Local action of endogenous renal tubular atrial natriuretic peptide

Up-regulation of atrial natriuretic peptide (ANP) mRNA in the kidneys in several disorders has been demonstrated; however, evidence that ANP synthesized by the kidney exerts a local function has never been produced. Therefore, we investigated whether endogenous ANP could modulate high glucose-stimulated TGF-beta1, collagen type I and nuclear factor-kappaB (NF-kappaB) in NRK-52E cells using transfection of ANP and ANP small interfering RNA (siANP). NRK-52E cells were grown with or without transfection with ANP plasmid; cells were also transfected with ANP siRNA or control siRNA. These cells were then stimulated with a high glucose concentration to modulate ANP, TGF-beta1, collagen type I, NF-kappaB and IkappaB-alpha, and the results showed that ANP, TGF-beta1, collagen type I and NF-kappaB significantly increased in untransfected cells, and the transfection of ANP significantly attenuated high glucose-activated TGF-beta1, collagen I and NF-kappaB expression. ANP siRNA knocked-down ANP but significantly increased TGF-beta1 and collagen I under normal glucose conditions; ANP siRNA decreased IkappaB-alpha but strongly enhanced high glucose-activated TGF-beta1, collagen type I and NF-kappaB. In contrast, medium from ANP-transfected cells attenuated high glucose-activated TGF-beta1 and collagen type I expression in NRK-52E cells transfected with siANP. In conclusion, our results demonstrated that siANP increased activation of TGF-beta1, collagen type I and NF-kappaB in NRK-52E cells under high glucose conditions, and medium from ANP-transfected cells attenuated high glucose-activated TGF-beta1 and collagen type I. This is the first study to demonstrate the auto/paracrine action of endogenous ANP in renal tubular cells on the attenuation of hyperglycemia-activated TGF-beta1 and NF-kappaB expression. J. Cell. Physiol. 219: 776-786, 2009. (c) 2009 Wiley-Liss, Inc.

Elevated serum retinol-binding protein 4 concentrations are associated with renal dysfunction and uric acid in type 2 diabetic patients

BACKGROUND

While some studies have reported that retinol-binding protein 4 (RBP4) might induce insulin resistance, other studies have demonstrated that the presence of albuminuria in diabetic patients and increased uric acid are related to insulin resistance. Therefore, this study attempted to further investigate the relationship among serum RBP4, serum uric acid, and the severity of albuminuria in diabetic patients.

METHODS

A total of 95 type 2 diabetic patients and 16 healthy subjects participated in this study. Diabetic patients were classified into normoalbuminuria, microalbuminuria and macroalbuminuria groups according to their urine albumin-to-creatinine ratio (ACR). Serum RBP4 was measured by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum RBP4 was significantly elevated in type 2 diabetic patients with normoalbuminuria (43.4 +/- 14.9 microg/mL), microalbuminuria (57.3 +/- 24.2 microg/mL) and macroalbuminuria (64.7 +/- 27.6 microg/mL) as compared with control patients (32.6 +/- 10.0 microg/mL). Serum RBP4 was also significantly elevated in type 2 diabetic patients with microalbuminuria or macroalbuminuria as compared with the normoalbuminuric group. Serum RBP4 in diabetic subjects was positively correlated with triglycerides, uric acid and ACR, and negatively correlated with low-density lipoprotein cholesterol and estimated glomerular filtration rate (eGFR; with age and gender adjustment in each parameter). Multiple stepwise linear regression analysis showed that uric acid and eGFR remained significantly associated with serum RBP4.

CONCLUSIONS

Both eGFR and uric acid are significant determinants of serum RBP4, suggesting that the impaired renal clearance of early diabetic nephropathy affects RBP4 and indirectly supporting the hypothesized link among metabolic syndrome, uric acid and insulin resistance.

Pioglitazone retrieves hepatic antioxidant DNA repair in a mice model of high fat diet

Background

Pioglitazone was reported to improve hepatic steatosis and necroinflammation in human studies. To investigate whether the hepato-protective effect of pioglitazone was associated with an improvement of antioxidant defense mechanism, oxidative DNA damage and repair activity were determined in a high fat diet model. Male C57BL/6 mice were respectively fed with a 30% fat diet, the same diet with pioglitazone 100 mg/kg/day, or a chow diet as control for 8 weeks. Tissue oxidative stress was indicated by malondialdehyde concentration. Oxidative DNA damage was detected by immunohistochemical 8-oxoG staining. Enzymatic antioxidant defense was detected by the real-time PCR of superoxide dismutase (Sod1, Sod2) and DNA glycosylase (Ogg1, MutY). Oxidative DNA repair was detected by immunohistochemical staining and western blotting of OGG1 expression.

