Relationship between serum adiponectin concentration, pulse wave velocity and nonalcoholic fatty liver disease

OBJECTIVES

We aimed to investigate the relationship between nonalcoholic fatty liver disease (NAFLD), serum adiponectin concentration and brachial-ankle pulse wave velocity (baPWV) as a risk marker for atherosclerosis.

METHODS

A total of 213 nonalcoholic subjects (67 males, 146 females) participated in this study. Division of subjects into the NAFLD group or the normal group was based on the existence of fatty liver detected by sonography.

RESULTS

Serum adiponectin levels in the NAFLD group were significantly lower than those in the normal group. After adjusting for age, body-mass index (BMI) and the homeostasis model of assessment (HOMA), there was a significant negative correlation between NAFLD and serum adiponectin level only in females (r = -0.22, P = 0.008). Multiple logistic regression analysis showed a tendency of inverse correlation between NAFLD and serum adiponectin level in females (P = 0.055). After adjustment for age, BMI and HOMA value, serum adiponectin levels were inversely correlated with serum alanine aminotransferase (ALT) and gamma-glutamyltranspeptidase (GGT) levels (r = -0.199 (P = 0.004) and r = -0.282 (P < 0.001)). On the other hand, baPWV in the NAFLD group was also significantly higher than that in the normal group in females (P = 0.005). Individual levels of serum ALT, aspatate aminotransferase (AST), alkaline phosphatase (ALP) and GGT were positively correlated with baPWV after adjusting for age, sex, BMI, HOMA and systolic blood pressure (P < 0.05).

CONCLUSION

Serum adiponectin level and baPWV were significantly associated with NAFLD and various liver enzymes, especially in females.

Inflammation, insulin resistance, and glucose intolerance in acute myocardial infarction patients without a previous diagnosis of diabetes mellitus

We examined the prevalence of impaired glucose metabolism and its association with inflammation and insulin resistance (IR) in acute myocardial infarction (AMI) patients without a previous diagnosis of diabetes. This prospective study enrolled 52 AMI patients, and 75-g oral glucose tolerance testing was performed on 30 patients at discharge and again 3 months later. We also measured serum adiponectin, high sensitive C-reactive protein, and IL-6 on both occasions. Data were compared with those of 30 type 2 diabetic patients without a history of AMI. Forty percent and 36.7% of AMI patients had impaired glucose tolerance (IGT) at discharge and at 3 months, respectively. The corresponding proportions for newly diagnosed diabetes are 33.0% and 30.0%. At discharge, AMI patients with IGT or diabetes showed higher high sensitive C-reactive protein and IL-6 levels compared with AMI patients with normal glucose tolerance or control type 2 diabetic patients. Furthermore, AMI patients with IGT or diabetes exhibited higher IR and lower serum adiponectin levels than AMI patients with normal glucose tolerance at 3 months after discharge. Previously undiagnosed diabetes and IGT are common in Korean patients with AMI. These glycometabolic abnormalities are associated with inflammation, IR, and serum adiponectin levels.

Relationship between brachial-ankle pulse wave velocity and cardiovascular risk factors of the metabolic syndrome

In this study, we investigated the association between brachial-ankle pulse wave velocity (baPWV), a novel non-invasive means of measuring atherosclerosis, and the cardiovascular risk factors of the metabolic syndrome. The study group comprised of 368 Koreans without history of diabetes or hypertension. Anthropometric parameters, blood pressure, fasting blood glucose (FBG), lipid profiles, ankle-brachial pressure index (ABI), and baPWV were measured in each subject. ABI and baPWV levels were higher in men than in women. ABI and baPWV levels were not correlated with each other. In women, baPWV was closely associated with the cardiovascular risk factors of the metabolic syndrome. Women with the metabolic syndrome showed higher baPWV levels compared to those without the metabolic syndrome (1540 +/- 281 versus 1312 +/- 223, P < 0.001). Multiple regression analysis showed that baPWV was significantly associated with systolic blood pressure, age, sex, waist circumference, and FBG (adjusted R2 = 0.548). The present study shows that baPWV is significantly associated with the features of the metabolic syndrome in Korean women.

Plasma and urinary vascular endothelial growth factor and diabetic nephropathy in Type 2 diabetes mellitus

AIMS

Vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis of diabetes mellitus. We determined whether alterations of plasma and urinary VEGF levels are related to diabetic nephropathy in Type 2 diabetic patients.

METHODS

One hundred and seven patients and 47 healthy controls were studied. Study subjects were divided into four groups using urinary albumin-to-creatinine ratio (ACR): a non-diabetic healthy control group (n = 47), a normoalbuminuric diabetic group (n = 37), a microalbuminuric diabetic group (n = 37) and an overt proteinuric diabetic group (n = 33). VEGF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary VEGF concentrations were significantly higher in the diabetic groups, even at the normoalbuminuric stage (log VEGF/Cr, normoalbuminuria; 4.33 +/- 1.06 vs. control; 3.53 +/- 0.79, P = 0.009). Urinary VEGF excretions increased as diabetic nephropathy advanced. (ii) Plasma and urinary VEGF levels were higher in hypertensive diabetic patients than in the normotensive individuals with diabetes. (iii) In those with diabetes, plasma VEGF levels were found to be positively correlated with plasma urea (r = 0.398, P = 0.039) and urinary ACR (r = 0.251, P = 0.044), and urinary VEGF to be positively correlated with urinary ACR (r = 0.645, P < 0.001), and creatinine (r = 0.336, P = 0.009), and to be negatively correlated with serum albumin (r = -0.557, P < 0.001). Urinary VEGF and serum creatinine were independently correlated with urinary ACR.

CONCLUSIONS

Urinary excretion of VEGF increased during the earlier stage of diabetic nephropathy and was significantly correlated with urinary albumin excretion. This suggests that urinary VEGF might be used as a sensitive marker of diabetic nephropathy and for predicting disease progression.

Serum adiponectin concentrations predict the developments of type 2 diabetes and the metabolic syndrome in elderly Koreans

OBJECTIVE

To determine whether low serum adiponectin concentrations are able to predict the future developments of type 2 diabetes and the metabolic syndrome using the National Cholesterol Education Programme (NCEP) criteria. We also investigated the stability of adiponectin levels and the relationships between baseline adiponectin levels and changes in the parameters related to the metabolic syndrome over a period of 3 years.

PATIENTS AND MEASUREMENTS

This prospective cohort study included 372 elderly Koreans who participate in the SWS (South-West Seoul) study, which was conducted in 1999 and 2002 in Seoul, Korea. Fasting and postchallenge 2-h plasma glucose, body mass index (BMI), waist-to-hip ratio (WHR), blood pressure, lipid profiles and serum adiponectin data obtained in 1999 and 2002 were examined.

RESULTS

The within-person variation between 1999 and 2002 of serum adiponectin was not significant (P = 0.61). Serum adiponectin was closely correlated with the risks factors of cardiovascular disease (CVD), that is negatively with BMI, WHR, blood pressure, triglyceride and blood glucose levels, and positively with high density lipoprotein (HDL)-cholesterol levels. Subjects with the metabolic syndrome showed lower serum adiponectin concentrations than those without the metabolic syndrome (P < 0.0001). Baseline adiponectin levels were found to be correlated with subsequent changes in WHR, low density lipoprotein (LDL)-cholesterol, fasting and postload 2-h glucose over the 3-year period, after adjusting for baseline values. Multiple logistic regression analysis showed that lower baseline serum adiponectin concentrations were significantly associated with the developments of type 2 diabetes and the metabolic syndrome after adjusting for age, sex, obesity, history of impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), hypertension and dyslipidaemia.

CONCLUSIONS

Reduced concentrations of adiponectin were found to be independently associated with increased risk of both type 2 diabetes and the metabolic syndrome in elderly Koreans.

Plasma and urinary vascular endothelial growth factor and diabetic nephropathy in Type 2 diabetes mellitus

AIMS

Vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis of diabetes mellitus. We determined whether alterations of plasma and urinary VEGF levels are related to diabetic nephropathy in Type 2 diabetic patients.

