A novel subepidermal blistering disease with autoantibodies to a 200-kDa antigen of the basement membrane zone

Several components of the basement membrane zone (BMZ) have been identified as antigenic targets in autoimmune bullous diseases. We report a novel disease with autoantibodies to a BMZ antigen that is different from the targets described so far. The patient suffering from this disorder showed tense bullae and severe mucous membrane involvement rapidly responding to oral tetracyclines and colchicine. Histopathologic findings resembled those of dermatitis herpetiformis. Direct immunofluorescence microscopy showed linear deposits of IgG and C3 at the BMZ. By indirect immunofluorescence studies on split human skin, using both 1 M NaCl and suction blistering for dermal-epidermal separation, IgG antibodies localized exclusively to the dermal side of the split. The antibodies were mainly of the IgG4 sub-class. By Western blot analysis of epidermal and dermal extracts, the patient's serum unequivocally reacted with a dermal antigen of 200 kDa. It did not recognize bullous pemphigoid antigens (the autoantigen of epidermolysis bullosa acquisita), purified preparations of laminin-1 and laminin-5, or the recently described 105-kDa BMZ antigen. By immunoblotting of concentrated conditioned SCC-25 medium, the patient's antibodies reacted with a band of 200 kDa and several bands of lower molecular weight. No reactivity was seen with extracts of cultured human fibroblasts. By indirect immunogold electron microscopy, immunoreactants localized to the lower lamina lucida. After clearance of skin lesions, both indirect immunofluorescence and Western blot analysis became negative. This patient suffers from a novel autoimmune bullous disease with autoantibodies to a 200-kDa antigen of the BMZ.

Clinical significance of abnormal postexercise systolic blood pressure response in patients with hypertrophic cardiomyopathy

The clinical significance of abnormal postexercise systolic blood pressure (SBP) response in patients with hypertrophic cardiomyopathy (HCM) was assessed by treadmill exercise testing in 30 normal subjects and 96 patients with HCM. SBP recovery ratios were derived by dividing the SBP at 1 and 3 min after exercise by the peak exercise SBP. The upper normal limit of the SBP ratio was defined by two standard deviations (SD) from the mean in 30 normal subjects. A postexercise SBP ratio that exceeded the upper normal limits of the SBP ratio was considered to be an abnormal SBP response in patients with HCM. Twenty-seven (28%) of 96 patients with HCM showed an abnormal SBP response. Compared with the normal SBP response group (69 cases) among patients with HCM, the abnormal SBP response group had lower SBP response during exercise (22 +/- 25 vs 62 +/- 26 mmHg : mean +/- 1 SD, p < 0.05), more prolonged QRS width (110 +/- 21 vs 92 +/- 20 msec, p < 0.05), higher incidences of ventricular tachycardia (12 vs 7 cases, p < 0.001), and sudden death (7 vs 0 cases, p < 0.0001). The defect area of Tl-201 myocardial scintigraphy was more extensive in the abnormal SBP response group (2.9 +/- 1.7 segments) than in the normal SBP response group (1.1 +/- 1.3 segments, p < 0.05). During atrial pacing (120/min), pulmonary artery wedge pressure was slightly elevated from 10 +/- 2 (at rest) to 14 +/- 3 mmHg (during pacing) (p<0.001), cardiac index showed no significant changes, and time constant T was shortened from 58 +/- 13 to 48 +/- 10 msec (p < 0.001) in the normal SBP response group, but in the abnormal SBP response group pulmonary artery wedge pressure was highly elevated from 12 +/- 5 to 20 +/- 3 mmHg (p < 0.0001), cardiac index was decreased from 2.5 +/- 0.7 to 2.1 +/- 0.6 l/min/m2 (p < 0.05), and the time constant T had no significant changes. These observations suggest that patients with HCM and abnormal postexercise SBP response have an abnormal cardiac response during exercise and extensive myocardial damage.

Intravascular gas within an ovarian tumor: a CT sign of ovarian torsion

A case of twisted ovarian tumor with intravascular gas is presented, and the mechanism of the gas formation is discussed. On the basis of the probable mechanism of gas formation observed in dead fetuses, the gas seen in the present case is considered to have been oxygen released from trapped oxyhemoglobin within the tumor vessels. "Intravascular gas" within an ovarian tumor, although extremely rare, is diagnostic of ovarian torsion.

Angiotensin II augments cytokine-stimulated nitric oxide synthesis in rat cardiac myocytes

BACKGROUND

Nitric oxide (NO) has been shown to modulate cardiac function. We investigated the effect of angiotensin II (Ang II) on NO synthase activity in cardiac myocytes.

METHODS AND RESULTS

Using the Griess reagent, we measured the production of nitrite, a stable metabolite of NO, by cultured neonatal rat cardiac myocytes. The expression of inducible NO synthase (iNOS) mRNA was assayed by Northern blotting. Incubation of cardiac myocytes for 24 hours with interleukin-1 beta (IL-1 beta) caused a significant increase in NO production. Ang II significantly augmented NO synthesis in IL-1 beta-stimulated but not in unstimulated cells in a dose-dependent manner. The angiotensin type I receptor antagonist CV 11974 inhibited the effect of Ang II dose-dependently. Simultaneous incubation of Ang II with NG-monomethyl-L-arginine or actinomycin D also completely inhibited the effect of Ang II. The Ang II-induced NO production by IL-1 beta-stimulated cells was accompanied by increased iNOS mRNA accumulation. Phorbol 12-myristate 13-acetate (PMA) also augmented NO synthesis in IL-1 beta-stimulated but not in unstimulated cells in a dose-dependent manner. The protein kinase C inhibitor calphostin C dose-dependently blocked the effect of Ang II. After protein kinase C activity was functionally depleted by treatment of cells with PMA for 24 hours, Ang II did not augment IL-1 beta-induced NO production.

CONCLUSIONS

These results indicate that Ang II upregulates IL-1 beta-induced iNOS expression in cardiac myocytes, which is mediated at least partially via activation of protein kinase C.

