Biomedical subjects

H Tomioka

Publications and source records attributed to H Tomioka.

At least 19 recordsLinked to original sources

PubMed2006

Comparative studies on the roles of mediator molecules in expression of the suppressor activity of Mycobacterium avium complex-induced immunosuppressive macrophages against T cell and B cell mitogenic responses.

Mycobacterium avium complex-induced immunosuppressive macrophages (MAC-MPhis) exhibit suppressor activity against concanavalin A-induced T cell mitogenesis (T cell Con A mitogenesis). We examined the profiles of the MAC-MPhi-mediated suppression of lipopolysaccharide-induced B cell mitogenesis (B cell LPS mitogenesis) and found the following. First, although N(G)-monomethyl-L-arginine and carboxy-PTIO effectively blocked the MAC-MPhi's suppressor activity against T cell Con A mitogenesis, MAC-MPhi's action against B cell LPS mitogenesis was only weakly affected by these NO-reducing agents. Second, B cell LPS mitogenesis was remarkably more susceptible to MAC-MPhi-derived reactive oxygen intermediates than T cell Con A mitogenesis. Third, B cell LPS mitogenesis was less susceptible to the inhibitory effects of the other MAC-MPhi-derived suppressor mediators, including free fatty acids, TGF-beta and prostaglandin E(2), than T cell Con A mitogenesis. Fourth, MAC-MPhi's suppressor activity was strongly dependent on B7-1 like molecule-mediated cell contact with target cells only in the case of T cell Con A mitogenesis. Therefore, there are significant differences in the modes of suppressor action of MAC-MPhis against T cell and B cell mitogenesis.

Animals↗

PubMed2004

Comparative roles of macrophages and NK cells in the host innate resistance of mice to Mycobacterium fortuitum infection.

OBJECTIVES: Profiles of host innate resistance to Mycobacterium fortuitum (MFT) infection in mice and the roles of macrophages (Mphis) and NK cells in host resistance to MFT infection were studied. METHODS: MFT-infected mice with or without the treatments to reduce Mphis and NK cells were examined for survival and the bacterial loads in the kidneys during the course of infection. RESULTS: A unique profile of strain difference was found in the innate resistance of mice to MFT. A/J, C3H/He and DBA/2 mice were susceptible, while BALB/c, B10A and C57BL/6 mice were resistant, in terms of survival after MFT infection. Such profiles of host resistance to MFT were essentially correlated with the ability of individual strain mice to prevent the bacterial growth in the early periods after infection. These profiles were different from the strain difference controlled by Bcg gene. Studies using carrageenan, anti-asialo GM1 antibody, and NK cell-deficient beige mice indicated the important roles of Mphis and NK cells in the host innate defense against MFT. CONCLUSIONS: These findings suggest that Bcg gene does not control the host resistance to MFT and that both Mphis and NK cells play crucial roles in the host innate resistance to MFT infection.

Animals↗

PubMed2004

The role of B7 molecules in the cell contact-mediated suppression of T cell mitogenesis by immunosuppressive macrophages induced with mycobacterial infection.

We found previously that immunosuppressive macrophages (Mphis) induced by Mycobacterium intracellulare infection (MI-Mphis) transmitted their suppressor signals to target T cells through cell contact with target T cells. In this study, we examined what kinds of Mphi surface molecules are required for such cell-to-cell interaction. First, it was found that a B7-1-like molecule (B7-1LM) recognizable with one of three test clones of anti-B7-1 monoclonal antibodies (mAbs) was required for expression of the Mphi suppressor activity. Neither anti-B7-2, anti-ICAM-1, nor anti-VCAM-1 mAb blocked the Mphi suppressor activity. Second, MI-Mphis increased the expression of B7-1LM in parallel with the acquisition of the suppressor activity. Moreover, MI-Mphis bound with target T cells in a B7-1LM-dependent fashion. Third, mAb blocking of CTLA-4 on target T cells did not reduce the suppressor activity of MI-Mphis, suggesting the role of a putative molecule on target T cells other than CTLA-4 as the receptor for B7-1LM of MI-Mphis. Fourth, concanavalin A (Con A) stimulation of MI-Mphis was needed for effective cell contact with target T cells and subsequent expression of the suppressor activity of MI-Mphis. Fifth, the Con A-induced increase in the suppressor activity of MI-Mphis was inhibited by KN-62 but not by herbimycin A, H-7, nor H-88, indicating that Con A-induced up-regulation of MI-Mphi function is mediated by calmodulin-dependent protein kinase II or ATP/P2Z receptors, but independent of protein tyrosine kinase, protein kinase C, and protein kinase A. These findings indicate that a B7/CTLA-4-independent mechanism is needed for the transmission of the suppressor signals from MI-Mphis to target T cells.

