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Biomedical subjects

H Cho

Publications and source records attributed to H Cho.

At least 181 records · Page 10Linked to original sources
PubMed1989

Effect of breast-feeding on immune response to BCG vaccination.

The effect on BCG immunisation of feeding either formula or breast milk was assessed in Canadian Cree infants who were vaccinated either at birth or after 1 month of age. The response to BCG was measured in terms of lymphocyte blastogenesis stimulated by purified protein derivative of Mycobacterium tuberculosis. Breast-feeding significantly enhanced cell-mediated immune response to BCG vaccine given at birth, but had no significant effect if vaccine was given after 1 month. These findings were not related to maternal history of tuberculosis or BCG vaccination, and the feeding method did not influence lymphocyte stimulation by candida or streptococcal antigens.

Age Factors↗
PubMed1989

Dihydropyrimidines: novel calcium antagonists with potent and long-lasting vasodilative and antihypertensive activity.

The novel calcium antagonists 3-N-substituted-3,4-dihydropyrimidines 1 and 9 and 3-N-substituted-dihydro-pyrimidin-2(1H)-ones 8 were regioselectively synthesized in good yields. Compounds 1 [especially 1s [R1 = (CH2)2N(benzyl)(2-naphthylmethyl), R2 = i-Pr, X = 0-NO2] and 1t [R1 = (CH2)2N(benzyl)(3,4-dichlorobenzyl), R2 = i-Pr, X = 0-NO2]] exhibited not only more potent and longer lasting vasodilative action but also a hypotensive activity with slow onset as compared with dihydropyridines. Moreover, some dihydropyrimidines [1q [R1 = (CH2)2N(benzyl)(3-phenylpropyl), R2 = CH2(cyclopropyl), X = 0-NO2], 1s, and 1t] were weaker in blocking atrioventricular conduction in anesthetized open-chest dogs and less toxic than the dihydropyridines.

Animals↗
PubMed1988

Re-evaluation of normal human urinary proteins fractionated by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

Proteins in normal human urine were clearly fractionated into 26 bands with molecular weights from 14,000 to 230,000 by means of one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with silver staining. The main band contained uromucoid, and the second main band had albumin. However, when urine samples from healthy persons were electrophoresed in the absence of SDS using polyacrylamide gel or agarose gel, or a cellulose acetate membrane, albumin but not uromucoid, frequently formed the main protein band. It is suggested that this is due to the complexing of uromucoid subunits to form a large molecule which cannot penetrate into the gel. In order to correctly fractionate all the proteins contained in normal human urine, it was concluded that it was best to treat a urine sample with SDS with pre-condensation, fractionate it by SDS-PAGE and stain fractionated proteins by a highly sensitive method such as silver staining.

Adult↗
PubMed1988

An improved method of high-voltage isoelectric focusing on cellulose acetate membranes.

An apparatus and the procedure for cellulose acetate isoelectric focusing were refined and optimized for routine use in clinical laboratories. The space in the electrophoretic chamber was minimized to maintain high humidity during the run. The water content of the thin cellulose acetate membranes in the chamber was well controlled during isoelectric focusing and the effect of atmospheric carbon dioxide was also excluded. The temperature of the membranes was kept below 2 degrees C, even under conditions of high electric field strength for faster isoelectric focusing of high-molecular-weight proteins. No special training was required for technicians in clinical laboratories to obtain reproducible isoelectric profiles of human serum proteins.

Blood Proteins↗
PubMed1988

Proximal renal tubular acidosis associated with glycogen storage disease, type 9.

A 2 1/2-year-old Japanese boy with glycogen storage disease, type 9, developed proximal renal tubular acidosis (RTA). The RTA significantly improved in response to cornstarch therapy, implying a direct causal relationship between subtle metabolic derangements in glycogen storage disease, type 9, and proximal RTA.

Acidosis, Renal Tubular↗
PubMed1988

[Endocrinological and metabolic disorders in the patients with massive bowel resection in the newborn period].

