Oxygenation reactions of various tricyclic fused aromatic compounds using Escherichia coli and Streptomyces lividans transformants carrying several arene dioxygenase genes

Bioconversion (biotransformation) experiments on arenes (aromatic compounds), including various tricyclic fused aromatic compounds such as fluorene, dibenzofuran, dibenzothiophene, carbazole, acridene, and phenanthridine, were done using the cells of Escherichia coli transformants expressing several arene dioxygenase genes. E. coli carrying the phenanthrene dioxygenase (phdABCD) genes derived from the marine bacterium Nocardioides sp. strain KP7 converted all of these tricyclic aromatic compounds, while E. coli carrying the Pseudomonas putida F1 toluene dioxygenase (todC1C2BA) genes or the P. pseudoalcaligenes KF707 biphenyl dioxygenase (bphA1A2A3A4) genes was not able to convert these substrates. Surprisingly, E. coli carrying hybrid dioxygenase (todC1::bphA2A3A4) genes with a subunit substitution between the toluene and biphenyl dioxygenases was able to convert fluorene, dibenzofuran, and dibenzothiophene. The cells of a Streptomyces lividans transformant carrying the phenanthrene dioxygenase genes were also evaluated for bioconversion of various tricyclic fused aromatic compounds. The ability of this actinomycete in their conversion was similar to that of E. coli carrying the corresponding genes. Products converted from the aromatic compounds with these recombinant bacterial cells were purified by column chromatography on silica gel, and identified by their MS and 1H and 13C NMR analyses. Several products, e.g., 4-hydroxyfluorene converted from fluorene, and cis-1,2-dihydroxy-1,2-dihydrophenanthridine, cis-9,10-dihydroxy-9,10-dihydrophenanthridine, and 10-hydroxyphenanthridine, which were converted from phenanthridine, were novel compounds.

Expression of transcription factor AP-1 in rat lens epithelial cells during wound repair

We examined the spatial and temporal expression patterns of proteins and mRNAs of the components of transcription factor activator protein 1 (AP-1) to examine the activation pattern of lens epithelial cells during lens wound repair following an anterior capsular injury. One eye of adult Wistar rats (n = 106) were used. After making a lens anterior capsule incision with a hypodermic needle, the affected eye was enucleated 0 and 30 min, 1, 3, 5, 8, 10, 15, 20, 24 hr after injury. Forty six globes were processed for in situ hybridization with oligonucleotide probes for c-fos, fosB, c-jun, junB and junD mRNAs, and 60 globes were immunohistochemically analysed using anti-c-Fos and anti-c-Jun antibodies. Normal lens epithelial cells expressed mRNA signals for junD, but not for c-fos, fosB, c-jun, and junB. mRNAs for c-fos, fosB, c-jun, and junB were detected in the whole lens epithelium from the vicinity to the wound to the equator from 30 min to 8 hr post-injury with their peaks after 30 min to 1 hr, but were no longer detected at 10 hr or later. Expression of c-fos mRNA in the equatorial lens cells was more marked than that of c-jun mRNA. Immunohistochemistry showed that c-Fos protein was expressed in the lens epithelial cells in both the anterior and equatorial regions of the injured lens from 1 to 10 hr after injury, and was no longer detected at 12 hr. C-Jun protein was detected only in the equatorial lens cells from 1 to 5 hr after injury, and was no longer detected at 8 hr. Lens epithelial cells except those in the equatorial region did not express c-Jun protein. These findings indicate that transcriptional activation of lens epithelial cells is initiated in the very early phase after the lens injury, i.e. 30 min post-injury, suggesting that AP-1 may play important roles in regulating lens cell behavior during lens wound repair in rats.

