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Biomedical subjects

T Hirose

Publications and source records attributed to T Hirose.

At least 721 records · Page 40Linked to original sources

Electrophysiological similarities between two eyes with X-linked recessive retinoschisis.

Electroretinograms (ERG) and electro-oculograms (EOG) were studied in 88 eyes of 44 male patients with X-linked recessive retinoschisis. Differences of fundus appearance, ERG, and EOG between the eyes of each patient were analyzed. Fundus abnormalities were symmetrical in 77.3% of the cases. The amplitude of the ERG a-wave was normal in 26.1% and was abnormally low in 73.9%. The amplitude of the b-wave was below normal in all eyes; thus a small b-wave/a-wave ratio, which is characteristic of X-linked recessive retinoschisis, was observed in every case. The light peak to dark trough (LP/DT) ratio of the EOG was normal in 90.8% of the cases. The relative electrophysiological differences between the two eyes were calculated and showed that a-wave amplitude was not different between eyes in 75.0% of the cases; b-wave amplitude was not different in 77.3% of the cases; b-wave/a-wave ratio was symmetrical in 93.2% of the cases; and the LP/DT ratio was consistent between eyes in 86.8% of the cases. These results suggest that in most cases of X-linked recessive retinoschisis the fundus appearance, ERG, and EOG are similarly affected in both eyes of the patient.

Adolescent↗

Primary structure of delta subunit precursor of calf muscle acetylcholine receptor deduced from cDNA sequence.

Clones carrying cDNA sequences for the delta subunit precursor of the acetylcholine receptor from calf skeletal muscle have been isolated. Nucleotide sequence analysis of the cloned cDNA has indicated that this polypeptide consists of 516 amino acids including a hydrophobic prepeptide of 21 amino acids. The delta subunit of the calf muscle acetylcholine receptor, like the alpha, beta and gamma subunits of the same receptor as well as the alpha and gamma subunits of its human counterpart, exhibits structural features common to all four subunits of the Torpedo electroplax receptor, apparently being oriented across the membrane in the same manner as proposed for the fish receptor subunits. The degree of amino acid sequence homology between the calf and Torpedo delta subunits (60%) is comparable to that between the beta subunits (59%) and to that between the gamma subunits (56%), but is lower than that between the alpha subunits of the two species (81%). This suggests that the alpha subunit evolved more slowly than the three other subunits. A dendrogram representing the sequence relatedness among the four subunit precursors of the mammalian and fish acetylcholine receptors has been constructed. Some regions of the delta subunit molecule, including the region containing the putative disulphide bridge and that encompassing the clustered putative transmembrane segments M1, M2 and M3, are relatively well conserved between calf and Torpedo. The relative pattern of regional homology is similar for all four subunit precursors.

Amino Acid Sequence↗

In situ actin distribution in excised retrolental membranes in retinopathy of prematurity.

Actin, an intracellular contractile protein, is associated with cell movements in both muscle and nonmuscle tissues. Using the fluorescent derivative of the mushroom toxin, phallacidin, which specifically binds to polymerized (filamentous) actin, we demonstrated the distribution of actin in retrolental membranes excised during open-sky vitrectomy from six infants with leukokoria due to retrolental fibroplasia. Actin was detected in ubiquitous linear bundles, which is consistent with the existence of contractile forces. Actin was also concentrated in the cortical cytoplasm of cells, thus outlining the plasma membranes. Transmission electron microscopy has identified many of these cells to be myofibroblastlike in appearance. Myofibroblasts are known to contract like smooth-muscle cells and have been reported as the putative causal factor in the contraction of scars and transvitreal membranes.

Actins↗

Cellular characteristics of neoplastic angioendotheliosis. An immunohistological marker study of 6 cases.

Neoplastic angioendotheliosis (NAE) is a rare, mostly fatal disease characterized by proliferation of large blastoid cells in small vessels of various organs. The origin of neoplastic cells remain undetermined. In this study, cell markers were studied immunohistologically on paraffin sections of six cases of NAE, by applying avidin-biotin-peroxidase (ABC) method and five antibodies which can demonstrate marker antigens on formalin fixed and paraffin embedded specimens. It was shown that the neoplastic cells were heavily stained with an anti-B lymphocyte monoclonal antibody LN-1 (6/6), moderately stained with another anti-B lymphocyte antibody LN-2 (5/6) and heavily stained with a monoclonal antibody which reacts with all levels of leukocytes (Dako-LC) (6/6). The cells did not show positive reaction with an anti-myelomonocytic antibody anti-Leu M1. The reaction against anti-Factor VIII, which can depict endothelial cells, was mostly negative, and if positive, was faint and indefinite, leading to an assumption that the reaction was against antigens in serum and not against neoplastic cells. These results suggest that the neoplastic cells of NAE are in the B lymphocyte lineage.

