[Purification and properties of alkaline cellulase from alkalophilic Bacillus N6-27]

The alkaline cellulase produced by alkalophilic Bacillus sp. N6-27 was purified to electrophoresis homogeneity by (NH4)2SO4 fractionation, Sepharose CL-4B hydrophobic interaction chromatography, Bio-gel P-150 chromatography. The molecular weight and pI determined by SDS-PAGE and by PAGE-IEF were 94,000 and 4.2, respectively. The optimum temperature and pH for the enzymatic catalysis were 55 degrees C and 8.5, respectively. The enzyme activity was stable under 50 degrees C and in the pH range of 6-11. The substrate was carboxymethylcellulose (CMC). The enzyme activity was strongly inhibited by Fe2+, Cu2+ and Hg2+.

[The study on the relationship between luteal phase serum sex hormone levels and pregnancy outcome in in vitro fertilization embryo transfer cycle]

OBJECTIVE

To study the influence of maternal endocrine factors on clinical pregnancy outcome in an in Vitro Fertilization Embryo Transfer (IVF-ET) program.

METHODS

62 IVF-ET treatment cylces were studied. Luteal phase serum sex hormone levels [estrogen (E2), progesterone (P), prolactin (PRL)] in natural and superovulation cycles were measured by radioimmunoassay and the clinical pregnancy outcome was observed.

RESULTS

Serum luteal phase sex hormone levels were higher than in natural cycles (P < 0.05). P level and P/E2 ratio in progesterone supplementation group were higher than the group without progesterone supplementation (P < 0.05). In pregnancy group serum E2(4,885.5 +/- 1,269.0 pmol/L) was lower, PRL (66.4 +/- 26.8 micrograms/L), P/E2 (373.0 +/- 152.5) were higher than in nonpregnancy group (E2 6,091.2 +/- 1,522.1 pmol/L, PRL 49.1 +/- 24.1 micrograms/L, P/E2 227.4 +/- 116.7) (P < 0.05). When P/E2 ratio was between 300-400 and PRL level was between 60-100 micrograms/L, the clinical pregnancy rate increased markedly (P < 0.05).

CONCLUSION

Luteal phase serum sex hormone level may influence embryo implantation in IVF-ET. In order to improve the clinical pregnancy rate, it is very necessary to supplement progesterone for the IVF-ET patients according to the different sex hormone levels.

The dynamic regulation of myocardial oxidative phosphorylation: analysis of the response time of oxygen consumption

Although usually steady-state fluxes and metabolite levels are assessed for the study of metabolic regulation, much can be learned from studying the transient response during quick changes of an input to the system. To this end we study the transient response of O2 consumption in the heart during steps in heart rate. The time course is characterized by the mean response time of O2 consumption which is the first statistical moment of the impulse response function of the system (for mono-exponential responses equal to the time constant). The time course of O2 uptake during quick changes is measured with O2 electrodes in the arterial perfusate and venous effluent of the heart, but the venous signal is delayed with respect to O2 consumption in the mitochondria due to O2 diffusion and vascular transport. We correct for this transport delay by using the mass balance of O2, with all terms (e.g. O2 consumption and vascular O2 transport) taken as function of time. Integration of this mass balance over the duration of the response yields a relation between the mean transit time for O2 and changes in cardiac O2 content. Experimental data on the response times of venous [O2] during step changes in arterial [O2] or in perfusion flow are used to calculate the transport time between mitochondria and the venous O2 electrode. By subtracting the transport time from the response time measured in the venous outflow the mean response time of mitochondrial O2 consumption (tmito) to the step in heart rate is obtained. In isolated rabbit heart we found that tmito to heart rate steps is 4-12 s at 37 degrees C. This means that oxidative phosphorylation responds to changing ATP hydrolysis with some delay, so that the phosphocreatine levels in the heart must be decreased, at least in the early stages after an increase in cardiac ATP hydrolysis. Changes in ADP and inorganic phosphate (Pi) thus play a role in regulating the dynamic adaptation of oxidative phosphorylation, although most steady state NMR measurements in the heart had suggested that ADP and Pi do not change. Indeed, we found with 31P-NMR spectroscopy that phosphocreatine (PCr) and Pi change in the first seconds after a quick change in ATP hydrolysis, but remarkably they do this significantly faster (time constant approximately 2.5 s) than mitochondrial O2 consumption (time constant 12 s). Although it is quite likely that other factors besides ADP and Pi regulate cardiac oxidative phosphorylation, a fascinating alternative explanation is that the first changes in PCr measured with NMR spectroscopy took exclusively place in or near the myofibrils, and that a metabolic wave must then travel with some delay to the mitochondria to stimulate oxidative phosphorylation. The tmito slows with falling temperature, intracellular acidosis, and sometimes also during reperfusion following ischemia and with decreased mitochondrial aerobic capacity. In conclusion, the study of the dynamic adaptation of cardiac oxidative phosphorylation to demand using the mean response time of cardiac mitochondrial O2 consumption is a very valuable tool to investigate the regulation of cardiac mitochondrial energy metabolism in health and disease.

