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Biomedical subjects

Y Sakai

Publications and source records attributed to Y Sakai.

At least 199 records · Page 11Linked to original sources
PubMed2000

Correlation between interventricular septal motion and left ventricular systolic-diastolic function in patients with left bundle branch block.

The echocardiographic correlation between abnormal interventricular septal motion including systolic paradoxical, flat motion and early diastolic notch and ejection fraction, mean ventricular circumferential fiber shortening and early diastolic mitral filling velocity was studied in 46 patients with complete left bundle branch block. Systolic normal interventricular septal motion was used as the control. Ejection fraction was significantly smaller in the paradoxical(0.44 +/- 0.13, p < 0.02) and flat motion groups(0.38 +/- 0.09, p < 0.001) than in the normal group(0.54 +/- 0.1). Mean ventricular circumferential fiber shortening was significantly smaller in the flat motion group than in the normal group(0.72 +/- 0.19 vs 0.99 +/- 0.23 circ/sec, p < 0.002). The size of the notch was significantly smaller in the flat motion group than in the normal group (2.3 +/- 0.2 vs 4.8 +/- 0.8 mm, p < 0.0001). The deceleration rate of the notch was significantly slower in the paradoxical and flat motion groups than in the normal group(37.3 +/- 12.2, 31.3 +/- 8.1 vs 69.1 +/- 2.5 cm/sec, p < 0.0001). Early diastolic mitral filling velocity was slower in the flat motion group than in the other 2 groups. In conclusion, systolic flat interventricular septal motion showed more severe disturbances of left ventricular systolic and diastolic function than paradoxical interventricular septal motion in patients with complete left bundle branch block.

Aged↗
PubMed2000

[Experimental study of calcification of the xenopericardia].

UNLABELLED: We studied the calcification of four kinds of xenopericardium used in cardiac surgery. Group 1: bovine Pericardium (Tissueguard. Biovascular, inc), Group 2: bovine pericardium (No-React. Shelhigh, inc), Group 3: porcine pericardium (Rigg. Polystan, inc), Group 4: equine pericardium (Xenomedica. Baxter-Edwards, inc). Each pericardium was implanted in abdominal subcutaneous pouches of rats. The mean calcium content of each Group after eight weeks of subcutaneous implantation were 0.67 +/- 0.15 mg/g, 0.51 +/- 0.15 mg/g, 161 +/- 18 mg/g and 173 +/- 18 mg/g in Group 1, Group 2, Group 3 and Group 4, respectively. There was no significant difference between Group 1 and 2, or between Group 3 and 4. On the other hand, there were significant differences between Group 1, 2 and Group 3, 4 (p < 0.001). The deposition of calcium and inflammatory changes were markedly observed microscopically in Group 3 and 4, but in Group 1 and 2, they were only slightly observed. CONCLUSION: Two kinds of bovine pericardium are superior to both porcine and equine pericardium in the point of less calcium deposition and inflammatory cellular response after implantation.

Animals↗
PubMed2000

[A case of giant hemorrhagic adrenal pseudocyst with infection].

A 51-year-old woman was admitted with general fatigue, high fever and left upper abdominal pain. Abdominal computed tomography revealed a left adrenal mass, 15 cm in diameter with regular margins, the contents of which were not enhanced with contrast medium. The mass had heterogeneous echogenicity on the abdominal ultrasonograph. Serum hormonal levels were almost normal. Despite treatment with antibiotics, the high fever persisted. Based on these findings, the differential diagnosis was adrenal abscess or a nonfunctional adrenal tumor. Transabdominal left adrenalectomy was performed. Pathological examination revealed a hemorrhagic adrenal pseudocyst with infection. The patient's condition improved soon after the operation.

Adrenal Gland Diseases↗
PubMed2000

[Myocardial fatty acid imaging using iodine-123-BMIPP in patients with hypertensive intracranial hemorrhage].

