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Biomedical subjects

H Kawakami

Publications and source records attributed to H Kawakami.

At least 127 records · Page 7Linked to original sources
PubMed1996

Cloning and expression of a rat brain basic helix-loop-helix factor.

We cloned two rat cDNAs of brain basic helix-loop-helix factor 1 (BHF1). These have an identical coding region, contain 357 amino acids and exhibit 94.6% identity to MATH-2/NEX1 in the basic helix-loop-helix region. BHF1mRNAs are dominantly expressed in the brain particularly in the cerebellum, in the adult bovine, rat and mouse. Two shorter BHF1mRNAs (1.6 kb and 1.8 kb) were also detected in the mouse embryo, and these decreased in the developmental process. These results suggest that BHF1 may play important roles in cerebellum-specific functions and development of neurons.

Amino Acid Sequence↗
PubMed1996

Molecular cloning and characterization of a cDNA encoding a novel basic helix-loop-helix protein structurally related to Neuro-D/BHF1.

We cloned a novel basic helix-loop-helix protein, NDRF (NeuroD-related factor), cDNA. NDRF contains 383 amino acids and exhibits 53.4% and 52.2% sequence identity to NeuroD and MATH-2/NEX-1, respectively. NDRF mRNA appears in the brain of 12-day-old mouse embryos and is localized in certain regions of the adult brain, such as the hippocampus, dentate gyrus and cerebellum, Thus, the structure and expression patterns of NDRF are similar to but distinct from those of NeuroD and MATH-2/NEX-1, suggesting that NDRF may play distinct roles in neural development and plasticity as a novel member of the NeuroD family.

Amino Acid Sequence↗
PubMed1996

Pancreatoblastoma: case report and review of treatment in the literature.

A case of pancreatoblastoma arising from the body-to-tail of the pancreas in a 5-year-old boy is presented. The patient underwent exploratory laparotomy and, 11 days later, resection of the tumor (partial pancreatectomy, pyloroplasty, and splenectomy). Before resection, cyclophosphamide and vincristine were administered. Because of tumor spillage during resection, a combination of chemotherapy (administration of cyclophosphamide and adriamycin on that day) and postoperative radiotherapy was given. Nine months after resection, partial hepatectomy was performed for liver metastasis and consolidated by a more intensive chemotherapy regimen using cisplatin, adriamycin, vincristine, and cyclophosphamide. After completion of the chemotherapy, the patient had a 14-month uneventful course, and a locally recurrent tumor was treated by the fourth surgery (extirpation of the recurrent tumor, partial hepatectomy, partial colectomy, and partial gastrectomy) and intraoperative radiation. Thereafter, the boy has shown no evidence of disease at 3 years 8 months. The literature of pancreatoblastoma is reviewed from the therapeutic viewpoint.

Child, Preschool↗
PubMed1996

Immunohistochemical localization of androgen receptor in mouse testicular germ cells during fetal and postnatal development.

BACKGROUND: Determination of the cellular distribution of the androgen receptor (AR) in testicular cells is necessary for understanding the mode of AR action in the testis. We here investigated immunohistochemically the localization of AR by use of anti-human AR polyclonal antibody NH27, with special reference to the AR in germ cells in the developing mouse testis. METHODS: ICR mouse testes taken from day 14 post coitum (p.c.) to day 56 post partum (p.p) were used for AR immunohistochemistry by the routine immunoperoxidase method at the light microscopic level and the pre-embedding method at the electron microscopic level. RESULTS: On day 14 p.c., AR immunoreactivity was present in nuclei of prospermatogonia but not in those of Sertoli cells or interstitial cells. On day 14 p.p., the AR was detected in the nuclei of spermatogonia, Sertoli cells, and myoid cells. AR immunoreactivity in nuclei of Leydig cells appeared on day 21 p.p. In the mature mouse testis, the AR was present in the nuclei of spermatogonia, Sertoli cells, myoid cells, and Leydig cells. CONCLUSIONS: AR was present both in germ cells and in somatic cells during fetal and postnatal development of the mouse testis. In the fetal testis, AR was localized exclusively in prospermatogonia and spermatogonia, suggesting that androgen may act directly on germ cells during prespermatogenesis and the early stage of spermatogenesis. Based on the fact that AR is expressed in Sertoli cells, myoid cells, and Leydig cells around the onset of spermatogenesis, the regulation of AR expression in the germ cells seems to be different from that in the somatic cells. Furthermore, our present data suggest the ultrastructural localization in nuclei of mouse testicular cells is similar to that of some other steroid receptors, both in germ cells and somatic cells.