Preparation and blood compatibility of new silica-chitosan hybrid biomaterials

The development of new materials containing both organic and inorganic structures is of great interest with respect to achievement of obtaining the special properties, and the solgel process has provided new opportunities for making such materials. In this paper, new silica-chitosan hybrid biomaterials were produced by this technique, using biopolymer chitosan and its heparin-like derivative as the organic species to be incorporated into the silicon alkoxide (TEOS) based network. All the samples made were in form of thin, flexible films with optical clarity. Microphase separated structure was observed in the hybrid surface, with hydrophobic SiO2 and hydrophilic chitosan interleaved. These hybrid materials displayed good blood compatibility in comparison with their single component systems.

[Synthesis and antitumor activity of new heterocyclic 5-fluorouracil derivatives]

Two new compounds I and II of 5-FU derivatives have been synthesized. The structures of the new compounds were confirmed by 1HNMR, MS, IR, UV and elemental analysis. The antitumor activities of compound I was tested against KB, HCT-8 and A2780. The preliminary results showed that the activity of compound I was stronger than that of HCFU and 5-FU.

Importance of glucose-6-phosphate dehydrogenase activity for cell growth

The intracellular redox potential, which is determined by the level of oxidants and reductants, has been shown to play an important role in the regulation of cell growth. The principal intracellular reductant is NADPH, which is mainly produced by the pentose phosphate pathway through the actions of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway, and by 6-phosphogluconate dehydrogenase. Previous research has suggested that an increase in G6PD activity is important for cell growth. In this article, we suggest that G6PD activity plays a critical role in cell growth by providing NADPH for redox regulation. The results show the following: 1) inhibition of G6PD activity abrogated growth factor stimulation of [3H]thymidine incorporation in all cell lines tested; 2) overexpression of G6PD stimulated cell growth, as measured by an increase in [3H]thymidine incorporations as compared with cells transfected with vector alone; 3) inhibition of G6PD caused cells to be more susceptible to the growth inhibitory effects of H2O2; 4) inhibition of G6PD led to a 30-40% decrease in the NADPH/NADP ratio; and 5) inhibition of G6PD inhibited cell anchorage and significantly decreased the growth-related stimulation of tyrosine phosphorylation.

[Changes in the contents of membrane phospholipid and membrane phospholipid asymmetry in glucose-6-phosphate dehydrogenase deficient erythrocyte]

OBJECTIVE

To study the effect of G6PD deficiency on membrane phospholipid structures.

METHODS

Treatment of intact erythrocyte with phospholipase A2 was used for the membrane phospholipid asymmetry. Membrane phospholipid was determined by high performance liquid chromatography (HPLC).

RESULTS

The contents of phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS) were 5.18 +/- 1.86, 1.51 +/- 0.58 and 5.70 +/- 1.91 mg/mg membrane protein, respectively, in G6PD deficient erythrocytes and were 5.59 +/- 1.16, 2.92 +/- 0.50 and 6.64 +/- 0.92 mg/mg membrane protein, respectively, in normal erythrocytes. In normal erythrocytes, 17.6% +/- 2.5% PE and 57.9% +/- 4.7% PC were present and no PS was found on the outer leaflet of the membrane. While in G6PD deficient ones, 30.2% +/- 5.7% PE, 53.8% +/- 7.4% PC and 27.2% +/- 5.8% PS were present on the outer leaflet.

