Biomedical subjects

A Miki

Publications and source records attributed to A Miki.

At least 55 records · Page 3Linked to original sources

PubMed1998

Detection of designer drugs in human hair by ion mobility spectrometry (IMS).

Since its inception in the early 1970s under the name plasma chromatography, ion mobility spectrometry (IMS) has undergone great changes. It is now utilized more and more in forensic science laboratories where it is used to detect explosives and environmental pollutants [1-4] as well as its use in detecting drugs of abuse [5-8]. Although IMS is known for nearly 30 years now [9], relatively few cases of the application of ion mobility spectrometry to the analysis of human hair have been reported [10-12]. The authors report a new and quick method to rapidly screen and determine MDMA ('ecstasy', 'Adam') and MDEA ('Eve') in human hair. The proposed method using trihexylamine as internal standard resulted in a rapid procedure useful in screening human hair specimens for designer drugs.

3,4-Methylenedioxyamphetamine↗

PubMed1998

Developmental expression of the tight junction protein, occludin, in the gastrointestinal tract of the chick embryo.

The developmental expression of occludin was studied biochemically in whole chick embryos to determine when intercellular tight junctions develop. Occludin mRNA was first detected after 3 days of incubation by the reverse transcriptase-polymerase chain reaction. On northern blot analysis, although occludin mRNA was not discernible in 3-day-old embryos, weak but clear expression was noted on day 4 of incubation and increased dramatically in 5-day-old embryos. Occludin was not detectable on days 3 or 4 of incubation by western blot analysis, and was first detected in 5-day-old embryos. In addition, the expression of occludin was examined immunohistochemically in the gastrointestinal tract of 3- to 21-day-old embryos. Immunoreactivity for occludin was not expressed on day 3 of incubation. On day 4 of incubation, weak immunoreactivity was demonstrated in the gastrointestinal tract, and gradually became stronger with development. By day 11 of incubation, a positive immunoreaction was obtained only on the apical surfaces of the epithelial cells, i.e., at the junctional complexes, while weak immunoreactivity was diffusely distributed throughout the epithelial cells. The possible roles of occludin in the developing gastrointestinal tract are discussed.

Animals↗

PubMed1998

Immunotherapy before and during pregnancy improves pregnancy outcome in women who suffer from recurrent abortion and did not benefit from immunotherapy before pregnancy.

PROBLEM: The appropriate modality of immunotherapy with the husband's mononuclear cells in women with a history of recurrent abortion who aborted despite the immunotherapy performed before pregnancy was explored. METHOD OF STUDY: Nineteen patients who had suffered from recurrent abortion who had received the immunotherapy only before pregnancy and had aborted were treated with further immunotherapy performed either only before pregnancy or twice: before and during pregnancy. RESULTS: In 9 out of the 19 women who received further immunotherapy before pregnancy, 2 had healthy babies and 7 aborted again. In the remaining 10 patients who received further immunotherapy twice, before and during pregnancy, 8 had healthy babies and 2 aborted again. CONCLUSION: Our results indicate that immunotherapy performed before and during pregnancy produces a better outcome compared with that performed only before pregnancy, especially in patients who showed no benefit from the immunotherapy performed only before pregnancy.

Abortion, Habitual↗

PubMed1998

Human lymphocytes obtained from decidual tissue express killer activatory receptors as well as killer inhibitory receptors: analysis using a single strand conformation polymorphism method.

PROBLEM: The objective was to clarify whether lymphocytes in decidual tissue express only killer inhibitory receptors (KIRs) or both KIRs and killer activatory receptors (KARs). METHOD OF STUDY: A polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis method, using cDNA as a template, was applied to detect as many natural killer receptors (NKRs) expressed on natural killer (NK) cells as possible and to distinguish between KIRs and KARs. Using this method, we analyzed NKRs on lymphocytes in decidual tissue and maternal peripheral blood mononuclear cells (PBMCs) (n = 10) from the same individuals. RESULTS: More than 20 SSCP bands were detected for NKRs on both the lymphocytes in decidual tissue and the maternal PBMCs. The SSCP band patterns were different for each individual. KARs mRNA was detected in lymphocytes in decidual tissue according to the SSCP analysis results. CONCLUSION: Lymphocytes in decidual tissue express not only KIRs but also KARs; this finding suggests their roles in placentation and the maintenance of pregnancy.

