[Association between maternal immune activation and neurodevelopmental disorders in children]

During pregnancy, as a special period, mother is vulnerable to adverse exposure, affecting the health of offspring. Maternal immune activation (MIA) due to maternal immune imbalance during pregnancy can affect the neurodevelopment of offspring. Evidence from epidemiological studies and animal studies supports an association between MIA and neurodevelopmental disorders (NDDs) in offspring. A variety of factors, such as genetic background, maternal nutritional status and maternal gut microbes, can influence the strength of the association. Studies have shown that MIA affects synapsis formation and pruning in offspring through a variety of pathways, and the placenta also plays a role in such association. This article summarizes the recent research of the association between MIA and neurodevelopmental disorders in children, and provides suggestion for the prevention of the incidence of NDDs.

[A pre-conception cohort study of fertility and its related factors among couples with the intention of conception]

Objective: To describe fertility and explore factors associated with it among pre-conception couples of childbearing age. Methods: Based on the pre-conceptional offspring trajectory study of the School of Public Health of Fudan University, couples of childbearing age who participated in the pre-conception physical examination in Shanghai Jiading District from 2016 to 2021 were recruited and followed up. Couples' time to pregnancy (TTP) was analyzed and Cox proportional hazards regression model was used to explore the factors associated with TTP. Kaplan-Meier was used to calculate each menstrual cycle's cumulative pregnancy rate. Results: A total of 1 095 preconception couples were included in the analysis, the M(Q₁,Q₃)of TTP was 4.33 (2.41, 9.78) menstrual cycles. Age of women (FR=0.90, 95%CI: 0.85-0.95, P<0.001), women who were overweight or obese before pregnancy (FR=0.36, 95%CI: 0.24-0.55, P<0.001), women who were exposed to second-hand smoking (FR=0.63, 95%CI: 0.44-0.92, P=0.016), women whose home or office had been renovated in the past 2 years and had a particular smell (FR=0.46, 95%CI: 0.26-0.81, P=0.008) were risk factors for impaired fertility. Regular menstrual cycles (FR=1.64, 95%CI: 1.16-2.31, P=0.005), females who often drank tea/coffee (FR=1.55, 95%CI: 1.11-2.17, P=0.011) and males who took folic acid before conception (FR=2.35, 95%CI: 1.38-4.23, P=0.002) were associated with better fertility. The cumulative pregnancy rate of 3, 6, and 12 menstrual cycles was 37.6%, 64.4%, and 78.4%, respectively. Conclusion: Older couples, overweight or obesity before pregnancy, irregular menstruation, exposure to secondhand smoke and decoration pollutants in females are associated with impaired fertility. Frequent tea/coffee drinking before pregnancy in females and taking folic acid before pregnancy in males are associated with shortened conception time.

[Effect analysis of treating intracranial wide-neck bifurcation aneurysms through Woven EndoBridge]

Objective: To explore the clinical effect of Woven EndoBridge (WEB) in the treatment of wide-neck bifurcation aneurysms. Methods: The clinical and imaging data of 11 patients with intracranial wide-neck bifurcation aneurysms treated by WEB alone at Department of Neurosurgery of the Northern Theater General Hospital from September 2017 to May 2018, were retrospectively analyzed. The patients were 7 males and 4 females, aged (54±11) years (ranged from 31 to 66 years). The aneurysms of 5 patients were located in the anterior communicating artery, 3 in the top of the basilar artery, and 3 in the bifurcation of the middle cerebral artery. The intraoperative and postoperative conditions of the patients were recorded, and the degree of aneurysm embolization was evaluated by WEB embolization aneurysm occlusion scale (WOS). Results: The intraoperative WEB release of all the 11 patients was good, with 3 cases of WOS grade A, 1 of grade B and 7 of grade C, with no intraoperative acute complications occurring. The imaging follow-up was not carried out in 1 patient due to economic reason, and the clinical follow-up was good until 3 years after the operation; 10 patients were followed up by imaging for 6 months to 3 years, and no postoperative complications occurred in the target treatment area. Among the 2 patients with WOS grade A and 1 patient with grade B during operation, according to the postoperative follow-up, all were WOS grade A; among the 7 patients with WOS grade C during operation, 4 were still of grade C and 3 were of grade D according to the follow-up. Among the 3 patients with WOS grade D, 1 patient received secondary embolization due to poor recurrence morphology, unstable hemodynamics and high possibility of rupture of aneurysm, stent assisted coil embolization was adopted, with good immediate effect; the other 2 cases had recurrent aneurysms, but the aneurysms had good morphology and stable hemodynamics, therefore, clinical follow-up was continued and no secondary surgery was performed. No complications occurred in all these 11 patients. Conclusions: The operation of treating unruptured intracranial wide-neck bifurcation aneurysms with WEB device alone is simple, and there is no need for anticoagulation and antiplatelet treatment before and after the operation, the clinical effect is being good. WEB device provides a new treatment option for intracranial wide-neck bifurcation aneurysms.

[Analysis of the effect of stent-assisted embolization for low-grade subarachnoid hemorrhage caused by V4 segment dissecting aneurysm of vertebral artery]

Objective: To investigate the efficacy and safety of different stents assisted embolization in the treatment of subarachnoid hemorrhage(SAH) caused by V4 dissecting aneurysm of vertebral artery. Methods: The clinical data of 39 patients with spontaneous SAH V4 dissecting aneurysm treated at the Department of Neurosurgery, the Northern Theater General Hospital from January 2016 to June 2019 were analyzed retrospectively.There were 21 males and 18 females, aged (48±17) years(range:35 to 68 years).There were 24 cases of HUNT-HESS grade Ⅰ and 15 cases of grade Ⅱ.Among them, 20 cases were treated with single stent-assisted embolization, 9 cases with multi-stent-assisted embolization, 9 cases with semi-dense mesh-assisted embolization, and 1 case with dense-mesh stent-assisted embolization.The perioperative and postoperative complications, postoperative recurrence were collected. Results: Intraoperative complications included 2 cases of aneurysm rupture and 2 cases of acute thrombosis.All aneurysms were densely packed according to the angiography performed immediately after operation.Postoperative complications included 3 cases of long-term responsible vascular ischemia(modified Rankin score<2). The patients were followed up for 15.1 months(range: 12 to 29 months). At the last follow-up, aneurysms recurrence occured in 10 cases, the recurrence rate was 25.6%(10/39). There were 6 cases of recurrence and 2 cases of complications in 20 cases with single stent-assisted embolization, 3 cases of recurrence and 4 cases of complications in 9 cases with multi-stent-assisted embolization, 1 case of recurrence and 1 case of complications in 9 cases with semi-dense mesh stent. Conclusion: Endovascular treatment is feasible for patients with vertebral artery dissecting aneurysm, and the appropriate surgical method should be selected according to the vascular structure and the location of the aneurysm.

