[In vitro optical assessment of three types of non-diffractive extended depth-of-focus intraocular lenses]

Objective: To evaluate the in vitro optical performance of three types of non-diffractive extended depth-of-focus (EDoF) intraocular lenses (IOLs). Methods: Experimental study. Three Vivity IOLs, three Eyhance IOLs, and three ES60 IOLs were included. The professional optical bench OptiSpheric® IOL PRO 2 and an ISO-2 corneal model were applied. The through-focus modulation transfer function (MTF) and predicted visual acuity (logarithm of the minimum angle of resolution) of different spatial frequencies and different focuses under apertures of 3.0 mm and 4.5 mm were recorded. The aspheric monofocal (Tecnis ZCB00), diffractive EDoF (Tecnis Symfony), and trifocus (STF1) IOLs, as well as the lowest visual requirement criteria of EDoF IOLs of American Academy of Ophthalmology served as assessment controls. Results: For the 3.0-mm aperture, the peak value of the MTF was highest with ZCB00, followed by Eyhance, ES60, Vivity, Symfony, and STF1. All experimental non-diffractive EDoF IOLs had two MTF peaks, and the distance between both peaks was longest with Vivity (1.76 D), followed by ES60 (1.43 D) and Eyhance (1.36 D). Among the control IOLs, Symfony had two MTF peaks, and the peak MTF of the intermediate focus was highest. STF1 had three MTF peaks, and the peak MTF of the near focus was highest. For the 4.5-mm aperture, the ranking of the MTF peak of the six types of IOLs was the same as that for the 3.0-mm aperture. Vivity had an increased MTF peak of the distance focus, but a decreased intermediate focus MTF peak, while the MTF peaks of the distance, intermediate, and near focuses in the other IOLs decreased, compared to those for the 3.0-mm aperture. The predicted visual acuity of the distance focus of the three types of non-diffractive EDoF IOLs was all better than 0.0. The predicted visual acuity of the intermediate focus of the Vivity IOL and the ES60 IOL was 0.11 and 0.05 better than that of the Eyhance IOL, respectively. Based on the predicted visual acuity of 0.2, Vivity and ES60 had a depth of focus of at least 0.50 D exceeding ZCB00, while Eyhance had a depth of focus of 0.40 D exceeding ZCB00. Conclusion: In the experiments in vitro, the three types of non-diffractive EDoF IOLs exhibited varying degrees of intermediate to near focus optical performance while maintaining distance focus optical performance. The Eyhance IOL showed better distance focus optical performance than ES60 and Vivity IOL. The Vivity IOL and the ES60 IOL showed better depth of focus extensions than the Eyhance IOL and met the lowest visual requirement criteria of EDoF IOLs of American Academy of Ophthalmology.

OCULAR DECOMPRESSION RETINOPATHY WITH BRANCH RETINAL VEIN OCCLUSION MTHF-R GENETIC MUTATION

PURPOSE

An atypical case of a sectorial decompression retinopathy with branch retinal vein occlusion following trabeculectomy was reported and was diagnosed with optical coherence tomography angiography for which systemic genetic assessment revealed a MTHF-R mutation.

METHOD

Single case report.

RESULTS

A 68-year-old woman diagnosed with an uncontrolled bilateral creeping angle glaucoma went through an uncomplicated trabeculectomy in both eyes. Best-corrected visual acuity was 20/20. Intraocular pressure changed from 28 mmHg preoperatively to 5 mmHG postoperatively in the right eye. On the first postoperative day, best-corrected visual acuity was 20/32 with intraocular pressure measured to 5 mmHg. Fundus examination revealed sectorial temporal hemorrhages with tortuous temporal superior retinal vein arcade and choroidal folds. Fluorescein angiography evidenced a slight delay in venous filling along the supratemporal arcade. Three months later, optical coherence tomography angiography showed macular capillary loops in the superotemporal area of the retina. This sectorial decompression retinopathy was evocative of a branch retinal vein occlusion. At 6 months, best-corrected visual acuity returned to 20/20, with full regression of the hemorrhages. Systemic workup was normal, but genetic assessment revealed a MTHF-R mutation.

CONCLUSION

Retinal vein occlusion can be considered as a feature of ocular decompression retinopathy. The present case is the first case to associate branch retinal vein occlusion secondary to ocular decompression retinopathy to a MTHF-R mutation.

[Application value of serum protein indicators in constructing the early prediction model for the prognosis of patients with pulmonary tuberculosis]

Objective: To analyze the clinical significance of laboratory examination indicators as the key prognostic factors and to construct an early prediction model for prognosis assessment of pulmonary tuberculosis patients. Methods: The basic information, biochemical indexes and blood routine items of 163 tuberculosis patients (144 males and 19 females, aged 41-70 years, with an average age of 56 years) and 118 healthy persons who underwent physical examination (101 males and 17 females, aged 46-64 years, with an average age of 54 years) in Suzhou Fifth People's Hospital from January 2012 to December 2020 were retrospectively collected. According to the presence of Mycobacterium tuberculosis after six months of treatment, the enrolled patients were divided into a cured group (96 cases) and a treatment failure group (67 cases). To analyze the baseline levels of laboratory examination indicators between these two groups, we screened the key predictors and the binary logistic regression method in SPSS statistics software was used to construct the prediction model. Results: The baseline levels of total protein, albumin, prealbumin, glutamic-pyruvic transaminase, erythrocyte, hemoglobin and lymphocyte were significantly higher in the cured group than in the treatment failure group. After 6 months of treatment, the indexes of total protein, albumin and prealbumin increased significantly in the cured group, but remained at the low levels in the treatment failure group. Receiver operating characteristic (ROC) curve analysis showed that total protein, albumin and prealbumin as independent predictors for forecasting the prognosis of pulmonary tuberculosis patients had the highest prediction accuracy. Logistic regression analysis showed that the combination of these three key predictors could construct the best early prediction model for assessing the prognosis of pulmonary tuberculosis patients, with a prediction accuracy of 0.924 (0.886-0.961), sensitivity of 75.0%, specificity of 94%, showing an ideal prediction accuracy. Conclusions: The routine test indexes of total protein, albumin and prealbumin show good application value in the construction of early prediction model for prognosis evaluation of pulmonary tuberculosis treatment. The combined prediction model consisting of total protein, albumin and prealbumin is expected to provide a theoretical basis and reference model for precision treatment and prognosis assessment of tuberculosis patients.

[Study of incubation period of infection with 2019-nCoV Omicron variant BA.5.1.3]

Objective: To study the incubation period of the infection with 2019-nCoV Omicron variant BA.5.1.3. Methods: Based on the epidemiological survey data of 315 COVID-19 cases and the characteristics of interval censored data structure, log-normal distribution and Gamma distribution were used to estimate the incubation. Bayes estimation was performed for the parameters of each distribution function using discrete time Markov chain Monte Carlo algorithm. Results: The mean age of the 315 COVID-19 cases was (42.01±16.54) years, and men accounted for 30.16%. A total of 156 cases with mean age of (41.65±16.32) years reported the times when symptoms occurred. The log-normal distribution and Gamma distribution indicated that the M (Q₁, Q₃) of the incubation period from exposure to symptom onset was 2.53 (1.86, 3.44) days and 2.64 (1.91, 3.52) days, respectively, and the M (Q₁, Q₃) of the incubation period from exposure to the first positive nucleic acid detection was 2.45 (1.76, 3.40) days and 2.57 (1.81, 3.52) days, respectively. Conclusions: The incubation period by Bayes estimation based on log-normal distribution and Gamma distribution, respectively, was similar to each other, and the best distribution of incubation period was Gamma distribution, the difference between the incubation period from exposure to the first positive nucleic acid detection and the incubation period from exposure to symptom onset was small. The median of incubation period of infection caused by Omicron variant BA.5.1.3 was shorter than those of previous Omicron variants.

