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.

[Effect of renal function on sarcopenia in elderly male patients with chronic kidney disease]

Objective: To evaluate the effect of renal function on sarcopenia in elderly male patients with chronic kidney disease (CKD). Methods: A total of 105 male CKD patients aged ≥65 years who were admitted to the Chinese PLA General Hospital between October 1, 2018 and January 30, 2019 were included in this study. Using two different equations to estimate glomerular filtration rate (GFR), respectively. According to the sarcopenia criteria, the participants were categorized as the non-sarcopenia group (n=72) and the sarcopenia group (n=33), respectively. The association of estimated GFR (eGFR) and the sarcopenia in the male CKD patients was analyzed using the model of multivariate logistic regression. Results: Among the 105 patients, the median age was 74 (68, 77) years old. The prevalence of sarcopenia was 31.4% (33/105). According to the multivariate logistic regression analysis, eGFR based on serum creatinine and Cys-C (eGFRscr-cys) lower than 45 ml·min(-1)·(1.73 m(2))(-1) (OR=4.17, 95%CI:1.08-16.02, P=0.038) and eGFR based on Cys-C (eGFRcys) lower than 45 ml·min(-1)·(1.73 m(2))(-1) (OR=3.99, 95%CI:1.08-14.75, P=0.038) were independent risk factors for underlying sarcopenic, respectively. The area under the receiver operating characteristics curve (AUC) revealed that eGFRscr-cys (AUC=0.67) was more suitable than eGFRcys (AUC=0.64) to predict the sarcopenia in elderly male patients with CKD. Conclusion: The increased incidence of sarcopenia in elderly men with CKD is accompanied with deterioration of renal function.

[Related factors of frailty in the elderly male patients with chronic kidney disease]

Objective: To investigate the characteristics of frailty in the elderly male patients with chronic kidney disease (CKD) and the effects of renal function on the incidence of frailty. Methods: A total of 105 non-dialysis CKD patients aged ≥65 years who were admitted to the Chinese PLA General Hospital between October 1, 2018 and January 30, 2019 were included in this study. Their clinical data and laboratory indicators were collected. Frailty was defined according to Fried frailty criteria. According to the frailty scores, the participants were categorized as non-frail (n=37), intermediately frail (n=37) and frail (n=31). The association of frailty and the level of estimated glomerular filtration rate (eGFR) in the patients was analyzed using the model of multivariate Logistic regression. Results: Among the 105 patients, the mean age was 74 (68, 77) years old. The incidence of frail and intermediate frail was 35.2% (37/105) and 29.5% (31/105), respectively. Multivariate logistic analysis showed statistically significant associations of frailty with age (OR=1.14, 95%CI:1.08-1.20, P<0.001), body mass index (OR=0.87, 95%CI:0.79-0.95, P=0.001) and the level of eGFR (OR=0.98, 95%CI:0.96-0.99, P=0.003) in those patients. The incidence of frail in patients with eGFR<45 ml·min(-1)·(1.73 m(2))(-1) and 45-59 ml·min(-1)·(1.73 m(2))(-1) was 1.02 (OR=2.02, 95%CI: 1.06~3.87) and 0.84 (OR=1.84, 95%CI: 1.05-3.22) times higher than that of eGFR≥60 ml·min(-1)·(1.73 m(2))(-1), respectively. Conclusion: The incidence of frailty in the elderly patients with CKD is affected by many factors, such as age, body mass index and renal function, and increases with decreased renal function.

[Efficacy and mechanism of loading dose clopidogrel in patients with transient ischemic attack and minor stroke]

Objective: To assess outcome, safety and possible mechanism of loading dose clopidogrel in patients with transient ischemic attack (TIA) and minor stroke. Methods: We reviewed patients with confirmed TIA and minor stroke admitted between July 2016 and December 2017 into the First Affiliated Hospital of Soochow University. Loss-of-function allele carriers of CYP2C19 were included and randomly divided into loading dose group (first dose of 300 mg clopidogrel) and standard dose group (first dose of 75 mg clopidogrel), 100 mg aspirin was gave at the same time, followed by aspirin 100 mg/d plus clopidogrel 75 mg/d maintaining for 20 days. Platelet aggregation (maximum aggregation ratio, MAR) induced by Adenosine diphosphate (ADP) was examined before and 3 days after administration. The National Institutes of Health Stroke Scale (NIHSS) score method was employed to assess the NIHSS scores before and after treatment in each group of patients; the modified Rankin Scale (mRS) was used to assess the 3-month functional outcome. Results: There was no significant difference in baseline data between the two groups (P>0.05).The proportion of early neurological function improvement in the two groups was 75.0% and 54.8%, and the difference was statistically significant (χ(2)=4.498, P=0.034). The 3-month prognosis was 79.5% and 61.3%, and the difference was statistically significant (χ(2)=4.000, P=0.045). Adverse events: 1 case in the loading dose group, 1 case in the standard dose group, the difference was not statistically significant (2.3% vs 1.6%, χ(2)=0.061, P=0.806). After 3 days of antiplatelet therapy, the MAR of the loading dose group decreased (11%±8%), and the MAR of the standard dose group decreased (9%±4%), the difference was statistically significant (P=0.013).In the loading dose group, there were 32 (72.7%)CYP2C19*2 carriers and 42 (95.5%)CYP2C19*2+*3 carriers; early neurological function improvement in 33 cases, accounting for 93.8% and 76.2%, respectively, and the difference was statistically significant (χ(2)=4.122, P=0.042). There were 35 patients with good prognosis in 3 months, accounting for 96.9% and 81.0%, respectively. The difference was statistically significant (χ(2)=4.310, P=0.038); MAR of CYP2C19*2 carrier was decreased (15%±5%), and MAR of CYP2C19*2+*3 carrier was decreased (12%±8%). The difference was statistically significant (P=0.039). Conclusions: Loading dose clopidogrel can improve the clinical prognosis of minor stroke/TIA without increasing the risk of bleeding. Loading dose clopidogrel may improve the prognosis of minor stroke/TIA by decreasing MAR of CYP2C19*2 carriers.

