Biomedical subjects

H Tsuda

Publications and source records attributed to H Tsuda.

At least 361 records · Page 20Linked to original sources

PubMed1993

Overexpression of c-erbB-2 protein in gastric cancer. Its correlation with long-term survival of patients.

BACKGROUND: Overexpression of c-erbB-2 protein in breast cancer has been reported to be associated with poor prognosis. However, clinical significance of c-erbB-2 protein overexpression has not been demonstrated clearly in gastric cancer. METHODS: Immunohistochemical reactivity to c-erbB-2 protein was examined in formalin-fixed, paraffin-embedded tissue sections from patients with gastric cancer. RESULTS: First, primary stomach cancers in 106 patients were examined. Among 58 cases of papillary or well- to moderately differentiated tubular adenocarcinoma, staining of c-erbB-2 protein was positive on the plasma membrane of cancer cells in 8 cases (14%). Conversely, among 47 cases of poorly differentiated adenocarcinoma or signet ring cell carcinoma, positive staining of c-erbB-2 protein was detected in one case only (2%), where the histopathologic type was poorly differentiated adenocarcinoma with a cohesive structure. Among tubular adenocarcinomas, no significant association was shown between overexpression of c-erbB-2 protein and the depth of tumor invasion, extent of lymph node metastasis, or tumor location. To investigate the correlation between the staining of c-erbB-2 protein and prognosis in gastric cancer, an additional 108 cases of papillary or well- to moderately differentiated tubular adenocarcinoma invasive as far as the muscularis propria were examined immunohistochemically for expression of c-erbB-2 protein. Twelve cases (11%) showed positive staining on the plasma membrane, and their survival curve showed a significantly poorer prognosis (P < 0.01). CONCLUSIONS: These results suggest that overexpression of c-erbB-2 protein occurs selectively in cohesive gastric cancer, and it can be considered an important prognostic indicator.

Adenocarcinoma↗

PubMed1993

Development of antitissue factor antibodies in patients after liver surgery.

After liver surgery, two patients developed unexplainable prolonged prothrombin times (PT) that were not associated with bleeding tendency. The substitution of rabbit thromboplastin for either human or monkey thromboplastin in performing PT tests resulted in a normal clotting time. Tissue factor (TF) procoagulant activity assays and an immunoblotting analysis showed that these patients had developed IgG lambda-type immediate anticoagulants directed against both rabbit and bovine TF that did not crossreact with human or monkey TF. In a chromogenic assay, the patient IgG caused a decrease in both the Km and the Vmax of the factor X activation by rabbit TF-factor VIIa complex. The lack of reactivity of the patient IgG with human TF presumably explained why there was no clinical bleeding. Both patients had been treated earlier with a topical hemostatic agent prepared from bovine corium, microfibrillar collagen hemostat, while undergoing previous surgery. In an immunoblotting analysis, the patient IgG stained a 42-Kd band in the Triton extract of the collagen preparation under either reducing or nonreducing conditions. The Triton extract of the collagen preparation blocked the binding of the patient IgG to bovine TF. Thus, it is suggested that the iatrogenic immunization by intraoperative exposure of bovine TF retained in the collagen preparation may be responsible for the development of anti-TF antibodies in these patients. The anti-TF antibodies resulted in a clinical error in the evaluation of coagulation status after the use of rabbit thromboplastin.

Animals↗

PubMed1993

Allelic loss at chromosome band 8p21.3-p22 is associated with progression of hepatocellular carcinoma.

Human hepatocellular carcinomas (HCC) frequently show loss of heterozygosity at loci on the short arm of chromosome 8. To define a region on 8p commonly deleted in HCC, we used 20 restriction fragment length polymorphism markers to carry out detailed deletion mapping in 142 HCC. Of the 124 informative cases, 56 (45%) showed allelic losses in tumors. While more than half of them had lost alleles at every locus on the short arm, others lost them partially or interstitially. Common deletion of an 8-cM region flanked by cMSR-32 and cC18-245, at 8p21.3-p22, suggested the presence of a tumor suppressor gene(s) in this interval. Correlation between allelic losses on 8p and clinicopathological parameters were examined in the 51 cases for which detailed clinical data were available; allelic losses on 8p were observed in none of five tumors at stage T1 (0%), nine of 20 tumors at stage T2 (45%), and 17 of 26 tumors at stage T3/T4 (65%). A higher frequency of allelic losses on 8p was observed in poorly differentiated tumors (10/14, 71%) than in well differentiated tumors (3/13, 23%). The association of allelic losses on 8p with advanced clinical stage and poor differentiation implies that loss or inactivation of a tumor suppressor gene(s) on 8p may play a role in the progression of HCC.

