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Biomedical subjects

T Kanno

Publications and source records attributed to T Kanno.

At least 289 records · Page 16Linked to original sources
PubMed1994

Education in clinical chemistry in Japan.

In Japan, the education of clinical chemists has mainly depended on personal efforts of individuals in medical schools, pharmacy schools and independent laboratories for medical analysis. Through the Board of Clinical Pathologists, the Japanese Society of Clinical Pathology at present provides certification in clinical chemistry as a subspecialty to physicians and the Society also certifies medical technologists at two levels for several subspecialties, including clinical chemistry. At the same time, the Education Committee of the Japanese Society of Clinical Chemistry offers annual summer and winter seminars for continuing education. In the future, these programs will be integrated into a regular postgraduate continuing education structure. However, it is urgent for the Japanese Society of Clinical Chemistry to establish alternate qualification and certification programs for clinical chemists.

Chemistry, Clinical↗
PubMed1994

Human T-cell leukemia virus type I Tax-protein-mediated activation of NF-kappa B from p100 (NF-kappa B2)-inhibited cytoplasmic reservoirs.

The human T-cell leukemia virus type I Tax protein transforms T cells through induced expression of many cellular genes, including those encoding the growth-related proteins interleukin 2 and the alpha chain of its receptor. Induction of these genes is mediated, at least in part, through Tax-dependent posttranslational activation of NF-kappa B, typically heterodimers of p50 (NF-kappa B1) and p65 (RelA). The preexisting NF-kappa B proteins are retained in the cytoplasm of cells by association with inhibitory ankyrin-motif-containing I kappa B proteins, primarily I kappa B-alpha but also including the precursor proteins p105 (NF-kappa B1) and p100 (NF-kappa B2). Here we demonstrate the existence of a previously undescribed multimeric cytoplasmic complex in which NF-kappa B dimers are associated with the p100 inhibitor in a manner dependent on the precursor protein's ankyrin domain. We also demonstrate an antagonistic effect of the Tax protein on the cytoplasmic sequestration function of p100; this in turn leads to nuclear translocation of NF-kappa B dimers liberated from multimeric complexes. Tax may exert these effects through the physical association with p100. Tax also relieves the p100-mediated inhibition of DNA binding by p50-p65 heterodimers in vitro. The results demonstrate a mechanism by which Tax may activate NF-kappa B in T cells.

Cell Compartmentation↗
PubMed1994

Distribution of immunoreactive malondialdehyde-modified low-density lipoprotein in human serum.

We developed a sensitive enzyme-linked immunosorbent assay (ELISA) for detection of malondialdehyde-modified low-density lipoprotein (MDA-LDL) in human serum. A monoclonal antibody against MDA-LDL (ML25) used in our method recognized not only MDA-LDL but also other MDA-modified proteins. However, MDA-LDL was able to be detected specifically by using a combination of ML25 and an antibody specific for apolipoprotein B (apo B) (AB16), which was conjugated with beta-galactosidase. Using this method, measurable amounts of MDA-LDL were detected in the sera of 40 healthy individuals. MDA-LDL was observed to be mainly distributed in the human LDL fraction separated by density gradient ultracentrifugation, while in each lipoprotein subfraction the largest amount of MDA-LDL per protein was found at a subfraction between LDL and HDL. The particle size of LDL in this fraction was smaller than that of LDL in the main LDL fraction, as assessed by electrophoresis. In addition, LDL oxidized by Cu2+ was also detectable with this method. We conclude that our method is sensitive and specific for MDA-LDL and might be useful for investigating MDA-LDL in the human circulation.

Antibodies, Monoclonal↗
PubMed1994

[Development of real-time CT fluoroscopy].

A new CT system that permits real-time monitoring of CT images was developed. Phantom and volunteer studies revealed that the images were displayed at a rate of six per second with a delay time of 0.83 second with clinically sufficient resolution (256 x 256) using the newly developed fast image processor and partial-reconstruction algorithm. The clinical trial of stereotactic aspiration of intracerebral hematoma was successful. The initial trial with CT fluoroscopy revealed potential usefulness of the system in biopsy and other CT-guided interventions.

Biopsy, Needle↗
PubMed1994

[Detectability of cerebral aneurysms and surrounding vessels by three-dimensional evaluation using helical scanning CT (HES-CT)].

