Effect of internal phase particle size on properties of site mixed emulsion explosive at plateau environment

To study the effect of internal particle size on the microstructure properties and thermal decomposition characteristics of site mixed emulsion explosive at different altitudes. Site mixed emulsion explosive was prepared with different shear rate. The particle size, viscosity, sensitized bubbles, detonation velocity and peak pressure of the emulsion explosive were tested after stored at different simulated altitudes. The thermal decomposition characteristics of emulsion matrix prepared at three different rotational speeds were measured by thermogravimetric analyzer and kinetic analysis was performed by non-isothermal model Kissinger-Akah-Sunose (KAS) method. The results show that with the increase in altitude, the internal phase size showed a trend of first increasing and then decreasing, and the number of sensitized bubbles within the emulsion explosive decreases. At an altitude of 0 m, the detonation velocity and peak overpressure of the emulsion explosive prepared by 1600 r min-1 increased 4.78% and 29.09%, respectively compared with 1200 r min-1, and at an altitude of 4500 m, the detonation velocity increased 11.87%, the peak overpressure increased 43.98%. The thermal decomposition activation energy of the emulsion matrix at 1600 r min-1 increased 13.14% compared to 1200 r min-1. It shows that in the production of site mixed emulsion explosive at high altitude, reducing the particle size of the internal phase of emulsion explosives in a certain range can effectively improve the performance of emulsion explosives.

[Clinicopathological features of olfactory carcinoma]

Objective: To investigate the clinicopathological features and differential diagnosis of olfactory carcinoma (OC). Methods: Twenty-one cases of sinonasal tumors, including those initially diagnosed as olfactory neuroblastoma (ONB) and those with uncertain diagnosis, were collected from the Department of Pathology, the First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) from January 2016 to August 2022, among which 3 cases were reclassified as OC. The clinicopathological features were investigated, and the remaining 18 cases were used as control. Results: Of the three OC patients, 2 were male and 1 was female, with an average age of 57 years ranging from 35 to 74 years. Microscopically, the tumor cells were arranged in solid, nested or lobulated patterns with occasional palisading around the solid nests. The stroma was highly vascular with focal neurofibrillary areas. There were prominent rosettes or pseudorosettes formation. The tumor cells were mainly ovoid to spindly with scant to moderate amount of cytoplasm, one or several small nucleoli, and fine chromatin content. Brisk mitotic figures were seen. In all 3 cases of OC, there were scanty atypical glands and some were ciliated. Immunohistochemically, at least one epithelial marker and neuroendocrine marker were diffusely expressed in the tumor. Some of the tumor cells were positive for p40 and p63, and the sustentacular cells showed the expression of S-100 protein. All cases tested were negative for NUT, CD99 and desmin, with intact expression of SMARCA4 (BRG1) and SMARCB1 (INI-1). Ki-67 proliferation index varied from 20% to 80%. Follow-up after 16-18 months showed no mortality with tumor recurrence from 1 patient after 16 months. Conclusion: OC is a rare sinonasal tumor with neuroepithelial differentiation, its histomorphology is diverse, and the combination of immunohistochemical markers is essential for appropriate diagnosis.

[Comparative study of the effects between second toe tibial dorsal artery flap and second toe tibial plantar proper artery flap in repairing finger skin and soft tissue defects]

Objective: To compare the effects between second toe tibial dorsal artery flap (2-TDAF) and second toe tibial plantar proper artery flap (2-TPPAF) in repairing finger skin and soft tissue defects. Methods: A retrospective cohort study was conducted. From January 2019 to June 2020, 27 patients with skin and soft tissue defects at the fingertips with area of 1.5 cm×1.2 cm-2.6 cm×1.8 cm after debridement who met the inclusion criteria were admitted to Suzhou Ruihua Orthopaedic Hospital, including 21 males and 6 females, aged 19-59 (37±10) years. According to flap repair methods used in the defective fingers, the patients were divided into 2-TDAF group (12 cases) and 2-TPPAF group (15 cases). The area of 2-TDAF ranged from 1.5 cm×1.2 cm to 2.5 cm×1.6 cm, and the area of 2-TPPAF ranged from 1.7 cm×1.3 cm to 2.6 cm×1.8 cm. Full-thickness skin grafts from the medial side of the ipsilateral leg were grafted to the wounds in donor sites, and the wounds in donor sites of skin grafts were directly sutured. Flap arterial diameter, flap excision time, flap survival situation of patients in 2 weeks after operation, and follow-up time were recorded. At the last follow-up, the two-point discrimination distance of flap graft site, total action motion (TAM) of the finger joints, and wound healing of the flap donor site were recorded; the Vancouver scar scale (VSS) was used to score the scar in donor area of the second toe and the recipient area of fingers; the appearance and self-satisfaction subscales of the Michigan hand outcomes questionnaire (MHQ) were used to evaluate the affected finger. Data were statistically analyzed with independent sample t test or Fisher's exact probability test. Results: The flap artery diameter of patients in 2-TDAF group was 0.35-0.80 (0.56±0.14) mm and the flap cutting time was (14.0±2.7) min, which were significantly shorter than 0.80-1.35 (1.02±0.16) mm and (19.7±3.4) min in 2-TPPAF group (with t values of 7.81 and 4.79, respectively, P<0.01). The flaps of patients in the 2 groups in recipient areas survived well in 2 weeks after operation, and the wounds in donor areas of flaps of patients in the 2 groups healed well at the last follow-up. There was no statistically significant difference in the postoperative follow-up time, and two-point discrimination distance of flap graft site, TAM of the finger joints, VSS score of scar in the second toe donor site and the finger recipient site, and the appearance and self-satisfaction of MHQ scores of the affected finger at the last follow-up (P>0.05). Conclusions: Compared with 2-TPPAF, 2-TDAF has a shallower anatomical layer and shorter time for surgical flap removal, which can preserve the proper arteries and nerves at the base of the toes and reduce the damage to the donor site.

Molecular Engineering on Bis(benzothiophene-S,S-dioxide)-Based Large-Band Gap Polymers for Interfacial Modifications in Polymer Solar Cells

The development of effectively universal interfacial materials for both conventional and inverted polymer solar cells (PSCs) plays a very crucial role in achieving highly photovoltaic performance and feasible device engineering. In this study, two novel alcohol-soluble conjugated polymers (PBSON-P and PBSON-FEO) with bis(benzothiophene-S,S-dioxide)-fused aromatics (FBTO) as the core unit and amino as functional groups are synthesized. They are utilized as universal cathode interfacial layers for both conventional and inverted PSCs simultaneously. Ascribing to the enlarged conjugated planarity and higher electron affinity for an FBTO unit, both PBSON-P and PBSON-FEO exhibit versatile electron-transporting abilities. They show wide band gaps that are important for light absorption in inverted PSCs, at which point PBSON-P and PBSON-FEO are more progressive than some of the reported small band gap cathode interfacial materials. Importantly, PBSON-P and PBSON-FEO display deep highest occupied molecular orbital energy levels, which can block holes at the cathode and thus increase the fill factor. As a result, both conventional and inverted PSCs using PBSON-P and PBSON-FEO as cathode interlayers realize high photovoltaic performance. Therefore, this series of novel polymers are amphibious cathode interfacial materials for high-performance conventional and inverted PSCs.