[A multi-center cross-sectional survey of medicine application in patients with osteoarthritis in China]

OBJECTIVE

To investigate the clinical characteristics, the medicine application and to evaluate the disease activity in patients with osteoarthritis (OA) in China.

METHODS

This was a cross-sectional study. Totally 1 066 cases of OA from 40 hospitals in China from April to October 2017 were retrospectively enrolled. Demographic characteristics, clinical data, medicine application, and joint function were evaluated. All the data were analyzed by SPSS software 19.0. t test, Mann-Whitney U test and chi-square test were used for statistical analysis.

RESULTS

In the 1 066 cases, the male-to-female ratio was 1:3.6 and the average age was (61.9±11.0) years, with an age range from 36 to 94 years. The incidence of knee OA, hip OA, and hand OA were respectively 81.9% (873/1 066), 14.1% (150/1 066), and 36.3% (387/1 066). In the study, 242 (22.7%) cases had two kinds of joint areas involved and three joint areas were involved in 51 cases (4.8%), and 56.6% (603/1 066) of the patients used more than one kind of non-steroid anti-inflammatory drugs (NSAIDs) while 61.2% (652/1 066) used disease modifying osteoarthritis drugs (DMOADs), including glucosamine (37.5%, 400/1 066), chondroitin sulfate (2.0%, 21/1 066), diacetate (5.9%, 63/1 066), and the combination of these drugs (15.8%, 168/1 066). 8.6% (92/1 066) patients only took analgesics to relieve the pain, not using any kind of NSAIDs or DMOADs. And 232 patients (21.7%) had intra-articular injections, including 9.2% (98/1 066) sodium hyaluronate, 4.5%(48/1 066) glucocorticoid, and 8.1% (86/1 066) combination of the two drugs. The proportion of the patients taking topical drugs accounted for 26.5% (283/1 066) and physical therapy accounted for 15.8% (168/1 066). Compared with those who suffered from knee OA, the patients who suffered from hip OA had more severe disease assessment. Moreover, there were significant differences in pain (Z=-7.625, P<0.001), morning stiffness (Z=-6.229, P<0.001), and joint function (Z=-6.777, P<0.001) between the two groups of the patients who suffered from knee or hip OA with The Western Ontario and McMaster Universities (WOMAC) osteoarthritis index. Furthermore, patients with hip OA took more analgesics (χ²=24.838, P<0.001).

CONCLUSION

Oral NSAIDs and DMOADs are wildly used in patients with OA in China. However, the treatment of some patients still need to be improved. Patients with hip OA are more seriously ill and require aggressive treatment.

[Effect of interleukin-6 promoter DNA methylation on the pathogenesis of systemic lupus erythematosus]

Objective: To analyze peripheral blood interleukin-6 (IL-6) promoter DNA methylation status and its clinical significance in patients with systemic lupus erythematosus (SLE). Methods: Blood samples of 41 adult patients with SLE and 20 healthy controls were collected.The methylation status of IL-6 promoter was determined by methylation specific polymerase chain reaction (MSP). The IL-6 expression was detected by real-time PCR.Correlations between IL-6 promoter methylation status and clinical features or laboratory findings in patients with SLE were analyzed. Results: The levels of IL-6 mRNA were significantly higher in peripheral blood of SLE.DNA methylation levels of IL-6 promoter were reduced in SLE patients as compared with healthy controls.The methylation status and expression of IL-6 in peripheral blood reflected the levels in peripheral blood mononuclear cells (PBMCs). Significantly positive correlation was found between IL-6 hypomethylation and renal disorder, as well as hypocomplementemia in patients with SLE. Conclusion: Hypomethylation of interleukin-6 promoter in peripheral blood might be involved in the etiology of SLE.

Comparison of 30 mCi and 50 mCi I-131 doses for ablation of thyroid remnant in papillary thyroid cancer patients

PURPOSE OF THE STUDY

To compare efficacy of thyroid remnant ablation using 30 mCi or 50 mCi 131-I in papillary thyroid cancer patients.

MATERIALS AND METHODS

Five hundred and fifteen consecutive patients with Tumor-Node-Metastasis (TNM) stages T1-T3 N1/N0/NX receiving either 30 mCi or 50 mCi I-131 were analyzed for the effectiveness of remnant ablation using rhTSH-stimulated serum thyroglobulin. One hundred and five consecutive patients receiving 100 mCi I-131 were analyzed for the incidence of radiation thyroiditis and sialadenitis.

