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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 1,135 records · Page 63Linked to original sources
PubMed1989

Association of IgA nephropathy and myasthenia gravis.

Three patients with IgA nephropathy associated with myasthenia gravis are described. In all 3 cases, myasthenia gravis emerged after the discovery of glomerulonephritis. Myasthenic symptoms were improved by thymectomy in 2 cases, but progression of the renal disease was not improved. Some systemic abnormalities, including immunological aberrations, were observed in these two disorders. It is postulated that T cell abnormalities in IgA nephropathy might be independent of the development of myasthenia gravis.

Adult↗
PubMed1989

Application of monoclonal antibody KH2 against lactosyl and neolactotetraosyl ceramide to immunohistochemical study of human cancers.

Monoclonal antibody KH2 (IgM) reactive with lactosyl ceramide and neolactotetraosyl ceramide was applied for the first time to the staining of human cancerous and noncancerous tissues which were fixed with formalin and embedded in paraffin. Digestive-tract cancers originating from stomach, colon, pancreas, gallbladder and bile duct were clearly stained. The staining intensity was especially strong in the apical portion and the intraluminal content of adenocarcinomas. In noncancerous tissues, it was of interest that gastric intestinal metaplasia and certain fetal tissues were stained. A part of the tubules of the kidney, pancreatic ductal cells, lung alveolar epithelial cells and polymorphonuclear leukocytes were stained in normal adult tissues in our study. Enhancement of the intensity of immunostaining by neuraminidase treatment indicated that most of the antigenic determinants should be sialylated and the antigenicity exposed after neuraminidase treatment in several kinds of cancerous and noncancerous tissues. These data suggest that the monoclonal antibody KH2 may be useful in the immunohistologic diagnosis of formalin-fixed human cancerous tissues.

Antibodies, Monoclonal↗
PubMed1989

Pituitary concentration of GH messenger ribonucleic acid in rats with anterolateral hypothalamic deafferentation.

To study neuronal mechanism through which the hypothalamus exerts its influence on growth hormone (GH) synthesis, anterolateral hypothalamic knife cuts (ALHD) were used. After ALHD, GH messenger RNA (mRNA) content in the pituitary was reduced to 47% of the control value. Neither the prolactin mRNA level nor the total DNA content showed any significant change. In such animals, the serum GH level was significantly higher (184%) and pituitary GH content was lower (43%) than the control values. These results suggest that neuronal factor(s) outside the mediobasal hypothalamus plays an important role in the regulation of GH synthesis.

Animals↗
PubMed1989

Role of renin-angiotensin system in the pathogenesis of spontaneous myocardial fibrosis in Sprague-Dawley rats: effect of long-term administration of captopril.

The role of endogenous renin-angiotensin system in the pathogenesis of spontaneous myocardial fibrosis in male and female Sprague-Dawley rats was examined by long-term inhibition of endogenous angiotensin II production. For this purpose captopril, angiotensin I converting enzyme inhibitor (ACEI), was given at 30 or 100 mg/kg/day mixed with commercial powdered standard diet (CE-2, Japan Clea Co., Tokyo) for 52 weeks. Myocardial lesions consisting of focal fibrosis and minute necrotic foci of muscle cells intermingled with monocytic infiltration appeared preferentially in the subendocardial areas of the left ventricle. The incidence of myocardial fibrosis was very low in female rats, but in male rats, the incidence and severity of the lesion was significantly reduced in the captopril-treated groups than in the control group. These findings suggest that endogenous angiotensin II acts as a facilitatory effect on the pathogenesis of spontaneous myocardial lesion which can be effectively reduced by long-term administration of nontoxic dose of ACEI. The authors speculate that ACEI may have a therapeutic use in clinical cases of idiopathic myocarditis.

Animals↗
PubMed1989

Hb Miyano or alpha 41(C6)Thr----Ser: a new high oxygen affinity alpha chain variant found in an erythremic blood donor.

An abnormal hemoglobin found in an erythremic blood donor was separable only by isoelectrofocusing, where it was located at the cathodic edge of Hb A. Cation exchange high performance liquid chromatography of a tryptic digest from the total alpha chain revealed splitting of the alpha T-6 peak, although our routine procedures failed to uncover the abnormality. This enabled the chemical characterization and quantitation of the abnormal hemoglobin as alpha 41(C6)Thr----Ser comprising about 30% of the total hemoglobin. The purified hemoglobin showed increased oxygen affinity, decreased subunit cooperativity and effect of organic phosphates, and normal Bohr effect.