[A preliminary study on the construction and application of the smart classroom teaching mode in endodontics]

Objective: To evaluate the application effect of smart classroom teaching mode in undergraduate teaching of endodontics. Methods: Through micro-lecture and massive open online course which were closely integrated with clinical practice and frontier advances, we build a new smart classroom teaching mode of endodontics relying on information technology such as the medical education cloud APP platform. The mode was applied to the undergraduate teaching of grade 2017 (110 students) and grade 2018 (107 students) in 2020 and 2021 respectively (experimental group). The theoretical examination was conducted for the grade 2016 (control group, 111 students applied traditional teaching methods) in 2019, and for two experimental grades in 2020 and 2021 respectively. A questionnaire survey was conducted for the 2018 undergraduates to investigate the experience of the smart classroom teaching mode, and the application effect of the smart classroom teaching mode was evaluated by comparing the offline theoretical test scores of grades 2016, 2017 and 2018. Results: The results of the questionnaire showed that students in grade 2018 recognized the overall form of smart classroom teaching mode, and 75.2% (79/105) of the students satisfied with the teaching process, considering that it could enhance learning interest and enthusiasm, improve self-learning ability, facilitate the understanding and memory of knowledge points, as well as increase the extension and expansion of professional knowledge. Thirty-seven point one percent (39/105) of the students thought that smart classroom teaching mode was not conducive to the interaction between teachers and students and couldn't improve learning efficiency. Comparing the final theoretical examination scores of students in three years, it was found that the average scores of 2021 (78.79±9.88) and 2020 (76.45±8.33) were significantly higher than that of 2019 (67.67±10.58) (t=6.77, P<0.001; t=8.51, P<0.001). The average score in 2021 was higher than that in 2020, although the difference was not significant (t=1.79, P=0.223). Conclusions: The application of smart classroom mode improved the teaching effect of endodontics, which is worthy of further promotion to provide a positive reference in improving the educating effects of oral medicine.

[Mechanism of pepsin promoting lingual tonsil hypertrophy by stimulating macrophage]

Objective: To investigate the possible pathophysiological mechanism of laryngopharyngeal reflux (LPR) in the development of lingual tonsil hypertrophy (LTH). Methods: The lingual tonsil tissues were collected from 73 patients [48 males and 25 females, aged from 24 to 76 (52.86±12.04) years] who underwent surgery for laryngopharyngeal diseases at the Department of Otolaryngology and Head and Neck Surgery, Southern Hospital of Southern Medical University from October 2019 to December 2020, and the lingual tonsil grade (LTG), reflux symptom index (RSI) and reflux finding score (RFS) were assessed. The expression of pepsin in LTH was detected by immunohistochemistry. The coexpression of pepsin and macrophages were detected by immunohistofluorescence. In vitro, cytological experiments and pathway assays were performed on macrophages stimulated by pepsin. Pathway alterations of macrophages in pepsin-positive high-grade LTH were detected by double-fluorescence immunohistochemistry. Data were analyzed by SPSS 20.0 software. Results: There were 44 clinically significant LPRD patients with LTG 3 and 4, and the pepsin positive rate was 88.6% (39/44). While, the pepsin positive rate of LTG 1 and 2 was 48.3% (14/29). LTG was significantly positively correlated with RFS/RSI positive rate(χ²=23.01/19.62, P<0.001/0.001; r=0.54/0.51, P<0.001/0.001) and pepsin tissue staining intensity (H=21.58, P<0.001; r=0.53, P<0.001), respectively. Pepsin and macrophages were clearly colocalized in high grade LTH. In vitro, pepsin promoted macrophage proliferation (P<0.05) and production of IL-6/IL-8 (P<0.05). Pepsin significantly up-regulated the p38/JNK MAPK pathway in macrophages (P<0.05). Pepsin up-regulated the expression of IL-6 and IL-8 of macrophages by activating the p38 MAPK pathway (P<0.05), and up-regulated the expression of IL-8 by activating the JNK pathway (P<0.05). The p38/JNK MAPK pathways were highly expressed in macrophages of pepsin-positive LTH (P<0.05). Conclusions: LPR is an important pathogenic factor in LTH. Macrophages may mediate pepsin-induced inflammation and the pathogenesis of LTH.

Thermally-assisted milling and hydrogenolysis for synthesizing ultrafine MgH2with destabilized thermodynamics

A novel process has been developed to synthesize MgH₂nanoparticles by combining ball milling and thermal hydrogenolysis of di-n-butylmagnesium (C₄H₉)₂Mg, denoted as MgBu₂. With the aid of mechanical impact, the hydrogenolysis temperature of MgBu₂in heptane and cyclohexane solution was considerably lowered down to 100 °C, and the MgH₂nanoparticles with an average particle size ofca.8.9 nm were obtained without scaffolds. The nano-size effect of the MgH₂nanoparticles causes a notable decrease in the onset dehydrogenation temperature of 225 °C and enthalpy of 69.78 kJ mol^-1 · H₂. This thermally-assisted milling and hydrogenolysis process may also be extended for synthesizing other nanomaterials.

[Evaluation and embolization strategy by ASITN/SIR grade for injured internal carotid artery of nasopharyngeal carcinoma]

Objective: To study the strategy of endovascular treatment for patients with the risks of internal carotid artery (ICA) rupture and bleeding during the treatment of nasopharyngeal carcinoma (NPC) based on American Society of Intervention and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grade of collateral circulation. Methods: A total of 56 patients (45 males and 11 females, aged from 28 to 76 years old) diagnosed with nasopharyngeal carcinoma and admitted to the Department of Neurosurgery, the Third Affiliated Hospital of Southern Medical University from July 2018 to January 2020 were retrospectively analyzed. There were 15 cases of ASITN/SIR grade 4, 24 cases of ASITN/SIR grade 3, 5 cases of ASITN/SIR grade 2, 5 cases of ASITN/SIR grade 1, and 7 cases of ASITN/SIR grade 0. The events of stroke and death were analyzed statistically. Results: ALL patients with ASITN/SIR grade 4 or 3 and some of patients with ASITN/SIR grades 2-0 passed balloon occlusion test and electrophysiological monitoring. ICA pseudoaneurysm was found in 35 patients, and one-stage ICA embolization was performed in 29 patients after evaluation. Among them, 8 cases of ASITN/SIR grade 4 and 10 cases of ASITN/SIR grade 3 with obvious posterior circulation compensation obtained successful one-stage ICA embolization without cerebral ischemia; cerebral ischemic events occurred in 5 (55.6%) of 9 patients with ASITN/SIR grade 3 and in 1(50.0%) of 2 patients with ASITN/SIR grade 2. The total incidence of ischemic events was 20.7% (6/29) and 1 case was disabled (1/29, 3.4%). Among patients with ASITN/SIR 3, there were statistically significant differences in stroke event rate between patients with obvious posterior circulation compensation and patients with slight or without posterior circulation compensation (0/10 vs. 5/9, χ(2)=4.95, P=0.026). Follow-up time was 10.1±7.8 months, and 46 patients were survival (46/56, 82.1%) and 10 patients died (10/56, 17.9%) with a mean survival time of 2.6±1.4 months. Conclusions: For NPC patients with ICA invasion, ASITN/SIR based on DSA can simplify the assessment process of cerebral blood flow compensation. ICA can be embolized directly in patients with ASITN/SIR 4 or 3 with obvious posterior communicating compensation.

