Biomedical subjects

H Imai

Publications and source records attributed to H Imai.

At least 361 records · Page 20Linked to original sources

PubMed1992

Detection of HIV-1 RNA in heparinized plasma of HIV-1 seropositive individuals.

The interference of reverse transcription by heparin was removed by heparinase. When the HIV-1 RNA in the presence of heparin was detected by a combination of reverse transcription and the polymerase chain reaction (PCR), heparinase treatment followed by removal of Ca2+ before the reverse transcription step permitted the efficient detection of HIV-1 RNA. Prior treatment with heparinase revealed HIV-1 RNA in 68% (13/19) of heparinized plasma samples from HIV-1 carriers, whereas only 26% (5/19) of the same specimens were positive without the heparinase step. Heparinase removed the inhibition of reverse transcription by heparin and is highly recommended when detecting low levels of viral RNA in heparinized plasma.

HIV Reverse Transcriptase↗

PubMed1992

Renal localization of the constitutive 73-kDa heat-shock protein in normal and PAN rats.

We purified the constitutive 73-kDa heat-shock protein (HSP73) from the bovine brain, and produced a specific antibody against the protein in a rabbit. On immunoblotting, the antibody cross reacted only with a protein band with a molecular mass of 73 kDa in a crude extract from normal rat kidneys, which was regarded as rat renal HSP73. The intrarenal immunohistochemical distribution of HSP73 was examined by using this antibody, on both normal rat kidneys and kidneys with puromycin aminonucleoside nephrosis. HSP73 was predominantly present in epithelial cells of the glomeruli and the tubules. In normal kidneys, HSP73 was generally localized in both the cytoplasm and the nucleus of these epithelial cells, except for proximal tubular epithelial cells. On the other hand, in kidneys with puromycin aminonucleoside nephrosis, HSP73 accumulated in the cytoplasm at a level higher than in the nucleus in association with the severity of renal dysfunction and proteinuria. These findings indicate that HSP73 is mainly expressed in glomerular and tubular epithelial cells in the kidney under a physiological condition, and that its expression changes from the nucleus to the cytoplasm under pathological conditions such as a protein overload to these epithelial cells.

Animals↗

PubMed1992

Localization of phosphoinositide-specific phospholipase C-alpha in porcine kidney.

The presence of multiple forms of phosphoinositide-specific phospholipase C (PLC), an important enzyme in the cell signal transduction, suggests that specialized functions of tissues and cells may require different modes of PLC regulation. In the present study, we have purified a 54-kDa heparin-binding protein from a 4 M guanidine hydrochloride extract of porcine kidney, and identified it as one of isoenzymes of PLC on the basis of its partial amino acid sequence. Among 194 determined sequences of the porcine protein, 186 residues were identical with those deduced from nucleotide sequence of the cDNA encoding rat PLC-alpha. The subcellular distribution of porcine renal PLC-alpha was examined by Western blotting by using a specific antibody against the purified protein. Quantitation of the Western blots revealed that 70% of PLC-alpha was membrane-associated. Immunohistochemical studies showed a specific localization of PLC-alpha in epithelial cells of distal tubules and collecting ducts of normal porcine kidney, but not in other cells composing the nephron. Moreover, the highest expression of PLC-alpha was observed in apical membranes in these epithelial cells. Thus, this form of PLC is considered to have a specific role in the signal transduction process related to regional renal tubular functions.

Amino Acid Sequence↗

PubMed1992

Case report: nephrotic syndrome associated with a total hydatidiform mole.

The authors describe a 51-year-old Japanese woman who developed nephrotic syndrome in association with a total hydatidiform mole. The nephrotic syndrome remitted completely following hysterectomy. A renal biopsy performed before the operation showed diffuse mesangial cell proliferation of a moderate degree, and thickened capillary walls with focal and segmental subendothelial deposits, as well as circumferential mesangial interposition. Occasional foci of the mesangiolysis were also observed. Immunofluorescence microscopy revealed granular staining of IgM along the glomerular capillary walls in a fringe pattern. A review of the literature revealed that this patient appears to be the first case of nephrotic syndrome associated with a total mole, although there have been two cases of nephrotic syndrome due to preeclamptic nephropathy associated with a partial or transitional mole.

Female↗

PubMed1992

Kappa light chain nodular glomerulosclerosis with conspicuous crescent formation and tubulointerstitial injury. Report of a case.