Animals↗

PubMed2003

Comparative antimicrobial activities of gatifloxacin, sitafloxacin and levofloxacin against Mycobacterium tuberculosis replicating within Mono Mac 6 human macrophage and A-549 type II alveolar cell lines.

Mycobacterium tuberculosis (MTB) is capable of invading not only macrophages (Mphis) but also type II pneumocytes. In this study, we compared the antimicrobial activities of fluoroquinolones, including gatifloxacin, sitafloxacin and levofloxacin, against the MTB replication in the Mono Mac 6 human Mphi cell line (MM6-Mphis) and the A-549 human type II alveolar epithelial cell line (A-549 cells). When test quinolones were added at the MIC (0.125, 0.06 and 0.25 mg/l for gatifloxacin, sitafloxacin and levofloxacin, respectively) to the culture media of MTB-infected cells, these drugs exerted growth-inhibitory activity against intracellular organisms in the order of sitafloxacin > gatifloxacin > levofloxacin. On the other hand, when test quinolones were added at Cmax in the blood (1.7, 1.0 and 2.0 mg/l for gatifloxacin, sitafloxacin and levofloxacin, respectively), these drugs exhibited bactericidal activity against intracellular MTB in the order of gatifloxacin > sitafloxacin > or = levofloxacin. In addition, when test drugs were added at 1/8 C(max) to 1/2 C(max), the efficacy was in the order of sitafloxacin > gatifloxacin > levofloxacin. Thus, it appears that the MIC values of fluoroquinolones are not always predictive of their antimicrobial activity against intracellular MTB. In this context, it was also found that intracellular uptake of these quinolones by MM6-Mphis and A-549 cells was in the order of sitafloxacin > gatifloxacin > levofloxacin. This implies that the cellular permeability of these quinolones is an important factor that determines their efficacy to eliminate intracellular MTB organisms.

Anti-Infective Agents↗

PubMed2003

Effect of different proton pump inhibitors, differences in CYP2C19 genotype and antibiotic resistance on the eradication rate of Helicobacter pylori infection by a 1-week regimen of proton pump inhibitor, amoxicillin and clarithromycin.

AIM: To investigate the effect of different proton pump inhibitors, S-mephenytoin 4'-hydroxylase (CYP2C19) genotype and antibiotic susceptibility on the eradication rate of Helicobacter pylori. METHODS: One hundred and eighty-seven H. pylori-infected peptic ulcer patients were randomly treated with either rabeprazole (10 mg b.d.) or lansoprazole (30 mg b.d.) plus amoxicillin (750 mg b.d.) and clarithromycin (400 mg b.d.) for 1 week. The antibiotic susceptibility and CYP2C19 genotype (extensive or poor metabolizer) were investigated. RESULTS: The eradication rates in the rabeprazole-amoxicillin-clarithromycin (RAC) and lansoprazole-amoxicillin-clarithromycin (LAC) groups were 75% and 69%, respectively, on an intention-to-treat basis, and 80% and 75%, respectively, on a per protocol basis. The eradication rate for clarithromycin-resistant strains was significantly lower than that for clarithromycin-sensitive strains (24% vs. 86%, P < 0.05). For clarithromycin-sensitive strains in the LAC group, there was a tendency for a lower eradication rate in extensive than poor metabolizers. The eradication rate in extensive metabolizers in the RAC group tended to be higher than that in extensive metabolizers in the LAC group (89% vs. 78%, P = 0.079726). CONCLUSIONS: The success of the 1-week proton pump inhibitor-amoxicillin-clarithromycin regimen depends on the susceptibility of H. pylori to clarithromycin. Moreover, differences in CYP2C19 genotype influence the eradication rates of lansoprazole-based therapy, and the rabeprazole-based regimen has an advantage especially in extensive metabolizers.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2003

[Comparative study of hypothermic circulatory arrest and normothermic distal perfusion for thoracoabdominal aortic aneurysm repair].