Results

Our results show that hepatic steatosis was induced by a high-fat diet and improved by adding pioglitazone. Malondialdehyde concentration and 8-oxoG staining were strongly increased in the high-fat diet group, but attenuated by pioglitazone. Gene expressions of antioxidant defense mechanism: Sod1, Sod2, Ogg1 and MutY significantly decreased in the high-fat diet group but reversed by pioglitazone co-administration.

Conclusion

The attenuation of hepatic oxidative DNA damage by pioglitazone in a high-fat diet may be mediated by up-regulation of the antioxidant defense mechanism and oxidative DNA repair activity. The diminution of oxidative damage may explain the clinical benefit of pioglitazone treatment in patients with non-alcoholic fatty liver disease.

Association between polymorphisms in DNA base excision repair genes XRCC1, APE1, and ADPRT and differentiated thyroid carcinoma

PURPOSE

DNA BER pathway is related with carcinogenesis. We hypothesized that functional polymorphisms of three BER genes, XRCC1, apurinic/apyrimidinic endonuclease (APE1), and ADPRT, confer risks for DTC and its progression.

EXPERIMENTAL DESIGN

Five common nonsynonymous single nucleotide polymorphisms (Arg194Trp, Arg280His, and Arg399Gln for XRCC1; Asp148Glu for APE1; and Val762Ala for ADPRT) were genotyped in Chinese DTC cases and controls.

RESULTS

The XRCC1-194Trp/Trp genotype showed a significantly increased risk for DTC (odds ratio, 1.85; 95% confidence interval, 1.11-3.07; P = 0.018). Subset analysis based on regional LN metastasis showed that the genetic effect came primarily from the subjects with LN metastasis (odds ratio, 4.54; 95% confidence interval, 2.11-9.79; P = 0.0001), but no significant association for subjects without LN metastasis. The other four single nucleotide polymorphisms did not show significant results. Haplotype analysis of XRCC1 polymorphisms yielded a significant result (P = 0.004), especially in the subjects with LN metastasis (P = 0.0002). Moreover, we found that XRCC1-194Trp and ADPRT-762Ala variants collectively contributed to an increased risk of the disease and LN metastasis, with the combined variant homozygotes exhibiting the highest 3.18-fold risk for DTC (P = 0.046) and 9.25-fold risk for DTC with LN metastasis (P = 0.004).

CONCLUSIONS

The XRCC1 polymorphisms, especially the 194Trp allele, may have an effect on DTC development and progression. This variant can interact with ADPRT-762Ala variant to further substantially increase susceptibility to the disease and regional LN metastasis. Identifying these risk genetic markers could provide more insight into the DTC pathogenesis and may also provide information to develop better prevention and therapeutic strategies.

Reappraisal of the characteristics of glucose abnormalities in patients with chronic hepatitis C infection

OBJECTIVES

There is growing evidence suggesting the mutual link between type 2 diabetes mellitus (T2DM) and hepatitis C virus (HCV) infection. However, the impact of HCV infection on the suite of glucose abnormalities has rarely been investigated. The study aimed to determine the difference regarding the prevalence and the characteristics of glucose abnormalities between chronic hepatitis C (CHC) patients and community-based controls. It also aimed to investigate the related clinical, virological, and histological features of glucose abnormalities in HCV infection.

METHODS

Six hundred eighty-three CHC patients and 515 sex-/age-matched controls were included. Oral glucose tolerance test (OGTT) was performed in 522 CHC patients and 447 controls without known T2DM. Clinical data were assessed upon the different stages of glucose abnormalities based on OGTT results.

RESULTS

The prevalence of normoglycemia, IGT, and T2DM in 683 CHC patients was 27.7%, 34.6%, and 37.8%, respectively. There was a significant linear trend from normoglycemia to T2DM in terms of age, family history of T2DM, and advanced liver fibrosis in CHC patients. For those CHC patients without fibrosis, the prevalence of glucose abnormalities reached 67.9% high. All CHC patients carried a significantly higher prevalence than controls regarding those aged <65 yr. For those without known DM, there was a 3.5-fold increase in the prevalence of glucose abnormalities in CHC (65.8%) patients in comparison with controls (35.3%) (OR 3.51, 95% CI 2.70-4.56, P < 0.001).

CONCLUSIONS

CHC patients carried a high prevalence of glucose abnormalities. Determination of glucose abnormalities by OGTT may be suggested.

