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Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 217 records · Page 12Linked to original sources

Second generation hepatitis C virus antibody-positive rate in children: investigation of the route of hepatitis C virus infection in children with no history of transfusion.

Hepatitis C virus (HCV) antibody and HCV-RNA screening was undertaken in 1864 children, aged from 0 to 15 years who did not have a history of transfusion. Anti-HCV was tested by the second generation enzyme-linked immunosorbent assay (ELISA). HCV RNA was examined by reverse transcriptase-nested polymerase chain reaction (PCR). Two of the 1864 children were positive for serum HCV RNA. They had no history of transfusion, no episodes of horizontal transmission, but the mother in each case was positive for serum HCV RNA, implying mother-to-infant infection. Eleven children who were positive for HCV antibody with low values and negative for serum HCV RNA were classified as belonging to the high bovine milk (composed primarily of casein)-specific IgG4 value group. This suggested that many of the children who were falsely positive for HCV antibody using ELISA had antibodies to casein.

Adolescent↗

Abnormal structure of the Y chromosome detected in bovine gonadal hypoplasia (XY female) by FISH.

The structure of the Y chromosome was investigated by FISH and G banding in 3 cases of bovine XY females shown by PCR to lack the SRY gene. Although 2 different repeat-DNA sequences (BC1.2 and btDYZ-1) hybridized to the short arm of the Y chromosome in a normal bull, they hybridized to both arms of the Y chromosome in the XY females. In the Y chromosome from XY females, only the centromeric region was darkly stained by G banding, in comparison with dark staining on the long arm of a normal Y chromosome. From the results obtained, it seemed that the Y chromosome from the XY females was structurally abnormal, namely an isochromosome with an identical short arm. Our results also confirm that SRY is located on the long arm of the Y chromosome in bovine.

Animals↗

Analysis of the hypervariable region of hepatitis C virus E2/NS1 gene in an infant infected by blood transfusion.

We investigated the sequential change in the hypervariable region 1 (HVR 1) of hepatitis C virus (HCV) E2/NS1 gene in an infant. He was transfused with 160 mL of blood containing the HCV (0.7 Meq/mL) on the 6th d after birth and subsequently developed chronic viremia. At 16 mo, the HVR1 amino acid sequences of HCV observed in the infant's sera were very similar to those from the donor (his maternal grandfather) on the day of transfusion. However, highly variable amino acid sequences of HVR1 were observed throughout infancy. These results demonstrate that an adaptive response of HCV to evade host immunity seems to occur, as in adult cases, even in early infancy when the ability to produce humoral immunoglobulin is thought to be low.

Amino Acid Sequence↗

The possibility of early estimation for fertility in bovine heterosexual twin females.

To diagnose the possibility of early estimation for fertility in bovine heterosexual twin females, we designed a new diagnostic program. The 9 freemartins (FM) and 5 normal females (Normal) were used in this study. All 14 cases, at 4 months of age, were given Pregnant Mare Serum Gonadotrophin (PMSG) and human Chorionic Gonadotrophin (hCG) 1.5-2 days later. Thereafter, the concentration of estradiol-17 beta (E2) was determined by RIA, and that of progesterone (P) was done by RIA and EIA (Ovcheck EIA Kit). The concentration of E2 in the Group of Normal rapidly increased after administration of PMSG, but in the Group of FM, the concentration of E2 changed in very low levels over 14 days. The concentration of P in the Group of Normal rapidly increased after administration of PMSG, but in the Group of FM, the concentration of P changed in very low levels over 14 days.

Aging↗

Homology of E2 gene in 8 child-mother pairs infected with hepatitis C virus.

