Effects of the endothelin ETA-receptor antagonist FR139317 on development of hypertension and cardiovascular hypertrophy in deoxycorticosterone acetate-salt hypertensive rats

We investigated the role of endothelin-1 (ET-1) in the development of hypertension and cardiovascular hypertrophy in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Two weeks after the start of DOCA-salt treatment, the rats were divided into two groups and were given FR139317 [(R)2-[(R)-2-[(S)-2-[[1-(hexahydro-1H-azepinyl)]- carbonyl]amino-4-methyl-pentanoyl]amino-3-[3-(1-methyl-1H-indolyl)] propionyl]amino-3-(2-pyridyl) propionic acid], a specific ETA-receptor antagonist, or its vehicle for 2 weeks. Uninephrectomized rats without DOCA-salt treatment served as controls. Vehicle-treated DOCA-salt rats developed marked hypertension after 4 weeks. FR139317 significantly suppressed the increase in systolic blood pressure with values averaging 163 +/- 8 mmHg (P < 0.05 vs DOCA-salt rats receiving vehicle, 195 +/- 9 mmHg). Morphological studies in the rats given the vehicle showed vascular medial hypertrophy, with a significant increase in the wall area and wall-to-lumen ratio. A marked decrease in vascular wall hypertrophy was observed in the FR139317-treated DOCA-salt rats. The cardiac hypertrophy in DOCA-salt hypertensive rats was also significantly reduced by FR139317. Therefore, these results suggest that ET-1 plays an important role in the development of DOCA-salt hypertension presumably by stimulating the ETA receptor. In addition, we found that an ETA-receptor antagonist effectively reduced cardiovascular hypertrophy in the rats, so the cardiovascular hypertrophy noted in DOCA-salt hypertensive rats may be related to ET-1.

The prolyl 4-hydroxylase inhibitor HOE 077 prevents activation of Ito cells, reducing procollagen gene expression in rat liver fibrosis induced by choline-deficient L-amino acid-defined diet

No effective therapy has yet developed for liver fibrosis by directory inhibiting the accumulation of extracellular matrix. The effect of a newly synthesized prolyl4-hydroxylase (PH) inhibitor, HOE 077 (pyridine-2, 4-di-carboxylic-di(2-methoxyethyl)amide), was examined using the model of choline-deficient L-amino acid (CDAA) defined diet-induced liver fibrosis in 16-week-old male Wistar rats. HOE 077 at doses up to 200 ppm prevented fibrosis in a dose-dependent manner, as indicated by reduced hydroxyproline content in liver as well as inhibition of increased serum fibrotic markers (PIIIP, 7S, hyaluronic acid). HOE 077 at 200 ppm reduced expression of type III procollagen alpha 1, messenger RNA (mRNA) in the liver, with a good correlation with serum PIIIP and hydroxyproline content of the liver. Histologically, HOE 077 at 200 ppm also reduced proliferation of myofibroblastlike cells (activated Ito cells). These results indicate that a PH inhibitor can prevent fibrosis by inhibiting not only the hydroxylation of proline but also the activation of Ito cells, which are considered the main collagen-producing cells, resulting in reduced expression of procollagen mRNA.

Characterization of p53 gene mutations in basal-cell carcinomas: comparison between sun-exposed and less-exposed skin areas

Mutations in the p53 gene in 32 basal-cell carcinomas (BCC) developed in Japanese patients were identified by the polymerase chain reaction and single-strand-conformation polymorphism analysis, followed by sequencing the DNA. Among 16 BCC developed in continuously sun-exposed areas, 6 tumors showed 7 base substitutions, most of which were G:C to A:T transitions, mainly at the dipyrimidine sites. Seven out of 16 BCC developed in less-exposed areas showed 8 base substitutions, but the majority (75.0%) of them were transversions. These results suggest that the mutation in the p53 gene plays a significant role in the tumorigenesis of BCC developed in less-exposed areas as well as those in sun-exposed areas in Japanese patients. There must be therefore causative factors other than UV irradiation for BCC in less-exposed areas.

