Comprehensive behavioural study of GluR4 knockout mice: implication in cognitive function

Fast excitatory transmission in the mammalian central nervous system is mediated by AMPA-type glutamate receptors. The tetrameric AMPA receptor complexes are composed of four subunits, GluR1-4. The GluR4 subunit is highly expressed in the cerebellum and the early postnatal hippocampus and is thought to be involved in synaptic plasticity and the development of functional neural circuitry through the recruitment of other AMPA receptor subunits. Previously, we reported an association of the human GluR4 gene (GRIA4) with schizophrenia. To examine the role of the GluR4 subunit in the higher brain function, we generated GluR4 knockout mice and conducted electrophysiological and behavioural analyses. The mutant mice showed normal long-term potentiation (LTP) in the CA1 region of the hippocampus. The GluR4 knockout mice showed mildly improved spatial working memory in the T-maze test. Although the retention of spatial reference memory was intact in the mutant mice, the acquisition of spatial reference memory was impaired in the Barnes circular maze test. The GluR4 knockout mice showed impaired prepulse inhibition. These results suggest the involvement of the GluR4 subunit in cognitive function.

High prevalence of mutators among Enterobacter cloacae nosocomial isolates and their association with antimicrobial resistance and repetitive detection

We determined the mutation frequencies of 59 nosocomial isolates of Enterobacter cloacae, and investigated their association with antimicrobial susceptibility, genotype, and history of exposure to antimicrobials. The frequencies of mutations leading to rifampicin resistance ranged from 5.8 × 10(-9) to 8.0 × 10(-6) (median, 5.0 × 10(-8)). Seven of the 59 (12%) isolates were graded as strong mutators exhibiting a more than 50-fold increase in the mutation frequency relative to that of E. cloacae ATCC 13047, and 30 (52%) were graded as weak mutators exhibiting a more than five-fold and not more than 50-fold increase in the mutation frequency. The isolates with higher grade of mutation frequency were resistant to significantly more antimicrobials (medians of two, one and zero agents for strong mutators, weak mutators and non-mutators, respectively; p 0.0078). The 59 isolates were classified into 36 genotypes, and all of the seven strong mutators had distinct genotypes. Mutation frequencies varied more than 10(2)-fold within a clone. In patient-based, univariate analysis, intensive-care unit admission, dense antimicrobial exposure (glycopeptide or multiple classes) and repetitive detection of this species were significantly more common among all of the four patients from whom strong mutators were obtained. Strong mutators are highly prevalent in surgical isolates of E. cloacae. Higher mutation frequency was associated with antimicrobial resistance and repetitive detection, and may contribute to the adaptability of this species.

Platelet-derived growth factor and transforming growth factor-beta modulate the expression of matrix metalloproteinases and migratory function of human airway smooth muscle cells

BACKGROUND

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) have been suggested to be involved in the pathogenesis of asthma. Their expression in airway smooth muscle (ASM) cells could be involved in collagen turnover and migration of these cells and thus may contribute to airway remodelling.

OBJECTIVE

To examine the effect of pro-fibrotic growth factors TGF-beta and platelet-derived growth factor (PDGF) on the expression of MMPs/TIMPs in cultured human ASM cells and to examine the role of MMP in the migration of ASM cells.

METHODS

ASM cells were stimulated with TGF-beta and/or PDGF. Expression and activity of MMP-1, MMP-2, MMP-3, TIMP-1 and TIMP-2 were evaluated by quantitative RT-PCR, Western blot and zymography. Modified Boyden-chamber migration assay was performed to investigate the effect of secreted MMP-3 and TIMP-1 on ASM-cell migration.

