Biomedical subjects

Junko Ito

Publications and source records attributed to Junko Ito.

10 recordsLinked to original sources

PubMed2006

A pair-feeding study reveals that a Y5 antagonist causes weight loss in diet-induced obese mice by modulating food intake and energy expenditure.

Neuropeptide Y (NPY) is thought to have a significant role in the physiological control of energy homeostasis. We recently reported that an NPY Y5 antagonist inhibits body weight gain in diet-induced obese (DIO) mice, with a moderate reduction in food intake. To clarify the mechanism of the antiobesity effects of the Y5 antagonist, we conducted a pair-feeding study in DIO mice. The Y5 antagonist at 100 mg/kg produced a moderate feeding suppression leading to an 18% decrease in body weight, without altering body temperature. In contrast, the pair-fed group showed only a transient weight reduction and a reduced body temperature, thus indicating that the Y5 antagonist stimulates thermogenesis. The Y5 antagonist-treated mice showed an up-regulation of uncoupling protein mRNA in brown adipose tissue (BAT) and white adipose tissue (WAT), suggesting that both BAT and WAT contribute to energy expenditure. Thus, the Y5 antagonist induces its antiobesity effects by acting on both energy intake and expenditure.

Adipose Tissue↗

PubMed2006

Novel potent neuropeptide Y Y5 receptor antagonists: synthesis and structure-activity relationships of phenylpiperazine derivatives.

A series of phenylpiperazine derivatives were synthesized and evaluated for their neuropeptide Y (NPY) Y5 receptor antagonistic activities. The benzindane portion of 2 was replaced by 1-phenylpiperazine, resulting in novel urea derivative 3f. Subsequent optimization of the phenylpiperazine template by substitution of the phenyl moiety resulted in a series of (2-methanesulfonamidephenyl)piperazine derivatives that showed potent binding affinity and antagonistic activity for the Y5 receptor.

Humans↗

PubMed2006

Cytotoxic Alangium alkaloids from Alangium longiflorum.

Seven alkaloids (1-7) were isolated from the stem bark of Alangium longiflorum. Compound 1, (-)-10-O-demethylisocephaeline, was isolated for the first time as a naturally occurring product from a plant source. All structures were elucidated by detailed spectroscopic analysis. Biological evaluation showed that 2, 10-O-demethylcephaeline, exhibited potent cytotoxic activity against human lung carcinoma (A549) and breast adenocarcinoma (MCF-7) with ED(50) values of 0.013 and 0.062 microM, respectively. The stereoisomer 1 was less potent than 2, and related compounds with different hydroxy/methoxy substitution patterns were also less potent or inactive. Thus, compound 2 merits attention as a cytotoxic lead for further study.

Alangiaceae↗

PubMed2006

Performance monitoring and error processing during a lexical decision task in patients with Parkinson's disease.

To evaluate performance monitoring and error processing during lexical decision tasks, event-related potentials (ERPs) obtained by time-locked to correct and error responses were studied in 17 Parkinson's disease (PD) patients without dementia and 15 healthy elderly participants. The amplitude of error negativity (Ne) obtained by averages time-locked to error response was significantly reduced in the PD patients, whereas there were no significant differences in the negative component for the correct response (Nc) between the two participant groups. The amplitude of the error positivity (Pe) and correct positivity (Pc) after the Ne and Nc components was also significantly reduced in the PD patients. The PD patients showed significantly slower reaction times and higher error rates. The reduced amplitude of the Ne, Pe, and Pc components in the PD patients suggested impaired performance and conflict monitoring as well as abnormal response strategy adjustments and deviant in later error monitoring processes associated with emotional, conscious evaluation of the error.

Aged↗

PubMed2005

Error processing in patients with Alzheimer's disease.

Patients with dementia are prone to make errors while they perform a task. To evaluate error detection and action monitoring in patients with dementia of the Alzheimer type (DAT) at a relatively early stage of the illness, error negativity (Ne) and error positivity (Pe) of event-related potentials (ERPs) obtained by averages time-locked to error response were studied using a lexical recognition paradigm composed of Japanese 'kanji' ideogram characters. In the DAT patients, reaction times were significantly slower and error rates were higher. Not only in healthy elderly subjects but also in the DAT patients, the Ne component obtained by averages time-locked to error response showed a larger amplitude than negativity for correct response (Nc). The Ne and Pe amplitudes were significantly smaller for the DAT patients than for the healthy elderly subjects, whereas there were no significant differences in the Nc amplitude between the two subject groups. Latencies of the Ne, Pe and positivity for correct response (Pc) were prolonged in the DAT patients. These findings suggest that information processing and error detection are slower and somewhat impaired at a relatively early stage of DAT, although error detection and awareness are still preserved.

Journal Article↗

PubMed2005

Evaluation of a newly developed identification kit, RID Zyme CAS test, for Candida albicans.

To evaluate a newly developed identification kit, the RID Zyme CAS test for Candida albicans, 1136 C. albicans and 403 non-albicans Candida strains were tested. Distinction of medically important non-albicans strains, with the exception of C. dubliniensis, was obtained. These results show that this new kit is simple and effective for the identification of C. albicans in clinical samples. Furthermore, the one hour period for identification makes it very attractive.

Candida↗

PubMed2003

Diagnosis of histoplasmosis by detection of the internal transcribed spacer region of fungal rRNA gene from a paraffin-embedded skin sample from a dog in Japan.