We describe a 39-year-old man who developed kappa light chain nodular glomerulosclerosis with superimposed conspicuous crescent formation and extensive tubulointerstitial injury. The clinical picture was characterized by nephrotic syndrome and rapidly progressive glomerulonephritis. Incessantly progressive loss of renal function culminated in irreversible renal failure 7 weeks after initial manifestations of renal insufficiency. The patient has since been maintained on thrice weekly hemodialysis with chemotherapy for five years. At the time of pathologic diagnosis by renal biopsy, there was no evidence of multiple myeloma, and no serum M-component or Bence-Jones proteinuria was detected. An initial bone marrow aspirate revealed the presence of 0.6% atypical lymphocytes as the sole abnormality, although these were later identified as atypical plasma cells. These cells had also infiltrated the renal interstitium. Crescentic kappa light chain nodular glomerulosclerosis lacking evidence of plasma cell dyscrasia should be included in the differential diagnosis of rapidly progressive glomerulonephritis.

Adult↗

PubMed1992

Orthostatic tremor associated with voice tremor.

We report a 67-year-old female with orthostatic and voice tremor. Her orthostatic tremor mainly affected her lower extremities, alternating between antagonist muscle groups at a frequency of 4.4-4.8 Hz. The voice tremor ranged between 4.8 and 8.8 Hz. In this case, the frequency of voice tremor was same as that of orthostatic tremor, suggesting a common origin from a tremor-generating mechanism. These tremors were diagnosed as 'forme fruste' of the essential tremor, not the incipient stage of Parkinson's disease. Medications including clonazepam, perphenazine, Dopa and trihexyphenidyl hydrochloride had no effect on both the orthostatic and voice tremors, but propranolol was somewhat beneficial on voice tremor.

Aged↗

PubMed1992

An acute mercuric mercury poisoning: chemical speciation of hair mercury shows a peak of inorganic mercury value.

A woman ingested a dose of sublimate (approximately 0.9 g) in an attempted suicide. She survived and recovered in response to a combination of therapies including chelate (BAL) therapy, plasma exchange, haemodialysis and peritoneal dialysis. Serum inorganic mercury concentration, urinary inorganic mercury excretion and hair inorganic and organic mercury and selenium concentrations, along the length from the scalp to the distal part, were measured. Longitudinal analysis of hair, revealed a peak in inorganic mercury corresponding to the time of mercury ingestion. Organic mercury and selenium in the hair had different patterns of longitudinal variation from that of inorganic mercury. The biological half-life (23.5 d) of serum inorganic mercury levels was in good agreement with values previously reported in the literature.

Adult↗

PubMed1992

High-energy phosphate metabolism of the myocardium in normal subjects and patients with various cardiomyopathies--the study using ECG gated MR spectroscopy with a localization technique.

Nuclear magnetic resonance spectroscopy (MRS) is a new technique for the evaluation of myocardial metabolism. Recently, localized MRS has been clinically available to measure by a non-invasive method the relative concentrations of the high-energy phosphate metabolites in the myocardium. We performed ECG gated P-31 MRS using ISIS (image-selected in vivo spectroscopy) in 15 normal volunteers, 12 patients with hypertrophic cardiomyopathy, 12 with left ventricular hypertrophy, 6 with dilated cardiomyopathy and 11 with specific heart muscle disease. Myocardial peak height ratios of PCr/gamma-ATP, Pi/gamma-ATP and PCr/Pi were measured. Myocardial P-31 MRS demonstrated a significant decrease in the ratio PCr/ATP in patients with hypertrophic cardiomyopathy and specific heart muscle disease as compared with normal subjects, indicating myocardial metabolic disturbance in these patients. The ratio of PCr/ATP in patients with dilated cardiomyopathy did not differ significantly from that of normal subjects. However, exercise MRS revealed a marked decrease of PCr peak in an asymptomatic patient with dilated cardiomyopathy, which may indicate a latent metabolic disturbance in the myocardium of dilated cardiomyopathy.

Adenosine Triphosphate↗

PubMed1992

48, XXYY syndrome associated with ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia.

A 56-yr-old man with hypogonadism, gynecomastia, and mental retardation was evaluated for chromosome constitution and thrombocytopenia. Chromosomal analysis demonstrated the mosaicism of 48, XXYY and 47, XXY in the peripheral lymphocytes. Twenty out of twenty-five cells were 48, XXYY karyotype and the remaining five were 47, XXY karyotype. Thrombocytopenia was the EDTA-dependent pseudothrombocytopenia type 1 (platelet agglutination). Serological examination suggests that the platelet agglutinin belongs to IgM-kappa type. The present case exhibited both EDTA-dependent pseudothrombocytopenia and the 48, XXYY syndrome. Although this combination may have occurred purely by change, the possibility of whether or not the mosaicism of lymphocytes produces platelet agglutinin remains to be clarified.

