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Biomedical subjects

A Aoki

Publications and source records attributed to A Aoki.

At least 91 records · Page 5Linked to original sources
PubMed1996

beta 2-Glycoprotein I-dependent anticardiolipin antibodies as a predictor of adverse pregnancy outcomes in healthy pregnant women.

Our aim was to elucidate prospectively whether beta 2-glycoprotein I-dependent anticardiolipin antibodies (beta 2GPI-dependent aCL; autoimmune type) can predict an adverse pregnancy outcome in healthy pregnant women and whether beta 2GPI-dependent aCL should be applied for routine screening of the pregnant population. A prospective cohort study was performed on 1600 healthy pregnant women from whom blood samples were obtained at about week 10 of gestation. We used a modified enzyme-linked immunosorbent assay with which to divide the subjects into three study groups: beta 2GPI-independent aCL positive, beta 2GPI-dependent aCL positive and aCL negative. Their subsequent pregnancy outcomes were ascertained and the three study groups were compared statistically for the following poor pregnancy outcomes: intrauterine fetal death (IUFD) after 12 gestational weeks, intrauterine growth retardation (IUGR) and pre-eclampsia. The total number of patients eligible for this study was 1125. The prevalence of beta 2GPI-dependent aCL positive was eight (0.7%), beta 2GPI-independent aCL positive was 17 (1.5%) and aCL negative was 1100 (97.8%). Beta 2-GPI-dependent aCL positivity was significantly associated with poor pregnancy outcome: 25.0% of beta 2GPI-dependent aCL-positive and 0.5% of aCL-negative patients experienced IUFD [relative risk 52.4; 95% confidence interval (CI), 12.7-216.3; P = 0.0009]; 37.5% of beta 2GPI-dependent aCL-positive and 2.9% of aCL-negative patients experienced IUGR (relative risk 18.4; 95% CI, 4.6-74.0; P = 0.001); and 50.0% of beta 2GPI-dependent aCL-positive and 4.0% aCL-negative patients experienced pre-eclampsia (relative risk 22.1; 95% CI, 5.7-85.7; P = 0.0002). In contrast, beta 2GPI-independent aCL did not show any significant association with such adverse pregnancy outcomes. beta 2GPI-dependent aCL are significantly highly associated with adverse pregnancy outcomes in healthy pregnant women and can be used for prediction purposes, whereas beta 2GPI-independent aCL cannot. Our results suggest that routine screening for beta 2GPI-dependent aCL should be introduced for the general pregnant population.

Adult↗
PubMed1996

Isolation of human uteroglobin from blood filtrate.

The purpose of this study was to assess the possibility of isolating biologically active peptides from human blood using large volumes of blood filtrate, which are available from patients undergoing extracorporeal ultrafiltration because of renal insufficiency. This filtrate was submitted to six chromatographic separation steps, yielding one purified peptide which was completely analysed in its primary structure. It was found to be strikingly similar to proteins, described initially as rabbit uteroglobin (or blastokinin) and, more recently, from human bronchial lavage as the '10 kDa Clare cell protein', as well as from human urine as 'protein-1'. The natural molecule contains two chains of identical amino acid sequences of 70 residues which are arranged as an antiparallel dimer due to the disulphide bonds between two cysteines at positions 3 and 69. Mass analysis of the molecular forms yielded molecular weights from 15827 Da (non-oxidized form) to 15859 Da (bi-oxidized form). We conclude that this peptide isolated from the filtrate represents the human uteroglobin, and we demonstrate for the first time that this peptide may be involved as a humoral factor in reproductive or other physiological functions.

Amino Acid Sequence↗
PubMed1996

Prurigo pigmentosa, ketonemia and diabetes mellitus.

The etiology of prurigo pigmentosa still remains unknown. We present a 16-year-old female patient with ketonemia caused by diabetes mellitus. The eruption subsided when blood glucose and total ketone levels were controlled by subcutaneous insulin injection. We propose that ketonemia caused by diabetes mellitus may play a role in the pathogenesis of prurigo pigmentosa.

Adolescent↗
PubMed1996

Influence of L-triiodothyronine on rat somatotroph cells.

