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Biomedical subjects

Y Higashi

Publications and source records attributed to Y Higashi.

At least 199 records · Page 11Linked to original sources
PubMed1992

Detection of hepatitis C virus by polymerase chain reaction and response to interferon-alpha therapy: relationship to genotypes of hepatitis C virus.

To investigate the relationship between genotypes of hepatitis C virus and response to interferon-alpha therapy, hepatitis C virus RNA was assayed by polymerase chain reaction with three sets of primers and probes in 70 patients with non-A, non-B chronic hepatitis who received interferon-alpha. Twenty-four patients sustained long-term remissions (complete responders). Polymerase chain reaction for 5'-terminal noncoding region detected hepatitis C virus RNA in 94.3% (66 of 70) of the patients. Polymerase chain reaction for nonstructural region 3, in which primers and a probe were synthesized to be identical to hepatitis C virus-J, detected hepatitis C virus RNA in 40 patients. Polymerase chain reaction for nonstructural region 5-in which sequences of primers and a probe were derived from hepatitis C virus-K2, a genotype different from hepatitis C virus-J--detected hepatitis C virus RNA in 17 patients. Only one patient was positive on both nonstructural region 3 and nonstructural region 5 polymerase chain reaction. Nucleotide sequence of clones obtained from 5' terminal noncoding region polymerase chain reaction products of two patients positive on polymerase chain reaction for nonstructural region 3 and negative on polymerase chain reaction for nonstructural region 5 (group 1) corresponded to that of the hepatitis C virus-J group, and those of clones from two patients negative on polymerase chain reaction for nonstructural region 3 and positive on polymerase chain reaction for nonstructural region 5 (group 2) corresponded to that of hepatitis C virus-K2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Elevation of platelet-associated IgG in aplastic anemia.

We determined platelet-associated IgG (PAIgG) levels in patients with aplastic anemia, idiopathic thrombocytopenic purpura (ITP), iron deficiency anemia, and systemic lupus erythematosus (SLE), as well as in normal healthy adults as a control group. To determine PAIgG levels, we used a competitive micro enzyme-linked immunosorbent assay, which had excellent reproducibility, recovery, and dilution. We confirmed its reliability by comparing it to the immunoradiometric assay. Both the aplastic anemia group (n = 27, mean +/- SD = 218.6 +/- 244.6 ng/10(7) platelets) and the ITP group (n = 82, mean +/- SD = 212.5 +/- 327.8 ng/10(7) platelets) had higher PAIgG levels than the SLE group (n = 4, mean +/- SD = 38.4 +/- 22.4 ng/10(7) platelets), iron deficiency anemia group (n = 10, mean +/- SD = 16.1 +/- 3.6 ng/10(7) platelets), and normal control group (n = 69, mean +/- SD = 16.1 +/- 3.6 ng/10(7) platelets. The higher platelet-associated IgG levels in aplastic anemia suggest that autoimmune mechanisms are involved.

Adolescent↗
PubMed1992

Effects of transforming growth factor-beta 1 against the inhibitory action of interferon on DNA synthesis and viral replication in hepatitis B virus DNA-transfected cell.

Studies were undertaken to examine the effects of recombinant human transforming growth factor beta 1 (TGF-beta 1) on DNA synthesis and antiviral actions of interferons (IFNs) in HepG2 cell, a hepatoma cell line, transfected with hepatitis B virus (HBV) DNA. The inhibitory effects of IFN-alpha and -gamma on DNA synthesis of HepG2 cells were enhanced in a dose-dependent manner by a simultaneous addition of TGF-beta. The degree of suppression by the reagents was greater in HBV-nontransfected cells than in transfected cells. Inhibition of DNA synthesis was not due to direct cytotoxic effects of the additives, since the viability of HepG2 cells was comparable in the control and treated cultures as determined by trypan blue exclusion. Treatment of HBV DNA-transfected HepG2 cells with IFNs resulted in decrease in production of HB surface and e antigens, and in the level of HBV DNA, but TGF-beta reversed the IFN-induced antiviral state in HBV DNA-transfected HepG2 cells. TGF-beta had no direct effect on HBV replication. These results indicate that rTGF-beta 1 exerts a differential effect against the inhibitory actions of IFN on DNA synthesis and viral replication in HepG2 cells.

DNA, Viral↗
PubMed1992

The twitcher mouse: immunocytochemical study of Ia expression in macrophages.