CONCLUSION

Membrane phospholipid changes in G6PD deficient erythrocytes might be one of the factors causing hemolysis.

Superoxide dismutase-dependent, catalase-sensitive peroxides in human endothelial cells infected by Rickettsia rickettsii

The generation and intracellular accumulation of reactive oxygen species have been shown to be associated with the infection of human umbilical vein endothelial cells (HUVEC) by Rickettsia rickettsii. In response to the oxidant superoxide, the activity of the enzyme superoxide dismutase (SOD) increases following infection by this obligate intracellular bacterium. Other oxidants which are capable of oxidizing the fluorescent probe 2',7'-dichlorofluorescin (DCFH) also accumulate intracellularly within infected cells. In the study reported here, we show that (i) an inhibitor of SOD, diethyldithiocarbamic acid, reduces the observed rise in SOD activity in infected cells by 40 to 60% and at the same time reduces the degree of intracellular oxidation of DCFH; (ii) catalase-sensitive peroxides can be detected in supernatants of R. rickettsii-infected cells shortly after rickettsial exposure; and (iii) fluorescence-activated cell sorter analysis demonstrates significant intracellular oxidant activity in infected cells within 5 h after exposure to R. rickettsii. The results of these experiments indicate that hydrogen peroxide is a major oxidant associated with infection of HUVEC by R. rickettsii and that intracellular oxidant activity sensitive to SOD inhibition is detectable early and prior to significant rickettsial multiplication and much earlier than the ultrastructural manifestations of cell injury seen by electron microscopy.

HLA-DRB1 genes in 5 rheumatic disease multi-case families

OBJECTIVE

To detect HLA-DRB1 (DR1-10) alleles in 5 families with multi-case rheumatic diseases, and to study the possible influence of DRB1 genes in the pathogenesis of rheumatic diseases.

METHODS

Sequence-Specific Primer PCR (PCR-SSP) method was used to examine HLA-DRB1 alleles. Totally 36 members of 5 families and 166 healthy people were involved in this study. The results were assessed by Chi-square test.

RESULTS

The HLA-DRB1 allele frequency in the patients and their relatives was similar. No significant difference was found. But DR4 allele frequency in the patients (90.9%) and their relatives (68%) was much higher than that in normal controls (16.8%) and the difference was statistically significant (P < 0.0001). In family 4, two RA patients have different DRB1 alleles, while in family 5, two patients have the same DRB1 alleles, one developed SLE and the other developed RA.

CONCLUSIONS

DR4 is closely related to rheumatoid arthritis. The nelatives of RA patients may be at greater risk to develop RA than individuals without family history. Some patients had the same DRB1 allele but developed different rheumatic diseases. This suggested that there might be some common pathways in genetic predisposing of rheumatic diseases. On the other hand, only a few patients with the same DRB1 allele developed rheumatic diseases during their life, so other factors besides DRB1 gene might also be involved in the pathogenesis of rheumatic diseases.

[A study on the relationship between serum anticardiolipin antibody and embryo implantation in an in vitro fertilization and embryo transfer program]

OBJECTIVE

To study the role of serum anticardiolipin antibody in embryo implantation in an in-vitro fertilization and embryo transfer program.

METHODS

150 in vitro fertilization and embryo transfer (IVF-ET) treatment cycles from Nov. 1994 to May, 1996 were studied. Serum anticardiolipin antibody was measured by enzyme-linked immunosorbent assay (ELISA), and the clinical pregnancy outcome observed.

RESULTS

Lower pregnancy rate 9.5% was found in 21 cycles of anticardiolipin antibody seropositive women compared with 26.3% in 129 cycles of anticardiolipin antibody seronegative women (P < 0.05). Patients with biochemical pregnancy and no pregnancy had seropositive anticardiolipin antibody in 20.0% and 16.2% compared with 5.6% in the patients with clinical pregnancy (P < 0.05).

