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Biomedical subjects

K Hara

Publications and source records attributed to K Hara.

At least 685 records · Page 38Linked to original sources
PubMed1992

[Epidemiology of HTLV-I carriers in Hirado Island and virological and immunological investigation of HTLV-I associated pulmonary disease].

Adult T-cell leukemia (ATL) is endemic in Kyushu. Our study at Hirado island in Nagasaki prefecture revealed a higher incidence (35.9%) of HTLV-I carriers in villages with fishing than in those without (16.5%). HTLV-I carriers showed a higher incidence of abnormal findings on chest roentgenogram (21.7%) than non-carriers (16.5%), but most were lesions of old pulmonary tuberculosis and pleural thickening. Virological and immunological investigations were performed for 10 HTLV-I carriers, 3 patients with HTLV-I associated myelopathy (HAM), and 3 patients with ATL to determine the presence of HTLV-I associated pulmonary disease. In HAM patients, there were high titers of anti HTLV-I antibody, positive IgA reaction to HTLV-I, and an increase in interleukin-2 receptor (IL-2)-positive T-cells in the peripheral blood; and lymphocytosis and an increase in IL-2-positive T-cells in the bronchoalveolar lavage fluid (BALF). Virological examination showed the presence of pX gene and tax1/rex1 mRNA in the peripheral blood and BALF. Similar immunological and virological findings in 2 of 10 carriers suggested the presence of HTLV-I associated pulmonary disease.

Aged↗
PubMed1991

Insulin and 12-O-tetradecanoylphorbol-13-acetate activation of two immunologically distinct myelin basic protein/microtubule-associated protein 2 (MBP/MAP2) kinases via de novo phosphorylation of threonine and tyrosine residues.

Two site-specific antibodies have been prepared by immunizing rabbits with chemically synthesized peptides derived from the partial cDNA-predicted amino acid sequence of extracellular signal-regulated kinase 1 (ERK1), which has been proposed to encode the microtubule-associated protein 2 (MAP2) kinase (Boulton, T. G., Yancopoulos, G. D., Gregory, J. S., Slauer, C., Moomaw, C., Hsu, J., and Cobb, M. H. (1990) Science 249, 64-67). With immunoprecipitation in the presence of sodium dodecyl sulfate (SDS) and Western blotting, an antibody to the peptide containing triple tyrosine residues (alpha Y91) resembling one of the insulin receptor autophosphorylation sites specifically recognized 42- and 44-kDa proteins. On the other hand, an antibody to the peptide corresponding to the COOH terminus portions (alpha C92) of the ERK1 cDNA gene product recognized the 44-kDa protein much more efficiently than the 42-kDa protein. With immunoprecipitation in the absence of SDS, alpha Y91 could barely recognize these two proteins and alpha C92 recognized the 44-kDa protein but failed to recognize the 42-kDa protein. Kinase assays in myelin basic protein (MBP)-containing gel, after SDS-polyacrylamide gel electrophoresis, revealed that insulin or 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated MBP kinase activity in alpha Y91 immunoprecipitates comigrated at molecular mass 42 and 44 kDa. On the other hand, the stimulated MBP kinase activity in alpha C92 immunoprecipitates comigrated only at molecular mass 44 kDa. Insulin stimulated the MBP kinase activity in gels and phosphorylation of these two proteins by greater than 10-fold with a maximal level at 5 min. Insulin and TPA rapidly stimulate the phosphorylation of the 42- and 44-kDa proteins via de novo threonine and tyrosine phosphorylation. Tryptic phosphopeptide mapping analysis of the 42- and 44-kDa proteins, respectively, revealed a single major phosphopeptide containing phosphothreonine and phosphotyrosine, which was common to both insulin- and TPA-stimulated phosphoproteins. Protein phosphatase 2A treatment of these two phosphoproteins caused a complete loss of kinase activity with selective dephosphorylation of phosphothreonine. These data strongly suggest that these two proteins are highly related to the mitogen-activated protein (MAP) kinase with an apparent molecular mass of 42 kDa (Ray, L. B., and Sturgill, T. W. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 3753-3757) and that these two immunologically similar but distinct MBP/MAP2 kinases may represent isozymic forms of MBP/MAP2 kinases. These data also demonstrate that insulin and TPA activate MBP/MAP2 kinase activity by de novo phosphorylation of threonine and tyrosine residues via a very similar pathway.

