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Biomedical subjects

Y Wada

Publications and source records attributed to Y Wada.

At least 235 records · Page 13Linked to original sources
PubMed2000

A new Leu253Arg mutation in the RP2 gene in a Japanese family with X-linked retinitis pigmentosa.

PURPOSE: To identify the clinical findings in a Japanese family with X-linked retinitis pigmentosa associated with mutation in codon 253 (Leu253Arg) in the RP2 gene. METHODS: Case reports included clinical features and results of fluorescein angiography, electroretinogram, kinetic visual field testing, and DNA analysis. Two affected hemizygotes with retinitis pigmentosa associated with transversion mutations in codon 253 (Leu253Arg) of the RP2 gene and the obligate carriers were examined. RESULTS: A novel Leu253Arg mutation of the RP2 gene was found to cosegregate with retinal degeneration in two affected males and two carriers in female heterozygote in a Japanese family. The ophthalmic findings in hemizygote showed severe retinal degeneration. In the obligate carrier, mild chorioretinal degeneration was observed in both eyes but a tapetal-like reflex of the fundus was not apparent. CONCLUSIONS: The mutation at codon 253 of the RP2 gene is the first mutation reported in a Japanese family. It is concluded that the mutation of the RP2 gene also causes the X-linked retinitis pigmentosa in Japanese patients.

Adult↗
PubMed2000

Luminescence of Novel Neodymium Sulfonylaminate Complexes in Organic Media.

Luminescence of Nd(III) in an organic solvent having C-H bonds was achieved for the first time by complexing Nd(III) with long-chain perfluoroalkylated ligands such as bis(perfluorooctylsulfonyl)aminate (pos). The complex [Nd(pos)(3)] gave an emission quantum yield of 3.0+/-0.5 % in undeuterated acetone. The bulky pos ligands suppress the excitation of C-H vibrations, energy migration at diffusional collision, and the coordination of acetone molecules (see picture) to the Nd(III) center, which otherwise quench the luminescence.

Journal Article↗
PubMed2000

Rapid screening of high-risk patients for disorders of purine and pyrimidine metabolism using HPLC-electrospray tandem mass spectrometry of liquid urine or urine-soaked filter paper strips.

BACKGROUND: A rapid and specific screening method for patients at risk of inherited disorders of purine and pyrimidine metabolism is desirable because symptoms are varied and nonspecific. The aim of this study was to develop a rapid and specific method for screening with use of liquid urine samples or urine-soaked filter paper strips. METHODS: Reverse-phase HPLC was combined with electrospray ionization (ESI), tandem mass spectrometry (MS/MS), and detection performed by multiple reaction monitoring. Transitions and instrument settings were established for 17 purines or pyrimidines. Stable-isotope-labeled reference compounds were used as internal standards when available. RESULTS: Total analysis time of this method was 15 min, approximately one-third that of conventional HPLC with ultraviolet detection. Recoveries were 96-107% in urine with added analyte, with two exceptions (hypoxanthine, 64%; xanthine, 79%), and 89-110% in urine-soaked filter paper strips, with three exceptions (hypoxanthine, 65%; xanthine, 77%; 5-hydroxymethyluracil, 80%). The expected abnormalities were easily found in samples from patients with purine nucleoside phosphorylase deficiency, ornithine transcarbamylase deficiency, molybdenum cofactor deficiency, adenylosuccinase deficiency, or dihydropyrimidine dehydrogenase deficiency. CONCLUSIONS: HPLC-ESI MS/MS of urine allows rapid screening for disorders of purine and pyrimidine metabolism. The filter paper strips offer the advantage of easy collection, transport, and storage of the urine samples.

Chromatography, High Pressure Liquid↗
PubMed2000

Experimental diabetes-induced regression of the rat prostate is associated with an increased expression of transforming growth factor-beta.

PURPOSE: Transforming growth factor-beta (TGF-beta), a potent inhibitor of cell growth, plays an important role in the androgen-dependent processes of the prostate through a complex network of growth factors. TGF-beta expression in the prostate is under negative regulatory control of androgen. As experimental diabetes causes a regression of the prostate and decrease in serum testosterone levels in rats, we examined TGF-beta alterations at the mRNA and protein levels in the diabetic rat prostate. MATERIALS AND METHODS: The expression of TGF-beta1 and TGF-beta2 and their respective mRNAs in prostates from streptozotocin (STZ)-induced diabetic, insulin-treated diabetic and age-matched control rats were investigated, using relative multiplex RT-PCR, semi-quantitative Western blotting, and immunohistochemistry. RESULTS: Induction of diabetes caused a significant reduction in prostatic weight and in serum testosterone levels in rats. Both mRNA and protein levels of TGF-beta1, and mRNA level of TGF-beta2 were up-regulated in the diabetic rat prostate. Insulin-treatment normalized changes observed in prostatic weight and serum testosterone levels, and reversed the alterations in the TGF-beta1 and TGF-beta2 expression at the gene transcript and protein levels to control levels. Immunohistochemical studies demonstrated that TGF-beta1 is localized to prostatic stromal cells, whereas TGF-beta2 is located in both epithelial and stromal cells. CONCLUSION: These results suggest that TGF-beta1 and TGF-beta2 may be involved in the diabetes-induced regression of the prostate gland.

