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Biomedical subjects

M Arai

Publications and source records attributed to M Arai.

At least 361 records · Page 20Linked to original sources
PubMed1994

Crystallization and preliminary crystallographic data of the alpha-amylase inhibitors, Haim I and Paim I.

Two proteins that act as alpha-amylase inhibitors, Haim I and Paim I, were crystallized and preliminary X-ray diffraction studies on them were carried out. We also sequenced Haim I prepared from Streptomyces griseosporeus YM-25 and confirmed that it is composed of 78 amino acid residues. Crystals of Haim I were grown from ammonium sulfate solution mixed with ethanol by the vapor diffusion technique. The crystals grew as hexagonal bipyramids and diffracted X-rays beyond 2.0 A resolution. They belong to the space group P6(1)22 (or P6(5)22) with unit cell dimensions of a = b = 36.7 A, c = 192.4 A, and contain one molecule per asymmetric unit. Paim I, a protein of 39 amino acid residues produced by Streptomyces corchorusii, was crystallized under similar conditions to Haim I. The crystals diffracted X-rays beyond 2.5 A. They belong to the space group P4(1)2(1)2 (or P4(3)2(1)2) with unit cell dimensions of a = b = 65.4 A, c = 96.1 A, and contain three molecules per asymmetric unit.

Amino Acid Sequence↗
PubMed1994

Increased activity of insulin-like growth factor-binding protein in human thyroid papillary cancer tissue.

It has been shown that both insulin-like growth factor-I (IGF-I) and IGF-binding proteins (IGFBPs) are produced by thyroid cells in culture and that the cells respond to IGF-I with increased DNA synthesis, suggesting an autocrine/paracrine role of IGF-I in the regulation of thyroid cell growth. We investigated the tissue contents of immunoreactive IGF-I (irIGF-I) and IGFBPs in human papillary carcinoma and compared them with those of normal thyroid tissue. When irIGF-I was measured after separation of the IGFBPs by gel-filtration, its content in carcinoma tissue was not different from that in adjacent normal tissue (566 +/- 58 vs. 424 +/- 75 pg/mg protein, N = 10). Nor was there any difference in the abundance of IGF-I mRNA expression determined by slot blot analysis. On the other hand, IGFBP activity measured in terms of 125I-IGF-I binding was significantly higher in cancer extracts. Western ligand blot analysis of IGFBPs revealed several species (24-42 kDa) of IGFBPs. The IGF-I-binding activity of 38-41 kDa species (corresponding to IGFBP-3) was not different between extracts of cancer tissue and those of normal tissue, whereas that of 28-32 kDa species was significantly higher in cancer tissue extracts. Since IGFBPs have been reported to modulate cellular responses to IGF-I, the present data suggest that higher IGFBP activity in cancer tissue is involved in regulating growth of thyroid papillary carcinoma cells.

Adenoma↗
PubMed1994

Oxidative stress in hepatocytes and stimulatory state of Kupffer cells after reperfusion differ between warm and cold ischemia in rats.

Rat liver was kept at 4 degrees C or 37 degrees C in MEM, and reperfused through a closed circulation from the hepatic vein to the portal vein at 37 degrees C with the same solution. Although purine nucleoside phosphorylase and ALT activities were increased in the perfusate, depending on the duration of ischemia at both 4 degrees C and 37 degrees C, the ratio of the latter to the former was significantly higher after 37 degrees C-ischemia than after 4 degrees C-ischemia. The stimulation stage of Kupffer cells evaluated in situ by formazan deposition after liver perfusion with nitro blue tetrazolium and phorbol myristate acetate was elevated after 4 degrees C-ischemia longer than 1 h, but not after 37 degrees C-ischemia. In contrast, the degree of oxidative stress in hepatocytes assessed by formazan deposition after liver perfusion with nitro blue tetrazolium alone was greater after 37 degrees C-ischemia than after 4 degrees C-ischemia. These results suggest that oxidative stress in hepatocytes and the stimulatory state of Kupffer cells after ischemia-reperfusion may differ between 4 degrees C-ischemia and 37 degrees C-ischemia, probably leading to different development of liver damage.

Alanine Transaminase↗
PubMed1994

Anterior chamber depth after posterior chamber intraocular lens implantation.

