Activation of Na+-independent Mg2+ efflux by 20-hydroxyeicosatetraenoic acid in rat renal epithelial cells

Renal epithelial cells may have Mg(2+) transport pathways that regulate intracellular free Mg(2+) concentration ([Mg(2+)](i)) and reabsorption into the body. In mag-fura 2 fluorescent measurement, extracellular Mg(2+) removal induced a Na(+)-independent [Mg(2+)](i) decrease. The [Mg(2+)](i) decrease was suppressed by methyl arachidonyl fluorophosphonate, a cytosolic and Ca(2+)-independent phospholipase A(2) (iPLA(2)) inhibitor, and bromoenol lactone, an iPLA(2) inhibitor, but it was not suppressed by a secretory phospholipase A(2) inhibitor. On the contrary, the [Mg(2+)](i) decrease was enhanced by the addition of exogenous arachidonic acid (AA). Next, we examined the effect of AA metabolite inhibitors on the [Mg(2+)](i) decrease. 17-octadecynoic acid inhibited the [Mg(2+)](i) decrease, but indomethacin and nordihydroguaiaretic acid did not. In the 17-octadecynoic acid-treated cells, 20-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoic acid (20-HETE) recovered the [Mg(2+)](i) decrease. Nicardipine inhibited both the basal and the 20-HETE-enhanced [Mg(2+)](i) decrease. These results suggest that 20-HETE is a key mediator in the activation of Na(+)-independent Mg(2+) efflux.

Modulation of TNF-alpha gene expression by IFN-gamma and pamidronate in murine macrophages: regulation by STAT1-dependent pathways

Aminobisphosphonates are drugs used in the treatment of hypercalcemia, Paget's disease, osteoporosis, and malignancy. Some patients treated with aminobisphosphonates have a transient febrile reaction that may be caused by an increased serum concentration of proinflammatory cytokines. Aminobisphosphonates induce the production of certain proinflammatory cytokines in vitro, especially in cells of monocytic lineage. A unique feature of aminobisphosphonates is that they bind the Vgamma2Vdelta2 class of T cells, which are found only in primates, and stimulate cytokine production. The effects of aminobisphosphonates on other cells, including macrophages, are incompletely understood. We show in this study that treatment of murine macrophages with pamidronate, a second generation aminobisphosphonate, induces TNF-alpha production. Furthermore, pretreatment of murine macrophages with pamidronate before stimulation with IFN-gamma significantly augments IFN-gamma-dependent production of TNF-alpha. This pamidronate-mediated augmentation of TNF-alpha production results in sustained phosphorylation of the tyrosine residue at position 701 of STAT1 after IFN-gamma treatment. Our data suggest that this sustained phosphorylation results from inhibition of protein tyrosine phosphatase activity. We also show that pamidronate treatment increases TNF-alpha production in vivo in mice. Pamidronate-augmented TNF-alpha production by macrophages might be a useful strategy for cytokine-based anticancer therapy.

Direct observation of slow molecular relaxation by high-resolution light scattering spectroscopy

We developed a novel dynamic light scattering system to observe elastic relaxation phenomena with hyper frequency resolution. The principle of the measurement is based on the theory, which describes the dynamic structure factor of fluid under the condition of the frequency dependent compressibility. The dynamic structure factor, which is usually composed of the Brillouin and Rayleigh triplet, is modulated and shows an additional central component that directly reflects the whole aspect of the relaxation. In the experiment, the output from a frequency-doubled cw-YAG laser was incident into the liquid sample and the power spectrum of the light scattered into the backward direction was analyzed by the optical beating spectroscopy technique. The sample is liquid acetic acid that is known to show a strong ultrasonic relaxation around 1 MHz due to the molecular association process. We could find in the observed spectrum, the central component introduced by the phenomenon, whose relaxation frequency and the strength can be obtained from the width and the intensity of the observed central peak, respectively. The results show very good agreement with those previously obtained by the conventional ultrasonic spectroscopy technique.

One day exposure to FGF-2 was sufficient for the regenerative repair of full-thickness defects of articular cartilage in rabbits

OBJECTIVES

Administration of fibroblast growth factor (FGF)-2 for 2 weeks induces a successful cartilaginous repair response in 5-mm full-thickness articular cartilage defects in rabbits. The purpose of this study was to investigate the effects of a short time exposure to FGF-2 on the repair of the defects.

METHODS

Five-mm-diameter cylindrical defects, which do not repair spontaneously, were created in the femoral trochlea of the rabbit knees. The defects were administered sterile saline or FGF-2 (150pg/h) via an osmotic pump for the initial 1 day, 3 days, or 2 weeks, and we assessed the FGF-2 action on the proliferation and migration of mesenchymal cells in the reparative tissue. Using a total of 126 rabbits, we performed three sets of experiments. We also studied the effect of FGF-2 on migration of marrow-derived mesenchymal cells in vitro.

RESULTS

FGF-2 treatment for 1 day or 3 days induced the sequential chondrogenic repair responses that led to successful cartilaginous resurfacing of defects within 8 weeks as well as the 2-week treatment did. We confirmed by a radioisotope study that FGF-2 injected was rapidly eliminated from the defects (a residual ratio of 50% within 30min). The effect of FGF-2 on cultured marrow-derived cells suggested that FGF-2 facilitated the mobilization and migration of replicating mesenchymal cells from bone marrow.

CONCLUSIONS

Only 1 day exposure to FGF-2 is sufficient for induction of the chondrogenic repair response in 5-mm-diameter full-thickness defects of articular cartilage in rabbits. FGF-2 stimulated the recruitment of mesenchymal cells into the defects, which was a limiting step for the induction of cartilage.

Amplification of the synovial inflammatory response through activation of mitogen-activated protein kinases and nuclear factor kappaB using ligation of CD40 on CD14+ synovial cells from patients with rheumatoid arthritis

OBJECTIVE

To determine the signal transduction pathways in CD14+ synovial cells from patients with rheumatoid arthritis (RA) after CD40 ligation, and to examine their role in amplifying synovial inflammation in affected joints.

METHODS

Expression of messenger RNA was analyzed using quantitative reverse transcription-polymerase chain reaction. Cytokines and chemokines were measured using enzyme-linked immunosorbent assay. Activation of kinases was detected using Western blotting. Nuclear translocation of NF-kappaB was examined using immunohistochemistry. CD14+ synovial cells were enriched using magnetic cell sorting. Fibroblast-like synoviocytes (FLS) were obtained by passaging primary synovial cell culture.