METHODS

One hundred and seven patients and 47 healthy controls were studied. Study subjects were divided into four groups using urinary albumin-to-creatinine ratio (ACR): a non-diabetic healthy control group (n = 47), a normoalbuminuric diabetic group (n = 37), a microalbuminuric diabetic group (n = 37) and an overt proteinuric diabetic group (n = 33). VEGF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary VEGF concentrations were significantly higher in the diabetic groups, even at the normoalbuminuric stage (log VEGF/Cr, normoalbuminuria; 4.33 +/- 1.06 vs. control; 3.53 +/- 0.79, P = 0.009). Urinary VEGF excretions increased as diabetic nephropathy advanced. (ii) Plasma and urinary VEGF levels were higher in hypertensive diabetic patients than in the normotensive individuals with diabetes. (iii) In those with diabetes, plasma VEGF levels were found to be positively correlated with plasma urea (r = 0.398, P = 0.039) and urinary ACR (r = 0.251, P = 0.044), and urinary VEGF to be positively correlated with urinary ACR (r = 0.645, P < 0.001), and creatinine (r = 0.336, P = 0.009), and to be negatively correlated with serum albumin (r = -0.557, P < 0.001). Urinary VEGF and serum creatinine were independently correlated with urinary ACR.

CONCLUSIONS

Urinary excretion of VEGF increased during the earlier stage of diabetic nephropathy and was significantly correlated with urinary albumin excretion. This suggests that urinary VEGF might be used as a sensitive marker of diabetic nephropathy and for predicting disease progression.

The associations between plasma adiponectin, ghrelin levels and cardiovascular risk factors

OBJECTIVE

Ghrelin is a recently discovered peptide, which is produced primarily in the stomach. This orexigenic peptide participates not only in the induction of mealtime hunger but also in long-term body weight regulation and energy homeostasis. Adiponectin is a protein secreted by adipocytes, and has been proposed to mediate obesity-related insulin resistance. Moreover, concentrations of adiponectin are reduced in individuals with obesity, insulin resistance and cardiovascular disease. However, human data are sparse about the direct relationship between adiponectin, ghrelin and cardiovascular risk factors including insulin resistance.

DESIGN

Three hundred and thirty-eight elderly Korean women (mean age+/-s.d., 72.3+/-5.5 years) were included in the present study.

METHODS

Plasma ghrelin and adiponectin levels were measured by RIA. Anthropometric measurements were taken and a 75 g oral glucose tolerance test performed. Fasting insulin and lipid profile were measured and insulin resistance was determined using the homeostasis model assessment insulin resistance index (HOMA-R) and the quantitative insulin sensitivity check index.

RESULTS

Plasma adiponectin levels were negatively correlated with central obesity indices such as waist circumference (r=-0.27, P<0.001) and waist-to-hip ratio (WHR) (r=-0.32, P<0.001), and with insulin resistance indices such as fasting insulin (r=-0.17, P=0.004) and HOMA-R (r=-0.13, P=0.035). Plasma ghrelin levels were negatively correlated with WHR (r=-0.12, P=0.03), but plasma adiponectin and ghrelin levels were not correlated (r=0.03, P=0.66). Multiple regression analysis showed that adiponectin was associated with WHR, fasting insulin and fasting glucose levels. When ghrelin was used as a dependent variable, only WHR remained in the final fitted model.

CONCLUSION

Fasting plasma adiponectin and ghrelin levels were found to be associated with central obesity or insulin resistance. However, plasma adiponectin and ghrelin concentrations were not associated with each other in elderly Korean women.

Comparison of serum concentrations of C-reactive protein, TNF-alpha, and interleukin 6 between elderly Korean women with normal and impaired glucose tolerance

This study was performed to compare concentrations of pro-inflammatory cytokines, such as interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha) as well as acute-phase protein, such as C-reactive protein (CRP) between subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT). The purpose of this study was to verify whether the pro-inflammatory cytokine-induced acute-phase response is a pathogenic mechanism in type 2 diabetes in elderly Korean women. A total of 1737 elderly subjects aged over 60 years participated in a population based study in Seoul, Korea (SWS Study 1999). Amongst them, a total of 232 non-smoking and non-diabetic female subjects aged 60-89 years was randomly selected and compared with each other. Higher serum high-sensitivity CRP (hs-CRP) concentrations were shown in subjects with IGT than those with normal glucose tolerance (median 1.2 versus 0.9, P < 0.05). Moreover, a relationship between serum hs-CRP concentrations and many components of the metabolic syndrome were detected. Serum pro-inflammatory cytokine IL-6 or TNF-alpha concentrations, however, were neither increased in subjects with IGT nor closely correlated with the components of the metabolic syndrome. In multiple regression analysis with stepwise selection method using hs-CRP as a dependent variable, it was found that white blood cell (WBC) counts, body mass index (BMI), fasting insulin, post-load 2h glucose, hematocrit and LDL cholesterol were significant independent variables. Our study confirms that increased acute-phase reaction is associated with impaired glucose tolerance and the metabolic syndrome in elderly Korean women. However, the hypothesis that pro-inflammatory cytokine-induced systemic inflammation is an early metabolic defect prior to onset of type 2 diabetes, is not supported in our study of elderly Korean women.

Relation between insulin resistance and hematological parameters in elderly Koreans-Southwest Seoul (SWS) Study

In this study, we investigated the relation between insulin resistance and hematological parameters in elderly Koreans. This study included 1314 non-diabetic subjects over the age of 60, selected from a cross-sectional study, which was conducted in 1999 in Seoul, Korea. We measured fasting and post-load 2 h plasma glucose, insulin levels, lipid profiles, anthropometric measures, and hematological parameters. The degree of insulin resistance was assessed using the homeostasis model assessment (HOMA). We found a correlation between insulin resistance and hemoglobin concentrations in non-smoking men (r=0.20, P=0.0186). In non-smoking women, insulin resistance correlated with hemoglobin (r=0.10, P=0.0017) and with white blood cell (WBC) count (r=0.15, P=0.001). Hemoglobin concentrations and WBC counts were also associated with other components of the insulin resistance syndrome such as body mass index, blood pressure, lipid profiles and fasting plasma insulin levels (surrogate for insulin resistance). Furthermore, the group in the upper quartile for insulin resistance showed higher hemoglobin concentrations and WBC counts than the lower quartile, independent of smoking status and serum iron concentrations. Using HOMA-IR as a dependent variable in a multiple regression analysis, age, body mass index (BMI), waist-to-hip ratio (WHR), systolic blood pressure, HDL cholesterol, triglyceride, WBC count, hemoglobin, hematocrit and serum TIBC were significant. Our results provide support for a relation between insulin resistance/hyperinsulinemia and hematological parameters such as hemoglobin concentrations and WBC counts in elderly Koreans. This suggests that increased erythropoiesis and subclinical inflammation could be part of the metabolic syndrome in elderly Koreans.

Factor analysis of the metabolic syndrome among elderly Koreans--the South-west Seoul Study

AIMS

To examine the relationship between the components of the metabolic syndrome and to explore whether insulin resistance unifies the clustering of components of the metabolic syndrome among urban elderly Koreans using exploratory factor analysis.

METHODS

We included 1314 non-diabetic subjects over the age of 60 years, selected from a cross-sectional study, which was conducted in 1999 in Seoul, Korea. Factor analysis was carried out using the principle components analysis with Varimax orthogonal rotation of the components of the metabolic syndrome.

RESULTS

We found four major factors of cardiovascular disease risk variables in our study subjects. Impaired glucose tolerance, dyslipidaemia, hypertension and obesity aggregated as the major domain. Obesity and dyslipidaemia variables were closely related and loaded on the same factor. However, hypertension was not linked closely with other factors of the metabolic syndrome.

