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Biomedical subjects

S Ueda

Publications and source records attributed to S Ueda.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Intrarenal arterial Doppler sonography in patients with various renal disease: correlation of resistive index with biopsy findings].

Duplex Doppler sonography (ultrasonic equipment: Toshiba SSA-270A) were performed in the patients with various renal disease (male 44, female 32) admitted to our hospital between June 1990 and August 1991. Interlobar arterial blood flow velocity was measured at the side of renal pyramid through a longitudinal scan. Both the maximum blood flow velocity (Vmax) and the minimum blood flow velocity (Vmin) were measured quantitatively and resistive index (RI: defined as (Vmax-Vmin)/Vmax) were calculated. Vmax and Vmin correlated well with the creatinine clearance (Ccr) (r = 0.56, r = 0.66 respectively), whereas RI, by which we can detect Doppler waveform changes, correlated weak with Ccr (r = 0.39). We found twenty-nine patients (40%) with an elevated RI (greater than or equal to 0.70). They had severe renal dysfunction and active pathologic findings in the tubulo-interstitial or vascular compartment of the kidney. Doppler examination of renal blood flow velocity was valuable not only to estimate renal function but also to assess pathophysiology of renal disease.

Adult↗
PubMed1992

Dinucleotide repeat polymorphism at the apolipoprotein AII locus--phenotyping from peripheral blood and hair.

The genomes of eukaryotes including humans contain very short simple sequence repeats such as (dA-dC)n and (dG-dT)n. Recently, these repeats have been reported to exhibit marked length polymorphism due to wide variation in their reiteration numbers. We report here dinucleotide repeat polymorphism at the apolipoprotein AII locus in Japanese subjects. The informativeness in Japanese was as high as in Caucasians (PIC value and heterozygosity of 0.67 and 0.72, respectively), but their allele frequencies were different with statistical significance. We also discuss the advantages of using dinucleotide repeat polymorphisms in forensic science, demonstrating determination of phenotype from not only a single hair root but also a short hair shaft.

Apolipoprotein A-II↗
PubMed1992

[Two cases of lateral approach for thoraco-lumbar junctional lesions: experiment of Kaneda's device].

Case 1: a 32-year-old woman was admitted to our hospital with major complaints of gait disturbance and urinary incontinence. The tendon reflex was markedly increased in the bilateral lower extremities, and both Babinski's reflex and clonus were strongly positive. Myelography revealed complete block in the 10th thoracic vertebral level. On April 15, 1989, a tumor in the vertebral region was exposed and excised via a right posterolateral approach. Kaneda's device was used for internal fixation. The tumor was diagnosed as myeloma histologically. The postoperative course was uneventful. Postoperatively, the patient became capable of walking by herself. Case 2: an 18-year-old woman was admitted because of burst fractures of the 1st and 2nd lumbar vertebrae due to a traffic accident in January of 1989. The fractured bones had been manually repositioned and fixed with plaster. However, the patient still had gait disturbance (intermittent claudication). Myelography revealed a complete block in the 2nd lumbar vertebral region. On May 7, the vertebral foramen was opened via a left anterolateral approach, and internal fixation was performed using Kaneda's device. Postoperatively, the patient recovered full ability to walk, and returned to normal social activity. From our experience, it is thought to be useful to employ a right posterolateral approach to the thoracic vertebrae, and a left anterolateral approach to the lumbar vertebrae. We used Kaneda's device for internal fixation, successfully. However, this device has the following disadvantages; (1) there are few plates designed for females, whose vertebrae are small, (2) it is difficult to preserve the arteries of Adamkiewicz and (3) postoperative MRI becomes impossible.

Adolescent↗
PubMed1991

Transformation of a methylotrophic bacterium, Methylobacterium extorquens, with a broad-host-range plasmid by electroporation.

Electroporation was used to transform the methylotrophic bacterium Methylobacterium extorquens with broad-host-range plasmid pLA2917, which contains a gene specifying resistance to kanamycin. Plasmid DNA was introduced into M. extorquens in the presence of an electric pulse, and kanamycin-resistant transformants were obtained. These transformants harbored plasmid DNA that was identical to plasmid pLA2917. We examined several factors independently and found up to 8 x 10(3) transformants per microgram of DNA using 10 pulses with a duration of 300 microseconds at a field strength of 10 kV/cm.

Cell Survival↗
PubMed1991

Collateral sprouting of serotonergic fibers in the cingulate cortex and the septum following cortical-hippocampal lesions.