Plasmin stimulates expression of endothelin-1 mRNA and endothelin-1 release in vascular endothelial cells

Incubation of cultured porcine aortic endothelial cells (ECs) with plasmin resulted in a significant and concentration-dependent increase in endothelin-1 (ET-1) release from the cells. This increasing effect was completely inhibited by aprotinin but not by tranexamic acid, thereby suggesting that the plasmin-induced stimulation of ET-1 release requires the catalytic site but not the lysine binding site, in plasmin molecule. Plasmin stimulated the expression of prepro ET-1 mRNA in ECs. Actinomycin D chase experiments suggested that enhanced stability of ET-T mRNA could not account for the above plasmin-induced stimulation. It is likely that plasmin potentiates the endothelial ET-1 production, probably by the stimulation of ET-1 gene transcription. It remains to be seen whether the endothelial ET-1 production is enhanced after the thrombolytic therapy.

Effect of sodium nitroprusside on norepinephrine overflow and antidiuresis induced by stimulation of renal nerves in anesthetized dogs

To investigate the role of nitric oxide (NO) in the regulation of renal sympathetic nerve activity and renal function, we examined the effect of sodium nitroprusside (SNP), a NO donor, on renal actions induced by renal nerve stimulation (RNS) in anesthetized dogs, with or without blockade of an endogenous NO generation by NG-nitro-L-arginine (NOARG), a NO synthase inhibitor. Low-frequency RNS (0.5-2.0 Hz) enhanced the rate of norepinephrine secretion rate (NESR) from the kidney and decreased urine flow (UF), urinary excretion of sodium (U(Na)V), and fractional excretion of sodium (FENa, without affecting systemic and renal hemodynamics. The intrarenal arterial infusion of SNP, in a dose (1 mu g/kg/min) that does not affect renal hemodynamics and urine formation at the basal level, significantly attenuated the RNS-induced decreases in UF, UNa V and FENa. The intrarenal administration of NOARG (40 mu g/kg/min) elicited renal vasoconstriction and reduced urine formation. RNS during NOARG administration reduced renal blood flow (RBF) and glomerular filtration rate (GFR) and augmented RNS-induced reduction in urine formation. Simultaneously, NESR was markedly enhanced. The renal actions observed with NOARG administration during control and RNS periods were almost completely abolished by treatment with SNP. Therefore, we suggest that NO plays an important role in the regulation of renal function. Endogenous NO probably functions as an inhibitory modulator of renal noradrenergic neurotransmission at the prejunctional level.

Cell death induced by baicalein in human hepatocellular carcinoma cell lines

We examined the action of baicalein, a flavonoid contained in the herbal medicine sho-saiko-to (TJ-9), on three cell lines of human hepatocellular carcinoma (HCC). Treatment with baicalein strongly inhibited the activity of topoisomerase II and suppressed the proliferation of all three HCC cell lines. But the mode of cell death induced by baicalein differed according to the cell line. Baicalein induced apoptosis in a concentration-dependent manner in only one cell line, and an increased concentration of baicalein produced cell death via necrosis in the other two lines. These results suggest that the inhibition of topoisomerase II is not by itself sufficient for induction of apoptosis, and that there is a more important mechanism which can account for the difference in susceptibility of cells to apoptosis induced by baicalein.

Enhanced susceptibility to transglutaminase reaction of alpha-lactalbumin in the molten globule state

The susceptibility of alpha-lactalbumin to transglutaminase reactions was studied using an enzyme from Streptoverticillium which can catalyze the reactions irrespective of the presence or absence of Ca2+. Transglutaminase-catalyzed polymerization of alpha-lactalbumin in the native state occurred to a very limited extent. Transformation from the native state to the molten globule state brought about by Ca(2+)-removal from holo-alpha-lactalbumin enhanced the polymerization of the protein catalyzed by transglutaminase. The incorporation of Carbobenzoxy-Gln-Gly into alpha-lactalbumin through the enzyme reaction was investigated to determine the amounts of lysine residues which are present at molecular surface and available to the enzyme. There was no significant difference in the amount of available lysine residues between the native and the molten globule molecule. However, the amount of surface glutamine residues incorporated with monodansylcadaverine by transglutaminase was remarkably higher in the molten globule state than that in the native state. The monodansylcadaverine-incorporated site of alpha-lactalbumin in the molten globule state was identified as Gln-54 by amino-acid sequence analysis of fluorescence-labeled peptides separated from chymotryptic digests of the protein. Possible reason for selective labeling of Gln-54 in molten globule alpha-lactalbumin was proposed.