[The preliminary clinical study on radical prostatectomy without preoperative prostate biopsy]

Objective: To investigate the feasibility and safety of minimally invasive radical prostatectomy for prostate cancer patients without preoperative prostate biopsy in the new era of the continuous development of comprehensive new imaging diagnostic mode and minimally invasive surgery technology. Methods: From August 2018 to October 2019, 17 patients with prostate cancer were enrolled in this study in the Cancer Hospital, Chinese Academy of Medical Sciences. All patients were highly suspected of prostate cancer by PSMA-PET/CT-based imaging diagnostic techniques and underwent 3D laparoscopic radical prostatectomy without prostate biopsy. The perioperative data, postoperative pathology, postoperative complications and follow-up results were recorded and analyzed. Results: The average age of 17 patients with prostate cancer was (65±7) years. The body mass index (BMI) average was (24.4±3.0) kg/m(2). The American Society of Anesthesiologists (ASA) score was 1 (1-2) and the Charlson comorbidity index (CCI) score was 1 (0-4). The preoperative value of PSA was (19±11) μg/L. The PSMA PET/CT showed abnormally high expression foci and the great possibility of prostate cancer for all the 17 patients. Prostate puncture biopsy: the results of prostate biopsy were negative in 3 cases. The digital rectal examination found that the prostate volume was Ⅰ or Ⅱ degree large, 10 cases touched hard and the nodule was touched in two cases. Three patients had undergone a previous prostate biopsy, but prostate cancer was not found. All the 17 operations were successfully performed without conversion to open surgery. The surgery time was (85±21) (range from 45 to 120) min, the estimated blood loss was (25±18) (range from5 to 100) ml, the time of intake of liquid diet was (14.3±4.4) h, the intestinal recovery time was (23±10) h, the postoperative activity time was (22±7) h, the drainage duration was (3.7±0.8) d, the postoperative hospital stay was (4.9±1.2) days, and the catheter removal time was (7.4±1.5) days. In the early postoperative period (within 30 days after surgery), no obvious complications occurred. The postoperative final pathology confirmed that all the 17 specimens were prostate cancer. After a median follow-up of 6.5 months, the patient's urinary control rate reached 81.3% at postoperative 1 month, 92.3% at postoperative 3 months after surgery, and the urinary control rate reached 100% at postoperative 6 months. Postoperative PSA value was (0.08±0.08) μg/L, significantly lower than preoperative PSA level (P<0.001). There was significant difference between the preoperative and postoperative QOL (Quality of life) score (57±5 and 47±5 respectively, P<0.001) which indicated that the patients' postoperative quality of life was greatly improved. Conclusions: It is safe and feasible to perform minimally invasive radical prostatectomy without preoperative prostate biopsy for patients with highly suspected prostate cancer by comprehensive diagnostic mode based on modern new imaging technology.

[Application of Endo-GIA stapler in laparoscopic radicalcystectomy]

Objective: To explore the application of Endo-GIA stapler in laparoscopic radical cystectomy, especially in the treatment of lateral bladder ligament, and to evaluate its clinical feasibility and practicability. Methods: A retrospective analysis of clinical data about 38 cases of laparoscopic radical cystectomy (LRC) treated in the Department of Urology, Chaoyang Hospital of Beijing and Cancer Hospital, Chinese Academy of Medical Sciences from July 2017 to June 2019 were conducted. The patients were divided into Endo-GIA stopler group(18 cases) and non-Endo-GIA stopler group (20 cases) according to whether Endo-GIA stapler were used. The basic clinical data, operation time of bladder lateral ligament, operation time of bladder lateral wall, operation time of bladder resection, amount of bleeding during operation, pathological data after operation and related indicators of recovery after operation were compared between the two groups. Results: All 38 patients underwent radical cystectomy (RC) successfully under 3-D laparoscopy without conversion to open surgery. The operation time of bladder lateral ligament in Endo-GIA stapler group was significantly shorter than that in non-Endo-GIA stapler group [(3.25±0.75) min vs (9.20±2.95) min, P=0.042]; the operation time of bladder lateral wall in Endo-GIA stapler group was significantly shorter than that in non-Endo-GIA stapler group [(8.06±1.66) min vs (14.30±3.37) min, P=0.016]. The operation time of cystectomy in the Endo-GIA stapler group was significantly shorter than that in the non-Endo-GIA stapler group [(47.06±4.70) min vs (61.60±14.91) min,P=0.003]. The amount of bleeding in the Endo-GIA stapler group was significantly shorter than that in the non-Endo-GIA stapler group [(37.77±21.30) ml vs (114.50±39.80) ml, P=0.015]. The time of drainage tube removal in Endo-GIA group was significantly shorter than that in the non-Endo-GIA group [(5.83±1.54) d vs (7.30±3.00) d, P=0.002]. The length of post-hospitalization in Endo-GIA group was significantly shorter than that in the non-Endo-GIA group [(7.67±1.78) d vs (9.60±3.25) d,P=0.036]. However, there was no significant difference in other basic clinical data, post-operative pathology and post-operative recovery related indicators. Conclusions: Laparoscopic radical cystectomy using Endo-GIA stapler device is safe and feasible. It is easy to operate, shorten the operation time significantly, and reduce the amount of bleeding. To a certain extent, it is conducive to the recovery of patients after operation to some extent, and worthy of clinical application.

[Evaluation of vestibular evoked myogenic potential, caloric test and cochlear electrogram in the diagnosis of Meniere's disease]

Objective:The aim of this study is to evaluate the diagnostic value of vestibular-evoked myogenic potential （cVEMP and oVEMP）, caloric test, and cochlear electrogram （EcochG） in patients with Meniere's disease （MD） and non-Meniere's disease. Method:Sixty-four patients （64 ears） with Unilateral Meniere's disease were enrolled in the study group （MD group）, and 127 cases（254 ears） of non-Meniere's disease patients as non-MD group, including vertigo migraine in 40 cases, benign paroxysmal positional vertigo in 48 cases, benign recurrent vertigo in 13 cases, vestibular paroxysmia in 3 cases, vestibular neuritis in 5 cases and other undiagnosed vertigo in 18 cases. Both group undertake cVEMP, oVEMP, caloric test and ECochG. Use Medcale software to draw ROC curve of ECochG and calculate the area under curve（AUC）, Jordan index and optimal diagnostic cut-off points. Make the cut-off point as the point of -SP/AP, then evaluate the sensitivity, specificity, positive predictive value（PPV）, negative predictive value（NPV） and diagnostic accuracy of cVEMP, oVEMP, caloric test and ECochG in MD group and non-MD group. Result:The AUC of ECochG ROC curve was 0.74, the Jordan index was 0.47 and the cut-off point was 0.4. The sensitivity and specificity of cVEMP（62% and 68%）, oVEMP（61% and 53%） and caloric test（53% and 57%） were all below ECochG（65% and 78%）. The positive predictive value and of ECochG was the highest（61.9%）, the negative predictive value of cVEMP was highest（87.5%）. The diagnostic accuracy of ECochG was highest（74%）, followed with cVEMP（67%）, oVEMP（55%） and caloric test（56%）. Conclusion:Compared with the vestibular function tests, the sensitivity, specificity, diagnostic accuracy and NPV were all higher in ECochG, and the diagnostic benefit can be maximized when -SP/AP value>0.4. So the value of single vestibular function examination in the diagnosis of Meniere's disease is limited. The diagnosis of MD still requires a comprehensive evaluation in combination with medical history, audiological tests and vestibular function examinations.

