Cerebral hyperperfusion syndrome after revascularization surgery in patients with moyamoya disease

Moyamoya disease (MMD) is a progressive occlusive disease of the distal internal carotid artery that is primarily treated by superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Despite its effectiveness, several postoperative complications have been reported with STA-MCA bypass. Cerebral hyperperfusion syndrome (CHS) after STA-MCA has attracted considerable attention as a hemodynamics-related complication because more cases of CHS after STA-MCA bypass are reported in MMD than in non-MMD patients. The mechanisms underlying CHS after revascularization in MMD patients are poorly understood. This report presents a comprehensive review of the literature on CHS after revascularization in MMD patients, focusing on the pathogenesis, clinical features, imaging techniques, treatment, and prognosis of CHS. Impaired cerebrovascular autoregulation has been implicated in the pathogenesis of CHS, which is characterized by unilateral headache, face and eye pain, seizures, and focal neurological deficits secondary to cerebral edema, and intracranial hemorrhage. Imaging techniques, such as single photon emission computed tomography (SPECT), 3-T magnetic resonance imaging/angiography, and selective arterial spin-labeling magnetic resonance imaging, are valuable for identifying patients at risk for CHS. Treatment strategies include strict blood pressure control, intracranial hemorrhage prevention, and free oxygen radical scavenger administration. Most patients can achieve a satisfying prognosis after effective treatment.

Comparative proteomic analysis of the nucleus accumbens during extinction and reinstatement of morphine dependence

BACKGROUND

The aim of this study was to detect differentially expressed proteins in the nucleus accumbens between the states of extinction and reinstatement ofmorphine addiction. Numerous studies on the neurobiological mechanisms concerning drug craving and relapse have been reported to date, but data on their relationship with the underlying key molecular mechanisms involved remain limited.

METHODS

In this study, 40 male Sprague-Dawley rats were equally randomized into a saline group and a morphine group. Both groups received drug self-administration training, after which extinction models were established naturally. The groups were further divided into two subgroups for extinction and reinstatement tests. Cerebral nucleus accumbens masses were measured for total protein extraction. Two-dimensional electrophoresis was performed to determine differential protein spots. These differential proteins were then enzymolysed and identified using mass spectrography.

RESULTS

The proteins were classified as fatty acid-binding protein, serine/threonine protein phosphatase 2A catalytic subunit beta isoform, serine/threonine protein phosphatase 2A catalytic subunit alpha isoform, serine/threonine protein phosphatase 2A regulatory subunit B2 subunit gamma or heat shock protein 90 co-chaperone CDC37.

CONCLUSION

Significant changes in five proteins were detected between extinction and reinstatement. These proteins are correlated with phosphorylation and the tricarboxylic acid cycle.

Report of a mental health survey among Chinese international students at Yale University

OBJECTIVE

To examine the prevalence of depression and anxiety symptoms in Chinese international students, to identify factors that might be associated with these 2 symptom complexes, and to investigate their perception of mental health issues and counseling services.

PARTICIPANTS

Chinese students (N = 130) at Yale University.

METHODS

Participants completed an anonymous online survey in fall 2009.

RESULTS

Forty-five percent reported symptoms of depression, and 29% reported symptoms of anxiety. A self-evaluation of poor current health, a poor relationship with one's advisor, and a low exercise regimen were associated with a higher prevalence of depression and anxiety symptoms. Twenty-seven percent of responders were not aware of the availability of mental health and counseling services on campus.

CONCLUSIONS

This study suggests that efforts should be made to improve the relationship between students and their advisors and to enhance the awareness of and the accessibility to mental health and counseling services to improve the mental health of Chinese international students.

Cloning and characterization of three chemosensory proteins from Spodoptera exigua and effects of gene silencing on female survival and reproduction