RESULTS

Stimulation of CD14+ synovial cells from RA patients by recombinant soluble CD154 (rsCD154) significantly induced expression of tumor necrosis factor alpha (TNFalpha), interleukin-1alpha (IL-1alpha), and IL-1beta. CD14+ RA synovial cells stimulated with rsCD154 plus interferon-gamma (IFNgamma) induced significantly higher production of IL-6, IL-8, and monocyte chemoattractant protein 1 by FLS compared with unstimulated CD14+ synovial cells, through TNFalpha-, IL-1alpha-, and IL-1beta-mediated pathways. Stimulation with rsCD154 plus IFNgamma induced the activation of ERK-1/2, p38 MAPK, and NF-kappaB. Specific inhibitors of MAPK/ERK-1/2 kinases and p38 MAPK significantly reduced the production of TNFalpha and IL-1beta by rsCD154 plus IFNgamma-stimulated CD14+ synovial cells, and also inhibited production of these cytokines by freshly isolated synovial cells from RA patients.

CONCLUSION

These data indicate that the CD40-CD154 interaction activates the ERK, p38, and NF-kappaB pathways in CD14+ synovial cells from RA patients to produce TNFalpha, IL-1alpha, and IL-1beta, which in turn amplifies inflammatory responses by stimulating FLS. Inhibition of the CD40-CD154 interaction or its signal transduction pathways would be a strong and efficient strategy for the management of synovial inflammation in RA.

Antioxidant effect of MCI-186, a new Free-Radical scavenger, on ischemia-reperfusion injury in a rat hindlimb amputation model

BACKGROUND

A newly synthesized free-radical scavenger, MCI-186 (3-methyl-1-phenyl-2-pyrazolin-5-1), was recently approved in Japan for treating acute brain infarction. The purpose of this study was to investigate whether or not MCI-186 is effective in reducing ischemia-reperfusion injury in the extremities.

MATERIALS AND METHODS

Warm ischemia was sustained for 4 hours. The animals were divided into 4 groups: (1) sham group, (2) control group (saline injection), (3) MCI group (MCI-186 injection), and (4) EPC group (EPC-K1 [(l-ascorbic acid 2-[3,4-dihydro-2, 5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl hydrogen phosphate] potassium salt], a hydroxyl-radical scavenger, injection). Wet and dry (W/D) weights of the gastrocnemius and tibialis anterior muscles, muscle contractile function, and serum levels of creatine phosphokinase (CPK), lactate dehydrogenase (LDH), glutamic oxaloacetic transminase (GOT), and mitochondrial glutamic oxaloacetic transminase (GOT-m) were measured after 24 h of reperfusion. The cytotoxic aldehydes malondialdehyde and 4-hydroxy-2-nonenal as indices of lipid peroxidation (LPO), and neutrophil-specific enzyme myeloperoxidase (MPO) as an index of neutrophil infiltration, were measured in the gastrocnemius muscle.

RESULTS

Contractile functions in the MCI and EPC groups were significantly better than in the control group. In the tibialis anterior muscle, the contractile function was better in the MCI group than in the EPC group. W/D ratios and serum levels of CPK, LDH, GOT, and GOT-m were lower in the sham and MCI groups than in the control group. Levels of LPO and MPO activity were significantly lower in the MCI and EPC groups than in the control group. Histological findings demonstrated that inflammatory tissue reactions rarely occurred in the MCI group.

CONCLUSION

MCI-186 is effective in preventing ischemia-reperfusion injury in extremities. MCI-186 seems to have promise as a therapeutic agent, because it prevents ischemia-reperfusion injury even in the tibialis anterior muscle, which contains fast-twitch glycolytic fibers, known to be very susceptible to ischemic insult.

Single nucleotide polymorphism of the MxA gene promoter influences the response to interferon monotherapy in patients with hepatitis C viral infection

The biological activity of interferon (IFN) is mediated by the induction of intracellular antiviral proteins, such as 2'-5' oligoadenylate synthetase, dsRNA-activated protein kinase and MxA protein. Among these, MxA protein is assumed to be the most specific surrogate parameter for IFN action. This study was performed to elucidate whether a single nucleotide polymorphism (SNP) (G/T at nt-88) in the promoter region of the MxA gene influences the response to IFN therapy in patients with chronic hepatitis C virus (HCV) infection. Polymorphisms of the MxA gene in 235 HCV patients were determined by polymerase chain reaction-restriction fragment length polymorphism. The frequency of SNP was compared between sustained-responders (n = 78) and nonresponders (n = 157), as determined by biochemical and virological responses to IFN. Multivariate analysis showed that among all patients, HCV genotype, HCV RNA level and the SNP of the MxA gene were independent and significant determinants of the outcome of IFN therapy [odds ratio 3.8 (95% confidence interval 2.0-7.0), P < 0.0001; 0.27 (0.15-0.50), P < 0.0001; 1.8 (1.0-3.4), P = 0.0464, respectively]. Furthermore, among patients with a low viral load (< or =2.0 Meq/mL), MxA-T-positive patients were more likely to show a sustained response compared with MxA-T-negative patients [2.87 (1.3-6.3); 62%vs 36%; P = 0.0075]. Our findings suggested that the SNP of the MxA gene is one of the important host factors that independently influences the response to IFN in patients with chronic HCV infection, especially those with a low viral load.

Serum nitric oxide (NO) levels in systemic sclerosis patients: correlation between NO levels and clinical features

Vascular damage in systemic sclerosis (SSc) may be a factor in the abnormal regulation of several vasoactive agents. It has been well confirmed that plasma endothelin-1, as a vasoconstrictive factor, is elevated in patients with SSc. However, it is still controversial whether the levels of serum nitric oxide (NO), a strong vasodilator, are increased or decreased in SSc patients compared to healthy donors. In this study, we measured the levels of serum NO metabolites in SSc patients and determined the contribution of the excessive production of NO synthase (NOS)-2 by skin fibroblasts to NO synthesis. Serum NO levels of 45 patients with SSc were significantly higher than those of 20 healthy volunteers. In addition, some clinical features of SSc (the extent of skin fibrosis, short disease duration, and the complication of active fibrosing alveolitis) were all correlated positively with the levels of NO metabolites in SSc patients. To evaluate the levels of NOS-2 produced by skin fibroblasts, skin fibroblast cultures were established from SSc patients and healthy volunteers. Reverse transcription-polymerase chain reaction indicated that NOS-2 mRNA was spontaneously expressed in cultured fibroblasts derived from SSc patients, but not in those derived from healthy normal controls. Immunohistochemical staining also showed that NOS-2 proteins were detected in SSc fibroblasts but not in normal fibroblasts. The production of NO by cultured fibroblasts was visualized directly by a reagent (DAF-2 DA) used for the fluorescent detection of NO. Cultured SSc fibroblasts were capable of NO synthesis in culture media containing L-arginine, whereas normal fibroblasts (with no expression of NOS-2) did not synthesize detectable NO. These observations indicate that NO production is increased markedly in early-stage diffuse cutaneous SSc patients with active fibrosing alveolitis, and that constitutive NOS-2 expression in SSc fibroblasts may contribute to increased NO production.