An evaluation of myocardial fatty acid metabolism in hypertensive patients with major complication has not been previously established. To assess the myocardial fatty acid metabolism in hypertensive patients with intracranial hemorrhage (IH), we performed myocardial image using 123I-15-p-iodophenyl-3-methyl pentadecanoic acid (BMIPP). Seventeen hypertensive patients with IH (HIH) and 27 hypertensive patients without IH (HT) were studied. A dose of 111 MBq of BMIPP was injected intravenously at rest, and a myocardial image was recorded 30 minutes after the injection. Myocardial perfusion image using Thallium-201 (Tl) was also performed within 2 weeks after BMIPP study. The regional myocardial uptakes of BMIPP and Tl were visually assessed in 17 segments with a four-point scoring system (0 = absent to 3 = normal uptake). Cardiac hypertrophy was evaluated by electrocardiography (ECG) and two-dimensional ultrasonic cardiography (UCG). Sum of uptake scores of Tl was similar in both groups (45.1 +/- 5.4 vs. 47.9 +/- 4.2), but that of BMIPP in HIH was lower than HT (35.9 +/- 7.9 vs. 45.6 +/- 4.8, p < 0.001). Evaluation of cardiac hypertrophy using ECG and UCG revealed no significant difference between two groups. HIH have much more eccentric hypertrophy in UCG study than HT (53% vs. 37%). These data suggest that hypertensive patients with intracranial hemorrhage have a more impaired myocardial fatty acid metabolism compared to the hypertensive patients with similar cardiac hypertrophy. BMIPP imaging might be useful to evaluate the severity of myocardial fatty acid metabolism in hypertensive patients.

Cerebral Hemorrhage↗
PubMed2000

Bacterial adherence in a rat bladder augmentation model: ileocystoplasty versus colocystoplasty.

PURPOSE: Various intestinal segments are used to reconstruct the urinary tract. For unclear reasons asymptomatic chronic bacteriuria is common in patients treated with reconstruction. We compared bacterial adherence in ileum, colon and bladder in rats with ileal and colonic bladder augmentation. MATERIALS AND METHODS: Bladder augmentation using ileum or colon was performed in 8-week-old rats. After 3 months urinary pH was measured and urine was cultured. Urovirulence factors of Escherichia coli aspirated from the augmented bladders were detected by polymerase chain reaction. In rats with negative urine culture after augmentation experimental cystitis was induced by the transurethral inoculation of E. coli C5, with type I pili and aerobactin or E. coli C92 with type I pili, P fimbriae and aerobactin at a concentration of 10(5) colony forming units per 0.3 ml. After 14 days we counted the colony forming units per cm.(2) of bladder and cm.(2) of intestinal augmentation tissue. RESULTS: When cultures were negative, mean urinary pH plus or minus standard deviation for ileocystoplasty (7.35 +/- 0.33) was significantly higher than that for colocystoplasty (6.80 +/- 0.45) or in controls (6.67 +/- 0.30). Bacterial colonization occurred in 60 of 96 ileocystoplasties (62.5%) and 36 of 68 colocystoplasties (52.9%). All 32 E. coli strains aspirated from ileocystoplasties had type I pili. In colocystoplasties 14 strains had type I pili, 4 had P fimbriae and type I pili, and 1 had no virulence factor. In experimental cystitis in the ileal patch and bladder there were 10(3.2) to 10(6.2) (log mean 4.9) and 10(1.1) to 10(5.1) (log mean 3.5) colony forming units of E. coli C5, respectively. In the colonic patch and bladder there were 10(2.2) to 10(6.2) (log mean 3.9) and 10(2.1) to 10(5.1) (log mean 3.7) colony forming units of E. coli C5, respectively. In the ileal patch and bladder versus the colonic patch and bladder there were 10(3.2) to 10(6.2) (log mean 5.0) and 10(3.1) to 10(6.1) (log mean 4.5) versus 10(3.2) to 10(6.2) (log mean 4.3) and 10(2.1) to 10(6.1) (log mean 3.8) colony forming units of E. coli C92, respectively. E. coli C5 adhered to more ileum than bladder, while bacterial adherence did not differ for colon and bladder. Adherence of E. coli C92 did not differ significantly in bladder and implanted ileum or colon. CONCLUSIONS: The colonic segment offers more resistance to E. coli than the ileal segment in urinary diversion.

