Non-genomic inhibitory effect of glucocorticoids on activated peripheral blood basophils through suppression of lipid raft formation

We investigated the non-genomic effects of glucocorticoids (GCs) on inhibition of plasma membrane lipid raft formation in activated human basophils. Human basophils obtained from house dust mite (HDM)-sensitive volunteers were pretreated with hydrocortisone (CORT) or dexamethasone (Dex) for 30 min and then primed with phorbol 12-myristate 13-acetate (PMA, 10 ng/ml) or HDM (10 µg/ml). The expression of CD63, a basophil activation marker, was assessed by flow cytometry. Membrane-bound GC receptors (mGCRs) were analysed by flow cytometry and confocal laser microscopy. Lipid rafts were assessed using a GM1 ganglioside probe and visualization by confocal laser microscopy. Pretreatment of basophils with CORT (10(-4) M and 10(-5) M) and Dex (10(-7) M) significantly inhibited CD63 expression 20 min after addition of PMA or HDM. The inhibitory effects of GCs were not altered by the nuclear GC receptor (GCR) antagonist RU486 (10(-5) M) or the protein synthesis inhibitor cycloheximide (10(-4) M) (P < 0·05). CORT coupled to bovine serum albumin (BSA-CORT) mimicked the rapid inhibitory effects of CORT, suggesting the involvement of mGCRs. mGCRs were detectable on the plasma membrane of resting basophils and formed nanoclusters following treatment with PMA or HDM. Pretreatment of cells with BSA-CORT inhibited the expression of mGCRs and nanoclustering of ganglioside GM1 in lipid rafts. The study provides evidence that non-genomic mechanisms are involved in the rapid inhibitory effect of GCs on the formation of lipid raft nanoclusters, through binding to mGCRs on the plasma membrane of activated basophils.

Matrix metalloproteinase 2 and 9 in esophageal cancer

To search for the biochemical properties of esophageal carcinoma relevant to its aggressive behavior, we studied metalloproteinases released from surgical specimens of the carcinoma. In an assay with [H-3]-labeled gelatin, esophageal carcinoma tissues showed gelatinolytic activities clearly higher than those of paired normal mucosae. EDTA and TIMP-1 could strongly suppress these activities, suggesting that the activities belong to metalloproteinases. In addition, levels of TIMP-1 expression did not show good correlation with these activities, suggesting that tumor-specific elevation of gelatinolytic activity depended on metalloproteinase per se rather than the suppression of TIMP-1-secretion. By zymographic analysis, two gelatinase bands of 82- and 62-kDa were found specifically in carcinoma tissues, in addition to the other 6 bands detected both in normal and carcinoma tissues. Immunoprecipitation and immunoblotting of gelatinases with anti-MMP-9 or anti-MMP-2 monoclonal antibody, and treatment of the enzymes with APMA showed that these 82- and 62-kDa gelatinases were cleaved products of MMP-9 and MMP-2, respectively. These results imply that enhanced secretion and proteolytic activation of MMP-2 and MMP-9 take place specifically in the esophageal carcinoma tissues. Moreover, the levels of gelatinolytic activity expressed good correlation with the organ metastasis rate of the carcinoma, suggesting that MMPs play an important role in tumor metastasis.

Interleukin-18-deficient mice exhibit diminished chronic inflammation and airway remodelling in ovalbumin-induced asthma model

Interleukin (IL)-18, which is produced by activated monocytes/macrophages and airway epithelial cells, is suggested to contribute to the pathophysiology of asthma by modulating airway inflammation. However, the involvement of IL-18 on modulating chronic airway inflammation and airway remodelling, which are characterized in a refractory asthma model exposed to long-term antigen, has not been investigated sufficiently. We examined the role of IL-18 in chronic airway inflammation and airway remodelling by long-term antigen exposure. IL-18-deficient and C57BL/6-wild-type mice were sensitized by ovalbumin (OVA) and were then exposed to aerosolized OVA twice a week for 12 weeks. We assessed airway inflammation by assessing the infiltration of cells into the airspace and lung tissues, and airway remodelling by airway mucus expression, peribronchial fibrosis and smooth muscle thickness. In IL-18-deficient mice, when exposed to OVA, the total cells and neutrophils of the bronchoalveolar lavage fluid (BALF) were diminished, as were the number of infiltrated cells in the lung tissues. IL-18-deficient mice exposed to OVA after 12 weeks showed significantly decreased levels of interferon (IFN)-gamma, IL-13 and transforming growth factor (TGF)-beta1 in the BALF. The airway hyperresponsiveness to acetyl-beta-methacholine chloride was inhibited in IL-18-deficient mice in comparison with wild-type mice. In addition, IL-18-deficient mice exposed to OVA had fewer significant features of airway remodelling. These findings suggest that IL-18 may enhance chronic airway inflammation and airway remodelling through the production of IFN-gamma, IL-13 and TGF-beta1 in the OVA-induced asthma mouse model.

Plical resection in pre-temporal approach for basilar bifurcation aneurysms: preliminary surgical experience and cadaveric study

OBJECT

Although a pre-temporal approach (PA) can provide a wide space for preservation of thalamoperforating atrteries in direct surgery for basilar bifurcation aneurysms (BBAs), it cannot always secure adequate proximal control. The authors described the advantages of plical resection added to PA for BBAs.

METHODS

Between October 1998 and April 2000, eight consecutive patients with BBAs were treated in the neurosurgical department of Kurashiki Central Hospital. Among them, five patients received direct clipping using this method. There were four females and one male, ages ranging from 61 to 77 (mean 70.8 years). Mean aneurysmal size and distance between the in"terclinoidal line and the aneurysmal neck was 4.5 and 9.5 mm, respectively. The operative procedures consisted of the following components; 1) fronto-temporal craniotomy with translocation of orbito-zygomatico-malar bone for PA, 2) preservation of lateral branches of the superficial sylvian veins, 3) resection of plica dural folds to increase the operative field up to the oculomotor nerve (OMN).

RESULTS

Complete clipping was achieved without thalamic infarction or temporal contusion in all patients. Three of the five patients suffered from transient right OMN palsy which recovered within two months after surgery.

CONCLUSION

Plical resection in the pre-temporal approach might be beneficial in the surgical treatment of BBAs when proximal control seems difficult.

