Spontaneous pneumomediastinum complicating pneumonia in children infected with the 2009 pandemic influenza A (H1N1) virus

We report two occurrences of spontaneous pneumomediastinum (SPM) complicating pneumonia in Japanese children infected with the novel influenza A (H1N1) virus (IV). General practitioners especially should suspect possible SPM when examining and treating children with the novel influenza accompanied by status asthmaticus or wheezing. The presented patients illustrate the specific clinical and radiological signs associated with SPM complicating pneumonia in children infected with A(H1N1)v.

Antifouling properties of tough gels against barnacles in a long-term marine environment experiment

In the marine environment, the antifouling (AF) properties of various kinds of hydrogels against sessile marine organisms (algae, sea squirts, barnacles) were tested in a long-term experiment. The results demonstrate that most hydrogels can endure at least 2 months in the marine environment. In particular, mechanically tough PAMPS/PAAm DN and PVA gels exhibited AF activity against marine sessile organisms, especially barnacles, for as long as 330 days. The AF ability of hydrogels toward barnacles is explained in terms of an 'easy-release' mechanism in which the high water content and the elastic modulus of the gel are two important parameters.

Preparation and characterization of beta-tricalcium phosphate co-doped with monovalent and divalent antibacterial metal ions

Ag(+) and Zn(2+) or Cu(2+) ions were co-doped with beta-tricalcium phosphate (AgZn-TCP and AgCu-TCP), and their substitution models, antimicrobial activities, mechanisms and cytotoxicities were investigated. The lattice constants (a-axis and c-axis) of AgZn-TCP and AgCu-TCP decreased linearly with the amount of Zn(2+) or Cu(2+) ions up to 9.09 mol.%, which indicated that Ag(+) ions were doped at the Ca(4) site and a vacancy in the beta-TCP structure, and Zn(2+) or Cu(2+) ions were doped at the Ca(5) site. Antibacterial activities of AgZn-TCP and AgCu-TCP on Escherichia coli and Staphylococcus aureus were higher than those of Ag(+) ions-doped beta-TCP (Ag-TCP) and pure beta-TCP. These antimicrobial activities suggested that an interaction occurred between bacteria and Ag(+), Zn(2+) and Cu(2+) ions eluted from AgZn-TCP and AgCu-TCP and between bacteria and the free radicals generated by antibacterial agents or in bacterial cells. AgZn-TCP and AgCu-TCP can be used over long periods of time with high antimicrobial activity, because the rate at which Ag(+) ions are released from AgZn-TCP and AgCu-TCP is slower than that at which Ag(+) ions are released from Ag-TCP. However, it is necessary to determine the suitable amounts of Ag(+), Zn(2+) and Cu(2+) ions in AgZn-TCP and AgCu-TCP by considering both their antimicrobial activities and cytotoxicities, because beta-TCP doped with a large amount of these metal ions exhibits cytotoxicity. Furthermore, AgZn-TCP and AgCu-TCP are considered to be promising materials for use in various fields.

Functional interaction of HTLV-1 tax protein with the POZ domain of the transcriptional repressor BCL6

The Tax protein encoded by human T-cell leukaemia virus type 1 (HTLV-1) has a pivotal role in T-cell transformation by deregulating cellular signalling pathways. Using the yeast two-hybrid system to screen a human leukocyte cDNA library, we identified BCL6 (B-cell lymphoma 6) as a cellular protein, which interacts with Tax 1. The BCL6 gene encodes a sequence-specific transcriptional repressor that contains a conserved N-terminal poxvirus and zinc finger (POZ) repressor domain and a C-terminal Kruppel-like zinc finger DNA binding domain. Using both in vivo and in vitro methods, we demonstrate that the POZ domain of BCL6 is sufficient for its interaction with Tax 1. Using functional assays, we demonstrate that Tax 1 enhanced the repressive activity of BCL6 and increased the levels of apoptosis induced by BCL6 in osteosarcoma cells indicating that both proteins cooperate in vivo to cause a physiological affect. Furthermore, BCL6 recruited Tax 1 into punctate nuclear structures, which suggests that Tax 1 colocalizes with BCL6 in repressor complexes in vivo. BCL6 expression significantly downregulated both basal and Tax-induced nuclear factor-kappaB and long terminal repeat activation. This suggests that the expression of BCL6 in HTLV infected cells may contribute to the silencing of viral gene expression and to the long clinical latency associated with HTLV infection.

