A responsive finite element method to aid interactive geometric modeling.

Current computer-aided engineering systems use numerical-simulation methods mainly as offline verification tools to reject designs that don't satisfy the required constraints, rather than as tools to guide users toward better designs. However, integrating real-time finite element method (FEM) into interactive geometric modeling can provide user guidance. During interactive editing, real-time feedback from numerical simulation guides users toward an improved design without tedious trial-and-error iterations. Careful reuse of previous computation results, such as meshes and matrices, on the basis of speed and accuracy trade-offs, have helped produce fast FEM analysis during interactive editing. Several 2D example applications and informal user studies show this approach's effectiveness. Such tools could help nonexpert users design objects that satisfy physical constraints and help those users understand the underlying physical properties.

Unfavourable prognosis associated with K-ras gene mutation in pancreatic cancer surgical margins.

BACKGROUND: Despite intent to cure surgery with negative resection margins, locoregional recurrence is common in pancreatic cancer. AIMS: To determine whether detection of K-ras gene mutation in the histologically negative surgical margins of pancreatic cancer reflects unrecognised disease. PATIENTS: Seventy patients who underwent curative resection for pancreatic ductal adenocarcinoma were evaluated. METHODS: All patients had surgical resection margins (pancreatic transection and retroperitoneal) that were histologically free of invasive cancer. DNA was extracted from these paraffin embedded surgical margins and assessed by quantitative real time polymerase chain reaction to detect the K-ras gene mutation at codon 12. Detection of K-ras mutation was correlated with standard clinicopathological factors. RESULTS: K-ras mutation was detected in histologically negative surgical margins of 37 of 70 (53%) patients. A significant difference in overall survival was demonstrated between patients with margins that were K-ras mutation positive compared with negative (median 15 v 55 months, respectively; p = 0.0008). By univariate and multivariate analyses, detection of K-ras mutation in the margins was a significant prognostic factor for poor survival (hazard ratio (HR) 2.8 (95% confidence interval (CI) 1.5-5.3), p = 0.0009; and HR 2.8 (95% CI 1.4-5.5), p = 0.004, respectively). CONCLUSIONS: Detection of cells harbouring K-ras mutation in histologically negative surgical margins of pancreatic cancer may represent unrecognised disease and correlates with poor disease outcome. The study demonstrates that molecular-genetic evaluation of surgical resection margins can improve pathological staging and prognostic evaluation of patients with pancreatic ductal adenocarcinoma.

Microsatellite instability of cancers and concomitant adenomas in synchronous multiple colorectal cancer patients.

The precise role of microsatellite instability (MSI) in the development of multiple colorectal cancers has not been elucidated. In the present study, the authors examined MSI and the clinicopathological features of both cancers and concomitant adenomas in nonfamilial multiple synchronous colorectal cancer (multiple CC) patients. Fifty adenomas and 108 cancers were obtained from the surgically resected specimens of 51 multiple CC patients. Nine microsatellite markers were used to determine MSI by polymerase chain reaction (PCR). The frequency of MSI-H adenomas in multiple CC patients was higher than that in single CC patients, while MSI-H frequency of cancers was similar to that in single CC patients. There was a tendency that, in multiple CC patients, when a patient has an MSI-H adenoma, he/she also has MSI-H cancer. The clinicopathological features of multiple CC were similar to those of single CC except the ratio of mucinous cancer and concomitant adenomas. According to this study, in some multiple CC patients, genetic instability seems to play an important role in the development of cancers as well as adenomas. We regard MSI testing for multiple CC patients is useful to distinguish "MSI-related" multiple CC from "MSI-unrelated" multiple CC, and MSI-related multiple CC should be followed up carefully as hereditary nonpolyposis colorectal cancer (HNPCC) patients.

Carcinoembryonic antigen mRNA in abdominal cavity as a useful predictor of peritoneal recurrence of gastric cancer with serosal exposure.