Phylogenetic re-evaluation of Thielavia with the introduction of a new family Podosporaceae

The genus Thielavia is morphologically defined by having non-ostiolate ascomata with a thin peridium composed of textura epidermoidea, and smooth, single-celled, pigmented ascospores with one germ pore. Thielavia is typified with Th. basicola that grows in close association with a hyphomycete which was traditionally identified as Thielaviopsis basicola. Besides Th. basicola exhibiting the mycoparasitic nature, the majority of the described Thielavia species are from soil, and some have economic and ecological importance. Unfortunately, no living type material of Th. basicola exists, hindering a proper understanding of the classification of Thielavia. Therefore, Thielavia basicola was neotypified by material of a mycoparasite presenting the same ecology and morphology as described in the original description. We subsequently performed a multi-gene phylogenetic analyses (rpb2, tub2, ITS and LSU) to resolve the phylogenetic relationships of the species currently recognised in Thielavia. Our results demonstrate that Thielavia is highly polyphyletic, being related to three family-level lineages in two orders. The redefined genus Thielavia is restricted to its type species, Th. basicola, which belongs to the Ceratostomataceae (Melanosporales) and its host is demonstrated to be Berkeleyomyces rouxiae, one of the two species in the "Thielaviopsis basicola" species complex. The new family Podosporaceae is sister to the Chaetomiaceae in the Sordariales and accommodates the re-defined genera Podospora, Trangularia and Cladorrhinum, with the last genus including two former Thielavia species (Th. hyalocarpa and Th. intermedia). This family also includes the genetic model species Podospora anserina, which was combined in Triangularia (as Triangularia anserina). The remaining Thielavia species fall in ten unrelated clades in the Chaetomiaceae, leading to the proposal of nine new genera (Carteria, Chrysanthotrichum, Condenascus, Hyalosphaerella, Microthielavia, Parathielavia, Pseudothielavia, Stolonocarpus and Thermothielavioides). The genus Canariomyces is transferred from Microascaceae (Microascales) to Chaetomiaceae based on its type species Can. notabilis. Canariomyces is closely related to the human-pathogenic genus Madurella, and includes three thielavia-like species and one novel species. Three monotypic genera with a chaetomium-like morph (Brachychaeta, Chrysocorona and Floropilus) are introduced to better resolve the Chaetomiaceae and the thielavia-like species in the family. Chrysocorona lucknowensis and Brachychaeta variospora are closely related to Acrophialophora and three newly introduced genera containing thielavia-like species; Floropilus chiversii is closely related to the industrially important and thermophilic species Thermothielavioides terrestris (syn. Th. terrestris). This study shows that the thielavia-like morph is a homoplastic form that originates from several separate evolutionary events. Furthermore, our results provide new insights into the taxonomy of Sordariales and the polyphyletic Lasiosphaeriaceae.

[Preliminary observation of galvanic vestibular stimulation-vestibular evoked myogenic potentials in healthy young people]

Objective: To introduce the method of galvanic vestibular stimulation-vestibular evoked myogenic potentials (GVS-VEMP) as well as to observe and analyze the parameters and elicited rate of GVS-cVEMP and GVS-oVEMP in healthy young people in China. Methods: Twenty six normal young subjects were recruited for conventional examinations of GVS-VEMP. The subjects were 21-37 years old, average age was (25.8±3.7) years old, including 13 males and 13 females. The galvanic stimulation intensity of 3 mA/1 ms was used to evoke cVEMP and oVEMP on the sternocleidomastoid and inferior extraocular muscles respectively, and the intensity of stimulus was decreased until the response disappeared, the threshold, latency, amplitude, interval phase and interaural amplitude ratio(IAR) were calculated. SPSS18.0 software was used for statistical analysis. Results: All subjects were elicited normal GVS-cVEMP and GVS-oVEMP under 3 mA/1 ms, the elicited rate was 100%. The threshold of GVS-cVEMP was (1.18±0.47) mA, p1 latency was (10.43±1.54) ms, n1 latency was (17.91±1.20) ms, the amplitude was (102.47±56.77) uV and IAR was (0.26±0.20). The threshold of GVS-oVEMP was (1.12±0.50) mA, n1 latency was (8.46±1.05) ms, p1 latency was (11.83±1.27) ms, the amplitude was (9.12±6.82) uV and IAR was (0.25±0.20). In terms of gender and lateral comparison, only the GVS-oVEMP amplitude was higher for male than for female, which had significant statistical difference (P<0.05), and there was no statistical difference in the other parameters between GVS-cVEMP and GVS-oVEMP. Conclusion: GVS-cVEMP and GVS-oVEMP could be elicited in healthy youth population, and the parameters could provide reference for subsequent vestibular function evaluation.

[Clinical experiences of laparoscopic radical cystectomy and urinary diversion in the elderly patients with bladder cancer]

Objective: To optimize the surgical procedures of laparoscopic radical cystectomy and urinary diversion for the elderly patients with bladder cancer, generalize operating technique, summarize clinical experiences. Methods: From July 2004 to October 2016, laparoscopic radical cystectomy (LRC) and urinary diversion was performed in 68 elderly patients (≥75 years old) diagnosed with bladder cancer in urology department of Beijing Chaoyang Hospital, Capital Medical University, and the relevant clinical and follow-up data were retrospectively reviewed. All the patients were pathologically diagnosed and their perioperative data, postoperative pathological results, postoperative complications and follow-up outcomes were recorded and analyzed. Results: Among 68 elderly patients with bladder cancer, fifty patients were male and 18 were female, the age of whom were (79±4) (range 75 to 91) years old. The Charlson comorbidity index (CCI) score was 6±1 (range 5 to 7). All the 68 operations were successfully performed without conversion to open surgery. There were 26 cases receiving cutaneous ureterostomy, 34 cases receiving ileal conduit (intracorporeal for 16 cases and extracorporeal for 18 cases) and 8 cases receiving orthotopic ileal neobladder (intracorporeal for 4 cases and extracorporeal for 4 cases; Xing's technique for 4 cases, T-Pouch for 2 cases and Studer-Pouch for 2 cases) respectively, and the operation time of these three groups were (221±47) min, (315±70) min and (358±90) min respectively, the estimated blood loss were 100 (87, 200)ml, 300 (250, 500) ml and 250 (113, 725) ml respectively, the time of intake of liquid diet were 3 (2, 4) d, 6 (5, 7) d and 9 (5, 12) d respectively, and the postoperative hospital stay were (12±6) d, (24±11) d, and (27±11) d respectively. Postoperative pathological results showed urothelial carcinoma in 64 patients, squamous cell carcinoma in 2 patients and adenocarcinoma in 2 patients. Sixty patients received laparoscopic pelvic lymphadenectomy and the number of dissected lymph nodes was 17.1±7.0. There were 46 cases with T stage greater than or equal to T2 (46/68, 67.6%), 4 cases of low grade (4/68, 5.9%) and 60 cases of high grade (60/68, 88.2%). All the early postoperative (within 30 days after the operation) complications were grade Ⅰ-Ⅱ mainly manifested as fever, pain and infection that could get better with symptomatic treatment, and the incidence rate were 30.8% for cutaneous ureterostomy, 29.4% for ileal conduit and 37.5% for orthotopic ileal neobladder. The patients were followed up for a median period of 93.5 months without obvious hydronephrosis and impaired renal function. The 5-year cancer specific survival rate and overall survival rate were 57% and 50% respectively. There was significant difference between the preoperative and postoperative QOL (quality of life) score (56.0±10.0 and 47.4±5.8 respectively, P<0.05) which indicated that the patients' postoperative quality of life was greatly improved. Conclusions: Laparoscopic radical cystectomy and urinary diversion for the elderly patients with bladder cancer is safe and feasible, and owns great therapeutic value.