The lesions of histoplasmosis in dogs in Japan differ from those in dogs in North America. Affected dogs in Japan have had multiple granulomatous or ulcerated foci in skin or gingiva and have not had pulmonary or gastrointestinal lesions. The present report introduces a polymerase chain reaction (PCR) diagnosis of canine histoplasmosis and the characteristic of disease in Japan. The surgically removed skin ulcerate samples from a 5-years-old female Shiba-inu native to Japan without traveling out of the country were evaluated. Tissue samples had many yeast-like organisms in the macrophages. DNA was extracted from paraffin-embedded tissue samples. A nested PCR technique was applied. The detected sequence of the internal transcribed spacer of ribosomal RNA gene had 99.7% in homology with Ajellomyces capsulatus (the teleomorph of Histoplasma capsulatum). Clinical manifestations, historical background of equine epizootic lymphangitis in Japan, and a human autochthonous case of histoplasmosis farciminosi indicated that this dog might have been infected with H. capsulatum var. farciminosum as a heteroecism.

Animals↗

PubMed2003

Characterization of neuropeptide Y (NPY) Y5 receptor-mediated obesity in mice: chronic intracerebroventricular infusion of D-Trp(34)NPY.

To clarify the role of the neuropeptide Y (NPY) Y5 receptor subtype in energy homeostasis, the effect of the intracerebroventricular infusion of a selective Y5 agonist, D-Trp(34)NPY, was investigated in C57BL/6J mice. Intracerebroventricular infusion of D-Trp(34)NPY (5 and 10 microg/d) produced hyperphagia and body weight gain, accompanied by increased adipose tissue weight, hypercholesterolemia, hyperinsulinemia, and hyperleptinemia. Oral administration of a selective Y5 antagonist at a dose of 100 mg/kg twice a day completely suppressed all of these D-Trp(34)NPY-induced changes, indicating that chronic activation of the Y5 receptor produces hyperphagia and obesity. In addition, D-Trp(34)NPY still resulted in an increase in adipose tissue weight accompanied by hyperleptinemia and hypercholesterolemia, although D-Trp(34)NPY-induced food intake was restricted by pair-feeding. Under the pair-fed condition, D-Trp(34)NPY decreased hormone-sensitive lipase activity in white adipose tissue and uncoupling protein-1 mRNA expression in brown adipose tissue. These findings indicate that Y5-mediated obesity may involve metabolic changes, such as decreased lipolysis and thermogenesis, as well as hyperphagia. Therefore, the Y5 receptor can play a key role in regulating energy homeostasis.

Animals↗

PubMed2002

Melanin-concentrating hormone receptor subtypes 1 and 2: species-specific gene expression.

To assess the contribution of potential central nervous system pathways implicated in the control of appetite regulation and energy metabolism, it is essential to first identify appropriate animal models. Melanin-concentrating hormone (MCH), a conserved cyclic neuropeptide implicated in the modulation of food intake, has been shown to bind and activate two G-protein-coupled receptors, called GPR24 and MCHR2, expressed in human brain and other tissues. Here we show that several non-human species (rat, mouse, hamster, guinea pig, and rabbit) do not have functional MCHR2 receptors, or encode a nonfunctional MCHR2 pseudogene while retaining GPR24 expression. We identified three species for further evaluation that express both MCH receptor subtypes. We cloned and functionally characterized dog, ferret, and rhesus GPR24 and MCHR2 in mammalian cells and studied their brain distribution patterns by in situ hybridization. The homology, expression profile, and functional similarity of the receptors in the dog, ferret, and rhesus to that of human support the potential use of these species as preclinical animal models in the development of therapeutic agents for obesity or other MCH-mediated disorders.

Amino Acid Sequence↗

PubMed2002

[Nerve conduction studies of suprascapular nerve for site-of-lesion diagnosis].

Shoulder pain is a common symptom, resulting not only from bone and shoulder joint diseases, but also from neurogenic lesions. Entrapment neuropathy of the suprascapular nerve also causes shoulder symptoms. Conduction of the suprascapular nerve was studied in 12 healthy control subjects and 25 patients suffering from shoulder pain and/or dysfunction. Surface stimulation was performed at Erb's point, and compound muscle action potentials(M waves) were recorded from the supraspinatus and the infraspinatus muscles with concentric needle electrodes. To determine the optimal site for recording M waves from the infraspinatus muscle, simultaneous multi-channel recordings of M waves using pairs of surface electrodes were obtained from different sites over the infraspinatus muscle. In two patients, latency of the M waves to the infraspinatus muscle was prolonged, whereas that to the supraspinatus muscle was normal. These findings indicate entrapment neuropathy at the spinoglenoid notch. In three patients, the latency to the infraspinatus and supraspinatus muscles was prolonged. These findings are compatible with entrapment neuropathy at the suprascapular notch. The latency to the supraspinatus and infraspinatus muscles was prolonged in patients with brachial plexus injury and in those with suprascapular nerve injury. In patients with myopathy, those with neuralgic amyotrophy and those with cervical radiculopathy, the latency was normal. Thus, conduction studies of the suprascapular nerve using multiple-channel recordings are useful, especially for the diagnosis of entrapment neuropathy of the suprascapular nerve.

Adult↗