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Biomedical subjects

T Cho

Publications and source records attributed to T Cho.

At least 55 records · Page 3Linked to original sources
PubMed1992

[The influence of infusion volume on hemodynamics during experimental laparotomy].

The influence of infusion volume on hemodynamics was studied in adult mongrel dogs undergoing laparotomy. Study 1: Total blood volume (TBV) was measured in 5 dogs undergoing laparotomy without fluid administration for 180 min. TBV before surgery was 71.2 +/- 10.7 ml.kg-1 and remarkably decreased to 59.9 +/- 11.5 ml.kg-1, at a rate of 3.8 ml.kg-1.h-1. Study 2: 21 dogs were divided into 3 groups. Group C had restricted fluids during the study. Group I had infusion of lactated Ringer's solution (LR) at a rate of 10 ml.kg-1.min-1 and Group II at a rate of 20 ml.kg-1.min-1 for 180 min. In group C, mAP and HR were unchanged but CVP, cardiac output, renal blood flow (RBF) and skin blood flow decreased after laparotomy. On the other hand, CVP and RBF were maintained until 180 min in Group I. In Group II, though the hemodynamic parameters were well maintained and urine output was maximal, Ht, Na, concentration and especially plasma colloid osmotic pressure (Pcop) decreased. These results suggest that administration of LR at a rate of 20 ml.kg-1.min-1 is rational to prevent the decrease of TBV and to maintain the peripheral circulation during the surgical procedure, but it may decrease Pcop.

Animals↗
PubMed1990

Bioreactor development for production of viral pesticides or heterologous proteins in insect cell cultures.

The insect cell-baculovirus expression system has significant potential for producing proteins requiring some degree of posttranslational modification. T. ni cells appear to be as good a host as S. frugiperda cells for heterologous protein production as demonstrated by production of beta-galactosidase. Attachment-dependent cells of T. ni can be effectively cultured in a packed-bed reactor using glass beads. When cell in such a reactor were infected, they produced 35% of the total protein as beta-galactosidase. No cell detachment was observed even 70 h postinfection. A model of viral entry has been proposed and tested.

Animals↗
PubMed1990

Activation of the plasma kallikrein-kinin system by Candida albicans proteinase.

An extracellular carboxyl proteinase produced by the yeast Candida albicans enhanced vascular permeability when injected into the dorsal skin of guinea pigs. The character and mechanism of the permeability-enhancing reaction were studied in vivo and in vitro. Permeability was not enhanced when the C. albicans proteinase was heat treated (100 degrees C, 5 min) or when it was treated with pepstatin, a specific carboxyl proteinase inhibitor. The permeability reaction induced by the C. albicans proteinase was not affected by pretreatment with antihistamine but was greatly augmented by simultaneous injection of a kinin potentiator, carboxypeptidase N inhibitor. However, the simultaneous injection of a kinin-degrading enzyme, carboxypeptidase B, interfered with the reaction. Furthermore, in vitro conversion of plasma prekallikrein to kallikrein by the C. albicans proteinase was observed, and the reaction was inhibited by corn trypsin inhibitor, an inhibitor of activated Hageman factor, and soybean trypsin inhibitor, a well-known inhibitor of plasma kallikrein. These results indicate that C. albicans proteinase enhances vascular permeability through activation of the plasma kallikrein-kinin system, which generates bradykinin.

Animals↗
PubMed1989

Distribution and frequency of neuro-epithelial bodies in post-natal rabbit lung: quantitative study with monoclonal antibody against serotonin.

