Dynamic Changes and Prognostic Value of Gut Microbiota-Dependent Trimethylamine-N-Oxide in Acute Ischemic Stroke

Background: Acute ischemic stroke (AIS) is an atherothrombotic disease. Trimethylamine-N-oxide (TMAO), a gut microbiota-dependent metabolite, has been shown to be proatherogenic and prothrombotic. However, the involvement of TMAO in AIS remains unclear. This study aimed to observe the dynamic changes of TMAO in AIS patients and identify the prognostic value of TMAO for major ischemic events and unfavorable functional outcomes. Methods: This study included 204 AIS patients and 108 healthy controls. Blood samples for TMAO analyses were drawn at admission, 2 and 7 days of admission. Logistic regression models and receiver operating characteristic curves were established to identify associations between TMAO levels and major ischemic events (ischemic stroke, myocardial infarction, or death from an ischemic vascular event), as well as unfavorable functional outcomes (modified Rankin Scale score ≥3), at 90 days and 12 months. Results: TMAO levels showed no significant changes before and within 24 h of AIS treatment (at admission) but decreased significantly thereafter. Elevated log₂-transformed baseline TMAO levels were associated with increased risks of 90-day [odds ratio (OR), 2.62; 95% confidence interval (CI), 1.55-4.45; p < 0.001] and 12-month (OR, 3.59; 95% CI, 2.12-6.09; p < 0.001) major ischemic events, as well as 90-day (OR, 2.89; 95% CI, 1.46-5.71; p = 0.002) and 12-month (OR, 2.58; 95% CI, 1.50-4.46; p = 0.001) unfavorable functional outcomes, after adjustments for confounding factors. The areas under curve of baseline TMAO levels for predicting 90-day and 12-month major ischemic events were 0.72 (95% CI, 0.61-0.83; p < 0.001) and 0.76 (95% CI, 0.66-0.85; p < 0.001). Baseline TMAO levels improved the prognostic accuracy of conventional risk factors, National Institutes of Health Stroke Scale (NIHSS) score and N-terminal B-type natriuretic peptide (NT-proBNP) level. Conclusions: TMAO levels decreased with time since stroke onset. Elevated TMAO levels at an earlier period portended poor stroke outcomes, broadening the potential clinical utility of TMAO as an independent prognostic marker and therapeutic target.

[Single-stage repair of penile urethral stricture using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap]

OBJECTIVE

To evaluate the clinical effect of single-stage repair of penile urethral stricture using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap.

METHODS

We retrospectively reviewed the clinical database of 22 male patients with penile urethral stricture who received single-stage repair using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap from November 2015 to October 2018. All the cases had no complications, such as skin fistula. The causes of stricture included iatrogenic (14/22, 63.6%), inflammation (2/22, 9.1%) and idiopathic (6/22, 27.3%). A ventral urethrotomy was made in the segment of stricture and extended proximally and distally until the normal calibre urethra was encountered. The oral mucosa graft was secured to the corpus spongiosum in dorsal onlay fashion or underlying corpora cavernosum after resection of the severe scarred urethra. Then the prepared Orandi fasciocutaneous penile skin flap was secured to edges of corpus spongiosum or oral mucosa graft. A 16 F or 14 F Foley catheter was left in situ for a minimum of 3 weeks, at which time a urethrogram was performed to look for extravasation, and the urethroscopy was performed if necessary. Success was defined as an open urethra with Qmax≥15 mL/s and no need for further surgical intervention.

RESULTS

all the 22 patients with a mean age of 52.6 (18-73) years underwent the combined tissue-transfer technique. The mean length of the penile urethral stricture was 5.3 (2.5-10.0) cm and the mean preoperative Qmax was 6.7 mL/s. the mean length of oral mucosa grafts and fasciocutaneous skin flaps were 5.5 (3.2-10.5) cm and 6.0 (3.5-11.0) cm, respectively. The mean operation time was 225 (150-420) minutes and the mean evaluated blood loss was 53 (20.0-110.0) mL. The grafts included buccal mucosa (19/22, 86.4%) and lingual mucosa (3/22, 13.6%). The mean postoperative Q max was 21.2 (15-32) mL/s. A case of skin fistula and 2 cases of recurrent stricture were found, so the technique success rate was 81.8% (18/22) at a mean follow-up of 20.5 (5-51) months. The perioperative complications included 2 cases of infection and skin necrosis, which healed well after conservative treatment.