Characterization of carotid atherosclerosis and detection of soft plaque with use of black-blood MR imaging

BACKGROUND AND PURPOSE

In the treatment of carotid atherosclerosis, the rate of stenosis and characteristics of plaque should be assessed to diagnose vulnerable plaques that increase the risk for cerebral infarction. We performed carotid black-blood (BB) MR imaging to diagnose plaque components and assess plaque hardness based on MR signals.

MATERIALS AND METHODS

Three images of BB-MR imaging per plaque were obtained from 70 consecutive patients who underwent carotid endarterectomy (CEA) to generate T1- and T2-weighted images. To evaluate the relative signal intensity (rSI) of plaque components and the relationship between histologic findings and symptoms, we prepared sections at 2-mm intervals from 34 intact plaques. We then calculated the relative overall signal intensity (roSI) of 70 plaques to assess the relationship between MR signal intensity and plaque hardness and symptoms.

RESULTS

The characteristics of rSI values on T1- and T2-weighted images of fibrous cap (FC), fibrosis, calcification, myxomatous tissue, lipid core (LC) with intraplaque hemorrhage (IPH), and LC without IPH differed. Symptomatic plaques were associated with FC disruption (P < .001) and LC with IPH (P < .05). The roSI on T1-weighted images was significantly higher for soft than nonsoft plaques. When the roSI cutoff value was set at 1.25 (mean of the roSI), soft plaques were diagnosed with 79.4% sensitivity and 84.4% specificity. The roSI was also significantly higher for symptomatic than for asymptomatic plaques. Soft and nonsoft plaques as well as symptomatic and asymptomatic plaques did not significantly differ on T2-weighted images.

CONCLUSION

BB-MR imaging can diagnose plaque components and predict plaque hardness. This procedure provides useful information for planning therapeutic strategies of carotid atherosclerosis.

Transplatin, a cisplatin trans-isomer, may enhance the anticancer effect of 5-fluorouracil

Transplatin (TDDP), a trans-isomer of cisplatin (CDDP), is well known to have faint cytotoxicity because its geometric structure allows less adduct formation with DNA than does CDDP. However, TDDP might have the potential to enhance the anticancer effect of 5-fluorouracil (5-FU) as well as CDDP. In this study, five gastric cancer cell lines were used. Cells were treated with 5-FU, TDDP, TDDP+5-FU, CDDP, and CDDP+5-FU, for 72 hrs. Synergistic effects between TDDP and 5-FU were observed in OCUM-2MD3, OCUM-2M, and OCUM-11, though they were not observed in MKN-45 or MKN-28. The cell lines in which synergistic effects were observed between TDDP and 5-FU were the same ones in which synergistic effects are shown between CDDP and 5-FU. The cell lines without synergism between 5-FU +TDDP/CDDP had lower thymidylate synthase (TS) activities than those with synergism, suggesting TS might be attributable to the synergistic mechanism. TDDP alone, compared to CDDP alone, gave rather low cytotoxicity for these cell lines. In conclusion, TDDP might be a clinically useful modulator of 5-FU.

Mucocele in an Onodi cell responsible for acute optic neuropathy

An Onodi cell is defined as the most posterior ethmoid cell, which pneumatizes laterally and superiorly to the sphenoid sinus. A rare case of an isolated mucocele in an Onodi cell with unilateral acute visual disturbance is presented. MRI was imperative for the early and accurate diagnosis, and prompt surgical drainage resulted in dramatic visual recovery.

Gene therapy for human small-cell lung carcinoma by inactivation of Skp-2 with virally mediated RNA interference

Increase of Skp-2, which is involved in the degradation of cell cycle regulators including p27Kip1, p21 and c-myc, is one of the important mechanisms for dysregulation of cell cycles in various cancers. We applied RNA interference (RNAi) for Skp-2 by using HIV-lentiviral or adenoviral vectors for a human small-cell lung carcinoma cell line with increased Skp-2 to evaluate RNAi strategy for cancer gene therapy. HIV-lentivirus-mediated RNAi for Skp-2 resulted in efficient inhibition of the in vitro cell growth of cancer cells with increased Skp-2 through the increase of p27Kip1 and p21, but no significant effect on the growth of cells without high Skp-2 expression. Furthermore, intratumoral administration of adenovirus siRNA vector for Skp-2 efficiently inhibited growth of established subcutaneous tumor on NOD/SCID mice. These results indicate that the Skp-2 RNAi may be a useful strategy for gene therapy of cancers with high Skp-2 expression.

[Thoracoscopic surgery using a new bronchial blocker]

We report use of a new bronchial blocker through a single-lumen endotracheal tube to achieve one-lung ventilation to perform thoracoscopic operation in patients in whom placement of the double-lumen tube failed and difficult intubation is predicted. The bronchial blocker tube was placed into the aimed bronchus under the bronchoscopic vision and the cuff of the blocker was inflated to achieve one-lung ventilation. In all of the 4 patients, the bronchial blocker could be inserted and placed safely, quickly, and exactly under the fiberoptic flexible bronchoscopic vision to perform thoracoscopic operation without any complications. The new bronchial blocker tube through the indwelling endotracheal tube may have advantages in situations where placement of double-lumen endotracheal tubes is technically impossible or inappropriate. The use of the new bronchial blocker tube will, however, require careful evaluation in larger series.

[Thoracoscopic pericardial resections for malignant pericardial effusions]

We have performed 5 thoracoscopic pericardial resections for malignant pericardial effusions. An initial trocar was placed in the seventh or eighth intercostal space posterior to the midaxillary line. Two additional trocars were placed, usually in the sixth intercostals spaces in the anterior axillary and posterior axillary lines. Using an endoscopic grasping instrument and scissors through the working ports, a pericardial resection was performed. All patients were successfully managed by thoracoscopic pericardial resections. Two of the 5 patients had associated malignant pleural effusions that were able to be managed at the same time by thoracoscopy. The average chest tube duration was 1.8 days. There has been no reaccumulation of pericardial effusions in all patients at an average follow-up of 5 months. The thoracoscopic approach could be minimally invasive and the procedure of choice in performing pericardial resections in selected patients with malignant pericardial effusions who are expected to have a reasonable life expectancy.