CONCLUSIONS

Failure of embryo implantation is associated with many factors. Our study demonstrated the serum anticardiolipin antibody in patients may play a part in embryo implantation and very early postimplantation loss.

[Complex surgical therapy for severe hepatic trauma]

OBJECTIVE

To improve the result of surgical therapy for patients with severe hepatic injury.

METHODS

Retrospective analysis was made on the result of surgical treatment of 237 patients with hepatic trauma during the past 8 years. 180 patients underwent surgery. Procedures such as packing with the omentum for the laceration of hepatic parenchyma, debridement or irregular hepatectomy under the direct control of lacerated hepatic blood vessels or Pringle's maneuvre and selective ligation of hepatic artery were used for patients with severe hepatic injury (Grad III-V).

RESULTS

Among the 180 patients, 154 were cured, and 8 of 23 with posthepatic IVC injury were cured with the maximum blood transfusion of 12,000 ml. The overall morality rate was 11.8%(28 of 237 patients). Besides associated injuries inside and outside the abdomen, exsanguination with or without coagulopathy was the main cause of death.

CONCLUSION

Accurate liver packing with appropriate adjunctive procedures is effective in the treatment of retrohepatic venous injury.

Ultrastructural observation on spermatocytogenesis in Taeniid cestodes

AIM

To study the spermatocytogenesis of taeniid cestodes at the ultrastructural leaves.

METHODS

Transmission electron microscopy.

RESULTS

The ultrastructural observation on spermatocytogenesis in Taenia solium, T. saginata and T. pisiformis were made by TEM. Two types of spermatogonia; type A and B, as well as the supporting cells surrounding the peripheral of spermatogonia are recognized. The type A spermatogonia are stem cells and the type B are mother cells which produce 16 primary spermatocytes by mitosis for 4 times with the cells unseparated. The primary spermatocytes are characterized by the ribosome masses in the cytoplasm. 32 secondary spermatocytes arranged in roselike were produced by reductive division of primary spermatocytes. The secondary spermatocytes become the spermatid quickly by short time development.

CONCLUSION

The dividing mode of spermatogonia in Taeniid cestodes is mitosis with cells unseparated.

[The role of decidua tissue lymphocytes in early pregnancy]

OBJECTIVE

To investigate the role of lymphocytes in early pregnancy decidua tissue.

METHODS

Immunohistochemical and in situ hybridization techniques were employed to demonstrate the population, phenotype and mediator of lymphocytes in early pregnancy decidua.

RESULTS

In early pregnancy decidua, CD8+ suppressor/cytotoxic T lymphocytes were very few. CD4+ helper lymphocytes were few and CD56+ lymphocytes (also named NK-like cell) were abundant. CD56+ lymphocytes containing perforin protein and expressing perforin mRNA were observed.

CONCLUSIONS

The lymphocytes in early pregnancy decidua are specific and may play an important role in early pregnancy. They probably exert some positive influence on embryo implantation and placental development, and maintain the balance between trophoblastic cells and decidua tissue.

[The study of autoantibodies in women with habitual abortion of unknown etiology]

OBJECTIVE

To evaluate the relationship between habitual abortion of unknown etiology and autoantibodies.

METHODS

IgG and IgA antibodies against cardiolipin, specific antinuclear double-stranded DNA and single-stranded DNA were measured by enzyme linked immunosorbent assay (ELISA). Antinuclear antibody, smooth muscle antibody, antimitochondrial antibody and antiheart muscle antibody were performed by indirect immunofluorescence assay. Antiextractable nuclear antigen's antibodies were determined by immunodiffusion assay.

RESULTS

Most women with habitual abortion of unknown etiology showed higher incidence of antibodies to cardiolipin, nuclear, smooth muscle compared with normal multigravida control (P < 0.05).