CONCLUSION

Single-stage repair of penile urethral stricture using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap appears to be an excellent option to repair penile urethral stricture with unsalvageable urethral plate and the penile skin is available. The present clinical series showed a successful rate of 81.8% (18/22).

Impact of molecular structure and charge property of chitosan based polymers on flocculation conditioning of advanced anaerobically digested sludge for dewaterability improvement

Anaerobically digested sludge is generally difficult to dewater due to the release of sticky soluble microbial products in anaerobic digestion. Traditional flocculation processes have the disadvantages of high chemical dosing and solid increase, thus affecting subsequent land application. Therefore, it is desirable to develop low-cost, biodegradable, nontoxic and environmentally friendly sludge conditioners. In this work, the chitosan (CTS) was chemically modified by incorporating functional groups (amino group and the carboxyl group) to improve its water solubility and flocculation efficiency, and the anaerobically digested sludge conditioning effectiveness of different chitosan based flocculants were comparatively investigated. Results indicated that aminated chitosan (CTS-DMDAAC) and CTS performed well in sludge dewatering improvement in terms of specific resistance to filtration (SRF) and Capillary suction time (CST), which decreased to a minimum when the concentration of conditioner reached to 35 mg/g TSS. Flocs conditioned by CTS-DMDAAC were more compact and aggregated more efficiently than that flocculated with CTS and C-CTS (carboxylated chitosan). CTS-DMDAAC and CTS interacted with extracellular polymeric substance (EPS) by charge neutralization and complexation adsorption, which caused the densification of gel-like structure and enhancement of floc strength of sludge. Scanning electron microscope (SEM) analysis showed that after CTS-DMDAAC treatment, there were plentiful large pores distributed on floc surface, which provided channels for water release under pressure filtration. Confocal laser scanning microscopy (CLSM) confirmed that protein-like substances were agglomerated under flocculation conditioning, which was responsible for the promotion of sludge dewatering performance. This study provides a green and promising solution for the improvement of anaerobically digested sludge dewatering performance.

Characterization of changes in extracellular polymeric substances and heavy metal speciation of waste activated sludge during typical oxidation solubilization processes

Biopolymer solubilization is considered to be the rate-limiting stage of anaerobic digestion of waste activated sludge (WAS). Oxidation processes have been proven to be effective in disrupting sludge flocs and causing solubilization of the solid biopolymers. In this study, WAS was treated by NaNO₂ or H₂O₂ oxidation at pH of 2. The changes in extracellular polymeric substances properties and the speciation of heavy metals were investigated. The results revealed that both NaNO₂ and H₂O₂ treatments were effective in solubilizing organics in WAS, while the conversion of biopolymers in the two treatment processes was different. Free nitrous acid destroyed the gel network structure of EPS, and organic materials were released from the solid phase to the supernatant. Indigenous peroxidase catalyzed H₂O₂ to produce hydroxyl radicals which caused significant solubilization of biopolymers, and the protein-like substances were further degraded into micro-molecule polypeptides or amino acids at high dosages of H₂O₂. During the oxidation processes, Zn, Cd and Cu, with excellent mobility, tended to migrate to the supernatant, and thus were easy to remove through the liquid-solid separation process. Ni and As showed moderate migration ability, of which the residual fraction tended to transform into reducible and soluble fractions. With poor mobility, Cr and Pb mainly existed in the forms of residual and oxidizable fractions, which were difficult to dissolve and remove from WAS. Both NaNO₂ and H₂O₂ treatment resulted in the enhancement of sludge solubilization efficiency and heavy metal mobility in WAS, but different heavy metals showed distinct migration and transformation behaviors.