CONCLUSIONS

Insulin resistance is not the only contributor to the metabolic syndrome among urban elderly Koreans. Although the components of the metabolic syndrome were closely related, the finding of more than one factor suggests that more than one pathophysiological mechanism underlies full expression of the metabolic syndrome among elderly Koreans.

Comparison of ADA and WHO criteria for the diagnosis of diabetes in elderly Koreans

AIMS

This study was conducted to compare the prevalence and cardiovascular risk factors of different categories of glucose tolerance in the elderly Korean population using World Health Organization (WHO) and American Diabetes Association (ADA) criteria.

METHODS

This study included 1456 non-diabetic subjects over the age of 60 years, selected from a cross-sectional study, which was conducted in 1999 in Seoul, Korea. Fasting and post-challenge 2-h plasma glucose, insulin levels, body mass index (BMI), waist-hip ratio (WHR), blood pressure, and lipid profiles were examined. Prevalence of glucose tolerance categories and the level of agreement (kappa statistics) were obtained using WHO 2-h criteria and ADA fasting criteria. Comparison of cardiovascular risk factors among several concordant and discordant glucose intolerance groups was done.

RESULTS

The prevalence rates of newly diagnosed diabetes of elderly men defined by WHO 2-h criteria and ADA fasting criteria were 11.8% and 4.8%, respectively. That of elderly women was 8.1% by WHO 2-h criteria and 3.1% by ADA fasting criteria. The prevalence of impaired glucose tolerance (IGT) by WHO criteria was also higher than that of impaired fasting glucose (IFG) by ADA criteria (23.5% vs. 10.0% men, 23.7% vs. 7.5% women). The level of agreement between ADA fasting criteria and WHO 2-h criteria was low (weighted kappa = 0.228 men, weighted kappa = 0.301 women). The concordant diabetic women by both ADA fasting criteria and WHO 2-h criteria showed higher BMI, WHR, diastolic blood pressure, total cholesterol and triglyceride levels than concordant normal subjects. However, the isolated post-challenge hyperglycaemia (IPH) women group was not different significantly from the concordant normal women group except in BMI.

CONCLUSIONS

Our results clearly show that the 1997 ADA fasting criteria are less sensitive for diagnosing diabetes than oral glucose tolerance test (OGTT)-based WHO criteria in elderly Koreans. Also, there is a poor agreement of different categories of glucose tolerance between ADA and WHO criteria; therefore, the OGTT remains a valuable test in diagnosing diabetes and classifying various categories of glucose intolerance, especially in elderly Koreans.

Molecules with shape memory based on restricted rotation

[reaction--see text] Diimide 1 and octaimide 2 both adopt two stable conformations at room temperature as a result of restricted rotation about two C(aryl)-N(imide) single bonds, a compact "folded" and an open "unfolded" structure. Predictable ratios of folded and unfolded rotamers can be achieved by heating in solvents of appropriate polarity as measured by the Reichardt's parameter (E(T30)). On cooling to room temperature, the resulting conformational changes are "locked in" as restricted rotation is reestablished.

Localization of matrix metalloproteinases on endometrial cancer cell invasion in vitro

OBJECTIVES

In this study, we have established an in vitro three-dimensional (3D) coculture, where normal endometrial stromal cells and endometrial cancer cells were cocultured under defined hormonal conditions, to investigate the potential paracrine effects on synthesis and secretion of matrix metalloproteinases (MMPs) and, thus, cancer invasion.

METHODS

Endometrial stromal cells were obtained by biopsy, cultured in the presence of 100 nM estrogen for 3 days, and then mixed with extracellular matrix (ECM) composed of collagen I and matrigel in a 4:1 ratio. After 3 more days in culture, a 3D coculture was established with HEC-1A cells, an endometrial adenocarcinoma cell line, grown on top of the mixture under various ovarian steroids (no steroid, 100 nM beta-estradiol (E2), or 1.0 microM progesterone (P4)) for 10 days. The expression and localization of MMP-2, MMP-9, and integrin beta 3 subunit were visualized by immunocytochemistry and analyzed by reverse transcription polymerase chain reaction (RT-PCR). The extent of cancer invasion was quantified by Boyden's chamber assay.

RESULTS

Integrin beta 3 subunit was localized along the cell surface of HEC-1A cell under all three hormonal conditions. MMP-2 was located in the cytoplasm of stromal cells and on the surface of HEC-1A cells. Synthesis and secretion of stromal MMP-2 were increased in the presence of ovarian steroids. In contrast, expression of stromal MMP-9 was suppressed in the presence of ovarian steroids. No MMPs were synthesized in HEC-1A cells. Invasion assay revealed that HEC-1A cells achieved high tumoral invasiveness in the presence of beta-estradiol.

CONCLUSIONS

These findings suggest that stromal cell-derived MMP-2 is translocated to the surface of HEC-1A cells. Integrin beta 3 subunit might contribute, in part, to providing a binding site for MMP-2. Thus, HEC-1A cells invade by recruiting MMP-2 secreted by stromal cells, which is greatly enhanced in the presence of beta-estradiol. The 3D coculture provides an excellent experimental system in which single parameters can be isolated from a complex in vivo system in the process of endometrial cancer invasion.

A case of adrenocortical tumor coexisted with paragangliomas

We report a case of adrenocortical tumor that coexisted with paragangliomas. A 35-year-old woman was admitted to the hospital because of left upper abdominal pain. A palm-sized mass was palpated at left upper quadrant. Hormonal studies revealed the features of pheochromocytoma. An emergency operation was performed because hemorrhage of the tumor was suspected. A 10 cm diameter ruptured mass was found in the left adrenal area and other tumors were also noted adjacent to inferior vena cava (IVC). The pathologic report revealed that the adrenal mass was an adrenocortical tumor with hemorrhagic necrosis and that the tumors adjacent to IVC were paragangliomas. This was the first case of adrenocortical tumor with paragangliomas in our Medline search result, hence we report the case with a review of the literature.

Investigation of juxtasellar and cerebellopontine angle meningiomas and neurogenic tumours: two-phase helical CT

We performed two-phase helical CT in 31 patients with juxtasellar region and cerebellopontine angle tumours to evaluate its usefulness in differentiating meningiomas from neurogenic tumours. After the intravenous injection of 90 ml contrast medium at 3 ml/s, axial helical images were obtained with delays of 30 and 120 s. After the delayed axial images, we acquired coronal images. Changes in attenuation were assessed visually and quantitatively (by comparing the attenuation in Hounsfield units). There were 17 meningiomas and 14 neurogenic tumours, all pathologically proven. Two-phase helical CT showed a decrease in attenuation in 15 (88%) meningiomas and an increase in 14 (100%) neurogenic tumours from early to delayed axial images. Coronal images showed a decrease in attenuation in all 17 meningiomas and an increase in 13 (93%) of the neurogenic tumours. The mean HU and their ratios were significantly different between meningiomas and neurogenic tumours.

Fra-1 expression in malignant and benign thyroid tumor

BACKGROUND

The differential diagnosis of thyroid nodules is very important in deciding the treatment modality and the fine needle aspiration is the best diagnostic method. But, there are some limitations in use because of inadequate test materials and difficulty in interpreting. According to the study of oncogene and tumor suppressor gene about the origin of thyroid tumor, expression of Fra-1, one of AP-1 complex, is increased in thyroid neoplasm, though not present in the normal tissue. So, there is a possibility that it will be used as a method for the differential diagnosis of thyroid nodules. We tried to know whether presence or absence of Fra-1 expression can be used as a diagnostic method in differential diagnosis of thyroid nodules using the immunohistochemical (IHC) staining method.

METHODS

In 4 types of thyroid tumor that were confirmed by histologic diagnosis after operation (18 cases of adenomatous goiter, 16 cases of follicular adenoma, 30 cases of papillary cancer, 10 cases of follicular cancer), IHC staining method was performed to evaluate the expression of Fra-1.

