Inhibition of angiogenic factor production from murine mast cells by an antiallergic agent (epinastine hydrochloride) in vitro.

Angiogenesis is an important event both in the development of allergic inflammatory responses and in the pathophysiology of tissue remodeling in allergic diseases. In the present study, therefore, we examined the influence of antihistamines on angiogenesis through the choice of epinastine hydrochloride (EP) and murine mast cells in vitro. Mast cells (5 x 10(5) cells/mL) presensitized with murine IgE specific for ovalbumin (OVA) were stimulated with 10 ng/mL OVA in the presence of various concentrations of EP for 4 hours. The levels of angiogenesis factors, keratinocyte-derived chemokine (KC), tumor necrosis factor-alpha (TNF), and vascular endothelial growth factor (VEGF) in culture supernatants, were examined by ELISA. We also examined mRNA expression for the angiogenesis factors by RT-PCR. EP significantly inhibited the production of KC, TNF, and VEGF induced by IgE-dependent mechanism at more than 25 ng/mL. Semiquantitative analysis using RT-PCR showed that EP also significantly reduced mRNA expressions for KC, TNF, and VEGF. These results strongly suggest that EP suppresses angiogenesis factor production through the inhibition of mRNA expression in mast cells and results in favorable modification of clinical conditions of allergic diseases.

Promoter polymorphism in the macrophage migration inhibitory factor gene is associated with obesity.

OBJECTIVE: To explore the association of promoter polymorphisms of macrophage migration inhibitory factor (MIF) gene with obesity. SUBJECTS: In total, 213 nondiabetic Japanese subjects. They were divided into three groups according to World Health Organization definitions: lean (body mass index (BMI) <25 kg/m2), overweight (25 < or = BMI < 30 kg/m2) and obese (BMI> or = 30 kg/m2). METHODS: We examined two polymorphic loci in the MIF gene in the subjects: a single-nucleotide polymorphism at position -173 (G/C) and a CATT-tetranucleotide repeat polymorphism at position -794, which both can affect promoter activity in different cells. RESULTS: We detected four alleles: 5-, 6-, 7- and 8-CATT at position -794. Genotypes without the 5-CATT allele (X/X, X refers to 6-, 7- or 8-CATT alleles) were more common in obese subjects than in lean or overweight groups (P = 0.013). The X-CATT allele was more frequent in obese subjects than in lean or overweight subjects (P = 0.030). In contrast, -173G/C was not associated with obesity. Among the haplotypes of the two promoter polymorphisms, G/5-CATT ((-173G/C)/(-794[CATT](5-8))) was associated with a decreased risk of obesity (P = 0.025) and G/6-CATT with an increased risk of overweight (P=0.028). CONCLUSION: Promoter polymorphism in the MIF gene is linked with obesity.

Increased glomerular cytosolic phospholipase A2 activity of OLETF rats with early diabetes.

In view of the potential role of prostaglandins (PGs) in development of glomerular hyperfiltration leading to diabetic nephropathy, we studied the temporal relationship of the activity of cytosolic phospholipase A2 (cPLA2), a rate-limiting enzyme for eicosanoid biosynthesis, with hyperfiltration and the histological changes in glomeruli using OLETF rats, a model for non-insulin-dependent diabetes mellitus (NIDDM). Diabetes mellitus and associated histopathological changes, which developed spontaneously by 30-46 weeks after birth of OLETF rats, were accompanied by approximately 65% increase in glomerular cPLA2 activity that showed significant correlations with elevated plasma glucose levels and creatinine clearance. Moreover, mesangial cells cultured for 5 days with high glucose exhibited approximately 2-fold higher cPLA2 activity than those cultured with physiologic level of glucose. These data suggest that increased glomerular cPLA2 activity leads to production of PGs, which may promote the progression of early diabetic glomerular hyperfiltration and subsequent diabetic nephropathy.

Regulation of macrophage migration inhibitory factor (MIF) expression by glucose and insulin in adipocytes in vitro.