Peritoneal dissemination is the most frequent type of recurrence in patients with gastric cancer with serosal exposure, irrespective of whether they have undergone curative gastrectomy. The purpose of this study was to establish a method to detect micrometastatic cells in the abdominal cavity and predict peritoneal recurrence in patients with such gastric carcinomas. A total of 86 patients with gastric carcinoma, undergoing gastrectomy, were examined. Reverse transcriptase-polymerase chain reaction (RT-PCR) assay was used to detect carcinoembryonic antigen (CEA) mRNA in abdominal lavage fluid. Twenty-four cases without serosal exposure were negative, while all 13 cases with macroscopic peritoneal dissemination were positive for CEA mRNA. Among the 49 cases with macroscopic serosal invasion and without peritoneal metastasis, cancer cells were detected in 27 cases with RT-PCR while in only 6 cases with conventional cytology. All cytologically-positive cases were also positive for CEA mRNA. Among the 27 CEA-positive cases, 15 patients (56%) relapsed with peritoneal metastasis within 12 months after gastrectomy. In contrast, none of the 22 CEA-negative cases had peritoneal recurrence within 16-60 months of observation, whereas in 43 cytologically-negative cases, 10 patients relapsed with peritoneal recurrence. As compared with conventional cytological examination, this method would be clinically more beneficial for detecting free cancer cells in the peritoneal cavity and for predicting peritoneal recurrence in gastric carcinoma with serosal invasion.

Microsatellite instability of colorectal cancer and adenoma in synchronous multiple colorectal cancer patients with associated extracolonic malignancies.

We examined microsatellite instability (MSI) in nonfamilial multiple synchronous colorectal cancer (multiple CC) patients. We divided the patients into two groups, those with and without extracolonic primary malignancies, and compared the frequency of MSI between the two groups. A colectomy was performed in 52 multiple CC patients between 1985 and 1998. Of them, 10 patients had extracolonic malignancies, while the other 42 patients did not. The MSI frequency was higher in the patients with extracolonic malignancies than in those without extracolonic malignancies, although it was not statistically significant (40% vs 19%, P = 0.21). Regarding the lesions, MSI frequency of cancers was higher in the multiple CC with extracolonic malignancies than in those without extracolonic malignancies (33% vs 13%, P = 0.033). From our results, there was statistically no difference in the existence of extracolonic malignancies between the patients with at least one MSI-positive cancer and those patients without any MSI-positive cancers. On the other hand, there was a significant correlation between MSI-positivity and the existence of extracolonic malignancies.

Superficial depressed early carcinoma that developed into protuberant advanced carcinoma in the transverse colon.

A screening colonoscopic examination in a 70-year-old man revealed a nonpolypoid type superficial depressed early carcinoma, about 2cm in diameter, in the transverse colon. The lesion was not resected and was observed because of coexisting nonresectable hepatocellular carcinoma (HCC). Fifteen months later, follow-up examinations revealed a polypoid type protuberant advanced carcinoma, about 6 cm in diameter, at the same site. Because complete response of the HCC had been induced by transarterial embolization, the colon carcinoma was operatively resected. There is an indefinite concept that colorectal carcinomas develop without substantial morphological changes, and no superficial depressed carcinoma that developed into a protuberant type advanced carcinoma has been reported. The case reported here provides evidence that some polypoid carcinomas arise from superficial depressed precursors. There is some intermingling between the two postulated colorectal carcinogenic pathways, the conventional polypoid pathway named the "adenoma-carcinoma sequence", and the nonpolypoid pathway, including so-called "de-novo" carcinogenesis.

Effect of high ligation on the long-term result of patients with operable colon cancer, particularly those with limited nodal involvement.

OBJECTIVE: To find out what effect the extent of nodal dissection has on patients with operable colonic cancer. DESIGN: Retrospective study. SETTING: Teaching hospital, Japan. PATIENTS: 564 consecutive patients who had potentially curative operations for colon cancer. Patients treated by limited nodal dissection, in which only pericolonic nodes were dissected, were excluded. MAIN OUTCOME MEASURES: Disease free survival classified by extent of nodal dissection. RESULTS: High ligation gave no significant advantage when patients were subgrouped according to degree of nodal involvement. However, number of patients with aggressive involvement (including intermediate or central nodes) was small. 511 patients (91%) had limited nodal involvement (no nodal involvement or nodal involvement confined to pericolonic nodes). High ligation of the vessels gave no advantage even with meticulous subgrouping according to age, site, and depth of invasion. CONCLUSION: Most patients with colonic cancer had limited nodal involvement. High ligation did not affect the long term results in these patients, so, less invasive low ligation should be considered. A larger study will be necessary to clarify the indications for low and high ligation for patients with aggressive nodal involvement.

Rectosigmoidal adenomatous polyposis: a novel entity of polyposis? Report of a case.

