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Biomedical subjects

M Fukuda

Publications and source records attributed to M Fukuda.

At least 37 records · Page 2Linked to original sources
PubMed2004

Zoonotic onchocerciasis caused by a parasite from wild boar in Oita, Japan. A comprehensive analysis of morphological characteristics of the worms for its diagnosis.

Histological examination of a nodule removed from the back of the hand of a 58-year-old woman from Oita, Kyushu, Japan showed an Onchocerca female sectioned through the posterior region of the worm (ovaries identifiable) and young (thin cuticle). Six Onchocerca species are enzootic in that area: O. gutturosa and O. lienalis in cattle, O. suzukii in serows (Capricornis crispus), O. skrjabini and an Onchocerca sp. in Cervus nippon nippon, and O. dewittei japonica in wild boar (Sus scrofa leucomystax). Diagnostic characters of female Onchocerca species, such as the cuticle and its ridges, change along the body length. Tables of the histologic morphology of the mid- and posterior body-regions of the local species are presented. In addition, it was observed that transverse ridges arose and thickened during the adult stage (examination of fourth stage and juvenile females of O. volvulus). The specimen described in this report, with its prominent and widely spaced ridges, was identified as O. d. japonica. Four of the 10 zoonotic cases of onchocerciasis reported worldwide were from Oita, three of them being caused by O. d. japonica, the prevalence of which in local wild boar was 22 of 24 (92%).

Animals↗
PubMed2004

Determination of vitamin B12 using the enzyme glycerol dehydrase.

Glycerol dehydrase is an enzyme that catalyzes dehydration of glycerol into beta-propionaldehyde. It requires 5'-deoxyadenosylcobalamin, one of the forms of vitamin B12, as a coenzyme. The enzyme is inactivated in vitro by all forms of vitamin B12 stoichiometrically. The objective of this study was to determine vitamin B12 content by utilizing the inactivation of the enzyme by vitamin B12. After various examinations, an excellent standard curve was obtained up to 1 pmol vitamin B12 using 14 mU of the enzyme per tube. Glycerol dehydrase does not respond to vitamin B12 if it is bound to haptocorrin, a vitamin B12-binding protein. This necessitates a procedure for extraction of vitamin B12 from samples before assay. The enzyme was less inactivated by 5'-deoxyadenosylcobalamin than any other form of vitamin B12. However, this did not matter because all forms of vitamin B12 were converted into cyanocobalamin during the extraction procedure cited above, which was performed in a buffer containing potassium cyanide.

Aldehydes↗
PubMed2004

Effect of an early intervention programme on low birthweight infants with cerebral injuries.

OBJECTIVE: To determine the effect of an early intervention programme (EIP) on low birthweight infants with cerebral injuries. METHODS: Subjects were 23 high-risk low birthweight infants (periventricular leukomalacia 15, intraventricular haemorrhage 5, both 3) receiving care in the neonatal intensive care unit (NICU) at Nagasaki University Hospital. Subjects were randomly assigned to the EIP group (n = 12) or the control group (n = 11). Participants in the EIP group received a Neonatal Behavioral Assessment scale (NBAS)-based intervention combined with developmental support designed to enhance the infants' development and the quality of the parent-infant relationship. The control group received routine medical nursing care without the EIP. The EIP began prior to discharge from the NICU and lasted until 6 months of corrected age. All children were examined on the NBAS preintervention and again at 44 weeks postconceptional age. Maternal anxiety status (STAI) and maternal feelings of confidence in dealing with her baby (LCC) were measured pre and postintervention. Mental and motor development was assessed postintervention using the Bayley Scale of Infant Development. RESULTS: Orientation and State Regulation of infant behavioural profiles, the STAI and LCC scores significantly improved in the EIP group (mean difference (95% CI): Orientation 0.7 (0.4, 1.1), State Regulation 0.9 (0.3, 1.5), STAI -5.5 (- 9.1, -1.9, LCC 5.3 (4.2, 6.5)), but not in the control group. Bayley mental developmental index (MDI) score in the EIP group was higher than in the control group, but there was no significant difference between the two groups (mean difference (95% CI): MDI 8.5 (- 0.8, 17.8), PDI 6.7 (- 1.9, 15.4)). CONCLUSION: The EIP has beneficial effects on neonatal neurobehavioural development and maternal mental health of low birthweight infants with cerebral injuries. This evidence suggests that short-term changes in maternal mental health and infant neurobehaviour promoted by an EIP may serve to initiate a positive interaction between parents and infants.

Apgar Score↗
PubMed2004

Relationship between C-reactive protein and visceral adipose tissue in healthy Japanese subjects.