Abortion, Induced↗

PubMed1998

Peripheral blood mononuclear cells from women with recurrent abortion exhibit an aberrant reaction to release cytokines upon the direct contact of human leukocyte antigen-G-expressing cells.

PROBLEM: In search for pathogenesis of recurrent abortion, we examined whether lymphocytes/macrophages from women with recurrent abortion exhibited an aberrant ability to release cytokines upon the direct contact of human leukocyte antigen (HLA)-G. METHOD OF STUDY: The amounts of cytokines released from peripheral blood mononuclear cells (PBMCs) from women with recurrent abortion were compared with those from normal multiparous women or normal nulligravidous women when cocultured with or without HLA-G-expressing target cells. RESULTS: When cocultured with HLA-G-expressing target cells, the amount of interleukin-1 beta released from PBMCs was increased in recurrent aborters whereas it decreased in both normal multiparous and nulligravidous women. The amount of interleukin-3 released from PBMCs did not differ with or without HLA-G-expressing cells in recurrent aborters, whereas it increased in the presence of HLA-G-expressing cells in normal controls. The amount of tumor necrosis factor-alpha released from PBMCs was decreased in the presence of HLA-G-expressing cells in both recurrent aborters and normal controls. CONCLUSION: The aberrant reaction of maternal lymphocytes/macrophages in releasing cytokines upon the contact of HLA-G expressed on trophoblasts may impact negatively on trophoblastic growth, which may be pathogenic in recurrent abortion.

Abortion, Habitual↗

PubMed1998

Increased conversion ratio of tryptophan to niacin in severe food restriction.

The effect of food restriction on the conversion ratio of tryptophan to niacin was investigated, because it is known that the conversion ratio is influenced by nutritional factors. A 20% casein diet was fed to rats ad libitum (control), 1/2 the food of the control. 1/4 the food of the control, or starved for 9 days, and urine samples were collected to measure the urinary excretion of such tryptophan metabolites as kynurenic acid, xanthurenic acid, and nicotinamide. The conversion ratio in the 1/2, 1/4, or starving group increased at day 1 of the experiment, but returned to the original value from day 2. Only in the starving group did the conversion ratio extremely increase from day 6 to day 9, being about 5-times higher than that of the original value on day 9. The possible mechanism by which the conversion ratio increased during food restriction is discussed.

Animals↗

PubMed1997

Application of ion mobility spectrometry to the rapid screening of methamphetamine incorporated in hair.

Using ion mobility spectrometry (IMS), a simple, sensitive and rapid screening for methamphetamine (MA) incorporated in user's hair has been developed. To completely unbind MA from hair matrix and to achieve its effective vaporization for the IMS detection, the hair sample was digested in 5 M NaOH (methanol-water, 4:1, v/v) solution prior to IMS measurement. MA in hair was semi-quantitatively detected by monitoring the digested hair sample employing dibenzylamine (DBA) as internal standard. The minimum amount of hair sample required was 2 mg and its digested sample was ample for four IMS measurements. The detection limit of MA in hair was 0.5 ng mg(-1). This proposed method was applicable to the semi-quantitative detection of MA in users' hair samples, and to the sectional analysis for MA in a limited amount of user's hair. The IMS results obtained were in good agreement with their GC-MS determination.

Hair↗

PubMed1997

Fatal overdose of clozapine.

