE/delta SaO2, delta P0.1/delta SaO2, delta VE/delta PaCO2 and delta P0.1/delta PaCO2 between the two groups (P > 0.05). (2) The above parameters measured during sleep compared with that measured during wake: In NREM I + II and NREM III + IV, normal subjects showed no significant decrease in P0.1, delta P0.1/delta SaO2, delta P0.1/delta PaCO2 (P > 0.05), but delta VE/delta SaO2 and delta VE/delta PaCO2 decreased significantly (P < 0.05). In REM1 P0.1 maintained the same level as that during wake, but both hypoxic and hypercapnic responses decreased remarkably (P < 0.05). In the OSAS patients, P0.1 decreased during NREM I + II and REM sleep (P < 0.5), but not during NREM III + IV (P > 0.05). delta VE/delta SaO2, delta P0.1/delta SaO2, delta P0.1/delta PaCO2 and delta VE/delta PaCO2 decreased markedly during all sleep stages (P < 0.01). (3) From wake to sleep, delta VE/delta SaO2 decreased by 51.6 +/- 30.4% (Mean +/- SD) in the OSAS patients vs 33.6 +/- 26.0% decreased in the normal subjects; delta VE/delta PaCO2 decreased by 56.9 +/- 25.5% in OSAS vs 40.8 +/- 17.5% in the normal subjects; The hypoxic and hypercapnic responses in OSAS patients decreased much more than those in the normal subjects during sleep (P < 0.05).

CONCLUSION

This is the first study to measure the hypoxic and hypercapnic responses successfully in OSAS patients during sleep. It was found that the breathing drive was significantly reduced in sleeping OSAS patients, which may play an important role in the development of OSAS, possibly through the reduced action upon the dilators causing the upper airway in predilection for collapse.

[The study on in vivo erythropoietin gene transfer for treatment of renal anemia in animal model]

To explore the possibility of gene therapy to renal anemia, the receptor mediated erythropoietin (EPO) gene transfer in vivo had been tested. EPO gene was inserted to an EBV replicon expression vector to form the plasmid pEPO, Renal anemia rat had been induced by feeding with adenine, and 450 micrograms of the pEPO was delivered by perfusion into the rat peripheral circulation in the form of soluble DNA/galactosylate histone complex. 13 days after injection, the number of peripheral red cells was counted and the concentration of hemoglobin was measured. The results demonstrated that symptom of anemia had been significantly improved(P < 0.01), when compared with that of the control test. (the red cell number was 492 vs 409, and the hemoglobin was 11.4 vs 9.1).

Synteny with rice: analysis of barley malting quality QTLs and rpg4 chromosome regions

The barley (Hordeum vulgare L.) chromosome 1 centromere region contains two adjacent overlapping quantitative trait loci (QTLs) for malting quality traits, and the chromosome 7L subtelomere region contains the stem rust (causal agent Puccinia graminis f.sp. tritici) resistance gene rpg4. To facilitate the saturation mapping of these two target regions, a synteny-based approach was employed. Syntenic relationships between the barley target regions and the rice (Oryza sativa) genome were established through comparative mapping. The barley chromosome 1 centromere region was found to be syntenic with rice chromosome 8 and parts of rice chromosomes 3 and 10. A 6- to 15-fold difference in genetic distance between barley and rice in the syntenic region was observed, owing to the apparent suppressed recombination in the barley chromosome 1 centromere region. Barley chromosome 7L was found to be syntenic with rice chromosome 3. The establishment of synteny with rice in the two target regions allows well-established and characterized rice resources to be utilized in fine mapping and map-based cloning studies.Key words: genome synteny, quantitative trait loci, QTL, disease resistance gene, Triticeae.