Two-color allele-specific polymerase chain reaction (PCR-SSP) assay of the leptin receptor gene (Leprdb) for genotyping mouse diabetes mutation

An allele specific polymerase chain reaction (PCR-SSP) assay for genotyping the mouse leptin receptor (Leprdb) mutation and its wild type (Lepr+) gene was developed using two different fluorescent dye-labeled primers. First, we determined the Leprdb and Lepr+ allele by PCR-SSP assay with usual dye-unlabeled primers. However this method requires two separate PCR reactions because the amplified products specific for each allele are almost the same size. We further developed a simple and reliable two-color PCR-SSP method that uses a color complementation strategy to distinguish the Leprdb and Lepr+ alleles. Leprdb/Leprdb, Leprdb/Lepr+ and Lepr+/Lepr+ of mice (5 each) were clearly genotyped by the two-color PCR-SSP. We also performed PCR-direct sequencing for the same samples and confirmed the accuracy of this method. This method makes it possible to reduce the number of PCR reactions because both alleles are amplified in the same reaction mixture.

Contamination of transplantable human tumor-bearing lines by Helicobacter hepaticus and its elimination

Helicobacter hepaticus contaminating nonfrozen tumors was transmissible to severe combined immunodeficient (SCID) mice, but the organism in cryopreserved samples was not. This suggests that H. hepaticus has the ability to spread via biomaterials and that freezing-thawing is able to reduce the numbers of organisms to levels insufficient for subcutaneous infection of SCID mice.

Surgical posterior vitreous detachment combined with gas/air tamponade for treating macular edema associated with branch retinal vein occlusion: retinal tomography and visual outcome

PURPOSE

To assess the effectiveness of surgical posterior vitreous detachment (PVD) together with gas/air tamponade in treating visual impairment from macular edema associated with branch retinal vein occlusion (BRVO-macular edema).

METHODS

A cohort study was conducted. To treat visual disturbance caused by BRVO-macular edema in 19 consecutive patients at a University Hospital, phacoemulsification, intraocular lens implantation, and vitrectomy were performed, together with gas/air tamponade. Patients were followed up postoperatively for 3-18 months. Foveal structure was defined using optical coherence tomography (OCT). Preoperative visual acuity, central retinal thickness, and interval between BRVO onset and operation were compared between patients with postoperative visual improvement and those without improvement.

RESULTS

Ten patients recovered normal or near-normal foveal configuration, while nine patients did not. Mean postoperative visual acuity in the former group of patients was significantly higher than in the latter. Mean foveal retinal thickness decreased significantly after the operation. The interval from onset of BRVO until operation was significantly shorter in patients with improved postoperative vision than in other patients, and patients operated on within 11 months had significantly increased postoperative visual acuity.

CONCLUSIONS

Surgical PVD and gas/air tamponade appears effective in treating BRVO-macular edema, although relatively short duration from disease onset until operation is critical for improvement of vision. When a good postoperative foveal contour is seen, it seems to be associated with better visual outcome.

Effect of minoxidil on rabbit lens epithelial cell behavior in vitro and in situ

BACKGROUND

Lens epithelial cell (LEC) proliferation and the associated production of extracellular matrix (ECM) are responsible for capsular opacification after cataract-IOL surgery. Minoxidil is an inhibitor of lysyl hydroxylase, an enzyme involved in procollagen hydroxylation. To evaluate the potential efficacy of minoxidil in inhibiting postoperative capsular opacification, we examined the effects of minoxidil on LEC behavior in cell and organ cultures.

METHODS

We examined minoxidil effects on collagen production, migration and proliferation of cultured rabbit LECs as well as its ultrastructural effects, and also its effects on the cell population in organ-cultured capsular bag.

RESULTS

No cytotoxicity was identified by MTT assay at the concentrations up to 3.0 mM of minoxidil, whereas it decreased the collagen production in LECs. Minoxidil also inhibited migration and proliferation of cells. Ultrastructural observation revealed the presence of dilated endoplasmic reticulum in LECs treated with minoxidil, indicating the accumulation of protein, probably underhydroxylated collagen precursors. The capsules cultured with minoxidil appeared less opaque than control specimens. On histological examination the numbers of cells on equatorial capsules were found to be significantly lower in minoxidil culture than in control culture. No lens cells were detected on the central posterior capsule of minoxidil culture, whereas they were seen in control.

