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Biomedical subjects

S Cho

Publications and source records attributed to S Cho.

At least 199 records · Page 11Linked to original sources
PubMed1991

Synergistic action of purified alpha-fetoprotein and growth factors on the proliferation of porcine granulosa cells in monolayer culture.

alpha-Fetoprotein (AFP) is present in high levels in fetal fluids, certain neoplasias, and regenerating liver. Although AFP's physiological role remains an enigma, we have recently demonstrated mitogenic activity for AFP. Using a primary monolayer culture system, we have further investigated the proliferative activity of purified AFP. Porcine granulosa cells from small ovarian follicles were attached for 2 days in Ham's F-12-Dulbecco's Modified Eagle's Medium (1:1) and 5% fetal calf serum, followed by 6 days of culture in medium containing 0.25% plasma-derived serum plus 25 micrograms/ml low density lipoprotein with or without growth factors and/or purified human AFP. In this system AFP alone does not stimulate proliferation. However, when combined with epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I; 10 ng/ml each), AFP (5 micrograms/ml) significantly (P less than 0.01) enhanced growth factor-mediated proliferation 4.5-fold over that of medium controls. Equivalent doses of purified human serum albumin or transferrin demonstrated no effect. The effects of AFP were dose dependent, with significant (P less than 0.05) enhancement of proliferation (2.7-fold over controls) observed with as little as 0.313 micrograms/ml AFP. Increased proliferation was noticed as early as 24 h after the addition of AFP and by 48 h AFP, EGF, and IGF-I had significantly (P less than 0.05) increased proliferation over that seen in medium controls, cells treated with EGF plus IGF-I, or cells treated with 10% fetal calf serum plus EGF, and this trend continued linearly over 5 days of culture. AFP (5 micrograms/ml) significantly increased the proliferative response observed with increasing doses of EGF, IGF-I, or EGF plus IGF-I, but did not appear to alter the dose-response curves. AFP dose-dependently (1.25-5 micrograms/ml) and significantly (P less than 0.05) increased proliferation of porcine granulosa cells in response to platelet-derived growth factor (PDGF) and EGF (25 and 10 ng/ml, respectively), but not to PDGF alone. In contrast, AFP produced no further proliferation of porcine thecal cells in response to PDGF plus EGF. Binding of EGF, IGF-I, or PDGF to purified AFP could not be demonstrated. These results demonstrate that physiological levels of AFP, although not mitogenic alone, can significantly enhance the mitogenic activity of EGF plus IGF-I/PDGF and may function to modulate growth factor-mediated cell proliferation during development and neoplasia.

Animals↗
PubMed1991

[Pharmacokinetic and clinical study of cefpirome in children].

Pharmacokinetic and clinical studies of cefpirome (CPR) in children were carried out, and the following results were obtained. 1. Peak serum levels were obtained at the end of drip infusion of 20.0, 17.5 and 6.8 mg/kg for 30 minutes and the half-lives were 1.93, 1.91 and 0.48 hours, respectively. 2. Urinary excretion rates in 6 hours were 40.0-96.2%. 3. Thirty-two patients including 17 with respiratory infections, 7 with urinary tract infections and 8 with skin and soft tissue infections were treated with CPR at 52.2-92 mg/kg per day by intravenous administration. Clinical effects were excellent in 12 cases, good in 13 cases, fair in 3 cases and unknown in 4 cases, and the overall efficacy rate was 89.3% (25 cases/28 cases). 4. Bacterial eradication rate was 93.8% (15 strains/16 strains). 5. Rash and diarrhea were found in 1 case each, and abnormal laboratory test values were found in 7 cases.

Adolescent↗
PubMed1990

Transport protein genes in the murine MHC: possible implications for antigen processing.

T lymphocyte activation requires recognition by the T cell of peptide fragments of foreign antigen bound to a self major histocompatibility complex (MHC) molecule. Genetic evidence suggests that part of the class II region of the MHC influences the expression, in trans, of MHC class I antigens on the cell surface, by regulating the availability of peptides that bind to and stabilize the class I molecule. Two closely related genes in this region, HAM1 and HAM2, were cloned and had sequence similarities to a superfamily of genes involved in the ATP-dependent transport of a variety of substrates across cell membranes. Thus, these MHC-linked transport protein genes may be involved in transporting antigen, or peptide fragments thereof, from the cytoplasm into a membrane-bounded compartment containing newly synthesized MHC molecules.

Amino Acid Sequence↗
PubMed1990

Characterization of human alpha fetoprotein charge microheterogeneity during fetal development.