The L-Triiodothyronine (L-T3) has a direct influence on the population of somatotrophs in rat pituitary gland. This effect is dose-dependent and induces both proliferation of somatotrophs and striking changes in the synthesis and secretion of growth hormone (GH). Daily injections of 5 micrograms L-T3 for 7 days increased significantly the synthesis and storage of GH in pituitary gland, but the GH release was partially blocked. By contrast, injections of 10 micrograms L-T3 promote rapid synthesis and secretion of GH with removal of the cytoplasmic stores of the hormone and a consequent rise of serum levels. A close correlation was found between levels of stimulation and proliferation or retrogression of lactotroph cell population.

Animals↗
PubMed1995

Activation of IL-4 and IL-6 secreting cells by antigen.

The number, antigenic specificity and phenotype of cells secreting IL-4 and IL-6 in mice immunized with ovalbumin or keyhole limpet haemocyanin (KLH) in Freund's adjuvant (FA) was studied. The frequency of cells producing either of these cytokines began to rise 6 days post immunization, peaked at 11-14 days post-immunization, and fell to background by 21 days. The number of spleen cells secreting IL-6 was higher than the number producing IL-4 at all time points. Boosting elicited an anamnestic response characterized by a significant increase in the number of cytokine secreting cells within 4 days. Cytokine production was induced in multiple strains of normal mice, and was critically dependent on the use of Complete FA in addition to antigen. Immunization induced IL-4 and IL-6 production in vivo while 'priming' additional cells to release these cytokines when reexposed to soluble antigen in vitro. The latter response was antigen specific and was dominated by non-B/non-T cells. Those cells may serve to boost the immune response in cases of persistent or repeated antigenic challenge.

Animals↗
PubMed1995

Bioactivity and immunoreactivity of rat pituitary prolactin submitted to various extraction procedures.

Pituitary glands of rats, injected with estrogen to increase the prolactin (PRL) storage in secretory granules, were submitted to various extraction procedures for prolactin. Homogenization and centrifugation of pituitary tissue, in Tris-HCl buffer, pH 7.3, yielded a small amount of radioimmunoassayable prolactin, which increased remarkably after extraction in alkaline pH, disruption of granular membranes with Lubrol and specially after treatment with 2.5 mol/l urea. Nb2 lymphoma cell and pigeon crop sac bioassay (BA) revealed higher levels of bioactivity after extraction in Tris buffer, pH 7.3, in comparison to RIA, with BA/RIA ratios of 1.4 and 2.3, respectively. Bioassays of pituitary PRL extracted with Lubrol and alkaline medium, were less effective in quantifying PRL than RIA. Treatment of pituitary homogenates with urea produced the highest levels of PRL by both BA and RIA, with BA/RIA ratios close to 1. The thorough depolymerization of big PRL effected by urea produced the release of monomeric subunits which allows a complete quantification of the total content in the pituitary gland.

Animals↗
PubMed1995

Influence of ejection fraction on hospital mortality, morbidity, and costs for CABG patients.

BACKGROUND: Preoperative ejection fraction (EF) has been shown to adversely affect postoperative hospital mortality and morbidity for patients undergoing isolated coronary artery bypass grafting. METHODS: To investigate influence of EF on isolated coronary artery bypass grafting outcomes (overall hospital mortality, hospital cardiac mortality, hospital morbidity, and hospital costs), data were reviewed from 1,354 consecutive patients who underwent isolated coronary artery bypass grafting between January 1, 1990, and April 30, 1992, at a single nonprofit hospital. Overall hospital mortality was 4.06% (cardiac, 2.36%). Hospital morbidity was 14.25% (including mortality). Hospital costs (not charges) averaged $16,673 per patient. To explore the impact of preoperative EF, EF was stratified into regular intervals. Each interval was then compared with regard to hospital mortality, morbidity, and average costs. A new statistical tool, discharge analysis, was developed to analyze the cost data. This was necessary because previous efforts at cost analysis have used tools inappropriate for real world cost data. RESULTS: The statistical analysis showed that patients with EF of 0.40 or greater had the best outcomes (lowest mortality, morbidity, and cost). Once the EF is 0.40 or greater the EF does not carry further predictive value. At EF less than 0.40, patients with EF less than 0.30 have a poorer outcome than patients with EF of 0.30 to 0.39. CONCLUSIONS: (1) Ejection fraction is a valid predictor of mortality, morbidity and resource utilization based on statistical analysis. (2) Patients can be broadly grouped as having EF greater than 0.40, less than 0.30, or from 0.30 to 0.39 with regard to clinical and cost outcomes. (3) Postoperative length of stay is not predicted by risk-adjusted EF. (4) A new tool, discharge analysis, is presented to facilitate cost analysis.