PURPOSE: We report a patient with rectosigmoidal adenomatous polyposis. METHODS: A 57-year-old male presented with a submucosally invasive well-differentiated adenocarcinoma in the rectum and approximately 100 adenomatous polyps with an extremely unusual distribution limited exclusively to the rectum and sigmoid colon. RESULTS: There was no family history of colorectal disease or any related disorders. No extracolonic manifestations were found. Because this case was considered to be a discriminative phenotype of familial adenomatous polyposis, DNA from a peripheral sample of whole blood was screened for APC germline mutation by a combination of protein truncation test and single stranded conformation polymorphism, but no mutation was found. CONCLUSION: This patient may have a novel entity of adenomatous polyposis with a peculiar distribution. It may be caused by some genetic alteration other than APC mutation.

Retrospective radiographic analysis of nonpedunculated colorectal carcinomas with special reference to tumor doubling time and morphological change.

OBJECTIVE: Our aim was to characterize the development of nonpedunculated colorectal carcinomas by retrospective radiographic analysis, with special reference to tumor doubling time and morphological change. METHODS: Eleven colorectal carcinomas, which were observed for >6 months by barium enema examinations, were collected and retrospectively reviewed. There were five early and six advanced carcinomas, including submucosally invasive, superficial depressed carcinomas. RESULTS: Mean diameter of lesions at initial barium enema examination was 13.5 mm (early, 10.4 mm; advanced, 16.0 mm) and that at final barium enema examination was 30.9 mm (early, 18.2 mm; advanced, 41.5 mm). Initial morphology of the lesions was superficial in three, sessile in seven, and semipedunculated in 1. There was no pedunculated lesion. Macroscopic morphology of the five early carcinomas was superficial depressed (IIc) in two cases, mostly depressed but partly elevated (IIc+IIa) in one case, and superficial elevated with a depressed component (IIa+IIc) in two cases; all of the advanced carcinomas were of the ulcerated type. Mean doubling time was 6.8 months (early, 9.4 months; advanced, 4.7 months). Early carcinomas had significantly longer doubling times than advanced carcinomas (p = 0.017, Wilcoxon's text). The lesions with the longest doubling times were superficial depressed lesions. CONCLUSIONS: Early carcinomas have longer doubling times than advanced carcinomas. Most nonpedunculated colorectal carcinomas grow without significant morphological changes. Superficial depressed type tumors grow slowly, maintaining their macroscopic morphology.

Diagnostic primer sets for microsatellite instability optimized for a minimal amount of damaged DNA from colorectal tissue samples.

BACKGROUND: The diagnosis of microsatellite instability from a minimal amount of highly damaged DNA, extracted from formalin-fixed, paraffin-embedded tissue by the microdissection method, is difficult. Therefore, optimized primer sets were newly designed for substitution of documented ones. METHODS: DNA was extracted from 15 archival colorectal carcinomas and used as templates for polymerase chain reaction. Nine standard microsatellite markers (BAT-25, BAT-26, BAT-40, D18S69, D2S123, D5S346, D10S197, D17S250, and D18S58) were selected for diagnosis of microsatellite instability in colorectal carcinomas. All polymerase chain reaction conditions for primer sets were unified to save experimental time. RESULTS: The primer sets for the latter five markers documented in the literature were redesigned because of poor efficiency for damaged DNA. As a result, the number of DNA samples, sufficiently amplified at all markers, improved from 0% to 93%. CONCLUSIONS: Diagnostic primer sets for microsatellite instability, optimized for a minimal amount of damaged DNA from colorectal tissue samples, were established.

Characterization of dihydropyrimidine dehydrogenase on immunohistochemistry in colon carcinoma, and correlation between immunohistochemical score and protein level or messenger RNA expression.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD) is the first enzyme that metabolizes 5-fluorouracil (5-FU). Until now, enzymatic activity or mRNA expression of DPD has been investigated. However, there are no papers on immunohistochemical evaluation of DPD. We investigated DPD staining on immunohistochemistry, and examined the relationship among immunohistochemical score, protein level and mRNA expression of DPD. MATERIALS AND METHODS: Forty-seven resected colon cancer specimens, four colon cancer cell lines, two xenografts by colon cancer cell lines, and human mononuclear cells were used. Immunohistochemistry was performed using DPD monoclonal antibody. Protein levels were determined by Western blot analysis. And mRNA levels were calculated by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: DPD was strongly expressed in the cytoplasm of cancer cells, and in the cytoplasm of macrophage and plasma cells. The immunohistochemical score was more correlated with protein levels (P = 0.0054) than mRNA expression (P = 0.9028). CONCLUSIONS: We investigated the characterization of DPD immunohistochemically, and showed that immunohistochemical expression of DPD can be used to predict the sensitivity of colorectal carcinomas to 5-FU.