Animals↗
PubMed2000

A frequent 1085delC/insGAAG mutation in the RDH5 gene in Japanese patients with fundus albipunctatus.

PURPOSE: To identify the frequency of a mutation of the RDH5 gene in Japanese patients with hereditary retinal degeneration and to characterize clinical findings for the patients associated with a 1085delC/insGAAG mutation in the RDH5 gene. METHODS: Mutation screening by single-strand conformation polymorphism was performed on 6 patients with fundus albipunctatus and 150 patients with autosomal recessive retinitis pigmentosa. The DNA fragment that showed abnormal mobility on SSCP was then sequenced. Clinical features were characterized by visual acuity, slit-lamp biomicroscopy, electroretinography, fluorescein angiography, kinetic visual field testing, and dark adaptometry. RESULTS: A novel 1085delC/insGAAG mutation in the RDH5 gene was identified in all 6 patients, from 4 unrelated families with fundus albipunctatus. The ophthalmic findings of each affected member were very similar, which may provide the natural course of the phenotype produced by the 1085delC/insGAAG mutation. CONCLUSIONS: A homozygous1085delC/insGAAG mutation in the RDH5 gene produces fundus albipunctatus in Japanese patients. These findings suggest that this mutation was a founder effect in Japanese patients with fundus albipunctatus.

Adult↗
PubMed2000

[Dissociation of voluntary eye closure--to keep the eyes closed and to blink--following right hemisphere stroke].

We report a case of a unique eye sign following right hemispheric infarction. This patient was a 78 year old right-handed woman. There was a history of a left hemispheric stroke 1 year previously. On admission, she showed left hemianopia, dysarthria, mild left central facial paresis, bilateral sensory deficit and quadriparesis which were marked on the left side. Babinski sign was elicited on the left. She did not have anosognosia or visual neglect. She had mild orofacial apraxia, but ideomotor and ideational apraxia was absent. There was no motor impersistence. Magnetic resonance imaging of the brain revealed a recent infarction in the territory of the right middle cerebral artery and an old infarction in the left tempro-parietal lobe. The patient could not open her eyelids to verbal command or voluntarily until about two weeks later, when she became able to open her eyes but showed difficulty keeping her left eye closed. She was aware of this problem and could repeat the command and comprehend what was requested to her. On verbal command to close the eyes, her right eye would be closed continuously and excessively and the left eye would only blink. When requested to blink, however, she could blink correctly without excessive eye closure. Spontaneous, reflex and voluntary blinking were normal. Her eyes were closed normally during sleep. Blepharospasm was not seen. The patient showed a striking dissociation between a failure to close her eyes continuously and a preserved ability to blink voluntarily. We suggest that her ability to contract palpebral portion of her left orbicularis oculi muscle is preserved. Regarding the mechanism of the voluntary eye closure system, separate control mechanisms should exist on closing eyes continuously and blinking.

Aged↗
PubMed2000

[Homocystinuria with generalized chorea and other movement disorders: a case report].

We report a 50-year-old right-handed woman who, at age 20, was diagnosed to have homocystinuria presumably due to cystathionine beta-synthase deficiency. At age 40 years, involuntary movements developed insidiously, affecting her face, neck and upper limbs. During the next 10 years, involuntary movements progressed and she could no longer walk. Examination disclosed bilateral lens dislocation and marfanoid skeletal deformity. Muscle strength was mildly decreased in the right arm and bilateral legs. There was hyperreflexia in the right upper and bilateral lower extremities without Babinski sign. Muscle tone was mildly increased in the neck and bilateral upper extremities. She had persistent generalized choreic movements, dystonia affecting the face and neck, and resting and postural tremor in the upper limbs and tongue. A cranial CT scan showed an old low density lesion in the left frontal area. Involuntary movements in homocystinuria is rare and, to our knowledge, only 9 cases have been reported. This case was unique in that involuntary movements developed in the adulthood.

Chorea↗
PubMed2000

[Application of DNA-DNA hybridization, DDH MYCOBACTERIA 'Kyokuto' to species-identification of mycobacteria grown in Middlebrook 7H9 broth].