Amino Acid Sequence↗
PubMed1991

Palmitoylation of cysteine 69 from the COOH-terminal of band 3 protein in the human erythrocyte membrane. Acylation occurs in the middle of the consensus sequence of F--I-IICLAVL found in band 3 protein and G2 protein of Rift Valley fever virus.

One of the major physiologic functions of erythrocytes is the mediation of chloride-bicarbonate exchange in the transport of carbon dioxide from the tissues to the lungs. The anion exchange is mediated by a typical polytopic transmembrane protein in the cell membrane, designated Band 3. A carboxyl-terminal peptide of Band 3 was affinity-labeled with pyridoxal phosphate, a substrate for the anion transport system, and then sequenced (Kawano, Y., Okubo, K., Tokunaga, F., Miyata, T., Iwanaga, S., and Hamasaki, N. (1988) J. Biol. Chem. 263, 8232-8238). The 10th amino acid residue of the peptide could not be determined, suggesting post-translational modification of the residue. In the present communication, we have investigated the molecular structure of human Band 3 and the COOH-terminal 8500-dalton peptide using gas-liquid chromatography-mass spectrometry. Band 3 was modified covalently by fatty acids and these acids were released from Band 3 by hydroxylamine treatment at either pH 7 or 11, indicating that the linkage between Band 3 and the fatty acid is a thio ester bond. 1 mol of Band 3 interacted with 1 mol of fatty acid at a cysteine residue located 69 residues from the COOH terminus of Band 3. The fatty acids used in the modification were myristate, palmitate, oleate, and stearate, with palmitate being the major component. The esterified site is close to the site affinity-labeled with pyridoxal phosphate (Kawano, Y., Okubo, K., Tokunaga, F., Miyata, T., Iwanaga, S., and Hamasaki, N. (1988) J. Biol. Chem. 263, 8232-8238). The amino acid sequence including the acylation site was Phe-Thr-Gly-Ile-Gln-Ile-Ile-Cys-Leu-Ala-Val-Leu, which is conserved in the G2 protein of Rift Valley fever virus as Phe-Ser-Ser-Ile-Ala-Ile-Ile-Cys-Leu-Ala-Val-Leu. The G2 protein, like Band 3, is a polytopic transmembrane protein. Although acylation of the cysteine residue of G2 protein has not been examined, the Phe-X-X-Ile-X-Ile-Ile-Cys-Leu-Ala-Val-Leu sequence could be a common motif for fatty acylation of certain membrane proteins.

Acylation↗
PubMed1991

[MR cholangiography].

A time-reversed gradient echo pulse sequence (PSIF; Siemens), one of the MR imaging methods based on steady-state free precession of excited spins, makes the bile duct quite bright relative to the surrounding tissue. Using this sequence under breath hold combined with a two or three-dimensional data set and maximum intensity projection method provided fair delineation of the dilated bile duct and the site of its obstruction or stricture. Though the clinical experience is limited, this technique is considered to be of value in the non-invasive evaluation of bile duct system in the patient of obstructive jaundice.

Cholestasis↗
PubMed1991

Increased sympathetic outflow in cirrhosis and ascites: direct evidence from intraneural recordings.