Redefining Humicola sensu stricto and related genera in the Chaetomiaceae

The traditional concept of the genus Humicola includes species that produce pigmented, thick-walled and single-celled spores laterally or terminally on hyphae or minimally differentiated conidiophores. More than 50 species have been described in the genus. Species commonly occur in soil, indoor environments, and compost habitats. The taxonomy of Humicola and morphologically similar genera is poorly understood in modern terms. Based on a four-locus phylogeny, the morphological concept of Humicola proved to be polyphyletic. The type of Humicola, H. fuscoatra, belongs to the Chaetomiaceae. In the Chaetomiaceae, species producing humicola-like thick-walled spores are distributed among four lineages: Humicola sensu stricto, Mycothermus, Staphylotrichum, and Trichocladium. In our revised concept of Humicola, asexual and sexually reproducing species both occur. The re-defined Humicola contains 24 species (seven new and thirteen new combinations), which are described and illustrated in this study. The species in this genus produce conidia that are lateral, intercalary or terminal on/in hyphae, and conidiophores are not formed or are minimally developed (micronematous). The ascospores of sexual Humicola species are limoniform to quadrangular in face view and bilaterally flattened with one apical germ pore. Seven species are accepted in Staphylotrichum (four new species, one new combination). Thick-walled conidia of Staphylotrichum species usually arise either from hyphae (micronematous) or from apically branched, seta-like conidiophores (macronematous). The sexual morph represented by Staphylotrichum longicolleum (= Chaetomium longicolleum) produces ascomata with long necks composed of a fused basal part of the terminal hairs, and ascospores that are broad limoniform to nearly globose, bilaterally flattened, with an apical germ pore. The Trichocladium lineage has a high morphological diversity in both asexual and sexual structures. Phylogenetic analysis revealed four subclades in this lineage. However, these subclades are genetically closely related, and no distinctive phenotypic characters are linked to any of them. Fourteen species are accepted in Trichocladium, including one new species, twelve new combinations. The type species of Gilmaniella, G. humicola, belongs to the polyphyletic family Lasiosphaeriaceae (Sordariales), but G. macrospora phylogenetically belongs to Trichocladium. The thermophilic genus Mycothermus and the type species My. thermophilum are validated, and one new Mycothermus species is described. Phylogenetic analyses show that Remersonia, another thermophilic genus, is sister to Mycothermus and two species are known, including one new species. Thermomyces verrucosus produces humicola-like conidia and is transferred to Botryotrichum based on phylogenetic affinities. This study is a first attempt to establish an inclusive modern classification of Humicola and humicola-like genera of the Chaetomiaceae. More research is needed to determine the phylogenetic relationships of “humicola”-like species outside the Chaetomiaceae.

Tuning bacterial hydrodynamics with magnetic fields

Magnetotactic bacteria are a group of motile prokaryotes that synthesize chains of lipid-bound, magnetic nanoparticles called magnetosomes. This study exploits their innate magnetism to investigate previously unexplored facets of bacterial hydrodynamics at surfaces. Through use of weak, uniform, external magnetic fields and local, micromagnetic surface patterns, the relative strength of hydrodynamic, magnetic, and flagellar force components is tuned through magnetic control of the bacteria's orientation. The resulting swimming behaviors provide a means to experimentally determine hydrodynamic parameters and offer a high degree of control over large numbers of living microscopic entities. The implications of this controlled motion for studies of bacterial motility near surfaces and for micro- and nanotechnology are discussed.

Robust Zero-Field Skyrmion Formation in FeGe Epitaxial Thin Films

B20 phase magnetic materials have been of significant interest because they enable magnetic Skyrmions. One major effort in this emerging field is the stabilization of Skyrmions at room temperature and zero magnetic field. We grow phase-pure, high crystalline quality FeGe epitaxial films on Si(111). Hall effect measurements reveal a strong topological Hall effect after subtracting the ordinary and anomalous Hall effects, demonstrating the formation of high density Skyrmions in FeGe films between 5 and 275 K. In particular, a substantial topological Hall effect was observed at a zero magnetic field, showing a robust Skyrmion phase without the need of an external magnetic field.

Quantitative STEM Imaging of Order-Disorder Phenomena in Double Perovskite Thin Films

Using aberration-corrected high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), we investigate ordering phenomena in epitaxial thin films of the double perovskite Sr_{2}CrReO_{6}. Experimental and simulated imaging and diffraction are used to identify antiphase domains in the films. Image simulation provides insight into the effects of atomic-scale ordering along the beam direction on HAADF-STEM intensity. We show that probe channeling results in ±20% variation in intensity for a given composition, allowing 3D ordering information to be probed using quantitative STEM.

Epitaxial growth of iridate pyrochlore Nd2Ir2O7 films

Epitaxial films of the pyrochlore Nd₂Ir₂O₇ have been grown on (111)-oriented yttria-stabilized zirconia (YSZ) substrates by off-axis sputtering followed by post-growth annealing. X-ray diffraction (XRD) results demonstrate phase-pure epitaxial growth of the pyrochlore films on YSZ. Scanning transmission electron microscopy (STEM) investigation of an Nd₂Ir₂O₇ film with a short post-annealing provides insight into the mechanism for crystallization of Nd₂Ir₂O₇ during the post-annealing process. STEM images reveal clear pyrochlore ordering of Nd and Ir in the films. The epitaxial relationship between the YSZ and Nd₂Ir₂O₇ is observed clearly while some interfacial regions show a thin region with polycrystalline Ir nanocrystals.

Biological significance of miR-126 expression in atrial fibrillation and heart failure

We investigated the biological significance of microRNA-126 (miR-126) expression in patients with atrial fibrillation (AF) and/or heart failure (HF) to examine the possible mechanism of miR-126-dependent AF and development of HF. A total of 103 patients were divided into three groups: AF group (18 men and 17 women, mean age: 65.62±12.72 years), HF group (17 men and 15 women, mean age: 63.95±19.71 years), and HF-AF group (20 men and 16 women, mean age: 66.56±14.37 years). Quantitative real-time PCR was used to measure relative miR-126 expression as calculated by the 2-ΔΔCt method. miR-126 was frequently downregulated in the 3 patient groups compared with controls. This reduction was significantly lower in permanent and persistent AF patients than in those with paroxysmal AF (P<0.05, t-test). Moreover, miR-126 expression was markedly lower in the HF-AF group compared with the AF and HF groups. The 3 patient groups had higher N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels, lower left ventricular ejection fraction (LVEF), larger left atrial diameter, and higher cardiothoracic ratio compared with controls. There were significant differences in NT-proBNP levels and LVEF among the AF, HF, and HF-AF groups. Pearson correlation analysis showed that relative miR-126 expression was positively associated with LVEF, logarithm of NT-proBNP, left atrial diameter, cardiothoracic ratio, and age in HF-AF patients. Multiple linear regression analysis showed that miR-126 expression was positively correlated with LVEF, but negatively correlated with the logarithm of NT-pro BNP and the cardiothoracic ratio (all P<0.05). Serum miR-126 levels could serve as a potential candidate biomarker for evaluating the severity of AF and HF. However, to confirm these results, future studies with a larger and diverse patient population are necessary.

