Gap junction remodelling by chronic pressure overload is related to the increased susceptibility to atrial fibrillation in rat heart.

AIMS: Left atrial (LA) fibrosis caused by various pathological stimuli is a common finding. However, the difference of atrial remodelling via haemodynamic change in diverse cardiomyopathy has not been elucidated. METHODS AND RESULTS: Male Sprague-Dawley rats (6-8 weeks, n = 180) were randomly assigned to three groups and corresponding sham control groups: (i) ischaemic cardiomyopathy, (ii) left ventricular hypertrophy (LVH), and (iii) dilated cardiomyopathy. At 12 weeks after operation, atrial fibrillation (AF) inducibility and duration were assessed by in vivo burst transoesophageal pacing. Using the Langendorff apparatus, left ventricular (LV) function and pressure were measured. The expression of connexin-43 (Cx43) and alpha-smooth muscle actin (α-SMA) in atrial tissues was assessed by quantitative real-time polymerase chain reaction and immunohistochemical staining. Fibrosis was analysed by Masson's trichrome staining. Compared with controls, the LA weight/heart weight ratio was increased in the LVH group alone, and was significantly correlated with AF duration (P < 0.001, R = 0.388). Atrial fibrillation inducibility and duration were higher and longer only in the LVH group (P = 0.002, 0.079, respectively), and isolated LV diastolic dysfunction and elevated LV pressure were observed. Although α-SMA expression and fibrosis were increased in all three cardiomyopathy models, down-regulation of Cx43 expression in the LA was observed in the LVH group alone. CONCLUSION: Chronic pressure overload in the absence of LV systolic dysfunction resulted in LA hypertrophy and increased susceptibility to AF, which might be related to conduction abnormality via decreased expression and lateral distribution of Cx43 as well as interstitial fibrosis.

Large cell calcifying sertoli cell tumor of the testis: a case study and review of the literature.

A 24-year-old man was admitted due to an incidentally detected mass in his left testis, which showed radiopaque calcification on plain X-ray film. Left orchiectomy was performed, and the resected testis contained a well-demarcated, hard mass measuring 1.1 cm. Histological analysis revealed that the tumor was composed of neoplastic cells, fibrotic stroma, and laminated or irregularly shaped calcific bodies. The individual cells had abundant eosinophilic or clear cytoplasm with round nuclei, each of which contained one or two conspicuous nucleoli. They were arranged in cords, trabeculae, clusters, and diffuse sheets. There were several foci of intra-tubular growth patterns, with thickening of the basal lamina. Immunohistochemically, the neoplastic cells were positive for S-100 protein and vimentin, focally positive for inhibin alpha, and negative for cytokeratin, CD10, and Melan-A. In addition to reporting this rare case, we also review the relevant literature regarding large cell calcifying Sertoli cell tumors.

Effectiveness of gastric cancer screening programs in South Korea: organized vs opportunistic models.

AIM: To investigate the outcome and effectiveness of two screening programs, National Cancer Screening Program (NCSP) and opportunistic screening (OS), for the detection of gastric cancer. METHODS: A total of 45  654 subjects underwent upper endoscopy as part of the NCSP or OS at the Chung-Ang University Healthcare System in Korea between January 2007 and December 2010. The study population was comprised of subjects over the age of 40 years. More specifically, subjects who took part in the NCSP were Medicaid recipients and beneficiaries of the National Health Insurance Corporation. Still photographs from the endoscopies diagnosed as gastric cancer were reviewed by two experienced endoscopists. RESULTS: The mean age of the screened subjects was 55 years for men and 54 years for women. A total of 126 cases (0.28%) of gastric cancer were detected from both screening programs; 100 cases (0.3%) from NCSP and in 26 cases (0.2%) from OS. The proportion of early gastric cancer (EGC) detected in NCSP was higher than that in OS (74.0% vs 53.8%, P = 0.046). Among the 34  416 screenees in NCSP, 6585 (19.1%) underwent upper endoscopy every other year as scheduled. Among the 11  238 screenees in OS, 3050 (27.1%) underwent upper endoscopy at least once every two years during the study period. The detection rate of gastric cancer was found to be significantly higher during irregular follow-up than during regular follow-up in both screening programs (0.3% vs 0.2%, P = 0.036). A higher incidence of EGC than advanced gastric cancer was observed during regular follow-up compared with irregular follow-up. CONCLUSION: Compliance to the screening program is more important than the type of screening system used.