The parietal cortex and dorsal hippocampus of adult rats were unilaterally ablated. One and 3 months after this operation, changes in serotonergic fiber distribution in the forebrain were studied immunohistochemically. At 1 month, increased numbers of serotonergic fibers were seen in the cingulate cortex and the medial and lateral septal nuclei of the lesioned side. This increase continued to 3 months in the ipsilateral cingulate cortex. In the present study, two different processes of serotonergic fiber collateral sprouting were noted. Plastic changes in serotonergic fibers in the ipsilateral septal nuclei and cingulate cortex may be attributable to the collateral sprouting underlying reactive synaptogenesis and the pruning effect, respectively.

Animals↗
PubMed1991

[Tumor embolism of pulmonary arteries and subsequent pulmonary infarction observed in two hepatocellular carcinoma cases].

Tumor emboli of the pulmonary arteries are infrequent and premortem detection of this lesion is rare. We encountered two cases of hepatocellular carcinoma associated with tumor emboli of the pulmonary arteries and subsequent pulmonary infarctions. Plain radiographs and CT demonstrated multiple metastatic pulmonary nodules as well as pleural-based pulmonary consolidations representing pulmonary infarctions. Postcontrast CT also showed filling defects in the main pulmonary arteries. These radiographic and CT features are considered to be characteristic of tumor emboli of pulmonary arteries and subsequent pulmonary infarction. In one patient whose initial symptoms were chest pain and bloody sputum, CT was useful in detecting the primary site of tumor emboli of the pulmonary arteries. It should be kept in mind that neoplasm with a tendency to venous invasion can cause tumor emboli of the pulmonary arteries and subsequent pulmonary infarction.

Aged↗
PubMed1991

Transplantation of fetal mesencephalic and medullary raphe tissues into the cerebellum of denervated adult rats--an immunohistochemical study.

Pieces of mesencephalic and medullary raphe tissues were transplanted into the cerebella of 5,6-dihydroxytryptamine-treated adult rats. The extent of axonal outgrowth of serotonergic and dopaminergic neurons in the grafts was immunohistochemically studied. At 3 months after transplantation, numerous dopaminergic neurons with many processes extending within the graft were detected in the mesencephalic raphe graft, but not in the medullary raphe graft. In contrast, both the mesencephalic and medullary raphe grafts contained numerous serotonergic neurons and a dense plexus of their fibers. The outgrowing serotonergic fibers from the mesencephalic raphe graft showed a hyperinnervation pattern in the cerebellar cortex adjacent to the graft. Furthermore, a glomerulus-like accumulation of serotonergic fibers was observed in the granular layer. In the cases of medullary raphe grafts, the relatively abundant outgrowing serotonergic fibers showed a laminar organization in the cerebellar cortex near the graft, which was similar to the normal distributional pattern. These results indicate that serotonergic and dopaminergic neurons located within the mesencephalic raphe graft clearly differed from each other in their ability to extend their processes into the host cerebellum, which provides further evidence for the existence of specific interactions between outgrowing serotonergic fibers and their terminal fields (targets).

5,6-Dihydroxytryptamine↗
PubMed1991

Determination of urinary Tamm-Horsfall protein by ELISA using a maleimide method for enzyme-antibody conjugation.

A method for enzyme-antibody conjugation using a new maleimide derivative as coupling reagent has been developed. Since a monomeric conjugate of horseradish peroxidase and Fab' antibody could be readily prepared with high efficiency and reproducibility, the enzyme activity and antigen-binding activity were well preserved and nonspecific staining was greatly reduced. The conjugate is suitable for use in both ELISA procedures and immunohistochemistry. Using both methods we examined the pathophysiological significance of Tamm-Horsfall protein (THP) and the present study describes the ELISA method to quantify urinary THP using the new method with rabbit anti-THP antibody. A low concentration (0.04 M) of urea added to the urine samples increased the linearity of the standard curve and the sensitivity of the assay, permitting the detection of as little as 20 ng/ml THP. Freezing and thawing the urine resulted in variable or lower values of THP concentration. THP concentrations in urine as determined by ELISA were stable for at least one month after -70 degrees C storage, but not after -30 degrees C storage. There was no correlation between THP concentrations in 24 h urine samples and the morning urine of the same patient. These results suggest that it is essential to use fresh or -70 degrees C stored 24 h urine samples with added urea (0.04 M) for the determination of THP concentrations in urine by the present enzyme-antibody conjugation method. The THP concentration in normal 24 h urine of young children was found to be less than 51.8 mg/g Cr.