The precise behavior of the anterior chamber depth after intraocular lens implantation is uncertain. To ascertain variations in the values at different time points, we measured the anterior chamber depth in 38 eyes that had undergone extracapsular cataract extraction and posterior chamber intraocular lens implantation. Measurements were performed by ultrasonography preoperatively and at 2 days, 1 and 2 weeks postoperatively, and at 1-month intervals thereafter up to 10 months (mean follow-up period, 9 months). Results showed that two peaks of the anterior chamber depth occurred at 1 week and 3 months postoperatively (means +/- SD, 3.54 +/- 0.39 and 3.59 +/- 0.43 mm, respectively). A significant difference was found between the values measured preoperatively (3.29 +/- 0.57) and at 2 days postoperatively (3.33 +/- 0.39) and the 1-week postoperative value (p < 0.05, using the one-way analysis of variance test). A significant difference also was found between the preoperative and the monthly measurements and the 3-month postoperative measurement (p < 0.05). We also calculated the refractive error and found that during the second postoperative week, the refraction tended toward higher myopia that became more hyperopic 3 months postoperatively. This anterior chamber depth variation may cause variations in vision after cataract surgery with intraocular lens implantation.

Aged↗
PubMed1994

[Effects of aging on urinary secretion of 3-hydroxyproline and its importance for cancer screening in the elderly with ROC analysis].

OBJECTIVE: to observe the influence of aging on urinary secretion of 3-hydroxyproline (3-Hyp) in normal subjects and in cancer patients and study the effects of aging on the accuracy of urinary 3-Hyp as a general-purpose cancer screening test. DESIGN: We reanalyzed, from the aspect of gerontology, the amounts of 3-Hyp in the urine samples of the 211 healthy persons and 94 patients with cancer reported earlier. The two groups were divided in 3 age subgroups: adult, 30 to 44 years, middle-aged, 45 to 64 years, and aged, 65 years and older. The cancer stage was separated into 3 categories: stage 1, the early stage without any invasion, stage 2, locally invasive with no distant metastasis, and stage 3, advanced cancer. The correlation of age and urinary 3-Hyp was analyzed in normal subjects and cancer patients. Sensitivity and specificity were calculated for different cutoff points in the diverse groups to construct the receiver operating characteristic (ROC) curves. MAIN RESULTS: We observed that aging decreases the urinary secretion of 3-Hyp in normal subjects, with a correlation coefficient of -0.250 (p < 0.001). The mean levels of urinary 3-Hyp in patients with cancer were significantly higher than in the normal subjects, p = 0.005. The correlation coefficient of urinary 3-Hyp and age was not significant (0.100) in cancer patients. The cutoff points of 0.800 mg/g creatinine of urinary 3-Hyp for persons under 65 years of age and 0.600 mg/g creatinine for persons 65 years or older were the best thresholds for cancer screening. In the ROC analyses, we observed that 3-Hyp has higher accuracy for cancer screening in the aged group for all stages together and in the aged and middle-aged for early stages of cancer. CONCLUSIONS: The urinary 3-Hyp test was more effective for cancer screening in old persons (65 years or older), where cancer is more frequent and more difficult to discover. The authors stress the necessity and importance of verifying the effectiveness of urinary 3-Hyp for general cancer screening in a larger population and in a community set.

Adult↗
PubMed1994

Molecular cloning and nucleotide sequence of the beta-galactosidase gene from Enterobacter cloacae GAO.

The gene encoding a beta-galactosidase from Enterobacter cloacae GAO was cloned and expressed in Escherichia coli. The nucleotide sequence of the insert of a positive clone had an open reading frame of 3084 bp that encoded a polypeptide of 1028 amino acid residues with a calculated molecular mass of 116,677 daltons. The amino acid sequence of beta-galactosidase deduced from the nucleotide sequence, especially the sequence around the putative active site and of the fourteen regions, showed significant homology to beta-galactosidases of other microorganisms, E. coli, Klebsiella pneumoniae, Lactobacillus bulgaricus, and Clostridium acetobutylicum.

Amino Acid Sequence↗
PubMed1994

Expression of the cellulase (FI-CMCase) gene of Aspergillus aculeatus in Saccharomyces cerevisiae.

As a step to breed a Saccharomyces cerevisiae strain able to produce ethanol directly from cellulose, we combined cDNA for Aspergillus aculeatus FI-CMCase (FI-carboxymethyl cellulase) with the GAP (glyceraldehyde-3-phosphate dehydrogenase) promoter of S. cerevisiae and used the resultant plasmid, pYEC91, to transform S. cerevisiae. The transformed cells produced active FI-CMCase within the cytoplasm. Western-blot analysis following SDS-polyacrylamide gel electrophoresis demonstrated that the cells contained a peptide having the same molecular mass and immunological identity as A. aculeatus FI-CMCase.

Amino Acid Sequence↗
PubMed1994

Avian tuberculosis which occurred in an imported pigeon and pathogenicity of the isolates.