CONCLUSIONS

These results indicate that most women with habitual abortion of unknown etiology have a higher level of autoreactivity, which may affect the course of pregnancy. The incidence of antismooth muscle antibody in women with habitual abortion of unknown etiology is also increased compared with normal multigravida control.

Study on stress distribution of the condyle

OBJECTIVE

To investigate the internal state of stress distribution in healthy human condyles and to offer some references for application of the temporomandibular joint (TMJ) biomechanics.

METHODS

Six male volunteers were selected to perform CT examination of the TMJ with 1.5 mm-thick sections at 1.5 mm intervals. Three dimensional image reconstruction of the joint was performed in the SUN workstation and the CT data were converted into the decimal system. The three dimensional finite element model mesh generation resulted from 1188 elements and 264 nodes in each condyle. Stress calculation was performed with SAP-V program, and the results were converted into mechanical density scalar. During the study, the internal state of stress distribution on each side condyle in every subject was analysed on the basis of loading on the anterior articular surface of the condyle.

RESULTS

Stress was concentrated in the anterior articular surface of the condyle and was highest at the loading point. The condylar cortical bone was the main load-bearing area. The level of stress distribution in the cancellous bone of the condyle was very low. Near condylar neck stress was well-distributed on the cortical. The internal state of stress was essentially symmetrical on the same cuts of both side condyles.

CONCLUSIONS

The results showed that three dimensional finite element analysis may indicate the internal state of stress distribution in the condyle, suggesting that a combination of the three dimensional finite element methods and the three dimensional imaging technique may be a useful means for diagnosis and treatment of TMJ diseases.

[Detection of flaviviruses by reverse-transcription polymerase chain reaction with universal primer set]

For the purpose of early and rapid diagnosis of flavivirus infection, the universal primer set was selected on the NS1 gene. Another five different internal primers were selected on the NS1 genes of DEN1, 2, 3, 4 and JEV. With the universal primer set designed, the NS1 fragment about the size of 413 bp and with the five internal primers, the NS1 fragments about the sizes of 262 bp (DEN1), 189 bp (DEN2), 392 bp (DEN3), 97 bp (DEN4) and 323 bp (JEV) were amplified respectively. The reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify gene fragments of flaviviruses. cDNA of DEN1, 2, 3, 4 and JEV were successfully amplified with universal primer set and internal primers. Sera from 78 patients with dengue fever were assayed by nested PCR, DEN1 was detected from 18 of the 40 patients' sera and DEN2 was detected from 48 patients' sera. Sera from 42 patients with Japanese encephalitis were also assayed by nested PCR, JEV was detected from 35 of the 42 patients' sera. By nested PCR, we completed identification of flaviviruses within 2 days. The results showed that this method has the potential value in rapid clinical diagnosis of flavivirus infection.

[A knowledge-based method for 3D segmentation and display of human brain]

From the view of the artificial intelligence, a new method of segmentation and display of human brain medical images is descrided. On the basis of the knowledge of brain anatomy and image processing, we have built the 3D knowledge mobel using frame as the main knowledge expression method. Under the guide of the knowledge, the main structures in the brain are segmented and displayed by means of the "inelligent ray-tracing".

Study of the interaction between novel ruthenium(II)-polypyridyl complexes and calf thymus DNA

Four new complexes L2RuL'2+, where L = 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), L' are Schiff bases or phenylhydrazones derived from 4,5-diazafluoren-9-one (AFO), were prepared. They were characterized by elemental analyses, absorption, IR, and emission spectra. The binding of these complexes to calf thymus DNA has been investigated by absorption, circular dichroism spectroscopy, and viscosity measurement. The experimental results show that the complexes bind to calf thymus DNA by three kinds of binding modes, respectively-electrostatic mode, nonintercalative binding mode, and intercalative binding mode.

[Changes of erythrocyte membrane lipid in hereditary G6PD deficiency]

OBJECTIVE

To explore the biochemical mechanism of G6PD deficiency.

METHODS

A fluorescence polarization technique with 1,6-dipheny 1,1,3,5-heratciene (DPH) as a fluorescent probe was used to determine the fluidity of erythrocyte membrane lipid from G6PD deficient patients and normal controls. The polarization of fluorescence was measured between 0 degrees and 90 degrees.

