Biomedical subjects
Publications and source records attributed to M Takagi.
A new focal pattern stimulator was developed. Since this system enables direct observation of ocular fundus during examination, it may be useful for the objective assessment of visual function in patients with various kinds of eye diseases.
To reveal the impairment of the temporal modulation transfer function of vision in patients with optic neuritis, the pattern visual evoked potentials (P-VEPs) were recorded at reversal frequencies ranging from 4 to 24 per second, and the fast Fourier transform (FFT) of VEPs were investigated. In normal subjects, curves of the square root of the power of the FFTs of P-VEPs versus temporal frequency showed the maximum peak at 6 Hz (12 reversals/s). The specific distribution of the power spectrum could be found at each temporal frequency, and the amplitudes of higher harmonic components decreased while a single power spectrum peak became prominent as the temporal frequency increased. In patients with optic neuritis, an abnormality of the power spectrum of steady-state P-VEPs could by detected by estimating the 1st and 2nd harmonic components. The abnormality of the power spectrum of transient P-VEPs could be detected by estimating the higher harmonic components of the power spectrum.
Subjective contrast sensitivity for the stationary and horizontally drifting vertical stripe patterns was measured in normal subjects and in patients with glaucoma, optic neuritis and optic atrophy. Contrast sensitivity was also determined objectively using an eye movement reflex (optokinetic nystagmus) recorded by means of electro-oculography. The contrast sensitivity for the drifting stripe patterns in normal subjects was characterized by a depression of sensitivity at the high spatial frequency and an increased contrast sensitivity at the low spatial frequency in comparison with the results of stationary stripe patterns. The measurement of contrast sensitivity for the horizontally drifting vertical stripe patterns was found to be more sensitive for detection of minor damage to the optic nerve than that for the stationary patterns. The results of the subjective contrast sensitivity and the objective one determined using an eye movement reflex showed a good correlation.
We isolated 18 cDNA candidates that were expected to encode parts of the self-incompatibility-associated RNase of Lycopersicon peruvianum PI 126441 (S11a-plant) from a style cDNA library. Polymerase chain reaction was used with oligonucleotides derived from conserved amino acid sequences of RNases from fungi and S-associated RNases in other species of Solanaceae. Two of these clones (both do not have full length sequences) gave 826-bp and 730-bp sequences, and they had the same open reading frame, named ORF-1. Comparison of the deduced amino acid sequence of ORF-1 with S-associated RNase of other Solanaceous plants showed a high degree of similarity. mRNA encoding this ORF-1 was about 1000 bases long and detected only in the style tissue by Northern analysis. Using one of the cDNA clones as a probe, we detected sequence variability among three different S-genotypes of randomly chosen wild-type tomatoes by Southern analysis. From these results, it was concluded that ORF-1 encodes the self-incompatibility associated S-glycoprotein of L. peruvianum PI 126441 (S11a-plant).
We clarified the evolutionary position of Candida maltosa, an n-alkane-assimilating yeast, by sequencing the nucleotides of the small-subunit ribosomal RNA gene. Phylogenetic analyses showed the close evolutionary relationships of C. maltosa with C. tropicalis, C. viswanathii, C. albicans, C. parapsilosis, and C. guilliermondii, forming a sub-group within this genus.
Pseudomonas paucimobilis UT26 grows on gamma-hexachlorocyclohexane (gamma-HCH) as a sole source of carbon and energy. Tn5 mutation was introduced into UT26, and two kinds of mutants defective in gamma-HCH degradation were phenotypically isolated; one (UT64) completely lacked the activity to degrade gamma-HCH, while the other (UT61) retained a very low level of activity. Tagging and sequencing analysis showed that both mutants had a Tn5 insertion at the same site of the linA (gamma-HCH dehydrochlorinase encoding) gene. However, UT61 had an additional rearrangement, which could be the cause of its retaining a low level of activity. An in vitro complementation test with a crude extract from UT64 plus partially purified LinA protein showed that LinA was essential not only for the first-step reaction (gamma-HCH to gamma-pentachloro-cyclohexene; gamma-PCCH), but also for the second-step reaction (gamma-PCCH to compound B) of gamma-HCH degradation in UT26.