Adult↗
PubMed1991

Distribution and characterization of immunoreactive porcine C-type natriuretic peptide.

C-type natriuretic peptide (CNP) is a new member of the natriuretic peptide family recently identified in porcine brain (1). We raised an antiserum against porcine CNP and set up a radioimmunoassay (RIA) for CNP. Using this RIA system, distribution of immunoreactive (ir-) CNP in porcine tissue was measured and compared with that of ir-atrial natriuretic peptide (ANP) and ir-brain natriuretic peptide (BNP). Tissue concentration of ir-CNP in brain was the highest of the three natriuretic peptides at about 0.79 pmol/g wet wt. CNP was present in medulla-pons in high concentration, with a significant concentration detected in cerebellum. In contrast, ir-CNP was not detected in peripheral tissue, including heart, in a significant concentration. These data demonstrated sharp contrasts in the distribution of the three natriuretic peptides, suggesting that CNP is a natriuretic peptide functioning in the central nervous system.

Animals↗
PubMed1991

Ischemic neuronal injury in the rat hippocampus following transient forebrain ischemia: evaluation using in vivo microdialysis.

Neuronal vulnerability to ischemia in the rat hippocampus was investigated by the measurement of high potassium evoked overflow of neurotransmitters using in vivo microdialysis. Changes in the extracellular level of amino acids caused by high potassium (100 mM) stimulation were measured on the 5th day after 20 min of forebrain ischemia, and the ratio of stimulated to basal levels or the peak concentration following the stimulation were correlated to neuronal activities. The responses to high potassium stimulation of glutamate and aspartate were reduced to 35-40% of the control values on the 5th day after 20 min ischemia, whereas the responses of gamma-aminobutyric acid (GABA) and taurine were not reduced on the 5th day after the ischemia. These results suggest that excitatory amino acid neurons (glutamatergic and aspartatergic) are more vulnerable than inhibitory amino acid neurons (GABAergic and taurinergic) in the hippocampus. Histologically, hippocampal CA1 pyramidal cells, which are believed to be glutamatergic or aspartatergic, demonstrated a marked neuronal necrosis on the 5th days after 20 min ischemia. Biochemical features revealed by high potassium stimulation may be an expression of 'delayed neuronal death' in the hippocampal CA1 area.

Alanine↗
PubMed1991

Structural and functional role of the amino-terminal region of porcine cytosolic aspartate aminotransferase. Catalytic and structural properties of enzyme derivatives truncated on the amino-terminal side.

In porcine cytosolic aspartate aminotransferase, a dimeric enzyme, the amino-terminal region anchoring onto the neighboring subunit is linked to the adjoining floppy peptide segment (residues 12-47), an integral part of the small domain whose facile movement upon substrate binding is a striking "induced fit" feature of this enzyme. To assess the contribution by the amino-terminal region to small domain movement and protein stability, a series of enzyme derivatives truncated on the amino-terminal side (residues 1-9) was prepared by using oligonucleotide-directed in vitro mutagenesis. Deletion of residues 1-3 showed no effect on catalytic activity and heat stability. Del 1-5 mutant enzyme with an extra methionine at position 5 showed only 43% of the kappa cat value (in the overall transamination) of the wild-type enzyme. Further deletion up to residue 9 resulted in a slight decrease in kappa cat values. Del 1-9 mutant enzyme still retained a kappa cat value of 33% that of wild-type enzyme. Km values for aspartate and 2-oxoglutarate increased sharply upon deletion of residues 1-9. Accordingly, Del 1-9 mutant enzyme showed a striking decrease in the kappa cat/Km value, to only 2% of that for the wild-type enzyme. Deletion of amino-terminal residues 1-9 resulted also in a large decrease in thermostability and in an enhanced susceptibility to limited proteolysis by protease 401, which is known to cleave at Leu20 of the wild-type enzyme. These findings indicate that an increase in the conformational freedom of the floppy segment (residues 12-47) would occur upon the loss of most of the anchorage region, thereby presenting an entropic barrier to conformational changes that facilitate substrate binding with high affinity.

Amino Acid Sequence↗
PubMed1991

Target-specific innervation by autonomic and sensory nerve fibers in hairy fetal skin transplanted into the anterior eye chamber of adult rat.