Aldosterone inhibits nitric oxide synthesis in rat vascular smooth muscle cells induced by interleukin-1 beta

We investigated the effects of aldosterone on nitric oxide (NO) synthesis in vascular smooth muscle cells. We measured the production of nitrite, a stable metabolite of NO, and the expression of inducible NO synthase mRNA and protein in cultured rat vascular smooth muscle cells. Incubation of the cultures with interleukin-1 beta (10 ng/ml) for 24 h caused a significant increase in nitrite generation. The interleukin-1 beta-induced nitrite production by vascular smooth muscle cells was significantly inhibited by aldosterone in a dose (10(-9) approximately 10(-6) M)-dependent manner. Incubation with interleukin-1 beta for 12 approximately 24 h caused inducible NO synthase mRNA expression in vascular smooth muscle cells, whereas aldosterone had a suppressive effect on its expression. Aldosterone also decreased interleukin-1 beta-induced NO synthase protein accumulation. These results indicate that aldosterone inhibits NO synthesis under interleukin-1 beta-stimulated conditions in vascular smooth muscle cells.

Angiotensin II transduces its signal to focal adhesions via angiotensin II type 1 receptors in vascular smooth muscle cells

In cultured vascular smooth muscle cells (VSMCs), angiotensin II (Ang II) stimulated tyrosine phosphorylation of several proteins including a cluster of 70-80-kDa proteins as assessed by anti-phosphotyrosine immunoblotting. These 70-80-kDa proteins were identified as a focal adhesion-associated protein, paxillin, by anti-paxillin immunoprecipitation. Ang II-stimulated tyrosine phosphorylation of paxillin was detectable within 1 min and maximal at around 10 min and was concentration dependent (half-maximal effect at around 1 nM). Ang II also stimulated tyrosine phosphorylation of focal adhesion kinase in a time- and concentration-dependent manner. The Ang II type 1 (AT1) receptor antagonist, CV-11974, but not the Ang II type 2 receptor antagonist, PD123319, inhibited these reactions. These results indicate that Ang II transduces its signal to focal adhesions via AT1 receptors in cultured VSMCs.

Nitric oxide synthesis in cardiac myocytes and fibroblasts by inflammatory cytokines

OBJECTIVE

The aim was to investigate nitric oxide (NO) synthase activity in cultured neonatal rat cardiac myocytes and fibroblasts upon treatment with inflammatory cytokines interleukin 1 beta (IL-1 beta), tumour necrosis factor alpha (TNF-alpha), IL-2, IL-6, IL-8, transforming growth factor beta (TGF-beta) and gram negative bacterial lipopolysaccharide (LPS).

METHODS

NO and guanosine 3',5'-cyclic monophosphate (cGMP) synthesis was measured in cultured neonatal rat cardiac myocytes and fibroblasts, using Griess reagent and an enzyme immunoassay kit, respectively. The expression of inducible NO synthase (iNOS) mRNA and protein was assayed by northern and western blotting, respectively.

RESULTS

Incubation of cardiac myocytes for 24 h with IL-1 beta (10 ng.ml-1) or LPS (1 microgram.ml-1) caused significant increases in NO and cGMP production. TNF-alpha, IL-2, IL-6, IL-8, and TGF-beta showed no significant effect on their production. IL-1 beta induced NO and cGMP production in a time and dose dependent manner. IL-1 beta also increased iNOS mRNA and protein accumulation in cardiac myocytes. Simultaneous incubation of IL-1 beta with NG-monomethyl-L-arginine, genistein, calphostin C, cycloheximide, or actinomycin D completely inhibited the IL-1 beta induced NO production by cardiac myocytes. TGF-beta, dexamethasone, or cyclosporin A also dose dependently inhibited the IL-1 beta induced NO production. Exposure to IL-1 beta for 12-24 h decreased the beating rate of cardiac myocytes, but addition of dexamethasone completely overcame this inhibition. In contrast to cardiac myocytes, incubation of cardiac fibroblasts for 24 h with IL-1 beta or LPS showed no significant effect on NO or cGMP production.

CONCLUSIONS

These observations suggest that IL-1 beta/LPS responsive iNOS, which is an important regulator of contractile function of the heart, is present in cardiac myocytes but not in cardiac fibroblasts.

Immunoblot analysis using recombinant protein of the 180 kD bullous pemphigoid antigen NC16a domain as an aid to the diagnosis of atypical subepidermal autoimmune bullous skin diseases

We have recently developed a novel immunoblotting system using bacterial fusion protein containing the NC16a domain, the most immunogenic region, of the 180 kD bullous pemphigoid (BP) antigen, which was shown to be highly sensitive and specific method to detect the antigen and to be very useful for the diagnosis of BP. In this study, using this immunoblot assay, we investigated sera obtained from 26 patients who showed atypical clinical features. The sera of these cases showed in general very weak reactivity with the basement membrane zone on immunofluorescence, and very weak and variable results in detection of either the 230 kD or 180 kD BP antigen with immunoblotting of human epidermal extracts. However, with immunoblotting of the BP180 NC16a domain fusion protein, this protein was detected by 21 out of the 26 cases. These results indicated that this new assay system is the most sensitive method to detect BP antigen, and should be very useful for the diagnosis for these atypical cases.

Delayed-type allergenicity of triforine (Saprol)

The delayed-type allergenicity of triforine (Saprol), 1,4-bis (2,2,2-trichloro-1-formamidoethyl) piperazine, was studied. In a mass examination of chrysanthemum growers among whom triforine was commonly used, the highest rate of positive patch test reaction was seen to triforine (17%) among the 7 pesticides and chrysanthemum extracts tested. A higher prevalence rate of work-related skin symptoms was seen in subjects with a positive patch test reaction to triforine (44%) than in those with negative reactions to all allergens tested (15%) (p < 0.05). 12 subjects (67%) with positive patch test reactions to triforine were also positive to dichlorvos (DDVP), with a high kappa coefficient (0.65). The grading of guinea pig maximization test to triforine was grade IV (66%), defined as "strong". Cross-sensitization between triforine and dichlorvos was also shown. The present results confirm that triforine is capable of including delayed-type allergy among chrysanthemum growers and of showing cross-reactivity with dichlorvos.