Static-dynamic friction transition of FRP esthetic orthodontic wires on various brackets by suspension-type friction test

A new testing apparatus for the measurement of frictional properties was designed and the frictional coefficients were obtained and compared with each other in various combinations of brackets and orthodontic wires, including esthetic fiber-reinforced plastic (FRP) wire that was especially designed and manufactured. Three kinds of wires (stainless steel, nickel-titanium, and FRP) and four brackets (single-crystal alumina, polycrystalline alumina, polycarbonate, and stainless steel) were used. The testing was done under dry and wet conditions. The friction testing equipment was designed to attach the bracket to a C-shaped bar suspended with a variable mass, and sliding along a fixed wire. The transition between static and dynamic friction was measured as a breakaway force, with the use of a universal test machine. In addition to material properties, this testing fixture eliminates geometrical factors, such as the rotational moment at the edge of the bracket slot, deflection of the orthodontic wire, and tension of the ligature wire. Nearly ideal frictional properties between materials are obtained. The frictional properties of FRP wire were similar to those of metal wires on all brackets, except the polycrystalline alumina bracket. The frictional coefficient between the polycrystalline ceramic bracket and FRP wire was larger than that of other combinations. There was little difference in frictional coefficients between dry and wet conditions.

[A thoracoscopic technique with fibrin glue and polyglycolic acid mesh for the injured lung during thoracoscopic operation]

The injury of the lung occurred during thoracoscopic operation, especially, of the fragile, severely emphysematous lung is often difficult to treat. A fibrin glue spraying device in which an air compressor was connected to an intravenous catheter was constructed, and connected to a Dupuloject syringe. Fibrin glue was administered by spraying on the target lesion under a thoracoscopic vision. The procedure was done while the tip of the intravenous catheter was held and manipulated with forceps through a thoracoport. And then, the polyglycolic acid (PGA) mesh that had been cut into small pieces was put on the target lesion with forceps. Fibrin glue was sprayed on the lesion again in the above-mentioned manner. When necessary, the procedure was repeated. Our technique during thoracoscopic operation may be easy to manipulate and be able to apply the target lesion uniformly within a short time with a successful repair.

Xanthine oxidase inhibition reduces reactive nitrogen species production in COPD airways

Reactive nitrogen species (RNS) have been reported to be involved in the inflammatory process in chronic obstructive pulmonary disease (COPD). However, there are no studies on the modulation of RNS in COPD. It was hypothesised that inhibition of xanthine oxidase (XO) might decrease RNS production in COPD airways through the suppression of superoxide anion production. Ten COPD and six healthy subjects participated in the study. The XO inhibitor allopurinol (300 mg x day(-1) p.o. for 4 weeks) was administered to COPD patients. RNS production in the airway was assessed by 3-nitrotyrosine immunoreactivity and enzymic activity of XO in induced sputum as well as by exhaled nitric oxide (eNO) concentration. XO activity in the airway was significantly elevated in COPD compared with healthy subjects. Allopurinol administration to COPD subjects significantly decreased XO activity and nitrotyrosine formation. In contrast, eNO concentration was significantly increased by allopurinol administration. These results suggest that oral administration of the xanthine oxidase inhibitor allopurinol reduces airway reactive nitrogen species production in chronic obstructive pulmonary disease subjects. This intervention may be useful in the future management of chronic obstructive pulmonary disease.

Room-temperature ferromagnetism in a II-VI diluted magnetic semiconductor Zn(1-x)Cr(x)Te

The magnetic and magneto-optical properties of a Cr-doped II-VI semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the sp carriers and localized d spins, indicating that Zn(1-x)Cr(x)Te is a diluted magnetic semiconductor. The Curie temperature of the film with x=0.20 was estimated to be 300+/-10 K, which is the highest value ever reported for a diluted magnetic semiconductor in which sp-d interactions were confirmed. In spite of its high Curie temperature, Zn(1-x)Cr(x)Te film shows semiconducting electrical transport properties.

Correlation between change in pulmonary function and suppression of reactive nitrogen species production following steroid treatment in COPD

BACKGROUND

Reactive nitrogen species (RNS) have a number of inflammatory actions and the production of these molecules has been reported to be increased in the airways of patients with chronic obstructive pulmonary disease (COPD), which suggests that they may be involved in the inflammatory and obstructive process in COPD.

METHODS

The relationship between the reduction in RNS and the improvement in pulmonary function was studied in 18 patients with COPD following steroid treatment (800 micro g beclomethasone dipropionate inhalation for 4 weeks). Twelve patients were treated with inhaled steroids and the others received placebo treatment. Forced expiratory volume in 1 second (FEV(1)) and airway responsiveness to histamine were measured before and after treatment. Induced sputum cells were stained with anti-nitrotyrosine antibody, a footprint of RNS, and RNS formation was assessed by measuring nitrotyrosine immunoreactivity. The immunoreactivity of inducible nitric oxide synthase (iNOS) in induced sputum and exhaled NO levels were also measured.

RESULTS

Treatment with steroids resulted in a significant reduction in both nitrotyrosine and iNOS immunoreactivity in sputum cells compared with pretreatment levels (both p<0.01). The reduction rates in both parameters were significantly related (p<0.05). The reduction in nitrotyrosine and iNOS immunoreactivity was correlated with the improvement in FEV(1) (p<0.05) and airway responsiveness to histamine (p<0.01). None of the parameters was significantly changed by placebo administration.

CONCLUSIONS

These results suggest that RNS may be involved in the reversible component of inflammation in COPD that is suppressed by steroids. Further studies using specific inhibitors for RNS are needed to clarify their effects on the long term progression of COPD.

