Biomedical subjects

S Cho

Publications and source records attributed to S Cho.

At least 181 records · Page 10Linked to original sources

PubMed1994

[Expression of activation antigen, CD69, on human local eosinophils].

The activation antigen, CD69, has been shown to be expressed on activated lymphocytes. CD69 has also been shown to be associated with the signal transduction process. Recently, we demonstrated the expression of CD69 on lung eosinophils obtained from the bronchoalveolar lavage fluid of patients with eosinophilic pneumonia. In this study, we performed flowcytometric analysis of CD69 expression on eosinophils obtained from the bronchoalveolar lavage fluid, pleural effusion or peripheral blood of various patients. Whatever the disease, local eosinophils expressed significant levels of CD69, whereas most peripheral blood eosinophils did not express CD69. These findings suggest that CD69 is a marker for local eosinophils and that local eosinophils may differ functionally from peripheral blood eosinophils.

Adult↗

PubMed1994

Mixed germ cell malignancy of the ovary concurrent with pregnancy.

BACKGROUND: A rare malignant germ cell tumor of the ovary during pregnancy was detected by screening of maternal serum alpha-fetoprotein (MSAFP). Treatment of this uncommon tumor during pregnancy incorporated combination chemotherapy including etoposide. CASE: An 18-year-old primiparous woman undergoing antenatal genetic screening was found to have an extremely elevated MSAFP of 477.8 IU/mL, or 12.46 multiples of the median. Oophorectomy and staging laparotomy at 20.5 weeks' gestation resulted in the diagnosis of mixed germ cell tumor of the ovary, with both endodermal sinus tumor and grade 3 immature teratoma. The patient received three courses of cis-platinum, etoposide, and bleomycin. Maternal serum AFP titers had returned to normal pregnancy levels by the start of the second course. A healthy female infant was delivered at 39 weeks' gestation following induction of labor for pregnancy-induced hypertension. CONCLUSION: Elevated MSAFP levels may be a presenting sign of malignant ovarian germ cell neoplasms. This report describes both surgical and chemotherapeutic treatment of a germ cell malignancy during pregnancy, with delivery at term. To date, major fetal toxicity from chemotherapy has not been identified.

Adolescent↗

PubMed1993

Multiple disorder diagnosis with adaptive competitive neural networks.

Backpropagation neural networks have repeatedly been used for diagnostic problem-solving, but have not been demonstrated to work well when multiple disorders are present. We hypothesized that letting nodes in a backpropagation neural network compete to be part of a diagnostic solution would produce better performance than the use of existing backpropagation methods. To test this hypothesis, we derived an error backpropagation learning rule that can be used with competitive units (competitive backpropagation). Artificial neural networks were then trained using both this new learning rule and standard error backpropagation on a specific medical diagnosis problem: identification of the location of damage in the brain given a set of examination findings. Training samples included solely 'prototypical' cases where a single location of damage is present. The trained networks were then tested with atypical cases where the manifestations of more than one disorder were present or only a single manifestation was present. Networks employing competition among units were found to perform qualitatively better with these multiple-disorder cases than standard networks and also to perform better on single-manifestation cases. The reasons for this are explained. The competitive backpropagation learning rule described here provides a promising new tool for adaptive diagnostic problem-solving.

Diagnosis, Computer-Assisted↗

PubMed1993

Genetic study of hydatidiform moles by restriction fragment length polymorphisms (RFLPs) analysis.

Twenty three hydatidiform moles (HMs) were studied using the techniques of "RFLPs" employing a minisatellite deoxyribonucleic acid probe. Among the 23 HMs, 17 were homozygous types resulting from a duplicated haploid sperm, and two were heterozygous types resulting from fertilization two independent sperms (dispermy). It was revealed that the four histopathologically diagnosed complete HMs (CHMs) were partial HMs (PHMs) with one maternal and 2 paternal chromosome contribution (diandry) or two maternal and 1 paternal alleles (digyny). The locus specific minisatellite probes were useful in classifying CHM into heterozygous and homozygous types as well as in diagnosing PHM. One heterozygous (50%) and 5 homozygous (29.4%) CHMs, and one PHM (25%) progressed to persistent gestational trophoblastic disease (p > 0.5).