Carcinoma, Hepatocellular↗

PubMed1993

Mutations of the p53 tumor suppressor gene and the ras gene family in intrahepatic cholangiocellular carcinomas in Japan and Thailand.

The incidence and pattern of mutations of the ras oncogenes and the p53 tumor suppressor gene have been shown to differ among different cancer types and even among the same cancer types with different etiological backgrounds. For example, in a previous study we showed that not only the etiology but also the incidence of point mutation of the c-Ki-ras oncogene in cholangiocellular carcinomas (CCCs) differ between Japanese and Thai patients. In the study presented here, we examined the incidence of mutations in the ras gene family and the p53 gene in CCCs of both Japanese and Thai patients by single-strand conformation polymorphism and direct sequencing analyses and compared the pattern of p53 mutation between these two CCC groups. Although the incidence of ras mutation differed markedly between Japanese (seven of 12, 58%) and Thai (two of 26, 8%) cases, the incidence of p53 mutation was similar: four of 12 (33%) and nine of 26 (35%), respectively. Except for one case in which deletion-insertion was detected in the second exon of the N-ras gene, all ras mutations occurred at codon 12 or 13 of the c-Ki-ras gene. All p53 mutations but one were detected in a highly conserved region, and the predominant form of the mutations was G:C-->A:T transition at CpG sites in both Japanese and Thai cases, similar to that reported for colorectal cancers. Therefore, in contrast to the ras oncogenes, mutation of the p53 gene was frequently involved in the development of CCCs in both Japanese and Thai patients, irrespective of any difference in etiology.

Adult↗

PubMed1993

A clinicopathological analysis of breast cancer in patients with a family history.

A study was conducted to investigate the clinical and pathological characteristics of breast cancer in patients with a family history (FH). Among 4,481 primary breast cancer patients, 394 (8.8%) had families which included two or more breast cancer patients within three generations (FH(+)group). This group was compared with the remaining 3,969 patients (FH(-) group) with the following results: (1) The tumor diameter in the FH(+) group was slightly less than that in the FH(-) group [not significant (NS)], with fewer lymph node metastases (P < 0.05); (2) the positive rates for the estrogen receptor were 52% (138/266) and 49% (1,216/2,481), respectively (NS); (3) expression of the c-erbB-2 protein was observed in 14 out of 40 (35%) and 32 out of 100 cases (32%), respectively (NS); (4) the relative risk of bilateral occurrence in the FH(+) group was 1.4, with a 95% confidence interval of 0.9-2.4; (5) the 15-year survival rate was 72% and 60%, respectively, suggesting a better prognosis for the FH(+) group (P < 0.01); and (6) multivariate analysis showed that the contribution of FH to postoperative survival was marginal (P = 0.07). Factors related to the hormonal environment such as age at menarche (P = 0.08) and age at menopause (P = 0.08) made a greater but non-significant contribution to the prognosis of the FH(+) group than to that of the FH(-) group. However, further genetic and molecular biological analyses of familial breast cancer are needed in order to clarify the mechanisms of cancer accumulation within families.

Adult↗

PubMed1993

GABA-gated chloride ion influx in brains of tremor rats.

We measured the GABA-gated chloride ion influx and GABA concentrations in the cerebral cortex and the hippocampus of young (5 weeks old) and older (15 weeks old) tremor rats. GABA-gated chloride ion influx in these tremor rats was significantly greater than in the controls of both the 5 week- and 15 week-old groups. GABA concentrations in the cerebral cortex and hippocampus of the tremor rats increased compared with controls of 5 weeks and decreased compared with controls of 15 weeks. These findings suggest that the GABAergic presynaptic neurons in the cortex and hippocampus of the tremor rat are disturbed with aging. This change may be related to the appearance of absence-like seizures in the rats. The increased GABA-gated chloride ion influx in tremor rats may be a compensatory mechanism against the genetically-determined seizure susceptibility of these rats. Furthermore, the increased GABA levels and GABA-gated chloride ion influx found in 5 week-old tremor rats may be related to the tremor movements.

Animals↗

PubMed1993

Age- and seizure-related changes in noradrenaline and dopamine in several brain regions of epileptic El mice.