Insect chemosensory proteins (CSPs) are supposed to transport hydrophobic chemicals to receptors on sensory neurons. However, CSPs are broadly expressed in various insect tissues, suggesting their involvement in the physiological processes beyond chemoreception. So, the exact physiological roles of CSPs in insects still need to be unraveled. In this study, three full-length of CSP genes from Spodoptera exigua have been cloned and characterized. The deduced amino acid sequences of SexiCSP1, SexiCSP2 and SexiCSP3 revealed open reading frames of 128, 128 and 126 amino acids, respectively, with four conserved cysteine residues. The expression patterns of the three SexiCSPs were further investigated by real-time PCR. Three SexiCSPs were expressed in antennae, heads, legs, wings, thoraxes, abdomens, testes and ovaries, with the highest expression level in female and male antennae. Furthermore, all three SexiCSPs mRNA were distributed extensively in the tested development stages with the highest expression level in pupae. RNAi-based gene silencing study resulted in a dramatic reduction of corresponding mRNA in female S. exigua after injection with dsRNA of all three SexiCSPs. Consequentially, 42.5% of mortalities, 68.3% (compare to DEPC water injected control) and 71.4% (compare to uninjected control) oviposition inhibition, and significantly effected egg hatching were observed in the female S. exigua injected with dsSexiCSP3 as compared to control treatments. On the other hand, dsSexiCSP1 and dsSexiCSP2 injected female adults did not show effects on survival and reproduction. Our study confirms the utility of RNAi approach to functional characterization of CSP genes in S. exigua and provides a starting point for further studies on female survival and reproduction in this insect. It also reveals the potential pest controlling method, as insect behavior regulation agent that disrupts the expression of chemosensory proteins.

Development of a fluorescent-intercalating-dye-based reverse transcription loop-mediated isothermal amplification assay for rapid detection of seasonal Japanese B encephalitis outbreaks in pigs

The standardization and validation of a one-step, single-tube, accelerated fluorescent-intercalating-dye-based reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay targeting the NS3 gene of Japanese B encephalitis virus (JEV) is described for rapid, simple, and high-throughput detection of JEV. The amplification can be completed in 35 min under isothermal conditions at 63°C by employing a set of six primers targeting the NS3 gene of JEV. The RT-LAMP assay described demonstrated high sensitivity for detecting JEV, with a detection limit in swine samples of 8.13 PFU/ml. The specificity of the selected primer sets was established by cross-reactivity studies with pathogens that exhibit similar clinical signs and testing of samples from healthy animals. The clinical applicability of the RT-LAMP assay was validated using either spiked samples or samples from seasonal outbreaks. The comparative evaluation of the RT-LAMP assay revealed 79.59 % concordance with conventional RT-PCR targeting the E gene of JEV. The RT-LAMP assay reported here is a valuable tool for rapid real-time and high-throughput seasonal infection surveillance and quarantine after outbreak through blood sampling by using ordinary real-time PCR thermocyclers without purchasing an expensive Loopamp real-time turbidimeter.

Amino-Nogo-A antagonizes reactive oxygen species generation and protects immature primary cortical neurons from oxidative toxicity

Nogo-A is originally identified as an inhibitor of axon regeneration from the CNS myelin. Nogo-A is mainly expressed by oligodendrocytes, and also by some neuronal subpopulations, particularly in the developing nervous system. Although extensive studies have uncovered regulatory roles of Nogo-A in neurite outgrowth inhibition, precursor migration, neuronal homeostasis, plasticity and neurodegeneration, its cell-autonomous functions in neurons are largely uncharacterized. Here, we show that HIV-1 trans-activating-mediated amino-Nogo-A protein transduction into cultured primary cortical neurons achieves an almost complete neuroprotection against oxidative stress induced by exogenous hydrogen peroxide (H(2)O(2)). Endogenously expressed neuronal Nogo-A is significantly downregulated upon H(2)O(2) treatment. Furthermore, knockdown of Nogo-A results in more susceptibility to acute oxidative insults and markedly increases neuronal death. Interacting with peroxiredoxin 2 (Prdx2), amino-Nogo-A reduces reactive oxygen species (ROS) generation and extracellular signal-regulated kinase phosphorylation to exert neuroprotective effects. Structure-function mapping experiments reveal that, out of NiG-Δ20, a novel region comprising residues 290-562 of amino-Nogo-A is indispensable for preventing oxidative neuronal death. Moreover, mutagenesis analysis confirms that cysteine residues 424, 464 and 559 are involved in the inhibition of ROS generation and neuroprotective role of amino-Nogo-A. Our data suggest that neuronal Nogo-A might play a cell-autonomous role in improving neuronal survival against oxidative insult through interacting with Prdx2 and scavenging of ROS.

Loss of macrophage migration inhibitory factor impairs the growth properties of human HeLa cervical cancer cells

OBJECTIVES

  This study aims to determine the role of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine associated with cell proliferation and tumour growth in vivo.

MATERIALS AND METHODS

  Our team used RNA interference technology to knock down MIF expression in human HeLa cervical cancer cells and to establish a stable cell line lacking MIF function.