CONCLUSION

Minoxidil inhibited LEC migration and proliferation in vitro, as well as collagen secretion. Collagen secretion may be essential for LEC migration and proliferation. Minoxidil also attenuated repopulation of LECs on the inner surface of organ-cultured capsules. Minoxidil may be a potential inhibitor of postoperative capsular opacification.

Monophasic action potentials of the right atrium in patients with paroxysmal atrial fibrillation

To investigate the mechanism of atrial fibrillation (AF), monophasic action potentials (MAPs) from the atrial myocardium were studied in 7 patients with paroxysmal AF (PAF) and in 7 control individuals. The MAPs were recorded using a contact catheter during sinus rhythm and continuous pacing at the high right atrium (HRA) with pacing cycle lengths of 600, 500 and 400 ms. MAPs were obtained from 6 sites in each participant. The MAPD90 was measured from onset to 90% of MAP repolarization. Average, maximal and minimal MAPD90 (avMAPD90, maxMAPD90 and minMAPD90) were obtained from all participants. The dispersion of MAPD90 (dispMAPD90) was defined as the difference between maxMAPD90 and minMAPD90. The width of each atrial potential (WAP) and the wavelength index (WLI=MAPD90/WAP) were determined. Average, maximal and minimal WLI (avWLI, maxWLI and minWLI) were obtained from all participants. The avMAPD90 and maxMAPD90 did not significantly differ between the 2 groups. The minMAPD90 in the PAF group was significantly smaller than that in the control group at HRA pacing with cycle lengths of 500 and 400 ms (210+/-18ms vs 245+/-14 ms, p<0.05; 207+/-23 ms vs 238+/-20 ms, p<0.05; respectively). The dispMAPD90 was significantly longer in the PAF group than in the control group during sinus and HRA pacing. The WAP value did not differ between the 2 groups. The minWLI in the PAF group was significantly smaller than that in the control group at HRA pacing with cycle lengths of 500 and 400 ms (3.3+/-0.5 vs 3.8+/-0.3, p<0.05; 3.2+/-0.4 vs 3.7+/-0.3, p<0.02). A shortened and widened dispersion of atrial refractoriness may play an important role in the genesis of AF. Furthermore, smaller wavelengths may form in the atrium of patients with PAF.

Genetic variation in 16S-23S rDNA internal transcribed spacer regions and the possible use of this genetic variation for molecular diagnosis of Bacteroides species

The structural variation in 16S-23S rDNA internal transcribed spacer regions (ITS) among Bacteroides species was assessed by PCR amplification and sequencing analysis, and its possible use for molecular diagnosis of these species was evaluated. Ninety strains of the genus Bacteroides, including the species B. distasonis, B. eggerthii, B. fragilis, B. ovatus, B. thetaiotaomicron, B. uniformis and B. vulgatus, produced one to three ITS amplification products with sizes ranging from 615 to 810 bp. Some Bacteroides strains could be differentiated at species level on the basis of ITS amplification patterns and restriction fragment length polymorphism (RFLP) analysis using a four-nucleotide-recognizing enzyme, Msp I. The results of sequence analysis of ITS amplification products revealed genes for Ile-tRNA and Ala-tRNA in all strains tested. The nucleotide sequence, except for that in tRNA-coding regions, was highly variable and characteristic for each species, but a common sequence among B. fragilis, B. thetaiotaomicron and B. ovatus was observed. A digoxigenin-labeled oligonucleotide probe (named FOT1), which was designed from this conserved sequence, specifically hybridized to the ITS amplification products from B. fragilis, B. thetaiotaomicron and B. ovatus. These results suggest that the ITS region is a useful target for the development of rapid and accurate techniques for identification of Bacteroides species.