BACKGROUND: Hypothermic bypass with circulatory arrest for thoracoabdominal aortic aneurysm (TAAA) repair is employed for its protective effect on spinal cord function and because it avoids clamping the diseased aorta. However, organ dysfunction caused by reperfusion injury as well as bleeding tendencies due to deep hypothermia have been described. In this paper we compared the efficacies of the hypothermic and normothermic operations. METHODS: Between February 1996 and June 2000, 28 patients underwent thoracoabdominal aortic repair. Twenty-three patients were men, 5 were women, and the median age was 55.3 (range 23 to 75 years). Fourteen patients had aortic dissection, and 7 had Marfan syndrome. Fourteen patients required reconstruction of visceral arteries. Twelve patients underwent TAAA repair under deep hypothermic circulatory arrest (H group), and 15 under normothermic distal perfusion (N group), while 1 patient underwent a simple clamp procedure. Perioperative data and early outcomes were compared between groups. RESULTS: The overall 30-day mortality rate was 0%, but 3 patients (25.0%) in II group, and 1 patient (6.3%) in N group died during hospital stay. Operation time and bypass time were longer in H group than N group (operative time 793 min vs. 481 min (p < 0.05): cardiopulmonary bypass (CPB) time 255 min vs. 102 min (p < 0.05). Also, more intraoperative bleeding was found in H group than in N group (3,506 ml vs. 1,220 ml). Spinal cord neurologic deficit did not occur in either group. Respiratory failure occurred in 3 patients (25.0%) in H group and one (6.3%) in N group. Renal failure occurred in 3 (25.0%) in H group, and none in N group. CONCLUSION: Early and mid-term outcome of TAAA repair was almost satisfactory and without neurospiral complications. The deep hypothermic operation is more likely to induce postoperative respiratory and renal dysfunction than the normothermic operation. TAAA repair using deep hypothermic circulatory arrest should be limited to patients with TAAA involving the distal arch or a severely calcified aortic wall.

Adult↗

PubMed2003

Progress in the treatment of aneurysms of the distal aortic arch: approach through median sternotomy.

AIM: A review of past and current operative procedures for the treatment of aneurysms of the distal aortic arch is presented in conjunction with a series of 43 patients. In this study, distal aortic arch aneurysm refers to an aneurysm involving at least the origin of the left subclavian artery, but not extending beyond the left common carotid artery. We excluded dissection aneurysm and extended aneurysm to the descending thoracic aorta from this study. METHODS: Between January, 1985, and March, 2000, 43 consecutive patients (37 males, 6 females; mean age 67.5 years) underwent repair of aneurysms of the distal aortic arch. The approach to the aneurysm was through a left thoracotomy in 4 patients and a median sternotomy in 39 patients, including an additional left thoracotomy continued to a median sternotomy in 2 patients. The supportive methods during surgery were left heart bypass using a centrifugal pump in 4 patients (LHB group), cardiopulmonary bypass with selective cerebral perfusion in 11 patients (SCP group), and cardiopulmonary bypass with continuous retrograde cerebral perfusion in 28 patients (RCP group). In the RCP group, the "aortic no-touch technique" was applied in 21 patients. The operative methods were patch closure in 4 patients, graft replacement of the distal arch using the inclusion technique in 14 patients, and total arch replacement using the exclusion technique in 25 patients. RESULTS: There were 5 hospital deaths: 1 patient in the LHB group, intractable bleeding; 1 patient in the SCP group, rupture of the distal anastomosis; 3 patients in the RCP group, stroke, rupture of the dissection arising from the distal anastomosis, and perioperative myocardial infarction. Stroke occurred in 1 patient (25%) with LHB, 3 patients (27.2%) with SCP, and 1 patient (3.6%) with RCP. Among the postoperative survivors, a new onset of left recurrent nerve palsy occurred in 2 patients (66.7%) with LHB, 1 patient (10%) with SCP, and in 1 patient (4%) with RCP. No neurological injury or left recurrent nerve palsy occurred in the patients who underwent the "aortic no-touch technique". CONCLUSION: Total arch replacement with the graft exclusion technique under profound hypothermic circulatory arrest using RCP through the median sternotomy is a promising surgical treatment for atherosclerotic distal aortic arch aneurysm. The "aortic no-touch technique" further improved the surgical results of the distal aortic arch aneurysm.

