Effect of 6-fluoro-8-methoxy quinolone (AM-1155) against chronic airway infection with Pseudomonas aeruginosa in a rat model

We studied the effect of AM-1155, a newly developed quinolone, against chronic airway infection with Pseudomonas aeruginosa using a previously described rat model. AM-1155 (25 mg/kg) or ciprofloxacin (25 mg/kg) or saline (controls) were injected s.c. for 14 days (from day 4 to day 17) after the inoculation of agar beads containing P. aeruginosa. The number of viable cells of intrapulmonary P. aeruginosa, histological findings of the lungs and immunoglobulin levels of serum and bronchoalveolar lavage fluid were examined in rats 11 and 18 days after the treatment. The findings indicated that the number of viable cells of P. aeruginosa in lungs was significantly decreased in the AM-1155- or ciprofloxacin-treated group compared with the non-treated control group. Histological examination in the non-treated control group showed hyperplasia of bronchus-associated lymphoid tissue as well as cellular infiltration in airways, but not prominently in the AM-1155- or ciprofloxacin-treated group. The IgG and IgA levels in serum and bronchoalveolar lavage fluid were significantly lower in the AM-1155- and ciprofloxacin-treated groups than in the control group. These in-vivo effects of AM-1155 were comparable to those of ciprofloxacin. These findings suggest that treatment with AM-1155 and ciprofloxacin suppressed excessive immune responses, preventing progression of airway damage in the chronic infectious state.

Isolated collagen IV retains the potential to form an 18-nm sided polygonal meshwork of the lamina densa

Polygonal meshworks were revealed in the aggregates reconstituted from isolated collagen IV as well as in the lamina densa of mouse pancreas by the quick-freezing and deep-etching technique. Collagen IV solution with acetic acid from the bovine lens capsules and that isolated from the pepsin-solubilized fraction of human placenta reconstituted polygonal meshworks, which were dimensionally similar to the meshwork seen in the lamina densa of mouse pancreas. The average lengths between branching points in the lamina densa, and the meshworks of collagen IV derived from the bovine lens capsules and from the human placenta were 20.1 +/- 7.7 nm (mode = 18 nm), 21.6 +/- 11.3 nm (mode = 14 nm), and 21.6 +/- 9.0 nm (mode = 18 nm), respectively. These observations suggest that collagen IV can, in the absence of other macromolecules including laminins, comprise a skeletal meshwork similar in dimensions to that of the lamina densa.

Responses of monkeys with pollinosis to two major allergens of Japanese cedar pollen

We examined the responses of two Japanese monkeys with pollinosis to two major allergens (Cry j 1 and Cry j 2) of Japanese cedar pollen. The two monkeys (A and B) had specific IgE antibodies to the allergens and showed a strong positive reaction to both of them in the intradermal test. In the histamine release test with peripheral blood mononuclear cells (PBMC), monkey A showed a typical pattern similar to that seen in human patients, while monkey B released a low level of histamine. The proliferative response of PBMC to both allergens in monkey A was weak, but was typical in monkey B. From clinical as well as immunological points of view, these monkeys may be a suitable animal model for Japanese cedar pollinosis in humans.

[Accuracy of three-step diagnosis in discriminating subtypes of acute ischemic stroke]

