Images of the month: Crystalglobulin-induced nephropathy.

We report a patient with chronic diabetes and was referred for recent onset proteinuria. Light microscopy of the renal biopsy specimen showed mildly expanded mesangium with mesangial hypercellularity and segmental sclerosis, features compatible with diabetic glomerulosclerosis. However, crystalglobulin-induced nephropathy with crystal deposit was identified on electron microscopy. Renal biopsy is often performed for diabetic patients who present with proteinuria and light microscopy often shows features of diabetic glomerulosclerosis. Additional information may occasionally be revealed on electron microscopy, altering the subsequent plan of management.

Histopathological correlations of islet amyloidosis with apolipoprotein E polymorphisms in type 2 diabetic Chinese patients.

OBJECTIVE: Islet amyloidosis and arteriosclerosis are histopathological hallmarks in type 2 diabetes. Apolipoprotein E (ApoE) is a common component of amyloidosis. ApoE [Latin Small Letter Open E]4 allele is associated with arteriosclerosis and cerebral amyloidosis in Alzheimer disease. We examined the correlations of ApoE polymorphisms with islet amyloidosis in type 2 diabetes. METHODS: Genomic DNA samples were obtained from 117 autopsy cases with type 2 diabetes and 209 nondiabetic cases. ApoE genotypes and amylin gene mutations were determined by polymerase chain reaction-ligase detection reaction analysis. Islet amyloidosis and arteriosclerosis were evaluated by staining of thioflavin T, amylin, ApoE, and amyloid P component. RESULTS: In the diabetic group, 33.3% in group [Latin Small Letter Open E]2 ([Latin Small Letter Open E]2[Latin Small Letter Open E]2, [Latin Small Letter Open E]2[Latin Small Letter Open E]3), 23.6% in group [Latin Small Letter Open E]3 ([Latin Small Letter Open E]3[Latin Small Letter Open E]3), and 62.5% in group [Latin Small Letter Open E]4 ([Latin Small Letter Open E]4[Latin Small Letter Open E]4, [Latin Small Letter Open E]3[Latin Small Letter Open E]4) had islet amyloidosis. After adjustment for confounders, group [Latin Small Letter Open E]4 had an odds ratio of 7.0 (95% confidence interval, 1.3-38.0; P = 0.023) in having islet amyloidosis compared to group [Latin Small Letter Open E]3. Diabetic cases with islet amyloidosis had more severe arteriosclerosis (P = 0.0111), arteriolar hyalinosis (P = 0.0369), and interstitial fibrosis (P = 0.0188) than those without amyloidosis. Immunoreactivity of both ApoE and amyloid P component was detected in islet amyloid deposits and arteriosclerotic lesions. CONCLUSIONS: In type 2 diabetes, islet amyloidosis and arteriosclerosis share common pathophysiological features with ApoE [Latin Small Letter Open E]4 as a probable linking factor.

Fatty acids inhibit insulin-mediated glucose transport associated with actin remodeling in rat L6 muscle cells.

In skeletal muscle cells, insulin stimulates cytoskeleton actin remodeling to facilitate the translocation of glucose transporter GLUT4 to plasma membrane. Defect of insulin-induced GLUT4 translocation and actin remodeling may cause insulin resistance. Free fatty acids cause insulin resistance in skeletal muscle. The aim of this study was to investigate the effects of fatty acids on glucose transport and actin remodeling. Differentiated L6 muscle cells expressing c-myc epitope-tagged GLUT4 were treated with palmitic acid, linoleic acid and oleic acid. Surface GLUT4 and 2-deoxyglucose uptake were measured in parallel with the morphological imaging of actin remodeling and GLUT4 immunoreactivity with fluorescence, confocal and transmission electron microscopy. Differentiated L6 cells showed concentration responses of insulin-induced actin remodeling and glucose uptake. The ultrastructure of insulin-induced actin remodeling was cell projections clustered with actin and GLUT4. Acute and chronic treatment with the 3 fatty acids had no effect on insulin-induced actin remodeling and GLUT4 immunoreactivity. However, insulin-mediated glucose uptake significantly decreased by palmitic acid (25, 50, 75, 100 µmol/L), oleic acid (180, 300 µmol/L) and linoleic acid (120, 180, 300 µmol/L). Oleic acid (120, 300 µmol/L) and linoleic acid (300 µmol/L), but not palmitic acid, significantly decreased insulin-mediated GLUT4 translocation. These data suggest that fatty acids inhibit insulin-induced glucose transport associated with actin remodeling in L6 muscle cells.

