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Biomedical subjects

Hiroshi Fujimoto

Publications and source records attributed to Hiroshi Fujimoto.

15 recordsLinked to original sources
PubMed2006

Hormonal stimulation increases the recruitment of bone marrow-derived myoepithelial cells and periductal fibroblasts into the mammary gland.

Recent reports have revealed that bone marrow (BM)-derived cells can be constituents in a number of organs, especially in remodeling tissue. Using bone marrow transplantation (BMT) technique, we found that BM can serve as a source of both myoepithelial cells and periductal fibroblasts in the mammary gland. The numbers of BM-derived myoepithelial cell were 4.8-fold, and those of periductal fibroblast were 2.4-fold higher in the mice when BMT which was performed at the pubertal stage, as compared with BMT was performed at the postpubertal stage. Treatment with estrogen+progesterone pellet increased numbers of BM-derived myoepithelial cells and periductal fibroblasts, to levels 4.5- and 2.6-fold higher than in placebo mice, respectively. In situ hybridization revealed BM-derived periductal fibroblasts expressed insulin-like growth factor I mRNAs that are known to regulate mammary gland. These results suggest that drastic structural change that is induced by hormonal stimulation increased the recruitment of BM-derived myoepithelial cells and periductal fibroblasts to the mammary gland context.

Animals↗
PubMed2006

Theoretical study of NH3 adsorption on Fe(110) and Fe(111) surfaces.

With the aim of understanding the nature of the interactions between organic molecules and metal surfaces, the adsorption of NH3 onto model Fe(110) and Fe(111) surfaces has been studied with use of the molecular orbital and density functional theories. B3LYP calculations have revealed that the on-top site is most suitable for adsorption of NH3 both on Fe(110) and on Fe(111). Mulliken population analysis in terms of the MO's of the two fragment systems suggested that electron delocalization from NH3 to the Fe surface should play a key role in the adsorption. Then, our transformation scheme of fragment orbitals has demonstrated that the electron delocalization is represented well only by a pair of interaction orbitals. The NH3 molecule provides the occupied interaction orbital bearing a close resemblance to the highest occupied (HO) MO, whereas the Fe surface prepares the paired unoccupied orbital that is localized at the adsorption site and overlaps in-phase with the orbital of NH3. Not only the lowest unoccupied (LU) MO but also other unoccupied MO's have been shown to participate significantly in the interaction. The reason the on-top site is the most preferable position for NH3 attack has been elucidated by investigating the interaction orbitals.

Journal Article↗
PubMed2005

Gait analysis of people walking on tactile ground surface indicators.

Tactile ground surface indicators installed on sidewalks help visually impaired people walk safely. The visually impaired distinguish the indicators by stepping into its convexities and following them. However, these indicators sometimes cause the nonvisually impaired to stumble. This study examines the effects of these indicators by comparing the kinematic and kinetic variables of walking on paths with and without indicators. The results suggest that walking on the indicators causes extra movements of the lower extremities such as increased minimum toe heights during the midswing phase, increased peak hip flex moments, and increased peak hip heights. This study also suggests that a functional leg length discrepancy while walking on the indicators is one of the reasons for the extra movements of the lower extremities. Therefore, we designed a new recessed tactile surface to offset the differences of surface depth while walking on the path containing indicators, and found that the newly designed recessed tactile surface was effective in reducing the extra movements while walking on the path in which indicators were installed. These indicators may help both the visually impaired and elderly people with normal vision to walk safely.

Adult↗
PubMed2004

An unexpected outbreak of Japanese encephalitis in the Chugoku district of Japan, 2002.

Six patients unexpectedly presented with Japanese encephalitis (JE) from early August to mid-September 2002 in the Chugoku district of Japan. The mean age was 67.5 years (range 42 - 89 years); the onset period in two patients shifted to the middle of September. The JE virus was isolated from the cerebrospinal fluid samples from two patients, and the strain isolated in the one was identified as genotype III. Neurologically, consciousness impairment, meningeal signs, rigidity, hemiparesis, tetraparesis, and convulsive seizures were commonly observed. Magnetic resonance imaging uniformly revealed high signal intensities in the bilateral thalami, brainstem (substantia nigra), hippocampi, and brain cortices. In all patients, acyclovir was used, due to the unexpected outbreak of JE. Five patients, except for one without sequelae, had a severe outcome, including one death. This report indicates that JE in Japan is still a threat to adults and the elderly with decreased or absent immunity to the JE virus.