RESULTS

  Our results showed that long-term loss of MIF had little effect on cell morphology, but significantly inhibited their population growth and proliferation. The HeLa MIF-knockdown cells retained normal apoptotic signalling pathways in response to TNF-alpha treatment; however, they exhibited unique DNA profiles following doxorubicin treatment, suggesting that MIF may regulate a cell cycle checkpoint upon DNA damage. Our data also showed that knockdown of MIF expression in HeLa cells led to increased cell adhesion and therefore impaired their migratory capacity. More importantly, cells lacking MIF failed to either proliferate in soft agar or form tumours in vivo, when administered to nude mice.

CONCLUSION

  MIF plays a pivotal role in proliferation and tumourigenesis of human HeLa cervical carcinoma cells, and may represent a promising therapeutic target for cancer intervention.

Endovascular treatment of intracranial ruptured aneurysms associated with arteriovenous malformations: a clinical analysis of 14 hemorrhagic cases

This study investigated and summarized endovascular therapeutic strategies for intracranial ruptured aneurysms associated with arteriovenous malformations (AVMs). Between June 2005 and June 2009, we identified 16 aneurysms in 14 hemorrhagic cases of intracranial AVM using digital subtraction angiography (DSA). Of the 16 aneurysms, 14 were ruptured and two were unruptured. Aneurysms were classified as types I to IV, and were treated. Aneurysm treatment was followed by AVM treatment via various therapies, including embolization, gamma knife radiotherapy, or follow-up and observation to reduce the risk of aneurysm rupture or intracranial hemorrhage. Over a follow-up period ranging from six months to one year, none of the patients had aneurysm ruptures or intracranial hemorrhage. Most (13/14) patients had a Glasgow Outcome Scale (GOS) score of 5, and one patient had a score of 4. Sixteen aneurysms were treated successfully, as confirmed by DSA examination, and no AVMs re-grew. Clinical therapeutic strategies for intracranial ruptured aneurysms associated with AVMs should include aneurysm treatment first to reduce the risk of rupture and intracranial hemorrhage, eventually leading to a better prognosis.

In vivo assessment of chitosan/β-glycerophosphate as a new liquid embolic agent

We sought to assess the feasibility of using thermosensitive chitosan/β-glycerophosphate forembolotherapy. The renal arteries in nine rabbits were embolized with chitosan/β-glycero-phosphate. The animals were studied angiographically and sacrificed at one week (n = 3), four weeks (n = 3), and eight weeks (n = 3) after embolotherapy. Histology was obtained at these three time points. Delivery of chitosan/β-glycerophosphate was successful in all cases. Complete occlusion was achieved in all cases. No recanalization was observed in the follow-up angiograms. No untoward inflammatory reactions were observed in the target renal arteries and infarcted kidneys during the histological examinations. Our preliminary feasibility evaluation in rabbit renal arteries indicates that C/GP is a satisfactory embolization agent.

Fenton-biological treatment of reverse osmosis membrane concentrate from a metal plating wastewater recycle system

Although reverse osmosis (RO) has been widely used in the recycling of metal plating wastewater, organic compounds and heavy metals in the RO concentrate are difficult to remove by conventional treatment. A combination process including Fenton oxidation and a biological aerated filter was used to treat RO concentrate containing complex Cu and Ni from metal plating. During the Fenton treatment, Cu and Ni ions were released due to degradation of organic compounds and then removed by pH adjustment and coagulation. The concentrate was further treated using by a biological aerated filter. Optimum conditions were as follows: initial pH of influent of 4.0; dosage of H2O2 of 5.0 mmol l(-1); ratio of n(Fe2+)/n(H2O2) of 0.8; precipitation pH of Cu and Ni ions of 8.0; and a hydraulic retention time of the biological aerated filter of 2.5 h. The results showed that concentrations of effluent COD, Cu and Ni ions were less than 40 mg l(-1), 0.5 mg l(-1) and 0.3 mg l(-1), respectively; this means the treated effluent meets the emission standards for pollutants from electroplating set by China's Environmental Protection Agency.