Animals↗
PubMed2000

Purification and characterization of the allergenic components of shimeji mushroom (Tricholoma conglobatum) spore for shimeji workers' hypersensitivity pneumonitis.

Respiratory symptoms and hypersensitivity pneumonitis (HP) among mushroom workers have been well documented. Inhalation of shimeji mushroom (Tricholoma conglobatum) spore has been assumed to be the cause of HP among indoor shimeji cultivating workers. We isolated and partially characterized the allergenic components of shimeji. The sera from 9 HP patients, 10 asymptomatic shimeji workers and 15 normal individuals were examined for shimeji specific IgG and IgA antibodies by ELISA using crude shimeji extract. Shimeji specific IgG- and IgA-antibodies were higher in sera from HP patients than in sera from control subjects. Crude shimeji spore extract was separated and purified by HPLC followed by SDS-PAGE, and their antigenic activity was studied by immunoblotting with a pool of sera from patients. Sera from all HP patients showed IgG and IgA antibody activities to 21, 16 and 14 kD proteins extracted from shimeji spore. The 21 kD protein contained internal peptide amino acid sequence of Gly-Gly-Thr-Val-Ile-Asn-Leu-Leu-Gly, Gln-Arg-Phe-Glu-Glu and Gln-Gly-Ile-Tyr. These results demonstrate that shimeji spore extract contains multiple proteinous components, which have antigenic activity to react with the sera from HP patients among shimeji workers. These proteins may be the potent sensitizing allergens to cause HP among shimeji cultivating workers.

Adult↗
PubMed1999

[Arrhythmia].

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Arrhythmias, Cardiac↗
PubMed1999

PLP-I: a novel prolactin-like gene in rodents.

In this report, we describe molecular cloning and characterization of cDNAs encoding a novel rat prolactin-like protein. The rat cDNAs were isolated from the decidua and the gene was named PLP-I. cDNAs for the mouse equivalent were also cloned by the cross-hybridization technique. Pregnancy-specific expression of the rat PLP-I gene was observed in the rat placenta by Northern analysis. Location of signal peptide cleavage sites in rat and mouse pre-PLP-I proteins was predicted using a theoretical method. A molecular phylogenetic tree for the growth hormone-prolactin superfamily including the novel member, PLP-I, constructed using the neighbor-joining method, places rat/mouse PLP-I closest to rat/mouse placental lactogen I and II.

Amino Acid Sequence↗
PubMed1999

Production of fungal fructosyl amino acid oxidase useful for diabetic diagnosis in the peroxisome of Candida boidinii.

A high-level production of fructosyl amino acid oxidase (FAOD), whose production was toxic in Escherichia coli, was investigated through attempts to utilize the peroxisome of Candida boidinii as the place for protein accumulation. The alcohol oxidase-depleted strain (strain aod1Delta) produced FAOD at a four to five times higher level than the wild type strain in terms of protein amount and enzyme activity, although the transcriptional level was similar. As a result of this study, we could improve FAOD productivity approximately 47-fold from the original transformant, and FAOD accumulated within membrane-bound peroxisomes up to 18% of the total soluble proteins.

Amino Acid Oxidoreductases↗
PubMed1999

Light and electron microscopic immunocytochemical study on the innervation of the pineal gland of the tree shrew (Tupaia glis), with special reference to peptidergic synaptic junctions with pinealocytes.

