[Susceptibilities of bacteria isolated from patients with respiratory infectious diseases to antibiotics (1993)]

Bacteria isolated from respiratory tract infections were collected in cooperation with institutions located throughout Japan, since 1981, and the Ikemotor et al. have been investigating susceptibilities of the isolates of various antibacterial agents and antibiotics, and the relationships between the isolates and backgrounds of the patients and so forth each year. We discuss the results in detail. In 20 institutions around the entire Japan from October 1993 to September 1994, 584 strains of bacteria were isolated mainly from sputa of 473 patients with respiratory tract infections and presumed to be the etiological agents. MICs of various antibacterial agents and antibiotics were determined against 91 strains of Staphylococcus aureus, 98 strains of Streptococcus pneumoniae, 122 strains of Haemophilus influenzae, 91 strains of Pseudomonas aeruginosa (non-mucoid), 34 strains of Pseudomonas aeruginosa (mucoid), 42 strains of Moraxella subgenus Branhamella catarrhalis, 25 strains of Klebsiella pneumoniae etc., and the drug susceptibilities of these strains were measured except the strains which died during transportation. 1. S. aureus S. aureus strain sfor which MICs of methicillin was higher than 4 micrograms/ml (methicillin-resistant S. aureus) accounted for 56.0%, but this frequency of the drug resistant bacteria was lower than the previous year's 61.4%. Arbekacin and vancomycin showed the highest activities against MRSA and MIC80s were 1 microgram/ml. 2. S. pneumoniae Benzylpenicillin among the penicillins showed potent activities against S. pneumoniae. Cefuzonam, cefotaxime and cefmenoxime among the cephems showed excellent antimicrobial activities against S. pneumoniae. Imipenem; carbapenems, showed the most potent activity, and MIC90 was 0.063 microgram/ml. 3. H. influenzae All the drugs tested were quite active against H. influenzae. Cefotaxime, cefmenoxime, cefuzonam and cefixime among the cephems showed the most potent activities, and MIC90 were 0.063 microgram/ml against H. influenzae. Ofloxacin also showed MIC90 of 0.063 microgram/ml. 4. P. aeruginosa (mucoid) Tobramycin showed the most potent activity against P. aeruginosa (mucoid), and MIC80 was 1 microgram/ml. Ceftazidime, cefsulodin, imipenem, aztreonam, gentamicin and ciprofloxacin showed potent activities with MIC80s of 2 micrograms/ml. 5. P. aeruginosa (non-mucoid) Tobramycin showed the highest activity against P. aeruginosa (non-mucoid), and MIC80 was 1 microgram/ml, followed by ciprofloxacin with MIC80 of 2 micrograms/ml. Comparing to activities against P. aeruginosa (mucoid), all the drugs tested had relatively low activities against P. aeruginosa (non-mucoid). 6. K. pneumoniae. The activities of all drugs except ampicillin and minocycline were high against K. pneumoniae. Cefozopran, imipenem and carumonam showed the highest activities and MIC80s were 0.125 microgram/ml. Flomoxef showed the next highest activities with an MIC80 of 0.25 microgram/ml. 7. M.(B.) catarrhalis Imipenem showed the most potent activity against M.(B.) catarrhalis, with an MIC80 of 0.063 microgram/ml, followed minocycline and ofloxacin with their MIC80s of 0.125 microgram/ml. We also investigated year to year changes in the background of patients, as well as types of respiratory infectious diseases, and the etiological agents. As for patients background, there were many infectious diseases found among patients a high age bracket, and the patients over age 60 accounted for 61.3% of the diseases. The distribution by respiratory tract infections was as follows: chronic bronchitis and bacterial pneumonia accounted for the greatest numbers of cases with 31.1% and 26.0%, respectively, followed by bronchiectasis with 10.4%. In this year chronic bronchitis under age 29 were 41.7%, thus was much higher than 12.5% in previous year. This marked change was first noted in your research during the recent 5 years. As for frequencies of etiologic bacteria by respiratory tract infections, S. pneumoniae (ABSTRACT TRUNCATED)

[Susceptibilities of bacteria isolated from patients with respiratory infectious diseases to antibiotics (1992)]