[Thoracoscopic surgery for metastatic lung tumors: computed tomography-guided localization with use of a needle with a suture]

When a metastatic lung tumor is found to be deep to the visceral surface of the pleura, or when it is found to be a small lesion, it may important to help identify the lesion by preoperative methods in order to localize it at the time of thoracoscopic operation. We performed computed tomography-guided localization of metastatic lung tumors with use of a needle with a suture in 11 cases prior to thoracoscopic resection. Placement of the needle, immediately before moving to the operation room were successfully performed in all patients. It took from 16 to 25 minutes (20.3 minutes on average). Complications included minimal pneumothorax in 8 patients, mild airway bleeding in 2, and penetration through the middle lobe to the lower lobe of the right lung in 1. However, treatment was not necessary in any of the patients. Thoracoscopic resections were successfully achieved in all patients. Our technique may be a simpler technique and advantageous for identification of small lesions and lesions deep to the visceral surface of the pleura during the thoracoscopic operation for metastatic lung tumors.

iNOS depletion completely diminishes reactive nitrogen-species formation after an allergic response

Nitric oxide (NO) shows proinflammatory actions mainly via reactive nitrogen species (RNS) formation through superoxide- and peroxidase-dependent mechanisms. The purpose of this study was to examine the role of inducible NO synthase (iNOS) in RNS production, airway hyperresponsiveness, and inflammation after allergen challenge. Ovalbumin (OVA)-sensitised, iNOS-deficient and wild-type mice were used. RNS production was assessed by nitrotyrosine (NT) immunoreactivity in the airways. Airway inflammation and responsiveness were evaluated by eosinophil accumulation and methacholine (i.v.) challenge, respectively. In wild-type mice, OVA-inhalation challenge increased iNOS immunoreactivity in airway epithelial cells as well as iNOS protein measured by Western blotting. The total amounts of nitrite and nitrate in bronchoalveolar lavage (BAL) fluid were increased, and NT immunoreactivity was also observed abundantly in airway inflammatory cells. In iNOS-deficient mice, both iNOS expression and NT formation were completely abolished, and the total amounts of nitrite and nitrate in BAL fluid were significantly decreased. In contrast, OVA-induced airway eosinophil recruitment and hyperresponsiveness were observed almost equally in wild-type and iNOS-deficient mice. These data suggest that reactive nitrogen species production after allergic reaction occurs totally via inducible nitric oxide synthase-dependent pathways. Allergen-mediated airway eosinophil recruitment and hyperresponsiveness appear to be independent of reactive nitrogen species production.

Ganglioside GD1a inhibits HGF-induced motility and scattering of cancer cells through suppression of tyrosine phosphorylation of c-Met

We previously reported that ganglioside GD1a, which is highly expressed in poorly metastatic FBJ-S1 cells, inhibits the serum-induced motility of FBJ-LL cells and that the metastatic potential of FBJ-LL cells is completely suppressed by enforced GD1a expression (Hyuga et al., Int J Cancer 1999;83:685-91). We recently discovered that hepatocyte growth factor (HGF) induces FBJ-LL cell motility. In the present study, the HGF-induced motility of FBJ-S1 cells was found to be one-thirtieth that of FBJ-LL cells. This motility of GD1a-expressing transfectants, which were produced by transfection of FBJ-LL cells with GM2/GD2 synthase cDNA, decreased with increases in their GD1a expression and HGF induced almost no motility in GD1a-pretreated FBJ-LL cells, indicating that GD1a inhibits the HGF-induced motility of FBJ-LL cells. The expression of the HGF receptor c-Met on FBJ-S1 cells, FBJ-LL cells, transfectants and a mock-transfectant was almost the same. The level of tyrosine phosphorylation of c-Met after HGF stimulation in FBJ-S1 cells, GD1a-pretreated FBJ-LL cells and a GD1a-expressing transfectant was significantly lower than in FBJ-LL cells and a mock-transfectant. These findings suggested that GD1a inhibits the HGF-induced motility of FBJ-LL cells through suppression of tyrosine phosphorylation of c-Met. HepG2 cells, a human hepatoma cell line, were used to investigate whether GD1a interferes with other cancer cells expressing c-Met. HepG2 cells did not express GD1a. HGF induced cell scattering of HepG2 cells and the scattering was inhibited by pretreating the cells with GD1a. The c-Met in the cells was autophosphorylated by stimulation with HGF, but after treating the cells with GD1a, the HGF-induced autophosphorylation of c-Met was suppressed. These results suggest that GD1a acts as a negative regulator of c-Met in cancer cells.

Cloning and overexpression of the oah1 gene encoding O-acetyl-L-homoserine sulfhydrylase of Thermus thermophilus HB8 and characterization of the gene product

The oah1 gene of an extremely thermophilic bacterium, Thermus thermophilus HB8, was cloned, sequenced, and overexpressed in Escherichia coli cells. The gene product having a high O-acetyl-L-homoserine sulfhydrylase (EC 4.2.99.10) activity was purified to homogeneity, with a recovery of approximately 40% and a purification ratio of 81-fold, both calculated from the cell-homogenate. The protein showed molecular masses of approximately 163000 (for the native form) and 47000 (for the subunit). The isoelectric point was pH 6.0. The optimum temperature and pH for the activity were approximately 70 degrees C and pH 7.8, respectively. The enzyme was also shown to be very stable at high temperature (90% activity remaining at 90 degrees C for 60 min at pH 7.8) and in a wide range of pH (pH 4-12 at room temperature). The absorption spectrum showed a peak at 425 nm, and hydroxylamine hydrochloride (0.1 mM) inhibited approximately 90% of the activity, suggesting formation of a Schiff base with pyridoxal 5'-phosphate. The enzyme showed an apparent K(m) value of 6.8 mM for O-acetyl-L-homoserine, a V(max) value of 165 micromol/min per mg of protein at a fixed sulfide concentration of 5 mM, and also an apparent K(m) value of approximately 1.3 mM for sulfide (with 25 mM acetylhomoserine). L-Methionine (1 mM) inhibited the enzyme activity by 67%. Based on these findings, it was discussed that this enzyme might be inactive under ordinary conditions but might become active as an alternative homocysteine synthase in T. thermophilus HB8, only under such conditions as deficiency in transsulfuration, bringing about a sufficient amount of sulfide available in the cell.

[Magnetic resonance imaging findings of postresuscitation encephalopathy: sequential change and correlation with clinical outcome]

OBJECTIVE

The purpose of this study was to describe the findings of sequential magnetic resonance imaging (MRI) in postresuscitation encephalopathy. Although its outcome is known to be overwhelming, but its acute findings by variable imaging methods are subtle and show only limited values. The correlation of the findings of MRI with clinical outcome were also analyzed.

METHODS

Twelve patients with global cerebral anoxia who underwent MRI with conventional and diffusion-weighted imaging were enrolled in this study. Compared with normal MRI images, abnormal signal regions were checked and described in cortex, basal ganglia and white matter. Also medical records were carefully reviewed to study the cause, the time necessary for resuscitation and long term clinical outcome.