Histological features and immune cell changes in skin lesions of engraftment syndrome of children undergoing hematopoietic stem cell transplantation.

Various skin eruptions are encountered during hematopoietic stem cell transplantation (HSCT) of children with hematologic malignancies. Engraftment syndrome (ES) is a disease characterized by fever, weight gain, maculopapular skin rash and noncardiogenic pulmonary edema. ES occurs during neutrophil recovery without identifiable causes of infection. Early detection of ES is critical to reduce mortality and morbidity, but identical morphologic changes found in skin lesions from ES and graft-versus-host disease (GVHD) are a challenging problem for histology-based diagnosis. To resolve this issue, immunopathologic changes in skin lesions of ES were studied. Five skin biopsies from patients with symptoms clinically compatible with ES were retrieved and compared to 15 age- and sex-matched cases of acute GVHD with antibodies to CD3, CD4, CD8 and CD1a. Mean numbers of epidermal CD8+ cells and CD1a+ cells were lower in ES than in GVHD. However, there were no significant differences in mean score of GVHD grade, mean numbers of lymphoid cells, CD3+ cells, or CD4+ cells. In the setting of HSCT in children, the dominance of CD4+ cells and a decreased number of CD1a+ cells in the epidermis are specific features for the skin lesions of ES.

Clinical features and prognosis of early colorectal cancer treated by endoscopic mucosal resection.

BACKGROUND AND AIMS: The incidence of early colorectal cancer (ECC) has been increasing. The aim of this study was to evaluate the clinical outcome and prognosis of ECC treated by endoscopic mucosal resection (EMR). METHODS: A total of 129 ECC patients who were initially treated by EMR between April 2005 and August 2007 were enrolled. Clinicopathological characteristics and prognoses were evaluated retrospectively. RESULTS: En bloc resection was performed in 85% of ECC patients, and piecemeal resection was performed in 15% of patients. Clear lateral and deep margins were achieved in 86% of cases. Of the 129 patients, 64 were found to have intramucosal cancer and 65 had submucosal cancer. Clinical characteristics were not different between patients with intramucosal cancer and submucosal cancer; however, poor differentiation and the absence of background adenoma showed significant association with submucosal cancer. Seven patients with submucosal cancer underwent subsequent surgical resection; five had lymphovascular invasion or a positive resection margin, one had perforation, and one patient requested surgical resection. Of these seven patients, one had residual cancer and two had lymph node metastasis. All patients with intramucosal cancer had no recurrence during the follow-up period. Seven patients with submucosal cancer showed adverse outcomes within 3 years, such as residual/recurrence of primary cancer or lymph node metastasis; five showed lymphovascular invasion or a positive deep margin, and two had no histological risk factors. CONCLUSIONS: Our results suggest that intramucosal cancer shows good prognosis, and a cure could be expected after EMR; however, adverse outcomes can occur in submucosal cancer. Therefore, meticulous endoscopic follow up is needed in patients with submucosal cancer for at least 3 years after EMR.

Evaluation of osteoarthritis induced by treadmill-running exercise using the modified Mankin and the new OARSI assessment system.

To apply the Osteoarthritis Research Society International (OARSI) assessment system to an osteoarthritis model, 44 Wistar rats were randomized into treadmill-running exercise or control group. At 6, 8, and 10 weeks, medial knee joints were histopathologically evaluated, and aggrecan neoepitope and TUNEL staining were performed. Cartilage changes in exercise group were histopathologically and histochemically compatible with early OA. Total modified Mankin system (MMS) scores were significantly higher at all time points (each P ≤ 0.01) in exercise than in control group. However, only tibial OARSI scores of runners were higher at 10 weeks (P < 0.05), although OARSI scores were found to be significantly correlated with MMS scores. Both total MMS (Spearman's coefficient ρ = 0.786) and OARSI scores (ρ = 0.443 for femoral; ρ = 0.604 for tibial) were significantly associated with the exercise duration. In conclusion, the OARSI system may not be sensitive to early OA changes induced by treadmill exercise.

Lupus erythematosus panniculitis: clinicopathological, immunophenotypic, and molecular studies.