RESULTS AND CONCLUSIONS

Doses of 30 mCi and 50 mCi were equally effective for low- and moderate-risk disease but 30 mCi was less effective for T1T2NX disease, and 50 mCi was less effective for T3 compared to T1T2 disease. Low dose radiation hypersensitivity or unknown more extensive disease may have accounted for observed differences. Radiation thyroiditis and sialadenitis were more common in a comparison series of 100 mCi dose compared to 30 mCi, but not more common than in 50 mCi doses.

[A cross-sectional study on application of glucocorticoid in systemic lupus erythematosus patients]

Objective: To explore the status of glucocorticoid application in patients with systemic lupus erythematosus (SLE) in China. Methods: Epidemiological survey was used. The SLE patients who met the 1997 classification criteria of American College of Rheumatology were enrolled. The usage of glucocorticoid and related adverse reactions were recorded and analyzed. Results: A total of 400 SLE patients were enrolled, including 35 men and 365 women. The average age was (37.4±14.0) years old, and the average duration of disease was (6.7±5.8) years. There were 310 patients using glucocorticoid as maintenance. Sixty-one percent (n=244) patients started using medium dose (prednisone 30-<60 mg/d) as the initial treatment of glucocorticoid, which lasted for(37±11)days.The time of drug duration in patients with low dose prednisone (7.5-<30 mg/d)and high dose (60-100 mg/d) was(92±20)and(17±3)days respectively (P<0.05 between 3 groups). However, patients receiving different initial dosage were of no discrepancy in the maintenance therapy. During maintenance, even though 51.0% (n=158) patients were on prednisone 2.5-5 mg/d, the duration of drug use in >5-10 mg/d groupwas longer[(29.9±3.3) months]. Patients with involvement of internal organs had a higher tendency to use 60-100 mg/d prednisone or pulse-dose therapy in the initial treatment, nevertheless these two groups had no difference of maintenance dosage. Among all 400 patients, 62 patients withdrew glucocorticoid, including 17 patients with disease remission (4.3%), 44 by self-withdrawal and one with adverse reaction. Conclusion: In China, the medium dosage of glucocorticoid is the most common initial treatment in patients with SLE.Prednisone 2.5-5 mg/d was the most common choicefor maintenance therapy. Currently, the proportion of glucocorticoid withdrawal remains low in SLE patients achieving remission.

Mapping QTLs for drought tolerance in an F2:3 population from an inter-specific cross between Gossypium tomentosum and Gossypium hirsutum

Cotton is one of the most important natural fiber crops in the world. Its growth and yield is greatly limited by drought. A quantitative trait locus (QTL) analysis was therefore conducted to investigate the genetic basis of drought tolerance in cotton (Gossypium spp) using 188 F2:3 lines developed from an inter-specific cross between a wild cotton species, G. tomentosum, and an upland cotton, G. hirsutum (CRI-12). A genetic map was constructed using 1295 simple sequence repeat markers, which amplified 1342 loci, distributed on 26 chromosomes, covering 3328.24 cM. A field experiment was conducted in two consecutive years (2014 and 2015) and 11 morphological and physiological traits were recorded under water-limited (W1)/well-watered (W2) regimes at three growth stages (bud, flowering, and full boll). The traits measured included chlorophyll content, plant height, leaf area, leaf number, leaf fresh weight, leaf dry weight, boll weight, number of bolls per plant, and the number of fruiting branches. Sixty-seven and 35 QTLs were found under the W1 and W2 conditions, respectively. Of these, the majority exhibited partial dominance or over-dominance genetic effects for increasing the trait values. Four consistent QTLs were found under the W1 treatment on chromosomes 5, 8, 9, and 16, whereas no consistent QTL was found in W2. Thirteen QTL clusters were also identified on nine chromosomes (2, 3, 5, 6, 9, 14, 15, 16, and 21). These results will help to elucidate the genetic basis of drought tolerance in cotton.

[Pathogens and clinical characteristics of bacterial infection in hematology department between 2010 and 2014]

OBJECTIVE

To analyze the characteristics of distribution and drug resistance of bacterial infection in several different parts of hematology department inpatients of Anhui Provincial Hospital from January 2010 to December 2014, including patients who had received hematopoietic stem cell transplantation (HSCT).

METHODS

Anti-microbial susceptibility test was done by Kirby-Bauer method and automated systems and the data were analysed by WHONET 5.6 software.

RESULTS

A total of 3 312 copies of inspection samples were analyzed, including 2 716 (82%) blood samples and other 596 specimens (18%). 634 bacterial strains were isolated from 3 312 samples (19.14%) including 488 samples (76.97%) from blood culture. 427 (67.35%) bacterial strains were gram-negative, and the other 207 (32.65%) were gram-positive. Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were most common gram-negative bacterial and the resistant rates to imipenem were 0.8%, 11.8% and 3.3%, respectively. Detection rates of Extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae were 83.9% and 75.0%, respectively. At the same time, Coagulase negative Staphylococcus, Streptococcus and Enterococcus were most common kinds of gram-positive bacteria. Methicillin-resistant coagulase negative staphylococcus accounted for 65.9% antibiotic resistance. No vancomycin and/or linezolid and/or tigecycline resistant strains of Staphylococcus spp. and Enterococcus spp. were found in those patients.

