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Search Results: 1 - 10 of 3463 matches for " Akira Hara "
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Cancer chemoprevention through the induction of apoptosis by natural compounds  [PDF]
Toshiya Kuno, Testuya Tsukamoto, Akira Hara, Takuji Tanaka
Journal of Biophysical Chemistry (JBPC) , 2012, DOI: 10.4236/jbpc.2012.32018
Abstract: As cell and tissue homeostasis are mediated by the balance between proliferation and apoptosis, controlling this balance is important for cancer chemoprevention. Cancer chemoprevention can be achieved by the use of natural, synthetic or biologic compounds that reverse, suppress or prevent the development of epithelial malignancies. Natural compounds including flavonoids are able to reduce oxidative stress, which is the most likely mechanism mediating the protective effects against cancer development. In addition, in vitro and in vivo studies have suggested that flavonoids, such as (-)-epigallocatechin-3-gallete (EGCG), quercetin, and curcumin, act by induction of apoptosis. Several natural compounds inhibit cell proliferation and angiogenesis. Certain natural products have been shown to inhibit the activation of nuclear factor kappa B (NF-κB) and Akt signaling pathways, both of which are known to maintain a homeostatic balance between cell survival and apoptosis. Understanding the mechanism of these natural products will contribute to the development of more specific preventive strategies against cancer development. Here we focus on the ability of natural cancer chemopreventive agents to induce apoptosis, and attempt to provide evidence for the preventive and therapeutic effects of natural compounds, EGCG, quercetin, and curcumin, in a succinct manner highlightingκand Akt signaling pathways in vivo.
Effects of NSAIDs on the Inner Ear: Possible Involvement in Cochlear Protection
Tomofumi Hoshino,Keiji Tabuchi,Akira Hara
Pharmaceuticals , 2010, DOI: 10.3390/ph3051286
Abstract: Cyclooxygenase and lipoxygenase, two important enzymes involved in arachidonic acid metabolism, are major targets of non-steroidal anti-inflammatory drugs (NSAIDs). Recent investigations suggest that arachidonic cascades and their metabolites may be involved in maintaining inner ear functions. The excessive use of aspirin may cause tinnitus in humans and impairment of the outer hair cell functions in experimental animals. On the other hand, NSAIDs reportedly exhibit protective effects against various kinds of inner ear disorder. The present review summarizes the effects of NSAIDs on cochlear pathophysiology. NSAIDs are a useful ameliorative adjunct in the management of inner ear disorders.
Knowledge Acquisition from Computer Log Files by ADG with Variable Agent Size
Akira Hara,Yoshiaki Kurosawa,Takumi Ichimura
IAENG International Journal of Computer Science , 2007,
Abstract:
Short Report: Association of IL-15 with Peripheral and Hepatic Insulin Sensitivity in Healthy Middle-Aged Men  [PDF]
Yuichiro Nishida, Kumpei Tokuyama, Shoichiro Nagasaka, Akira Kiyonaga, Yasuki Higaki, Megumi Hara, Keitaro Tanaka, Hiroaki Tanaka
Open Journal of Endocrine and Metabolic Diseases (OJEMD) , 2014, DOI: 10.4236/ojemd.2014.43007
Abstract:


Rodent study suggests that interleukin (IL)-15 administration enhances insulin sensitivity. Although it is well known that circulating levels of typical inflammatory markers (C-reactive protein [CRP] and IL-6) are positively associated with homeostasis model assessment-insulin resistance (HOMA-IR), there are no studies investigating the associations of other inflammatory markers including IL-15 with peripheral/hepatic insulin sensitivity in humans. The current study aimed to examine the relationship between the levels of adiopokines or inflammatory cytokines and insulin sensitivity in 8 healthy middle-aged men. Circulating levels of 10 insulin sensitizing adipokines or inflammatory cytokines (total adiponectin [APN], high molecular weight adiponectin [HMW-APN], IL-4, IL-5, IL-6, IL-8, IL-15, interferon [IFN]-γ, tumor necrosis factor [TNF]-α, and TNF-β) were measured. A stable-labeled frequently sampled intravenous glucose tolerance test was performed to assess peripheral (\"\") and hepatic (\"\") insulin sensitivity estimated by 2-compartment minimal model. The levels of 3 inflammatory cytokines (IL-4, IL-6, and IL-15) were significantly and inversely correlated with either \"\" and \"\". The association between IL-15 and either \"\" or \"\" was significant even after adjusting for age and percent body fat (p < 0.01). The current study showed a possible inverse association between serum IL-15 level and peripheral/hepatic insulin sensitivity in healthy middle-aged males, independent of percent body fat; this association in humans warrants further study.