RESULTS

The earliest finding was obtained by diffusion-weighted image less than 24 hours (acute period) in bilateral cerebral cortex as bright high signal intensity regions. Similar abnormality of bright high signal area in FLAIR and T 2 was followed according to the time elapsed in early subacute period (1-13 days). Succeedingly, white matter was involved and laminar necrosis in cortical area was observed in late subacute period (14-20 days). Finally, diffuse brain atrophy and obtundation of gray-white matter junction were seen in chronic stage (after 21 days). These MR findings were coincided well with histopathological findings reported in literatures. The poor outcome was closely and significantly correlated with abnormality in MR images.

CONCLUSION

MRI was a useful diagnostic modality to diagnose the whole brain ischemic encephalopathy and to predict the prognosis.

Milrinone for the treatment of cerebral vasospasm after subarachnoid hemorrhage: report of seven cases

OBJECTIVE

The intra-arterial infusion of papaverine has been used for dilation of spastic cerebral vessels after aneurysmal subarachnoid hemorrhage, although its efficacy is controversial. Milrinone is an inotropic drug that dilates vessels by phosphodiesterase inhibition in a mechanism similar to that of papaverine. We examined the effects of intra-arterial and subsequent intravenous administration of milrinone on patients with symptomatic cerebral vasospasm.

METHODS

Seven patients with cerebral vasospasm were enrolled in this study. Milrinone was delivered intra-arterially via catheter at a rate of 0.25 mg/min. The total delivered dose was between 2.5 and 15 mg. Radiological measurement of the middle cerebral artery diameter and cerebral blood flow was carried out before and after arterial infusion. Intravenous treatment followed at 0.50 or 0.75 microg/kg/min for up to 2 weeks from the onset of subarachnoid hemorrhage.

RESULTS

Dilation of the vasospastic vessels occurred in all patients. The rate of cerebral blood flow was calculated in six patients and was increased in all. Subsequent intravenous infusion was effective in preventing a recurrence of symptomatic vasospasm in four of the seven patients.

CONCLUSION

It is suggested that milrinone was effective and safe for the treatment of cerebral vasospasm after subarachnoid hemorrhage in the patients in this series. Intra-arterial infusion with adjunctive intravenous infusion holds promise as a clinically advantageous treatment regimen.

Occurrence of transsulfuration in synthesis of L-homocysteine in an extremely thermophilic bacterium, Thermus thermophilus HB8

A cell extract of an extremely thermophilic bacterium, Thermus thermophilus HB8, cultured in a synthetic medium catalyzed cystathionine gamma-synthesis with O-acetyl-L-homoserine and L-cysteine as substrates but not beta-synthesis with DL-homocysteine and L-serine (or O-acetyl-L-serine). The amounts of synthesized enzymes metabolizing sulfur-containing amino acids were estimated by determining their catalytic activities in cell extracts. The syntheses of cystathionine beta-lyase (EC 4.4.1.8) and O-acetyl-L-serine sulfhydrylase (EC 4.2.99.8) were markedly repressed by L-methionine supplemented to the medium. L-Cysteine and glutathione, both at 0.5 mM, added to the medium as the sole sulfur source repressed the synthesis of O-acetylserine sulfhydrylase by 55 and 73%, respectively, confirming that this enzyme functions as a cysteine synthase. Methionine employed at 1 to 5 mM in the same way derepressed the synthesis of O-acetylserine sulfhydrylase 2.1- to 2.5-fold. A method for assaying a low concentration of sulfide (0.01 to 0.05 mM) liberated from homocysteine by determining cysteine synthesized with it in the presence of excess amounts of O-acetylserine and a purified preparation of the sulfhydrylase was established. The extract of cells catalyzed the homocysteine gamma-lyase reaction, with a specific activity of 5 to 7 nmol/min/mg of protein, but not the methionine gamma-lyase reaction. These results suggested that cysteine was also synthesized under the conditions employed by the catalysis of O-acetylserine sulfhydrylase using sulfur of homocysteine derived from methionine. Methionine inhibited O-acetylserine sulfhydrylase markedly. The effects of sulfur sources added to the medium on the synthesis of O-acetylhomoserine sulfhydrylase and the inhibition of the enzyme activity by methionine were mostly understood by assuming that the organism has two proteins having O-acetylhomoserine sulfhydrylase activity, one of which is cystathionine gamma-synthase. Although it has been reported that homocysteine is directly synthesized in T. thermophilus HB27 by the catalysis of O-acetylhomoserine sulfhydrylase on the basis of genetic studies (T. Kosuge, D. Gao, and T. Hoshino, J. Biosci. Bioeng. 90:271-279, 2000), the results obtained in this study for the behaviors of related enzymes indicate that sulfur is first incorporated into cysteine and then transferred to homocysteine via cystathionine in T. thermophilus HB8.

Allergic airway hyperresponsiveness and eosinophil infiltration is reduced by a selective iNOS inhibitor, 1400W, in mice

Nitric oxide (NO) hyperproduction has been reported in asthmatic airways and may contribute to airway inflammatory responses. The purpose of this study was to examine the role of NO via inducible NO synthase (iNOS) in allergic airway inflammation using a selective iNOS inhibitor, N-[3-(aminomethyl)benzyl] acetamidine (1400W), in ovalbumin (OVA)-sensitized Balb/c mice. Sensitized animals were challenged with aerosolized 0.5% OVA for 1 h on two occasions 4 h apart. 1400W or the vehicle was administered by osmotic mini-pump from 2 h before to 24 h after OVA challenge. Twenty-four hours after OVA challenge, the vehicle-treated mice showed a significant airway hyperresponsiveness to intravenous methacholine (P<0.05) as well as an influx of eosinophils into the airways (P<0.05). iNOS immunoreactivity was obvious in the epithelial and, to a lesser extent, the infiltrated inflammatory cells. iNOS protein in the airway assessed by Western blotting also increased. Pretreatment with 1400W almost completely abolished the OVA-induced airway hyperresponsiveness and to a lesser extent eosinophil accumulation into the airways. These results suggest that NO synthesized by iNOS may participate in airway hyperresponsiveness and eosinophil infiltration into the airways after allergic reaction.