RESULTS

PDGF strongly up-regulated the expression of MMP-1 at mRNA and protein levels. PDGF, when combined with TGF-beta, caused synergistic up-regulation of MMP-3. TIMP-1 was additively up-regulated by TGF-beta and PDGF. These growth factors had no effect on the expression of MMP-2 and TIMP-2. U0126, an extracellular signal-regulated kinase (ERK) pathway inhibitor, inhibited the up-regulation of MMP-1 by PDGF. The synergistic/additive up-regulation of MMP-3 and TIMP-1 was inhibited by U0126 and SB431542, a Smad pathway inhibitor. Supernatant from ASM cells in which MMP-3 production was knocked down by RNA interference showed a decreased migratory effect on ASM cells, whereas supernatant from cells with suppressed TIMP-1 expression resulted in increased migration.

CONCLUSION

Our results suggest that PDGF with/without TGF-beta could facilitate migration of ASM cells by modification of MMP-TIMP balance through the ERK pathway.

Association study of a polymorphism of the CTGF gene and susceptibility to systemic sclerosis in the Japanese population

OBJECTIVES

To validate the association of a single nucleotide polymorphism (SNP) of the connective tissue growth factor gene (CTGF) with susceptibility to systemic sclerosis (SSc) in the Japanese population.

METHODS

395 Japanese patients with SSc, 115 patients with rheumatoid arthritis and 269 healthy Japanese volunteers were enrolled in the study. An SNP (rs6918698) at -945 bp from the start codon in the promoter region of the CTGF gene was determined by allelic discrimination with the use of a specific TaqMan probe.

RESULTS

The G allele showed a significantly higher frequency in patients with SSc than in controls (p<0.001; odds ratio 1.5; 95% confidence interval 1.2 to 1.9). In particular, the clinical subsets of SSc showed a more significant association between the G allele and diffuse cutaneous SSc (p<0.001) and the presence of interstitial lung disease (p<0.001), the presence of anti-topoisomerase I antibody (p<0.001) and anti-U1RNP antibody (p = 0.010). Association analyses using the genotype of the SNP yielded results similar to those of analyses using the allele.

CONCLUSIONS

This study confirms the association between an SNP in the CTGF gene and susceptibility to SSc, especially in the presence of diffuse cutaneous SSc, interstitial lung disease and anti-topoisomerase I antibody. The results strongly suggest that this SNP may be a powerful indicator of severe skin and lung involvement in patients with SSc.

Sputum levels of transforming growth factor-beta1 in asthma: relation to clinical and computed tomography findings

BACKGROUND

Transforming growth factor (TGF) beta1 is considered to play central roles in the pathogenesis of airway remodeling in asthma. This notion is based primarily on the results of experimental studies; clinical evidence is limited.

OBJECTIVES

To ascertain the involvement of TGF-beta1 in asthma.

METHODS

We studied 27 patients with moderate-to-severe, but stable, asthma treated with inhaled corticosteroids and 8 healthy controls. Helical computed tomography scans were acquired at full inspiration. Airway wall thickness (WT) was assessed on the basis of wall area corrected for body surface area (WA/BSA) and absolute WT corrected for BSA (WT/square root of BSA) according to a validated method. Induced sputum concentrations of TGF-beta1 were measured by enzyme-linked immunosorbent assay. Pulmonary function was evaluated.

RESULTS

Indices of expiratory airflow were significantly lower in the asthmatic patients than in the controls. WA/BSA, WT/square root of square root of BSA, and sputum concentrations of TGF-beta1 were significantly higher in the asthmatic patients. Sputum TGF-beta1 concentrations correlated positively with WA/BSA and WT/square root of BSA and negatively with forced expiratory volume in 1 second in both asthmatic and control subjects.

CONCLUSIONS

Levels of TGF-beta1 in induced sputum are elevated in asthmatic patients despite treatment with inhaled corticosteroids and are associated with airflow obstruction and airway wall thickening. TGF-beta1 is involved in the pathogenesis of airway remodeling and resultant functional impairment and it may be a target for specific medical treatment.