Dysbiosis of the intestinal microbiota in neurocritically ill patients and the risk for death

Background

Despite the essential functions of the intestinal microbiota in human physiology, little has been reported about the microbiome in neurocritically ill patients. This investigation aimed to evaluate the characteristics of the gut microbiome in neurocritically ill patients and its changes after admission. Furthermore, we investigated whether the characteristics of the gut microbiome at admission were a risk factor for death within 180 days.

Methods

This prospective observational cohort study included neurocritically ill patients admitted to the neurological intensive care unit of a large university-affiliated academic hospital in Guangzhou. Faecal samples were collected within 72 h after admission (before antibiotic treatment) and serially each week. Healthy volunteers were recruited from a community in Guangzhou. The gut microbiome was monitored via 16S rRNA gene sequence analysis, and the associations with the clinical outcome were evaluated by a Cox proportional hazards model.

Results

In total, 98 patients and 84 age- and sex-matched healthy subjects were included in the analysis. Compared with healthy subjects, the neurocritically ill patients exhibited significantly different compositions of intestinal microbiota. During hospitalization, the α-diversity and abundance of Ruminococcaceae and Lachnospiraceae decreased significantly over time in patients followed longitudinally. The abundance of Enterobacteriaceae was positively associated with the modified Rankin Scale at discharge. In the multivariate Cox regression analysis, Christensenellaceae and Erysipelotrichaceae were associated with an increased risk of death. The increases in intestinal Enterobacteriales and Enterobacteriaceae during the first week in the neurological intensive care unit were associated with increases of 92% in the risk of 180-day mortality after adjustments.

Conclusions

This analysis of the gut microbiome in 98 neurocritically ill patients indicates that the gut microbiota composition in these patients differs significantly from that in a healthy population and that the magnitude of this dysbiosis increases during hospitalization in a neurological intensive care unit. The gut microbiota characteristics seem to have an impact on patients’ 180-day mortality. Gut microbiota analysis could hopefully predict outcome in the future.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2488-4) contains supplementary material, which is available to authorized users.

[Clinical significance of continuous transfixion suture for nasal septum in septoplasty]

Objective:To systemically evaluate the clinical significance of continuous transfixion suture for nasal septum in septoplasty. Method:Forty patients with nasal septum deviation were randomly assigned to the suture group including 20 patients who underwent endoscopic septoplasty followed by continuous transfixion suture for nasal septum, or the nasal packing group including 20 patients who underwent endoscopic septoplasty followed by nasal packing. Two groups were compared for the visual analogue scale (VAS) scores for postoperative rhinalgia, headache, lacrimation, dysphagia and sleep disorder, changes in mucociliary transport time (MTT) before and after surgery, and postoperative capillary hemorrhage. Patients were followed up for 2 weeks to observe the short-term postoperative complications. Result:Mean VAS scores for rhinalgia, headache, lacrimation, dysphagia and sleep disorder were all higher in nasal packing group than those in suture group (P<0.05); compared to suture group, there was greater prolongation of MTT before and after surgery in packing group (P<0.05); there was significant difference between two groups in postoperative capillary hemorrhage volume (P<0.05); in the nasal packing group, nasal synechia, nasal dryness and hyposmia were observed in 1, 3 and 2 patients, respectively, within 2 weeks postoperatively, whereas no short-term complications were observed in the suture group. Conclusion:Use of continuous transfixion suture in place of nasal packing following septoplasty can significantly improve the postoperative symptoms, protect nasal mucociliary clearance, and reduce short-term postoperative complications.