Amino Acid Sequence↗
PubMed1989

Hb Moriguchi or alpha 2 beta 2(97) (FG4)His---Tyr substitution at the alpha 1-beta 2 interface.

An abnormal profile of cation exchange high performance liquid chromatography for the determination of Hb A1c led to the discovery of a new hemoglobin variant with a His----Tyr substitution at position 97(FG4) of the beta chain. The variant comprised about equal proportion to normal Hb A. It showed an increased oxygen affinity, normal n value and slightly reduced alkaline Bohr effect. However, the magnitude of the functional deviation is less than that of other variants with substitutions at the same position, and the heterozygous carrier was not erythremic.

Adult↗
PubMed1989

[Silent myocardial ischemia evaluated by ambulatory left ventricular function monitoring].

To determine whether left ventricular function is less disturbed in asymptomatic ischemia than in symptomatic ischemia, exercise-induced left ventricular function was measured in beat-to-beat using an ambulatory left ventricular function monitoring system. The study subjects were 22 patients with coronary artery disease. Supine and sitting ergometer exercise tests were performed. Of 44 exercise tests, 33 showed significant ST depression on electrocardiograms. Among these 33, 17 were asymptomatic: 16, symptomatic. The left ventricular functions during exercise of these 33 were analyzed and compared with those of five normal controls. The changes in end-diastolic volume were not so significant either in controls or in the asymptomatic and symptomatic groups, but the changes in end-systolic volume were reversed in the diseased groups, particularly in the symptomatic group. The changes in ejection fraction (EF), therefore, were significantly negative in the diseased group, particularly in the symptomatic group. The correlation between exercise-induced left ventricular dysfunction and symptoms was evaluated among the 33 patients. Symptoms were present in 35% (6/17) in less than 10% decrease in EF, 44% (4/9) in 10-15% decrease, and 85% (6/7) in greater than or equal to 15% decrease, respectively. Thus, asymptomatic ischemia represents a lesser degree of myocardial ischemia as indicated by mild left ventricular dysfunction, compared with symptomatic ischemia. However, some cases of severe myocardial ischemia did not develop symptoms. We concluded that silent myocardial ischemia is responsible for a lesser degree of myocardial ischemia and decreased pain perception.

Electrocardiography, Ambulatory↗
PubMed1989

[Malignant lymphoma displaying rearrangements of both immunoglobulin and T-cell receptor genes].

A 65-year-old male was admitted to our hospital due to recurred malignant lymphoma of left tonsil origin. Studies using flow cytometry on mononuclear cells in peripheral blood revealed the appearance of intermediate B cells, and examinations on gastrointestinal tract showed diffuse infiltration of medium-sized lymphoid cells into stomach and colon, that had the same phenotype as tumor cells in peripheral blood. They suggested leukemic change and gastrointestinal tract infiltration of malignant lymphoma. Southern blot analysis revealed T-cell receptor beta-chain gene rearrangement as well as immunoglobulin gene rearrangement. Analysis by histo in situ hybridization on infiltrated gastric mucosa specimen showed diffuse expression of immunoglobulin mRNA in tumor cells, but no message of T-cell receptor beta-chain gene. Northern blot analysis showed the same result. It suggests that in this case, the rearrangement of T-cell receptor beta-chain gene is ineffective rearrangement without transcription to mRNA.

Aged↗
PubMed1989

[Significance of "overshoot" elevation of ejection fraction in early recovery period after exercise in patients with coronary artery disease].

To investigate the relationship between "overshoot" elevation of left ventricular (LV) ejection fraction (EF) in the early recovery period after exercise and myocardial ischemia, LV function was measured in 5 healthy volunteers and 47 pts with coronary artery disease (CAD) using supine ergometer. EF at rest (EFRE), at peak exercise (EFEX), at peak of overshoot (EFOS) and time from cessation of exercise to peak of overshoot (T-OS) were measured using an ambulatory LV function monitor system with a high sensitive CdTe detector. The patients were classified into 3 groups according to EF depression (EFRE-EFEX) by exercise, i.e., D1 (EF decreases less than 5%): 15 pts, D2 (EF decreases 5-10%): 12 pts, D3 (EF decreases greater than or equal to 10%): 20 pts. Degree of overshoot which shows difference in EF between rest and peak of overshoot was 23.8 +/- 2.13% (mean +/- SD) in the normal group, 11.72 +/- 5.12% in D1, 9.56 +/- 6.51 in D2 and 6.12 +/- 4.15% in D3, respectively. T-OS was 1.4 +/- 0.48 in the normal group, 2.8 +/- 0.54 in D1, 4.5 +/- 2.36 in D2 and 5.6 +/- 1.93 min in D3, respectively. We conclude that left ventricular dysfunction was proportionally related to time-lapse from cessation of exercise to peak of overshoot while inversely related to degree of overshoot.