BACKGROUND: It has been reported that macrophage migration inhibitory factor (MIF) stimulated insulin secretion from pancreatic islet beta-cells in an autocrine manner, which suggests its pivotal role in the glucose metabolism. According to this finding, we evaluated MIF expression in cultured adipocytes and epididymal fat pads of obese and diabetic rats to investigate its role in adipose tissue. MATERIALS AND METHODS: The murine adipocyte cell line 3T3-L1 was used to examine MIF mRNA expression and production of MIF protein in response to various concentrations of glucose and insulin. Epididymal fat pads of Otsuka Long-Evans Tokushima fatty (OLETF) and Wistar fatty rats, animal models of obesity and diabetes, were subjected to Northern blot analysis to determine MIF mRNA levels. RESULTS: MIF mRNA of 3T3-L1 adipocytes was up-regulated by costimulation with glucose and insulin. Intracellular MIF content was significantly increased by stimulation, whereas its content in the culture medium was decreased. When the cells were treated with cytochalasin B, MIF secretion in the medium was increased. Pioglitazone significantly increased MIF content in the culture medium of 3T3-L1 cells. However, MIF mRNA expression of both epididymal fat pads of OLETF and Wistar fatty rats was down-regulated despite a high plasma glucose level. The plasma MIF level of Wistar fatty rats was significantly increased by treatment with pioglitazone. CONCLUSION: We show here that the intracellular glucose level is critical to determining the MIF mRNA level as well as its protein content in adipose tissue. MIF is known to play an important role in glucose metabolism as a positive regulator of insulin secretion. In this context, it is conceivable that MIF may affect the pathophysiology of obesity and diabetes.

Tumor necrosis factor-alpha regulates the gene expression of macrophage migration inhibitory factor through tyrosine kinase-dependent pathway in 3T3-L1 adipocytes.

Macrophage migration inhibitory factor (MIF) has been rediscovered as a proinflammatory cytokine, pituitary hormone, and glucocorticoid-induced immunoregulator. We have recently identified the expression of MIF in adipocytes and found that tumor necrosis factor (TNF)-alpha stimulates its secretion from 3T3-L1 adipocytes. Since adipocytes are regarded as a potential source of various biologically active substances, we examined in more detail the effect of TNF-alpha on MIF expression in 3T3-L1 adipocytes in the present study. We found that TNF-alpha induced MIF mRNA in dose- and time-dependent manners. After stimulation with TNF-alpha, the amount of intracellular MIF protein was unchanged or slightly decreased, concomitant with increased release of this protein into the extracellular space. This observation indicates that TNF-alpha stimulates MIF secretion from the constitutively expressed intracellular pool of 3T3-L1 adipocytes and promotes de novo synthesis of MIF. From evaluation of the mechanism of MIF gene expression, we found that tyrosine kinase inhibitors, either genistein or herbimycin A, suppressed the MIF mRNA induction by TNF-alpha. The results suggest the possibility that upregulation of MIF mRNA expression by TNF-alpha is mediated by a tyrosine kinase-dependent pathway. Taken together, the present observations shed light on the role of MIF in the metabolism of obesity and diabetes.

Identification of macrophage migration inhibitory factor in adipose tissue and its induction by tumor necrosis factor-alpha.

Macrophage migration inhibitory factor (MIF) has been rediscovered as a proinflammatory cytokine, pituitary hormone, and glucocorticoid-induced immunoregulator. A survey of tissue distribution revealed that MIF expression is not limited to T lymphocytes, but exists in several other tissues; however, its presence in adipose tissue has never been investigated. In this study, we examined the expression of MIF in adipose tissue using the rat epididymal fat pad and murine 3T3-L1 adipocytes. Northern and Western blot analyses revealed the expression of MIF mRNA and MIF protein, respectively, in both the fat pad and the adipocyte cell line. In immunohistochemistry, a positive staining reaction with an anti-rat MIF antibody was detected largely in the cytosol of adipocytes of the epididymal fat pad. To examine the production and release of MIF by adipocytes, we examined its content in the culture medium of the 3T3-L1 adipocytes. The results showed that MIF content was 1.6 +/- 0.48 ng/ml (mean +/- SD) after 24 hr culture, and the content was increased up to 9.7 +/- 2.8 ng/ml by stimulation with TNF-alpha (50 nM). Since TNF-alpha produced in adipocytes is known to induce insulin resistance, the results suggest the possibility that MIF plays an important role in the mechanism of insulin resistance often observed in obesity and diabetes via regulation of TNF-alpha expression.