Bacteria isolated from lower respiratory tract infections were collected in cooperation with institutions located throughout Japan since 1981, and Ikemoto et al. have been investigating susceptibilities of the isolates to various antibacterial agents and antibiotics, and the relationships between the isolates and characteristics of the patients and so forth each year. We discuss the results in detail. In 20 institutions around the entire Japan from October 1992 to September 1993, 690 strains of bacteria were isolated mainly from sputa of 549 patients with lower respiratory tract infections and presumed to be the etiological bacteria. MICs of various antibacterial agents and antibiotics were determined against 101 strains of Staphylococcus aureus, 121 strains of Streptococcus pneumoniae, 122 strains of Haemophilus influenzae, 92 strains of Pseudomonas aeruginosa (non-mucoid), 32 strains of Pseudomonas aeruginosa (mucoid), 52 strains of Moraxella subgenus Branhamella catarrhalis, 28 strains of Klebsiella pneumoniae etc., and the drug susceptibilities of these strains were measured except the strains which died during transportation. 1. S. aureus S. aureus strains for which MICs of methicillin were higher than 4 micrograms/ml (methicillin-resistant S. aureus) accounted for 61.4% and the frequency of the drug resistant bacteria was higher than the previous year's 58.3%. MICs values indicated that arbekacin was as active as vancomycin against all the strains on S. aureus. 2. S. pneumoniae Benzylpenicillin among the penicillins showed potent activities against S. pneumoniae. Cefuzonam, cefazolin, cefotaxime and cefmenoxime among the cephems showed excellent antimicrobial activities against S. pneumoniae. Imipenem; carbapenems, showed the most potent activity, and MIC80 was 0.015 microgram/ml. 3. H. influenzae All the drugs tested were potent against H. influenzae. Ampicillin among the penicillins showed MIC80 1 microgram/ml against H. influenzae. Cefotaxime, cefmenoxime, cefuzonam and cefixime showed the most potent activities, and MIC80s were 0.063 microgram/ml. The antimicrobial activity of ofloxacin was equivalent to those of cephems. 4. P. aeruginosa (mucoid) Ciprofloxacin showed the most potent activity against P. aeruginosa (mucoid), and MIC80 was 1 microgram/ml. Cefsulodin, aztreonam, carumonam and tobramycin showed the next most potent activities with an MIC80s of 2 micrograms/ml. 5. P. aeruginosa (non-mucoid) Tobramycin and ciprofloxacin showed the highest activities against P. aeruginosa (non-mucoid) with an MIC80s of 2 micrograms/ml. Norfloxacin also showed some activity, and MIC80 was 4 micrograms/ml. Comparing to activities against P. aeruginosa (mucoid), all the drugs tested showed lower activities against P. aeruginosa (non-mucoid). 6. K. pneumoniae The activities of all drugs except penicillins were high activities against K. pneumoniae. Carumonam showed the most potent activity with an MIC80 of 0.063 microgram/ml, followed by flomoxef, cefixime and cefozopran with their MIC80s of 0.125 microgram/ml. 7. M.(B.) catarrhalis Imipenem; carbapenems, showed the most potent activity against M.(B.) catarrhalis with an MIC80 0.063 microgram/ml. Minocycline and ofloxacin showed MIC80s 0.125 microgram/ml, respectively. We also investigated year to year changes in the background of patients, as well as types of respiratory infectious diseases, and the etiological bacteria. As for patients backgrounds, there were many infectious diseases found among patients in a high age bracket, and the patients over age 60 accounted for 60.8% of the diseases. The distribution by lower respiratory tract infections was as follows: bacterial pneumonia and chronic bronchitis accounted for the greatest numbers of cases with 30.4%, 29.5%, respectively, followed by bronchiectasis with 12.2%. As for frequencies of etiologic bacteria for respiratory tract infections, H. influenzae: 22.2%, and S. pneumoniae: 15.1% in chronic bronchitis; S. pneumoniae: 2

Nitrogen dioxide exposure increases airway contractile response to histamine by decreasing histamine N-methyltransferase activity in guinea pigs