Significant association of ABCG8:D19H gene polymorphism with hypercholesterolemia and insulin resistance

The absorption efficiency of cholesterol is closely correlated to dietary phytosterol content and determined by genetic factors. The ATP-binding cassette (ABC) transporters ABCG5 and ABCG8 act as a sterol efflux pump to regulate the absorption of cholesterol and phytosterol. The levels of cholesterol and phytosterol associated with a Chinese diet are very different from those associated with a Western diet. This study aims to explore the association between serum total cholesterol/LDL-C levels and ABCG5/ABCG8 polymorphisms in a Taiwanese population consuming an ordinary Chinese diet. A total of 1,046 subjects (894 men and 152 women) were recruited in a hospital-based health check-up center in Kaohsiung Medical University Hospital. Five nonsynonymous polymorphisms of Q604E (ABCG5), D19H, C54Y, T400 K and A632 V (ABCG8) were analyzed by TaqMan genotyping assay. Analysis showed that the D19H polymorphism of the ABCG8 gene was significantly associated with serum total cholesterol, LDL-C levels and HOMA-IR index. Adjusting for sex and age, subjects with the D19H (GC) genotype were significantly associated with a threefold higher risk of high cholesterol and LDL-C levels than subjects with D19 (GG). These results suggest that the D19H polymorphism of ABCG8 could be considered a susceptible gene marker indicating an increased likelihood of developing high cholesterol and LDL-C levels in Taiwanese consuming an ordinary Chinese diet. It is supposed that the coexistence of higher insulin resistance and hypercholesterolemia for carriers of the D19H polymorphism may result in a greater risk of cardiovascular disease.

Thiazolidinedione addition reduces the serum retinol-binding protein 4 in type 2 diabetic patients treated with metformin and sulfonylurea

Retinol-binding protein 4 (RBP4) has been found to induce insulin resistance and to be increased in type 2 diabetes. Thiazolidinediones (TZDs) can improve insulin sensitivity through the activation of peroxisome proliferators-activated receptor-gamma (PPAR-gamma) and have been suggested as an adjunct to metformin (MF) and sulfonylurea (SU) in type 2 diabetes in a consensus statement from the ADA and EASD. Therefore, we investigated whether TZD could affect serum RBP4 level in type 2 diabetes already treated with MF and/or SU. Eighty-one type 2 diabetic patients were divided into 2 groups: (1) TZD group (n = 55): Pioglitazone 30 mg/day was given as an add-on medication; (2) SU group (n = 26): Gliclazide MR 30-120 mg or glimepiride 2-8 mg/day was prescribed. The average period of study was 97.1 days. Serum RBP4 and adiponectin were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. The addition of pioglitazone (TZD group) markedly decreased homeostasis model assessment of insulin resistance (HOMA-IR) (P = 0.021) compared with the SU group (P = 0.688). The change of RBP4 in the TZD group (-3.87 +/- 11.27 microg/mL) significantly differed from that in the SU group (2.52 +/- 8.24 microg/mL, P < 0.012). The increase of adiponectin in the TZD group (11.49 +/- 7.85 microg/mL) was apparently higher than that in the SU group (1.54 +/- 5.62 microg/mL, P < 0.001). Despite the change of glycosylated hemoglobin (HbA1c) did not differ (-0.77 +/- 1.3 vs -0.50 +/- 1.7, P = 0.446), the addition of pioglitazone could significantly lower serum RBP4 and HOMA-IR values, whereas an increased dosage of sulfonylurea agents did not alter HOMA-IR, RBP4, or adiponectin in type 2 diabetic patients who had been treated with metformin and/or sulfonylurea.

Significant correlations between severe fatty liver and risk factors for metabolic syndrome

BACKGROUND AND AIM

It is known that ultrasonography (US) cannot differentiate between non-alcoholic fatty liver disease (NAFLD) and steatohepatitis. However, US can accurately estimate the severity of the steatosis. The clinical significance of severe hepatic fatty change by US has not been explored. The aim of this study was to investigate the relationship between the severity of the fatty liver, classified by US, and the degree of metabolic disorders with insulin resistance.

METHODS

In 16 486 Taiwanese patients, severity of fatty change on US was classified as follows: group A (n = 6950), absence of fatty change; group B (n = 8694), mild; and group C (n = 842), severe fatty liver change. Biometabolic parameters included body mass index (BMI), blood pressure (BP), fasting plasma glucose, triglycerides, cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum creatinine. Nominal logistic regression analysis was used to estimate the odds ratio for different degrees of fatty liver.

RESULTS

The frequencies of obesity, hypertension, glucose intolerance and hypertriglyceridemia were all significantly higher in group C than in group A or B (P < 0.0001), and the mean values of BMI, BP, fasting glucose, triglyceride and ALT were also higher in group C (P < 0.0001). High BMI (>or=30 kg/m(2)) appears to be the most important factor for progression from mild to severe fatty liver in both sexes.

CONCLUSIONS

The presence of severe fatty liver by US correlated significantly with the prevalence and degree of hypertension, abnormal glucose and triglyceride metabolism. Patients with severe fatty liver could be at an increased risk of atherosclerotic cardiovascular disease and should be screened regularly for metabolic disorders. The physician may also evaluate ALT and hepatic fat content by US in patients with metabolic syndrome. Evaluating the severity of fatty liver by US may be useful because it correlates with the status of hyperinsulinemia, the risks of developing cardiovascular disease, and the threshold for oxidative stress.