[Effect of two kinds of materials on the prevention of early erosive enamel wear]

Objective: To investigate the preventive effect of resin infiltration and adhesive on early erosive enamel wear. Methods: Orthodontic reduction premolars collected from Central Laboratory of Nanjing Stomatological Hospital, Medical School of Nanjing University were used to prepare 70 specimens. Forty samples were divided into eight groups (n=5) and treated with different conditions (pH=1.6, 2.4, 3.2 or 4.0 hydrochloric acid solution, etching time was 30 or 60 s), and the conditions for obtaining early erosive enamel samples were selected. Based on this procedure, thirty early erosive enamel samples were made and divided into three groups: control group, resin infiltration group, and adhesive group. And the treatment of 30 days acid abrasion cycle was carried out. Confocal microscopy was used to measure the thickness changes of enamel or material before and after cycle. Results: Early erosive enamel samples was obtained when pH was 4.0 and etching time was 60 s. After 30 days cycle, the wear of enamel was (29.71±6.72) μm in control group, (5.60±2.24) μm in resin infiltration group and (2.89±1.03) μm in adhesive group. In infiltration group and adhesive group, lower enamel was not affected by the cycle, and the material loss ratios of the infiltration resin group and adhesive group were 0.41±0.14 and 0.29±0.13, respectively. The ratio of material loss was not significantly different (P>0.05). But infiltration group lost (12.95±2.22) μm of enamel during the application of the material. Conclusions: Resin infiltration and adhesive have the same short-term protective effect against early erosive enamel wear. Adhesive has less damage to enamel and better effect.

[Effect of emergency thoracic endovascular aortic repair in patients with acute traumatic thoracic aortic injury]

Objective: To investigate the effect of emergency thoracic endovascular aortic repair (TEVAR) in patients with acute traumatic thoracic aortic injury. Method: From January 2014 to December 2016, a total of 35 patients with acute traumatic thoracic aortic injuries were treated with emergency TEVAR in our hospital, their clinical data were analyzed retrospectively in this study. Results: The patients were 42 (34, 55) years old,and there were 31 males.All cases were diagnosed by emergency aorta computed tomography angiography (CTA),and 5 cases were diagnosed as aortic transaction, 13 cases were diagnosed as aortic pseudoaneurysm, 7 cases were diagnosed as aortic dissection, and 10 cases were diagnosed as aortic intramural hematoma combined hemothorax.The concomitant injuries included cerebral contusion (3 cases, 8.6%), pulmonary contusion with rib fracture (31 cases, 88.5%), long bone fracture (7 cases, 22.5%), contusion of viscera or internal organs (3 cases, 8.6%).Emergency TEVAR were performed with vascular suture system preset under local anesthesia after diagnosis,and combined injury was treated in related departments.CTA was repeated after 1, 3 and 6 months and yearly thereafter. One patient died before transferring to catheter room,and 34 (97.1%) patients underwent TEVAR procedure successfully.Time from door to operating room was (88.6±26.6) minutes,and the procedure time was (52.0±9.4) minutes. A total of 69 Perclose Proglide vascular suture system were used,and 2 cases underwent surgical suture because of hematoma and pseudoaneurysm formation in femoral arteries.The involved length of thoracic aorta was (44.5±7.4)mm. A total of 46 stent-grafts were implanted, the length of stent-graft was (164.3±15.2)mm,and the proximal oversize rate was (22.3±8.6)%. The follow-up time was 24 (12,24) months, and there were no procedure related complication such as endoleak and paraplegia. Complete aortic remodeling was observed in 14 cases. Fully thrombolization at stent segments were observed in 7 cases. Fully thrombalization of pseudoaneurysms were observed in 13 cases. One patient complained mild left upper limb weakness due to left subclavian artery occlusion. Conclusion: Emergency TEVAR is safe and effective procedure for the treatment of patients with acute traumatic thoracic aortic injury.

Cycle oxidation behavior and anti-oxidation mechanism of hot-dipped aluminum coating on TiBw/Ti6Al4V composites with network microstructure

Controlled and compacted TiAl₃ coating was successfully fabricated on the network structured TiBw/Ti6Al4V composites by hot-dipping aluminum and subsequent interdiffusion treatment. The network structure of the composites was inherited to the TiAl₃ coating, which effectively reduces the thermal stress and avoids the cracks appeared in the coating. Moreover, TiB reinforcements could pin the TiAl₃ coating which can effectively improve the bonding strength between the coating and composite substrate. The cycle oxidation behavior of the network structured coating on 873 K, 973 K and 1073 K for 100 h were investigated. The results showed the coating can remarkably improve the high temperature oxidation resistance of the TiBw/Ti6Al4V composites. The network structure was also inherited to the Al₂O₃ oxide scale, which effectively decreases the tendency of cracking even spalling about the oxide scale. Certainly, no crack was observed in the coating after long-term oxidation due to the division effect of network structured coating and pinning effect of TiB reinforcements. Interfacial reaction between the coating and the composite substrate occurred and a bilayer structure of TiAl/TiAl₂ formed next to the substrate after oxidation at 973 K and 1073 K. The anti-oxidation mechanism of the network structured coating was also discussed.

[Feasibility and efficacy of transcatheter closure of anastomotic leakage after aortic surgery using Amplatzer Vascular Plug Ⅲ]

Objective: To investigate the feasibility and efficacy of transcatheter closure of anastomotic leakage after aortic surgery using Amplatzer Vascular Plug Ⅲ (AVP Ⅲ). Methods: A retrospective analysis was performed in 5 patients with anastomotic leakage after aortic surgery, who underwent transcatheter closure in our hospital from January to June 2017 using AVP Ⅲ. Surgeries were performed in 3 cases of Standford type A dissection, 1 case of ascending aortic aneurysm and 1 case of persistent truncus.There were 3 males,and age was (43.8±13.1) years old. Anastomotic leakages located at the ascending aorta in 4 patients, and the other one located between the aortic arch and the stent-graft.Three of them had aorta-right atrium fistula and patients suffered from progressive heart failure. False aneurysm between aorta and pulmonary artery was formed in 1 patient, and patent aortic false lumenwas found in the other patient. All the AVP Ⅲ were deployed based on a femoral arteriosus loop. Patients were followed up after transcatheter closure to observe the clinical results. Results: Six AVP Ⅲ were successfully implanted in the 5 patients. Trivial residual shunt was seen in 1 patient after closure. The patients were followed up 6 (1, 6) months. The cardiac function improved from NYHA class Ⅱ-Ⅳ to class Ⅰ-Ⅱ after the procedure in 3 congestive heart failure patients.The right atrium systolic pressure was significantly reduced after the procedure((8.7±1.8) mmHg (1 mmHg=0.133 kPa) vs. (24.3±2.3) mmHg, P=0.03). The diameter of the false aneurysm reduced in 1 patient after the procedure. Complete thrombosis formation of the thoracic false lumen was observed in 1 patient. Conclusion: Transcatheter closure of anastomotic leakage after aortic surgery using AVP Ⅲ is feasible and effective according to our primary experience.