Effects of antiinflammatory drugs on migration of the rabbit corneal epithelium

PURPOSE

To evaluate and compare the effects of diclofenac sodium 0.1% and betamethasone phosphate 0.1% on corneal wound healing.

SETTING

Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan.

METHODS

Using the method described by Nishida et al., corneal epithelial spreading was measured in vitro in a rabbit corneal block in the presence or absence of 2 antiinflammatory agents at various doses.

RESULTS

At clinical doses (1 microg/mL and 10 microg/mL), the drugs did not suppress migration of the corneal epithelium. At high doses (20 microg/mL, 50 microg/mL, and 100 microg/mL), they did inhibit the migration. There was no between-group difference in corneal epithelial migration at clinical doses. At high doses, corneal epithelial migration was inhibited in the diclofenac sodium group compared with the betamethasone group.

CONCLUSIONS

At clinical doses, diclofenac sodium and betamethasone did not inhibit corneal epithelial migration. However, these drugs should be prescribed cautiously in patient with high-risk diseases such as diabetes mellitus and glaucoma.

The A-factor regulatory cascade and cAMP in the regulation of physiological and morphological development in Streptomyces griseus

In the A-factor regulatory cascade leading to the onset of streptomycin biosynthesis and aerial mycelium formation in Streptomyces griseus, the A-factor receptor protein (ArpA) serves as a DNA-binding repressor and A-factor releases the repression by binding to ArpA and dissociating it from the DNA. Mutants defective in arpA therefore produce streptomycin and aerial hyphae in the absence of A-factor. A gene that inhibits streptomycin production and aerial hyphae formation in an arpA mutant was cloned on a high-copy-number plasmid and found to encode a eukaryotic-type adenylate cyclase (CyaA). Consistent with this, an exogenous supply of cAMP at high concentration almost abolished streptomycin production and aerial hyphae formation. On the other hand, cAMP at lower concentrations stimulated or accelerated these developmental processes. The effects of cAMP were detectable only in arpA mutants, and not in the wild -type strain; an exogenous supply of cAMP or cyaA disruption in the wild-type strain caused almost no effect on these phenotypes. Thus the effects of cAMP became apparent only in the arpA-defective background. cAMP at high concentrations inhibited stringent response factor ppGpp production, which is important for the onset of antibiotic biosynthesis. cAMP also influenced the timing of tyrosine phosphorylation of more than nine proteins. These findings show that a cAMP regulatory relay for physiological and morphological development functions in a concerted and interdependent way with other signal transduction pathways.

Gene transfer by adenovirus in rabbit iris sphincter muscle

The effect of insertion of an exogenous gene on smooth muscle function in rabbit iris sphincter muscle was investigated. An adenoviral vector encoding the bacterial LacZ gene (AdLacZ, 10(7) pfu) and viscoelastics were injected into the posterior chamber of eyes of albino rabbits. Three days after injection, the effects of acetylcholine (Ach), carbachol (Carb), substance P (SP) and electrical field stimuli on isolated iris sphincter were investigated using isometric tension-recording methods. X-Gal histostaining showed that iris sphincter smooth muscle cells were transfected in 7 of 11 muscle strips. Contraction-response curves for Ach, Carb or SP were not different from control. We conclude that the iris sphincter muscle can be gene-transfected by posterior chamber infusion of an adenoviral vector with viscoelastics. Adenovirus-mediated gene transfer per se had no measurable effect on tension development.