The aim of this study is to evaluate the accuracy of three-step diagnosis in discriminating subtypes of acute ischemic stroke. A total of 120 consecutive patients with first-ever ischemic stroke, admitted to one general hospital, were prospectively studied. In the first step (within 24 hours of clinical onset), the first diagnosis was made according to clinical symptoms and signs, and patients were subdivided into four groups according to the classification of Oxfordshire Community Stroke Project: lacunar infarcts (LACI), total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI), and posterior circulation infarcts (POCI). In the second step (24 hours to 72 hours from the onset), neuroimaging diagnosis was performed by CT and/or MRI. Four lesion sites were classified: 1) small subcortical infarction < or = 1.5 cm in diameter in the perforating artery territory (SSI), 2) supratentorial cortical or striatocapsular infarction (CI), 3) low-flow infarction (LFI) which includes centrum semiovale infarct and internal junctional infarct, and 4) posterior circulation infarction other than SSI (PI). In the third step, etiological diagnosis was made by examination including trans-thoracic echocardiography and MRA (3-D, PC). In accordance with the TOAST Study, the presumed stroke mechanism was categorized as either small-vessel occlusion (lacune), cardioembolism (CE), large-artery atherosclerosis (LAA), or others. The majority of patients with TACI, PACI or POCI showed the corresponding lesions on CT or MRI, while only 69% of LACI patients demonstrated SSI. Seventy-five percent of patients with TACI were categorized as CE in the third diagnosis, while the etiology of the patients with PACI was either CE or LAA in equal numbers. Only 60% of LACI patients were classified as lacune and 21% of them as LAA. Patients with LACI but classified as LAA usually had atypical clinical symptoms (e.g. monoparesis) and lesions other than SSI. The positive predictive value (PPV) of lacune in the combination of LACI and SSI was 0.75. Eighty-two percent of patients with CE had atrial fibrillation (af), which was the most frequent cardioembolic source. When patients with TACI or PACI had af, the PPV of CE was 0.93, but when they did not, the PPV of LAA was only 0.68. The etiology of POCI was variable. In conclusion, the agreement of the three-step diagnosis is considerable, but more rigorous clinical examination is needed for some clinical groups (POCI and LACI) and the etiological diagnosis of LAA.

Serum vitamin K level and bone mineral density in post-menopausal women

OBJECTIVE

Vitamin K is known to influence bone metabolism by facilitating the synthesis of osteocalcin (BGP). The bone mineral density decreases drastically after menopause. We investigated the relationship of bone mineral density, vitamin K levels and other biological parameters of bone metabolism in post-menopausal women.

METHODS

Serum levels of vitamin K, BGP and other markers of bone metabolism were measured in 71 post-menopausal women (19 with reduced bone mineral density and 52 with normal bone density), and 24 women with climacteric symptoms receiving hormone replacement therapy (HRT), (6 with reduced bone mineral density and 18 with normal density).

RESULTS

In the first group, women with reduced bone mineral density showed lower levels of vitamin K1 and K2 than those with normal bone mineral density. In the other group, the level of BGP decreased but levels of vitamin K showed no increase during HRT.

CONCLUSION

The present findings suggested that vitamin K was related to post-menopausal bone mineral loss.

Increased Fas antigen on T cells in multiple sclerosis

Programmed cell death of antigen specific T cells (apoptosis) may be an important process in the pathogenesis of autoimmune diseases such as multiple sclerosis (MS). Fas antigen was recognized as an apoptosis-related antigen. To investigate Fas antigen in multiple sclerosis (MS), we measured the expression rate of Fas antigen and activation markers on T cells in peripheral blood (PB) of 19 MS patients, 18 controls and in cerebrospinal fluid (CSF) of nine MS patients by flow cytometry. The positive rate of Fas antigen in MS patients was higher than that of healthy controls in PB. In patients with MS, the expression rates of Fas antigen and activation markers were higher in CSF than in PB. The above findings suggest that there is acceleration or impairment of apoptosis on activated T cells in MS.

Bronchiolar disease in rheumatoid arthritis

The pulmonary manifestations of rheumatoid arthritis (RA) include bronchiolar diseases such as follicular bronchiolitis (FB) and bronchiolitis obliterans (BO). In this study, we investigated the clinical and pathologic features of FB and BO, as well as the effect of erythromycin (EM) on these diseases. The subjects included 15 RA patients with biopsy-proven bronchiolar disease (eight with FB, seven with BO). None of the patients had Sjögren's syndrome. Eleven patients (73%) had chronic sinusitis, and 14 (93%) had a chronic cough with sputum. Bacterial culture of sputum was positive in 50% and 71% of the FB and BO patients, respectively. High-resolution computed tomography (HRCT) revealed small nodular shadows in the centrilobular regions (FB and BO), patchy areas of low attenuation (BO), and peribronchial thickening (FB and BO). Eleven patients who received EM therapy showed a significant improvement of symptoms. In addition, none of the 15 patients died of the bronchiolar disease during follow-up. In conclusion, RA patients with FB or BO basically have a chronic clinical course with main complaint of productive cough, and EM may be useful for the management of these diseases.