Endovascular treatment of aneurysms arising from the basilar artery trunk and branches

This study reports our experience with the endovascular treatment of basilar artery (BA) trunk and branch aneurysms. Subjects included 16 patients with BA trunk and branch aneurysms who underwent endovascular treatment in our hospital from October 2000 to October 2009, including four patients with associated arteriovenous malformation (AVM), two with associated moyamoya disease, one with multiple aneurysms at adjacent sites, and one with a distant aneurysm. Endovascular coil embolization, together with stent or balloon assistance when necessary, or while occluding the parent artery was performed. Associated diseases were managed intraoperatively or in the second stage, or treated with gamma knife radiotherapy, or followed up. Two patients with unsuccessful embolization died of re-rupture at the fourth month and fifth month follow-up. The remaining 14 patients reported good outcomes and experienced no re-rupture of either the aneurysm or associated disease. Angiographic follow-ups were conducted for the 14 patients for six to 12 months. Digital subtraction angiography (DSA) examination at the last follow-up showed no recurrence of the BA trunk and branch aneurysms. Together, BA trunk and branch aneurysms should be actively managed via endovascular techniques to prevent serious consequences due to aneurysm rupture and bleeding. Favorable outcomes can be obtained by the proper selection of endovascular treatment regimens.

Endovascular embolization of distal anterior choroidal artery aneurysms associated with moyamoya disease. A report of two cases and a literature review

We evaluated the feasibility of endovascular embolization for the management of distal anterior choroidal artery (AChA) aneurysms associated with moyamoya disease and performed a literature review to summarize their clinical features and treatment. We describe two cases of moyamoya disease-associated distal AChA aneurysms treated by endovascular embolization. In both cases, a good outcome was observed. We performed a MEDLINE (1980-2010) search which identified 13 similar cases. Our analysis of the clinical data from these 15 cases led us to conclude that (i) endovascular embolization is an effective and feasible treatment for distal AChA aneurysms associated with moyamoya disease; (ii) aneurysm location and the preservation of the parent artery are two major prognostic factors for moyamoya disease-associated distal AChA aneurysms subjected to craniotomy or endovascular therapy; (iii) the parent artery should be preserved when the aneurysm is located in the temporal horn of the lateral ventricle, but sacrificed when it is located in the trigone of the lateral ventricle.

Endovascular treatment of intracranial aneurysms associated with moyamoya disease or moyamoya syndrome

Direct surgical clipping proves to be difficult and dangerous for intracranial aneurysms associated with moyamoya disease (MMD) or moyamoya syndrome (MMS). This study presents our clinical experience of endovascular embolization of intracranial aneurysms associated with these diseases. A total of 13 cases of intracranial aneurysms associated with MMD or MMS were treated by endovascular embolization between January 2001 and January 2009. Patients were divided into two groups: a saccular aneurysm group (n=10) and a pseudoaneurysm group (n=3). Different endovascular therapeutic strategies were employed for each type of case. Of the 13 cases, 11 received successful endovascular embolization and had an uneventful postoperative course during one to two years of follow-up. However, endovascular embolization failed in the other two cases, of whom one died from rebleeding after the five-month follow-up, while the other was conservatively treated and experienced no rebleeding during the two-year follow-up. A favorable prognosis may be secured through careful selection of endovascular treatment regimens for patients with intracranial aneurysms associated with MMD or MMS according to the site of intracranial aneurysms.

Microsurgical clipping of intracranial aneurysms following unsuccessful endovascular treatment. Analysis of ten cases

The purpose of the current study was to examine the reasons for failed endovascular aneurysm coiling and to determine the outcome of immediate microsurgical clipping. From July 2006 to July 2008, 198 patients underwent endovascular coiling at our institute; among them, ten cases were unsuccessful. All of the patients were diagnosed with intracranial aneurysms (ICAs) by cranial computed tomography angiography (CTA), and all underwent endovascular treatment without digital subtraction angiography (DSA). When endovascular coiling failed, the patients were immediately transferred to the operating room for microsurgical clipping under the same anesthetic. The ten patients were divided into three groups based on the cause of endovascular failure and associated clinical features. The clinical follow-up period was between 6-12 months, and all 10 patients had good outcomes following the surgery. Taken together, the results of this study suggest that immediate microsurgical clipping after failed endovascular coiling is efficient and may provide improved outcomes by preventing rebleeding.