[Synthesis and preliminary study on cleavage activity of ribozyme to hepatitis B virus preS2 gene in vitro]

In this paper, a multi-target hammerhead ribozyme gene was synthesized directed against 110, 122 and 132 sites of nucleotide of HBV preS2 gene. The target gene fragment was cut from HBV genome containing plasmid pCP10. Both of the ribozyme and the target gene fragments were cloned into pGEM3Zf(-) plasmid and sequenced by dideoxy chain termination method. The transcription of both gene fragments was performed in vitro utilizing T7 RNA promoter in pGEM3Zf (-) plasmid. The cleavage activity of ribozyme to substrate was confirmed in vitro. For further evaluating intracellular function of ribozyme, two ribozyme-retroviral recombinant plasmids with different promoter type pDOR-ripe and tRNA-ripe were constructed. Pseudo-virus was collected through routine packaging procedure and transduted into 2.2.15 cells. RIA data showed a stable inhibition of pHSA-R antigen expression to the lowest extent of 41.01% +/- 4.16 and the highest extent of 51.45% +/- 4.57 within 4 weeks after transduction. No influence, however, on HBsAg and HBeAg expression was demonstrated after ribozyme gene transfer.

[Cloning and expression of subunit genes of pertussis toxin and its immunological evaluation]

OBJECTIVE

To clone the gene encoding pertussis toxin (PT) from Bordetella Pertussis CS strain and five genes encoding subunits of PT, to investigate the possibility of expressing the genes encoding for mature methionyl subunits of PT in insect cell and to evaluate the immunological characteristics of recombinant subunits.

METHODS

The genes encoding for PT and its subunits were cloned by PCR and confirmed by restriction enzyme digestion and Southern blot. Using recombinant baculovirus technology, the recombinant subunits were expressed in Sf9 insect cells and analyzed by immunofluorescence assay. The immunological properties of recombinant subunits were analyzed by ELISA.

RESULTS

The genes encoding for PT and its subunits were cloned and expressed in Sf9 cells. The level of specific antibodies against nature PT induced by five recombinant subunits polymerized was higher than that unpolymerized and polymerized by four recombinant subunits (without S1) in mice. The results indicate that PT subunits had weak ability to induce specific antibodies against PT, and also anti-nature PT sera had poor recognition to PT subunits.

CONCLUSION

The ability of PT to induce specific antibody is conformation dependent of intact PT, and antibody induction domains are located dominantly in S1 subunit of intact PT.

[Molecular biological evidence for the genetic stability of in vivo passaged doxorubicin resistant cell line S-180R]

OBJECTIVE

To assess the genetic stability of doxorubicin resistant sarcoma 180 cell line(S-180R) after in vivo passages.

METHODS

Flow cytometry, Southern blot, Northern blot and RT-PCR were used to examine genes and molecules related to drug resistance.

RESULTS

The drug-efflux of S-180R was nearly 100-fold as high as that of the parental cells. The ratio of half peak width to peak height was 0.23 as compared to 0.56 measured two years before when the S-180R cell line was initially established. The mdr-1 gene was significantly amplified and transcribed while the transcription of topoisomerase II alpha gene was decreased. However there was no increase in mRNA expression of the multidrug resistance associated protein(MRP).

CONCLUSION

Compared with the initially established S-180R, its resistance to doxorubicin is not only maintained but in fact has been increased since in vivo passage for 2 years. The major mechanism is amplification and over-expression of mdr-1 gene, but decreased topoisomerase II alpha also contributes. S-180R is an ideal experimental model for the study of doxorubicin resistance and its reversion.

[Orbito-facial reconstruction after extensive anterior skull base, head and neck resection using a rectus abdominis musculocutaneous flap]

In response to the recent advances in aggressive excision of skull base and head and neck malignancies, a more sophisticated method primary reconstruction has been developed using a craniofacial techniques for preservation of postoperative quality of life. We have developed an inferior pedicled rectus abdominis musculocutaneous flap with rib cartilages for reconstruction of the orbito-facial region. The advantages of this flap are as follows; 1) Simultaneous flap elevation in a supine position is possible, 2) Easy, versatile and reliable flap adjustment can be made for complicated space defect, 3) Curvature of the ipsilateral rib cartilages is suitable for inferior orbital rim, 4) Lower risk of pleura laceration as compared with a superior pedicled flap. In the past 5 years, the composite free flaps have been applied for 3 cases of hemi orbito-facial defect, with better results than in previous cases. Our technique for the flap application in a representative case is illustrated.