[Estimation on the health life expectancy of adults in Zhejiang province, 2016]

Objective: To estimate the health-adjusted life expectancy (HALE) of adults in Zhejiang province and evaluate the health status of the adults. Methods: This study was based on the mortality data collected from Zhejiang Chronic Disease Surveillance Information and Management System, and mortality rates from the underreporting survey and self-reported health data in 2016. Hierarchical Ordered Probit (HOPIT) model was used to estimate the severity-weighted prevalence of disability. Sullivan's method was used to calculate the HALE. Results: After adjustment by HOPIT model, the severity-weighted prevalence of disability increased significantly with age (χ(2)=5 795.81,P<0.001), and it was higher in females than in males (χ(2)=5 353.27, P<0.001). The life expectancy and self-evaluated HALE were 59.08 years and 48.68 years, respectively, in those aged ≥20 years, the difference was 10.40 years due to disability. The proportion of HALE loss due to disability in the total life expectancy was 17.61%, and it increased with age. HALE was higher in males than in females (49.21 years vs. 48.14 years), and in urban residents than in rural residents (49.92 years vs. 47.43 years). Conclusion: The proportion of loss of HALE in the total life expectancy in adults was high in Zhejiang, and it higher in males than in females, in urban residents than rural residents. Programs on improving health care in women and rural residents should be promoted.

miR-140-5p-mediated regulation of the proliferation and differentiation of human dental pulp stem cells occurs through the lipopolysaccharide/toll-like receptor 4 signaling pathway

Human dental pulp stem cells (DPSCs) are oral mesenchymal stem cells with potential to differentiate into various cell types. Recent studies of DPSCs have focused on microRNAs (miRNAs), a class of small noncoding RNAs that play crucial roles in regulating DPSC phenotypes. In the current study, the expression of miR-140-5p was significantly decreased during lipopolysaccharide (LPS)-mediated differentiation of DPSCs in vitro. Overexpression of miR-140-5p enhanced proliferation of DPSCs and inhibited DPSC differentiation, whereas suppression of miR-140-5p produced the opposite effect. Moreover, the expression of toll-like receptor 4 (TLR-4), a critical regulator of DPSCs, was negatively correlated with the levels of miR-140-5p. A luciferase reporter analysis confirmed that miR-140-5p could regulate TLR-4 by directly binding to the 3'-untranslated region (3'-UTR) of the TLR4 mRNA. Additionally, we suppressed TLR-4 expression by treating cells with a TLR-4 inhibitor, CLI-095, and demonstrated that the effect of the miR-140-5p inhibitor on DPSC proliferation and differentiation could be partially reversed by blocking TLR-4. Taken together, our data suggest that miR-140-5p is a novel miRNA that regulates DPSC proliferation and differentiation.

A comparative study of the effects of terminal aromatic moieties in spirobifluorene core-based diketopyrrolopyrrole non-fullerene acceptors

Trifluorobenzene and fused-ring moieties (benzo[b]thiophene and benzo[b]furan) were separately introduced into promising DPP-based nonfullerenes SF-DPP-EH to extend conjugation.

[Enhancement of thermal damage to EpCAM-positive tumor cells by novel aptamer-guided magnetic nanoparticles]

Objective: To explore the thermal damage to epithelial cell adhesion molecule(EpCAM)-positive tumor cells by novel aptamer-guided magnetic nanoparticles(AptNPs). Methods: EpCAM aptamer SYL3C was connected to NPs via biotin-streptavidin reaction. The diameter of AptNPs were characterized by Dynamic Light Scattering(DLS). The binding feature of the aptamer to EpCAM-positive tumor cells was evaluated by Prussian blue dyeing. Thermal damage under alternative magnetic field was measured bylactate dehydrogenase (LDH). The apoptosis of EpCAM-positive tumor cells was detected by acridine orange/ethidium bromide (AO/EB) double staining. Results: The average size of AptNPs was 282 nm. Flow cytometry and Prussian blue dyeing showed that AptNPs exhibited strong binding to the EpCAM-positive tumor cells but not to the EpCAM-negative tumor cells. Moreover, when incubated with 1.5×10(8) AptNPs under alternative electromagnetic fieldfor 5 hours, the viability of EpCAM-positive HCT116 cells and A549 cells was 28.9% and 54.4%, respectively, significantly lower than 76.7% of EpCAM-negative HepG2 cells (P<0.05). Conclusions: AptNPs can improve the thermal damage to EpCAM-positive tumor cells, and may have potential utility in the development of tumor targeted therapy.

Applying Thienyl Side Chains and Different π-Bridge to Aromatic Side-Chain Substituted Indacenodithiophene-Based Small Molecule Donors for High-Performance Organic Solar Cells

A pair of linear tetrafluorinated small molecular donors, named as ThIDTTh4F and ThIDTSe4F, which are with tetrathienyl-substituted IDT as electron-rich central core, electron-deficient difluorobenzothiadiazole as acceptor units, and donor end-capping groups, but having differences in the π-bridge (thiophene and selenophene), were successfully synthesized and evaluated as donor materials in organic solar cells. Such π-bridge and core units in these small molecules play a decisive role in the formation of the nanoscale separation of the blend films, which were systematically investigated through absorption spectra, grazing incidence X-ray diffraction pattern, transmission electron microscopy images, resonant soft X-ray scattering profiles, and charge mobility measurement. The ThIDTSe4F (with selenophene π-bridge)-based device exhibited superior performance than devices based on ThIDTh4F (with thiophene π-bridge) after post annealing treatment owing to optimized film morphology and improved charge transport. Power conversion efficiency of 7.31% and fill factor of ∼0.70 were obtained by using a blend of ThIDTSe4F and PC₇₁BM with thermal annealing and solvent vapor annealing treatments, which is the highest PCE from aromatic side-chain substituted IDT-based small molecular solar cells. The scope of this study is to reveal the structure-property relationship of the aromatic side-chain substituted IDT-based donor materials as a function of π-bridge and the post annealing conditions.