CONCLUSION

Patients with hematology diseases had a higher risk of bacterial infections, mainly caused by Gram-negative bacteria. There are different distributions of bacterial in different wards.

Radiological follow-up results of untreated anterior disc displacement without reduction in adults

The aim of this study was to assess the radiographic changes in untreated adults with bilateral anterior disc displacement without reduction. A cohort study was designed to compare the bone changes, effusion, disc configuration, and pseudo-disc changes on two magnetic resonance images obtained at least 24 months apart. Twenty-eight patients (22 female, six male) with a mean age of 33.1 years (range 20-57 years) were included. The mean interval between the initial visit and the follow-up visit was 36.2 months. At the initial visit, the frequencies of bone changes, effusion, disc deformation, and pseudo-disc changes were 51.79%, 35.71%, 100%, and 0%, respectively. At follow-up, the frequency of effusion had decreased significantly. The frequency of bone changes had increased significantly to 75%, but newly formed cortical bone was present in five condyles. All discs remained deformed. Pseudo-disc changes were detected in five joints. Over a long period of observation, there was a significant decrease in effusion and a significant increase in bone changes. However, some adaptive changes occurred.

Construction and characterization of a bacterial artificial chromosome library for the allotetraploid Gossypium tomentosum

Gossypium tomentosum is a wild allotetraploid species with the (AD)5 genome. It is characterized by many useful traits including finer fiber fineness, drought tolerance, and Fusarium and Verticillium resistance. We constructed the first bacterial artificial chromosome library for Gossypium tomentosum. With high quality and broad coverage, this library includes 200,832 clones, with an average insert size of about 122 kb and fewer than 3% empty clones. Our library is approximately 10-fold the size of the (AD)5-genome (2400 Mb) and provides a 99.7% probability of isolating genes of interest or their sequences. Seven of eight simple sequence repeats markers that are located on five different chromosomes and linked with resistance to Verticillium wilt could amplify the 50 superpools and obtained one to five hits. This high capacity library will be an important genomic resource for classifying and analyzing the evolution of allotetraploid cotton species as well as for isolating disease-resistance and drought-tolerance genes.

Genetic diversity and relationship analysis of Gossypium arboreum accessions

Simple sequence repeat techniques were used to identify the genetic diversity of 101 Gossypium arboreum accessions collected from India, Vietnam, and the southwest of China (Guizhou, Guangxi, and Yunnan provinces). Twenty-six pairs of SSR primers produced a total of 103 polymorphic loci with an average of 3.96 polymorphic loci per primer. The average of the effective number of alleles, Nei's gene diversity, and Shannon's information index were 0.59, 0.2835, and 0.4361, respectively. The diversity varied among different geographic regions. The result of principal component analysis was consistent with that of unweighted pair group method with arithmetic mean clustering analysis. The 101 G. arboreum accessions were clustered into 2 groups.

Lenalidomide affect expression level of cereblon protein in multiple myeloma cell line RPMI8226

We investigated the mechanisms of action of immuno-modulatory drug (lenalidomide) on the protein expression of cereblon (CRBN) and their therapeutic targets in the multiple myeloma cell line RPMI8226. The multiple myeloma cell line RPMI8226 was cultured and treated with different concentrations of lenalidomide and bortezomib to determine the proliferation inhibition rate, apoptosis rate, and protein expression of CRBN. The results revealed that both lenalidomide and bortezomib inhibited the proliferation of RPMI8226 and promoted cell apoptosis. However, the protein expression of CRBN decreased signifi-cantly after treatment with lenalidomide, while bortezomib had no effect on the expression of CRBN. We confirmed that CRBN may be a target of lenalidomide.

Characterization and development of chloroplast microsatellite markers for Gossypium hirsutum, and cross-species amplification in other Gossypium species

Cotton is an important economic crop worldwide; its fiber, commonly known as cotton lint, is the main natural source for the textile industry. Sixty chloroplast microsatellites were identified and characterized from the complete sequence of the Gossypium hirsutum chloroplast genome using a bioinformatic approach. Twenty chloroplast microsatellite loci were polymorphic in the 66 Gossypium germplasm accessions. A total of 85 alleles were detected, with allele numbers varying from 2-7 per locus. Polymorphism information content varied from 0.02-0.66, with a mean of 0.48. Additionally, transferability of the 20 polymorphic chloroplast microsatellite primers was evaluated in other 31 Gossypium species. Sixteen markers were successfully amplified across all species tested, while the remaining 4 markers cross-amplified in most species tested. These polymorphic chloroplast microsatellite markers may be useful tool for studies of individual identification, genetic diversity, evolution, conservation genetics, and molecular breeding in Gossypium.

Treatment of advanced non-small-cell lung cancer with Chinese herbal medicine by stages combined with chemotherapy

PURPOSE

To observe the effect of Chinese herbal medicine by stages combined with chemotherapy in treating patients with non-small-cell lung cancer (NSCLC) of stage III or IV.