Adult↗
PubMed2003

A case of adult-onset Alexander disease with Arg416Trp human glial fibrillary acidic protein gene mutation.

Heterozygous point mutations in the coding region of the human glial fibrillary acidic protein (GFAP) gene have been reported in patients with various forms of Alexander disease (AD). We report a case of genetically confirmed adult-onset AD with palatal myoclonus, pyramidal tract signs, cerebellar signs, and marked atrophy of the medulla oblongata and spinal cord, autonomic dysfunction and heterozygous R416W GFAP mutation. Interestingly, this R416W mutation has also been reported in both infantile and juvenile forms of Alexander disease. The fact that a R416W mutation causes various types of AD suggests that clinical severities of AD are due not only to the different sites and nature of mutations in GFAP, but also to other modifying factor(s).

Adult↗
PubMed2003

Blood loss in patients for total knee arthroplasty.

Ninety-four patients with osteoarthritis (OA) and 180 with rheumatoid arthritis (RA) undergoing unilateral total knee arthroplasty (TKA) were analyzed to clarify the necessity for preoperative autogenous blood deposition or homologous blood transfusion. Two hundred and twenty-four and 50 patients underwent TKA with cement and without cement, respectively. The difference in average blood loss in patients between with (372 ml) and without cementation (449 ml) was significant. In the OA group the average blood loss significantly decreased after cementation but not in the RA group. Although the rate of avoiding transfusion in the OA group did not significantly decrease with the use of cement (92.4% vs. 93.3%), that in the RA group did (80% to 57.1%). Eight of 159 patients with hemoglobin level (Hb) of 11.0 g/dl or higher received homologous blood transfusion. Of these eight patients five had associated disorders. Only one patient with Hb of 12.0 g/dl or higher underwent homologous blood transfusion. Patients with Hb of 12.0 g/dl or higher are not indicated for preoperative autologous blood deposition. In patients with Hb between 11.0 and 12.0 g/dl preoperative blood deposition may be planned after consideration of general condition and complication. Patients with Hb lower than 11.0 g/dl should undergo preoperative blood deposition.

Adult↗
PubMed2003

The effects of replacing dihydropyridine calcium-channel blockers with angiotensin II receptor blocker on the quality of life of hypertensive patients.

Hypertension is a major risk factor for cardiovascular events and the goal of treating hypertension is to prevent complications due to these events. However, some other properties, including few side-effects and improvement of the quality of life (QOL), are desirable in a drug as well as its antihypertensive effect. Dehydropydine calcium-channel blockers (DCCBs) are the most frequently used antihypertensive agents in Japan. The antihypertensive effect of DCCBs is satisfactory, but side-effects, e.g. nocturia, flushing and palpitations, are a problem. The aim was to evaluate the effects of a change of treatment from DCCBs on the QOL of hypertensive patients. An open study was performed to evaluate the effects of switching treatment from DCCBs to angiotensin II receptor blocker (ARB) therapy on the QOL of hypertensive patients. The ARBs have been reported to be effective and well-tolerated antihypertensive drugs. Candesartan cilexetil was selected because it is the most frequently used ARB in Japan. One hundred patients with mild to moderate hypertension, being treated with DCCBs, were randomly selected to receive candesartan cilexetil (8-12 mg once a day). The patients were followed for 3 months, while blood pressure (BP), side-effects and QOL were monitored. BP was equally well controlled before and after the change of antihypertensive therapy. The candesartan cilexetil-treated patients exhibited improvement of several aspects of QOL, including general symptoms, physical symptoms and well-being, work and satisfaction and sleep scale. Emotional state and cognitive function also improved. Patients aged 65 years or younger achieved significant improvement of sexual function. Changing treatment from DCCBs to ARB therapy achieved equal BP control with a lower drug dose. Moreover, the change to cadesartan cilexetil had a positive impact on the QOL.

Adult↗
PubMed2003

Epstein-Barr virus infections of the central nervous system.