An epizootic of foal diarrhea due to serotype 3 rotavirus (RV) was observed in 89 of 168 cases (53%) during the period from March to July in 1987. A total of 51 strains of RV were isolated from the 62 diarrheal feces examined, and one isolate (CH-3) showed a unique electropherotype of viral RNA which differed from the others that widely prevailed on this farm. No positive reaction was observed between strain CH-3 and each of the antisera against serotypes 1 to 12 of human and animal RV in neutralization tests. However, dsRNAs of the CH-3 virus were hybridized with a probe prepared from a strain of equine serotype 3 RV.
This study compared the "Clock-Drawing Task" to the Mini-Mental State Test (MMST) in 834 elderly persons. A cut-off score of 20 or less on the MMST was used to determine cognitive impairment. The "Clock drawing Task" was score of 20 or less on the MMST was used to determine cognitive impairment. The "Clock drawing Task" was scored by three components; frame, numbers, and two hands. Using a criterion of completion on two or more of the three components, the sensitivity, specificity, and correct identification of the diagnosis of cognitive impairment of "Clock Drawing Task" were 89%, 65% and 83% respectively. "Clock Drawing" appears to be a practical test which can be useful for clinicians as a screening for cognitive impairment in old age.
Proteoglycans (PGs) have been visualized in the predentine and dentine with cationic dyes by staining thin sections with Alcian Blue, bismuth nitrate, or using Spicer's high-iron diamine (HID) method. The precise location may be obtained by adding cationic dyes such as Cuprolinic Blue, ruthenium hexamine trichloride or cationic detergent (cetylpyridinium chloride) to the fixative. These methods induced the formation of aggregates which varied in shape and number according to the method used. Rapid freezing followed by freeze-substitution revealed an amorphous ground substance, homogeneously stained with Alcian Blue, located in the predentine between the collagen fibres. These PGs may be involved in transport and diffusion in predentine. In dentine, small granules and needle-like structures were observed along the collagen fibres. This second group of PGs differs in composition, distribution and functions from the predentine PGs. The same distribution was seen when hyaluronidase-gold labelling was used. Labelling with antibodies and autoradiography also gave evidence of two distinct groups of PGs. In predentine, as an hydrated gel, PGs seems to act as mineral inhibitors, whereas immobilized on a surface, as seen at the dentine edge, they act as nucleating agents. The interaction between PGs and phospholipids seems also to play a role in the mineralization process.
A 47-year-old woman with antiphospholipid syndrome was referred to us for hemostatic control at the time of extraction of teeth. After administration of intravenous gammaglobulin of 0.4g/kg daily for 5 days, lupus anticoagulant activity disappeared and platelet count slightly increased. Furthermore, she had a transfusion of platelet-rich plasma before operation and no hemorrhagic or thrombotic complications occurred. These findings suggest that gammaglobulin infusion therapy is useful in preventing the complications at operation in patients with antiphospholipid syndrome.
The monoclonal rat anti-c-kit antibody (ACK2), which abrogates colony growth supported by stem cell factor (SCF), significantly inhibited the interleukin-6 (IL-6)-dependent growth of hematopoietic progenitors derived from spleen cells of normal and 5-fluorouracil (5-FU)-treated mice and from bone marrow cells of normal mice in serum-containing culture. The numbers and types of colonies supported by IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), however, were not influenced by the addition of ACK2 to the cultures of the bone marrow cells from normal mice. In replating experiments with pooled blast cells, ACK2 caused a partial, but significant, inhibition of GM colony growth supported by a combination of IL-6 and fetal bovine serum (FBS), which suggests that FBS is one source of the SCF activity. Conversely, the addition of SCF or FBS with IL-6 to a serum-free culture had significant synergistic effects on the total number of colonies derived from post-5-FU spleen cells and from pooled blast cells. The dose response study showed that the ability of 30% FBS to interact with IL-6 on the colony growth by post-5-FU spleen cells was equivalent to that of approximately 5 ng/mL SCF. These findings suggest that c-kit plays an important role in the growth of hematopoietic progenitors responding to IL-6, and that SCF in the serum affects the development of hematopoietic progenitors in serum-containing cultures.
