Differential contribution of three mitogen-activated protein kinases to PDGF-BB-induced mesangial cell proliferation and gene expression

This study examined the role of mitogen-activated protein (MAP) kinase in PDGF-BB-induced proliferation and gene expression of human mesangial cells (MC). PDGF-BB stimulation of MC increased mRNA for transforming growth factor-beta1 (TGF-beta1), monocyte chemoattractant protein-1 (MCP-1), and plasminogen activator inhibitor-1 (PAI-1) and increased the cell numbers. To inhibit activation of extracellular signal-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38, MC were infected with recombinant adenovirus containing dominant-negative mutants of ERK, JNK, and p38 (Ad-DN-ERK, Ad-DN-JNK, Ad-DN-p38, respectively), respectively. Infection of MC with Ad-DN-ERK or Ad-DN-JNK inhibited PDGF-BB-induced increase in [(3)H]thymidine incorporation and cell numbers, whereas Ad-DN-p38 did not. Ad-DN-ERK inhibited MCP-1 and PAI-1 mRNA expression in MC, but not TGF-beta1. Ad-DN-JNK and Ad-DN-p38 inhibited TGF-beta1 and MCP-1 mRNA expression, but not PAI-1. The inhibition of activator protein-1 (AP-1) in MC, by adenovirus containing dominant-negative mutant of c-Jun (Ad-DN-c-Jun), inhibited PDGF-BB-induced cell proliferation and TGF-beta1, MCP-1, and PAI-1 expressions. Furthermore, Ad-DN-JNK or Ad-DN-p38, but not Ad-DN-ERK, attenuated PDGF-BB-induced AP-1 activation in MC, indicating the involvement of JNK and p38 in AP-1 activation. Our results indicated that ERK and JNK, but not p38, participated in PDGF-BB-induced MC proliferation. PDGF-BB-induced expression of TGF-beta1 was mediated by JNK and p38, MCP-1 expression was through ERK, JNK, and p38, whereas PAI-1 expression was due to only ERK. AP-1 activation, which was partially due to JNK and p38 activations, was involved in MC proliferation and these three gene expressions. Thus, three MAP kinases seem to contribute to progression of glomerular disease via different molecular mechanisms.     

Experimental and Clinical Studies Investigating the Efficacy of Distal Anastomosis with Patch Plasty in Bypass Operations with Expanded Polytetrafluoroethylene Grafts

Purpose: We investigated the efficiency of distal anastomosis with patch plasty (DAPP), both experimentally and clinically. Methods: In our experimental study, dogs were divided into two groups: a control group in which anastomosis was performed without DAPP (n = 7), and a DAPP group in which DAPP was performed at the distal anastomosis (n = 7). In our clinical study, 169 femoropopliteal bypasses were divided into three groups and analyzed. In one group, the saphenous vein was used (SVG group, n = 65); in one group, an expanded polytetrafluoroethylene (ePTFE) graft was used without DAPP (ePTFE group, n = 64); and in one group, an ePTFE graft was used with DAPP (DAPP group, n = 40). Results: In the experimental study, the ratio between the area of thrombus adherence and the entire area of the intraluminal surface of the graft, defined as the thrombus covering ratio, was 48.9% in the control group and 30.2% in the DAPP group. The ratio in the DAPP group was significantly lower than that in the control group. In the clinical study, although there were no significant differences among the three groups in cumulative patency rates of the femoral above-knee popliteal arterial bypasses, the patency in the DAPP group was excellent. The cumulative patency rates of the femoral below-knee popliteal arterial bypasses in the ePTFE group were significantly lower than those in the other two groups. Conclusion: There results suggest that the addition of DAPP may achieve excellent graft patency. Received: February 14, 2002 /Accepted: November 19, 2002 Reprint requests to: K. Dairaku     

Primary symptoms of 301 patients with prostate cancer: Nagoya Urology Hospital experience

PURPOSE: Primary symptoms were reviewed retrospectively in patients with prostate cancer diagnosed in our hospital with the aim of promoting early detection. MATERIALS AND METHODS: The subjects included 301 cases with prostate cancer diagnosed histologically in Nagoya Urology Hospital from August, 1988 to December, 2001. The mean age was 72.7 years, and the median PSA was 20.0 ng/ml. Primary symptoms were classified according to the General Rule for Clinical and Pathological Studies on Prostate Cancer (The 3rd Edition). RESULTS: Out of 301 cases, 274 (91%) visited our hospital with clinical symptoms. Of them, 272 had primary urological symptoms. In these 272 cases, 250 (92%) and 19 (7%) had lower urinary tract symptoms (LUTS) and macroscopic or microscopic hematuria, respectively. The majority of patients (82%) referred from other urologists had already undergone PSA measurement, compared to 50% in those referred from physicians other than urologists (p < 0.0005). CONCLUSION: The present data revealed that LUTS were important primary symptoms for the detection of prostate cancer, particularly in an area like Nagoya where the mass screening for prostate cancer is still unavailable. In terms of the early detection of prostate cancer, PSA has to be measured in patients with LUTS even when they visit physicians who are not urologists.     