Study on titanium-magnesium composites with bicontinuous structure fabricated by powder metallurgy and ultrasonic infiltration

Titanium-magnesium (Ti-Mg) composites with bicontinuous structure have been successfully fabricated by powder metallurgy and ultrasonic infiltration for biomaterial potential. In the composites, Ti phase is distributed continuously by sintering necks, while Mg phase is also continuous, distributing at the interconnected pores surrounding the Ti phase. The results showed that the fabricated Ti-Mg composites exhibited low modulus and high strength, which are very suitable for load bearing biomedical materials. The composites with 100 µm and 230 µm particle sizes exhibited Young's modulus of 37.6 GPa and 23.4 GPa, 500.7 MPa and 340 MPa of compressive strength and 631.5 MPa and 375.2 MPa of bending strength, respectively. Moreover, both of the modulus and strength of the composites increase with decreasing of Ti particle sizes. In vitro study has been done for the preliminary evaluation of the Ti-Mg composites.

[Application and analysis of abdominal aortic branch malperfusion pattern in thoracic endovascular aortic repair for Stanford B aortic dissection]

OBJECTIVE

To evaluate the efficiency of thoracic endovascular aortic repair (TEVAR) in dealing with abdominal aortic branch malperfusion based on the analysis of aortic computed tomography angiography (CTA) images in pre- and post-TEVAR.

METHODS

Retrospective analysis from September 2015 to March 2016 in single institution to 32 patients, diagnosed as Stanford B aortic dissection with abdominal aortic branch malperfusion, CTA images in pre- and post-TEVAR were collected. Based on the aortic branch malperfusion pattern redefined by Nagamine, we identified and characterized branch malperfusion pattern for four abdominal aortic branches (celiac trunk, superior mesenteric artery, bilateral renal artery) in statistical analysis.

RESULTS

In the four abdominal aortic branches (total 128 branches), 86 branches (67.2%) expressed with Class I patterns, in which subtype I-b presented with 0.8%, subtype I-c with 5.5%; 14 branches (10.9%) expressed with Class II patterns, in which subtype II-b-1 with 3.9%, subtype II-b-2 with 3.1%; 16 branches (12.5%) expressed with Class III patterns, all with subtype III-a, no subtype III-b and III-c presented. The remaining 12 branches were normal. The 100% successful rate of TEVAR obtained in 32 patients performed. The mean following-up was 4 months. Aortic CTA showed that among the 14 "high-risk" abdominal aortic branch malperfusion, 13 (92.9%) with obvious branch malperfusion in post-TEVAR were observed to improve, and the remaining one branch malperfusion (7.1%) was observed to change from subtype I-b to I-c.

CONCLUSION

Few ratios in abdominal aortic branches suffered with obvious malperfusion complicated by Stanford B aortic dissection. For branches with "high-risk" malperfusion pattern, optimal changes were observed in abdominal aortic branch without revascularization in post-TEVAR, as well other branches with non-"high-risk" pattern perfusion were mostly stable in post-TEVAR. It could be of profound benefit to extend branch malperfusion patterns redefined by Nagamine in clinical practice to assess aortic dissection and in further guide for revascularization or not.

[Molecular epidemiology of Japanese encephalitis viruses isolated in Yunnan province, 1977-2010]

Objective: To understand the genetic and molecular epidemiologic characteristics of 63 strains of Japanese encephalitis virus (JEV) isolated in Yunnan province, China during 1977-2010. Methods: Suckling mice were inoculated with viruses continuously and the viral nucleic acid were extracted from the brain-grinding supernatants of the infected and moribund mice, then the gene fragments of E region were amplified by RT-PCR. Bioinformatics (Clustal X, DNAstar, Mega 5.0 and other software) was used to analyze the nucleotide and deduced amino acid sequences and phylogenetic trees. Results: Yunnan strains of JEV could cause illness and deaths in suckling mice. The results of virus nucleic acid detection and sequencing indicated that nucleotide sequences of E gene of the 63 virus strains were obtained. Phylogenetic tree and homology analyses based on E genomes showed that 47 strains of the experimental virus belonged to genotype 1 (G-1) and 16 strains belonged to genotype 3 (G-3). The 47 isolates of G-1 were divided into 2 clades, of them, the earliest isolates of G-1 (M28, 1977 and BN82215, 1982) in Yunnan of China and the early isolates of G-1 (U70416, 1982; DQ084229, the year is unknown) in Thailand were in one clade, and the isolates of G-1 from 2007-2010 in Yunnan could be divided into 2 subgroups. The 16 isolates of G-3 from Yunnan were divided into 3 clades, among them, the isolates from 1970-1990s in Yunnan were in two clades, and the isolates from 2004 in Yunnan were in one clade. In addition, their main amino acid sites of antigenicity, pathogenic, virulence of both G-1 and G-3 had no significant change. Conclusion: JEV G-1 and G-3 co-circulated in Yunnan, and G-1 was predominant. The JEV strains isolated in different years and areas in Yunnan had different molecular epidemiologic characteristics and genetic diversity. The results of this study suggested that JEV G-1 might originate from Yunnan of China and adjacent Southeast Asia region.

Significantly enhanced creep resistance of low volume fraction in-situ TiBw/Ti6Al4V composites by architectured network reinforcements

We present a new class of TiBw/Ti6Al4V composites with a network reinforcement architecture that exhibits a significant creep resistance compared to monolithic Ti6Al4V alloys. Creep tests performed at temperatures between 773 K and 923 K and stress range of 100 MPa-300 MPa indicate both a significant improvement of the composites creep resistance due to the network architecture made by the TiB whiskers (TiBw), and a decrease of the steady-state creep rates by augmenting the local volume fractions of TiBw in the network region. The deformation behavior is driven by a diffusion-controlled dislocation climb process. Moreover, the activation energies of these composites are significantly higher than that of Ti6Al4V alloys, indicating a higher creep resistance. The increase of the activation energy can be attributed to the TiBw architecture that severely impedes the movements of dislocation and grain boundary sliding and provides a tailoring of the stress transfer. These micromechanical mechanisms lead to a remarkable improvement of the creep resistance of these networked TiBw/Ti6Al4V composites featuring the special networked architecture.

Activating JAK2 mutants reveal cytokine receptor coupling differences that impact outcomes in myeloproliferative neoplasm

Janus tyrosine kinase 2 (JAK2) mediates downstream signaling of cytokine receptors in all hematological lineages, yet constitutively active JAK2 mutants are able to drive selective expansion of particular lineage(s) in myeloproliferative neoplasm (MPN). The molecular basis of lineage specificity is unclear. Here, we show that three activating JAK2 mutants with similar kinase activities in vitro elicit distinctive MPN phenotypes in mice by differentially expanding erythroid vs granulocytic precursors. Molecularly, this reflects the differential binding of JAK2 mutants to cytokine receptors EpoR and GCSFR in the erythroid vs granulocytic lineage and the creation of unique receptor/JAK2 complexes that generate qualitatively distinct downstream signals. Our results demonstrate that activating JAK2 mutants can differentially couple to selective cytokine receptors and change the signaling repertoire, revealing the molecular basis for phenotypic differences elicited by JAK2 (V617F) or mutations in exon 12. On the basis of these findings, receptor-JAK2 interactions could represent new targets of lineage-specific therapeutic approaches against MPN, which may be applicable to other cancers with aberrant JAK-STAT signaling.

