Biomedical subjects

K Yamanaka

Publications and source records attributed to K Yamanaka.

At least 19 recordsLinked to original sources

PubMed2006

Topical suplatast tosilate (IPD) ameliorates Th2 cytokine-mediated dermatitis in caspase-1 transgenic mice by downregulating interleukin-4 and interleukin-5.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by elevated serum levels of IgE. AD is associated with Th2 cytokines including interleukin (IL)-4, IL-5, IL-13 and IL-10. Systemic administration of suplatast tosilate (IPD) is currently used to treat Th2 cytokine-mediated AD. OBJECTIVES: To evaluate the effect of topical IPD on skin lesions of AD using a genetically engineered AD mouse model (K14/caspase-1 transgenic mouse: KCASP1Tg). METHODS: IPD ointment (3%) and white petrolatum (WP) were applied to KCASP1Tg mice every other day from 6 to 14 weeks after birth. Histopathological analysis of skin lesions and measurement of mRNA expression of cytokines in skin lesions and spleen cells were carried out. We also compared changes in serum parameters between IPD-treated and WP-treated KCASP1Tg mice. RESULTS: WP-treated mice developed dermatitis at 8 weeks after birth. However, skin lesions in IPD-treated mice were limited. Histopathologically, skin lesions in WP-treated KCASP1Tg mice showed marked inflammatory changes with increased mast cell infiltration. However, mice treated with IPD showed minimum skin lesions with scarce mast cell infiltration. WP-treated KCASP1Tg mice had significant elevation in the serum levels of histamine, IgE and IL-18 as compared with IPD-treated KCASP1Tg mice. mRNA expression of IL-4 and IL-5 in the skin lesions from WP-treated KCASP1Tg mice was significantly higher than in those from IPD-treated mice. In the spleen, the expression of IL-4, IL-5 and interferon-gamma was significantly increased in WP-treated KCASP1Tg mice as compared with their IPD-treated counterparts. CONCLUSIONS: This study shows that topical therapy with IPD inhibits the expression of IL-4 and IL-5 and ameliorates skin manifestations in an AD mouse model, suggesting the potential usefulness of topical IPD for the treatment of AD.

Administration, Topical↗

PubMed2005

Relationship between muscle strength in various isokinetic movements and kick performance among soccer players.

AIM: The present study was carried out to examine relationships between muscular strength and ball velocity with respect to 3 different approach angles and focussing on both the kicking leg and the supporting leg among soccer players of different skill levels. METHODS: Fourteen university soccer players were divided into 2 groups (superior group, average group), and kicked the ball with maximal effort towards a target 15 m away. The angles of approach to the stationary ball varied in 3 directions (free, 1.57, 2.36 rad to the kick direction). Mean ball velocity and the success rate of striking the target with the ball were measured. Maximal isokinetic and concentric muscular strength was measured in terms of motions of the knee Ext/Flex, hip Ext/Flex and hip Abd/Add using an isokinetic dynamometer. RESULTS: The mean ball velocity at free and 1.57 rad approach angles related significantly with hip Add but not with knee Ext strength for the kicking leg. In contrast, the ball velocity at an approach angle of 2.36 rad significantly correlated with knee Ext and hip Flex of the kicking leg. Although ball velocity at the free and the 1.57 rad approach angles showed no relation to strength of the supporting leg, the ball velocity at the 2.36 rad approach angle showed a significant relationship with knee Flex, hip Ext and hip Abd strength of the supporting leg. Furthermore, the superior group had more strength variables related to performance than the average group. CONCLUSIONS: Different approach angles would alter the requirement on muscle strength potential of both kicking and supporting leg during kicking. Especially an angled approach to the kick direction could require greater hip extension and abduction strength on the supporting leg for a higher capability for stabilizing body balance. Besides, skill level may alter the importance of muscle strength requirement to kick performance.

Adult↗

PubMed2004

Irreducible lateral dislocation of the proximal interphalangeal joint--a case report.