Dibenzothiophene-S,S-dioxide and Bispyridinium-Based Cationic Polyfluorene Derivative as an Efficient Cathode Modifier for Polymer Solar Cells

A novel n-type conjugated polymer containing dibenzothiophene-S,S-dioxide (FSO), bispyridinium, and fluorene scaffolds in the backbone (PFSOPyCl) was synthesized and used in the cathode interfacial layers (CILs) of conventional polymer solar cells (PSCs). The high electron affinities and large planar structures of the FSO and bispyridinium units endowed this polymer with good energy level alignments with [6,6]-phenyl-C₇₁ butyric acid methyl ester (PC₇₁BM) and metal cathode, and excellent electron transport and extraction properties. Polymer solar cells (PSCs) based on the poly[N-9″-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT):PC₇₁BM system with PFSOPyCl CIL exhibited simultaneous enhancement in open-circuit voltage (V_oc), short-circuit current density (J_sc), and fill factor (FF), while the power conversion efficiency increased from 5.47% to 6.79%, relative to the bare Al device. Besides, PSC based on the poly[4,8-bis(2-ethylhexyloxyl)benzo[1,2-b:4,5-b']dithio-phene-2,6-diyl-alt-ethylhexyl-3-fluorothithieno [3,4-b]thiophene-2-carboxylate-4,6-diyl] (PTB7):PC₇₁BM system achieved a PCE of 8.43% when using PFSOPyCl as CIL. Hence, PFSOPyCl is a promising candidate CIL for PSCs.

[Morbidity and mortality of malignant tumor in Zhejiang province, 2014]

OBJECTIVE

To analyze the morbidity and mortality of malignant tumor in Zhejiang province in 2014.

METHODS

The data were collected from Zhejiang provincial chronic disease surveillance system in 2014. The crude rate, age-standardized rate, cumulative rate(0-74 years old), cut rate(35-64 years old), age-specific and area-specific morbidity/mortality as well as the constitution of top 10 leading cancers were then calculated and analyzed. The age-standardized rate was calculated according to the standard population in China in 1982 and the Segi' s world standard population.

RESULTS

The crude morbidity was 348.80/100 000(370.74/100 000 in males and 326.51/100 000 in females). The age-standardized morbidity according to the standard population in China and according to world standard population were 168.84/100 000 and 217.23/100 000 respectively, the cumulative morbidity was 24.66% and the cut morbidity was 376.40/100 000. Age-specific morbidity in age group 0-34 years remained low; however, the morbidity increased obviously in age group ≥35 years, increased more rapidly in age group ≥50 years and finally reached the peak in age group 80-84 years(1 618.20/100 000). The morbidity of malignant tumor, age-standardized morbidity(China standard)and age-standardized morbidity(world standard)were 381.81/100 000, 185.15/100 000 and 236.27/100 000 respectively in urban area, and 330.23/100 000 , 159.47/100 000 and 206.29/100 000, respectively in rural area. The crude mortality was 189.08/100 000(248.57/100 000 in males, 128.72/100 000 in females), and the age-standardized mortality according to China population and world population were 97.56/100 000 and 135.54/100 000 respectively. The cumulative mortality was 15.08%, and the cut mortality was 162.75/100 000. Age-specific mortality increased in age group 45-49 years(92.29/1000 000)and reached the peak in age group ≥85 years(2 263.70/100 000). The mortality was higher in rural area(190.60/100 000)than in urban area(186.38/100 000). The leading cancers were lung cancer, colorectum cancer, thyroid cancer, stomach cancer and liver cancer, accounting for 58.64% of the total. Lung cancer, liver cancer, stomach cancer, colorectum cancer and esophagus cancer were the major cancers causing deaths, accounting for 70.72% of all the total.

CONCLUSION

The leading cancers were lung cancer, colorectum cancer, thyroid cancer, stomach cancer and liver cancer in Zhejiang in 2014, close attention should be paid to thyroid cancer in women. The disease burden of malignant tumor is increasing,it is necessary for health department to take effective measures to reduce the disease burden caused by malignant tumor.

Pyridine-incorporated alcohol-soluble neutral polyfluorene derivatives as efficient cathode-modifying layers for polymer solar cells

A class of novel alcohol-soluble polyfluorene derivatives with a pyridine group incorporating at the side chains of fluorene is developed to modify the cathode interfaces of both conventional and inverted polymer solar cells.

Rapidly rising incidence of Type 1 diabetes in children and adolescents aged 0-19 years in Zhejiang, China, 2007 to 2013

AIMS

To investigate the incidence rates and trends in Type 1 diabetes in children and adolescents aged 0-19 years in the registered Zhejiang population over the period 2007-2013 by age, sex and calendar year.

METHODS

In total, 611 individuals with newly diagnosed Type 1 diabetes were identified from 30 districts in Zhejiang province over the study period. Annual incidence and 95% confidence intervals (CI) by age group and sex were calculated per 100 000 person-years. Trends in diabetes incidence and the associations of age and sex with Type 1 diabetes were assessed using Poisson regression models.

RESULTS

The mean annual age-standardized incidence of diabetes was 2.02/100 000 person-years (95% CI: 1.92-2.12), with an average annual increase of 12.0% (95% CI: 7.6-16.6%) over the study period. The risk for Type 1 diabetes in girls was estimated to be 1.25 (95% CI: 1.07-1.47) times higher than that in boys. Compared with those aged 0-4 years, the 5-9, 10-14 and 15-19 years age groups were at significantly greater risk, with adjusting incidence rate ratios of 3.54, 6.58 and 5.39, respectively. The mean age at diagnosis decreased significantly from 12.85 years in 2007 to 11.21 years in 2013. A steep rise in diabetes incidence was observed in the under 5 years age group, which showed the greatest increase at 33.61%.

CONCLUSIONS

The incidence of diabetes in Zhejiang was relatively low, although rapidly rising trends have been found in recent years, particularly in younger children. Further monitoring and research are urgently required to better understand possible environmental risk factors and formulate preventive strategies.

Synthesis, photophysics, electrochemistry, thermal stability and electroluminescent performances of a new europium complex with bis(β-diketone) ligand containing carbazole group

We synthesized a new europium complex [Eu(ecbpd)₃ (Phen)] with bis(β-diketone) ligand containing a carbazole group, in which ecbpd and Phen are dehydro-3,3'-(9-ethyl-9H-carbazole-3,6-diyl)bis(1-phenylpropane-1,3-dione) and 1,10-phenanthroline, respectively. Its UV/vis and photoluminescent spectra, quantum yield, luminescence lifetime, electrochemistry, thermal stability and electroluminescent performances were studied. This europium complex showed low efficiency luminescence, which is probably due to the mismatching energy levels of its ligand and Eu³⁺ , as well as the double Eu³⁺ core resonance.