Brain-derived neurotrophic factor (BDNF) and set-shifting in currently ill and recovered anorexia nervosa (AN) patients

BACKGROUND

Studies of patients with anorexia nervosa (AN) have shown that they do not perform well in set-shifting tasks but little is known about the neurobiological correlates of this aspect of executive function. The aim of this study was to measure serum brain-derived neurotrophic factor (BDNF) and to establish whether set-shifting difficulties are present in people with current AN and in those recovered from AN, and whether serum BDNF concentrations are correlated with set-shifting ability.

METHOD

Serum BDNF concentrations were measured in 29 women with current AN (AN group), 18 women who had recovered from AN (ANRec group) and 28 age-matched healthy controls (HC group). Set-shifting was measured using the Wisconsin Card Sorting Test (WCST). Eating-related psychopathology and depressive, anxiety and obsessive-compulsive symptomatology were evaluated using the Eating Disorder Examination Questionnaire (EDEQ), the Hospital Anxiety and Depression Scale (HADS), and the Maudsley Obsessive-Compulsive Inventory (MOCI) respectively.

RESULTS

Serum BDNF concentrations (mean+/-s.d.) were significantly lower in the AN group (11.7+/-4.9 ng/ml) compared to the HC group (15.1+/-5.5 ng/ml, p=0.04) and also compared to the ANRec group (17.6+/-4.8 ng/ml, p=0.001). The AN group made significantly more errors (total and perseverative) in the WCST relative to the HC group. There was no significant correlation between serum BDNF concentrations and performance on the WCST.

CONCLUSIONS

Serum BDNF may be a biological marker for eating-related psychopathology and of recovery in AN. Longitudinal studies are needed to explore possible associations between serum BDNF concentrations, illness and recovery and neuropsychological traits.

Microwave surface-impedance measurements of the magnetic penetration depth in single crystal Ba1-xKxFe2As2 superconductors: evidence for a disorder-dependent superfluid density

We report high-sensitivity microwave measurements of the in-plane penetration depth lambda_{ab} and quasiparticle scattering rate 1/tau in several single crystals of the hole-doped Fe-based superconductor Ba(1-x)K(x)Fe(2)As(2) (x approximately 0.55). While a power-law temperature dependence of lambda_{ab} with a power approximately 2 is found in crystals with large 1/tau, we observe an exponential temperature dependence of the superfluid density consistent with the existence of fully opened two gaps in the cleanest crystal we studied. The difference may be a consequence of different levels of disorder inherent in the crystals. We also find a linear relation between the low-temperature scattering rate and the density of quasiparticles, which shows a clear contrast to the case of d-wave cuprate superconductors with nodes in the gap. These results demonstrate intrinsically nodeless order parameters in the Fe arsenides.

Possible phase transition deep inside the hidden order phase of ultraclean URu2Si2

To elucidate the underlying nature of the hidden order (HO) state in heavy-fermion compound URu(2)Si(2), we measure electrical transport properties of ultraclean crystals in a high field, low temperature regime. Unlike previous studies, the present system with much less impurity scattering resolves a distinct anomaly of the Hall resistivity at H;{*} = 22.5 T, well below the destruction field of the HO phase = or approximately 36 T. In addition, a novel quantum oscillation appears above a magnetic field slightly below H;{*}. These results indicate an abrupt reconstruction of the Fermi surface, which implies a possible phase transition well within the HO phase caused by a band-dependent destruction of the HO parameter.

