Bone formation of the coracoid bone graft after the Bristow procedure assessed using three-dimensional computed tomography

BACKGROUND

The Bristow procedure has been shown to be a reliable method to prevent recurrent anterior shoulder instability by compensating for glenoid bone loss and producing the sling effect. The degree of postoperative morphological change in the coracoid bone graft is speculated to influence glenohumeral joint stability; however, the details of these changes after the Bristow procedure remain unknown. This study was performed to quantify the postoperative change in the coracoid bone graft volume as assessed by three-dimensional computed tomography (3D-CT).

METHODS

The Bristow procedure was performed on 17 shoulders in 17 patients from August 2018 to January 2020. All patients were men, and their mean age at surgery was 17.9 years. The mean follow-up duration was 21.4 months. Within the first week after the operation (Time 0) and at the final follow-up, 3D-CT was used to determine the total coracoid bone graft volume. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) shoulder score, the University of California Los Angeles (UCLA) shoulder score, and the Western Ontario Shoulder Instability Index (WOSI).

RESULTS

The mean volume of the total coracoid bone graft was 1.26 ± 0.29 cm3 at Time 0 and 1.90 ± 0.36 cm3 at the final follow-up (p < 0.0001). The mean JOA score, UCLA score, and WOSI were significantly better at the final follow-up than preoperatively (p < 0.001). No postoperative infection, neurovascular injury, or recurrent instability of the glenohumeral joint occurred.

CONCLUSIONS

In the Bristow procedure, the volume of the total coracoid bone graft as shown by 3D-CT was significantly greater at the final follow-up than at Time 0, and bone formation of the coracoid bone graft was found after the Bristow procedure.

Development of a radiopaque tiltmeter to improve reproducibility for Fowler's position on chest radiography

INTRODUCTION

We have developed a novel radiopaque tiltmeter (ROT) that can indicate patient tilt during a radiography examination and display it on X-ray images. This study evaluated the effect of variation of patient tilt on the reproducibility of Fowler's position for chest radiography and the accuracy of the ROT.

METHODS

We evaluated the reproducibility of Fowler's position based on changes from the first day in the central venous catheter (CVC) tip position and the cardiothoracic ratio (CTR) with and without a digital tiltmeter to verify its efficacy in patients who underwent mobile chest radiography. The ROT contains radiopaque liquid consisting of white barium sulfate solution and oil and has a scale bar of 15°-75° with increments of 15° to indicate ROT tilt. The ROT tilt was increased from 10° to 80° in increments of 10°. We then evaluated (1) the difference between the ROT tilt and the tilt measured with a digital tiltmeter, and (2) the ROT tilt displayed on the X-ray image.

RESULTS

With regard to reproducibility in Fowler's position, changes in the CVC tip position were 2.8 ± 3.9 mm and 10.7 ± 10.6 mm with and without the tiltmeter, respectively (p < 0.05) and the respective rates of change in the CTR were 0.7% ± 0.6% and 4.0% ± 2.1% (p < 0.05). Differences between the ROT tilt and the tilt measured by the digital tiltmeter were within ±2.5°. All ROT tilts displayed on the X-ray images were recognized exactly as each tilt.

CONCLUSION

Our novel ROT had the potential to accurately indicate patient tilt during chest radiography, which could be helpful in terms of reproducibility and precise follow-up.

IMPLICATIONS FOR PRACTICE

Use of the ROT for determination of patient tilt can improve reproducibility in Fowler's position, allowing more accurate serial X-ray imaging.

Histopathologic evaluation of bone marrow lesions in early stage subchondral insufficiency fracture of the medial femoral condyle

Subchondral insufficiency fracture (SIF) of the medial femoral condyle has been proposed to be a primary event in so-called 'spontaneous osteonecrosis of the knee'. SIF is also known to be associated with bone marrow lesions (BML), but the detailed histopathology of the BML has not been fully clarified. We thus investigated the pathophysiology of BML based on MRI and histology in the 4 consecutive patients diagnosed with SIF, whose onset was within 4 months. In all cases, BMLs were enhanced on T1 Gd-enhanced MRI. Histologically, BMLs comprised serous exudate, fibrous tissue, and vascular-rich granulation tissue in the marrow space. In addition, a lower signal intensity line was observed within the BML in all cases on T1 MRI. Histologically, this line showed thickened bone trabeculae accompanied by fibrovascular tissue in two cases, while the other two cases showed formation of woven bone trabeculae around the original fractured bone trabeculae indicating the presence of another fracture in the bone marrow space. In summary, BML in SIF was considered to be a secondary phenomenon resulting from a subchondral fracture.

Attenuated relationship between salivary oxytocin levels and attention to social information in adolescents and adults with autism spectrum disorder: a comparative study

BACKGROUND

Previous research studies have assessed the relationship between attention to social information and peripheral (e.g., plasma and salivary) oxytocin (OT) levels in typically developing (TD) children and children with autism spectrum disorder (ASD). A relationship between them was observed in TD children, but not in children with ASD. However, this relationship remains unexamined in other age groups. To clarify whether this lack of association is maintained throughout development in individuals with ASD, we aimed to assess the relationship between salivary OT levels and attention to social information in adolescents and adults with and without ASD.

METHODS

We recruited male adolescents and adults with ASD (n = 17) and TD participants (n = 24). Using the all-in-one eye-tracking system Gazefinder, we measured the percentage fixation time allocated to social information. We also measured the salivary OT levels and Autism Spectrum Quotient (AQ) of participants. Subsequently, we confirmed group differences and conducted a correlation analysis to investigate the relationships between these three measures.

RESULTS

Salivary OT levels did not show any significant difference between the ASD and TD groups and were negatively correlated with the AQ in the whole-group analysis, but not in within-group analysis. Individuals with ASD had significantly lower percentage fixation times than did TD individuals for eye regions in human faces with/without mouth motion, for upright biological motion, and for people regions in the people and geometry movies. The percentage of fixation for geometric shapes in the people and geometry movies was significantly higher in the ASD than in the TD group. In the TD group, salivary OT levels were positively correlated with percentage fixation times for upright biological motion and people and negatively correlated with inverted biological motion and geometry. However, no significant correlations were found in the ASD group.

CONCLUSIONS

Our exploratory results suggest that salivary OT levels in adolescents and adults with ASD are less indicative of attention to social stimuli than they are in TD adolescents and adults. It is suggested that their association is slightly weaker in adolescents and adults with ASD and that this attenuated relationship appears to be maintained throughout development.