Noradrenaline (NA) and dopamine (DA) levels in six brain regions of stimulated and nonstimulated El (El[s] and El[ns]) mice and their maternal ddY mice were determined at various ages and various times after a convulsion. The NA levels in the striatum and hippocampus of 12-week-old El[s] and El[ns] mice were lower than in ddY mice, and remained lower in 23-week-old El[s] mice, but not in El[ns] mice. DA levels were lower in the striatum of El[s] mice than in El[ns] and ddY mice at 16 and 23 weeks of age. NA levels decreased during seizure in the striatum and hippocampus of El[s] mice, and returned to preconvulsive levels 1 hr after convulsion in the striatum and 30 min in the hippocampus. DA levels in the striatum of El[s] mice decreased during convulsion and increased from 1 to 10 min after convulsion. These changes suggest that the NAergic systems in the striatum and hippocampus and the DAergic system in the striatum have important roles in relation to seizure susceptibility in El mice.

Aging↗

PubMed1993

A mucous histochemical and immunohistochemical study of precancerous and neoplastic lesions in the human pancreas.

A total of 44 cases of pancreatic lesions, including hyperplasia (six) cases, adenoma (mucinous cystadenomas [eight] and intraductal papillary adenoma [eight]), noninvasive intraductal papillary tumors (five), and invasive ductal carcinomas (17) were investigated possibly to establish a diagnostic marker. We examined the type of mucin secreted and immunoreactivities of antibodies to ras-p21 and c-erB-2 oncogene products. A significant decrease in the amount of mucin was found in invasive lesions, and this was associated with a shift toward production of neutral mucins and especially sialomucins. Hyperplasia and adenoma, in contrast, demonstrated a predominance of neutral mucin. The sulfated mucins found in normal epithelium were only very weakly stained in any of the tumor types. Thirty-three percent of non-invasive intraductal papillary tumors and 88% of invasive ductal adenocarcinomas demonstrated strong binding of the ras-p21 antibody. In contrast no obvious differences in expression of c-erbB-2 were evident between the groups. In conclusion, a combined mucin histochemical/immunohistochemical approach may facilitate accurate diagnosis.

Biomarkers, Tumor↗

PubMed1993

Depth EEG in mutant epileptic E1 mice: demonstration of secondary generalization of the seizure from the hippocampus.

Mutant epileptic E1 mice are thought to have focal epilepsy of hippocampal origin because glucose utilization is increased in the hippocampus (HPC) during seizures in these mice. However, direct electrographic evidence is still lacking for the notion. We recorded electroencephalograms (EEGs) using depth electrodes in E1 and non-epileptic ddY mice. All the mice were subjected to a conventional seizure-provoking maneuver during EEG recording; each mouse was placed on a mesh floor and observed for 3 min, and then tossed up in the air. When the E1 mice showed signs of abortive seizures or prodromal symptoms including squeaking, running and myoclonus, sporadic spikes or sharp waves were generated exclusively in the HPC. When generalized convulsions followed these prodromes, the sporadic discharges evolved into a burst of generalized spikes which again predominated in the HPC. We also observed the cerebral cortex, amygdaloid, caudate, centro-median thalamic and ventral postero-lateral thalamic nuclei, all of which were found to be only secondarily involved. These findings provide the first electrical evidence that E1 mice have a secondarily generalized seizure that has its initiating focus in the HPC.

Animals↗

PubMed1993

Acrylamide; induction of DNA damage, chromosomal aberrations and cell transformation without gene mutations.

The genotoxic potential of acrylamide monomer (AA), a compound familiar as a raw material of polyacrylamide electrophoresis gel, was extensively investigated in vitro. The results were clear cut: AA did not induce any gene mutations in Salmonella/microsome test systems (TA98, TA100, TA1535, TA1537), Escherichia coli/microsome assay (WP2 uvrA-) up to a dose of 50 mg AA/plate, or in HPRT-locus in Chinese hamster V79H3 cells (AA, 1-7 mM, 24 h treatment). On the other hand, AA showed a strong positive response: (a) in a Bacillus subtilis spore-rec assay (DNA damage) at 10-50 mg/disc, (b) to a chromosomal structural change test (AA, 2-5 mM, 24 h treatment), (c) to a polyploidy test (AA, 1-5 mM, 24 h treatment) in Chinese hamster V79H3 cells, (d) to a cell transformation assay in mouse BALB/c3T3 cells (AA, 1-2 mM, 72 h treatment). Sister chromatid exchange was also weakly but significantly induced by AA (AA, 1-2.5 mM, 24 h treatment) in Chinese hamster V79H3 cells. Carcinogenic potential of AA was reported in mice and rats several years ago. AA thus seems to be a typical clastogenic rodent carcinogen without any gene mutation potential. Furthermore, this experiment showed for the first time positive response of AA to a microbial test system (B. subtilis spore-rec assay).