Angiotensin II in the lesional skin of systemic sclerosis patients contributes to tissue fibrosis via angiotensin II type 1 receptors

OBJECTIVE

Tissue fibrosis in systemic sclerosis (SSc) is attributed to excessive deposition of extracellular matrix components produced by fibroblasts in skin lesions. Angiotensin II (Ang II), a vasoconstrictive peptide, is reported to have profibrotic activity as a result of induction of the extracellular matrix. The aim of the present study was to examine the expression of Ang II and its type 1 (AT(1)) and type 2 (AT(2)) receptors in affected skin and dermal fibroblasts from patients with SSc and to study the role of Ang II in collagen production by SSc dermal fibroblasts.

METHODS

Levels of Ang II in sera from SSc patients and normal subjects were measured by a solid-phase immobilized-epitope immunoassay. Expression of angiotensinogen (Angt) in the skin was evaluated by immunohistochemistry. Expression of Angt, AT(1), and AT(2) in cultured dermal fibroblasts was analyzed by reverse transcription-polymerase chain reaction and immunohistochemistry. Levels of type I procollagen produced by cultured dermal fibroblasts were measured by enzyme-linked immunosorbent assay.

RESULTS

Serum Ang II levels in patients with diffuse cutaneous SSc were significantly higher than those in patients with limited cutaneous SSc and in healthy donors. Immunohistochemical and immunoblotting analyses showed that Angt was present in skin from SSc patients, but not in normal skin. Angt messenger RNA (mRNA) was expressed in fibroblasts from patients with diffuse cutaneous SSc who had high levels of serum Ang II, but not in normal fibroblasts. AT(1) mRNA expression was found in both SSc and normal fibroblasts, whereas AT(2) mRNA was found only in SSc fibroblasts. Exogenous Ang II augmented the production of type I procollagen and transforming growth factor beta1 by cultured fibroblasts via activation of AT(1).

CONCLUSION

Aberrant Ang II production may be involved in tissue fibrosis through excessive production of the extracellular matrix components in SSc dermal fibroblasts. This suggests that the use of AT(1) receptor antagonists may be a novel strategy for the treatment of tissue fibrosis in SSc patients.

Theophylline induces apoptosis of the IL-3 activated eosinophils of patients with bronchial asthma

In bronchial asthma, eosinophils are upregulated and their survival is suggested to be prolonged by the action of some cytokines such as Interleukin (IL)-3, IL-5 and granulocyte-macrophage colony-stimulating factor (GM-CSF). We find here that the survival of eosinophils in the peripheral blood of patients with asthma is correlated with the serum levels of IL-3 but not of IL-5 and GM-CSF. Interestingly, theophylline is revealed to induce apoptosis of the prolonged survival eosinophils by IL-3, as judged by morphological changes and nucleosomal DNA fragmentation. During the apoptosis, caspase-3 in eosinophils stimulated by IL-3 is activated by theophylline. The substrate of caspase-3, poly (ADP-ribose) polymerase (PARP), is cleaved in the eosinophils after theophylline treatment. These results suggest that theophylline is able to induce apoptosis of the IL-3 activated eosinophils in patients with bronchial asthma, and that its clinical effectiveness may be due to the reduction of inflammatory cells in the airway.

Increased CD40 expression in skin fibroblasts from patients with systemic sclerosis (SSc): role of CD40-CD154 in the phenotype of SSc fibroblasts

Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology that is characterized by tissue fibrosis, which may result from the activation of lesional fibroblasts exhibiting excessive production of extracellular matrix components. However, it has yet to be determined how SSc fibroblasts are activated. CD40 is a cell surface molecule expressed on various cells that is important for the response to activated T cells through CD154. CD40 mRNA was found to be constitutively expressed in both SSc and normal fibroblasts by reverse transcription PCR. Expression of CD40 protein was increased on SSc fibroblasts compared to normal fibroblasts as measured by flow cytometry. Ligation of CD40 by recombinant human CD154 (0.5-2 microg/ml) resulted in increased production of IL-6, IL-8, and monocyte chemoattractant protein-1 in SSc fibroblasts in a dose-dependent manner, whereas these phenomena were not shown in normal fibroblasts even with the addition of CD154. CD80, a costimulatory molecule, was also induced on SSc fibroblasts by CD40 ligation. In the present study, our findings suggest the possibility of a cell-mediated response between fibroblasts and T cells in the lesional skin of SSc patients. Since it is suggested that the CD40-CD154 system may play a crucial role in the aberrant production of immune mediators by SSc fibroblasts, blockage of CD40-CD154 may be a novel therapeutic strategy for SSc.

Gastric restitution is inhibited by dexamethasone, which is reversed by hepatocyte growth factor and rebamipide

BACKGROUND

Glucocorticoids have been shown to induce peptic ulcers, especially when co-administered with NSAIDs. Hepatocyte growth factor (HGF) plays a role in gastric ulcer repair, facilitating the restitution of gastric mucosal epithelial cells. HGF expression is induced by PGs in gastric fibroblasts. We hypothesized that dexamethasone (DEX) may inhibit PG production and HGF expression, thus inhibiting HGF-induced gastric epithelial restitution.

AIM

To investigate the effect of DEX on gastric restitution, using cultured gastric cells, the role of HGF in the restitution inhibited by DEX, and the effect of rebamipide on DEX- inhibited restitution.

METHODS

Human gastric fibroblasts were prepared from human stomach obtained at surgery; PGE2 and HGF is determined by ELISA; Restitution was assessed by the round wound restitution model, using coculture of gastric fibroblasts and epithelial cells; COX-2 and HGF mRNA were quantified by TaqMan RT-PCR system.

RESULTS

1. DEX inhibited HGF mRNA and COX-2 mRNA. Accordingly, it inhibited PGE2 and HGF release. 2. DEX inhibited the restitution of gastric cells. 3. The inhibition of restitution was reversed by HGF and rebamipide to the same extent. 4. Rebamipide induced PGE2 and HGF.

CONCLUSION

DEX inhibits restitution via HGF depletion, and rebamipide reverses the inhibited restitution by HGF induction.

Compression and stretching of the brachial plexus in thoracic outlet syndrome: correlation between neuroradiographic findings and symptoms and signs produced by provocation manoeuvres

In order to investigate the mechanism of nerve irritation in thoracic outlet syndrome (TOS), we studied 150 patients who presented with symptoms of neurologic TOS between 1985 and 1999. They first performed various provocative physical manoeuvres and then underwent injection of contrast medium into the supraclavicular part of the brachial plexus. Several of the provocative manoeuvres were then repeated and radiographs were again obtained. Based on the neuroradiographs, we identified three subsets of patients; those with only compression (type 1 TOS, n=27, 18%), those with combined compression and stretching (type 2 TOS, n=111, 74%), and those with only stretching (type 3 TOS, n=12, 8%). We were able to correlate the neuroradiological subsets with symptoms elicited by pre-radiographic provocative manoeuvres; in 92 patients (61%) these were elicited by traction manoeuvres. We conclude that stretching is an important factor of nerve irritation in TOS.