To determine the mechanism responsible for nitrogen dioxide (NO2)-induced airway hyperresponsiveness, we examined the effects of NO2 exposure on the contractile response to histamine and the level of histamine N-methyltransferase (HMT) activity, a histamine-degrading enzyme, in guinea pig trachea in vitro. Guinea pigs were divided into seven groups. Each group received continuous NO2 exposure (2.0 ppm) for either 2, 6, 12, 24, 48, or 96 h. The remaining group did not receive NO2 exposure (control). HMT activity in trachea was decreased from the control value of 70.3 +/- 7.7 pmol/min/mg protein to 34.6 +/- 6.7 pmol/min/mg protein by 12 h exposures of NO2. However, 24 and 48 h exposures of NO2 did not significantly alter HMT activity. In contrast, HMT activity exceeded the control value by 96 h exposures of NO2 (85.5 +/- 5.1 pmol/min/mg protein). Twelve hour exposures of NO2 shifted the concentration-response curves to histamine to lower concentrations and significantly reduced the median effective concentration (EC50) of histamine (log M) from the control value of -5.16 +/- 0.09 to -6.15 +/- 0.14 (P < 0.01). In contrast, the EC50 concentration of histamine (log M) increased from the control value of -5.20 +/- 0.10 to -4.90 +/- 0.11 by 96 h exposures of NO2 (P < 0.05). However, NO2 exposure did not alter the contractile response to acetylcholine. Morphologically, tracheal epithelial cells had vacuoles after 12 h exposures of NO2, but denudation of the epithelium did not occur during this experiment. In situ hybridization for HMT mRNA demonstrated that the level of HMT mRNA increased dominantly in tracheal epithelial cells after 96 h exposures of NO2. The present results indicated that the decrease in the level of HMT activity in the trachea was closely associated with the increase in the airway contractile response to histamine, suggesting that NO2-induced transient airway hyperresponsiveness to histamine is due to the decreased capacity of histamine catabolism in airway.

Development and applications of new technology for two-dimensional space-time characterization and correlation analysis of ultraweak biophoton information

We describe the spatial distribution and temporal correlation analysis of ultraweak biophoton emission based on photoelectron pulse time series and position measurement techniques. Experimental results on the spatio-temporal variation of biophoton emission from soybean seedlings after physical and chemical stimulation to the root tip are analyzed. Our results suggest the potential usefulness of this technique to quantify the transmission mechanisms of biological signals in the living system by measuring the biophoton emission.

[Familial posterior cortical atrophy with visual agnosia and Bálint's syndrome]

We report a patient of posterior cortical atrophy with progressive visual agnosia, Bálint's syndrome and dementia in which posterior cortical atrophy with similar characteristics on CT and progressive dementia were found in a sister. The patient was a 75-year-old woman who noted the onset of a progressive visual disorder at the age of 70, and whose family first noticed disoriented behavior at around the same period. Ophthalmologic examinations revealed mild cataract but no evidence of peripheral optic nerve or retinal lesions. Neuropsychological examination showed right homonymous hemianopia, visual agnosia, Bálint's syndrome, mild transcortical sensory aphasia, Gerstmann's syndrome, constructional apraxia, mild ideomotor apraxia and memory disorder. MRI showed marked dilatation of both lateral ventricles, especially the posterior horns, and severe atrophy of the occipital lobes, hippocampus, and the parahippocampal gyrus. Assessment of regional cerebral blood flow by IMP-SPECT revealed a generalized decrease in the temporo-parieto-occipital region bilaterally. The patient's sister began to show evidence of progressive dementia at 80 years of age and CT of the brain revealed marked atrophy, predominantly in the occipital lobes, similar to that of the patient. We believe this to be the first report of posterior cortical atrophy with a positive family history, suggesting the possibility of a hereditary syndrome.

Quantitation of heteroplasmy of mitochondrial tRNA(Leu(UUR)) gene using PCR-SSCP

We have devised a novel method for quantitative analysis of the MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) tRNA(Leu(UUR)) mutation of mitochondrial DNA using a PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) method, and compared the results obtained using the PCR-SSCP method with those obtained using other methods including Southern blotting, last one cycle hot PCR, and conventional PCR-RFLP (restriction fragment length polymorphism). The standard curve obtained using the PCR-SSCP method is linear, with a correlation coefficient of 0.999; it was determined that this method is more accurate than other methods for quantitative analysis. The PCR-SSCP method does not require restriction digestions, thereby avoiding potential problems of partial digestions or heteroduplex formation during PCR. The method is quite simple and should have a broad range of application for quantitation of mutant mtDNAs in various mitochondrial encephalomyopathies. We applied the method for quantitation of mutant mitochondrial DNA carrying a single base substitution in the tRNA(Leu(UUR)) gene in two autopsied cases of MELAS. In both cases, the mutant mtDNA is abundantly present (82-95%) withd little variation among tissues.