Psychosis is an extension of mood swings from the perspective of neuronal plasticity impairments

We previously hypothesized that depressive and manic states may be consecutive presentations of the same underlying neuronal plasticity, and that moderate impairments in neuronal plasticity cause depressive states while further impairment to neuronal plasticity causes manic states. Psychopathological or biological relationships between bipolar disorder and schizophrenia have also been revealed. Therefore, in addition to depressive and manic states, psychosis may also be considered a manifestation resulting from additional impairments to neuronal plasticity. In the present manuscript, we hypothesize that moderate and more severe impairments to neuronal plasticity cause depressive and manic states, respectively, and that more serious impairments to neuronal plasticity cause psychosis. Many studies have suggested that impairments in neuronal plasticity contribute to schizophrenia and other mental disorders with psychotic features, and that the impairment of neuronal plasticity in schizophrenia is more severe than that in bipolar disorder. Therefore, we hypothesize more specifically that impairments in neuronal plasticity may be more severe in the order of the cases featuring psychosis, mania, and depression. This progression notably overlaps with the arrangement of schizophrenia, bipolar disorder, and depressive disorder in the DSM-5. Psychotic symptoms are thought to appear further towards the base of the psychopathological hierarchy than are manic or depressive symptoms. If impairments to neuronal plasticity contribute to this psychopathological hierarchy, as we contest that they do, our hypothesis may serve as a bridge between clinical psychopathology, diagnosis, and biological psychiatry.

Oxytocin efficacy is modulated by dosage and oxytocin receptor genotype in young adults with high-functioning autism: a 24-week randomized clinical trial

Recent studies have suggested that long-term oxytocin administration can alleviate the symptoms of autism spectrum disorder (ASD); however, factors influencing its efficacy are still unclear. We conducted a single-center phase 2, pilot, randomized, double-blind, placebo-controlled, parallel-group, clinical trial in young adults with high-functioning ASD, to determine whether oxytocin dosage and genetic background of the oxytocin receptor affects oxytocin efficacy. This trial consisted of double-blind (12 weeks), open-label (12 weeks) and follow-up phases (8 weeks). To examine dose dependency, 60 participants were randomly assigned to high-dose (32 IU per day) or low-dose intranasal oxytocin (16 IU per day), or placebo groups during the double-blind phase. Next, we measured single-nucleotide polymorphisms (SNPs) in the oxytocin receptor gene (OXTR). In the intention-to-treat population, no outcomes were improved after oxytocin administration. However, in male participants, Clinical Global Impression-Improvement (CGI-I) scores in the high-dose group, but not the low-dose group, were significantly higher than in the placebo group. Furthermore, we examined whether oxytocin efficacy, reflected in the CGI-I scores, is influenced by estimated daily dosage and OXTR polymorphisms in male participants. We found that >21 IU per day oxytocin was more effective than ⩽21 IU per day, and that a SNP in OXTR (rs6791619) predicted CGI-I scores for ⩽21 IU per day oxytocin treatment. No severe adverse events occurred. These results suggest that efficacy of long-term oxytocin administration in young men with high-functioning ASD depends on the oxytocin dosage and genetic background of the oxytocin receptor, which contributes to the effectiveness of oxytocin treatment of ASD.

Interferon γ and plasminogen activator inhibitor 1 regulate adhesion formation after partial hepatectomy

BACKGROUND

The pathophysiology of intra-abdominal adhesions has not been studied extensively. The aim of this study was to elucidate the molecular mechanisms underlying adhesion formation in a murine model and in patients undergoing hepatectomy.

METHODS

Partial hepatectomy was performed using bipolar forceps in mice. Wild-type mice, antibodies to CD4 and interferon (IFN) γ, IFN-γ, natural killer T (NKT) cells and plasminogen activator inhibitor (PAI) 1 knockout (KO) mice were used. Recombinant hepatocyte growth factor (HGF) was tested for its ability to prevent adhesions. Liver specimens were obtained during surgery from patients undergoing hepatectomy. Adhesion formation was evaluated using a scoring system that ranged from 0 (no adhesions) to 5 (severe adhesions). Levels of IFN-γ and PAI-1 mRNA, and protein concentration of PAI-I were measured, and fluorescence immunostaining was performed.

RESULTS

Adhesion formation depended on IFN-γ produced by NKT cells, and NKT KO mice developed few adhesions (mean(s.d.) 1·7(0·3) versus 4·6(0·4) in wild-type mice; P = 0·037). In wild-type mice, the level of PAI-1 mRNA increased after hepatectomy, followed by a decrease in the tissue plasminogen activator (tPA) mRNA level. Adhesion formation was inhibited completely in PAI-1 KO mice (0(0) versus 4·1(0·8) in wild-type mice; P = 0·002). HGF inhibited formation of abdominal adhesions after hepatectomy by reducing IFN-γ and PAI-1 levels, and increasing tPA levels compared with those in mice treated with phosphate-buffered saline (P < 0·001, P = 0·002 and P = 0·035 respectively). In human liver specimens, NKT cells accumulated in the liver after hepatectomy, and PAI-1 expression was increased 5·25-fold (P = 0·030).

CONCLUSION

IFN-γ is a key molecule for abdominal adhesion formation after hepatectomy, acting via the reciprocal balance of PAI-1 and tPA. This molecular mechanism may also regulate adhesion formation in patients following hepatectomy. HGF inhibited formation of adhesions by regulating IFN-γ and PAI-1, suggesting that it may be an important target for prevention of adhesions after hepatectomy. SURGICAL RELEVANCE: Postoperative intra-abdominal adhesions can be asymptomatic or cause significant morbidity and mortality. Adhesion formation after hepatectomy has not been studied extensively. In the present study, the molecular mechanisms underlying intra-abdominal adhesions after hepatectomy were investigated in a murine model and in patients. Interferon (IFN) γ produced by natural killer T cells is a key molecule for adhesion formation after hepatectomy in mice, acting via the reciprocal balance between plasminogen activator inhibitor (PAI) 1 and tissue plasminogen activator, the pivotal factors in fibrinolytic activity. This mechanism was also involved in the regulation of adhesions in human tissue samples. Hepatocyte growth factor (HGF) strongly inhibited adhesion formation by regulating IFN-γ and PAI-1. These results indicate that IFN-γ and PAI-1 are possible therapeutic targets, and HGF could prevent postoperative adhesion formation after hepatectomy.

Evaluation of the ARKRAY AUTION Eleven reflectometer in detecting microalbuminuria with AUTION Screen test strips and proteinuria with AUTION Sticks 10PA strips

OBJECTIVE

Albumin/creatinine and protein/creatinine ratios were measured with the ARKRAY AUTION Eleven reflectometer using AUTION Screen and AUTION Sticks 10PA strips, respectively, against quantitative Siemens Advia reference procedures from 368 patient urines, as an evaluation of their applicability for use in points-of-care and small laboratories.

MATERIAL AND METHODS

Direct reflectance measurements were utilized to estimate imprecision, as well as to suggest reclassification of ordinal scale categories into normoalbuminuria, microalbuminuria and macroalbuminuria groups (3.4 g/mol and 34 g/mol cut-off limits, corresponding to 30 mg/g and 300 mg/g creatinine in conventional units).