Preventive effect of betamipron on nephrotoxicity and uptake of carbapenems in rabbit renal cortex

The preventive effect of betamipron (N-benzoyl-3-propionic acid: BP) on the renal uptake and nephrotoxicity of carbapenems (panipenem and imipenem) was studied in rabbits. Panipenem, a new carbapenem antibiotic, induced nephrotoxicity at a dose of 200 mg/kg, i.v., but this was less severe than that caused by a single dose of imipenem or cephaloridine. Along with the significant reduction of nephrotoxicity, the uptake of these carbapenems in the renal cortex was remarkably inhibited by simultaneous treatment with BP (200 mg/kg, i.v.). These results suggest that BP reduces the nephrotoxicity of carbapenems through inhibiting the active transport of carbapenems in the renal cortex. Because of the low toxicity of BP (LD50 in the rat, more than 3,000 mg/kg, i.v.), it was concluded that BP might be a good candidate for reducing the nephrotoxicity induced by panipenem or imipenem.

Enantiospecific determination of ibuprofen in rat plasma using chiral fluorescence derivatization reagent, (-)-2-[4-(1-aminoethyl)phenyl]-6- methoxybenzoxazole

A highly sensitive and reversed-phase high-performance liquid chromatographic method for the determination of the enantiomeric composition of ibuprofen in rat plasma is described. The method is based on the resolution of the diastereomeric amides formed on reaction of the ibuprofen enantiomers with (-)-2-[4-(1-aminoethyl)phenyl]-6-methoxybenzoxazole ((-)-APMB) in the presence of 2,2'-dipyridyl disulphide (DPDS) and triphenylphosphine (TPP) in dichloromethane. The reaction mixture was allowed to stand at room temperature for 5 min, and the reaction was completed by evaporation with a stream of nitrogen at 40 degrees C. The minimum quantifiable concentrations were 0.2 microgram/mL and 0.4 microgram/mL for S-ibuprofen and R-ibuprofen, respectively, in a 10 microL injection volume. The method was applied to the determination of enantiomeric ibuprofen in plasma after oral administration to rats.

Angiotensin II inhibits cytokine-stimulated inducible nitric oxide synthase expression in vascular smooth muscle cells

In cultured vascular smooth muscle cells (VSMC), inflammatory cytokines such as interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha stimulated nitric oxide (NO) production via the expression of an inducible type of NO synthase (iNOS). A potent vasoconstrictor, angiotensin II (Ang II), which causes a rapid phospholipase C-mediated phosphoinositide hydrolysis via the Ang II type 1 (AT1) receptor in VSMC, by itself did not stimulate the production of nitrite, a stable metabolite of NO, but dose dependently inhibited the IL-1 beta-induced nitrite production. This inhibitory effect of Ang II was blocked by an AT1 receptor antagonist, CV-11974, but not by an Ang II type 2 receptor antagonist, PD 123319. The presence of Ang II during the early induction phase of iNOS was required for this inhibition. Consistently, Ang II suppressed IL-1 beta-induced increases in iNOS mRNA and protein levels. Ang II also inhibited increases in nitrite production and iNOS mRNA and protein levels caused by tumor necrosis factor alpha. A protein kinase C-activating phorbol ester, phorbol 12-myristate 13-acetate, and a membrane-permeable diacylglycerol, 1,2-dioctanoyl-glycerol, similarly inhibited the IL-1 beta-induced nitrite production and iNOS mRNA and protein expression, although repetitive additions were needed in the case of diacylglycerol. These results indicate that Ang II negatively modulates cytokine-induced NO production by blocking iNOS expression via the AT1 receptor in VSMC and suggest that protein kinase C could be involved in this process.

Expression of nitric oxide synthase by cytokines in vascular smooth muscle cells

In cultured vascular smooth muscle cells, the baseline mRNA and protein levels of an inducible type of nitric oxide synthase were barely detectable. Interferon gamma, tumor necrosis factor-alpha, and interleukin-1 beta each markedly increased mRNA and protein levels of this enzyme in parallel with the production of nitrite, a stable oxidative metabolite of nitric oxide. Actinomycin D abolished the cytokine-induced increases in mRNA levels and nitrite production. Cycloheximide, which abolished the cytokine-induced increase in nitrite production, had no effect on the interferon-gamma-induced increase in mRNA levels but partially inhibited that induced by interleukin-1 beta and markedly inhibited that induced by tumor necrosis factor-alpha. Transforming growth factor-beta 1, which inhibited the interferon gamma-, interleukin-1 beta-, and tumor necrosis factor-alpha-induced nitrite production, did not affect the increases in mRNA levels caused by these cytokines. Transforming growth factor-beta 1, however, significantly inhibited the increase in protein levels caused by these cytokines. These findings suggest that interferon gamma directly induces the expression of the inducible nitric oxide synthase gene, whereas tumor necrosis factor-alpha and interleukin-1 beta induce it, at least in part, via the induction of intermediary protein(s), and that transforming growth factor-beta 1 inhibits cytokine-induced nitric oxide production by blocking the posttranscriptional synthesis of inducible nitric oxide synthase.

Nitric oxide synthesis in rat cardiac myocytes and fibroblasts

We investigated nitric oxide (NO) synthase activity in cultured neonatal rat cardiac myocytes and fibroblasts upon treatment with interleukin 1 beta (IL-1 beta) and lipopolysaccharide (LPS). Incubation of cardiac myocytes for 24 h with IL-1 beta or LPS caused a significant increase in NO and cGMP production. Simultaneous incubation of IL-1 beta with NG-monomethyl-L-arginine or transforming growth factor beta (TGF-beta) completely inhibited the IL-1 beta-induced NO and cGMP production in cardiac myocytes. In contrast, incubation of cardiac fibroblasts for 24 h with IL-1 beta or LPS showed no significant effect on NO or cGMP production. Addition of IL-1 beta decreased the beating rate of cardiac myocytes, but TGF-beta overcame that inhibition. These observations suggest the presence of iNOS in cardiac myocytes, which is an important regulator of contractile function of the heart.