[Value discussion of radical sinus surgery for difficult-to-treat rhinosinusitis]

Objective:To investigate the efficacy of radical sinus surgery (RSS) on difficult-to-treat rhinosinusitis(DTRS) with nasal polyps. Method: We retrospectively analyzed the clinical data of 26 patients with DTRS that treated with RSS and patients who were not treated with RSS in our hospital from August 2013 to June 2017.The effect of RSS were evaluated by comparing the CT Lund-Kennery score,endoscope Lund-Kennery score,global VAS score and dysosmia VAS score before operation and 6 months after operation. Result: RSS group had more severe Lund-Kennery score,global VAS score and dysosmia VAS score than non-RSS group,and also had more previous surgeries,higher ratio of olfactory region polyps,and higher ratio of co-existing asthma and allergic rhinitis. However RSS group had a lower ratio with pus anot than non-RSS group. The eosinophil count in periheral blood between two groups had no statistical significance. Six months after RSS,the score of endoscope Lund-Kennery,global VAS and dysosmia VAS dependence. 14 patients were successfully cured(53.8%), 12 patients showed improvement(46.2%), no invalid cases. Conclusion: The global symptoms and olfaction of DTRS patients can be improved by RSS combine individual perioperative drug therapy.

[Comprehensive evaluation on disease burden of injury and improvement of the related evidence system on injury prevention]

With rapid social and economic development in this country, injury has become one of the three major health issues with public concern. To reduce the burden of diseases as disability and medical treatment that caused by injury also became important in public health. Programs related to comprehensive evaluation on disease burden caused by injury and evidence-based strategies on injury-related prevention became substantially important. Our article- "The Disease Burden caused by Injury" , we involved a series of papers based on the systematic databases which focusing on the current status and the change of types of injuries in the Chinese population. Hopefully, it could provide key clues for the development of injury prevention and control programs in the future.

Rapid on-site evaluation of the development of resistance to quinone outside inhibitors in Botrytis cinerea

Botrytis cinerea, a typical "high-risk" pathogenic fungus that rapidly develops resistance to fungicides, affects more than 1,000 species of 586 plant genera native to most continents and causes great economic losses. Therefore, a rapid and sensitive assay of fungicide resistance development in B. cinerea populations is crucial for scientific management. In this study, we established a Loop-mediated isothermal amplification (LAMP) system for the monitoring and evaluation of the risk of development of B. cinerea resistance to QoI fungicides; the method uses two LAMP assays. The first assay detects G143A mutants of B. cinerea, which are highly resistance to QoI fungicides. BCbi143/144 introns in B. cinerea are then detected by the second assay. HNB acts as a visual LAMP reaction indicator. The optimum reaction conditions of the LAMP assays were 61 °C for 50 min, and the detection limit of the LAMP assays was 100 × 10-4 ng/μl. We directly pre-treated the field samples by using All-DNA-Fast-Out to extract DNA within ten minutes, then performed the LAMP assay to achieve one-step rapid detection. In conclusion, we established a rapid and sensitive LAMP assay system for resistance risk assessment and for monitoring QoI-resistance of B. cinerea in the field.

[Analysis on life expectancy and healthy life expectancy in China, 1990-2015]

Objective: To understand the life expectancy (LE) and health life expectancy (HALE) of Chinese during 1990-2015. Methods: Using the results of global burden of disease study 2015 (GBD 2015), we compared the Chinese LE and HALE in 2015 with those of other countries and analyzed the differences between LE and HALE in Chinese and the changes of LE and HALE during 1990-2015 at both national level and provincial level. Results: In 2015, the LE and the HALE of Chinese were 76.2 and 68.0 years, 4.4 and 5.2 years higher than the global averages, respectively. The LE and HALE were higher in women than in men. The high LE and HALE were observed in developed provinces or areas, such as Shanghai, Beijing, Hong Kong, Macau, Zhejiang, Jiangsu, Tianjin and Guangdong, while the low LE and HALE were found in underdeveloped provinces, such as Tibet, Qinghai, Guizhou, Xinjiang and Yunnan. Between 1990 and 2015, the LE and HALE of Chinese increased substantially by 9.5 and 8.4 years, respectively. The increase of LE was greater than that of HALE at both national level and provincial level. Conclusion: LE and HALE of Chinese increased substantially from 1990 to 2015, but the differences among provinces were obvious.