Visceral obesity is associated with the metabolic syndrome and elevated plasma retinol binding protein-4 level in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is related to the increased prevalence of cardiovascular disease and metabolic syndrome (MS). A novel adipokine, retinol binding protein-4 (RBP4), was reported to be associated with insulin resistance and the prevalence of type 2 diabetes. To examine whether plasma RBP4 is associated with insulin resistance and MS development in OSAS, we measured plasma RBP4 levels in 181 Japanese men (24 healthy controls and 40 mild, 64 moderate, and 53 severe OSAS) of whom 26 had mild glucose intolerance with HbA1c < or = 6.0%. After a full polysomnography, blood was collected between 06:00 and 07:00 AM. Plasma RBP4 levels in moderate/severe OSAS patients were higher than in control subjects. Plasma RBP4 was not correlated with apnea variables, HOMA-IR, or blood pressure. However, it was positively correlated with visceral fat areas and plasma triglyceride levels. The prevalence of MS was higher in severe OSAS patients than in mild/moderate OSAS and control subjects. Plasma RBP4 was higher in OSAS patients with MS than in those without MS. This study indicates that plasma RBP4 is associated with dyslipidemia, but not with insulin resistance, glucose intolerance, or hypertension in patients with OSAS. Visceral obesity may play key roles in increasing the plasma RBP4 level and MS development in OSAS.

Peripheral administration of nesfatin-1 reduces food intake in mice: the leptin-independent mechanism

Nesfatin-1 is a novel satiety molecule in the hypothalamus and is also present in peripheral tissues. Here we sought to identify the active segment of nesfatin-1 and to determine the mechanisms of its action after peripheral administration in mice. Intraperitoneal injection of nesfatin-1 suppressed food intake in a dose-dependent manner. Nesfatin-1 has three distinct segments; we tested the effect of each segment on food intake. Injection of the midsegment decreased food intake under leptin-resistant conditions such as db/db mice and mice fed a high-fat diet. After injection of the midsegment, expression of c-Fos was significantly activated in the brainstem nucleus tractus solitarius (NTS) but not in the hypothalamic arcuate nucleus; the nicotinic cholinergic pathway to the NTS contributed to midsegment-induced anorexia. Midsegment injection significantly increased expression of proopiomelanocortin and cocaine- and amphetamine-regulated transcript genes in the NTS but not in the arcuate nucleus. Investigation of mutant midsegments demonstrated that a region with amino acid sequence similarity to the active site of agouti-related peptide was indispensable for anorexigenic induction. Our findings indicate that the midsegment of nesfatin-1 causes anorexia, possibly by activating POMC and CART neurons in the NTS via a leptin-independent mechanism after peripheral stimulation.

Microwave penetration depth and quasiparticle conductivity of PrFeAsO1-y single crystals: evidence for a full-gap superconductor

In-plane microwave penetration depth lambda_{ab} and quasiparticle conductivity at 28 GHz are measured in underdoped single crystals of the Fe-based superconductor PrFeAsO_{1-y} (T_{c} approximately 35 K) by using a sensitive superconducting cavity resonator. lambda_{ab}(T) shows flat dependence at low temperatures, which is incompatible with the presence of nodes in the superconducting gap Delta(k). The temperature dependence of the superfluid density demonstrates that the gap is nonzero (Delta/k_{B}T_{c} greater, similar1.6) all over the Fermi surface. The microwave conductivity below T_{c} exhibits an enhancement larger than the coherence peak, reminiscent of high-T_{c} cuprate superconductors.

Influence of parallel fiber-Purkinje cell synapse formation on postnatal development of climbing fiber-Purkinje cell synapses in the cerebellum

The climbing fiber (CF) to Purkinje cell (PC) synapse in the cerebellum provides an ideal model for the study of developmental rearrangements of neural circuits. At birth, each PC is innervated by multiple CFs. These surplus CFs are eliminated during postnatal development, and mono innervation is attained by postnatal day 20 (P20) in mice. Earlier studies on spontaneous mutant mice and animals with "hypogranular" cerebella indicate that regression of surplus CFs requires normal generation of granule cells and their axons, parallel fibers (PFs), and normal formation of PF-PC synapses. Our understanding of how PF-PC synapse formation affects development of CF-PC synapse has been greatly advanced by analyses of mutant mice deficient in glutamate receptor delta2 subunit (GluRdelta2), an orphan receptor expressed selectively in PCs. Deletion of GluRdelta2 results in impairment of PF-PC synapse formation, which leads to defects in development of CF-PC synapses. In this article, we review how impaired PF-PC synapse formation affects wiring of CFs to PCs based mostly on our data on GluRdelta2 knockout mice. We propose a new scheme that CF-PC synapses are shaped by the three consecutive events, namely functional differentiation of multiple CFs into one strong and a few weak inputs from P3 to P7, "early phase" of CF synapse elimination from P7 to around P11, and "late phase" of CF synapse elimination from around P12. Normal PF-PC synapse formation is required for the "late phase" of CF synapse elimination.