Selection of desorbing solvents for organic compounds from active carbon tubes

To ensure the effective performance of active carbon tubes for working environment measurements, suitable desorbing solvents were selected for 46 kinds of organic compounds by the phase equilibrium method. The criteria for suitable desorbing solvents in this study was desorption of the objective compounds from active carbon at efficiencies greater than 90% and to give good separation between its own peak and that of the objective compound on a gas chromatogram. For most non-polar or hydrophobic compounds, carbon disulfide was a versatile and effective solvent. But for polar and hydrophilic compounds like alcohol, N,N-dimethylformamide and dimethylsulfoxide were good desorbing solvents if their peaks did not overlap with those of the objective compounds. Mixtures of lower molecular weight alcohols with carbon disulfide or dichloromethane could be alternative solvents for hydrophilic compounds as well. A thermodynamic parameter of the solute-solvent system, i.e., the mixing energy derived from the solubility parameter, gave a rough indication of the effectiveness of solvents but it could not be used as a critical indicator for the efficient desorbing solvents for organic vapors collected on active carbon.

[Infective endocarditis associated with vertebral osteomyelitis: report of two cases]

A 42-year-old man and a 65-year-old woman with infective endocarditis suffered onset of severe back pain. Magnetic resonance imaging and technetium-99 m bone scanning demonstrated osteomyelitis in the lumbar spine which is an unusual complication of infective endocarditis. The man was treated by antibiotics and finally aortic valve replacement and laminectomy with bone grafting. The woman had small patent ductus arteriosus and developed aortic regurgitation, but was treated by antibiotics and corset application with good result. The possibility of osteomyelitis in the lumbar spine should be considered in a patient with endocarditis complaining of severe back pain. The appropriate antibiotic therapy over a prolonged period is recommended.

[An elderly patient with Leriche syndrome complicated by congestive heart failure and rhabdomyolysis]

A 64-year-old man, who had had bilateral intermittent claudication and leg pain for five years, was admitted because of sudden onset of severe leg pain, and acute respiratory failure. Laboratory data showed markedly elevated serum CK of 73,050 IU/L, and urinary myoglobin of 430,000 ng/ml. A diagnosis of rhabdomyolysis was made. Renal dialysis was required for the next two days because of acute renal failure. The aortogram was performed on the 32nd day and disclosed complete obstruction of the abdominal aorta immediately distal to the bilateral renal arteries. Good collateral flow was noted to the popliteal arteries. On the 49th day, the patient successfully underwent extra-anatomical bypass surgery (axillo-bifemoral bypass). The mechanism of rhabdomyolysis in this elderly patient was discussed.

[Two cases of Candida endocarditis associated with abdominal disease]

Two cases of Candida endocarditis are reported. The first case was of a 63-year-old man who had a positive blood culture for Candida albicans during treatment for liver abscess and early gastric cancer. He was transferred to our department, and aortic and tricuspid regurgitation due to Candida endocarditis was diagnosed. The patient was successfully treated with aortic valve replacement, tricuspid valve plasty and anti-fungal agents. The second case was of a 65-year-old man who complained of fever. Despite a diagnosis of common bile duct cancer and resection of the tumor, the fever persisted. He was transferred to our department and was diagnosed having aortic regurgitation due to Candida endocarditis, complicated by heart failure. Although intense medical therapy including antifungal agents, diuretics, catecholamines and digoxin was initiated, the patient died from multiple embolisms 9 days later. In the treatment of Candida endocarditis, early diagnosis and early decision-making for either surgical or medical therapy is indispensable. Although the prevalence of Candida endocarditis is low, the differentiation of this disease should be taken into account in febrile elderly patients with long-standing therapy with antibiotics.

Mutagenicity of alkyl azides

Alkyl azides showed mutagenicity for S. typhimurium TA100 strain with S9 mix. However, no significant activity was observed for TA98 either with or without S9 mix or for TA100 without S9 mix. On the other hand, 3-azido-1,2-propanediol showed the enantioselective activity regardless of S9 mix. Two aryl azides tested were not mutagenic, and trimethylsilyl azide exhibited potent activity for TA100. Their structure-activity relationships are discussed.