AIM: Recent studies have suggested that the elevated C-reactive protein (CRP) levels are associated with body fat, especially visceral adipose tissue, but most of them were investigated in Westerners who had higher body mass index (BMI) than Asians. To investigate the association between CRP concentrations, parameters of visceral obesity, the insulin resistance syndrome and carotid atherosclerosis in healthy Japanese who had a lower BMI than Westerners. METHODS: We explored the relationships between fatness and visceral obesity parameters [by anthropometry, bioelectrical impedance analysis and abdominal computed tomography (CT)] and CRP (high sensitivity) and examined their associations with components of insulin resistance syndrome, interleukin-6 (IL-6), tissue necrosis factor-alpha (TNF-alpha) and intima-media thickness (IMT) of common carotid arteries (CCAs) by ultrasonograms in 116 healthy Japanese subjects. RESULTS: In crude regression analyses, CRP was significantly associated with measures of obesity. After adjustment for age, gender and smoking, the association with CRP was stronger for parameters of visceral obesity (waist circumference, waist-to-hip ratio and visceral adipose tissue accumulation) than for other parameters of obesity. IL-6 and TNF-alpha were not associated with CRP. Blood pressure (BP), metabolic variables and CCA-IMT were also significantly associated with CRP. But, after being adjusted for age, gender, smoking and BMI, BP and high-density lipoprotein cholesterol (HDLc) were significantly associated. CONCLUSION: CRP level is associated with visceral adipose tissue and is significantly associated with the components of insulin resistance syndrome in healthy Japanese subjects. These data support a possible role of visceral adipose tissue in inflammation component of atherosclerosis, and further studies are needed to study the mechanism of CRP elevation caused by visceral adipose tissue.

Adipose Tissue↗
PubMed2004

Global change and the boreal forest: thresholds, shifting states or gradual change?

Changes in boreal climate of the magnitude projected for the 21st century have always caused vegetation changes large enough to be societally important. However, the rates and patterns of vegetation change are difficult to predict. We review evidence suggesting that these vegetation changes may be gradual at the northern forest limit or where seed dispersal limits species distribution. However, forest composition may be quite resilient to climate change in the central portions of a species range until some threshold is surpassed. At this point, changes can be rapid and unexpected, often causing a switch to very different ecosystem types. Many of these triggers for change are amenable to management, suggesting that our choice of policies in the coming decades will substantially influence the ecological and societal consequences of current climatic change.

Arctic Regions↗
PubMed2003

Polarimetry of short-pulse gamma rays produced through inverse Compton scattering of circularly polarized laser beams.

We have developed a polarimetry of ultrashort pulse gamma rays based on the fact that gamma rays penetrating in the forward direction through a magnetized iron carry information on the helicity of the original gamma rays. Polarized, short-pulse gamma rays of (1.1+/-0.2)x10(6)/bunch with a time duration of 31 ps and a maximum energy of 55.9 MeV were produced via Compton scattering of a circularly polarized laser beam of 532 nm off an electron beam of 1.28 GeV. The first demonstration of asymmetry measurements of short-pulse gamma rays was conducted using longitudinally magnetized iron of 15 cm length. It is found that the gamma-ray intensity is in good agreement with the simulated value of 1.0x10(6). Varying the degree of laser polarization, the asymmetry for 100% laser polarization was derived to be (1.29+/-0.12)%, which is also consistent with the expected value of 1.3%.

Journal Article↗
PubMed2003

Effects of levodopa on motor sequence learning in Parkinson's disease.

BACKGROUND: Dopaminergic therapy with levodopa improves motor function in PD patients, but the effects of levodopa on cognition in PD remain uncertain. OBJECTIVE: To use H(2)(15)O and PET to assess the effect of levodopa infusion on motor sequence learning in PD. METHODS: Seven right-handed PD patients were scanned "on" and "off" levodopa while performing a sequence learning task. The changes in learning performance and regional brain activation that occurred during this intervention were assessed. RESULTS: During PET imaging, levodopa infusion reduced learning performance as measured by subject report (p < 0.05). This behavioral change was accompanied by enhanced activation during treatment in the right premotor cortex and a decline in the ipsilateral occipital association area (p < 0.01). Levodopa-induced changes in learning-related activation responses in the occipital association cortex correlated with changes in learning indexes (p < 0.01). CONCLUSIONS: Levodopa treatment appears to have subtle detrimental effects on cognitive function in nondemented PD patients. These effects may be mediated through an impairment in brain activation in occipital association cortex.

Aged↗
PubMed2003

Rapid identification of 1-aminocyclopropane-1-carboxylate (ACC) synthase genotypes in cultivars of Japanese pear (Pyrus pyrifolia Nakai) using CAPS markers.