RESULTS

In papillary and follicular thyroid cancers, the expression of Fra-1 was stronger than in benign thyroid tumor, but there was no difference in Fra-1 expression between the two types of carcinoma. Weak expression of Fra-1 was observed in all cases of follicular adenoma, though it was weaker than in carcinoma, and it was also weakly expressed only in some cases (33%) of adenomatous goiter.

CONCLUSION

The expression of Fra-1 was stronger in thyroid cancer than in benign thyroid tumor, but it was impossible to differentiate thyroid cancer from benign thyroid tumor by presence or absence of Fra-1 expression using IHC staining method.

Transgenic and gene "knockout" models in alcohol research

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Paula L. Hoffman and Takeshi Yagi. The presentations were (1) cAMP signaling in ethanol sensitivity and tolerance, by Boris Tabakoff; (2) Synaptic signaling pathways of Fyn-tyrosine kinase, by Takeshi Yagi; (3) Ethanol drinking and sensitization in dopaminergic and serotonergic receptor knockouts, by Tamara J. Phillips; (4) ICAM-1 is involved in early alcohol-induced liver injury in the mouse given enteral alcohol, by Hiroshi Kono; and (5) Strategies for targeted and regulated knockouts, by Robert O. Messing and Doo-Sup Choi.

Dicobalt octacarbonyl catalyzed carbonylated cycloaddition of triynes to functionalized tetracycles

[reaction: see text]. We have demonstrated that a dicobalt octacarbonyl catalyzed double [2 + 2 + 1] carbonylative cycloaddition reaction of triyne can be carried out to yield a novel 5.5.5.6 tetracyclic di-enone system.

Inhibitory activity of berberine on DNA strand cleavage induced by hydrogen peroxide and cytochrome c

The inhibitory activity of berberine on the DNA single-strand cleavage induced by hydrogen peroxide and cytochrome c was measured. Berberine effectively inhibited single-strand cleavage of DNA and its effectiveness was concentration-dependent. As the berberine concentration increased, the inhibitory activity against the DNA single-strand cleavage increased. The treatments with 1, 5, 10, 50, and 100 microM berberine showed 7.7, 10.8, 32.2, 39.5, and 51.6% inhibition of DNA cleavage. This inhibitory activity of berberine against the DNA single-strand cleavage has never been reported previously. The inhibitory activity of berberine against DNA cleavage was stronger than caffeic acid and ascorbic acid. Berberine did not show strong hydroxyl radical scavenging activity, but showed strong superoxide anion radical quenching ability.

Cloning of a novel isoform of the mouse NBMPR-sensitive equilibrative nucleoside transporter (ENT1) lacking a putative phosphorylation site

We have isolated a mouse cDNA clone corresponding to a novel isoform of the NBMPR-sensitive equilibrative nucleoside transporter (ENT1). The cDNA contains a 6 bp deletion in the open reading frame that changes the amino acid composition in a consensus casein kinase II (CKII) phosphorylation site at Ser-254. The clone containing Ser-254 is termed mENT1.1 and the clone lacking the serine termed mENT1.2. The deduced amino acid sequence of mENT1.1 corresponds to the previously cloned human and rat ENT1 proteins at Ser-254. Tissue distribution studies show that mRNA for both ENT1 isoforms are ubiquitously co-expressed in mouse. Analysis of genomic DNA corresponding to mouse ENT1 indicates the isoforms can be produced by alternative splicing at the end of exon 7. CEM/C19 cells stably expressing mENT1.1 and mENT1.2 show similar dose response curves for NBMPR and dipyridamole inhibition of [(3)H]adenosine uptake as well as exhibiting comparable selectivity for both purine and pyrimidine nucleosides but not the corresponding nucleobases.

Serum insulin, proinsulin and proinsulin/insulin ratio in type 2 diabetic patients: as an index of beta-cell function or insulin resistance

BACKGROUND

Although insulin resistance and decreased insulin secretion are characteristics of established type 2 DM, which of these metabolic abnormalities is the primary determinant of type 2 DM is controversial. It is also not well known how insulin resistance and beta cell dysfunction influence serum insulin, proinsulin, proinsulin/insulin ratio in type 2 DM.

METHODS

We compared serum insulin, proinsulin and proinsulin/insulin ratio in type 2 diabetic patients and control subjects. We also investigated the relationship between serum insulin, proinsulin and proinsulin/insulin ratio and several biochemical markers which represent insulin resistance or beta cell function.

RESULTS

Insulin, proinsulin and proinsulin/insulin ratio were significantly higher in type 2 DM than control(p < 0.001). In diabetic patients, total insulin level was correlated with urinary albumin excretion rates(r = 0.224, p = 0.025) and body mass index(r = 0.269, p = 0.014). Proinsulin level was correlated with fasting C-peptide(r = 0.43, p = 0.002), postprandial 2 hour blood glucose(r = 0.213, p = 0.05) and triglyceride(r = 0.28, p = 0.022). Proinsulin/insulin ratio was positively correlated with fasting C-peptide(r = 0.236, p = 0.031), fasting blood glucose (r = 0.264, p = 0.015), postprandial 2 hour blood glucose(r = 0.277, p = 0.001) and triglyceride(r = 0.428, p < 0.001). In control subjects, insulin level was correlated with triglyceride(r = 0.366, p = 0.002). Proinsulin/insulin ratio was correlated with age(r = 0.241, p = 0.044).

CONCLUSION

The serum levels of insulin and proinsulin seem to be associated with several markers of insulin resistance. Whereas proinsulin/insulin ratio might represent beta cell function rather than insulin resistance. But more studies are needed to clarify the mechanisms of elevated proinsulin/insulin ratio in type 2 DM.

Genomic organization and expression of the mouse equilibrative, nitrobenzylthioinosine-sensitive nucleoside transporter 1 (ENT1) gene

We have cloned and characterized the genomic structure of the mouse gene for the NBMPR-sensitive equilibrative nucleoside transporter (mENT1), which is located on chromosome 17C. About 12-kb of genomic DNA was sequenced including the promoter region, 12 exons, 11 introns, and the 3'-untranslated region. All exon-intron junction sequences conform to the GT/AG rule. Primer extension analysis demonstrated a transcription initiation site located 252 bp upstream of the translation start site. Analysis of the 2.5-kb 5'-flanking sequence shows putative binding sites for several transcription factors, including GATA-1, IRF-2, Pit-1, myogenin, CREB, Sp-1, Ap-2, MAZ, and GR. We demonstrated that mouse ENT1 mRNA was highly expressed in heart, spleen, lung, liver, and testis. Lower levels of expression were detected in brain and kidney. Functional analysis of the 5'-flanking region showed that the nucleotide sequence from -652 to -111 contains cis-regulatory elements that promote gene expression. We found two Sp-1 binding sites (-296/-303, -307/-313) and two MAZ binding sites (-353/-359, -522/-528) in this region. Luciferase assay results suggest that MAZ and Sp-1 transcription factors are important positive regulators of transcription for the ENT1 gene in NG108-15 cells.

Serotonin 2B receptor is required for heart development

Several lines of evidence suggest that the serotonin (5-hydroxytryptamine, 5-HT) regulates cardiovascular functions during embryogenesis and adulthood. 5-HT binds to numerous cognate receptors to initiate its biological effects. However, none of the 5-HT receptor disruptions in mice have yet resulted in embryonic defects. Here we show that 5-HT(2B) receptor is an important regulator of cardiac development. We found that inactivation of 5-HT(2B) gene leads to embryonic and neonatal death caused by heart defects. 5-HT(2B) mutant embryos exhibit a lack of trabeculae in the heart and a specific reduction in the expression levels of a tyrosine kinase receptor, ErbB-2, leading to midgestation lethality. These in vivo data suggest that the Gq-coupled receptor 5-HT(2B) uses the signaling pathway of tyrosine kinase receptor ErbB-2 for cardiac differentiation. All surviving newborn mice display a severe ventricular hypoplasia caused by impaired proliferative capacity of myocytes. In adult mutant mice, cardiac histopathological changes including myocyte disarray and ventricular dilation were consistently observed. Our results constitute genetic evidence that 5-HT via 5-HT(2B) receptor regulates differentiation and proliferation of developing and adult heart. This mutation provides a genetic model for cardiopathy and should facilitate studies of both the pathogenesis and therapy of cardiac disorders in humans.