Lupus erythematosus panniculitis (LEP) is an inflammatory disorder of the subcutaneous fat in patients with lupus erythematosus (LE). It is a rare variant of the disease, which occurs approximately in 1%-3% of patients with cutaneous LE. The purpose of this study was to investigate the clinical, histopathologic, immunophenotypical, and molecular profiles of LEP. We performed a retrospective study of 19 biopsy specimens from 17 patients with LEP. We reviewed their clinical data and reexamined the histopathology. Immunophenotyping and molecular studies were done using sections from paraffin-embedded formalin-fixed tissue. The most common clinical manifestation was a depressed patch on upper arm. Patients showed good response to variable treatment modalities, but, generally, relapse of panniculitis was noted when treatment was discontinued. Histopathologically, most specimens revealed lymphoplasmacytic lobular panniculitis with epidermal and dermal changes of LE, hyaline fat necrosis, and lymphoid follicles. Immunohistochemistry showed a mixture of T and B cells in dermis and subcutis with a slight preponderance of T cell. Although the polymerase chain reaction analysis of the T-cell receptor-gamma gene rearrangement showed a polyclonal smear in 89.5% of cases, a small portion of specimens demonstrated monoclonality. LEP is a chronic recurrent disease with characteristic features. Its diagnosis is often challenging, and a precise diagnosis is achievable only upon elaborate clinicopathologic correlation and integrated interpretation of all diagnostic criteria.

The multiplex bead array approach to identifying serum biomarkers associated with breast cancer.

INTRODUCTION: Breast cancer is the most common type of cancer seen in women in western countries. Thus, diagnostic modalities sensitive to early-stage breast cancer are needed. Antibody-based array platforms of a data-driven type, which are expected to facilitate more rapid and sensitive detection of novel biomarkers, have emerged as a direct, rapid means for profiling cancer-specific signatures using small samples. In line with this concept, our group constructed an antibody bead array panel for 35 analytes that were selected during the discovery step. This study was aimed at testing the performance of this 35-plex array panel in profiling signatures specific for primary non-metastatic breast cancer and validating its diagnostic utility in this independent population. METHODS: Thirty-five analytes were selected from more than 50 markers through screening steps using a serum bank consisting of 4,500 samples from various types of cancer. An antibody-bead array of 35 markers was constructed using the Luminex bead array platform. A study population consisting of 98 breast cancer patients and 96 normal subjects was analysed using this panel. Multivariate classification algorithms were used to find discriminating biomarkers and validated with another independent population of 90 breast cancer and 79 healthy controls. RESULTS: Serum concentrations of epidermal growth factor, soluble CD40-ligand and proapolipoprotein A1 were increased in breast cancer patients. High-molecular-weight-kininogen, apolipoprotein A1, soluble vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, vitamin-D binding protein and vitronectin were decreased in the cancer group. Multivariate classification algorithms distinguished breast cancer patients from the normal population with high accuracy (91.8% with random forest, 91.5% with support vector machine, 87.6% with linear discriminant analysis). Combinatorial markers also detected breast cancer at an early stage with greater sensitivity. CONCLUSIONS: The current study demonstrated the usefulness of the antibody-bead array approach in finding signatures specific for primary non-metastatic breast cancer and illustrated the potential for early, high sensitivity detection of breast cancer. Further validation is required before array-based technology is used routinely for early detection of breast cancer.

Aneurysmal benign fibrous histiocytoma with atrophic features.

Aneurysmal benign fibrous histiocytoma is an uncommon pathologic variant of dermatofibroma. In addition to the features of a typical dermatofibroma, it has large cleft-like or cavernous blood-filled spaces with numerous hemosiderin pigments. It should be differentiated from angiomatoid malignant fibrous histiocytoma, malignant melanoma, and vascular tumors such as Kaposi's sarcoma and angiosarcoma. Atrophic dermatofibroma is also a rare variant of dermatofibroma, and the combination of aneurysmal and atrophic features is rarer still. We report a case of aneurysmal benign fibrous histiocytoma with atrophic features in a 27-year-old male who had a grayish-brown atrophic patchy lesion on his back for 2 years.

Experimental study on acute ischemic small bowel changes induced by superselective embolization of superior mesenteric artery branches with N-butyl cyanoacrylate.

