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Biomedical subjects

T Yao

Publications and source records attributed to T Yao.

At least 325 records · Page 18Linked to original sources
PubMed1986

Immunological studies on Crohn's disease. VI. Increased chemiluminescent response of peripheral blood monocytes.

Oxidative metabolic activity can be measured by a luminol-dependent chemiluminescence (CL) assay. To investigate the phagocytic activity of blood cells, CL responses were assessed in 26 patients with Crohn's disease (CD) and 26 healthy controls, using heparinized peripheral blood. Significantly (p less than 0.005) increased CL responses of whole blood cells were found in 26 patients with CD. However, CL activity was not directly related to disease activity nor to other clinical parameters. The CL responses did not correlate with the number of white blood cells, neutrophils nor monocytes. In consideration of the increased CL, there is the possibility that functional abnormalities in some components of blood cells leads to elevations in CL responses of whole blood cells. To obtain support for this proposal, blood cells were separated into neutrophils and monocytes, and CL of neutrophils or monocytes were studied, using the same number of each type of cells as that of the controls. The oxidative metabolism of monocytes from CD patients was significantly (p less than 0.005) higher than that of controls, while the phagocytic activity of neutrophils was similar to that in the controls. These data suggest that elevations in CL activity of whole blood cells were not due to alterations of the neutrophils but rather to abnormalities in the monocytes. Further attention directed to the significance of monocyte function in the pathogenesis of CD is warranted.

Crohn Disease↗
PubMed1986

Immunological studies on Crohn's disease. IV. Decreased ADCC activity.

Antibody dependent cell-mediated cytotoxicity (ADCC) activity was studied in 16 Japanese patients with Crohn's disease (CD) and 16 healthy controls. ADCC activity was assessed by measuring 51Cr release from antibody coated human B-cell line. Significantly (p less than 0.002) depressed ADCC activity was found in patients with CD, although ADCC activity was not directly related to the disease activity. To determine causative factors related to reductions in ADCC activity, circulating immune complex (CIC) was also assayed by C1q-binding method. CIC levels in patients with CD were similar to those in the control group, thereby suggesting that this impaired ADCC activity was not due to blocking of the FC-receptor on K cells by CIC. However, serum zinc concentrations did correlate to the ADCC activity. Hence, an assumption can be made that a decreased ADCC activity may be caused by malnutrition, mainly zinc deficiency, a phenomena linked to CD. The significance of serum zinc in considerations of immunological abnormalities was given attention.

Adolescent↗
PubMed1986

[Multiple rectal carcinoids--with special reference to the histogenesis of these lesions].

A 61 year-old man was diagnosed prior to surgery as having multiple carcinoids of the rectum. Postoperative histological examination revealed 52 carcinoids, 1-6 mm in diameter, invading the submucosal layer, and innumerable endocrine cell micronests, less than 0.1 mm in diameter, were present in the rectum. A careful examination revealed several argyrophil cell micronests "budding from" the basis of the glands. Most of the tumor cells showed a positive reaction for Grimelius stain and some immunoreactivities for GLI, PP, PYY, insulin and NSE by the PAP method. Moreover, PYY cell hyperplasia was detected in the rectal mucosa, markedly in the areas surrounding the carcinoids. The authors suggest that (initiative) progenitor cells may develop into these lesions due to unknown factors.

Carcinoid Tumor↗
PubMed1985

Renal and cardiovascular effects of acute and chronic administration of felodipine to SHR.

Renal function and salt and water turnover were studied in SHR during acute and chronic administration of felodipine, which is an efficient antihypertensive vasodilating Ca2+ antagonist. In conscious SHR acute administration of felodipine in hypotensive doses increased renal sympathetic nerve activity but caused renal vasodilation, increases in GFR and a 2-3 fold increase in urinary flow rate and sodium excretion. The fraction of filtered sodium excreted (FENa) was approximately doubled. The diuretic and natriuretic effects of felodipine are therefore suggested to be due to a direct inhibitory action on the renal tubular cells, resulting in reduced sodium reabsorption. Nifedipine also induced diuresis and natriuresis in this system, while minoxidil reduced water and sodium excretion. Throughout 6 months of felodipine treatment, the mean arterial pressure (MAP), remained 25-20 per cent reduced. Felodipine in combination with metoprolol reduced MAP 25-30 per cent and also caused regression of left ventricular hypertrophy, while felodipine alone prevented its further progression. Also during chronic administration, felodipine induced diuresis but had no effect on plasma volume and on sodium or potassium excretion in SHR. It is concluded that in SHR felodipine induces diuresis; on acute treatment this is secondary to reduced tubular sodium reabsorption, although during chronic treatment the sodium loss is compensated for while the diuresis remains. Thus, the cardiovascular and renal effects of Ca2+ antagonists like felodipine differ substantially from those of other potent antihypertensive vasodilators e.g. minoxidil.

Animals↗
PubMed1985

Cimetidine vs a combination of antacid and anticholinergic for hospitalized patients with gastric ulcer.

