In vivo suppression of mafA mRNA with siRNA and analysis of the resulting alteration of the gene expression profile in mouse pancreas by the microarray method

Maf is a family of transcription factor proteins that is characterized by a typical bZip structure, and one of the large mafs, mafA is a strong transactivator of insulin. To explore the role of mafA in the pancreas, we modified the mafA mRNA level in vivo in mice by the RNA interference (siRNA) technique and analyzed the resulting alteration of the expressed gene profile with a microarray system. The mafA expression level in siRNA-treated mice was reduced approximately 60% compared with control-siRNA-treated animals. Microarray analysis revealed changes in the expression level of several genes in the siRNA-treated mice, with prominent down-regulated expression of the genes encoding insulin, glucagon, and adipocytokines, suggesting possible role of mafA in the pathophysiological states of impaired metabolic responses or inflammatory reactions.

Safety and efficacy of low-dose pioglitazone (7.5 mg/day) vs. standard-dose pioglitazone (15 mg/day) in Japanese women with type 2 diabetes mellitus

It is well known that pioglitazone, a potent thiazolidinedione, improves metabolic control. However, weight gain or peripheral edema may be of major clinical concern when using this agent. The purpose of our study was to prospectively evaluate the effects of low-dose pioglitazone (7.5 mg/day) on metabolic control, weight gain and the incidence of edema compared with a standard dose of pioglitazone (15.0 mg/day) in patients with type 2 diabetes mellitus (T2DM). Ninety-five Japanese female patients (mean age 58.4 +/- 10.4 years) with newly diagnosed T2DM were selected for this study. They were randomly divided into the following 2 groups according to therapy regimens, and examined every month for 6 months after diagnosis. Group A consisted of 54 patients treated with low-dose pioglitazone orally; Group B, the control-group, consisted of 41 patients treated with standard-dose pioglitazone orally. The incidence of peripheral edema was significantly much lower in group A (2/54) than in group B (11/41) (p = 0.0014). In addition, % change of body weight during the 6-month treatment in group A was significantly less than that in group B (p < 0.0001). On the other hand, the % change of biochemical parameters including HbA1c did not differ significantly between group A and group B, although glucose and lipid control significantly improved from baseline in both groups. Our results demonstrate the safety and efficacy of low-dose pioglitazone, suggesting that it could be another good choice of treatment for Japanese women with T2DM.

Clinical significance of risedronate for osteoporosis in the initial treatment of male patients with Graves' disease

It has been well established that hyperthyroidism leads to diminished bone mineral density (BMD), and that a previous history of hyperthyroidism remains a risk factor for fractures. However, little is known about how to manage the reduction in BMD caused by hyperthyroidism. The purpose of this study was to evaluate the efficacy of risedronate for the treatment of osteoporosis/osteopenia in patients with Graves' disease (GD). Of 34 Japanese male patients with newly diagnosed GD, 27 with osteoporosis/osteopenia were included in this study. They were randomly divided into two groups by therapeutic regimen. Group A consisted of 14 patients treated with an antithyroid drug and risedronate. Group B consisted of 13 patients treated with the same antithyroid drug only. We used dual-energy X-ray absorptiometry to measure BMD at the lumber spine, femoral neck, and distal radius at baseline, and at 6 and 12 months after the trial. Bone-specific alkaline phosphatase and urinary N-terminal telopeptide of type I collagen normalized by creatinine were significantly more reduced in group A than in group B after both 6 and 12 months. The percentage increases in BMD at the lumbar spine and distal radius were significantly greater in group A than in group B. These beneficial effects of risedronate for patients with osteoporosis/osteopenia caused by GD may lead to a reduced risk of future fractures. We thus conclude that risedronate should be considered for the treatment of decreased bone mass associated with GD.

Negative correlation between bone mineral density and TSH receptor antibodies in male patients with untreated Graves' disease

INTRODUCTION

Although it has been established that hyperthyroidism leads to reduced bone mineral density (BMD), with accelerated bone turnover promoting bone resorption in female patients, there is a dearth of data for male patients with hyperthyroidism. This study evaluated BMD and bone metabolism in male patients with Graves' disease.

METHODS

The study included 56 Japanese male patients with newly diagnosed Graves' disease and 34 normal Japanese male control subjects of similar age and body mass index. We used dual energy x-ray absorptiometry to measure BMD at sites with different cortical/cancellous bone ratios (lumbar spine, femoral neck, and distal radius).

RESULTS

At the lumbar spine and the distal radius, BMD and T-scores were significantly lower for patients than for controls. At the femoral neck, on the other hand, the same values were relatively, but not significantly, lower in patients than in controls. However, Z-scores at all three sites were significantly lower for patients than for controls. The Z -score at the distal radius of patients was significantly lower than that at their lumbar spine and femoral neck. In addition, Z-score at the distal radius correlated negatively with age, free thyroxine, thyroid stimulating hormone receptor antibodies, thyroid stimulating antibody, and urinary N-terminal telopeptide of type I collagen normalized by creatinine.