Controllable two-scale network architecture and enhanced mechanical properties of (Ti5Si3+TiBw)/Ti6Al4V composites

Novel Ti6Al4V alloy matrix composites with a controllable two-scale network architecture were successfully fabricated by reaction hot pressing (RHP). TiB whiskers (TiBw) were in-situ synthesized around the Ti6Al4V matrix particles, and formed the first-scale network structure (FSNS). Ti₅Si₃ needles (Ti₅Si₃) precipitated in the β phase around the equiaxed α phase, and formed the secondary-scale network structure (SSNS). This resulted in increased deformation compatibility accompanied with enhanced mechanical properties. Apart from the reinforcement distribution and the volume fraction, the ratio between Ti₅Si₃ and TiBw fraction were controlled. The prepared (Ti₅Si₃ + TiBw)/Ti6Al4V composites showed higher tensile strength and ductility than the composites with a one-scale microstructure, and superior wear resistance over the Ti6Al4V alloy under dry sliding wear conditions at room temperature.

Highly efficient beamline and spectrometer for inelastic soft X-ray scattering at high resolution

The design, construction and commissioning of a beamline and spectrometer for inelastic soft X-ray scattering at high resolution in a highly efficient system are presented. Based on the energy-compensation principle of grating dispersion, the design of the monochromator-spectrometer system greatly enhances the efficiency of measurement of inelastic soft X-rays scattering. Comprising two bendable gratings, the set-up effectively diminishes the defocus and coma aberrations. At commissioning, this system showed results of spin-flip, d-d and charge-transfer excitations of NiO. These results are consistent with published results but exhibit improved spectral resolution and increased efficiency of measurement. The best energy resolution of the set-up in terms of full width at half-maximum is 108 meV at an incident photon energy tuned about the Ni L3-edge.

Vasorelaxation of Rat Thoracic Aorta Caused by Two Ca2+-Channel Blockers, HA-22 and HA-23

The pharmacological effects of HA-22 (2-(4′methoxyphenylmethyl)-3,4-dimethylpyrano[2,3-c]pyrazol-6(2H)-one) and HA-23 (2-(2′-thienylmethyl)-3,4-dimethylpyrano[2,3-c]pyrazol-6(2H)-one) on rat isolated thoracic aorta have been examined. In high potassium medium (60 Mm), Ca2+ (0·03–3 Mm)-induced vasoconstriction was inhibited by HA-22 and HA-23 (10–100 μg mL−1). Cromakalim-relaxed aortic rings precontracted with 15 Mm but not 60 Mm K+. However, HA-22, HA-23 and verapamil produced a greater relaxation in 60 Mm than in 15 Mm K+-induced contraction. The tonic contractions elicited by KCl (60 Mm) and Bay K 8644 (10−7  m) were also relaxed by the addition of HA-22 and HA-23. The phenylephrine concentration-response curves displayed antagonism by HA-22 and HA-23 (10–100 μg mL−1) in a non-competitive manner. The caffeine (10 Mm)-induced contraction and cAMP or cGMP levels were not affected by HA-22 or HA-23. It is concluded that HA-22 and HA-23 relaxed the rat aorta by suppressing the Ca2+ influx through both voltage-dependent and receptor-operated Ca2+ channels.

Biodegradation of nicotine from tobacco waste extract by Ochrobactrum intermedium DN2

Ochrobactrum intermedium DN2 was used to degrade nicotine in tobacco waste extracts. The optimal temperature and pH of nicotine degradation by strain DN2 was 30-37 degrees C and 7.0, respectively. Under these optimal conditions, the average degradation rate of nicotine in a 30L fed-batch culture was 140.5 mg 1(-1) h(-1). The results of this study indicate that strain DN2 may be useful for reducing the nicotine content of reconstituted tobacco.

Optimization of a medium for enhancing nicotine biodegradation by Ochrobactrum intermedium DN2

AIMS

To optimize a medium for nicotine degradation by Ochrobactrum intermedium DN2 in presence of yeast extract, glucose and Tween 80 using response surface methodology (RSM).

METHODS AND RESULTS

In this study, the effects of yeast extract, glucose and Tween 80 on nicotine degradation were investigated in flasks using a novel nicotine-degrading bacterium, O. intermedium DN2. A full factorial central composite design was applied in the design of experiments and in the analysis of the experimental data. The results showed that the most significant variable influencing nicotine degradation was yeast extract, followed by glucose, and then Tween 80. Moreover these three factors interacted with each other and combined to produce positive effects on nicotine degradation. The experimental data also allowed the development of an empirical model (P < 0.0001) describing the inter-relationship between independent and dependent variables. By solving the regression equation, the optimal values of the variables were determined as: yeast extracts 0.094%, glucose 0.101% and Tween 80 0.080%. Using the medium obtained, about 1,220 mg l(-1) of nicotine was degraded (95.55%) within 10 h at the specific biodegradation of 116.59 mg l(-1) h(-1) in 30-l bioreactor containing 25-l tobacco extract.

CONCLUSIONS

An optimal medium of nicotine degradation by the strain DN2 was obtained.

SIGNIFICANCE AND IMPACT OF THE STUDY

RSM proved to be reliable in developing the model, optimizing factors and analysing interaction effects. The results provide better understanding on the interactions between yeast extract, glucose and Tween 80 for nicotine biodegradation.

The N-terminal domain of Janus kinase 2 is required for Golgi processing and cell surface expression of erythropoietin receptor

We show that Janus kinase 2 (JAK2), and more specifically just its intact N-terminal domain, binds to the erythropoietin receptor (EpoR) in the endoplasmic reticulum and promotes its cell surface expression. This interaction is specific as JAK1 has no effect. Residues 32 to 58 of the JAK2 JH7 domain are required for EpoR surface expression. Alanine scanning mutagenesis of the EpoR membrane proximal region reveals two modes of EpoR-JAK2 interaction. A continuous block of EpoR residues is required for functional, ligand-independent binding to JAK2 and cell surface receptor expression, whereas four specific residues are essential in switching on prebound JAK2 after ligand binding. Thus, in addition to its kinase activity required for cytokine receptor signaling, JAK is also an essential subunit required for surface expression of cytokine receptors.

[The clinical assessment of zygomatic complex fracture treated via infraorbital incision and rigid fixation]

OBJECTIVE

To investigate the clinical effect of zygomatic complex (ZC) fracture via infraorbital incision and rigid fixation.

METHODS

To clinically classify 65 cases with ZC fractures,which treated with open reduction and minor titanium-plate internal fixation.

RESULTS

(1) The operated area can be widely exposed via infraorbital incision. (2) ZC fractures can be reducted timely and correctly. (3) The fragments can be fixed rigidly with minor Ti-plaets. No injury to the facial nerve.The satisfactory rate of recovery was 95.4% (63/65).