Up-regulated pancreatic tissue microRNA-375 associates with human type 2 diabetes through beta-cell deficit and islet amyloid deposition.

OBJECTIVES: The aim of this study was to examine correlations of the islet-specific microRNA-375 expression to islet amyloid formation and pancreatic islet damage in human type 2 diabetes. METHODS: Autopsy pancreas samples from 40 type 2 diabetic and 15 nondiabetic patients were used to detect microRNA-375 expression using real-time quantitative polymerase chain reaction. Serial paraffin sections of the corresponding type 2 diabetic and nondiabetic cases were stained by immunofluorescence to evaluate for amylin expression, amyloid formation, and proportions of alpha and beta cells. RESULTS: Pancreatic microRNA-375 expression was increased in type 2 diabetic patients comparing with the nondiabetic patients (median, 4.02 for the diabetic patients vs 0.92 for the nondiabetic patients; P = 0.0001). The median was 6.14 for the diabetic patients with islet amyloid and 3.51 for islet amyloid-free diabetic patients. The expression level of microRNA-375 correlated positively with the frequency and the severity of islet amyloid formation and negatively with proportions of islet beta-cells and amylin-positive area, and islet mitochondria density. CONCLUSIONS: Up-regulated microRNA-375 is associated with type 2 diabetes and pancreatic islet amyloid formation and beta-cell deficit. microRNA-375 may serve as a biomarker for known and novel pathways in the pathogenesis of type 2 diabetes related to islet amyloid deposition and beta-cell dysfunction.

Intrarenal expression of microRNAs in patients with IgA nephropathy.

MicroRNAs (miRNAs) are noncoding, single-stranded RNA molecules that have important roles in a number of physiological and pathological processes. Previous studies have proved that miRNAs targeting ZEB1 and ZEB2 may repress epithelial-to-mesenchymal transition. In this work, we studied the intrarenal expression of miR-200 family, miR-205 and miR-192 in patients with immunoglobulin A (IgA) nephropathy. We studied 43 patients with biopsy-proven IgA nephropathy (IgA group). The intrarenal expression of miRNAs was quantified and compared with that of 15 patients with noninflammatory glomerulosclerosis (GS group) and 20 patients with nephrectomy for kidney cancer as controls (CTL group). The level of intrarenal miR-200c was downregulated, whereas the levels of intrarenal miR-141, miR-205 and miR-192 were upregulated in IgA but not GS group. Proteinuria significantly correlated with the intrarenal expression of miR-200c (r=-0.324, P=0.011) and glomerular filtration rate (GFR) significantly correlated with the intrarenal expression of miR-205 (r=-0.280, P=0.030). The degree of tubulointerstitial scarring correlated with miR-205 expression (r=0.389, P=0.021), whereas glomerulosclerosis correlated with miR-192 expression (r=-0.311, P=0.045). The rate of GFR decline significantly correlated with the intrarenal expression of miR-192 (r=0.373, P=0.015). The intrarenal expression of E-cadherin significantly correlated with the intrarenal expression of miR-200c (r=0.392, P=0.002). The results show that intrarenal expression of miR-200c, miR-141, miR-205 and miR-192 was diversely regulated and correlated with disease severity and progression in patients with IgA nephropathy. These miRNA species may be important in the pathogenesis and progression of IgA nephropathy.

Urinary FOXP3 mRNA in patients with lupus nephritis--relation with disease activity and treatment response.