Protective effect of N-acyl amino acids (NAAs) on cephaloridine (CER) nephrotoxicity in rabbits

The protective effect of N-acyl amino acids (NAAs) against cephaloridine (CER)-induced nephrotoxicity was studied in rabbits. A large single intravenous dose of CER (more than 100 mg/kg) induced severe proximal tubular necrosis. Simultaneous treatment with several NAAs (at dosages of 100, 200 mg/kg, etc., i.v.), such as N-benzoyl-beta-alanine (NBBA), N-benzoyl-6-aminocaproic acid, and N alpha,epsilon-dibenzoyl-D,L-lysine, remarkably suppressed the histopathological damage in the kidney induced by CER. NAAs have generally low toxicity in laboratory animals (e.g., the LD50 of NBBA was more than 3,000 mg/kg, i.v. in rats), and NAAs were suggested to be good candidates for reducing the nephrotoxicity of CER and other beta-lactam antibiotics.

Cyclic AMP-elevating agents induce an inducible type of nitric oxide synthase in cultured vascular smooth muscle cells. Synergism with the induction elicited by inflammatory cytokines

In cultured vascular smooth muscle cells, interferon gamma (IFN-gamma) induced the accumulation of nitrite, a stable metabolite of nitric oxide, in a dose- and time-dependent manner. In parallel with this reaction, this cytokine increased the mRNA and protein levels of an inducible macrophage-type of nitric oxide synthase (iNOS). Forskolin, a direct activator of adenylate cyclase, or dibutyryl cAMP alone caused small increases in nitrite accumulation and iNOS mRNA and protein levels and synergistically enhanced the IFN-gamma-stimulated reactions. 8-Bromo-cGMP neither increased by itself nor synergized with IFN-gamma to increase the same reactions. Prostaglandin E1 and beraprost, a stable analogue of prostaglandin I2, which by themselves showed only marginal effects on these reactions, also synergized with IFN-gamma to stimulate the reactions. Interleukin 1 beta or tumor necrosis factor alpha stimulated the same reactions which were similarly enhanced by forskolin. These results indicate that an elevation of intracellular cAMP, particularly in combination with inflammatory cytokines, positively regulates nitric oxide production at the level of iNOS mRNA expression in vascular smooth muscle cells.

The relationship of trabecular and cortical bone mineral density to spinal fractures

RATIONALE AND OBJECTIVES

The relationships between trabecular, cortical, or integral bone mineral densities (BMD) to spontaneous vertebral fractures was investigated.

METHODS

In 360 Japanese women, ranging from 20 to 83 years of age, vertebral trabecular and cortical BMD were measured using quantitative computed tomography (QCT). Among 46 oophorectomized women, BMD was measured using QCT and dual-energy x-ray absorptiometry (DXA).

RESULTS

For patients in their sixth and seventh decades, those with fractures could be differentiated from those without fractures by measuring their trabecular BMD using QCT. Cortical BMD of women with fractures and trabecular BMD more than 80 mg/mL was significantly lower than that of women without fractures and trabecular BMD less than 70 mg/mL.

CONCLUSIONS

Trabecular BMD can be a good predictor of spinal fracture. Cortical BMD may be important in cases with decreased trabecular BMD.

Determination of polycyclic aromatic hydrocarbons in the lung

Polycyclic aromatic hydrocarbons (PAHs) accumulated in human lung samples from men (n = 236) and women (n = 128) were determined by high-performance liquid chromatography (HPLC) to examine their association with lung cancer. The mean values for benzo[a]pyrene (BaP), benzo[k]fluoranthene (BkF), and benzo[g,h,i]perylene (BghiP) in lungs (ng/g dry lung) of Japanese autopsied patients were 0.54, 0.44, and 0.87, respectively. The modal values were 0.3, 0.3 and 0.5, respectively. Each of the PAH concentrations was highly correlated with the others (r > 0.83). PAH concentrations in the lungs showed age-related increases with low correlation-coefficient values. BaP, BkF and BghiP concentrations in lungs of various subgroups were in the following order: male > female; and lung cancer > all cancers > non-cancer among male not female group. Only BghiP concentration in the lungs of the male smoker group is significantly higher (P < 0.10) than that of the male non-smoker group. Even among non-smoker groups, PAH concentrations in the lungs of male group were significantly higher than those of female group. In the male population, excess exposure to PAHs together with fine carbon particles, such as tobacco smoke or diesel exhaust, correlated with increased prevalence of lung cancer.

Cytokine-induced expression of an inducible type of nitric oxide synthase gene in cultured vascular smooth muscle cells

In unstimulated cultured vascular smooth muscle cells (VSMC), mRNA of an inducible macrophage-type of nitric oxide synthase (iNOS) was barely detectable. Interferon gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha) markedly increased iNOS mRNA levels in time- and dose-dependent manners. The induction of iNOS mRNA paralleled the cytokine-induced nitrite production. Actinomycin D abolished the IFN gamma- and TNF alpha-induced increases in iNOS mRNA and nitrite production. Cycloheximide, which abolished both the IFN gamma- and TNF alpha-induced increases in nitrite production, had no effect on the IFN gamma-induced increase in iNOS mRNA but markedly inhibited the TNF alpha-induced one. These results suggest that IFN gamma directly induces the expression of the iNOS gene whereas TNF alpha mainly induces it via the induction of an intermediary protein in cultured VSMC.