Vascular endothelial growth factor gene polymorphisms in thyroid cancer

Vascular endothelial growth factor (VEGF) is a potent stimulator for angiogenesis. It has been implicated in growth and metastasis of thyroid cancer. Three functional single nucleotide polymorphisms (SNPs) of VEGF (-2578C/A, -634G/C, and +936C/T) are known to be related with VEGF expression. We conducted a case-control study to evaluate the genetic effects of these three functional SNPs on the development of thyroid cancer and lymph node metastasis. A total of 332 cases and 261 controls were recruited for this study. The genotypes were determined by the TaqMan 5'-nuclease assay. Hardy-Weinberg equilibrium (HWE) was tested for each SNP, and genetic effects were evaluated by the chi(2)-test and multiple logistic regression. We used Bonferroni correction to account for multiple testing, and a two-tailed P value <0.017 was considered statistically significant. All three SNPs were in HWE. The A allele of -2578C/A (i.e. SNP rs699947) increased a risk for thyroid cancer (adjusted OR=136, 95% CI=1.02-1.81, P=0.039). Haplotype analysis yielded a less significant result (an empirical P value of 0.07). There was a tendency of increasing the frequency of the risk allele from controls, patients without lymph node metastasis to patients with lymph node metastasis (P(trend)=0.019). Further analysis showed that the genetic effect was only in men (adjusted OR=1.97, 95% CI=1.16-3.37, P=0.013) but not in women (adjusted OR=1.15, 95% CI=0.81-1.62, P=0.435). The other two SNPs did not show significant results. The A allele of the SNP rs699947 increased the risk of thyroid cancer development and regional lymph node metastasis in men.

A novel mutation of transferrin receptor 2 in a Taiwanese woman with type 3 hemochromatosis

Hereditary hemochromatosis (HH) is very rare in Asia. Here, we describe a Taiwanese woman presenting with fully developed characteristics of HH including bronze skin, DM, decreased MRI T2 signal intensity over liver and pituitary gland. Biochemistry of iron profile indicated a severe status of iron overload by serum iron: 194 microg/dL, serum ferritin: 6640 microg/L, transferrin saturation: 92.8%. By measuring the hepatic iron index 8.48 (>1.9) of her liver biopsy tissue, the diagnosis of HH was established. Diagnosis of non-HFE HH was carried out since the whole HFE genome was sequenced but failed to localize any genetic alterations. The whole genome of transferrin receptor 2 (TfR2) was sequenced and a novel mutation of 13528 G-->A (Arg 481 His) in exon 11 was detected. Therefore, type 3 hemochromatosis was confirmed. The distinct clinical features, extremely high iron index and impressive iron staining in her liver biopsy tissue may represent an aggravated iron deposition in the liver caused by this novel mutation. Our finding implicates functional importance of histidine in exchange of arginine at amino acid 481 of transferrin receptor 2 in iron homeostasis. This case reminds physicians in Asia to keep in mind that hemochromatosis could be a rare cause of DM.

Hepatitis C viremia increases the association with type 2 diabetes mellitus in a hepatitis B and C endemic area: an epidemiological link with virological implication

OBJECTIVES

There is growing evidence with regard to the association between hepatitis C virus (HCV) infection and type 2 diabetes mellitus (T2DM). However, the mutual link and related virological implication have not been fully clarified. The impact of hepatitis B virus (HBV) infection on the epidemiological link remains unclear. This study aimed to elucidate the link between T2DM and viral hepatitis infections, especially HCV infection. It also aimed to analyze the associated virological characteristics and implication.

METHODS

Cross-sectional analysis of a computer-sampling survey among 10,975 participants (aged 40-65 yr) was performed in an area endemic for HBV and HCV infections in Taiwan. Outcome measures included prevalence of T2DM among different groups of viral hepatitis infection, and comparison of related biochemical and virological profiles.

RESULTS

Of 10,975 participants studied, 9,932 eligible participants were analyzed. The prevalence of T2DM, seropositivity for HBV surface antigen (HBsAg) and HCV antibodies (anti-HCV), and HCV viremia was 12.5%, 13.1%, 6.5%, and 4.8%, respectively. Prevalence of HCV viremia showed significant difference between T2DM and non-T2DM subjects (6.9% vs 4.5%, P<0.001), whereas anti-HCV seropositivity showed borderline significance (7.8% vs 6.3%, P=0.047). There was no HCV genotype-specific difference between HCV genotype 1 and 2 in the association with T2DM. On the other side, the prevalence of HBsAg (+) did not differ between T2DM and non-T2DM subjects (12.5% vs 13.9%, P=0.19). The prevalence of T2DM among HCV viremic subjects (18.0%, 86/478) was significantly higher than HBsAg (+) subjects (11.4%, 155/1,363, P=0.001) and those negative for both viral hepatitis markers (12.5%, 997/8,004, P=0.001). Multivariate logistic regression analyses showed that HCV viremia was the leading significant factor associated with T2DM, followed by male gender, hypertension, body mass index, and age.