Pneumococcal surface protein A family types of Streptococcus pneumoniae from community-acquired pneumonia patients in Japan

We assessed pneumococcal surface protein A (PspA) family types of 141 isolates of Streptococcus pneumoniae from community-acquired pneumonia patients in Japan. Families 1 and 2 were expressed in 78 (55.3%) and 58 (41.1%) isolates, respectively. Five isolates were not typed either as family 1 or 2. PspA family types were not associated with age, sex, or pneumonia severity. Penicillin-resistant S. pneumoniae was more likely to belong to family 2 whereas organisms highly resistant to erythromycin and positive for ermB were more prevalent in family 1. The association of PspA type with antimicrobial resistance was possibly affected by prevalent serotypes or resistance clones. It would therefore be necessary to include both family 1 and 2 proteins in a PspA-containing vaccine to cover the major PspA families and to reduce antimicrobial resistance.

Endoscopic mucosal resection of superficially spreading colonic neoplasms larger than 5 cm in the right colon after injection of dilute sodium hyaluronate: report of two cases

Submucosal injection is the most important procedure for the safe performance of endoscopic mucosal resection in the large intestine while avoiding the risk of perforation. We used dilute sodium hyaluronate containing Bosmin and achieved safe piecemeal resection of large superficial tumors in the right colon in two patients. Piecemeal snare resection is considered to be acceptable if all the tissue pieces can be collected for histopathological diagnosis.

Fibrogenic and inflammatory cytokines modulate mRNA expressions of matrix metalloproteinase-3 and tissue inhibitor of metalloproteinase-3 in type II pneumocytes

BACKGROUND

Imbalance between proteinases and their inhibitors released from alveolar type II pneumocytes may cause development of inflammatory lung diseases.

OBJECTIVES AND METHODS

We examined mRNA expressions of matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in a cell line (A549) and in primary culture of normal adult human type II pneumocytes using reverse transcription-competitive polymerase chain reaction.

RESULTS

Interleukin-1beta (IL-1beta) and transforming growth factor-beta1 (TGF-beta1) increased MMP-3 and TIMP-3 expressions in A549 cells in a time- and concentration-dependent manner. IL-1beta mainly augmented MMP-3 expression, while TGF-beta1 mainly augmented TIMP-3 expression. Dexamethasone attenuated both IL-1beta- and TGF-beta1-stimulated expressions of MMP-3 and TIMP-3. Interleukin-10 had no significant effect. Hepatocyte growth factor alone had no effect on constitutive MMP-3 expression or TIMP-3 expression, but it augmented TGF-beta1-stimulated MMP-3 expression. The constitutive expressions were higher in normal type II pneumocytes than in A549 cells, but the regulations were similar.

CONCLUSIONS

These data indicated that the matrix degradation is enhanced by IL-1beta and suppressed by TGF-beta1 via regulations in the balance between MMP-3 and TIMP-3. Further, these regulations were shown to be modulated by glucocorticoids and growth factors.

Survey on occupational health management of VDT workers among 84 Japanese companies

This survey of 84 companies described the present status of occupational health management of VDT workers in Japan, in relation to the official Guideline (Guidelines on Occupational Health for VDT Work, 1985). The majority admitted 80% or more of their workers engage in VDT works. Four hours of VDT work per day was widely used as a criteria for the eligibility to the VDT health examination. Some specific measurement was performed at health examination among 54.8% of the companies. The most popular item was "near vision." A larger number of follow-up measures was performed with ophthalmic cases than with muscloskeletal cases. From these findings, with consideration to the results of the preceding literatures, we made 8 suggestions for the on-going revision of the Guideline: 1) including recommendation for flat panel display and portable computers, 2) widening target of VDT health education also to general workers, 3) clarification of the categorization of VDT workers, 4) offering practical measures to secure off VDT period, 5) use of subjective symptoms to screen high-risk workers, 6) supply of the latest scientific information on each measuring item, 7) periodical revision to provide state-of-the-art management, and 8) clear statement of the purpose and limitation of the Guideline.