OBJECTIVE: Regulatory T lymphocytes (Tregs) probably play an important role in the pathogenesis of SLE. METHODS: We quantified messenger RNA (mRNA) expression of FOXP3, a critical regulator for the development and function of Tregs, in the urinary sediment of 25 subjects with active lupus nephritis (LN), 17 with inactive lupus and 7 healthy subjects. RESULTS: We found that the expression level of FOXP3 was significantly higher in urine from patients with active LN than from subjects with inactive lupus and healthy controls (24.5 +/- 45.8 vs 0.8 +/- 1.0 vs 0.6 +/- 0.8 copy; P < 0.001). In the active group, urinary FOXP3 mRNA expression level was higher in patients with proliferative LN than non-proliferative nephritis (34.6 +/- 56.3 vs 2.7 +/- 2.1 copy; P = 0.019). Urinary FOXP3 mRNA level significantly correlated with SLEDAI (r = 0.668; P < 0.001) and proteinuria (r = 0.414; P = 0.006). In the active group, urinary FOXP3 mRNA level also significantly correlated with histological activity index (r = 0.541; P = 0.009) and marginally with intra-renal FOXP3 mRNA level (r = 0.360; P = 0.08). Urinary FOXP3 mRNA in patients with no response to therapy was higher than those with partial response or complete response (57.6 +/- 69.8 vs 2.4 +/- 1.9 copies; P = 0.02). CONCLUSION: We concluded that urinary FOXP3 mRNA is markedly up-regulated in patients with active LN, and the level of expression is closely correlated with the clinical and histological disease activity. A high urinary FOXP3 mRNA in LN predicts a poor therapeutic response. Measurement of FOXP3 mRNA in urine sediment may be a non-invasive biomarker for assessing the severity and risk stratification in LN.

Progressive increase of genetic alteration in urinary bladder cancer by combined allelotyping analysis and comparative genomic hybridization.

Bladder cancer is the ninth most common cancer in the world. Urothelial carcinoma (formerly known as transitional cell carcinoma) comprises the majority of bladder cancers. In order to decipher the genetic alteration leading to the carcinogenesis of urothelial cancer, we performed genome-wide allelotyping analysis using 384 microsatellite markers spanning 22 autosomes together with comparative genomic hybridization (CGH) in 21 urothelial cancer. High frequency of allelic imbalance was observed in chromosome arm 1q (61.9%), 3p (61.9%), 4q (66.67%), 8p (57.14%), 9p (76.2%) and 9q (66.67%). Allelic imbalance with frequency above average was also observed in chromosome arm 2q, 10p, 10q, 11p, 11q, 12q, 13q, 15q, 17p and 19q. The allelic imbalance of each case and fractional allelic loss for each chromosome was associated with higher tumor grade and stage (P<0.05). We have also delineated several minimal deletion regions on chromosome 3p, 4q, 8p, 9p, 9q, 11p, 13q, 16q and 17p. By CGH analysis, common chromosomal alterations included gain of 1p, 1q, 12q, 16p, 17q and 19p as well as loss of 4q and 9p in most of the cases. Our findings may provide valuable information to locate putative oncogenes and tumor suppressor genes in the carcinogenesis of bladder cancer in this locality.

Apolipoprotein E polymorphism and expression in type 2 diabetic patients with nephropathy: clinicopathological correlation.

BACKGROUND: Diabetic nephropathy represents a heterogeneous group of renal pathologies that may be associated with genetic susceptibility. There have been clinical reports on the risk association of diabetic nephropathy with an apolipoprotein E (ApoE) exon 4 polymorphism although its correlations with renal histopathological changes have not been explored. METHODS: A total of 213 adult autopsies with type 2 diabetes and 111 non-diabetic control cases were analysed. Genomic DNA samples were obtained from spleen tissues. The ApoE genotype was determined by PCR-LDR analysis. Histopathological examination of kidney sections was performed in a subset of 51 diabetic and 111 control cases. ApoE protein expression in diabetic carriers with similar clinical status was examined by immunohistochemical staining. RESULTS: In type 2 diabetes, epsilon2 carriers (P = 0.04; odds ratio = 5.42; 95% CI: 1.10-26.8) and epsilon3/epsilon4 (P = 0.04; odds ratio = 22.5; 95% CI: 1.11-454.90) genotype carriers were more likely to have glomerular hypertrophy than were epsilon3/epsilon3 carriers. The epsilon2 carriers showed an increase in glomerular ApoE protein expression. A correlation between ApoE genotype and nodular glomerulosclerosis was not found. CONCLUSIONS: Our findings confirm the risk association of the ApoE polymorphism with diabetic nephropathy in clinical studies and is the first study demonstrating the correlations between ApoE genotypes, protein expression and structural changes in diabetic nephropathy.