Acrylamide↗

PubMed1993

p53 mutations and c-erbB-2 amplification in intraductal and invasive breast carcinomas of high histologic grade.

In order to clarify the clinical significance of mutations of the p53 gene and amplification of the c-erbB-2 gene in breast carcinoma, these gene alterations were examined in 101 invasive, seven predominantly intraductal and 10 intraductal breast carcinomas by single-strand conformation polymorphism-direct sequencing or Southern blot-hybridization analysis. p53 mutations were detected in 32 (32%) of the invasive cases and two (12%) of the 17 intraductal/predominantly intraductal cases, whereas c-erbB-2 amplification was detected in 14 (14%) of the invasive and six (35%) of the intraductal/predominantly intraductal cases. Irrespective of differences in the positions and types of the mutations, cases carrying p53 mutations were almost always Grade 3 histologically and with a low hormone-receptor value. Since p53 mutations as well as c-erbB-2 amplification were detected almost selectively in Grade 3 cases but were not associated with lymph nodal status in invasive breast cancer, these two gene alterations could be indicators of prognosis of disease independent of lymph nodal status. Even in intraductal/predominantly intraductal carcinoma, these gene alterations were almost always detected in tumors of higher histologic grade. Thus, it is suggested that these gene alterations occur in breast cancers showing a high proliferation rate irrespective of the presence of invasion, and that other molecular alterations are involved in the process of breast cancer invasion.

Adult↗

PubMed1993

Interleukin-2 prevents programmed cell death in adult T-cell leukemia cells.

Adult T-cell leukemia (ATL) is a prototype of the lymphoma/leukemia syndromes involving immunologically mature T-lymphocytes. The first retrovirus described in humans, HTLV-1, is causally related to the disease. In this study, we examined whether ATL cells die in vitro through programmed cell death (PCD), which has been shown to occur in cells affected by several other acute and chronic leukemias. When ATL cells from peripheral blood were cultured in serum-free complete medium, a substantial proportion of them spontaneously died by PCD. After 48 h of culture, approximately 30% of the total DNA was fragmented. Electrophoresis indicated that the DNA of the ATL cells had been cleaved into regular oligonucleosome fragments each comprising approximately 180-200 base pairs. This process was significantly promoted by methylprednisolone and the protein kinase A (PKA) activator Sp-cAMPS in at least some cases. Since all ATL cells possess interleukin-2 receptors on the cell membrane, the effect of IL-2 on spontaneous PCD was assessed. PCD after 48 h of culture was inhibited by 30-50% by 100 U/ml interleukin-2 (IL-2). This effect of IL-2 to prevent spontaneous PCD was dose- and time-dependent. These findings suggest that the viability of ATL cells in vivo is regulated positively and negatively by intrinsic IL-2, glucocorticoid and regulators of PKA activity. Furthermore, the process of cell death may be involved in the development of the disease.

Apoptosis↗

PubMed1993

Number of simultaneously expressed enzyme alterations correlates with progression of N-ethyl-N-hydroxyethylnitrosamine-induced hepatocarcinogenesis in rats.

Preneoplastic and neoplastic liver cell lesions, induced by EHEN (N-ethyl-N-hydroxyethylnitrosamine) in rats, were investigated to establish the numbers of simultaneously expressed altered enzyme phenotypes within the lesion cells. The lesions were divided into 5 classes on the basis of altered expression in one or more of the following 5 enzymes: glutathione S-transferase placental form, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, adenosine triphosphatase, and gamma-glutamyl transpeptidase. Class 1 lesions contained cells expressing one altered enzyme. Similarly, class 2, 3, 4 and 5 lesions had cells simultaneously expressing 2, 3, 4, and 5 enzyme alterations, respectively. Four histopathological categories of lesions, ACF (altered cell foci) (274 lesions), HN (hyperplastic nodules) (47 lesions), HCC (hepatocellular carcinomas) (99 lesions) and THC (transplanted hepatocellular carcinomas) (5 lesions) were studied. Proliferation potential was assessed in terms of 5-bromo-2'-deoxyuridine (BrdU) incorporation. The distribution profiles of classes 1 to 5 showed a clear reciprocal change from low class (1 to 2 enzymes) predominance in ACF to high class (4 to 5 enzymes) predominance in HN. Increase of BrdU labeling indices was clearly correlated with progression from HN to HCC. Only a small population of class 5 ACF showed a high BrdU labeling index, indicating particular potential for further development. Thus, the stages of EHEN-induced neoplasia were found to be characterized by gradual increase in the number of altered enzyme phenotypes, with acquisition of proliferative potential being associated with further progression towards malignant conversion.