The cells expressing immune response associated antigen (Ia) were investigated in the nervous system of the twitcher mouse (an authentic murine model of globoid cell leukodystrophy in humans). With immunocytochemistry using a monoclonal antibody against Mac-1 antigen, many Mac-1 immunoreactive cells (Mac-1 positive cells) were detected in the central as well as the peripheral nervous systems (CNS and PNS). In the CNS, Mac-1 positive cells in the gray matter showed cellular morphology of ramified microglia with delicate cellular processes, while in the white matter Mac-1 positive cells were more plump in shape. Ia expressing cells (Ia positive cells) were also largely confined to the white matter. About 10% of the Mac-1 positive cells were Ia positive. The Ia and Mac-1 positive cells were slender and spindle shaped, and morphologically similar to Ia positive cells in the peripheral nerves while the cells expressing Mac-1 only were more plump in shape. With immunoelectron microscopy, however, both slender Ia positive and plump Ia negative and Mac-1 positive cells revealed electron lucent cytoplasmic vacuoles containing characteristic tubular inclusions of globoid cell leukodystrophy. The results suggest that Ia positive cells are a subset of macrophages in the CNS. Whether Ia expression was induced to "endogenous" microglia or whether Ia expressing cells were exogenous cells infiltrated in the CNS in response to pathological lesions is yet to be determined.

Animals↗
PubMed1992

An activity which restores theta toxin activity in some theta toxin-deficient mutants of Clostridium perfringens.

Group a mutants of Clostridium perfringens are deficient in theta toxin but release a dialyzable substance ("substance A"), which restores theta toxin activity to group b mutants, into a culture supernatant; group b mutants are defective in "substance A" release. "Substance A" activity appeared in the exponentially growing phase of group a mutants and disappeared in the stationary phase. "Substance A" activity was most stable at pH 5.0 and 0 C and even increased threefold in the first 5 hr, but gradually decreased during the following 15 hr. It was quickly inactivated at neutral and higher pHs at 0 C.

Bacterial Proteins↗
PubMed1992

Age-related changes in occipital alpha rhythm of adults with Down syndrome.

A power spectral analysis was performed on occipital EEGs recorded from 36 Down Syndrome (DS) subjects aged 15 to 54 and compared with two control groups; 47 healthy volunteers (Control) and 42 mentally retarded people without DS (MR). The frequencies of occipital alpha rhythms of DS showed a significant inverse correlation with chronological age, while Control and MR did not. The average frequencies of DS were significantly low even in the youngest age-group in comparison with those of Control, and also decreased in the age-groups of 35 and older compared with MR. It was considered that a slowing of alpha rhythm was a manifestation of premature aging that occurred in the underdeveloped brains of DS.

Adolescent↗
PubMed1992

Brain and cerebrospinal fluid distributions of metoprolol in rats.

The distribution of metoprolol tartrate (MPL) into the brain and cerebrospinal fluid (CSF) from plasma was determined at 2 different steady-state plasma concentrations (2 and 20 nmol/ml) and following intravenous bolus administration (100 nmol/kg) in rats. Under steady-state condition, no difference in the brain and CSF distributions of MPL was observed between 2 different plasma MPL concentrations, and the value of brain- or CSF-to-plasma partition coefficients were 5.7 and 1.5, respectively. Following intravenous administration, MPL distributed into CSF very rapidly and its initial uptake phase was not detected. On the other hand, MPL distribution into the brain was relatively slow with the uptake phase. Thus, the brain uptake of MPL from the plasma was pharmacokinetically analyzed using a modified 2-compartment model and deconvolution method, whereas the CSF distribution of MPL was not adequate for kinetic analysis because of the lack of uptake phase. The analysis of brain uptake of MPL by both compartment model and deconvolution gave the same results and the calculated brain Kp value of MPL was almost comparable with that of observed Kp value under steady-state plasma concentration. The distribution of MPL into CSF was considered mainly depending on the pH difference between the plasma and CSF, and the mutual transfer of MPL between CSF and the brain tissue was considered to be negligible from an in vitro study.

Animals↗
PubMed1992

Application of microdialysis for study of caffeine distribution into brain and cerebrospinal fluid in rats.