CONCLUSIONS

HBV infection did not increase the association with T2DM. A significant mutual link between T2DM and HCV viremia existed in this HBV/HCV endemic area. There was no HCV genotype-specific difference between HCV genotype 1 and 2 in the association with T2DM.

Metabolic risk factors in southern Taiwanese with impaired fasting glucose of 100 to 109 mg/dL

This study investigates the influence of changes in impaired fasting glucose (IFG) criteria by the American Diabetes Association in 2003 in estimating the prevalence and cardiovascular risks in Taiwanese with fasting plasma glucose (FPG) between 100 and 109 mg/dL. Data came from a cross-sectional study on 1411 participants aged 30 years and older without known diabetes in southern Taiwan. Besides collection of anthropometric and biochemistry data, a 75-g oral glucose tolerance test was performed. The new IFG criteria additionally identified 14.2% of all participants as having IFG100, with FPG between 100 and 109 mg/dL, among which the percentage of normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and diabetes mellitus were 7.7%, 5.0%, and 1.5%, respectively. Mean body weight, body mass index, abdominal girth, systolic blood pressure, diastolic blood pressure (DBP), 2-hour glucose, and triglyceride were significantly higher in the IFG100 group than in normal fasting glucose (NFG) group (FPG, <100 mg/dL). Moreover, body weight, body mass index, systolic blood pressure, DBP, and 2-hour glucose were statistically higher in subgroups of IFG100/IGT than in NFG/NGT. In contrast, only DBP and 2-hour glucose were significantly higher in the IFG100/NGT group than in the NFG/NGT group. The 2003 criteria increased the prevalence of IFG and identified more IGT and diabetes. However, the increase of cardiovascular risks among newly identified IFG100 subjects came from those who concomitantly had IGT.

SUMO4 M55V variant is associated with diabetic nephropathy in type 2 diabetes

OBJECTIVE-SUMO4 mRNA was recently found to be mainly expressed in the kidney, and the methionine-to-valine substitution at codon 55 (M55V) variant of SUMO4 may induce higher nuclear factor-kappaB (NF-kappaB) activity. Because NF-kappaB is known to mediate the development of diabetic nephropathy, we examined the association between the SUMO4 M55V variant and the severity of diabetic nephropathy. RESEARCH DESIGN AND METHODS-We recruited a total of 430 patients with type 2 diabetes. The M55V (rs237025, 163A-->G) polymorphism of SUMO4 was genotyped by real-time PCR, and urine albumin concentration was measured by radioimmunoassay. RESULTS-The frequencies of SUMO4 AA, GA, and GG were 52.6, 40.7, and 6.7%, respectively, in the normoalbuminuric group; 45.5, 47.3, and 7.1% in the microalbuminuric group; and 36.9, 46.2, and 16.9% in the macroalbuminuric group. We detected a significant linear trend for SUMO4 genotype between the macroalbuminuric and normoalbuminuric groups. The mean urine albumin-to-creatinine ratio (42.3 +/- 108.82 mg/mmol) in the GG group was significantly higher than in the AA (14.9 +/- 51.49 mg/mmol) and GA (17.0 +/- 43.74 mg/mmol) groups. Multivariate logistic regression analysis showed the SUMO4 M55V variant to be independently associated with the severity of diabetic nephropathy. CONCLUSIONS-This study indicates that the SUMO4 gene M55V variant is associated with severity of diabetic nephropathy in patients with type 2 diabetes.

ST-segment Elevation Acute Myocardial Infarction in a Patient with Acromegaly: A Case Report and Literature Review

Acromegaly is a disorder caused by the excess production of pituitary growth hormone and is characterized by the enlargement of the hands, feet and head. Increased morbidity and mortality with acromegaly is associated with cardiovascular complications, hypertension, glucose intolerance, cardiomyopathy and coronary artery disease. We report a case of acromegaly, which presented with ST-segment elevation acute myocardial infarction. The patient received successful primary transluminal coronary angioplasty with stent implantation. Acromegaly was suspected from typical appearance, and confirmed with hormonal examination and imaging of the pituitary mass. We discuss this case in comparison with previous literature.

