Search PubMed⌕ Search

Biomedical subjects

C Y Hong

Publications and source records attributed to C Y Hong.

At least 127 records · Page 7Linked to original sources
PubMed1993

Linoleate-rich triacylglycerol in Panax pseudo-ginseng improves erythrocyte deformability in vitro.

With Reid's filtration techniques as a bioassay for evaluating red blood cell (RBC) deformability, we purified from Panax pseudo-ginseng an active component that improved the deformability of calcium-loaded RBC. NMR and mass spectrometric studies showed that the purified substance was a triacylglycerol (TG) with linoleic acid as the major fatty acid residue in the esterified positions of glycerol. The mechanism for this TG to improve RBC deformability could be a modification of membrane fluidity rather than a competitive antagonism with calcium ion.

Erythrocyte Deformability↗
PubMed1993

Modification of human sperm function by human follicular fluid: a review.

This review assesses whether human follicular fluid (hFF) is able to modify human sperm function in vitro. Addition of hFF has been found to stimulate the motility of washed human spermatozoa, to increase the percentage of hyperactivated spermatozoa, to induce the acrosome reaction, to attract spermatozoa to the site of fertilization and to facilitate penetration of the oocyte by spermatozoa. It is possible that hFF could provide a favourable environment around the oocyte for fertilization by spermatozoa. Inclusion of hFF in gamete transfer medium may also improve the success rate of assisted reproduction technology. Purification of individual components in hFF which modify different aspects of sperm function awaits further investigation.

Animals↗
PubMed1993

Hearts with twisted atrioventricular connections: findings at MR imaging.

The "crisscross" heart and the heart with "superoinferior ventricles" are closely related congenital cardiac malformations that are characterized by twisted atrioventricular connections. The authors studied the morphologic characteristics of three hearts with twisted atrioventricular connections as seen on magnetic resonance (MR) images. The most important clue to the diagnosis was the distorted atrioventricular connections that were demonstrated on serial images. The axes of the atrioventricular connections through the atrioventricular valves were not parallel to each other. The presence of unusual recesses in the cardiac chambers, the angulated or curved configuration of the atrial and ventricular septa, and the unexpected great arterial relationship for the given combination of segmental connections supported the findings of twisted atrioventricular connections. MR imaging facilitated the precise morphologic diagnosis of these hearts.

Child, Preschool↗
PubMed1992

Takayasu arteritis in Korean children: clinical report of seventy cases.

Seventy cases of Takayasu arteritis in Korean children are reported. There were 57 females and 13 males (male-to-female ratio; 1:4.4). The youngest patient was a 3-year-old female. Family history was positive in one patient. The most common chief complaints on admission were dyspnea, headache, palpitation, and edema which were due to hypertension and congestive heart failure. Hypertension was seen in 65 out of 70 patients (92.8%). The abdominal aorta, thoracic aorta, and renal arteries were the most commonly involved sites in these children. Two patients had nephrotic syndrome. The frequency of positive tuberculin reaction was much higher in children with Takayasu arteritis compared with the general population, and the intensity of the reaction was also stronger. The majority of the patients required immediate medical treatment to control congestive heart failure due to hypertension at initial presentation. When ESR was elevated, corticosteroid was administered. Surgical treatment showed good results in six out of ten cases. Percutaneous intraluminal angioplasty was effective for lowering the blood pressure in six out of nine cases. In three cases, restenosis occurred and angioplasty was repeated in two cases.

Adolescent↗
PubMed1992

Purification of a sperm motility stimulator from porcine follicular fluid.

1. We purified a glycoprotein possessing a potent ability to stimulate porcine sperm motility, from porcine ovarian follicular fluid. 2. The protein, of molecular weight 52,000, has an N-terminal sequence similar to that of antithrombin III, indicating that it is identical to or highly homologous to antithrombin III. 3. Thus it is proposed that antithrombin III or its homologue is involved in the mammalian fertilization process.