Adult↗
PubMed1989

[CD33-positive acute lymphoblastic leukemia with breast tumor and cavernous sinus tumor].

A 38-year-old woman was diagnosed as acute lymphoblastic leukemia (L2) in Oct. 1985. After VP and AdVEMP therapy, complete remission was obtained. In Oct. 1987, she noticed bilateral breast tumors and leukemic cell infiltrations were shown in a biopsy specimen of the breast tumor. Bone marrow was occupied with 94 percent blasts. The second complete remission was achieved by the AdVP therapy. In Nov. 1988, she developed double vision and photophobia. The examinations of CT and MRI showed cavernous sinus tumor, and 20 percent blasts were recognized in a bone marrow aspirate. The leukemic cells were negative for peroxidase, but were positive for both lymphoid and myeloid cell surface markers (CD2, CD5, CD7, CD33). The two color flowcytometry showed that CD5 and CD33 were simultaneously expressed on the leukemic cells.

Adult↗
PubMed1989

[Clinical application of anti-idiotypic antibody].

The concept of idiotype networks are supposed to play important roles in regulation of the immune response, and anti-idiotypic (anti-Id) antibodies have enabled to analyze the pathogenesis of autoimmune diseases and structural relations of receptors and ligands in clinical fields. We applied anti-idiotypic monoclonal antibodies (MoAb) to tumor immunology to analyze idiotype network system of tumor associated antigen (TAA) and to investigate the fine structure of TAAs and their corresponding antibodies. New assays were established to detect circulating TAAs, anti-TAA antibodies and their immune complex regarding YH 206 antigen and carcinoembryonic antigen (CEA) systems. The measurement of anti-TAA antibodies and immune complex was found to be of value for the cancer diagnosis. The results about immune response with use of anti-Id monoclonal antibodies suggest that some of the anti-Id antibodies might be useful for cancer therapy, since anti-Id antibody could induce anti-anti-Id antibodies reactive with tumor antigen. In this review, the usefulness of anti-Id MoAb to serodiagnosis and immunotherapy for cancer was discussed.

Antibodies, Monoclonal↗
PubMed1989

[A case of testicular infarction in the newborn].

A 6-day-old male was pointed out to have right intrascrotal swelling at birth. Surgical exploration did not reveal torsion of the spermatic cord. The testicle was suspected to have a malignant tumor and then right inguinal orchiectomy was performed. Orchiopexy of the contralateral testicle was not performed due to lack of torsion. Histological examination showed coagulation necrosis of the testicle. Sixty-three cases of testicular infarction in the newborns including our case from Japanese literature were reviewed and discussed.

Humans↗
PubMed1989

[An epidemiological approach to increase mass screening efficiency, by finding high-risk group of esophageal cancer].

An improvement of mass screening efficiency for esophageal cancer was studied by a simple form of questionnaire on the basis of case-control study in Saitama prefecture. This questionnaire consisted of several questions on risk-associating factors and the answers were scored such that the exposure to plural factors was quantified. The high-scored group is then regarded to be at high risk and to be examined for the cancer. The selection of factors for questionnaire was made by estimating the efficiency of screening. The expected detection rates were high with the range from 0.16 to 0.27% for males and 0.04 to 0.09% for females, contrasting to the rates of 0.05 and 0.01% without pre-screening by the questionnaire.

Adult↗
PubMed1989

Structural and functional consequences of amino acid substitutions in hemoglobin as manifested in natural and artificial mutants.

Compiled data for more than 440 natural human hemoglobin mutants with single amino acid substitutions indicate that molecular properties (oxygen binding, structural stability, ease of autooxidization, etc.) of more than half of them are altered in some way and that the mode of alteration is closely related to the region within the hemoglobin molecule in which the substitution takes place. The present study gives a quantitative basis for the correlations. By means of protein engineering, including site-directed mutagenesis, several artificial mutants of human hemoglobin were prepared and their oxygen binding properties were studied to investigate the functional consequences of the amino acid substitutions which have not yet been isolated in natural mutants. These artificial mutants gave straight-forward information regarding the major factors regulating the oxygen affinity of heme and the identification of a Bohr group in the alpha chain. On the other hand the mutants, which were designed to test some hypotheses for the molecular evolution in hemoglobin, did not necessarily give the results predicted from accumulated structure-function data obtained from the study of natural mutants and X-ray crystallographic analyses.

Alligators and Crocodiles↗