Coordinate expression of membrane type-matrix metalloproteinases-2 and 3 (MT2-MMP and MT3-MMP) and matrix metalloproteinase-2 (MMP-2) in primary and metastatic melanoma cells

Expression of MMP-2 in melanoma cells has been demonstrated to be involved in the degradation of extracellular matrix during melanoma growth and to correlate with later melanoma metastasis. MMP-2 is considered to be activated by membrane-associated matrix metalloproteinases (MT-MMPs). To know whether MT-MMPs are involved in the activation of MMP-2 in melanoma cells, immunohistochemical studies were performed in primary and metastatic melanoma by use of the antibodies for MT1-MMP, MT2-MMP and MT3-MMP. Expression of MT1-MMP, MT2-MMP, MT3-MMP and MMP-2 in nevocellular nevus (n = 5), dysplastic nevus (n = 2) and juvenile melanoma (n = 3) was undetectable or detected in only a few cells. Superficial spreading melanoma (SSM) (n = 3) and acral lentiginous melanoma (ALM) (n = 3) showed a moderate expression of MT1 approximately 3-MMP. In nodular melanoma (NM) (n = 2) and metastatic melanoma (n = 3), MT1 approximately 3-MMP was more intensely expressed. Double immunofluorescence demonstrated a consistent colocalization of MT2-MMP/MMP-2 and MT3-MMP/MMP-2 in the NM and metastatic melanoma cells. The colocalization of MT2,3-MMP and MMP-2 in nodular and metastatic melanoma cells suggests that MT-MMPs and MMP-2 co-operate in the invasive and metastatic process of melanoma cells.

Biotransformation of phenanthrene and 1-methoxynaphthalene with Streptomyces lividans cells expressing a marine bacterial phenanthrene dioxygenase gene cluster

The phdABCD gene cluster in a marine bacterium Nocardioides sp. strain KP7 codes for the multicomponent enzyme phenanthrene dioxygenase. phdA encoding an iron-sulfur protein large subunit alpha, phdB encoding its small subunit beta, phdC encoding ferredoxin, and phdD encoding ferredoxin reductase, were replaced in such a way that the termination codons of the preceding open reading frames were overlapped with the initiation codons of the following genes. This manipulated phdABCD gene cluster was positioned downstream of the thiostrepton-inducible promoter PtipA in a high-copy-number vector pIJ6021, and introduced into the gram-positive, soil-inhabiting, filamentous bacterium Streptomyces lividans. The recombinant S. lividans cells converted phenanthrene into a cis-diol form, which was determined to be cis-3,4-dihydroxy-3,4-dihydrophenanthrene by its UV spectral data as well as HPLC property, using the authentic sample for comparison. This biotransformation proceeded very efficiently; 200 microM and 2 mm of phenanthrene were almost completely converted to its cis-diol form in 6 h and 32 h, respectively. In addition, the S. lividans cells carrying the phdABCD gene cluster were found to transform 1-methoxynaphthalene to two products, which were identified to be 8-methoxy-2-naphthol in addition to 8-methoxy-1,2-dihydro-1,2-naphthalenediol by their EI-MS, 1H- and 13C-NMR spectral data.

Calcium and phosphorus in aged human cerebral arteries

To elucidate the compositional changes of the cerebral arteries with aging, the authors investigated age-related changes of the calcium and phosphorus contents in the cerebral arteries by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 11 men and 5 women, ranging in age from 52 to 96 yr. The anterior, middle, and posterior cerebral arteries derived from the same subjects were used in the present study. It was found that there were no significant relationships between age and calcium or phosphorus content in the anterior, middle, and posterior cerebral arteries, indicating that the accumulation of calcium and phosphorus scarcely occurred in the anterior, middle, and posterior cerebral arteries with aging. It was examined whether there were relationships in the calcium and phosphorus contents among the anterior, middle, and posterior cerebral arteries, It was found that there was a significant relationship in both the contents of calcium and phosphorus between the middle and posterior cerebral arteries, but not between the anterior and middle cerebral arteries nor between the anterior and posterior cerebral arteries.