OBJECTIVE: Epstein-Barr virus (EBV), a lymphotropic herpes virus causing infectious mononucleosis (IM), also causes various central nervous system (CNS) infections. In the present study, EBV CNS infections were investigated. PATIENTS AND METHODS: For adult inpatients in our hospital and related hospitals between 1984-2002, CNS syndromes with IM symptoms were examined, and serologic positives were assessed according to established criteria. Polymerase chain reaction (PCR) was performed for cerebrospinal fluid (CSF) from seven patients. RESULTS: Ten patients with EBV-related CNS infections were found; their mean age was 36 years (20-79 years). The neurologic forms were as follows: acute encephalitis (4 patients), acute cerebellar ataxia (1), acute disseminated encephalomyelitis (ADEM) (2), myelitis (1), and meningitis (2). The PCR from CSF was positive in two patients with meningitis, one patient with ADEM, and one patient with encephalitis-associated chronic EVB infection. One case of encephalitis and another of relapsing ADEM were attributed to chronic EBV infection. CONCLUSION: Our study identified a variety of EBV-related CNS infections. EBV CNS infections are divided into two groups: 1) CNS syndromes associated with primary EBV or reactivated infection, and 2) those associated with chronic EBV infection; it is notable that in the former, diverse CNS syndromes including ADEM can occur, whereas in the latter, chronic or recurrent CNS syndromes are produced.

Adult↗
PubMed2003

Effects of irradiation on the components of implantable pacemakers.

The purpose of this study was to examine the effects of irradiation on implantable pacemaker components. The pacemaker was divided into three components: lead wire and electrode, battery, and electrical circuit, and each component was irradiated by X-ray and electron beams, respectively. The pacemaker parameters were measured by both telemetry data of the programmer and directly measured data from the output terminal. The following results were obtained. For the lead wire and electrode, there was no effect on the pacemaker function due to irradiation by X-ray and electron beams. In the case of battery irradiation, there was no change in battery voltage or current up to 236Gy X-ray dose. In the electrical circuit, the pacemaker reverted to the regular beating rate (fixed-rate mode) immediately after the start of X-ray irradiation, and it continued in this mode during irradiation. In patients with their own heartbeat rhythm, changing to the fixed-rate mode may cause dangerous conditions such as ventricular fibrillation. When the accumulated irradiation dose is increased, another failure can be seen in the output voltage of the pacemaker. The pacing output voltage dropped rapidly by about 40 % at 30-88Gy. Decreasing the output voltage results in pacing disorders, and heart failure may occur. In the telemetry data of the programmer, no change in output voltage could be detected, highlighting the difference between telemetry data and actual pacing data.

Electrodes, Implanted↗
PubMed2002

Lewis acidity of gallium halides.

The Lewis acidity of GaF(3), GaF(2)Cl, GaFCl(2), and GaCl(3) in acid-base interactions has been studied by taking ammonia as their electron-donating counterpart. We have derived an unoccupied reactive orbital that shows the maximum localization on the Ga atomic center for each species. The orbital is located lower in energy compared to those in the corresponding boron and aluminum halides. In contrast to boron halides, the unoccupied reactive orbital of the acid site tends to be delocalized considerably on the halogens as the fluorines are substituted by chlorines in gallium halides. The trend observed in the effects of fluorine and chlorine on the acidity of the gallium halides is opposite to those found in the boron halides. This cannot be interpreted solely in terms of the electron-accepting strength of the gallium center, but can be understood by including electrostatic interactions and closed-shell repulsion with ammonia in the adducts. The origin of the difference in Lewis acidity of BCl(3), AlCl(3), and GaCl(3) has been clarified.

Journal Article↗
PubMed2002

Acute viral encephalitis: the recent progress.