Unrelated donor bone marrow transplantation for acute mixed lineage (myeloid and B-lymphoid lineage) leukemia in an adult with Down syndrome

This article describes a rare case of bone marrow transplantation (BMT) from an unrelated donor (URD) in an adult Japanese male with Down syndrome (DS) diagnosed as having acute mixed lineage leukemia. Examination of peripheral blood demonstrated WBC 6.2 x 10(9)/l with 45.5% blasts at admission. Leukemic blasts with positive peroxidase stain, but negative periodic acid-Schiff stain comprised 91.6% on bone marrow specimen. Surface marker analysis of these blasts showed the following: CD3(-), CD5(-), CD7(-), CD10(+), CD19(+), CD13(+), CD14(-), CD33(+), CD34(+), CD41a(-), and CD56(-). Based on these data, he was diagnosed as having acute mixed lineage (myeloid and B-lymphoid lineage) leukemia. He achieved complete remission (CR) by lymphoid-oriented chemotherapy performed after ineffective myeloid-oriented therapy. After four courses of consolidation chemotherapy for lymphoid lineage blasts, recurrence due to proliferation of myeloblasts had occurred. Thereafter, a second CR was obtained by low dose cytosine arabinoside (AraC) therapy. As this patient was considered to have a high risk of relapse, we selected allogeneic BMT from URD. Severe stomatitis due to methotrexate (MTX) occurred probably due to altered pharmacokinetics usually observed in DS patients. Though acute graft-versus-host disease (GVHD) of systemic skin (grade II) and pneumonia were observed during neutropenia due to the post-conditioning regimen, he could be discharged from our hospital on the 135th day after BMT. On day 205 post-BMT, however, bronchiolitis obliterans (BO) occurred as a chronic GVHD disorder. Despite therapy with prednisolone and FK506, he died on day 400 post-BMT because of respiratory failure due to BO. In DS patients, superfluous toxicities due to MTX and AraC treatment have been reported, and these toxicities have been considered due to altered pharmacokinetics in patients with DS. This patient could tolerate the transplant conditioning regimen commonly used in patients without DS.

RhoA is associated with invasion and lymph node metastasis in upper urinary tract cancer

OBJECTIVE

To assess the roles of RhoA small GTPase (RhoA) in upper urinary tract cancer by analysing the mRNA and protein levels of RhoA.

PATIENTS AND METHODS

The mRNA and protein levels of RhoA in matched sets of tumour, non-tumour and metastatic lymph node tissues of surgical specimens were analysed in 47 consecutive patients with renal pelvic/ureteric cancer, using the polymerase chain reaction after reverse transcription and Western blotting. The relationship between mRNA and protein levels of RhoA in tumour tissues and the clinicopathological features of the patients was also assessed.

RESULTS

The mRNA levels of RhoA and RhoA protein were greater in tumour and metastatic lymph node tissues than in non-tumour tissues (all P < 0.001). The expression levels of RhoA mRNA and protein levels in primary tumours was related to poorly differentiated grade (both P < 0.05) and muscle invasion (P < 0.01 and < 0.001, respectively). Kaplan-Meier plots of survival in patients with low or high RhoA showed that high mRNA and protein levels were associated with a shorter disease-free (P < 0.01) and overall survival (P < 0.001). Multivariate analysis using the Cox proportional hazards model showed that a high RhoA protein level was an independent prognostic factor, second to stage, in disease-free and overall survival (both P < 0.05).

CONCLUSIONS

These findings suggest that RhoA is involved in the invasion and metastasis of upper urinary tract cancer, indicating that RhoA may be a useful prognostic factor in this disease.

Artificial inseminations with frozen semen and application of DNA fingerprint for parents/offspring conformation on Great Pyrenees

Frozen semen of Great Pyrenees, air-shipped from France, was artificially inseminated (AI) to two Great Pyrenees bitches. Blood LH and P concentrations and vulval width principally determined optimal breeding time of bitches. AI were performed on 17 to 21 days from the onset of estrous bleeding, and 25 days after final Al, pregnancy of one bitch, with two fetuses, was identified by ultrasound image diagnostic equipment. On 62 days, the bitch whelped one male pup and one female pup. Blood samples were obtained from four parents and offspring, and their DNA was extracted. DNA samples digested with four kinds of restriction endonucleases, and resulting fragmented DNA were used as test samples for DNA fingerprinting with Myo prove. As a result bands from pups, displayed by any enzyme, were inherited from either parent, and clear parent-offspring relationships were identified.

Use of microsatellite markers for parentage testing of two litters of beagles born after artifcial insemination with mixed fresh semen

This study was undertaken to determine if 20 kinds of microsatellite markers, which have already been reported, were useful for the parentage testing of 16 Beagle puppies born after artificial insemination using intentionally mixed semen from six male Beagles. Of the 20 kinds of markers used in this study, 17 kinds (the exceptions were CPH6, FH0020 and FH0419) produced 3 to 5 kinds of alleles, and using these markers, the parentage was finally established for all of the 16 puppies. These 17 kinds of markers showed sufficient amplification in PCR and had no non-specific PCR products or alleles with single-base-alterations, which makes them very useful as markers for identification of individual Beagles and useful for parentage testing.

Expression of hepatocyte growth factor and its receptor (c-met) in skin fibroblasts from patients with systemic sclerosis

OBJECTIVE

To determine the effect of excessive induction of hepatocyte growth factor (HGF)/c-met signaling in fibroblasts derived from patients with systemic sclerosis (SSc).

METHODS

Fibroblasts were obtained from skin of patients with SSc and healthy controls. The 2.4 kb interleukin 1alpha (IL-1alpha) cDNA was subcloned into pcDNA3 expression vector, which was stably transfected into normal fibroblasts by lipofection. HGF production in cultured fibroblasts was measured by ELISA. C-met protein (a receptor for HGF) in cultured fibroblasts was evaluated by immunocytochemistry using polyclonal anti-c-met antibody. Production of procollagen type I was estimated by an ELISA system using antibodies against procollagen type I C-peptide.

RESULTS

Cultured skin fibroblasts expressed mRNA and protein of HGF constitutively in both SSc and control cultures. However, HGF production in SSc fibroblasts was significantly higher than in normal fibroblasts. In both SSc and normal fibroblasts, HGF production was dose dependently increased by the addition of recombinant IL-1alpha. Immunocytochemical staining revealed that c-met was spontaneously expressed in SSc fibroblasts, whereas no expression of c-met was detected in normal fibroblasts. C-met mRNA was expressed in normal fibroblasts transfected with the IL-1alpha gene. Addition of recombinant HGF (100 ng/ml) to cultured SSc fibroblasts significantly decreased procollagen type I production.

CONCLUSION

High concentration of HGF inhibited collagen production in cultured fibroblasts derived from patients with SSc. Overexpression of HGF/c-met appears to be a biological feedback response to the fibrotic process of SSc, suggesting that the antifibrotic effect of HGF might be used as a novel strategy for treatment of SSc.

Leukotriene receptor antagonist, montelukast, can reduce the need for inhaled steroid while maintaining the clinical stability of asthmatic patients

BACKGROUND

Oral leukotriene receptor antagonists have been shown to have efficacy in chronic asthma.