Antibodies, Heterophile↗

Measurement of contrast sensitivity function using pattern-reversal visual evoked responses.

In order to determine whether pattern-reversal visual evoked response (VER) can be used to measure contrast sensitivity function (CSF), we investigated the effect of change of contrast upon pattern-reversal VER. Contrast thresholds for VER were extrapolated in five spatial frequencies. The CSF curve obtained from the VER showed the inverted U-shape as the psychophysical CSF curve. However, the low frequency fall-off that is usually seen in psychophysical CSF was less evident in the electrophysiological CSF. The difference between the electrophysiological CSF and the psychophysical CSF increased along with the spatial frequency. Proper stimulus conditions would make this method of evaluation of CSF by pattern reversal VER useful in relatively young children in whom psychophysical tests cannot be performed.

Adult↗

Cryptotia: our classification and treatment.

Our classification of cryptotia is based on recognition that the deformity is the result of an anomaly of the intrinsic transverse and oblique auricular muscles. Our treatment, in the first instance, is a non-surgical correction. This should be started early, if possible in the first 6 months of the baby's life. Even in the case of older children, success can sometimes be achieved and a non-surgical correction should be considered first. If non-surgical management fails the deformity can be corrected surgically by dividing the muscle fibres that produce the anomaly of the external ear through a small incision. Our new surgical approach involves moving the available skin in the region of the inferior cephalo-auricular sulcus to the superior part where skin is needed by a rotation flap. This operation has several advantages.

Age Factors↗

Norrie's disease: a study of two families.

Norrie's disease, or congenital progressive oculo-acoustico-cerebral degeneration, is a rare X-linked recessive syndrome of retinal malformation, deafness, and mental retardation and/or deterioration. The natural history of the disorder in two families with five affected males, four living and one deceased, is described. The histopathology of two patients, one from each family, is reported. Differential diagnosis, treatment, and genetic counseling are discussed.

Adolescent↗

The pharmacokinetic and bactericidal characteristics of oral cefixime.

The pharmacokinetics of cefixime (FK 027), a broad-spectrum cephalosporin, were assessed in 12 normal subjects after single oral doses of 50, 100, 200, and 400 mg. Mean peak serum concentrations were 1.02, 1.46, 2.63, and 3.85 micrograms/ml after the four respective doses. Respective mean serum levels at 12 hours were 0.16, 0.33, 0.72, and 1.13 micrograms/ml. Volumes of distribution averaged 0.1 L/kg body weight, and the elimination t1/2 was 3 hours for all doses. The AUC was 7.01, 11.4, 22.5, and 36.4 micrograms X hr/ml for the four doses, respectively. Serum clearance averaged 0.4 mg/min/kg and mean 24-hour urinary recovery was 21%, 19%, 20%, and 16% for the four respective doses. Serum bactericidal titers at 4 hours exceeded 1:16 for Streptococcus pneumoniae, S. pyogenes, Hemophilus influenzae, and Branhamella catarrhalis. Urine bactericidal titers exceeded 1:8 for Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae resistant to the available oral cephalosporins.

Administration, Oral↗

Bone scanning in patients with breast carcinoma. Should it be a routine examination in every stage group?

Skeletal imaging using radionuclides has proved to be a sensitive method for the detection of early bony metastases from breast carcinoma. Recent studies have found a relatively low rate of abnormal scans in patients with Stage I and II breast cancers, and therefore it is open to question whether bone scanning should be part of the preoperative evaluation of any patient prior to breast surgery. We reviewed our experience with bone scans in 329 patients out of 406 histologically proven breast cancer patients to determine if any or all patients should have this procedure done routinely prior to breast surgery.

Adult↗

Abnormal production of and response to B-cell growth factor and B-cell differentiation factor in patients with systemic lupus erythematosus.