[Anti-virus effect of hepatocyte stimulating substance (HSS) on duck hepatitis B virus in vivo]

We used one day old Beijing ducklings infected by duck hepatitis B virus as experimental model to observe anti-virus effect of HSS. Beijing ducklings hatched within one day were injected intravenously with duck hepatitis B virus (DHBV). Positive DHBV-DNA in ducklings' sera were detected 7 days later. Serum samples were obtained from all ducklings before, during and after drug treatment at different times and stored at -70 degrees C. The collected samples were detected DHBV-DNA by dot-blot hybridization test at the same time. The therapeutic effects were evaluated by OD value of dot-blot and by the inhibitory rate of DHBV-DNA. The results showed that HSS (with 50 mg/kg/day and 200 mg/kg/day) were effective in inhibition of DHBV-DNA during and after drug treatment, especially in the HSS group of large dosage. The inhibitory effect appeared early and high dynamic. The inhibitory rate of DHBV-DNA during and after drug treatment were higher than the NS group (P < 0.05). No inhibitory effect was observed in NS group. The hepatic biopsy showed HSS groups had milder damage than NS group, indicating that the HSS could inhibit the replication of DHBV-DNA in Beijing ducklings.

pH-dependent changes of nitric oxide, peroxynitrite, and reactive oxygen species in hepatocellular damage

Low arterial blood pH and sustained nitric oxide (NO) production are critical parameters in inflammatory events such as sepsis, and appropriate treatment is still under debate. Because the stability of nitrogen and oxygen intermediates is dependent on the surrounding pH, we investigated whether the relationship among NO, peroxynitrite (ONOO-), and reactive oxygen species production also depends on the pH value, particularly with respect to their effects on hepatocellular damage. Our studies demonstrate that the extracellular pH influences NO and hydroxyl radical (OH) production in hepatocytes. Acidification (pH 7.0) of the medium revealed a significant increase (P < 0.05) of OH-like radicals, enhanced hepatocellular damage, and a sharp drop in cellular glutathione (GSH) content compared with levels measured at physiological or alkaline pH conditions. Furthermore, inhibition of NO synthesis at all pH conditions resulted in decreased NO production and cellular GSH levels but a simultaneous increase of OH-like radicals and hepatocellular damage with a maximum seen at pH 7.0. Our results suggest that hepatocellular damage is in part regulated by the surrounding pH and that inhibition of NO synthesis at acidic conditions (e.g., in sepsis) leads to increased reactive oxygen-mediated cell injury.

Towards map-based cloning of the barley stem rust resistance genes Rpg1 and rpg4 using rice as an intergenomic cloning vehicle

The barley stem rust resistance genes Rpg1 and rpg4 were mapped in barley on chromosomes 1P and 7M, respectively and the syntenous rice chromosomes identified as 6P and 3P by mapping common probes in barley and rice. Rice yeast artificial chromosome (YAC), bacterial artificial chromosome (BAC) and cosmid clones were used to isolate probes mapping to the barley Rpg1 region. The rice BAC isolated with the pM13 probe was a particularly excellent source of probes. A high-resolution map of the Rpg1 region was established with 1400 gametes yielding a map density of 3.6 markers per 0.1 cM. A detailed physical map was established for the rice BAC fragment containing the Rpg1-flanking markers pM13 and B24. This fragment covers a barley genetic distance of 0.6 cM and a rice DNA physical distance of ca. 70 kb. The distribution of barley cross-overs in relation to the rice DNA physical distances was extremely uneven. The barley genetic distance between the pM13 marker and Rpg1 was 0.1 cM per ca. 55 kb, while on the proximal side it was 0.5 cm per ca. 15 kb. Three probes from the distal end of the pM13 BAC mapped 3.0 cm proximal of Rpg1 and out of synteny with rice. These experiments confirm the validity of using large insert rice clones as probe sources to saturate small barley (and other large genome cereals) genome regions with markers. They also establish a note of caution that even in regions of high microsynteny, there may be small DNA fragments that have transposed and are no longer in syntenous positions.

[DNA polymorphism analysis by capillary electrophoresis]

A review is given here to describe the principle and methods of gene polymorphism analysis by capillary electrophoresis (CE). DNA length polymorphism and sequence polymorphism are very important phenomena in gene molecular biology. Some practical works of gene length polymorphism analysis and sequence polymorphism analysis are listed. SSCP and HPA methods detecting gene point mutations are demonstrated. Applications of gene polymorphism analysis by CE in clinical, forensic and biological research are also discussed in this paper.