Quantum Hall transition in real space: from localized to extended states

Using scanning tunneling spectroscopy in an ultrahigh vacuum at low temperature (T=0.3 K) and high magnetic fields (B<or=12 T), we directly probe electronic wave functions across an integer quantum Hall transition. In accordance with theoretical predictions, we observe the evolution from localized drift states in the insulating phases to branched extended drift states at the quantum critical point. The observed microscopic behavior close to the extended state indicates points of localized quantum tunneling, which are considered to be decisive for a quantitative description of the transition.

[Treatment of a massive tracheal bleeding with percutaneous cardiopulmonary support]

A 69-year-old woman was admitted to our hospital with heart failure. Echocardiography demonstrated severe mitral valve regurgitation due to chordae rupture of the posterior mitral leaflet. Although she was intubated and ventilation was initiated, her condition did not improve. On the 17th hospital day, she was scheduled to undergo mitral valve plasty. After induction of anesthesia, massive bleeding occurred from the tracheal granuloma (diameter, 3 cm), which had developed at the tip of the tracheal tube, and the airway was obstructed. Emergency percutaneous cardiopulmonary support (PCPS) was then introduced. Thereafter, endoscopic hemostasis was performed, followed by the excision of the granulation tissue using a gastric fiberscope. After excising the tissue, the patient could be ventilated; therefore, she was weaned from PCPS. The maximum PCPS flow was 4.0 l/min, and it was conducted for a 210-minutes duration. Her respiratory condition improved, and she was weaned from the ventilator 3 days after surgery. Mitral valve plasty was performed 55 days after the first operation, and she was discharged from the hospital in good health.

Serum levels of P-selectin in men with high-functioning autism

Immune dysfunction has been proposed as a mechanism for the pathophysiology of autistic-spectrum disorders. The selectin family of adhesion molecules plays a prominent role in immune/inflammatory responses. We determined the serum levels of three types of soluble-form selectin (sP, sL and sE) in 15 men with high-functioning autism and 22 age-matched healthy controls by enzyme-linked immunosorbent assay. Levels of sP-selectin and sL-selectin were significantly lower in patients than in controls. Furthermore, sP-selectin levels were negatively correlated with impaired social development during early childhood.

Topical application of royal jelly has a healing effect for 5-fluorouracil-induced experimental oral mucositis in hamsters

The aim of this study was to evaluate the effects of bee products such as honey, royal jelly and propolis on 5-fluorouracil-induced experimental oral mucositis in hamsters. Oral mucositis was induced in hamsters through a combination of 5-fluorouracil and mild abrasions that were made on the cheek pouch. Honey, royal jelly and propolis were thereafter topically administered to the oral mucosa, and then the healing process was examined by measuring the size of the mucositis. Honey (1%, 10% and 100%) and propolis (0.3%, 1% and 3%) ointments did not reduce the size of the mucositis in comparison to the vaseline-treated control group. However, the royal jelly (3%, 10% and 30%) ointments significantly improved the recovery from 5-fluorouracil-induced damage in a dose-dependent manner. These results suggest the possibility that the topical application of royal jelly has a healing effect on severe oral mucositis induced by chemotherapy.

Paired stimulation study of the median nerve sensory action potential in diabetic patients

OBJECTIVES

Conventional nerve conduction studies (NCS) are not sensitive to detect mild diabetic neuropathy. In order to detect subtle changes, we compared the conventional NCS with the relative refractory period (RRP) measurement of the median sensory nerve action potential by a paired stimulation method.