Azido glycoside primer: a versatile building block for the biocombinatorial synthesis of glycosphingolipid analogues

A lactoside primer, 12-azidododecyl beta-lactoside, was synthesized via the Koenigs-Knorr method by glycosylation of 1,12-dodecyldiol with perbenzoylated lactosyl bromide. The presence of the 2-O-acyl substituent in the donor gave the beta-lactoside, and an excess of acceptor ensured monoglycosylation of the diol. Mesylation of the omega-hydroxyl group in the aglycon, followed by displacement of the mesylate with azide and subsequent O-debenzoylation gave the desired omega-azidododecyl beta-lactoside. The azido glycoside primer was examined in mouse B16 melanoma cells for its feasibility as a building block for oligosaccharide biosynthesis. Uptake of the azido glycoside primer by B16 cells resulted in the sialylation of the galactose residue of the primer to give a glycosylated product having the same glycan as in ganglioside GM3. After 24 h incubation of B16 cells with the primers, the amount of sialylated omega-azidododecyl beta-lactoside primer was 75% of the amount of sialylated n-dodecyl beta-lactoside. However, after 48 h incubation, both primers gave equal amounts of the sialylated products. Interestingly, the remaining azido glycoside primer after 48 h incubation was 5.6-fold greater than that of the alkyl primer, indicating degradation of the alkyl primer to a larger extent than the omega-azido glycoside primer. The facile chemical synthesis and the efficient uptake in cells make the azido glycoside primer a versatile building block for the biocombinatorial synthesis of glycolipid oligosaccharides.

Carotid stenting with the use of wallstent

SUMMARY

We performed carotid stenting with Wallstent for 22 cases. The mean stenosis was 74.3 +/- 11.2% before stenting and 14.2 +/- 8.8% after stenting. The technical success (< 40% residual stenosis) was 100%. We experienced 2 embolic complications (one TIA and one minor stroke). Permanent neurological deficits were not encountered in all the patients (0%). Restenosis was observed in 2 cases (12.5%). The both lesions revealed intimal hyperplasia on intravascular ultrasound (IVUS). MRI diffusion weighted study showed that distal embolism happened more often (46.2%) than we expected although most of them were asymptomatic.We must wait for the long term result to conclude that carotid stenting has become one of the treatment modalities.

Characterization of O-acetyl-L-serine sulfhydrylase purified from an alkaliphilic bacterium

O-Acetyl-L-serine sulfhydrylase (EC 4.2.99.8) activity was shown to be very high compared with O-acetyl-L-homoserine sulfhydrylase (EC 4.2.99.10) activity and L-cystathionine cleaving activities, in an extract of cells of an alkaliphilic bacterium grown in a synthetic medium. The synthesis of the first enzyme was repressed by approximately 55% by both L-cystine and L-djenkolic acid added to the medium at a concentration of 0.5 mM, but L-methionine (1 mM) and S-adenosyl-L-methionine (0.5 mM) affected it to lesser extents. Its enzyme activity was inhibited by 25% and 12% by methionine (10 mM) and S-adenosylmethionine (5 mM), respectively. The enzyme was purified from the extract through ammonium sulfate fractionation, heat treatment, and chromatography on columns of DEAE-cellulose, Sephacryl S-300, and Octyl Sepharose CL-4B with a recovery of 21%. Polyacrylamide gel electrophoresis with sodium dodecylsulfate of the preparation obtained finally showed its homogeneity and the molecular mass of 37,000 Da for dissociated subunits. Gel filtration of the enzyme on a Sephacryl S-300 column showed an approximate molecular mass of 72,000 Da, suggesting that the enzyme was comprised of two identical subunits. The enzyme catalyzed the beta-replacement reaction with O-acetylserine as a substrate, and showed no reactivity to other O-substituted amino acids tested. The reaction proceeded best at 40 degrees C (when tested at pH 7.5), and at pH 6.5 (at 40 degrees C). The enzyme kept 90% its activity after incubation at 65 degrees C (at pH 7.5) for 30 min, and more than 90% after 30 min incubation at pHs 7-12 at 30 degrees C. The enzyme had a Km of 4 mM for O-acetyl-L-serine and a Vmax of 37.0 micromol/min/mg of protein, a very low value compared with those of other organisms. However, the content of the enzyme in the extract was calculated to be approximately 3.5% total protein. Sensitivity of the enzyme to carbonyl reagents was very low, although it was shown to have pyridoxal 5'-phosphate as a cofactor by examination of its absorption spectrum. Sulfhydryl reagents tested showed no inhibition. The novelty of this enzyme among analogous sulfhydrylases purified from other organisms was discussed.

Small advanced colorectal cancers: clinicopathological characteristics and pathogenetic origin

BACKGROUND

Recently, increasing numbers of small but deeply invading colorectal cancers have been detected. We conducted the present study to examine the hypothesis that these small advanced cancers are more biologically malignant than larger cancers and to elucidate their pathogenetic origin.

METHODS

We analyzed the clinicopathological characteristics of 23 advanced cancers not exceeding 2 cm in diameter (Small-Ca) in comparison with 1117 advanced cancers larger than 2 cm (Large-Ca). We compared the frequency of K-ras mutation and the growth pattern (polypoid growth, PG; non-polypoid growth, NPG) between Small-Ca and 60 submucosal cancers not exceeding 2 cm in diameter (Early-Ca).

RESULTS

Generally, Small-Ca showed less malignant characteristics than Large-Ca. However, Small-Ca with NPG pattern invaded more deeply and metastasized more frequently than those with PG pattern. In Small-Ca, all ulcerated lesions showed NPG pattern, whereas only 14% of protruded lesions did. In Early-Ca, 90% of non-polypoid lesions showed NPG pattern, whereas only 16% of polypoid lesions did. K-ras mutation was less frequent in ulcerated Small-Ca than in polypoid cancers (33 vs 57%). In Early-Ca, non-polypoid cancers showed a lower frequency of K-ras mutation than polypoid cancers (9% vs 46%).

CONCLUSIONS

Small-Ca, in general, were less malignant clinicopathologically than Large-Ca; however, Small-Ca with NPG pattern showed a tendency to be more aggressive than those with PG pattern. The similarity of the K-ras mutation rate and growth pattern of ulcerated Small-Ca and non-polypoid Early-Ca suggests that the majority of ulcerated Small-Ca may originate from non-polypoid Early-Ca.