Helical scanning CT (HES-CT) is a new technique to enable high-speed volumetric data acquisition. We have applied HES-CT to the diagnosis of cerebral vascular diseases. In our experience, the relationship between the scanning parameters of HES-CT and image quality was complex and reciprocal, so that optimization of the parameters according to the clinical demands was essential. We compared HES-CT with conventional cerebral angiography to determine the detectability of the aneurysm and surrounding vessels, and sought the optimal parameters to delineate small vessels. All aneurysms were detected in multiplanar reconstruction (MPR) images. The smallest one was 3 x 4 mm. MPR images were found to have some advantages over conventional cerebral angiography in delineation of intracranial aneurysms: 1) scanning was over in a short time (30s), 2) the relationship between the aneurysm and surrounding vessels was easily recognized, 3) the diameter of the neck could be measured, because the neck of the aneurysm and parent artery could be imaged on the same plane without overlapping another vessel, 4) calcified lesions on the aneurysmal wall were detected, and 5) HES-CT was done safety without arterial puncture. However, the detectability of unknown aneurysm was less than the detectability of known aneurysm in MPR images. The 180 degrees interpolation algorithm and 1 mm slice were effective in detecting small vessels. However, vessels with a diameter less than 1 mm could not be detected by HES-CT. HES-CT was considered to be useful as a supplementary examination to conventional angiography for the diagnosis of intracranial aneurysms.

Adolescent↗
PubMed1994

Thermosensitization and modification of cytosolic calcium concentration by verapamil and diltiazem in mouse mammary carcinoma cells.

PURPOSE: The cardinal role of Ca2+ signaling in the development of heat damage at 42 degrees C and 44 degrees C and the effect of verapamil and diltiazem on the change of cytosolic Ca2+ concentration, [Ca2+]c, were investigated. METHODS AND MATERIALS: Hyperthermic treatment was performed by immersing the tubes containing the mouse mammary carcinoma FM3A cells in a water-bath set at 42.0 degrees C or 44.0 degrees C. The [Ca2+]c of a single cell after hyperthermia was monitored by a digital image analyzing technique using Fura-2. Influx of Ca2+ was examined by the measurement of the radioactivity of 45Ca2+ incorporated into the cells for 60 min during or after hyperthermia. RESULTS: While the [Ca2+]c of the cells treated at 37 degrees C for 60 min was less than 230 nM, the percentage of the cells showing more than 230 nM increased after 42 degrees C hyperthermia and that of the cells showing more than 300 nM increased after 44 degrees C hyperthermia. When cellular uptake of 45Ca2+ during and after hyperthermia was examined, the increase in 45Ca2+ uptake was observed only for 44 degrees C hyperthermia. Verapamil or diltiazem (100 microM) enhanced a delay of cell growth, an increase in [Ca2+]c and an increase in 45Ca2+ influx for 42 degrees C and 44 degrees C hyperthermia. CONCLUSION: These results are compatible with the view that the increase in [Ca2+]c after 42 degrees C hyperthermia results from intracellular release from calcium store sites whereas the rise in [Ca2+]c after 44 degrees C hyperthermia is mainly due to entry of extracellular Ca2+. Verapamil or diltiazem combined with hyperthermia increased [Ca2+]c, which may play a cardinal role in thermosensitization by these agents.

Animals↗
PubMed1994

Substance P antagonist does not block the stimulation of rapidly adapting pulmonary stretch receptors by ammonia.

We investigated the effects of the substance P (SP) blocker [D-Pro2,D-Trp7,9]-SP on the response of rapidly adapting pulmonary stretch receptors (RARs) to SP administered into the right atrium, or ammonia vapor inhaled into the lungs in anesthetized, spontaneously breathing rabbits. Right atrial administration of SP (0.3, 1.0, and 3.0 micrograms/kg) caused an increase in the RAR activity, and this increase became more prominent as the dose of SP was increased. The RARs increased their activity following inhalation of vapor from 5 and 10% ammonia solutions, and the increase was concentration dependent. The excitatory responses of RAR activity to SP at different doses were greatly diminished or completely blocked by administration of the selective SP antagonist (300 and 500 micrograms/kg). However, the ammonia-induced RAR stimulation was not significantly altered by prior treatment with the SP blocker (300 and 500 micrograms/kg). These results suggest that the stimulation of RARs by ammonia does not occur as a result of the release of SP from sensory nerves in the airways and lungs.