Clinical trial with traditional Chinese medicine intervention ''tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment'' for chronic hepatitis B-associated liver failure

AIM: To study the clinical efficacy of traditional Chinese medicine (TCM) intervention “tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment” (“TTK”) for treating liver failure due to chronic hepatitis B.

METHODS: We designed the study as a randomized controlled clinical trial. Registration number of Chinese Clinical Trial Registry is ChiCTR-TRC-12002961. A total of 144 patients with liver failure due to infection with chronic hepatitis B virus were enrolled in this randomized controlled clinical study. Participants were randomly assigned to the following three groups: (1) a modern medicine control group (MMC group, 36 patients); (2) a “tonifying qi and detoxification” (“TQD”) group (72 patients); and (3) a “tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment” (“TTK”) group (36 patients). Patients in the MMC group received general internal medicine treatment; patients in the “TQD” group were given a TCM formula “tonifying qi and detoxification” and general internal medicine treatment; patients in the “TTK” group were given a TCM formula of “TTK” and general internal medicine treatment. All participants were treated for 8 wk and then followed at 48 wk following their final treatment. The primary efficacy end point was the patient fatality rate in each group. Measurements of various virological and biochemical indicators served as secondary endpoints. The one-way analysis of variance and the t-test were used to compare patient outcomes in the different treatment groups.

RESULTS: At the 48-wk post-treatment time point, the patient fatality rates in the MMC, “TQD”, and “TTK” groups were 51.61%, 35.38%, and 16.67%, respectively, and the differences between groups were statistically significant (P < 0.05). However, there were no significant differences in the levels of hepatitis B virus DNA or prothrombin activity among the three groups (P > 0.05). Patients in the “TTK” group had significantly higher levels of serum total bilirubin compared to MMC subjects (339.40 μmol/L ± 270.09 μmol/L vs 176.13 μmol/L ± 185.70 μmol/L, P = 0.014). Serum albumin levels were significantly increased in both the “TQD” group and “TTK” group as compared with the MMC group (31.30 g/L ± 4.77 g/L, 30.72 g/L ± 2.89 g/L vs 28.57 g/L ± 4.56 g/L, P < 0.05). There were no significant differences in levels of alanine transaminase among the three groups (P > 0.05). Safety data showed that there was one case of stomachache in the “TQD” group and one case of gastrointestinal side effect in the “TTK” group.

CONCLUSION: Treatment with “TTK” improved the survival rates of patients with liver failure due to chronic hepatitis B. Additionally, liver tissue was regenerated and liver function was restored.

Supercritical CO2 in injection molding can produce open porous polyurethane scaffolds – a parameter study

There are several methods of producing open porous polymer structures for medical use. However, very few are applicable to industries and are therefore limited to both number of samples and batch variations. This study presents an industrial microcellular injection molding process, known as MuCell® technology, which was used to produce highly porous scaffolds of thermoplastic polyurethane. A parameter study was performed to quantify and analyze the effect of the processing parameters on the porous structure. Six key parameters (gas content, weight reduction, injection speed, mold temperature, plasticizing pressure, and temperature) were tested with an iteration method. The pore structure was determined with advanced micro Computer Tomography algorithm. All key processing parameters were identified. Gas content and weight reduction showed a more profound effect on the pore morphology than other parameters on the pore structure. It was possible to produce scaffolds with open porosity as high as 71%. The study concludes that MuCell® technology is an accurate and liable production method for large-scale production of open porous thermoplastic polyurethane scaffolds, and supercritical fluid could, therefore, be a potential production method for polymer scaffolds.

The Effects of Mold Design on the Pore Morphology of Polymers Produced with MuCell ®Technology

In this study two molds were designed and used in MuCell® technology to generate implants with a porous structure. To arrive the desired pore structure many process parameters were investigated for indicating the effects of process parameters on the pore morphology. This process parameter investigation was performed on each mold respectively, so that the influences of the mold design on the pore morphology have been researched by the same process parameter setting. It was found that the mold design also had effects on the pore structure in MuCell® technology. A proper mold design could improve the generated pore structure, such as porosity, pore diameter, and interconnectivity.

[Comparative study on the shaping ability of canals with 2 new nickel- titanium rotary instruments]

PURPOSE

To compare the shaping ability of two nickel-titanium rotary systems: Mtwo and K3.

METHODS

Thirty-six mesio-buccal root canals of maxillary first molars were divided into two groups: group A(> or =20> or =) and group B(<20 degrees ),according to the angle of the canal. Then, each group was randomly divided into two subsets and prepared by Mtwo,K3, respectively. All root canals were injected with the contrast medium and digital images of all canals were recorded before and after instrumentation. The computer assistant analyze image software was used to form the geometrical central line of pre-instrumented canals. Then the central line was imaged to the post-instrumented canals. The canal transportation and the decrease of curvature were measured. All the data was analyzed with SPSS11.0 software package.

RESULTS

Difference between groups was compared using t test.When the curvature of canal > or =20 degrees ,the transportation at the beginning of the curvature and the decrease of curvature of Mtwo were significantly less than those of K3(P<0.05).When the curvature of canal <20 degrees there was no significant difference between Mtwo and K3 in the transportation and decrease of curvature(P>0.05).

CONCLUSIONS

Both Mtwo and K3 systems show good preservation of the original geometry of the root canals, the Mtwo system can better preserve original curvature of canals, when the curvature of canal is larger than 20 degrees .

[Anterior radical debridement and bone grafting with one-stage instrumentation anteriorly or posteriorly for the treatment of thoracic and lumbar spinal tuberculosis]

OBJECTIVE

To evaluate the clinical outcomes of anterior radical debridement and autologous ilium or titanium cage interbody autografting with one-stage instrumentation anteriorly or posteriorly for the treatment of thoracic and lumbar tuberculosis.

METHODS

Sixty-eight cases of thoracic and lumbar tuberculosis were surgically treated with anterior radical debridement and autologous ilium or titanium cage interbody autografting with one-stage instrumentation anteriorly or posteriorly from Jan 2001 to Feb 2006. Thirty-nine were male and 29 were female age ranged from 28 to 76 years, (average 36.8 years. The course of illness was from 3 months to 1.5 years average 8 months). Fifty-five of them underwent anterior instrumentations, and the remaining underwent posterior instrumentations. All patients were followed up to determine the stages of intervertebral bony fusion and the corrections of spinal kyphosis and the restoration of neurological deficit

RESULTS

The follow-up period ranged from 1.5 years to 5 years (mean 36 months). Sinus formation occurred in 3 cases and healed after continuous dressing changes. The ESR of these patients decreased to normal levels after an average of 3.2 months postoperatively. The functions of feeling, motion and sphincter in 27 cases among all 28 paraplegia cases gradually recovered 24 h to 3 months postoperatively and ASIA grades increased at least one grade at the final follow-up. Only 1 case did not recover at all and ASIA grade did not increase at the final follow-up. Intervertebral bony fusions were all achieved for a mean of 4.8 months (ranged from 3 to 15 months) postoperatively. No internal fixation devices were loose, extracted or broken. Average Cobb angle of kyphotic deformities was 41.2 degree preoperatively and decreased to 13.6 degree at 1 week postoperatively. The average correction was 27.6 degree. The average Cobb angle was 15.8 degree at the final follow-up and the average loss of correction was only 2.2 degree. There were no recurrences in all cases.