A colorimetric DNA-DNA hybridization for the genetic identification of mycobacteria, DDH MYCOBACTERIA 'KYOKUTO' (Kyokuto Pharmaceuticals, Tokyo) was evaluated for the clinical isolates of mycobacteria grown in Middlebrook 7H9 broth of MB/BacT (Organon Teknika, Durham, NC, U.S.A.). When the MB/BacT gave the positive interpretation, 10 ml of Middlebrook 7H9 broth was collected from the bottle. After centrifugation at 3,000 rpm for 10 min, two drops of acetone were added to the pellet, then let it stand for one hour at the room temperature. The air-dried pellet was resuspended in a small volume of distilled water, and proceeded to the identification described. Of 136 clinical isolates of mycobacteria, comprising of 76 M. tuberculosis complex and 60 nontuberculous mycobacteria (NTM), ninety-five (70%) were correctly identified when compared to the reference identification. Thirty (22%) isolates resulted in the unidentified due to negative reaction throughout the test wells, and the remaining 11 (8%) were also unidentified due to low likelihoods. According to the package insert, the DDH MYCOBACTERIA may not be applicable to the isolates grown in Middlebrook broth. However, our test procedure using acetone prior to the extraction of bacterial DNA enables us to directly identify the isolates of mycobacteria grown in Middlebrook 7H9 broth of MB/BacT.

Acetone↗
PubMed2000

[Orthostatic hypotension with repeated bilateral limb shaking and metamorphopsia. A case of hemodynamic transient ischemic attacks].

A 78-year-old right-handed man with idiopathic orthostatic hypotension and a history of Hashimoto's thyroiditis presented over 2 years with recurrent, stereotyped attacks of bilateral limb shaking and metamorphopsia, which were precipitated by standing more than 3 or 4 minutes, or walking a few meters. These symptoms would resolve upon squatting or lying down and did not occur spontaneously at rest. He did not lose consciousness during the attacks. Speech, power, and sensation were preserved during these attacks. He had no history of seizures or habit of smoking. On examination, his supine blood pressure was 110/60 mmHg, and 62/27 mmHg on standing, with the pulse rate being 61/min and 66/min, respectively. Although he showed orthostatic hypotension, he did not complain of fainting or lightheadedness on standing alone. Magnetic resonance imaging of the brain revealed mild periventricular white matter changes and multiple small ischemic lesions bilaterally in the cerebral deep white matter. An electroencephalogram (EEG) showed mild, generalized slowing of nonspecific feature. EEG monitoring during a limb shaking episode showed no epileptiform abnormalities. Cerebral angiogram revealed a moderate degree of stenosis of the left internal carotid and a mild degree of stenosis of the right internal carotid, the right vertebral arteries and the left vertebral arteries. A single-photon emission computed tomography (SPECT) showed a moderate compromise of perfusion of the left internal carotid territory. After managing both hypotension and orthostatic hypotension with antihypotensive medication and levothyroxine sodium, his symptoms dramatically disappeared. Thus, we diagnosed that transient hemodynamic insufficiency due to combination of vascular stenosis and hypotension was the cause of these symptoms. Limb shaking is a well-described presentation of carotid artery occlusive disease and is usually unilateral. Bilateral limb shaking is rare and only 2 cases have been reported. Metamorphopsia is also a rare symptom of vertebrobasilar ischemia. We suggest that bilateral limb shaking correlates with hypoperfusion in the anterior border zones and metamorphopsia with that in the posterior border zones of both hemispheres. Hemodynamic TIA should be considered as a cause of movement disorders affecting four limbs.

Aged↗
PubMed2000

[Pharmacokinetics of cisplatin and methotrexate in a patient suffering from advanced ureteral tumor accompanied by chronic renal failure, undergoing combined hemodialysis and systemic M-VAC chemotherapy].

The pharmacokinetics of cisplatin and methotrexate were determined in a patient suffering from advanced ureteral tumor accompanied by chronic renal failure undergoing 4 consecutive cycles of M-VAC chemotherapy and hemodialysis. No significant difference was observed in t1/2, AUC or CLtot of total platinum between the patient with the chronic renal failure and patients with normal renal function. The AUC and CLtot of free platinum in the patient with the chronic renal failure were higher and lower, respectively, than in the patients with normal renal function. The free cisplatin rebounded remarkably after the end of dialysis, which may be partly attributed to an increase in the AUC and decrease in CLtot. However, the dialysis index was about 75 and 85% in the 3rd and 4th cycles, respectively. The t1/2 and CLtot of methotrexate in the patient with the chronic renal failure tended to be longer and smaller than those in patients with normal renal function, respectively. Seventy-two hours after administration, the methotrexate level was 0.02 microM, which was not at the high-risk level of high-dose therapy. After four cycles of M-VAC therapy, the rest of the right ureteral tumor was extirpated and the clinical response was CR. In conclusion, it is considered that cisplatin and methotrexate can be given to a patient with chronic renal failure. However, the cisplatin and methotrexate serum levels must be monitored, even after very low doses.