Aged↗

PubMed2002

Profiles of cell-to-cell interaction of Mycobacterium intracellulare-induced immunosuppressive macrophages with target T cells in terms of suppressor signal transmission.

Previously, we have found that immunosuppressive macrophages (M(phi)s) induced by Mycobacterium intracellulare-infection (MI-M(phi)s) required cell contact with target T cells to express their suppressor activity against concanavalin A (Con A)-induced T cell mitogenesis. In this study, we examined the profiles of cell-to-cell interaction of MI-M(phi)s with target T cells. First, MI-M(phi)s displayed suppressor activity in an H-2 allele-unrestricted manner, indicating that MHC molecules are not required for cell contact. The suppressor activity of MI-M(phi)s was reduced markedly by paraformaldehyde fixation or treatment with cytochalasin B or colchicine, indicating that vital membrane functions are required for their suppressor activity. Secondly, the suppressor activity of MI-M(phi)s was independent of cell-to-cell interaction via CD40 ligand/CD40 and M(phi)-derived indoleamine 2,3-dioxygenase, which causes rapid degradation of tryptophan in T cells. Thirdly, precultivation of splenocytes with MI-M(phi)s, allowing cell-to-cell contact, reduced Con A- or anti-CD3 antibody-induced mitogenesis but not phorbol myristate acetate/calcium ionophore A23187-elicited proliferation of T cells. In addition, co-cultivation of T cells with MI-M(phi)s caused marked changes in profiles of the tyrosine phosphorylation of 33 kDa, 34 kDa and 35-kDa proteins and, moreover, the activation of protein kinase C and its translocation to the cell membrane. It thus appears that suppressor signals of MI-M(phi)s, which are transmitted to the target T cells via cell contact, principally cross-talk with the early signalling events before the activation of PKC and/or intracellular calcium mobilization.

Animals↗

PubMed2002

Anti-Mycobacterium tuberculosis activities of new fluoroquinolones in combination with other antituberculous drugs.

OBJECTIVES: Studies were undertaken in order to assess the anti- Mycobacterium tuberculosis (MTB) activities of newly developed fluoroquinolones in combination with other antituberculous drugs. METHODS: A new C-8-methoxyl fluoroquinolone, gatifloxacin (GFLX), and a new C-8-chloro fluoroquinolone, sitafloxacin (STFX), in combination with other drugs were examined for their activities against extracellular growing MTB organisms and those replicating in RAW264.7 macrophages (RAW-M phis s). RESULTS: STFX but not GFLX potentiated the activities of rifampin and rifalazil against extracellular MTB. Both GFLX and STFX exhibited combined activities against intramacrophage MTB, when used in combination with rifampin, rifalazil, isoniazid, pyrazinamide, ethambutol, streptomycin, or clofazimine. CONCLUSIONS: Although the observed combined effects varied to some extent from case to case depending on drug combinations, the present findings suggest the usefulness of these new fluoroquinolones in multi-drug regimens for tuberculosis patients.

Animals↗

PubMed2002

[Surgical treatment of Marfan syndrome; late results and new strategy].