Alpaca fiber growth is mediated by microRNA let-7b via down-regulation of target gene FGF5

MicroRNAs are very small endogenous RNA molecules that play a crucial role in an array of biological processes, including regulation of skin morphogenesis. The microRNA let-7b is thought to modulate animal hair growth, by binding target genes that encode growth factors. Fibroblast growth factor 5 (FGF5) has been previously reported to be involved in the initiation of the catagen phase of hair growth. In this study, we combined previous reports with bioinformatic analysis techniques to identify and validate FGF5 and, using lucerifase assay, confirmed targeted binding of let-7b to FGF5. To investigate the interaction between let-7b and FGF5, alpaca skin fibroblasts were transfected with let-7b over-expression vectors, and then mRNA and protein expression levels of FGF5 and the gene encoding its receptor, FGFR1, were evaluated. Levels of FGF5 mRNA and protein were remarkably lower in transfected groups, as compared to controls. In summary, this study confirmed that let-7b acts as a regulator of skin morphogenesis, by directly targeting FGF5 and down-regulating its expression. It provides the evidence of hair growth regulated by miRNAs in animals and may have important applications in wool production.

Proton pump inhibitor use and risk of spontaneous bacterial peritonitis in cirrhotic patients: a systematic review and meta-analysis

We used a meta-analysis approach to investigate the association between proton pump inhibitor (PPI) use and risk of spontaneous bacterial peritonitis (SBP) in cirrhotic patients. We searched Ovid Medline, Embase, and the Cochrane Library to identify eligible studies. We included studies that compared cirrhotic patients who did or did not use PPIs. The primary outcome was SBP, and the secondary outcome was overall bacterial infection. Results were pooled using random-effect models. This process led to identification of 12 journal articles and 5 conference abstracts. The pooled data showed that PPI use in patients with cirrhosis and ascites was significantly associated with an increased risk of SBP [odds ratio (OR) = 2.17; 95% confidence interval (CI) = 1.46-3.23; P < 0.05; I2 = 85.6%] and overall risk of bacterial infection (OR = 1.98; 95%CI = 1.36-2.87; P < 0.05; I2 = 0). Subgroup analysis revealed that journal articles and studies reporting adjusted effect estimates demonstrated that PPI users had a significantly increased risk of SBP (OR = 2.13; 95%CI = 1.61-2.82; P < 0.05; I2 = 29.4%; and OR = 1.98; 95%CI = 1.42-2.77; P < 0.05; I2 = 67%, respectively). In conclusion, PPI use increased the risk of SBP and overall bacterial infection in patients with cirrhosis and ascites. PPIs should be administered after careful assessment of the indications in cirrhotic patients. Future well-designed prospective studies are warranted to clarify the dose relationships and to compare infection risks associated with different classes of PPIs.

Apocynum venetum leaf extract, an antihypertensive herb, inhibits rat aortic contraction induced by angiotensin II: a nitric oxide and superoxide connection

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves extract of Apocynum venetum (AVLE), also known as "luobuma", have long been used in traditional Chinese medicine to treat hypertension and depression in parts of China and it has been shown to possess anti-oxidant and anti-lipid peroxidation effects. AVLE (10 μg/ml) has been reported to have a long-lasting endothelium-dependent relaxant effect and this effect has been proposed to be due to its nitric oxide(NO)-releasing and superoxide anion(SOA)-scavenging properties.

AIM OF THE STUDY

The present study seeks to evaluate the differential actions of AVLE extract between Ang II- and PE-induced vasoconstriction and the involvement of superoxide anions.

MATERIALS AND METHODS

Single dose of Ang II (100 nM and 1 nM)- or PE (0.1 μM)-induced contraction were assessed in both endothelium-intact and -denuded aortic rings after pre-incubation of AVLE (10 μg/ml) for 15 min. The experiment was repeated in either the presence of NO synthase inhibitor, L-NAME (300 μM) or selective AT(1) receptor inhibitor, losartan (0.1 nM), or superoxide scavenger, tiron (1 mM) or a combination of L-NAME and AVLE. Superoxide production was measured by using enhanced-chemiluminescence assay.