Effects of conjugated linoleic acid on the expression levels of miR-27 and miR-143 in pig adipose tissue

In this study, we evaluated the effect and possible mech-anism of action of dietary conjugated linoleic acid (CLA) on pig body fat deposition. Landrace piglets (N = 48) were randomly divided into three groups, which were fed diets containing 0% (control), 1%, or 2% CLA. Dorsal and abdominal subcutaneous adipose tissues were col-lected, and real-time polymerase chain reaction (PCR) was used to de-termine the expression of adipocyte differentiation marker genes and associated microRNAs (miRNAs). Our results indicated that dietary CLA significantly decreased body fat deposition in the pig dorsum. The expression of adipocyte differentiation marker genes, including peroxi-some proliferator-activated receptor (PPAR)-γ and CCAAT/enhancer-binding protein α (C/EBPα) were not affected, whereas the expression of fatty acid binding protein 4 (FABP4) was significantly enhanced (P < 0.05). The expression of miR-27 and miR-143 in adipose tissue was significantly decreased. Data analysis indicated a significant negative correlation between miR-27 and FABP4 expression in the dorsal sub-cutaneous adipose tissue. In addition, the expression of miR-143 and miR-27 exhibited a significant negative relationship with FABP4 and PPARγ in the abdominal subcutaneous adipose tissue. Thus, miRNA levels in adipose tissues could be modulated by CLA, thereby affecting adipose metabolism.

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels

The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from 10(7) to 10(10) cfu/g during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to 10(9) cfu/g DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

Cloning and sequence analysis of sucrose phosphate synthase gene from varieties of Pennisetum species

Sucrose phosphate synthase (SPS) is an enzyme used by higher plants for sucrose synthesis. In this study, three primer sets were designed on the basis of known SPS sequences from maize (GenBank: NM_001112224.1) and sugarcane (GenBank: JN584485.1), and five novel SPS genes were identified by RT-PCR from the genomes of Pennisetum spp (the hybrid P. americanum x P. purpureum, P. purpureum Schum., P. purpureum Schum. cv. Red, P. purpureum Schum. cv. Taiwan, and P. purpureum Schum. cv. Mott). The cloned sequences showed 99.9% identity and 80-88% similarity to the SPS sequences of other plants. The SPS gene of hybrid Pennisetum had one nucleotide and four amino acid polymorphisms compared to the other four germplasms, and cluster analysis was performed to assess genetic diversity in this species. Additional characterization of the SPS gene product can potentially allow Pennisetum to be exploited as a biofuel source.

Isolation of the P5CS gene from reed canary grass and its expression under salt stress

Reed canary grass (RCG) is a perennial grass traditionally cultivated for forage. It is also used as fuel to produce energy in Finland and Sweden, and other countries have expressed interest in the cultivation of RCG. In China, arable land is limited. Salinity is considered to be a major factor limiting plant crop development and productivity. To boost biofuel production of RCG and extend its range in saline soil, we seek to improve its salt tolerance. Proline acts as an osmolyte that accumulates when plants are subjected to abiotic stress. P5CS plays a crucial role in proline biosynthesis. We isolated a P5CS gene from RCG, designated B231P5CS (GenBank accession No. JQ622685). B231P5CS is a fragment (971 bp) that encodes a 323-amino acid polypeptide. We also cloned an actin gene fragment from RCG as a reference gene in expression analysis of B231P5CS gene. Expression analysis revealed that B231P5CS transcripts were upregulated in leaves after treatment with salt (200 mM NaCl) and that transcript levels of B231P5CS reached a maximum 12 h after exposure, which was 14.69 times the level in control plants. The trends of expression were exactly opposite in roots; transcripts were downregulated after salt treatment. Proline concentration increased in leaves after stress. In contrast, proline content of roots decreased up to 3.6-fold relative to controls. Changes in proline concentration after stress were correlated with B231P5CS expression. Our results suggest that B231P5CS is a stress-inducible gene and plays a non-redundant role in plant development. This gene may be used to improve stress tolerance of RGC and other bioenergy feedstock.

Characteristics of Lactobacillus parafarraginis ZH1 and its role in improving the aerobic stability of silages

AIMS

Lactobacillus parafarraginis ZH1 isolated from silage was characterized, and the effects of inoculating ZH1 and Lact. buchneri (LB) on the aerobic stability of sweet corn stalk (SCS) silage and whole-plant oat (WPO) silage ensiled at 15 and 30°C were studied.

METHODS AND RESULTS

After ensiling of SCS or WPO in plastic bottle silo for 45 days, silos were opened, and aerobic stability was studied by monitoring temperature change with thermo recorders in silage for 6 days. SCS silage and WPO silage were well conserved naturally at both storage temperatures. However, silages were prone to aerobic deterioration due to the presence of residual yeasts. ZH1 inoculated silages ensiled at both temperatures, LB inoculated silages ensiled at 30°C had better aerobic stability than the uninoculated silages and the LB-inoculated silage at 15°C.

CONCLUSIONS

Strain ZH1 improved the aerobic stability of SCS silage and WPO silage ensiled at both 15 and 30°C, while LB improved the aerobic stability of silage only ensiled at the high temperature of 30°C.

SIGNIFICANCE AND IMPACT OF THE STUDY

The new strain ZH1 can be used as an effective inhibitor for aerobic deterioration of silage maintained from 15 to 30°C.

Scaling of spin Hall angle in 3d, 4d, and 5d metals from Y3Fe5O12/metal spin pumping

We have investigated spin pumping from Y3Fe5O12 thin films into Cu, Ag, Ta, W, Pt, and Au with varying spin-orbit coupling strengths. From measurements of Gilbert damping enhancement and inverse spin Hall signals spanning 3 orders of magnitude, we determine the spin Hall angles and interfacial spin mixing conductances for the six metals. The spin Hall angles largely vary as Z(4) (Z: atomic number), corroborating the role of spin-orbit coupling. Amongst the four 5d metals, the variation of the spin Hall angle is dominated by the sensitivity of the d-orbital moment to the d-electron count, confirming theoretical predictions.

Probing the spin pumping mechanism: exchange coupling with exponential decay in Y3Fe5O12/barrier/Pt heterostructures

It is widely believed that the mechanism for spin pumping in ferromagnet-nonmagnet bilayers is the exchange interaction between the ferromagnet and nonmagnetic material. We observe 1000-fold exponential decay of spin pumping from thin Y3Fe5O12 films to Pt across insulating barriers, from which exponential decay lengths of 0.16, 0.19, and 0.23 nm are extracted for oxide barriers having band gaps of 4.91, 3.40, and 2.36 eV, respectively. This archetypal signature of quantum tunneling through a barrier underscores the importance of exchange coupling for spin pumping and reveals its dependence on the characteristics of the barrier material.

First Report of Sclerotinia Rot of Chinese Atractylodes Caused by Sclerotinia nivalis in China

