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Biomedical subjects

S Kamei

Publications and source records attributed to S Kamei.

At least 91 records · Page 5Linked to original sources
PubMed1993

Myelodysplastic syndrome associated with myelofibrosis, a report of 3 cases.

Three cases of primary myelodysplastic syndrome (MDS) associated with myelofibrosis were initially diagnosed as refractory anemia by the presence of bicytopenia or pancytopenia and having normo- or hypercellular marrow with dysplastic features. The bone marrow aspiration of these patients showed dry tap a few months after admission, or on admission. Their bone marrow biopsy specimens revealed various grades of increased formation of reticulin fibers. One patient entered into complete remission in response to metenolone, while the other two patients died of cerebral hemorrhage several months after admission. These results indicate that this disease should be classified as a distinct subgroup of MDS.

Aged↗
PubMed1993

Antitumor effects of angiogenesis inhibitor TNP-470 in rabbits bearing VX-2 carcinoma by arterial administration of microspheres and oil solution.

The antitumor activities of an angiogenesis inhibitor, (3R,4S,5S,6R)-5- methoxy-4-[(2R,3R)-2-methyl-3-(3-methyl-2-butenyl)-oxiranyl]-1- oxaspiro[2,5]oct-6-yl(chloroacetyl) carbamate (TNP-470), administered s.c., i.v. and intra-arterially using a chemoembolization technique, were examined in rabbits bearing VX-2 carcinoma. Repeated s.c. injection of TNP-470 aqueous solution clearly inhibited the tumor growth in proportion to the dose, and improved efficacy was obtained with once a week s.c. administration of microspheres, which provide sustained release of TNP-470. Moreover, the injection of the TNP-470 microspheres into the predominant artery of the tumor via a catheter, chemoembolization, resulted in dramatic regression of the tumor. This antitumor effect was enhanced by coadministration of doxorubicin hydrochloride aqueous solution. Arterial administration of TNP-470 oil solution provided more persistent tumor growth inhibition due to the prolonged release and targeting of the angiogenesis inhibitor to the tumor.

Animals↗
PubMed1993

[A unilateral large demyelinating lesion in the cerebral white matter with slowly progressive hemiplegia and intrathecal JC virus antibody production].

A 59-year-old male patient presented in 1991 with left-sided hemiplegia and hemihypesthesia and left homonymous hemianopsia, which had developed for the preceding 12 months. The cerebrospinal fluid (CSF) level of protein was mildly elevated, oligoclonal IgG band was initially negative, but finally positive and myelin basic protein was absent. Magnetic resonance imaging and X-ray computed tomography (CT) of the brain revealed a unilateral demarcated lesion extending around the posterior horn and triagular part of the right lateral ventricle, apparently capped by remarkably gadolinium enhancement at its front, which had no mass effect, and several small isolated plaques were also observed in other areas of the brain. All lesions appeared as high intensity areas on T2 weighted images and hypodense areas on CT. The JC virus hemagglutination-inhibition antibody titers were 1:32 in serum and 1:8 in CSF; the antibody titer ratio and index both suggested an intrathecal antibody production. Pathological examination of brain biopsy specimen taken from the large lesion demonstrated profound demyelination with preservation of axons, a large number of macrophages and spotted perivascular lymphocyte cuffings. Based on this experience, we discussed the features in this case which differentiated it from multiple sclerosis, leukodystrophy and typical progressive multifocal leukoencephalopathy (PML). Diffuse-disseminated sclerosis or transitional sclerosis was most likely so far as the clinical picture, imaging and histology were concerned. However, we implicated the possible involvement of JC virus infection to the etio-pathogenesis of the demyelinating lesions in view of the intrathecal JC virus antibody production in CSF observed in this case.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Viral↗
PubMed1992

Absence of point mutation of N-ras oncogene in bone marrow cells with aplastic anemia.

