The effects of chymase on matrix metalloproteinase-2 activation in neointimal hyperplasia after balloon injury in dogs.

Chymase is known to generate angiotensin II in the vascular wall. In this study we investigated a novel role for chymase other than angiotensin II production in vascular proliferation after balloon injury. Chymase promoted the migration of vascular smooth muscle cells in the matrix-coated invasion chambers and activated promatrix metalloproteinase-2 obtained from the culture medium of vascular smooth muscle cells. Two weeks after balloon injury, significant neointimal formation was found in dog carotid arteries. After injury, active matrix metalloproteinase-2 was increased in parallel with the augmentation of chymase activity that was seen in the proliferating region of the vascular wall. The oral administration of NK3201 (1 mg/kg per day), a chymase inhibitor, prevented neointimal formation and significantly suppressed both active matrix metalloproteinase-2 and chymase activities 2 weeks after injury. These results suggest that chymase inhibitors can prevent the development of intimal hyperplasia via the inhibition of matrix metalloproteinase-2 activation in balloon-injured arteries.     

Metabolic syndrome, C-reactive protein and increased arterial stiffness in Japanese subjects.

The aim of this study was to investigate whether the metabolic syndrome (MS) was associated with an elevated level of C-reactive protein (CRP) and increased arterial stiffness, and to clarify whether combined MS and CRP data had a stronger relation to arterial stiffness than did MS data alone. Brachial-ankle pulse wave velocity (baPWV), CRP, and conventional risk factors were evaluated in 3,412 men and 854 women. Adjusted mean values of baPWV in men with 0, 1, 2, and > or = 3 components were 1,309, 1,372, 1,422, and 1,462 cm/s, respectively (p for trend <0.001). Adjusted mean values of baPWV in women with 0, 1, 2, and > or =3 components were 1,212, 1,292, 1,357, and 1,391 cm/s, respectively (p for trend <0.001). Adjusted geometric mean concentrations of CRP in men with 0, 1, 2, and > or = 3 components were 0.036, 0.049, 0.059, and 0.076 mg/dI, respectively (p for trend <0.001). Adjusted geometric mean concentrations of CRP in women with 0, 1, 2, and > or = 3 components were 0.023, 0.030, 0.057, and 0.077 mg/dI, respectively (p for trend <0.001). In analyses of adjusted mean values of baPWV according to the number of MS components and according to CRP levels within or without top quartile levels, the p value for the trend was significant (<0.001) in both men and women but, in post hoc analyses, comparing high and low CRP levels in each MS component-number group, no significant difference was found. These results suggest that, for prediction of increased arterial stiffness, combining MS and CRP data has little additive effect compared to the use of MS data alone.     

Pressure overload-induced transient oxidative stress mediates perivascular inflammation and cardiac fibrosis through angiotensin II.

Oxidative stress is implicated in the pathogenesis of various cardiovascular diseases. We have shown that in Wistar rats with a suprarenal aortic constriction (AC), pressure overload-induced transient perivascular inflammation (monocyte chemoattractant protein-1 [MCP-1] induction and macrophage accumulation) in the early phase is the determinant of reactive myocardial fibrosis and resultant diastolic dysfunction in the late phase. Thus, we investigated the role of reactive oxygen species production in cardiac remodeling in AC rats. Superoxide production and the footprint of lipid peroxidation were assessed using dihydroethidium staining and immunohistostaining against 4-hydroxy-2-nonenal (4-HNE), respectively. In sham rats, dihydroethidium and 4-HNE signals were scarcely found in the heart. At day 3, AC rats showed dihydroethidium signals mainly in the intramyocardial arterial wall, whereas modest 4-HNE staining was observed diffusely in the myocardium. These signals declined to lower levels by day 14 despite sustained hypertension. Chronic administration of a subdepressor dose of an angiotensin II type 1 receptor blocker candesartan reduced the pressure overload-induced dihydroethidium and 4-HNE signals at day 3. Moreover, candesartan decreased MCP-1 induction and macrophage infiltration at day 3 and prevented myocardial fibrosis at day 14, without affecting left ventricle and myocyte hypertrophy. In conclusion, acute pressure overload induced self-limited superoxide production mainly in the vascular wall. The reactive oxygen species production would contribute to the perivascular inflammation and subsequent myocardial fibrosis. Angiotensin II was suggested to have a pressure-independent effect on the reactive oxygen species production.     

Increased expression of gp91phox homologues of NAD(P)H oxidase in the aortic media during chronic hypertension: involvement of the renin-angiotensin system.

