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Biomedical subjects

K Ono

Publications and source records attributed to K Ono.

At least 361 records · Page 20Linked to original sources
PubMed1998

[Serial MRI study on a case of anterior spinal artery syndrome].

A 63-year-old woman suddenly began to suffer from left chest pain. She gradually became unable to walk and was admitted to the emergency room at another hospital. When she became paraplegic in spite of steroid therapy, she was admitted to our hospital. Her affliction was diagnosed as anterior spinal artery syndrome because of flaccid paraplegia and dissociated sensory loss below the Th4 dermatome. Hematological study indicated a compensated DIC and hepatic enzyme abnormality, while the CSF examinations showed an elevation of protein and positive myelin basic protein (MBP) elevation. The initial MRI taken in the acute stage showed no abnormal signals on T1-weighted (T1) and Gd-enhanced images. The sagittal T2-weighted image (T2) revealed central high intensity (HI) with longitudinal extension from Th2 through the Th11 vertebral level. On axial T2, HI was located on the gray matter at the Th3 and Th4 vertebral level, the ventral two-thirds at the Th8 vertebral level, the central ventral side at the Th9 and Th10 vertebral level, and the entire cross section at the Th12 and L1. A follow-up MRI examination showed that the range of HI on the sagittal T2 had been reduced to 5 segments from Th6 through Th10 vertebral level. The T2 HI lesion on the axial aspect had become reduced so as to localize on the left ventral side at the Th8 vertebral level and on the central ventral side at Th9 and Th10.

Female↗
PubMed1998

Toxoplasma antibody prevalence in Nepalese pregnant women and women with bad obstetric history.

Sera from randomly selected 345 pregnant Nepalese women aged 16-36 years and 13 women with bad obstetric history (BOH) were tested for the presence of Toxoplasma antibodies using microlatex agglutination (MLA) and ELISA methods. The overall prevalence was 55.4% (191/345). Prevalence was slightly higher (59.0%) in older age-group (27-36 years) compared with younger age-group (16-26 years) (52.2%). No significant difference in antibody prevalence in women belonging to two different ethnic-groups (Tibeto-Burmans 57.8%, Indo-Aryans 52.7%) was observed (p>0.05). MLA antibody titer ranged from 1:16 to 1:2,048. Over three-fourth of the women showed either high (1:510 or over) or low (1:16 or 1:32) antibody titer. Three percent (6/191) of MLA antibody positive subjects had Toxoplasma IgM antibodies by IgM-ELISA. All six IgM antibody positive pregnant women had MLA antibody titer of over 1:510. Of the total 13 women with BOH, 5 (38.5%) had Toxoplasma antibodies of which 2 (40.0%) were positive for Toxoplasma-IgM antibodies.

Adolescent↗
PubMed1998

Fluorine-18-labeled fluoroboronophenylalanine PET in patients with glioma.

UNLABELLED: We synthesized fluorine-18-labeled fluoroboronophenylalanine (18F-10B-FBPA), an analog of boronophenylalanine (10B-BPA), and characterized its pharmacokinetics in patients with glioma. We conducted PET studies on three types of gliomas to clarify the relationship between tumor grade and each rate constant [K1 (ml/g/min), k2 (min[-1]) and k3 (min[-1])], and here, we discuss the metabolism of the 10B-BPA analog (18F-10B-FBPA). METHODS: Thirty-three cases of primary gliomas were studied by dynamic PET using DL-18F-10B-FBPA or L-18F-10B-FBPA. Dynamic PET images of 18F-10B-FBPA incorporation into tumors were obtained, and the arterial blood samplings were performed in all cases. RESULTS: When the dynamic PET data were represented as Gjedde-Patlak plots, there was a positive slope, suggesting the involvement of the putative metabolic pool of this tracer. A three-compartment model using rate constants (K1, k2 and k3) was used for the kinetic analysis. The accumulation of 18F-10B-FBPA was found to correlate with the degree of malignancy, and the L form of 18F-10B-FBPA was taken up better than was the DL form. The results of dynamic PET analysis suggested that K1 (measuring amino acid transport process) is a major factor determining the accumulation of 18F-10B-FBPA. A comparison of the rate constants revealed that k3 (metabolic process) did not correlate with the degree of malignancy. The absence of evident differences in k3 between DL and L forms suggests that k3 represents phenomena that are not dependent on the native form of L. CONCLUSION: These PET data will be of practical use for diagnosis of malignancy and direct prediction of the effectiveness of boron neutron capture therapy using 10B-BPA.

Astrocytoma↗
PubMed1998

[Developmental plasticity of corticospinal projections in the spinal cord gray matter of normal and hemicortectomized rat].