Aged↗
PubMed1995

Effects of aluminum adjuvant on systemic reactions of lipopolysaccharides in swine.

In vivo effects of aluminum adjuvant on systemic reaction of bacterial lipopolysaccharide (LPS) in piglets were investigated. Intramuscular injection of 0.1 mg kg-1 of LPS added to aluminum hydroxide gel (LPS(+)AL) mitigated the leukopenia, trembling and serum levels of TNF-alpha and cortisol compared with the injection of LPS suspended in LPS-free saline (LPS(+)SALINE). The serum endotoxin levels were reduced remarkably but relatively long-lasting in the LPS(+)AL. The lethality in mice injected with LPS added to aluminum hydroxide gel was significantly reduced. Likewise, the Limulus activity of a test LPS was reduced by the addition of aluminum hydroxide gel or aluminum chloride.

Adjuvants, Immunologic↗
PubMed1995

Differential proliferation of somatostatin and glucagon cells in rat pancreatic islets submitted to various stimuli.

The populations of endocrine cells in pancreatic islets are subjected to striking fluctuations in their size when subjected to sustained stimulation and/or inhibition of their secretory activity. The stimulation of a specific endocrine secretion is followed by proliferation of its producing cell, a situation that is reversed after interruption or inhibition of the stimulus. Morphometric and cytological modifications of somatostatin and glucagon producing cells (D and A cells respectively) in the islets of Langerhans have been studied by electron microscopy, immunocytochemistry and morphometry in pancreas of rats submitted to the following experimental conditions: 1) Adrenalectomized (ADX), 2) ADX treated with hydrocortisone, 3) Diabetic and 4) Cysteamine (CSH) treated rats. In addition to ultrastructural changes, the populations of A and D cells were analyzed morphometrically applying a computerized system for light microscopy of paraffin sections immunostained with peroxidase-antiperoxidase (PAP) technique. Glucagon cell population displayed striking alterations in fine structural features and in the volume density in the different experimental conditions examined. By contrast, the cytological organization and the size of somatostatin cell population were little or not affected except in the diabetic rats where the massive degeneration of beta cells grossly distorted the structure of the islets. These observations led to the conclusion that the population of D cells constitutes a stable of endocrine system, at variance to the profound modifications occurring in A cells when they are submitted to various experimental conditions that stimulate or inhibit their secretory activity.

Adrenalectomy↗
PubMed1995

Intracellular localization of the testicular and sperm-specific lactate dehydrogenase isozyme C4 in mice.

The proposed dual intracellular distribution of the sperm-specific lactate dehydrogenase (EC 1.1.1.27) isozyme C4 (LDH C4) has been based on indirect evidence. In order to obtain direct evidence on the localization of this LDH isozyme in mice, postembedding immunocytochemistry at ultrastructural level was performed on testes, epididymal spermatozoa, and isolated testicular mitochondria. The immunogold technique was applied to thin sections incubated first in partially purified specific anti-LDH C4 rabbit IgG, and immunoreactive sites were detected with colloidal gold adsorbed to anti-rabbit IgG. In the testis, immunostaining was found in the cytoplasm of spermatocytes and spermatids and in the principal and middle pieces of differentiating spermatozoa. Spermatozoa from epididymis also exhibited heavy labeling of colloidal gold in their middle and principal pieces, but the immunostaining was weak in the special type of mitochondria present in spermatocytes, spermatids, and spermatozoa (sperm-type mitochondria, STM). The isolation of STM produced several morphological changes in comparison with those in situ, including an enhancement of the LDH C4 labeling in the mitochondrial matrix. The other type of mitochondria (non-STM) from spermatocytes and nonspermatogenic cells were not immunostained and served as background control. The results presented here confirm previous findings, gathered by indirect methods, indicating a dual localization of LDH C4 in the cytosol of spermatocytes, spermatids, and spermatozoa, as well as in the matrix of sperm-type mitochondria.