OBJECTIVE

To determine whether the addition of montelukast could lead to a reduction in inhaled corticosteroid dose without a significant decrease in peak expiratory flow rate (PEFR).

METHODS

After a 4-week run-in period, 191 moderate-to-severe asthmatic patients whose asthma had been well controlled with daily inhaled corticosteroid therapy (beclometasone dipropionate 800 to 1600 micro g/day), were randomly assigned to one of two treatments - placebo (n = 98) or montelukast 10 mg once daily (n = 93) - for a 24-week, multicentre, double-blind, treatment period. At the beginning of the active treatment period, the daily dose of inhaled corticosteroid was halved in all of the patients. In addition, the inhaled corticosteroid dose was subsequently titrated every 8 weeks, based on PEFR, asthma symptoms and beta-agonist use.

RESULTS

After 8 weeks of a 50% reduction in inhaled corticosteroid use, morning PEFR increased by 5.3 +/- 32.3 L/min from baseline in patients receiving montelukast and significantly decreased by 6.9 +/- 29.0 L/min in those receiving placebo (P = 0.035). In addition, evening PEFR significantly decreased by 9.8 +/- 28.5 L/min (P = 0.003) in the placebo group, but was maintained in the montelukast group. In spite of a subsequent 50% reduction in the inhaled corticosteroid dose every 8 weeks, morning and evening PEFRs were maintained over the 24-week treatment period in the montelukast group; PEFR significantly decreased in the placebo group. There was a significant difference between the two groups with regard to morning PEFR, therapy score and asthmatic score at weeks 8, 16 and 24, as well as evening PEFR at week 8. However, the symptom scores were not significantly different between the two groups or within each group.

CONCLUSION

These data suggest that montelukast reduces the need for inhaled corticosteroids while maintaining asthma control over a 24-week period. Therefore, montelukast may be useful for long-term treatment in patients with asthma who require high doses of inhaled corticosteroids.

Increased IL-15 production of muscle cells in polymyositis and dermatomyositis

In polymyositis (PM)/dermatomyositis (DM), various cytokines, especially macrophage-derived cytokines such as IL-1alpha, IL-1beta and tumor necrosis factor (TNF)-alpha, are expressed in the inflammatory foci. We previously reported that IL-15, a novel cytokine with a biological activity similar to that of IL-2, is expressed in muscle cells in PM/DM. In the present study, we set out to investigate the regulation of IL-15 in cultured myoblasts. Myoblasts constitutively produced a low level of IL-15 and the production was augmented by stimulation with IFN-gamma, IL-1alpha, IL-1beta, TNF-alpha or lipopolysaccharide (LPS) in a dose-dependent manner. These stimuli also enhanced the expression of IL-15 mRNA. About 30-40% of IL-15 was detected intracellularly, while the rest was released into the culture supernatant. Immunohistochemical staining revealed that intracellular IL-15 was localized in the perinuclear area of the cytoplasm in the myoblasts. Despite the considerable amounts of intracellular IL-15, the myoblasts predominantly expressed authentic IL-15 mRNA isoform. This isoform generates IL-15 with long signal peptide preprotein, which is all to be secreted. The biological activity of IL-15 secreted from the myoblasts was examined using an IL-15-dependent murine T cell line, CTLL-2. Culture supernatants of the myoblasts induced a proliferative response of CTLL-2 and this was specifically inhibited by anti-IL-15 antibody. These results suggest that inflammatory stimuli induce the production of IL-15 in the muscle cells in PM/DM, and IL-15 may contribute to the immunopathogenesis by augmenting recruitment and activation of the infiltrating T cells. Blocking of IL-15 production might be of therapeutic value in PM/DM.

Structure of a quinohemoprotein amine dehydrogenase with an uncommon redox cofactor and highly unusual crosslinking

The crystal structure of the heterotrimeric quinohemoprotein amine dehydrogenase from Paracoccus denitrificans has been determined at 2.05-A resolution. Within an 82-residue subunit is contained an unusual redox cofactor, cysteine tryptophylquinone (CTQ), consisting of an orthoquinone-modified tryptophan side chain covalently linked to a nearby cysteine side chain. The subunit is surrounded on three sides by a 489-residue, four-domain subunit that includes a diheme cytochrome c. Both subunits sit on the surface of a third subunit, a 337-residue seven-bladed beta-propeller that forms part of the enzyme active site. The small catalytic subunit is internally crosslinked by three highly unusual covalent cysteine to aspartic or glutamic acid thioether linkages in addition to the cofactor crossbridge. The catalytic function of the enzyme as well as the biosynthesis of the unusual catalytic subunit is discussed.

Effect of endotoxin on P-glycoprotein-mediated biliary and renal excretion of rhodamine-123 in rats

The effects of Klebsiella pneumoniae endotoxin on the biliary excretion and renal handling of rhodamine-123 were investigated in rats at different times after intraperitoneal injection (1 mg/kg of body weight). The typical substrates for P glycoprotein, i.e., cyclosporine, colchicine, and erythromycin, inhibited the biliary clearance of rhodamine-123, whereas a substrate for organic cation transporter, cimetidine, did not inhibit clearance, suggesting that rhodamine-123 is transported mainly by P glycoprotein. The biliary, renal, and tubular secretory clearances of rhodamine-123 and the glomerular filtration rate significantly decreased 6 h after injection of endotoxin but returned to control levels by 24 h. These results suggest that endotoxin-induced decreases in P-glycoprotein-mediated biliary excretion and renal handling of rhodamine-123 were probably due to impairment of P-glycoprotein-mediated transport ability. Pretreatment with pentoxifylline (50 mg/kg) significantly inhibited endotoxin-induced increases in tumor necrosis factor alpha (TNF-alpha) levels in plasma, which ameliorated the endotoxin-induced reduction of the biliary excretion of rhodamine-123. It is likely that endotoxin-induced impairment of the transport of rhodamine-123 is caused, in part, by overproduction of TNF-alpha. The effect of endotoxin on the expression of P-glycoprotein mRNA in liver and kidneys of rats was investigated by using a reverse transcriptase PCR. The expression of Mdr1a mRNA in both liver and kidney decreased 6 h after endotoxin injection and returned to control levels after 24 h, whereas the expression of Mdr1b mRNA in liver increased at both times and that in kidney decreased at 24 h. These findings suggest that K. pneumoniae endotoxin dramatically decreases P-glycoprotein-mediated biliary and renal excretion of rhodamine-123 probably by decreasing the expression of Mdr1a, which is likely due to increased plasma TNF-alpha levels.