Expression of vascular endothelial growth factor in response to high glucose in rat mesangial cells

Diabetic nephropathy associated with hyperglycemia is characterized by glomerular hyperfiltration and endothelial dysfunction. Vascular endothelial growth factor (VEGF) is known to be primarily involved in neoangiogenesis and increased endothelial permeability. The purpose of this study was to investigate VEGF expression in response to high glucose in rat cultured mesangial cells and to identify its signal pathway via protein kinase C (PKC). Rat mesangial cells were cultured with different concentrations of glucose: normal (5 mM d-glucose), medium (15 mM d-glucose) and high (30 mm d-glucose). Calphostin-C as a PKC inhibitor and phorbol myristate acetate (PMA) as a PKC downregulator were instillated into culture media to evaluate the role of PKC in mediating the glucose-induced increase in VEGF expression. High glucose increased expression of VEGF at the mRNA and protein levels, identified by semi-quantitative RT-PCR and western blotting, within 3 h and in a time- and glucose concentration-dependent manner. Calphostin-C and PMA inhibited glucose-induced increases in VEGF expression at the mRNA and protein levels. In conclusion, high glucose can directly increase VEGF expression in rat mesangial cells via a PKC-dependent mechanism. These results suggest that VEGF could be a potential mediator of glomerular hyperfiltration and proteinuria in diabetic nephropathy.

Serum ferritin in healthy subjects and type 2 diabetic patients

In order to study the relationship between the serum ferritin level and the components of the insulin resistance syndrome in type 2 diabetic patients, we evaluated fifty type 2 diabetic patients who were selected according to NDDG/WHO criteria from those patients attending Korea University Hospital from 1997 to 1998. Twenty-five healthy non-diabetic subjects of comparable age and sex distribution acted as a control group. The results showed that the value of log ferritin was higher in the type 2 diabetes patients than the control subjects, but not at a statistically significant level (p = 0.09). Log ferritin was correlated with fasting blood sugar level (r = 0.235, p = 0.048) and body mass index (BMI) (r = 0.285, p = 0.05). In the type 2 diabetic patients, log ferritin was correlated with fasting C-peptide (r = 0.478, p = 0.009). In the control subjects, log ferritin was correlated only with BMI (r = 0.477, p = 0.012). In a stepwise multiple regression analysis, the diabetic group showed a significant correlation between fasting C-peptide and log ferritin (p = 0.001). In the control group, the fasting sugar level was significantly correlated with log ferritin (p = 0.034). These results suggest that serum ferritin can be employed as a marker of not only glucose homeostasis but also insulin resistance both in type 2 diabetic and control subjects.

Changes in biochemical bone markers during pregnancy and puerperium

To elucidate the changes in bone turnover during pregnancy and puerperium, we measured serially the levels of serum osteocalcin and urine deoxypyridinoline (Dpy) as markers of bone formation and bone resorption, respectively, in 22 healthy women with normal pregnancy. Nineteen non-pregnant women served as control. The Dpy levels increased significantly at 16 weeks of pregnancy and remained elevated thereafter. The levels of osteocalcin, however, were significantly decreased at 16 weeks of pregnancy and elevated later at 6 weeks postpartum. Bone turnover ratio (Dpy/osteocalcin) continued to rise during pregnancy, but returned to control levels 6 weeks after delivery. Dpy levels and bone turnover ratio during puerperium tended to be higher in 17 breast-feeding women than those of 5 exclusive bottle-feeders. In conclusion, bone resorption begins to increase from the second trimester of pregnancy and calcium release from bone tissue might play a major role in calcium homeostasis during the whole period of pregnancy as well as during lactation.

Basal signaling activity of human dopamine D2L receptor demonstrated with an ecdysone-inducible mammalian expression system

Basal signaling activity of the dopamine D2L (long isoform) receptor was investigated using an ecdysone-inducible mammalian expression system. Whereas basal signaling activity had been demonstrated for the D1, D2S (short isoform), D3, and D5 receptor subtypes, this issue has yet to be clearly resolved for the D2L receptors. An ecdysone-inducible mammalian expression system was used to express the dopamine D2L receptor in human embryonic kidney cells (HEK293). The two ecdysone analogs, muristerone A and ponasterone A, induced D2L receptor expression dose-dependently from 120 (non-induced) to 2000 fmol/mg protein which is similar to physiological D2 receptor density in dopaminergic brain regions. With this approach, we demonstrate significant basal D2L receptor activity. Basal and agonist-stimulated signaling activity, determined with assays of cAMP levels and [35S]GTPgammaS binding to assess G protein coupling, correlated with the level of receptor expression. Furthermore, among several antagonists tested, only fluphenazine and trifluoperazine exhibited clearly detectable inverse agonist activity. This differs from the D2S receptors, where most antagonists were reported to display full inverse agonism. Differences between inverse agonist effects of D2L and D2S antagonists may be relevant to the treatment of diseases involving dopamine D2 receptors.

Functional MR imaging of working memory in the human brain

OBJECTIVE

In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed.

MATERIALS AND METHODS

In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p <.001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks.

RESULTS

The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere.

CONCLUSION

The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory.

The expression of the high mobility group I(Y) mRNA in thyroid cancers: useful tool of differential diagnosis of thyroid nodules

OBJECTIVE

Thyroid nodule is frequent and occurs in about 5% of the general population. In contrast, thyroid cancer is much less frequent and occurs in about 5-10% of thyroid nodules. Distinguishing between benign and malignant lesions is an important task that is best accomplished by fine needle aspiration. Recently, Chiappetta et al. reported that the expression of the high mobility group (HMG) I(Y) proteins correlates with the malignant phenotype of human thyroid neoplasia, and suggested that the detection of the HMG I(Y) proteins might be a valid tool for an easy and sensitive discrimination assay between benign and malignant neoplastic thyroid disease.

METHODS

We evaluated the expression of the HMG I(Y) mRNA in 39 frozen thyroid tissues from patients with thyroid nodule by semiquantitative RT-PCR.

RESULTS

The expression of the HMG I(Y) mRNA was low in all of 10 normal thyroid tissues. In all of 3 adenomatous goiters, 6 follicular adenomas and 2 Hürthle cell adenomas, the HMG I(Y) mRNA expression level was low. In 11 of 13 papillary carcinomas and all of 5 follicular carcinomas, the HMG I(Y) mRNA expression level was high.

CONCLUSION

These results indicate that there is a correlation between the expression of HMG I(Y) and the malignant phenotype of thyroid cancer, suggesting that these proteins may be useful as a marker in thyroid cancer.

Salivary gland tumors: evaluation with two-phase helical CT

PURPOSE

To evaluate two-phase helical computed tomography (CT) in the characterization of salivary gland tumors.

MATERIALS AND METHODS

Sixty-four patients with major salivary gland tumors underwent two-phase helical CT. The histopathologic diagnosis was obtained by means of surgical resection or biopsy in all patients. After the injection of 90 mL of contrast material at a rate of 3 mL/sec, helical CT scans were obtained at early and delayed phases with scanning delays of 30 and 120 seconds, respectively. The attenuation change and enhancement patterns in the tumors were assessed. The attenuation change in the tumor also was assessed quantitatively as the ratio of the CT number (in Hounsfield units) at delayed phase scanning to that at early phase scanning.

RESULTS

There were 35 pleomorphic adenomas, nine Warthin tumors, and 20 malignant tumors. Two-phase helical CT showed increase in attenuation in 30 (86%) pleomorphic adenomas, decrease in eight (89%) Warthin tumors, and increase in 11 (55%) and no change in eight (40%) malignant tumors at delayed phase scanning. A multinodular enhancement pattern was found in only 12 (34%) pleomorphic adenomas. The ratio of CT numbers was significantly different between Warthin tumors and pleomorphic adenomas and between Warthin tumors and malignant tumors.