An ingestion of an unknown quantity of Leponex (clozapine) tablets in a suicide is described. Although clozapine is known for over 30 years now, relatively few cases of intoxications due to clozapine overdose have been reported. The authors report a new and quick method to analyze and determine the clozapine and N-desmethylclozapine concentration in body fluids. The analytes and an internal standard (zolpidem) were extracted from alkalinized samples into ethyl acetate before GC/NPD analysis. The proposed method resulted in a rapid procedure most useful in cases of deliberate poisoning with the neuroleptic drug Leponex.

Adolescent↗

PubMed1997

Immunological effects of CaEDTA injection: observations in two lead workers.

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 micrograms/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection.

Antibody Formation↗

PubMed1997

Functional magnetic resonance imaging of visual function in postpapilledema optic atrophy.

We studied a girl with intraventricular brain tumor who developed postpapilledema optic atrophy and severe concentric visual field constriction in both eyes. The patient had mild symptoms despite severe visual field loss. We performed functional magnetic resonance imaging using two kinds of visual stimulation to assess her residual visual function. The functional magnetic resonance imaging demonstrated that the activity in her association visual cortex was largely intact bilaterally, although the activation of the calcarine cortex was decreased in the left calcarine cortex. Her activity in the visual cortex seemed to correspond well to her visual symptom. Functional magnetic resonance imaging may be useful in objectively documenting residual visual function in patients with severe visual loss.

Adolescent↗

PubMed1996

Expression of alpha-, beta-, and gamma-subspecies of protein kinase C in the motor neurons in the embryonic and postnatal rat spinal cord.

Using polyclonal antibodies against alpha-, beta- and gamma-subspecies of protein kinase C, developmental changes in expression of these subspecies in the motor neurons in the rat cervical spinal cord were immunohistochemically investigated. On embryonic day-12, the motor neurons began to differentiate from undifferentiated neuroepithelial cells. On embryonic day-13, they began to express weak immunoreactivity for alpha- and beta-protein kinase C and slightly more evident immunoreactivity for gamma-protein kinase C. Immunoreactivity for protein kinase C in these neurons gradually became stronger, as the development progressed. Between embryonic day-18 and postnatal day-7, the motor neurons showed distinct immunoreactivity in the nucleus, perikaryal cytoplasm, axon and dendrites. At these stages, distribution and intensity of immunoreactivity for alpha-, beta- and gamma-protein kinase C were very similar. Thereafter, the expression of this enzyme in the nucleus gradually declined, while in the other structures, expression of each subspecies changed independently. On postnatal day-28 and 35, expression of beta-protein kinase C in the axons was stronger than that of alpha- and gamma-protein kinase C, and immunoreactivity for gamma-protein kinase C in the perikaryal cytoplasm and dendrites was slightly weaker than that for alpha- and beta-protein kinase C. Expression of this enzyme in the motor neurons at these stages was almost the same as in the adult animal. Electron microscopically, immunoreactivity for protein kinase C was randomly distributed in the nucleus, and in the perikaryal cytoplasm, often near the cisterns of the endoplasmic reticulum. Expression of protein kinase C in the growing axons was quite different from that in the mature axons. In the dendrites, immunoreactivity for protein kinase C was distributed randomly in the cytoplasm and at the postsynaptic densities. These findings suggest that protein kinase C might regulate not only the neural functions, but also several aspects of the differentiation process in the motor neurons.

Animals↗

PubMed1996

Developmental expression of alpha-, beta- and gamma-subspecies of protein kinase C in the dorsal corticospinal tract in the rat spinal cord.