Administration, Inhalation↗
PubMed1994

Population screening of lactate dehydrogenase deficiencies in Fukuoka Prefecture in Japan and molecular characterization of three independent mutations in the lactate dehydrogenase-B(H) gene.

Screening for lactate dehydrogenase (LDH) subunit deficiencies was performed on 2880 blood samples from healthy individuals in the Fukuoka Prefecture in Japan by means of electrophoresis. The frequencies of heterozygotes with either LDH-A or LDH-B deficiency were found to be 0.104% at each locus. These estimated frequencies of either LDH-A or LDH-B deficiencies were slightly lower than, but not significantly different from, those found previously in Shizuoka Prefecture. The genetic mutations in individuals heterozygous for LDH-B deficiency were analyzed by the polymerase chain reaction and DNA conformation polymorphism. Abnormal migration patterns were observed in individuals heterozygous for LDH-B deficiency. Subsequent sequence determination of the mutant alleles revealed three novel mutations: an eight-base duplication in exon 3, a four-base duplication in exon 4, and a one-base deletion in exon 7 of the LDH-B gene. These three mutations result in frame-shift translation and premature termination. In addition, the mutations resulting in the duplication of eight or four nucleotides appear to cause a decrease in the levels of LDH-B mRNA.

Amino Acid Sequence↗
PubMed1994

Effects of veratridine and nifedipine on ammonia-induced rapidly adapting pulmonary stretch receptor stimulation in vagotomized rabbits.

We studied the effects of aerosol administration of veratridine (a sodium channel opener) or nifedipine (a calcium channel blocker) on the responses of rapidly adapting pulmonary stretch receptors (RARs) and dynamic lung compliance (Cdyn) to aerosols of 2 and 4% ammonia solutions in anesthetized spontaneously breathing rabbits without intact vagi. The RARs increased their activity following ammonia aerosol, and the increase was concentration-dependent. However, ammonia aerosol did not significantly alter the value of Cdyn. The RARs following aerosol administration of veratridine (about 200 micrograms) showed their characteristic firing pattern with several phases; each phase was characterized by the long high-frequency continuous discharges. Under these conditions, the response was not associated with any significant change in Cdyn. Even though the change in receptor activity produced by veratridine was restored to control level, subsequent aerosol application of ammonia led to similar firing patterns, as veratridine was given by aerosol, but had no significant effect on Cdyn. Following aerosol administration of nifedipine (about 1 and 2 mg) the RAR activity and Cdyn were similar to those during control. Furthermore, the ammonia-induced RAR stimulation was not significantly affected by nifedipine aerosol. These results suggest that the stimulation of RARs by ammonia in vagotomized rabbits is independent of changes in Cdyn and speculate that their excitatory effect is at least in part related to the activation of Na+ influx to the receptive terminals but is not involved in the secondary entry of Ca2+ ions to the receptor membrane, through voltage-dependent calcium channels.

Administration, Inhalation↗
PubMed1994

Stimulus-secretion coupling and Ca2+ dynamics in pancreatic acinar cells.

1. Unique spatiotemporal dynamics in cytosolic Ca2+ concentration, [Ca2+]c, were characterized in various cell types. In pancreatic acinar cells, physiological concentrations of cholecystokinin octapeptide, CCK-8, (< 10 pM) induce repetitive [Ca2+]c spikes commonly termed Ca2+ oscillation, whereas relatively higher concentrations (30 pM-1 nM) evoke biphasic [Ca2+]c dynamics; a rapid transient peak followed by a sustained increase. Much higher concentrations (> 1 nM) induce a large transient followed by a steep decay. 2. These [Ca2+]c dynamics correspond to secretory responses. Repetitive [Ca2+]c change is attributable to the upstroke of the bell-shaped dose-response relationship and the biphasic change is responsible for the downstroke of the relation (so called high-dose inhibited secretion). The large transient [Ca2+]c increase is associated with morphological changes such as bleb formation. 3. Possible interrelation between dose of secretagogues, secretory responses, [Ca2+]c dynamics, IP3 production, receptor occupation and morphological change will be discussed from both pharmacological and physiological points of view.

Animals↗
PubMed1994

Long term urinary prognosis of cervical cord injury patients.