Aged↗
PubMed2000

Defects in pyrimidine degradation identified by HPLC-electrospray tandem mass spectrometry of urine specimens or urine-soaked filter paper strips.

BACKGROUND: Urinary concentrations of thymine, uracil, and their degradation products are useful indicators of deficiencies of enzymes of the pyrimidine degradation pathway. We describe a rapid, specific method to measure these concentrations to detect inborn errors of pyrimidine metabolism. METHODS: We used urine or urine-soaked filter-paper strips as samples and measured thymine, uracil, and their degradation products dihydrothymine, dihydrouracil, N:-carbamyl-ss-aminoisobutyric acid, and N:-carbamyl-ss-alanine. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry, and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled reference compounds were used as internal standards. RESULTS: All pyrimidine degradation products could be measured in one analytical run of 15 min. Detection limits were 0.4-4 micromol/L. The intraassay imprecision (CV) of urine samples with added compounds was 1.3-12% for liquid urines and 1. 0-10% for filter-paper extracts of the urines. The interassay imprecision (CV) was 3-11% (100-200 micromol/L). Recoveries were 89-99% at 100-200 micromol/L and 95-106% at 1 mmol/L in liquid urines, and 93-103% at 100-200 micromol/L and 100-106% at 1 mmol/L in filter-paper samples. Correct identifications of deficiencies of the pyrimidine-degrading enzymes were readily made with urine samples from patients with known defects. CONCLUSIONS: HPLC with electrospray ionization tandem mass spectrometry allows rapid testing for disorders of the pyrimidine degradation pathway, and filter-paper samples allow easy collection, transport, and storage of urine samples.

Chromatography, High Pressure Liquid↗
PubMed1999

Disruption of clh-1, a chloride channel gene, results in a wider body of Caenorhabditis elegans.

We cloned the clh-1 gene coding for a putative ClC chloride channel in Caenorhabditis elegans. The gene product exhibited a high degree of homology with human ClC-1 and ClC-2. The clh-1 gene was predominantly expressed in the hypodermis, including seam cells. Null mutations of clh-1 caused a significantly wider body and an abnormal alae structure. High osmolarity in the culture medium restored the normal body width of the clh-1 mutants. These results suggest that the clh-1 gene contributes to maintenance of the body width through regulation of osmolarity.

Amino Acid Sequence↗
PubMed1999

Mechanical rotation of the c subunit oligomer in ATP synthase (F0F1): direct observation.

F0F1, found in mitochondria or bacterial membranes, synthesizes adenosine 5'-triphosphate (ATP) coupling with an electrochemical proton gradient and also reversibly hydrolyzes ATP to form the gradient. An actin filament connected to a c subunit oligomer of F0 was able to rotate by using the energy of ATP hydrolysis. The rotary torque produced by the c subunit oligomer reached about 40 piconewton-nanometers, which is similar to that generated by the gamma subunit in the F1 motor. These results suggest that the gamma and c subunits rotate together during ATP hydrolysis and synthesis. Thus, coupled rotation may be essential for energy coupling between proton transport through F0 and ATP hydrolysis or synthesis in F1.

Actins↗
PubMed1999

Remodeling of cell-cell and cell-extracellular matrix interactions at the border zone of rat myocardial infarcts.

At the border zone of myocardial infarcts, surviving cardiomyocytes achieve drastic remodeling of cell-cell and cell-extracellular matrix interactions. Spatiotemporal changes in these interactions are likely related to each other and possibly have significant impact on cardiac function. To elucidate the changes, we conducted experimental infarction in rats and performed 3-dimensional analysis of the localization of gap junctions (connexin43), desmosomes (desmoplakin), adherens junctions (cadherin), and integrins (beta(1)-integrin) by immunoconfocal microscopy. After myocardial infarction, changes in the distribution of gap junctions, desmosomes, and adherens junctions showed a similar but nonidentical tendency. In the early phase, gap junctions almost disappeared at stumps (longitudinal edges of cardiomyocytes facing the infarct), and, although desmosomes and adherens junctions decreased, they still remained. In the healing phase, at stumps, connexin43, desmoplakin, and cadherin were closely associated between multiple cell processes originating from a single cardiomyocyte. Electron microscopy confirmed the presence of junctional complexes between the cell processes. beta(1)-Integrin at the cell process increased during the formation of papillary myotendinous junction-like structures. Abnormal localization of connexin43 was often accompanied by desmoplakin and cadherin on lateral surfaces of surviving cardiomyocytes. These findings suggested that remodeling of gap junction distribution was closely linked to changes in desmosomes and adherens junctions and that temporary formation of intracellular junctional complexes was an element of the remodeling of cell-cell and cell-extracellular matrix interactions after myocardial infarction. Moreover, the remodeling of the intercalated disk region at the myocardial interface with area of scar tissues was associated with the acquisition of extracellular matrix and beta(1)-integrin.

Animals↗