Involvement of APC and K-ras mutation in non-polypoid colorectal tumorigenesis.

The aim of this study was to clarify the role of APC and K-ras mutations in non-polypoid colorectal tumorigenesis. DNA from 63 adenomas (31 polypoid, 17 superficial elevated, 15 superficial depressed), 66 submucosally invasive carcinomas (47 polypoid, 19 non-polypoid) and 34 advanced carcinomas were examined for K-ras codon 12 point mutations and APC mutations in the mutation cluster region. K-ras mutation: the frequency in superficial depressed adenomas was lower than that in polypoid adenomas (0% vs 31%: P= 0.018). The frequency in non-polypoid carcinomas was lower than that in polypoid carcinomas (11% vs 56%: P = 0.0008), and was relatively low compared with that in polypoid adenomas (11% vs 31%). APC mutation: the frequency in superficial depressed adenomas was lower than that in polypoid adenomas (7% vs 43%: P = 0.016), and that in polypoid carcinomas was similar to that in non-polypoid carcinomas. Polypoid adenomas, polypoid carcinomas and advanced carcinomas had almost the same frequency. There may be some pathway other than the conventional adenoma-carcinoma sequence in development of non-polypoid carcinomas. The precursors of most non-polypoid carcinomas are considered to be de novo or superficial depressed adenomas. In this non-polypoid pathway, APC mutation seems to be requisite but K-ras mutation not. It is possible that new APC mutations are acquired after the development of superficial depressed adenomas.

Small advanced colorectal cancers: clinicopathological characteristics and pathogenetic origin.

BACKGROUND: Recently, increasing numbers of small but deeply invading colorectal cancers have been detected. We conducted the present study to examine the hypothesis that these small advanced cancers are more biologically malignant than larger cancers and to elucidate their pathogenetic origin. METHODS: We analyzed the clinicopathological characteristics of 23 advanced cancers not exceeding 2 cm in diameter (Small-Ca) in comparison with 1117 advanced cancers larger than 2 cm (Large-Ca). We compared the frequency of K-ras mutation and the growth pattern (polypoid growth, PG; non-polypoid growth, NPG) between Small-Ca and 60 submucosal cancers not exceeding 2 cm in diameter (Early-Ca). RESULTS: Generally, Small-Ca showed less malignant characteristics than Large-Ca. However, Small-Ca with NPG pattern invaded more deeply and metastasized more frequently than those with PG pattern. In Small-Ca, all ulcerated lesions showed NPG pattern, whereas only 14% of protruded lesions did. In Early-Ca, 90% of non-polypoid lesions showed NPG pattern, whereas only 16% of polypoid lesions did. K-ras mutation was less frequent in ulcerated Small-Ca than in polypoid cancers (33 vs 57%). In Early-Ca, non-polypoid cancers showed a lower frequency of K-ras mutation than polypoid cancers (9% vs 46%). CONCLUSIONS: Small-Ca, in general, were less malignant clinicopathologically than Large-Ca; however, Small-Ca with NPG pattern showed a tendency to be more aggressive than those with PG pattern. The similarity of the K-ras mutation rate and growth pattern of ulcerated Small-Ca and non-polypoid Early-Ca suggests that the majority of ulcerated Small-Ca may originate from non-polypoid Early-Ca.

Genetic alterations in ulcerative colitis-associated neoplasia focusing on APC, K-ras gene and microsatellite instability.