UNLABELLED: Rapid progress has been made in the treatment of Marfan syndrome. Today, the treatment is relatively established and the results have also improved. Even if surgery is performed, however, vascular lesions may recur late after operation and late prognosis is poor considering the age of patients. Issues such as whether a reoperation should be conducted or how the late results might be improved are subjects of debate. Based on an analysis of recent late data, we have performed operations according to the new treatment policy, and here report the results. A total of 203 consecutive operations were conducted in 141 patients with Marfan syndrome who underwent surgery for aortic aneurysm at our department between February 1973 and August 2001. The mean age of patients was 39 (11 years with a male/female ratio of 95:46. At the first operation, 72 patients were diagnosed with annuloaortic ectasia (AAE), 17 patients with AAE + chronic dissection (DeBakey I), 14 patients with AAE + chronic dissection (DeBakey II), 6 patients with AAE + acute dissection (Stanford A), 11 patients with AAE + dissection (DeBakey III), 9 patients with dissection (DeBakey III) only, 3 patients with AAE + abdominal aortic aneurysm only, and 2 patients with abdominal aortic aneurysm only. The cause of reoperation were a new lesion in 17 patients, dissection in 13 patients and a true aneurysm in 4 patients. In 36 patients, an increase in the remaining lesion occurred or a scheduled stage 2 operation was performed. Reoperation was performed following the Bentall operation in 7 patients, dehiscence of the anastomotic region of the coronary artery in 5 patients, aneurysm of the anastomotic region of the coronary artery in 1 patients, and infection of the artificial valve with aneurysm of the anastomotic region of the coronary artery in 1 patient. Hospital deaths were reported in 8 (6%) patients who underwent composite valve graft replacement (including simultaneous arch replacement) for AAE. Hospital deaths also occurred in 8 (13%) patients who underwent a replacement of the aortic arch, descending thoracic or thoracoabdominal aorta, with no cases of paraplegia reported. In all cases, the replacement was extensive. The observed 10-year survival rate was 70% with a freedom from reoperation of 64%. Although dissection did not reduce the observed survival rate, the 10-year freedom from reoperation was significantly decreased at 49% (p = 0.0007). CONCLUSIONS: (1) Surgery is indicated for AAE when the maximum diameter of the aneurysm prior to onset of dissection is 5 cm. In the case of aortic arch without dissection, the Bentall operation with simultaneous arch replacement should be aggressively performed in order to minimize the future risk of vascular events and to eliminate the need for extensive replacement in a reoperation, a procedure which is associated with a high level of risk. (2) Extensive replacement which is associated with poor results should be avoided where possible and, instead, scheduled staged surgery should be aggressively performed in the early stage when the maximum diameter of the aneurysm in the descending aorta is 5 cm or less. (3) By paying adequate attention to patient education, outpatient follow-up using detailed diagnostic imaging, drug therapy, periodic late surveillance, expedition of scheduled surgery, and to the basic approach as well as endeavoring to improve surgical results by the use of new methods of treatment, it is anticipated that further improvement will be observed in late results.

Adolescent↗

PubMed2001

Suppressive effects of F-1322 on the antigen-induced late asthmatic response and pulmonary eosinophilia in guinea pigs.

We investigated the effects of F-1322 (N-[2-[4-(benzhydryloxy)piperidino]ethyl]-3-hydroxy-5-(3-pyridylmethoxy)-2-naphthamide), a new compound that inhibits both thromboxane A2 synthetase and 5-lipoxygenase and that functions as a histamine antagonist, on the Ascaris antigen-induced late asthmatic response and pulmonary eosinophilia in guinea pigs. Oral administration of F-1322 (10-100 mg/kg) inhibited the antigen-induced late asthmatic response in a dose-dependent manner. Histological analysis revealed that F-1322 prevented the accumulation of eosinophils in the airways and this was paralleled by a decrease in the number of eosinophils and lymphocytes recovered in bronchoalveolar lavage fluid. F-1322 (0.1-10 microM) inhibited eotaxin-induced chemotaxis and actin polymerization of eosinophils in vitro in a concentration-dependent manner, while oral administration of F-1322 dose-dependently suppressed the migration of eosinophils into the airways in vivo in response to infusion of interleukin 5 and eotaxin in combination. F-1322 may, thus, improve the late asthmatic response in this model, in part, by preventing the accumulation of eosinophils in the airways. The pharmacological profile of F-1322 indicates that this drug is likely to be useful in the treatment of allergic diseases such as asthma.

Airway Resistance↗

PubMed2001

Generation and characterization of a fairly stable triplet carbene.