We present a rare case of a lateral dislocation of the proximal interphalangeal joint that required open reduction. During an operation, we found the collateral ligament and the capsule interposing into the joint space. After reducing the soft tissue and reproducing the collateral ligament with a suture anchor, sufficient joint stability and full range of motion was achieved.

Collateral Ligaments↗

PubMed2004

The effects of Hochu-ekki-to in patients with atopic dermatitis resistant to conventional treatment.

Hochu-ekki-to is one of Kampo formulas containing Astragalus root, liquorice, jujube, ginseng, white Atractylodes rhizome, fresh ginger and Chinese angelica root. This formula has been identified as an effective drug to improve the function of digestive systems and to strengthen defensive systems against many kinds of infections. We examined serum IgE levels and eosinophils before and after the administration of Hochu-ekki-to in patients with recalcitrant atopic dermatitis. The increased numbers of eosinophils was statistically decreased after 3 months' use of this formula. Serum IgE levels showed a tendency to decrease after the administration of this substance.

Adolescent↗

PubMed2004

Diet and Japanese herbal medicine for recalcitrant atopic dermatitis: efficacy and safety.

We have been utilizing Kampo, a Japanese herbal medicine, together with lifestyle advice, for recalcitrant atopic dermatitis. To estimate the safety and efficacy of the treatment, we administered Kampo formulas to patients in whom conventional treatment failed to improve symptoms, along with dietary advice recommending traditional Japanese food. The therapeutic effects of Kampo formulas were assessed in 95 patients with recalcitrant atopic dermatitis who consulted our clinic from January to June, 2000. The overall result was 'markedly effective" in 19 patients (20%), "moderately effective" in 33 (35%), "slightly effective" in 36 (38%) and "ineffective" in four (4%). Three patients dropped out of the study. No adverse reactions in laboratory data were noted in examined patients. The most commonly used formula was Hochu-ekki-to containing Astragalus root, liquorice, jujube, ginseng, white Atractylodes rhizome, fresh ginger and Chinese Angelica root. Diet and Japanese herbal medicine are thought to be useful as an alternative therapy of intractable atopic dermatitis.

Adolescent↗

PubMed2003

Diaphragmatic hernia resulting from injury during microwave-assisted laparoscopic hepatectomy.

A 31-year-old woman underwent microwave-assisted laparoscopic hepatectomy of the left lateral segment for focal nodular hyperplasia on January 14, 1998. On September 9, 1998, she felt continuous left abdominal pain and was admitted to our hospital for further examination. An upper gastrointestinal series showed converging folds of the greater curvature of the upper third of the stomach and craniad displacement of this portion. Thoracic magnetic resonance imaging showed herniation of the stomach into the pleural cavity. The patient was referred to our department, where she underwent surgery for a diaphragmatic hernia. The fundus of the stomach had escaped into the left pleural cavity through a defect in the diaphragm near where laparoscopic hepatectomy had been performed. The stomach was returned to the peritoneal cavity and the defect sutured. The patients postoperative course was uneventful. Although diaphragmatic hernia after laparoscopic surgery is a rare complication, with the performance of more advanced laparoscopic procedures and the use of higher-technology tissue-destruction/hemostatic devices such as the microwave coagulator, more caution should be observed to prevent injury to adjacent organs such as the diaphragm.

Abdominal Pain↗

PubMed2003

Induction of cutaneous delayed hypersensitivity reactions in mice sensitized with intragastrically administered hapten: activation of Langerhans cells in the sensitization and elicitation phases.