Conventional and immunocytochemical, light- and electron-microscopic studies on the innervation of the pineal gland of the tree shrew (Tupaia glis) were made. Neuropeptide Y (NPY)-immunoreactive fibers, which were abundantly distributed in the gland, disappeared almost completely after superior cervical ganglionectomy, suggesting that these fibers are mostly postganglionic sympathetic fibers. By contrast, tyrosine hydroxylase (TH)-immunoreactive fibers, which were less numerous than NPY-fibers, remained in considerable numbers in ganglionectomized animals, indicating the innervation of TH-positive fibers from extrasympathetic sources. Bundles of substance P (SP)- or calcitonin gene-related peptide (CGRP)-immunoreactive fibers, entering the gland at its distal end, were left intact after ganglionectomy. SP-fibers were numerous, but CGRP-fibers were scarce in the gland. SP-immunoreactive fibers were myelinated and nonmyelinated, and were regarded as peripheral fibers because of the presence of a Schwann cell sheath. NPY- and SP-immunoreactive fibers and endings were mainly localized in the pineal parenchyma. NPY-immunoreactive endings synapsed frequently, and SP-positive ones did less frequently, with the cell bodies of pinealocytes. The results suggest that NPY and SP directly control the activity of pinealocytes. Sections stained for myelin showed that thick and less thick bundles of myelinated fibers entered the gland by way of the habenular and posterior commissures, respectively. Under the electron microscope, the bundles were found to contain also unmyelinated fibers. A considerable number of nerve endings synapsing with the cell bodies of pinealocytes remained in ganglionectomized animals; these endings were not immunoreactive for TH or SP. Such synaptic endings may be the terminals of commissural fibers.

Animals↗
PubMed1999

Alcohol oxidase hybrid oligomers formed in vivo and in vitro.

Cell-free extract prepared from methanol-grown cells of the methylotrophic yeast Pichia methanolica showed nine multiple alcohol oxidase (AOD) bands on active staining in native polyacrylamide gel electrophoresis. Their molecular basis was investigated and two AOD-encoding genes, MOD1 and MOD2, were cloned from P. methanolica genome. When the two genes were expressed in a heterologous host, an alcohol oxidase-depleted strain of Candida boidinii(aod1Delta strain), both MOD1 and MOD2 partially complemented growth defect of the host strain on methanol. While expression of either MOD1 or MOD2 in C. boidinii aod1Delta strain gave a single AOD band corresponding to the band with the largest and smallest mobility among the nine AOD bands, respectively, co-expression of MOD1 and MOD2 resulted in multiple band formation. Mixed oligomerization of Mod1p and Mod2p in vitro also gave nine multiple bands. From these results, we concluded that the nine multiple forms of AOD observed on native-PAGE represent two homo-octamers and seven hetero-octamers of Mod1p and Mod2p. Using this zymogram analysis, we also found that Mod1p was preferably produced at low methanol concentrations in the media, while Mod2p was produced at higher methanol concentrations. This shows distinct regulatory features of the two AOD-encoding genes in this methylotrophic yeast.

Alcohol Oxidoreductases↗
PubMed1999

Enhanced anti-HIV-1 activity of CC-chemokine LD78beta, a non-allelic variant of MIP-1alpha/LD78alpha.

We compared the anti-HIV-1 activity of CC-chemokine LD78beta with that of MIP-1alpha, another CC-chemokine which shows 94% sequence homology with LD78beta. Despite its close similarity to MIP-1alpha, the anti-HIV-1 activity of LD78beta appeared to be nearly 10 times higher than that of MIP-1alpha. Mutagenesis of MIP-1alpha showed that the N-terminal additional tetrapeptide, which was present in LD78beta and absent in MIP-1alpha, is responsible for enhanced anti-HIV-1 activity. The N-terminal structure-function relationship of LD78beta described here will be of value in understanding the chemokine-receptor interactions and designing anti-HIV-1 compounds based on LD78beta.

Animals↗
PubMed1999

Accommodation of foreign genes into the Sendai virus genome: sizes of inserted genes and viral replication.

Sendai virus (SeV) is an enveloped virus with a negative sense genome RNA of about 15.3 kb. We previously established a system to recover an infectious virus entirely from SeV cDNA and illustrated the feasibility of using SeV as a novel expression vector. Here, we have attempted to insert a series of foreign genes into SeV of different lengths to learn how far SeV can accommodate extra genes and how the length of inserted genes affects viral replication in cells cultured in vitro and in the natural host, mice. We show that a gene up to 3.2 kb can be inserted and efficiently expressed and that the replication speed as well as the final virus titers in cell culture are proportionally reduced as the inserted gene length increases. In vivo, such a size-dependent effect was not very clear but a remarkably attenuated replication and pathogenicity were generally seen. Our data further confirmed reinforcement of foreign gene expression in vitro from the V(-) version of SeV in which the accessory V gene had been knocked out. Based on these results, we discuss the utility of SeV vector in terms of both efficiency and safety.