Bone mineral and other bone components in vertebrae evaluated by QCT and MRI

To evaluate the usefulness of assessing bone components using magnetic resonance imaging (MRI), the contributions of bone components, including mineral, fat and collagen, to bone mineral density (BMD) and T1 relaxation time (T1) were studied using phantoms. Excised human vertebrae were also evaluated by quantitative computed tomography (QCT) and MRI. T1 was shortened with increasing quantities of fat and collagen. In water, T1 was significantly affected by bone density, while in oil, T1 became slightly longer as bone density increased. The presence of fat and collagen caused under- and overestimations of BMD, respectively. There was good correlation between T1 and BMD in osteoporotic vertebrae and the vertebrae with long T1 showed an increased content of hematopoietic marrow and/or abnormally increased bone mineral. It was concluded that the experimental data showed that MRI can contribute to the assessment of bone quality.

Pharmacokinetics of temocapril hydrochloride, a novel angiotensin converting enzyme inhibitor, in renal insufficiency

The pharmacokinetics of temocapril hydrochloride, a novel prodrug-type angiotensin-I converting enzyme (ACE) inhibitor, has been studied in patients with mild (Group II) to severe (Group III) renal insufficiency in comparison with subjects with normal renal function (Group I). The pharmacokinetic parameters of the active diacid metabolite, including Cmax, AUC and half-life (t1/2), showed only slight changes between the three groups: AUC (0-inaffinity) was significantly larger in Group III than Group I, and t1/2 tended to be prolonged in Group III, but the change was not significant. The urinary recovery of the diacid was significantly decreased in Group III. (Group I, 28.1%, Group II, 21.6%, Group III, 12.8%). Compared with other ACE inhibitors, which are mainly excreted through the kidney, the plasma concentration of the active diacid metabolite was hardly influenced by renal function. It was speculated that lowering of the dose of temocapril might be recommended only in patients with severe renal insufficiency.

Endothelin-1 stimulates tyrosine phosphorylation and the activities of two mitogen-activated protein kinases in cultured vascular smooth muscle cells

OBJECTIVE

Endothelin-1 (ET-1) has been reported to stimulate the expression of the proto-oncogenes c-fos and c-myc, and to cause DNA synthesis in vascular smooth muscle cells (VSMC). The purpose of this study was to clarify the signalling pathway from ET receptors to the nucleus.

DESIGN

Mitogen-activated protein (MAP) kinase, which is activated by various growth factors via phosphorylation of tyrosine and threonine residues, plays important roles as an intermediate in the signalling pathways from growth factor receptors to the ribosomes and nucleus. We examined the effect of ET-1 on the phosphorylation and activation of MAP kinase in cultured VSMC.

METHODS

Extracts of ET-1-stimulated VSMC were analysed by one- and two-dimensional gel electrophoresis and anion-exchange column chromatography. Tyrosine-phosphorylated proteins and MAP kinases were detected by immunoblot analyses with anti-phosphotyrosine and anti-MAP kinase antibodies, respectively. The MAP kinase activity was measured using myelin basic protein as a substrate. The MAP kinases were isolated from 32P-labelled VSMC and subjected to phosphoamino acid analysis.

RESULTS

ET-1 induced tyrosine phosphorylation of at least five proteins of about 79, 77, 73, 45 and 40 kDa in VSMC. The mobilities of the tyrosine-phosphorylated 45- and 40-kDa proteins were identical with those of the two proteins that were recognized by anti-MAP kinase antibody upon one- and two-dimensional gel electrophoresis. ET-1 stimulated MAP kinase activity in a time-course similar to that of the tyrosine phosphorylation of the 45- and 40-kDa proteins. The ET-1-stimulated MAP kinase activity was resolved almost equally into two peaks upon Mono Q column chromatography (kinase 1 and kinase 2). Kinase 1 and kinase 2 were co-eluted with the tyrosine-phosphorylated 40- and 45-kDa proteins, respectively. The apparent molecular masses of kinase 1 and kinase 2 estimated by MAP kinase assay in polyacrylamide gel were identical with those of tyrosine-phosphorylated 40- and 45-kDa proteins, respectively. Upon phosphoamino acid analysis, ET-1 stimulated phosphorylation of MAP kinases not only on tyrosine but also on threonine residues.

CONCLUSIONS

ET-1 induces tyrosine and threonine phosphorylation and the activation of two species of MAP kinases of 40 and 45 kDa in VSMC.

Involvement of MAP kinase activators in angiotensin II-induced activation of MAP kinases in cultured vascular smooth muscle cells

In cultured vascular smooth muscle cells (VSMC) angiotensin II (ang II) induces tyrosine and serine/threonine phosphorylation and activation of two mitogen-activated protein (MAP) kinases. When extracts of ang II-stimulated VSMC were fractionated by Mono Q anion-exchange column chromatography, three peaks of the activities which in vitro activate inactive MAP kinases were detected. These MAP kinase activator activities were not detected in extracts of unstimulated VSMC. In vitro activation of MAP kinases by the MAP kinase activators was accompanied by tyrosine and serine/threonine phosphorylation of MAP kinases. These results suggest that the MAP kinase activators are involved in the ang II-induced phosphorylation and activation of MAP kinases in VSMC.

[Long-term follow-up of clinical features and ECG changes in 50 patients with HCM]

We studied the relation of ECG changes during the clinical course in patients with hypertrophic cardiomyopathy (HCM). Fifty patients with HCM were categorized in two groups; 20 patients with, and 30 patients without signs of deterioration of clinical state. The changes between the first and the final ECG were compared in these two groups. The average follow-up period was 7.6 years. Twenty patients with clinical deterioration presented increase in QRS intervals (0.06----0.071 sec, p less than 0.025), decrease in voltage of RV5 (2.81----2.38 sec, p less than 0.025), increase in newly developed abnormal Q waves, and P wave changes. In contrast to these cases, 30 patients without clinical deterioration presented no significant ECG changes. Amplitudes of the negative T wave were unchanged in both groups. We conclude that electrocardiographic observations proved to be useful for predicting clinical features in patients with HCM.