RESULTS

Analytically, ordinal scale albumin/creatinine ratios agreed in 86% of cases with those obtained from Advia measurements, resulting in a kappa coefficient of 0.79. Protein/creatinine ratios of the AUTION Sticks 10PA strip were classified into three groups at limits of 11.3 g/mol and 56.6 g/mol (100 mg/g and 500 mg/g in conventional units), with an agreement of 77% and a kappa coefficient of 0.65 against Advia procedures. To optimize clinical outcomes, cut-off reflectances of ordinal scale categories of AUTION Eleven were adjusted. The clinical specificity of detecting an increased albumin/creatinine ratio was then increased from 81% to 95%, with clinical sensitivity kept at 88% at the 3.4 g/mol limit of the reference procedure. Clinical specificity of the albuminuria field alone (at a clinical sensitivity of 88%) was only 73%. Adjustments to cut-off reflectances of the reported categories for protein/creatinine ratios increased clinical specificity from 54% to 94%, while losing clinical sensitivity from 97% to 89% only, with an improved concordance of 83% and a kappa coefficient of 0.75 against Advia measurements. The combination to creatinine measurements improved clinical specificity compared to 50% by the protein field alone. In economic terms, it is estimated that population screening for microalbuminuria using the AUTION Eleven reflectometer is cheaper than by quantitative albumin/creatinine measurements alone, based on the incidence of end-stage renal disease of 90 patients/million/year at the Northern Ostrobothnia Hospital District.

Rapid telomere movement in meiotic prophase is promoted by NDJ1, MPS3, and CSM4 and is modulated by recombination

Haploidization of the genome in meiosis requires that chromosomes be sorted exclusively into pairs stabilized by synaptonemal complexes (SCs) and crossovers. This sorting and pairing is accompanied by active chromosome positioning in meiotic prophase in which telomeres cluster near the spindle pole to form the bouquet before dispersing around the nuclear envelope. We now describe telomere-led rapid prophase movements (RPMs) that frequently exceed 1 microm/s and persist throughout meiotic prophase. Bouquet formation and RPMs depend on NDJ1, MPS3, and a new member of this pathway, CSM4, which encodes a meiosis-specific nuclear envelope protein required specifically for telomere mobility. RPMs initiate independently of recombination but differ quantitatively in mutants that fail to complete recombination, suggesting that RPMs respond to recombination status. Together with recombination defects described for ndj1, our observations suggest that RPMs and SCs balance the disruption and stabilization of recombinational interactions, respectively, to regulate crossing over.

Minimally invasive technique for direct repair of the pars defects in young adults using a spinal endoscope: a technical note

Pars defect (spondylolysis) of the lumbar spine can cause chronic low back pain, and it sometimes requires surgical intervention. Direct repair is selected for the surgery if young adult patients do not present significant disc degeneration and lumbar instability. In order to lessen damages of back muscles during surgery, we added the use of a spinal endoscope to the "Buck's screwing procedure" the direct repair. There are four steps in this procedure: 1) identification of the defect, 2) curettage (refresh) of the defect, 3) percutaneous insertion of the annulated screws and 4) cancellous bone grafting. All these steps can be done endoscopically. We treated 3 young adults--a baseball player, a professional cycle-racer and a sculptor--using this endoscopic procedure. There were no complications during or after the operation. Union was obtained in all defects within 3 months, and they returned to their previous activities within 6 months after the surgery.

Statins induce S1P1 receptors and enhance endothelial nitric oxide production in response to high-density lipoproteins

BACKGROUND AND PURPOSE

Sphingosine 1-phosphate (S1P) is a serum-borne naturally occurring sphingolipid, specifically enriched in high-density lipoprotein (HDL) fractions. S1P binds to G-protein-coupled S1P1 receptors to activate endothelial NO synthase (eNOS) in vascular endothelial cells. We explored whether and how statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, modulate expression of S1P1 receptors and endothelial responses for subsequent stimulation with S1P or with HDL.

EXPERIMENTAL APPROACH

Protein expression and phosphorylation and mRNA expression in cultured bovine aortic endothelial cells (BAEC) were determined using immunoblots and reverse transcription PCR analyses, respectively. NO synthesis was assessed as nitrite production.

KEY RESULTS

Stimulation of BAEC with pitavastatin or atorvastatin led to significant increases in S1P1-receptors, at levels of protein and mRNA, in a dose-dependent manner. When BAEC were treated with pitavastatin prior to stimulation with S1P or with normal human HDL, phosphorylation and activation of eNOS evoked by S1P or by HDL was enhanced. These effects of statins were counteracted by L-mevalonate and were mimicked by an inhibitor of geranylgeranyl transferase I, suggesting that inhibition of HMG-CoA reductase activity and subsequent decreases in protein geranylgeranylation may contribute to these actions of statins. Specific knock down of S1P1 receptors by small interfering RNA led to attenuation of eNOS responses to HDL.

CONCLUSIONS AND IMPLICATIONS

Statins induce S1P1 receptors and potentiate responses of endothelial cells to HDL-associated sphingolipids, identifying a novel aspect of the pleiotropic actions of statins through which they may exert NO-dependent vascular protective effects.

Abnormal pontine activation in pathological laughing as shown by functional magnetic resonance imaging

To explore the aetiology of pathological laughing, a 65-year-old woman with pathological laughing was examined by 3-T functional magnetic resonance imaging (fMRI) before and after treatment with drugs. Here, we report that the patient consistently showed exaggerated pontine activation during the performance of three tasks before treatment, whereas abnormal pontine activation was no longer found after successful treatment with the selective serotonin reuptake inhibitor, paroxetine. Our findings in this first fMRI study of pathological laughing suggest that serotonergic replacement decreases the aberrant activity in a circuit that involves the pons.

Preservation of C7 spinous process does not influence the long-term outcome after laminoplasty for cervical spondylotic myelopathy

Axial pain is one of the major complications after laminoplasty, and preservation of C7 spinous process during the procedure can reduce the axial pain. However, it has not been elucidated whether laminoplasty preserving the C7 spinous process can maintain neurological improvement for a long time. The purpose of our retrospective study was to investigate the long-term neurological outcome after open-door laminoplasty preserving the C7 spinous process for cervical spondylotic myelopathy (CSM). Clinical and radiological outcomes were analysed in 42 patients who underwent open-door laminoplasty preserving C7 spinous process and followed up for more than 5 years. Neurological function was evaluated by means of the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy. Axial pain was assessed using a visual analog scale (VAS) at the last examination. Alignment and motion of the cervical spine were measured from radiographs, and magnetic resonance imaging (MRI) was used to evaluate postoperative compression at C7. The mean JOA score was 9.4 before surgery and 12.0 at the latest follow-up. The mean VAS score in 26 patients score was 9.7/100. No compression of the spinal cord was observed in any MRI at the latest follow-up. Preservation of the C7 spinous process does not influence the long-term outcome of CSM after laminoplasty. Although we did not have a comparative group, the procedure described here should be considered as the solution.