PURPOSE: To evaluate the degree of ischemic changes of the small bowel after superselective embolization of superior mesenteric artery (SMA) branches at the vasa recta level with N-butyl cyanoacrylate (NBCA) in dogs. MATERIALS AND METHODS: In six dogs, superselective embolization was performed with NBCA in five isolated branches of the SMA at the vasa recta level. All dogs were sacrificed 24 hours after embolization. According to the extent of the NBCA mixtures on radiographs of the specimen, embolized segments were divided into group A (embolization of three or fewer vasa recta) or group B (embolization of four or more vasa recta). Histologic evaluation of the mucosal, submucosal, and muscle layers of the embolized segments was performed by a pathologist. RESULTS: In group A (n=15), histologic findings were normal in seven segments (47%). Mild ischemic changes were noted in the mucosal layer in eight segments, the submucosal layer in four segments, and the muscle layer in one segment. In group B (n=15), ischemic changes were noted in the mucosal layer in all 15 segments, the submucosal layer in 14 segments, and the muscle layer in 10 segments. The difference in ischemic damage between groups A and B was statistically significant. CONCLUSIONS: Superselective embolization involving three or fewer vasa recta of the SMA was relatively tolerable, and embolization involving four or more vasa recta carried an increased risk of substantial ischemic bowel damage. Further studies are necessary to determine the clinical implications of our findings in human subjects.

Localizations and expressions of alpha-1A, alpha-1B and alpha-1D adrenoceptors in human ureter.

This study was designed to determine the expression and localization of the alpha-adrenoceptor (AR) subtypes in human ureteral tissue. The expression of the alpha-AR subtypes was examined by immunohistochemistry using subtype selective antibodies in proximal, mid and distal ureter. Ureter samples were obtained from pathological specimens of nephroureterectomy. A single pathologist scored the expression of receptor (grade 0, no staining; grade 1, 0-25% cells positive; grade 2, 26-50% cells positive; and grade 3, greater than 50%). We compared the mean grades of alpha-AR 1A, 1B and 1D and the percentage of receptor expression with grade 2 or more between receptor subtypes in each ureter level. The expression levels of all three subtypes are altered according to the level of ureter. In the proximal ureter, the mean grades of the alpha-1A, -1B and -1D receptors were 1.0 +/- 0.5, 1.1 +/- 0.6, and 2.1 +/- 0.7. Corresponding grades in the mid and distal ureter were 1.1 +/- 0.6, 0.8 +/- 0.6 and 2.0 +/- 0.8, and 2.0 +/- 0.7, 1.8 +/- 0.6 and 2.5 +/- 0.5, respectively. When compared with percentage of high expression, in the proximal and mid ureter, alpha-1D high expression percentage was significantly higher than alpha-1A and -1B subtype (80, 10, 20, and 90, 20, 10%, respectively). In the distal ureter, alpha-1D expression was higher than alpha-1A and -1B subtype but there was no statistical significance (100, 80, 70%). The distal ureter had higher density of alpha-AR receptors than proximal and mid ureter. The expression of alpha-1A and alpha-1B AR in distal ureter was significantly higher than proximal and mid ureter. alpha-1D expression in distal ureter was also higher than proximal and mid ureter but was not statistically significant (p = 0.28, 0.19, respectively). Our results show that alpha-1A, -1B and -1D AR subtypes are localized in human ureter irrespective of location. The expression levels of subtypes are altered according to level of ureter and subtype.

CD99 activates T cells via a costimulatory function that promotes raft association of TCR complex and tyrosine phosphorylation of TCR zeta.

We investigated the co-stimulatory role of a cell-surface protein, CD99. Co-ligation of CD99 and suboptimal CD3 induced T-cell activation to a level comparable to that obtained with optimal CD3 or CD3+CD28. We also noted concomitant enhancement of the earliest T-cell receptor (TCR) signaling events. In addition, co-ligation of CD99 and CD3 led to translocation of TCR complexes into the lipid raft, without concomitant migration of CD99 to the raft, and consequent enhancement of TCR zeta-mediated signal 1. These data demonstrate the unique properties of CD99 co-stimulation that distinguish this molecule from CD28 and other raft-resident co-stimulatory factors.

NKT cells play critical roles in the induction of oral tolerance by inducing regulatory T cells producing IL-10 and transforming growth factor beta, and by clonally deleting antigen-specific T cells.