METHODS

Subjects were 29 diabetic patients whose conventional NCS were all normal. They were divided into two groups: neurologically symptomatic and asymptomatic groups. Twenty-eight age-matched control subjects were also studied.

RESULTS

The RRP of the symptomatic diabetic patients (5.9 +/- 0.5 ms) and that of the asymptomatic patients (5.6 +/- 0.5 ms) was significantly longer than that of the control subjects (4.9 +/- 0.6 ms). There was no significant difference in RRP between the symptomatic and asymptomatic patients. This may be due to the fact that NCS reflects mainly large myelinated fiber function and early symptoms represent mainly thin myelinated or unmyelinated fiber function.

CONCLUSIONS

The RRP measurement could reveal some mild involvement of peripheral nerves undetectable by conventional NCS, even though they caused no clinical symptoms.

[Reoperation due to failure of a Freestyle bioprosthesis]

We report re-do aortic valve and ascending aorta replacements by using the valve-on-valve technique for primary tissue failure of a Freestyle bioprosthesis. A 74-year-old male, who had had a 25 mm Freestyle bioprosthetic valve implanted by the sub-coronary method 5 years previously for aortic valve regurgitation due to congenital bicuspid valve, was referred to our hospital for dyspnea and palpitation. He presented with heart failure secondary to aortic regurgitation due to primary tissue failure, and computed tomography demonstrated an enlarged ascending aorta (5 cm in diameter). The operative findings revealed that the Freestyle bioprosthetic valve had a leaflet tear at the left coronary cusp. We replaced the degenerated Freestyle bioprosthesis with a 19 mm Mosaic aortic bioprosthesis by using the valve-on-valve technique, and ascending aorta replacement was performed simultaneously. This technique can be useful for re-do surgery for degenerated stentless valves to avoid potential risks of complete excision of the bioprosthesis.

[Evaluation of a new portable device for measuring prothrombin time-internatinal normalized ratio; comparison between the conventional method and the new CoagCheck XS]

We evaluated a new portable device (CoaguCheck XS) for measuring the prothrombin time-international normalized ratio (PT-INR) in 63 patients after cardiac surgery, and compared the results with those of the conventional method. There was a good correlation between the PT-INR values measured conventionally and those obtained with the CoaguCheck XS. This new device was easy to use, data were obtained rapidly, and the results were reliable. The CoaguCheck XS will be particularly useful for outpatients. PT-INR self-management is expected to be introduced as soon as health insurance coverage is obtained.

[Anticoagulant and antiplatelet therapy for cardiac surgery]

Anticoagulants prevent the formation of harmful thrombi by decreasing the ability of the blood to clot. They are prescribed for a number of reasons, such as after replacement of a heart valve to prevent thrombosis or after myocardial infarction to prevent another infarct or stroke. However, there is an increased risk of severe bleeding among patients who are taking such medications. In order to optimize the therapeutic effect and avoid dangerous side effects like bleeding, careful monitoring is required during treatment, as directed by the 2006 American Heart Association (AHA)/American College of Cardiology (ACC) guidelines and the 2002-2003 Japanese guideline on anticoagulant therapy. Heparin is used in hospitals immediately before and after cardiac surgery, while oral medications like warfarin or aspirin are being adjusted. As oral anticoagulants are long-acting drugs, so these medications need to be stopped before elective surgery and the patient is switched to intravenous or subcutaneous shorter-acting heparin in hospital before the operation. However, heparin-induced thrombocytopenia (HIT) is a potentially life-threatening problem that is encountered in patients having cardiac surgery, and it is increasingly being recognized with the widespread use of heparin. The evidence suggests that heparin should not be used and that alternative anticoagulant therapy with one of the newer agents such as argatroban would be of benefit for avoiding harmful events.

[Unruptured aneurysm of the sinus of Valsalva associated with right ventricular outflow tract stenosis; report of a case]

A 51-year-old female was referred to our hospital for heart murmur and was diagnosed with right ventricular outflow stenosis by echocardiography. Six years later, follow-up echocardiogram revealed that the stenosis was caused by an aneurysm of the sinus of Valsalva (2 cm in diameter) originated from the right coronary sinus. Resection and patch closure of the aneurysm were carried out under complete cardiopulmonary bypass. The aneurysm was not associated with ventricular septal defect and was categorized as Sakakibara-Konno type I. Postoperative state was uneventful. Systolic murmur disappeared and pressure difference in the right ventricular outflow was normalized.