CONCLUSION

The analysis of enhancement patterns by using two-phase helical CT will be helpful in the differential diagnosis of salivary gland tumors.

BCG vaccine prevents insulitis in low dose streptozotocin-induced diabetic mice

Autoimmune type 1 diabetes mellitus is caused by the immunologic destruction of pancreatic beta-cells; therefore, there have been many attempts at immunologic modulation as a block or prevention of the underlying process. The aim of this study is to investigate the effect of BCG vaccination on low dose streptozotocin-induced diabetic (LDSD) mice. The mice were pretreated with BCG 7 days before starting low dose streptozotocin (STZ), observed body weight and blood glucose for 2 months, then analyzed the severity of the STZ-induced insulitis after the animals were sacrificed. In this experiment, the mean body weights in the BCG-STZ group on days 1, 19, 33, 47, and 61 of the experiment were 37.5 +/- 3.6, 37.3 +/- 3.6, 37.5 +/- 3.5, 39.4 +/- 3.9, and 39.3 +/- 4.5 (g), respectively. Those in the STZ group were 37.7 +/- 3.5, 38.3 +/- 4.5, 38.4 +/- 3.9, 36.2 +/- 4.5, and 36.3 +/- 4.0 (g), respectively (P < 0.05). The mean blood glucose levels in the BCG-STZ group on days 1, 19, 33, 47, and 61 were 106.5 +/- 8, 150 +/- 37, 147 +/- 54, 143 +/- 60, and 142 +/- 66 (mg/dl), respectively. Those in the STZ group were 103 +/- 12, 196 +/- 90, 261 +/- 236, 236 +/- 91, and 224 +/- 89 (mg/dl), respectively (P < 0.05). The numbers developing grade 0, I, II, III, and IV insulitis in the BCG-treated group were 63, 48, 33, 4, and 2, respectively, and in the control group were 16, 23, 31, 45, and 35, respectively. This study indicates that BCG vaccination reduces the development of insulitis and overt diabetes in LDSD mice.

Induction of c-Jun mRNA without changes of estrogen and progesterone receptor expression in myometrium during human labor

To elucidate the endocrine mechanism of human parturition, the expression of c-Jun and c-Fos mRNA were examined in relation to estrogen receptor (ER) and progesterone receptor (PR) in human myometrium. c-Jun mRNA was detected in all myometrial tissues (n=5) during labor but not before labor (n=5) and in oxytocin-resistant postterm pregnancy (n=3). c-Fos mRNA was detected in only one myometrial tissue from a woman in labor. The distribution and intensity of immunostaining for ER and PR were semiquantitatively scored. During the late pregnancies, no significant difference was seen in the receptor scores for myometrial ER and PR between the patients who experienced labor and those who did not. Receptor scores for ER and PR were significantly lower in postterm pregnancy than in late pregnancy, regardless of the labor status. These data suggest that there are no changes in ER and PR in human myometrium during parturition. On the other hand, postterm pregnancy is associated with low ER and PR. c-Jun, induced during labor without changes in ER and PR, may play a role as a signaling mechanism in human myometrium.

Mouse 5-HT2B receptor-mediated serotonin trophic functions

5-HT2B receptors, in addition to phospholipase C stimulation, are able to trigger activation of the proto-oncogene product p21ras. During mouse embryogenesis, a peak of 5-HT2B receptor expression is detected at the neurulation stage; we localized the 5-HT2B expression in neural crest cells, heart myocardium, and somites. The requirement for functional 5-HT2B receptors shortly after gastrulation, is supported by culture of embryos exposed to 5-HT2B-high affinity antagonist such as ritanserin, which induces morphological defects in the cephalic region, heart and neural tube. Functional 5-HT2B receptors are also expressed during the serotonergic differentiation of the mouse F9 teratocarcinoma-derived clonal cell line 1C11. Upon 2 days of induction by cAMP, 5-HT2B receptors become functional, and on day 4, the appearance of 5-HT2A receptors coincides with the onset of active serotonin transporter by these cells. Active serotonin uptake is modulated by serotonin suggesting autoreceptor functions for 5-HT2B receptors.

Apoptosis as a mechanism of 2-chloroethylethyl sulfide-induced cytotoxicity

Apoptosis is a mode of active cell death. We have examined whether 2-chloroethylethyl sulfide (CEES), a sulfur vesicating agent, triggers apoptosis as a cytotoxic mechanism. Incubation of thymocytes with CEES, resulted in an induction of apoptotic features of cell death. Treatment of cells with 100 microM CEES for 5 h increased DNA fragmentation to approximately 40% of control. The fragmentation of DNA was visualized by agarose gel electrophoresis. It showed ladder pattern of DNA fragmentation, which indicates internucleosomal cleavage of DNA. Further evidence of apoptosis was observed in morphological changes of nuclei by using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. The percentage of TUNEL positive cells was dependent upon CEES concentrations. CEES induced the classical morphological features of apoptosis in nucleus. These features were accompanied by condensation of chromatin, which arranged in sharply declined clumps and fragmentation of nucleus. To study requirement for synthesis of new protein in CEES-induced apoptosis, we studied the effect of cycloheximide for apoptotic activity. This protein synthesis inhibitor did not suppress the CEES-induced apoptotic activity. Taken together, these results suggest that CEES-induced apoptosis as a cytotoxicmechanism and this process occurs independent of synthesis of new protein.

Preferential expression of 5-HT1D over 5-HT1B receptors during early embryogenesis

The cloning and pharmacological characterization of mouse 5-HT1D receptors as well as the comparative analysis of its embryonic expression vs that of 5-HT1B receptors are reported. High densities of both 5-HT1D receptors mRNA and specific 5-HT1D binding sites were detected at 8, 9.5, 10.5 and 13.5 days of prenatal development. In contrast, no specific 5-HT1B binding sites could be detected until 13.5 days of development, when they were present at lower levels than 5-HT1D receptors. This differs markedly from the situation in the adult brain, in which 5-HT1B receptors are present at a much higher density than the 5-HT1D subtype. These data suggest the involvement of 5-HT1D receptors in the mitogenic and proliferative effects of serotonin during early embryonic development.

Rat ovarian insulin-like growth factor binding protein-4: a hormone-dependent granulosa cell-derived antigonadotropin

OBJECTIVE

To assess the in vivo regulation of ovarian insulin-like growth factor binding protein-4 (IGFBP-4) mRNA expression by gonadotropins and estrogen.

METHODS

Whole ovarian RNA, obtained from two models of follicular development, was extracted and analyzed by Northern blotting. Immature rats were treated with pregnant more serum gonadotropin (PMSG) followed 48 hours later with hCG, or alternatively were hypophysectomized and treated with FSH and/or diethylstilbestrol (DES). Localization of IGFBP-4 expression was assessed in the former study by in situ hybridization. Finally, the ability of human IGFBP-4 to antagonize FSH-stimulated progesterone accumulation was assessed in vitro.

RESULTS

The ovarian content of IGFBP-4 transcripts increased threefold (P < .05) at 12 hours after PMSG but was near baseline at 24 and 48 hours. The abundance of IGFBP-4 mRNA increased (P < .05) again at 6 and 24 hours after hCG. The expression of IGFBP-4 was localized to granulosa cells of preantral (untreated) and small antral (12 hours after PMSG) follicles. No IGFBP-4 expression was noted in large (gonadotropin-primed) antral follicles. Hypophysectomy increased (P < .05) the ovarian content of IGFBP-4 mRNA by 1.5-fold, an effect further enhanced (1.8-fold; P < .05) by the provision of FSH and DES. In vitro studies revealed the ability of increasing concentrations (0.01-1 microgram/mL) of recombinant human IGFBP-4 to inhibit the FSH-supported accumulation of progesterone.