OBJECTIVE: To determine if central sympathetic outflow is increased in patients with cirrhosis and ascites. PATIENTS: Eleven patients with cirrhosis and ascites, 8 patients with cirrhosis but without ascites, and 7 age-matched and 8 young healthy volunteers. METHODS: With subjects supine, direct microneurographic recordings of efferent post-ganglionic muscle sympathetic nerve activity were obtained from the peroneal nerve, and sympathetic burst frequency was compared with subjects' blood pressure, heart rate, sodium excretion, catecholamines, and plasma renin activity. All patients with cirrhosis were studied at least 5 days after withdrawal from all medications and after 7 days of a 20 mmol/d sodium, 1-L fluid-restricted diet. Age-matched volunteers were studied after 7 days of 20 mmol/d sodium intake and young healthy volunteers after 7 days of 150 mmol/d sodium intake. RESULTS: Sympathetic nerve activity in ascitic patients (65 +/- 15 bursts/min; mean +/- SD) was markedly increased, whether compared with patients with cirrhosis but without ascites (34 +/- 16 bursts/min; P less than 0.001), age-matched healthy volunteers on similar sodium intake (27 +/- 22 bursts/min; P less than 0.001), or young healthy subjects (21 +/- 10 bursts/min; P less than 0.001). The frequency of muscle sympathetic nerve discharge was directly related to plasma norepinephrine and epinephrine concentrations, plasma renin activity, and heart rate, all of which were increased in those patients with cirrhosis and ascites, and inversely related to 24-hour urinary sodium excretion, the fractional excretion of sodium, and subjects' pulse pressures. Sympathetic nerve activity fell from 78 to 6 bursts/min in one patient after liver transplantation. CONCLUSIONS: This study provides the first direct evidence that elevated plasma norepinephrine concentrations in patients with cirrhosis and ascites are due to increased central sympathetic outflow. Sympathetic nerve activity is not increased in patients with cirrhosis but without ascites. Because there were direct positive correlations of sympathetic nerve activity with plasma norepinephrine concentrations, plasma epinephrine concentrations, plasma renin activity, and heart rate, the increase in central sympathetic outflow in patients with cirrhosis and ascites appears generalized and not restricted to muscle nerves. The anti-natriuretic effects of parallel increases in renal and muscle sympathetic nerve activity could account for the inverse correlation between muscle sympathetic nerve activity and sodium excretion.

Adult↗
PubMed1991

[Determination of bromide ion concentration in urine using a head-space gas chromatography and an ion chromatography--biological monitoring for methyl bromide exposure].

A head-space gas chromatography (GC) and an ion chromatography coupled with a conductive detector (IC) were used to evaluate levels of bromide ion in urine. The GC method followed by methylation with dimethyl sulfate, showed higher accuracy (2.7% of relative standard deviation) and lower minimum detection limit (0.4 mg/l) compared to the IC procedure of those values which were 8.7% and 1.0 mg/l. The correlation coefficient between the analytical results of 15 urinary samples by the two methods was 0.793. The bromide ion concentrations detected in 36 urine samples of workers exposed to methyl bromide were averaged at 13.3 +/- 7.7 mg/l. The average bromide ion of the non-exposed group was 7.1 +/- 2.1 mg/l (n = 6). Exposed methyl bromide concentrations of workers were monitored with passive samplers during their work shifts (8 hr). No significant correlation between exposed methyl bromide and bromide ion concentrations in urine was observed.

Bromides↗
PubMed1991

[Stereoscopic MR cisternography].

A time-reversed gradient echo pulse sequence, one of the MR imaging methods based on steady-state free procession of the excited spins, makes the cerebrospinal fluid (CSF) quite bright relative to the normal brain tissue. Using this sequence combined with a three-dimensional data set and maximum intensity projection method, which provided clear delineation of the spatial distribution of the CSF space in the brain. Though the clinical experience is limited, this technique is considered to be of value in the evaluation of CSF pathology.

Cerebrospinal Fluid↗
PubMed1991

Determination of kerosene and light oil components in blood.

A sensitive and rapid method to analyse fuel components in blood from rats exposed to kerosene or light oil vapour was developed by making use of capillary gas chromatography/mass spectrometry. The aliphatic hydrocarbons with carbon numbers 8-10 and aromatics such as toluene, xylene, 3- and 4-ethyltoluene and trimethylbenzenes were clearly detected in blood from rats exposed to kerosene or light oil vapour, using the head-space method combined with the salting-out technique. The concentration ratio of pseudocumene to toluene in blood exposed to light oil was higher than that in the case of exposure to kerosene. The lower limits of detection were 50 pg and 1 ng in toluene and pseudocumene, respectively. Our suggestion is that this method is useful in forensic investigations to detect fuel components in blood and for the purposes of differentiating kerosene and light oil in blood tissues.