Comparison of image validity between cone beam computed tomography for dental use and multidetector row helical computed tomography

OBJECTIVES

To evaluate and compare the image validity of a cone beam CT machine for dental use (3DX) and the latest medical CT system, multidetector row helical CT (MDCT).

METHODS

A dried right maxilla of an Asian adult was used as a phantom. It was cut from the zygomatic process towards the midline, parallel to the midline plane, into eight slices of 2 mm thickness. This phantom was imaged with the 3DX and MDCT machines. Images were evaluated by comparing them with one selected bone slice from the phantom. In this comparison, two types of MDCT images were used: one with the window level (WL) and window width (WW) suitable for observing teeth (MDCT tooth image), and the other appropriate for observing bone (MDCT bone image). Three dentists and one radiographer then used our reported subjective five-level scale to evaluate and compare images generated by the two systems in terms of validity. Cancellous bone as well as enamel, dentin, pulp cavity, periodontal ligament space, lamina dura and overall impression were evaluated.

RESULTS

Statistically significant differences (P<0.05) were found for almost all observation items. Our subjective evaluation clarified that 3DX was superior to MDCT in terms of image validity. Few significant intra- or interevaluator errors were found.

CONCLUSIONS

Our subjective evaluation of image validity clarified 3DX as being superior to MDCT. Taken together with the low skin dose we previously reported for 3DX, the results demonstrate 3DX to be beneficial for imaging diagnosis of hard tissues in the maxillofacial region.

Molecular and cellular events in alcohol-induced muscle disease

Alcohol consumption induces a dose-dependent noxious effect on skeletal muscle, leading to progressive functional and structural damage of myocytes, with concomitant reductions in lean body mass. Nearly half of high-dose chronic alcohol consumers develop alcoholic skeletal myopathy. The pathogenic mechanisms that lie between alcohol intake and loss of muscle tissue involve multiple pathways, making the elucidation of the disease somewhat difficult. This review discusses the recent advances in basic and clinical research on the molecular and cellular events involved in the development of alcohol-induced muscle disease. The main areas of recent research interest on this field are as follows: (i) molecular mechanisms in alcohol exposed muscle in the rat model; (ii) gene expression changes in alcohol exposed muscle; (iii) the role of trace elements and oxidative stress in alcoholic myopathy; and (iv) the role of apoptosis and preapoptotic pathways in alcoholic myopathy. These aforementioned areas are crucial in understanding the pathogenesis of this disease. For example, there is overwhelming evidence that both chronic alcohol ingestion and acute alcohol intoxication impair the rate of protein synthesis of myofibrillar proteins, in particular, under both postabsorptive and postprandial conditions. Perturbations in gene expression are contributory factors to the development of alcoholic myopathy, as ethanol-induced alterations are detected in over 400 genes and the protein profile (i.e., the proteome) of muscle is also affected. There is supportive evidence that oxidative damage is involved in the pathogenesis of alcoholic myopathy. Increased lipid peroxidation is related to muscle fibre atrophy, and reduced serum levels of some antioxidants may be related to loss of muscle mass and muscle strength. Finally, ethanol induces skeletal muscle apoptosis and increases both pro- and antiapoptotic regulatory mechanisms.

Assessment of hemorrhage in pituitary macroadenoma by T2*-weighted gradient-echo MR imaging

BACKGROUND AND PURPOSE

Intratumoral hemorrhage occurs frequently in pituitary macroadenoma and manifests as pituitary apoplexy and recent or old silent hemorrhage. T2*-weighted gradient-echo (GE) MR imaging is the most sensitive sequence for the detection of acute and old intracranial hemorrhage. T2*-weighted GE MR imaging was used to investigate intratumoral hemorrhage in pituitary macroadenomas.