Regulation of T cell apoptosis via T cell receptors and steroid receptors

Less than 5% of immature CD4/CD8 double-positive (DP) thymocytes are positively selected to survive and differentiate into single-positive CD4 and CD8 T cells, while self-reactive DP thymocytes undergo apoptosis (negative selection). Both positive and negative selection events are active processes that involve signaling through the T cell receptors (TCRs) and through some accessory molecules. The two events differ quantitatively in the strength of the interaction between TCR and peptide/major histocompatibility complex molecules. We established an in vitro model of positive selection that can be analyzed quantitatively. Positive selection is likely to inhibit glucocorticoid-induced apoptosis in DP thymocytes. Proper crosslinking of TCR together with CD4, CD8, or LFA-1 inhibits the death, and its inhibitory activity is mimicked by proper combinations of ionomycin, a calcium ionophore, and phorbol myristate acetate (PMA), a protein kinase C (PKC) activator. The drug concentrations are within narrow ranges, and are lower than those which are required for the proliferation of mature T cells. Transient stimulation with the combinations of ionomycin and PMA induces differentiation and commitment of isolated DP thymocytes to the CD4 or CD8 T cell lineage in suspension cultures. The level of PKC activity appears to determine the lineage to commit. Functional mature T cells are induced from the committed cells upon secondary stimulation. Activation of calcineurin, a Ca2+/calmodulin-dependent protein phosphatase, also appears to be essential for positive selection as well as for the inhibition of glucocorticoid-induced apoptosis. Negative selection and the regulation of mature T cell apoptosis through TCR and steroid receptors are also discussed.

[Bronchiolitis obliterans preceding rheumatoid arthritis: effect of clarithromycin]

A 62-year-old man was referred to our department because of exertional dyspnea and a 6-year history of coughing and sputum production. He had never smoked, and had had an operation for chronic paranasal sinusitis. Coarse crackles and rhonchi were audible over both lower lung fields. The cold hemagglutinin titers were high. pulmonary function tests showed airflow obstruction, and a sputum culture revealed Hemophilus influenzae A chest X-ray film and a CT scan showed diffuse micronodular shadows in the centrilobular regions, mild ectasis of bronchioles mainly in the lower lung fields, and mild hyperinflation. A specimen of lung tissue was obtained by thoracoscopic biopsy, and histologic examination showed bronchiolitis obliterans, with bronchiolar narrowing or obliteration due to submucosal fibrosis and inflammation. Rheumatoid arthritis was diagnosed 14 months after the operation. The patient was treated with clarithromycin for 3 years. Respiratory symptoms were relieved and pulmonary function gradually improved.

[Fulminant interstitial pneumonia associated with polyarteritis nodosa]