Cloning and characterization of Pseudomonas putida genes encoding the phosphate-specific transport system

The pstSCAB genes of Pseudomonas putida PRS2000, encoding the phosphate (Pi)-specific transport (Pst) system, were cloned. The pstS gene of Pseudomonas aeruginosa PAO1, of which the pstCAB genes had been cloned previously, was also cloned (Nikata, T. et al., Mol. Gen. Genet., 250, 692-698, 1996). The predicted translation products of the P. putida pstSCAB genes showed 83, 75, 78 and 88% amino acid identity with their P. aeruginosa counterparts. Two well-conserved Pho box sequences were found in the region upstream of the pstS gene (15/18 base identity with the consensus Pho box sequence) and in the intercistronic region between the pstS and pstC genes (11/18 base identity) of P. putida PRS2000. To investigate the functions of PstSCAB, the pstSC genes were inactivated by inserting a kanamycin resistance gene cassette into the chromosome of P. putida PRS2000. The resultant mutant, designated PNT1, failed to take up 32Pi even under conditions of Pi limitation. Strain PNT1 was also constitutive for alkaline phosphatase synthesis, as well as chemotaxis toward Pi, indicating that the Pst system is involved in the negative regulation of the pho regulon in P. putida. Although overexpression of the pstSCAB genes in P. putida PRS2000 resulted in decreased cell growth, this recombinant strain could remove Pi at a rate similar to that seen with the control strain.

Modification of cytokine milieu by A2A adenosine receptor signaling--possible application for inflammatory diseases

Pro-inflammatory cytokine TNF-alpha (TNF) production from in vitro lipopolysaccharide (LPS)-stimulated human peripheral blood CD14+ cells (PB-CD14) was inhibited by A2A adenosine receptor (AdoR) (A2AR) or beta2 adrenergic receptor (ADR) (beta2R) signaling in a concentration-dependent manner. These inhibitory effects were presumably mediated by the increase in intracellular cAMP. Furthermore A2AR agonist and beta2R agonist synergistically inhibited the TNF production of LPS-stimulated PB-CD14 cells. These results suggest that the anti-inflammatory effect of extracellular adenosine is, at least in part, due to the modification of the cytokine milieu via A2A signaling, and that the targeting of both A2AR and beta2R may have strong therapeutic potential for the inflammatory diseases.

Individual trait anxiety levels characterizing the properties of zen meditation

Meditation is a specific consciousness state in which deep relaxation and increased internalized attention coexist. There have been various neurophysiological studies on meditation. However, the personal predispositions/traits that characterize the properties of meditation have not been adequately studied. We analyzed changes in neurophysiological parameters [EEG coherence and autonomic nervous activity using heart rate variability (HRV) as an index] during Zen meditation, and evaluated the results in association with trait anxiety (assessed by Spielberger's State-Trait Anxiety Inventory) in 22 healthy adults who had not previously practiced any form of meditation. During meditation, in terms of mean values in all subjects, an increase in slow alpha interhemispheric EEG coherence in the frontal region, an increase in high-frequency (HF) power (as a parasympathetic index of HRV), and a decrease in the ratio of low-frequency to HF power (as a sympathetic index of HRV) were observed. Further evaluation of these changes in individuals showed a negative correlation between the percent change (with the control condition as the baseline) in slow alpha interhemispheric coherence reflecting internalized attention and the percent change in HF reflecting relaxation. The trait anxiety score was negatively correlated with the percent change in slow alpha interhemispheric coherence in the frontal region and was positively correlated with the percent change in HF. These results suggest that lower trait anxiety more readily induces meditation with a predominance of internalized attention, while higher trait anxiety more readily induces meditation with a predominance of relaxation.

Inhibition of nuclear factor kappa B activation and inducible nitric oxide synthase transcription by prolonged exposure to high glucose in the human keratinocyte cell line HaCaT

BACKGROUND

In human skin, inducible nitric oxide synthase (iNOS) appears to be a key enzyme during wound healing and has roles in protection from infection. We speculated that diabetic skin complications such as delayed wound healing and skin infection were due to iNOS activity altered by high glucose in skin keratinocytes.

OBJECTIVES

The purpose of this study was to see how high levels of glucose affect iNOS activity in the human keratinocyte cell line (HaCaT).

METHODS

HaCaT cells were exposed to high glucose for 1 day or 10 days. We measured nitric oxide (NO) end product nitrite in the culture medium using the Griess reagent, and intracellular tetrahydrobiopterin (BH(4), a cofactor of NOS) content by using high-performance liquid chromatography, analysed the expression level of iNOS mRNA by the reverse transcriptase-polymerase chain reaction method and evaluated the DNA binding activity of nuclear factor kappa B (NF-kappaB) by enzyme-immunoassay.

RESULTS

Short-term exposure (1 day) to a high level of glucose increased BH(4) and iNOS activity at the post-translational level. However, long-term exposure (10 days) to high glucose downregulates NF-kappaB binding activity and inhibits iNOS transcription and its activity.

CONCLUSIONS

Pretreatment with high glucose for 10 days down-regulated NF-kappaB activity and inhibited iNOS transcription and NO production, implying the involvement of a deficiency in NO synthesis in both skin infection and impaired wound healing in diabetic patients.

Neural substrates participating in acquisition of facial familiarity: an fMRI study

The amygdala is related to recognition of faces and emotions, and functional magnetic resonance imaging (fMRI) studies have reported that the amygdala is habituated over time with repetition of facial stimuli. When subjects are presented repeatedly with unfamiliar faces, they come to gradually recognize the unfamiliar faces as familiar. To investigate the brain areas participating in the acquisition of familiarity to repeatedly presented unfamiliar faces, we conducted an fMRI study in 16 healthy subjects. During the task periods, the subjects were instructed to see presented unfamiliar faces repeatedly and to judge whether the face was male or female or whether the face had emotional valences. The experiment consisted of nine sessions. To clarify the brain areas that showed increasing or decreasing activation as the experimental session proceeded, we analyzed the fMRI data using specified linear covariates in the face recognition task from the first session to the ninth session. Imaging data were investigated on a voxel-by-voxel basis for single-group analysis according to the random effect model using Statistical Parametric Mapping. The bilateral posterior cingulate cortices showed significant increases in activity as the experimental sessions proceeded, while the activation in the right amygdala and the left medial fusiform gyrus decreased. Thus, the posterior cingulate cortex may play an important role in the acquisition of facial familiarity.

Abnormal nocturnal blood pressure fall in senile-onset depression with subcortical silent cerebral infarction

Recent studies have shown that the complication rate of silent cerebral infarction (SCI) in patients with geriatric depression increases with the age at the onset of depression. This study investigated the cardiovascular factors involved in the development of SCI in geriatric depression. Thirty-six patients with geriatric depression were classified according to the age at onset into 16 who developed depression at the age of <50 years (early-onset group) and 20 who developed depression at the age of > or =50 years (late-onset group). The incidence of SCI assessed by subcortical hyperintensity on MRI images, office blood pressure (BP), nocturnal systolic BP fall pattern examined by 24-hour ambulatory BP monitoring, and the severity of carotid atherosclerosis examined by B-mode ultrasonography were compared between the two groups. Furthermore, the association between the presence or absence of SCI and the nocturnal systolic BP fall pattern or the severity of carotid atherosclerosis was evaluated. The SCI complication rate was higher in the late-onset group (55.0%) than in the early-onset group (18.7%). The office BP and mean 24-hour BP did not differ significantly between the two groups. Abnormal nocturnal systolic BP fall patterns were observed in 85.0% (nondipper type showing a fall of <10% in 60.0%, extreme-dipper type showing a fall of > or =20% in 25.0%) in the late-onset group, which was significantly higher than the incidence in the early-onset group (18.7%). No significant difference was observed in any parameter of carotid atherosclerosis between the two groups. In addition, the patients with SCI more frequently showed abnormal nocturnal systolic BP fall patterns than those without SCI. These results suggest that abnormal nocturnal BP fall patterns appear to be involved in the development of SCI in senile-onset depression.