Pieces of hairy skin tissue of fetal rat were transplanted into the anterior eye chamber of adult rats. The ability of autonomic and sensory nerve fibers from the host iris to innervate the grafted skin tissue was immunohistochemically and enzyme-histochemically examined using antisera against tyrosine hydroxylase (TH), substance P (SP), calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP), and a reaction medium for acetylcholinesterase (AchE). The grafted tissue was successfully implanted and connected with the host iris. Epidermis, dermis, subcutaneous tissue, hairs, hair follicles, sebaceous glands, and piloerector muscles developed in the graft. Two weeks after transplantation, TH-, SP-, and CGRP-immunoreactive fibers were observed in association with the blood vessels in the graft. Four weeks after transplantation, TH-immunoreactive fibers were distributed in the piloerector muscles, whereas SP- and CGRP-immunoreactive fibers were present around the hair follicles. VIP-immunoreactive and AchE-positive fibers were restricted to the host iris at all survival times. These results suggest that the outgrowth of autonomic and sensory nerve fibers from the host iris show target specificity for the grafted skin tissue.

Animals↗
PubMed1991

Generation and characterization of the human immunodeficiency virus type 1 mutants.

Mutations were introduced by recombinant DNA techniques into 9 genes of an infectious molecular clone of human immunodeficiency virus type 1. The 24 mutants generated were characterized biochemically and biologically by transfection and infection experiments. None of the mutants which have mutations in gag (p17, p24, and p15 regions), pol (protease, reverse transcriptase, and endonuclease domains), env (gp120 region), tat, or rev were infectious, whereas vif, vpr, vpu, some of env (gp41) and nef mutants could grow in human CD4+ cells to various degrees. Of the non-infectious mutants, only endonuclease (pol) and gp41 mutants exhibited normal phenotypes with respect to the production of functional reverse transcriptase, the expression of gag, pol, and env proteins, and the generation of progeny virions, when examined in transient assays. All infectious mutants killed the CD4+ cells with the exception of a mutant carrying a defect in the vif gene.

Blotting, Western↗
PubMed1991

A new typing method for the avian infectious bronchitis virus using polymerase chain reaction and restriction enzyme fragment length polymorphism.

Two primers with the length of 22 bases each and 400 bases apart on the spike protein gene of avian infectious bronchitis virus (IBV) were prepared. Using these primers, the genome RNA from twelve strains of the various serotypes were reverse-transcribed to cDNA and amplified by polymerase chain reaction (PCR). With all strains, 400 base DNA was amplified, indicating that there were no apparent insertions or deletions in this region. However, the amplified DNA showed different cleavage patterns by the restriction enzymes. These 12 strains were classified into 5 groups. The strain typing based on a comparison of the cleavage patterns was consistent with the previous serological typing. This study thus provides a simple and rapid method for typing of IBV.

Animals↗
PubMed1991

Whole-cell K+ current activation in response to voltages and carbachol in gastric parietal cells isolated from guinea pig.

Patch-clamp studies of whole-cell ionic currents were carried out in parietal cells obtained by collagenase digestion of the gastric fundus of the guinea pig stomach. Applications of positive command pulses induced outward currents. The conductance became progressively augmented with increasing command voltages, exhibiting an outwardly rectifying current-voltage relation. The current displayed a slow time course for activation. In contrast, inward currents were activated upon hyperpolarizing voltage applications at more negative potentials than the equilibrium potential to K+ (EK). The inward currents showed time-dependent inactivation and an inwardly rectifying current-voltage relation. Tail currents elicited by voltage steps which had activated either outward or inward currents reversed at near EK, indicating that both time-dependent and voltage-gated currents were due to K+ conductances. Both outward and inward K+ currents were suppressed by extracellular application of Ba2+, but little affected by quinine. Tetraethylammonium inhibited the outward current without impairing the inward current, whereas Cs+ blocked the inward current but not the outward current. The conductance of inward K+ currents, but not outward K+ currents, became larger with increasing extracellular K+ concentration. A Ca(2+)-mobilizing acid secretagogue, carbachol, and a Ca2+ ionophore, ionomycin, brought about activation of another type of outward K+ currents and voltage-independent cation currents. Both currents were abolished by cytosolic Ca2+ chelation. Quinine preferentially inhibited this K+ current. It is concluded that resting parietal cells of the guinea pig have two distinct types of voltage-dependent K+ channels, inward rectifier and outward rectifier, and that the cells have Ca(2+)-activated K+ channels which might be involved in acid secretion under stimulation by Ca(2+)-mobilizing secretagogues.

Animals↗