MATERIALS AND METHODS

Twenty-five consecutive patients who underwent total or subtotal resection of pituitary macroadenoma with heights from 17 to 53 mm, including 1 patient with classic pituitary apoplexy, underwent MR imaging before surgery, including T2*-weighted GE MR imaging. For histologic assessment of the hemorrhage in whole surgical specimens, we used hematoxylin-eosin staining.

RESULTS

T2*-weighted GE MR imaging detected various types of dark lesions, such as "rim," "mass," "spot," and "diffuse" and combinations, indicating clinical and subclinical intratumoral hemorrhage in 12 of the 25 patients. The presence of intratumoral dark lesions on T2*-weighted GE MR imaging correlated significantly with the hemorrhagic findings on T1- and T2-weighted MR imaging (P < .02 and <.01, respectively), and the surgical and histologic hemorrhagic findings (P < .001 and <.001, respectively).

CONCLUSION

T2*-weighted GE MR imaging could detect intratumoral hemorrhage in pituitary adenomas as various dark appearances. Therefore, this technique might be useful for the assessment of recent and old intratumoral hemorrhagic events in patients with pituitary macroadenomas.

Cysteinyl leukotrienes enhance tumour necrosis factor-alpha-induced matrix metalloproteinase-9 in human monocytes/macrophages

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) is an important enzyme responsible for airway remodelling. Monocytes/macrophages have a cysteinyl leukotriene 1 (cysLT1) receptor, but its function is poorly understood.

OBJECTIVE

To elucidate the function of the cysLT1 receptor of human monocytes/macrophages in MMP-9 production.

METHODS

We examined the effect of cysLTs (LTC4, -D4 and -E4) on TNF-alpha-induced MMP-9 production in THP-1 cells, a human monocytic leukaemia cell line and peripheral blood CD14+ monocytes/macrophages. In addition, we examined the effect of pranlukast, a cysLT1 receptor antagonist, on the enhancement of TNF-alpha-induced MMP-9 production by cysLTs.

RESULTS

ELISA revealed that LTC4 and -D4, but not -E4, enhanced TNF-alpha-induced MMP-9 production in THP-1 cells and peripheral blood CD14+ monocytes/macrophages. Real-time polymerase chain reaction demonstrated that LTC4 and -D4, but not -E4, increased MMP-9 mRNA expression induced by TNF-alpha in THP-1 cells. Moreover, we demonstrated that pranlukast completely inhibited the enhancement of TNF-alpha-induced MMP-9 production by LTC4 and -D4 in THP-1 cells and peripheral blood CD14+ monocytes/macrophages.

CONCLUSION

LTC4 and -D4 enhanced the TNF-alpha-induced MMP-9 production via binding the cysLT1 receptor in human monocytes/macrophages. Pranlukast inhibited the enhancements by LTC4 and D4.

Comparison of the efficacy of salmeterol/fluticasone propionate combination in Japanese and Caucasian asthmatics

INTRODUCTION

The effect of ethnicity on the efficacy of salmeterol (S)+fluticasone propionate (FP) has not been examined in Japanese and Caucasian asthmatics. In this study, the efficacy of combination treatment with S and FP from a single inhaler (SFC) was compared with concurrent treatment with S and FP administration from separate inhalers (S+FP) in Japanese and Caucasian asthmatics.

METHODS

This was a randomised, double-blind, crossover study in male and female Japanese (n=18) and Caucasian (n=17) asthmatics (50-100% predicted FEV(1); >35% reversibility in sGaw). Subjects received SFC (S 50 mcg/FP 250 mcg b.i.d.) and S+FP (S 50 mcg b.i.d.+FP 250 mcg b.i.d.) for 14 days. sGaw and FEV(1) were determined 0-12h after the first and last doses.

RESULTS

Treatment with both SFC and S+FP produced marked bronchodilation, which was maintained 0-12h after the first dose. Baseline sGaw and FEV(1) increased up to 51% and 180 mL, respectively, in Japanese subjects over 2 weeks of treatment, with similar improvements in Caucasian subjects. On Day 14 the 0-12h S+FP:SFC treatment ratios (90% CI) for sGaw AUC and peak were 1.05 (0.98, 1.12) and 1.05 (0.97, 1.14), respectively, in Japanese subjects, and 0.99 (0.92, 1.07) and 0.98 (0.89, 1.07), respectively, in Caucasian subjects, with no difference between the two ethnic groups.

