Satoshi Shiozawa

Participation of macrophages in glomerular sclerosis through the expression and activation of matrix metalloproteinases

In order to investigate the role of macrophages in glomeruli in the progression of glomerular sclerosis, methyl‐cellulose (MC) was administered intraperitoneally to Wistar rats, in addition to intravenous injection of anti‐thy1‐1 antibody. In this group of rats (Thy‐1 + MC group), many macrophages infiltrated in the lytic mesangium accompanied by rupture of capillary loops at an early stage and stayed with abundant deposition of mesangial matrices until day 35, whereas the proliferative lesions following mesangiolysis almost vanished in the rats treated with anti‐thy1‐1 antibody alone (Thy‐1 group). In immunostaining, matrix metalloproteinase (MMP)‐9 was expressed along regenerating capillaries of the Thy‐1 group and in extracapillary lesions of the Thy‐1 + MC group after day 7. In gelatin zymography, the gelatinolytic band for MMP‐9 was expressed much more strongly in the Thy‐1 + MC group than in the Thy‐1 group at day 3, but it was expressed a little more strongly in the Thy‐1 group than in the Thy‐1 + MC group at day 7. The bands for an active form of MMP‐2 were more strongly expressed in the Thy‐1 + MC group than in the Thy‐1 group throughout the experimental period. These results suggest that persistent accumulation of macrophages in mesangium induces glomerular sclerosis through expression and activation of MMP.

Intraductal carcinoma with complex fusion of tubular glands without macroscopic mucus in main pancreatic duct: Dilemma in classification

An 84‐year‐old man, who was being followed up after lobectomy for lung carcinoma, was referred for evaluation of a dilated main pancreatic duct (MPD) from the body to the tail. Endoscopic ultrasonography demonstrated a low‐echo mass occupying the MPD from the body to the tail. Endoscopic retrograde pancreatography showed an occlusion of the MPD in the body, and brush cytology indicated malignant cells. Distal pancreatectomy was performed. Grossly, a white–yellow, irregular‐shaped solid mass without macroscopic mucus filled the lumen of the MPD. Histologically, the mass consisted of a complex fusion of tubular glands with atypical nuclei, which did not have intracellular mucus and oncocytic cytoplasm. The tumor mass showed abrupt transition to the normal epithelium. Immunohistochemically the tumor cells were partially positive for mucin 1 (MUC1) and MUC6, and negative for MUC2, MUC5AC, and lipase. Unfortunately the patient died of brain metastasis from lung carcinoma 15 months later. A review of reported cases of intraductal tubular tumors of the pancreas showed that the present case involved characteristics and immunohistochemical staining pattern similar to those of intraductal tubular carcinoma, although it might not be described as a typical intraductal tubular carcinoma under the existing Japanese rules.

Renal involvement in bone marrow transplantation

SUMMARY:  Bone marrow transplantation (BMT) is an effective therapeutic strategy for leukaemic malignancies and depressed bone marrow following cancer. However, its side effects on kidneys have been reported. Some drugs and irradiation are also suggested to be nephrotoxic. It is well known that haemolytic uraemic syndrome (HUS) after BMT develops as late‐onset BMT nephropathy. Cyclosporine A (CsA) is a possible cause. Radiation nephropathy shows changes that are similar to the histology of HUS. These findings suggest that endothelial damage is closely associated with the pathogenesis of post‐BMT nephropathy. Recently, some patients have developed glomerulonephritis accompanied by graft‐versus‐host disease (GVHD) after BMT. In these patients immune deposits are found mainly in subepithelium and mesangium equal to those of secondary membranous glomerulonephritis. A murine experimental model of GVHD manifests similar symptoms and histological changes to those of actual patients and may suggest the pathogenesis of glomerulonephritis.