We made a retrospective comparative study of 88 cervical cord injury patients concerning their long term urological prognosis. In all, 129 urinary complications have occurred in 54 cases (61.4%). The incidence of urinary complications was high in those with higher levels of injury (except C integral of 4 lesions), a complete injury, a younger age of onset and a longer period after injury. Patients who had an indwelling catheter and a suprapubic cystostomy showed a higher rate of urinary complications. Urodynamically, there was no significant difference between the presence and absence of detrusor hyperreflexia. Those with detrusor-sphincter dyssynergia (DSD) also showed no difference compared to those without DSD. For the prevention of urinary complications in cervical cord injury patients, proper urinary management with clean intermittent catheterisation (CIC), or low pressure voiding is necessary in the early period after the onset of the injury.

Adult↗
PubMed1994

Preliminary report on an automated screening test for detection of antibody to human immunodeficiency virus type 1 in whole blood.

We developed and evaluated an automated screening test for antibody to human immunodeficiency virus type 1 (HIV-1) using EDTA-2Na-treated whole blood and an extract of paper disk-absorbed dried whole blood from 60 hemophiliacs infected with HIV-1 and 210 diseased and healthy controls. The specificity and the sensitivity of this system were judged to be 100% with both the whole blood and the extract. This test allows measurement of HIV-1 antibody in whole blood and dried whole blood on a small paper disk and gives a result within 13 minutes; the system can process 150 samples per hour. Therefore, it may be useful at many testing sites, such as emergency departments, intensive care units, blood banks, and commercial laboratories, as well as for mail-order testing from remote areas and developing countries.

AIDS Serodiagnosis↗
PubMed1994

A hydrophilic tetrahydro-beta-carboline in human urine.

A substance that exhibited a tryptophan-like fluorescence peak at 354 nm on excitation at 295 nm at neutral pH was isolated from human urine. This compound was determined by visible-light absorption spectroscopy, fluorescence spectroscopy, 1H and 13C NMR spectroscopies, and FAB-MS to be 1-(1',2',3',4',5'-pentahydroxypentyl)-1,2,3,4-tetrahydro-2-carboli ne-3- carboxylic acid. This compound, named tetrahydropentoxyline, is a new type of hydrophilic tetrahydro-beta-carboline, and its elution position was between those of 4-pyridoxic acid and kynurenic acid on C18 reversed-phase HPLC. The amount of tetrahydropentoxyline excreted in the urine of normal subjects [n = 21; age, 45 (SD 20) years] was about 5.2 (SD 1.0) mg per day.

Carbolines↗
PubMed1994

Kinetic analysis of human T-cell leukemia virus type I Tax-mediated activation of NF-kappa B.

The human T-cell leukemia virus type I (HTLV-I) Tax protein induces the expression of cellular genes, at least in part, by activating the endogenous NF-kappa B transcription factors. Induced expression of cellular genes is thought to be important for transformation of T cells to continued growth, a prelude to the establishment of adult T-cell leukemia. However, neither underlying mechanisms nor kinetics of the Tax-mediated activation of NF-kappa B are understood. We have analyzed a permanently transfected Jurkat T-cell line in which the expression of Tax is entirely dependent on addition of heavy metals. The initial NF-kappa B binding activity seen after induction of Tax is due almost exclusively to p50/p65 heterodimers. At later times, NF-kappa B complexes containing c-Rel and/or p52 accumulate. The early activation of p50/p65 complexes is a posttranslational event, since neither mRNA nor protein levels of NF-kappa B subunits had increased at that time. We demonstrate for the first time a Tax-induced proteolytic degradation of the NF-kappa B inhibitor, I kappa B-alpha, which may trigger the initial nuclear translocation of NF-kappa B. As nuclear NF-kappa B rapidly and potently stimulates resynthesis of I kappa B-alpha, the steady-state level of I kappa B-alpha does not significantly change. Thus, the dramatic Tax-induced increase in the I kappa B-alpha turnover may continually weaken inhibition and activate NF-kappa B. Additional, distinct actions of Tax may contribute further to the high levels of NF-kappa B activity seen.

Chlorides↗
PubMed1994

Hemodynamic responses of the venous system during global brain ischemia related to the reflex bradycardia in the rabbit.