ETA receptor-mediated role of endothelin in the kidney of DOCA-salt hypertensive rats

Renal effects of FR139317, an endothelin ETA receptor antagonist, were examined using anesthetized normotensive and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. The intravenous bolus injection of FR139317 (10 mg/kg) produced a slight decrease in mean blood pressure (MAP; -13%) in the control rats and this hypotension was accompanied by a moderate renal vasodilation (renal vascular resistance: RVR; -12%). In the DOCA-salt hypertensive rat, FR139317 had a more pronounced hypotensive effect (MAP; -26%) accompanied by a potent renal vasodilation (RVR; -33%). FR139317 significantly increased renal blood flow only in the DOCA-salt rats. In contrast, FR139317 produced a significant decrease in urine flow and urinary sodium excretion only in control rats. Northern blot analysis revealed that the renal prepro endothelin-1 (ET-1) mRNA level was significantly increased in DOCA-salt hypertensive rats. Thus, it seems likely that endogenous ET-1 is responsible for the maintenance of DOCA-salt-induced hypertension. We also suggest that at least in part, ET-1 and ETA receptors are involved in renal hemodynamic abnormalities in DOCA-salt-induced hypertension. The augmentation of renal ET-1 production may possibly have a function in the development and maintenance of DOCA-salt-induced hypertension.

Abnormal retention of intron 9 in CD44 gene transcripts in human gastrointestinal tumors

We have recently identified a new exon of the CD44 gene and demonstrated abnormal retention of a noncoding section, intron 9, in mRNA from bladder carcinomas. To analyze this further, the present study examined CD44 gene expression in cell lines from 14 esophageal, 3 colonic, and 4 breast carcinomas and in fresh samples from 20 colorectal carcinomas and corresponding normal colonic mucosa, using reverse transcriptase followed by the polymerase chain reaction (RT-PCR). This confirmed that there was abnormal assembly of several exons of the gene in cell lines and in tumor tissues from these organs. However, the most striking new finding was that intron 9 was present in RNA from 11 esophageal, 3 colon, and 1 breast carcinoma cell line, respectively. This was confirmed by RNase and DNase digestion analysis. Moreover, it was detected both in nuclear and cytoplasmic mRNA fractions, indicating that abnormal splicing of pre-mRNA occurs in cancer cells. The abnormal retention of intron 9 in CD44 gene transcripts was also demonstrated in tumor tissues from 16 (80%) of 20 patients with colon carcinoma, but there was no correlation with Dukes' stage. The biological significance of these observations is not yet understood. However, it is clear that, as with the abnormal expression pattern of CD44 variant exons, intron 9 retention is a good-candidate molecular diagnostic tool for colorectal carcinomas.

High prevalence of mutations in the p53 gene in poorly differentiated squamous cell carcinomas in xeroderma pigmentosum patients

Mutations in the p53 gene were analyzed in 23 squamous cell carcinomas (SCCs) and five basal cell carcinomas from 10 xeroderma pigmentosum patients in Tunisia. Fourteen mutations were detected. Most occurred at the dipyrimidine sequences of DNA, suggesting that they were caused by ultraviolet light. A strong correlation was noted between the presence of the p53 mutations and clinical characteristics such as histology and growth of SCC. In well-differentiated grade 1 SCCs, three (27.3%) of 11 tumors had the p53 gene mutations, whereas in grade 2 and grade 3 SCCs, six (85.7%) of seven tumors had the p53 gene mutations (p < 0.05). Tumors less than 8.0 mm in diameter showed a relatively low frequency of mutation (two of 10 tumors, 20.0%), whereas most of the tumors larger than 8.1 mm (seven of eight tumors, 87.5%) had mutations of the p53 gene (p < 0.025). Multiple tumors in the same xeroderma pigmentosum patients also showed this relation. These results suggest that mutations in the p53 gene lead to the invasive and rapid-growing character of SCC.

Antihypertensive effect of sesamin. II. Protection against two-kidney, one-clip renal hypertension and cardiovascular hypertrophy

We investigated the antihypertensive effect of sesamin, a lignan from sesame oil, using two-kidney, one-clip (2K,1C) renal hypertensive rats. After clipping the left renal artery, animals were assigned to either a normal diet group (control group) or a sesamin-containing (1% (w/w)) diet group (sesamin group). The sham-operated rats (sham group) were fed a normal diet and tap water. The systolic blood pressure of the control group increased progressively in comparison with the sham group. This 2K,1C-induced hypertension was markedly reduced by feeding the sesamin-containing diet. The systolic blood pressure after 4 weeks was 123.60 +/- 4.01 mmHg in the sham group, 187.43 +/- 5.69 mmHg in the control group and 145.57 +/- 6.78 mmHg in the sesamin group, respectively. There were significant increases in left ventricle plus septum weight-body weight ratio in the control group compared with the sham group. This rise was also significantly reduced in the sesamin group. When the thoracic aorta was histochemically evaluated, the wall thickness and wall-to-lumen ratio in the control group were significantly increased, compared with the sham group, indicating that vascular hypertrophy had occurred in the control group. The sesamin diet tended to ameliorate this vascular hypertrophy, although its effect was not statistically significant. These findings suggest that sesamin is useful as prophylactic treatment to combat the development of renal hypertension and cardiac hypertrophy.