Amino Acid Sequence↗
PubMed1992

Astragalus membranaceus stimulates human sperm motility in vitro.

Poor sperm motility is an important cause of male infertility. In an attempt to identify Chinese medicinal herbs that might improve human sperm motility in vitro, we screened water extracts of 18 herbs with a trans-membrane migration method which measured the percentage of sperm that moved across the 5 micron pores of a Nucleopore membrane from a semen-drug mixture into phosphate buffered saline during 2 hours incubation. Astragalus membranaceus was the only herb that showed a significant stimulatory effect. At 10 mg/ml, it increased the motility of sperm in semen to 146.6 +/- 22.6% of control. It also increased the motility of washed sperm to 138.2 +/- 13.8% of control. Purification of the active component(s) from this herb as well as its application in assisted reproduction technology await further investigation.

Astragalus propinquus↗
PubMed1992

Long-term nicotine exposure increases aortic endothelial cell death and enhances transendothelial macromolecular transport in rats.

Repeated endothelial cell injury has been suggested as an initiating factor in atherogenesis. Dying or dead endothelial cells have been shown to make significant contributions to the local enhancement of transendothelial macromolecular transport. Since cigarette smoking is one of the major risk factors for atherosclerosis, we examined the hypothesis that smoking accelerates atherogenesis by increasing the frequency of endothelial cell death and hence transendothelial macromolecular transport. Sixteen male Sprague-Dawley rats were given nicotine at a weight-adjusted dose of 5 mg/kg body wt per day in their drinking water over a period of 6 weeks. A group of 16 age-matched male Sprague-Dawley rats not exposed to nicotine and maintained over the same time period served as the control group. In en face preparations of thoracic aorta, immunoglobulin G-containing dying or dead endothelial cells were identified by the indirect immunoperoxidase method, and endothelial leakage to Evans blue-albumin (EBA) complexes (5 minutes after intravenous injection) was visualized by fluorescence microscopy. The results showed that in nicotine-treated rats, 51% of dead endothelial cells were associated with EBA leakage, which was responsible for 57% of total EBA leaky foci. Both the frequency of endothelial cell death (0.94 +/- 0.11% versus 0.40 +/- 0.04%, p < 0.0001 by two-tailed, unpaired Student's t test) and the number density of EBA leaky foci (6.45 +/- 1.23/mm2 versus 3.30 +/- 0.49/mm2, p < 0.05 by two-tailed, unpaired t test) were significantly greater in nicotine-treated rats than in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Routine immunisation against chickenpox. Is it time?

Natural varicella in healthy children is normally not a severe illness. Nevertheless, the need to be away from school such as during an important examination, or from work, may be inopportune. It is therefore attractive to be able to prevent chickenpox. Such a proposition became a reality in 1974 with the development of a live attenuated varicella vaccine (the Oka strain). This has since been used in leukaemic children and children with other malignancies, and found to be safe and effective. Some of these children were immunised without complete suspension of anticancer therapy. The vaccine has also been used on healthy children and adults, mainly in Japan and North America. The results too indicated the vaccine to be safe and immunogenic, with minimal side effects. It has been shown to confer protection even if given within 3 days of exposure. The occurrence of zoster appears to be no higher than in natural infection. The vaccine has so far been shown to be protective up to 10 years post-immunisation. It appears safe enough to offer the vaccine routinely to those who are at risk of infection. One dose of vaccine given subcutaneously is usually sufficient for healthy children, but two doses are needed for immunocompromised children and adults.

Adolescent↗
PubMed1991

The periapical tissue reactions to a calcium phosphate cement in the teeth of monkeys.