In the new Japanese control law for infectious diseases, most varieties of acute viral encephalitis belong to Category IV requiring report of all cases at sentinel hospitals. Herpes simplex virus type 1 (HSV-1) encephalitis comprises the majority of cases. With the increased prevalence of diagnostic procedures such as polymerase chain reaction (PCR), several forms of HSV-1, and -2 central nervous system (CNS) infections, including acute disseminated encephalomyelitis, brainstem encephalitis, and myelitis, have been clarified. Since 1990 we have conducted a survey of HSV CNS infections in the Kyushu and Okinawa regions, and the data are reviewed here. Trends include an increase in a new subtype of non-herpetic acute limbic encephalitis. In contrast, the incidence of Japanese encephalitis (JE) in Japan has dramatically decreased to a few patients per year; however, JE remains a threat for those with decreased or absent immunity to the JE virus. Imported emerging and reemerging CNS infections such as Murray Valley and West Nile encephalitis can occur in Japan. Influenza-associated encephalitis/encephalopathy is also described as a threat for adults as well as young children.

Acute Disease↗
PubMed1999

Theoretical Study of Endo Selectivity in the Diels-Alder Reactions between Butadienes and Cyclopropene.

The endo selectivity in the Diels-Alder reactions of some substituted butadienes with cyclopropene has been investigated theoretically. Electron delocalization between a diene and the dienophile has been presented in terms of pairs of interaction orbitals. In addition to the principal orbital interactions to form new sigma bonds between the diene and the dienophile, the cyclopropene occupied interaction orbital shows significant amplitudes on the methylenic hydrogens to overlap in phase with the paired unoccupied interaction orbital of butadiene at the backbone C(2) and C(3) carbons. The contribution of this secondary orbital interaction to the stabilization of the transition state has been estimated numerically. It has been demonstrated that neither electron delocalization nor the electrostatic interaction interprets preference of the endo-addition over the exo-addition, but the sum of the two terms has been found to show a correlation with the difference in the barrier heights for the two modes of cycloadditions.

Journal Article↗
PubMed1997

Theoretical Study of Strong Basicity in Aromatic Diamines.

The basic strength of NH(3), NH(2)(CH(3)), NH(CH(3))(2), and N(CH(3))(3) has been evaluated by generating for each species the orbital that plays the dominant role in electron delocalization to an attached proton. The theoretically determined strength has been found to correlate well with the calculated value of proton affinity. The analysis has then been extended to a so-called "proton-sponge" compound, 1,8-bis(dimethylamino)naphthalene. The major component of the orbital of the diamine that captures the proton has been demonstrated to be an in-phase combination of two lone-pair orbitals. The out-of-phase combination elevated in energy by a strong antibonding interaction between two lone pairs of electrons is not necessarily the source of the exceptionally high basicity. The electrostatic interaction has been shown to be the major origin of stabilizing the protonated system, but the location of the captured proton is governed by electron delocalization. A similar conclusion has also been derived for 4,5-bis(dimethylamino)fluorene.

Journal Article↗
PubMed1996

Mechanisms of the Cycloaddition Reaction of Methylenecyclopropane-Palladium and Oxa- and Azatrimethylenemethane-Palladium Complexes with Olefins.

Mechanisms of palladium-catalyzed cycloaddition reactions of methylenecyclopropane with olefins and those of oxatrimethylenemethane (OTMM) and azatrimethylenemethane (ATMM) complexes with olefins have been studied by applying the ab initio molecular orbital method. Assuming an intramolecular coupling mechanism, we have examined some model complexes, Pd(eta(2)-methylenecyclopropane)(ethylene)(PH(3)) and Pd(eta(3)-OTMM or eta(3)-ATMM)(ethylene)(PH(3)), to determine the transition state structures. The coupling of methylenecyclopropane, OTMM, and ATMM with ethylene on the metal center takes place in two steps. In the reaction of methylenecyclopropane, the first step involves an opening of the cyclopropane ring promoted by an attack of ethylene. The methylenecyclopropane moiety has a pi-allylic form at the first transition state which leads to a metallacyclic intermediate. The first transition state of the reactions of OTMM and ATMM complexes looks very similar to that of the methylenecyclopropane complex, having pi-allylic coordinations. The two paths are separated in the second step. A [3 + 2] addition product is obtained by a reductive elimination from the intermediate metallacycle, whereas a prototropic shift followed by a reductive elimination affords a [2 + 1] addition product. It is the energetics of the second stage starting from the metallacycles that differentiates the reactions of the OTMM and ATMM complexes from the reaction of the methylenecyclopropane complex. The relative stabilities of various isomeric forms of these complexes have also been studied.

Journal Article↗