Animals↗
PubMed1991

A model of the mechanism of cooperativity and associativity of long-term potentiation in the hippocampus: a fundamental mechanism of associative memory and learning.

Long-Term Potentiation (LTP) has three properties: (1) input specificity, (2) cooperativity and (3) associativity. In a previous paper, we proposed an integrated model of the mechanisms of the induction and maintenance of LTP with input specificity. In this paper, a model of the mechanism of cooperative and associative LTP is described. According to computer simulations of the model, its mechanism is based on the spread of synaptic potentials.

Animals↗
PubMed1991

Postmortem changes in hapten-specific IgE antibody responses in mice.

This Study was carried out to examine the post-mortem stability of hapten-specific immunoglobulin E (IgE) antibody in mice by the passive cutaneous anaphylaxis test in rats. In vitro IgE antibody responses in blood were stable for 3 days at room temperature. Even in cases when blood could not be obtained from the cadaver it was possible to measure the hapten-specific IgE antibody response up to 3 days after death using the supernatant of the visceral homogenates.

Animals↗
PubMed1991

Corneal edema induced by bis (tributyltin) oxide.

Corneal edema induced by bis (tributyltin) oxide (TBTO) was studied with an electron microscope and the accumulation sites of tin were determined with an X-ray microanalyzer. Male Wistar rats received an intramuscular injection of 0.5 ml/kg TBTO. After time intervals of 2, 4, 6, 8, 10, 12 h after injection, corneas were isolated and provided for electron microscopy. Corneas from untreated rats served as controls. Marked swelling of mitochondria in the corneal endothelial cells occurred at 4 h after TBTO injection. The corneal edema appeared in the endothelial layer and the stroma at 6 h after injection. By X-ray microanalysis, Sn peaks were obtained from swollen mitochondria in the endothelial cells. At 12 h after TBTO injection, edematous swelling of the corneal tissue became more advanced. These results indicated that parenterally administered TBTO accumulated in the mitochondria of corneal endothelial cells. The direct toxic effects of TBTO on the mitochondria might cause the interference with active pump function of endothelial cells and induced the corneal edema.

Animals↗
PubMed1991

Serological and immunohistochemical studies on sialylated carbohydrate antigens in colorectal carcinoma.

Sialylated carbohydrate antigens, such as CA19-9 (sialyl Lea), CA-50 (sialyl Le4), CSLEX1 (sialyl Lex) and SLX (sialyl Lex-i), were assayed in the same preoperative serum samples of 63 patients with colorectal cancer, and compared with CEA. In addition immunohistochemical expressions of sialyl Lea, sialyl lex and sialyl Lex-i antigens were studied in 62 colorectal carcinomas and 42 normal mucosal sites remote from the malignant lesion using monoclonal antibodies CSLEA1, CSLEX1 and FH-6, respectively, in order to elucidate their tumor-specificity and clinical usefulness as a tumor-associated antigen. Serologically, the percent positive rates of CA19-9, CA-50, CSLEX1, SLX and CEA were 30.2%, 17.7%, 23.8%, 16.1% and 44.4%, respectively. In dukes' A and B, these sialylated carbohydrate antigens, especially CSLEX1 and SLX, showed low positive rates, but the percent positive rates of CSLEX1 and SLX correlated with operative radicality. The positive spectrum of CSLEX1 differed from that of CA19-9 in sera, and CEA had no correlation with these two antigens. The immunohistochemical expression rates of sialyl Lea, sialyl Lex and sialyl Lex-i were 88.1%, 17.0% and 9.5% in normal mucosa, but were 77.8%, 90.5% and 71.4% in carcinoma, respectively. These data suggested that the type 2 chain antigens CSLEX1 and SLX, which have high tumor-specificity compared with CA19-9, may be useful in preoperative diagnosis for extension of carcinoma and operative radicality, although early diagnosis using these sialylated carbohydrate antigens may be difficult, while the combined use of CA19-9, CSLEX1 and CEA should make it possible to detect a wide range of colorectal cancer patients.

Antibodies, Monoclonal↗
PubMed1991

Cadmium toxicity in the thyroid gland of pregnant rats.