CONCLUSION

The method of anterior radical debridement and interbody grafting with one-stage instrumentation anteriorly or posteriorly was effective for the treatment of thoracic and lumbar spinal tuberculosis.

Physical characterization of oleanolic acid nonsolvate and solvates prepared by solvent recrystallization

Oleanolic acid is a naturally occurring compound used clinically in China for the treatment of hepatitis B. The solid-state chemistry of oleanolic acid recrystallized from a variety of solvents was investigated. Glassy materials were prepared from dichloromethane and chloroform solvents. The oleanolic acid non-solvate prepared from acetone (OA-acetone), and the two oleanolic acid solvates prepared from methanol (OA-methanol) and ethanol (OA-ethanol) were physicochemically characterized. Upon desolvation, both the methanol and ethanol solvates were found to undergo phase transformation to a crystalline phase similar to OA-acetone around 190-195 degrees C. The PXRD patterns of commercial pharmaceutical grade OA and the OA-methanol were similar, so the commercial form is probably desolvated oleanolic acid methanol solvate.

High-Efficiency Electrophosphorescent Copolymers Containing Charged Iridium Complexes in the Side Chains

A convenient approach to novel charged Ir polymers for optoelectronic devices to achieve red emission was developed. 2-(Pyridin-2-yl)benzimidazole units grafted into the side chains of macroligands (PFCz and PFP) served as ligands for the formation of charged Ir complex pendants with 1-phenylisoquinoline (1-piq). The charged Ir polymers (PFPIrPiq and PFCzIrPiq) showed exclusive Ir(1-piq)(2){N-[2-(pyridin-2-yl)benzimidazole]hexyl}(+)BF(4)(-) (IrPiq) emission, with the peak at 595 nm. The best device performances were obtained from PFCzIrPiq4 with the device configuration of ITO/PEDOT:PSS/PFCzIrPiq4+PBD (30 wt %)/TPBI/Ba/Al (PBD: 5-(4-tert-butylphenyl)-2-(biphenyl-4-yl)-1,3,4-oxadiazole; TPBI: 1,3,5-tris-(2-N-phenylbenzimidazolyl)benzene). A maximum external quantum efficiency (EQE) of 7.3 % and a luminous efficiency (LE) of 6.9 cd A(-1) with a luminance of 138 cd m(-2) were achieved at a current density of 1.9 mA cm(-2). The efficiencies remained as high as EQE=3.4 % and LE=3.3 cd A(-1) with a luminance of 3770 cd m(-2) at a current density of 115 mA cm(-2). The single-layer devices based on charged Ir polymers also showed high efficiency with the high work-function metal Ag as cathode. The maximum external quantum efficiencies of the devices were 0.64 % and 0.66 % for PFPIrPiq2 and PFPIrPiq10, respectively. A possible mechanism of an electrochemical cell associated with its electrochemical redox pathway for single-layer devices has been proposed. The results showed that the charged Ir polymers are promising candidate materials for polymer optoelectronic devices.

Humoral immune responses of the grouper Epinephelus akaara against the microsporidium Glugea epinephelusis

The humoral immune responses of grouper Epinephelus akaara to a natural infection with Glugea epinephelusis was studied by ELISA utilizing intact mature spores as the coated antigen. Results showed that a specific humoral immune response was elicited, but the intensity of infection (in terms of the number of cysts) was not related to the antibody level in naturally infected hosts. The differences in the antigenicity of intact mature spores and soluble spore proteins derived from cracked mature spores were also analyzed. Results suggested that similar antigen epitopes existed between the 2 groups. Additionally, antigen component patterns and the distribution of antigen with immunogenicity were investigated by using the western blot and the immunofluorescent antibody technique (IFAT). The new parasitic microsporidium has specific polypeptide patterns comparable to the reported fish microsporidians. The main antigenic substances are concentrated on the surface of spores, and are mostly located on the anterior and posterior end of the spore bodies. Most surface components of the G. epinephelusis spores are soluble. The potential role of the surface components in initiating infection was also discussed.

Association of differentially expressed genes with activation of mouse hepatic stellate cells by high-density cDNA mircoarray

AIM: To characterize the gene expression profiles associated with activation of mouse hepatic stellate cell (HSC) and provide novel insights into the pathogenesis of hepatic fibrosis.

METHODS: Mice HSCs were isolated from BALB/c mice by in situ perfusion of collagenase and pronase and single-step density Nycodenz gradient. Total RNA and mRNA of quiescent HSC and culture-activated HSC were extracted, quantified and reversely transcripted into cDNA. cDNAs from activated HSC were labeled with Cy5 and cDNAs from the quiescent HSC were labeled with Cy3, which were mixed with equal quantity, then hybridized with cDNA chips containing 4000 genes. Chips were washed, scanned and analyzed. Increased expression of 4 genes and decreased expression of one gene in activated HSC were confirmed by reverse transcription- polymerase chain reaction (RT-PCR).

RESULTS: A total of 835 differentially expressed genes were identified by cDNA chip between activated and quiescent HSC, and 465 genes were highly expressed in activated HSC. The differentially expressed genes included those involved in protein synthesis, cell-cycle regulation, apoptosis, and DNA damage response.

CONCLUSION: Many genes implicated in intrahepatic inflammation, fibrosis and proliferation were up-regulated in activated HSC. cDNA microarray is an effective technique in screening for differentially expressed genes between two different situations of the HSC. Further analysis of the obtained genes will help understand the molecular mechanism of activation of HSC and hepatic fibrosis.

Effects of the tyrosine protein kinase inhibitor genistein on the proliferation, activation of cultured rat hepatic stellate cells

AIM: Hepatic stellate cell (HSC) plays a pivotal role in liver fibrosis and is considered as the therapeutic target for the treatment of hepatic fibrosis. Tyrosine protein kinase plays an important role in the proliferation, activation of HSC. The purpose of the study is to investigate the effects of the tyrosine protein kinase inhibitor genistein on the proliferation and activation of cultured rat HSC.