The frequency of genetic homology of hepatitis C virus (HCV) E2 gene in 8 child-mother pairs was investigated. The route of HCV infection of all children suggested mother-to-child infection by their past history. In this study, we analyzed at least 5 complementary DNA (cDNA) clones for each case. In 6 of the 8 (75%) child-mother pairs, for the region between hypervariable region (HVR)-1 and HVR-2, the similarity of the nucleotide sequence of all 5 cDNA clones between each child and the mother was higher than that between the child and the other children, the other mothers and the sequences from GenBank. One of the 8 (13%) child-mother pairs showed a great similarity in parts of all cDNA clones. This was also confirmed by phylogenetic analyses of the sequences of cDNA clones from families and that from GenBank. These results suggested that the homology search of nucleotide sequence of this region was useful to confirm mother-to-child transmission of HCV.

Amino Acid Sequence↗

The case fatality rate of methicillin-resistant Staphylococcus aureus (MRSA) infection among the elderly in a geriatric hospital and their risk factors.

From April 1991 to March 1993, there were 49 elderly patients with methicillin-resistant Staphylococcus aureus (MRSA) infection in a geriatric hospital in Fukuoka, Japan. The retrospective study was carried out in order to evaluate the various factors which may influence the case fatality rate of MRSA infection among the elderly. Among them, 33 patients (67.3%) died while only 16 patients became culture-negative for MRSA and discharged after recovering from MRSA infection. A univariate analysis revealed that male sex (odds ratio [OR] = 12.25, 95% confidence interval [CI] = 2.80-53.55), hypoalbuminemia (OR = 3.83, 95% CI = 1.11-13.21) and an excessive usage of antibiotics (OR = 6.67, 95% CI = 1.70-26.09) were risk factors for death among the patients with MRSA infection. In a multivariate analysis, male sex and an excessive usage of antibiotics were still risk factors while hypoalbuminemia was not. However, hypoalbuminemina was more common in male patients than female patients (78.3% vs. 42.3%, p < 0.05). These findings suggest that the case fatality rate of MRSA infection may be high and also suggest that the elderly with MRSA infection who had hypoalbuminemia and/or received many antibiotics may have a poor prognosis.

Aged↗

Histocompatibility antigens and polymyalgia rheumatica in a Japanese patient with insulin-dependent diabetes mellitus.

A 30-year-old Japanese female developed insulin-dependent diabetes mellitus (IDDM). She later complained of muscle pains at the age of 37. Erythrocyte sedimentation rate and C-reactive protein were abnormal, with negative antinuclear antibody and rheumatoid factor tests. The diagnosis of polymyalgia rheumatica (PMR) was made. She had HLA phenotypes including A2 and without DR4, consistent with common types of Japanese PMR. Her DNA typing included DQB1*0303 which is positively associated with Japanese IDDM. It seems likely that she suffered from these diseases at a young age on the basis of having the HLA-susceptibility to both PMR and IDDM.

Adult↗

Effect of arginine vasopressin on breathing movements of chronically instrumented fetal lambs.

BACKGROUND: In hypoxic conditions, fetal breathing movements (FBM) are reportedly inhibited with simultaneous elevation of the plasma level of catecholamines and arginine vasopressin (AVP). Although some kinds of catecholamines are reported to inhibit FBM, the effects of AVP on FBM are still unknown. The present study was undertaken to elucidate whether or not AVP has an inhibitory effect on FBM and electrocortical activities in chronically instrumented fetal lambs. METHODS: Arginine vasopressin was injected slowly into the fetal external jugular vein via a catheter over a 30 minute period at an infusion rate of 4.9 approximately 10.0 mIU/minute/body. In 15 fetuses (36 estimations) the mean fetal age, mean estimated fetal body weight, and mean infusion dose were 132.4 +/- 4.5 days, 3.4 +/- 0.3 kg and 1.7 +/- 0.3 mIU/kg/min. RESULTS: The infusion caused a persistent decrease in the fetal heart rate and an increase in the fetal arterial pressure during the 30 minute period. The infusion of AVP resulted in a significant decrease in the incidence of FBM from 36.1 +/- 14.8% to 12.4 +/- 14.9% (p <0.01). However, there were no significant differences in the incidence of the low voltage fast (LVF) activity before and during infusion of AVP. CONCLUSION: AVP has an inhibitory effect on FBM. The mechanism of this inhibition was not a direct suppression of the CNS as there was a dissociation between FBM and the electrocortical activity during infusion of AVP.