BACKGROUND: As seen in atopic dermatitis, allergic diseases often produce lesions both in the gastrointestinal tract and the skin, suggesting the involvement of an immunological relationship between the two organs in the pathogenesis. OBJECTIVES: To study the role of gastric and epidermal Langerhans cells (LCs) in the sensitization and elicitation phases, respectively, of cutaneous delayed-type hypersensitivity (DTH) reactions to intragastrically administered hapten. METHODS: BALB/c mice, which were subjected to intragastric administration of trinitrochlorobenzene 5 days previously, received an elicitative challenge of the same hapten to the ear skin. Sections of the ear were immunostained for CD4 and CD8. Epidermal sheets of the ear and epithelial sheets of the forestomach were immunostained for I-A and observed under a confocal laser scanning microscope. RESULTS: Cutaneous DTH reactions were induced in mice, as demonstrated by an increase in ear thickness and a prominent infiltration of CD4+ and CD8+ lymphocytes at 24-36 h after the elicitative challenge. In the elicitation phase, epidermal LCs showed a significant increase in size, indicating in vivo activation, at 24 h. In the sensitization phase, gastric LCs increased in size at 2 h, became round at 6 h, and decreased in number at 24 h, possibly representing the sequential events of LC activation and migration from the epithelium. CONCLUSIONS: The present study demonstrated that gastric LCs and epidermal LCs were activated in vivo in the sensitization and elicitation phases, respectively, of cutaneous DTH reactions in orally sensitized mice.

Animals↗

PubMed2003

[Surgical treatment of Budd-Chiari syndrome associated with superior vena cava obstruction; report of a case].

We report a case of a 37-year-old woman with Budd-Chiari syndrome who underwent a radical treatment. She had had ascites, general edema, and liver dysfunction for 5 years. Preoperative cineangiogram showed a membranous stenosis at the retrohepatic inferior vena cava and the catheter could not be advanced into superior vena cava. In the operation, obstructed superior vena cava was identified. Membranous tissue at retrohepatic inferior vena cava was removed, and patch cavoplasty was performed under circulatory arrest through Senning procedure. Postoperative cavogram revealed good patency of inferior vena cava and her symptoms were disappeared.

Adult↗

PubMed2003

Hochu-ekki-to suppresses development of dermatitis and elevation of serum IgE level in NC/Nga mice.

The Japanese herbal medicine Hochu-ekki-to (Chinese name: Bu-Zhong-Yi-Qi-tang) is composed of ten species of medical plants and is used for many therapeutic purposes such as recovery from weakness, dysfunction of the digestive system and fatigue. In certain groups of patients with intractable atopic dermatitis this prescription has shown clinical effectiveness. We examined the ability of Hochu-ekki-to to inhibit dermatitis and IgE production in atopic NC/Nga mice. Oral administration of Hochu-ekki-to suppressed spontaneous dermatitis and serum IgE levels in NC/Nga mice. This finding provides evidence that Hochu-ekki-to may have immunological effects in atopic dermatitis.

Administration, Oral↗

PubMed2003

[Aortic regurgitation caused by prolapsed noncoronary cusp associated with dissecting aortic aneurysm treated by placing a prosthetic graft onto the anulus: report of a case].

A 70-year-old man with severe aortic regurgitation (AR) associated with dissecting aortic aneurysm underwent a radical operation. AR was thought to be due to dilated sinotubular junction and prolapsed noncoronary cusp caused by dissecting flap extended into the sinus of Valsalva. At operation, the noncoronary cusp was slightly prolapsed into the left ventricle, but all cusps were seemed to be thin and pliable. An isolated "tongue shaped" graft was placed onto the anulus of the noncoronary cusp, and a 26 mm Woven Dacron graft was used to replace the ascending aorta. Postoperative angiogram showed mild AR and improved left ventricular (LV) function. This procedure was effective to repair AR caused by prolapsed noncoronary cusp without elongation or thickening of the valve.

Aged↗

PubMed2002

[Assessment of saphenous vein grafts flow by Doppler echocardiography].

In an effort to evaluate flow characteristics of the saphenous vein grafts (SVG) after coronary artery bypass grafting, we performed duplex scanning of SVG which were anastomosed to the left anterior descending artery in 12 patients, and compared those indexes with 34 internal thoracic artery grafts (ITAG). The SVG were observed with a 7.5 MHz duplex scanner through the anterior intercostal space. The diameter of the vessel, systolic peak velocity, and diastolic peak velocity were recorded in both groups, and systolic flow volume, diastolic flow volume, and velocity ratio were calculated. The systolic and diastolic peak velocity of SVG were predominantly lower than ITAG. No difference in the diameter and flow ratio could not be demonstrated between 2 groups. The flow volume of SVG were also predominantly lower than that of ITAG throughout cardiac cycle. This study reveals that advanced stenotic change were caused in the SVG group and suggest the occurrence of vein grafts disease long after coronary artery bypass grafting.