Oral tolerance is the systemic unresponsiveness induced by orally administered proteins. To explore the roles of natural killer T (NKT) cells in oral tolerance, we induced oral tolerance to ovalbumin (OVA) in NKT cell-deficient mice. In CD1d-/- mice, the induction of tolerance to orally administered high- or low-dose OVA was impaired. Dendritic cells (DCs) in the Peyer's patches (PPs) of CD1d-/- mice fed OVA showed high expression of major histocompatibility complex (MHC) class II and B7 molecules, whereas DCs of control mice fed OVA expressed low levels of these molecules. The adoptive transfer of NKT cells restored oral tolerance and induction of tolerogenic DCs in the PPs and spleens of CD1d-/- mice. Moreover, interleukin (IL)-10 and transforming growth factor (TGF)-beta1 production in vitro were reduced in cells from the spleen and PPs of CD1d-/- mice compared with those of control mice fed OVA. The numbers of OVA-specific CD4+ KJ1-26+ T cells were significantly reduced in the PPs and spleens of DO11.10 mice fed OVA. In contrast, OVA-specific CD4+ KJ1-26+ T cells were not deleted in the PPs or spleens of DO11.10 CD1d-/- mice. In conclusion, NKT cells were found to play an indispensable role in oral tolerance by inducing regulatory T cells, and clonally deleting antigen-specific CD4+ T cells.

Engagement of glucocorticoid-induced TNF receptor costimulates NKT cell activation in vitro and in vivo.

Glucocorticoid-induced TNF receptor (GITR) is known to provide costimulatory signals to CD4+CD25- and CD4+CD25+ T cells during immune responses in vivo. However, the functional roles of GITR expressed on NKT cells have not been well characterized. In this study, we have explored the functions of GITR as a costimulatory factor on NKT cells. GITR was found to be constitutively expressed on NKT cells and its expression was enhanced by TCR signals. GITR engagement using DTA-1, an agonistic mAb against GITR, in the presence of TCR signals, augmented IL-2 production, the expression of activation markers, cell cycle progression, and the nuclear translocations of NF-kappaB p50 and p65. Furthermore, GITR engagement enhanced the production of IL-4, IL-10, IL-13, and IFN-gamma by NKT cells and the expression level of phosphorylated p65 in NKT cells in the presence of TCR engagement, indicating that GITR provides costimulatory signals to NKT cells. The costimulatory effects of GITR on NKT cells were comparable to those of CD28 in terms of cytokine production. Moreover, the coinjection of DTA-1 and alpha-galactosylceramide into B6 mice induced more IL-4 and IFN-gamma production than the coinjection of control mAbs and alpha-galactosylceramide. In addition, the adoptive transfer of DTA-1-pretreated NKT cells into CD1d(-/-) mice attenuated hypersensitivity pneumonitis more than control IgG pretreated NKT cells in these mice. These findings demonstrate that GITR engagement on NKT cells modulates immune responses in hypersensitivity pneumonitis in vivo. Taken together, our findings suggest that GITR engagement costimulates NKT cells and contributes to the regulation of immune-associated disease processes in vivo.

T cell expression of CIITA represses Th1 immunity.

Despite the fact that major histocompatibility complex class II transactivator (CIITA) has been known to be involved in Th1/Th2 balance in addition to its major role as a master regulator for the expression of MHC class II genes, the exact role of CIITA in Th1/Th2 balance is still controversial. To investigate whether the Th1/Th2 balance could be modulated by T cell specific expression of CIITA, we generated CIITA-transgenic mice, in which the CIITA expression is controlled by the distal promoter of p56lck, resulting in constitutive expression of CIITA predominantly in peripheral T cells. Naive CD4+ T cells from CIITA-transgenic mice exhibited a low level of IFN-gamma secretion as well as impaired Th1 polarization in vitro, while IL-4 secretion was enhanced under Th2 condition. In addition, the development of experimental autoimmune encephalomyelitis (EAE), a prototype of Th1-mediated disease, was repressed in CIITA-transgenic mice. Resistance to EAE was correlated with reduced production of IFN-gamma in response to MOG35-55, while the proliferation of MOG35-55 -specific T cells was not affected in CIITA-transgenic mice. Together, these data demonstrate that overexpression of CIITA in T cells inhibits Th1 differentiation and function, suggesting that the expression of CIITA in T cells might play a role in the regulation of the Th1/Th2 balance during the T cell lineage commitment.

Activation of the TGF-beta/Smad signaling pathway in focal segmental glomerulosclerosis.