Age Factors↗
PubMed1996

Localization of the gene encoding the human L-glutamate transporter (GLT-1) to 11p11.2-p13 by fluorescence in situ hybridization.

High affinity glutamate transporters regulate levels of extracellular glutamate in the central nervous system. Impaired glutamate transport has been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). The glutamate transporter subtypes GluT-1 and EAAC1 have previously been mapped to human chromosomes 5p13 and 9p24, respectively. In the present study, the GLT-1 subtype was mapped to human chromosome 11p11.2-p13 by fluorescence in situ hybridization. The possible clinical implications of this finding are discussed.

ATP-Binding Cassette Transporters↗
PubMed1996

Reevaluation of the exact CAG repeat length in hereditary cerebellar ataxias using highly denaturing conditions and long PCR.

Hereditary cerebellar ataxias, including spinocerebellar ataxia type I (SCA1), dentato-rubro-pallidoluysian atrophy (DRPLA), and Machado-Joseph disease (MJD), have been associated with unstable CAG repeats. The length of the CAG repeat is a major factor in determining the age of onset of these diseases. In electrophoresis through acrylamide gels with formamide, the CAG repeat length following the polymerase chain reaction (PCR) coincides with the sequence-determined repeat length after subcloning. However, without formamide, PCR products with long CAG repeats appear 1-4 repeats shorter than when electrophoresed with formamide, and the repeat lengths are variable. In addition, the larger the CAG repeats are, the more difficult are the PCR reactions. A mixture containing thermostable Taq and Pwo DNA polymerases (so-called "long PCR") is much more sensitive than that with Taq polymerase alone in detecting- expanded CAG repeats. Therefore, highly denaturing conditions, especially formamide gel electrophoresis, and the "long PCR" protocol should be used to evaluate the exact CAG repeat length. We have used these principles to detect unstable CAG repeats. The normal ranges are 14-34 repeats for MJD, 6-31 repeats for DRPLA, and 21-32 repeats for SCA1.

Alleles↗
PubMed1996

Expression of three glutamate transporter subtype mRNAs in human brain regions and peripheral tissues.

We compared the expression of mRNAs for three human glutamate transporter subtypes in human central nervous system (CNS) and other organs by Northern blot analysis. hGLT-1 and hGLuT-1 mRNAs were most abundantly expressed in the brain, while hEAAC1 mRNA expression (3.8 kb and 2,4 kb) was strongest in peripheral organs. All subtype mRNAs were expressed throughout the CNS with hGLT-1 predominant in frontal lobe, striatum and limbic areas, and hGluT-1 predominant in cerebellum.

ATP-Binding Cassette Transporters↗
PubMed1996

Serum deprivation alters the expression and the splicing at exons 7, 8 and 15 of the beta-amyloid precursor protein in the C6 glioma cell line.

Amyloid deposition characterizes the pathological lesions of Alzheimer's disease. We investigated the effect of serum deprivation on the regulation of beta-amyloid precursor protein (APP) mRNA expression in C6 glioma cells. Serum deprivation increased APP mRNA levels approximately 4-fold over controls. This increase was accompanied by changes in the pattern of alternative splicing, including the novel alternatively spliced site at exon 15. The proportion of isoforms containing exons 7 and 8 significantly increased from 61% to 68%, while isoforms lacking these exons decreased from 14% to 8%. The proportion of leukocyte-derived APP, which is a novel alternatively spliced isoform lacking exon 15, significantly increased from 19% to 40%. Among the six major isoforms produced by the two independent splicing sites, L-APP752 which contains exons 7 and 8, but lacks exon 15, increased the most (approximately 10-fold). Our findings provide evidence linking APP expression to alterations in alternative splicing at exon 15. These results demonstrate that in glial cells, APP mRNA regulation involves the alteration in alternative splicing at exons 7, 8 and 15, suggesting that not only increased expression but also an imbalance in the relative abundance of the six APP isoforms in stressed condition might affect the amyloidogenesis in Alzheimer's disease.