Role of transforming growth factor-beta 1 on platelet-induced enhancement of endothelin-1 production in cultured vascular endothelial cells

We and other investigators obtained evidence that platelets stimulate endothelin-1 (ET-1) production at both message and protein levels in vascular endothelial cells (ECs), and that platelet-derived transforming growth factor-beta 1 (TGF-beta 1) is responsible for this stimulation. In the present study, we examined the effects of acidification or heat treatment, known to activate latent TGF-beta 1, on the platelet supernatant-induced ET-1 production in cultured porcine aortic ECs. Supernatant of platelets (6.0 x 10(8) platelets/ml) aggregated by adenosine diphosphate contained large amounts of TGF-beta 1, but were almost in a latent form, and the proportion of active TGF-beta 1 in the supernatant was increased markedly in the case of acidification or heat treatment. These treatments also significantly potentiated the supernatant-induced stimulation of prepro ET-1 mRNA expression and the ET-1 release in ECs. Purified TGF-beta 1 also enhanced ET-1 release, dose-dependently, but the enhancement declined at the higher concentrations. Thus, powerful stimulation of ET-1 production by platelet supernatant after acidification or heat treatment cannot be explained only by increments in active TGF-beta 1. The supernatant-induced stimulation of ET-1 synthesis was significantly inhibited by concomitant treatment of TGF-beta 1 neutralizing antibody, but this inhibition was incomplete even at a concentration that abolished TGF-beta 1-induced maximal stimulation. These results suggest that platelet-induced stimulation and subsequent acidification and heat treatment-induced potentiation on endothelial ET-1 production depend closely on release and activation of TGF-beta 1 derived from platelets.(ABSTRACT TRUNCATED AT 250 WORDS)

Unusual retention of introns in CD44 gene transcripts in bladder cancer provides new diagnostic and clinical oncological opportunities

Increased and disorganised expression of CD44 variant exons has been demonstrated in biopsy samples of several types of human malignancy by many groups. This abnormality can be used to detect exfoliated tumour cells in the urine of bladder cancer patients. The present report demonstrates that the deranged activity of this gene in neoplasia also results in the accumulation of immature mRNA transcripts containing non-coding sequences (introns) from this gene in cancer tissues and cells. There is simultaneous overexpression of a newly identified 437 bp exon (coding sequence) located in the variably active region of the gene and of many abnormal variant exon combinations. This is the first report describing the specific retention of introns in gene transcripts in clinical diagnostic samples of tumour tissues and cells. The phenomenon was seen repeatedly in samples from cancer patients and in a cancer cell line, and thus could form the basis for a unique new and specific method of cancer diagnosis.

[Surgical treatment of metastatic lung tumor from colorectal cancer]

We have experienced thirty-one operations of metastatic lung tumors from colorectal cancer. Various factors affecting prognosis are studied based on 5-year survival in this report. Overall 5-year survival rate was 32%. Statistical significance was present in the relationship between the prognosis and both maximum diameter of lesions and the disease free intervals (DFI) after surgery for metastatic lesions. Though not significant, sex, stage of primary lesion, nodal involvement, surgical procedure, postoperative serum CEA were likely affecting factors on the prognosis. In contrast, there were no relationship between the prognosis and following factors: age, location of the metastatic lesion, DFI after the operation for primary lesion and chemotherapy. Although pulmonary metastasis is essentially an index of the advanced state of malignant diseases leading to poor prognosis, long-term survivors were encountered in our series of surgical treatments for pulmonary metastases from colorectal cancers. It was concluded to be important to make efforts to extend the indication for surgical treatment, since the appropriate selection of patients revealed to give excellent results from our experience of colorectal cancer. In order to improve the prognosis, early detection of pulmonary metastases is quite important, since the incidence of nodal involvement proved to be higher in lesions with larger diameter resulting in inferior survivals from the present study. In addition, low incidence of nodal involvement in small-sized lesion may support possible applicability of thoracoscopic surgery in the excision of metastatic tumors locating at peripheral lesion.