A 54-year-old man was referred to our hospital because of fever, abdominal pain, hematemesis, and dyspnea on exertion. Laboratory examination on admission revealed elevations of WBC count and CRP. a low serum complement level, hypoxemia, and microhematuria. A chest X-ray film and a CT scan showed bilateral interstitial pneumonia and cardiomegaly. Angiography showed microaneurysms in peripheral branches of the superior mesenteric artery, the hepatic artery, and the right renal artery. Examination of a specimen of the right quadriceps muscle revealed arteritis with fibrinoid necrosis in a small artery, which was consistent with polyarteritis nodosa (PN). A specimen obtained by transbronchial lung biopsy before treatment showed interstitial mononuclear cell infiltration and edema. PN with interstitial pneumonia was diagnosed and the patient was treated with 1 g of methylprednisolone for 3 days, followed by 60 mg of prednisolone and 100 mg of cyclophosphamide daily. The interstitial pneumonia progressed. Despite a second trial of steroid pulse therapy in addition to mechanical ventilation and various kinds of antibiotics, the patient died of respiratory failure on the 35th hospital day. A specimen obtained by transbronchial lung biopsy 3 days before death revealed proliferation of fibroblasts, mononuclear cell infiltration in the interstitium, and hyaline membrane formation in air spaces. No evidence of infection was found. Interstitial pneumonia associated with PN had been considered to be quite rare, but recently some cases resembling the present case have been reported. We believe that interstitial pneumonia associated with PN might not be rare, and the present case shows that it can be fulminant.

Intracerebral expression of gonadotropin-releasing hormone and growth hormone-releasing hormone is delayed until smoltification in the salmon

A developmental strategy was employed to investigate the functional assembly of neuropeptidergic systems in the migratory species of chum salmon Oncorhynchus keta. Using immunocytochemistry we have demonstrated that different groups of gonadotropin-releasing hormone- (GnRH)- and growth hormone-releasing hormone- (GHRH)-synthesizing neurons emerged according to very different developmental timetables. From the eye pigmentation stage (23 +/- 2 days after fertilisation (DAF)) through to the pre-smoltification stage (136 DAF), salmon-GnRH neurons originating from the olfactory placodes remained restricted to the extracerebral course of the terminal nerve. At the climax of smoltification (downstream migration 167 DAF), basal forebrain and midbrain GnRH neurons with elaborate neurite outgrowths in the brain and the pituitary became detectable. The GnRH neuroanatomical organization in the post-smoltification stage (197 DAF) was similar to that in the smoltification stage (167 DAF). In contrast to the case for other teleosts, chicken-GnRHII neurons were not found in the midbrain but were localized along the medial regions of the olfactory nerve. Growth hormone-releasing hormone immunoreactivity in the olfactory apparatus (21 DAF), and fibers along the basal telencephalon and hypothalamus and in the pituitary were observed during early embryogenesis (51 DAF) and in cells in the preoptic area on 167 DAF. The intracerebral expression of GnRH and GHRH was not detected until the peak of smoltification, which coincided with a peak in thyroid hormones, and precisely with downstream migratory behavior.

[A case of neuroborreliosis with unilateral radiculoneuropathy and elevated serum antibodies for Borrelia garinii and Borrelia afzelii]

A 24-year-old male patient was admitted to our hospital because of dysesthesia and weakness of the right leg. Six weeks before admission he traveled to southern China. A week later he noticed multiple papules with itching on his right leg that were suspected to be insect bites. Four days later numbness of the right leg developed. Then he began to limp because of the leg weakness. Two weeks before admission severe pain in the right leg developed. On admission neurological examination revealed hypesthesia, muscle weakness and atrophy, areflexia, radicular pain and Lasègue sign of the right leg, and patchy hypesthesia of the left leg. The cranial nerves were intact, and meningeal signs were negative. Complete blood counts and serum biochemistry were unremarkable except for eosinophilia and mild elevation of IgE. A test for antinuclear antibody was positive. Cerebrospinal fluid was normal. Nerve conduction study and sural nerve biopsy showed multifocal severe axonopathy. Although antibody for Borrelia burgdorferi sensu stricto was negative, antibodies for B. garinii and for B. afzelii were positive in serum immunoblotting. Neurological symptoms improved after administration of intravenous ceftriaxon following oral doxycycline. In Japan, this is the second case of neuroborreliosis not due to B. burgdorferi sensu stricto. To test antibodies for B.garinii and for B. afzelii is recommended in patients with suspected neuroborreliosis.