Aliquotes of human amniotic fluid (AF), fetal serum (FS), and cord blood (CB) were obtained as by-products of routine clinical diagnostic procedures at term or in the second trimester of pregnancy. When samples of CB were applied to a pH 5.5-4 chromatofocusing gradient, three isoforms of AFP could be resolved; a pl 4.57 form (isoform IA, 52% AFP), a pl 4.27 form (isoform IB, 43% AFP), and one species that was bound to the column but could be eluted with 1.0 M NaCl (isoform II, pl less than 4.00, 5% AFP). Term AF displayed a profile similar to that observed in term CB. When samples of 15-20-week gestation AF were chromatofocused, the immunoreactive AFP recovered was distributed between isoform IA and IB (60%) and isoform II (40%). FS and AF obtained from same pregnancy (23-26 weeks) displayed an identical chromatofocusing profile. Aliquotes of AF subjected to conA revealed 83% reactive variants compared with greater than 95% reactive variants for CB. FS displayed a conA profile identical to CB. When individual CB charge isoforms were isolated and subjected to conA analysis, greater than 97% of the AFP bound to conA. In contrast, when AFP isoform IA and IB were isolated from midgestation AF, approximately 22% of the AFP did not bind to the lectin while 100% of isolated AFP isoform II eluted as the reactive variant. These data suggest that human AFP exists as at least three charge and two lectin variants and that the charge profile may change during fetal development.

Amniotic Fluid↗
PubMed1990

Aprosencephaly: review of the literature and report of a case with cerebellar hypoplasia, pigmented epithelial cyst and Rathke's cleft cyst.

Aprosencephaly is a very rare brain malformation that occurs in isolated and sydromatic forms. The syndromatic form has been named "XK-aprosencephaly", and is characterized by near total absence of prosencephalon with a midline oculofacial defect similar to the most severe forms of holoprosencephaly, in association with limb and genital anomalies. We present a case of syndromatic aprosencephaly with absence of thumb and abnormal external genitalia. A previously undescribed finding was a Rathke's cleft cyst. Two other cystic structure were also identified--an ependymal cyst, which may represent a dorsal cyst as in holoprosencephaly, and a pigmented epithelial cyst, which may represent a rudimentary eye. Additional findings were extensive calcific vasculopathy in the rudimentary prosencephalon, absence of pituitary gland, forking of the aqueduct of Sylvius and marked cerebellar hypoplasia. Since calcific vasculopathy is a common accompaniment of other inflammatory diseases of the central nervous system, its presence in this case suggests that destructive processes may be involved in the genesis of some cases of aprosencephaly.

Abnormalities, Multiple↗
PubMed1990

Traumatic superior mesenteric artery--portal vein fistula.

An interesting and rare case of traumatic superior mesenteric artery-to-portal vein arteriovenous fistula is presented. Initial operative control of the bleeding superior mesenteric artery injury required ligation of the superior mesenteric artery at its origin to prevent exsanguination in an extremely unstable patient with multiple injuries. Early postoperative visceral arteriography documented ligation of the superior mesenteric artery with a proximal superior mesenteric artery-to-portal vein arteriovenous fistula. Percutaneous catheter embolization of the arteriovenous fistula was undertaken successfully at this time. Superior mesenteric artery ligation was surprisingly well tolerated. Major arterioportal fistulas require treatment to prevent long-term complications of intestinal ischemia, portal hypertension, and cirrhosis. Although traditional treatment involves ligation of the arteriovenous fistula and arterial bypass, percutaneous embolization is becoming a viable alternative. Arteriography remains the cornerstone of diagnosis and treatment planning.

Abdominal Injuries↗
PubMed1990

Protection against rabies in mice by a cytotoxic T cell clone recognizing the glycoprotein of rabies virus.

By the use of liposomes containing the purified surface glycoprotein (G) of rabies virus and the haemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins of Sendai virus, the target antigen of anti-rabies virus cytotoxic T lymphocyte (CTL) clones isolated in a previous study was identified as the G protein. Recognition of the H-2K determinant of the class I major histocompatibility complex (MHC) was necessary for target lysis by the CTL clones. One of the CTL clones was examined for the ability to protect mice against a lethal rabies virus infection. CTL were transferred into syngeneic mice which had been infected in the hind footpad with the ERA strain of rabies virus. The infection was converted into a lethal infection by cyclophosphamide treatment 1 day after virus infection. Transfer of CTL 2 to 3 days after virus infection protected approximately 50% of mice during the observation period of 4 weeks. Greater protection was obtained in mice receiving both anti-rabies virus antibodies and CTL cells.