Angiotensin II stimulates two myelin basic protein/microtubule-associated protein 2 kinases in cultured vascular smooth muscle cells

In cultured vascular smooth muscle cells, angiotensin II (Ang II) stimulated a cytosolic protein kinase activity toward myelin basic protein (MBP) in a time- and dose-dependent manner. Phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate also increased the MBP kinase activity. Downregulation of protein kinase C by prolonged treatment of the cells with phorbol 12,13-dibutyrate markedly attenuated the Ang II- and PMA-induced MBP kinase activation. The Ang II- and PMA-stimulated MBP kinase activities were resolved almost equally into two distinct fractions on Mono-Q HR5/5 column chromatography (kinase 1 and kinase 2). The kinase assay in polyacrylamide gel revealed that apparent molecular masses of kinase 1 and kinase 2 were 40 and 45 kd, respectively. Microtubule-associated protein 2 also served as a substrate for both the kinases. Immunoblot analysis with an antiphosphotyrosine antibody suggested that both the kinases were tyrosine-phosphorylated during the action of Ang II. Phosphoamino acid analysis revealed that Ang II and PMA induced phosphorylation of both the kinases on serine/threonine as well as tyrosine residues. Phosphopeptide mapping patterns of kinase 1 and kinase 2 isolated from Ang II-stimulated cells were almost identical with those from PMA-stimulated cells. These results indicate that in vascular smooth muscle cells Ang II activates two species of MBP/microtubule-associated protein 2 kinases mainly through the protein kinase C-signaling pathway and suggest that tyrosine and serine/threonine phosphorylation may be involved in this process.

[A case of miliary tuberculosis presenting as fever and jaundice with hepatic failure looking like the course of fulminant hepatitis]

A 79-year-old male was admitted to the Metropolitan Hiroo Hospital with chief complaints of icterus and fever. A few weeks prior to admission, he developed fever and swelling of right side of the neck and was seen at a local hospital where an anti-inflammatory agent was prescribed. The fever subsided in a few days, but recurred together with development of icterus a few weeks later, precipitating this hospitalization. After admission, hepatic failure progressed rapidly, indicating a fulminant hepatitis. Renal failure also developed and he died. Autopsy revealed diffuse caseous necrosis with demonstration of acid-fast bacilli in the liver, as did in the spleen, kidney and bone marrow. This case epitomizes a subset of miliary tuberculosis in which the hepatic failure predominates the clinical presentation while lacking the ante-mortem chest X-ray features suggestive of pulmonary tuberculosis and post-mortem macroscopic changes indicative of tuberculosis.

Prediction of human pharmacokinetics of panipenem-betamipron, a new carbapenem, from animal data

The pharmacokinetic behavior of panipenem (PAPM)-betamipron (BP), a new carbapenem, in humans was successfully predicted from data collected from six animal species. PAPM and BP were biphasically eliminated from plasma after intravenous (i.v.) administration of PAPM-BP to mice, guinea pigs, rats, rabbits, monkeys, and dogs. Elimination rates of PAPM and BP were correlated with animal size: the larger the animal was, the slower the elimination was. As for PAPM and BP, log-log plots of total plasma clearance (CLtot) versus body weight and log-log plots of distribution volume at steady state (VSS) versus body weight for six animal species were linear, with high correlation coefficients. These allometric equations were extrapolated to predict CLtot and VSS for PAPM and BP in humans. In addition, concentration in plasma-time profiles for humans were predicted by using two-exponent equations fitted to the complex Dedrick plot of animal data. Predicted values for CLtot and VSS for PAPM and BP in humans agreed well with observed values in humans given 750/750 mg of PAPM-BP as an i.v. drip infusion for 30 min. Predicted concentration in plasma-time profiles for humans approximated observed profiles. Thus, the pharmacokinetics of PAPM-BP extrapolated well from animal species to humans when allometric equations and the complex Dedrick plot were used.

Hyperventilation syndrome and the assessment of treatment for functional cardiac symptoms

Three methods of breathing retraining (guided breathing retraining, guided breathing retraining with physiologic monitoring of thoracic and abdominal movement plus peripheral temperature, and guided breathing retraining with physiologic monitoring of thoracic and abdominal movement, peripheral temperature and end-tidal carbon dioxide) were compared with a no-treatment control group to determine the effectiveness of breathing retraining on modifying respiratory physiology and reducing functional cardiac symptoms in subjects with signs associated with hyperventilation syndrome. Of 41 subjects studied, 16 were diagnosed with mitral valve prolapse. Results demonstrated that all 3 methods of breathing retraining were equally effective in modifying respiratory physiology and reducing the frequency of functional cardiac symptoms. Results determined that respiratory rate and subject's perception that training had generalized were the best predictors of treatment success. Furthermore, it was found that subjects with mitral valve prolapse responded as well to treatment as did those without prolapse.

[A case of Sjögren syndrome associated with sarcoidosis]

A 70 year-old female with a 6-year history of primary Sjögren syndrome was admitted with fever and loss of weight. Examinations such as the lip biopsy reconfirmed the diagnosis of primary Sjögren syndrome. Abdominal CT and gallium scan showed lymphadenopathy in the abdominal cavity, and an exploratory biopsy was done. Lymph nodes and liver biopsy specimens revealed multiple noncaseating granulomata with some Langhans' giant cells, consistent with sarcoidosis. It has been previously proposed that connective tissue disease and sarcoidosis are related in terms of pathogenesis because both diseases share common immunological features and abnormalities in regard to cellular and humoral immunity. Indeed some data in the literature show a striking similarity between the lymphocyte subpopulation in the parotid gland of Sjögren syndrome and the bronchoalveolar lavage fluid of sarcoidosis. However, it is difficult to assume the same pathogenesis for both diseases, because this aspect of the diseases has not been completely clarified. Despite the fact that the two share common immunological features and abnormalities, the coexistence of primary Sjögren syndrome and sarcoidosis has rarely reported.