[Comparison of anti-hepatitis C virus (HCV) IgM and HCV-RNA detection in serum samples of patients with HCV infection]

Anti-HCV IgG is the routine assay for the diagnosis hepatitis C. But the method is ineffective in early detection of hepatitis C. We have detected anti-HCV IgM in hospital hepatitis C patients by Enzyme-Linked Immunosorbent Assay (ELISA) and compared the results with those of HCV-RNA and total antibody. Our studies indicate that anti-HCV IgM is detected in all hepatitis C marker positive sera. But the amount of anti-HCV IgM in HCV-RNA positive sera is significantly higher than that of in the corresponding negative sera. This subjects that anti-HCV IgM and HCV-RNA are somewhat correlated and they have different clinical interests. Anti-HCV IgM can be expected and hepatitis activities and its actual clinical interests are to be further studied.

[Drug resistance mechanism of doxorubicin-resistant human gastric cancer cells BGC-823/DOX]

To further investigate drug resistance mechanism of BGC-823/DOX, we analysed the amplication, transcription and overexpression of genes associated with drug resistance by Southern blot, RT-PCR, immunohisto clogical assay and the concentration of Doxorubicin in the cells by flow cytometry. The results showed that parent cells of BGC-823 were cell line with intrinsic drug resistance similar to the gastrointestinal tumors. Multidrug resistance was the main mechanism of drug resistance in BGC-823/DOX. There was a significant difference between the doxorubicin-resistant cells line from parent cells with intrinsic drug resistance and from parent cells without intrinsic drug resistance in drug resistance.

[Establishment and characterization of doxorubicin-resistant BGC-823/DOX of human gastric cancer cell line]

To study drug resistance mechanism of gastrointestinal tumor, doxorubicin resistant cell line of human gastric cancer, we developed BGC-823/DOX, by increasing doses of doxorubicin. We completed chromosomal analysis, double time of cell grow, cell cycle distributions, drug resistance and cross-resistance, and studied reversing drug resistance. The results showed that chromosome of BGC-823/DOX was subtriploid karyotype. Cell morphology, double time, cell cycle distributions were different from its parent cells and 6.35 times more resistant to cytotoxic action of doxorubicin, cross-resistant to VP-16. Verapamil showed modified effect on doxorubicin resistance. BGC-823/DOX with doxorubicin resistance has many characteristics of gastrointestinal tumors.

Pathological classification and diagnosis of intestinal duplication

OBJECTIVE

To determine the pathological classification and the clinical characteristics of intestinal duplication.

METHODS

Eighty-four pediatric patients with intestinal duplication were proved on operation in the last 20 years in the Second Hospital of Harbin Medical University and Harbin Children's Hospital. The pathological classifications were as follows: enteral septum type (2), parietal cyst type (9), parenteral canal type (31), parenteral cyst type (35), and solitary type (1). The clinical presentations and complications included: abdominal mass (24), illius (41), hemorrhage of digestive tract (15) and intestinal perforation with peritonitis (3). Two asymptomatic cases were discovered incidentally.

RESULTS

Among the 84 patients, 82 healed, 1 newborn complicated by intestinal fistula died of septicemia, and the other one died of toxic shock.

CONCLUSIONS

Recognizing the pathological types, common presentations and complications, and applying the corresponding examination methods timely, doctors may improve the diagnostic accuracy.

[Effects of some Chinese herbal medicine and green tea antagonizing mutagenesis caused by cigarette tar]

Anti-mutagenic effects of some Chinese herbal medicine and green tea antagonizing cigarette tar was studied with unscheduled DNA synthesis (UDS) test in human peripheral lymphocytes in order to exploit the better use of Chinese herbal resources. Results showed that Scutellaria barbata, Hedyotis diffusa wildi, Xihuangwan, green tea and tea polyphenol all had anti-mutagenic effects, to some extent. And, 125 g/L of Scutellaria barbata, 125 g/L Hedyotis diffusa wildi, 325 g/L Xihuangwan, 78 g/L green tea and 25 g/L tea polyphenol could inhibit obviously the damage to DNA in lymphocytes caused by the total particle material (TPM) extracted from cigarette tar. If the Chinese herbal medicine and green tea were injected into cigarettes beforehand, extracted TPM (containing herbal medicine and green tea) also could protect DNA in lymphocytes from damage caused by cigarette tar, to even greater extent. This result is basically consistent with other anti-mutagenesis tests.