Most molecules are held together by covalent bonds-electron pairs jointly shared by the two atoms that are linked by the bond. Free radicals, in contrast, have at least one unpaired electron. In the case of carbon-based radicals, the carbon atom at the radical centre no longer makes four bonds with other atoms as it would do in its normal, tetravalent state. The presence of unpaired electrons renders such radicals highly reactive, so they normally occur only as transient intermediates during chemical reactions. But the discovery by Gomberg in 1900 of triphenylmethyl, the first relatively stable free radical containing a central trivalent carbon atom, illustrated that radicals with suitable geometrical and electronic structures can be stable. Compounds containing a divalent carbon atom that uses only two of its four valence electrons for bonding are usually less stable than Gomberg-type radicals with trivalent carbon. Although the role of these so-called carbenes in chemical reactions has long been postulated, they were unambiguously identified only in the 1950s. More recently, stable carbenes have been prepared, but the singlet state of these molecules, with the two nonbonding valence electrons paired, means that they are not radicals. Carbenes in the second possible electronic state, the triplet state, are radicals: the two nonbonding electrons have parallel spins and occupy different orbitals. Here we report the preparation and characterization of a triplet carbene, whose half-life of 19 minutes at room temperature shows it to be significantly more stable than previously observed triplet carbenes.

Journal Article↗

PubMed2001

Expression profiles of low molecular mass heat shock proteins by Mycobacterium avium and Mycobacterium intracellulare.

Closely related non-tuberculous mycobacterial species, Mycobacterium avium and Mycobacterium intracellulare, were compared for the profiles of their production of low molecular mass heat shock proteins at 45 degrees C, by performing polyacrylamide gel electrophoresis analysis of bacterial cell lysate proteins. All of the M. intracellulare but not M. avium strains potently increased the production of the 18-kDa heat shock protein, when cultured at 45 degrees C. Half of the M. intracellulare strains with high sensitivity to 45 degrees C produced not only the 18-kDa heat shock protein but also the 16-kDa heat shock protein at 45 degrees C. These findings indicate that M. avium and M. intracellulare differentially respond to 45 degrees C heat shock in terms of the production of low molecular mass heat shock proteins.

Heat-Shock Proteins↗

PubMed2001

The elusive benzocyclobutenylidene: a combined computational and experimental attempt.

Ab initio and density functional theory calculations predict that benzocyclobutenylidene (1) has a singlet ground state in contrast to the parent phenylcarbene and many other simply substituted arylcarbenes. Calculations also predict that 1 should lie in a relatively deep potential well, while its triplet state is 14.5 kcal mol(-)(1) higher in energy. However, attempts to observe 1 directly by photolysis of two different nitrogenous precursors were not successful. Irradiation of diazobenzocyclobutene (7) (lambda > 534 nm or lambda > 300 nm) or azibenzocyclobutene (10) (lambda > 328 nm) in Ar matrixes at 10 K leads to the formation of the strained cycloalkyne 7-methylenecyclohepta-3,5-dien-1-yne (3). (13)C-Labeled 3 was also prepared in a similar manner. There is very good agreement between experimental IR spectra and computationally derived harmonic vibrational frequencies for 3 and [(13)C]-3 and excellent agreement between observed and calculated isotopic shifts. Prolonged short-wavelength irradiation converts 3 into benzocyclobutadiene (5). Phenylacetylene (6) and benzocyclobutadiene dimer (11) were identified as products arising from flash vacuum pyrolysis of diazirine 10 at 500 degrees C.

Journal Article↗

PubMed2001

p-Phenylenecarbenonitrene and its halogen derivatives: how does resonance interaction between a nitrene and a carbene center affect the overall electronic configuration?

A series of para-conjugatively coupled phenylenecarbenonitrenes [(4-nitrenophenyl)methylene (3a), (4-nitrenophenyl)fluoromethylene (3b), (4-nitrenophenyl)chloromethylene (3c), and (4-nitrenophenyl)bromomethylene (3d)] were generated in argon matrix at low temperature (10 or 13 K) and characterized by IR and UV/vis spectroscopy. Density functional theory (B3LYP/6-31G(d)) and ab initio (MCSCF, CASPT2) methods were used to study the ground- and some low-lying excited states of 3a-d. The experimental and computational data suggest that 3a-d have singlet ground states (S0) and can be thought of as quinonoidal biradicals. In all cases, the lowest triplet (T1) and quintet (Q1) states lie about 2 kcal mol(-1) and 28-29 kcal mol(-1), respectively, higher in energy than S0. On the other hand the substituent is found to have a significant effect on the relative energy of the second excited triplet (T2) state. This state tends to become relatively more stable as the ability of the substituent to enforce a closed-shell configuration at the carbene subunit increases. Interestingly, the energy difference between the T2 and S0 states in 3a-d is found to depend linearly on the S-T gap of the corresponding phenylcarbenes 7a-d. This relationship is helpful in predicting when a substituted p-phenylenecarbenonitrene may have a triplet ground state instead of a singlet one.