In Japanese pear (Pyrus pyrifolia Nakai), fruit storage potential is closely related to the amount of ethylene produced. We have developed a rapid and accurate method for analyzing genes involved in high ethylene production during fruit ripening in Japanese pear. This involves cleaved-amplified polymorphic sequences (CAPS) of two 1-aminocyclopropane-1-carboxylate (ACC) synthase genes (PPACS1 and PPACS2). Two CAPS markers (A for PPACS1 and B for PPACS2), associated with the amount of ethylene produced, were identified. Marker A was associated with high ethylene producers and marker B with moderate ethylene producers. The absence of these two markers enabled the identification of low ethylene producers. Using these markers, we have identified ethylene genotypes for 40 Japanese pear cultivars and two Chinese pear (P. bretschneideri) cultivars that are commercially important and used in breeding programs. Furthermore, we performed linkage analysis of these two genes in the F(2) population, which revealed that the recombination frequency between the two markers was 20.8 +/- 3.6%. This information is critical to the selection of parents and in breeding strategies to improve storage ability of Japanese pears.

Alleles↗
PubMed2003

Intrinsic collaterals of layer 6 Meynert cells and functional columns in primate V1.

Meynert cells are a distinct type of large neuron which project to area MT/V5 and to subcortical targets, including the superior colliculus. They have recently been shown to have extensive intrinsic collaterals spreading up to 8.0 mm within layer 6 of area V1 [J Comp Neurol 441 (2001) 134]. Using intrinsic signal imaging combined with tracer injections, this study investigates how Meynert cell collaterals are mapped in relation to the functional architecture of area V1 in macaque monkeys. In particular, we examined whether terminations of individual axon segments are selective for same-eye or opposite-eye domains. Analysis of 39 anterogradely labeled axon segments (from six injection sites in four hemispheres) showed that terminal segments cross over several pairs of ocular dominance columns (ODCs) and contact both left- and right-eye ODCs, with a slight bias for the contralateral eye. This contrasts with the same-eye bias previously reported for intrinsic collaterals of pyramidal neurons in layer 3. The suggestion is that the system of Meynert intrinsic collaterals is involved with binocular interactions over wide sectors of the visual field. This might be related to processes such as optic flow or, especially given the wide-field spread, even contour completion or interpolation.

Animals↗
PubMed2003

Cerebellar infarction secondary to os odontoideum.

A 43-year-old man developed cerebellar infarction due to atlantoaxial dislocation associated with os odontoideum. Cervical X-ray films confirmed os odontoideum, and conventional angiography revealed irregular narrowing of the right vertebral artery at the axis level. A correlation between the vertebral artery lesion and atlantoaxial instability was shown with 3-dimensional (3-D) computed tomographic (CT) angiography. This is the first case of atlantoaxial dislocation with vertebral artery stenosis demonstrated 3-D CT angiography. 3-D CT angiography can support the conventional angiography with respect to the diagnosis and management of vertebral artery insufficiency associated with occipitocervical deformity.

Adult↗
PubMed2003

Levofloxacin based triple therapy as a second-line treatment after failure of helicobacter pylori eradication with standard triple therapy.

BACKGROUND: Successful eradication of Helicobacter pylori infection after failure of standard triple therapy is difficult. The efficacy and safety of levofloxacin based triple therapy as a first-line therapy has-been studied. AIMS: The aim was to evaluate the efficacy and tolerability of levofloxacin based therapy after a failed standard triple therapy. PATIENTS: We conducted a prospective, uncontrolled study of a consecutive series of 33 patients who failed eradication with 1 week of lansoprazole-amoxicillin-clarithromycin triple therapy. METHODS: The subjects were retreated with 1 week of LA-LVFX triple therapy (lansoprazole, 30 mg twice daily; amoxicillin, 1000 mg twice daily: levofloxacin, 200 mg twice daily). Cure of infection was defined as negative results from culture, histology and a urea breath test 4 to 8 weeks after the second-line therapy. RESULTS: The eradication rate was 69.7% (23/33) by both intention-to-treat and per-protocol analyses (95% confidence interval=61-79%). Seven (21.2%) patients experienced mild side-effects, such as soft stools and taste disturbance. No patient stopped the medication on account of adverse effects. CONCLUSIONS: Levofloxacin based triple therapy is an effective second-line treatment after a failed standard triple therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

Dentoalveolar reconstruction of a missing premaxilla using bone graft and endosteal implants.