Endovascular Treatment of Intracranial Wide-Necked Aneurysms with GDCs Combined with Balloon or Stent

This article introduces our experience in embolizing wide-necked intracranial aneurysms with GDCs combined with balloon or stent. Fifty-five patients with wide-necked intracranial aneurysms (aneurysm neck ranged 2.1-7.0 mm, body/neck ≤2) underwent embolizing treatment with GDCs combined with balloon or stent. Twenty patients were treated with balloon technique. Only one complication occurred when one loop of a coil herniated into the parent artery after the GDC were detached, but no parent artery obstruction occurred. One patient died because from aneurysm rupture caused by herniation of the balloon through the over wide neck into the aneurysm during inflating. Thirty-five patients were treated with the stent technique. Five aneurysms were treated using a stent alone. Two of the five aneurysms could not be recognized from DSA after the stents were released (three and six month follow-ups showed no recurrence), one of the five ruptured leading to the patient's death two weeks after the operation. There was no aneurysm recurrence seen by DSA in the post operative follow-up of six to 12 months. GDCs combined with balloon or stent techniques are safe and effective in treatment of wide-necked intracranial aneurysms.

Improved GFR estimation by combined creatinine and cystatin C measurements

Plasma creatinine may not reflect glomerular filtration rate (GFR) especially in the early stages of chronic kidney disease (CKD). Plasma cystatin C (cysC), however, has the potential to more accurately determine early GFR reduction. We sought to improve the creatinine-based GFR estimation by including cysC measurements. We derived a reference GFR from standard dual plasma sampling (99m)Tc-DTPA clearance in a training cohort of 376 randomly selected adult Chinese patients with CKD. We compared reference values to estimated GFR and applied multiple regression models to one equation based solely on cysC, and to another combining plasma creatinine (Pcr) and cysC measurements of the training cohort. The results were validated by testing an additional 191 patients. The difference, precision, and accuracy of the two estimates were compared with the modified Modification of Diet in Renal Disease (MDRD) equation for Chinese patients, and another estimate combining cysC and modified MDRD calculations. The estimated GFR combining Pcr and cysC measurements more accurately matched the reference GFR at all stages of CKD than the other equations, particularly in patients with near-normal kidney function.

Export of toxic chemicals - a review of the case of uncontrolled electronic-waste recycling

This paper reviews the concentrations of persistent organic pollutants such as flame retardants (PBDEs), dioxins/furans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals/metalloid concentrations of different environmental media at Guiyu, a traditional rice-growing village located in southeastern Guangdong Province (PR China), which has turned into an intensive electronic-waste (e-waste) recycling site. Incomplete combustion of e-waste in open air and dumping of processed materials are the major sources of various toxic chemicals. By comparing with existing data available in other areas and also guidelines adopted in different countries, it is obvious that the environment is highly contaminated by these toxic chemicals derived from the recycling processes. For example, the monthly concentration of the sum of 22 PBDE congeners contained in PM(2.5) (16.8ngm(-3)) of air samples at Guiyu was 100 times higher than published data. In order to safeguard the environment and human health, detailed investigations are urgently needed, especially on tracking the exposure pathways of different toxic chemicals which may affect the workers and local residents especially mothers, infants and children.

The interference of operant task performance by emotional distracters: an antagonistic relationship between the amygdala and frontoparietal cortices

This fMRI study investigates neural activity associated with the interfering effects of emotional distracters. While in the scanner, participants made simple motor responses to target stimuli that were preceded and followed by positive, negative, or neutral images. Despite instructions to disregard the pictorial images, participants were slower to respond in the presence of positive or negative relative to neutral distracters, and significantly slower for negative relative to positive distracters. Enhanced activity in the amygdala and visual cortex was evident during trials that included positive and negative distracters. In contrast, increased activity in inferior frontal gyrus (BA 47) was only observed during trials that involved negative distracters. Connectivity analysis showed that activity in right amygdala correlated with activity in cingulate gyrus, posterior cingulate, middle temporal cortex, and was negatively correlated with activity in lateral superior frontal gyrus, middle frontal/orbital gyrus, and parietal cortex. The pattern of neural activity observed was interpreted within the framework of current cognitive models of attention. During a task demonstrating behavioural interference in the context of emotional distracters, increased activity in neural regions implicated in emotional processing (the amygdala) was associated with reduced activity in regions thought to be involved in exerting attentional control over task-relevant sensory representations (a frontoparietal network).