Animals↗

[Treatment of gingivitis in elderly patients in a nursing home].

For 3 months, 4 patients in a nursing home for the elderly received supervised professional oral care in conjunction with oral hygiene instruction. Within the first month after the start of this program, plaque was reduced to 1/3 and gingivitis was reduced to 1/9 of their respective initial levels. In 5 patients who did not receive either oral hygiene instruction or professional oral care, plaque retention and gingivitis were unchanged. We conclude that professional oral care combined with oral hygiene instruction supervised by dental professionals can help to control gingivitis in the elderly.

Aged↗

[Pharyngeal bacteria and professional oral health care in elderly people].

In 15 elderly residents of an old-age home, we measured the total number of bacteria and the numbers of streptococci and staphylococci in the pharynx over 5 months. Seven residents received professional oral health care from dentists and dental hygienists and eight practiced oral care by themselves or together with a helper. During the 5 months, the total number of bacteria and the numbers of streptococci and staphylococci decreased (p < 0.01) in those who received professional care. In contrast, the total number of bacteria and the numbers of streptococci and staphylococci neither did not change or increased in those who did not receive professional care. These findings show that professional oral health care by dentists and dental hygienists can decrease the total number of bacteria and the numbers of streptococci and staphylococci in the pharynx of elderly people, which might prevent aspiration pneumonia.

Aged↗

Recording multifocal electroretinograms with fundus monitoring.

PURPOSE: To record multifocal electroretinograms (ERGs) with simultaneous fundus monitoring. METHODS: An infrared television fundus camera was used to monitor the fundus. A tightly packed array of 19 yellow light-emitting diodes (LEDs) was used as the stimulus source and LEDs were alternated between on and off according to a binary m-sequence at a rate of 75 Hz. The stimulus array subtended approximately 25 degrees of the visual angle. Multifocal ERGs were recorded with a Burian-Allen bipolar contact lens electrode from two normal subjects and a patient with macular dystrophy. RESULTS: When the center of the stimulus was positioned on the fovea, the amplitude of the response was largest at the fovea and decreased toward the peripheral retina; the response pattern corresponded to the spatial distribution of cone cells. When the center of the stimulus was positioned on the optic disc, the response at the optic disc was undetectable. A reliable multifocal ERG was obtained from a patient with macular dystrophy. CONCLUSIONS: This system made it possible to monitor the stimulus on the fundus and to adjust the stimulus to the correct retinal locations with exact focusing. The authors' findings indicate that this method especially can be useful in patients with poor fixation. In addition, the authors' results suggests that the stray light effect in the multifocal stimulus system is minimal if any.

Adult↗

[Indocyanine green angiography in Stargardt's disease].

We performed indocyanine green angiography (ICG angiography) and fluorescein angiography in order to investigate the choroidal circulation in patients with Stargardt's flavimaculatus. Eight eyes of 4 patients in Groups 2 approximately 3 (Noble classification) were included in this study. In the area with "dark choroid" in fluorescein angiography, ICG angiography revealed large choroidal vessels in all eyes, but some fluorescent choroidal vessels were dark around the atrophic macula and in the peripapillary area, which indicated a greater storage of lipofuscin within the retinal pigment epithelium in those areas. In the atrophic macula area, irregular hypofluorescence was observed in ICG angiography, which might be caused by filling defect and/or block. Many flecks revealed hyperfluorescence in fluorescein angiography and hypofluorescence in ICG angiography, suggesting that focal circulatory disturbances in the choriocapillaries exist beneath the flecks.

Adolescent↗

[Aging and the focal macular electroretinogram].