The toxic effects of cadmium on the thyroid gland of pregnant rats were studied with an electron microscope and an X-ray microanalyzer. Serum levels of thyroid hormones (T3 and T4) were also analyzed. Deterioration of the rough-surfaced endoplasmic reticulum occurred in the thyroid follicular epithelium on the fifth day of cadmium treatment. Large intracellular vacuoles, which arose from dilated cisternae of the rough-surfaced endoplasmic reticulum, were fused together, and marked swelling of the mitochondria was also noted. Thyroglobulin-secreting granules at the apical cytoplasm were decreased in number. By energy dispersive X-ray microanalysis, cadmium peaks were preferentially obtained from swollen mitochondria in the follicular epithelial cells. Serum levels of T3 and T4 were significantly decreased in cadmium-treated rats dams when compared to those of controls. In the present experiment, cycloheximide also caused degenerative changes in the rough-surfaced endoplasmic reticulum and the disappearance of thyroglobulin-secreting granules. Cycloheximide is a known inhibitor of protein synthesis on cytosolic ribosomes. These results indicated that accumulated cadmium in the mitochondria of thyroid follicular epithelial cells might disturb the oxidative phosphorylation of this organelle and the loss of energy supply possibly caused the inhibition of the synthesis and release of thyroid hormones.

Animals↗
PubMed1991

Antitumor effects of human recombinant interferon-gamma and tumor necrosis factor on five cervical adenocarcinoma cell lines, in vivo and in vitro.

We examined the antitumor effects of recombinant interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) on cervical adenocarcinoma cell lines, in vitro and in vivo. Four of five cell lines showed a high sensitivity to IFN-gamma, in vitro. One of five cell lines showed a remarkable sensitivity to TNF, in vitro. Only one cell line resistant to both IFN and TNF was derived from a well-differentiated adenocarcinoma of endocervical type. Experiments using nude mice bearing transplanted tumors revealed that these cytokines were also effective against tumors in vivo. All these observations suggest that IFN-gamma or TNF can have positive effects in the treatment of patients with adenocarcinoma of the uterine cervix.

Adenocarcinoma↗
PubMed1991

The role of medical treatment of distal type aortic dissection.

We analyzed the short-term and long-term outcome of 42 patients with distal type aortic dissection. Twenty-eight patients underwent intensive medical therapy within two weeks after the onset of pain (acute dissection). The remaining 14 patients had chronic dissection. The goals of medical treatment were to control blood pressure and to attain a negative C-reactive protein test result. Hospital survival rate in the patients with acute dissection was 96% (27/28). In-hospital complications included changes in mental status, renal dysfunction, bradycardia, orthostatic hypotension, and liver dysfunction, all of which were managed medically. Three of these patients underwent surgical therapy in the chronic phase and were discharged uneventfully. Fifteen (62.5%) of the 24 medically treated patients were discharged with negative C-reactive protein tests. Spontaneous resolution of a dissection was demonstrated by radiological examinations in 8 cases. Five-year survival rates in 24 medically treated patients was 93%. Hospital survival rate in the patients with chronic dissection was 100% (14/14). The rigorous control of blood pressure in the acute phase, and subsequent meticulous evaluation of the dissection by radiological tests and C-reactive protein test provides acceptable short-term and long-term outcomes of patients with acute distal dissection without the need for emergency surgical intervention.

Adult↗
PubMed1991

Identification of human hair stained with oxidation hair dyes by gas chromatographic-mass spectrometric analysis.

This paper describes the gas chromatographic-mass spectrometric (GCMS) analysis of oxidation hair dyes from human hair. Diamines from the dyes were directly extracted from the hair in basic solution and aminophenols were extracted after neutralization. Both extracts were derivatised with trifluoroacetic anhydride and analysed by GCMS. Five components of oxidation hair dyes namely, p-phenylenediamine, toluene-2,5-diamine, o-aminophenol, m-aminophenol and p-aminophenol were clearly identified, whilst no other compounds originating from the hair dyes were detected. The presence and relative amounts of these dye components from hair extracts may assist in the discrimination of human hair especially in cases involving forensic science.

Aminophenols↗