Biomedical subjects
Publications and source records attributed to S Hayasaka.
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Arthrobacter 4-44-2 (ATCC 25581), capable of subterminal oxidation of n-hexadecane to 2-, 3-, and 4-alcoholic and ketonic products, was examined for the ability of this methylene hydroxylase capability to be induced and repressed and for structural relationships influencing methylene function oxidation. Induction was best carried out by use of n-alkanes from 10 to 16 carbons in length and was especially strong with methylcyclohexane among cyclic compounds tested. Induction was not observed with several related alcohols, 1-unsaturated compounds, or methoxy and ethoxy compounds tested. After induction, n-alkanes 14 and 16 carbons in length were transformed to the corresponding internal oxidation products; however, no activity was observed with even-carbon alkanes of shorter chain length. Hexadecene-1 and all alcohols tested, including cyclododecanol, were transformed to corresponding ketonic or aldehydic products. Cyclic compounds tested, including cyclododecane, were not oxidized by induced cells, suggesting that a methyl group plays a role in orientation of the substrate for the methylene hydroxylation but that the methyl function was not as critical after completion of the hydroxylation step regardless of structural configuration. Acetate strongly repressed induction of n-hexadecane methylene hydroxylase activity. Inducibility of methylene hydroxylase activity was confirmed by use of cell-free systems with methylcyclohexane as an inducer. A stimulation of methylene hydroxylase activity by addition of reduced pyridine nucleotides and ferrous ion was indicated.
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Intrusive thoughts about cancer, often identified as 'cancer-specific worries' or 'cancer-specific distress', have been postulated to be associated with dysfunction in women at increased risk of developing breast or ovarian cancer. The current study discusses the development and validation of a measure designed to assess women's perceptions of the interference such worries create in their daily functioning. Analyses revealed that approximately two-thirds of a high-risk breast cancer clinic sample perceived worries about breast cancer as interfering with their functioning across a variety of life domains. Multiple regression analyses indicated that worry interference scores predicted Profile of Mood States (POMS) Anxiety and Confusion, and Short Form-36 (SF-36) Role-Emotional and Mental Health scores after the effects of other variables such as frequency of worry about breast cancer, and having a family history of cancer had been considered. Women who perceived their worries as interfering with their functioning reported higher levels of anxiety and confusion, and diminished mental health and role functioning. The results add to the expanding area of anxiety/distress in at-risk populations by providing (1) a direct measure of the perceived interference associated with breast cancer-specific thoughts, (2) a validation of the measure via its associations with standard measures of emotional distress and health functioning, and (3) evidence of the measure's incremental predictive value in explaining distress and quality of life, after consideration of background variables, such as having a family history of cancer.
We examined visual evoked potentials and pattern electroretinograms in a patient with Tolosa-Hunt syndrome associated with optic nerve involvement. The 82-year-old woman developed unilateral painful ophthalmoplegia and visual loss in the right eye. Magnetic resonance imaging showed an abnormal soft-tissue area in the right cavernous sinus and the right orbital apex. Symptoms responded rapidly to treatment with corticosteroid. Visual evoked potentials to flash and pattern stimuli were both remarkably reduced and delayed in the right eye in the acute stage; however they improved to almost normal after steroid therapy. The pattern electroretinogram recorded in the acute stage was normal bilaterally. These results indicate that optic nerve involvement in Tolosa-Hunt syndrome can be mild and reversible.
The purpose of this study was to assess the hypothesis that lower serum sodium levels are associated with cardiovascular sequelae in patients with Kawasaki disease (KD). We used the database of the 16th nationwide survey of KD in Japan. We investigated the distribution of serum sodium levels and the relationship between serum sodium levels and cardiovascular sequelae. Of the reported cases, serum sodium levels were reported in 13,569 patients (89%). The proportion of patients with serum sodium levels 130 mEq/L or less, was greater in complete cases than in incomplete cases. The proportion of patients with serum sodium levels 130 mEq/L or less was increased with age. The largest proportion of patients with serum sodium levels 130 mEq/L or less was found in the category of 3-5 days since onset of illness. A serum sodium of level 135 mEq/L or less was an independent risk factor for cardiovascular sequelae (odds ratio, 1.79, 95% confidence interval, 1.42-2.26). Among patients with KD, there are significant differences in serum sodium levels between diagnostic categories, age, and days since the onset of illness. The sodium level may be a simple predictor of cardiovascular sequelae.
Lysosomal enzymes are distributed widely in various ocular tissues. Among these tissues, the uvea and retina show the higher enzyme activities of acid phosphates, beta-blucuronidase, alpha-fucosidase, alpha-mannosidase, arylsulfatase, cathepsin D, cathepsin B and others. The particular role of lysosomal enzymes in the pathogenic processes of ocular diseases such as storage disease, uveitis, retinal degeneration, retinal detachment, corneal dystrophy and glaucoma is strongly suggested. The enzymes also have additional importance in ocular physiopathology.