Aged↗

PubMed2001

Flow fractionation of microparticles under a dielectrophoretic field in a quadrupole electrode capillary.

A technique of fractionation for microparticles was proposed that utilized a unique combination of a dielectrophoretic (DEP) field generated by a quadrupole electrode and a laminar flow in a capillary of 82.5 microm in radius. The fabricated capillary possessed four platinum wires in its inside wall as a quadrupole electrode. In a nonuniform electric field generated by the quadrupole electrode, microparticles, such as polystyrene and carbon, in water experienced DEP forces in the radial direction. When a sample solution was pumped in, an ideal laminar flow perpendicular to the DEP force was formed inside the capillary. The microparticles dynamically migrated by the DEP force across the laminar flow while they were carried by the flow. A theoretical model taking the DEP force and the laminar flow pattern into account predicted the elution profiles of the single microparticles quantitatively. The elution times of the microparticles depended on the dielectric properties and the sizes of the microparticles, as well as the voltage and frequency of the applied alternating current.

Journal Article↗

PubMed2001

Lower excitability of the corticospinal tract to transcranial magnetic stimulation during lengthening contractions in human elbow flexors.

The purpose of this study was to characterize the neuromuscular control during shortening (SHO) and lengthening (LEN) contractions by investigating the input-output (I/O) property in the corticospinal tract. To this end, the relation between various stimulus intensities applied via transcranial magnetic stimulation and the size of motor evoked potentials was investigated in six healthy subjects during elbow flexion and extension. The measured I/O property demonstrates a sigmoidal shape, and is characterized by a plateau value, maximum slope and threshold. The results demonstrated that both the plateau value and maximum slope were significantly lower during LEN contraction than during SHO contraction (P<0.05), whereas the threshold was found not to be significantly different. These results suggest that both the maximum excitation level and the gain of the corticospinal tract are reduced during LEN contractions.

Action Potentials↗

PubMed2001

Single oral dose of geranylgeranylacetone induces heat-shock protein 72 and renders protection against ischemia/reperfusion injury in rat heart.

BACKGROUND: Induction of heat-shock proteins (HSPs) results in cardioprotection against ischemic insult. Geranylgeranylacetone (GGA), known as an antiulcer agent, reportedly induces HSP72 in the gastric mucosa and small intestine of rats. The present study tested the hypothesis that oral GGA would induce HSP72 in the heart and thus render cardioprotection against ischemia/reperfusion injury in rats. METHODS AND RESULTS: Cardiac expression of HSPs was quantitatively evaluated in rats by Western blot analysis. Ten minutes of whole-body hyperthermia induced HSP72 expression in the rat hearts. A single oral dose of GGA (200 mg/kg) also induced expression of HSP72, which peaked at 24 hours after administration. Therefore, isolated perfused heart experiments using a Langendorff apparatus were performed 24 hours after administration of 200 mg/kg GGA (GGA group) or vehicle (control group). After a 5-minute stabilization period, no-flow global ischemia was given for 20, 40, or 60 minutes, followed by 30 minutes of reperfusion. During reperfusion, the functional recovery was greater and the released creatine kinase was less in the GGA group than in the control group. Electron microscopy findings revealed that the ischemia/reperfusion-induced damage of myocardial cells was prevented in GGA-treated myocytes. CONCLUSIONS: The results suggest that oral GGA is cardioprotective against ischemic insult through its induction of HSP72.

Administration, Oral↗

PubMed2001

Oral exposure of dimethylarsinic acid, a main metabolite of inorganic arsenics, in mice leads to an increase in 8-Oxo-2'-deoxyguanosine level, specifically in the target organs for arsenic carcinogenesis.