Interleukin-10 expression is correlated with growth fraction in human non-small cell lung cancer xenografts

We examined IL-10 and IL-10 receptor (IL-10R) gene expression in 44 xenografts of human non-small cell lung cancer (NSCLC) by reverse transcription-polymerase chain reaction (RT-PCR) assay with human-specific primers. IL-10 gene expression was detected in 10 (22.7%) of 44 xenografts (0/11 adenocarcinomas, 6/19 squamous cell carcinomas, 4/14 large cell carcinomas) and IL-10R expression in 8 (18.2%) xenografts. The IL-10-positive xenografts immunohistochemically showed significantly increased growth fractions of neoplastic cells (471.0 +/- 112.2) relative to IL-10-negative xenografts (208.4 +/- 96.3) (p=0.009, Mann-Whitney U test), and showed significantly increased vascular number (p=0.008, Mann-Whitney U test). These results suggested that IL-10 expression is correlated with growth features in human NSCLC.

Role of reticulocytes on gametocytogenesis in chickens infected with Leucocytozoon caulleryi

Reticulocytes, known as late polychromatic erythrocytes, were induced in blood of chickens infected with Leucocytozoon caulleryi by bleeding when the second-generation merozoites were released into the blood from the second-generation schizonts. The second-generation merozoites preferentially invaded into reticulocytes and developed to stage II gametocytes. Enhanced development of stage II gametocytes to mature gametocytes was observed in the reticulocytes in vivo and in vitro in the bleeding group. Nevertheless, invasion of reticulocytes by the second-generation merozoites was not considered to be absolutely necessary for the development of gametocytes.

[Intraoperative assessment of cardiac function with transesophageal echocardiography during the Batista operation]

We experienced anesthetic management for six cases of the Batista operation and measured cardiac function before and after cardiopulmonary bypass (CPB) with transesophageal echocardiography. In the successful three patients, left ventricle ejection fraction and ejection time were maintained over 25% and 200 msec after CPB, respectively. In the other three resulting in implantation of left ventricular assist device, ejection fraction remained below 20% and ejection time under 200 msec after CPB. Intraoperative transesophageal echocardiography may be useful not only for monitoring of cardiac function but also for the prediction of prognosis.

Comparison of Scheimpflug images of posterior capsule opacification and histological findings in rabbits and humans

PURPOSE

To compare the posterior capsule opacification in Scheimpflug photographic images produced by an electronic anterior eye segment analysis system with the histopathological findings in rabbits and humans.

SETTING

Department of Ophthalmology, Wakayama Medical College, Japan.

METHODS

Opacified posterior capsules were photographed using the EAS-1000 system (Nidek) and were then extracted during vitreous surgery for proliferative diabetic retinopathy or proliferative vitreoretinopathy in 2 patients. In rabbits, phacoemulsification and aspiration (PEA) with intraocular lens (IOL) implantation was performed. The IOL was implanted in the bag or in the sulcus. After intervals of healing, the posterior capsule was photographed with the EAS-1000 and the animals were then killed. In both clinical and experimental specimens, the posterior capsule was processed for light microscopic histology and immunohistochemistry.

RESULTS

Opacified human capsules were well imaged by the EAS-1000. Histology showed that lens epithelial cells proliferated with and without an accumulation of extracellular matrix. Details such as rolling of the capsulotomy edge were seen well. Regenerated lens fibers of Soemmering's ring were seen as a mass within the capsule. In the rabbit model, Scheimpflug images accurately represented the capsules as they appeared histologically.

CONCLUSION

The EAS-1000 system provided faithful, relatively high-resolution images that corresponded to the histologic findings in the posterior capsules after PEA-IOL surgery in humans and rabbits.