Animals↗
PubMed1995

In-vivo induction of apoptosis in murine lymphocytes by bacterial lipopolysaccharides.

The effect of bacterial lipopolysaccharide (LPS) on the lymphoid organs in C3H/HeN and C3H/HeJ mice was investigated. In C3H/HeN mice, LPS induced apoptosis, characterised by morphological nuclear condensation and DNA fragmentation resulting in thymic atrophy. Similar but less severe changes were also observed in the spleen and lymph nodes. In C3H/HeJ mice, only a slight depletion of lymphocyte numbers was observed in the lymphoid organs. The plasma endotoxin levels were dependent on the LPS dose regardless of mouse strain. On the other hand, the plasma TNF-alpha levels were significantly elevated in C3H/HeN mice 1 h post-injection and the time course of plasma corticosterone concentration correlated well with the development of apoptosis. These findings suggest that TNF-alpha and corticosterone may play an important role in LPS-induced apoptosis of lymphocytes.

Animals↗
PubMed1995

Reversible expression of motility and flagella in Clostridium chauvoei and their relationship to virulence.

Clostridium chauvoei strain Okinawa produced spontaneous non-motile variants at an unusually high rate (approx. 10(-4) per generation) under normal conditions without mutagen. Revertants of non-motile variants were detected at a rate of approximately 10(-3). Biochemically, every variant corresponded well with the parental strain. By transmission electron microscopy, three of nine non-motile variants of strain Okinawa were found to be flagellate, while the other six were found to be aflagellate. These phenotypes were confirmed by Western blot analysis using monoclonal antibodies directed against the flagella of C. chauvoei. Moreover, the parental flagellate strain and non-motile flagellate variants were significantly more virulent in mice than non-motile, aflagellate variants. Our results demonstrated that phase variation in motility and flagellation occurs in C. chauvoei, and that the flagella are associated with the full expression of virulence.

Animals↗
PubMed1995

Lipopolysaccharide-induced apoptosis in swine lymphocytes in vivo.

The in vivo effects of bacterial lipopolysaccharide (LPS) on the immune systems of piglets were investigated. Intravenous injection of 0.5 mg of LPS per kilogram of body weight induced apoptosis, which was characterized by nuclear chromatin condensation and fragmentation and a ladder formation of nucleosomal DNA in lymphocytes both in the cortex of the thymus and in the germinal centers and paracortical areas of mesenteric lymph nodes at 24 h postinjection. The levels of endotoxin, tumor necrosis factor alpha, and cortisol in serum increased, generally according to the dose of LPS. These findings suggest that LPS can induce in vivo apoptosis of lymphocytes in piglets and support the notion that cytokine and endocrine responses may play an important role in LPS-induced apoptosis in the immune system.

Animals↗
PubMed1995

Non-cushingoid Cushing's syndrome due to adrenocorticotropic hormone-independent bilateral adrenocortical macronodular hyperplasia.

This case report describes a 68-year-old man with Cushing's syndrome due to adrenocorticotropic hormone (ACTH)-independent bilateral adrenocortical macronodular hyperplasia (AIMAH). He was referred to our hospital for evaluation of bilateral enlargement of the adrenal glands found incidentally by computed tomography (CT). He had a ten-year history of hypertension. Although he was normokalemic and did not show Cushingoid features, the diagnosis of ACTH-independent Cushing's syndrome was established by endocrinological examinations. His plasma cortisol showed no diurnal rhythm and was unsuppressible by high-dose (8 mg/day) dexamethasone. Plasma ACTH was undetectable and did not respond to corticotropin-releasing hormone. Excised adrenal glands were markedly enlarged (right 28 g and left 64 g). Macroscopic appearance of the glands showed multiple yellowish nodules typical for AIMAH; microscopic findings were also compatible with AIMAH. The present case indicates that patients with AIMAH sometimes do not show typical Cushingoid features and therefore AIMAH can be found incidentally from ultrasound or CT examination of the abdomen.