Autoradiography↗

PubMed1993

[A case of eosinophilic pneumonia with histologically proven mediastinal lymph node involvement].

Intrathoracic lymphadenopathy in eosinophilic pneumonia is very rare and few cases have been confirmed histologically. This is the first case of eosinophilic pneumonia with mediastinoscopic lymph node biopsy reported in Japan. The case is a 42-year-old man who was admitted to our hospital complaining of cough, general fatigue and dyspnea of one month's duration. Chest X-ray demonstrated bilateral hilar and mediastinal lymph node enlargement with interlobar pleural thickening and infiltrative shadows in right lower lung field. Computed tomography revealed infiltrative shadows at right S4, S5, S8 and S9 and S10 segments and #2, #3, #5, #6 lymph node enlargement. Biopsy of the lymph node via mediastinoscopy demonstrated that the architecture was preserved, sinusoids were filled with histiocytes and eosinophils, and lymphoid follicles were compressed. Immunohistochemical technique using monoclonal antibody EG2 which reacts with the secreted form of Eosinophilic Cationic Protein (ECP), demonstrated that eosinophils infiltrating the mediastinal lymph nodes were activated. The pathogenesis of mediastinal lymphadenopathy in eosinophilic pneumonia remains to be determined, but our case suggests that mediastinal lymph nodes may play a role in eosinophilic pneumonia.

Adult↗

PubMed1992

Switch in glutamate receptor subunit gene expression in CA1 subfield of hippocampus following global ischemia in rats.

Severe, transient global ischemia of the brain induces delayed damage to specific neuronal populations. Sustained Ca2+ influx through glutamate receptor channels is thought to play a critical role in postischemic cell death. Although most kainate-type glutamate receptors are Ca(2+)-impermeable, Ca(2+)-permeable kainate receptors have been reported in specific kinds of neurons and glia. Recombinant receptors assembled from GluR1 and/or GluR3 subunits in exogenous expression systems are permeable to Ca2+; heteromeric channels containing GluR2 subunits are Ca(2+)-impermeable. Thus, altered expression of GluR2 in development or following a neurological insult or injury to the brain can act as a switch to modify Ca2+ permeability. To investigate the molecular mechanism underlying delayed postischemic cell death, GluR1, GluR2, and GluR3 gene expression was examined by in situ hybridization in postischemic rats. Following severe, transient forebrain ischemia GluR2 gene expression was preferentially reduced in CA1 hippocampal neurons at a time point that preceded their degeneration. The switch in expression of kainate/AMPA receptor subunits coincided with the previously reported increase in Ca2+ influx into CA1 cells. Timing of the switch indicates that it may play a causal role in postischemic cell death.

Analysis of Variance↗

PubMed1992

The effects of hyperthermia on the spinal cord.

This study was conducted to obtain information about the critical temperature of the spinal cord in hyperthermia produced by radiofrequency waves applied to the spine. The first component of the spinal cord evoked potential was analyzed as an indicator of spinal cord function. The spinal cords were heated by radiofrequency waves to a maximum of 47 degrees C momentarily or for 30 minutes. The temperatures were measured with a thermosensor in the epidural space. In momentary heating, the reductions in amplitude were almost parallel with the increases in temperature. In maintained heating for 30 minutes, at 44 degrees C and below, the amplitudes decreased by one-quarter to three-quarters of the control value in the first 5 minutes and recovered to over three-quarters of the control value in 30 minutes. The amplitudes returned to almost the control value after restoration of normal spinal cord temperatures. At 45 degrees C and above, however, the amplitudes were prominently reduced or disappeared in the first 5 minutes and remained depressed during the remainder of the heating. On normalizing the temperature, the amplitudes did not return to the control value. These results suggest that 44 degrees C in the epidural space is the highest tolerable temperature for normal spinal cord function.

Animals↗

PubMed1992

Purified human alpha fetoprotein inhibits growth factor-stimulated estradiol production by porcine granulosa cells in monolayer culture.