Hypertriglyceridemia in a 5-day-old newborn--a case report

Neonatal hypertriglyceridaemia is extremely rare in pediatrics. We narrowed down the possibilities to a case of lipoprotein lipase (LPL) deficiency through a designed process of elimination with this particular patient. The biochemical hallmark of the disease is the presence of hyperchylomicronemia in fasting plasma. The patient responded well to a special formula containing median chain triglyceride (MCT). This was one of the youngest cases of hyperlipidemia and hyperlipoproteinemia to be reported during the neonatal period. Therefore the approach is mainly through the process of elimination because of inadequate laboratory facilities.

Insulin action and insulin secretion in newly diagnosed type 2 diabetic patients

To clarify the insulin action and insulin secretion in newly diagnosed type 2 diabetic subjects, we investigated insulin and C-peptide response to an oral glucose tolerance test (OGTT) in 15 newly diagnosed type 2 diabetic patients and 17 healthy subjects. For insulin action, we found fasting hyperinsulinemia (8.4 +/- 0.8 vs. 6.0 +/- 0.5 microIU/ml, p = 0.014), higher insulin resistance by homeostasis model assessment (HOMA) (4.33 +/- 0.2 vs. 1.34 +/- 0.1 microIU/ml.mmol/l, p < 0.001), and lower insulin sensitivity index (ISI) (51.0 +/- 0.7 vs. 104.0 +/- 0.8, p < 0.001) in newly diagnosed diabetic patients compared to normal subjects. For insulin secretion, the increments of AUCI (area under curve of insulin) and AUCC-P (area under curve of C-peptide) (increment of AUCI: 26.1 +/- 1.4 vs. 82.8 +/- 4.5 microIU/ml.hour, p < 0.001; increment of AUCC-P: 3.9 +/- 0.2 vs. 11.4 +/- 0.6 ng/ml.hour, p < 0.001), insulin secretion by HOMA model (20.7 +/- 1.2 vs. 79.1 +/- 3.8 IU/mol, p < 0.001), and ratio of 30 min increment of fasting insulin to glucose during OGTT (1.14 +/- 0.1 vs. 13.1 +/- 0.5 IU/mol, p < 0.001) were significantly lower in the newly diagnosed diabetic patients than normal subjects. In addition, body mass index (BMI) in our type 2 diabetes is relatively lower (24 +/- 0.65 kg/m2) than those in western countries. These findings revealed poor insulin action and decreased insulin secretion in relatively less obese Taiwanese with newly diagnosed type 2 diabetes.

Association of nephropathy and retinopathy, blood pressure, age in newly diagnosed type 2 diabetes mellitus

In this study, we investigated the prevalence of chronic complications, including nephropathy and retinopathy, in patients newly diagnosed as type 2 diabetes mellitus. All hyperglycemic subjects were recruited into our study when they visited the outpatient department at Kaohsiung Medical University Hospital over a one-year period. These subjects had fasting plasma glucose higher than 140 mg/dl, or plasma glucose higher than 200 mg/dl in the 2nd hour during an oral glucose tolerance test. Among 148 patients registered as newly diagnosed type 2 diabetes mellitus, 18.2% of the patients had nephropathy, noted by measuring their urine albumin excretion rate and daily protein loss, and 25.5% had retinopathy, noted by fundoscope and fluorescent angiography. The age of overt proteinuric patients (41.5 +/- 3.4 yrs) was significantly younger than those without nephropathy (51.8 +/- 1.0 yrs). Systolic and diastolic blood pressure was significantly higher in patients with microalbuminuria (142.4 +/- 6.0/88.8 +/- 2.6 mmHg) and overt proteinuria (153.8 +/- 13.6/96.8 +/- 9.5 mmHg) than normoalbuminuric patients (128.3 +/- 2.3/81.9 +/- 1.1 mmHg). There was no significant difference in cholesterol, triglyceride, HbA1C, sex or body mass index among normoalbuminric, microalbuminuric, or overt proteinuric patients. The severity of retinopathy was parallel with the severity of nephropathy. Based on our results, chronic diabetic complications, including nephropathy and retinopathy, may occur even when diabetes is newly diagnosed. It is necessary to look for complications, especially in newly documented diabetic patients who are young and hypertensive.

Thyroid metastasis from intraductal papillary-mucinous carcinoma of the pancreas. A case report

BACKGROUND

Intraductal papillary-mucinous carcinoma (IPMC) of the pancreas is a newly identified clinicopathologic entity of the exocrine pancreas. It has been considered a slowly growing and less-aggressive carcinoma with a favorable prognosis. There have been only a few documents reporting its distant metastasis and cytologic features, with no report of thyroid metastasis until the present.

CASE

A case of IPMC occurred in a 45-year-old male, who was admitted with rapid growth and tenderness of the thyroid. Abdominal computed tomography showed the typical cystic dilatation of IPMC with adjacent organ metastasis. Fine needle aspiration of the thyroid yielded papillary fronds of carcinoma cells with nuclear pleomorphism, abundant cytoplasm and prominent nucleoli in a mucinous background. Immunohistochemical findings from the skin and thyroid characterized the papillary-mucinous carcinoma as having originated in the pancreas.