RESULTS

We have demonstrated that AVLE (10 μg/ml) effectively suppressed the Ang II-induced contraction (100 nM and 1 nM) of both endothelium-intact and -denuded rat aortic rings. In endothelium-intact rings, L-NAME, reversed AVLE-induced inhibition of Ang II-contraction. PE-induced contraction was significantly inhibited by AVLE in endothelium-intact rings, but not in endothelium-denuded rings. The inhibition by AVLE of PE-induced contraction was totally abolished in the presence of L-NAME. Ang II-induced SOA production concentration dependently with the optimal effect seen at 100 nM of Ang II, and AVLE (0.3, 1, 10 μg/ml) reduced this effect. SOA production in Ang II-stimulated rings was significantly higher than unstimulated control rings, while PE did not stimulate SOA production at all. SOA formation in the presence of Ang II was also inhibited in the presence of SOD (superoxide scavenger), DPI (NADPH inhibitor) and losartan (specific AT(1) receptor antagonist).

CONCLUSION

These results collectively suggest that the ability of AVLE in inhibiting Ang II-induced contraction via its SOA scavenging properties and nitric oxide releasing effect may account for its usage as an antihypertensive treatment in traditional folk medicine.

Common crystalline and magnetic structure of superconducting A2Fe4Se5 (A=K,Rb,Cs,Tl) single crystals measured using neutron diffraction

Single-crystal neutron diffraction studies on superconductors A(2)Fe(4)Se(5), where A=Rb, Cs, (Tl, Rb), and (Tl, K) (T(c) ∼ 30 K), uncover the same Fe vacancy ordered crystal structure and the same block antiferromagnetic order as in K(2)Fe(4)Se(5). The Fe order-disorder transition occurs at T(S)=500-578 K, and the antiferromagnetic transition at T(N) = 471-559 K with an ordered magnetic moment ∼3.3μ(B)/Fe at 10 K. Thus, all recently discovered A intercalated iron selenide superconductors share the common crystalline and magnetic structure, which are very different from previous families of Fe-based superconductors, and constitute a distinct new 245 family.

Protection abilities of influenza B virus DNA vaccines expressing hemagglutinin, neuraminidase, or both in mice

Every year, a vaccination against Influenza B virus (IBV) is essential due to an antigenic variation. Development of an efficient and convenient vaccine is important for the prevention of viral infection. This study reports examination of the protective immunity in mice evoked by a single inoculation of plasmid DNA expressing hemagglutinin (HA DNA) or neuraminidase (NA DNA) of IBV. The HA DNA or NA DNA was injected intramuscularly into BALB/c mice separately or as a mixture. The injection of plasmid was followed by an electroporation close to the site of puncture. Four weeks later, the immunized mice were challenged with a lethal dose of IBV. The protective abilities of DNA vaccines were evaluated by the detection of specific antibodies in serum, survival rate, virus titer in lungs, and change of body weight. We found that a single dose of HA DNA or NA DNA induced the formation of specific antibodies and conferred effective protection against the lethal challenge of IBV. However, the combined vaccine HA DNA and NA DNA enhanced the protective ability of immunized mice. The obtained results suggested that immunization with single dose of HA DNA, NA DNA or with combination of both could be an efficient method for preventing IBV infection.

The role of central arginine vasopressin in corticotropin releasing hormone-induced fever in rats

The purpose of the present study was to investigate the role of central arginine vasopressin (AVP) in corticotropin releasing hormone (CRH) induced fever in the rat. Guide cannulae were inserted into the third ventricle and placed over the ventral septal area (VSA). The content of arginine vasopressin in the VSA of the brain was determined by radioimmunoassay. Colon temperature was monitored in lightly restrained rats by insertion of a catheter mounted thermistor probe 5 cm in the rectum. The results demonstrated that intracerebroventricular (icv) injection of CRH increased AVP level in the VSA and the colonic temperature of the rats. Microinjection of AVP V(1) antagonist into the VSA 10 min before CRH administration significantly enhanced CRH-induced febrile response, while AVP V(1) antagonist itself did not have a significant effect on the colonic temperature. Furthermore, injection of AVP into the VSA 5 min before CRH administration (icv) suppressed the fever evoked by CRH. These findings suggest that CRH is an important factor that stimulates the release of AVP in the VSA during fever, and endogenous AVP in the VSA has an antipyretic action on the CRH-induced fever.