Significance of K-ras mutation and CEA level in pancreatic juice in the diagnosis of pancreatic cancer

The early diagnosis of pancreatic carcinoma is essential for increasing patient survival rates. In this study, 52 patients with suspected pancreatic diseases were examined to investigate the value of K-ras codon 12 point mutation, levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9), and cytology of pancreatic juice in the diagnosis of pancreatic carcinoma. Pancreatic juice was taken without secretin stimulation. K-ras mutation was detected by enriched polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP). K-ras mutation in pancreatic juice was more frequent in carcinoma than in benign diseases (P = 0.0448). The positive predictive value of K-ras mutation for the diagnosis of neoplastic disease was 83%. The CEA level in pancreatic juice in carcinoma was significantly greater than that in benign disease (P< 0.0001). When the cutoff level of CEA was set at 50 ng/ml, its accuracy for the diagnosis of carcinoma was 85%. A multivariate analysis showed that K-ras mutation and CEA level in pancreatic juice, as well as serum CA19-9 level and age of the patient were independent variables for the diagnosis of carcinoma, and the accuracy of diagnosis by this analysis was increased to 90%. In conclusion, both K-ras mutation and CEA level in pancreatic juice may be valuable for the diagnosis of carcinoma. Better discrimination was possible with a multivariate analysis.

[Stenting for intracranial internal carotid artery stenosis with the use of a coronary stent: a case report]

A 61-year-old man was admitted to our hospital for mild left hemiparesis and speech disturbance. An initial angiogram revealed occlusion of the right internal carotid artery (ICA) but with sufficient collateral flow by compensated the contralateral carotid artery. Severe stenosis (70%) in the intracavernous (C4-5) portion was identified in the left ICA. Cerebral blood flow was remarkably decreased in both hemispheres. The patient's hemiparesis fluctuated according to the systemic blood pressure in such a manner that induced hypertension therapy was mandatory. On the 19th hospital day, we performed stenting of the left ICA stenosis using a coronary stent. A flexible coronary stent, NIR PRIMO stent 3.0 mm/16 mm (SCIMED, Boston Scientific) was deployed after the predilatation (2.5 mm/10 atm). The initial 70% stenosis was reduced to 6% after the postdilatation (3.75 mm/8 atm). The neurological status was stable after the procedure and we stopped the induced hypertension therapy the next day. We consider that intracranial artery stenting will be a common therapeutic modality in the near future.

Event-related evoked potential study of repetition priming to attended and unattended words

The filtering stage of ignored stimuli is one of main issues in the selective attention mechanism. We investigated whether unattended ignored stimuli show repetition priming effects on event-related brain potentials (ERPs), using a lexical decision task involving Japanese Kanji words. The repeated words in the unattended field generated a negative shift of the ERP over the frontal scalp sites. This suggested that unattended stimuli were processed implicitly to some degree and that different neural mechanisms contribute to repetition priming effects to attended and unattended stimuli.

Terson syndrome caused by ventricular hemorrhage associated with moyamoya disease--case report

A 24-year-old female presented with Terson syndrome secondary to bilateral ventricular hemorrhage as a complication of moyamoya disease. Ophthalmoscopy and magnetic resonance imaging clearly demonstrated vitreous hemorrhage in the left eye globe. Various visual symptoms are associated with moyamoya disease, almost all of which result from ischemic lesions in the visual cortex and optic pathways. In this case, the visual disturbance was caused by Terson syndrome secondary to ventricular hemorrhage. Close ophthalmological and radiological evaluation is mandatory even in patients with moyamoya disease and hemorrhagic manifestation located in the intracerebral, subarachnoid, or intraventricular space.

Increase in reactive nitrogen species production in chronic obstructive pulmonary disease airways

Peroxynitrite, nitrogen dioxide, and other reactive nitrogen species (RNS) that are formed in the reaction of nitric oxide (NO) with superoxide anion, and in peroxidase-dependent mechanisms, have a potent inflammatory action. These molecules may therefore increase in number and have a role in inflammatory airway diseases. In the present study, we quantified RNS using immunostaining of nitrotyrosine and inducible NO synthase (iNOS) in airway inflammatory cells obtained by the induced sputum technique, and also quantified the exhaled NO concentration in subjects with chronic obstructive pulmonary disease (COPD), subjects with asthma, and healthy subjects (HS). Immunoreactivity for iNOS observed in the airway inflammatory cells was significantly and similarly higher in subjects with COPD and asthma than in HS, although exhaled NO levels were increased only in subjects with asthma. Inflammatory cells showed obvious nitrotyrosine immunoreactivity in subjects with COPD and to a lesser extent in those with asthma, but not in HS. There was a significant negative correlation between the percent predicted values of FEV(1) and the amount of nitrotyrosine formation in subjects with COPD, but not in those with asthma and HS. These results suggest that: (1) RNS may be involved in the pathobiology of the airway inflammatory and obstructive process in COPD; and (2) NO produced in the airways, presumably via iNOS, is consumed by its reaction with superoxide anion and/or peroxidase-dependent mechanisms.

Possible role of hepatocyte growth factor/scatter factor and activin A produced by the target organ in liver metastasis

The molecular mechanism of organ-specific metastasis to the liver remains largely unknown. However, it is conceivable that paracrine growth factors produced by a target organ induce migration and proliferation of malignant cells to that organ, and this is the cause of organ-specific metastasis. In this study, we investigated the effect of hepatocyte growth factor/scatter factor (HGF/SF) and activin A, which are known to be produced by the liver, on the motility and growth of liver-metastatic cell line FBJ-LL. HGF/SF and activin A induced motility synergistically, but they did not affect the proliferation of FBJ-LL cells. Expression of the HGF/SF receptor, the c-met gene, and the activin-receptor type IA, type IB, and type IIA genes in FBJ-LL cells was detected by reverse transcription polymerase chain reaction. These findings suggest that both HGF/SF and activin A promote organ-specific metastasis to the liver by induction of migration through their specific receptors on liver-metastatic cells.