METHODS: Rat HSC were isolated from Wistar rats by in situ perfusion of collagenase and pronase and single-step density Nycodenz gradient. Culture-activated HSC were serum-starved and incubated with 10^-9 to 10^-5 mol/L concentration of genistein for 24, 48 or 72 h. In PDGF-induced HSC proliferation, HSC were stimulated with 10 μg·L^-1 PDGF-BB for 15 min, and then treated with genistein for the same time. Cell proliferation was measured by MTT assay and based on flow cytometric analysis of cell cycle. The α-smooth muscle actin (α-SMA) expression in HSC was studied with confocal laser microscopy and flow cytometry. c-fos, c-jun and cyclin D1 expression in HSC was also detected by flow cytometry.

RESULTS: Genistein inhibited basal and PDGF-induced proliferation of HSC at the concentration of 10^-8 to 10^-5 mol/L, and treatment with 10^-7 mol/L concentration of genistein for 48 h inhibited the HSC proliferation significantly (the inhibition rate was 70.3%, P < 0.05). Immunofluorescence detected by confocal laser microscopy and flow cytometry showed that treatment with 10^-7 mol/L genistein for 48 h suppressed the expression of α-SMA significantly in HSC (the specific fluorescence intensity were 60.2 ± 21.5 vs 35.3 ± 11.6 and 12.8 ± 10.4 vs 9.54 ± 6.39, respectively, both P < 0.05). The intensity of c-fos, c-jun and cyclin D1 expression of HSCs treated with 10^-7 mol/L genistein for 48 h was also significantly decreased compared with the controls.

CONCLUSION: Genistein influences proliferation of HSC, suppresses the expression of α-SMA in HSC and t inhibits the intensity of c-fos, c-jun and cyclin D1 expression of HSCs. Genistein has therapeutic potential against liver fibrosis.

Apoptosis of rat hepatic stellate cells induced by anti-focal adhesion kinase antibody

AIM: To explore the role of focal adhesion kinase (FAK) in the apoptosis in culture-activated rat hepatic stellate cells (HSCs) using a specific anti-FAK antibody.

METHODS: Rat HSCs were prepared from Wistar rats by in situ perfusion of collagenase and pronase and single-step density Nycodenze gradient. Culture-activated HSCs were serum-starved and treated with the anti-FAK antibodies for 24, 48 or 72 h. The apoptosis of HSC was detected by DNA-fragment assay, flow cytometry and caspase-3 activity determination. The expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) mRNA was assessed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS: The experiment showed that anti-FAK antibodies induced apoptosis of culture-activated rat HSCs. This phenomenon displayed the classical features of apoptotic cell death (DNA fragmentation, cell cycle analysis) after treated with 30 mg·L^-1 FAK antibody for 72 h, and accompanied by a significant increase of caspase-3 activity (1208 ± 76) vs (309 ± 28) nmol·min^-1·g^-1, t = 208.5, P < 0.05. Meanwhile, treatment with the FAK antibody in HSCs could markedly decrease the TIMP-1 mRNA expression (0.07 ± 0.01 vs 0.38 ± 0.03, t = 2.72, P < 0.05).

CONCLUSION: FAK plays an important role in the survival of HSCs and the specific anti-FAK antibody could induce the apoptosis in rat HSCs.

Onset of Asian desertification by 22 Myr ago inferred from loess deposits in China

The initial desertification in the Asian interior is thought to be one of the most prominent climate changes in the Northern Hemisphere during the Cenozoic era. But the dating of this transition is uncertain, partly because desert sediments are usually scattered, discontinuous and difficult to date. Here we report nearly continuous aeolian deposits covering the interval from 22 to 6.2 million years ago, on the basis of palaeomagnetic measurements and fossil evidence. A total of 231 visually definable aeolian layers occur as brownish loesses interbedded with reddish soils. This new evidence indicates that large source areas of aeolian dust and energetic winter monsoon winds to transport the material must have existed in the interior of Asia by the early Miocene epoch, at least 14 million years earlier than previously thought. Regional tectonic changes and ongoing global cooling are probable causes of these changes in aridity and circulation in Asia.

Sex differences in cocaine-induced behavioral sensitization

To further understand how sex differences affect the development and maintenance of sensitization, 48 adult Fischer rats (24 female and 24 male) received chronic administration (14 days) of cocaine (15 mg/kg, i.p.) or saline or a challenge dose (7 days after chronic cocaine administration). Sex differences were observed in the development and maintenance of cocaine-induced total locomotor, ambulatory and rearing activity. Although, overall cocaine administration increased stereotypic activity in both male and female rats, female rats had significantly higher stereotypic activity than male rats across the three behavioral test days (1, 7 and 14). Female rats had statistically significant higher benzoylecognine levels after acute cocaine administration than male rats. However, no differences between male and female rats in benzoylecognine plasma levels were observed after chronic and challenge doses of cocaine administration. Interestingly, after acute and challenge cocaine administration, corticosterone levels were significantly higher in female rats when compared to male rats. This study confirms previous reports that there are sex differences in the behavioral response to cocaine. Moreover, this study expands previous studies by demonstrating that sex differences occur in only certain aspects of cocaine-induced behavioral activation and the development and maintenance of cocaine-induced behavioral sensitization.

[Observation of the effectiveness of APFI gel to prevent dental caries]

OBJECTIVE

To observe the effectiveness of APFI Gel applied to pupils to prevent dental caries.

METHODS

2918 cases of 6 to 13 years old pupils from four urban and countryside primary schools were randomly divided into two groups,the experiment group and the control group. By theirs different school and classes and groups, APFI Gel was used to 2 160 cases of the experimental group to prevent dental caries. The control group consisted of 758 cases. The incidence of dental caries of the two groups were observed in the same time and using the same way.

RESULTS

Statistical analysis indicated that the incidence of dental caries in the experimental group decreased by 52.3%,the newly increased DMFT decreased by 60.14% (P<0.01). The incidence of dental caries of the first molar decreased by 52.43%,the newly increased DMFT decreased by 65.52% (P<0.01).

CONCLUSION

It is effective to use APFI Gel to prevent caries.