Characterization of K-ras gene mutations in association with mucinous hypersecretion in intraductal papillary-mucinous neoplasms

Background/Purpose Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas have a favorable prognosis. However, invasive ductal carcinomas of the pancreas show a rapid progression. The aim of this study was to investigate gene mutations in pure pancreatic juice from IPMN patients and to define these genetic mutations in relation to the histopathological and clinical features of IPMNs. Methods Twenty-two patients with IPMN, 21 patients with ductal carcinoma, and 20 patients with normal pancreas or chronic pancreatitis were recruited for this study. We measured the main pancreatic duct’s largest diameter and the maximum size of a dilated branch was assessed by ultrasonography or endoscopic ultrasonography. Pure pancreatic juice was collected and was investigated for K-ras, p16, and p53 mutations. Results Mutant K-ras gene was detected in 13 of the 22 patients (59.1%) with IPMNs. Different kinds of mutations were detected in the same patient in 4 cases. In the 13 patients with mutant K-ras gene, the diameter of the most dilated part of the main pancreatic duct was 2–8 mm (average, 4.5 mm) and in 7 patients with wild-type K-ras gene, the diameter was 2–5 mm (average, 2.7 mm). There was a significant difference in the diameter of the main pancreatic duct between patients with and without the mutant K-ras gene (P = 0.0323). Conclusions The incidence of K-ras mutation may be associated with the hypersecretion of mucin.     

A simple and safe operation method for brachiocephalic artery aneurysms

A 64-year-old man was referred to our hospital due to dyspnea and fever. The chest computed tomogram revealed a 60-mm aneurysm of the brachiocephalic artery with mural thrombus. The aneurysm of the brachiocephalic artery and the right subclavian artery were exposed through only median sternotomy. Cardiopulmonary bypass with synchronized pulsatile perfusion was established with the ascending aorta and bi-caval cannulation. A mean arterial pressure was kept at between 60 and 70 mmHg with the unloaded beating heart. Mild hypothermia was induced (blood temperature 27 degrees C, nasopharyngeal temperature 32 degrees C). The brachiocephalic artery, right carotid artery, and right subclavian artery were clamped when nasopharyngeal temperature was 32 degrees C after decreasing blood temperature to 27 degrees C. After opening the aneurysm, the mural thrombus and calcified aneurysmal wall were removed. First, an ascending aorta to the right common carotid artery bypass was performed using a 16-8 mm Y- prosthetic graft with side-clamp forceps. After the anastomosis, the right side cerebral perfusion was restarted and the patient was rewarmed. Then the right subclavian artery was anastomosed in an end-to-end fashion. The duration of the right side cerebral circulatory arrest was 30 minutes. The patient left hospital seven days after the operation.     

Matrix metalloproteinase expressions in arteriosclerotic aneurysmal disease

Medial degeneration of extracellular matrix (ECM) proteins in the wall of abdominal aortas results in smooth muscle cell destruction, a loss of architectural integrity, and abdominal aortic aneurysm (AAA) formation. It has been theorized that an imbalance between proteinases and their naturally occurring inhibitors is the cause of these observed histologic abnormalities. Therefore, the purpose of this investigation was to determine if differences in the matrix metalloproteinase (MMP) -2 and -9, tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA) protein and activity levels existed between infrarenal AAA and normal abdominal aortic tissue specimens. Between November 1995 and January 1997, 10 patients undergoing elective infrarenal AAA repair had a portion of their aneurysm walls snap frozen in liquid nitrogen and processed for subsequent western blot or zymographic analysis. Tissue specimens from 6 normal abdominal aortas obtained from fresh cadaver specimens were similarly processed and served as controls. Protein levels for MMP-2, MMP-9, TIMP-1, uPA, and tPA were analyzed by western blotting. The degree of MMP-2 and MMP-9 gelatinolytic activity was analyzed by zymography. Detection and immunolocalization for MMP-2, MMP-9 and CD68 was performed on tissue sections of AAA and normal infrarenal abdominal aortas fixed in 10% formalin. MMP-9 and tPA protein levels were increased in AAAs compared to controls by western blotting. However, uPA levels were slightly increased in controls. No differences in TIMP-1 protein levels were identified. Similarly, zymography demonstrated increased MMP-2 and MMP-9 gelatinolytic activity in AAAs compared to controls (p < or = 0.05). CD68-positive cells (macrophages) in the adventitia and media demonstrated immunoreactivity to MMP-9. This investigation demonstrated increased MMP-9 proteinase activity and tPA protein levels in the walls of AAAs, as well as inflammatory leukocyte invasion of the adventitia and media compared to controls. These data suggest that leukocyte-derived MMP-9 is associated with aortic wall degeneration and aneurysm formation. Furthermore, activation of MMP-9 may be caused by increased tPA levels in the walls of AAAs.     