Inflammatory involvement of the hypophysis in Tolosa-Hunt syndrome

We report a case of painful ophthalmoplegia (Tolosa-Hunt syndrome), which was complicated with diabetes insipidus (DI) and pituitary-adrenal axis hypofunction. A 42-year-old man hospitalized for left orbital pain and impairment of left cranial nerves III, IV, V, VI, developed diabetes insipidus during the corticosteroid treatment. Neuroimaging studies disclosed a thickened, highly contrast-enhanced pituitary stalk, swollen pituitary gland and widened left cavernous sinus up to the superior orbital fissure, which were accompanied by diabetes insipidus and hypofunction of the pituitary-adrenal axis. These were indicative of an extension of granulomatous inflammation of the cavernous sinus to the pituitary portal system and the gland itself.

The 8,344 mutation in mitochondrial DNA: a comparison between the proportion of mutant DNA and clinico-pathologic findings

Ten patients, two men and eight women with mitochondrial encephalomyopathy, had an A-G mutation at nucleotide pair 8,344 in the mitochondrial DNA, the most common genetic defect in myoclonus epilepsy with ragged-red fibers (MERRF). Eight patients had the clinical and pathologic characteristics of MERRF including myoclonus, seizures, cerebellar ataxia and myopathy with ragged-red fibers. Two patients had atypical symptoms such as early onset of fatal cardiac failure and late onset of rapid mental deterioration, respectively. The striking feature in our patients with the 8,344 mutation cardiac involvement and two developed progressive heart failure. In the typical MERRF patients, the proportion of mutant mitochondrial DNA in their skeletal muscles, quantified by a single strand conformation polymorphism analysis, was above 85%. However, there was no significant correlation between clinical severity, histopathological findings and the proportion of mutant mtDNA in muscle biopsy samples, suggesting that non-ragged-red fibers play an important role in the phenotype expression of the mutants.

IL-5, IL-8 and GM-CSF immunostaining of sputum cells in bronchial asthma and chronic bronchitis

BACKGROUND

Granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin (IL)-5 or IL-8 have been suggested to play an important role in the pathogenesis of eosinophilic airway inflammation in bronchial asthma or neutrophilic airway inflammation in chronic bronchitis, respectively, However, GM-CSF and IL-8 have biological activities to either eosinophils or neutrophils.

OBJECTIVE

To investigate the contribution of these cytokines to airway inflammation, we compared the cellular differential and immunolocalization of GM-CSF, IL-5 and IL-8 in sputum cells from patients with bronchial asthma and chronic bronchitis.

METHODS

Cytospins of sputum cells from 12 patients with bronchial asthma and 12 with chronic bronchitis were subjected to cellular differential counting and immuno-cytochemistry with anti-human GM-CSF, IL-5 and IL-8 antibody.

RESULTS

The predominant cells in bronchial asthma were eosinophils and lymphocytes, while those in chronic bronchitis were neutrophils. All cytokines examined were detected in either bronchial asthma or chronic bronchitis, although the percentage of GM-CSF and Il-5 positive cells in bronchial asthma (53.4 +/- 6.0 [mean +/- SEM]% and 9.7 +/- 2.8%, respectively) was significantly higher than that in chronic bronchitis (11.4 +/- 2.5%; P < 0.001 and 1.7 +/- 0.3%; P < 0.007, respectively). In contrast, the percentage of IL-8 positive cells in chronic bronchitis (23.8 +/- 7.0%) was significantly higher than that in bronchial asthma (7.& +/- 1.9%; P < 0.04). The cells positive for IL-5 were lymphocytes in bronchial asthma and chronic bronchitis. The cells positive for GM-CSF in bronchial asthma were predominantly eosinophils, while those in chronic bronchitis were monocytes/macrophages and neutrophils. In contrast, neutrophils are mainly positive for IL-8 in chronic bronchitis, while monocytes/macrophages and bronchial epithelial cells are positive for IL-8 in bronchial asthma.