The status of genetic alterations in ulcerative colitis (UC)-associated neoplasia (UCAN) was investigated focusing on microsatellite instability (MSI) which is seen in a certain fraction of colorectal carcinomas, and adenomatous polyposis coli (APC) gene and K-ras gene, in which mutations occur in the early stage of sporadic colorectal tumorigenesis. Thirty-one UCAN from 15 UC patients who had undergone colorectal resection at our institution were investigated. There were 8 lesions of invasive carcinoma, 15 high-grade dysplasia (HGD) and 8 low-grade dysplasia (LGD). DNA was extracted from each neoplastic lesion and corresponding non-neoplastic tissue by a microdissection method. MSI status at 9 microsatellite loci, loss of heterozygosity (LOH) at the APC locus, and K-ras codon 12 point mutation were examined. As for MSI, 4/31 (13%) UCAN (carcinoma: 1/8 (13%), HGD: 2/15 (13%), LGD: 1/8 (13%)) were MSI-high (3 or more unstable loci) and 12/31 (39%) UCAN (carcinoma: 3/8 (38%), HGD: 6/15 (40%), LGD: 3/8 (38%)) were MSI-low (1 or 2 unstable loci). LOH at the APC locus was not found in 9 UCAN from 6 informative (heterozygous) cases. The K-ras mutation rate of UCAN was 3/31 (9.7%) (carcinoma: 2/8 (25%), HGD: 1/15 (7%) and LGD: 0/8). MSI is relatively common in UCAN and is present at the early stage of tumorigenesis of UCAN, while the involvement of genetic alterations of the APC gene and K-ras gene is small. MSI may be one of the mechanisms of the increased neoplastic risk in UC, and UCAN may develop through a different carcinogenic pathway from sporadic carcinomas.

Microsatellite instability is associated with the macroscopic configuration of neoplasms in patients with multiple colorectal adenomas.

BACKGROUND: The management of patients with multiple colorectal adenomas, 10-100 in number, is often troublesome clinically. To establish the reasonable management of such cases, genetic backgrounds should be made clear. METHODS: For a total of 19 adenomas and four carcinomas from four patients with multiple colorectal adenomas, we analyzed genetic instability at four selected microsatellite loci and screened exon 1-4 of the APC gene with special reference to macroscopic configurations of adenomas and carcinomas. RESULTS: RER-positive phenotypes were detected in none of 13 protruded type adenomas, two (33%) out of six superficial elevated type adenomas and two (50%) out of four carcinomas. We detected no mutation of exon 1-4 of the APC gene in any sample. In patients with multiple colorectral adenomas, the proportion of superficial elevated type adenomas exhibiting genetic instability was significantly higher than that of protruded type adenomas. CONCLUSIONS: The results suggested that RER-positive phenotype was an early event in tumorigenesis through superficial elevated type adenomas.

Characteristics in primary signet-ring cell carcinoma of the colorectum, from clinicopathological observations.

BACKGROUND: The biological behavior of signet-ring cell carcinomas in colorectum tends to be worse than that of mucinous carcinomas. However, in previous studies, clinicopathological features of this disease have been somewhat ill-defined because various histological criteria of this disease were adopted. METHODS: We selected 11 cases of signet-ring cell carcinomas and 29 cases of mucinous carcinomas among 1595 consecutive colorectal carcinomas on defined criteria and compared clinicopathological and molecular biological features between these two types of carcinomas. RESULTS: Clinical staging of signet-ring cell carcinomas were far advanced and their prognosis tended to be worse than that of mucinous carcinomas. Furthermore, the incidence of K-ras mutations in signet-ring cell and mucinous carcinomas showed no difference between these two types of carcinomas. However, the incidence of K-ras mutation in these diseases was slightly lower than that in 30 ordinary colorectal carcinomas examined as a comparison. CONCLUSIONS: These results suggest that the carcinogenesis of signet-ring cell and mucinous carcinomas are different from that of ordinary colorectal carcinomas and that there may exist other genes related to malignancy of signet-ring cell carcinomas.

Lovastatin inhibits gene expression of type-I scavenger receptor in THP-1 human macrophages.

Lovastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, inhibits the synthesis of mevalonic acid and is widely used as an anti-atherosclerotic drug. The macrophage scavenger receptor (SCR), a trimeric membrane glycoprotein, is postulated to play a key role in atheroma macrophage foam cell formation. HMG-CoA reductase is involved in the control of the synthesis of glycoproteins and farnesylated proteins, including ras proteins, which are involved in the transcriptional regulation of SCR gene expression. Accordingly, we examined whether lovastatin alters the gene expression of SCRs in THP-1 cell derived human macrophages. Lovastatin (5-15 microM) caused a significant dose-related reduction in steady state levels of type-I SCR mRNA in phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells. The addition of exogenous mevalonate (1 mM) completely restored the lovastatin-induced decrease of type-I SCR mRNA levels. While the addition of the isoprenoid end-product, isopentenyl adenine (50 microM), had little effect on the type-I SCR mRNA levels in lovastatin treated cells, the addition of isoprenoid farnesol (5 microM) largely restored the lovastatin-induced decrease of type-I SCR mRNA levels. Actinomycin D treatment showed that degradation rates of type-I SCR mRNA did not differ between the THP-1 derived cells with and without lovastatin treatment. Nuclear run-on assays showed that lovastatin markedly decreased the transcription of SCR gene in the cells. These results suggest that lovastatin inhibits the transcription of type-I SCR gene by affecting mevalonate metabolism, possibly through the farnesyl-pyrophosphate related end-product(s) in the THP-1-derived macrophages.