In the previous study we demonstrated in rats that aberrant ipsilateral CST fibers were increased when the cerebral cortex was surgically ablated unilaterally during the neonatal period. Origin of these aberrant fibers was confirmed to involve collateral axons, ramified from their parent axons. In this study, possible plastic change and the critical period for the outgrowth of CST fibers into the spinal cord gray matter in the rat after unilateral (right side) cortical damage at different ages measured in days were examined using anterograde horseradish peroxidase (HRP). HRP was injected into the left sensorimotor cortex in both normal and experimental rats. In the normal control rats, the outgrowth of HRP positive axons into the spinal gray matter was first noticed at 7 day of age in the vicinity of the right dorsal funiculus, and then reached maximal density and extension at 10 and 14 days of age, respectively. From 21 days onwards, the density and extension of HRP positive axons in the gray matter decreased rapidly except in the medial part close to the dorsal funiculus. In rats whose right cerebral cortex were damaged at day 1 of age, the pattern of the outgrowth of HRP positive axons into the right gray matter was much the same as that in age-matched controls. However, significantly different from the control, many HRP positive axons were noted even in the contralateral gray matter. HRP-positive axons in the contralateral left gray matter were also abundant in the rats who sustained cortical damage at 7 and 14 days, but were decreased considerably when the cerebral cortex was damaged at 28 days of age. When damage occurred at 56 days of age, HRP-positive axons did not increase in the left gray matter, indicating that the critical period of axonal plasticity after localized damage was before 4 weeks of age in rats.

Animals↗
PubMed1998

Positron emission tomography-based boron neutron capture therapy using boronophenylalanine for high-grade gliomas: part I.

Determination of tumor boron-10 (10B) levels is required for accurate neutron dosimetry during boron neutron capture therapy. We assessed a new method for quantitative measurement of boronated drug uptake in high-grade gliomas. This method uses positron emission tomography (PET) with fluorine-18-labeled L-fluoroborono-phenylalanine (L-18F-10B-FBPA), which was synthesized as an analogue of L-boronophenylalanine. We studied the accumulation of L-18F-10B-FBPA by PET in patients with high-grade gliomas. Dynamic PET studies of brain tumors revealed that L-18F-10B-FBPA accumulated gradually after bolus injection, and the value of PET activity divided by the integrated plasma activity reached a constant level 42 min after injection, which was defined as the incorporation constant (Ic*). This constant reflected the appropriate L-18F-10B-FBPA accumulation in tumor tissue. Based on the Ic* constant, the methods for estimating tumor 10B concentration were devised. With this method, the estimated values of 10B concentration in gliomas were very close to the 10B levels in surgical specimens. This method was based solely on PET and can potentially provide data that would assist in the selection of patients for future treatment with boron neutron capture therapy after surgical resection of their brain tumors.

Boron↗
PubMed1998

Positron emission tomography-based boron neutron capture therapy using boronophenylalanine for high-grade gliomas: part II.

Based on pharmacokinetic findings of fluorine-18-labeled L-fluoroboronophenylalanine by positron emission tomography (PET), methods for estimating tumor 10B concentration were devised. In clinical practice of boron neutron capture therapy (BNCT) for high-grade gliomas, a large amount of L-boronophenylalanine (L-10B-BPA)-fructose solution is used. Under these conditions, a slow i.v. infusion of L-10B-BPA-fructose solution should be performed for BNCT; therefore, the changes over time in 10B concentration in the target tissue were estimated by convoluting the actual time course of changes in plasma 10B concentration with a PET-based weight function including the proper rate constants [K1 (ml/g/min), k2 (min(-1)), k3 (min(-1)), and k4 (min(-1))]. With this method, the estimated values of 10B concentration in gliomas were very close to the 10B levels in surgical specimens. This demonstrated the similarity in pharmacokinetics between fluorine-18-labeled L-fluoroboronophenylalanine and L-10B-BPA. This method, using the appropriate rate constant, permits the determination of tumor 10B concentration and is widely suitable for clinical BNCT, because the averaged PET data are enough to use in future patients without individual PET study.

Boron↗
PubMed1998

[Comparison of the amnesic effects of propofol and isoflurane anesthesia].

Sixty adult patients were assigned to one of 3 groups according to the anesthetic technique chosen: isolfurane inhalation, propofol infusion at a higher rate, and propofol infusion at a lower rate supplemented with epidural anesthesia. When the patients regained consciousness and orientation after surgery, they were shown a digit and asked to confirm it verbally. Memory of the digit was tested on the following day. The percentages of the patients who were able to recall the digit were significantly different among the 3 groups, 5%, 40% and 80%, respectively. We concluded that the amnesic effect of propofol was weaker than that of isoflurane when compared immediately after anesthesia. This tendency was more conspicuous when the dose of propofol was less with epidural anesthesia.