Although vascular cells express multiple members of the Nox family of nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase, including gp91phox, Nox1, and Nox4, the reasons for the different expressions and specific roles of these members in vascular injury in chronic hypertension have remained unclear. Thus, we quantified the mRNA expressions of these NAD(P)H oxidase components by real-time polymerase chain reaction and evaluated superoxide production and morphological changes in the aortas of 32-week-old stroke-prone spontaneously hypertensive rats (SHRSP) and age-matched Wistar Kyoto rats (WKY). The aortic media of SHRSP had an approximately 2.5-fold greater level of Nox4 mRNA and an approximately 10-fold greater level of Nox1 mRNA than WKY. The mRNA expressions of gp91phox and p22phox in SHRSP and WKY were comparable. SHRSP were treated from 24 weeks of age for 8 weeks with either high or low doses of candesartan (4 mg/kg/day or 0.2 mg/kg/day), or a combination of hydralazine (30 mg/kg/day) and hydrochlorothiazide (4.5 mg/kg/day). The high-dose candesartan or the hydralazine plus hydrochlorothiazide decreased the blood pressure of SHRSP to that of WKY, whereas the low-dose candesartan exerted no significant antihypertensive action. Media thickening and fibrosis, as well as the increased production of superoxide in SHRSP, were nearly normalized with high-dose candesartan and partially corrected with low-dose candesartan or hydralazine plus hydrochlorothiazide. These changes by antihypertensive treatment paralleled the decrease in mRNA expression of Nox4 and Nox1. These results suggest that blood pressure and angiotensin II type 1 receptor activation are involved in the up-regulation of Nox1 and Nox4 expression, which could contribute to vascular injury during chronic hypertension.     

PEUTZ‐JEGHERS SYNDROME ASSOCIATED WITH RENAL AND GASTRIC CANCER THAT DEMONSTRATED AN STK11 MISSENSE MUTATION

A 75‐year‐old male was admitted to the gastroenterology unit of Nagoya City University Hospital due to epigastralgia after surgical treatment for right renal cancer. Endoscopy revealed advanced type 1 gastric cancer in the corpus of the stomach and multiple polypoid lesions in the stomach and duodenum. X‐ray examination of the small intestine using barium showed multiple polyps in the upper jejunum. Faint pigmentation on the palm was also detected. Peutz‐Jeghers syndrome (PJS) was diagnosed, despite a lack of family history. Total gastrectomy, resection of part of the upper jejunum and intraoperative endoscopic polypectomy of duodenal polyps was performed. This is the second reported case of PJS associated with renal cancer. We also detected a missense mutation in the tumor suppressor gene STK11 that, when mutated, is causative for PJS.     

Veno-arterial ECLA (extracorporeal lung assist) for severe respiratory failure due to meconium aspiration

A full term newborn female, 3262g, aspirated meconium at birth and began to suffer from severe hypoxia and acidosis due to progressing pneumonitis, pneumothorax and pneumomediastinum. She also had severe hypotension and anuria. Venoarterial ECLA with a Kolobow membrane lung via the right internal jugular vein and the right common carotid artery was initiated. Blood gas parameters and blood pressure improved, and urine output increased to normal. ECLA permitted a reduction in FIO2 and airway pressure of mechanical ventilation, as well as frequent lavage of the lung. As the physical condition improved, the bypass flow was gradually decreased from 200 ml.kg-1.min-1 at the start to 130 ml.kg-1.min-1 for maintenance, then to 25 ml.kg-1.min-1 at the end. Bleeding throughout the ECLA for 69 hours could be minimized by a meticulous control of the activated coagulation time with a minimum dose of heparin and the transfusion of fresh frozen and platelet rich plasma. After ECLA, the carotid artery was simply ligated, and mechanical ventilatory support was carried out for 5 days. Her condition improved and she left the hospital without any neurological sequelae. ECLA will become an effective means of life support for a baby with severe MAS irresponsive to conventional ventilatory support.     

Preoperative evaluation of endometrial carcinoma by selective hysterography: a preliminary report

Using a new instrument designed by the Authors having two cannulas to allow filling of a contrast medium exclusively in the cervical canal and uterine cavity, selective hysterography was performed for 22 cases of endometrial carcinoma. This method was useful not only for evaluation of the size, location and growth patterns but also for estimation of the cervical involvement of endometrial carcinoma.     

Development of gamma-aminobutyric acid (GABA)ergic neurons in cerebral cortical neurons in primary culture

The developmental patterns of gamma-aminobutyric acid (GABA)ergic neurons in primary culture obtained from the neopallium of 15-day-old fetus of mouse were investigated in terms of morphological features, GABA metabolism and GABA receptor binding. Morphological investigations revealed that these cells possessed typical features of neurons and the formation of synapses was detected at 10 days after the inoculation. During neuronal growth on polylysine surfaces, GABA contents and activity of GABA transaminase (GABA-T) showed a progressive increase in the time of culture. Similarly, L-glutamic acid decarboxylase (GAD) showed a progressive elevation during neuronal development in vitro, which corresponded well with the change in immunoreactivity to anti-GAD examined immunohistochemically. In addition, the high K+-evoked release of [3H]GABA also showed an enhancement during the growth in vitro. The numbers of binding sites (Bmax) for [3H]muscimol and [3H]flunitrazepam (FLN) also showed increases with the time of incubation, although affinity (Kd) to the labeled ligands did not show any noticeable changes. Moreover, it was observed that [3H]FLN binding was enhanced by GABA even in neurons cultured for 7 days. These results indicate that cerebral cortical neurons in primary culture possess GABA biosynthesizing and degrading systems including a high-affinity uptake mechanism for GABA. The present results also indicate that these cells possess synaptic contacts as well as GABAA receptors coupled with benzodiazepine receptor from a relatively early stage of cellular development.