Adenosine Triphosphatases↗

PubMed1993

Decreased dimethylnitrosamine-induced O6- and N7-methyldeoxyguanosine levels correlate with development and progression of lesions in rat hepatocarcinogenesis.

Formation and repair of O6-medG and N7-medG (O6- and N7-methyldeoxyguanosine) in glutathione S-transferase-P form (GST-P)-positive liver cell foci, nodules, primary hepatocellular carcinoma (HCC) and transplanted hepatocellular carcinoma (TRP) induced by N-ethyl-N-hydroxyethylnitrosamine (EHEN) were immunohistochemically assessed following a single exposure to dimethylnitrosamine (DMN). Male Fischer 344 rats received a 0.1% solution of EHEN as their drinking water for 4 weeks and were maintained on basal diet until week 40, when a single 50 mg/kg body weight dose of DMN was administered intraperitoneally. Nude rats (NIH rnu/rnu) bearing TRP were similarly treated. Sequential killing 6, 12, 24, 48 and 72 h thereafter revealed significantly decreased indices of cells binding antibodies to O6-medG and N7-medG adducts in GST-P-positive foci and nodules, and particularly HCC and TRP, as compared to background parenchyma values. Similarly, differences between foci/nodules and HCC/TRP were also significant, indicating that decrease in adduct formation is associated with further malignant conversion. The rate of DNA adduct repair in foci and nodules subsequent to the peak found at the 12 h time-point did not appear to be significantly different from that in the surrounding tissue at the dose of DMN studied. The results indicate decreased formation of DMN-associated DNA damage, in line with the known metabolic profile of carcinogen-induced focal liver lesions.

Animals↗

PubMed1993

Determination of c-erbB-2 protein in primary breast cancer tissue extract using an enzyme immunoassay.

The c-erbB-2 protein in breast cancer tissue extract was determined by using an enzyme-immunoassay (EIA) to see whether the quantitative determination of the oncoprotein correlates with the results of immunohistochemistry and other prognostic factors. Primary breast cancer from 104 patients was assayed for c-erbB-2 protein with an EIA that used two monoclonal antibodies directed against the extracellular domain of the protein. Pelleted tissue homogenate prepared routinely for hormone receptor assay was used as the starting material. The mean quantity of c-erbB-2 protein was 695 unit/mg protein (range 23 to 5939), and this correlated well with the results of immunohistochemical staining (P < 0.00001). It was found that 17.3% (18/104) of all tumors contained amounts of c-erbB-2 protein exceeding 1000 units/mg protein. All tumors with negative or weakly positive staining contained the oncoprotein as less than 1000 units/mg protein. The content of c-erbB-2 protein was correlated with the histologic grade (P = 0.0022), mitotic index (P = 0.0002) and degree of nuclear atypia (P = 0.013). It was inversely correlated with progesterone receptor (P = 0.006) and less strongly with estrogen receptor status (P = 0.016). Values of hormone receptor concentration and c-erbB-2 protein content showed a hyperbolic relationship that suggested biological interactions between c-erbB-2 protein and steroid hormone receptors. We conclude that c-erbB-2 protein in tissue extracts of primary breast cancer can be determined reliably by EIA, and it seems feasible to explore further the advantages of introducing EIA as a routine laboratory examination for providing additional information about the biological aspects of breast cancer.

Adult↗

PubMed1993

Influence of aging on multi-organ carcinogenesis in rats induced by N-methyl-N-nitrosourea.