Point mutation of N-ras oncogene at codons 12, 13 and 61 was studied in the bone marrow cells of patients with typical aplastic anemia using the polymerase chain reaction method for DNA amplification and dot blot hybridization to synthetic oligonucleotide probes. Point mutation was observed in none of the 15 patients studied. These findings indicate either that the pathogenesis of typical aplastic anemia is different from that of preleukemic states of myelodysplastic syndrome or acute leukemia in clonal evolution, or that the overlapping area sharing a common pathogenesis is much smaller than was presumed.

Anemia, Aplastic↗
PubMed1992

Amyotrophic lateral sclerosis with ophthalmoplegia and multisystem degeneration in patients on long-term use of respirators.

We describe two patients with sporadic amyotrophic lateral sclerosis (ALS), who had developed progressive external ophthalmoplegia of a predominantly supranuclear type while they survived on respirators, and displayed histopathological abnormalities both typical and atypical of ALS. Patient 1 was a 43-year-old man with ALS of 5-year duration, who had initially exhibited fulminant ALS, and remained on a respirator for 4 years. Patient 2 was a 51-year-old man with ALS of 13-year duration, who remained on a respirator for 8 years. Both patients died in a "totally locked-in state". Autopsy of both patients revealed not only histopathological abnormalities consistent with ALS, but also multisystem degeneration which involved the pontine tegmentum, substantia nigra, Clarke's dorsal nuclei and spinocerebellar tracts. In addition, Patient 2 displayed intracytoplasmic neuronal basophilic inclusion bodies which exhibited marked immunoreactivity to anti-ubiquitin antibodies. Our case reports indicate that the longer survival which is possible through the use of respirators may make one subgroup of ALS patients prone to develop atypical clinical and neuropathological features which are not observed during the natural course of ALS.

Adult↗
PubMed1992

New method for analysis of biodegradable polyesters by high-performance liquid chromatography after alkali hydrolysis.

A new method was developed for analysis of biodegradable polyesters, which involves alkali hydrolysis of polyesters to the corresponding hydroxyacids and determination of the hydroxyacids by high-performance liquid chromatography. It can be used to monitor weight change in polyesters and change in molecular ratio of the hydroxyacid constituents of polyesters during in vitro and in vivo degradation.

Animals↗
PubMed1992

[Protective effect of dextromethorphan on the ischemic retinal damage in rabbit].

To investigate the effect of dextromethorphan (DEX), N-methyl-D-aspartate (NMDA) receptor antagonist, on the retinal ischemia, 0.4%DEX hydrobromide was intravenously given to rabbits before, during and after retinal ischemia. Retinal function was monitored by electroretinogram (ERG). Retinal ischemia was induced by increasing intraocular pressure to 130 mmHg for 90 or 120 min. Amplitudes of ERG.b-waves recorded after the 90 min ischemia recovered to 72.5 +/- 9.0% in the DEX group and 38.5 +/- 8.5% in the control group which was given normal saline. The maximal recovery rates of b-wave amplitudes after the 120 min ischemia were 44.0 +/- 7.9% in the DEX group and 21.0 +/- 1.3% in the control group. The recovery rates of the b-wave amplitudes in DEX group were significantly higher than in the control group (p less than 0.01). It was found that the effective dose of DEX was 0.1-0.4%.

Animals↗
PubMed1992

[Clinical application of data measured by automated blood cell counter].

Rapid progress has been made in automated blood cell counting techniques using several kinds of apparatuses based on different mechanisms of measurement. We report a method of clinical application of the measurements made by an automated blood cell counter in the diagnosis and treatment of diseases, and discuss its usefulness, and its weaknesses that require improvement.

Blood Cell Count↗
PubMed1992

[The viability of the detached retina of the rabbit eye--electrophysiological observation of influence of duration of the detachment].