Adult↗
PubMed1998

[Diagnostic muscle MRI abnormality in a patient with inclusion body myositis].

A 64-year-old woman was admitted to our hospital because of muscle weakness and atrophy in the extremities. Four years before admission, he was noticed to have elevated creatine kinase (CK) level, but had no further evaluation. Two years later, she became difficult in standing up and needed a wheelchair. Six months before admission, she noticed muscle wasting in the buttock, thigh, bilateral forearms, and weakness in the upper limbs. On neurologic examination, she had weakness in sternocleidomastoid and all limb muscles, predominantly in the distal portion of the upper extremities. Laboratory study revealed elevated CK, LDH, and aldolase levels, and myogenic change with fibrillation on needle EMG. Muscle biopsy showed myopathic changes with infiltration of mononuclear cells and rimmed vacuoles. The clinical manifestations as well as poor response to corticosteroids therapy were supportive of the diagnosis of inclusion body myositis. However, the distribution of muscle weakness in her wrist, weaker in the extensors than in the flexors, was not characteristic to IBM. This problem was solved by the right forearm MRI which showed a high signal intensity area in flexor muscles, but not in extensors on T1 and T2 weighted images. Accordingly, the muscle MRI of forearm was a diagnostic aid of IBM in this patient.

Female↗
PubMed1998

[What 100 HPN patients taught us].

Recently, Terumo Corporation has developed a new management system, 'Home-Joint', which helps hospitals discharge patients easily. Several hospitals have adopted this system for HPN (home parenteral nutrition) patients, as it can provide discharge program from the hospital and provide items required in alternate site care. This report gives an evaluation of 100 HPN patients who underwent 'Home-Joint' program in 1997. 1) Profiles of patients. Number: 100 (female 47, male 53) Age: 26-96 (61 patients over 70) DIAGNOSIS: cancer 57, others 21, unknown 22 Therapeutic periods: average 53 days (2-617) for terminated 84 patients. Infusion Devices: ambulatory pump 55, stationary pump 41, gravity 4. 2) Important factors for HPN support 1. Be reliable for patients and staff. 2. Train patients well before discharge. 3. The simpler the device the better. 4. Trial or short home-coming required. 3) Issues. 1. Compared with other home therapies, HPN blood access requires much care. 2. Therapeutic period too short. 3. Pay for HPN service too small for a business HPN is very useful for the hospital to discharge the patient comfortably, but requires a complete service system and suitable reimbursement for business.

Adult↗
PubMed1998

[Life supports for terminal cancer patients].

An In-home medical care center was established at Tokyo Women's Medical University in 1997, and supported 14 cases that were treated at home. According to these cases, we understood that the terminal cancer patients and their family had various ways of thinking, especially misgivings about their surroundings. Causes of the misgivings were divided into 6 elements, such as experience, environment, situations, patients themselves, information and time management. To remove these uneasy feelings, we thought that our medical care center should play an important role in providing early consultation for cancer patients and their families. We concluded that the most important thing was collaboration with regional medical staff.

Aged↗
PubMed1998

Neutron capture therapy with a new boron-porphyrin compound in the rat 9L glioma model.

Neutron capture therapy with a new boron-porphyrin compound was tested in a rat brain tumor model. Although the concentration of boron in the tumor was too low to elicit a therapeutic effect, prominent histopathologic changes, such as necrosis, congestion and bleeding were observed in the tumors of the rats which were administered the boron neutron capture therapy.

Animals↗
PubMed1997

The fates of the callosal neurons in neocortex after bisection of the corpus callosum, using the technique of retrograde neuronal labeling with two fluorescent dyes.

The fate of callosal neurons after callosotomy is yet unclear although this has become a common surgical procedure for intractable generalized epilepsies. Using retrograde neuronal labeling with two fluorescent dyes, we demonstrated that callosal neurons in the parietal cortex of the adult rat survive up to 20 weeks after callosotomy. Our data suggest that these neurons possess numerous ipsilateral axon collaterals with indispensable functions in the ipsilateral hemisphere.

Amidines↗
PubMed1997

Both hypertrophic and dilated cardiomyopathies are caused by mutation of the same gene, delta-sarcoglycan, in hamster: an animal model of disrupted dystrophin-associated glycoprotein complex.