Purified alpha fetoprotein (AFP) synergizes with transforming growth factor alpha (TGF alpha) and insulin-like growth factor I (IGF-I) to enhance proliferation of porcine granulosa cells (pGC) in primary culture, suggesting a role for AFP in the modulation of growth factor-mediated cell growth. TGF alpha stimulates basal estrogen production by pGC and is in fact more potent than FSH in these cells. In this study, we investigated the effects of AFP on growth factor-stimulated estradiol (E2) production by pGC. Basal production of E2 was not altered by the addition of AFP. AFP dose-dependently inhibited TGF alpha-stimulated E2 production with statistically significant inhibition observed with 2.5 micrograms/ml. We have previously shown that the mitogenic effects of AFP are maximized with TGF alpha+IGF-I. E2 production was even more sensitive to AFP inhibition when the two growth factors were combined. Human serum albumin (HSA; 10 micrograms/ml) was without effect. AFP did not interfere with the E2 RIA, affect the uptake of or display specific in vitro binding of the androgen substrate. Furthermore, human AFP and HSA did not exhibit specific in vitro binding of E2, in contrast to purified rat AFP (positive control). These data indicate that physiological concentrations of purified AFP significantly and dose-dependently inhibit growth factor-stimulated E2 production by pGC in culture. Since AFP is known to increase TGF alpha+IGF-I mediated cell growth, these data suggest that AFP may be inhibiting the differentiated function (steroidogenesis) of pGC while enhancing the proliferation of these cells.

Amniotic Fluid↗

PubMed1992

[Nutritional assessment and the effect of supplementary oral nutrition in patients with pulmonary emphysema].

Nutritional status and its relation to respiratory function and respiratory muscle strength were assessed in patients with pulmonary emphysema. Energy metabolism was also examined in order to elucidate the mechanism of their malnutrition. BCAA/AAA ratio of plasma amino acid was positively correlated with FEV1.0%. Resting energy expenditure (REE) was negatively correlated with FEV1.0%, and REE/REEpred ratio was also negatively correlated with BCAA/AAA and PImax. These findings suggest that increased mechanical work load, associated with airway obstruction and reduced respiratory muscle efficiency, contribute to the increased energy expenditure and amino acid imbalance. Oral nutritional supplementation using BCAA enriched-elemental diet was found to be effective, as assessed by nutritional parameters, PImax, D.O.E., and QOL index, in malnourished emphysema patients.

Aged↗

PubMed1992

[Relation of airway obstruction and respiratory muscle weakness to energy metabolism in pulmonary emphysema].

Resting energy expenditure (REE) was assessed and its relationship to nutritional status, pulmonary function and respiratory muscle function was studied in 25 patients with pulmonary emphysema. The mean value of REE was 1413 +/- 251 Cal and the ratio of REE/REEpred was 1.398 +/- 0.23, suggesting the existence of a hypermetabolic state in these patients. REE/REEpred ratio was inversely correlated with plasma amino acid BCAA/AAA ratio and body muscle mass; and PImax. REE was inversely correlated with FEV1.0%. REE in the patient subgroup with severe hyperinflation (%RV > or = 200) was significantly higher than that in the subgroup with moderate hyperinflation. Malnourished patients showed significantly more severe hyperinflation than well-nourished patients. These findings suggest that augmented REE contributes to malnutrition in patients with emphysema, and that the increase in REE was related to the increase in mechanical work load on the basis of airway obstruction, respiratory muscle weakness and hyperinflation.

Aged↗

PubMed1992

[Supplementary nutrition therapy is effective in patients with chronic obstructive pulmonary disease].

We examined the effects of supplementary nutritional therapy (calorie:REEx1.5) for one year using branched-chain amino acid (BCAA) enriched-elemental diet in addition to usual diet in 12 malnourished patients with COPD. Improvement in nutritional status was assessed by BW, %IBW, %AMC, transferrin, and plasma amino acid BCAA. PImax was significantly increased after 3 months' therapy. Although no significant change was found in pulmonary function and arterial blood gases, subjective symptoms evaluated by D.O.E., oxygen cost score and QOL index were improved. Significant correlations were found between delta BW and delta AMC and delta TSF, delta PImax and delta AMC, delta oxygen cost score and delta PImax, which suggest that improvements in nutritional status contributed to the improvement in respiratory muscle function and subjective symptoms. These findings suggest the effectiveness of supplementary nutritional therapy using BCAA-enriched elemental diet in patients with COPD.

Aged↗

PubMed1992

[Evaluation of tissue eosinophils in eosinophilic pneumonia].