Developmental expression of alpha-, beta- and gamma-subspecies of protein kinase C in the dorsal corticospinal tract was immunohistochemically investigated at the cervical level of the postnatal rat spinal cord. On postnatal day 0, immunoreactivity for these subspecies was uniformly distributed throughout the posterior funiculus. On postnatal day 7, immunoreactivity for this enzyme in the posterior funiculus began to decline. On postnatal days 14 and 21, the immunoreactivity in the posterior funiculus became weak, while the dorsal corticospinal tract forming in the most ventral portion of the posterior funiculus exhibited strong immunoreactivity for these three subspecies of protein kinase C. Thereafter, immunoreactivity in the corticospinal tract rapidly declined, and on postnatal days 28 and 35, weak immunoreaction was demonstrated as very fine granular deposits in the tract. Expression of this enzyme in the dorsal corticospinal tract at these stages resembled that in the adult rat. Electron microscopically, growth cones and nascent axonal shafts were first noted on postnatal day 2 in the most ventral portion of the posterior funiculus, and thereafter, the axonal shaft gradually thickened and on postnatal day 14 some axons began to be myelinated. The growth cones and thin axonal shafts randomly exhibited weak immunoreactivity in the axoplasm. The thicker unmyelinated axonal shafts showed distinct immunoreactivity uniformly throughout the axoplasm and along the axolemma as granular deposits. In these developing axons, intensity and distribution of immunoreactivity for all three subspecies were principally similar. In the mature myelinated axons, the intensity and distribution of immunoreactivity for each subspecies of protein kinase C were quite different, i.e. immunoreactivity for alpha-subspecies was randomly distributed on some cytoskeletal elements, and that for beta-subspecies was uniformly detected on most of the cytoskeletal elements. In contrast, immunoreactivity for gamma-subspecies was distributed mainly on the endoplasmic reticulum. These findings suggest that in growing corticospinal axons protein kinase C might be involved in several important aspects of axonal development, and that in mature axons this enzyme might participate in different aspects of axonal function.

Animals↗

PubMed1996

Functional magnetic resonance imaging in homonymous hemianopsia.

PURPOSE: We performed functional magnetic resonance imaging associated with brain activity to evaluate the abnormality of the visual pathway in hemianoptic patients. METHODS: We studied five patients with homonymous hemianopsia caused by retrochiasmal lesions and five control subjects. On the basis of a blood oxygenation level-dependent contrast mechanism, magnetic resonance imaging was performed with a standard clinical 1.5-tesla system. We evaluated the asymmetrically increased signal intensities in the calcarine cortex during visual stimulation and compared them with the findings of Goldmann perimetry. RESULTS: Cortical activations with a marked interhemispheric contrast of the primary visual cortex consistent with the visual field defects were observed in three of the five patients. In two of the patients without macular field preservation in the defective hemifield, functional magnetic resonance imaging showed an absence of response in the primary visual cortex of the affected side. In the patient with superior quadrantanopsia, we could detect clear laterality by selecting the imaging plane inferior to the calcarine fissure. The other two hemianoptic patients with macular sparing showed symmetric responses. CONCLUSIONS: These findings suggest that functional magnetic resonance imaging is valuable in assessing local brain function in patients with visual deficits; therefore, it is a promising method for the objective detection of abnormalities in the afferent visual system.

Adolescent↗

PubMed1996

Detection of visual dysfunction in optic atrophy by functional magnetic resonance imaging during monocular visual stimulation.

PURPOSE: To evaluate functional magnetic resonance imaging as an objective method for detecting visual dysfunction in various ophthalmologic disorders involving the optic nerve and the chiasm. METHODS: We performed functional magnetic resonance imaging during monocular visual stimulation on seven patients with visual field loss caused by lesions of the optic nerve and the chiasm and on three normal control subjects with no visual field loss. We correlated static threshold perimetry in the seven patients with the results of functional magnetic resonance imaging. RESULTS: In the three normal control subjects, we found good intrasubject similarity in areas of bilateral occipital lobe activation between monocular stimulation of the right and left eyes. In the patients with unilateral optic neuropathy, including glaucoma, stimulation of the affected eye induced no activation of the primary visual cortex in the portion corresponding to the central visual field defects and reduced activity of the associated visual cortex. In the patients with chiasmal compression, monocular stimulation resulted in a marked asymmetry of activation in the primary visual cortex, which corresponded to the visual field abnormality. CONCLUSIONS: Functional magnetic resonance imaging appears to be useful in confirming the clinical diagnosis of optic atrophy because it can objectively disclose visual field loss, even a small defect such as central scotoma.