Amyloid oligomers in diabetic and nondiabetic human pancreas.

The amyloid hypothesis of type 2 diabetes mellitus postulates that elevated levels of normally expressed monomeric proteins of human islet amyloid polypeptide (hIAPP) trigger oligomerization that independently causes fibril formation and disease progression. The aim of this study was to demonstrate the existence of amyloid oligomers in human pancreatic islets. Human pancreas tissues were obtained at autopsy of 8 nondiabetic control subjects (mean age = 75.8 +/- 11.7 years, 4 males), 8 type 2 diabetic cases without islet amyloid (mean age = 78.8 +/- 8.5 years, 4 males), and 8 type 2 diabetic patients with islet amyloid (mean age = 73.7 +/- 14.2 years, 4 males). Several markers for insulin, IAPP, amyloid fibrils (thioflavin T), and apoptosis (cleaved caspase-3) were used in combination with an oligomer-specific antibody. Two distinct forms of oligomers were found in pancreatic islets. Small spherical puncta were found in approximately 3% to 20% of the islet cells of nondiabetic subjects, and large curvilinear structures as extracellular oligomers were identified frequently in diabetic islets. Large oligomers were spatially localized adjacent to amyloid fibrils and were associated with apoptosis. This report demonstrates the presence of 2 morphologic classes of amyloid oligomers in human pancreatic islets. The observations warrant function studies to investigate the clinical implications of the amyloid oligomerization in the pathogenesis of type 2 diabetes.

Higher islet amyloid load in men than in women with type 2 diabetes mellitus.

OBJECTIVES: Type 2 diabetes mellitus is characterized histopathologically by islet amyloid deposits formed from islet amyloid polypeptide. The aim of this study was to investigate sex difference in islet amyloid of type 2 diabetic patients. METHODS: Pancreas specimens were collected from 235 autopsies with type 2 diabetes mellitus. Islet amyloid was identified with Congo red stain. The load of islet amyloid deposits was assessed by prevalence (percentage of cases with islet amyloid deposits), frequency (percentage of islets containing amyloid deposits), and severity (percentage of islet area occupied by amyloid deposits). RESULTS: Women (n = 80) and men (n = 155) had similar age of death, duration of diabetes, body mass index, and hemoglobin (Hb)A1c level. Islet amyloid was found in 30.0% of the women and in 44.5% of the men (P = 0.035). None of 9 women younger than 50 years had islet amyloid. Frequency of amyloid-affected islets was 31.5% +/- 13.1% in women and 41.1% +/- 14.3% in men (P = 0.008). Severity of amyloid-affected islet area was 29.0% +/- 12.5% in women and 38.5% +/- 14.6% in men (P = 0.007). CONCLUSIONS: Sex is a determinant of the development of islet amyloid in type 2 diabetes mellitus. This sex difference in islet amyloid may be related to a potential benefit of female sex hormones.

Fat redistribution and adipocyte transformation in uninephrectomized rats.

Dyslipidemia complicates renal function leading to disturbances of major homeostatic organs in the body. Here we examined the effect of chronic renal dysfunction induced by uninephrectomy on fat redistribution and lipid peroxidation in rats treated with an angiotensin-converting enzyme (ACE) inhibitor (lisinopril) for up to 10 months. Uninephrectomized rats developed fat redistribution and hypercholesterolemia typical of chronic renal failure when compared with sham-operated rats or lisinopril-treated uninephrectomized rats. The weight of the peri-renal fat was significantly less in the untreated compared to the lisinopril-treated uninephrectomized rats or those rats with a sham operation. We also found that there was a shift of heat-protecting unilocular adipocytes to heat-producing multilocular fat cells in the untreated uninephrectomized rats. Similarly in these rats we found a shift of subcutaneous and visceral fat to ectopic fat with excessive lipid accumulation and lipofuscin pigmentation. Lisinopril treatment prevented fat redistribution or transformation and lipid peroxidation. This study shows that ACE inhibition may prevent the fat anomalies associated with chronic renal dysfunction.