Animals↗
PubMed1990

Hypertensive-diabetic cardiomyopathy in rats.

Left ventricular papillary muscle function, transmembrane action potentials, myosin adenosinetriphosphatase (ATPase) and isoenzyme distribution, and myocardial pathology were studied in hypertensive (H), diabetic (D), hypertensive-diabetic (HD), and control (C) rats. There was approximately 50% relative left ventricular hypertrophy in H and HD rats. Relative lung and liver weights were greater in HD rats. Peak velocity of shortening tended to decrease progressively in H, D, and HD rats. The duration of contraction and relaxation was markedly prolonged in Ds and HDs. The length-developed tension relation was blunted in HDs. The negative inotropic effect of verapamil was similar in all groups. Resting membrane potential and amplitude were decreased in D and HD rats. Action potential duration was increased in H, D, and especially HD rats. The shortening of action potential duration with increased stimulus frequency was greater in H, D, and especially HD rats than in Cs. Left ventricular myosin ATPase and V1 isoenzyme content decreased progressively in H, D, and HD rats. Right ventricular V1 isoenzyme content was not affected in H rats but was markedly decreased in D and HD rats. Left (and right) ventricular pathology was unchanged in rats with diabetes but was increased in rats with hypertension. These data suggest that the combination of myocardial pathology (due to hypertension) and cellular dysfunction (caused mainly by diabetes) may result in cardiomyopathy and congestive heart failure in the HD rat.

Analysis of Variance↗
PubMed1989

Extreme hyperpyrexia in childhood. Presentation similar to hemorrhagic shock and encephalopathy.

The authors report the cases of five previously well children, aged 8 to 33 months, who were seen over a 14-year period, with admission temperatures in excess of 42.0 degrees C (107.6 degrees F). Four of the patients died. Each child had a similar clinical illness in which the hyperpyrexia played a critical role. Negative blood, cerebrospinal fluid, and stool cultures excluded bacterial sepsis as a possible etiology. This illness is similar, if not identical, to the newly described syndrome of hemorrhagic shock and encephalopathy (HSES) reported in European and American infants.

Brain Diseases↗
PubMed1989

A microcomputer data base system for maternal serum alpha fetoprotein screening programmed in BASIC.

A computer program was developed for the IBM PC computer to be used for maternal serum alpha fetoprotein screening (MSAFP). This program, written in BASIC, 1) maintains a data base for patients tested, 2) allows input and storage of MSAFP results, 3) calculates the gestational age dependent result in multiple of the median (MOM), 4) makes an individualized interpretation of the result based on maternal age, weight and diabetes, 5) makes an appropriate recommendation for subsequent action based on the result, and 6) prints a report containing the above information. In addition, the program will print a daily log of patients tested, provides a follow-up sheet to assist in tracking abnormal results to term, converts the data files into files which can be easily intergrated into more powerful data base programs, and generates a monthly statement for billing purposes. The program can be easily modified by someone with minimal training in the BASIC programming language.

Female↗
PubMed1989

Immunohistochemical localization of an HIV epitope in cerebral aneurysmal arteriopathy in pediatric acquired immunodeficiency syndrome (AIDS).

A 6-year-old boy with acquired immunodeficiency syndrome (AIDS) developed aphasia and quadriplegia 3 months before his death. Cerebral vascular ectasia and multiple cerebral infarcts were noted on premortem radiological studies. Postmortem evaluation revealed diffuse aneurysmal dilatation of the circle of Willis associated with fresh and organizing thrombi, destruction of the elastic lamina, and marked intimal fibroplasia. Multiple cerebral infarcts and subacute AIDS encephalitis with basal ganglia calcification were also present. Immunohistochemistry with a monoclonal antibody (anti-gp41) to human immunodeficiency virus (HIV) demonstrated positively stained cells in the arterial wall of the circle of Willis and in the cerebral parenchyma. Double immunostaining demonstrated that gp41-positive cells in the circle of Willis were also positive for a macrophage marker or leukocyte-common antigen, but not with an endothelial marker. Some macrophages or microglia in the cerebrum were also colabeled with anti-gp41. These results suggest that HIV may be directly involved in vascular pathology associated with pediatric AIDS.

AIDS Dementia Complex↗
PubMed1989

The emergence of a health insurance system in a developing country: the case of South Korea.