The effects of aging on the multi-organ carcinogenesis induced in rats by N-methyl-N-nitrosourea (MNU), a direct carcinogen which does not need metabolic activation to exert carcinogenicity, were examined in male F344 rats. In the first experiment, rats at 6, 52, and 98 weeks of age were treated with MNU (20 mg/kg body weight, i.p.) twice weekly for 6 weeks and then maintained without any further treatment for 24 weeks in the case of young and middle-aged rats and for 18 weeks in the case of the old rats. In young rats, malignant lymphomas, particularly thymic types, were observed at significantly high incidence. A striking result in the middle-aged rats was the significantly higher incidence of adenocarcinomas in the small intestine than in young or old animals. The induction of proliferative and neoplastic lesions of the large intestine also tended to be increased in middle-aged rats. In addition, epithelial hyperplasia of the tongue, but not the forestomach, occurred at the highest incidence in the middle-aged group. There were no differences in the induction of epithelial lesions in the urinary bladder among the groups. In a second experiment, investigation of DNA synthesis in the tongue, small and large intestines, urinary bladder and lymph nodes did reveal significant increases or tendency for increase in the MNU-treated groups, but without differences with age. In contrast, the thymus of young rats showed significantly increased incorporation of BrdU label after administration of MNU, whereas it was markedly reduced in middle-aged rats. In a third experiment, O6-methyldeoxyguanine (O6-medG) DNA adduct formation was immunohistochemically detected in various organs including the thymus, forestomach, and small intestine without any differences with age. Thus, the results demonstrated that while the target organs of MNU are modified by the age of the animals, levels of DNA synthesis and O6-medG DNA adduct formation in most cases can not explain the observed differences in carcinogenic susceptibility.

Adenocarcinoma↗

PubMed1993

Demonstration of initiation potential of carcinogens by induction of preneoplastic glutathione S-transferase P-form-positive liver cell foci: possible in vivo assay system for environmental carcinogens.

In a development trial for an initiation bioassay system, 7 known carcinogens and 1 suspected carcinogen were examined. In experiment 1, group 1 animals were initially subjected to partial hepatectomy (PH) 12 h before administration of diethylnitrosamine, 2-amino-3-methylimidazo[4,5-f]-quinoline (IQ), captafol, alpha-hexachlorocyclohexane or diethylstilbestrol (DES), then 2 weeks later underwent a promotion procedure comprising administration of phenobarbital (0.05% in diet) for 8 weeks and D-galactosamine (300 mg/kg, i.g.) at week 3. Group 2 received the promotion protocol alone as in group 1. Initiating potential was assayed on the basis of significant increase in values of preneoplastic placental form glutathione S-transferase-positive (GST-P+) foci of more than 3 cells in cross section at week 10. Numbers and areas of GST-P+ foci in group 1 given IQ, captafol and DES were significantly increased as compared to group 2, confirming the validity of the protocol as an initiation assay. In Experiment 2, group 1 rats were subjected to PH and 12 h later received a suspected carcinogenic mixture of opium pyrolysate (OP) or carcinogenic pesticide p,p'-dichloro-diphenyltrichloroethane or hexachlorobenzene. Application of a modified promotion procedure comprising cholic acid (0.15%) and carbon tetrachloride (1 ml/kg, i.g.) revealed significant initiation potential for OP. Overall the results indicate that the current protocols may be useful for detection of the initiation potential of carcinogens irrespective of their mutagenicity.

Animals↗

PubMed1993

Roles of eosinophils and catecholamines in pathophysiology of exercise-induced asthma.

To study the roles of eosinophils and catecholamines in the pathophysiology of exercise-induced asthma (EIA), an exercise challenge test was performed in 22 asthmatic children, using a bicycle ergometer, and the changes in lung function, plasma norepinephrine (NE), epinephrine (E) and eosinophil cationic protein (ECP) levels with exercise were evaluated. Subjects were classified into three groups from the results of lung function test, respectively: EIA-negative group. EIA-positive groups with good recovery and poor recovery. Eosinophil counts before exercise in the EIA-positive groups were significantly higher than those in the EIA-negative group. The ECP levels rose with exercise in all groups. Five minutes after exercise, ECP values fell to the pre-exercise level in the EIA-negative group, but rose to higher levels in EIA-positive groups. Plasma E levels rose with exercise and showed 4-fold increase in the EIA-negative group, whereas only 1.5-fold increase of plasma E levels was observed in the EIA-positive group with poor recovery. From these findings, a possible contribution of sympathoadrenal hypofunction and a probable involvement of eosinophils in the pathophysiology of EIA have been suggested.

Adolescent↗