Topographical associations between islet endocrine cells and duct epithelial cells in the adult human pancreas.

OBJECTIVES: The pancreatic ducts, endocrine islets and exocrine acini are three functionally related components. From birth to adulthood, the islets and ducts are regarded as independent entities. The objective of this study is to investigate the topographical associations between the islet endocrine cells and duct epithelial cells in the adult human pancreas. MATERIALS AND METHODS: Panels of immunomarkers for the exocrine acinar cells (amylase), duct cells [cytokeratin 19 (CK19)], endocrine cells (chromogranin A, neurone specific enolase, synaptophysin) and islet hormones (glucagon, insulin, somatostatin, pancreatic polypeptide) were applied to sequential pancreatic tissue sections obtained from autopsy specimens of 10-nondiabetic human adults. Double immunofluorescent staining with CK19 and islet hormones was performed to confirm the islet to duct interrelationship. RESULTS: Sequential sectioning and immunostaining showed that 45% of the 172 islets examined appeared as single endocrine cell units or small clusters of < 10 endocrine cells on at least one plane of section. A topographical association was found between the islet endocrine cells and duct epithelial cells. Topographical associations with CK 19-stained duct cells occurred in 10.9% of the islet insulin-containing beta-cells and in 8.9% of the islet glucagon-producing alpha-cells. The frequency of topographical associations increased toward the more distally located duct systems. The CK19-stained duct cells and amylase-labelled acinar cells were less frequently in association with other islet hormone-producing cells. CONCLUSIONS: Topographical associations between islet endocrine cells and pancreatic duct cells are frequent in adult human pancreas. The islet-duct association suggests possible functional interactions between the two interrelated pancreatic compartments.

Use of the University of California Los Angeles Integrated Staging System (UISS) to predict survival in localized renal cell carcinoma in an Asian population.

OBJECTIVES: To evaluate the applicability of the University of California Los Angeles Integrated Staging System (UISS) in predicting the prognosis of Chinese patients with localized renal cell carcinoma after radical nephrectomy, with reference to that reported by Patard et al in an international multicenter study (J Clin Oncol 2004, 22:3316-3322). METHODOLOGY: One hundred and twenty-eight Chinese patients with localized renal cell carcinoma were stratified into low risk (LR), intermediate risk (IR) and high risk (HR) groups according to the UISS, based on the TMN staging and Fuhrman grading of the tumor and the Eastern Cooperative Oncology Group performance status of the patients. The survival curves of each risk group were then calculated. RESULTS: The number of patients in the LR, IR and HR was 24 (18.8%), 94 (73.4%) and 10 (7.8%) respectively. The estimated 2-year survival rates were 100%, 89.9% and 100% for the LR, IR and HR groups respectively. Whereas the estimated 5-year survival rates were 93.3%, 72.4% and 80% for the LR, IR and HR groups respectively. The LR and IR patients had comparable 2-year and 5-year estimated survival rates with those reported by Patard et al. However, the estimated survival rate for HR patients was better than that reported. CONCLUSIONS: UISS provided a valuable tool in predicting the survival of Chinese patients with localized renal cell carcinoma of LR and IR groups, as reported in other international centers. Further large scale study may be needed to confirm the applicability in HR population.

Expression and functional study of estrogen receptor-related receptors in human prostatic cells and tissues.