METHODS

Adopting prospective, randomized, controlled, multi-centered trial design, 121 patients enrolled were assigned to the treatment group (n = 65) and the control group (n = 56). All the patients were randomized to receive chemotherapy alone or chemotherapy and Chinese herbal medicine combined (Kangliuzengxiao decoction during chemotherapy and Feiyanning decoction after chemotherapy). The main outcome measures were survival time, Karnofsky score, main clinical symptoms, and adverse reactions.

RESULTS

Five patients discontinued from the trial due to oral administration of Iressa after disease progression or other reasons, and 116 patients were evaluable for clinical efficacy with 63 in the treatment group and 53 in the control group. The overall response rate were 15.87% vs. 7.55% (P = 0.170), and the disease control rate were 85.71% vs. 71.70% in the treatment and control group (P = 0.063), respectively. The median survival time was 16.17 months vs. 12.00 months in the treatment and control group (P = 0.165), respectively. In addition, adverse reactions such as leucopenia in the treatment group were less than those in the control group (P = 0.039).

CONCLUSIONS

Chinese herbal medicine combined with chemotherapy showed favorable effect in improving quality of life and prolonging survival time on patients with advanced NSCLC.

Correlation between disc displacements and locations of disc perforation in the temporomandibular joint

OBJECTIVES

The aim of this study was to investigate the correlation between disc displacement types and locations of disc perforation in the temporomandibular joint (TMJ).

METHODS

157 patients (162 joints) with disc perforation observed through arthroscopy were included in this study. The types of disc displacement were analysed by TMJ MRI before operation. The locations of disc perforation under arthroscopy were recorded. The correlation between types of disc displacement and locations of disc perforation was analysed by Fisher's exact test.

RESULTS

Medial disc perforation was observed in 55.6% of patients with anterolateral displacement without reduction, but was observed in only 3.7% of patients with pure anterior displacement, and was not observed in patients with anteromedial displacement without reduction. There was a statistically significant difference between these groups in the incidence of medial disc perforation.

CONCLUSIONS

There is a correlation between different disc displacements and locations of disc perforation. The incidence of medial disc perforation in patients with anterolateral displacement was significantly higher. The types of disc displacement may have direct influence over the locations of disc perforation.

Cryoloop vitrification of rabbit oocytes

BACKGROUND

Vitrification is assumed to be a promising method to cryopreserve human oocytes but still needs optimization. In this study, rabbit oocytes (fertilized by ICSI) were vitrified with cryoloops, and the effect of three different cryopreservation protocols on spindle configuration and embryo quality was assessed.

METHODS

Metaphase II rabbit oocytes were randomly assigned to one of four groups: (i) control; (ii) E40 [40% ethylene glycol (EG)]; (iii) ED20 [20% EG + 20% dimethylsulphoxide (DMSO)]; and (iv) ED20 + M (20% EG + 20% DMSO + vitrification machine). After warming, one part of each group was fertilized by ICSI to examine the fertilization and embryo cleavage ability, and the others were immunostained for tubulin and chromatin before visualization using confocal microscopy.

RESULTS

The survival rates after warming were 79.1, 83.1 and 82.3%, respectively. In protocols E40 and ED20, the spindles were severely injured and the embryo quality not good compared with those in the ED20 + M group.

CONCLUSIONS

The fastest cooling rate in combination with EG and DMSO as cryoprotectants had the fewest adverse effects on the spindle configuration of rabbit oocytes and embryo development.

[An experimental study on arthroscopic chondrocytes transplantation for repair of osteochondral defects in TMJ]

OBJECTIVE

To certify the feasibility of arthroscopic chondrocytes transplantation in temporomandibular joint (TMJ) and the nature of repaired tissue with autologous chondrocytes transplantation in osteochondral defects.

METHODS

The animal models of osteochondral defects in TMJ were established in 12 rhesus monkeys. Autologous auricular chondrocytes were transplanted to the defects by arthroscope. Healing of the defects was assessed by gross examination, light microscope, immunohistochemical staining.

RESULTS

The repaired tissues with chondrocytes transplantation were fibrocartilages.

CONCLUSION

The technique of arthroscopic chondrocytes transplantation is feasible and the nature of repaired tissue is closest to the normal cartilage, compared with those of subchondral drilling and cartilage transplantation.

[A experimental study on arthroscopic auricular cartilage transplantation for repair of osteochondral defect of temporomandibular joint(TMJ)]

OBJECTIVE

To study the feasibility and resurfacing ability of auricular cartilage transplantation for osteochondral defect of TMJ.

METHODS

Arthroscopic auricular cartilage transplantations were undertaken in 12 rhesus monkeys(24 joints) to repair the osteochondral defects in TMJs. The repaired tissues were examined by gross examination, light microscope and immunohistochemistry(IHC) 4 weeks,8 weeks,12 weeks and 24 weeks postoperatively.

RESULTS

The defects were repaired 8 weeks after operation. As time goes on, the chondrocytes in defects declined and fibroblast increased at the same time. The IHC showed slight positive stain of type II collagen.

CONCLUSION

The osteochondral defects of TMJ can be restored by autologous auricular cartilage. The nature of repaired tissue was fibrocartilage like tissue at first and then fibrotic tissue.

[A experimental study on arthroscopic subchondral drilling for repair of osteochondral defect of temporomandibular joint (TMJ)]

OBJECTIVE

To investigate the resurfacing ability of TMJ cartilage of rhesus monkeys with osteochondral defect.