CONCLUSION

Increased expression after administration of PMSG, hCG, and FSH/DES suggests that IGFBP-4 is a dynamic and hormonally responsive component of the ovarian cycle. The lack of expression in preovulatory follicles and its antigonadotropic actions in vitro imply that the attenuated expression of IGFBP-4 may constitute a requirement for successful follicular maturation.

5-HT2B receptor-mediated serotonin morphogenetic functions in mouse cranial neural crest and myocardiac cells

During embryogenesis, serotonin has been reported to be involved in craniofacial and cardiovascular morphogenesis. The detailed molecular mechanisms underlying these functions, however remain unknown. From mouse and human species, we have recently reported the cloning of 5-HT2B receptors which share signal transduction pathways with other 5-HT2 receptor subtypes (5-HT2A and 5-HT2C). In addition to phospholipase C stimulation, it appears that these three subtypes of receptor transduce a common serotonin-induced mitogenic activity, which could be important for cell differentiation and proliferation. We have first investigated the expression of 5-HT2 receptor mRNAs in the mouse embryo. Interestingly, a peak of 5-HT2B receptor mRNA expression was detected 8–9 days postcoitum, whereas there was only low level 5-HT2A and no 5-HT2C receptor mRNA expression at this stage. Expression of this receptor was confirmed by binding assays using a 5-HT2-specific ligand which revealed a peak of binding to membrane preparations from 9 days postcoitum embryos. In addition, whole mount in situ hybridisation and immunohistochemistry on similar stage embryos detected 5-HT2B expression in neural crest cells, heart myocardium and somites. The requirement for functional 5-HT2B receptors between 8 and 9 days postcoitum is supported by culture of embryos exposed to 5-HT2-specific ligands; 5-HT2B high-affinity antagonist such as ritanserin, induced morphological defects in the cephalic region, heart and neural tube. These antagonistic treatments interfere with cranial neural crest cell migration, induce their apoptosis, and are responsible for abnormal sarcomeric organisation of the subepicardial layer and for the absence of the trabecular cell layer in the ventricular myocardium. This report indicates for the first time that 5-HT2B receptors are actively mediating the action of serotonin on embryonic morphogenesis, probably by preventing the differentiation of cranial neural crest cells and myocardial precursor cells.

Detection of hypervascular nodular hepatocellular carcinomas: value of triphasic helical CT compared with iodized-oil CT

OBJECTIVE

The objective of this study was to compare the capability of arterial, portal venous, and delayed phases of helical CT with that of iodized-oil CT for revealing nodular hepatocellular carcinomas.

MATERIALS AND METHODS

Forty-eight patients with nodular hepatocellular carcinomas underwent triphasic helical CT examination with 10-mm collimation at 10-mm/sec table speed. We injected 120 ml of contrast material (36 g of iodine) at the rate of 3 ml/sec. Arterial-phase, portal venous-phase, and delayed-phase images were obtained with 30-sec, 65-sec, and 360-sec delays, respectively. All 48 patients also underwent angiography and intraarterial infusion of iodized oil after helical CT; iodized-oil CT was performed about 2 weeks after infusion of iodized oil. Helical CT images were compared with iodized-oil CT images for revealing hepatic nodules.

RESULTS

In 48 patients, 79 hepatocellular carcinomas were seen with iodized-oil CT. Using helical CT, the arterial phase revealed 68 lesions (86%), the portal venous phase revealed 53 lesions (67%), and the delayed phase revealed 57 lesions (72%). The arterial phase proved superior to the portal venous and delayed phases for revealing lesions (p = .0025). The portal venous phase showed no significant difference for revealing lesions compared with the delayed phase. When combined, helical CT of the arterial and portal venous phases revealed 73 lesions (92%); a combination of the arterial and delayed phases revealed 72 lesions (91%); and a combination of the portal venous and delayed phases revealed 63 lesions (80%). Any combination of two phases that included the arterial phase proved superior to the combination of the portal venous and delayed phases (p = .0033). Overall, the combination of the arterial and portal venous phases (92%) or the combination of all three phases (92%) proved best at revealing lesions.

CONCLUSION

The arterial phase of helical CT is better for revealing nodular hypervascular hepatocellular carcinoma than are the portal venous and delayed phases. The combination of the arterial and portal venous phases is superior to the arterial phase alone. Also, the combination of the arterial and portal venous phases is equal to the combination of the three phases for revealing hypervascular hepatocellular carcinomas.

Effects of calmodulin antagonists and anesthetics on the skin lesions induced by 2-chloroethylethyl sulfide

The effects of calmodulin antagonists and anesthetics on the skin lesions induced by an alkylating vesicant, 2-chloroethylethyl sulfide, were investigated using female hairless mice. 2-Chloroethylethyl sulfide, topically applied (0.6 microliter/5 mm in diameter) on the back skin of hairless mice, induced mild to moderate petechiae on the 1st day, and ulcers with a thick scab after 3 days. The healing process started after 6 days, resulting in shedding of scabs on 9.52 days. Water-soluble ointment bases showed some beneficial effects, whereas oily bases made the skin lesions worse. Trifluoperazine (0.5-1%) and thioridazine (2%), potent calmodulin antagonists, in Pluronic F-127 base substantially prevented the development of 2-chloroethylethyl sulfide-induced skin lesions. A similar effect was achieved with pentamidine (10%), another type of calmodulin antagonist, but not with ketoconazole, a weak calmodulin antagonist. In addition, anesthetics, such as lidocaine and pentobarbital, showed some protection, although at high concentrations (> 5%). As judged by the microscopic appearance, trifluoperazine successfully reduced the hemorrhage and the infiltration of inflammatory cells in early skin lesions, and the formation of thick scabs, which leads to granulomatous scar tissue in late lesions. These results suggest that some calmodulin antagonists and anesthetics in water-soluble bases might be a choice for the treatment of 2-chloroethylethyl sulfide-induced skin burns.

Spiral CT for the detection of hepatocellular carcinomas:relative value of arterial- and late-phase scanning

BACKGROUND

Spiral computed tomography (CT) can image the liver during arterial and late phases of contrast and optimize the evaluation of hypervascular tumor. The objective of this study was to evaluate the relative value of arterial- and late-phase spiral CT in the detection of hepatocellular carcinomas.

METHODS

Fifty-eight patients with hepatocellular carcinomas underwent two-phase spiral CT examination with 10-mm collimation at 10 mm/s table speed (Siemens Somatom Plus S), and 120 mL of contrast material (36 g iodine) was injected at the rate of 3 mL/s. CT images of hepatic arterial and late phases were obtained with a 35-s and 180-s delay, respectively.

RESULTS

In 58 patients, 111 hepatocellular carcinoma lesions were seen. The arterial phase detected 93 (84%) and the late phase 75 (68%) lesions (p < 0.01). The arterial phase detected more lesions in 11 patients, and the late phase detected more in two patients and an equal number in 45 patients. If lesions larger than 2 cm are excluded, the arterial phase detected 40 (74%) and the late phase 21 (39%) of 54 lesions (p < 0.001).

CONCLUSION

The arterial phase of spiral CT greatly improves the detection of hepatocellular carcinoma when compared with the late phase.

Immunohistochemical localisation of the serotonin 5-HT2B receptor in mouse gut, cardiovascular system, and brain

We recently reported the cloning of a new member of the serotonin 5-HT2 family, the 5-HT2B receptor. We now report the production and characterisation of a specific antiserum directed against the C-terminal portion of the mouse 5-HT2B receptor. After affinity purification, this polyclonal antibody recognises specifically the mouse 5-HT2B receptor. Immunohistochemical analysis of cryosections from various adult mouse tissues reveals a major 5-HT2B receptor expression in stomach, intestine and pulmonary smooth muscles as well as in myocardium. Furthermore, the antiserum recognises specific areas of the mouse brain, including cerebellar Purkinje cells and their projection areas.