Estrogen receptor-related receptors (ERRs; alpha, beta, gamma) are orphan nuclear receptors and constitutively active without binding to estrogen. Like estrogen receptors (ERs), ERRs bind to estrogen receptor elements and estrogen receptor element-related repeats. Growing evidence suggests that ERRs can cross-talk with ERs in different cell types via competition for DNA sites and coactivators. We hypothesize that ERRs might play regulatory roles in normal and neoplastic prostatic cells by sharing similar ER-mediated pathways or acting independently. In this study, we investigated mRNA and protein expression patterns of three ERR members in normal human prostate epithelial cells, established cell lines, cancer xenografts, and prostatic tissues. Additionally, effects of transient transfection of ERRs on prostatic cell proliferation and ER expression were also examined. RT-PCR showed that ERRalpha and ERRgamma transcripts were detected in most cell lines and xenografts, whereas ERRbeta was detected in normal epithelial cells and few immortalized cell lines but not in most cancer lines. Similar results were demonstrated in clinical prostatic specimens. Western blottings and immunohistochemistry confirmed similar expression patterns that ERR proteins were detected as nuclear proteins in epithelial cells, whereas their expressions became reduced or undetected in neoplastic prostatic cells. Transient transfection confirmed that ERRs were expressed in prostatic cells as nuclear proteins and transcriptionally active in the absence of estradiol. Transfection results showed that overexpression of ERRs inhibited cell proliferation and repressed ERalpha transcription in PC-3 cells. Our study shows that ERRs, which are coexpressed with ERs in prostatic cells, could regulate cell growth and modulate ER-mediated pathways via interference on ERalpha transcription in prostatic cells.

Clinicopathologic characteristics of nodular glomerulosclerosis in Chinese patients with type 2 diabetes.

BACKGROUND: Nodular glomerulosclerosis is a distinct entity that is highly specific for diabetic glomerulopathy. However, clinicopathologic characteristics of this nodular lesion are largely undefined in patients with type 2 diabetes. METHODS: An autopsy study was conducted to investigate the clinical, histopathologic, and histochemical characteristics of 351 consecutive cases with type 2 diabetes. In addition, immunohistochemical staining was performed in a representative subset of 50 cases. RESULTS: Nodular glomerulosclerosis was found in 37.6%. Hypertension, elevated serum creatinine and urea levels, renal failure, myocardial infarction, low body mass index, and large glomerular matrix area were the significant risk factors for nodular glomerulosclerosis. Proteinuria (protein > 0.5 g/24 h), renal insufficiency (serum creatinine > or = 2.0 mg/dL [> or =178 micromol/L]), and renal failure were found in 28.1%, 33.6%, and 7.6% of patients with type 2 diabetes with nodular glomerulosclerosis, respectively. Glomerular matrix fractions were 42.1% +/- 13.3%, 32.3% +/- 15.3%, and 22.7% +/- 8.0% in patients with nodular glomerulosclerosis, non-nodular glomerulopathy (glomerulopathy in the absence of Kimmelstiel-Wilson nodule), and near-normal glomeruli with age-related minimal changes, respectively (analysis of variance, P < 0.001). Immunoreactivity for collagen type IV, fibronectin, and laminin was localized at the periphery of mesangial nodules. Mesangial cells at the periphery of mesangial nodules showed increased staining intensity for alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta1 (TGF-beta1). Nodular lesions also showed a marked increase in number of glomerular CD68-positive macrophages. CONCLUSION: In patients with type 2 diabetes, nodular glomerulosclerosis is related to hypertension, advanced renal disease, and prevalent myocardial infarction. Glomerular macrophage infiltration, expression of alpha-SMA by mesangial cells, and overexpression of TGF-beta1 are the cellular changes associated with abnormal extracellular matrix deposition in nodular glomerulosclerosis.

Association of glomerulopathy with the 5'-end polymorphism of the aldose reductase gene and renal insufficiency in type 2 diabetic patients.