Alternative Splicing↗
PubMed1996

Transmission of Helicobacter pylori infection via flexible fiberoptic endoscopy.

BACKGROUND: Public concern has been raised with regard to the possibility of transmission of instrument mediated Helicobacter pylori infection after upper gastrointestinal endoscopy. METHODS: Disinfection procedures for gastrointestinal endoscopes were surveyed in 20 Japanese institutions, and in vitro bactericidal activities of seven disinfectants against H. pylori were determined. RESULTS: Screening tests for infection before endoscopy were not consistently performed; only 11 institutions always screened for hepatitis B virus, nine for hepatitis C virus, and two for tuberculosis. All 20 institutions used the same flexible fiberoptic endoscope on more than one patient in succession, with minimal cleanings only. Only two used glutaraldehyde for disinfection. Most used ethyl alcohol, benzalkonium chloride, or alkyldiaminoethylglycine hydrochloride as an external wipe. Bactericidal testing of nine strains of H. pylori against disinfectants revealed that ethyl alcohol (80%) and glutaraldehyde (0.5%) killed all nine strains within 15 seconds, whereas chlorhexidine gluconate (0.05%, 0.1%), benzalkonium chloride (0.025%, 0.1%), alkyldiaminoethylglycine hydrochloride (0.1%), povidone-iodine (0.1%), and sodium hypochlorite (150 ppm) killed all nine strains within 30 seconds. CONCLUSION: H. pylori is readily killed by many common disinfectants and antiseptics. However, practices for disinfection of flexible fiberoptic endoscope were not appropriate.

Cross Infection↗
PubMed1996

Alteration of atrial natriuretic peptide and brain natriuretic peptide gene expression associated with progression and regression of cardiac hypertrophy in renovascular hypertensive rats.

1. We assessed the changes of atrial natriuretic peptide and brain natriuretic peptide gene expression associated with progression and regression of cardiac hypertrophy in renovascular hypertensive rats (RHR). 2. Two-kidney, one-clip hypertensive rats (6-week-old male Wistar) were made and studied 6 (RHR-1) and 10 weeks (RHR-2) after the procedure. Regression of cardiac hypertrophy was induced by nephrectomy at 6 weeks after constriction, and the nephrectomized rats were maintained further for 4 weeks (nephrectomized rat: NEP). Sham operation was performed, and the rats were studied after 6 (Sham-1) and 10 weeks (Sham-2). Atrial natriuretic peptide and brain natriuretic peptide gene expression in the left ventricle was analysed by Northern blotting. 3. Plasma atrial natriuretic peptide and brain natriuretic peptide were significantly higher in RHR-1 and RHR-2 than in Sham-1, Sham-2 and NEP. Atrial natriuretic peptide and brain natriuretic peptide mRNA levels in RHR-1 were approximately 7.2-fold and 1.8-fold higher than those in Sham-1, respectively, and the corresponding levels in RHR-2 were 13.0-fold and 2.4-fold higher than those in Sham-2, respectively. Atrial natriuretic peptide and brain natriuretic peptide mRNA levels of NEP were normalized. Levels of atrial natriuretic peptide and brain natriuretic peptide mRNA were well correlated positively with left ventricular weight/body weight ratios. There was a significant positive correlation between the levels of atrial natriuretic peptide and brain natriuretic peptide mRNA (r = 0.86, P < 0.01). 4. We conclude that the expression of atrial natriuretic peptide and brain natriuretic peptide genes is regulated in accordance with the degree of myocardial hypertrophy and that the augmented expression of these two natriuretic peptides may play an important role in the maintenance of cardiovascular haemodynamics in renovascular hypertension.