Novel polymorphisms and haplotypes in the human coagulation factor XIII A-subunit gene

Novel polymorphic sites within the coding region of the human coagulation factor XIII A-subunit (F13A) gene and their haplotypic combinations with the other polymorphic sites thus far reported are presented. Polymorphic bands were detected in exons 2, 5, 8, 12 and 14 by using single strand conformational polymorphism analysis and antithetic forms of the polymorphic exons were linked with each other, cosegregating as distinct sequence haplotypes. In Finnish, German, and Russian populations a total of 18 haplotypes were observed of possible 72 haplotypic combinations of the 5 exons. Ten of the haplotypes detected were found to have no novel mutations but to be only combinations of preexisting mutations. No tightly associated combinations in pairwise comparisons between antithetic forms of the polymorphic exons were observed, indicating that there may be recombinational hotspots within the F13A gene region.

A chondroitin sulfate/keratan sulfate proteoglycan, PG-1000, forms complexes which are concentrated in the reticular laminae of electric organ basement membranes

Previously, we identified PG-1000 as part of a disulfide-linked complex of two large proteoglycans (PG-1000 and the beta component) and three smaller proteins purified from the extracellular matrix of elasmobranch electric organ (Iwata and Carlson, 1991, J. Biol. Chem. 266: 323-333). PG-1000 is a chondroitin sulfate/keratan sulfate proteoglycan with a molecular mass of about 1.2 x 16(6) daltons. When visualized in the electron microscope, PG-1000 has the typical "bottle-brush" appearance expected for a proteoglycan with an average total length of about 345 nm and about 20 chains of approximately 110 nm (Carlson and Wight, 1987, J. Cell Biol. 105: 3075-3086). Using immunocytochemical methods, we now demonstrate that PG-1000 is a component of the interstitial extracellular matrix of the electric organ. PG-1000 immunoreactivity is found throughout the interstitial matrix, but it is highly concentrated in that region of the matrix immediately adjacent to the basal lamina, the reticular lamina. The reticular and basal laminae together form the basement membrane. PG-1000 immunoreactivity is especially apparent on basal laminae that surround nerve fibers and nerve terminals. When the disulfide-linked PG-1000 complexes are purified and examined in the electron microscope following rotary shadowing, they appear as bottle-brush structures which are often attached at a central region and radiate like spokes of a wheel. These aggregates contain two to six proteoglycan monomers. We hypothesize that the PG-1000 complexes are disulfide-stabilized parts of an extended network of linked proteoglycans in the reticular lamina.

Modulation of carbachol-induced [Ca2+]i oscillations by Ca2+ influx in single intestinal smooth muscle cells

1. Oscillations of cytosolic Ca2+ concentration ([Ca2+]i) evoked by carbachol (CCh; 2 microM), a muscarinic agonist, were detected as oscillatory changes of muscarinic receptor-coupled cationic current (Icat) in guinea-pig ileal smooth muscle cells by the whole cell patch-clamp technique. 2. Reduction of extracellular Ca2+ from 2 mM to 0.2 or 0.05 mM, during CCh-induced Icat oscillations, caused them to disappear or to decrease markedly in frequency. A return to 2 mM Ca2+ concentration restored the initial Icat oscillations. 3. Application of nifedipine (1-3 microM) or D600 (2-5 microM) to block the voltage-gated Ca2+ channel (VGCC) decreased the frequency of the ongoing Icat oscillations in the cells held at -20 mV, but it was without effect in cells held at -60 mV. 4. Displacement of the holding potential of -20 mV to -60 mV to deactivate VGCC produced a decrease, an increase or no noticeable change in the frequency of the Icat oscillations in different cells. Displacement to 20 mV to inactivate VGCC invariably produced a decrease in the frequency. In nifedipine-treated cells, the Icat oscillations varied in frequency voltage-dependently in a reverse and linear way within the range -80 to 40 mV. 5. Application of thapsigargin (1 or 2 microM), an inhibitor of Ca(2+)-ATPase in the membrane of internal Ca2+ stores, caused CCh-induced Icat oscillations to disappear with a progressing phase during which their amplitude, but not frequency, declined. 6. The results suggest that membrane Ca2+ entry has a crucial role to play in regulation of the frequency of CCh-induced [Ca2+]i oscillations in addition to persistence of their generation, and that the effect is brought about by a potential mechanism independent of Ca2+ store replenishment. They also provide evidence that two types of Ca2+ permeant channels, VGCC and an as yet unidentified channel, are involved in the Ca2+ entry responsible for modulation of [Ca2+]i oscillations.