CONCLUSIONS

These results indicate a high prevalence of cortical bone loss in male patients with Graves' disease, especially elderly patients. We conclude that BMD measurement is crucial in all Graves' disease patients regardless of their gender and that the radial BMD as well as BMD at the lumbar spine and femoral neck should be monitored to effectively prevent bone loss and subsequent fracture.

Anaplastic thyroid carcinoma associated with Graves' disease

This report concerns a 79-year-old woman with coexisting anaplastic thyroid carcinoma (ATC) and Graves' disease (GD). The patient was referred to our clinic because of palpitation and a palpable mass on the left side of her neck. Thyroid function tests showed hyperthyroidism with elevated thyroid-stimulating antibodies. Ultrasonography of the thyroid demonstrated an adenomatous nodule-like marcated nodule (27.6 x 26.5 x 36.4 mm) with cystic degeneration inside the left lobe. (123)I thyroid scintigraphic imaging showed a cold area corresponding to the nodule with continuous uptake in the remaining thyroid tissue despite suppressed TSH levels. These findings led to a diagnosis of GD. On the other hand, the thyroid nodule could not be definitely diagnosed even after fine needle aspiration biopsy (FNAB) which produced findings suggestive of both papillary thyroid carcinoma and ATC. Open biopsy of the nodule showed an ATC. Regional lymph node metastases as well as multiple lung metastases, which could not be found at the initial visit, had been already developed by that time. Our case is pathophysiologically interesting because it suggests that GD or thyroid-stimulating antibodies (TSAb) may stimulate malignant transformation of differentiated carcinoma. It is also clinically important because it indicates that all thyroid nodules, particularly palpable cold nodules, associated with GD require careful management to detect malignancy because they are at higher risk of harboring malignancy.

Decreased bone mineral density at the distal radius, but not at the lumbar spine or the femoral neck, in Japanese type 2 diabetic patients

The purpose of this study is to assess the association between type 2 diabetes and bone mineral density. This study included 145 Japanese patients (64 men and 81 women) with type 2 diabetes and 95 non-diabetic control subjects (41 men and 54 women) of similar age. We measured bone mineral density (BMD) at the sites with different cortical/cancellous bone ratio (lumbar spine, femoral neck, and distal radius) using dual-energy X-ray absorptiometry. BMD and Z score at the distal radius were significantly lower in type 2 diabetic patients than those in control subjects, and in type 2 diabetic patients, the Z score at the distal radius was lower than that at their own lumbar spine and femoral neck. In type 2 diabetic patients, negative correlation between BMD and the mean HbA1c during the previous 2 years was found significantly at the distal radius in both genders and at the femoral neck in women. These results indicate the selective cortical bone loss in type 2 diabetes and suggest the importance of also determining BMD at the radius and keeping good metabolic control to prevent bone loss in type 2 diabetic patients.

Papillary thyroid carcinoma without metastases manifesting as an autonomously functioning thyroid nodule

A 59-year-old woman with papillary thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this report. The patient was referred to our clinic because of rapid weight loss and swelling on the left side of the neck. Ultrasonography of the thyroid demonstrated a nonhomogeneous nodule in the lower part of an enlarged left lobe. Both 99mTc and 123I thyroid scintigraphic imaging showed a hot area corresponding to the nodule with lower uptake in the remaining thyroid tissue. Histopathological examination of the nodule revealed papillary adenocarcinoma, and the immunohistochemistry proved weak but positive staining for triiodothyronine and thyroxine. Based on these findings, the nodule was diagnosed as a functioning papillary adenocarcinoma. Although thyroid carcinoma manifesting as a hot nodule on the radionuclide isotope scan is an extremely rare occurrence, the current case is clinically important because it suggests that the diagnosis of a hot nodule cannot always rule out thyroid carcinoma in the nodule, and that even a hot nodule requires careful management so that the malignancy is not overlooked.

Impaired blood rheology by remnant-like lipoprotein particles: studies in patients with fatty liver disease

Fatty liver disease (FLD) characterised by a high plasma levels of lipoproteins and remnant-like lipoproteins (RLP) is a risk factor for impaired microvascular blood flow, endothelial cell dysfunction and atherosclerosis. Using an immunoseparation technique with a gel mixture containing human monoclonal antibodies to apo A-I and apo B-100, we separated and measured RLP cholesterol (RLP-C) levels which reflect RLP in patients with FLD (n=20). Whole blood transit time (TT) was determined by a microchannel method (MC-FAN) which allows blood flow to be viewed via a microscope connected to an image display unit. RLP-C levels were higher (P<0.01) in FLD, 15.6 +/- 1.0 mg/dl compared with 4.8 +/- 0.5 mg/dl for controls (n=20). Similarly, TT was longer (P<0.01) in FLD, 284.5 +/- 26.1 sec/100 microl compared with 82.8 +/- 1.0 sec/100 microl for controls. Since the liver is a major site for RLP formation and degradation, it is affected to a greater extent in patients with FLD. It is likely that high levels of RLP can impair microvascular perfusion in the liver tissue and contribute to the development and progression of FLD.