Immunotherapy of a human papillomavirus type 16 E7-expressing tumor by administration of fusion protein comprised of Mycobacterium bovis BCG Hsp65 and HPV16 E7

Human papillomavirus type 16 (HPV16) infection has been linked to the development of cervical and anal dysplasia and cancer. One hallmark of persistent infection is the synthesis of the viral E7 protein in cervical epithelial cells. The expression of E7 in dysplastic and transformed cells and its recognition by the immune system as a foreign antigen make it an ideal target for immunotherapy. Utilizing the E7-expressing murine tumor cell line, TC-1, as a model of cervical carcinoma, an immunotherapy based on the administration of an adjuvant-free fusion protein comprised of Mycobacterium bovis BCG Hsp65 linked to HPV16 E7 (HspE7) has been developed. Initial in vitro analyses indicate that immunization with HspE7 results in the induction of a type 1 immune response based on the pattern of secreted cytokines and the presence of cytolytic activity following antigenic recall. It has been previously shown that prophylactic immunization with HspE7 protected mice against challenge with TC-1 cells and that these tumor-free animals are also protected against rechallenge with TC-1 cells. The present report shows that a single therapeutic immunization with HspE7 induces regression of palpable tumors, confers protection against tumor rechallenge, and is associated with long-term survival (>253 days). In vivo studies using mice with targeted mutations in CD8 or MHC class II or depleted of CD8 or CD4 lymphocyte subsets demonstrate that tumor regression following therapeutic HspE7 immunization is CD8 dependent and CD4 independent. These studies extend previous observations on the induction of CTL by Hsp fusion proteins and are consistent with the clinical application of HspE7 as an immunotherapy for human cervical and anal dysplasia and cancer.

Immunotherapy of a human papillomavirus (HPV) type 16 E7-expressing tumour by administration of fusion protein comprising Mycobacterium bovis bacille Calmette-Guérin (BCG) hsp65 and HPV16 E7

Human papillomavirus type 16 (HPV16) infection has been linked to the development of cervical and anal dysplasia and cancer. One hallmark of persistent infection is the synthesis of the viral E7 protein in cervical epithelial cells. The expression of E7 in dysplastic and transformed cells and its recognition by the immune system as a foreign antigen make it an ideal target for immunotherapy. Utilizing the E7-expressing murine tumour cell line, TC-1, as a model of cervical carcinoma, an immunotherapy based on the administration of an adjuvant-free fusion protein comprising Mycobacterium bovis BCG heat shock protein (hsp)65 linked to HPV16 E7 (hspE7) has been developed. The data show that prophylactic immunization with hspE7 protects mice against challenge with TC-1 cells and that these tumour-free animals are also protected against re-challenge with TC-1 cells. In addition, therapeutic immunization with hspE7 induces regression of palpable tumours, confers protection against tumour re-challenge and is associated with long-term survival (> 253 days). In vitro analyses indicated that immunization with hspE7 leads to the induction of a Th1-like cell-mediated immune response based on the pattern of secreted cytokines and the presence of cytolytic activity following antigenic recall. In vivo studies using mice with targeted mutations in CD8 or MHC class II or depleted of CD8 or CD4 lymphocyte subsets demonstrate that tumour regression following therapeutic hspE7 immunization is CD8-dependent and CD4-independent. These studies extend previous observations on the induction of cytotoxic T lymphocytes by hsp fusion proteins and are consistent with the clinical application of hspE7 as an immunotherapy for human cervical and anal dysplasia and cancer.

[Ultraviolet radiation and long term space flight]

With the prolongation of space flight, influences of various aerospace environmental factors on the astronauts become more and more severe, while ultraviolet radiation is lacking. Some studies indicated that low doses of ultraviolet rays are useful and essential for human body. In space flight, ultraviolet rays can improve the hygienic condition in the space cabin, enhance astronaut's working ability and resistance to unfavorable factors, prevent mineral metabolic disorders, cure purulent skin diseases and deallergize the allergens. So in long-term space flight, moderate amount of ultraviolet rays in the space cabin would be beneficial.

Characterization of the inhibition of DNA synthesis in proliferating mink lung epithelial cells by insulin-like growth factor binding protein-3

Insulin-like growth factor binding protein-3 (IGFBP-3) can inhibit cell growth by directly interacting with cells, as well as by forming complexes with IGF-I and IGF-II that prevent their growth-promoting activity. The present study examines the mechanism of inhibition of DNA synthesis by IGFBP-3 in CCL64 mink lung epithelial cells. DNA synthesis was measured by the incorporation of 5-bromo-2'-deoxyuridine, using an immunocolorimetric assay. Recombinant human IGFBP-3 (rh[N109D,N172D]IGFBP-3) inhibited DNA synthesis in proliferating and quiescent CCL64 cells. Inhibition was abolished by co-incubation of IGFBP-3 with a 20% molar excess of Leu(60)-IGF-I, a biologically inactive IGF-I analogue that binds to IGFBP-3 but not to IGF-I receptors. DNA synthesis was not inhibited by incubation with a preformed 1:1 molar complex of Leu(60)-IGF-I and IGFBP-3, indicating that only free IGFBP-3 inhibits CCL64 DNA synthesis. Inhibition by IGFBP-3 is not due to the formation of biologically inactive complexes with free IGF, since endogenous IGFs could not be detected in CCL64 conditioned media; any IGFs that might have been present could only have existed in inactive complexes, since endogenous IGFBPs were present in excess; and biologically active IGFs were not displaced from endogenous IGFBP complexes by Leu(60)-IGF-I. After incubation with CCL64 cells, (125)I-IGFBP-3 was covalently cross-linked to a major thick similar400-kDa complex. This complex co-migrated with a complex formed after incubation with (125)I-labeled transforming growth factor-beta (TGF-beta) that has been designated the type V TGF-beta receptor. (125)I-IGFBP-3 binding to the thick similar400-kDa receptor was inhibited by co-incubation with unlabeled IGF-I or Leu(60)-IGF-I. The ability of Leu(60)-IGF-I to decrease both the inhibition of DNA synthesis by IGFBP-3 and IGFBP-3 binding to the thick similar400-kDa receptor is consistent with the hypothesis that the thick similar400-kDa IGFBP-3 receptor mediates the inhibition of CCL64 DNA synthesis by IGFBP-3.

The absence of 150-kDa insulin-like growth factor complexes in fetal rat serum is not due to a lack of functional acid-labile subunit

Most of the insulin-like growth factors (IGFs) in adult rat or human plasma circulate in 150-kDa heterotrimeric complexes with IGF-binding protein-3 (IGFBP-3) and an acid-labile subunit (ALS). These 150-kDa complexes are not present, however, in rat serum at birth. As ALS is the critical determinant in the formation of the 150-kDa complexes in adult rat serum, the present study asks whether the absence of 150-kDa complexes in fetal rat serum results from a low abundance of ALS. We report that ALS mRNA is expressed in term fetal rat liver at 30% of the levels in adult liver, that radioiodinated rat ALS is not proteolyzed by incubation with fetal rat serum, and that sufficient functional ALS is present in fetal rat serum to form 150-kDa complexes with recombinant human IGFBP-3. These results indicate that the low levels of 150-kDa complexes in perinatal rat serum are not due to low circulating levels of ALS.