[Mid-ventricular obstructive hypertrophic cardiomyopathy associated with an apical aneurysm and sustained ventricular tachycardia: a case report]

A 60-year-old woman presented with mid-ventricular obstructive hypertrophic cardiomyopathy associated with an apical aneurysm and sustained ventricular tachycardia. She was admitted because of drug refractory ventricular tachycardia. She had been treated with several antiarrhythmic agents, including amiodarone, but symptomatic episodes had continued. Echocardiography, magnetic resonance imaging, and left ventriculography showed mid-ventricular obstructive hypertrophic cardiomyopathy with an apical aneurysm. Electrophysiological study easily reproduced sustained pleomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and ventricular fibrillation. The patient underwent implantation of a cardioverter-defibrillator. The relationship between mid-ventricular hypertrophic cardiomyopathy and apical aneurysm is unknown, but mid-ventricular hypertrophic cardiomyopathy is one of the causes of severe ventricular arrhythmias and sudden death.

Dioxin and fly ash free incineration by ash pelletization and reburning

Dioxins (DXNs) in municipal waste incinerator fly ash were effectively reduced by pelletizing the mixture of ash, cement, and sodium phosphate and reburning the pellets in a laboratory scale bubbling fluidized bed (BFB) furnace. Three types of pellets--A, B and C, of various sizes and compositions were used in the experiments. The efficiency of DXN reduction in the pellet matrix was proportional to the incineration time, temperature, and degree of pellet incineration. At 700 degrees C and incineration time sufficient for a complete burnout, the efficiency of DXN reduction in the pellets of type A and C was found to be 99.9% and 99.7%, respectively. Correspondingly, the DXN concentration in the pellets decreased from 862 ng TEQ/kg to 0.9 ng TEQ/kg for pellets A and 2.2 ng TEQ/kg for pellets C. The residual concentration of coplanar polychlorinated biphenyls (coplanar PCBs) was below 0.2 ng TEQ/kg and 0.4 ng TEQ/kg, respectively. Assuming a tortuosity factor of tau = 3 and the reaction rate constants of 0.013 m/s (at 700 degrees C) and 0.025 m/s (at 800 degrees C), the experimental pellet incineration times were reasonably predicted by using the shrinking core model. Possible DXN evaporation from the pellets was also studied. The amount of DXNs in the flue gas captured by an impinger trap was less than 3% when the reactor was operated at 700 and 800 degrees C. The described method of fly ash pelletization and reburning seems to be a relatively easy and inexpensive way to reduce both the emission of DXNs and the amount of fly ash.

[Strategy for post coronary artery bypass grafting in patients with bypass graft stenosis: comparison of percutaneous transluminal coronary angioplasty for the native coronary artery, internal mammary artery and saphenous vein graft]

OBJECTIVES

The strategy for post coronary artery bypass grafting (CABG) was investigated in patients with graft stenosis.

METHODS

The study included 123 post-CABG patients with graft stenosis. The patients were divided into three groups according to target vessels; saphenous vein graft (SVG; n = 72), internal mammary artery (IMA; n = 21) and native coronary artery (n = 30). Furthermore, SVG lesions were divided into proximal anastomosis (n = 23), body (n = 40) and distal anastomosis (n = 9). The procedural success rate and late patency rate were compared between the three groups. Furthermore, the relationships between pre percutaneous transluminal coronary angioplasty (PTCA) percentage diameter stenosis, procedural success rate and late patency rate were evaluated.

RESULTS

Procedural success rate was similar in the three groups, but late patency rate was higher in the IMA group. Procedural success rate and late patency rate were significantly lower in proximal anastomoses compared to other sites of SVG stenoses, IMA group and native coronary artery group (p < 0.05). Totally occluded native coronary artery lesions had a high procedural success rate compared with occluded IMA and SVG lesions, but the late patency rate was not higher. Procedural success rate showed no significant difference for 75-99% stenotic lesions, but the late patency rate was significantly higher in the IMA group (p < 0.05). Patients in the stenting group had a greater late patency rate compared with the balloon angioplasty group. There was no significant difference in late patency rate between the IMA group and SVG group.