Ochratoxin A (a mycotoxin) is known to cause cell death in the developing brain of embryos 1-2 days after treatment. Microcephaly was observed with high frequency in mice by prenatal treatment with ochratoxin A. Using a stereological method, the numerical densities of neurons and synapses were investigated in the somatosensory cortex of 6-week-old microcephalic mice. The numerical density of neurons in ochratoxin A-treated mice represented a 39% increase compared to the control mice, but there was no difference in the numerical density of synapses. The somatosensory cortices of control mice had about 13,000 synapses per neuron, whereas ochratoxin A-treated mice had about 9,400 synapses per neuron. The deficits in synapse-to-neuron ratios seen in ochratoxin A-induced microcephalic brain seemed to result from a reduced dendritic growth.
PURPOSE: To examine rhodopsin gene mutations in Japanese patients with retinitis pigmentosa. METHODS: We performed a mutational analysis of the rhodopsin gene in 42 patients from 40 families with retinitis pigmentosa. Genomic DNA was amplified by polymerase chain reaction (PCR) and the PCR products were sequenced. Restriction enzyme analysis was performed in family members of 1 patient with a rhodopsin gene mutation (Gly106Arg) and in 100 normal individuals. RESULTS: Among the patients with retinitis pigmentosa, 3 patients in one family had a heterozygous Gly106Arg mutation of the rhodopsin gene. They had night blindness and sectorial retinal dystrophy (predominantly at the inferior fundus) in both eyes. None of the 100 individuals with normal fundi had the Gly106Arg mutation of the rhodopsin gene. CONCLUSION: The Gly106Arg mutation of the rhodopsin gene has been found in Japanese patients with sectorial retinitis pigmentosa.
PURPOSE: To report branch retinal vein occlusion and retinal hemorrhages associated with tsutsugamushi disease. METHODS: Case report of a 60-year-old woman who complained of fever, chills, headache, lymphadenopathy, and blurred vision in the right eye following an insect bite to the lower right forehead. RESULTS: Serological findings showed elevated titers for the strains of Rickettsia tsutsugamushi. Ophthalmologic examination disclosed bilateral conjunctival injection, flame-shaped hemorrhage in her right fundus, and scattered hemorrhage in her left fundus. Fluorescein angiography demonstrated dye leakage and dilation of capillaries. CONCLUSIONS: Branch retinal vein occlusion associated with classical tsutsugamushi disease, as demonstrated in our patient, may be rare.
PURPOSE: To evaluate the effects of the alpha(2)-adrenergic agonists (clonidine, apraclonidine, and guanfacine) on lipopolysaccharide (LPS)-induced aqueous flare elevation in pigmented rabbits. METHODS: Anterior uveitis was induced with an intravenous injection of LPS (0.5 microg/kg) in an ear vein. The reproducibility of experimental uveitis induced by LPS (0.5 microg/kg) was also determined. Clonidine (0.01, 0.05, 0.25, or 1%), apraclonidine (1%), or guanfacine (1%) was topically instilled in the right eye 30 and 5 minutes before and 30 minutes after LPS application (N = 6 animals, respectively). Clonidine (0.25%) was topically administered three times at 30-minute intervals from 240 or 120 minutes before, or 120 or 240 minutes after LPS application (N = 6 animals, respectively). Then 1 mg/kg of yohimbine was injected into an ear vein 30 minutes before each topical three-time instillation of clonidine 1%, apraclonidine 1% or guanfacine 1% (N = 6 animals, respectively). Aqueous flare was measured with a laser flare-cell meter. Aqueous flare elevation was expressed as the area under the curve (AUC) in arbitrary units. Rabbits received the first LPS intravenous injection, and the control values of the AUC were obtained. Three months later, the alpha(2)-agonist and the second LPS administration were given to the same animals. RESULTS: The AUCs (5,184 +/- 1,255 units) after the first application of LPS were similar to those (5,033 +/- 1,290) after the second application 3 months after the first administration. Topical instillation of clonidine inhibited LPS-induced aqueous flare elevation in a dose-dependent manner (0.01-0.25%). Topical instillation of clonidine 1%, apraclonidine 1% or guanfacine 1% inhibited LPS-induced aqueous flare elevation by 98 +/- 2.0% (mean +/- SD), 86 +/- 14% and 94 +/- 5.7%, respectively. Pretreatment with intravenous yohimbine prevented the inhibitory effect on flare elevation induced by each agent. CONCLUSION: The present findings suggested that topical instillation of some alpha(2)-agonists may have an inhibitory effect on ocular inflammation, which is mediated in part by alpha(2)-receptors.