Primary hepatic leiomyosarcoma in a woman after renal transplantation: report of a case

In contrast to malignant lymphomas or skin cancer, smooth muscle tumors including leiomyosarcoma are rarely associated with transplant recipients. We herein present a 33-year-old woman with end-stage renal disease who received a transplant at 27 years of age. Four years after the transplantation, at age 31, she underwent a mastectomy because of primary right breast cancer, which was found to be a 5-mm-sized mucinous carcinoma with no regional lymph node metastasis. Six years after the transplantation, a liver tumor was unexpectedly discovered. An explorative laparotomy revealed a well-encapsulated tumor occupying the posterior portion of the right lobe of the liver. The patient underwent a posterior segmentectomy. Histologically, the tumor possessed intermingling fascicles of spindle cells with eosinophilic cytoplasm and elongated nuclei. Based on an immunohistochemical examination, the tumor cells were positive for the muscle-associated antibody. In addition, RNA probes for Epstein-Barr virus were negative based on in situ hybridization. The histologic, immunohistochemical findings were considered to be diagnostic for leiomyosarcoma, which is a low-grade malignancy. Two years after surgery, the patient is doing well with no recurrence of liver tumors or breast cancer. Received: April 16, 2001 / Accepted: September 11, 2001     

Immediate interlocking nailing versus external fixation followed by delayed interlocking nailing for Gustilo type IIIB open tibial fractures

PURPOSE: To compare immediate interlocking nailing with external fixation followed by delayed interlocking nailing, for Gustilo type IIIB open tibial fractures. METHODS: 23 patients with Gustilo IIIB open tibial fractures were treated with either immediate unreamed interlocking nailing (n=9) or external fixation followed by delayed unreamed interlocking nailing (n=14). Patient age, sex ratio, fracture site, fracture type, and severity were similar in both groups. The time to union, deep infection rate, and nonunion rate in the 2 groups were compared. RESULTS: In the immediate and delayed nailing groups, respective mean times to union were 21 (standard deviation [SD], 14) months and 14 (SD, 8) months; nonunion rates were 44% (4/9) and 36% (5/14), and deep infection rates were 22% (2/9) and 7% (1/14). All corresponding differences were not statistically significant. CONCLUSION: Prospective, randomised, multicentre studies are needed to assess whether there are significant differences between the 2 treatment methods.     

Involvement of Pax-2 in the action of activin A on tubular cell regeneration

It has been recently shown that in ischemic rat kidneys activin A is induced in tubular cells and inhibits their regeneration. The present study was conducted to further investigate the action of activin A in tubular cells during regeneration. Among genes thought to be critical for kidney development, Pax-2 was upregulated in tubular cells during regeneration after renal ischemia. Pax-2 protein was localized in nuclei of tubular and interstitial cells, some of which co-expressed a mesenchymal cell marker, vimentin, suggesting that a population of Pax-2-positive cells have properties of immature progenitor-like tubular cells. The Pax-2-expressing cells co-expressed a cell proliferation marker, BrdU, activin A, and the type II activin receptor. Activin A modulated growth of BrdU/Pax-2 double-positive cells since an administration of follistatin increased; conversely, exogenous activin A decreased the number of BrdU/Pax-2 double-positive cells after renal ischemia. Activin A also reduced the expression of Pax-2 in cultured metanephroi. A proximal tubular cell line, LLC-PK(1) cells, was used to further study the mode of action of activin A. The expression of Pax-2 was not detected in quiescent LLC-PK(1) cells, but it was markedly increased when growth was stimulated. Under this condition, activin A significantly inhibited DNA synthesis and reduced the expression of Pax-2 in LLC-PK(1) cells. In contrast, blockade of the activin signaling by overexpressing dominantly negative mutant receptor enhanced the expression level of Pax-2 in LLC-PK(1) cells and induced an immature phenotype. These results suggest that activin A regulates tubular cell growth and differentiation by modulating the expression of Pax-2 during regeneration.     

A case presenting brain abscess with multiple infectious aneurysms

We report a case presenting a brain abscess with multiple infectious aneurysms. A 59-year-old man was transferred to our hospital suffering from left hemiparesis. MRI demonstrated a huge mass in the right frontal lobe with marked brain edema in the surrounding area. Diffusion-weighted image revealed heterogenous intensity, which is not typical in cases of brain abscess. Surgical removal was planned, and preoperative angiography was performed. Angiography demonstrated aneurysms at the distal branch of both the right middle cerebral artery and the anterior cerebral artery. These aneurysms were surgically resected, and the abscess was totally removed. Postoperative course was uneventful. Left hemiparasis was resolved, and there was no ischemic lesion seen on postoperative MRI. In the treatment of brain abscess, stereotactic aspiration has recently been preferred to removal by craniotomy. We conclude that cerebral angiography might be necessary to evaluate cerebrovascular complications including infectious aneurysms, in cases presenting atypical findings in neuroimaging study.