Effects of theophylline withdrawal in well-controlled asthmatics treated with inhaled corticosteroid

We examined effects of theophylline withdrawal in 17 adult asthmatics whose symptoms were well controlled under a treatment of a combination of theophylline and inhaled beclomethasone dipropionate (iBDP). We measured daily symptoms, daily peak flow values, spirometry, peripheral blood eosinophil count (EOS), and serum eosinophil cationic protein (sECP) at intervals of 1-3 weeks for 3 months after theophylline withdrawal. Twelve patients experienced exacerbation of asthma (exacerbation group), whereas the remaining 5 patients exhibited no symptoms (stationary group). In the exacerbation group, forced expiratory volume in 1 sec (FEV1) and percent vital capacity (% VC) gradually decreased until exacerbation of asthma, and the extent of these decreases within the first week after the withdrawal was greater compared with that at later than the third week. V25/HT decreased in both the exacerbation and stationary groups. In particular, the extent of the velocity of expiratory flow at 25% of the vital capacity/height (V25/HT) decrease in the exacerbation group was much greater than that of FEV1 or % VC in this group. Neither EOS nor sECP changed significantly during the clinical course in any patient. The rapid decrease in FEV1 and % VC after the withdrawal suggests that under treatment with iBDP, theophylline causes direct bronchodilating effects on smooth muscle, rather than anti-inflammatory effects. These results also suggest the importance of theophylline on peripheral as well as central airways.

Differential effect of phosphodiesterase inhibitors on IL-13 release from peripheral blood mononuclear cells

Increased cyclic AMP (cAMP)-phosphodiesterase (PDE) activity in peripheral blood leucocytes is associated with the immunological inflammation that characterizes allergic diseases, such as atopic dermatitis and allergic rhinitis. Recently, it has been found that IL-13 has similar biological functions to IL-4. The aim of this study was to investigate the possible involvement of cAMP-PDE activity on IL-13 release from peripheral blood mononuclears cells (PBMC) from atopic asthma patients. Phytohaemagglutinin (PHA)-induced IL-13 release from PBMC was concentration-dependently inhibited by rolipram, a type 4 PDE inhibitor, as well as by dibutyryl cAMP, a membrane-permeant cAMP analogue. However, theophylline, a non-specific PDE inhibitor, and cilostazol, a type 3 PDE inhibitor, failed to inhibit IL-13 release. The inhibitory effect of rolipram was enhanced by the addition of forskolin (10(-4) m), an adenylyl cyclase stimulator. PHA itself did not alter the intracellular cAMP level. Rolipram concentration-dependently increased cAMP level in PHA-stimulated PBMC, and this increase was synergistically facilitated by the addition of forskolin (10(-4) m). These results suggest that type 4 PDE inhibitors, alone or synergistically in combination with forskolin, inhibit PHA-induced IL-13 release from PBMC of atopic asthma patients by elevating intracellular cAMP concentrations. These inhibitors have the potential to exert an anti-inflammatory effect by inhibiting IL-13 production in allergic diseases such as atopic asthma.

Effect of perfusion during ischemia on skeletal muscle

BACKGROUND

Despite the established preservation method for major organs of perfusion followed by immersion at hypothermia, a standard preservation technique for skeletal muscle is still a matter of controversy. The purpose of this study is to examine the effect of perfusion on the preservation of skeletal muscle in amputated limbs.

MATERIALS AND METHOD

The rat hindlimb was amputated for perfusion with Euro-Collins (EC) or University of Wisconsin (UW) solution at different perfusion pressures (40 or 100 cm-gravity). After certain ischemic periods (4 or 5 h), the skeletal muscle viability was determined by measuring the tissue content of adenosine triphosphate (ATP).

RESULT

The UW solution perfusion group maintained better ATP levels than the EC solution group when the ischemic period was extended to 5 h. The perfusion pressure of 100 cm-gravity was more effective for preserving muscle viability than 40 cm-gravity with both EC and UW solutions.

CONCLUSION

UW solution might be adequate to preserve muscle viability and perfusion pressure is recommended at 100 cm-gravity rather than at minimal pressure (40 cm-gravity), which washes out stagnant blood.

Identification of receptor-binding sites of monocyte chemotactic S19 ribosomal protein dimer

The S19 ribosomal protein (RP S19) cross-linked homo-dimer attracts monocyte migration by binding to C5a receptor on monocytes (H Nishiura, Y Shibuya, T Yamamoto, Laboratory Investigation, 1998, 78:1615-1623). Using site-directed mutants of recombinant RP S19 and synthetic peptides mimicking RP S19 molecular regions, we currently identified the binding sites of the RP S19 dimer to the C5a receptor. The RP S19 dimer activated the receptor by a two-step binding mechanism as in the case of C5a. The first binding site was a basic cluster region containing a -Lys41-His42-Lys43- sequence. The second one was the -Leu131-Asp132-Arg133- moiety, localized 12 residues upstream from the COOH-terminal. The second binding triggered the chemotactic response. The first binding would have a role in achieving a high-binding affinity between the ligand and receptor. The first and second ligand-binding sites of C5a receptor seem to be shared by C5a and the RP S19 dimer, although overall homology between the amino acid sequences of these ligands is only 4%.

Endotoxin impairs biliary transport of sparfloxacin and its glucuronide in rats

The effect of endotoxin on glucuronidation and hepatobiliary transport of quinolone antimicrobial agents was investigated in rats using sparfloxacin and p-nitrophenyl glucuronide as model drugs. The biliary clearance experiments were performed 24 h after a single intraperitoneal injection of endotoxin (1 mg/kg). Endotoxin significantly delayed the disappearance of sparfloxacin from plasma and increased plasma concentration of its glucuronide after intravenous injection of sparfloxacin (10 mg/kg). Significant decreases in the systemic clearance of sparfloxacin and the biliary clearance of sparfloxacin and the glucuronide were observed. Endotoxin had no effect on in vitro glucuronidation activity using p-nitrophenol as a substrate. When p-nitrophenyl glucuronide (8 mg/kg) was administered in endotoxin-pretreated rats, significant decreases in the systemic clearance, biliary clearance and renal clearance of p-nitrophenyl glucuronide were observed. These findings suggest that endotoxin decreases the biliary excretion of sparfloxacin and its glucuronide probably due to impairment of their hepatobiliary transport systems and renal handling.

Induction of histamine release from rat peritoneal mast cells by histatins

Human salivary histatins (Hsts), which belong to a salivary polypeptide family, have potent antifungal activity against Candida albicans and Cryptococcus neoformans, and are expected to be useful as therapeutic reagents against Candida species. However, little is known about the effect of Hsts on host immune systems. Thus we conducted a series of in vitro experiments with rat mast cells to determine whether histatin 5 (Hst 5) or histatin 8 (Hst 8) has a histamine-releasing effect on mast cells. Both Hst 5 and Hst 8 induced histamine release from rat peritoneal mast cells in a dose-dependent manner (10(-9) to 10(-5) M). Hst 5 had a stronger releasing effect than Hst 8. The histamine release induced by Hst 5 (10(-6) M) was increased by the presence of 0.5 mM Ca2+, but decreased by 2mM Ca2+. Alternatively, the histamine release induced by Hst 8 (10(-6) M) was inhibited by the presence of Ca2+ (0.5 to 2 mM). These results suggest that Hsts have limited usefulness as therapeutic agents due to induction of histamine release from mast cells.