The distribution, frequency and size of neuroepithelial bodies (NEB) were studied in lungs of rabbits during different stages of development (27-day fetus, newborn, 6, 11, 21, 28 and 56 days postnatally). NEB were visualized by immunostaining with monoclonal antibody against serotonin. Detailed quantitation of NEB was performed by use of camera lucida drawings of immunostained serial sections from the same anatomical region, i.e. the lower lobe of the left lung. The total number of NEB was counted and expressed per epithelial length of airway, surface area and volume. The size of NEB defined as surface area as well as the position of NEB in relation to the airway bifurcations was assessed in airways of different sizes. The overall number and size of NEB were found to increase during the immediate perinatal period followed by a sharp decline at 56 days of age. The number of NEB peaked at 6 days postnatally (mean 175.5 NEB/mm3 of airway epithelium) and declined significantly (3.0 NEB/mm3) at 56 days of postnatal age. The size of NEB reached its maximum at 11 days (mean surface area 659.54 microns 2, with the largest NEB measuring 1839.98 microns 2). By 56 days of age, NEB became significantly smaller (mean surface area 177.29 microns 2) consisting of small clusters of cells situated deep within the airway epithelium. At all ages, about half of all NEB (mean 47.6%) were localized within the small peripheral airways with up to 63.9% located at airway bifurcations. These findings indicate that the "functional activity" of NEB may be confined predominantly to the perinatal period. The postulated functions of NEB include those of intrapulmonary hypoxia-sensitive chemoreceptors and/or endocrine-paracrine activity in the lung. Such functions(s) may be important during adaptation to extrauterine life as well as for growth and development of the lung.

Amines↗
PubMed1989

Starvation and germ tube formation in the exponential phase Candida albicans.

Two chemically defined media were developed for the induction of germ tubes in exponential phase cells of Candida albicans. One medium was N-acetyl-D-glucosamine medium which is composed of L-thiazolidine-4-carboxylic acid, L-proline, NaHCO3, sodium acetate, NaH2PO4 and N-acetyl-D-glucosamine. The other one was glucose medium in which N-acetyl-D-glucosamine is exchanged for glucose plus NH4Cl in N-acetyl-D-glucosamine medium. In these media, a high percentage of germ tube forming cells was obtained without a temperature shift. However, starvation of the cells in water at 37 degrees C was a necessary pretreatment to consistently obtain a high percentage of germ tube forming cells. The effect of starvation was remarkable in glucose medium, the percentages of germ tube forming cells among the normal cells and starved cells were 20 and 80, respectively. As for intracellular changes during starvation, a decrease in adenosine triphosphate concentration and an increase in adenosine 3',5'-cyclic monophosphate concentration were observed.

Acetylglucosamine↗
PubMed1988

Structure of the rat renin gene.

We have isolated the renin gene from a Sprague-Dawley rat genomic library and determined its complete nucleotide sequence. The single rat renin gene is approximately 11,000 bases in length and consists of nine exons and eight introns. The amino acid sequence predicted from the genomic sequence indicates that the rat renin precursor consists of 402 amino acid residues, and shows 85%, 82% and 68% homology to the mouse Ren-1 and Ren-2, and human renins, respectively. The canonical promoter "TATA" boxes, TATAAA and TAATAA, are found 27 and 57 base-pairs upstream from the putative cap site, respectively. Several attractive regulatory sequences analogous to glucocorticoid, estrogen receptor-binding sites, cAMP-responsive element and SV40 enhancer core sequences were noted in the 5'-flanking region of the gene. In the first intron, segments with an average size of 38 base-pairs containing a NcoI site are present at 46 tandem repeats within 1710 base-pairs. A "CA" element consisting of (CA)27 was identified in intron 3. Furthermore, intron 8 contains a sequence that shows about 93% homology to that of the neuronal identifier sequence.

Amino Acid Sequence↗
PubMed1988

Degradation of human dentine collagen by an enzyme produced by the yeast Candida albicans.

An extracellular collagenolytic enzyme separated from a culture medium of this pathogenic yeast was found to attack undenatured predentine collagen as seen in scanning electron micrographs. After treatment with the enzyme at pH 4.0, but not by that acidity alone, dentine tubules were less easily distinguished and the collagen fibres were less well-organized.

Candida albicans↗
PubMed1988

Degradation of bovine achilles tendon collagen by Candida albicans proteinase.

Candida albicans, when cultivated in a medium containing insoluble bovine achilles tendon as a nitrogen source, was able to produce a collagen degrading proteinase. The degradation of achilles tendon collagen by the proteinase was verified by morphological change and the release of hydroxyproline. The proteinase activity was inhibited by pepstatin.

Achilles Tendon↗
PubMed1987

Catecholamine-induced cardiopathy accompanied with pheochromocytoma.