A tubercular lesion (15 mm in diameter) was found on the skin of the caudal part of the cloaca in a 2-year-old male carrier-pigeon. Mycobacterium avium serovar 2 was isolated from the tubercular lesion on the skin and in the feces. The smooth and dome (SmD) variant (4.9 x 10(6) CFU) and rough and granular (RG) variant (3.7 x 10(7) CFU) of the isolates were injected into chickens intravenously. The chickens inoculated with the RG variant died on the 39th day and the one with the SmD variant died on the 77th day after inoculation. Enlargement of the liver and spleen was observed in all the inoculated chickens. Many white tubercular lesions were observed in the liver, spleen and lung of the chicken inoculated with the SmD variant, while no macroscopical change was observed in the bird inoculated with the RG variant. Inoculated organisms were recovered from the liver, spleen, kidneys, lungs and pancreas of each inoculated chicken.

Animals↗
PubMed1994

Interaction of endothelin-1 with porcine thyroid cells in culture: a possible autocrine factor regulating iodine metabolism.

Although endothelins were originally discovered as peptides with vasoconstrictor activity, recent studies have indicated a number of endothelin (ET)-induced hormonal functions in various tissues. We have studied the interaction of endothelins with porcine thyroid cells in culture. Specific binding of 125I-labelled ET-1 was demonstrated in porcine thyroid cells. The binding was displaced equally by unlabelled ET-1 and ET-2, but receptor affinity for ET-3 was lower than that for ET-1 and -2. Scatchard analysis of the data revealed a single class of high-affinity ET-1 receptors with a Kd of 0.45 nmol/l and a binding capacity of 2100 sites/cell. SDS-PAGE and autoradiography of 125I-labelled ET-1 cross-linked with thyroid cell membranes demonstrated ET-1 binding sites with an apparent molecular weight of 50 kDa. These results indicated that ET-1 receptors in thyroid cells are type A ET receptors. In association with the presence of ET-1 receptors, porcine thyroid cells responded to ET-1 and ET-2 with an increase in c-fos mRNA expression. Although ET-1 did not affect DNA synthesis stimulated by either EGF or IGF-I, it dose-dependently inhibited TSH-induced iodide uptake and also inhibited iodide uptake stimulated by forskolin and 8-bromo-cAMP. ET-1 had no effect on TSH-stimulated cAMP production. Thus, ET-1 inhibited TSH-induced iodine metabolism by acting at the steps distal to cAMP production. In agreement with a recent report, immunoreactive ET-1 was detected in medium conditioned by porcine thyroid cells. Antibody to ET-1 was found to increase TSH-induced iodide uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1994

Paramedian thalamic infarction following blunt head injury--case report.

A 19-year-old male was admitted following a blow to the face. Computed tomographic (CT) scans 1 hour after injury revealed low-density areas in the bilateral thalami and midbrain, which were enhanced postcontrast except for the core 3 hours later. CT scans 2 days after injury revealed that the size of the low-density areas had increased. CT scans and magnetic resonance images 3 weeks after injury disclosed only small infarcted lesions in the bilateral thalami, the right side of the midbrain, and the left internal capsule. These findings suggest that the injury initially caused thrombus on the basilar arterial wall, leading to occlusion of the perforators, but almost all affected perforators were recanalized. Bilateral thalamic infarction resulting from head injury is unusual, as is the transient nature of the infarction in this case.

Adult↗
PubMed1994

[A study on digitally processed sounds designed to improve speech sound perception].

This study was performed to improve the speech sound perception of patients with sensorineural deafness by using digitally processed sounds. The fourteen CV sounds (/pa, ta, ka, ba, da, ga, ha, sa, za, ma, na, ra, ja, wa/) were selected in this study, and the consonant burst and/or voice onset time (VOT) of these sounds were doubled and/or amplified by digital processing and stored in DAT. These processed sounds and the original unprocessed sound were presented to patients and with moderate sensorineural deafness. The following results were obtained from patients who had made a mistake in discriminating the original sounds. 1. The correct answer rate for /ta/ and /sa/ was improved by amplification of the consonant burst or VOT, and for /ka/, amplification and/or repetition improved the corredt answer rate. Amplification of the consonant burst, or of the consonant burst with VOT, was especially effective for unvoiced explosive sounds (/pa, ta, ka/). 2. In voiced sounds, for /za/ and /ra/ the correct answer rate was improved by repetition or elongation of the consonant burst or transition part, and for /ga/, /ma/, and /na/ the rate was improved by amplification. 3. Semivowels (/wa, ja/) and glottal sounds (/ha/) were seldom misunderstood, and required no processing. Digital filtering processing was performed on monosyllables with the "s" sound (/sa, su, se, so/), and these filtered sounds were presented to the patients and a comparison was made with the original sounds. As a result, it was revealed that the correct answer rate could be improved by filtering, although the pass band was changed slightly by the succeeding vowel. This improvement was more apparent in the presence of environmental noise than under quiet conditions.