Nitric oxide synthase inhibition by N(G)-nitro-L-arginine methyl ester retards vascular sprouting in angiogenesis

The present study was designed to evaluate the role of nitric oxide (NO) for angiogenesis. Angiogenesis was elicited upon mouse cornea by chemical cautery with silver nitrate. Angiogenic activity was evaluated by measuring the length of vascular sprout with or without administration of NO synthase (NOS) inhibitor, N((G))-nitro-L-arginine-methyl ester (L-NAME). In the pericorneal plexus, a circulatory loop situated in the same topological situation for all individuals was selected to observe vascular sprouting. At 72 h after cauterization, the length of the longest vascular sprout was measured using the perfused whole-mount cornea. The length of nontreated mice (83 +/- 83 microm) was significantly longer than that of L-NAME treated mice (33 +/- 24.6 microm). To address the possible contribution of production of vascular endothelial growth factor (VEGF) and NO, we measured mRNAs of VEGF and inducible NOS. The mRNA level of VEGF increased to 170% of the nontreated level at 12 h after cauterization and returned to the nontreated level by 24 h after cauterization. mRNA of inducible NOS remained elevated 24 h after cauterization. These results suggest that the response of preexisting vessels to angiogenic stimulus via NO is of importance in the process of angiogenesis, i.e., vascular sprouting is promoted by NO production. This might be attributable to enhancement of an increase in vascular permeability and /or vasodilation via NO.

Differential amygdala response during facial recognition in patients with schizophrenia: an fMRI study

Human lesion or neuroimaging studies suggest that amygdala is involved in facial emotion recognition. Although impairments in recognition of facial and/or emotional expression have been reported in schizophrenia, there are few neuroimaging studies that have examined differential brain activation during facial recognition between patients with schizophrenia and normal controls. To investigate amygdala responses during facial recognition in schizophrenia, we conducted a functional magnetic resonance imaging (fMRI) study with 12 right-handed medicated patients with schizophrenia and 12 age- and sex-matched healthy controls. The experiment task was a type of emotional intensity judgment task. During the task period, subjects were asked to view happy (or angry/disgusting/sad) and neutral faces simultaneously presented every 3 s and to judge which face was more emotional (positive or negative face discrimination). Imaging data were investigated in voxel-by-voxel basis for single-group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM). No significant difference in task accuracy was found between the schizophrenic and control groups. Positive face discrimination activated the bilateral amygdalae of both controls and schizophrenics, with more prominent activation of the right amygdala shown in the schizophrenic group. Negative face discrimination activated the bilateral amygdalae in the schizophrenic group whereas the right amygdala alone in the control group, although no significant group difference was found. Exaggerated amygdala activation during emotional intensity judgment found in the schizophrenic patients may reflect impaired gating of sensory input containing emotion.

[Relationship between the fecal mutagenicity and metal content, smoking habit and dietary intake]

OBJECTIVE

The study was carried out to collect basic data on exposure of mucous cells of the large intestine to mutagens by investigating the genotoxicity of fecal samples from the urban population. Simultaneously, relations with food intake (food groups and nutritive components), lifestyle factors and fecal metal content was investigated.

METHODS

A total of 199 self-collected fecal samples from middle aged healthy volunteer living in urban areas of Osaka city were freeze-dried and ground in a mill. The mutagenicity of aqueous extracts of the ground samples was measured by the umu-test. Metal content of the feces was analysed by atomic absorption spectrophotometlly. On the day previous to the feces collection, the contents of meals were recorded and confirmed by interview with a dietitian. Quantification of nutritive components was carried out using the 4th edition of the Japan Food Standard Vomposition Table.

RESULTS

Mutagenicity of feces was higher in males than in females, and in those aged 40-49 years than 50-69 years in males but not females. Large differences were found for content of 8 metals in the feces; concentrations were in the decreasing order of calcium, potassium, magnesium, sodium, zinc, iron, manganese and copper, the highest being 20.4 mg for calcium and the lowest was 53.5 micrograms for copper. Between the metal contents and mutagenicity, values for zinc and iron showed positive correlations and for sodium a negative correlation under S9(+) conditions. A weak but significant correlation was observed between the numbers of cigarettes smoked per day and S9 (+) mutagenicity. However we could not find any relation with food groups or nutritive components.

CONCLUSION

It is well known that human feces contain many mutagens and carcinogens and that these can act directly on the mucous membrane of large intestine. Therefore, it is very important to estimate exposure levels. From the present data we can conclude that relations between mutation-activity of the feces and diet are complex. Their elucidation will require a large number of volunteers who have similar living conditions to obtain appropriate data.

MRI white matter hyperintensities, (1)H-MR spectroscopy and cognitive function in geriatric depression: a comparison of early- and late-onset cases

BACKGROUND AND OBJECTIVES Geriatric depression is often thought to differ from that at other times of adulthood. Recently, several studies have shown that the incidence of white matter hyperintense lesions identified by brain MRI is higher in patients with geriatric depression than in healthy elderly subjects, but a consensus has not yet been reached on the relationship between the severity of white matter lesions and either cognitive impairment or depressive symptoms.

METHOD

Forty-seven patients aged 50 to 75 years with major depression were divided into two groups based on age at onset of depression: early-onset (< 50 years) group (20 patients; mean age, 62.7 +/- 6.7) and late-onset (> or =50 years) group (27 patients; mean age, 65.6 +/- 5.4). The severity of hyperintense white matter lesions on MRI was classified by region, then a proton magnetic resonance spectroscopy ((1)H-MRS) focusing on the white matter of the frontal lobes, multidimensional neuropsychological tests and evaluation of depressive symptoms were conducted.

RESULTS

The severity of the deep white matter lesions, the deterioration of cognitive function related to subcortical/frontal brain system and clinician-rated depressive symptoms were all more pronounced in the late-onset group compared with those in the early-onset group. It was further observed that the more severe the deep white matter lesions, the lower the levels of N-acetylaspartate/creatine. With the age of onset as the covariate, the patients with moderate deep white matter lesions had more pronounced cognitive impairment and clinician-rated depressive symptoms than those with none and/or mild lesions.