Cloning and mapping of a putative barley NADPH-dependent HC-toxin reductase

The NADPH-dependent HC-toxin reductase (HCTR), encoded by Hm1 in maize, inactivates HC-toxin produced by the fungus Cochliobolus carbonum, and thus confers resistance to the pathogen. The fact that C. carbonum only infects maize (Zea mays) and is the only species known to produce HC-toxin raises the question: What are the biological functions of HCTR in other plant species? An HCTR-like enzyme may function to detoxify toxins produced by pathogens which infect other plant species (R. B. Meeley, G. S. Johal, S. E. Briggs, and J. D. Walton, Plant Cell, 4:71-77, 1992). Hm1 homolog in rice (Y. Hihara, M. Umeda, C. Hara, Q. Liu, S. Aotsuka, K. Toriyama, and H. Uchimiya, unpublished) and HCTR activity in barley, wheat, oats and sorghum have been reported (R. B. Meeley and J. D. Walton, Plant Physiol. 97:1080-1086, 1993). To investigate the sequence conservation of Hm1 and HCTR in barley and the possible relationship of barley Hm1 homolog to the known disease resistance genes, we cloned and mapped a barley (Hordeum vulgare) Hm1-like gene. A putative full-length cDNA clone, Bhm1-18, was isolated from a cDNA library consisting of mRNA from young leaves, inflorescences, and immature embryos. This 1,297-bp clone encodes 363 amino acids which show great similarity (81.6%) with the amino acid sequence of HM1 in maize. Two loci were mapped to barley molecular marker linkage maps with Bhm1-18 as the probe; locus A (Bhm1A) on the long arm of chromosome 1, and locus B (Bhm1B) on the short arm of chromosome 1 which is syntenic to maize chromosome 9 containing the Hm2 locus. The Bhm1-18 probe hybridized strongly to a Southern blot of a wide range of grass species, indicating high conservation of HCTR at the DNA sequence level among grasses. The HCTR mRNA was detected in barley roots, leaves, inflorescences, and immature embryos. The conservation of the HCTR sequence, together with its expression in other plant species (R. B. Meeley and J. D. Walton, Plant Physiol. 97:1080-1086, 1993), suggest HCTR plays an important functional role in other plant species.

Isolation and characterization of GT335, a novel human gene conserved in Escherichia coli and mapping to 21q22.3

As part of efforts to identify candidate genes for disorders mapped to 21q22.3, we have constructed a 405-kb cosmid contig encompassing five tightly linked markers mapping to this region. A subset of these cosmids was used to identify cDNA fragments by the method of hybrid selection. We present here the cDNA sequence of one such gene (GT335) mapping to this region. The gene is expressed as a 1.7-kb transcript predominantly in heart and skeletal muscle, potentially displays alternate splicing, and is predicted to encode a protein 268 amino acids in length. GT335 spans an estimated 13 kb of genomic DNA and is split into seven exons. Five of the six introns conform to the GT . . . AG consensus for intronic splice junctions; the sixth contains nonconventional (AT . . . AC) intronic junctions. We screened this gene for single-basepair mutations using single-strand conformation polymorphism and sequence analysis of both cDNA and genomic DNA from a number of unrelated individuals and have identified several sequence variations, two of which cause conservative amino acid substitutions. This gene is well conserved evolutionarily, with homologs identified in zebrafish and Escherichia coli, suggesting that it plays an important role in basic cellular metabolism.

[The research of radioimmunoassay using double Abs for bradykinin]