Adult↗
PubMed1994

Detection of Plasmodium falciparum in human blood by a nested polymerase chain reaction.

We have developed a simple method for direct detection of Plasmodium falciparum parasites in infected human blood using a nested polymerase chain reaction. Whole blood (10 microliters) was obtained by finger puncture and suspended in a microcentrifuge tube containing phosphate-buffered saline. For removal of components that might inhibit the PCR, blood samples were treated with saponin and washed by centrifugation. After three cycles of a two-step incubation (3 min at 94 degrees C and 3 min at 55 degrees C), the first amplification was done with oligonucleotide primers specific for the junction region of the gene coding for the dihydrofolate reductase-thymidylate synthase in P. falciparum. A 1-microliter portion of the first amplification was then amplified again with a second set of primers, and 226-basepair fragments were generated. The amplified products were analyzed by agarose gel electrophoresis with ethidium bromide staining. Experiments with cultured parasites showed that the method could detect as few as 13 parasites in 10 microliters of whole blood. In 1991, 101 samples from 98 donors were collected in Guadalcanal, Solomon Islands. Eight of these samples gave positive results by both examination of thin blood smears and by the nested PCR. There was a correlation between parasite densities and the intensity of the results by the nested PCR. The method is suitable for detection of asymptomatic parasite carriers and evaluation of medical treatment on clinical cases.

Adolescent↗
PubMed1994

[Enterocolitis].

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Enterocolitis↗
PubMed1994

[Influence of refraction on the visual field defects in normal tension glaucoma and primary open angle glaucoma eyes].

The prevalence of normal tension glaucoma (NTG) or primary open angle glaucoma (POAG) is higher in myopic populations and the prevalence of myopia and NTG is relatively high in the Japanese. To evaluate the influence of myopic refractive error on the central visual field defect in NTG eyes, the data obtained from NTG eyes with the Humphrey Visual Field Analyser were analysed in comparison with those from POAG eyes. One hundred and twenty NTG eyes and one hundred and ninety-seven POAG eyes were included. All of them had clear ocular media, but no myopic degeneration in the fundus. Multiple linear regression analysis was performed with a dependent variable of the deviation of the measured threshold value from normal reference value (total deviation, STATPAC) and independent variables of refractive error and mean deviation (STATPAC). Myopic power was found to be positively correlated with the depression in the lower papillo-macular area in both NTG and POAG eyes, and it was negatively correlated with the depression in an upper arcuate area extending just nasal to the fixation only in NTG eyes.

Adult↗
PubMed1994

[An autopsied case of Fabry's disease presenting with parkinsonism and cardiomegaly as a cardinal clinical manifestation].

A 68-year-old male had been followed up under a clinical diagnosis of parkinsonism for 5 years. He was admitted to the Kanto Teishin Hospital with a chief complaint of difficulty in swallowing. Physical findings were almost normal. Neurological examination showed parkinsonism including mask-like face, positive Myerson's sign, mild rigidity, marche à petit pas, and retropulsion, and pyramidal signs including mild right hemiparesis, generalized hyperreflexia and positive Babinski's sign on both sides. Routine blood analysis was normal, except for elevated LDH level. He was found to have cardiac enlargement (CTR 58.7%) in chest roentogenogram, left ventricular hypertrophy (LVH), right bundle branch block and myocardial ischemia in electrocardiogram, as well as LVH, asymmetrical septal hypertrophy, mild MR and AR in echocardiogram. A T2 weighted brain MRI disclosed multiple high signal intensities in the basal ganglia and deep white matter regions which suggest parkinsonism resulting from multiple cerebral infarctions. An upper gastrointestinal endoscopic examination revealed esophageal and gastric carcinomas. He died of ventricular fibrillation 14 days after an operation of these carcinomas. Autopsy showed severe cardiomegaly (800 g) and vacuolar change of myocardium with lamellar body on electron microscopic examination. A definite biochemical diagnosis of Fabry's disease was made by demonstration of deposition of a large amount of trihexosylceramide in the myocardium, kidney, and liver. This case presented parkinsonism and cardiomegaly without typical signs of Fabry's disease. Therefore, Fabry's disease should be considered as one of possible underlying diseases, when a patient has cardiomegaly or ischemic cerebrovascular disease without risk factors, even if he has no typical signs of Fabry's disease.

Aged↗
PubMed1994

[Enterocolitis].

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Enterocolitis↗