Adult↗

PubMed1996

The 5'-flanking region of the human smooth muscle cell calponin gene contains a cis-acting domain for interaction with a methylated DNA-binding transcription repressor.

The human smooth muscle cell (SMC) calponin gene, which is composed of seven exons and six introns, spanning an approximately 11.2 kilobase (kb) genomic DNA, has been isolated and characterized by sequence analysis. As determined by primer extension mapping and rapid amplification of mRNA transcripts, a major transcription start site of the calponin gene is located at 101 base-pairs (bp) upstream of the ATG start codon. A striking feature of the 5'-flanking, 5'-untranslated, and amino-terminal protein coding regions is the presence of an Alu repetitive sequence and a stretch of DNA sequence identified using a methyl CpG-binding protein affinity column [Cross, S.H., Charlton, J.A., Nan, X., and Bird, A.P. (1994) Nature Genet, 6,236-244]. The results of this study provide a new insight into the molecular mechanism underlying regulation of SMC-lineage specific gene expression.

Base Composition↗

PubMed1996

Development of bioactive functions in hydrangeae dulcis folium. V. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (2). Thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-o-glucoside, and (+)-hydrangenol 4'-O-glucoside.

Following the characterization of thunberginols A, B, and F, six bioactive principles, thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-O-glucoside, and (+)-hydrangenol 4'-O-glucoside, were isolated from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, together with four kaempferol and quercetin oligoglycosides. Their chemical structures have been determined on the basis of chemical and physicochemical evidence. Thunberginols C, D, E, and G and (-)-hydrangenol 4'-O-glucoside showed antiallergic activity in the in vitro bioassay using the Schultz-Dale reaction. These components also exhibited inhibitory activities on the histamine release from rat mast cells and on the histamine-induced contraction in isolated guinea pig tracheal chain. In addition, thunberginols C, D, E, and G showed antimicrobial activities against oral bacteria.

Animals↗

PubMed1996

[Functional magnetic resonance imaging of the frontal eye fields during saccadic eye movements].

We evaluated activity-induced signal intensity changes in the human cerebral cortex during horizontal saccadic eye movements using functional magnetic resonance imaging (fMRI) based on the blood-oxygenation-level-dependent (BOLD) contrast method. Compared with central fixation, significant signal increases were observed bilaterally in the middle frontal gyrus (Brodmann area 8) during saccadic conditions. The location of the activated area was consistent with that of previously reported frontal eye fields (FEF). These results suggest that fMRI has potential merit for the study of cortical control of eye movements in humans.

Adult↗

PubMed1995

Developmental changes in the expression of alpha-, beta- and gamma-subspecies of protein kinase C at synapses in the ventral horn of the embryonic and postnatal rat spinal cord.

Developmental changes in expression of alpha-, beta- and gamma-subspecies of protein kinase C (PKC) at synapses in the ventral horn of the rat spinal cord were immunocytochemically investigated. On embryonic day 15, a few synapses were found in the ventral horn, and they gradually increased in number until postnatal day 21 or 28. During the embryonic period, immunoreactivity (IR) for all three subspecies was demonstrated in both the pre- and postsynaptic regions. In the former, IR was detected mainly along the outer surface of the synaptic vesicles, and in the latter, along the postsynaptic membranes. At these stages, synapses were morphologically immature, having a faint postsynaptic density and a few round synaptic vesicles. After birth, IR for PKCs at the postsynaptic densities became stronger, but gradually disappeared in most of the presynaptic regions. In adult, IR for PKCs was detected only at the postsynaptic densities. At the later postnatal stages, the synapses were fully mature, having a thick postsynaptic density, a great number of synaptic vesicles and a distinct synaptic cleft as those in adult animals. In addition, the developmental changes in expression of these subspecies of PKC in the presynaptic regions were quite different. These findings suggest that the increase in expression of PKC at postsynaptic densities might be closely related with the development of synaptic functions, and also that each subspecies of PKC may take part in different aspects of synaptogenesis.

Animals↗