Chinese atractylodes (Atractylodes japonica Koidz.ez Kitam.) is a perennial herb in the Compositae family, and is widely distributed in China. The dried rhizomes of the plant are used in traditional Chinese medicine. During the summer of 2011, typical signs and symptoms of Sclerotinia rot were observed on Chinese atractylodes in a production field of Liaoning Province of China. Symptoms were observed in plants at the flowering stage, distributed in patches throughout the rows, and with a disease incidence of approximately 10 to 15%. The lower mature leaves of infected plants first became yellow and wilted, basal stem areas showed a black-brown rot at the same time under conditions of high humidity, and white cottony mycelium formed along the basal stem and soil surfaces. Ultimately, the basal stem and roots rotted and the plants wilted and died quickly. Black, irregular sclerotia (average 0.8 to 6.9 mm in diameter) were also observed within the pith cavity of split stems and rotted roots. The pathogen was isolated from symptomatic tissues and sclerotia, surface disinfested with 2% sodium hypochlorite, and cultured on potato dextrose agar (PDA) (1). The fungus was mesophilic, with an optimum temperature for mycelial growth in culture of about 20°C. Colonies on PDA produced masses of white aerial mycelium, with small white flocci distributed among sclerotia. After 2 weeks, sclerotia 0.5 to 4.5 mm in diameter were produced near the margin in a uniform distribution. Sclerotia were spherical, elongated, or fused to form irregular shapes and tightly attached to the agar surface by their under surface, which could be seen through the bottom of the petri dishes. DNA sequences of five replicates were obtained using the TianGen DNA secure plant kit. The internal transcribed spacer (ITS) region of rDNA was amplified with primers ITS1/ITS4 and sequenced. BLAST analysis of the 513-bp segment showed high similarity (99%) with a sequence of Sclerotinia nivalis (GenBank Accession No. AB516670). A representative sequence was deposited in GenBank (Accession No. JX294862). The fungus isolated from symptomatic tissues was identified as S. nivalis Saito on the basis of morphological and cultural characteristics (2,3) and ITS sequence analysis. Symptoms were reproduced in the greenhouse by inoculating the basal stem and roots of 15 atractylodes plants at the 7- to 10-leaf stage. Inoculum was prepared by macerating 14-day-old PDA cultures of the fungus in a blender and placing the mixture (approximately 20 g) into the potting medium of each plant. Sterile PDA was used to inoculate the five control plants. Plants were maintained in a greenhouse at 22 to 25°C and about 75% relative humidity. After 7 to 10 days, symptoms were similar to those in the fields. Lower leaves of inoculated plants became yellow and wilted, and infected plants died 2 weeks after inoculation, whereas control plants remained healthy. The pathogen was successfully recovered from symptomatic tissues, completing Koch's postulates. To our knowledge, this is the first report of Sclerotinia rot of Chinese atractylodes. Given its wide host range, S. nivalis has great potential to become an economically important plant pathogen. References: (1) W. G. Kim and W. D. Cho. Mycobiology 30:41, 2002. (2) G. Q. Li et al. Mycol. Res. 104:232, 2000. (3) I. Saito. Mycoscience 38:227, 1997.

SRAP analysis of genetic diversity of nine native populations of wild sugarcane, Saccharum spontaneum, from Sichuan, China

Saccharum spontaneum is a wild sugarcane species that is native to and widely distributed in China. It has been extensively used in sugarcane breeding programs, and is being tested for the development of bioenergy cultivars. In order to provide basic information for the exploitation of this species, we analyzed genetic variation among and within native S. spontaneum populations collected from Sichuan, China. Eighty plants from nine native populations were sampled. Twenty-one sequence-related amplified polymorphism primer pairs generated 235 clearly scorable bands, of which 185 were polymorphic (78.7%). Nei's genetic diversity was 0.2801 and Shannon's information index was 0.4155 across the populations. Genetic diversity parameters, G(ST) value (0.2088) and N(m) value (1.8944), showed that the genetic variation within populations was greater than that among populations. In the cluster analysis, one major grouping was formed by populations from Ya'an and another one by populations from Sichuan basin; a population from Baoxing formed a single cluster. In order to fully comprehend the genetic diversity of cold-tolerant local germplasm in this species, germplasm should be collected from the heterogeneous environments along the northern regions of this species' distribution. The germplasm that we collected should be a valuable resource for Saccharum breeding.

Regulating Brownian fluctuations with tunable microscopic magnetic traps

A major challenge to achieving positional control of fluid borne submicron sized objects is regulating their Brownian fluctuations. We present a magnetic-field-based trap that regulates the thermal fluctuations of superparamagnetic beads in suspension. Local domain-wall fields originating from patterned magnetic wires, whose strength and profile are tuned by weak external fields, enable the bead trajectories within the trap to be managed and easily varied between strong confinements and delocalized spatial excursions that are described remarkably well by simulations.

First Report of Citrus bark cracking viroid and Citrus viroid V Infecting Citrus in China

Citrus is the most cultivated and highest value crop in the 15 southern provinces and municipalities in South China. Trifoliate orange (Poncirus trifoliata) is the main rootstock for citrus cultivars and is known to be susceptible to citrus viroids. Surveys conducted from 1995 to 2007 revealed 42 symptomatic samples from 33 cultivars (21 from sweet oranges (Citrus sinensis), 6 from mandarins (C. reticulata), 2 from satauma mandarins (C. unshiu), 6 from lemons (C. jambhiri), and 7 from mandarin hybrids). Symptoms included stunting, bark scaling, and cracking on the Trifoliate orange rootstock collected from citrus orchards in the Chongqing municipality, Sichuan, Zhejiang, Jiangxi, Hunan, and Yunnan provinces. Of the 42 samples, 27 were cultivars imported from abroad and 15 were local cultivars. Budwood from infected trees were grafted onto Arizona 861-S1 'Etrog citron' (C. medica) on rough lemon (C. jambhiri) rootstock. After more than 12 months, 39 of 42 samples revealed typical viroid symptoms of stunting, epinasty. and leaf rolling on the Etrog indicator plants. In September 2009, total RNA was extracted with TRIZOL Reagent and a one-step multiplex reverse transcription (RT)-PCR assay (3) was used to detect simultaneously Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), Hop stunt viroid (HSVd), and Citrus dwarfing viroid (CDVd). Also, a one-step RT-PCR protocol using two primer pairs targeting the complete genome sequences was used to detect Citrus bark cracking viroid (CBCVd) (1) and Citrus viroid V (CVd-V) (2). Of the 42 samples, 37 and 35 were positive for HSVd and CDVd, respectively. CEVd and CBLVd were found, respectively, in 14 and 13 of 42 samples. CBCVd was detected in cv. Meishan No. 9 (C. sinensis) from Sichuan Province and cvs. Akemi (C. reticulata) and Nishirokaori (C. reticulata) from Zhejiang Province. CVd-V was detected in cvs. Nishirokaori, Haruka (C. tamuranua), and Kiyomi (C. unshiu × C. sinensis) from Zhejiang, Hunan, and Chongqing Province, respectively. Only Meishan No. 9 is a local cultivar, whereas Akemi, Nishirokaori, Haruka, and Kiyomi are cultivars imported from Japan. Of 42 samples, 3 without typical symptoms on Etrog citrons were infected with HSVd only. Of 42 infected citrus plants, 36 harbored more than one viroid species. RT-PCR products of CBCVd and CVd-V were cloned by standard methods. Eight clones for CBCVd (one from Meishan No. 9 [Accession No. HM042742, 284 bp], three from Akemi [Accession Nos. HM042743-HM042745, 283 to 284 bp], and four from Nishirokaori [Accession Nos. HM042746-HM042749, 286 bp]) and six clones for CVd-V (four from Nishirokaori [Accession Nos. HM042750-HM042753, 294 bp], one from Kiyomi [Accession No. HM042754, 294 bp], and one from Haruka [Accession No. HM042755, 294 bp]) were sequenced and deposited in GenBank. BLAST analysis of the CBCVd (Accession No. HM042742) and CVd-V (Accession No. HM042751) sequences revealed highest nucleotide sequence identity (100 and 96%) to a CBCVd isolate from Cuba (Accession No. AJ630360) and a CVd-V isolate from Spain (Accession No. EF617306), respectively. To our knowledge, this is the first report of CBCVd and CVd-V in China. Our finding emphasizes the need for CBCVd and CVd-V indexing in production and distribution of pathogen-free citrus plants in China. References: (1) L. Bernard and N. Duran-Vila. Mol. Cell. Probes 20:105, 2006. (2) P. Serra et al. Phytopathology 98:1199, 2008. (3) X. F. Wang et al. Eur. J. Plant. Pathol. 124:175, 2009.