CONCLUSION

These results suggest that subcortical/frontal type cognitive impairment and the persistence of depressive symptoms in geriatric depression is related to moderate deep white matter lesions more often complicated in the late-onset group. The (1)H-MRS findings were suggested to be a useful indicator of neuronal/axonal loss in the white matter of the frontal lobes which precedes cognitive impairment.

Quantitative evaluation of magnetic resonance imaging of deep white matter hyperintensity in geriatric patients by multifractal analysis

Fractal analysis has played an important role in various fields such as physics, biology and medicine. Recently, multifractal analysis based on generalized concepts of fractals has been applied to biological tissues composed of complex structures. Deep white matter hyperintensity (DWMH) on brain magnetic resonance imaging (MRI) is more often observed in patients with geriatric depression than in healthy elderly subjects, and its clinical significance is receiving attention. We applied multifractal analysis to white matter images on brain T2-weighted MRI in 62 patients with geriatric depression (50-75 years). The local fractal dimensions, alpha(max) and alpha(min), which serve as indices of complexity, and their difference, alpha(max) - alpha(min), were closely correlated with the macroscopic grading according to Fazekas classification, suggesting that multifractal analysis is useful for quantitative evaluation of DWMH on MRI.

Neuronal nitric oxide synthase generates superoxide from the oxygenase domain

When l-arginine is depleted, neuronal nitric oxide synthase (nNOS) has been reported to generate superoxide. A flavoprotein module construct of nNOS has been demonstrated to be sufficient for superoxide production. In contrast, nNOS was reported not to be involved in superoxide formation, because such formation occurred with a mixture of the boiled enzyme and redox-active cofactors. We aimed to resolve these controversial issues by examining superoxide generation, without the addition of redox-active cofactors, by recombinant wild-type nNOS and by C415A-nNOS, which has a mutation in the haem proximal site. In a superoxide-sensitive adrenochrome assay, the initial lag period of C415A-nNOS was increased 2-fold compared with that of native nNOS. With ESR using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide, prominent signals of the superoxide adduct were obtained with wild-type nNOS, whereas an enzyme preparation boiled for 5 min did not produce superoxide. Higher concentrations of NaCN (10 mM) decreased superoxide formation by 63%. Although the activity of the reductase domain was intact, superoxide generation from C415A-nNOS was decreased markedly, to only 10% of that of the wild-type enzyme. These results demonstrate that nNOS truly catalyses superoxide formation, that this involves the oxygenase domain, and that full-length nNOS hinders the reductase domain from producing superoxide.

Neural interaction of the amygdala with the prefrontal and temporal cortices in the processing of facial expressions as revealed by fMRI

Some involvement of the human amygdala in the processing of facial expressions has been investigated in neuroimaging studies, although the neural mechanisms underlying motivated or emotional behavior in response to facial stimuli are not yet fully understood. We investigated, using functional magnetic resonance imaging (fMRI) and healthy volunteers, how the amygdala interacts with other cortical regions while subjects are judging the sex of faces with negative, positive, or neutral emotion. The data were analyzed by a subtractive method, then, to clarify possible interaction among regions within the brain, several kinds of analysis (i.e., a correlation analysis, a psychophysiological interaction analysis and a structural equation modeling) were performed. Overall, significant activation was observed in the bilateral fusiform gyrus, medial temporal lobe, prefrontal cortex, and the right parietal lobe during the task. The results of subtraction between the conditions showed that the left amygdala, right orbitofrontal cortex, and temporal cortices were predominantly involved in the processing of the negative expressions. The right angular gyrus was involved in the processing of the positive expressions when the negative condition was subtracted from the positive condition. The correlation analysis showed that activity in the left amygdala positively correlated with activity in the left prefrontal cortex under the negative minus neutral subtraction condition. The psychophysiological interaction revealed that the neural responses in the left amygdala and the right prefrontal cortex underwent the condition-specific changes between the negative and positive face conditions. The right amygdaloid activity also had an interactive effect with activity in the right hippocampus and middle temporal gyrus. These results may suggest that the left and right amygdalae play a differential role in effective processing of facial expressions in collaboration with other cortical or subcortical regions, with the left being related with the bilateral prefrontal cortex, and the right with the right temporal lobe.

Effects of furosemide on the tubular reabsorption of nitrates in anesthetized dogs

The present study was performed to determine the tubular sites of nitrite and nitrate (NO) reabsorption and the effects of furosemide on the renal handling of NOx in anesthetized dogs, using renal clearance and stop-flow methods. Furosemide (2 mg/kg, i.v.) increased the urinary excretion rates of Na+ (U(Na+)V) and NOx (U(NOx)V) with a reduction of tubular reabsorption rates of Na+ and NOx. During inhibition of renal nitric oxide (NO) synthesis by an intrarenal infusion of L-nitro arginine (30 microg/kg-min), furosemide also increased U(NOx)V and decreased tubular reabsorption rate of NOx from 96.5+/-0.8% to 86.6+/-1.7%. An intravenous infusion of 10% mannitol (0.5 ml/kg-min) also increased both U(Na+)V and U(NOx)V. In addition, after furosemide administration or mannitol infusion. U(NOx)V was correlated with U(Na+)V. In stop-flow experiments, the distal dip in NOx curve was observed and the site of the dip in NOx curve was identical to that of Na+ curve. Furosemide shifted upward the U/P(Na+)/U/P(Cr) and U/P(NOx)/U/P(Cr) at the distal dip, indicating inhibition of Na+ and NOx reabsorption at distal tubules. These results indicate that more than 96% of the filtered NOx is reabsorbed in the renal tubules, and that the tubular handling of NOx is very close to that of Na+. In addition, the stop-flow experiments demonstrate that furosemide inhibited the reabsorption of NOx as well as Na+ at the distal tubule.

A new IFN-like cytokine, limitin, modulates the immune response without influencing thymocyte development

A novel IFN-like molecule, limitin, was recently identified and revealed to suppress B lymphopoiesis through the IFN-alphabeta receptor, although it lacked growth suppression on myeloid and erythroid progenitors. Here we have studied diverse effects of limitin on T lymphocytes and compared limitin with previously known IFNs. Like IFN-alpha and -beta, limitin modified immunity in the following responses. It suppressed mitogen- and Ag-induced T cell proliferation through inhibiting the responsiveness to exogenous IL-2 rather than suppressing the production of IL-2. In contrast, limitin enhanced cytotoxic T lymphocyte activity associated with the perforin-granzyme pathway. To evaluate the effect of limitin in vivo, a lethal graft-versus-host disease assay was established. Limitin-treatment of host mice resulted in the enhancement of graft-versus-host disease. Limitin did not influence thymocyte development either in fetal thymus organ cultures or in newborn mice injected with limitin-Ig, suggesting that limitin is distinguishable from IFN-alpha and -beta. From these findings, it can be speculated that the human homolog of limitin may be applicable for clinical usage because of its IFN-like activities with low adverse effects on, for example, T lymphopoiesis, erythropoiesis, and myelopoiesis.