Distribution of Intraductal Lesions in Small Invasive Ductal Carcinoma of the Pancreas

Aims: To investigate the distribution of intraductal lesions in small invasive ductal carcinoma (IDC) of the pancreas. Methods: In 21 cases with IDCs microscopically ≤20 mm in diameter, the intraductal lesions around a mass were studied histologically and mapped according to the pancreatic intraepithelial neoplasia (PanIN) classification. Results: PanIN-3, PanIN-2, PanIN-1B and PanIN-1A were found in 17, 10, 20 and 21 of 21 cases, respectively, and were divided into lesions in adjacent and distal areas, respectively defined as within and beyond 10 mm from the mass as follows: 100% (17/17), 100% (10/10), 95.0% (19/20) and 90.5% (19/21) in the former, while 23.5% (4/17), 50.0% (5/10), 90.0% (18/20) and 95.2% (20/21) in the latter. PanIN-3 lesions were predominantly found in the area adjacent to the mass. In some cases, significant PanIN-3 appeared to show a consecutive geographic extension around the mass via the main pancreatic duct (MPD). The distance of PanIN-3 spread was within 25 (mean 10.5) mm from the mass edge. PanIN-2 lesions were found in the area adjacent to the mass and discontinuous with the mass or PanIN-3 lesions. PanIN-1B and PanIN-1A tended mainly to exist sporadically throughout the entire pancreas. In the MPD, PanIN-3 was found in 14 (82.4%) of 17 cases and in 36 (32.1%) of 112 lesions, which was most frequent in intraductal lesions. Conclusions: PanIN-3 lesions might be an intraductal extension of the main tumor. The resection margin of 25 mm, at least longer than 11 mm, from the mass edge will be necessary.

Prostacyclin Inhibits the Production of MMP-9 Induced by Phorbol Ester through Protein Kinase A Activation, but Does Not Affect the Production of MMP-2 in Human Cultured Mesangial Cells

Background/Aims: The imbalance between degradation and synthesis of the glomerular extracellular matrix (ECM) causes glomerular sclerosis in various types of glomerulonephritis. We investigated the effect of prostacyclin, which is an inflammatory mediator, on the production of matrix metalloproteinase (MMP)-9 and MMP-2 in human cultured mesangial cells. The synthesis of Jun proteins and Ets-1 proteins, which are related with MMP-9 gene, was also studied. Methods: The production of MMP-9 and MMP-2 was investigated by gelatin zymography. Western blotting was undertaken to analyze the protein synthesis of Jun and Ets-1. Results: Prostacyclin inhibited the production of MMP-9 induced by phorbol ester. The inhibitory effect by prostacyclin was reversed in part by the pretreatment with an inhibitor of protein kinase A, such as H-89. Forskolin also inhibited the production of MMP-9. The production of MMP-2 was constitutionally seen and was not influenced by prostacyclin and forskolin. The synthesis of Jun protein augmented by phorbol ester was suppressed by prostacyclin. Ets-1 protein was constitutionally synthesized and was not affected by phorbol ester and prostacyclin. Conclusion: Prostacyclin plays an important role in inflammatory glomerular disorders by regulating the metabolism of ECM. The production of MMP-9 and MMP-2 may be under the different control pathways.

Glomerulosclerosis develops in Thy-1 nephritis under persistent accumulation of macrophages

To clarify the relationship between macrophages and development of glomerulosclerosis, the authors developed a new experimental nephritis model with macrophages persisting in Thy‐1 nephritis. Methyl‐cellulose was administered intraperitoneally in addition to the intravenous injection of the anti‐Thy‐1 antibody to Wistar rats. Foamy macrophages influxed into the lytic mesangium and stayed to form nodular aggregates. Mesangial cells proliferated with the formation of extracellular matrices around these nodular aggregates of macrophages. Immunohistochemical analyses revealed that α‐smooth muscle actin (α‐SMA) was expressed in the proliferative area around these nodules of foamy macrophages from day 7. Type I collagen and type IV collagen were also expressed around the foamy macrophages in correspondence with α‐SMA expression from day 7. The electron microscopic study revealed that collagen fibrils were formed around the transformed mesangial cells. The expression of platelet endothelial cell adhesion molecule‐1 (PECAM‐1, CD31), a marker of glomerular vasculature endothelial cells, was not found in the area occupied by the foamy macrophages, suggesting the impairment of glomerular reconstruction. Macrophages may participate in the progression of glomerulosclerosis in Thy‐1 nephritis by enhancing the production of the extracellular matrix through transformed mesangial cells and preventing reconstruction of the capillary network.