Manipulation of magnetically labeled and unlabeled cells with mobile magnetic traps

A platform of discrete microscopic magnetic elements patterned on a surface offers dynamic control over the motion of fluid-borne cells by reprogramming the magnetization within the magnetic bits. T-lymphocyte cells tethered to magnetic microspheres and untethered leukemia cells are remotely manipulated and guided along desired trajectories on a silicon surface by directed forces with average speeds up to 20 microm/s. In addition to navigating cells, the microspheres can be operated from a distance to push biological and inert entities and act as local probes in fluidic environments.

Magnetic wire traps and programmable manipulation of biological cells

We present a multiplex method, based on microscopic programmable magnetic traps in zigzag wires patterned on a platform, to simultaneously apply directed forces on multiple fluid-borne cells or biologically inert magnetic microparticles or nanoparticles. The gentle tunable forces do not produce damage and retain cell viability. The technique is demonstrated with T-lymphocyte cells remotely manipulated (by a joystick) along desired trajectories on a silicon surface with average speeds up to 20 microm/s.

Reconstruction control of magnetic properties during epitaxial growth of ferromagnetic Mn3-deltaGa on Wurtzite GaN(0001)

Binary ferromagnetic Mn(3-delta)Ga (1.2<3-delta< or =1.5) crystalline thin films have been epitaxially grown on wurtzite GaN(0001) surfaces using rf N-plasma molecular beam epitaxy. The film structure is face-centered tetragonal with CuAu type-I (L1(0)) ordering with (111) orientation. The in-plane epitaxial relationship to GaN is nearly ideal with [110](MnGa) parallel[1100](GaN) and [112](MnGa) parallel[1120](GaN). We observe magnetic anisotropy along both the in-plane and out-of-plane directions. The magnetic moments are found to depend on the Mn/(Mn+Ga) flux ratio and can be controlled by observation of the surface reconstruction during growth, which varies from 1x1 to 2x2 with increasing Mn stoichiometry.

Intermittent exposure to reduced oxygen levels affects prey size selection and consumption in swimming crab Thalamita danae Stimpson

Portunid crabs Thalamita danae (carapace width: 46-56 mm) were exposed to low oxygen level (4.0 mg O2 l(-1)) and hypoxia (1.5 mg O2 l(-1)) for 6 h each day with three size classes (large: 15.0-19.9 mm, medium: 10.0-14.9 mm, small: 5.0-9.9 mm) of mussels Brachidontes variabilis offered as food. Consumption rate, prey size preference, and prey handling including breaking time, handling time, eating time and prey value, were studied during the time the crabs were exposed to reduced oxygen levels and results were compared with the crabs maintained at high oxygen level (8.0 mg O2 l(-1)) throughout the experiment. Consumption of mussels from all size classes was significantly higher at high oxygen level than at reduced oxygen levels. No mussel size preference was observed for crabs exposed to 4.0 or 8.0 mg O2 l(-1) but those crabs exposed to 1.5 mg O2 l(-1) preferred medium mussels. Both breaking time and handling time increased with mussel size but did not vary with oxygen level. Prey value of each mussel consumed (mg dry wt eaten crab(-1) s(-1)) was calculated by dividing the estimated dry weight of the mussel by the observed handling time. Mean prey value varied significantly with mussel size, with values obtained for large mussels being higher than small mussels at 4.0 and 8.0 mg O2 l(-1); the effect of oxygen level, however, was insignificant. In view of portunid crabs as major predators of mussels, results may help explain dominance of mussels in eutrophic harbours in Hong Kong.

Oscillatory exchange bias due to an antiferromagnet with incommensurate spin-density waves

Oscillatory exchange bias in both magnitude and in sign has been observed in epitaxial (100)Cr/Ni(81)Fe19 bilayers due to the incommensurate spin-density waves in antiferromagnetic (100)Cr layers. Salient effects due to the spin-flip transition between longitudinal and transverse spin-density waves as well as that of expanding wavelength have been observed.

Inhibition of thymidylate synthase activity by antisense oligodeoxynucleotide and possible role in thymineless treatment

Thymidylate synthase (TS) is an important target for chemotherapeutic treatment of cancer. However, efficacy of TS-targeted anticancer drugs is limited by the development of drug resistance as a result of TS gene amplification. In this work, a phosphorothioated antisense oligonucleotide (ODN), designated ATS-2, was used to suppress cellular synthesis of TS. ATS-2 at 0.2 microM concentration was mixed with lipofectin in a charge ratio of 1:1 and was used to treat the human embryonic kidney (HEK) cell line. A reduction of TS mRNA and protein was achieved. Furthermore, a dose-dependent reduction of cumulative viable cells of up to 98% was observed. Flow cytometer analysis of cell cycle progression indicates that ATS-2-treated cells were arrested and went into apoptosis at the S phase, possibly because of thymidine shortage, suggesting that ATS-2 is specifically effective for dividing cells. When used in combination with the anticancer drug FdUrd, ATS-2 exerted a additive inhibitory effect on cellular proliferation. To elucidate the possible role of cellular thymidine kinase (TdR kinase) in ATS-2 treatment, a second cell line, HeLa, was used. Both HEK and HeLa have similar rates of cell division and ODN uptake. In contrast to HEK, which was shown to have very low levels of TdR kinase activity in [(3)H]thymidine incorporation experiments, [(3)H]thymidine incorporation in HeLa was 15-fold greater than that of HEK. We found that HeLa cells were sensitive to FdUrd but were rather resistant to ATS-2. On the contrary, HEK cells were sensitive to ATS-2 but insensitive to FdUrd. Effects of ATS-2 and FdUrd are, therefore, complementary in thymineless treatment too.

Determination of the spin polarization of half-metallic CrO(2) by point contact Andreev reflection

Andreev reflection at a Pb/CrO(2) point contact has been used to determine the spin polarization of single-crystal CrO(2) films made by chemical vapor deposition. The spin polarization is found to be 0.96 +/- 0.01, which confirms that CrO(2) is a half-metallic ferromagnet, as theoretically predicted.

Spiraling spin structure in an exchange-coupled antiferromagnetic layer

Using trilayers of permalloy/FeMn/Co with various thicknesses t(AF) of the antiferromagnetic FeMn, we have observed evidence of a spiraling spin structure within FeMn. For t(AF)<90 A, the turn angle straight theta of the spiral varies as straight theta = (1.76 degrees /A)t(AF).

Large magnetoresistance of electrodeposited single-crystal bismuth thin films

Single-crystal bismuth thin films 1 to 20 micrometers thick were fabricated by electrodeposition and suitable annealing. Magnetoresistance up to 250 percent at 300 kelvin and 380,000 percent at 5 kelvin as well as clean Shubnikov-de Haas oscillations were observed, indicative of the high quality of these films. A hybrid structure was also made that showed a large magnetoresistive effect of 30 percent at 200 oersted and a field sensitivity of 0.2 percent magnetoresistance per oersted at room temperature.