In an attempt to understand the social forces and the economic and political conditions under which new social policies emerge in developing countries, this study outlines factors affecting the introduction of the health insurance system in South Korea. The emergence of the South Korean health insurance system was influenced by changing labor needs of the industrial sector, increasing social expectations, external and international pressures, increasing medical costs, and class conflict. These pressures compelled the South Korean government to respond to demands for the introduction of new social welfare policies in the 1970s. In the case of South Korea, the new health insurance system resulted from the government's attempts to cope with political, economic, and social pressures rather than from an ideological commitment to the well-being of the population. The resulting insurance system was a way to maintain the social order and legitimacy of the regime, and a means to promote the health of groups important to defense or production.

Humans↗
PubMed1989

Cardiac pathology in the hypertensive diabetic rat. Biventricular damage with right ventricular predominance.

The hypertensive-diabetic rat is a new small animal model of cardiomyopathy characterized by ventricular damage. To determine the extent of pathology in this model, quantitation of light microscopic changes in hearts from 15 hypertensive-diabetic rats and 15 age-matched controls was performed. The fraction of myocardium involved by interstitial fibrosis, myocyte necrosis, replacement fibrosis, vascular sclerosis and perivascular fibrosis was computed separately for right and left ventricles. Spontaneously dying as well as deliberately killed hypertensive-diabetic rats were studied. Spontaneously dying animals had higher systolic blood pressures compared with rats killed deliberately. Body weights were lower and lung weights higher in the former group. Left and right ventricular necrosis and fibrosis were increased in spontaneously dying compared with deliberately killed rats. The degree of right ventricular necrosis and fibrosis paralleled that in the left ventricle, but was, unexpectedly, several times greater in magnitude. Thus, quantitative histology in the hypertensive-diabetic rat reveals more cardiac necrosis and fibrosis, in either ventricle, from spontaneously dying animals compared with deliberately killed rats. This damage, coupled with major functional alterations in the viable myocardium, may lead to congestive heart failure or arrhythmia.

Animals↗
PubMed1988

Effect of long-term feeding of aluminium chloride on hexokinase and glucose-6-phosphate dehydrogenase in the brain.

Rats were fed 100 microM AlCl3 for 1 year in their drinking water, then killed and their brains homogenized in 0.1 M Tris (pH 7.4). The 800 g supernatants were assayed for Al3+ and the activities of acetylcholine esterase (ACE), hexokinase and glucose-6-phosphate dehydrogenase (G6PDH). The concentrations of Al in the homogenates, as computed on the original brain for the control and Al fed group were 40 ng and 80 ng/g wet wt, respectively. The activity of ACE was the same in both groups but that of hexokinase and G6PDH in the Al-fed group was about 73% and 80%, respectively, of the control. Dialysis restored the G6PDH but increased the hexokinase of the control group 2-fold and that of Al-fed group 2.7-fold. Thus at this elevated level it was same in both groups. The contribution of Al from the undialysed homogenates during assay was too low to account for the inhibition. It is therefore suggested that a dialyzable inhibitor for hexokinase is normally present in the brain and that Al feeding increases its concentration to further inhibit the utilization of glucose.

Acetylcholinesterase↗
PubMed1988

The anatomy and pathophysiology of the microvasculature in different organs: relationship to vasculogenic necrosis and tissue damage.

This chapter presents the methodology as well as various applications of a silicone rubber (Microfil) prefusion technique for evaluation of the microcirculation. In the heart, Microfil perfusion has been used in conjunction with clearing techniques to elucidate normal anatomic relationships, to identify areas of myocardium at risk following vascular occlusion, and to observe dynamic events in the development of various cardiomyopathies. Advantages of the technique include in vivo applicability, ease of vascular filling, and ability to discriminate between adjacent vascular fields. Preliminary data from work in other organ systems including skeletal muscle, brain, liver, and lung are also presented.

Animals↗
PubMed1987

Further delineation of the McKusick-Kaufman hydrometrocolpos-polydactyly syndrome.

Six cases of the McKusick-Kaufman syndrome (MKS), including two cases that were diagnosed prenatally, were studied. Review of the 54 previously described cases indicates that postaxial polydactyly and hydrometrocolpos in female patients are the hallmark features of this entity. Other manifestations, such as malformations of gastrointestinal, cardiovascular, and ophthalmic structures, occur less consistently. Affected children require careful medical follow-up. Recurrence of hydrometrocolpos following surgical repair may lead to serious sequelae, such as chronic renal failure. We believe that MKS is a distinct panethnic genetic entity, inherited in an autosomal recessive fashion, and that the diagnosis should be made only in female patients with hydrometrocolpos and polydactyly or in male patients with polydactyly who have an affected female relative.

Female↗