[A case of IgG-kappa type multiple myeloma complicated by Fanconi syndrome].

Fanconi syndrome is characterized by some absorptive defects of proximal renal tubules. It is observed either primarily, or secondarily to various diseases. A case of multiple myeloma complicated by Fanconi syndrome is reported. The patient was a 62-year-old female. The serum total protein was elevated, and monoclonal IgG-kappa protein was found on serum immunoelectrophoresis. Urinary Bence Jones protein was positive. Bone marrow aspiration disclosed increased dysplastic plasma cells, which led to the diagnosis of multiple myeloma. A diagnosis of Fanconi syndrome was based on renal glycosuria, hypophosphatemia, hypokalemia, and panaminoaciduria due to abnormal excretion from the kidney, and metabolic acidosis. After chemotherapy for multiple myeloma, serum IgG level and urine sugar decreased, and serum potassium level was corrected.

Reduction of required precision bits for back-propagation applied to pattern recognition.

The number of precision bits for operations and data are limited in the hardware implementations of backpropagation (BP). Reduction of rounding error due to this limited precision is crucial in the implementation. The new learning algorithm is based on overestimation of significant error in order to alleviate underflow and omission of weight updating for correctly recognized patterns. While the conventional BP algorithm minimizes the squared error between output signals and supervising data, the new learning algorithm minimizes the weighted error function. In the learning simulation of multifont capital recognition, this algorithm converged recognition accuracy to 100% with only 8-b precision. In addition, the recognition accuracy for characters that did not appear in the training data reached 94.9%. This performance is equivalent to that of a conventional BP with 12-b precision. Moreover, it is found that the performance of the weighted error function is high even when only a small number of hidden neurons is used. Consequently, the algorithm reduces the required amount of weight memory.

[Clinical significance of alpha(1----3)-L-fucosyltransferase activities in sera from patients with malignant diseases with a special reference to a potential tumor marker].

We measured alpha(1----3)-L-fucosyltransferase (alpha 13FT) activity in human plasma samples obtained from a group of 111 patients with malignant diseases, 86 patients with benign diseases, and 58 healthy controls using a newly developed assay method (Clin. Chem., 37: 2081-2086, 1991). The cutoff value was arbitrarily set at 73 units/ml (mean +/- 3SD of results for healthy controls). Forty-one of the 111 (36.9) plasma samples from patients with cancer showed high enzyme activity, and twelve of the 86 (13.6%) samples from patients with benign diseases were above the cutoff value. The levels of alpha 13FT were considerably high in samples obtained from the patients with esophagus, lung, liver and pancreatic and biliary cancer, and corresponding positive rates were 66.7, 64.7, 62.5 and 62.5%, respectively. The elevation of the enzyme activity was found in many samples from advanced cancer, whereas samples from patients with gastric and colon cancer in the clinical stage I showed high positive rates. No correlation was observed between the level of alpha 13FT and tumor--associated antigens such as carcinoembryonic antigen, CA19-9, and sialyl Tn (STN). These results suggest that alpha 13FT activity measured by the present assay method could have a potentiality for a new type of tumor marker.

[Hormone receptors (ER, PgR) as a prognostic factor in breast cancer].

To investigate the significance of the hormonal receptors (ER: estrogen receptors; PgR: Progesterone receptors) as prognostic factors in breast cancer, 213 patients with breast cancer (stages I-III) who were examined for both receptors and had not received adjuvant hormonal therapy have been studied so as to determine a disease-free survival rate. In stage I, the status of the hormonal receptors failed to show any statistically significant differences with regard to the disease-free curve. However, in patients in advanced stage, the presence of either PgR or both receptors positively correlated with the disease-free survival curve. In comparing the ER with the PgR as prognostic factors, the presence of the PgR seemed to be more important than the presence of the ER. These data suggest that the status of the hormonal receptors is considered to have prognostic significance.