Focal macular electroretinograms (MERGs) were recorded with a fundus monitor through an infrared television fundus camera in 112 eyes of 112 normal subjects (68 males, 44 females), using three stimulus spots 5 degrees, 10 degrees, and 15 degrees in diameter. The amplitude and the implicit time of the a-wave, h-wave, and oscillatory potentials (OPs), and the ratio of amplitude of the b-wave to the a-wave (b/a ratio) at each stimulus spot were compared in terms of aging and sex. The amplitude of all components decreased significantly (p < 0.01-0.05) after the fifth decade, and there was a tendency for OPs to decrease more than the a-wave and b-wave. There was no significant effect of age on the h/a ratio and the implicit time of each component. The ratio of increase of amplitude to the enlargement of stimulus spot showed no significant changes with age. There was no significant difference in each component in terms of amplitude and implicit time with sex. The decrease of amplitude of all components after the fifth decade suggests aging of the macular cones. The tendency toward decreasing OPs also suggests aging of the inner retina in the macular region. The proportional changes of amplitude recorded with three different sizes of stimulus spots indicate that there is no significant effect of aging on the fovea, parafovea, or perifovea.

Adult↗

[The effect of age on short-wavelength sensitive cone electroretinograms and long-and middle-wavelength sensitive cone electroretinograms].

We studied the effect of age on short-wavelength sensitive cone electroretinogram (S-cone ERG) and long-and middle-wavelength sensitive cone ERG (LM-cone ERG) using a contact lens electrode with a built-in light-emitting diode. We recorded ERGs in 31 pseudophakic subjects to avoid the effect of yellowing in human crystalline lens. The intensities of our stimuli were on the asymptote of the intensity-response curve. We performed linear regression analysis against age on the S-cone ERG b-wave (S-b), and the LM-cone ERG a-, b- and d-waves (LM-a, LM-b, LM-d). We found significant age-dependent reduction in the amplitude of S-b, LM-a, and LM-d, significant prolongation in the peak time of LM-b and LM-d, and significant increase in the b/a ratio of the LM-cone ERG, but no significant age correlation between the peak time of S-b and LM-a and the amplitude of the b-wave. Our results provide evidence that age-related changes in S- and LM-cone systems begin in the twenties in humans. Furthermore, a significant increase of the b/a ratio suggests that off-bipolar cells are more vulnerable to aging than on-bipolar cells.

Adult↗

[A case of congenital retinoschisis with unexpected appearance and spontaneous regression].

A case of congenital retinoschisis, with both unexpected appearance and spontaneous regression, is reported. The patient, a 22-year-old man, had been diagnosed with congenital retinoschisis when he was 11 years old. The ocular fundus showed bilateral foveal retinoschisis and peripheral retinoschisis in the right eye. Early in November 1991, he visited our hospital and complained of a visual field defect in the left eye. The ocular fundus of the left eye showed high ballooning retinoschisis. However, two weeks later, the ballooning retinoschisis had completely disappeared. Appearance and regression of peripheral retinoschisis of congenital retinoschis in an adult is a very rare occurrence.

Adult↗

[Binocular functions in amblyopia and strabismus].

Regarding the changing trends in the concept, definition, etiological classification, and criteria for diagnosis of amblyopia, we reviewed a total of 4,693 cases of amblyopia seen during the past 37 years. The amblyopia was divided into four types: strabismic, anisometropic, ametropic, and form vision deprivative. There was a definite trend for the incidence to decrease and for the diagnosis to be made during earlier age in recent years. Although favorable recovery of visual acuity is obtained after treatment of amblyopia and strabismus, there are difficulties in obtaining good binocular functions in early-onset amblyopia and strabismus. This feature was evaluated in regard to motion perception asymmetry (MPA) and binocular depth from motion (DFM). Many cases of early-onset amblyopia and strabismus showed no disparity stereopsis, or position stereopsis, in spite of the presence of DFM. The MPA appeared to be closely related to early-onset esotropia regardless of age, while it disappeared and motion perception became symmetric 4 to 5 months after birth in normal infants. The DFM seemed to play an important role in maintaining good motor alignment for several years after surgery. I developed a checkerboard pattern stimulator in 1978. This method proved to be useful in developing binocular functions and motor alignment by applying simultaneous bifoveolar stimulation and anti-suppression. Extensive exposure to the stimulation was essential for therapeutic success.

Adolescent↗