Basal Cell Carcinoma of the Head and Neck
Masahiro Nakayama,Keiji Tabuchi,Yasuhiro Nakamura,Akira Hara
Journal of Skin Cancer , 2011, DOI: 10.1155/2011/496910
Abstract: Basal cell carcinoma (BCC) is a malignant neoplasm derived from nonkeratinizing cells that originate from the basal layer of the epidermis and is the most frequent type of skin cancer in humans, with cumulative exposure to ultraviolet radiation as an important risk factor. BCC occurs most frequently at sun-exposed sites, with the head and neck being common areas. Tumors can be classified as nodular, superficial, morpheaform, infiltrating, metatypic, and fibroepithelioma of Pinkus. Several treatment options such as surgical excision and nonsurgical procedures are available. The choice of treatment should be determined based on the histological subtype of a lesion, cost, its size and location, patient age, medical condition of the patient, treatment availability, and the patient's wishes. The aim of any therapy selected for BCC treatment involving the head and neck is to ensure complete removal, the preservation of function, and a good cosmetic outcome. 1. Introduction Basal cell carcinoma (BCC) is defined by the World Health Organization Committee on the histological typing of skin tumors as “a locally invasive, slowly spreading tumor which rarely metastasize, arising in the epidermis or hair follicles and in which, in particular, the peripheral cells usually simulate the basal cells of the epidermis” [1]. BCC constitutes approximately 75% of nonmelanoma skin cancers. It is usually observed in older patients, especially in those frequently and intensively exposed to ultraviolet radiation during their lives. The most typical site of BCC is uncovered skin directly exposed to the sun. Thus, BCC is often observed in head and neck areas, especially the eyelid and nose. It occurs chiefly in the elderly and is more common in males. Generally speaking, the tumor grows slowly and behaves in a nonaggressive fashion. BCC may be treated by surgery, cryotherapy, radiotherapy, and curettage and electrodessication [2]. Other less frequently used treatment modalities include the topical application of 5-fluorouracil (5-FU) ointment, laser treatment, and systemic chemotherapy [3]. To achieve a favorable outcome, it is important to recognize the histological subtypes, identify the anatomic locations that can increase the risk of spread, and understand the limitations of all available treatment modalities. If surgical defects are repaired, it is necessary to carefully plan the reconstruction after the tumor margins have been cleared. This paper discusses the histopathology, clinical presentation, and management of BCC of the head and neck. Local flaps for reconstruction of
Early Detection of Nasopharyngeal Carcinoma
Keiji Tabuchi,Masahiro Nakayama,Bungo Nishimura,Kentaro Hayashi,Akira Hara
International Journal of Otolaryngology , 2011, DOI: 10.1155/2011/638058
Abstract: Nasopharyngeal carcinoma (NPC) is a unique disease with a clinical presentation, epidemiology, and histopathology differing from other squamous cell carcinomas of the head and neck. NPC is an Epstein-Barr virus-associated malignancy with a marked racial and geographic distribution. Specifically, it is highly prevalent in southern China, Southeast Asia, and the Middle East. To date, most NPC patients have been diagnosed in the advanced stage, but the treatment results for advanced NPC are not satisfactory. This paper provides a brief overview regarding NPC, with the focus on the early detection of initial and recurrent NPC lesions.