Changes in vasoactive substances during gastric ulcer healing

In order to study the roles of vasoactive peptides during tissue repair of gastric ulcers, we compared concentrations in tissue surrounding gastric ulcers of endothelin-1(ET-1), adrenomedullin (AM), and transforming growth factor-beta (TGF-beta) among different stages of ulcer development. A total of 82 cases were studied. Ulcers were located in the gastric angulus in 51 cases. All cases were positive for Helicobacter pylori (Hp). Ten cases were in the active stage (GA), 18 were in the healing stage (GH), and 28 were in the scarring stage (GS). As control, 17 cases of Hp-positive gastritis (gast+) and 14 of Hp-negative gastritis (gast-) were studied. The concentrations of endothelin (ET) and TGF-beta were in the order of GH> GA> GS, and those of AM were in the order of GS > GH > GA. On immunostaining, ET stained positively in endothelial cells and vascular smooth muscle cells (VSMCs) during the GH and GS stages, and AM stained positively in histiocytes during GA, GH and GS, and also stained positively in glandular epithelia and smooth muscle fibers during GH and GS. When our results were reviewed with respect to the regulation of vascular tonus and the proliferation of VSMCs, ET and AM were considered to have roles in the regulation of proliferation.

Changes of nitric oxide and growth factors during gastric ulcer healing

We measured the concentrations of vascular endothelial growth factor (VEGF), nitric oxide and endothelin-1 (ET-1) in the gastric mucosa and examined the relationships between these factors. VEGF, nitric oxide and ET participate in angiogenesis and vascular remodeling, important elements of gastric ulcer healing. We studied cases of gastric ulcer as confirmed by endoscopic examination. All 61 cases in the angulus were positive for Helicobacter pylori (Hp). Fifteen cases were active stage (GA), 23 were healing stage (GH), and 23 were scarring stage (GS). As control, 17 cases of Hp-positive gastritis (gast+) and 14 cases of Hp-negative gastritis (gast-) were studied. Biopsy samples taken from the angulus during endoscopic examination were frozen and sliced into thin sections. ET was measured by enzyme immunoassay, VEGF was measured by enzyme-linked immunosorbent assay (ELISA) and nitric oxide was measured in terms of metabolite oxides of nitrogen (NOx) as described by Griess. ET, VEGF and inducible nitric oxide synthase (iNOS) were immunostained. The GA group had the highest concentration of NOx, suggesting that nitric oxide participates in the early stage of mucosal repair. In the GH group, all three factors showed high concentrations, suggesting that all may be involved in increased production. In the GS group, all three factors were significantly lower than in the GA and GH groups. Immunohistochemical studies showed that the distribution of ET- and iNOS-positive cells differed according to the ulcer stage. In particular, ET- and iNOS-positive cells in the vascular wall were primarily endothelial cells during GA and GH and vascular smooth muscle cells (VSMCs) during GS. These findings suggest that endothelial cells produce increased amounts of ET, nitric oxide and VEGF early in ulcer healing, a period of active endothelial cell repair and angiogenesis. During the scarring stage, vascular remodeling may result from the effects of ET and nitric oxide in regulating the proliferation of VSMCs. Our results suggest that VEGF. nitric oxide and ET participate in angiogenesis, vascular remodeling and mucosal regeneration during ulcer healing.

Relationship between recurrence of gastric ulcer and the microcirculation

We investigated the relationship between microcirculatory disturbance and the host response to Helicobacter pylori infections in gastric ulcer scars to determine the role of endothelin-1 (ET) in ulcer recurrence. The subjects were divided into three groups. The GuS group consisted of patients who had red scarring (S1 stage) at the gastric angle with H. pylori, the gast+ group who had gastritis with H. pylori, and the gast- group who had gastritis without H. pylori. During endoscopic examination, biopsies were taken from the gastric angle. Mucosal ET, nitric oxide (NO), interleukin-8 (IL-8), and RANTES were measured. ET, inducible NO synthase (iNOS), and endothelial constitutive NOS (ecNOS) were immunostained. Mucosal ET and oxides of nitrogen (NOx) were significantly higher in the GuS group than in the other groups. IL-8 was elevated in the GuS and gast+ groups, and RANTES was elevated in the gast+ group (p < 0.01). There was prominent inflammatory cell infiltration in the GuS group. ET-positive cells were found in vascular smooth muscle, gastric epithelium, and gastric smooth muscle. iNOS-positive cells were found in vascular smooth muscle, gastric epithelium, gastric smooth muscle, and inflammatory cells. In conclusion, local inflammation and microcirculatory disturbance persist at the center of the ulcer scar (S1). Decreased cytokine levels and increased ET and NO (mainly synthesized by iNOS) levels suggested that microcirculatory disturbance is a more important factor than immune response in ulcer recurrence.