Paeoniflorin inhibits TGF-beta1-mediated collagen production by Schistosoma japonicum soluble egg antigen in vitro

The main pathological characteristics of hepatic fibrosis in schistosomiasis are the proliferation of hepatic stellate cells (HSCs) and the deposition of collagen type I (Col I) and collagen type III (Col III). Transforming growth factor beta-1 (TGF-beta1) plays an important role in hepatic fibrosis. Paeoniflorin (PAE) has been reported to have immunoregulatory effects; however, the mechanism of its anti-hepatic fibrosis in S. japonicum has not been elucidated. In the present study, we found that mouse peritoneal macrophages (PMphis) stimulated by soluble egg antigen (SEA) of S. japonicum could secrete TGF-beta1, and the TGF-beta1 in the peritoneal macrophage-conditioned medium (PMCM) could induce proliferation of HSCs and secretion of Col I and III. We selected PMCM at 1 : 2 dilution as the optimum PMCM (OPMCM). Then we treated HSCs pre-incubated with OPMCM with PAE, and found that the inhibition of HSC proliferation or Col I and III production were closely correlated with the concentration of PAE. Further investigation found that PAE significantly decreased the Smad3 transcription and phosphorylation in HSCs stimulated by OPMCM. In conclusion, SEA plays a key role in hepatic fibrosis by inducing TGF-beta1 from PMphis. PAE can exert anti-fibrogenic effects by inhibiting HSCs proliferation and down-regulating Smad3 expression and phosphorylation through TGF-beta1 signalling.

Photocatalytic oxidation of triclosan

In the spring of 2003, there was an outbreak of the severe respiratory syndrome (SARS) in Hong Kong. Health concerns have thus triggered an increased and predominant use of various types of household cleansing agents such as triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol). However, it has been reported recently that triclosan could be photochemically converted to toxic 2,8-dichlorodibenzo-p-dioxin (2,8-Cl(2)DD) in the environment. It is therefore necessary to develop environmentally friendly methods for the treatment of triclosan. To this end, photocatalytic degradation of triclosan in aqueous solution was conducted using TiO(2) (Degussa P25) under irradiation of UV light (lambda < 365 nm). It was found that triclosan could be degraded by this approach. Hydrogen peroxide was added to enhance the degradation process, and the optimal initial hydrogen peroxide concentration for triclosan degradation was 0.005% (w/v). Product identification indicated that triclosan oxidation occurred at its phenol moiety and yielded quinone and hydroquinone intermediates. The formation of a dichlorophenol intermediate in triclosan degradation suggested bond-breaking of the ether linkage occurred during the process. Moreover, no chlorinated dibenzo-p-dioxin congener was detected. These findings confirm that the photocatalytic degradation of triclosan is an environmentally friendly process.

Increase of the cure rate of burn patients by improving burn wound management methods

In order to summarize the progress of burn wound management of the patients in our burn ward and its correlation with the improvement of treatment results in the past 44 years, the general data (hospitalization time, cure rate, operation times) of 12,568 cases were analysed in terms of three periods, namely 1958 to 1980, 1981 to 1990, and 1991 to 2002. The bene?cial effects of the systemic application of recombinant human growth hormone, post-burn immediate escharectomy en masse, the external application of epithelial growth factor, and the coverage of split-thickness skin donor sites with razor-thick skin on wound healing and overall therapeutic results were also analysed. It was found that there was an increase in the number of burn patients admitted to our burn ward in recent decades. The overall cure rate, especially that of major burn patients, increased signi?cantly with the improvement of burn wound management. Hospitalization time was shortened and wound-healing time reduced. The analysis suggested that escharectomy en masse as early as possible, systemic application of growth hormone, and external application of epithelial growth factor are bene?cial to early burn wound healing.

Bipolar Microscissors

The authors present a novel bipolar-coagulation microscissors exclusively designed for microsurgical use which can be applied easily, safely and effectively. The device is particularly helpful in the management (coagulation and cutting) of cerebral microvessels during the resection of brain tumors rich in vascularity or AVMs. The advantages of the instrument are the avoidance of exchanges of bipolar and microscissors under the microscope, reduction of fatigue for the operator, and decreases of operative time and blood loss while still achieving a good result.

Wave dispersion near cyclotron resonance in pulsar plasmas

In a standard pulsar model, the radio emission is produced in the relativistic, strongly magnetized electron-positron plasma in the polar-cap region of the magnetosphere. Waves are generated well below the cyclotron frequency and must propagate through the cyclotron resonance region where they are affected by the resonance. Wave dispersion near the cyclotron resonance is discussed in the formalism of the weak anisotropy approximation in which the relevant waves are treated as transverse. Analytical approximations for the two orthogonal modes are derived, in the rest frame of the plasma, for nearly parallel, nearly antiparallel and nearly perpendicular propagation with respect to the magnetic field direction. It is shown that due to the relativistic distribution the wave dispersion varies smoothly across the resonance with initially elliptical polarization evolving to linear and then elliptical polarization with opposite handedness. The relevance of such a change in handedness to the interpretation of circular polarization is discussed.