Early Detection of Nasopharyngeal Carcinoma
Keiji Tabuchi,Masahiro Nakayama,Bungo Nishimura,Kentaro Hayashi,Akira Hara
International Journal of Otolaryngology , 2011, DOI: 10.1155/2011/638058
Abstract: Nasopharyngeal carcinoma (NPC) is a unique disease with a clinical presentation, epidemiology, and histopathology differing from other squamous cell carcinomas of the head and neck. NPC is an Epstein-Barr virus-associated malignancy with a marked racial and geographic distribution. Specifically, it is highly prevalent in southern China, Southeast Asia, and the Middle East. To date, most NPC patients have been diagnosed in the advanced stage, but the treatment results for advanced NPC are not satisfactory. This paper provides a brief overview regarding NPC, with the focus on the early detection of initial and recurrent NPC lesions. 1. Introduction Nasopharyngeal carcinoma (NPC) is a nonlymphomatous squamous cell carcinoma that occurs in the epithelial lining of the nasopharynx. This neoplasm shows varying degrees of differentiation and is frequently seen in the pharyngeal recess (Rosenmüller’s fossa), posteromedial to the medial crura of the Eustachian tube opening in the nasopharynx [1]. NPC is a distinct form of head and neck cancer that differs from other malignancies of the upper aerodigestive tract in terms of its etiology, epidemiology, pathology, clinical presentation, and response to treatment [2]. Outside of endemic areas in Southeast Asia, NPC is rare, occurring in less than 1/1,000,000 people [3]. In North America, NPC accounts for approximately 0.2% of all malignancies, with approximately 0.5–2 cases per 100,000 males and about one-third of that in females [4–6]. The incidence of NPC reportedly remains high among Chinese people who have emigrated to Southeast Asia or North America, but is lower among Chinese people born in North America than in those born in Southern China [7, 8]. This finding suggests that genetic as well as environmental factors play a role in the cause of the disease [9]. The mainstay of NPC treatment is radiotherapy, but treatment results for advanced NPC is not satisfactory. The focus of this review is to provide an overview of NPC, especially the recent insights regarding early detection of NPC. 2. Epidemiology and Etiology NPC is a relatively rare malignancy in most parts of the world. It accounts for 2% of all head and neck squamous cell carcinomas, with an incidence of 0.5 to 2 per 100,000 in the United States [10]. However, it is endemic in many geographical regions, including Southern China, Southeast Asia, Japan, and the Middle East/North Africa [10, 11]. Ho [12] reported that NPC is the third most common malignancy among men, with an incidence of between 50 per 100,000 in the Guangdong Province of Southern China.