CONCLUSION

This case suggests that papillary carcinoma fronds aspirated from the thyroid should be further differentiated from the primary site and that a pleomorphic nucleus in a mucinous background is a useful feature to exclude a thyroid origin. Before this, distant metastasis of IPMC to the skin and thyroid has not been reported. The prognosis of IPMC with wide, distant metastasis at an advanced stage is poor.

Neuronal and endothelial nitric oxide synthase expression in outer medulla of streptozotocin-induced diabetic rat kidney

AIMS/HYPOTHESIS

Several investigations have shown that the renal medulla has a greater capacity to generate nitric oxide than the renal cortex. To further evaluate the changes of nitric oxide synthesis in the kidney, particularly in the outer medulla, in disorders involving fluid and electrolyte imbalances, we sought to determine renal nitric oxide synthase expression in the diabetic rats.

METHODS

We determined renal nitric oxide synthase mRNA and urinary nitrite/nitrate excretion in 12 normal and 12 streptozotocin-induced diabetic rats by reverse transcription-polymerase chain reaction with Southern blot hybridization and with Griess reaction, respectively. Nitric oxide synthase immunoreactivity was detected by immunohistochemistry in four normal and four diabetic rats.

RESULTS

Neuronal and endothelial nitric oxide synthase mRNA were 3.5-fold and 1.8-fold increased in the outer medulla of 12 diabetic rats with no difference found in the cortex and inner medulla when compared with 12 normal rats. Urinary nitrite/nitrate excretion was significantly increased from the first week after diabetic induction. In normal rats, immunohistochemical studies showed positive neuronal and endothelial nitric oxide synthase immunostaining in almost all segments of renal tubules. Diabetic rats had the greatest enhancement of immunostaining for neuronal and endothelial nitric oxide synthase in the proximal straight tubule and medullary thick ascending limb.

CONCLUSION/INTERPRETATION

Our results indicate that increases in neuronal and endothelial nitric oxide synthase synthesis in the kidney, particularly in the outer medulla, possibly play an important part in the adaptation of renal function to hyperglycaemia and hyperosmolality in diabetes.

Increased nitric oxide synthase mRNA expression in the renal medulla of water-deprived rats

Increased nitric oxide synthase mRNA expression in the renal medulla of water-deprived rats.

BACKGROUND

Experiments were performed to investigate whether renal nitric oxide synthase (NOS) mRNA and protein expression are responsive to the alteration of body volume.

METHODS

Four days of water deprivation (WD) was initiated in 16 male Wistar rats, and 16 normal rats (NC) served as the control group. Neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) mRNAs and immunoreactivity were measured by reverse transcription-polymerase chain reaction (RT-PCR) followed by Southern blot hybridization and immunohistochemistry, respectively. Plasma angiotensin II, vasopressin, and atrial natriuretic peptide (ANP) concentrations were measured by radioimmunoassay.

RESULTS

The four-day WD increased plasma sodium and osmolality levels, but severely decreased daily urine sodium excretion and urine volume. Plasma angiotensin II and vasopressin concentrations were increased, but the plasma ANP level was significantly decreased in WD rats. nNOS, eNOS, and iNOS mRNA levels were increased by 5.2-, 3.3-, and 3. 4-fold in the outer medulla and 1.7-, 1.5-, and 1.8-fold in the inner medulla, whereas no significant difference was found in the renal cortex of WD rats as compared with NC rats. Additionally, immunohistochemistry revealed that the immunostaining intensity of nNOS, eNOS, and iNOS was clearly enhanced in the medullary thick ascending limb, proximal straight tubule, inner medullary collecting duct, and proximal convoluted tubule in WD rats. Kidney angiotensin II content as well as renin mRNA levels in renal cortex, outer medulla, and inner medulla in WD rats were apparently increased.

CONCLUSIONS

Our results indicate that the increases of nNOS, eNOS, and iNOS synthesis in the kidney, particularly in the renal medulla, may have a role in the adaptation of renal function to volume depletion in the face of an increase of systemic and intrarenal vasoconstrictive substances.