Edetic Acid↗

PubMed1992

Possible role of red cell deformability and microvasculature in microcirculation.

The roles of the deformability of red blood cells (RBC) and the microvasculature in the maintenance of blood flow were investigated in terms of the pressure (P)-flow rate (Q) relationships in human RBC suspension perfusions of bullfrog hind limb. Although isotonicity for the bullfrog is approximately 215 mOsm/kgH2O, perfusions in intact hind limbs showed no change in the P-Q relationship at test solution osmolalities ranging from approximately 150 to approximately 300 mOsm/kgH2O. The deformability of RBC was examined in glutaraldehyde-fixed hind limbs. Perfusion of fixed limbs with RBC suspension revealed minimum resistance to flow at osmolalities of approximately 250 to approximately 420 mOsm/kgH2O, whereas the same experiment in intact limbs revealed minimum flow resistance at osmolalities of approximately 200 to approximately 300 mOsm/kgH2O. It was noteworthy that the reduction of RBC deformability was not observed in intact limbs at osmolalities of approximately 250 to approximately 200 mOsm/kgH2O. Heinz body-forming RBC from a patient with unstable hemoglobin (Hb) disease (Hb Yokohama) exhibited a marked reduction in deformability as compared with normal RBC in fixed limbs, while there was no discernible difference between the two types of RBC in intact limbs, thereby suggesting that the microvascular bed can compensate, to an appreciable extent, for the impaired deformability of RBC, probably via its distensibility and/or a wall effect. The present study has considerable implications concerning the link between in vitro experiments and the in vivo situation, including the hemodynamic characteristics of RBC suspensions such as the effective viscosity.

Adult↗

PubMed1992

[Left ventricular trabeculae evaluated with MRI in dilated cardiomyopathy and old myocardial infarction].

The morphological examination of the left ventricular trabeculae was performed using MRI (0.5T) in 14 normal volunteers, 12 patients with dilated cardiomyopathy (DCM), and 9 patients with old myocardial infarction (OMI). Left ventricular trabeculae were observed at the free walls of the left ventricle in all subjects, but not at the septal wall. Left ventricular trabeculae were larger in DCM than in the normals. The trabeculae were scarce in OMI and inner sides of the infarcted myocardium were very smooth. The development of the left ventricular trabeculae was graded as diminished, ordinary, and marked. Ordinary trabeculae were seen in 86% of the normals, whereas; marked trabeculae in 75% of DCM, and diminished trabeculae in 78% of OMI. In patients with DCM, the mean area of the left ventricle with marked trabeculae was greater than that with ordinary trabeculae. The more dilated left ventricle, the thinner the anterior wall was and the lower the ejection fraction was in DCM and OMI, though there were no significant differences in values of these 3 items between DCM and OMI. The MRI findings on the development of the trabeculae were confirmed in patients with DCM at autopsy. Thus, the MRI findings were very useful in the differential diagnosis between DCM and OMI.

Adult↗

PubMed1992

Nucleolar antigens and autoantibodies in hepatocellular carcinoma and other malignancies.

Patients with hepatocellular carcinoma (HCC), gastrointestinal, lung, and ovarian cancers were shown to have autoantibodies to nuclear and nucleolar antigens as detected by immunofluorescence on cell substrates. The frequency of antinuclear antibodies (ANAs) was significantly higher (P less than 0.001) in patients with HCC (57/184 = 31%) than in patients with chronic hepatitis or liver cirrhosis (25/187 = 13%). Although a range of fluorescence patterns was observed, a higher percentage of nucleolar fluorescence was detected in HCC, and three of these nucleolar antigens were identified. They were NOR-90, nucleolus organizer region doublet polypeptides of 93 and 89 kDa involved in RNA polymerase I transcription; fibrillarin, a 34 kDa protein of the nucleolar U3 ribonucleoprotein particle which is engaged in preribosomal RNA processing; and nucleophosmin/protein B23, a 37 kDa polypeptide which is associated with ribosome maturation and cellular proliferation. All these antigens are nucleolar components that are engaged in some aspect of ribosome biosynthesis. Since autoantibodies to these nucleolar antigens have also been found in systemic autoimmune diseases, they do not represent autoimmune reactions unique to cancer but might reflect reaction pathways related to immune responses that are antigen-driven. The ANA response in HCC appears to be dynamic reactions to this antigen-drive since some patients with chronic liver disease showed seroconversion to ANA positivity, marked increase in titer and/or change in antibody specificity preceding or coincident with clinical detection of HCC. These changes in ANA showed a close temporal relationship with transformation from long-established chronic liver disease to HCC.