Stat3 in thymic epithelial cells is essential for postnatal maintenance of thymic architecture and thymocyte survival

This study describes abnormalities of the thymus in mice in which the Stat3 gene has been specifically disrupted behind the keratin 5 promoter. In these mice, virtually all of the thymic epithelial cells (TEC) were deficient for Stat3 activation. Adult mutant mice developed severe thymic hypoplasia, which included alterations in the cortical TEC architecture that coincided with the loss of thymocytes. Even during the asymptomatic period of preadolescence, these mice exhibited a higher susceptibility of the thymus to suboptimal doses of dexamethasone or gamma-irradiation, while their thymocytes per se were no more sensitive than controls. These results indicate that Stat3 in TEC plays an essential role in maintaining thymic architecture and thymocyte survival.

L-Arginine improves endothelial function in renal artery of hypertensive Dahl rats

OBJECTIVES

To clarify whether endothelium-derived contracting factor (EDCF) is developed in renal artery of hypertensive Dahl rats and whether prolonged oral L-arginine treatments prevent development of EDCF and hypertension.

DESIGN

The effect of prolonged salt treatment with or without L-arginine on the renal artery was examined.

METHODS AND RESULTS

Dahl salt-sensitive and -resistant rats were fed a 0.4 or an 8% NaCl diet for 4 weeks. High sodium intake increased arterial pressure in Dahl salt-sensitive rats. The rings of renal arteries were suspended for isometric tension recording. Only in the hypertensive rats, more than 1 micromol/l acetylcholine induced an endothelium-dependent contraction response. The contraction was completely inhibited by indomethacin or ONO-3708 [prostaglandin H2 (PGH2)/thromboxane A2 (TXA2) receptor antagonist], and partially inhibited by OKY-046 (TXA2 synthetase inhibitor). Acetylcholine-induced relaxation was significantly depressed in hypertensive rats, which was partially improved by SQ29548 (PGH2/TXA2 receptor antagonist). Oral L-arginine, but not ONO-8809 (orally active PGH2/TXA2 receptor antagonist) treatment, inhibited the contraction and amended the relaxation. The endothelium-independent contraction to TXA2 receptor agonist U46619 and relaxation to nitroprusside were not altered by L-arginine treatment The L-Arginine treatment reduced blood pressure and sodium retention with increases in urinary NO2-/NO3- and cGMP excretion. Hydralazine treatment also inhibited development of EDCF.

CONCLUSIONS

The present results suggest that impaired endothelium-dependent relaxation to acetylcholine is caused in part by induction of EDCF synthesis/release in renal arteries of hypertensive Dahl rats. L-arginine can attenuate sodium retention and development of hypertension, which lead to a decrease in EDCF synthesis in renal arteries.

Antimutagenic activity of isoflavone from Pueraria lobata

A methanol extract from Pueraria lobata showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The methanol extract from P. lobata was re-extracted with hexane, dichloromethane, ethyl acetate, butanol, and water, respectively. A suppressive compound in the dichloromethane and ethyl acetate extract fractions was isolated by SiO(2) column chromatography and identified as tectorigenin (1) by EI-MS and (1)H and (13)C NMR spectroscopy. Compound 1 and its methylated derivative [7,4'-di-O-methyltectorigenin (2)] had the suppressive effects on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against furylfuramide, 4-nitroquinoline-1-oxide, N-methyl-N'-nitrosoguanidine, and activated Trp-P-1, which do not require live metabolic activation by S9. These compounds also showed suppression of SOS-inducing activity against Trp-P-1 and AfB(1), which requires liver metabolizing enzymes. In addition to the antimutagenic activities of these compounds against furylfuramide, Trp-P-1 and activated Trp-P-1 were also assayed by an Ames test using S. typhimurium TA100.

Suppression of the furylfuramide-induced SOS response by monoterpenoids with a p-menthane skeleton using the Salmonella typhimurium TA1535/pSK1002 Umu test

Suppression of the furylfuramide-induced SOS response by 25 kinds monoterpenoids (hydrocarbons, alcohols, ketones, and aldehydes) with a p-menthane skeleton was studied. Suppression of the SOS-inducing activity by monoterpenoids was determined in the umu test using Salmonella typhimurium TA1535/pSK1002. The terpene alcohols, ketones, and aldehydes had potent suppressive effects, but the hydrocarbons did not. Especially, (+)-menthol, (+)-pulegone, piperitenone, and cuminaldehyde were shown to have the most potent suppressive effects, and the ID(50) (dose for 50% inhibition) was 0.52 micromol/mL.

Vitamin B6 phototoxicity induced by UVA radiation

We have previously reported that pyridoxine shows UVA-induced cytotoxicity. Four other vitamin B6 compounds (pyridoxal, pyridoxamine, pyridoxal phosphate, and pyridoxamine phosphate) are metabolically more important in vivo than pyridoxine. These compounds were examined for UVA phototoxicity to cultured human fibroblasts. The cytotoxicity was measured by post-UVA irradiation colony-forming ability. All the B6 compounds except pyridoxal phosphate showed cytotoxicity. Pyridoxamine phosphate, which is the most important form of vitamin B6 in vivo, had the strongest cytotoxic effect. To examine the involvement of reactive oxygen species in the phototoxicity, we performed an electron spin resonance study using the spin trapping agent, 5,5-dimethyl-1-pyrroline N-oxide, and diethylenetriaminepentaacetic acid. We failed to detect radicals derived from vitamin B6. The cytotoxic effect remained in UVA-irradiated solutions for at least 30 min after the end of UVA irradiation. Hydrogen peroxide was produced in the solution, but the amount was not enough to cause cytotoxicity. In addition, the cells from xeroderma pigmentosum patients who belong to group A or C showed survival curves similar to those of normal fibroblasts. This suggests that cyclobutane pyrimidine dimers or 6-4 photoproducts of DNA were not involved in this damage. These findings suggest that UVA-induced vitamin B6 cytotoxicity is caused by toxic photoproducts resulting from irradiated vitamin B6.

Synthesis and biological activity of alpha-methylene-gamma-lactones as new aroma chemicals

Seven kinds of alpha-methylene-gamma-lactones with an alkyl group at the C-4 position were synthesized according to a previously described method, with yields of 28-34%. These alpha-methylene-gamma-lactones had characteristic and unique odors. All alpha-methylene-gamma-lactones added a roast-like odor to materials. The antimicrobial effects of alpha-methylene-gamma-lactones were investigated by using a paper disk diffusion method. The results showed the alpha-methylene-gamma-lactones inhibited the growth of three bacteria (Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescens) and two fungi (Saccharomyces cerevisiae and Aspergillus niger). In particular, alpha-methylene-gamma-undecalactone and alpha-methylene-gamma-dodecalactone exhibited potent inhibition of the growth of these microorganisms compared to butyl p-hydroxybenzoate as standard antibiotic. The umu test revealed that the alpha-methylene-gamma-lactones suppressed the SOS-inducing activity of three mutagens, furylfuramide, UV irradiation, and Trp-P-1, respectively. The antimicrobial effects and the suppressive effects of SOS induction by alpha-methylene-gamma-lactones had a tendency to intensify as the number of carbons in the side chain increased.