Journal Article↗

PubMed2001

Connectivity effects in isomeric naphthalenedinitrenes.

[figure: see text] UV-vis, FTIR, and ESR spectroscopic studies were carried out on samples of 1,4- and 1,5-naphthalenediazide that were photolyzed at cryogenic temperatures in argon and frozen solvent matrices. Mononitrenes and diiminediyl systems are produced. Spectral and computational results are consistent with quinonoidal singlet ground-state structures for the diiminediyls, rather than aromatic dinitrene structures.

Journal Article↗

PubMed2001

The anxiolytic effect of Sho-ju-sen, a Japanese herbal medicine, assessed by an elevated plus-maze test in mice.

Sho-ju-sen (SK), a Japanese herbal medicine with a nourishing tonic action, is composed of a water extract of Kumazasa leaves (Sasa kurinensis Makino et Sibata) (SS), and ethanol extracts of Japanese red pine needles (Pinus densiflora Sieb. et Zucc) (PN) and Ginseng roots (Panax ginseng C. A. Meyer) (PX) in the ratio 8:1:1. In this study, an elevated plus-maze test in mice was carried out to assess whether SK had an anxiolytic effect. No significant change was observed in either the plus-maze or activity test following a single administration of SK (10 and 20 mL/kg p.o.). However, mice allowed a free intake of SK (10% solution) for 5 days and longer showed a significant prolongation of the time spent in the open arms (an anxiolytic effect), as long as that caused by the benzodiazepine anxiolytic diazepam (1 mg/kg p.o.). SK (1%, 3% and 30% solutions for 7 days) tended to develop the anxiolytic effect. Of the constituents of SK, SS (8% solution), but not PN (1% solution) or PX (1% solution), resulted in the anxiolytic effect. Except for a slight acceleration in the motor activity by PN (1% solution), no significant change in the motor activity was produced by any treatment with SK, SS or PX. The combined treatment of SK (10% solution) or SS (8% solution) with 1 mg/kg diazepam enhanced the anxiolytic effect. Flumazenil (0.1 mg/kg s.c.), a benzodiazepine receptor antagonist, alone did not change the time spent in the open arms. However, it completely reversed the anxiolytic effect of SK, SS and diazepam. The present results suggest that: (1) long-term treatment with SK develops an anxiolytic effect, (2) SS is the main constituent for the anxiolytic effect of SK, and (3) benzodiazepine receptors are involved in the anxiolytic effect of SK and SS.

Animals↗

PubMed2001

Covered Gianturco stent for tracheal stricture: application of polychlorovinylidene and polyurethane as covering materials.

The aim of this study was to assess the efficacy and safety of thin membranes of polychlorovinylidene (PCV) or polyurethane (PU) as covering materials for Gianturco stents in the treatment of severe tracheal stricture caused by intraluminal tumor. Manufactured Gianturco stents covered with PCV or PU membrane were used to treat six malignant and one benign tracheal stricture. The initial results, complications, clinical follow-up, bronchoscopic findings, and three autopsy microscopic examinations were reviewed. Informed consent was obtained after the nature of the treatment had been fully explained before every procedure. The stents successfully dilated the tracheal strictures, providing immediate relief of respiratory symptoms in all patients with no major complications. During the follow-up period, the covering materials prevented tumor ingrowth until death or intraluminal granuloma formation. Autopsies proved that no histological change occurs in the tracheal mucosa in response to the presence of PCV or PU; however, ulcer formation occurred in one patient and penetration of the stent struts into the tracheal wall in two. Bloody sputum with ulcer formation, minimal granuloma formation at the distal end of the stent, and abnormal bacterial load in the sputum were long-term complications. The Gianturco stent covered with PCV or PU membrane is a useful option as a palliative treatment for malignant and an emergent salvage for benign tracheal stricture, because both materials are thinner and less voluminous than the others. However, the indications for its use are limited to patients with poor prognoses, because hemoptysis, granuloma formation, and bacterial propagation remain problematic.

Aged↗