Animals↗
PubMed1996

Detection of bacterial antigens using immuno-PCR.

A new and very sensitive antigen detection technique, immuno-polymerase chain reaction (immuno-PCR), was developed. This method is basically similar to the enzyme-linked immunosorbent assay which detects an antigen-antibody reaction, but instead of an enzyme being conjugated to an antibody, a DNA fragment is used and this DNA can be amplified by PCR. We applied this method to the detection of the fish pathogen, Pasteurella piscicida, in naturally infected yellowtail. Using immuno-PCR, 3.4 cfu ml-1 of bacteria could be detected. In comparison, ELISA detected only 3.4 x 10(4) cfu ml-1. Immuno-PCR is a powerful method for detection of pathogens in host tissues.

Animals↗
PubMed1996

Gas transfer and blood compatibility of fluorinated polyimide membranes.

Fluorinated polyimide derived from 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and bis[4-(4-aminophenoxy) phenyl]sulfone (APPS) was synthesized to develop a novel membrane oxygenator combining excellent gas transfer and blood compatibility. The asymmetric gas exchange membranes of 6FDA-APPS made by a dry/wet process consisted of an ultrathin and defect-free skin layer supported by a porous substructure. O2 transfer through the 6FDA-APPS membrane was extremely augmented as compared with that of the presently available membrane, poly(dimethylsiloxane), and the previously reported 6FDA-DDS membrane. Since CO2 transfer through the 6FDA-APPS membrane increased with a decrease in CO2 pressure according to dual-mode transport theory, CO2 from the membrane was selectively removed at low CO2 pressure. For the evaluation of in vitro blood compatibility, the platelet adhesion and the plasma protein adsorption on the surface of the 6FDA-APPS membrane were observed by using scanning electron microscopy and the amounts of platelet and plasma protein were determined by an amino acid analyzer. The results indicated that the fluorinated polyimide membranes showed excellent blood compatibility.

Blood Gas Analysis↗
PubMed1996

Morphologic and histologic characterization of cardiac myxomas by magnetic resonance imaging.

The purpose of this study was to assess the role of ECG-gated spin-echo (SE) magnetic resonance (MR) images, cine MR images, and gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced MR images for the morphologic and histologic diagnosis of atrial myxomas. Four patients with left atrial myxoma were imaged with a 1.5-T MR imager. The T1-weighted images and the cine MR images were obtained before injection of Gd-DTPA. After the injection of Gd-DTPA, the T1-weighted images were obtained again. Gd-DTPA-enhanced images of the myxomas were histologically compared with the extracted specimens. The tumors were represented more clearly on the cine MR images as low-intensity areas than on the SE images as high-intensity areas. On post-Gd-DTPA images, the 2 tumors were homogeneously enhanced and the other 2 were inhomogeneously enhanced. The locus of enhancement on post-Gd-DTPA images fitted with histologic myxoma or inflammation, and the unenhanced region reflected the necrosis or cystic changes in the specimens, respectively. The morphologic diagnosis of cardiac myxomas by MRI first should be done with SE images, and when the images are unclear, the cine MR images must be supplemented to depict the tumor clearly. Moreover, Gd-DTPA-enhanced MRI could elucidate histologic characteristics in myxomas.

Adult↗
PubMed1996

Use of serial semithin frozen sections to evaluate the co-localization of estrogen receptors and progesterone receptors in cells of breast cancer tissues.