Animals↗
PubMed1999

Inner-arm dynein c of Chlamydomonas flagella is a single-headed processive motor.

Axonemal dyneins are force-generating ATPases that produce movement of eukaryotic cilia and flagella. Several studies indicate that inner-arm dyneins mainly produce bending moments in flagella and that these motors have inherent oscillations in force and motility. Processive motors such as kinesins have high duty ratios of attached to total ATPase cycle (attached plus detached) times compared to sliding motors such as myosin. Here we provide evidence that subspecies-c, a single-headed axonemal inner-arm dynein, is processive but has a low duty ratio. Ultrastructurally it is similar to other dyneins, with a single globular head, long stem and a slender stalk that attaches to microtubules. In vitro studies of microtubules sliding over surfaces coated with subspecies-c at low densities (measured by single-molecule fluorescence) show that a single molecule is sufficient to move a microtubule more than 1 microm at 0.7 microm s(-1). When many motors interact the velocity is 5.1 microm s(-1), fitting a duty ratio of 0.14. Using optical trap nanometry, we show that beads carrying a single subspecies-c motor move processively along the microtubules in 8-nm steps but slip backwards under high loads. These results indicate that dynein subspecies-c functions in a very different way from conventional motor proteins, and has properties that could produce self-oscillation in vivo.

Animals↗
PubMed1999

Establishment of an embryonic stem (ES) cell line derived from a non-obese diabetic (NOD) mouse: in vivo differentiation into lymphocytes and potential for germ line transmission.

A non-obese diabetic (NOD) mouse-derived embryonic stem (ES) cell line has been stably maintained in an undifferentiated state with a characteristic ES cell-like morphology, expressing the stem cell marker alkaline phosphatase, and displaying a normal diploid karyotype. After injecting the NOD-ES cells into blastocysts, chimeric mice were obtained. Small but significant numbers of lymphocytes expressed the NOD-derived MHC allele. When a chimeric mouse was mated with C57BL/6 mice, an agouti mouse was obtained, having the NOD-derived H-2 I-A(beta)g7 haplotype. Thus, an NOD-ES cell line which can differentiate into lymphocytes with potential for germ line transmission was successfully established.

Animals↗
PubMed1999

Genetic polymorphism of CYP2A6 in relation to cancer.

To clarify the roles of human cytochrome P450 (P450 or CYP) 2A6 and 2E1 on the metabolic activation of N-nitrosamines, we established genetically engineered Salmonella typhimurium strains harboring human CYP2A6 or CYP2E1 together with NADPH-P450 reductase (OR). The 5'-terminus of CYP cDNA was modified to achieve a high-level expression in S. typhimurium. Modified CYP2A6 or CYP2E1 cDNA and native OR cDNA were introduced into a pCW vector. S. typhimurium YG7108 cells were transformed with this vector. The mutagen producing ability of these enzymes for some N-nitrosamines were evaluated using the established S. typhimurium cells. We found that the substrate specificity of CYP2A6 and CYP2E1 was different among mutagens. CYP2A6 was responsible for the metabolic activation of N-nitrosamines possessing relatively long alkyl chains, whereas CYP2E1 was responsible for the metabolic activation of N-nitrosamines with relatively short alkyl chains. It is likely that CYP2A6 gene polymorphism is responsible for the interindividual variability on the cancer susceptibility. We found the whole deletion of CYP2A6 gene as a type of genetic polymorphism in Japanese. Thus, we developed a gene diagnosis method to detect the variant. We evaluated the relationship between the CYP2A6 gene whole deletion and the susceptibility to the lung cancer. The frequency of CYP2A6 gene whole deletion was significantly lower in the lung cancer patients than that of healthy volunteers.

Aryl Hydrocarbon Hydroxylases↗