Staphylococcus aureus-associated nephritis with histologic features resembling hemolytic uremic syndrome

A case that revealed the clinical and histologic features of superantigen-related nephritis and hemolytic uremic syndrome is reported. The patient was admitted with purulent arthritis due toStaphylococcus aureus infection, and showed rapidly progressive glomerulonephritic syndrome Clinical and histologic findings were similar to those of cases of superantigen-related nephritis previously reported, but our case had histologic evidence of various endothelial damage resembling that of hemolytic uremic syndrome. We suggest that such hemolytic uremic syndrome-like lesions may be one of the features of superantigen-related nephritis.

Methylation of Tumor Suppressor Genes in Autoimmune Pancreatitis.

Objectives Autoimmune pancreatitis (AIP) is a representative IgG4-related and inflammatory disease of unknown etiology. To clarify mechanisms of carcinogenesis resulting from AIP, we focused on methylation abnormalities and KRAS mutations in AIP. Methods Six tumor suppressor genes (NPTX2, Cyclin D2, FOXE1, TFPI2, ppENK, and p16) that exhibited hypermethylation in pancreatic carcinoma were selected for quantitative SYBR green methylation-specific polymerase chain reaction in 10 AIP specimens, 10 pancreatic adenocarcinoma cases without history of AIP containing carcinoma areas (CAs) and noncarcinoma areas (NCAs), and 11 normal pancreas (NP) samples. KRAS mutation in codons 12, 13, and 61 were also investigated using direct sequencing. Results Hypermethylation events (≥10%) were identified in NPTX2, Cyclin D2, FOXE1, TFPI2, ppENK, and p16 in 1, 2, 2, 0, 2, and 0 CA cases, respectively, but not in these 6 candidate genes in AIP, NCA, and NP. However, the TFPI2 methylation ratio was significantly higher in AIP than NCA and NP. Direct sequencing results for KRAS showed no single-point mutations in AIP. Conclusions These are the first studies characterizing methylation abnormalities in AIP. AIPs inflammatory condition may be related to carcinogenesis. Further study will elucidate methylation abnormalities associated with carcinogenesis in AIP.

Mucinous cystadenoma of the pancreas with huge mural hematoma

A 60‐year‐old woman was referred for evaluation of a cystic mass in the pancreatic body that extended to the tail. Transabdominal ultrasonography demonstrated an oval cystic mass 24 cm in diameter, filled with debris. On the cyst wall there was a wide‐based, smooth‐surfaced, heterogeneous high‐echoic protrusion that was 5 cm in diameter. On CT the protrusion showed internal enhancement. Endoscopic pancreatography showed no intraductal mucin or communication with the cyst. A distal pancreatectomy was performed under the diagnosis of mucinous cystadenocarcinoma. Grossly there was a brownish, hemispherical protrusion into the thin monolocular cyst. The cut surface of the protrusion showed a peripheral yellow‐brownish area and an internal wine‐colored area. Histopathologically the cyst wall consisted of tall columnar cells without atypical nuclei, ovarian‐type stroma beneath the epithelium, and fibrotic tissue with abundant capillary vessels, suggestive of a mucinous cystadenoma. The protrusion was composed of peripheral organized hematoma without a covering epithelium, and internal hemorrhage and many capillary vessels, with no evidence of tumor cell necrosis. These histopathological findings appear to be similar to those of chronic expanding hematoma. The formation of a huge mural hematoma in a mucinous cystic neoplasm can occur as a repair process after the breaking of intrawall vessels.

A case of an ABO-incompatible renal transplant with abundant intratubular basement membrane immune deposits

Abstract: We present a case of a 30‐year‐old man who received an ABO‐incompatible renal transplant from his mother in 1996 after haemodialysis for 3 years. Although his renal function was stable, a renal biopsy was performed while he was in hospital for treatment of herpes zoster in 1999. Light microscopy provided no evidence of obvious acute or chronic rejection but a double contour pattern was observed in many tubular basement membranes (TBM). Immunofluorescence microscopy revealed deposits of IgG and C3 on the TBM in the absence of glomerular deposition. Massive electron‐dense deposits were observed clearly by electron microscopy within TBM, revealing splitting and lamellation. This implies that the deposits resulted from the formation of immune complexes, but not from anti‐TBM antibody. Although the role of TBM deposits in tubular injury is controversial, careful observation of patients with such deposits may be required because of their potential ability to induce immune reactions.