CONCLUSION

Operation through infraorbital incision is suitable to ZC fractures.

Synthesis of 1-benzyl-3-(5'-hydroxymethyl-2'-furyl)indazole analogues as novel antiplatelet agents

1-Benzyl-3-(5'-hydroxymethyl-2'-furyl)indazole (28, YC-1) was selected as the lead compound for systemic structural modification. After screening for antiplatelet activity, SARs of YC-1 analogues were established. Among these potent active derivatives, compounds 29, 30, 31, 44, and 45 functioned as potent activators of sGC and inhibitors of PDE5 with potency comparable to that of YC-1. In addition, compound 58 was found to be a selective and potent inhibitor of protease-activated receptor type 4 (PAR4)-dependent platelet activation.

Inhibition of extracellular Ca(2+) entry by YC-1, an activator of soluble guanylyl cyclase, through a cyclic GMP-independent pathway in rat neutrophils

The effects of a soluble guanylyl cyclase (sGC) activator, 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), on formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated [Ca(2+)](i) elevation in rat neutrophils were examined. YC-1 produced a concentration-dependent inhibition of [Ca(2+)](i) elevation. Pretreatment of neutrophils with YC-1 did not enhance its inhibitory effect. YC-1 also inhibited the [Ca(2+)](i) changes caused by ionomycin. In a biphasic model, measuring the [Ca(2+)](i) stimulation by fMLP in a Ca(2+)-free medium followed by reintroduction of Ca(2+), YC-1 mainly affected Ca(2+) influx. YC-1 also inhibited active and passive Mn(2+) influx, and this inhibitory effect was not attenuated by the sGC inhibitor 6-anilino-5,8-quinolinequinone (LY83583). Sodium nitroprusside did not affect the fMLP-stimulated [Ca(2+)](i) changes. Pretreatment of neutrophils with the cyclic GMP-dependent protein kinase inhibitor 8-(4-chlorophenylthio) guanosine-3',5'-monophosphorothioate, Rp-isomer (Rp-8-pCPT-cGMPS), LY83583, the protein phosphatase 2B inhibitor cyclosporin A, or the protein kinase inhibitor staurosporine did not attenuate the inhibition of [Ca(2+)](i) by YC-1. YC-1 inhibited the fMLP-stimulated protein tyrosine phosphorylation. These results indicate that cyclic GMP does not play an important role in the regulation of [Ca(2+)](i) in rat neutrophils. Inhibition of fMLP-stimulated [Ca(2+)](i) changes by YC-1 is mainly via the blockade of Ca(2+) entry through the inhibition of tyrosine kinase activity, but not the stimulation of protein kinase C and protein phosphatase 2B.

Functional cloning of the proto-oncogene brain factor-1 (BF-1) as a Smad-binding antagonist of transforming growth factor-beta signaling

Using the plasminogen activator inhibitor (PAI) promoter to drive the expression of a reporter gene (mouse CD2), we devised a system to clone negative regulators of the transforming growth factor-beta (TGF-beta) signaling pathway. We infected a TGF-beta-responsive cell line (MvLu1) with a retroviral cDNA library, selecting by fluorescence-activated cell sorter single cells displaying low PAI promoter activity in response to TGF-beta. Using this strategy we cloned the proto-oncogene brain factor-1 (BF-1). BF-1 represses the PAI promoter in part by associating with both unphosphorylated Smad3 (in the cytoplasm) and phosphorylated Smad3 (in the nucleus), thus preventing its binding to DNA. BF-1 also associates with Smad1, -2, and -4; the Smad MH2 domain binds to BF-1, and the C-terminal segment of BF-1 is uniquely and solely required for binding to Smads. Further, BF-1 represses another TGF-beta-induced promoter (p15), it up-regulates a TGF-beta-repressed promoter (Cyclin A), and it reverses the growth arrest caused by TGF-beta. Our results suggest that BF-1 is a general inhibitor of TGF-beta signaling and as such may play a key role during brain development.

[Construction of a genetic map and location of quantitative trait loci for yield component traits in maize by SSR markers]

Using 230 F2:3 lines derived from the hybrid of ND3138, a SSR genetic linkage map of maize (Zea mays L.) was constructed on which 80 markers distribute among 10 linkage groups and spanning maize genome about 2033.4 cM with average distance between markers being 25.42 cM. The 230 F2:3 lines were grown in a random design of one-row plot with three replication, and evaluated for ear length, bared tip, ear diameter, row number, kernel number row-1, one thousand grains weight, ear weight and grain weight plant-1. With interval mapping procedure, 30 QTLs were revealed for all traits, which distributed on 9 of 10 chromosomes of maize except chromosome 6 and accounted for from 9.5% to 55.3% of the total phenotypic variation. Genetic effects and gene action were also determined.

[Structure elucidation of glycan of a glycoconjugate SPPA-1 isolated from Spirulina platensis]

AIM

To elucidate the structure of the glycan of SPPA-1, a glycoconjugate isolated from Spirulina platensis.

METHODS

Methylation analysis, GC/MS, and 1D, 2DNMR techniques were used to determine the structures of the glycoconjugate (SPPA-1).

RESULTS

SPPA-1 was only composed of alpha-D-glucose and shown to be a (1-->4) linked alpha-D-glucan to which a few glucosyl side chains are attached at O-6 of the glucosyl residues of the main chain.

CONCLUSION

The glycan of SPPA-1 is a new glucan.

[Delayed cardioprotection of captopril in patients undergoing open heart surgery]

OBJECTIVE

To investigate whether there is delayed cardioprotection of captopril pretreatment in open heart surgery.

METHODS

Twenty patients with ventricular septal defect (VSD) undergone open heart surgery were randomly divided into captopril group (CAP group) and control group. In the CAP group, patients were pretreated with captopril (1 mg.kg-1, oral) at 48 hours before operation, No special treatment was given at the same time in the control group. Release of creatine phosphokinase-MB (CK-MB) and myocardial adenosine triphosphate (ATP) content was studied. Heart shock protein 70 (HSP70) in myocardum was examined using Western blotting analysis.

RESULTS

No statistically significant difference was found in release of CK-MB between control group and CAP group. ATP depletion was (1.40 +/- 0.56) mumol.g-1, (2.06 +/- 0.72) mumol.g-1 in CAP group and control group respectively (P < 0.05). Western blotting analysis showed that both group had HSP70 expression. In CAP group, HSP70 expression was higher than that in control group.

CONCLUSION

The results suggest that captopril pretreatment 48 hours before operation could reduce ATP depletion in pediatric patients of VSD during open-heart surgery, and HSP70 might be involved in the delayed cardioprotection induced by captopril.

Synthesis of 4-alkoxy-2-phenylquinoline derivatives as potent antiplatelet agents

In our continuing search for novel antiplatelet agents, 4-alkoxy derivatives of 2-phenylquinoline as well as related compounds were prepared. Through biological screening, a preliminary structure antiplatelet activity relationship was established. Compounds 5-ethyl-4-methoxy-2-phenylquinoline (8), 4-ethoxy-5-ethyl-2-phenylquinoline (9), 4-ethoxycarbonylmethoxy-5-ethyl-2-phenylquinoline (10), 4-ethoxycarbonylbutoxy-5-ethyl-2-phenylquinoline (12) and 5-ethyl-4-(N-ethylcarboxido)methoxy-2-phenylquinoline (17) all demonstrated potent antiplatelet activity. Among them, compound 8 was the most potent with an IC50 value of 0.08 microM and was about 3-fold more active than indomethacin. The mechanism of antiplatelet action of 8 is possibly through its inhibition on cyclooxygenase or thromboxane synthetase.