The expression of nephropathy in type 2 diabetes has several levels of abnormalities. To define the primary abnormalities of diabetic nephropathy, we conducted an autopsy study of 186 consecutive patients with type 2 diabetes to determine correlations among the aldose reductase gene, renal histopathologies, extracellular matrix, glomerular function, and clinical characteristics. Compared with cases of near-normal renal structure (n = 51) and atypical diabetic glomerulopathy (n = 75), patients with classic diabetic glomerulopathy (n = 60) had advanced glomerular disease, as reflected by elevated plasma creatinine levels (133.2 +/- 59.8 vs. 166.0 +/- 65.7 vs. 243.8 +/- 82.6 micromol/l; P < 0.001), glomerular matrix fractions (20.8 +/- 6.7 vs. 33.5 +/- 16.8 vs. 39.2 +/- 14.3%; P < 0.001), and risk of renal failure (odds ratio [OR] 1 vs. 3.5 vs. 21.4; P < 0.001). Compared with noncarriers of the aldose reductase z-2 allele (n = 92) and z-2 heterozygotes (n = 77), z-2 homozygotes (n = 17) had elevated plasma creatinine (164.1 +/- 73.7 vs. 190.6 +/- 60.9 vs. 241.1 +/- 86.2 micromol/l; P < 0.001) and an increased risk of classic diabetic glomerulopathy (OR 1 vs. 0.9 vs. 3.3; P = 0.026). Overexpression of transforming growth factor-beta1, mesangial cell transdifferentiation by expression of alpha-smooth muscle actin, and aberrant deposition of collagen type IV, fibronectin, and laminin were found in classic diabetic glomerulopathy. These data suggest genetic, biochemical, pathophysiological, and clinical correlations among the aldose reductase gene, extracellular matrix, classic diabetic glomerulopathy, and renal insufficiency. Gene mutation, cellular transdifferentiation, growth factor upregulation, extracellular matrix expansion, and glomerular filtration impairment are the primary abnormalities in type 2 diabetic patients with nephropathy.

Prevalence and clinicopathological characteristics of islet amyloid in chinese patients with type 2 diabetes.

Islet amyloid has been suggested to be an important link between insulin resistance and beta-cell dysfunction in type 2 diabetes. To investigate the prevalence and clinicopathological characteristics of islet amyloid, we examined consecutive autopsies of 235 Chinese patients with type 2 diabetes and 533 nondiabetic subjects. Islet amyloid deposits were identified using Congo red staining and quantitated by image analysis. We found that 3.0% of the nondiabetic subjects versus 39.6% of the diabetic patients displayed islet amyloid (P < 0.001). In diabetic patients, the amyloid deposits occupied a mean islet area of 36.2%, which was positively associated with BMI, blood pressure, and glycemic control. Pancreatic fibrosis and fat infiltration were more frequently found in diabetic patients with islet amyloid than those without islet amyloid, whereas pancreatic arteriosclerosis was identified in all diabetic patients. These findings suggest that islet amyloid deposits reflect greater insulin resistance and islet failure in a subgroup of type 2 diabetic patients. Islet failure may also have been exacerbated by fat infiltration, fibrosis, and arteriosclerosis. Optimal blood pressure and metabolic control may reduce these pathological changes and help preserve islet cell mass.

Frequent hypermethylation of promoter region of RASSF1A in tumor tissues and voided urine of urinary bladder cancer patients.

High frequency loss of 3p21.3 region where RASSF1A located was demonstrated in several tumors. We aimed to investigate the methylation status of RASSF1A and the frequency of LOH in 3p21.3 region in bladder cancer. Three bladder cancer cell lines, 40 cases of bladder TCC and 14 cases of paired voided urine samples were subjected to methylation analysis. By methylation specific PCR, complete methylation of promoter region of RASSF1A gene were detected in cell lines T24 and UMUC3. Demethylation treatment re-expressed RASSF1A in these 2 cell lines. Methylation of RASSF1A was also detected in 47.5% (19/40) of the TCC cases but not in 6 carcinoma in situ (CIS) or 6 normal urothelium samples. For LOH study, loss of 3p21.3 region was detected in 57.9% (11/19) of our cases. Interestingly, methylation of RASSF1A was found in 72.7% (8/11) of the cases with LOH but only in 12.5% (1/8) of the cases without LOH. Methylation of RASSF1A was detected in 50% (7/14) of voided urine samples, but not in normal control. It showed a higher sensitivity than conventional urine cytology in detecting cancer cells, especially for low grade cases. In conclusion, our results demonstrated a high frequency of RASSF1A methylation with frequent LOH in 3p21.3 region in bladder cancer. It suggested that it may be a potential tumor suppressor gene in this chromosomal region and can be silenced by promoter hypermethylation. Detection of aberrant gene methylation in routine voided urine was feasible and may provide a non-invasive and sensitive approach for cancer detection.