Bradykinin (BK) is a potent vasodilative substance, and plays great physiological and pathological roles in animals and human beings. To measure the quantity of BK, the radioimmunoassay (RIA) has been devised, but the traditional RIA method has certain defects, such as presence of numerows interfering factors and errors and time consuming. Now, we produce anti-BK serum in rabbits by using BK-ovalbumin conjugate as an immunogen, and the 125I labeled Tyr8-BK by using a modified chloramine-T method. High specific activity has been obtained after purification with DEAE-Sephadex A-25 column chromatography. We use the donkey anti-rabbit Ab and PEG 6000 to separate the bound from the free 125I-Tyr8-BK. The limitation range of standard curve is from 25 to 1600 pg, NSB is 3.1% affinity constant (K) is 0.8 x 10(10) L/mol, and there is no significant interference with other biological BK analogues. The blood samples are treated by adding Polybrene (inhibitor) and PEG 6000 to deposit the big serum proteins in order to reduce the disturbing substances. This method has been shown to be a sensitive, specific, reliable, simple and convenient measure of the serum BK level. By this method, the serum BK quantities in men, women and rats are respectively 1584 +/- 347 pg/ml, 1642 +/- 302 pg/ml and 1805 +/- 225 pg/ml, the recycling rate is 95%, the intergroup CV is 5.0% and outergroup CV = 9.2%.

[Effects of gossypol acetic acid on human ejaculated sperm Ca2+ influx and rat vas deferens contraction action]

It has been reported that gossypol acetic acid (GAA) inhibits sperm motility and calcium plays an important role in regulating the function of the sperm flagella. In order to explore the mechanism by which GAA inhibits sperm motility, the effects of GAA on human ejaculated sperm Ca2+ influx and isolated rat vas deferens contraction action were studied. The results showed that GAA inhibited sperm Ca2+ influx in a dose-dependent manner, and breaked the dynamic equilibrium of sperm internal and external Ca2+ gradient concentrations. It may be one of important mechanism by which GAA inhibits sperm motility. But GAA exerts no effect on the high K+ induced contraction of smooth muscle of isolated rat vas deferens. It is likely that GAA has selective action on the sperm membrane of the rats.

Use of the additive main effects and multiplicative interaction model in QTL mapping for adaptation in barley

The additive main effects and multiplicative interaction (AMMI) model has emerged as a powerful analytical tool for genotype x environment studies. The objective of the present study was to assess its value in quantitative trait locus (QTL) mapping. This was done through the analysis of a large two-way table of genotype-by-environment data of barley (Hordeum vulgare L.) grain yields, where the genotypes constituted a genetic population suitable for mapping studies. Grain yield data of 150 doubled haploid lines derived from the 'Steptoe' x 'Morex' cross, and the two parental lines, were taken by the North American Barley Genome Mapping Project (NABGMP) at 16 environments throughout the barley production areas of the USA and Canada. Four regions of the genome were responsible for most of the differential genotypic expression across environments. They accounted for approximately 50% of the genotypic main effect and 30% of the genotype x environment interaction (GE) sums of squares. The magnitude and sign of AMMI scores for genotypes and sites facilitate inferences about specific interactions. The parallel use of classification (cluster analysis of environments) and ordination (principal component analysis of GE matrix) techniques allowed most of the variation present in the genotype x environment matrix to be summarized in just a few dimensions, specifically four QTLs showing differential adaptation to four clusters of environments. Thus, AMMI genotypic scores, when the genotypes constituted a population suitable for QTL mapping, could provide an adequate way of resolving the magnitude and nature of QTL x environment interactions.

Cloning of the human erythropoietin exons and their expression in COS-7 cells

Human erythropoietin exons (hEPO-E) were isolated from a Chinese fetal liver DNA library by using the PCR method with gene recombination. One nucleotide mutation was found in exon 3 leading to the Leu in position 62 being changed to Ser. The hEPO-E coding for the full-length mature protein was inserted into different clone sites of PSV-2-dhfr to create different transferring plasmids (pSV2-dhfr/F1, pSV2/F2, pSV2-dhfr/F3, pSV2-dhfr/F4, pSV2-dhfr/G1, and pSV2-dhfr/G3) which were transfected into COS-7 cells. Results obtained from the comparative experiments indicate that biological activity of hEPO was found in all culture supernatants and its expression level was higher than that of its genome.