Explore the source record for details and available documents.
The optic disc was studied by stereofluorescein angiography in 7 cases of the chronic stage of anterior ischemic optic neuropathy (AION) and 20 cases of low-tension glaucoma (LTG), to clarify the difference in vasculature. In the LTG patients, a selective and well-defined decrease of laminar and prelaminar capillaries in the upper and (or) lower temporal area of the optic disc was found in 38 (95%) of 40 eyes in the 20 cases. In the AION patients, a decrease of laminar and prelaminar capillaries was also found in 3 (43%) of 7 eyes in the 7 unilateral cases, but the specific area and form of vascular reduction were not found. These results show that the angiographic picture of the optic disc in LTG is clearly different from that in AION.
We recorded flash electroretinograms (ERGs), flash visual evoked potentials (VEPs), pattern ERGs and pattern VEPs in two siblings with adult form galactosialidosis. The amplitude of b-wave was decreased in flash ERGs. The peak latency of flash VEPs was within normal range. The pattern ERGs and VEPs were nonrecordable. These results suggested the damage of retinal ganglion cell and inner nuclear layer in these cases.
Explore the source record for details and available documents.
Disorder of cardiac conduction and automaticity have been widely reported in patients with progressive systemic scleroderma (PSS). In the present study, ventricular arrhythmias were monitored by 24-hour ambulatory electrocardiographic recording (Holter monitor) in 30 female patients with PSS and 20 apparently healthy female controls. The following results were obtained: 1) In the waking state, 8 cases of 30 patients showed grade III, IVA or IVB of ventricular arrhythmias, according to Lown's classification. On the other hand, ventricular arrhythmias, such as grade III, IVA or IVB, were not observed in the control group. 2) In the patient group, grade IVA arrhythmias were observed during defecation, driving or light working, and grade IVB were during defecation, urination, light working or sleeping. These results suggest that it is important to examine arrhythmias by Holter monitors in patients with PSS.
We applied subjective and psychophysical methods and pattern visual-evoked potential (VEP) P100peak latency as an objective index to measure spatial modulation transfer function (MTF) in normal subjects and patients with early primary open-angle glaucoma (POAG) in an effort to detect impairment of the spatial MTF of vision. To estimate spatial MTF objectively, the peak latency of the P100 component of pattern VEP was investigated. The mean contrast sensitivity in normal subjects derived from the pattern VEP peak latency was found to be maximum at the check size of 14.4 minutes of arc (i.e., 2.08 cycles per degree of spatial frequency), and the objective spatial MTF curve coincided well with that of the subjective one at all spatial frequencies examined. A statistically significant positive correlation was found between the objective (VEP) contrast threshold and the subjective one. Deterioration of the objective contrast sensitivity derived from the VEP peak latency was found to be much prominent that of the subjective one in patients with early glaucoma.
Nine pediatric patients with bacterial infections (5 cases of tonsillitis, 3 cases of impetigo and 1 case of UTI) were treated with S-1108, and the efficacy and the safety were evaluated. The clinical responses to S-1108 treatment were excellent in 7 cases and good in 2. The efficacy rate was 100%. Bacteriologically, the causative organisms (Streptococcus pyogenes, Staphylococcus aureus, Haemophilus parainfluenzae and Escherichia coli) were eradicated. No clinical side effects were observed. Elevation of CK in 2 cases and eosinophilia in 1 case were noted.