Determination of enalapril and its active metabolite enalaprilat in plasma and urine by gas chromatography/mass spectrometry

The method for the simultaneous determination of angiotensin-converting enzyme (ACE) inhibitor enalapril and its active metabolite enalaprilat in plasma and urine was developed by gas chromatography/mass spectrometry. Enalapril and enalaprilat in plasma and urine were extracted and cleaned up by using Sep-Pak C18 and silica cartridges. Derivatization was carried out using diazomethane and trifluoroacetic anhydride. Detection by selected ion monitoring was selected to m/z 288 (enalaprilat) and 302 (enalapril). The detection limit of enalapril and enalaprilat was 200 pg/mL in plasma and 2 ng/mL in urine. This method was applied to the pharmacokinetic analysis of enalapril and enalaprilat in body fluids.

[Effect of heart rate on cardiac hemodynamics in patients with aortic regurgitation]

We evaluated the effects of heart rate on cardiac hemodynamics in 10 patients with aortic regurgitation (AR, mean regurgitant fraction: 64.3%). Cardiac catheterization was performed in all patients, and the hemodynamic parameters were obtained by increasing heart rate (80.100.120.140) using right atrial pacing. Regurgitant fraction and total systemic resistance were improved up to 100/min, but aggravated on further increase in heart rate. Cardiac function curve was remarkably improved up to 100/min, but aggravated on further increase in heart rate. LV end-diastolic pressure-volume relation was moved toward the left lower direction up to 100/min, but toward the left upper direction on further increase in heart rate. Thus, it was concluded that in severe AR, cardiac function was improved up to 100/min, but aggravated on further increase in heart rate.

Stimulation of protein-tyrosine phosphorylation by endothelin-1 in cultured vascular smooth muscle cells

In cultured rat aortic smooth cells, endothelin-1 induced tyrosine phosphorylation of at least five proteins with molecular masses of about 79, 77, 73, 45 and 40 kDa in dose- and time-dependent manners. Platelet-derived growth factor also induced tyrosine phosphorylation of the same set of proteins in addition to other proteins including platelet-derived growth factor receptors. This growth factor markedly stimulated DNA synthesis and an increase in cell number in this cell type, but endothelin-1 failed to stimulate these responses under the same conditions. These results demonstrate for the first time that endothelin-1 induces tyrosine phosphorylation of some proteins but suggest that these reactions are not enough to stimulate proliferation of vascular smooth muscle cells.

Small GTP-binding proteins in bovine aortic smooth muscle

In bovine aortic smooth muscle, GTP-binding activity was equally distributed in the membrane and cytosol fractions. The most abundant GTP-binding proteins (G proteins) in each fraction were purified to near homogeneity and characterized. The most abundant G protein in the membrane fraction had a Mr value of about 22,000 (m22K G) as estimated on sodium dodecyl sulfate-polyacryl-amide gel electrophoresis (SDS-PAGE). m22K G and the human platelet smg p21, a ras p21 like G protein having the same effector domain as ras p21s, were eluted at the same retention time on C4 reversed-phase high performance liquid chromatography (HPLC). Moreover, m22K G was specifically recognized by an anti-smg p21 polyclonal antibody. m22K G was phosphorylated by cyclic AMP-dependent protein kinase with a stoichiometry of one phosphate/molecule of protein. The most abundant G protein in the cytosol fraction had a Mr value of about 21,000 (c21K G) as estimated on SDS-PAGE. c21K G was ADP-ribosylated by botulinum ADP-ribosyltransferase and about 0.4 mol of ADP-ribose was maximally incorporated into 1 mol of c21K G. c21K G and the bovine brain rhoA p21, another ras p21 like G protein, were eluted at the same retention time on C4 reversed-phase HPLC and migrated at the same position on two-dimensional gel electrophoresis. These results indicate that the major G proteins in the membrane and cytosol fractions of bovine aortic smooth muscle are smg p21 and rhoA p21, respectively. Possible roles of these G proteins in vascular smooth muscle are discussed.

[Exercise induced precordial T wave normalization associated with U wave inversion in detection of left anterior descending artery stenosis]

Although normalization of inverted T wave is not an uncommon finding during exercise tests, it's clinical significance is still unclear. Exercise 12-lead electrocardiograms (ECGs) were recorded by using Master's 2-step or ergometer. T wave normalization in the anterior chest leads was found in 20 patients with, and 14 patients without coronary artery disease (CAD). Coronary angiography and/or exercise Tl-201 myocardial imaging were also performed in every patient. Exercise-induced T wave normalization was defined as "inverted T wave at rest becoming upright during exercise". ST segment, T and U wave amplitudes were measured before and immediately after exercise. 1) All of the 20 patients (100%) with CAD demonstrated critical stenosis of the left anterior descending artery (LAD). 2) ST deviation was noted in none of the 14 patients (0%) without CAD, and in only 4 of the 20 patients (20%) with CAD. 3) T wave amplitude increased equally in patients both with and without CAD. 4) Exercise-induced U wave inversion was found in 16 of the 20 patients (80%) with CAD, whereas it was found in only 1 of the 14 patients (7%) without CAD. 5) The sensitivity of "U wave inversion" in detection of LAD stenosis was 80%, and the specificity was 93%. We conclude that exercise-induced T wave normalization associated with U wave inversion in anterior chest leads is highly indicative of the specific presence of critical LAD stenosis.