Impact of experimental acute hyponatremia on severe traumatic brain injury in rats: influences on injuries, permeability of blood-brain barrier, ultrastructural features, and aquaporin-4 expression.

The effects of acute hyponatremia on severe traumatic brain injury (TBI) in 35 adult male Sprague-Dawley rats were studied in a replicated focal and diffuse injury rat model. Such effects were assessed by the cerebral contusion volume and axonal injury (AI) densities, determined by quantitative immunoreactivity of beta-amyloid precursor protein, by blood-brain barrier (BBB) permeability based on endogenous IgG immunostaining, and by ultrastructural features. Significant increase of contusion volume (P < 0.05) and of AI in the segment of corpus callosum beneath the contusion (P < 0.05) and ipsilateral thalamus (P < 0.05) were observed at 4 h postinjury during the hyponatremic phase. No change in BBB permeability was observed in the hyponatremia + TBI (HT) groups. Significant swelling of perivascular astrocytic foot processes in the HT groups was seen at 4 h (P < 0.01) and 1 day postinjury (P < 0.01) by quantitative image analysis of ultrastructures. However, attenuated swelling of perivascular astrocytic foot processes in severely edematous medulla oblongata with simultaneous swelling of perikaryal astrocytic processes was observed in the HT 1-day group. The ultrastructural features were also correlated with the down-regulation of aquaporin-4 (AQP4) mRNA expression (P < 0.05). Results suggest that acute hyponatremia acts as one of the secondary insults following severe TBI. Such exacerbation may not be attributable to further disruption of BBB permeability, but rather to the ischemia resulting from the swelling of perivascular astrocytic foot processes impeding microcirculation. Down-regulated AQP4 mRNA expression may be one of the molecular mechanisms maintaining water homeostasis in diffusely injured brain exposed to acute hyponatremia.

Hypermethylation of multiple genes in tumor tissues and voided urine in urinary bladder cancer patients.

PURPOSE: We aimed to investigate the methylation pattern in bladder cancer and assess the diagnostic potential of such epigenetic changes in urine. EXPERIMENTAL DESIGN: The methylation status of 7 genes (RARbeta, DAPK, E-cadherin, p16, p15, GSTP1, and MGMT) in 98 cases of bladder transitional cell carcinoma and 4 cases of carcinoma in situ was analyzed by methylation-specific PCR. Twenty-two cases had paired voided urine samples for analysis. RESULTS: In transitional cell carcinoma tumor tissues, aberrant methylation was frequently detected in RARbeta (87.8%), DAPK (58.2%), E-cadherin (63.3%), and p16 (26.5%), whereas methylation of p15 (13.3%), GSTP1 (5.1%), and MGMT (5.1%) is not common. No association between methylation status and grading or muscle invasiveness was demonstrated. In 22 paired voided urine samples of bladder cancer, methylation of DAPK, RARbeta, E-cadherin, and p16 could be detected in 45.5%, 68.2%, 59.1%, and 13.6% of the cases, respectively. The sensitivity of methylation analysis (90.9%) was higher than that of urine cytology (45.5%) for cancer detection. Methylation of RARbeta(50%), DAPK (75%), and E-cadherin (50%) was also detected in carcinoma in situ. In 7 normal urothelium samples and 17 normal urine controls, no aberrant methylation was detected except for RARbeta methylation in 3 normal urothelium samples (42.9%) and 4 normal urine samples (23.5%), respectively. CONCLUSIONS: Our results demonstrated a distinct methylation pattern in bladder cancer with frequent methylation of RARbeta, DAPK, E-cadherin, and p16. Detection of gene methylation in routine voided urine using selected markers appeared to be more sensitive than conventional urine cytology.