METHODS

3-millimeter-diameter, 5-millimeter-depth, cylindrical full-thickness drilled osteochondral defect of articular cartilage on the functional slope of TMJ were made on 12 rhesus monkeys(24 joints) by arthroscope. Every 3 monkeys were sacrificed at 4, 8, 12 and 24 weeks postoperatively and the repaired tissue were studied by gross observation, histology and immunohistochemical staining (IHC).

RESULTS

The repaired tissues after subchondral drilling were dominated with fibrous tissues and IHC showed that Type II collagen stain was negative and Type I collagen stain was positive.

CONCLUSION

The osteochondral defect in TMJ can be repaired by arthroscopic subchondral drilling. The nature of repaired tissue is fibrous connective tissue, something different from normal cartilage. Subchondral drilling can be regarded as one of the treatments for articular cartilage defect.

[Establishment of an animal model of osteochondral defect by arthroscope in TMJ]

OBJECTIVE

To create an animal model of osteochondral defect in temporomandibular joint (TMJ) by arthroscope to minimize the surgical injury.

METHODS

Subchondral drilling on the anterior slope of condyle and posterior slope of eminence were performed on 12 rhesus monkeys (24 joints) by arthroscope.

RESULTS

The osteochondral defect models of TMJ were successfully made on 12 monkeys (24 joints).

CONCLUSION

There are fewer injuries and bias in the animal models of TMJ osteochondral defect by arthroscope than by open surgery.

High critical current density and enhanced irreversibility field in superconducting MgB2 thin films

The discovery of superconductivity at 39 K in magnesium diboride offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. This compound has twice the transition temperature of Nb3Sn and four times that of Nb-Ti alloy, and the vital prerequisite of strongly linked current flow has already been demonstrated. One possible drawback, however, is that the magnetic field at which superconductivity is destroyed is modest. Furthermore, the field which limits the range of practical applications-the irreversibility field H*(T)-is approximately 7 T at liquid helium temperature (4.2 K), significantly lower than about 10 T for Nb-Ti (ref. 6) and approximately 20 T for Nb3Sn (ref. 7). Here we show that MgB2 thin films that are alloyed with oxygen can exhibit a much steeper temperature dependence of H*(T) than is observed in bulk materials, yielding an H* value at 4.2 K greater than 14 T. In addition, very high critical current densities at 4.2 K are achieved: 1 MA cm-2 at 1 T and 105 A cm-2 at 10 T. These results demonstrate that MgB2 has potential for high-field superconducting applications.

Strongly linked current flow in polycrystalline forms of the superconductor MgB2

The discovery of superconductivity at 39 K in magnesium diboride, MgB2, raises many issues, a critical one being whether this material resembles a high-temperature copper oxide superconductor or a low-temperature metallic superconductor in terms of its behaviour in strong magnetic fields. Although the copper oxides exhibit very high transition temperatures, their in-field performance is compromized by their large anisotropy, the result of which is to restrict high bulk current densities to a region much less than the full magnetic-field-temperature (H-T) space over which superconductivity is found. Moreover, the weak coupling across grain boundaries makes transport current densities in untextured polycrystalline samples low and strongly sensitive to magnetic field. Here we report that, despite the multiphase, untextured, microscale, subdivided nature of our MgB2 samples, supercurrents flow throughout the material without exhibiting strong sensitivity to weak magnetic fields. Our combined magnetization, magneto-optical, microscopy and X-ray investigations show that the supercurrent density is mostly determined by flux pinning, rather than by the grain boundary connectivity. Our results therefore suggest that this new superconductor class is not compromized by weak-link problems, a conclusion of significance for practical applications if higher temperature analogues of this compound can be discovered.

Clinical significance of QT dispersion after exercise in patients with previous myocardial infarction

To evaluate the clinical significance of QT dispersion after exercise in patients with previous myocardial infarction, QT dispersion (QTd) and corrected QTd (QTcd) were assessed with standard 12 leads electrocardiogram in 90 patients with previous myocardial infarction and 30 healthy persons before and 3 min after a treadmill exercise test. In addition, 24 h ambulatory electrocardiogram and echo-cardiography were examined in all the subjects studied. Patients were followed up for 37.25 +/- 10.71 months. The results showed that there were no significant differences in the QTd and QTcd between the patients and the controls before exercise (36.11 +/- 13.42 ms versus 34.81 +/- 12.32 ms, P>0.05, 41.22 +/- 13.49 as versus 39.91 +/- 13.56 ms, P>0.05). Compared with those before exercise, QTd and QTcd were significantly increased in the patients 3 min after the exercise test (36.11 +/- 13.42 ms versus 47.20 +/- 14.41 ms, P<0.01, 41.22 +/- 13.49 ms versus 59.57 +/- 18.90 ms, P<0.01), but not in the controls (34.81 +/- 12.32 ms versus 38.76 +/- 12.09 ms, P>0.05, 39.91 +/- 13.56 ms versus 43.27 +/- 17.77 ms, P>0.05). The incidences of abnormal contraction of the left ventricular wall, aneurysms, NYHA III class, >III class of Lown's ventricular arrhythmia classification and cardiac sudden death were significantly higher in group A with QTcd >50 ms than that of group B with QTcd <50 ms (P<0.01). These findings indicate that the increased QT dispersion after exercise in 12 standard leads electrocardiogram might be associated with high incidences of sudden cardiac death and ventricular arrhythmia in the patients with previous myocardial infarction.