Guillain-Barré syndrome in northwestern China

We reviewed 100 patients with Guillan-Barré syndrome (GBS) from 1994 to 2000 from northwestern China. We examined clinical and electro-diagnostics features and compared them to patients from Europe, North America and northern China. Results indicated that among 100 patients with GBS, the demyelinating pattern was present in 51 patients, the axonal pattern in 25 patients, and 8 patients were inexcitable, 12 patients equivocal and 4 patients normal. The electrophysiological and clinical features of various subtypes of GBS in northwestern China seemed to be different in some ways from those in western countries and in northern China. However, in northwestern China, the demyelinating pattern is the major electrophysiological subtype.

Role of NADPH Oxidase in the Vascular Hypertrophic and Oxidative Stress Response to Angiotensin II in Mice

Abstract —Oxygen-derived free radicals are involved in the vascular response to angiotensin II (Ang II), but the role of NADPH oxidase, its subunit proteins, and their vascular localization remain controversial. Our purpose was to address the role of NADPH oxidase in the blood pressure (BP), aortic hypertrophic, and oxidant responses to Ang II by taking advantage of knockout (KO) mice that are genetically deficient in gp91 phox , an NADPH oxidase subunit protein. The baseline BP was significantly lower in KO mice than in wild-type (WT) (92±2 [KO] versus 101±1 [WT] mm Hg, P <0.01), but infusion of Ang II for 6 days caused similar increases in BP in the 2 strains (33±4 [KO] versus 38±2 [WT] mm Hg, P >0.4). Ang II increased aortic superoxide anion production 2-fold in the aorta of WT mice but did not do so in KO mice. Aortic medial area increased in WT (0.12±0.02 to 0.17±0.02 mm 2 , P <0.05), but did not do so in KO mice (0.10±0.01 to 0.11±0.01 mm 2 , P >0.05). Histochemistry and polymerase chain reaction demonstrated gp91 phox localized in endothelium and adventitia of WT mice. Levels of reactive oxidant species as indicated by 3-nitrotyrosine immunoreactivity increased in these regions in WT but not in KO mouse aorta in response to Ang II. These results indicate an essential role in vivo of gp91 phox and NADPH oxidase–derived superoxide anion in the regulation of basal BP and a pressure-independent vascular hypertrophic and oxidant stress response to Ang II.

Transcriptional regulation of the TATA-binding protein by Ras cellular signaling

Our previous studies have demonstrated that the level of the central transcription factor TATA-binding protein (TBP) is increased in cells expressing the hepatitis B virus (HBV) X protein through the activation of the Ras signaling pathway, which serves to enhance both RNA polymerase I and III promoter activities. To understand the mechanism by which TBP is regulated, we have investigated whether enhanced expression is modulated at the transcriptional level. Nuclear run-on assays revealed that the HBV X protein increases the number of active transcription complexes on the TBP gene. In transient-transfection assays with both transformed and primary hepatocytes, the human TBP promoter was shown to be induced by expression of the HBV X protein in a Ras-dependent manner, requiring both Ral guanine nucleotide dissociation stimulator (RalGDS) and Raf signaling. Transient overexpression of TBP did not affect TBP promoter activity. To further delineate the downstream Ras-mediated events contributing to TBP promoter regulation in primary rat hepatocytes, the best-characterized Ras effectors, Raf, phosphoinositide 3-kinase (PI-3 kinase), and RalGDS, were examined. Activation of either Raf or RalGDS, but not that of PI-3 kinase, was sufficient to induce TBP promoter activity. Both Raf- and RalGDS-mediated induction required the activation of mitogen-activated protein kinase kinase (MEK). In addition, another distinct Ras-activated pathway, which does not require MEK activation, appears to induce TBP promoter activity. Analysis of the DNA sequence requirement within the TBP promoter responsible for these regulatory events defined three distinct regions that modulate the abilities of Raf, RalGDS, and the Ras-dependent, MEK-independent pathways to regulate human TBP promoter activity. Together, these results provide new evidence that TBP can be regulated at the transcriptional level and identify three distinct Ras-activated pathways that modulate this central eukaryotic transcription factor.