The significance of the Trp 64 Arg mutation of the beta3-adrenergic receptor gene in impaired glucose tolerance, non-insulin-dependent diabetes mellitus, and insulin resistance in Japanese subjects

It has been reported that the Trp 64 Arg mutation of the human beta3-adrenergic receptor (beta3-AR) gene is related to an earlier age of onset of non-insulin-dependent diabetes mellitus (NIDDM) and features of insulin resistance and weight gain in morbidly obese patients. However, such findings have not been consistent in varying ethnic populations. In the present study, we investigated the frequency of the Trp 64 Arg mutation of the human beta3-AR gene in Japanese control subjects (n = 253) and in NIDDM (n = 314) and impaired glucose tolerance (IGT) patients (n = 100). We compared the frequency of the mutation with the body-mass index (BMI) in these groups and with the metabolic clearance rate (MCR) of glucose in the NIDDM patients. A Trp 64 Arg mutation was observed in 36.7%, 31.6%, and 37.0% of the control, NIDDM, and IGT subjects, respectively. The frequency of the homozygotes for the mutation was 4.3%, 4.8%, and 3.0%, respectively. Neither the genotype frequency (Trp/Arg, Arg/Arg) nor the frequency of the mutated allele was significantly different among the three groups. The BMI of the subjects with the mutation was not significantly higher than that of the subjects without the mutation in each group. Furthermore, the allele frequency (A) was not different among the subjects with different BMIs (BMI < 22.0, 22.0 < or = BMI < or = 26.4, BMI > 26.4) in each group. In a separate group of NIDDM patients, the MCR of the subjects with intermediate BMIs (22.0 < or = BMI < or = 26.4) with the mutation tended to be lower than that of those without the mutation. In addition, the MCR of the subjects with the mutation in this group was significantly lower compared with that of those with a BMI less than 22. These results indicate that the Trp 64 Arg mutation of the beta3-AR gene may not contribute to the development of NIDDM or be a determinant of obesity in the Japanese population. However, the mutation may contribute to insulin resistance in NIDDM patients with an intermediate BMI.

Clinical manifestations due to a point mutation of the mitochondrial tRNAleu(UUR) gene in five families with diabetes mellitus

It has been shown that an adenine (A) to guanine (G) transition at position 3243 of the mitochondrial transfer RNA(tRNA)leu(UUR) gene is associated with a subgroup of diabetes mellitus. Therefore, we screened for this transition in 86 patients with non-insulin-dependent diabetes mellitus (NIDDM) in which two or three generations were affected with diabetes, in 14 patients with insulin-dependent diabetes mellitus, and in 9 families with diabetes mellitus and/or associated disorders suggesting mitochondrial gene abnormalities. We failed to identify the mutation in 100 diabetic patients, 86 NIDDM and 14 insulin-dependent diabetes mellitus (IDDM). Out of the latter 9 families, we identified an A to G transition in 14 individuals in 5 families. Diabetes mellitus was shown to be maternally inherited in one family. In 9 of 14 patients with the mutation, insulin was required to treat diabetes mellitus, indicating impaired insulin secretion. A hyperglycemic clamp test performed in one subject revealed significant impairment of insulin secretion, whereas euglycemic clamp test showed normal insulin sensitivity in this patient. The heteroplasmy of the mutant mitochondrial DNA (mtDNA) in leukocytes does not appear to correlate with the severity of diabetes in terms of the insulin therapy required. Body mass index of the affected individuals was less than 23.3. In one family, in addition to diabetes mellitus and hearing loss, hypoparathyroidism was associated with the mutation, suggesting that hypoparathyroidism is caused by the impaired processing and/or secretion of proparathyroid hormone due to the mutation. In addition, the affected subjects presented with proteinuria at the time of diagnosis of diabetes mellitus which appeared not to be related with diabetic nephropathy.

Molecular screening of both the promoter and the protein coding regions in the human ob gene in Japanese obese subjects with non-insulin-dependent diabetes mellitus

OBJECTIVE

Although the molecular mechanism of obesity has been poorly understood, recent studies indicate that leptin plays a critical role in regulating both food intake and body weight. Because obesity decreases the sensitivity to insulin, the human ob gene is presumed to be one of the candidate genes for non-insulin-dependent diabetes mellitus (NIDDM) associated with obesity. Although the protein coding region in the ob gene has been screened for mutations, the promoter region and the non-coding first exon have not yet been studied. We investigated the involvement of the human ob gene, especially mutations at the promoter region and the non-coding first exon, in the development of NIDDM associated with obesity.

SUBJECTS

The study group comprised 60 Japanese obese subjects with NIDDM (body mass index (BMI) 43.6 > or = BMI > or = 26.4, 29.0+/-0.41 (mean+/-S.E.M.)) and 24 obese individuals with impaired glucose tolerance (IGT) (30 > or = BMI > or = 26.4, 27.1+/-0.22).

METHODS

Mutations at both the promoter region and all three exons in the human ob gene were screened by the single-stranded conformational polymorphism analysis. When aberrantly migrated bands were recognized, the PCR-amplified DNA fragment was directly sequenced.

RESULTS

In the protein coding region a silent mutation in the second exon was detected. The non-coding first exon and the about 100 bp 5'-flanking region of the gene which contains a proximal CCAAT/enhancer-binding protein site were screened, but no mutations were found.