Proteolysis of insulin-like growth factor binding protein-3 in serum from pregnant, non-pregnant and fetal rats by matrix metalloproteinases and serine proteases

The insulin-like growth factors (IGFs) in adult mammalian plasma circulate predominantly in 150-kDa complexes that also contain IGF-binding protein-3 (IGFBP-3) and an acid-labile subunit. Proteolysis of IGFBP-3 within the 150-kDa complex decreases its affinity for IGFs, facilitating their release to the tissues. By contrast, 150-kDa complexes are not detected in serum from fetal or pregnant adult rats. Decreased complex formation results from insufficient availability of IGFBP-3 due to increased IGFBP-3 proteolysis. The present study characterizes IGFBP-3 protease activity in serum from fetal, pregnant and non-pregnant adult rats by comparing the effect of different protease inhibitors. Proteolysis of exogenous recombinant human IGFBP-3 (for fetal and pregnancy serum) or endogenous IGFBP-3 (for non-pregnant adult rat serum) following incubation at 37 degrees C was measured by ligand blotting. In all three sera, IGFBP-3 proteolysis was inhibited completely by: (i) EDTA, a chelator of divalent cations. Inhibition was reversed by zinc, but not by calcium ions; (ii) 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), an inhibitor of serine proteases; and (iii) a specific tissue inhibitor of matrix metalloproteinases (TIMP-1). Recombinant human matrix metalloproteinase-3 (MMP-3) proteolyzed recombinant human IGFBP-3 or endogenous rat IGFBP-3 in non-pregnancy serum pretreated with AEBSF to inactivate endogenous serine proteases. These results suggest that serine proteases initiate the activation of latent MMP precursor, and that the activated MMP directly degrades IGFBP-3.

Insulin-like growth factor-I (IGF-I) concentration in 150-kilodalton complexes containing human IGF-binding protein-3 (hIGFBP-3) after intravenous injection of adult rats with hIGFBP-3

After i.v. injection into adult rats, human insulin-like growth factor-binding protein-3 (hIGFBP-3) forms 150-kDa complexes with excess endogenous rat acid-labile subunit (ALS) within 2 min (Lewitt et al., 1993, Endocrinology 133:1797). Because their previous in vitro studies indicated that hIGFBP-3 only bound to ALS in the presence of IGF-I, and because little free IGF-I is present in plasma, the authors postulated that IGF-I had been mobilized to the circulation to saturate the 150-kDa hIGFBP-3 complexes. We examined this hypothesis by determining whether the hIGFBP-3 that appears in 150-kDa complexes 2 min after i.v. injection is accompanied by an increase in IGF-I. Within 2 min, some of the injected hIGFBP-3 (approximately 30% as much as endogenous intact rat IGFBP-3) is present in complexes that are cleared slowly from the circulation and presumed to be 150-kDa complexes. Gel filtration and immunoprecipitation studies performed on blood collected 2 min after injection confirmed that the injected hIGFBP-3 (46-82% as much as rat IGFBP-3) was associated with ALS in 150-kDa complexes. The formation of 150-kDa complexes containing hIGFBP-3 was not accompanied by a corresponding change in the IGF-I content (determined by RIA) of whole serum or 150-kDa serum fractions, suggesting that the hIGFBP-3 had rapidly associated with rALS in vivo without mobilizing IGF-I. Surprisingly, however, hIGFBP-3 was cleared much more rapidly from 150-kDa complexes formed after injection of hIGFBP-3 than after injection of hIGFBP-3:IGF-I complexes, suggesting that the complexes observed after hIGFBP-3 injection might not have formed in vivo. In fact, 150-kDa complexes formed to a similar extent when hIGFBP-3 was added ex vivo to blood collected from rats that had not received hIGFBP-3. We conclude that hIGFBP-3 can rapidly associate with rALS to form 150-kDa complexes in vivo without the mobilization of IGF-I. Because 150-kDa complexes also are formed ex vivo, however, we are unable to resolve whether the complexes that formed in vivo formed as binary or ternary complexes.

A comparison of Zn(II) and Co(II) in the kinetics of inactivation of aminoacylase by 1,10-phenanthroline and reconstitution of the apoenzyme

The kinetics of reconstitution of apoacylase with either Zn(II) or Co(II) and the inactivation of the Co(II) reconstituted enzyme by 1,10-phenanthroline (OP) has been studied by following the substrate reaction continuously in presence of the metal ion or OP respectively. Although the native Zn(II)-containing and the Co(II)-reconstituted enzymes have closely similar Michaelis constants and maximal velocities, the kinetics for both the inactivation by OP and the reconstitution of the apoenzyme with the metal ions differs considerably. For Co(II), both the inactivation by OP and the reconstitution show simple kinetics, but for Zn(II), the inhibition by OP is a multi-phasic process [Wang, Wu, Wang, Zhou and Tsou (1992) Biochem. J. 281, 285-290], and the kinetics of reconstitution is also much more complicated. Both the native and the Co(II)-reconstituted enzymes are inhibited by excess of Zn(II), but not by Co(II). The inhibition by Zn(II) in excess and the reconstitution of the apoenzyme with Zn(II) are co-operative processes. The inhibition by Zn and its effect on the fluorescence emission of 1-anilinonaphthalene-8-sulphonic acid bound to the native enzyme indicate multiple Zn(II)-binding sites.

A modified Escherichia coli chaperonin (groEL) polypeptide synthesized in tobacco and targeted to the chloroplasts

The coding region for the Escherichia coli groEL (chaperonin-60) polypeptide was fused downstream of a pea rubisco small subunit transit peptide coding sequence under the control of a tandem 35S CaMV promoter. Transgenic tobacco plants (Nicotiana tabacum cv. Xanthi) containing this modified groEL gene were produced. The modified groEL polypeptide was correctly imported into chloroplasts and accumulated to high or low levels in different plants. The majority of the modified groEL polypeptide was processed correctly to the mature form within the chloroplasts. Approximately 20% of the imported polypeptides retained a portion of the N-terminal transit peptide (TPgroEL). Both groEL and TPgroEL polypeptides assembled into tetradecameric species in the chloroplasts. In plants accumulating high levels of these products, the majority of the plant chaperonin-60 polypeptides in the chloroplast were present in novel hybrid tetradecameric species containing both bacterial and plant chaperonin-60 polypeptides. In plants accumulating low levels of groEL, the predominant species present appeared to be authentic plant cpn60(14) and authentic bacterial groEL14. The growth and development of transgenic and control tobacco plants were indistinguishable.