Change in glutathione S-transferase and glyceraldehyde-3-phosphate dehydrogenase activities in the organs of mice treated with 2-chloroethyl ethyl sulfide or its oxidation products

Various organs or skin from male ICR mice treated intraperitoneally with 2-chloroethyl ethyl sulfide (CEES) or its oxidation derivatives 2-chloroethyl ethyl sulfoxide (CESSO) and 2-chloroethyl ethyl sulfone were analysed for changes in two thiol-containing enzymes, namely glutathione S-transferase (GST) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). CEES was more potent than its oxidation derivatives with respect to the decrease in organ weight and the loss in GAPDH activity, although the reverse was found in GST induction. Whereas the induction of GST was highest in the lung after multiple intraperitoneal intoxication with CEESO (8 and 32 mg/kg), the decrease in GAPDH activity after exposure to CEES (8 mg/kg body weight) was most remarkable in the spleen, the most susceptible organ to toxicity of CEES. GST and GAPDH activities in the skin of male hairless mice exposed subcutaneously to CEES (2 mg/kg body weight) were not altered significantly at 2-hr exposure, but decreased up to 60% of that of controls at 8 hr, when oedema formation was greatest. Taken together, it appears that GAPDH activity is a more sensitive biochemical parameter than GST activity in organs of mice treated with CEES or its oxidation products.

Ras involvement in signal transduction by the serotonin 5-HT2B receptor

The family of serotonin 5-HT2 receptors stimulates the phospholipase C second messenger pathway via the alpha subunit of the Gq GTP-binding protein. Here, we show that agonist stimulation of the 5-HT2B receptor subtype stably expressed in the mouse fibroblast LMTK- cell line causes a rapid and transient activation of the proto-oncogene product p21ras as measured by an increase in GTP-bound Ras in response to serotonin. Furthermore, 5-HT2B receptor stimulation activates p42mapk/p44mapk (ERK2/ERK1) mitogen-activated protein kinases as assayed by phosphorylation of myelin basic protein. Antibodies against p21ras, Galphaq, -beta, or -gamma2 subunits of the GTP-binding protein inhibit MAP kinase-dependent phosphorylation. The MAP kinase activation is correlated with a stimulation of cell division by serotonin. In addition to this mitogenic action, transforming activity of serotonin is mediated by the 5-HT2B receptor since its expression in LMTK- cells is absolutely required for foci formation and for these foci to form tumors in nude mice. Finally, we detected expression of the 5-HT2B receptor in spontaneous human and Mastomys natalensis carcinoid tumors and, similar to the 5-HT2B receptor transfected cells, the Mastomys tumor cells are also responsive to serotonin with similar coupling to p21ras activation.

Characterization of focal hepatic tumors. Value of two-phase scanning with spiral computed tomography

BACKGROUND

Spiral computed tomography (CT) allows imaging of the liver during the peak contrast material levels due to the capability of fast data acquisition. The objective of this study was to evaluate the usefulness of two-phase spiral CT in the differential diagnosis of focal hepatic tumors.

METHODS

One hundred two patients who had hepatic tumors (211 nodules; 149 hepatocellular carcinomas [HCCs], 36 metastases, and 26 hemangiomas) underwent two-phase spiral CT with 10-mm collimation at 10 mm/second table speed and 120 mL of contrast material injected at the rate of 3 mL/second. Computed tomography images of the hepatic arterial phase and late (equilibrium) phase were obtained at 35-second and 180-second delays, respectively. The enhancement patterns of tumors were divided into six types and were compared with the attenuation of surrounding liver parenchyma: totally high, peripherally high, centrally high, mixed, iso, and low.

RESULTS

The common enhancement patterns of HCC in two-phase spiral CT were totally high in the arterial phase and low (n = 63, 42%) or iso (n = 28, 19%) in the late phase. Metastasis showed peripherally nonnodular high attenuation (n = 9, 25%) or low attenuation (n = 9, 25%) in the arterial phase and low attenuation in the late phase, followed by totally high attenuation in the arterial phase and iso in the late phase (n = 6, 17%). Hemangiomas showed totally or peripherally nodular enhancement in the arterial and late phases (n = 23, 89%). In distinguishing hemangiomas from malignant tumors, totally high or peripherally nodular high attenuation in the late phase was the most useful contrast enhancement pattern (96% of hemangioma vs. 0% of malignant tumors). In distinguishing HCCs from metastases, a combination of contrast enhancement pattern of totally high attenuation in the arterial phase and low in the late phase was the most useful contrast enhancement pattern (42% of HCCs vs. 0% of metastases). The predictability of differentiation between hemangiomas and malignant tumors and between HCCs and metastases was 99% and 90% with spiral CT, respectively.

CONCLUSIONS

Two-phase spiral CT is useful in the differential diagnosis of focal hepatic tumors with evaluation of contrast enhancement patterns.

The mouse 5-HT2B receptor: homologous subtype or species variant?

The recently characterized 5-HT2B subfamily of serotonin receptors has now been reported from three different species: human, rat and mouse. Their genomic structures include 2 introns present at identical positions. Despite this similarity, their respective protein sequences show some diversities. In addition, the pharmacology of these receptors is distantly related, and their sites of expression vary amongst species. Thus, it appears difficult at present to unambiguously classify these receptors into the same subfamily, raising the possibility of the existence of other 5-HT2B-like receptors, yet to be discovered.

Contrast-enhanced MR angiography for the diagnosis of intracranial vascular disease: optimal dose of gadopentetate dimeglumine

OBJECTIVE

Although contrast-enhanced MR angiography has been shown useful in evaluating intracranial vascular lesions, particularly those with slow flow, the optimal dose of contrast material has not been found. Accordingly, we performed a study to determine the optimal dose of gadopentetate dimeglumine for contrast-enhanced MR angiography of intracranial vascular diseases.

SUBJECTS AND METHODS

In this prospective study, 152 consecutive adult patients suspected of having intracranial vascular diseases had cerebral MR angiograms. Images were obtained with a three-dimensional time-of-flight sequence with magnetization transfer saturation on a 1.5-T unit. Imaging parameters (43/8 [TR/TE], 20 degrees flip angle, 64 1-mm-thick sections) were identical in each MR angiogram. One hundred twenty-two of 152 patients were randomly assigned to receive one of four doses (0, 5, 10, or 20 ml) of gadopentetate dimeglumine for MR angiography (36, 37, 38, and 11 patients, respectively). In patients who had normal major cerebral arteries on MR angiograms, degree and extent of visualization of the cerebral veins and small intracranial arteries were rated blindly on a three-point scale, and the results were compared among the four groups given different doses of contrast material. In another 30 patients who had unenhanced and enhanced MR angiograms, the presence or absence of artifactual narrowing of the internal carotid artery or major cerebral arteries (caused by signal loss due to slow or turbulent flow seen only on unenhanced images) and the visibility of arteriovenous malformation were determined.

RESULTS

In nearly all patients, regardless of the dose of contrast material, the cerebral veins were well visualized on MR images. Degree and extent of visualization of the cerebral veins appeared to depend on the dose of contrast material. In the 20-ml injection group, venous overlap limited interpretation of the small and large arteries, whereas in the 5- and 10-ml groups, the signal intensity of the veins was much less intense, causing no difficulty in interpretation. However, no significant differences in visibility of the small arteries were apparent between the unenhanced and enhanced MR angiograms, even though the small vessels were better visualized in some patients who received either 5 or 10 ml of contrast material. In six of the 30 patients who had both unenhanced and enhanced MR angiograms, the unenhanced images showed artifactual narrowing of the internal carotid or middle cerebral arteries, which proved to be normal on contrast-enhanced MR angiograms. Venous sinuses or draining veins were better delineated on contrast-enhanced MR angiograms in all six patients with arteriovenous malformation.

CONCLUSION

Five to 10 milliliters of gadopentetate dimeglumine appears to be an optimal dose range for contrast-enhanced cerebral MR angiography. Use of this dose can help in differentiating true stenosis of large arteries from artifactual narrowing and in depicting small arteriovenous malformation with slow flow.