Cardiomyopathy (CM) is a primary degenerative disease of myocardium and is traditionally categorized into hypertrophic and dilated CMs (HCM and DCM) according to its gross appearance. Cardiomyopathic hamster (CM hamster), a representative model of human hereditary CM, has HCM and DCM inbred sublines, both of which descend from the same ancestor. Herein we show that both HCM and DCM hamsters share a common defect in a gene for delta-sarcoglycan (delta-SG), the functional role of which is yet to be characterized. A breakpoint causing genomic deletion was found to be located at 6.1 kb 5' upstream of the second exon of delta-SG gene, and its 5' upstream region of more than 27.4 kb, including the authentic first exon of delta-SG gene, was deleted. This deletion included the major transcription initiation site, resulting in a deficiency of delta-SG transcripts with the consequent loss of delta-SG protein in all the CM hamsters, despite the fact that the protein coding region of delta-SG starting from the second exon was conserved in all the CM hamsters. We elucidated the molecular interaction of dystrophin-associated glycoproteins including delta-SG, by using an in vitro pull-down study and ligand overlay assay, which indicates the functional role of delta-SG in stabilizing sarcolemma. The present study not only identifies CM hamster as a valuable animal model for studying the function of delta-SG in vivo but also provides a genetic target for diagnosis and treatment of human CM.

Amino Acid Sequence↗
PubMed1997

Nigral axon terminals are in contact with parvicellular reticular neurons which project to the motor trigeminal nucleus in the rat.

We examined whether in the rat the descending fibers from the substantia nigra pars reticulata (SNr) were in contact with premotor neurons projecting to the motor trigeminal nucleus (Vm), using a combined anterograde and retrograde tracing technique. After ipsilateral injections of cholera toxin B subunit (CTb) into the Vm and biotinylated dextranamine (BDA) into the SNr, numerous CTb-labeled neurons were distributed bilaterally with slightly ipsilateral dominance in the parvicellular reticular formation (RFp), where many BDA-labeled axons with bouton-like varicosities were found bilaterally with a clear-cut ipsilateral dominance. The overlapping distribution of these labeled axons and neurons was more prominent in the rostral RFp than in the caudal RFp. Within the neuropil of the RFp, some of the BDA-labeled axons made synapses with the somata and proximal dendrites of CTb-labeled neurons. Thus, the present study demonstrated the existence of an indirect pathway from the SNr to the Vm, relayed by the RFp.

Animals↗
PubMed1997

Enhancement of neurite outgrowth by the soluble form of human L1 (neural cell adhesion molecule).

L1, a neural cell adhesion molecule, is involved in neurite outgrowth, migration and fasciculation. Although L1 is a membrane glycoprotein expressed on neural cells, the soluble form of L1 is generated in vivo by proteolysis. In the present study, a stable transfectant of Chinese hamster ovary (CHO) cells secreting human L1 without cytoplasmic and membrane spanning domains was generated, and the function of the secreted L1 was examined. Explants from embryonic chick brain stem were cultured on a substrate coated with polyethylenimine (PEI) alone, on substrate-bound L1 or in medium containing soluble L1. The neurites induced by L1, both the substrate-bound form and the soluble form, were 2-3 times longer than those cultured on PEI. The ability of the soluble L1 to induce neurite formation was slightly greater than that of the substrate L1. The present results demonstrated that neurite outgrowth was induced not only by substrate-bound L1 but also by soluble L1. Soluble L1 could be a pharmaceutical candidate for the promotion of nerve regeneration.

Animals↗
PubMed1997

Amiodarone inhibits production of tumor necrosis factor-alpha by human mononuclear cells: a possible mechanism for its effect in heart failure.

BACKGROUND: Recent studies suggest that cytokines such as tumor necrosis factor (TNF)-alpha and interleukins (ILs) are capable of modulating cardiovascular function and that drugs used in the treatment of heart failure have various modulatory effects on the production of cytokines. This study was performed to examine the effects of amiodarone (a drug shown to be beneficial in some patients suffering from heart failure) versus other antiarrhythmic agents on the production of cytokines in vitro. METHODS AND RESULTS: Human peripheral blood mononuclear cells (PBMC) were obtained from healthy volunteers. PBMC were cultured with 0.1, 1, and 10 micromol/L of amiodarone, quinidine, disopyramide, and lidocaine in the presence of lipopolysaccharide. After 24 hours' incubation, TNF-alpha, IL-1beta, and IL-6 were measured in the culture supernatants by an enzyme-linked immunosorbent assay. TNF-alpha production was inhibited by amiodarone but stimulated by quinidine in a concentration-dependent manner. Disopyramide and lidocaine tended to increase TNF-alpha production. IL-6 production was decreased by amiodarone in all concentrations but was increased significantly by disopyramide. Modulation of IL-1beta production by amiodarone was biphasic and significantly increased at a concentration of 10 micromol/L. CONCLUSIONS: These previously unrecognized immunomodulatory effects of amiodarone may contribute to its beneficial effects in heart failure patients.

Amiodarone↗