Catecholamine-induced cardiopathy accompanied with pheochromocytoma in a 28-year-old female including two other cases are reported and the relationship between pheochromocytoma and cardiac change was also discussed. In the first case, catecholamine in the tumor tissue showed extremely high values; 94.22 micrograms/g of adrenaline and 6,332.42 micrograms/g of noradrenaline. Histologically, myocardial degeneration and inflammatory cell infiltration between myocardial fibers were noted. In the second case, hypertrophied heart showed focal degeneration of myocardial fibers with a few inflammatory cells in the stroma. The third case showed increase of heart weight, but neither myocardial degeneration nor inflammatory infiltration was noted except for moderate myocardial hypertrophy. Although the cause of difference in degree of myocardial changes is not yet clear, it may be attributed to the blood catecholamine level and/or duration of disease and/or area examined. A relative hypoxia theory is accepted for the mechanism of catecholamine-induced cardiopathy. This theory is supported by more severe lesions being noted near to the cardiac apex corresponding to peripheral coronary circulation.

Adrenal Gland Neoplasms↗
PubMed1987

Exstrophy of the cloacal membrane. A pathologic study of four cases.

Exstrophy of the cloaca is a rare congenital anomaly. The authors add the pathologic findings of four distinct cases reported in this article to those reported in the literature. In all cases, common anomalies were recognized. In addition, there were rare anomalies, such as single umbilical artery, vestige of the left superior vena cava, common mesenterium, calcification of the cerebellum, incomplete segmentation of the left lung, abnormal shape of the liver, and knock-knee. The embryology of this complex anomaly is difficult. It is considered that this anomalous condition results from breakdown and mesodermal invasion of the cloacal membrane.

Abnormalities, Multiple↗
PubMed1986

Aortic changes induced by hypercholesterolemia and hypercalcemia in rats.

The effects of vitamin D and cholesterol-rich diets on rat aortas were examined. Examination by electron microscopy showed a widening of the subendothelial space and the presence in this space of amorphous substances as early as the second week into mild hypercholesterolemia. After further time elapsed, basement membrane-like substances, microfilaments, migration of mononuclear cells, and modified smooth muscle cells were seen in the subendothelial space. In the vitamin D group, the main electron microscopic finding was of medial smooth muscle cell changes, such as focal degeneration and matrix vesicles. However, calcification was not observed in our present study. In rats fed a cholesterol-rich diet plus vitamin D, changes associated with both the cholesterol-rich diet only and vitamin D only were seen.

Animals↗
PubMed1986

Synthesis and characterization of human prorenin in Escherichia coli.

DNA sequences encoding Ile-Glu-Gly-Arg and human prorenin were joined and placed under the transcriptional control of the Escherichia coli trp promoter-operator in the expression vector pTR501. E. coli cells transformed with pTR501 expressed high levels (30% of total cell protein) of prorenin as part of a hybrid protein with the trp E gene product. The chimeric protein, accumulated in a sedimentable form, was dissolved in 6 M guanidine X HCl, purified to near homogeneity, and renatured by dialysis. The complete prorenin sequence was then excised from the renatured hybrid protein using blood coagulation factor Xa, a proteinase which is highly specific for the tetrapeptide insert Ile-Glu-Gly-Arg introduced between the 9 amino-terminal residues of the trp E gene product and the first amino acid (Thr 1) of prorenin. Human prorenin thus obtained was readily activatable with trypsin and showed close similarities to naturally occurring prorenin in its biochemical and immunochemical properties.

Base Sequence↗
PubMed1986

The relationship between arteriosclerosis and the wave line of aorta.

The wave line is a structure that is frequently observed in aorta. Grossly this structure (wave line), measuring 0.3-0.5 cm in width and 5-10 cm in length, runs longitudinally or spirally along the long axis of the aorta. The distribution and the relation with arteriosclerotic plaque of wave line were studied. The wave line had three predilection sites: A) the wave line running down from closure of Botallo duct to ostium of 6-8th intercostal artery, B) the wave line between ostium of both renal arteries, C) the wave line running down from lumbar artery to iliac arteries. The wave line observed in the aortae of neonates gradually increased with age. Its frequency is about 80-100% in the second and the third decades. The association of arteriosclerosis with the wave line was frequently observed, especially on "C" region. Fifty-five percent of arteriosclerotic plaques in the fourth decade corresponded with the wave line.

Adolescent↗