The usefulness of microdialysis was examined for the chronological determination of caffeine concentration in the brain and cerebrospinal fluids (CSF) following intravenous administration of caffeine in rats. The recovery percent of caffeine by microdialysis, the concentration ratio of caffeine in the dialysate against that in the brain tissue or CSF was determined. The recovery percent was proved to be constant at 5 different steady-state plasma concentrations of caffeine (0.1-280 nmol/ml) and in different collecting periods of dialysate ranging from 30 s to 10 min. The mean recovery percent in the brain and CSF were 10.9 and 13.1%, respectively. Thus, microdialysis was proved useful for determination of drug concentration in the tissue and biological fluids with time resolution of more than 30 s. The microdialysis method was then applied for the chronological determination of caffeine concentration in the brain and CSF following intravenous bolus administration. The estimated caffeine concentration in the brain and CSF was the same as those obtained by direct determination in isolated brain and CSF, respectively. Transfer of caffeine from plasma to brain and CSF were further pharmacokinetically analyzed using a modified 2-compartment model. In this kinetic model, the transfer of caffeine between the CSF and brain was neglected, since the mutual transfer of caffeine was not detected in in vivo experiments. Calculated curves were well fitted on observed caffeine concentrations in the plasma, brain and CSF.

Animals↗
PubMed1992

Effects of dexamethasone on the production of insulin-like growth factor-I and insulin-like growth factor binding proteins in primary cultures of rat hepatocytes.

The effects of dexamethasone (Dex) on insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-1 production were investigated in primary cultures of rat hepatocytes. Dex enhanced the secretion of IGFBP-1 as measured by ligand blot analysis but did not show any prominent effect on immunoreactive IGF-I secretion. EC50 of Dex on IGFBP-1 secretion was calculated to be 3 x 10(-8) M. The content of IGFBP-1 mRNA in the cells increased greatly in the presence of Dex but the IGF-I mRNA content did not change significantly under the same conditions. Insulin showed the opposite effect of Dex by decreasing the production of IGFBP-1 and the cellular content of IGFBP-1 mRNA. This effect of insulin was observed also with Dex in the medium. These results show that the gene expression of IGF-I and IGFBP-1 is differently regulated by glucocorticoids and insulin in primary cultures of rat hepatocytes. The results most possibly explain the in vivo effects of glucocorticoids and insulin in regulation of IGF-I and IGFBP-1 production by liver.

Animals↗
PubMed1992

A case of right atrial mobile thrombus complicating multiple pulmonary emboli.

Right atrial thrombi are usually immobile. However, a mobile type mimicking a cardiac tumor, especially myxoma, has been described on rare occasions. We report here a case of atrial thrombus which was mobile in the cardiac chambers. A 29-year-old male was admitted because of exertional dyspnea. On admission, his echocardiogram showed an abnormal mass in the right atrium with a stalk attached to the interatrial septum. It decreased in size on the next day. On the fourth day of admission, it moved to the right ventricle. Multiple pulmonary emboli were revealed by the lung perfusion scintigram. Two days after the administration of intravenous urokinase, the abnormal mass in the cardiac chambers was no longer seen on the echocardiogram. This was a rare case of mobile atrial thrombus associated with multiple pulmonary emboli. Thrombolytic therapy appeared to be effective in this case.

Adult↗
PubMed1992

[Thrombosis of the posterior scrotal vein: report of two cases].

A 47-year-old architect and a 30-year-old designer of audio goods presented with thrombosis of left and right posterior scrotal vein, respectively. Both had scrotal masses associated with a feeling of heaviness. Physical, operative and microscopic findings were similar. The lesions were palpated as nontender, slender, elastic masses and located parallel to the urethra in the posterior aspect of the scrotum. At surgical exploration the lesions appeared to be thrombosis of posterior scrotal vein and were removed. Both patients have remained well one year in one and four months in the other after operation. Pathological diagnosis for both surgical specimens was organized thrombosis of vein with eosinophilic infiltration. Eosinophilic infiltration to lesions in the present cases and the occupation of patients suggested that some immunological disorders and localized venous stasis for long time during their sitting work might relate to the formation of thrombosis in the posterior scrotal vein. To our knowledge this is the first report of thrombosis of the posterior scrotal vein.

Adult↗
PubMed1992

Scanning electron microscopy of intracellular organelles in the young odontoblasts of rats.

Intracellular structures of the odontoblasts were studied by scanning electron microscopy (SEM) using a modified AODO (aldehyde prefixed-osmium-DMSO-osmium) method. Well-developed flattened and layered rER (rough endoplasmic reticulum), paved with its associated ribosomes on its outer surface, were clearly observed in the odontoblast. Branched tubular mitochondria with nodules and swollen endings, interposing between and passing through the fenestrated layered rER, were demonstrated in the functional cells. Oblique and cross-sections of both the rER system and tubular mitochondria showed orthodox configurations similar to those usually described in transmission electron microscopy (TEM) studies. Many finger-like projections constructing the cristae directing towards the inner mitochondrial chamber were observed, and external chamber extending into the tubular cristae was also demonstrated.