We report here on a patient with bilateral cleft lip and palate (BCLP) and a missing premaxilla, who underwent dentoalveolar reconstruction of the cleft and premaxillary alveolus using endosteal implants after bone grafting. The patient, whose maxillary incisors and premaxilla were missing, had corticocancellous bone grafting from the iliac crest, followed by excellent bone formation at the anterior alveolus. After the placement of the endosteal implants and the completion of the pre-surgical orthodontic alignment, orthognathic surgery was performed for the restoration of a Class III open bite. After post-operative orthodontic preparation, the final fixed prostheses were completed. This treatment procedure offers an option of dentoalveolar reconstruction for BCLP patients with an excised premaxilla.

Adult↗
PubMed2003

Black flies (Diptera: Simuliidae) attracted to humans and water buffalos and natural infections with filarial larvae, probably Onchocerca sp., in northern Thailand.

Several Simulium species were investigated as to their biting habits and natural infections with filarial larvae at Ban Pan Fan, Chiang Mai Province, in northern Thailand. Female adults flies landing on or flighting around a human and a water buffalo were collected during the daytime from 06.00 to 19.00 hours on 22 June 2001. As a result, 217 S. nodosum, 86 S. asakoae and two S. nigrogilvum were obtained from a human attractant, and 416 S. nodosum, 25 S. nakhonense, 16 S. asakoae, four S. fenestratum and two S. nigrogilvum, from a water buffalo. The blood-feeding was confirmed only for S. nodosum and S. nigrogilvum on humans, and for S. nodosum and S. nakhonense on water buffalos. Dissections of these simuliids showed that S. nodosum was naturally infected with developing filarial larvae. Two types of microfilariae were distinguished but only one type of infective larvae. These larvae resembled Onchocerca suzukii, a parasite from a wild Japanese bovid, suggesting that an unknown Onchocerca species from ruminants was transmitted in Thailand. Infection rates with all stages of larvae and third-stage larvae were 2.3% (14/608) and 1.0% (6/608), respectively. This is the first report of natural infections of black flies with Onchocerca larvae in Southeast Asia, and the involved black fly species is shown to be not only anthropophilic but also zoophilic in this region.

Animals↗
PubMed2003

Magnetoencephalographic representation of the sensorimotor hand area in cases of intracerebral tumour.

OBJECTIVE: To assess the clinical value of magnetoencephalography (MEG) in localising the primary hand motor area and evaluating cortical distortion of the sensorimotor cortices in patients with intracerebral tumour. METHODS: 10 normal volunteers (controls) and 14 patients with an intracerebral tumour located around the central region were studied. Somatosensory evoked magnetic fields (SEFs) following median nerve stimulation, and movement related cerebral magnetic fields (MRCFs) following index finger extension, were measured in all subjects and analysed by the equivalent current dipole (ECD) method to ascertain the neuronal sources of the primary sensory and motor components (N20m and MF, respectively). These ECD locations were defined as the primary hand sensory and motor areas and the positional relations between these two functional areas in controls and patients were investigated. RESULTS: The standard range of ECD locations of MF to N20m was determined in controls. In 11 of the 14 patients, MRCFs could identify the primary motor hand area. ECD locations of MF were significantly closer to the N20m in the medial-lateral direction in patients than in controls. In patients with a tumour located below the sensorimotor hand area, relative ECD locations of MF to N20m moved anteriorly over the standard range determined in the control subjects. These MEG findings correlated well with radiological tumour locations. The mean estimated ECD strength of MF was significantly lower in patients than in controls. CONCLUSIONS: MRCF was useful in localising the primary motor hand area in patients with intracerebral tumour. The relative ECD locations of MF to N20m describe the anatomical distortion of the sensorimotor cortex.

Adult↗
PubMed2003

Detection of cancer clones in human gastric adenoma by increased DNA-instability and other biomarkers.