The erythropoietin receptor cytosolic juxtamembrane domain contains an essential, precisely oriented, hydrophobic motif

We report that the erythropoietin receptor cytosolic juxtamembrane region is conformationally rigid and contains a hydrophobic motif, composed of residues L253, I257, and W258, that is crucial for Janus kinase 2 (JAK2) activation and receptor signaling. Alanine insertion mutagenesis shows that the orientation of this motif and not its distance from the membrane bilayer is critical. Intragenic complementation studies suggest that L253 is contained within an alpha helix functionally continuous to the transmembrane alpha helix. The alpha-helical orientation of L53 is required not for JAK2 activation but for activated JAK2 to induce phosphorylation of the erythropoietin receptor. This motif is highly conserved among cytokine receptors and couples ligand-induced conformational changes in the receptor to intracellular activation of JAK2.

[Studies on the glycoconjugates and glycans from Lycium barbarum L in inhibiting low density lipoprotein (LDL) peroxidation]

AIM

To determine the effects of glycoconjugates and their glycans from Lycium barbarum L. on inhibiting low density lipoprotein (LDL) peroxidation.

METHODS

Using Cu(2+)-induced oxidation as a model, the oxidative production of thiobarbituric acid-reactive substances (TBARS) and the LDL electrophoresis migration on agarose gel were measured.

RESULTS

The effects of glycoconjugates and their glycans from Lycium barbarum L. on inhibiting LDL peroxidation were different, among them, glycoconjugate LbGp5 showed the best effect on inhibiting LDL peroxidation.

CONCLUSION

The glycoconjugates can inhibit LDL peroxidatin while their glycans showed no effects on inhibiting LDL peroxidation.

[Physico-chemical properties and biological activities of a glycoconjugate SPPA-1 from Spirulina platensis]

AIM

To isolate polysaccharide from Spirulina platensis and determine its sugar position, molecular weight and biological activities.

METHODS

Sephadex G-75 and CM-Sephadex C-50 were used. The sugar position was analyzed by gas chromatography, the molecular weight was determined by GPC. The homogeneity of this glycoconjugate was determined by HPLC and CE. IR and NMR spectra were used to determine the glycosidic linkage.

RESULTS

SPPA-1 was a homogeneous glycoconjugate, its carbohydrate chain was composed of alpha-glucopyranan, carbohydrate content is 91.70%, Nitrogen content was 0.96%, the molecular weight was 69.00 x 10(4), SPPA-1 could eliminate O2-. radicals.

CONCLUSION

SPPA-1 was an antioxidative glycoconjugate from Spirulina platensis.

6-Alkylamino- and 2,3-dihydro-3'-methoxy-2-phenyl-4-quinazolinones and related compounds: their synthesis, cytotoxicity, and inhibition of tubulin polymerization

As part of our continuing search for potential anticancer candidates among 2-phenyl-4-quinolones and 2-phenyl-4-quinazolinones, two series of 6,7,2',3',4',5'-substituted 2-phenyl-4-quinazolinones and 6,2',3',4',5'-substituted 2,3-dihydro-2-phenyl-4-quinazolinones were synthesized and evaluated for cytotoxicity and as inhibitors of tubulin polymerization. In general, a good correlation was found between the two activities. Five of the 6-substituted heterocyclic 2-phenyl-4-quinozolinones (37-51) showed significant cytotoxicity against a panel of human tumor cell lines with EC(50) values in the low micromolar to nanomolar concentration ranges. Compound 38 was the most potent of these compounds, as well as the most potent inhibitor of tubulin polymerization in this series. The activity of 38 was in the same range as those of the antimitotic natural products, colchicine, podophyllotoxin, and combretastatin A-4. Substituted 2-phenyl-4-quinazolinones and 2, 3-dihydro-2-phenyl-4-quinazolinones also displayed highly selective cytotoxicity against the ovarian cancer 1A9 and P-gp resistant KB-VIN cell lines.

6-Alkylamino- and 2,3-dihydro-3'-methoxy-2-phenyl-4-quinazolinones and related compounds: their synthesis, cytotoxicity, and inhibition of tubulin polymerization

As part of our continuing search for potential anticancer candidates among 2-phenyl-4-quinolones and 2-phenyl-4-quinazolinones, two series of 6,7,2',3',4',5'-substituted 2-phenyl-4-quinazolinones and 6,2',3',4',5'-substituted 2,3-dihydro-2-phenyl-4-quinazolinones were synthesized and evaluated for cytotoxicity and as inhibitors of tubulin polymerization. In general, a good correlation was found between the two activities. Five of the 6-substituted heterocyclic 2-phenyl-4-quinozolinones (37-51) showed significant cytotoxicity against a panel of human tumor cell lines with EC(50) values in the low micromolar to nanomolar concentration ranges. Compound 38 was the most potent of these compounds, as well as the most potent inhibitor of tubulin polymerization in this series. The activity of 38 was in the same range as those of the antimitotic natural products, colchicine, podophyllotoxin, and combretastatin A-4. Substituted 2-phenyl-4-quinazolinones and 2, 3-dihydro-2-phenyl-4-quinazolinones also displayed highly selective cytotoxicity against the ovarian cancer 1A9 and P-gp resistant KB-VIN cell lines.

Synthesis and anti-platelet, anti-inflammatory and anti-allergic activities of methoxyisoflavanquinone and related compounds

In a continuation of our search for novel anti-platelet agents, isoflavone quinone and isoflavanquinone were selected as lead compounds and the synthesis of their methoxy derivatives was carried out. Among them, the 4'- and 7-methoxy derivatives were successfully prepared, whereas the attempt to obtain 3'-methoxy derivatives resulted in their isomers, 3'-methoxyflavone quinone and 3'-methoxyflavanquinone, instead. After screening for their anti-platelet, anti-inflammatory and anti-allergic activities, a preliminary structure-activity relationship was established. Compounds 6c, 7a-c, 8c and 9a-c were found to exhibit significant activities. In particular, compound 7c demonstrated very potent anti-platelet, anti-inflammatory and anti-allergic activities and was then recommended for further pharmacological investigation.