The influence of the duration of the retinal detachment on the function of detached retina was electrophysiologically investigated in the rabbit eye. Experimental retinal detachment with a diameter of 4 mm was made by injecting sodium hyaluronate into the subretinal space. The transretinal ERG (TR-ERG) was recorded from the detached retina between a pair of double-barreled microelectrodes of which the longer tip was positioned into the subretinal space, penetrating the detached retina and the shorter tip in the vitreous body. The vitreal ERG (VERG) from the undetached retina was simultaneously recorded between the shorter tip and a scleral electrode. The amplitude of the TR-ERG b-wave significantly decreased 2 hours after the onset of the detachment, and was gradually reduced to minimal value until 96 hours after the detachment. The amplitude of the VERG b-wave remained unchanged. The slow P III amplitude of the TR-ERG gradually decreased and extinguished 96 hours after the detachment, while the c-wave amplitude of the VERG showed no significant changes. The results suggested that the viability of the detached retina reduces rapidly and extinguishes within 96 hours in the rabbit eye.

Animals↗
PubMed1992

[The recovery of the local ERG recorded from reattached retina after retinal detachment].

The functional recovery of the reattached retina after retinal detachment was investigated electrophysiologically. Experimental retinal detachment approximately 4 mm in diameter was made in the rabbit eye by injecting Hanks' solution (HS) or sodium hyaluronate (HNa) into the subretinal space. Local ERG (LERG) was recorded from the spontaneously reattached retina by a double-barreled microelectrode. The retinal detachments caused by HA reattached at an average of 321 +/- 56 minutes after making the detachment, while the detachments by HNa at 20.8 +/- 1.8 days. The recovery of the amplitudes of b-wave and slow P III of the LERG was slower and worse in HNa group than in HS group. In both groups, the amplitudes of the b-waves recovered earlier than the slow P IIIs. Result indicated that earlier reattachment is related to favorable recovery of the retinal function, and that the inner retina generating the b-wave restores its function earlier than the distal retina generating the slow P III.

Animals↗
PubMed1991

[Changes in retinal electrical response due to different size of experimental retinal detachment].

To investigate the influence of the size of detachment to function of the detached retina, transretinal ERG (TR-ERG) was recorded from experimentally detached retina. Retinal detachment 4 or 8 mm in diameter was made by injecting sodium hyaluronate in the subretinal space. The TR-ERG was recorded for two hours from the detached retina by a double barreled microelectrode of which a longer tip entered into the subretinal space of the detached retina while a shorter one remained in the vitreous. Vitreal ERG (VERG) was simultaneously recorded between the shorter electrode and a scleral electrode. The b-wave amplitude of the TR-ERG recorded from the retina with 4 mm detachment decreased two hours after detachment, whereas the b-wave recorded from the retina with 8 mm detachment remarkably decreased 30 min after detachment and was stable up to two hours. There were no significant differences in amplitudes of VERG b-waves between 4 and 8 mm detachments during the experimental course. Less extensively detached retina maintained its function to a greater degree than the largely detached retina. The volume of the subretinal space may influence the viability of the detached retina by changing the concentration of nutrients.

Animals↗
PubMed1991

[Endophthalmitis in Japan--a nationwide study with reference to type and etiology].

A nationwide clinical study on bacterial and fungal endophthalmitis was done with special reference to their type and etiology. Two hundred and eighty cases of endophthalmitis were reviewed. All cases were divided into two categories such as exogenous (trauma, surgery, and ulcer) and endogenous (metastasis). Penetrating trauma was responsible for 93 cases (33.2%), surgery for 88 cases (31.4%), ulcer for 11 cases (3.9%) and metastasis for 88 cases (31.4%). Out of the 280 cases, 79 cases (28.2%) were microbiologically diagnosed through aqueous or vitreous tap or biopsy. The total numbers of isolated organisms amounted to 87 consisting of 43 Gram-positive bacteria, 30 Gram-negative bacteria and 14 fungi. The positive isolation was 31 out of 86 (36%) from the aqueous and 52 out of 103 (50%) from the vitreous. Exogenous types associated with trauma, surgery or ulcer were mainly caused by Gram-positive bacteria of 37 strains, led by coagulase-negative staphylococci in 14 cases. On the other hand, endogenous cases were mainly due to Gram-negative bacteria of 14 strains including Klebsiella pneumoniae in 5 cases, E. coli in 4 cases and fungi of 11 strains including candida spp in 9 cases.