Circadian variation of the onset of acute myocardial infarction in the Osaka area, 1998-1999: characterization of morning and nighttime peaks

The onset of acute myocardial infarction (AMI) shows characteristic circadian variations; that is, a definite morning peak related to biologic rhythms and a vague nighttime peak related to socioeconomic factors. The recent economic recession in Japan may change the circadian variation, especially the nighttime peak. This study evaluated the recent circadian variation of AMI in Osaka and specified the patient subgroups showing either a morning or nighttime peak predominantly. Of 1,609 consecutive patients with AMI registered from April 1998 to January 2000, 1,252 whose onset of AMI was definitely identified were studied. The day was divided into six 4-h periods with a morning peak between 08.01 h and 12.00h, and nighttime peak between 20.01 h and 24.00h. When subgroup analysis was performed, female patients aged 65 years or more showed a morning peak alone and male patients aged less than 65 years with an occupation and the habits of cigarette smoking and alcohol intake showed a nighttime peak alone. Thus, in Osaka nighttime socioeconomic factors may currently be more potent triggers of AMI than the morning surges in younger male workers who smoke and drink.

Lens epithelial cell regeneration of a capsule-like structure during postoperative healing in rabbits

PURPOSE

To determine whether lens epithelial cells (LECs) can regenerate the lens capsule during healing after lens extraction and intraocular lens (IOL) implantation.

SETTING

Department of Ophthalmology, Wakayama Medical College, Japan.

METHODS

Extracapsular lens extraction and IOL implantation were performed in 5 adult albino rabbits. Lens capsules were examined histologically and immunohistochemically 3 and 5 months later.

RESULTS

Lens epithelial cells proliferated and regenerated lens fibers within the capsular bag. A multilayered homogenous capsule-like structure was present in the equatorial region. The structures contained type IV collagen but not type I collagen.

CONCLUSION

Lens epithelial cells can regenerate lens capsule-like structures during healing after lens extraction. Postoperative LECs without phenotypic conversion to a fibroblastic type may produce this structure.

Diesel exhaust-induced airway hyperresponsiveness in c-Ha-ras transgenic mice

Recently the quantity of diesel exhaust (DE) emissions, which contain a variety of chemicals and can induce pulmonary carcinoma in animals, has been increasing in Japan. To assess the toxicity of DE, we evaluated airway hyperresponsiveness after exposure to DE in the rasH2 (CB6F1-TgHras2) mouse, which carries c-Ha-ras genes and shows marked sensitivity to treatment with various genotoxic carcinogens such as methylnitrosourea and dimethylbenzanthracene. We exposed rasH2 mice (n=18) and their nontransgenic littermates (n=19) to room air or 3 mg/m(3) DE for 4 weeks, measured their respiratory resistance (Rrs) during inhalation of acetylcholine (ACh; 0.005, 0.01, 0.02, 0.04, 0.08, 0.16, 0.31, 0.63, 1.28, 2.5, 5, or 10 mg/ml) for 2 min, and calculated the provocative ACh concentration needed to cause a 50% increase (PC(150)) in Rrs. At all doses of ACh, Rrs was significantly higher (P<0.05) in rasH2 mice exposed to DE than in those exposed to room air. In addition, Rrs in the DE-exposed rasH2 animals was significantly higher (P<0.05) at 0.16, 0.31, and 0.63 mg/ml ACh than in DE-exposed nontransgenic littermates. The PC(150) (mean+/-standard error) of DE-exposed rasH2 mice was 3.4+/-1.9 mg/ml, that in rasH2 mice exposed to room air was 10.6+/-2.5 mg/ml, and that in DE-exposed nontransgenic animals was 10.9+/-3.7 mg/ml. In conclusion, DE causes airway hyperresponsiveness in rasH2 mice and may induce the expression of c-Ha-ras genes.