Sensing of Halocarbons Using Femtosecond Laser-Induced Fluorescence

A femtosecond laser-induced clean fluorescence technique was explored as a means to monitor halogenated alkanes in the atmosphere. Characteristic difluorocarbene radical (CF2) fluorescence in the UV-vis can be generated inside a femtosecond laser-induced filament for different halocarbons. We show that, due to different dissociation and excitation kinetics leading to fluorescence emission, it is possible to temporally resolve the characteristic fluorescence of CF2-containing halocarbons from that of background species, therefore enhancing the signal-to-noise ratio. Laboratory-scale experiments demonstrate the potential use of femtosecond laser-induced clean fluorescence for the remote sensing of halocarbons in the atmosphere. The combination of this detection strategy with LIDAR could allow the long-range monitoring of several atmospheric species with a single laser source, eventually leading to a better understanding of chemical and dynamic processes affecting global warming, ozone loss, tropospheric pollution, and weather prediction.

Expression of a novel regenerating gene product, Reg IV, by high density fermentation in Pichia pastoris: production, purification, and characterization

Human regenerating (Reg) gene products are regionally expressed by gut-derived tissues, and are markedly up-regulated in cancer and in diseases characterized by mucosal injury. We recently identified Reg IV, a novel regenerating gene product that is uniquely expressed by the normal distal gastrointestinal mucosa. The function remains poorly understood due to the lack of significant purified Reg IV for biochemical and functional studies. Recombinant human Reg IV was efficiently expressed under the control of the AOX1 gene promoter in Pichia pastoris using the MutS strain KM71H. We describe the unique conditions that are required for efficient production of Reg IV protein in high density fermentation. Optimal protein expression was obtained by reduction of the fermentation temperature and addition of casamino acids as a supplemental nitrogen source and to minimize the activity of yeast produced proteases. Recombinant Reg IV protein was purified by tangential flow filtration and reverse phase chromatography. The purified protein was characterized by amino terminus sequence analysis and MALDI-TOFMS showing that the engineered protein had the expected sequence and molecular weight without secondary modification. Recombinant Reg IV was further characterized by specific monoclonal and polyclonal reagents that function for Western blot analysis and for immunolocalization studies.

Characteristics of a bioflocculant produced by Bacillus mucilaginosus and its use in starch wastewater treatment

A bioflocculant, MBFA9, was produced from a strain of bioflocculant-producing bacteria isolated from a soil sample and identified as Bacillus mucilaginosus. MBFA9 had a good flocculating capability and could achieve a flocculating rate of 99.6% for kaolin suspension at a dosage of only 0.1 ml/l. The major component of MBFA9 was found to be polysaccharide composed mainly of uronic acid (19.1%), neutral sugar (47.4%) and amino sugar (2.7%). Infrared spectrum analysis showed the presence of carboxyl and hydroxyl groups in the bioflocculant. MBFA9 is nontoxic and can be used in food industries for suspended solids (SS) recovery. When applied to starch wastewater treatment, MBFA9 greatly accelerated the formation of flocs and the settling of organic particles in the presence of Ca(2+) salt. After 5 min of settling, the removal rate of SS and chemical oxygen demand were up to 85.5% and 68.5%, respectively, which is better than traditional chemical flocculants.

Wave dispersion in gyrotropic relativistic pulsar plasmas

Wave dispersion in a gyrotropic relativistic pulsar plasma is discussed. A pulsar plasma in general contains electrons, positrons, and possibly ions. Although electron-positron pairs are dominant in number density, charge neutrality is generally not satisfied and the gyrotropic terms need to be considered. These gyrotropic terms can lead to elliptical polarization that may be relevant for the observed circular polarization of pulsar radio emission. The wave dispersion and polarization are obtained numerically by calculating the response in terms of the three relativistic plasma dispersion functions. For waves propagating at an oblique angle (to the ambient magnetic field) a significant ellipticity requires the plasma to deviate substantially from the neutrality condition.