RESULTS

The fluorescence polarization parameter (rho) was high in G6PD deficient erythrocytes as compared with normal controls, indicating a decrease in erythrocyte membrane lipid fluidity. The determination of lipoperoxidation of erythrocyte membrane by fluorescence spectrometry also showed that the content of MDA was significantly higher in G6PD deficient erythrocytes than in normal controls. The percentage of unsaturated fatty acid C18:1 and C18:2 in total phosphalipids and phosphatidyl serine was decreased in G6PD deficient erythrocytes.

CONCLUSION

The decrease of erythrocyte membrane lipid fluidity is related to the lipid peroxidant, and the oxidative damage of erythrocyte membrane phosphalipids in G6PD deficient patients might be an important factor of hemolysis.

Reduction of vesicular acetylcholine transporter mRNA in the rat septum following lead exposure

We have previously observed that maternal exposure to lead (Pb) results in a reduction of levels of mRNA coding for cholineacetyltransferase (ChAT) in the septum of developing rat without affecting the dams. Here we report that Pb similarly affects the expression of vesicular acetylcholine transporter (VAChT) mRNA in the rat septum. In close agreement with the time course of ChAT mRNA expression, septal VAChT mRNA levels increased from 30% at postnatal day 7 to 78% and 100% of adult levels at days 14 and 21, respectively. Maternal exposure to 0.2% lead acetate in drinking water from gestational day 16 resulted in an approximately 30% reduction of VAChT in 7 and 21-day-old rat pups without affecting VAChT mRNA levels in the dams. These results indicate a developmental stage-dependent interference by Pb with ChAT/VAChT gene expression in the rat septum.

Antioxidative activity of 4-oxy- and 4-hydroxy-nitroxides in tissues and erythrocytes from rats

AIM

To compare the activities of antioxidation of 4-oxy- and 4-hydroxy-nitroxides in tissues and RBC from rats.

METHODS

The homogenates of liver, heart, and kidneys of rats were used to determine malondialdehyde (MDA) formation using TBA colorimetric method. H2O2-caused hemolysis was measured spectrometrically. Superoxide anion from zymosan-stimulated neutrophils of rats was assayed by NBT reduction method.

RESULTS

Nitroxide free radicals OTMPO and HTMPO inhibited MDA generation caused by .OH generation system (MIC 10.5 and 21 mumol.L-1, respectively), antagonized hemolysis induced by H2O2 (MIC: 338 and 168 mumol.L-1, respectively), but did not affect O2- formation from activated neutrophils. 1-Hydroxyl compounds OTMPOH and HTMPOH possessed similarly potent antilipoperoxidative activities. But nonfree radical OTMP and HTMP had no effect on peroxidation of tissues.

CONCLUSION

Nitroxides exert their antilipoperoxidative effect by specifically scavenging .OH free radicals in biological system. Trapping of .OH free radicals by nitroxides is not by reduction of NO. group in nitroxides. Both NO. group and NOH group are essential active groups.

[New species of Natronobacterium]

An extreme haloalkalophilic bacterium HAM-2 with pleomorphic rods was isolated from Hamatai soda lake in Inner Mongolia Autonomous Region. Growth occurs in 12%-30% NaCl, no growth below 12%, optimum 17.5%. pH range for good growth 7.8-10.4, optimum 9.0-9.5. The strain HAM-2 is non-motile, Gram-negative, pleomorphic, cell of which were 1.0-2.0 by 2.0-5.0 microns in size in liquid medium. The major polar lipids of the organisms are phosphatidylglycerol phosphate and phosphatidyglycerol and contains an unidentified phospholipid as a minor component PL4. G + C contant of DNA is 59.5 mol%. Based on the characteristics, the strain HAM-2 could be included in the genus Natronobacterium, but since HAM-2 differs from reported four species of this genus in cell shape, polar lipids and biochemical features. The name Natronobacterium innemongoliae sp. nov. is proposed. The type strain is designated HAM-2.