Massive (70%) resection of the small bowel was performed in seven newborn infants. Follow-up study was undertaken in four of these patients and the growth and endocrinological status were evaluated. Body weight and height of three patients were below 50th percentile. On glucose tolerance test, peak IRI was low and insulinogenic indices were below normal range. These findings suggest that there are some mechanisms which suppress the secretion of insulin. Pituitary and thyroid function were within normal limits but secondary sexual manifestation was not seen in a fifteen year old boy. Hyperoxaluria was seen in three children, and one had kidney stone with some impairment of renal function.

Adolescent↗
PubMed1988

Nerve regeneration in cornea after penetrating keratoplasty in rabbit, with special reference to relationship between regenerating nerves and basal laminae.

The pattern of nerve regeneration in the grafted rabbit cornea was investigated by electron microscopy. Grafted corneas were excised 2, 7, 14 and 28 days after grafting, and processed for observation by conventional electron microscopy. In the normal, unoperated cornea Schwann cell basal laminae are, unlike those of ordinary peripheral nerves, discontinuous and fragmentary on the fibers coursing through the corneal stroma. In the early stage of regeneration, while numbers of regenerating axons extended through the Schwann cell columns of regenerating axons extended through the Schwann cell columns in the grafts, many other regenerating axons elongated as single fibers through the corneal stroma outside the Schwann cell columns. These single naked axons were later enveloped by Schwann cell cytoplasm, contributing to the overall dense irregular pattern of regenerated nerves in the grafted cornea. It was thought that the regenerating axons can extend throughout the stroma without the guidance of basal lamina tubes, making the corneal stroma a favorable environment for nerve regeneration.

Animals↗
PubMed1987

Light and electron microscopic studies of a case with simultaneous Mondini and Michel deformities of the inner ears.

We performed light and electron microscopic studies on the temporal bones of a patient with genetic aplastic deafness, in which the right ear had a Mondini-type defect and the left ear a Michel-type anomaly. The round window of each ear was absent. The stapedial foot plate of the right ear was depressed at its central part and was covered by thin membrane. The course of the internal auditory meatus of the left ear was deviated ventrally. There was total aplasia of the cochlea in the left ear, while that of the right ear showed only three-quarters of a turn. In this ear, three sites of spherical bulging were found and were believed to represent outer hair cells. Other structures of the normal cochlear duct were not present. The modiolus of the left ear was round and dome-shaped, contained sparse nerve fibers and a primitive spiral ganglion. The saccule, utricle and semicircular canals of each ear were missing, so that a common cavity of the vestibular system was present. Several otoliths could be seen under the surface of the membrane covering the common cavity. No sensory cells or their related tissues could be found in either ear.

Aged↗
PubMed1987

Effects of prenatal nicotine exposure on neuronal development: selective actions on central and peripheral catecholaminergic pathways.

The effects of prenatal nicotine exposure on development of catecholaminergic pathways were examined through measurements of transmitter turnover and levels in both the central and peripheral nervous system. Administration of nicotine (3 mg/kg SC, twice daily) to pregnant rats on gestational days 3 through 20 resulted in growth retardation which did not spare the brain and which did not resolve until after weaning. Nicotine exposure produced an elevation in transmitter turnover in central noradrenergic pathways with a regional selectivity reflecting the timetable of cellular development: the most profound effects were seen in late-developing regions (cerebellum), intermediate effects were found in earlier-developing areas (cerebral cortex) and the least effect was obtained where maturation occurs earliest (midbrain + brainstem). Dopaminergic pathways were much less vulnerable than was the noradrenergic system. Effects on the peripheral sympathetic nervous system also were targeted toward specific neuronal populations: renal, cardiac and adrenal pathways were activated by prenatal nicotine exposure, whereas sympathetic innervation of the lung showed reduced activity. All the peripheral effects appeared only after the second postnatal week. These results indicate that prenatal nicotine exposure produces profound alterations in transmitter disposition which are targeted toward specific neuronal populations and which may depend upon generalized effects on cellular development of specific brain regions. Because altered peripheral nerve activity was seen only after the onset of central control of sympathetic tone, actions on central regulation may play a role in the relatively more profound effects in the autonomic nervous system.