Adolescent↗
PubMed1990

Coxsackie B antigen in the central nervous system of a patient with fatal acute encephalitis: immunohistochemical studies of formalin-fixed paraffin-embedded tissue.

A case of fatal acute encephalitis due to Coxsackie B1 virus is described. Confirmation of Coxsackie B virus as the etiological agent of encephalitis was based on identification of the virus antigen in formalin-fixed paraffin-embedded tissue sections. In the past, the diagnosis was obtained by serological studies of peripheral blood and viral isolation. This is the first report in which indirect immunofluorescent and immunoperoxidase methods using rabbit antiserum raised against Coxsackie B types 1-6 was utilized in determining the etiology of encephalitis. It must be emphasized that these methods can be used both on biopsy or autopsy specimens, even retrospectively.

Antigens, Viral↗
PubMed1990

[Cytomegalovirus encephalitis in immunologically normal adults].

We report two cases of cytomegalovirus (CMV) encephalitis in immunologically normal adults. Patient 1, a 53-year-old man: onset was acute with headache and pyrexia, followed by moderate disturbance of consciousness with meningeal signs. Repeated lumbar puncture revealed 58 CSF cells per microliters and 96 mg protein per dl. On the 11th day after onset, we started treatment with adenine arabinoside (ara-A). He recovered completely. With IgG-ELISA methods, antibody to CMV turned into positive on the third week, and into negative again on the fifth week, and these conversions were concomitant with the symptomatic aggravation and amelioration, respectively. Patient 2, a 78-year-old woman: onset was acute with general fatigue and pyrexia, followed by meningeal signs and mild disturbance of consciousness. Consciousness level was worsened and two courses of acyclovir (Acv) treatment were started on the 59th and on the 93rd day after onset, but consciousness level went down to coma and she died. Repeated lumbar puncture revealed 787 CSF cells per microliters and 229 mg protein per dl. CMV antibody titer (CF) in CSF was 1:32 and antibody index was 58 or more, suggesting antibody production in central nervous system. CMV encephalitis in immunologically normal adults is very rare, only 10 cases having been reported so far. Most patients recover spontaneously, but some may be fatal. In our view ara-A treatment should be taken in consideration in case of acute encephalitis unresponsive to Acv.

Aged↗
PubMed1990

[The relationship between amplitude and extent of detachment indicated by the ERG c-wave of rabbit eyes with experimental retinal detachment].

We recorded ERG b- and c-waves from rabbit eyes with experimental retinal detachment and investigated the relationship between amplitude of the ERG and extent of the detachment. Three different extents of detachment (20, 60, 100% of the fundus) were made in three different groups of rabbits. In all 3 groups, the amplitude of both b- and c-waves remarkably decreased 1 hour after detachment and recovered at 6 hours to values corresponding to the extent of detachment. At 12 hours, the b-wave amplitude remained at almost the same values at 6 hours, whereas the c-wave amplitude showed further reduction. It was suggested that functional disorder in undetached retina occurred earlier in the retinal pigment epithelium than in the sensory retina of the eyes in the acute stage of the retinal detachment.

Animals↗
PubMed1989

Polyamine detection system for high-performance liquid chromatography involving enzymatic and chemiluminescent reactions.

We have developed a new specific detection system for polyamines, separated by high-performance liquid chromatography, to replace the usual o-phthalaldehyde (OPA) postlabeling method. This system utilizes a chemiluminescent reaction to determine the amount of hydrogen peroxide generated through the enzymatic oxidation of polyamines. With this method, as little as 5 pmol of putrescine could be accurately determined (S/N = 4), and linearity between the amount of this polyamine and the relative chemiluminescence intensity was observed up to 500 pmol. In the cases of cadaverine, spermidine, and spermine, the linearity continued to 1 nmol. The within-assay coefficients of variation for these four polyamines ranged between 0.97% and 2.03%. As compared with the OPA method, the new method is highly specific for polyamines due to the high specificity of the enzyme used. Another advantage of the new method is the direct determination of polyamines in urine samples that contain various compounds that interfere with the OPA method.

Chromatography, High Pressure Liquid↗