CONCLUSIONS

Late patency rate of the IMA is higher than that of the native coronary artery. SVG with proximal anastomosis and severe stenosis shows a significantly lower late patency rate than the native coronary artery. Therefore, PTCA should be considered for the native coronary artery in the absence of chronic total occlusion.

[Pulmonary mucormycosis caused by Cunninghamella bertholletiae in a non-immunocompromised woman]

A 74-year-old woman was admitted for further examination because of an abnormal nodular shadow and thickening of the bronchovascular bundle in the left upper lobe on chest radiography and CT. The findings from a transbronchial biopsy specimen were not conclusive. A thoracoscopic lung biopsy specimen revealed a fungal infection, and partial resection of S1 + 2 of the left upper lobe was carried out. In the dilated bronchus, mucus of high viscosity was seen. Lymphocytes and plasma cells had infiltrated into the bronchioles and alveoli. Fungus was cultured from the mucus, and the morphological characteristics showed Cunninghamella bertholletiae. Pulmonary mucormycosis caused by C. bertholletiae in a non-immunocompromised person is very rare. Furthermore, this patient also had a wheeze, eosinophilia, elevation of the serum IgE level, and was positive for specific IgE to Mucor. We therefore consider that this case was an incomplete type of allergic bronchopulmonary fungusis (ABPF).

Culturally verified Mycoplasma pneumoniae pneumonia in Japan: a long-term observation from 1979-99

We describe the prevalence of community-acquired M. pneumoniae pneumonia diagnosed by culture methods in a single institute in Japan from January 1979 to December 1999. Cultures were performed in 2971 pneumonia cases and yielded M. Pneumoniae in 508 cases. The epidemic peaks recurred regularly at 4-year intervals (1980, 84, 88 and 91-2). Although a large epidemic has not occurred since 1992, traces of epidemic periodicity have still persisted from 1992 to 1999 at 3-year intervals.

Efficacy of transthoracic needle aspiration in community-acquired pneumonia

OBJECTIVE

To evaluate the indications, efficacy, and safety of transthoracic needle aspiration (TNA) in diagnosing community-acquired pneumonia (CAP).

METHODS

TNA procedure was performed using an ultrathin needle with ultrasonography and/or computed tomography. The aspirate samples were Gram-stained and sent for cultures. The results were compared with those from conventional microbiological studies.

PATIENTS

Sixty patients with CAP who were admitted to the hospital and were studied prospectively between July 1994 and June 1999 were included in the study.

RESULTS

TNA culture was positive in 30 cases (50.0%). Streptococcus pneumoniae was the most frequently isolated pathogen, followed by the Streptococcus milleri group, and anaerobes. The results of TNA were consistent with those of quantitative sputum cultures in 9 patients and with those of blood cultures in 4. Complications arose in 3 patients who developed small to moderate pneumothorax.

CONCLUSIONS

TNA is a safe procedure with a good diagnostic yield. In particular, anaerobes or microaerophils such as the S. milleri group were highly detectable by TNA. The results obtained by TNA were highly consistent with those obtained by the gold standard methods. Combined with conventional methods, TNA is considered highly useful for determining the etiology of CAP.