CONCLUSION

The immunochemical comparison of GM-CSF and IL-8 localization in sputum cells between bronchial asthma/chronic bronchitis suggests the differential regulation and roles of these cytokines in eosinophilic vs neutrophilic airway inflammation, resulting in the development of different types of airway inflammation.

In situ expression of the cell adhesion molecules in bronchial tissues from asthmatics with air flow limitation: in vivo evidence of VCAM-1/VLA-4 interaction in selective eosinophil infiltration

Eosinophils play a critical role in the pathogenesis of bronchial asthma by releasing various mediators. To understand the mechanisms of eosinophil migration to the site of inflammation, we examined the expression of adhesion molecules in the bronchial tissues of asthmatic subjects with air flow limitation. By immunohistochemical analysis, Mac-1, LFA-1, and VLA-4 were strongly positive in eosinophils and mononuclear cells infiltrated in the bronchial mucosa and submucosa. Their number was significantly increased compared with those in control tissue. Immunolocalization for ICAM-1, the ligand of Mac-1 and LFA-1, was detected in the endothelial cells of capillaries and venules, in the mononuclear cells in submucosa, and in the basal layer of the epithelium. Endothelial cells in capillaries and venules were also strongly positive for VCAM-1, the ligand of VLA-4. Immunolocalization for E-selectin was detected in some endothelial cells in capillaries and venules in bronchial submucosa, whereas there were very few positive cells in the bronchial tissues from control subjects. In situ hybridization demonstrated ICAM-1 mRNA expression in the endothelial cells and mononuclear cells in bronchial submucosa. Immunoelectron microscopy for ICAM-1, VCAM-1, and E-selectin demonstrated de novo synthesis of these molecules and their expression along the luminal cell membrane of endothelial cells. These results suggested that ICAM-1, VCAM-1, and E-selectin were newly synthesized prior to spontaneous asthma attacks, and that their expression, particularly that of VCAM-1, may play a key role in eosinophil infiltration into the airway.

Ulcerative colitis associated with Takayasu's disease

A 25-year-old Japanese woman had both ulcerative colitis and Takayasu's disease and was positive for HLA-A24, BW52, and DR2. She was found to have thickening of the wall of the carotid artery on contrast-enhanced computerized tomography of the neck and chest. Prednisolone, beraprost, and sulfapyridine achieved rapid remission of both diseases.

[A study on the resistance of methicillin resistant Staphylococcus aureus to antimicrobial agents]

The morbidity of the infections caused by methicillin resistant staphylococcus aureus increased in recent years. In order to know the resistance of MRSA to antimicrobial agents, the minimal inhibitory concentrations (MICs) of antimicrobial agents against S. Aureus isolated from inpatients were measured. The presence of beta-lactamase in and the types of coagulase of the strains tested were determined as well. The results showed that MRSA accounted for 50.7% of the strains tested, the incidence of MRSA producing beta-lactamase was 85.1% and the coagulase of MRSA was all of type II. MRSA showed resistance to most of the lactam antibiotics and some of the aminoglycosides. Vancomycin and arbikacin had the highest activity against MRSA; other effective antibiotics were in the following order: amikacin, minocycline, tosulfloxacin and imipenem. It is suggested that serious infections caused by MRSA may be cured by using vancomycin, arbikacin or other antibiotics mentioned above.

[Molecular genetic analysis for Leber's hereditary optic neuropathy (LHON)]

Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease characterized of acute visual loss predominantly affecting young men. So far twelve mutations in the mitochondrial DNA have been associated in this disease. We reviewed these mutations, and showed methods to detect these mutations which are being used in our laboratory. Seven mutations (nps 3460, 5244, 7444, 11778, 13708, 15257, 15812) can be detected by the the loss of the sites, and 4 mutations (nps 4216, 4917, 11778, 3394) can be detected by the appearance of the restriction sites. Since only two mutations (nps 4160 and 14484) don't affect the restriction sites, we use mismatched primers as a method to detect the mutations by polymerase chain reaction.