One hundred and eighty-five inpatients with ulcer in the gastric corpus and angle were treated with either 1 g cimetidine per day or with a combination of antacid and anticholinergic. At 2, 4, 6 and 8 weeks after entry into the study, the ulcer had healed in 3.3, 30.4, 55.4 and 87.0 per cent of patients treated with cimetidine, as compared with 0, 12.9, 51.6 and 73.1 per cent of those treated with a combination of antacid and anticholinergic (NS., p less than 0.01, NS., p less than 0.05), respectively. Factors that had a delaying effect on ulcer healing were seen more frequently in the cimetidine group. Thus, cimetidine proved to be superior to a combination of antacid and anticholinergic, for the treatment of gastric ulcer.

Adult↗
PubMed1985

Immunological studies on Crohn's disease. V. Enumeration of circulating lymphocytes subsets using monoclonal antibodies.

We found normal levels of suppressor cell activity and reduced natural killer (NK) and antibody dependent cell-mediated cytotoxicity (ADCC) activities in patients with Crohn's disease (CD). To further characterize these activities, studies were carried out using monoclonal antibodies. There were no changes in the proportion of OKT4+ (helper/inducer T cells), OKT8+ or Leu 2+ (suppressor/cytotoxic T cells) and Leu 7+ (large granular lymphocytes: LGL, NK + K cells), thereby suggesting that suppressor cell activity in CD is likely to be normal both in function and in number, and that depressed NK and ADCC activities are not due to a reduction in the number of NK or K cells but rather to functional defects. Using a double staining method, we noted a low percentage of both Leu 2 and Leu 7 positive cells in CD.

Antibodies, Monoclonal↗
PubMed1985

Amperometric assays of total and free cholesterols in serum by the combined use of immobilized cholesterol esterase and cholesterol oxidase reactors and peroxidase electrode in a flow injection system.

A flow injection system for assays of total cholesterol and free cholesterol was described. The total cholesterol assay system included an amperometric peroxidase electrode to measure hexacyanoferrate(III) converted from hydrogen peroxide, which was generated by injecting a 2-microliter sample into the packed-bed reactors of immobilized cholesterol esterase and cholesterol oxidase covalently bound to silica. The free cholesterol was assayed with the same system without the cholesterol esterase reactor. The peak current was linearly related to cholesterol in the range 2-160 mg/dl and to total cholesterol in the range 3-300 mg/dl; the assay speed was about 80 samples/h for free cholesterol and 40 samples/h for total cholesterol. Reliable results were obtained in the assays of free cholesterol and total cholesterol in human sera. Both the reactors and the peroxidase electrode retained over 90% of their original activities, even after repetitive use for 4 and 2 months, respectively.

3-Hydroxysteroid Dehydrogenases↗
PubMed1985

Natural history of fundic gland polyposis in patients with familial adenomatosis coli/Gardner's syndrome.

In order to study the natural history of fundic gland polyposis, 23 patients with familial adenomatosis coli/Gardner's syndrome were examined over a follow-up period ranging from 17 mo to 13 yr (average 6 yr). Examinations included gastric radiography and endoscopy with biopsy. Fundic gland polyps were found in 10 individuals. The size and number of polyps varied considerably. During the follow-up period, there was an increase in number or size of polyps, or both, in 5 patients (aged 8-27 yr), a decrease or disappearance in 2 patients (aged 36 and 41 yr), an initial decrease or disappearance followed by a late-occurring increase in 2 patients (aged 28 and 35 yr), In addition, malignant or adenomatous changes of fundic gland polyps were not observed in any patient. Therefore, fundic gland polyposis in patients with familial adenomatosis coli/Gardner's syndrome may appear as early as 8 yr of age. In some patients there is a gradual increase in number and size of polyps, whereas in others, polyp proliferation ceases and polyps may even decrease in number and size. Our findings indicate that the fundic gland polyposis does not require prophylactic surgery and that careful periodic follow-up should suffice.

Adolescent↗
PubMed1985

Immunological studies on Crohn's disease. II. Lack of evidence for humoral and cellular dysfunctions.

In 16 patients with Crohn's disease, we attempted to determine possible alterations in humoral and/or cellular immunologic dysfunctions. We examined the antinuclear, antithyroglobulin and antimicrosomal autoantibodies, circulating immunoglobulin levels and complement components. To clarify the significance of cellular immunity in Crohn's disease, mitogenic lymphocyte transformation and concanavalin A-induced suppressor cell activities were studied. Evidence for humoral and cellular immunological abnormalities was not obtained. The correlation between these immunological parameters and disease activity was also nil. These results suggest that Crohn's disease may not be an immunodysfunctional disorder such as systemic lupus erythematosus, but rather a multifactorial disease. The immunological abnormalities reported in the literature may represent phenomena related to states of malnutrition, since the patients we studied were clinically not in a severe stage of the disease.

Adolescent↗
PubMed1985

Immunological studies on Crohn's disease. III. Defective natural killer activity.

Natural killer (NK) activity was studied in 23 patients with Crohn's disease (CD) and 23 healthy controls, as assessed by lymphocyte cytotoxicity against K562 target cells. Severely impaired NK activity was found in patients with CD (p less than 0.001). The relationship between NK activity and disease activity was also analyzed. NK activity was not directly related to the disease activity, although NK function was lower in the patients with an active form of the disease.

Adult↗