Blood pressure regulates platelet-derived growth factor A-chain gene expression in vascular smooth muscle cells in vivo. An autocrine mechanism promoting hypertensive vascular hypertrophy.

To clarify the role of PDGF A-chain in hypertensive vascular hypertrophy of spontaneously hypertensive rats (SHRs), we studied levels of PDGF A-chain gene expression and transcription factors related to the gene in vascular smooth muscle cells (VSMCs) of SHRs in vivo. RNase protection assay and in situ hybridization showed that PDGF A-chain mRNA levels in VSMCs of SHRs were twofold higher than in those of normotensive Wistar-Kyoto rats. Gel retardation assays showed that levels of Sp1 and AP-2 in VSMCs of SHRs were twofold more abundant than in those of Wistar-Kyoto rats. Treatment with four pharmacologically different species of antihypertensive drugs for 2 wk decreased the levels of both PDGF A-chain mRNA and Sp1, but not AP-2 level in VSMCs of SHRs with regression of aortic hypertrophy, indicating that increases in levels of both PDGF A-chain mRNA and Sp1 in VSMCs of SHRs were associated with high blood pressure. These results suggest that high blood pressure is a stimulus which upregulates PDGF A-chain gene expression in VSMCs of SHRs, resulting in an autocrine enhancement in hypertensive vascular hypertrophy, and that the activation of the gene may be mediated through increases in Sp1 in these cells.

Anti-Ro/SS-A antibody-positive interstitial pneumonitis in a non-lupus patient.

We describe a 42-year-old anti-Ro/SS-A antibody positive non-lupus patient who developed interstitial pneumonitis in combination with several common clinical features with previously reported lupus pneumonitis patients whose anti-Ro/SS-A antibodies were positive, while whose antinuclear antibodies were negative. We consider that these patients may belong to a same new clinical entity. A variety of characteristic manifestations related to anti-Ro/SS-A antibodies has been reported in patients with systemic lupus erythematosus (SLE) and other connective tissue diseases [1] [2], and an association between these antibodies with pulmonary parenchymal involvement has been reported by Hedgpeth and Boulware in patients with SLE [3] [4]. We report here a 42-year-old non-lupus male patient with pulmonary fibrosis who presented with anti-Ro/SS-A antibodies.

Modulation of protein kinase C in aorta of spontaneously hypertensive rats with enalapril treatment.

We measured protein kinase C (PKC) activity, levels of PKC alpha enzyme and PKC alpha mRNA in aortic media of spontaneously hypertensive rats (SHR), normotensive Wistar Kyoto rats (WKY) and enalapril treated SHR (enal-SHR) to examine whether hypotensive treatment of enalapril modulates PKC in aortic media of SHR. The cytosolic PKC activity in crude samples of aortic media of SHR was higher than in those of WKY or enal-SHR (p < 0.01) and was closely associated with blood pressure (r = 0.84, p < 0.001). The membrane PKC activity was detected in samples of SHR, but virtually no activity was detected in samples of WKY or enal-SHR. The cytosolic PKC activity in DEAE column purified samples of SHR was also higher than in those of WKY or enal-SHR (p < 0.01). The PKC alpha enzyme levels (74-kDa and 77-kDa protein) detected by immunoblot were higher in SHR than in WKY or enal-SHR (p < 0.01). The mRNA levels of PKC alpha were higher in SHR than in WKY (p < 0.01) and were much decreased in enal-SHR (p < 0.01). Thus, PKC activity, PKC alpha and its mRNA levels were higher in aortic media of SHR than those in WKY and these increased levels were reversed with enalapril treatment. Considering the pivotal roles of PKC in the mechanism of cellular proliferation and the pathogenesis of hypertension, these results provide clues in understanding the pathogenesis of hypertension, mechanisms of vascular hypertrophy in hypertension and the beneficial effects of angiotensin converting enzyme inhibitor in the treatment of hypertension.