Verification of barley seed dormancy loci via linked molecular markers

Seed dormancy is a relatively complex trait in barley (Hordeum vulgare L.). Several dormancy loci were identified previously by quantitative trait locus analysis. Three reciprocal crosses were made in the present study between parents carrying specific dormancy alleles via linked molecular markers to verify individual dormancy locus effects and potential expression. Analyses of F2 progenies revealed that the dormancy allele at the locus flanked by the markers Ale and ABC302 on the long arm of chromosome 7 had a major effect on dormancy, and was at least partly epistatic to the dormancy locus in the ABC309-MWG851 interval near the telomere of the long arm of chromosome 7. In the absence of the dormancy allele in the Ale-ABC302 interval, the allele in the ABC309-MWG851 interval exerted moderate to large effects on dormancy. Cytoplasmic effects on dormancy were also observed. The germination percentages of progeny with relatively high levels of dormancy were more variable than those of non-dormant or less-dormant progeny, apparently due to environmental effects. Removal of the dormancy allele in the Ale-ABC302 interval, or introducing the dormancy allele in the ABC309-MWG851 interval, should suffice for adjusting dormancy levels in breeding programs to suit various production situations and end uses. The verification of dormancy loci via linked molecular markers allows manipulation of these loci in applied breeding programs.

Mapping of β-glucan content and β-glucanase activity loci in barley grain and malt

Genetic study of β-glucan content and β-glucanase activity has been facilitated by recent developments in quantitative trait loci (QTL) analysis. QTL for barley and malt β-glucan content and for green and finished malt β-glucanase activity were mapped using a 123-point molecular marker linkage map from the cross of Steptoe/Morex. Three QTL for barley β-glucan, 6 QTL for malt β-glucan, 3 QTL for β-glucanase in green malt and 5 QTL for β-glucanase in finished malt were detected by interval mapping procedures. The QTL with the largest effects on barley β-glucan, malt βglucan, green malt β-glucanase and finished malt βglucanase were identified on chromosomes 2,1,4 and 7, respectively. A genome map-based approach allows for dissection of relationships among barley and malt βglucan content, green and finished malt β-glucanase activity, and other malting quality parameters.

Speciation of organotin compounds by capillary electrophoresis using indirect ultraviolet absorbance detection

Capillary electrophoresis (CE) with indirect photometric detection was investigated for the separation of organotin species. Compounds such as dimethyltin (DMT), dibutyltin (DBT), and tributyltin (TBT) are important pollutants in the aqueous environment and techniques are needed to analyze directly aqueous environmental samples quickly and economically. By adjusting the mobile phase to pH 2.65 by HCl, tributyltin, dibutyltin and dimethyltin in aqueous solutions were separated by capillary electrophoresis using indirect ultraviolet (UV) absorbance detection. Pyridine was used as the UV absorption additive at 254 nm and separation was achieved in 6 min. Peak tailing obtained at higher pH suggests strong interaction between the dimethyltin cation and the negatively charged capillary wall. Cetyltrimethylammonium bromide (CTAB) was added to the mobile phase to improve the peak shapes when the pH of the mobile phase was greater than 3.5. Separations of organotin species in mobile phases with or without CTAB were compared. The change of electrophoretic mobility in mobile phases with different pH values indicates that DMT and DBT start to undergo hydrolysis at a pH 3.0. It was also found that the choice of the buffer anions is critical in the separation of the tin compounds as complexes appear to form with DMT and DBT in the presence of oxalate and citrate.

Efficient methods for the linearization and solution of phase-invariant equations

This paper describes a linear least-squares procedure, whereby, through quadrupole relationships, the 2 pi integers that linearize sets of unique phase-invariant estimates can be determined. It is subsequently shown that the phase solutions for these linear equations can be obtained, even for basis sets of thousands of phases, without having to either build or invert the full least-squares matrix. The final r.m.s. phase errors achieved by this method can typically be less that 5 or 10 degrees.

[Experimental studies on the pharmacokinetics of cefoperazone (CPZ) injection under burn eschar]

In this study, the rabbits were categorized into three groups. The scald (III degrees TBS 10%-15%) was caused by exposing these area to hot water at 90 degrees C for 40 seconds. Every rabbit was injected CPZ (25 mg/kg) three times. The changes in the concentration of CPZ were measured by employing MBPD and HPLC methods and experimental data were analyzed by using pharmacokinetic computer program.

RESULTS

1) The T1/2e of CPZ injection in subeschar region was longer and the Cmax was higher than that of intravenous route. 2) The concentration in blood was shown two times higher than after subeschar injection. 3) The levels of concentration were higher than MIC'S in an area of 6.5 cm diameter 24-36 hours after injection.

CONCLUSION

CPZ injection in subeschar region was the best route of treatment and prevention of subeschar infection.