Transbronchial biopsy specimens from ten patients with eosinophilic pneumonia were analysed to see whether the tissue contained activated eosinophils or secreted eosinophil cationic protein. The specimens showed many infiltrated tissue eosinophils in the intraalveolar spaces, and thickened alveolar septae and perivascular areas. Most of these eosinophils stained clearly with degranulation by immunohistochemical studies with monoclonal antibody EG2 (for the secreted form of eosinophil cationic protein), indicating that they were activated eosinophils. On the other hand, although pleural tissue obtained at bullectomy performed after pneumothorax showed eosinophilic infiltration, EG2-positive cells were few. Activated eosinophils may play an important role in the development of pulmonary lesions of eosinophilic pneumonia.

Adolescent↗

PubMed1991

Blockade of the AMPA receptor prevents CA1 hippocampal injury following severe but transient forebrain ischemia in adult rats.

The cytoprotective effect of NBQX, a selective AMPA receptor antagonist, was tested following 10 min of severe forebrain ischemia using the 4-vessel occlusion model. Immediately, and at 15 and 30 min following reperfusion, adult Wistar rats received intraperitoneal injections of either saline (n = 5), 1 mg lithium chloride (n = 17) or 30 mg/kg of the lithium salt of NBQX (n = 18). In saline-treated animals 82 +/- 12% of CA1 hippocampal neurons were lost. Of those treated with lithium 70 +/- 23% were injured, while those given NBQX sustained only 40 +/- 34% CA1 necrosis (P less than 0.01). Twelve of 18 NBQX-treated animals had less than 30% CA1 injury as compared with 1 of 17 lithium-treated animals. The AMPA receptor may play a more important role than the NMDA receptor in selective ischemic necrosis of hippocampal neurons.

Animals↗

PubMed1991

Beneficial effects of diltiazem on the natural history of hypertensive diabetic cardiomyopathy in rats.

Hypertensive diabetic rats develop a cardiomyopathy characterized by systolic and diastolic ventricular dysfunction, myocardial hypertrophy and fibrosis, pulmonary congestion and a very high mortality rate. Alterations in contractile proteins and sarcoplasmic reticular calcium (Ca2+) transport in diabetic myocardium and their partial reversal with verapamil suggest that calcium channel blockade may prevent death from congestive heart failure in hypertensive diabetic rats. A large group of rats with renovascular hypertension and streptozotocin diabetes were divided into four groups: untreated animals (Group 1) and animals treated with 100 (Group 2), 300 (Group 3) or 600 (Group 4) mg/kg per day of sustained release diltiazem mixed in their food. Treatment was begun shortly after the onset of hypertension and diabetes. Mortality rates after 4 months were 59% (19 of 32), 53% (17 of 32), 27% (7 of 26) and 35% (12 of 34) in Groups 1, 2, 3 and 4, respectively; the mortality rate in age-matched control rats was 5% (1 of 19). The reductions in mortality rates in Groups 3 and 4 were statistically significant. Diltiazem did not change systolic blood pressure, serum glucose concentration, heart rate or left ventricular mass. There was a trend to decreased left ventricular interstitial fibrosis and perivascular fibrosis in diltiazem-treated animals. Ventricular collagen concentration was similar in untreated hypertensive diabetic and control rats; levels were higher in hypertensive diabetic rats that died than in those that survived. There was a trend to decreased collagen concentration as diltiazem dose increased. Myosin isoenzyme distribution was not changed in Groups 3 and 4 (in comparison with Group 1). In all hypertensive diabetic groups, rats that died had a higher blood pressure, heart rate, relative left ventricular mass, lung weight and lung water than did survivors. The mortality rate was two to three times higher among rats with an initial blood pressure greater than or equal to 180 mm Hg. The beneficial effects of diltiazem on survival were most significant among rats with severe hypertension.

Animals↗

PubMed1991

A cluster of transcribed sequences between the Pb and Ob genes of the murine major histocompatibility complex.