[Molecular genetic analysis for myoclonus epilepsy associated with ragged-red fibers (MERRF)]

Two mutations in tRNA(Lys) gene of mitochondrial DNA were detected as the causes of this disease. We reviewed our previous studies and the recent literatures. We analyzed the mtDNA nucleotide sequence of a MERRF patient, the original case of MERRF described by Fukuhara et al., and identified a point mutation of 8,344 in tRNA(Lys) gene. This mutation detected in all 8 MERRF patients from 6 independent families, and not detected in 15 controls by polymerase chain reaction using a mismatched primer. We also quantitated the degrees of heteroplasmy of the point mutation at nt 8,344 of tRNA(Lys) in various postmortem tissues from two patients with MERRF. The percentages of the mutant mtDNA were similar in both clinically affected and unaffected tissues.

[Peripheral neuropathy in large granular lymphocytic leukemia]

A 16-year old woman with LGL leukemia developed peripheral neuropathy. She showed virus-associated hemophagocytic syndrome (VAHS)-like signs including high fever, liver dysfunction, huge splenomegaly, hepatomegaly and pancytopenia. The presence of chronic active EB virus infection was proved by marked high titers for IgG and IgA antibodies to the Epstein-Barr viral capsid and early antigens and low titers of antibody to Epstein-Barr nuclear antigens. She showed dysesthesia and paresthesia of bilateral lower extremities with marked swelling and tenderness, and later developed muscular weakness and atrophy with areflexia of lower extremities. Findings of the central nervous system dysfunction were not observed except for the acceleration of jaw jerk. Pleocytosis and increased protein levels in the cerebrospinal fluid were found. Pulse therapy of methyl-prednisolone and high dose intravenous immunoglobulin therapy (20 g/day for 3 days) were effective for neurological findings. The increased neopterin in the cerebrospinal fluid suggested that peripheral neuropathy was caused by activated macrophages.

Uniform tissue distribution of tRNA(Lys) mutation in mitochondrial DNA in MERRF patients

We documented the presence of a point mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA) in various postmortem tissues from two patients with myoclonus epilepsy associated with ragged-red fibers (MERRF). The percentages of the mutant mtDNA were similar (93 to 99%) in both clinically affected and unaffected tissues, suggesting that preferential clinical involvement of certain tissues in MERRF is based not only on the variation of distribution of the mutant mtDNA, but also on other factors such as differences in the threshold in various CNS regions and organs.

The effect of cytokines on the differentiation of an eosinophilic leukemia cell line (EoL-1) is associated with down regulation of c-myc gene expression

In this study, we measured hydrogen peroxide (H2O2) release as one of the functions of mature eosinophils, and utilized it as a quantitative index. We demonstrated that 1) the human eosinophilic leukemia cell line, EoL-1, did not release H2O2 when stimulated with phorbol myristate acetate (PMA), but after culturing with tumor necrosis factor (TNF) and interferon-gamma (IFN-gamma) it acquired the ability to release H2O2; 2) the ability to release H2O2 was time dependent and reached a peak after 4 days of culture; 3) administration of TGF-beta or GM-CSF, with TNF and IFN-gamma enhanced the PMA-induced release of H2O2 from EoL-1. To examine the potential relationship between c-myc gene expression and induction of the ability to release H2O2, Northern analysis of c-myc gene expression in EoL-1 cocultured with TNF and IFN-gamma was performed. The results showed that the c-myc gene was spontaneously expressed in EoL-1, and the level of c-myc mRNA was markedly reduced after the cells were cocultured with TNF and IFN-gamma, suggesting that the decrease of the c-myc mRNA level is closely associated with induction of the ability to release H2O2.

Strong correlation between the number of CAG repeats in androgen receptor genes and the clinical onset of features of spinal and bulbar muscular atrophy

X-linked spinal and bulbar muscular atrophy (SBMA), a motor neuron disease associated with androgen insensitivity, is caused by androgen receptor gene mutations with an increased number of tandem CAG repeats in exon 1. We investigated the increased number of CAG repeats in androgen receptor genes of 19 SBMA patients and found that this correlated strongly with the age at onset of muscle weakness. Thus, SBMA is the first genetic disease in which a strong correlation between the degree of genetic abnormality (number of CAG tandem repeats) and clinical phenotypic expression is demonstrable. The results further indicate that androgen gene mutation is directly involved in the degeneration of motor neurons.