BACKGROUND: Although the pathogenetic relevance of transforming growth factor-beta (TGF-beta) to glomerulosclerosis is well established, it is not known whether a signal transduction cascade of TGF-beta is involved in the development of focal segmental glomerulosclerosis (FSGS), nor is it clear how TGF-beta 1 is activated during the course of FSGS formation. METHODS: We examined the expression patterns of TGF-beta 1, thrombospondin-1 (TSP-1), TGF-beta type II receptor (TGF-beta IIR), phosphorylated Smad2/Smad3, and podocyte-specific epitopes [Wilms' tumor protein-1 (WT-1) and glomerular epithelial protein-1 (GLEPP-1)] in 15 renal biopsy specimens with idiopathic FSGS and six renal biopsies with no detectable abnormalities by means of immunohistochemistry. The mRNA expression patterns of TGF-beta 1, TGF-beta IIR, and TSP-1 were further evaluated by in situ hybridization in seven biopsies. RESULTS: In the controls, immunostaining for TGF-beta 1, TSP-1, TGF-beta IIR, and phosphorylated Smad2/Smad3 was almost negligible, but an apparent signal for TGF-beta 1, TSP-1, and TGF-beta IIR mRNAs was observed in the visceral glomerular epithelial cells (GEC). In the cases of FSGS, the expression levels of TGF-beta 1, TSP-1, and TGF-betaIIR proteins and mRNAs and phosphorylated Smad2/Smad3 were significantly increased, particularly in the GEC of the sclerotic segments, wherein WT-1 and GLEPP-1 were not detected. CONCLUSION: These results suggest that damage to podocyes may stimulate TGF-beta 1, TSP-1, and TGF-beta IIR expression in GEC, thereby activating the Smad signaling pathway and, in so doing, leading to overproduction of the extracellular matrix (ECM). Thus, a signal transduction cascade of the TGF-beta/Smad signaling pathway, which is activated in the GEC, appears to be involved in the development of FSGS.

Melanocins A, B and C, new melanin synthesis inhibitors produced by Eupenicillium shearii. I. Taxonomy, fermentation, isolation and biological properties.

New melanin synthesis inhibitors, melanocins A, B and C, were isolated from the fermentation broth and mycelium extract of Eupenicillium shearii F80695. Melanocin A, an isocyanide compound, inhibited mushroom tyrosinase and melanin biosynthesis of B16 melanoma cells with IC50 value of 9.0 nM and MIC value of 0.9 microM, respectively. Melanocin A also inhibited growth of Streptomyces bikiniensis. While, the structurally very related but non-isocyanide compounds melanocins B and C did not show inhibitory activity in these assays. Melanocins A, B and C showed potent antioxidant activity with scavenging activity of DPPH radical and superoxide anion radical.

Melanocins A, B and C, new melanin synthesis inhibitors produced by Eupenicillium shearii. II. Physico-chemical properties and structure elucidation.

New melanin synthesis inhibitors, melanocins A, B and C, were isolated from the fermentation broth and extract of mycelium of Eupenicillium shearii F80695. The structures of melanocins were established by spectroscopic methods. They are formamide compounds. In particular, melanocin A has an isocyanide group.

Differential expression of nephrin in acquired human proteinuric diseases.

BACKGROUND: The slit-diaphragm protein nephrin is an essential component of the glomerular filtration barrier. It is not clear whether renal injury in patients with acquired proteinuric diseases is associated with altered regulation of the nephrin gene or protein. METHODS: We examined expression patterns of nephrin protein and messenger RNA (mRNA) in renal biopsy specimens from patients with minimal lesion (n = 7), focal segmental glomerulosclerosis (FSGS; n = 14), or membranous nephropathy (MN; n = 7) and controls (n = 8) by immunohistochemistry, immunoelectron microscopy, in situ hybridization, and polymerase chain reaction (PCR) amplification of nephrin complementary DNA. RESULTS: In normal kidney, nephrin staining showed a diffuse interrupted linear pattern along the glomerular basement membrane (GBM). Nephrin staining in minimal lesion specimens showed a finely granular pattern along the GBM and was positive in cell bodies of visceral glomerular epithelial cells. Nephrin staining was most disrupted in FSGS specimens. Immunoelectron microscopy showed that nephrin-specific gold particles were almost absent in effaced foot processes in proteinuric patients. An in situ hybridization study showed significantly decreased nephrin mRNA-expressing cells in cases of FSGS and MN compared with controls. Reverse-transcription PCR showed significantly lower levels of nephrin mRNA in cases of FSGS and MN than controls, but no significant difference between minimal lesion cases and controls. Relative levels of glomerular nephrin mRNA correlated inversely with percentage of glomeruli with sclerosis in proteinuric diseases. CONCLUSION: These results suggest that nephrin-expression patterns in proteinuric diseases are different according to the specific glomerular disease or severity of glomerular damage.