Effect of a calcium sensitization modulator, Y-27632, on isolated human bronchus and pulmonary artery

A recently developed pyridine derivative, Y-27632, has been reported to inhibit smooth muscle contraction by inhibiting Ca(2+)sensitization in animal experiments. However, the effect of this compound in human tissues has not yet been elucidated. The aim of the present study was to evaluate the effect of Y-27632 on human bronchi and pulmonary arteries. The tissues were obtained from lung cancer patients undergoing lung resection. Tissue responses were assessed by isometric tension measurement. Y-27632 relaxed the bronchi at basal tone with an IC(50)(concentration causing 50% relaxation of the maximal response) of 2.0+/-0.3x10(-6)M. Y-27632 also dose-dependently relaxed the bronchi precontracted by acetylcholine (ACh), histamine and neurokinin A, and the IC(50)was 3.0+/-0.4x10(-6), 2.5+/-0.5x10(-6)and 1.8 +/-0.3x10(-6)M, respectively. The dilatory effect of Y-27632 was significantly smaller in ACh-precontracted tissues compared with those of basal or histamine- and neurokinin A-induced precontracted bronchi (P<0.05). Further, Y-27632 showed an inhibitory effect on cholinergic nerve stimulation- and ACh-induced bronchial contraction to the same degree, suggesting that a modulatory effect of this compound on ACh release from nerve terminals was unlikely. Y-27632 also dilated the pulmonary arteries precontracted by phenylephrine (IC(50)= 1.6+/-0.1x10(-6)M). These data suggest that Y-27632 has a dilatory capacity on human bronchi as well as on pulmonary arteries.

Cerebral asymmetry of the "top-down" allocation of attention to global and local features

Neuropsychological and neuroimaging studies have indicated that global and local features of a visual scene are processed differentially by the two hemispheres. Although visual selective attention is suggested to play a role in the hemispheric asymmetry, the precise mechanism of attentional control for the global-local processing is not fully understood. We investigated the neural correlates of cerebral asymmetry in directing attention to the global pattern and local components of a hierarchical stimulus. Event-related brain potentials (ERPs) were recorded while the subjects shifted their attention to the global or local level of a hierarchically structured letter. The shift direction was controlled by a preceding cue stimulus. The ERPs to the cue stimuli demonstrated that the right temporal-parietal and left posterior temporal regions were differentially activated during attentional allocation to the global and local levels, respectively. These effects started 240 msec after the cue stimulus. The late ERP components to the target stimuli also manifested the hemispheric global-local asymmetry as seen during the attentional shift. These electrophysiological results provided an asymmetrical neural basis for the "top-down" allocation of attention to global and local features and revealed the contribution of the temporal-parietal cortex to this attentional mechanism.

[The use of a modified vertical mandibular osteotomy for exposure of a distal cervical internal carotid artery]

We report herein the case of a 56-year-old woman who presented with repeated transient ischemic attacks (TIAs). Cerebral angiography revealed that the left redundant internal carotid artery (ICA) uncharacteristically curved medially. These findings were highly suggestive of an internal carotid artery aneurysm at the level between the first and second cervical vertebral bodies. The lesion was presumed to be difficult to access by the surgical procedure usually adopted in carotid endarterectomy. Thus, we decided to employ a modified vertical mandibular osteotomy. The operative view revealed that the lesion was atherosclerotic stenosis with ulceration, so carotid endarterectomy was indicated. This mandibular osteotomy not only provided us with wide, satisfactory exposure of the distal cervical internal carotid artery but also afforded good mandibular stability during the postoperative period.

Mutational analysis of ligand recognition by tcp, the citrate chemoreceptor of Salmonella enterica serovar typhimurium

The chemoreceptor Tcp mediates taxis to citrate. To identify citrate-binding residues, we substituted cysteine for seven basic or polar residues that are chosen based on the comparison of Tcp with the well-characterized chemoreceptors. The results suggest that Arg-63, Arg-68, Arg-72, Lys-75, and Tyr-150 (and probably other unidentified residues) are involved in the recognition of citrate.

Event-related brain potentials in response to novel sounds in dementia

OBJECTIVE

Non-target, deviant stimuli generate an earlier latency, front-central novelty P3, whereas correctly detected task-relevant stimuli generate a parietal maximal target P3. We examined whether the P3 component to novel stimuli is affected by dementing processes, and is therefore useful for distinguishing Alzheimer's type dementia (AD) from vascular dementia (VD).

METHODS

We recorded ERPs to task-relevant stimuli (target P3) and novel task-irrelevant stimuli (novelty P3) in an auditory oddball task in AD (n = 16), VD (n = 16), and age-matched controls (n = 18). The amplitude, latency, and scalp topography of target and novelty P3 were compared among 3 groups using ANOVA. The relationship between P3 measures and intelligence scores were evaluated by correlation analysis.

RESULTS

The amplitude, latency and scalp topography of the target P3 were comparably affected by both AD and VD. However, the amplitude of the novelty P3 was markedly reduced in VD, but not in AD, and the scalp topographics were different in the 3 groups. The amplitude was maximal at frontal sites in controls, at central sites in AD, and at parietal sites in VD. The target P3 latency was prolonged in both AD and VD, whereas the novelty P3 latency was only prolonged in VD. AD was discriminated satisfactorily from VD by using the novelty amplitude at Cz and the ratio of the amplitudes at Fz and Pz as independent variables.

CONCLUSIONS

These results suggest that the response to novel stimuli is differentially affected by dementia with degenerative and vascular etiology.

Suppression by ganglioside GD1A of migration capability, adhesion to vitronectin and metastatic potential of highly metastatic FBJ-LL cells

Ganglioside GD1a, which is highly expressed in poorly metastatic FBJ-S1 cells, has been shown to inhibit the serum-induced migration capability of highly metastatic FBJ-LL cells. In the present study, the capacity of FBJ-S1 cells to adhere to vitronectin was found to be about half that of FBJ-LL cells. Pre-treatment of FBJ-LL cells with GD1a decreased this capacity by 30% that of the control, whereas GM1-pre-treatment caused only a 10% decrease, indicating that GD1a specifically inhibits FBJ-LL cell adhesion to vitronectin. Since FBJ-LL cells contain almost no GD1a, transfectants capable of expressing GD1a to varying degrees were produced in this study by transfection of FBJ-LL cells with GM2/GD2-synthase cDNA. Decrease in the serum-induced migration capacity of these transfectants was accompanied by an increment in GD1a expression. Adhesion of the transfectants to vitronectin decreased by 30% as compared with mock-transfected cells. Within 4 to 5 weeks after GD1a-expressing transfectant and mock-transfected cells were transplanted into mice, metastatic nodules were observed in liver, lung, kidney and adrenal glands of mock-transplanted mice, but not in those with GD1a-expressing transfectants, indicating that GD1a suppresses the metastasis of FBJ-osteosarcoma cells, possibly by inhibiting cell migration and cell adhesion. The involvement of the ganglioside in the suppression of metastasis is clearly demonstrated in the present study.