CONCLUSION

These results suggest that no mutations in either the promoter region at the about 100 bp 5'-flanking region of the gene, or in any of the three exons, are involved in the development of NIDDM or IGT associated with obesity.

[Blood rheological study in rats with fatty liver--with special reference to effects of ethyl icosapentate]

A blood rheological study was conducted using Kikuchi's micro-channel method in rats with fatty liver. Effects of eicosapentaenoic acid (EPA) on blood rheology were also evaluated. Male SD rats given normal feed served as the control. One group was given choline-deficient feed for 4 weeks (EPA (-) group), while another group was daily given EPA (1000 mg/kg) for 4 weeks together with choline-deficient feed (EPA (+) group). The micro-channel passage time was determined using 100 microliters of whole blood. The passage time significantly increased in the EPA (-) group compared to the control (p < 0.01). It significantly decreased in the EPA (+) group compared to the EPA (-) group (p < 0.01). Findings obtained in the present study suggested that blood rheological factors are related to the development of fatty liver and that EPA inhibits fatty changes of the liver by improving these rheological factors.

Differential activation of mitogen-activated protein kinase by insulin and epidermal growth factor in 3T3-L1 adipocytes: a possible involvement of PI3-kinase in the activation of the MAP kinase by insulin

Mitogen-activated protein (MAP) kinase plays crucial roles in cell growth and differentiation. It has recently been shown that the MAP kinase cascade in growth factor signaling diverges and cross-talks with other signaling pathways. In the present study, we examined the effects of wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3-kinase), on the activation of Ras, Raf-1 kinase, and MAP kinase by insulin and epidermal growth factor (EGF). The effect of LY294002, a structurally distinct PI3-kinase inhibitor, on the activation of Raf-1 kinase by both ligands was also examined. In 3T3-L1 adipocytes, 25 nmol/l wortmannin inhibited the insulin-induced activation of Raf-1 kinase to the basal level, whereas the same dose of wortmannin had little effect on the EGF-induced activation of Raf-1 kinase. One hundred micromol/l LY294002 blocked insulin-induced activation of Raf-1 kinase without affecting EGF-induced activation of this kinase. Twenty-five nmol/l wortmannin inhibited the insulin-induced activation of MAP kinase to the basal level with no effect on the EGF-induced activation of this kinase. But the same dose of wortmannin did not affect the formation of guanosine 5'-triphosphate (GTP)-bound Ras stimulated by either ligand. In KB cells, results similar to those in 3T3-L1 adipocytes were obtained. In contrast, in Chinese hamster ovary cells overexpressing the human insulin receptor (CHO-HIR cells), neither wortmannin nor LY294002 inhibited the insulin-induced activation of Raf-1 kinase, and wortmannin had little effect on the activation of MAP kinase by insulin. These results indicate that 1) PI3-kinase or wortmannin-sensitive molecules are involved in the interaction between activated Ras and Raf-1 kinase in the insulin signaling in 3T3-L1 adipocytes, 2) the involvement of PI3-kinase or wortmannin-sensitive molecules in the insulin-induced activation of MAP kinase appears to be cell-type specific, and 3) differential mechanisms to activate Raf-1 kinase and MAP kinase by insulin and EGF exist.

Increase in hepatic tissue blood flow by teprenone

The major objective of the present study was to evaluate mechanisms by which teprenone, a gastric mucosal protecting agent, increases hepatic mucosal blood flow using male Sprague-Dawley rats. Hepatic and gastric blood flow was measured using a laser blood flow meter after administration of teprenone, dissolved in Tween 80, into the inferior vena cava. Teprenone itself increased hepatic and gastric blood flow. It also increased hepatic and gastric blood flow in rats with acute hepatic disorders due to carbon tetrachloride (CCL4) and improved histological changes, such as inflammatory cell infiltration and fatty changes in the liver. The fact that blood endothelin (ET) concentrations increased after administration of teprenone suggest that teprenone has great affinity for ET beta receptors and shows ET beta-receptor antagonist-like effects. Hepatic blood flow decreased after administration of N-nitro-L-arginine methyl ester, a nitric oxide (NO) synthetase inhibitor, suggesting that teprenone increase NO activity. Teprenone was thought to increase hepatic and gastric blood flow by different mechanisms, because it increased gastric mucosal prostaglandin E2 concentrations.