Antibodies, Neoplasm↗

PubMed1992

Circumferential mesangial interposition: a form of mesangiolysis.

A wide variety of glomerular lesions express circumferential mesangial interposition (CMI). The pathomorphogenesis of CMI involves low-grade mesangiolysis and subsequent passive dislocation of mesangial cells towards the lateral wall of glomerular capillaries through a high hydraulic pressure of blood flow penetrating the lytic mesangium. This is in contrast to the previous theories which advocate an active movement of mesangial cells. Moreover, circumferential mesangial interposition can disappear spontaneously or after treatment, suggesting that mesangial cells may return to the original site with their inherent contractility after the insults are removed, in order to restore handicapped filtering surfaces. But the precise mechanisms of its regression will be a subject for future investigation.

Capillaries↗

PubMed1992

Nasal T-cell lymphoma associated with hemophagocytic syndrome. Immunohistochemical and genotypic studies.

A 53-year-old man with nasal T-cell lymphoma exhibited hemophagocytic syndrome as a terminal event. Immunohistochemical studies revealed that neoplastic cells were derived from T cells. Genotypic analysis of DNA samples that were obtained from the frozen tissue specimens demonstrated clonal rearrangements of the T-cell receptor beta-chain genes. No rearrangement was observed in the immunoglobulin heavy-chain gene. To our knowledge, only three cases of nasal T-cell lymphoma with hemophagocytic syndrome have been reported before the present case. All of these cases occurred in Oriental patients. The present report suggests the beneficial effect of high-dose glucocorticoid therapy on the prolongation of survival compared with that of the other three cases.

Gene Rearrangement, beta-Chain T-Cell Antigen Rece↗

PubMed1992

Glomerular deposition of complex-forming glycoprotein heterogenous in charge (protein HC) in IgA nephropathy.

IgA immune complexes and polymeric IgA are presumed to play important roles in the development and progression of IgA nephropathy. Complex-forming glycoprotein heterogenous in charge (protein HC), being inhibitors of neutrophilic chemotaxis, has been reported as binding to IgA. As a working hypothesis it was assumed that complexes of protein HC and IgA are present in glomeruli from IgA nephropathy patient in stable state. In this study, we examined the glomerular deposition of protein HC in 40 patients with IgA nephropathy and in 10 patients with non-IgA nephropathy. We used highly specific antibody against protein HC, that does not cross-react with alpha-1-microglobulin. An immunofluorescent study revealed that 10 out of the 40 patients (25%) showed an intensity of 1+, 16 (40%) showed weak positive (+/-), and the other 14 (35%) were negative. There was no deposition of protein HC in non-IgA nephropathy patients. Histopathological analysis demonstrated a significant correlation between the intensity of glomerular-deposited protein HC and pathological activity (p less than 0.005); the latter was defined as having either crescents in more than 15% of the remaining glomeruli (excluding global sclerotic glomeruli), or segmental necrosis or sclerosis in more than 30% of the remaining glomeruli. A significant correlation was observed between pathological activity and the intensity of deposited IgG, IgA and IgM (p = 0.01), and lambda chain (p less than 0.005). Considering anti-inflammatory activity of protein HC, these results suggest that protein HC cannot protect sufficiently acute inflammation or tissue damages due to co-deposited IgG and IgM and/or other factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Clinical and neuroradiological studies on orbital myositis and Tolosa-Hunt syndrome].