A calcium phosphate cement, Grossman sealer, and Sargenti N2 were compared under conditions where root canals of monkey incisors were deliberately overfilled and the apical tissue responses were evaluated histologically. The periapical tissues exposed to Sargenti N2 revealed severe irritation at all times through the 6-month experimental period. The reactions to Grossman sealer were milder but persisted throughout the observation period. The calcium-phosphate-cement treated animals showed mild tissue irritation after 1 month, but thereafter the adverse tissue reactions were minimal. New bone formation adjacent to the cement was also observed. These results point to the possibility that calcium phosphate cement might be used in simplified endodontic procedures. The compatibility of calcium phosphate cement with the periapical tissue suggests that the cement may have other applications in dentistry and medicine.

Animals↗
PubMed1991

Pentoxifylline stimulates human sperm motility both in vitro and after oral therapy.

Pentoxifylline is a haemorrheologic agent often used in the treatment of peripheral vascular disorders. In this study, we measured sperm motility with a trans-membrane migration method and investigated the effect of this drug in the treatment of male infertility. We found that pentoxifylline increased motility of ejaculated spermatozoa in vitro from both normal and asthenozoospermic samples. After giving pentoxifylline to patients with asthenozoospermia for 3 months, sperm motility significantly increased, but sperm concentration did not increase. From the above results, it can be concluded that pentoxifylline is a useful drug in the treatment of normogonadotropic asthenozoospermia.

Administration, Oral↗
PubMed1991

MR anatomy of ventricular septal defect in double-outlet right ventricle with situs solitus and atrioventricular concordance.

Surgical treatment of patients with double-outlet right ventricle (DORV) depends on the spatial relation between the associated ventricular septal defect (VSD) and the arterial valves. This study was performed to refine the magnetic resonance (MR) imaging characteristics of VSD in DORV. Ten patients with DORV underwent MR imaging. Coronal, transverse, and oblique images were obtained with an electrocardiographic-gated multiple-section spin-echo technique. The transverse plane was the most valuable in defining the spatial relation of the VSD to the arterial valves. The site of fusion of the outlet septum with the VSD margin was diagnostically the most important feature in differentiating subaortic from subpulmonary VSD. The outlet septum fused with the anterior margin in subaortic VSD and the posterior margin in subpulmonary VSD; it was absent in doubly committed VSD. This study suggests that MR imaging can demonstrate the pertinent features of VSD and may be an indispensable adjunct to echocardiography in the preoperative evaluation of patients with DORV.

Angiocardiography↗
PubMed1991

cAMP and vascular action of endothelin.

Endothelin, a potent vasoconstricting peptide, induced maximal contraction of the rat tail artery within 3 min of administration. Endothelin also caused a dose-dependent decrease in tissue levels of cAMP. Concentrations of cAMP decreased about 60% 1 min after endothelin (10(-8) M) administration, but returned to basal levels in 5 min. By contrast, tissue levels of cGMP were not changed by endothelin. Modulation of cAMP production may provide one mechanism for the vascular action of endothelin.

Animals↗
PubMed1991

[Application of a trans-membrane migration method in the study of human sperm motility: a review].

Transmembrane migration method is a bioassay specifically designed to study drug effect on human sperm motility. It was first used in the study of sperm immobilizing agents which have a membrane stabilizing effect. Then it was used to investigate the relationship between calcium ion and sperm motility. Recently, this method has been used to screen drugs that stimulate sperm motility. It has also been modified for the study of porcine sperm motility. Computer assisted semen analysis showed that the transmembrane migration method is most suitable for studying drug effect on rapid and straight-forward motility of sperm.

Biological Assay↗
PubMed1991

Hypertension in the elderly--a review.

This report reviews the recent studies on the risks of excess morbidity and mortality from untreated hypertension in the elderly (aged 60 and above), and the possible benefits derived from therapeutic intervention. These studies suggest that the 'young-old' (aged 60-80) have definite measurable risks associated with elevated blood pressure, which are reduced by appropriate treatment, but the benefits of conventional treatment on those above 80 years old are not so clear cut. With these findings the review examines the existing issues, the accompanying risks, criteria and recommendations for evaluating the elderly hypertensive, and the modalities of treatment.

Aged↗