Insulin-induced activation of phosphoinositide 3-kinase in Fao cells

Phosphoinositide 3-kinase (PI3-kinase) plays a crucial role in insulin signal transduction. We studied the molecular mechanism of the insulin-induced activation of PI3-kinase in rat hepatoma Fao cells using an antibody against the 110-kDa catalytic subunit (p110) and two against the 85-kDa regulatory subunit (p85 alpha). PI3-kinase activity increased 1.6-fold in anti-p85 immunoprecipitates after insulin stimulation, whereas it did not increase when cell lysates were first immunoprecipitated with anti-phosphotyrosine or anti-insulin receptor substrate-1 (IRS-1), then with anti-p85, suggesting that the PI3-kinase which associates with tyrosyl phosphoproteins including IRS-1 is responsible for the increase in kinase activity. The activated PI3-kinase molecules constituted 4-6% of the total PI3-kinase, and their specific activity was 11-14 times higher than that of the basal state. Anti-p110 recognized the catalytically active form of p110, and immunoprecipitated p110 only after exposure to insulin. Hence, the epitope of anti-p110, P200-C215, seems to be included in the portion of p110, the conformation of which is changed by insulin stimulation. We conclude that, in response to insulin stimulation, only a small fraction of p85 in the PI3-kinase pool associates with tyrosyl phosphoproteins including IRS-1, and that the specific activity of p110 is increased presumably through a conformational change including the P200-C215 region.

Augmented expression of obese (ob) gene during the process of obesity in genetically obese-hyperglycemic Wistar fatty (fa/fa) rats

Expression of the obese (ob) gene is up-regulated in the adipose tissue in several obese rodent models. To study the regulation of the ob gene expression during the development of obesity, we examined the ob gene expression in genetically obese-hyperglycemic Wistar fatty (fa/fa) rats at several stages of obesity. The ob mRNA levels in the adipose tissue from Wistar fatty rats was unequivocally augmented and continued to rise in the process of obesity. Furthermore, the ob gene expression in this obese model was much more rapidly enhanced in the mesenteric fat than in the subcutaneous fat. Moreover, the ob gene expression was more greatly augmented in the mesenteric fat than the lipoprotein lipase gene expression. These results suggest the presence of obesity-linked and region-specific regulation of the ob gene expression.

Structural organization and chromosomal assignment of the human obese gene

The obese (ob) gene has been identified through a positional cloning approach; the mutation of this gene causes marked hereditary obesity and diabetes mellitus in mice. We report here the isolation and characterization of the human ob gene. Southern blot analysis demonstrated a single copy of the ob gene in the human genome. The human ob gene spanned approximately 20 kilobases (kb) and contained three exons separated by two introns. The first intron, approximately 10.6 kb in size, occurred in the 5'-untranslated region, 29 base pair (bp) upstream of the ATG start codon. The second intron of 2.3 kb in size was located at glutamine +49. By rapid amplification of 5'-cDNA ends, the transcription initiation sites were mapped 54-57 bp upstream of the ATG start codon. The 172-bp 5'-flanking region of the human ob gene contained a TATA box-like sequence and several cis-acting regulatory elements (three copies of GC boxes, an AP-2-binding site, and a CCAAT/enhancer-binding protein-binding site). By the fluorescence in situ hybridization technique, the ob gene was assigned to human chromosome 7q31.3. This study should establish the genetic basis for ob gene research in humans, thereby leading to the better understanding of the molecular mechanisms underlying the ob gene.

Molecular cloning of rat obese cDNA and augmented gene expression in genetically obese Zucker fatty (fa/fa) rats

The obese (ob) gene has recently been isolated through a positional cloning approach, the mutation of which causes a marked hereditary obesity and diabetes mellitus in mice. In the present study, we isolated rat ob cDNA and examined the tissue distribution of the ob gene expression in rats. We also studied the gene expression in genetically obese Zucker fatty (fa/fa) rats. The rat ob gene product, a 167 amino acid protein with a putative signal sequence, was 96 and 83% homologous to the mouse and human ob proteins, respectively. Northern blot analysis using the rat ob cDNA probe identified a single mRNA species of 4.5 kb in size in the adipose tissue, while no significant amount of ob mRNA was present in other tissues in rats. The ob gene was expressed in the adipose tissue with region specificities. The rank order of the ob mRNA level in the adipose tissue was epididymal, retroperitoneal, and pericardial white adipose tissue > mesenteric and subcutaneous white adipose tissue > or = interscapular brown adipose tissue. The ob gene expression occurred in mature adipocytes rather than in stromalvascular cells isolated from the rat adipose tissue. Expression of the ob gene was markedly augmented in all the adipose tissue examined in Zucker fatty (fa/fa) rats at the stage of established obesity. The present study leads to the better understanding of the physiologic and pathophysiologic roles of the ob gene.

Human obese gene expression. Adipocyte-specific expression and regional differences in the adipose tissue

The obese (ob) gene, the mutation of which results in severe hereditary obesity and diabetes in mice, has recently been isolated through positional cloning. In this study, we isolated a full-length human ob complementary DNA (cDNA) clone and examined the tissue distribution of ob gene expression in humans. The nucleotide sequences of the human ob cDNA coding region were 83% identical to those of the mouse and rat ob cDNA coding regions. Analysis of the deduced amino acid sequences revealed that the human ob protein is a 166-amino acid polypeptide with a putative signal sequence and is 84 and 83% homologous to the mouse and rat ob proteins, respectively. Northern blot analysis using the cloned human ob cDNA fragment as a probe identified a single messenger RNA (mRNA) species 4.5 kb in size found abundantly in the adipose tissues obtained from the subcutaneous, omental, retroperitoneal, perilymphatic, and mesenteric fat pads. However, no significant amount of ob mRNA was present in the brain, heart, lung, liver, stomach, pancreas, spleen, small intestine, kidney, prostate, testis, colon, or skeletal muscle. The ob mRNA level in the adipose tissue varied from region to region even in the same individual. Furthermore, in the human adipose tissue, ob gene expression occurred in mature adipocytes rather than in stromal-vascular cells. This study is the first report of the elucidation of ob gene expression in human tissues, thereby leading to better understanding of the physiological and clinical implications of the ob gene.