Reciprocal information flow between prefrontal cortex and ventral tegmental area in an animal model of schizophrenia

The medial prefrontal cortex (PFC) is anatomically and functionally connected with the ventral tegmental area (VTA), the neuronal source of mesocorticolimbic system that is pathophysiologically related to schizophrenia-like symptoms. Methamphetamine (MAP) was applied to examine the functional relationship between PFC and VTA in an animal model of schizophrenia. Hyperactivity and stereotyped behavior were observed accompanied by a distinctive direction of information flow. In hyperactivity, information flow in the direction from PFC to VTA was dominant. Contrarily, dominant information flow from VTA to PFC was found in stereotyped behavior. These results indicate that dysfunctional interaction between PFC and VTA is the neuronal basis of MAP-induced schizophrenia-like psychosis. The information flow and its direction can be useful tool to explain the neurogenesis of these abnormal behaviors.

Differential effects of Bcl-2 overexpression on hippocampal CA1 neurons and dentate granule cells following hypoxic ischemia in adult mice

In contrast to its known anti-apoptotic activity in sympathetic neurons, immortal neuronal cell lines, and primary cultured immature neurons of the central nervous system (CNS), the role of Bcl-2 in CNS neurons in the adult brain is poorly understood. In the present study, we examined effects of overexpression of Bcl-2 on selective neuronal death of the hippocampal CA1 neurons and the dentate granule cells induced by hypoxic ischemia in adult transgenic mice overexpressing human Bcl-2 under the control of neuron-specific enolase (NSE-hbcl-2). At the light microscopic level, numbers of TUNEL-positive cells with pyknotic nuclei were observed in the CA1 subfield of NSE-hbcl-2 transgenic mice, as well as that of wild-type mice, after hypoxic ischemic insult, although the onset of neuronal death was apparently delayed in NSE-hbcl-2 transgenic mice. The electron microscopic studies showed that morphological changes of the degenerating CA1 neurons from both groups were clearly distinct from ordinary apoptosis. In contrast, a significant amount of degenerating dentate granule cells from wild-type but not from transgenic mice had typical apoptotic nuclei by the treatment. The activation of caspase-3 was detected in the dentate granule cells but not that of the CA1 neurons. These results indicate that the overexpression of Bcl-2 effectively suppressed dentate granule cell apoptosis but only delayed cell death of the CA1 neurons induced by hypoxic ischemia, suggesting the occurrence of a non-apoptotic, caspase-3-independent mechanism for neuronal death in the CA1 subfield.

Antipyretic action of dexamethasone on egtazic acid-induced fever in rabbits

The purpose of the present study was to investigate whether the antipyretic effect of dexamethasone (DEX) delivered by intravenous injection (i.v.) on intracerebroventricularly (icv) administered egtazic acid-induced febrile response is relevant to the changes in cytosolic free calcium concentration of the hypothalamus. The colon temperatures were measured by a thermistor and the cytosolic free calcium concentration ([Ca2+]i) in dissociated brain cells was measured by Fura 2-AM. The results demonstrated that the pyretic action of egtazic acid (0.6 mumol, icv) was markedly inhibited by DEX (5 mg/kg, i.v.), but DEX (60-120 mumol/L) did't affect [Ca2+]i in dissociated hypothalamus cells. Actinomycin D, which interferes with gene transcription (3 nmol, icv), completely abolished the antipyretic action of DEX on egtazic acid-induced fever. These findings suggest that the antipyretic action of DEX on egtazic acid-induced fever is related to the activation of certain gene expression in the brain, but not to the changes of transmembrane calcium ion current in hypothalamus neurons.