Open-wedge osteotomy of the proximal tibia with hemicallotasis

Conventional high tibial osteotomy for osteoarthritis of the medial compartment of the knee with closed-wedge or dome osteotomy (DMO) may produce shortening of the patellar tendon and loss of inclination of the proximal tibial plateau or of the offset of the tibial condyle relative to its bony axis. This can make subsequent total knee arthroplasty technically demanding.

We undertook a prospective study comparing these changes after DMO with those after using open-wedge osteotomy hemicallotasis (HCO). A total of 50 knees with arthritis of the medial compartment in 46 consecutive patients was randomly allocated to either DMO or HCO. There were no significant differences between the groups with regard to age, gender, femorotibial angle before operation or the angle of correction.

Radiological studies showed that HCO caused little change in the length of the patellar tendon or the inclination angle of the tibial plateau, while after DMO both gradually decreased. The degree of tibial condylar offset increased in both groups, but less so in the HCO group.

Open-wedge osteotomy of the proximal tibia with hemicallotasis

Conventional high tibial osteotomy for losteoarthritis of the medial compartment of the knee with closed-wedge or dome osteotomy (DMO) may produce shortening of the patellar tendon and loss of inclination of the proximal tibial plateau or of the offset of the tibial condyle relative to its bony axis. This can make subsequent total knee arthroplasty technically demanding. We undertook a prospective study comparing these changes after DMO with those after using open-wedge osteotomy hemicallotasis (HCO). A total of 50 knees with arthritis of the medial compartment in 46 consecutive patients was randomly allocated to either DMO or HCO. There were no significant differences between the groups with regard to age, gender, femorotibial angle before operation or the angle of correction. Radiological studies showed that HCO caused little change in the length of the patellar tendon or the inclination angle of the tibial plateau, while after DMO both gradually decreased. The degree of tibial condylar offset increased in both groups, but less so in the HCO group.

Canine parentage testing based on microsatellite polymorphisms

To establish an accurate method for parentage testing in dogs, microsatellite DNA repeat length polymorphisms were examined. We selected twenty microsatellite markers reported previously and examined their application for parentage testing in Beagles and Labrador Retrievers. Heterozygosity (He), Polymorphism Information Content (PIC), the probabilities of Paternity Exclusion (PE) and the combined PE were calculated from allelic frequencies of the markers. All markers amplified by polymerase chain reactions were polymorphic and many markers showed high He and PIC in the both breeds. The final combined PEs in Beagles and Labrador Retrievers were 0.999994 and 0.999920, respectively. The results suggest that the twenty markers can be applied for routine parentage testing in dogs.

Congestion of superior mesenteric veins and small bowel mucosal injury after endoscopic treatment of esophageal varices in patients with portal hypertension

We investigated treatment-induced changes in venous return from the small bowel and small bowel intestinal mucosal injury induced by the treatment of esophageal varices in patients with portal hypertension. A total of 14 patients (age 59.8+/-9.5 years, five women and 9 men) who received prophylactic treatment of esophageal varices between December 1998 and March 1999 were investigated. Diamine oxidase (DAO) activity was measured before and after treatment. Changes in blood flow of the portal and superior mesenteric veins were investigated by Doppler ultrasonography in six patients. A significant decrease in DAO activity was observed three days after treatment (11.5+/-1.6 units/liter prior to treatment versus 8.6+/-1.6 units/liter three days after treatment; P < 0.001). Decreases in superior mesenteric and portal venous flow velocity were observed in four and three patients, respectively. In two patients with an increase in the cross-sectional area of the superior mesenteric vein with delayed venous return, a marked decrease in DAO activity was observed three days after treatment. In patients with portal hypertension, rapid reduction of pooling of portal flow caused by the treatment of esophageal varices can induce transient congestion of the mesenteric venous system which can produce some small bowel mucosal injury.

Bifurcation of osteoclasts and dendritic cells from common progenitors

Osteoclasts and dendritic cells are derived from monocyte/macrophage precursor cells; however, how their lineage commitment is regulated is unknown. This study investigated the differentiation pathways of osteoclasts and dendritic cells from common precursor cells at the single-cell level. Osteoclastogenesis induced by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kappaB ligand (RANKL) or tumor necrosis factor-alpha (TNF-alpha) is completely inhibited by addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 at early stages of differentiation. GM-CSF-treated cells express both c-Fms and RANK and also low levels of CD11c and DEC205, which are detected on dendritic cells. Addition of GM-CSF also reduces expression of both c-Fos and Fra-1, which is an important event for inhibition of osteoclastogenesis. Overexpression of c-Fos by retroviral infection or induction in transgenic mice can rescue a failure in osteoclast differentiation even in the presence of GM-CSF. By contrast, differentiation into dendritic cells is inhibited by M-CSF, indicating that M-CSF and GM-CSF reciprocally regulate the differentiation of both lineages. Dendritic cell maturation is also inhibited when c-Fos is expressed at an early stage of differentiation. Taken together, these findings suggest that c-Fos is a key mediator of the lineage commitment between osteoclasts and dendritic cells. The lineage determination of osteoclast progenitors seen following GM-CSF treatment functions through the regulation of c-Fos expression.

Incident-angle dependence of the phase conjugate reflectivity by nonlinear piezoelectric interaction in PZT ceramics

The reflectivity of an acoustic phase conjugator by nonlinear piezoelectric interaction in PZT ceramics was measured as a function of the incident angle. The phase conjugator was designed as a solid block with a flat surface for the acoustic incidence from water. The phase conjugate reflectivity showed incident angle dependence, which is mainly determined by the transmissivity of the acoustic waves, together with some effects of anisotropy. The field-reconstructing ability of this phase conjugator was simulated for focused incident beams.

Abnormal nucleotide repeat sequence in the TGF-betaRII gene in hepatocellular carcinoma and in uninvolved liver tissue

Replication error (RER)-related genetic alterations are associated with a subset of hepatocellular carcinomas (HCCs) with multiple primary cancers. This study investigated whether mutations in the nucleotide repeats of three putative target genes of RER are associated with hepatocarcinogenesis. The genes examined were those encoding transforming growth factor beta type II receptor (TGF-betaRII), BCL-2-associated X protein (BAX), and insulin-like growth factor II receptor (IGF-IIR). Tumour and non-tumour hepatic tissues were examined in 48 HCC patients, 34 with solitary HCC and 14 who had double cancer with gastric cancer. Four double-cancer cases showed an abnormal signal in the single nucleotide repeat (A)10 of the TGF-betaRII gene. These four were among the six RER-positive cases in this series. The genotypes of the poly A tract of the TGF-betaRII gene in the liver tumour tissue of the four cases with an abnormal signal were (A)9/10, (A)9/10, (A)9/10, and (A)9/9. Five uninvolved liver tissue specimens from these four patients showed (A)9/10 and (A)9/9, (A)9/10, (A)10/10 and (A)9/9, respectively. The genotype in the stomach cancer specimens of these four patients was (A)10/10, indicating no germline mutation of the TGF-betaRII gene. There were no mutations in the nucleotide repeats of the BAX and IGF-IIR genes in any of the liver tissue specimens. Abnormality of the nucleotide repeat in the TGF-betaRII gene occurred in the uninvolved liver tissue as well as the HCC tissue in some HCC patients. Such genetic instability may be gene-specific and tissue-specific in carcinogenesis.