We examined the production of and the response to B-cell growth factor (BCGF) and B-cell differentiation factor (BCDF) in 21 patients with systemic lupus erythematosus (SLE) and 23 normal subjects. T cells, 2.5 X 10(6)/ml, were cultured for 24 or 72 h with 1% phytohaemagglutinin (PHA). After absorption of PHA by chicken erythrocytes (CRBC), they were used for BCGF and BCDF. In inactive SLE, BCGF activity was significantly lower than that in normal subjects. Active SLE contained two separate groups, one showing normal BCGF activity and the other showing lower activity than normal. In contrast, BCDF activity from initial culture in active SLE was elevated. The B-cell response both to BCGF and BCDF was elevated in active SLE without Staphylococcus aureus Cowan I antigen (SAC) preactivation. However, the B-cell response to SAC was markedly disturbed. Thus SLE B cells were shifted to the mature state in vivo. We also demonstrated pivotal abnormalities of monocytes in SLE B-cell growth and differentiation. These results may contribute to the understanding of the abnormalities of T-B interactions and the overproduction of antibody in SLE.

Adolescent↗

Molecular genetic analysis of myelin-deficient mice: shiverer mutant mice show deletion in gene(s) coding for myelin basic protein.

The gene expression of myelin basic proteins (MBPs) in shiverer mutant mice was investigated by the Northern and Southern hybridization techniques. In the control mice RNA molecules from the brains which were about 2,300 nucleotides in length were hybridized to cDNA of 1.8 kb encoding for a mouse MBP, but RNA from the brains of 3-week-old shiverer mutant mice contained no detectable amount of MBP transcripts hybridizing to this probe. Moreover the shiverer mutant mice lost several restriction fragments that hybridized to the same probe in the control mice when each of the five restriction enzymes, i.e., HindIII, PstI, PvuII, AccI, and StuI, was used. These data suggest that the shiverer mutation may correspond to the deletion of a large portion of MBP exon(s) in the gene, and this deletion causes inefficient transcription leading to the depletion of MBPs in the myelin and the dysmyelination observed in these mice.

Animals↗

Objective evaluation of binocular function with pattern reversal VER. I. Effect of contrast.

The effect of change of contrast on the pattern reversal monocular VER, binocular VER, and binocular summation (binocular VER amplitude/monocular VER amplitude) was studied in normal subjects. The monocular VER amplitudes showed significant increase until the 0.50 contrast and saturation above that contrast. The largest binocular VER amplitude was observed at 0.20 contrast, and the amplitude tended to decrease with increasing contrast. The value of the binocular summation was highest at 0.20 contrast and decreased significantly with increasing contrast. At high contrast, there was no significant binocular summation. The difference of peak time (phase) between the binocular and the monocular VER was greatest at low contrast and decreased with increasing contrast. These results are explained by the difference of saturation level between the binocular and monocular systems. Our findings lead us to advocate strongly the use of low- to midlevel contrast for evaluating binocular function with pattern reversal VER in clinical ophthalmology.

Adult↗

Significance of thromboxane generation in ozone-induced airway hyperresponsiveness in dogs.

To determine whether thromboxane A2 may be involved in ozone (O3)-induced airway hyperresponsiveness, we studied the effect of a thromboxane synthase inhibitor (OKY-046, 100 micrograms X kg-1 X min-1 iv) in five dogs exposed to O3. Airway responsiveness was assessed by determining the provocative concentration of acetylcholine aerosol that increased total pulmonary resistance by 5 cmH2O X l-1 X s. O3 (3 ppm) increased airway responsiveness as demonstrated by a decrease in acetylcholine provocative concentration from 2.42 (geometric SEM = 1.64) to 0.14 mg/ml (geometric SEM = 1.30). OKY-046 significantly inhibited this effect without altering pre-O3 responsiveness or the O3-induced increase in neutrophils and airway epithelial cells in bronchoalveolar lavage fluid. To further examine the role of thromboxane A2, we studied the effect of a thromboxane A2 mimetic, U-46619, on airway responsiveness in five additional dogs. U-46619 in subthreshold doses (i.e., insufficient to increase base-line pulmonary resistance) caused a fourfold increase in airway responsiveness to acetylcholine. Subthreshold doses of histamine had no effect. These results suggest that thromboxane A2 may be an important mediator of O3-induced airway hyperresponsiveness.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

Reading disabilities in Japan: evidence against the myth of rarity.

The incidence of the reading disabilities among 250 Japanese children (8.5-13.4 years old) was measured by a standardized reading ability test which had recently been developed. It was found that 16.4% of the children tested have a one year delay, and 15.2% of the children have a two year delay. The results show that Makita's (1968) claim concerning the rarity of the incidence of reading disabilities in Japan is incorrect.

Adolescent↗