Increased urinary endothelin-1 excretion in newly diagnosed type 2 diabetic patients

To investigate whether urinary and plasma endothelin (ET)-1 concentrations are responsive to the alteration of intravascular blood volume in uncontrolled diabetic patients, we determined urinary ET-1 excretion and plasma ET-1 concentration in 42 newly diagnosed type 2 diabetic patients and 38 normal subjects. Mean fasting plasma glucose value (12.8 +/- 0.72 mmol l-1) and plasma renin activity (PRA, 2.80 +/- 0.44 ng ml-1 hr-1) in diabetic patients were significantly higher as compared to normal controls (mean plasma glucose value: 5.2 +/- 0.83 mmol l-1; mean PRA value: 1.34 +/- 0.17 ng ml-1 hr-1), whereas plasma ET-1 value (1.33 +/- 0.07 pmol l-1) was not significantly different from that (1.29 +/- 0.06 pmol l-1) of normal controls. Mean urinary ET-1 excretion level (7.53 +/- 0.74 nmol mol-1 creatinine) was significantly higher than that (5.36 +/- 0.37 nmol mol-1 creatinine) of normal controls. Urinary ET-1 excretion was correlated with plasma glucose value (r = 0.360, p < 0.05) and PRA value (r = 0.381, p < 0.05). Urinary ET-1 excretion rate (5.17 +/- 0.37 nmol mol-1 creatinine) and PRA value (1.42 +/- 0.18 ng ml-1 hr-1) declined to normal levels when mean plasma glucose value decreased to the level of 7.1 +/- 0.39 mmol l-1 in diabetic patients after 4 months of glycemic control. Our results indicated that renal-derived ET-1 was responsive to the alteration of intravascular blood volume in untreated newly diagnosed type 2 diabetic patients.

Increased urinary atrial natriuretic peptide-like immunoreactivity excretion but decreased plasma atrial natriuretic peptide concentration in patients with hyperosmolar-hyperglycemic nonketotic syndrome

OBJECTIVE

This study was undertaken to measure urinary atrial natriuretic peptide-like immunoreactivity (ANP-LI) and plasma ANP concentration in patients with hyperosmolar-hyperglycemic nonketotic syndrome (HHNS) to investigate the change of renal ANP-LI and cardiac ANP synthesis in volume-depleted diabetic patients.

RESEARCH DESIGN AND METHODS

The urine ANP-LI:creatinine ratio, plasma ANP level, and plasma renin activity (PRA) were measured in 12 patients with HHNS during the acute stage and after recovery, in 28 oral hypoglycemic agent (OHA)-treated type 2 diabetic patients, and in 23 normal subjects. ANP and PRA were measured by radioimmunoassay.

RESULTS

These HHNS patients had severe hyperglycemia and hyperosmolality as well as increased blood urea nitrogen, creatinine, and PRA levels, as compared with normal subjects and OHA-treated type 2 diabetic patients. In these patients, the urinary ANP-LI:creatinine ratio (11.69 +/- 2.11 pmol/mmol) was significantly increased in comparison with the normal group (1.78 +/- 0.11 pmol/mmol) and OHA-treated diabetic patients (2.43 +/- 0.45 pmol/mmol), whereas plasma ANP concentration (5.12 +/- 0.72 pmol/l) was significantly lower than the corresponding values of the normal group (7.39 +/- 0.85 pmol/l) and OHA-treated diabetic patients (8.43 +/- 1.05 pmol/l). All of these abnormalities were significantly ameliorated after insulin, fluid, and electrolyte replacement.

CONCLUSIONS

Our data show that urinary ANP-LI was significantly increased, whereas plasma ANP concentration was decreased, in the face of raised PRA in HHNS patients. This study indicates that renal ANP-LI substances and cardiac ANP may exhibit different responsiveness in diabetic patients with HHNS.

A patient of primary hyperparathyroidism with full-blown bone changes simulating malignancy

The two most common causes of hypercalcemia are malignancy and primary hyperparathyroidism (1 degree HPT). The radiographic presentations and the histological findings on bone biopsy are important for differential diagnosis of underlying diseases. We report a patient with hypercalcemia who presented unusual bone manifestations. A 43 y/o woman was admitted due to right femoral fracture. X-ray on the right tibia revealed several osteolytic cystic lesions with sclerotic rims. Blood biochemistry showed anemia, impaired renal function and hypercalcemia. Multiple osteolytic lesions on the skull and bilateral forearms were also noted. Malignancy, such as multiple myeloma or metastatic cancer was suspected. However, this was excluded because of the absence of M-component on serum protein electrophoresis and the negative finding of plasma cells or other malignant cell on bone biopsy examination. Abdominal sonography demonstrated bilateral medullary nephrocalcinosis. The final diagnosis of 1 degree HPT was made, based on the findings of classic pathological pictures (brown tumor) and the markedly elevated intact parathyroid hormone (1267.4 pg/ml) level. Sonography on the neck and 201Tl/99mTc parathyroid subtraction scan localized a left lower parathyroid tumor and fine needle aspiration confirmed the parathyroid origin. Diagnosis of 1 degree HPT could only be made from recurrent urolithiasis and X-ray picture of osteitis fibrosa cystica in the past. This patient presented the full-blown skeletal changes which are uncommonly seen nowadays. The characteristic sclerotic rims suggesting increased bone formation provides a further important clue for differential diagnosis of 1 degree HPT from other malignancies with osteolytic bone lesions.