Regulation of granulocyte colony-stimulating factor gene expression by interleukin-17

Interleukin-17 (IL-17) has been previously reported to induce stromal cells to produce a number of hematopoietic and proinflammatory cytokines, including granulocyte colony-stimulating factor (G-CSF). Here, we have evaluated the mechanisms responsible for the augmentation of G-CSF gene expression by IL-17, using the murine 3T3 fibroblast cell line. Treatment of 3T3 cells, but not primary bone marrow-derived macrophages or murine monocyte/macrophage cell lines, resulted in increased steady-state G-CSF mRNA levels within 2-4 h and augmented G-CSF protein production. The combination of IL-17 and LPS enhanced G-CSF expression in an additive fashion. Stability studies revealed that IL-17 stabilized G-CSF mRNA levels, with a t1/2 of 4 h, compared to a t1/2 of less than 2 h in medium or LPS-treated cells. Induction of G-CSF expression in 3T3 cells by IL-17 did not appear to require tyrosine kinase activation or de novo protein synthesis. These studies indicate that post-transcriptional mechanisms play an important role in IL-17-induced G-CSF expression in fibroblasts and suggest that IL-17 may be useful for further delineating mechanisms of G-CSF gene regulation.

A specific stimulator of granulocyte colony-stimulating factor accelerates recovery from cyclophosphamide-induced neutropenia in the mouse

We have identified a small molecular weight compound, SCH 14988, which specifically stimulates in vitro granulocyte-colony stimulating factor (G-CSF) production from activated human peripheral blood mononuclear cells and monocytes but not other cytokines or CSFs with hematoregulatory activity. In vivo administration of SCH 14988 to mice rendered neutropenic by cyclophosphamide treatment resulted in the accelerated recovery of the peripheral neutrophil compartment. This activity correlated with increased in vivo G-CSF levels and stimulation of marrow granulopoiesis, and was comparable to that of exogenously administered recombinant human G-CSF. No alterations to other leukocyte populations in peripheral blood, spleen, or the peritoneal cavity were observed. These findings suggest that SCH 14988 may be clinically useful to enhance neutrophil granulopoiesis, as well as to study the mechanisms involved in G-CSF gene regulation.

Expression, purification, and characterization of an activated cytokine-suppressive anti-inflammatory drug-binding protein 2 (CSBP2) kinase from baculovirus-infected insect cells

An activated form of the human cytokine-suppressive anti-inflammatory drug-binding protein 2 (CSBP2) kinase was expressed in Spodoptera frugiperda (SF9) cells from a baculovirus vector. To maximize expression and to facilitate purification of the recombinant protein, CSBP2 kinase was expressed as a carboxy-terminal fusion protein to glutathione S-transferase (GST). Under optimal conditions, 2-3 mg of GST-CSBP2 could be obtained per liter of infected cell culture. The fusion protein was easily purified from the soluble fraction of the total cell lysate under nondenaturing conditions by using a glutathione-Sepharose 4B affinity resin. As expected, the purified GST-CSBP2 fusion protein was approximately 68 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and reacted with antibodies directed toward either the GST or the CSBP amino terminus. To obtain activated CSBP2, SF9 cells were coinfected with two recombinant baculovirus vectors: one that directed the synthesis of the GST-CSBP2 fusion protein and a second vector that directed the synthesis of a constitutively active form of the CSBP activating kinase, MKK3. Coexpression of GST-CSBP2 kinase with the MKK3 activator increased GST-CSBP2 activity 8- to 10-fold based on the ability of GST-CSBP2 to phosphorylate the substrate, myelin basic protein (MBP), and the ATF2 transcription factor, in vitro. Moreover, activated GST-CSBP2 was capable of activating a bacterially derived mitogen-activated protein kinase-activating protein kinase 2 in vitro. The activity of insect-derived GST-CSBP2 was also inhibited by the CSBP inhibitor, SB202190. We anticipate that the preparation and purification techniques described in this study will facilitate further biochemical characterization of this kinase.

Ultraviolet A irradiation upregulates type VII collagen expression in human dermal fibroblasts

Type VII collagen, a major component of skin-anchoring fibrils, is synthesized by both fibroblasts and keratinocytes, the two principal cell types in the skin. In this study, we examined the effects of ultraviolet A (UVA) irradiation on the expression of type VII collagen in human fibroblasts. UVA irradiation (0-15 J/cm2) caused a dose-dependent increase (5- to 10-fold) in type VII collagen mRNA levels as detected by northern blot analysis. The UVA-induced enhancement of type VII collagen gene expression correlated with an increase in its protein level by immunoblot analysis of proteins secreted into the conditioned medium. The effect of UVA was observed at 12 h and reached its maximum by 18 h. Under these conditions, however, the expression of fibronectin, a major dermal matrix protein, remained unchanged, suggesting that the induction of type VII collagen expression was selective. Actinomycin D, a transcription inhibitor, blocked the UVA-mediated induction of type VII collagen gene expression, whereas cycloheximide, a protein synthesis inhibitor, superinduced the expression of type VII collagen, suggesting that de novo protein synthesis was not required for the action of UVA. Interestingly, in contrast to the increased type VII collagen expression in fibroblasts in response to UVA, a slight decrease in type VII collagen mRNA level was observed in the UVA-irradiated keratinocytes, suggesting that the effect of UVA on the type VII collagen expression is cell type specific.