We have proposed that oral administration of dimethylarsinic acid (DMA), a metabolite of inorganic arsenics in mammals, rather than inorganic arsenics themselves, promotes lung and skin tumors by way of the metabolic production of free radicals such as dimethylarsenic peroxy radical [(CH(3))(2)AsOO*]. The purpose of the present study was to examine if dimethylarsenic has the ability to induce oxidative damage. 8-oxo-2'-deoxyguanosine (8-oxodG) was used as a biomarker of DNA oxidation. The oral administration of DMA enhanced significantly the amounts of 8-oxodG specifically in the target organs (skin, lung, liver, and urinary bladder) of arsenic carcinogenesis and also in urine, whereas arsenite did not. The dimethylarsenics thus may play an important role in arsenic carcinogenesis through the induction of oxidative damage, particularly of base oxidation.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2001

NEDD8 recruits E2-ubiquitin to SCF E3 ligase.

NEDD8/Rub1 is a ubiquitin (Ub)-like post-translational modifier that is covalently linked to cullin (Cul)-family proteins in a manner analogous to ubiquitylation. NEDD8 is known to enhance the ubiquitylating activity of the SCF complex (composed of Skp1, Cul-1, ROC1 and F-box protein), but the mechanistic role is largely unknown. Using an in vitro reconstituted system, we report here that NEDD8 modification of Cul-1 enhances recruitment of Ub-conjugating enzyme Ubc4 (E2) to the SCF complex (E3). This recruitment requires thioester linkage of Ub to Ubc4. Our findings indicate that the NEDD8-modifying system accelerates the formation of the E2-E3 complex, which stimulates protein polyubiquitylation.

Anaphase-Promoting Complex-Cyclosome↗

PubMed2001

Purification and characterization of an acid amidase selective for N-palmitoylethanolamine, a putative endogenous anti-inflammatory substance.

N-Arachidonoylethanolamine (anandamide) is cannabimimetic, and N-palmitoylethanolamine is anti-inflammatory and immunosuppressive. We found an amidase that is more active with the latter than the former in contrast to the previously known anandamide amidohydrolase for which N-palmitoylethanolamine is a poor substrate. Proteins solubilized by freezing and thawing from the 12,000 x g pellet of various rat organs hydrolyzed [(14)C]N-palmitoylethanolamine to palmitic acid and ethanolamine. The specific enzyme activity was higher in the order of lung > spleen > small intestine > thymus > cecum, and high activity was found in peritoneal and alveolar macrophages. The enzyme with a molecular mass of 31 kDa was purified from rat lung to a specific activity of 1.8 micromol/min/mg protein. Relative reactivities of the enzyme with various N-acylethanolamines (100 microm) were as follows: N-palmitoylethanolamine, 100%; N-myristoylethanolamine, 48%; N-stearoylethanolamine, 21%; N-oleoylethanolamine, 20%; N-linoleoylethanolamine, 13%; anandamide, 8%. The enzyme was the most active at pH 5 and was activated 7-fold by Triton X-100. The enzyme was almost insensitive to methyl arachidonyl fluorophosphonate, which inhibited anandamide amidohydrolase potently. Thus, the new enzyme referred to as N-palmitoylethanolamine hydrolase was clearly distinguishable from anandamide amidohydrolase.

Amides↗

PubMed2001

Marked activation of the N-acylphosphatidylethanolamine-hydrolyzing phosphodiesterase by divalent cations.

N-Acylethanolamines including anandamide (an endogenous ligand for cannabinoid receptors) are released from N-acylphosphatidylethanolamine (N-acyl-PE) by the catalysis of a phosphodiesterase of the phospholipase D type. The enzyme was solubilized from the particulate fractions of rat heart with the aid of octyl glucoside, and partially purified by anion-exchange chromatography. The enzyme hydrolyzed N-palmitoyl-PE with a specific activity of 17 nmol/min/mg protein at 37 degrees C. The enzyme activity increased dramatically up to 30-fold by millimolar order of Ca(2+). Ca(2+) could be replaced with other divalent cations such as Co(2+), Mg(2+), Mn(2+), Ba(2+), Sr(2+) and Ni(2+). The hydrolysis of N-arachidonoyl-PE (a precursor of anandamide) was also markedly stimulated by Ca(2+).

Animals↗