Animals↗
PubMed1992

[Pyelolymphatic backflow complicating acute hemorrhagic cystitis: a case report].

The clinical course of a case of pyelolymphatic backflow complicated with acute hemorrhagic cystitis is reported. The patient was a 19-year-old woman. She had disturbed passage in the intravesical ureter due to acute hemorrhagic cystitis caused by adenovirus. Pyelolymphatic backflow occurred because of increased pelvic pressure.

Adenoviridae Infections↗
PubMed1992

[Visuo-postural control of schizophrenics--variations of sway area during horizontal eye movement].

In the present study, we investigated the neurological mechanism of commonly known specific or unnatural postures in schizophrenic patients. Using a gravimeter, body sway studied in 26 chronic schizophrenic patients, 10 schizoaffective disorder patients and 21 normal subjects. During eye fixation at a target while keeping an upright posture, schizophrenic patients presented a larger gravimetric area than the normal subjects and the patients with schizoaffective disorder. There was a negative correlation (r = -0.509) between the standard deviation of the sway gravimetric area during fixation and the dose of neuroleptics in schizophrenic patients, but no correlation was found in patients with schizoaffective disorder (r = -0.01), although they took neuroleptics in a similar regimen to that for the schizophrenics. There was no correlation between the standard deviation of the sway gravimetric area during fixation and the duration of illness. There was also no correlation between the former and the amplitude ratio of saccades during smooth pursuit eye movements. When horizontal eye movements pursuing the target were loaded in this experiment, both the normal subjects and the patients with schizoaffective disorder showed a decrease in a loaded gravimetric area and a tendency towards postural stabilization. However, schizophrenic patients having higher SANS scores (Andreasen) presented an increase in gravimetric area. This suggests that schizophrenic patients with higher SANS score may have organic cerebellar changes related to impairment of the mechanism of visual and postural coordinations.

Adult↗
PubMed1992

Papillary cystoadenocarcinoma of the prostate.

We report a papillary cystadenocarcinoma of the prostate found in a 66-year-old man presenting with gross hematuria. The tumor was identified as prostatic in origin because of positive immunohistochemical staining of prostate specific antigen.

Aged↗
PubMed1992

[A case of SSPE presenting visual disturbance and serial MRI study].

A case of subacute sclerosing panencephalitis (SSPE) was reported. The patient was a 16-year-old boy and he initially developed visual disturbance. His neurologic symptoms were myoclonus, dementia, and visual disturbance which was rare as an initial symptom in SSPE. Fundoscopy revealed bilateral pole chorioretinitis and macular degeneration. Serial MRI study demonstrated the lesions in the brain and right eye ball. The distribution varied as time went on. T2-weighted MR images showed the lesions more clearly than T1-weighted MR images. In this case dementia was marked but the lesions in the cerebrum on the MR images were considerably smaller than expected. Although MR image is useful to show the lesions, the discrepancy between clinical signs and MR images may be present in the early stage in SSPE.

Adolescent↗
PubMed1992

[A case of encephalitis with MRI abnormalities localized in the bilateral amygdala and hippocampus].

We report a patient with encephalitis who showed anterograde and retrograde amnesia with MRI abnormalities localized in the bilateral amygdala (AM) and hippocampus (HIPP). A 25-year-old man suddenly experienced a generalized tonic-clonic seizure (GTCS). He was admitted because of increasing lethargy with two further GTCSs during the following 6 days. The patient had high fever, and neurological examination revealed somnolence, disorientation, amnesia, and nuchal stiffness. MRI revealed bilateral symmetrical abnormalities localized in the AM and HIPP, which showed low intensity on T1-weighted images and high intensity on T2-weighted images. Cerebrospinal fluid examination showed a mildly elevated cell count. We suspected herpes simplex virus type I encephalitis and began treatment with acyclovir. After the patient regained a clear consciousness, his antero- and retrograde amnesia continued for several months. The MRI abnormality became less distinct with the improvement of amnesia. We consider that the MRI abnormality was indicative of inflammation and edema, and that the lesion in the AM and HIPP had induced the amnesia.

Acyclovir↗