Fiducial markers for increasing the versatility of optical correlation in the measurement of faults on integrated-circuit wafers

A microscope-coherent optical processor is used for the measurement of the registration errors on integrated-circuit wafers. The measurements are obtained from the optical correlation of wafers with reference wafer patterns by use of matched spatial filters. Previously, the intricate pattern of the active circuit area of wafers has been used in the correlation process, and a new matched spatial filter had to be created for each different integrated circuit. Here, the results of using comparatively plain fiducial markers on a wafer for the registration-error measurement are presented, and these show that the measurements can be made independent of the design of the integrated circuit while maintaining the advantages and accuracy of the optical correlation technique.

Wafer fault measurement by coherent optical processor

A microscope coherent optical processor based on the VanderLugt optical correlator is applied to the measurement of registration error in multilayer integrated-circuit wafers. A treatment of the effects of wafer faults on the correlation signal is given. Threshold criteria and fault-induced peak splitting of the correlation signal from reject production samples are exploited to demonstrate the easy and rapid detection of faults in partially processed integrated-circuit wafers.

Role of the metF and metJ genes on the vitamin B12 regulation of methionine gene expression: involvement of N5-methyltetrahydrofolic acid

The repression of MetE synthesis in Escherichia coli by vitamin B12 is known to require the MetH holoenzyme (B12-dependent methyltransferase) and the metF gene product. Experiments using trimethoprim, an inhibitor of dihydrofolate reductase, show that the MetF protein is not directly involved in the repression, but that N5-methyltetrahydrofolic acid (N5-methyl-H4-folate), the product of the MetF enzymatic reaction is required. Since the methyl group from N5-methyl-H4-folate is normally transferred to the MetH holoenzyme to form a methyl-B12 enzyme, the present results suggest that a methyl-B12 enzyme is involved in the vitamin B12 repression of metE expression. Other results argue against the possibility that a methyl-B12 enzyme functions in this repression solely by decreasing the cellular level of homocysteine, which is required for MetR activation of metE expression. Experiments with metJ mutants show that the MetJ protein mediates about 50% of the repression of metE expression by B12 but is totally responsible for the regulation of metF expression by vitamin B12.

The effect of homocysteine on MetR regulation of metE, metR and metH expression in vitro

An Escherichia coli S-30 DNA directed protein synthesis system was used to study the effect of homocysteine on the in vitro expression of the metE, metH and metR genes. In the presence of purified MetR protein, which is known to regulate the expression of these genes, homocysteine activates metE expression and inhibits both metR and metH expression. These findings support the recent in vivo results of Urbanowski, M.L. and Stauffer, G.V. (1989), J. Bacteriol. 171, 3277-3281.

Methionine synthesis in Escherichia coli: effect of the MetR protein on metE and metH expression

Studies by Urbanowski et al. [Urbanowski, M. L., Stauffer, L. T., Plamann, L. S. & Stauffer, G. V. (1987) J. Bacteriol. 169, 1391-1397] have identified a regulatory locus, called metR, required for the expression of the metE and metH genes. We recently purified the MetR protein from Escherichia coli and showed that it could stimulate the in vitro expression of the metE gene and autoregulate its own synthesis. In the present study, the purified MetR protein has been shown to stimulate the in vitro expression of the metH gene. Also, the in vitro synthesized MetE, MetH, and MetR proteins were shown to be biologically active. The transcription start sites for the metE and metR genes have been determined, and DNA footprinting experiments have identified regions in the metE-metR intergenic sequence that are protected by either the MetR or MetJ proteins.

Regulation of methionine synthesis in Escherichia coli: effect of the MetR protein on the expression of the metE and metR genes

A plasmid (pRSE562) containing the metE and metR genes of Escherichia coli was used to study the expression of these genes and the role of the MetR protein in regulating metE expression. DNA sequence analysis of the 236-base-pair region separating these genes showed the presence of seven putative met boxes. When this plasmid was used to transform either wild-type E. coli, metE mutant, or metR mutant, MetE enzyme activity increased 5- to 7-fold over wild-type levels. The metR gene was subcloned from pRSE562, and this plasmid, pMRIII, relieved the methionine auxotrophy of a metR mutant after transformation. The metR gene was also cloned into a vector containing the lambda PL promoter, and the MetR protein was overexpressed and purified to near homogeneity. This protein, when added to an in vitro DNA-dependent protein synthesis system in which the MetE and/or MetR proteins were synthesized, caused a large increase in the expression of the metE gene but a decrease in the expression of the metR gene. The in vitro expression of both genes was inhibited by the MetJ protein and S-adenosylmethionine in the presence or absence of MetR protein. These results provide evidence that the product of the metR gene is a trans-activator of the expression of the metE gene and that the expression of the metR gene is under autogenous regulation and is repressed by the MetJ protein.