The extent of co-expression of estrogen receptors (ER) and progesterone receptors (PgR) in breast cancer cells was examined immunocytochemically. Eight surgical cases of infiltrating ductal carcinoma designated as ER-positive and PgR-positive (ER+/PgR+) by enzyme immunoassay (EIA) were used. They were fixed with 4% formaldehyde and cut into serial frozen semithin sections. Using sections stained with either anti-ER or anti-PgR antibody, we ascertained the co-localization of ER and PgR in a single cell and estimated the ratio of the number of cells co-expressing ER and PgR. Twenty-six to 95% of the cells were immunopositive for both ER and PgR, 2-25% of them, varying in cases, were positive for ER but not for PgR, and <3% of the cells were positive for PgR but not for ER. The remaining 5-60% cells were positive for neither ER nor PgR. A significant percentage of breast cancer cells in tissues designated as ER+/PgR+ by EIA showed the phenotype of ER-positive but PgR-negative. The co-expression ratio of ER and PgR in biochemically detected ER+/PgR+ breast cancer may reflect a particular clinical parameter, such as the heterogeneous responsiveness of ER+/PgR+ breast cancers to hormonal treatment. Immunostaining of serial semithin frozen sections for two or more different antigens is a useful method to assess the correlation of localization of antigens.

Animals↗
PubMed1996

A family with Machado-Joseph disease, previously diagnosed as dentatorubral-pallidoluysian atrophy.

We report a family with Machado-Joseph disease (MJD) that was previously diagnosed with dentatorubral-pallidoluysian atrophy (DRPLA), on the basis of the neuropathologic findings. Because the clinical and pathologic reevaluation strongly suggested a diagnosis of MJD, we conducted a genetic study in the family. Two patients, aged 38 and 40, revealed CAG repeat lengths of the MJD1 gene of 80, 28 and 75, 14, confirming a final diagnosis of MJD.

Adult↗
PubMed1996

Effect of aging on the esophageal motor functions.

To clarify the changes of esophageal motility along with age, we performed esophageal manometry on 47 healthy volunteers, and compared the values of four groups under 49 years old (n = 11), 50 to 59 (n = 15), 60 to 69 (n = 11), and over 70 years old (n = 10). Resting lower esophageal sphincter (LES) pressure in the group over 70 years old showed the tendency of decrease, but not statistically significant. Nadir LES pressure on swallow-induced relaxation was not statistically different among 4 groups. On esophageal body testing, percentage of non-conduction sequence in the group 60 to 69 and over 70 years old was statistically higher compared with that of the group under 49 years old (p < 0.05) but spared in some elderly subjects. Percentage of simultaneous contractions was not statistically different among 4 groups. Peristaltic contraction amplitude in the group over 70 years old was significantly lower than that of the group under 49 years old both at the level of 5 cm above (p < 0.01) and 10 cm above LES (p < 0.05). We speculate that the influence of aging on esophageal motility is the reduced transmission sequence of peristalsis and contractility of esophageal body. This alteration along with age may differ from the pathological condition of scleroderma or diffuse esophageal spasm.

Adult↗
PubMed1996

[Familial hypertrophic cardiomyopathy generating a marked left ventricular pressure gradient in an 82-year-old woman].

Familial nonobstructive hypertrophic cardiomyopathy in 78-year-old woman was diagnosed in 1988. Since then she has been treated with a beta-blocking drug and a calcium antagonist. Her clinical condition was NYHA I or II for several years. Echocardiography revealed asymmetric septal hypertrophy in 1988 (interventricular septal thickness = 21 mm, posterior wall thickness = 10 mm). Systolic anterior motion of the mitral valve was first observed at the end of 1992. The left ventricular pressure gradient also gradually increased; it was about 138 mmHg in 1993 (age 82 yrs). The left ventricular ejection time index increased from 376 msec in May, 1992 to 459 msec in May, 1994. In September, 1994, the patient's condition gradually deteriorated (NYHA IV), and she was admitted to our hospital. To attenuate the left ventricular pressure gradient, 150 mg of disopyramide was administered. Her condition markedly improved: the left ventricular pressure gradient decreased from 180 mmHg to 76 mmHg, and the left ventricular ejection time index decreased from 485 msec to 419 msec. These results indicate that a left ventricular pressure gradient can be generated rapidly even in a very old patient, and that disopyramide may be useful to attenuate the left ventricular pressure gradient.

Aged↗