Quest for Potentials in the Quintessence Scenario  [PDF]
Tetsuya Hara
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.42027
Abstract:

The time evolution of the equation of state w for quintessence scenario with a scalar field as dark energy is studied up to the third derivative (d3w/da3) with respect to the scale factor a, in order to predict the future observations and specify the scalar potential parameters with the observables. The third derivative of w for general potential V is derived and applied to several types of potentials. They are the inverse power-law (V = M4 + α/Qα), the exponential ?\"\", the mixed \"\" , the cosine \"\" ?and the Gaussian types \"\" , which are prototypical potentials for the freezing and thawing models. If the parameter number for a potential form is n, it is necessary to find at least for n + 2 independent observations to identify the potential for0m and the evolution of the scalar field (Q and \"\"

Bronchodilator effect of deep inspiration and bronchoconstriction-triggered cough
Noriyuki Ohkura, Masaki Fujimura, Akira Tokuda, Johsuke Hara, Akihiro Hori, Masaru Nishitsuji, Miki Abo, Nobuyuki Katayama
Cough , 2009, DOI: 10.1186/1745-9974-5-9
Abstract: We measured airway responsiveness to methacholine using partial and full flow-volume curves in 28 healthy adults. The expiratory flow at 40% above residual volume from the full forced vital capacity (MEF40) was obtained and the volume was used as the reference volume to determine the isovolume flow from the partial curve (PEF40). Coughs were counted for 32 min during and following the inhalation of methacholine at the provocative concentration which produced a 20% fall or more in FEV1from the post-saline value (PC20-FEV1). The bronchodilator effect of DI on bronchoconstriction induced by methacholine at the PC20-FEV1 concentration was expressed as the ratio of (MEF40-PEF40)/PEF40 (DI index).The number of coughs for 32 min during and following the inhalation of PC20-FEV1 concentration of methacholine was 39.3 ± 29.7 (mean ± SD)/32 min. The number of coughs during and following the inhalation was correlated with DI index (r = 0.57, p = 0.0015), but not with PC20-FEV1 or change in FEV1 or PEF40 by inhalation of the PC20-FEV1 concentration of methacholine.We found that methacholine-induced cough was associated with the bronchodilator effect of DI on methacholine induced-bronchoconstriction in normal subjects.Cough is a common and distressing symptom. Eosinophilic airway disorders such as bronchial asthma (BA), cough variant asthma (CVA) [1], eosinophilic bronchitis without asthma [2], and atopic cough (AC) [3] are important causes of chronic non-productive cough. As the mechanism of cough, at least the following two are considered: one is a cough caused by cough reflex hypersensitivity that is relevant to AC, gastroesophageal reflux disease (GERD) [4] and angiotensin-converting enzyme inhibitor-induced cough [5]. Another is a cough triggered by bronchoconstriction in such as CVA and BA, which responds to bronchodilator therapy [1,6].Capsaicin has achieved widespread use for measurement of cough reflex sensitivity [7]. Several studies suggest that capsaicin-induced cough
C57BL/KsJ-db/db-ApcMin/+ Mice Exhibit an Increased Incidence of Intestinal Neoplasms
Kazuya Hata,Masaya Kubota,Masahito Shimizu,Hisataka Moriwaki,Toshiya Kuno,Takuji Tanaka,Akira Hara,Yoshinobu Hirose
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12118133
Abstract: The numbers of obese people and diabetic patients are ever increasing. Obesity and diabetes are high-risk conditions for chronic diseases, including certain types of cancer, such as colorectal cancer (CRC). The aim of this study was to develop a novel animal model in order to clarify the pathobiology of CRC development in obese and diabetic patients. We developed an animal model of obesity and colorectal cancer by breeding the C57BL/KsJ- db /db (db/db) mouse, an animal model of obesity and type II diabetes, and the C57BL/6J- ApcMin/+ (Min/+) mouse, a model of familial adenomatous polyposis. At 15 weeks of age, the N9 backcross generation of C57BL/KsJ- db /db- ApcMin/+ (db/db-Min/+) mice developed an increased incidence and multiplicity of adenomas in the intestinal tract when compared to the db/m-Min/+ and m/m-Min/+ mice. Blood biochemical profile showed significant increases in insulin (8.3-fold to 11.7-fold), cholesterol (1.2-fold to 1.7-fold), and triglyceride (1.2-fold to 1.3-fold) in the db/db-Min/+ mice, when compared to those of the db/m-Min/+ and m/m-Min/+ mice. Increases (1.4-fold to 2.6-fold) in RNA levels of insulin-like growth factor (IGF)-1, IRF-1R, and IGF-2 were also observed in the db/db-Min/+ mice. These results suggested that the IGFs, as well as hyperlipidemia and hyperinsulinemia, promoted adenoma formation in the db/db-Min/+ mice. Our results thus suggested that the db/db-Min/+ mice should be invaluable for studies on the pathogenesis of CRC in obese and diabetes patients and the therapy and prevention of CRC in these patients.
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