Global brain ischemia in anesthetized rabbits induces a pressor response, bradycardia, apnea, and a reduction in cardiac output. The bradycardia is virtually abolished by bilateral aortic denervation (ADN). To elucidate hemodynamic responses in the venous system and the role of bradycardia in these responses during brain ischemia, central venous pressure (CVP), femoral venous pressure (FVP), and circulation time (CT) of a dye in large veins were simultaneously measured before and after ADN. Cardiopulmonary blood volume (CPBV) and circulating blood volume (CBV) were also measured using a dye-dilution technique in separate experiments. Before brain ischemia, the value of CVP, FVP, mean arterial pressure (MAP), and heart rate (HR) were 0.2 +/- 1.2 cmH2O, 8.9 +/- 1.9 cmH2O, 76 +/- 16 mmHg, and 274 +/- 35 beats/min, respectively (n = 8, mean +/- SD). During brain ischemia, CVP, FVP, and MAP significantly increased to 5.8 +/- 2.6 cmH2O, 11.1 +/- 2.4 cmH2O, and 159 +/- 10 mmHg, respectively. HR decreased to 113 +/- 54 beats/min. After ADN, the changes of CVP, FVP, and HR evoked by brain ischemia were significantly suppressed to 2.4 +/- 1.6 cmH2O, 9.8 +/- 2.1 cmH2O, and 210 +/- 61 beats/min, respectively; however, the increase in MAP was not affected. During brain ischemia, CVP correlated negatively with HR, and positively with CT. CPBV tended to decrease and CBV significantly increased by 3.7 +/- 2.5 ml/kg from that before brain ischemia. It seems that the increased amount in CBV evoked by brain ischemia mainly exists in large veins. From these results we conclude that bradycardia is a major determinant of the blood volume in the cardiopulmonary system and prevents its overflow into pulmonary circulation during global brain ischemia in the rabbit when afterload to the left ventricle is extremely increased.

Animals↗
PubMed1994

Dysfunction of mouse liver mitochondria induced by 2,2'-azobis-(2-amidinopropane) dihydrochloride, a radical initiator, in vitro and in vivo.

Mouse liver mitochondria were uncoupled in a time dependent by intraperitoneal injection of a radical initiator, 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH) (100 mg/kg). State 3 respiration, ADP/O ratio and respiratory control ratio (RCR) were decreased 30 min after injection but there was no effect on state 4 respiration. Lipid peroxidation was increased and oxidative phosphorylation was uncoupled at one hr after drug injection but gradually recovered to normal levels after 14 hr in vivo. State 3 respiration, RCR and ADP/O ratio but not state 4 respiration of isolated mouse mitochondria were inhibited by short term incubation with AAPH in vitro. This inhibitory action was concentration dependent (ID50 = 5 mM) but was not prevented by alpha-tocopherol. AAPH had no effect on electron transport or the membrane potential of these isolated mitochondria. However, mitochondria were uncoupled via lipid peroxidation and swelling by long term incubation with AAPH. These inhibitory effects of AAPH were reduced by its spontaneous degradation not only in vitro but also in vivo. Thus AAPH induces mitochondrial dysfunction by direct action in the early period of treatment and free radicals produced from AAPH mediate mitochondrial swelling via lipid peroxidation in the late period. From these findings, it is concluded that mitochondrial phosphorylation plays an important role in the pathogenesis of liver injury induced by AAPH and that radicals generated by AAPH might be a source of liver injury and mitochondrial dysfunction in vivo.

Amidines↗
PubMed1994

Fast-type electrophoretic variant of lactate dehydrogenase M(A) and comparison with other missense mutations in lactate dehydrogenase M(A) and H(B) genes.

An electrophoretic variant of lactate dehydrogenase (LD) M(A) subunit was discovered in a female patient with chest pain. Her LD activity in serum was within the normal reference interval, and analysis of her LD isoenzyme pattern showed an abnormal migration indicating a fast-type LD-M(A) subunit variant. DNA analysis of the mutant LD-M gene detected a single base substitution, an A to G transition at codon 220 (AAA-->GAA). This mutation resulted in the replacement of a lysine by a glutamic acid (mutation K220E) and produced a subunit variant (electrophoretic fast type). This missense mutation was also observed in the patient's son, and genotypes of mother and son were consistent with their biochemical phenotypes, as evaluated by LD isoenzyme analysis.

Base Sequence↗