Effect of glycolysis on pancreatic microcirculation and cellular functions in anesthetized rats

It has been reported that aerobic glycolysis in the pancreas contributes less than 10% to oxidative phosphorylation based on in vitro experiments using pancreatic tissue segments. However, its contribution to aerobic glycolysis in vivo remains uncertain. We investigated the effect of inhibiting glycolysis on O2 metabolism in microvessels, exocrine enzyme secretion, and the blood glucose level in the pancreas of anesthetized rats in vivo. Inhibition of glycolysis, by superfusing the pancreas of anesthetized rats with 2-deoxyglucose (10 mM) or sodium fluoride (2 mM), significantly decreased O2 release from erythrocytes flowing in the microvessels by 30-40%. Inhibiting glycolysis did not affect the exocrine secretion of pancreatic juice but decreased the secretion of total protein by approximately or = to 40%. Inhibiting glycolysis decreased blood glucose levels by approximately or = to 40% and increased glucagon release twofold. Aerobic glycolysis may play more important roles in the regulation of O2, metabolism, pancreatic exocrine enzyme secretion and the blood glucose level in rat pancreas.

Identification and characterization of cell lines with a defect in a post-adsorption stage of Sendai virus-mediated membrane fusion

In the early stage of infection, Sendai virus delivers its genome into the cytoplasm by fusing the viral envelope with the cell membrane. Although the adsorption of virus particles to cell surface receptors has been characterized in detail, the ensuing complex process that leads to the fusion between the lipid bilayers remains mostly obscure. In the present study, we identified and characterized cell lines with a defect in the Sendai virus-mediated membrane fusion, using fusion-mediated delivery of fragment A of diphtheria toxin as an index. These cells, persistently infected with the temperature-sensitive variant Sendai virus, had primary viral receptors indistinguishable in number and affinity from those of parental susceptible cells. However, they proved to be thoroughly defective in the Sendai virus-mediated membrane fusion. We also found that viral HN protein expressed in the defective cells was responsible for the interference with membrane fusion. These results suggested the presence of a previously uncharacterized, HN-dependent intermediate stage in the Sendai virus-mediated membrane fusion.

Analysis of the human sleep electroencephalogram by the correlation dimension

Sleep electroencephalograms (EEG) of healthy male subjects were analyzed by the correlation dimension. The mean correlation dimensions significantly decreased from stage 'awake' to stages 1, 2 and 3 and increased during rapid eye movement sleep. The mean correlation dimensions of the sleep EEG in the second half of the night were significantly higher than those in the first half of the night. These significant changes were also seen during sleep stage 2.

Potassium augments vascular relaxation mediated by nitric oxide in the carotid arteries of hypertensive Dahl rats

The present study was designed to determine whether and how potassium supplementation improves the endothelial function of carotid arteries of hypertensive Dahl rats. Dahl salt-sensitive rats were fed a high sodium diet, a high sodium plus potassium-supplemented diet, a normal rat chow, or a potassium-supplemented diet for 4 weeks. High sodium intake significantly increased the blood pressure, which was attenuated by potassium supplementation. The isometric tension of rat-isolated carotid rings was measured. In norepinephrine-precontracted rings, the relaxation in response to acetylcholine, adenosine 5'-diphosphate (ADP), and isoproterenol were significantly attenuated in hypertensive Dahl rats, which was improved by potassium supplementation. Pretreatment with N(G)-nitro-L-arginine methyl ester blocked the responses to acetylcholine and ADP, and eliminated the difference in relaxation in response to isoproterenol. The endothelium-independent relaxation in response to forskolin, S-nitroso-N-acetyl-DL-penicillamine, and sodium nitroprusside was significantly attenuated in hypertensive Dahl rats, which was not affected by potassium supplementation. The results indicated that salt-induced hypertension was associated with marked alterations in the endothelial and vascular smooth muscle functions of the carotid arteries of Dahl rats. Potassium supplementation ameliorated the endothelial but not the smooth muscle function. The protective effect of potassium appeared to be achieved through increased endothelial nitric oxide production. The current studies, in conjunction with our recent studies on nitric oxide synthase activity in the kidney, strongly suggest that potassium attenuates development of hypertension by increasing nitric oxide production in Dahl rats.

Antimutagenic activity of flavonoids from Pogostemon cablin

A methanol extract from Pogostemon cablin showed a suppressive effect on umu gene expression of SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The methanol extract was re-extracted with hexane, dichloromethane, butanol, and water. A dichloromethane fraction showed a suppressive effect. Suppressive compounds against furylfuramide in the dichloromethane fraction were isolated by SiO(2) column chromatography and identified as 7,4'-di-O-methyleriodictyol (1), 7, 3',4'-tri-O-methyleriodictyol (2), and 3,7,4'-tri-O-methylkaempferol (3). In addition, three flavonoids, ombuine (4), pachypodol (5), and kumatakenin (6), were isolated and identified from the dichrolomethane fraction. Compounds 1 and 3 suppressed >50% of the SOS-inducing activity at <0.6 micromol/mL, and the ID(50) values of both compounds were 0.25 micromol/mL. Compound 2 showed a weakly suppressive effect (17%) at a concentration of 0.6 micromol/mL, and compounds 4-6 did not. These compounds were also assayed with 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), which requires liver metabolizing enzymes. Compounds 3-6 suppressed >80% of the SOS-inducing activity of Trp-P-1 at <0.06 micromol/mL, and compounds 1 and 2 suppressed 87 and 63% at a concentration of 0.3 micromol/mL. In addition, these compounds were assayed with activated Trp-P-1, and the suppressed effects of these compounds were further decreased when compared to Trp-P-1. The antimutagenic activities of these compounds against furylfuramide, Trp-P-1, and activated Trp-P-1 were assayed by the Ames test using S. typhimurium TA100.

Acute production of vascular superoxide by angiotensin II but not by catecholamines

OBJECTIVE

To determine whether vascular superoxide is rapidly released by angiotensin II and is involved in vascular contraction.

DESIGN

The effect of superoxide dismutase (SOD) on angiotensin II induced elevation of mean arterial blood pressure was measured. Subsequently, acute production of vascular superoxide by angiotensin II and its effect on isometric tension were measured in rat aortic rings. The effects of catecholamines were concomitantly measured.

METHODS AND RESULTS

The acute pressor effects of angiotensin II were significantly reduced when rats were pretreated intravenously with SOD. When angiotensin II was added on aortic segments in the presence of Cypridina luciferin analog, immediate elevations of chemiluminescence were observed which were inhibited by SOD. Furthermore, angiotensin II-induced elevations of isometric tension in aortic rings were significantly reduced by SOD. The effects of epinephrine and norepinephrine were concomitantly measured and were not significant

CONCLUSIONS

The acute superoxide producing effect is likely to be specific to angiotensin II, because such a significant modification of the effects was not observed for catecholamines. Our results suggest that angiotensin II causes acute vascular superoxide production, which may be involved in the acute pressor effects.