Effect of interferon therapy in a patient with chronic active hepatitis type C associated with interstitial pneumonia and rheumatoid arthritis: a case report

Interferon (IFN) is widely used to treat patients with chronic hepatitis types B and C but has been found to occasionally aggravate rheumatoid arthritis (RA) or cause interstitial pneumonia. We administered 6 MIU/d IFN-beta by intravenous injection for 6 weeks to a 55-year-old man with chronic active hepatitis type C associated with RA and interstitial pneumonia. Transaminase levels rapidly returned to normal after treatment and hepatitis C virus-RNA (nested RT-PCR method) was negative on completion of treatment. No significant adverse reactions or aggravation of RA or interstitial pneumonia occurred. These findings suggest that use of IFN-beta in the treatment of patients with chronic hepatitis type C associated with RA and/or interstitial pneumonia presents no problem if appropriate precautions are taken.

Role of eicosapentaenoic acid in lipid metabolism in the liver, with special reference to experimental fatty liver

Choline-deficient feed was given to three groups (n = 7 in each) of male Sprague-Dawley rats for 4 weeks to induce the development of fatty liver. In addition, two of the groups received eicosapentaenoic acid (EPA), 1000 mg/kg/d, administered orally either for all 4 weeks or for only the last 2 weeks of the study, respectively. The third group received the choline-deficient diet but no EPA. The untreated control group (n = 7) received only normal feed. The efficacy of EPA in preventing fatty liver was assessed based on the evaluation of pathologic and biochemical parameters and hepatic blood flow. EPA markedly improved fatty liver, probably due to both direct effects (inhibition of the synthesis of triglyceride in the liver) and indirect effects (increased hepatic blood flow). Decreased blood flow due to sinusoidal block is responsible for the progression of fatty liver. EPA has been shown to decrease thromboxane A2 production and blood viscosity and to enhance red cell deformability. These effects are thought to have contributed to the increases in hepatic blood flow.

An experience of ischemic limb salvage associated with myositis ossificans of the left thigh

A case of ischemic limb salvage associated with myositis ossificans of the left thigh in a 66-year-old man was reported. The patient had a medical history of cerebral palsy and a cervical spinal cord injury, and had an operative past history of hip arthroplasty for fracture of the left femoral neck 10 years before. He showed ischemic symptoms such as paleness, coldness, and loss of the left dorsal arterial pulsation in the left toe, and had a rapidly growing mass in the left thigh. Roentgenography and computed tomography showed a mass 10 cm by 10 cm by 8 cm in size with severe calcification in the left quariceps muscle. Occlusion of the left common femoral artery was found in the arteriogram. Surgery was carried out in order to establish an accurate diagnosis and to rescue the left lower limb. The arterial pulsation was recovered as the result of completely resecting the left quariceps muscle tumor. The pathohistological diagnosis was of myositis ossificans in the quariceps muscle of the thigh. Etidronate disodium was administered in order to prevent a recurrence postoperatively. The patient has been well for the 13 months since surgery.

A case report of substernal goiter

A case of substernal goiter is reported. A 78-year-old female was admitted to our hospital with no symptoms. Chest roentgenography on admission showed that a mass of 3 by 5 cm in size with calcification located in the substernal region. Computed tomography of the chest and aortography revealed that the mass was attached to the trachea, but the connection to the great vessels was not clear. Pathological findings of the incisional biopsy specimen showed thyroid tissue with no evidence of malignancy. Our clinical diagnosis was substernal goiter. Surgery was not carried out in this case, based on the literature. Surgery is indicated in case of malignancy or in cases with severe illness such as respiratory disorder and superior vena cava syndrome.

Inhibitory effect of ursodeoxycholic acid on the progression of chronic hepatic disorders with special reference to increases in blood flow

Ursodeoxycholic acid (UDCA), which is commonly used as a cholesterol-gallstone-dissolving agent, is now expected to be effective not only for primary biliary cirrhosis but for chronic active hepatitis as well. In this study, we administered 0.1% ethionine-added, choline-deficient diet for 8 weeks to male Sprague-Dawley rats to prepare an animal model of chronic hepatic disorders. At the same time, UDCA (50 mg/kg/day) was administered orally to these animals, and its effects on the liver, including effects on hepatic blood flow determined with a laser Doppler blood flow meter, were evaluated. Hepatic blood flow increased significantly in the UDCA group compared with the untreated groups. Transaminase levels decreased significantly in the UDCA group compared with the untreated group. Histologic differences were noted between the UDCA and untreated groups in histopathologic examinations of the liver, with liver cirrhosis or early liver cirrhosis being present in the untreated group, compared with only chronic active hepatitis in the UDCA group. These findings suggest that UDCA is able to prevent or inhibit the progression of chronic hepatic disorders, an effect that may be due in part to increases in hepatic blood flow.