Adrenal Glands↗
PubMed1995

[A case of p-ANCA positive necrotizing vasculitis associated with Graves' disease].

A 22-year-old female who had been suffering from Graves' disease developed p-ANCA positive necrotizing vasculitis. Her Graves' disease has been treated with propylthiouracil (PTI) for 6 years, which failed to improve serum TSH. She developed transient and recurrent polyarthralgia 4 years before. Because of microscopic hematuria and polyarthralgia, She visited our hospital last year. She had hypergammaglobulinemia and microhematuria at that time. But no autoantibody was noted except anti-microsomal antibody at that time. Skin biopsy from her finger subdermal nodule revealed necrotizing vasculitis of small vessels. Serum p-ANCA was positive. She was admitted under the diagnosis of p-ANCA positive necrotizing vasculitis. Renal biopsy revealed mesangium proliferative glomerulonephritis. Since she developed telescoped sediments after admission, predonisolone (PSL) 50 mg daily was started. Clinical and laboratory findings improved quite well. PSL was gradually tapered after 6 weeks. She is being maintained in good condition on tapering doses of both PSL and PTI. The coincidence of Graves' disease and vasculitis is rare. This case may provide some important immunological insights into the study of pathogenesis of necrotizing vasculitis and Graves' disease.

Adult↗
PubMed1995

Changes in thyrotroph and somatotroph cell populations induced by stimulation and inhibition of their secretory activity.

The populations of cells which produce immunoreactive growth hormone (GH) and thyroid stimulating hormone (TSH) in the rat pituitary gland do not occur in fixed percentages but vary greatly under different physiological and experimental conditions. These variations can be directly correlated to the levels of stimulation and/or inhibition of the specific secretory activity. In both types of cell, sustained stimulation with trophic hormones or blockage of the feedback mechanisms induces remarkable growth in the specific cell population. Conversely, the interruption or inhibition of the stimulus thwarted the hormonal secretion and caused a massive degeneration of redundant cells. The stimulation of both GH and TSH cells is accompanied by an enhanced secretory activity as judged by their higher concentrations in serum and hypertrophy of the cytoplasmic organelles involved in synthesis and intracellular processing of the hormones. By contrast, interruption of the stimulus is followed by a variable degree of disruption of the cytoplasmic organization, including a sizable degeneration of cells. In stimulated rats, the concentrations of both GH and TSH decreased significantly in pituitary tissue due to mobilization of the hormonal stores contained in secretory granules. On the other hand, the withdrawal of stimuli blocked the hormonal release; this is reflected by the accumulation of both hormones and secretory granules in pituitary tissue. The strict correlation between the size of the GH and TSH populations with stimulation and inhibition of hormonal secretory activity reported in this investigation further supports the critical role played by the cell renewal process in endocrine secretion.

Animals↗
PubMed1994

Effect of perchloroethylene inhalation on nasal mucosa in mice.

An experimental group of 16 male pure-bred mice was exposed to perchloroethylene gas at 300 ppm for 6h daily for 5 days. Histopathological study of the nasal mucosa was performed sequentially 1, 2, 4, and 7 days after exposure. Erosion of the olfactory epithelium and dilatation of Bowman's glands were observed from 1 to 7 days after exposure. Atrophy of the olfactory nerves was observed from 4 to 7 days after exposure. At 4 days after exposure, regenerating epithelial cells were observed, indicating that these cells represented the first step of the repair process after exposure. Nonetheless, epithelial degeneration in the nasal mucosa without erosion was observed for 4-7 days after exposure. Such epithelial lesions were more severe in the olfactory mucosa and appeared earlier than in other sites in the respiratory mucosa. The present study revealed that perchloroethylene gas exerted a more potent harmful action on the olfactory mucosa than on the general respiratory mucosa.

Administration, Inhalation↗