Further studies on Zn2+ -mediated domain-domain communication in human erythrocyte band 3

Human erythrocyte band 3 is purified and reconstituted into vesicles, forming right-side-out proteoliposomes. Zn2+ entrapped inside the proteoliposomes inhibits the anion transport activity of band 3, and removal of the cytoplasmic domain of band 3 is able to diminish Zn2+ inhibition. Thus, the inhibition of activity of band 3 results from the Zn2+ induced conformational change of the cytoplasmic domain, which in turn is transmitted to the membrane domain. The results of intrinsic fluorescence and its quenching by HB and the 35Cl NMR study indicate that the cytoplasmic domain is essential for the conformational change induced by Zn2+. SH-blocking reagents, CH(3)I and GSSG, are used to modify the cytoplasmic domain, where they specifically bind to Cys201 and Cys317. It is observed that the Zn2+ induced inhibition of anion transport activity is blocked. This demonstrates that Cys201 and Cys317 are required in Zn2+ -mediated domain-domain communication.

Gene synthesis by a LCR-based approach: high-level production of leptin-L54 using synthetic gene in Escherichia coli

Synthetic genes are very useful in genetic and protein engineering. Here we propose a general method for construction of synthetic genes. Short oligonucleotides are joined through ligase chain reaction (LCR) in high stringency conditions to make "unit fragments" which are then fused to form a full-length gene sequence by polymerase chain reaction. The procedure is simple and accurate and does not place constraints on sequence and length. In this report, a recombinant leptin gene was synthesized according to the codon preference of Escherichia coli. Besides, a substitution of the only Met at position 54 for Leu and an addition of a Met at the N-terminus were introduced in the synthetic gene. The gene was cloned in the pQE-31 expression vector and was expressed in E. coli. A large amount of recombinant leptin containing 6 x His tag was produced and purified by Ni-NTA affinity column. Finally, intact leptin-L54 was released after removing the tag by CNBr cleavage at the Met residue.

A method for uni-directional reconstitution of human erythrocyte glucose transporter

The glucose transporter of human erythrocytes (Glut1) was reconstituted into soybean phospholipid liposomes by a method of direct incorporation using the nonionic detergent n-octyl beta-D-glucopyranoside. The reconstituted proteoliposomes were proved to be intact and low ionic permeability. Freeze-fracture electron microscopy study showed that the diameter of the proteoliposomes was about 150 +/- 50 nm and the protein was randomly distributed. The kinetic parameters of the reconstituted transporter were: Km =16.23 mmol/L, Vmax = 34.48 nmol/sec x mg protein. Furthermore, about 90% of the glucose transporter in the reconstituted proteoliposomes were orientated inside-out. Until now it is a more efficient method for uni-directional reconstitution of Glut1 with good reproducibility and higher transport activity.

Sensitivity of Ca2+ transport of mitochondria to reactive oxygen species

The relationship between Ca2+ transport and energy transduction of myocardial mitochondria in the presence of reactive oxygen species was investigated. Following treatment with oxygen free radicals [superoxide(O2.-) or hydroxyl radical (.OH)], lipid free radicals in myocardial mitochondrial membrane could be detected by using the method of EPR spin trap. Simultaneously there were obvious alterations in the free Ca2+ ([Ca2+]m) in the mitochondrial matrix; the physical state of membrane lipid; the efficiency of oxidative phosphorylation (ADP/O); the value of the respiratory control ratio (RCR); and the membrane potential of the inner membrane of myocardial mitochondria. If the concentrations of reactive oxygen species were reduced by about 30%, the alterations in the physical state of the membrane lipid and energy transduction of myocardial mitochondria were not observed, but the changes in Ca2+ homeostasis remained. We conclude that Ca2+ transport by myocardial mitochondria is more sensitive to agents such as O2.- or OH, etc. than are oxidation phosphorylation and the respiratory chain.

The role of ganglioside GM3 in the modulation of conformation and activity of sarcoplasmic reticulum Ca(2+)-ATPase

Rabbit sarcoplasmic reticulum does contain trace amounts of gangliosides, and the main species is GM3. Incorporation of GM3 into the SR vesicles or addition of it to the soybean phospholipid used for reconstitution of proteoliposomes obviously increased ATP hydrolysis, as well as, Ca2+ uptake activity of sarcoplasmic reticulum Ca(2+)-ATPase. Conformation changes of Ca(2+)-ATPase induced by GM3 were also observed by circular dichroism, intrinsic fluorescence and fluorescence quenching measurements.

Membrane formation and cellular response on the surface of lenses implanted in rabbit eyes

PURPOSE

To study the pathogenesis of membrane formation and cellular response on the surface of posterior chamber intraocular lenses (IOLs) implanted in rabbits.

SETTING

Department of Histology and Embryology, Pathology, Ophthalmology. The First Military Medical University, Guangzhou, P.R. China.

METHODS

Thirty rabbits had extracapsular lens extraction and posterior chamber IOL implantation. The IOLs were removed 4, 7, 15, 30, and 90 days postoperatively. Membrane formation and cellular response on IOL surfaces were evaluated using light (n = 25), transmission (n = 5), and scanning electron (n = 5) microscopy.

RESULTS

On 30 IOLs, the incidence of cellular adhesion was 100%. Cellular components comprised macrophages, fibroblast-like cells, epithelioid cells, giant cells, ultralarge giant cells, and lymphocytes. A thin, proteinaceous film was also seen on the surface of the IOLs. The membrane of the IOL surface comprised fibrin, collagen fibrils, macrophages, fibroblast-like cells, giant cells, and fibroblasts.

CONCLUSION

The findings of this study might apply to humans because cellular elements and membranes have been reported in humans.

Lipids may not be involved in the recognition of apocytochrome C during its transportation

It was shown that apocytochrome c was less insertion into monolayers from outer mitochondrial membrane lipids than into those from microsomal membrane lipids; the alpha-helix content of apocytochrome c induced by small unilamellar vesicles prepared from outer mitochondrial membrane lipids was less than by those from microsomal membrane lipids; the import efficiency of apocytochrome c into large unilamellar vesicles from outer mitochondrial membrane lipids was also lower than into those from microsome membrane lipids. No specific affinity between apocytochrome c and outer mitochondrial membrane lipids could be found. Import of apocytochrome c across the intact mitochondria, sealed outer mitochondrial membrane and microsome membrane vesicles was compared. Results showed that apocytochrome c was accumulated only in mitochondria, but not the other two kinds of vesicles.

Se-mediated domain-domain communication in band 3 of human erythrocytes

Na2SeO3 could affect the anion flux of Band 3 of inside-out erythrocyte membrane vesicles (IOVs). Such effect was believed to be based on the interaction of SH groups of Band 3 with Na2SeO3. This effect could be eliminated when the cytoplasmic domain of Band 3 was proteolytically removed by trypsin. This suggested that SH groups in the cytoplasmic domain were involved in such interaction. Measurement of the pH dependence of intrinsic fluorescence intensity provided evidence that conformational changes of Band 3 occurred as a consequence of interaction with selenite. KI quenching of intrinsic fluorescence of Band 3 could also show that there was a conformational change in the cytoplasmic domain of Band 3 after reaction with Na2SeO3. Such conformational change in turn could be transmitted to the membrane domain of Band 3 monitored by quenching of intrinsic fluorescence of Band 3 using hypocrellin B (HB) (a photosensitive pigment obtained from a parasitic fungus growing in Yunnan, China). It is suggested that the cytoplasmic domain of Band 3 is not necessary for its anion flux, but is essential for the regulation (e.g., by Se) of its active site located at the membrane domain, and hence, it may provide evidence of communication between the cytoplasmic domain and the membrane domain of Band 3.