Role of chronic Pseudomonas aeruginosa infection in the development of bronchiectasis

To understand the role of Pseudomonas aeruginosa infection in the development of bronchiectasis, we investigated by CT the presence of bronchiectasis in two groups of chronic bronchitis patients and in a control group. There were no differences in clinical or laboratory findings between groups A and B. Three observers without any knowledge of these patients reported bronchiectasis on a scale of 0 to 3 and bronchial wall thickness on a scale of 0 to 3 in each lobe of both lungs. Bronchiectasis and wall thickness scores in group A (chronic bronchitis with P aeruginosa infection) were significantly higher than bronchiectasis scores and wall thickness in group B (chronic bronchitis without P aeruginosa infection). Both scores in group B were higher than those in group C (control group). These findings support the idea that chronic P aeruginosa infection plays a role in the development of bronchiectasis.

Functional analysis of alternatively spliced transcripts of the human histidine decarboxylase gene and its expression in human tissues and basophilic leukemia cells

L-Histidine decarboxylase (HisDC) is the enzyme catalyzing the formation of histamine from L-histidine. HisDC activity is expressed specifically in mast cells/basophils, endocrine cells in stomach, and histaminergic neurons in brain. As a first step in the analysis of the regulation of HisDC gene expression, we have cloned the cDNA coding for HisDC from a cDNA library of a human basophilic leukemia cell line, KU-812-F. We identified two types of HisDC cDNA, representing the 2.4-kb and 3.4-kb HisDC mRNA constitutively expressed in these cells. Sequence analysis of these cDNA revealed that the 3.4-kb mRNA contains the insert sequence of 824 bases and suggests that both 2.4-kb and 3.4-kb mRNA may represent the alternatively spliced transcripts of the HisDC gene. Using expression plasmids containing a cDNA for each HisDC mRNA, we analyzed the function of possible HisDC isoforms. We show that only the 2.4-kb mRNA encodes functional HisDC and is expressed in human brain and lung. However, we were unable to detect the 3.4-kb mRNA in these tissues. Thus, the 3.4-kb mRNA may be generated by KU-812-F cell-specific splicing of the HisDC gene transcripts. Furthermore, we demonstrated the increase in the level of 2.4-kb HisDC mRNA and HisDC activity in KU-812-F cells following treatment with phorbol 12-myristate 13-acetate.

Human lung mast cells and pulmonary macrophages produce tumor necrosis factor-alpha in sensitized lung tissue after IgE receptor triggering

Tumor necrosis factor (TNF) is considered to play a key role in the pathogenesis of allergic disorders. We examined TNF production in human lung fragments after IgE receptor triggering at mRNA and protein levels. IgE receptor triggering was performed by sensitizing lung fragments with monoclonal human IgE and then exposing them to anti-human IgE antibody. Cytotoxic activity against L929 cells appeared in the culture supernatant of lung fragments 2 h after IgE receptor triggering and increased for up to 4 h. This cytotoxic activity was completely neutralized by anti-human TNF antibody. Northern blot analysis demonstrated that 1.8-kb TNF mRNA transcripts in sensitized lung fragments were expressed as early as 1 h after IgE receptor triggering and continued up to 4 h. Immunohistochemical analysis revealed TNF localization in tissue mast cells, alveolar macrophages, tissue macrophages, and bronchial epithelial cells. Double staining with anti-TNF antibody and alcian blue clearly identified that lung mast cells are one of the TNF-positive cell types in the pulmonary tissue. With immunoelectron microscopy, TNF immunoreactivity was detected in the rough endoplasmic reticulum and the perinuclear spaces in tissue macrophages, and in the cytosol and the perinuclear spaces in bronchial epithelial cells. In addition, IgE was detected on the cell surface of mast cells, tissue macrophages, and alveolar macrophages. These results suggest that TNF is released from mast cells and pulmonary macrophages through IgE receptor triggering and may play a key role in the allergic reaction in human airway.