Effects of a new synthetic selectin blocker in an acute rat thrombotic glomerulonephritis

In an attempt to explore a novel therapeutic approach, a new synthetic sulfatide derivative (SKK60037) was evaluated in an acute rat model of P-selectin and leukocyte-dependent thrombotic glomerulonephritis (TG). In vitro, SKK60037 inhibits the function of P- and L-selectin more effectively than sialyl Lewis X (sLe(x)), a well-established selectin blocker. TG was induced by the intravenous administration of nephrotoxic globulin (NTG) to rats pretreated with a subclinical dose of lipopolysaccharide. In this model, platelet accumulation was remarkable within 10 minutes after induction of disease, followed by the infiltration of leukocytes, mainly neutrophils and macrophages. Thrombus formation and fibrinogen deposition in the glomeruli were observed within 1 hour, and they proceeded until 6 hours. P-selectin was highly expressed in glomeruli, whereas E-selectin and L-selectin ligands were not detected. We tested the effects of SKK60037 in this model in comparison with sLe(x) and antirat P-selectin monoclonal antibody (ARP2-4). SKK60037 blocked platelet accumulation in glomerular capillaries at 10 minutes after NTG injection. At 6 hours, leukocyte infiltration and thrombosis were significantly suppressed. Protective effects of SKK60037 were similar to those of ARP2-4, whereas sLe(x) showed minimum effect. The superior effects and more favorable characteristics of SKK60037 to sLe(x) suggest the potential of SKK60037 for clinical application.

Cytotoxic effects of cigarette smoke extract on an alveolar type II cell-derived cell line

Injury of the alveolar epithelium by cigarette smoke is presumed to be an important process in the pathogenesis of smoking-related pulmonary diseases. We investigated the cytotoxic effects of cigarette smoke extract (CSE) on an alveolar type II cell-derived cell line (A549). CSE caused apoptosis at concentrations of 5% or less and necrosis at 10% or more. When CSE was exposed to air before application to A549 cells, the cytotoxic effects were attenuated. CSE caused cell death without direct contact with the cells. Acrolein and hydrogen peroxide, two major volatile factors in cigarette smoke, caused cell death in a similar manner. Aldehyde dehydrogenase, a scavenger of aldehydes, and N-acetylcysteine, a scavenger of oxidants and aldehydes, completely inhibited CSE-induced apoptosis. CSE and acrolein increased intracellular oxidant activity. In conclusion, apoptosis of alveolar epithelial cells may be one of the mechanisms of lung injury induced by cigarette smoking. This cytotoxic effect might be due to an interaction between aldehydes and oxidants present in CSE or formed in CSE-exposed cells.

Effects of family-togetherness on the food selection by primary and junior high school students: family-togetherness means better food

To see how different foods were selected depending on family-togetherness at breakfast and dinner, we investigated the meals of eight thousand primary and four thousand junior high school students by questionnaire. About 70% of primary school children but less than 50% of junior high school children ate breakfast with their family. The food, eaten by children who ate meals together with their family, took more time for cooking and was more traditional with rice as the staple. Food eaten by children who did not eat with their family lacked both preparation time and staple base. Family-togetherness affects the foods of primary school children more than those of junior high school students.

[Intestinal permeability in Crohn's disease and effects of elemental dietary therapy]

Enteral intake of non-metabolic monosacharide and disaccharide, followed by measurement of the urinary excretion ratio of the two, is a method used to investigate intestinal permeability. L/R ratio (lactulose/1-rhamnose urinary excretion ratio) is considered an indicator of permeability of the small intestine. An increased L/R ratio is caused by mucosal disorders of the small intestine. The L/R ratio in all patients (n = 92) with Crohn's disease was 0.079 +/- 0.081 (mean +/- S.D.), which was significantly higher than the value in normal controls (0.027 +/- 0.009, n = 20, p < 0.05). In 39 patients with Crohn's disease, we assessed intestinal permeability before after treatment with an elemental diet, and during remission. The L/R ratio was 0.120 +/- 0.092, before treatment and 0.065 +/- 0.097 after treatment (p < 0.05), showing increased intestinal permeability before elemental dietary treatment. During remission, the L/R ratio was 0.035 +/- 0.028; this did not differ significantly from the value obtained after treatment. We conclude that intestinal permeability is useful for investigating disease activity in patients with Crohn's disease.