CONCLUSIONS

The finding of a similar significant bronchodilator response in Japanese and Caucasian asthmatics following concurrent and combination treatment with salmeterol and FP suggests that the therapeutic response to these agents is comparable and independent of ethnicity in Japanese and Caucasian asthma patients.

Association of human herpesvirus 6 reactivation with the flaring and severity of drug-induced hypersensitivity syndrome

BACKGROUND

Drug-induced hypersensitivity syndrome (DIHS) is an adverse reaction with clinical signs of fever, rash and internal organ involvement. In the vast majority of patients in Japan, the causative drugs for DIHS are limited to the following eight: carbamazepine, phenytoin, phenobarbital, zonisamide, mexiletine, dapsone, salazosulfapyridine and allopurinol. The association of human herpesvirus (HHV)-6 reactivation with DIHS has been reported by various groups.

OBJECTIVES

To confirm the relationship between the flaring and severity of DIHS and HHV-6 reactivation.

METHODS

We evaluated 100 patients with drug rash and systemic symptom(s) caused by the drugs associated with DIHS. HHV-6 reactivation was examined by serological antibody assay and quantitative real-time polymerase chain reaction assay of serial serum samples.

RESULTS

Anti-HHV-6 IgG titres increased in 62 of 100 patients, 14-28 days after the onset of symptoms. These patients suffered from severe organ involvement and a prolonged course compared with 38 patients showing no reactivation of HHV-6. Significant amounts of HHV-6 DNA were detected in serum samples from 18 of the 62 patients. Flaring of symptoms such as fever and hepatitis was closely related to HHV-6 reactivation in these 18 patients. It should be emphasized that all five patients with fatal outcome and 10 patients with renal failure were in the HHV-6 reactivation group.

CONCLUSIONS

A combination of immunological reaction to a drug and HHV-6 reactivation results in the severe course of DIHS. The demonstration of HHV-6 reactivation is a useful marker of diagnosis as well as prognosis in DIHS.

Human serum paraoxonase concentration predicts cardiovascular mortality in hemodialysis patients

AIMS

Human serum paraoxonase (PON1) is associated with high-density lipoprotein, and inhibits oxidative modification of low-density lipoprotein. Therefore, PON1 is supposed to contribute to the prevention of atherosclerosis. We and other investigators have shown that the enzymatic activities and concentrations of PON1 were decreased in maintenance hemodialysis (HD) patients. However, the effect of PON1 status on the long-term outcome of HD patients has not been reported. In this study, we examined the association between baseline PON 1 status and cardiovascular mortality in an observation study of an outpatient HD population.

PATIENTS AND METHODS

The relation between baseline cardiovascular risk factors and clinical events was investigated, during 6 years of follow-up, in 81 HD patients (50 males and 31 females) whose enzymatic activities, concentrations and genetic polymorphisms of PON1 had been determined in a previous study.

RESULTS

During follow-up for 6 years, we recorded 42 deaths, including 24 fatal cardiovascular events. In univariate analyses, baseline PON1 concentration was associated with not only cardiovascular mortality (p < 0.005), but also all-cause mortality (p < 0.001) during the period of follow-up, as were age, preexisting cardiovascular disease (CVD) and hemoglobin concentration. In a multivariate Cox regression analysis, PON1 concentration retained significant associations with cardiovascular mortality (p < 0.05) and all-cause mortality (p < 0.005) even after correction of known risk factors for CVD or mortality in HD patients. Using Kaplan-Meier survival curves, we assessed the association between low and high concentrations of PON1 divided according to the median value (7.52 U/ml). Significantly increased cardiovascular mortality (log rank 6.125, p = 0.01) and all-cause mortality (log rank 7.113, p < 0.01) were detected in the patients with low PON1 concentrations.

CONCLUSIONS

These data suggest that low PON 1 concentration may be an independent predictor of cardiovascular mortality in maintenance HD patients.