Adrenal Glands↗
PubMed1987

[Effect of proteolytic enzymes and bile salts combined with EDTA 4Na on the dissolution of calcium bilirubinate gallstones].

In vitro dissolution of the gallstones was studied in order to evaluate the effect of proteolytic enzyme (Pronase E) and bile acids (CA, CDCA, UDCA and TCA) on the dissolution of the calcium bilirubinate gallstones with ethylene diamine-tetraacetic acid (EDTA 4Na) solution. In this study, the slices and the whole concrement of the calcium bilirubinate gallstones were dissolved with an admixture of the chemical agents. It was shown that a pretreatment with 0.5-1.0% solution of Pronase E made the slices susceptible to the dissolution with EDTA 4Na (1.0%). Although, the addition of Pronase E to an admixture of CA and EDTA 4Na did not increase the efficacy of the slices dissolution, it seemed to be effective in the dissolution of the whole concrement. Regarding to the effect of the bile acids on the slices dissolution, each bile acid was not significantly different from the others when it was used as a 25mM admixture with EDTA 4Na. One hundred milimoles solution of TCA had 2-fold activity of a 25mM solution in the dissolution of both the slices and the whole concrement when it was used in combination with EDTA 4Na. The results suggest that a pretreatment of the calcium bilirubinate gallstones with Pronase E is of great advantage in dissolution therapy. It is also suggested that TCA (100mM in EDTA 4Na), which can be applied in human beings without any serious side effect, is helpful in the treatment of calcium bilirubinate gallstones in clinical cases.

Bile Acids and Salts↗
PubMed1986

Epithelial linings of the human semicircular canal. A scanning and transmission electron microscopic study.

We have used scanning and transmission electron microscopy to examine adult human semicircular canals taken at autopsy and an operation. Our findings can be summarized as follows. In the semicircular circular canals obtained at autopsy from a 30-year-old male, non-sensory ciliated cells having 50-60 cilia were seen sporadically in the canal side of the ampulla of the horizontal canal. A labyrinthine specimen taken at operation demonstrated folding of the cell membrane at the base of columnar cells lining the wall of that part of the canal close to the ampulla. Distal to this site, canal wall cells became progressively flattened and their intracytoplasmic organelles were seen to be progressively less abundant. These cells were found to be layered, facing the endolymphatic space. Dense filaments and fibrocytes were present outside these cells, between which were interposed single-layered basement membranes. Since the capillary network present was found to be sparse, we believe that the portion of the canal studied does not produce endolymph but plays a role in the maintenance of the composition of endolymph and perilymph.

Adult↗
PubMed1986

Effects of maternal nicotine injections on brain development in the rat: ornithine decarboxylase activity, nucleic acids and proteins in discrete brain regions.

Fetal exposure to nicotine via maternal cigarette smoking produces intrauterine growth retardation and postnatal behavioral abnormalities. In this study, biochemical characteristics of brain development were compared in normal rats and in rats whose mothers received chronic nicotine injections throughout pregnancy. Nicotine exposure produced a persistent elevation of fetal ornithine decarboxylase activity preferentially in brain; in keeping with this selectivity, there was no evidence of the sparing of brain growth which ordinarily accompanies non-specific toxic insult. After birth, DNA synthesis was suppressed throughout the brain and there was a subsequent rebound during the phase of "catch-up" growth. Evidence was also obtained for regional selectivity of the adverse effects of maternal nicotine injections: the effects on DNA synthesis and levels were most profound in cerebellum (a region which matures postnatally) and growth-impairment was least evident in midbrain & brainstem, an early-maturing region. The maternal nicotine group also displayed desynchronization of the ontogenetic patterns of DNA, RNA and proteins in every brain region. These data indicate that maternally-injected nicotine compromises early biochemical events which delineate brain cell replication and differentiation; these alterations are eventually translated into abnormalities in development of specific brain regions.

Animals↗