Familial adult onset primary alveolar hypoventilation syndrome

A 41-year-old man fell into type II respiratory failure after catching a cold, and became dependent on a respirator. Chest radiography showed no abnormalities and the hyperventilation test showed improved arterial blood gas findings. His sleep study showed marked nocturnal desaturation due to hypopnea and apnea with a decrease of thoracic and abdominal movement during sleep. Therefore, we diagnosed him as primary alveolar hypoventilation syndrome (PAH). Seven years previously, his 2-year elder sister had suffered from similar respiratory failure during her second pregnancy and had been diagnosed as PAH. While myopathy was suspected in both cases, attenuation of muscle strength was slight and it appeared not to be the main cause of alveolar hypoventilation. Since medication was not effective in each case, they underwent non-invasive positive pressure ventilation (NIPPV). While sustained mild hypercapnia remained during the daytime, it improved their respiratory failure. To our knowledge, this is the first study of familial adult onset PAH.

Smad translocation and growth suppression in lens epithelial cells by endogenous TGFbeta2 during wound repair

To determine whether endogenous TGFbeta affects lens epithelial cells during repair after an anterior capsule injury in mice, we studied translocation of Smad proteins, which carry the TGFbeta signal from cell surface receptors to promoters in nuclei. We immunolocalized Smads in murine lenses at intervals up to 8 weeks following capsular injury. Effects of injecting TGFbeta neutralizing antibodies on Smad4 location and cell proliferation were examined at 24 hr after injury. Finally, we examined whether exogenous TGFbeta2 induced Smad nuclear translocation in murine lenses in organ culture. Cell proliferation was quantitated by 5-bromo-2'-deoxyuridine (BrdU) labelling. In uninjured lenses, Smads were located in the cytoplasm. In injured lenses, nuclear localization of Smads was observed in cells next to the capsular break from 8 to 24 hr after the injury, and was observed peripheral to the break at 48 hr. Nuclear Smads then continued to be observed occasionally in a minority of cells. Injection of antibodies neutralizing TGFbeta2, but not TGFbeta1 or TGFbeta3, inhibited Smad4 nuclear translocation and resulted in the appearance of BrdU-positive anterior epithelial cells. With the lenses in culture, transient nuclear localization of Smads occurred between 3 and 24 hr in response to continuous exposure to TGFbeta2. No nuclear translocation was seen at 48 hr. Endogenous TGFbeta2 affects lens cells during wound repair after anterior capsule injury, inhibiting lens cell proliferation during the early phase. Nuclear translocation of Smads in lens epithelial cells is transient even with continuous exposure to TGFbeta2.

QT and JT dispersion in patients with monomorphic or polymorphic ventricular tachycardia/ventricular fibrillation

The present study evaluates the repolarization abnormalities in patients with monomorphic sustained ventricular tachycardia (MVT) and polymorphic ventricular tachycardia/ventricular fibrillation (PMVT/VF) by measuring QT and JT dispersion on the surface electrocardiogram (ECG). QT dispersion is a predictor of ventricular arrhythmias in several clinical settings. However, the value of QT and JT dispersion in identifying patients at risk for PMVT/VF is controversial. Maximum QT (JT) interval duration and QT (JT) dispersion were compared between 20 healthy individuals, 12 patients with inducible MVT during programmed electrical stimulation and seven patients with PMVT/VF recorded during 24-hour ambulatory ECG or induced by programmed electrical stimulation. QT dispersion was 40 +/- 9 ms in the control group, 63 +/- 21 ms in the MVT group, and 79 +/- 31 ms in the PMVT/VF group. QT dispersion in both the MVT and PMVT/VF groups were significantly greater than in the control group (P <.001 and P <.0001, respectively); however, there was no significant difference between the MVT and PMVT/VF groups. JT dispersion was 41 +/- 14 ms in the control group, 69 +/- 14 ms in the MVT group and 103 +/- 37 ms in the PMVT/VF group. JT dispersion differed significantly between the study groups and was significantly increased in PMVT/VF group than in the control group or MVT groups (P <.0001 vs. the control group, P <.005 vs. the MVT group). Patients with PMVT/VF have a greater dispersion of ventricular repolarization time. Repolarization abnormalities are important for ventricular arrhythmogenesis and detectable on the surface ECG.