NH2-Terminal targeting motifs direct dual specificity A-kinase-anchoring protein 1 (D-AKAP1) to either mitochondria or endoplasmic reticulum

Subcellular localization directed by specific targeting motifs is an emerging theme for regulating signal transduction pathways. For cAMP-dependent protein kinase (PKA), this is achieved primarily by its association with A-kinase-anchoring proteins (AKAPs). Dual specificity AKAP1, (D-AKAP1) binds to both type I and type II regulatory subunits and has two NH2-terminal (N0 and N1) and two COOH-terminal (C1 and C2) splice variants (. J. Biol. Chem. 272:8057). Here we report that the splice variants of D-AKAP1 are expressed in a tissue-specific manner with the NH2-terminal motifs serving as switches to localize D-AKAP1 at different sites. Northern blots showed that the N1 splice is expressed primarily in liver, while the C1 splice is predominant in testis. The C2 splice shows a general expression pattern. Microinjecting expression constructs of D-AKAP1(N0) epitope-tagged at either the NH2 or the COOH terminus showed their localization to the mitochondria based on immunocytochemistry. Deletion of N0(1-30) abolished mitochondrial targeting while N0(1-30)-GFP localized to mitochondria. Residues 1-30 of N0 are therefore necessary and sufficient for mitochondria targeting. Addition of the 33 residues of N1 targets D-AKAP1 to the ER and residues 1-63 fused to GFP are necessary and sufficient for ER targeting. Residues 14-33 of N1 are especially important for targeting to ER; however, residues 1-33 alone fused to GFP gave a diffuse distribution. N1(14-33) thus serves two functions: (a) it suppresses the mitochondrial-targeting motif located within residues 1-30 of N0 and (b) it exposes an ER-targeting motif that is at least partially contained within the N0(1-30) motif. This represents the first example of a differentially targeted AKAP and adds an additional level of complexity to the PKA signaling network.

Phosphorylation and inactivation of BAD by mitochondria-anchored protein kinase A

Signaling pathways between cell surface receptors and the BCL-2 family of proteins regulate cell death. Survival factors induce the phosphorylation and inactivation of BAD, a proapoptotic member. Purification of BAD kinase(s) identified membrane-based cAMP-dependent protein kinase (PKA) as a BAD Ser-112 (S112) site-specific kinase. PKA-specific inhibitors blocked the IL-3-induced phosphorylation on S112 of endogenous BAD as well as mitochondria-based BAD S112 kinase activity. A blocking peptide that disrupts type II PKA holoenzyme association with A-kinase-anchoring proteins (AKAPs) also inhibited BAD phosphorylation and eliminated the BAD S112 kinase activity at mitochondria. Thus, the anchoring of PKA to mitochondria represents a focused subcellular kinase/substrate interaction that inactivates BAD at its target organelle in response to a survival factor.

Structure elucidation of glycan of glycoconjugate LbGp3 isolated from the fruit of Lycium barbarum L

The structure of the repeat unit of the glycan of glycoconjugate LbGp3 with pronounced immunoactivity, isolated from the fruit of Lycium barbarum L. was elucidated based on methylation analysis, partial acid hydrolysis and 1H, 13C NMR spectroscopy of the original glycan and products of its partial hydrolysis.

Dimerization/docking domain of the type Ialpha regulatory subunit of cAMP-dependent protein kinase. Requirements for dimerization and docking are distinct but overlapping

Based on increasing evidence that the type I R subunits as well as the type II R subunits localize to specific subcellular sites, we have carried out an extensive characterization of the stable dimerization domain at the N terminus of RIalpha. Deletion mutants as well as alanine scanning mutagenesis were used to delineate critical regions as well as particular amino acids that are required for homodimerization. A set of nested deletion mutants defined a minimum core required for dimerization. Two single site mutations on the C37H template, RIalpha(F47A) and RIalpha(F52A), were sufficient to abolish dimerization. In addition to serving as a dimerization motif, this domain also serves as a docking surface for binding to dual specificity anchoring proteins (D-AKAPs) (Huang, L. J., Durick, K., Weiner, J. A., Chun, J., and Taylor, S. S. (1997) J. Biol. Chem. 272, 8057-8064; Huang, L. J., Durick, K., Weiner, J. A., Chun, J., and Taylor, S. S. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 11184-11189). A similar strategy was used to map the sequence requirements for anchoring of RIalpha to D-AKAP1. Although dimerization appears to be essential for anchoring to D-AKAP1, anchoring can also be abolished by the following single site mutations: C37H, V20A, and I25A. These sites define "hot spots" for the anchoring surface since each of these dimeric proteins are deficient in binding to D-AKAP1. In contrast to earlier predictions, the alignment of the dimerization/docking domains of RIalpha and RII show striking similarities yet subtle differences not only in their secondary structure (Newlon, M. G., Roy, M., Hausken, Z. E., Scott, J. D., and Jennings. P. A. (1997) J. Biol. Chem. 272, 23637-23644) but also in the distribution of residues important for both docking and dimerization functions.

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of substituted 3-chloro-5,8-dimethoxy-1,4-naphthoquinone and related compounds

2-Amino (6), 2-alkylamino (7-8), 2-methoxy (9), 2-acetamido (10), and 5,8-diacetoxy (11) derivatives of the lead compound 2,3-dichloro-5,8-dimethoxy-1,4-naphthoquinone (4) were synthesized, together with 6,7-dichloro-5,8dimethoxy-1,4-naphthoquinone (5), a positional isomer of 4. Antiplatelet, antiinflammatory, and antiallergic activities were evaluated, and most compounds were quite potent in all assays. Compounds 5 and 9-11 were especially active; however, 5 was ineffective against neutrophil superoxide formation, and 10 was ineffective against mast cell degranulation.

Involvement of cyclic AMP generation in the inhibition of respiratory burst by 2-phenyl-4-quinolone (YT-1) in rat neutrophils

The inhibitory effect of 2-phenyl-4-quinolone (YT-1) on respiratory burst in rat neutrophils was investigated, and the underlying mechanism of action was assessed. YT-1 caused a concentration-dependent inhibition of the rate of O2.- release from rat neutrophils in response to formylmethionyl-leucyl-phenylalanine (fMLP), but not to phorbol 12-myristate 13-acetate (PMA), with an IC50 value of 60.7+/-8.2 microM. A comparable effect was also demonstrated in the inhibition of O2 consumption. Unlike superoxide dismutase, YT-1 had no effect on O2.- generation in the xanthine-xanthine oxidase system and during dihydroxyfumaric acid autoxidation. The fMLP-induced inositol trisphosphate (IP3) formation was unaffected by YT-1. In addition, YT-1 did not affect the initial spike of [Ca2+]i, but it accelerated the rate of [Ca2+]i decline in cells in response to fMLP. YT-1 was found to have little effect on the activity of neutrophil cytosolic protein kinase C (PKC). YT-1 increased the cellular cyclic AMP level, while having no effect on the cyclic GMP level. In addition, YT-1 increased neutrophil cytosolic protein kinase A (PKA) activity, but had no direct effect on the enzyme activity of pure porcine heart PKA. When neutrophils were treated with (8R,9S,11S)-(-)-9-hydroxy-9-hexoxycarbonyl-8-methyl-2,3,9,10-tetra hydro-8,11-epoxy- 1H,8H,11H-2,7b,11a-triazadibenzo[a,g]cycloocta[cde]trinde n-1-one, (KT 5720), a PKA inhibitor, the inhibition of O2.- generation by YT-1, as well as by prostaglandin E1 (PGE1) and dibutyryl cyclic AMP, was attenuated effectively. YT-1 did not activate the adenylate cyclase associated with neutrophil particulate fraction but inhibited the cytosolic phosphodiesterase (PDE) activity in a concentration-dependent manner. Neutrophils treated with YT-1 had a more pronounced increase in cellular cyclic AMP level by PGE1. Moreover, the ability of PGE1 to inhibit the respiratory burst in neutrophils was greatly enhanced by YT-1. These results suggest that the increase in cellular cyclic AMP levels by YT-1 through the inhibition of PDE (probably PDE4 isoenzyme) activity is involved in its inhibition of fMLP-induced respiratory burst in rat neutrophils.