Tolosa-Hunt syndrome and orbital myositis have common features such as ocular pain, ophthalmoplegia and exophthalmos. Both syndromes are thought to be caused by a granulomatous inflammation involving the cavernous sinus area in the former and the orbital cavity in the latter. The question whether these two conditions represent different presentations of a single disease, or they belong to different entities has not been settled. To address this question, we reviewed our cases having clinical diagnosis of either Tolosa-Hunt syndrome or orbital myositis. Six cases were diagnosed as Tolosa-Hunt syndrome, and 7 orbital myositis. In the thin-slice enlarged orbital CT, hypertrophic and high-density changes of at least one of the extraocular muscles were found in all cases with orbital myositis, but in none of the patients with Tolosa-Hunt syndrome. The age of onset was younger and the duration of the disease before admission was shorter in Tolosa-Hunt syndrome. They responded to steroid therapy better than those with orbital myositis. These findings lead us to conclude that Tolosa-Hunt syndrome and orbital myositis belong to different syndromes, although clinical manifestations have many similarities. Then we studied the relationship between the hypertrophic change of the extraocular muscle and the direction of the oculomotor restriction. For this purpose four additional cases with dysthyroid ophthalmopathy were also studied. We found that the presence of hypertrophic change was frequently associated with the restriction of ocular movement to the direction not only of the hypertrophic muscle but also of the opposite muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Isolated cerebellar tumor formation in a patient with blastic crisis of chronic myelogenous leukemia].

A 42-year-old male was diagnosed as having Ph-positive chronic myelogenous leukemia (CML) in 1988. He had been treated with ranimustine and interferon alpha. In April 1990, he was admitted to our hospital because of hemorrhagic diathesis. Blood counts revealed a white blood cell count of 319,200/microliters with 12 per cent blasts, a hemoglobin level of 9.2 g/dl, and a platelet count of 48,000/microliters. The bone marrow aspiration revealed hypercellularity with 68.2 per cent blasts, and chromosomal analysis showed 48, XY, +8, double Ph. A combination chemotherapy containing vindesine, cytarabine and prednisolone was administered. Four days later, he suddenly complained of headache and vertigo. CT scan of the brain showed a high density area at the cerebellar vermis. He was then treated with intensive combination chemotherapy including enocitabine, daunomycin, 6-mercaptopurine and prednisolone. He attained a hematological response and clinical improvement temporarily, as the cerebellar tumor regressed. In September he had headache and vertigo again, and CT scan revealed a rapid increase in size of the cerebellar tumor. Local irradiation with total doses of 19 Gy brought about a partial resolution of the lesion, and relief from the symptoms. In November, his hematological conditions deteriorated gradually and he died of brain hemorrhage on November 22, 1990. Post-mortem examination disclosed a 1 x 1 cm sized mass in the cerebellar vermis which showed a fibrous change surrounded with hemosiderin-laden macrophages microscopically. We reviewed the eight reported cases of CML with intracranial tumors, and discussed the factors which had contributed to the prolongation of survival in our patient.

Adult↗

PubMed1992

The novel natural product YM-26567-1 [(+)-trans-4-(3-dodecanoyl-2,4,6- trihydroxyphenyl)-7-hydroxy-2-(4-hydroxyphenyl)chroman]: a competitive inhibitor of group II phospholipase A2.

(+)-trans-4-(3-dodecanoyl-2,4,6-trihydroxyphenyl)-7-hydroxy-2-(4- hydroxyphenyl)chroman (YM-26567-1), a novel natural product isolated from the fruit of Horsfieldia amygdaline, dose-dependently inhibited group II phospholipase A2 (PLA2) prepared from rabbit platelet with an IC50 value of 6.7 microM (4.6-9.6 microM, n = 4). In contrast to irreversible PLA2 inhibitors such as manoalide and p-bromophenacyl bromide, the PLA2 inhibition of YM-26567-1 was independent of preincubation time. Lineweaver-Burk analysis revealed that YM-26567-1 behaved as a competitive inhibitor of rabbit platelet PLA2 with a Ki value of 1.6 +/- 0.3 microM (n = 5). Although YM-26567-1 also competitively inhibited group I PLA2 derived from porcine pancreas, the Ki value was approximately 10-fold greater for porcine pancreas than for rabbit platelet PLA2. In vivo, topical application of YM-26567-1 to the mouse ear inhibited 12-O-tetradecanoylphorbol-13-acetate (1 micrograms/ear)-induced mouse ear edema in a dose-dependent manner with a 50% effective dose of 28 micrograms/ear (13-63 micrograms/ear, n = 10/dose), but did not improve arachidonic acid (4 mg/ear)-induced mouse ear edema at 1 mg/ear. These results suggest that YM-26567-1 is a competitive PLA2 inhibitor showing a higher affinity for group II than group I PLA2, and that it may act as a potent anti-inflammatory compound through its direct inhibition of PLA2.

Animals↗