Differential induction of helper and killer T cells from isolated CD4+CD8+ thymocytes in suspension culture

Thymocytes of T cell receptor transgenic mice with nonselecting and RAG-2 -/- backgrounds were developmentally arrested at the CD4+CD8+ stage before positive selection. These thymocytes underwent lineage commitment upon transient stimulation with a combination of ionomycin, a calcium ionophore, and phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, in suspension culture. The effective drug doses were limited within narrow ranges and much lower than those which induce proliferation of mature T cells. The doses corresponded to those which inhibit glucocorticoid-induced apoptosis in these thymocytes. CD4 lineage commitment required longer duration, higher intensity of the stimulation, or both, than CD8 lineage commitment. Functional helper T cells (Th1 and Th2) were induced from the CD4 lineage-committed cells upon secondary stimulation with a combination of ionomycin and PMA followed by lymphokine treatment. Cytotoxic T cells were induced from the CD8 lineage-committed cells upon incubation with concanavalin A and irradiated splenic dendritic cells, but not with the combination of ionomycin and PMA. These results indicate that positive selection is mimicked by the pharmacological stimulation in the absence of other cell types, but that final maturation of CD8 T cells may require a different signal.

Myoglobin inhibits proliferation of cultured human proximal tubular (HK-2) cells

Following nephrotoxic injury, renal repair is dependent on tubular regeneration. In the case of myoglobinuric acute renal failure (ARF), persistence of myoglobin within tubular cells, or sublethal injury sustained at the height of exposure to it, might retard this process. To test this hypothesis, a human proximal tubular cell line (HK-2) was cultured for 24 hours in the absence or presence of clinically relevant myoglobin concentrations (0.5, 1, 2, 4 mg/ml). Immediately following myoglobin removal, lethal cell injury (vital dye uptake), lipid peroxidation, and DNA damage (alkaline unwinding assay) were assessed. The extent of cell proliferation was estimated over the next four days by a tetrazolium based (MTT) assay and by determining total intracellular LDH. Myoglobin's effects on protein and DNA synthesis were also assessed (35S-methionine and bromodeoxyuridine incorporation, respectively). Myoglobin induced dose-dependent lipid peroxidation (malondialdehyde generation) and cell death (up to 80% vital dye uptake with the 4 mg/ml challenge). Although 1 mg/ml myoglobin caused no cell death, it induced nearly complete growth arrest. This lasted for approximately three days following myoglobin removal from the media. Neither of two control proteins (albumin; lysozyme) nor a second nephrotoxin (gentamicin; 1 mg/ml) reproduced this effect. The 1 mg/ml myoglobin challenge caused an 80 to 90% depression in protein and DNA synthesis. It also induced significant DNA damage, as assessed by the alkaline unwinding assay (P < 0.01). Iron chelation therapy (deferoxamine) mitigated myoglobin-induced cell killing. However, its addition following myoglobin loading worsened HK-2 outgrowth by exerting a direct anti-proliferative effect. These results indicate that: (1) sublethal myoglobin toxicity can induce transient proximal tubular cell growth arrest, potentially slowing recovery from ARF; (2) this effect correlates with, and could result from, heme-induced DNA damage and a blockade in DNA/protein synthesis; and (3) deferoxamine can inhibit proximal tubular cell proliferation. This possibility needs to be considered in designing clinical trials with DFO for myohemoglobinuric ARF.