The region of the murine major histocompatibility complex (MHC) between the Pb (A beta 3) and Ob (A beta 2) genes controls the expression of an intracellular complex named the LMP (low molecular weight polypeptide) complex. DNA probes for at least seven different genes mapping to this region were isolated. These hybridize to a minimum of eight different transcripts ranging from approximately 1.3 to 3.7 kilobases (kb). The deduced amino acid sequences of the corresponding cDNAs indicate that three of these genes are new members of the MHC class II gene family. These genes are transcribed in a tissue-specific pattern similar to that of the traditional class II genes. Two of the remaining four genes, HAM1 and HAM2, are homologous to one another and to a family of eukaryotic and prokaryotic transport proteins and may be involved in antigen processing. The tissue distribution of HAM1 transcripts is consistent with its proposed role in class I-restricted antigen processing, whereas HAM2 transcription appears more restricted and may be involved in antigen processing for class II-restricted T cells. The HAM2 gene may produce two differentially spliced transcripts. The identity of the remaining two genes is not known. Analyses of transcript sizes, tissue distribution, sequence, and genetic mapping data suggest that none of these genes code for LMP antigens.

Animals↗

PubMed1991

Human alpha-fetoprotein purified from amniotic fluid enhances growth factor-mediated cell proliferation in vitro.

Using a primary monolayer culture of porcine granulosa cells (pGC) as an in vitro cell proliferation assay, we have examined the growth-promoting activity of alpha-fetoprotein (AFP) purified from term cord blood and midtrimester amniotic fluid. Increasing concentrations (2.5-20%) of crude human cord blood (CB) increased pGC proliferation, while identical concentrations of crude amniotic fluid (AF) were ineffective. When the cell system was maximally stimulated, AF dose dependently decreased cell proliferation. AFP purified from AF and CB (1.25-5.0 micrograms/ml) was not mitogenic alone, but, in the presence of epidermal growth factor (EGF) + insulin-like growth factor (IGF-I) (10 ng/ml each), AFP dose dependently increased cell proliferation to nearly double that of EGF + IGF-I alone. The response of pGC to the proliferative effects of AF-AFP and CB-AFP were identical at each dose of AFP tested. These results indicate that although crude, pooled midtrimester AF does not display the mitogenic activity seen in cord blood, AFP purified from pooled AF significantly synergizes with growth factors to increase cell proliferation markedly.

Amniotic Fluid↗

PubMed1991

Neurological disease in xeroderma pigmentosum. Documentation of a late onset type of the juvenile onset form.

Xeroderma pigmentosum (XP) is an autosomal recessive, neurocutaneous disorder characterized by sunlight-induced skin cancers and defective DNA repair. Many XP children develop a primary neuronal degeneration. We describe 2 unusual XP patients who had a delayed onset of XP neurological disease. Somatic cell genetic studies indicated that they have the same defective DNA repair gene and are both in XP complementation group A. These 2 patients, together with a group A patient previously reported from London, establish as a distinct clinical entity the late onset type of the juvenile onset form of XP neurological disease. The functional capacity of these patients' cultured fibroblast strains to survive after treatment with ultraviolet radiation indicates that their DNA repair defect is less severe than that of typical group A patients who have a more severe neurodegeneration with an earlier symptomatic onset. The premature death of nerve cells in XP patients (which is presumably due to their inherited defects in DNA repair mechanisms) suggests that normal repair of damaged DNA in neurons is required to maintain integrity of the human nervous system.

Adolescent↗

PubMed1991

A study of adult T-cell leukemia virus (ATLV) infection in the field of obstetrics: its epidemiology, vertical transmission and familial clustering.

Nine hundred and seventy-one healthy individuals in Iwate Prefecture, 659 pregnant women in Ishigaki Island, 487 pregnant women in Chiba Prefecture and 108 familial members of the ATLA-Ab-positive pregnant women (pregnant carrier women) were tested for ATLA-Ab by the PA, EIA and WB tests. 1) The rate of agreement of EIA with the PA test was 88.4% and there were no false negative sera by both examinations. These results indicate the both tests are available for mass screening. 2) In Iwate and Chiba Prefectures, the ATLA-Ab-positive rates of pregnant women were 5.3 and 0.6%, respectively. In addition, the incidences for healthy individuals ranged from 5.3 to 21.1% by age in Iwate Prefecture. Thus, Iwate Prefecture was found to equal Ishigaki Island (7.1%) in ATLA-Ab detection rates. 3) Forty-five (41.7%) out of 108 familial members of 15 pregnant carrier women were found to be seropositive for ATLA-Ab, which confirms a certain familial clustering of ATLV.

Adolescent↗