An immunohistochemical differential staining of cancerous cells with anti-cytidine antibody after denaturation of nuclear DNA by acid hydrolysis with 2N HCl at 30 degree C for 20 min (DNA-instability test) has been used as a marker of malignancy. The test was applied to bioptic tissues of human gastric polyp assessed histopathologically as foveolar hyperplastic polyp (13 cases), mild (58 cases), moderate (86 cases), and severe (20 cases) dysplasia, and adenocarcinomas (14 cases). The serial sections of the same tissues were also subjected to immunohistochemical staining for Ki67, p53, DNA-fragmentation factor (DFF45), and basic fibroblast growth factor (bFGF). The DNA-instability test was positive in 14 (100%) adenocarcinoma cases, 20 (100%) severe dysplasia cases, 52 (60.5%) moderate dysplasia cases, and 12 (20.7%) mild dysplasia cases, indicating malignancy. All foveolar hyperplastic polyps were negative to the DNA-instability testing. Furthermore, the percentage of glands positive in the DNA-instability test steadily increased in going from mild (10%), to moderate (40%), to severe (100%) dysplasia, and adenocarcinoma (100%). All other biological markers tested in the present study showed significantly higher values in the adenoma glands, being positive to DNA-instability testing, irrespective of the dysplasia grade, as compared to those in the adenoma glands that were negative to DNA-instability testing. Furthermore, the former values were comparable to those in adenocarcinoma. These results indicate that cancer cell clones are already present at the adenoma stages showing a positive DNA-instability test, enhanced proliferative activity, p53 mutation, induction of DFF45 and bFGF. These factors allow cancer cell proliferation, producing heterogeneous subclones due to DNA-instability, enhancing their survival by escaping apoptosis, and providing abundant nutrients during the early-stage progression of gastric cancer. Based on these findings, we herein propose the concept of "procancer" (as opposed to "pre-cancer") as being a unique stage during the course of carcinogenesis and cancer progression. We designate the term to cancer clones at the very early stages of malignant progression that do not show distinguishable morphological atypia but do show positive DNA-instability testing and positive staining for various biomarkers such as Ki67, p53, DFF45, and bFGF. We also define the abnormal positive staining of these biomarkers, including the DNA-instability test as "functional atypia", compared to the ordinary morphological atypia.

Adenocarcinoma↗
PubMed2002

Neuronal hyperexcitability in stroke-like episodes of MELAS syndrome.

BACKGROUND: The pathogenesis of stroke-like episodes in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) remains unknown. METHODS: Fourteen stroke-like episodes in six patients with MELAS were studied using clinical, neuroradiologic, and electrophysiologic approaches. In two patients postmortem examination was done. RESULTS: Headache and epileptic seizure were the most common presenting symptoms. In 13 of 14 episodes the cerebral cortex was primarily involved with variable subcortical edema particularly in the temporal, occipital, and parietal cortex. Repeated MRI performed in two episodes revealed progressive spread of the cortical lesion to the surrounding cortex for a few weeks after the onset of symptoms. In 6 of 11 episodes T1-weighted hyperintense cortical signal compatible with cortical laminar necrosis was seen during subacute stage of the episode. Fat-suppression MRI confirmed intracortical gyral hemorrhage in one episode. Petechial gyral microhemorrhages were also pathologically confirmed in the autopsy of another patient. In 9 of 11 episodes focal epileptiform discharges on EEG were noted in the acute brain lesion. In seven of nine episodes focal cortical hyperperfusion was seen in SPECT studies. CONCLUSION: The stroke-like episodes in MELAS may reflect neuronal hyperexcitability, which increases energy demand and creates energy imbalance between energy requirement and adequate availability of adenosine triphosphate due to oxidative phosphorylation defect particularly in the susceptible neuronal population, causing cortical necrosis. The episodic nature of stroke-like episodes is unexplained.

Adult↗
PubMed2002

Effects of levodopa infusion on motor activation responses in Parkinson's disease.

BACKGROUND: Clinical improvement with levodopa therapy for PD is associated with specific regional changes in cerebral glucose metabolism. However, it is unknown how these effects of treatment in the resting state relate to alterations in brain function that occur during movement. In this study, the authors used PET to assess the effects of levodopa on motor activation responses and determined how these changes related to on-line recordings of movement speed and accuracy. METHODS: Seven right-handed PD patients were scanned with H(2)15O/PET while performing a predictable paced sequence of reaching movements and while observing the same screen displays and tones. PET studies were performed during "on" and "off" states with an individually titrated constant rate levodopa infusion; movements were kinematically controlled across treatment conditions. RESULTS: Levodopa improved "off" state UPDRS motor ratings (34%; p < 0.006) and movement time (18%; p = 0.001). Spatial errors worsened during levodopa infusion (24%; p = 0.02). Concurrent regional cerebral blood flow (rCBF) recordings revealed significant enhancement of motor activation responses in the posterior putamen bilaterally (p < 0.001), left ventral thalamus (p < 0.002), and pons (p < 0.005). Movement time improvement with treatment correlated with rCBF increases in the left globus pallidus and left ventral thalamus (p < 0.01). By contrast, the increase in spatial errors correlated with rCBF increases in the cerebellar vermis (p < 0.01). CONCLUSION: These results suggest that levodopa infusion may improve aspects of motor performance while worsening others. Different components of the motor cortico-striato-pallido-thalamo-cortical loop and related pathways may underlie motor improvement and adverse motoric effects of levodopa therapy for PD.

Aged↗