A case report of epithelioid leiomyosarcoma of transverse mesocolon: diagnosis and treatment

A case of epithelioid leiomyosarcoma of the transverse mesocolon in a 45-year-old man was reported. The patient had a rapidly growing mass in the left upper quadrant. Ultrasonography, gastrointestinography, and abdominal computed tomography showed that the mass was separated from the pancreas, the gastrointestinal tract, and the retroperitoneal organs. Preoperatively the primary origin of this tumor was related to the transverse mesocolon. On laparotomy the tumor of 5cm by 6cm by 3cm in size was found in the anterior left of the transverse mesocolon and the mass was resected entirely. The patient is well 18 months after surgical treatment with no evidence of recurrence.

Experimental use of pravastatin in patients with primary biliary cirrhosis associated with hypercholesterolemia

Primary biliary cirrhosis (PBC) is a refractory liver disease for which no medical treatment has been established. The investigators administered 20 mg/day of pravastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, to 2 PBC patients with hypercholesterolemia (1010 and 306 mg/dl) for 3 years and 10 months in order to decrease the blood concentration of bile acids and prevent adverse effects on the hepatocellular membrane. The drug markedly decreased not only cholesterol levels but also total bile acid levels, producing particularly pronounced decreases in cholic acid and chenodeoxycholic acid. Histologically, progression was inhibited in one patient, whereas improvement was seen in the other. Bile duct enzymes and other biochemical parameters showed improvement in both cases. General pruritus and blepharal and palmar xanthoma also improved. These findings suggest that pravastatin may be useful in the treatment of PBC associated with hypercholesterolemia.

Effects of a gastric mucosal protecting agent in rats with liver cirrhosis

Male Sprague-Dawley rats were fed a 0.1% ethionine-added choline-deficient diet for 8 weeks to induce liver cirrhosis. At the same time 100 mg/kg/day teprenone was administered orally in order to evaluate its effects on the liver and gastric mucosal blood flow. Blood flow increased not only in gastric mucosa but also in liver tissues in the teprenone group. Serum transaminase levels and histopathologic findings of the liver also improved. These findings suggest that teprenone alleviates hepatocellular injuries. This effect may be partly attributable to cytoprotective effects of the catenoid isoprenoid moiety of teprenone on liver cells.

[Effect of endothelin on gastric mucosal lesion in rats]

Gastric mucosal blood flow and gastric mucosal prostaglandin E2 (PGE2) and prostacyclin (PGI2) were investigated in male Wistar rats intraarterially injected with endothelin (ET), an endothelium-derived vasoconstrictor peptide. Immediately following ET (4 nmol/kg) administration, gastric mucosal blood flow decreased. Then 30 min later, the blood flow reached the minimum, but PGE2 and PGI2 showed the highest value. PGE2 showed a tendency to decrease 90 min later, while PGI2 continued to show high value. There were redness and hemorrhagic damage in the gastric mucosa. Endogenous PGs were presumed to be relate to the regulation of the development of the mucosal damage owing to decrease in the blood flow after ET administration.

[Clinical studies and sputum levels of ceftriaxone once daily administration in respiratory tract infection]

Ceftriaxone (CTRX), a new cephalosporin, was investigated by once daily administration for its clinical efficacy and safety on respiratory tract infections. The results obtained are summarized as follows: 1. Clinical responses to CTRX of a total of 39 cases with respiratory tract infections were excellent in 12 cases, good in 23, fair in 3, poor in 1 with an efficacy rate of 89.7%. Against acute bronchitis, lung abscess, bronchiectasis, chronic bronchitis and obstructive pneumonia, efficacy rates were 100%. 2. Serum levels and urinary excretion rates of CTRX were investigated in 2 cases after intravenous drip infusion of the drug at doses of 1 g and 2 g, respectively. Although urinary excretion rate tended to decrease with the deterioration of renal functions, prolongation of serum half-life was slight in those patients with normal liver function. In 1 case, it remained at 1.9 micrograms/ml at 12 hours and in another at 0.9 microgram/ml at 22 hours in sputum. According to the results, it appears that once daily administration of CTRX is effective and well tolerated in patients with acute respiratory infections.

[Immunological studies of aging and the family in gastric cancer, with special reference to cell-medical immunity]

Cell-mediated immunity of the aging and immune response in the family of gastric cancer have been investigated and the following results were obtained. Immune response particularly of cell-mediated immunity was found decreased in paralled with aging; decreases in peripheral lymphocyte and T-cell counts, rate of Con A and PHA induced blastoid transformation, and the tendency of increase in suppressor T-cell were noted. Investigations on the immune response in the family of gastric cancer revealed that cell-mediated immune response was recreased in the compared to age-matched healthy volunteers. These findings suggest that latent immunological failure may exist in the above family.