Adrenomedullin and proadrenomedullin N-terminal 20 peptide induce histamine release from rat peritoneal mast cell

Adrenomedullin (ADM)-induced histamine release from rat peritoneal mast cells was investigated. We compared the ability of full-length ADM to induce histamine release to the fragments ADM-(1-25) and ADM-(22-52), as well as proadrenomedullin N-terminal 20 peptide (PAMP). ADM (10(-8) to 10(-5) M) and PAMP (10(-8) to 10(-5) M) dose-dependently increased histamine release from peritoneal mast cell preparations. The effect of ADM-(1-25) was similar to ADM, whereas ADM-(22-52) did not show any effects. These data suggest the relative importance of the ADM C-terminal fragment, which contains a six-membered ring structure. Histamine release, induced by ADM, was significantly and dose-dependently inhibited by the addition of ADM-(22-52) (10(-5) M), Ca(2+) (0.5 to 2.0 mM), and benzalkonium chloride (3 to 7 microM), a selective inhibitor of Gi type G proteins. In contrast, PAMP (10(-5) M)-induced histamine release was not inhibited by Ca(2+). These results suggest that ADM induce histamine release via a putative ADM receptor in a manner sensitive to Gi-protein function and extracellular Ca(2+) concentration, and that PAMP might produce its effect by a different mechanism than ADM.

Post-ischemic administration of DY-9760e, a novel calmodulin antagonist, reduced infarct volume in the permanent focal ischemia model of spontaneously hypertensive rat

We assessed the effect of a novel calmodulin antagonist, DY-9760e (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate) in a spontaneously hypertensive rat (SHR) permanent focal cerebral ischemia. In experiment I, the left middle cerebral artery was permanently occluded in 62 SHRs. DY-9760e (0.5 mg kg(-1) h(-1)) or vehicle alone were administered continuously i.v. for 6 h, beginning 0, 30, or 60 min after the arterial occlusion. The infarct volume was measured 24 h of ischemia. In experiment II, the effect of DY-9760e on CBF was assessed in 10 SHRs. Administration without a delay resulted in a mean infarct volume of 166.7 +/- 21.0 mm3 (vehicle; n = 10) and 125.1 +/- 31.8 mm3 (DY-9760e; n = 9). Administration with a 30 min delay resulted in a mean infarct volume of 173.2 +/- 32.4 mm3 (vehicle; n = 12) and 143.3 +/- 35.3 mm3 (DY-9760e; n = 11). Dy-9760e significantly reduced the infarct under these conditions (p < 0.05). The administration with a 60 min delay failed to reduce the infarct. DY-9760e had no effect on the CBF. Continuous i.v. administration of DY-9760e reduced infarct volume in a SHR permanent focal ischemia without affecting ischemic CBF.

Proteasome inhibitor enhances growth hormone-binding protein release

We used murine Ba/F3 cells transfected with human growth hormone receptor (hGHR) cDNA to investigate the regulatory mechanisms of human growth hormone-binding protein (hGH-BP) release. The extracellular domain of hGHRs were cleaved and released as hGH-BPs (a soluble form of hGHR). The hGH-BP release was enhanced by phorbol 12,13-dibutyrate (PDBu), and suggested to be mediated by activation of PKC, the same as in human IM-9 cells. Thus, Ba/F3 cells have hGH-BP-releasing pathways similar to those of human cells. The proteasome inhibitors MG-132 and clasto-lactacystin beta-lactone also increased hGH-BP release from Ba/F3-hGHR cells, and MG-132 and PDBu synergistically increased hGH-BP release. The results obtained by using three PKC inhibitors Gö 6976, GF 109203X and Gö 6983 suggest that the enhancement of hGH-BP release by MG-132 and PDBu is mediated by different mechanisms probably involving different PKC isozymes.

Matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases in sputum from patients with bronchial asthma

To examine a possibility that matrix metalloproteinases (MMPs) participate in the pathogenesis of asthma and/or the development of asthma attack, we measured the concentrations of MMP-2, MMP-9, and their respective tissue inhibitors of metalloproteinases (TIMP)-2 and TIMP-1, in induced sputa collected from 28 patients with moderate to severe bronchial asthma. Specimens were collected during both the attack and the remission from 15 age- and sex-matched healthy control subjects. The concentration of MMP-9 was significantly (p < 0.05) higher in the patients, even during the remission, as compared to that in healthy controls. The concentrations of MMP-9 (p < 0.05) and its specific inhibitor TIMP-1 (p < 0.01), and MMP-2 (p < 0.01) in these patients during the attack were significantly higher than those in healthy controls. In these patients, the MMP-9 concentration was significantly higher (p < 0.05) during the attack than during the remission. These results suggest that MMPs and TIMPs may be involved in the pathogenesis of bronchial asthma, and that the increased MMP-9 might be involved in the development of attack in patients with chronic asthma.

Activated astrocytes with glycogen accumulation in ischemic penumbra during the early stage of brain infarction: immunohistochemical and electron microscopic studies

Brain infarction was induced in rats by injection of microspheres through the right internal carotid artery, and structural changes in the astrocytes were observed during the early period following the infarction. Necrotic foci, varying in size and shape, were found in the right hemisphere. After immunohistochemical staining for GFAP, GFAP-positive astrocytes in the perinecrotic area known as the ischemic penumbra had distinctly increased in number and size with elongation of cytoplasmic processes 3 days after infarction. Electron microscopic observation revealed that glycogen granules had markedly accumulated in the cytoplasm of astrocytes located in the ischemic penumbra 3 and 5 days after infarction. Seven days after infarction, however, the glycogen granules disappeared from the astrocytes. Intermediate filaments increasingly appeared in the protoplasmic astrocytes after 3 days and were abundant in the activated and hypertrophied astrocytes after 7 days. As a result of our present study, we conclude that: (1) the function of glucose uptake from blood vessels was not impaired in the astrocytes under hypoxic conditions; (2) the astrocytes actively ingested blood glucose through the endothelial cells and accumulated it as glycogen for activation of their functions, and the cell volume increased under hypoxic conditions; (3) the depression of energy metabolism and the decrease in the uptake of energy sources in the nerve cells promoted glycogen accumulation in the astrocytes under hypoxic conditions; (4) intermediate filaments (GFAP filaments) increased in number, coincident with the activation and enlargement of the astrocytes; and (5) protoplasmic astrocytes were transformed into fibrous astrocytes in the ischemic penumbra of the brain infarction.