Quantification and reduction of organic sulfur compound formation in a commercial wood pulping process

This study experimentally quantified the formation of organic sulfur compounds in a commercial SuperBatch kraft pulping process using a laboratory pilot-scale digester. The results indicate that wood chips not only can adsorb HS- but also methyl mercaptan (MM) in the black liquor used for pretreatment during the two pretreatment stages. The absorption rate of MM is much faster than that of HS-. In the third stage of SuperBatch pulping, the rate of formation of MM and dimethyl sulfide (DMS) is very similar to that found in conventional batch kraft pulping processes. The study examined the applicability of the phase transition cooking (PTC) concept for reducing organic sulfur compounds in pulping, previously developed in laboratory batch pulping using a bomb-type digester, in a SuperBatch process. It was confirmed that there is a phase transition point (PTP) corresponding to PTC in SuperBatch pulping beyond which further delignification significantly increases the formation of volatile organic sulfur compounds. The results indicate that a 40% reduction of TRS formation can be achieved by using PTC.

Quasilinear diffusion as a result of modulational instability in the pulsar plasma

Quasilinear diffusion due to modulational instability is considered in this paper. Interaction between the high-frequency, nearly transverse O mode (or the transverse X mode) and the low-frequency, nearly longitudinal L-O mode in a pulsar magnetospheric pair plasma can lead to modulational instability. The low-frequency L-O mode is superluminal, which is not subjected to usual Landau damping, and it is possible that excess wave energy is stored in this superluminal mode. The superluminal low-frequency L-O mode can dissipate in a way similar to the process of Langmuir wave collapse, that is, it cascades from the long- to short-wavelength regimes. When the phase speed becomes less than c, the waves can be damped through various resonances. We consider, in particular, damping through cyclotron resonance, which can lead to particle acceleration. The energetic beam particles, which have a very small spread initially, can develop a high-energy distribution tail, acquiring pitch angles through quasilinear diffusion. These particles can emit gamma rays through synchrotron radiation, contributing to the observed pulsar high-energy emission.

Multiple headspace extraction-gas chromatographic method for the study of process kinetics

A multiple headspace extraction gas chromatographic technique to automate the study of process kinetics that involves volatile species was developed in this study. The technique was demonstrated by using it to study methanol formation in kraft black liquor samples under an isothermal temperature of 70 degrees C. The results indicate that methanol formation in kraft black liquors under isothermal conditions follows an exponential decay function. The present method is very simple, efficient and fully automated. It can be easily applied to study slow kinetic processes, such as reaction or adsorption and desorption, involving volatile species in any environmental and industrial samples with complicated matrices.

[Modification of membrane lipid of human umbilical vein endothelia cells after direct lipopolysaccharide injury]

Our previous study showed that the membrane viscosity of human umbilical vein endothelial cells (HUVECs) increased with lipopolysaccharide (LPS) concentration after direct LPS damaging, implying that LPS could change the membrane structure and composition of HUVECs. The purpose of the present study was to investigate the modification of HUVECs membrane lipid by LPS under direct LPS injury to HUVECs. Phospholipid components of HUVEC membrane were determined with high performance capillary electrophoresis (HPCE), and HUVECs were directly damaged by LPS of different concentrations: 0, 0.313, 0.625, 1.25, 2.5, 5 and 10 microgram/ml for 3 h, and by 0.625 microgram/ml for 1, 3, 6, 12, 24 and 48 h. The results show that total phospholipid content of HUVECs increased with the increase of LPS concentration at 3 h, and decreased with the duration of LPS effect at 0.625 microgram/ml. Phosphatidylinositol (PI) and phosphatidylcholine (PC) contents increased with the increase of LPS concentration and decreased with the duration of LPS effect; LPS contents and its effect duration had slight effect on sphingomyelin (SM), phosphatidylethanolamine (PE) or phosphatidylserine (PS) contents. The LPS activating effect of HUVEC membrane lipid showed a typical property of enzymatic dynamics. These experimental results indicate that LPS directly activates the metabolism of HUVEC membrane lipid and induces the modification of HUVEC membrane phospholipid, which implies that the mechanism of the impairment of HUVECs by LPS may be related to the membrane structure of HUVECs and the metabolism of HUVEC membrane lipid.

[Field study on the removal of arsenic from dispersed drinking water]

Shanyin county, an area prevalent of endemic arsenic poisoning in Shanxi Province, was selected as the experimental field to verify the methods studied for removal arsenic from dispersed drinking water. The results showed that the desired goal has been achieved from the field study. The results confirmed that arsenate could be removed from drinking water by using ferric sulfate or aluminum sulfate as coagulants and employing sand filtration. Javelle water(sodium hypochlorite) is an effective oxidant for arsenite. The performance of iron oxide-coated sand developed in this study was good for arsenic removal. Further study and application is needed.