Determination in plasma of angiotensin-converting enzyme inhibitor by inhibitor-binding assay

A method of determining a new angiotensin-converting enzyme inhibitor (CS-622) and its active metabolite (RS-5139) in plasma by inhibitor-binding assay has been developed using high-performance liquid chromatography. The assay is based on the principle that the amount of inhibitor bound to the enzyme is inversely related to the amount of hippuric acid liberated on hydrolysis from the artificial substrate (hippuryl-L-histidyl-L-leucine). Plasma was heated at 60 degrees C for 15 min, to inactivate endogenous enzyme, and preincubated with rabbit-lung angiotensin-converting enzyme at 37 degrees C for 3 min. The artificial substrate (5.75 mg/ml in pH 8.3 phosphate buffer containing sodium chloride) was added to the resulting solution, and the mixture was incubated for 30 min. The reaction was terminated by the addition of 2 M hydrochloric acid. The hippuric acid liberated on hydrolysis was extracted with ethyl acetate and determined by reversed-phase chromatography using methylparaben as an internal standard. The total concentration of the inhibitor and its metabolite were determined by this method after de-esterification by rat-plasma esterase. The standard curve was obtained by the regression analysis of log concentration against logit response. The within-day and day-to-day precision were satisfactory. The proposed method is simple, rapid and sensitive enough to determine angiotensin-converting enzyme inhibitor in plasma.

[Treadmill exercise test in patients with hypertrophic cardiomyopathy with and without coronary artery disease]

We studied whether the treadmill exercise test can discriminate between normal and significant narrowing of coronary arteries in patients with hypertrophic cardiomyopathy (HCM) accompanied with chest pain, and we compared the extent of myocardial ischemia during exercise. Thirty one patients with HCM were divided into two groups; 21 with normal coronary arteries and 11 with significant narrowing of coronary arteries. The treadmill exercise test was carried out in both groups. The following parameters were more frequently seen in the group with coronary stenosis. (1) short treadmill time (338, sec vs 542, p less than 0.05). (2) delta SBP less than or equal to 60 mmHg (delta: end point minus rest, 10 cases vs 12, 0.05 less than p less than 0.1). (3) significant delta ST depression (0.17 mV vs 0.05, p less than 0.05). (4) large delta ST/delta HR (3.3 microV.min/beats vs 0.7). delta ST/delta HR greater than or equal to 2.0 was the most useful for differentiating the two groups, and it was 90% in index both sensitivity and specificity for diagnosis of HCM with significant narrowing of the coronary arteries. It was concluded that treadmill exercise induced more severe myocardial ischemia in patients with HCM who had significant narrowing of the coronary arteries than in patients with HCM who had angiographically normal coronary arteries. The delta ST/delta HR was the most useful index for diagnosis of HCM with significant narrowing of the coronary arteries.

Vasoconstrictor-induced protein-tyrosine phosphorylation in cultured vascular smooth muscle cells

In cultured rat aortic smooth muscle cells, angiotensin II induced tyrosine phosphorylation of at least 9 proteins with molecular masses of 190, 117, 105, 82, 79, 77, 73, 45 and 40 kDa in time- and dose-dependent manners. Other vasoconstrictors such as [Arg]vasopressin, 5-hydroxytryptamine and norepinephrine induced the tyrosine phosphorylation of the same set of proteins as angiotensin II. The tyrosine phosphorylation of these proteins was mimicked by the protein kinase C-activating phorbol ester, phorbol 12 myristate 13-acetate, and the Ca2+ ionophore, ionomycin. These results demonstrate that the vasoconstrictors stimulate the tyrosine phosphorylation of several proteins in vascular smooth muscle cells and suggest that the tyrosine phosphorylation reactions are the events distal to the activation of protein kinase C and Ca2+ mobilization in the intracellular signalling pathways of the vasoconstrictors.

Pathological aspects of radiofrequency catheter ablation of the canine atrioventricular node and bundle of His. With special reference to chronic incomplete atrioventricular block

Radiofrequency catheter ablation of the atrioventricular (AV) node or bundle of His was performed in 12 adult mongrel dogs. The aim was to create chronic incomplete AV block (first- and second-degree AV block) and to examine the histopathology of the ablated lesions. However, the late electrophysiological results (2-4 weeks follow-up) were various: normal in 2 dogs, mild PR prolongation (less than 50%) in 2 dogs, first-degree AV block (PR prolongation greater than or equal to 50%) in 2 dogs, second-degree AV block in 2 dogs, complete AV block in 4 dogs. The maximally ablated area (%) of the atrioventricular conduction system in serial histologic sections from dogs with these conditions was 69%, 75%, 89.5%, 95% and 99.5%, respectively. The number of intact conduction cells at the maximally ablated site varied from 6 to 30 in the four cases of incomplete AV block. The mean ablated volume (%) of either the AV node or penetrating His bundle correlated roughly with the degree of AV block. The ablated lesions were well demarcated and almost replaced by dense fibrous tissue at 4 weeks. Interruption (3 dogs) or thinning (1 dog) of the endocardial elastic lamellae was detected, in association with endocardial thickening (mean 913 microns). Endocardial thrombi were found in 3 dogs (2 fresh, 1 organized). We conclude that radiofrequency catheter ablation does not cause severe complicated lesions. Several possible conditions for creating chronic incomplete AV block are discussed.

The molecular heterogeneity of the smg-21/Krev-1/rap1 proteins, a GTP-binding protein having the same effector domain as ras p21s, in bovine aortic smooth muscle membranes

smg p21 is a member of the ras p21/ras p21-like small GTP-binding protein (G protein) superfamily, having the same putative effector domain as ras p21s. In the preceding report, we showed that smg p21 was a major G protein in bovine aortic smooth muscle membranes. Recently, two different smg p21 cDNA clones, designated smg-21A and -B, were isolated from a bovine brain cDNA library. In the present studies, we resolved the bovine aortic smg p21 fraction into two distinct G protein fractions on hydroxyapatite column chromatography and purified them separately to near homogeneity (22K G1 and -2). Both 22K G1 and -2 were specifically recognized by an anti-smg p21 polyclonal antibody. 22K G1 and -2 were identified as smg p21B and -A, respectively, by peptide map and amino acid sequence analyses. Purified smg p21A and -B showed GDP/GTP-binding and GTPase activities similar to each other. The GTPase activities of smg p21A and -B were equally stimulated by smg p21 GTPase activating protein 1 and -2. Moreover, both smg p21A and -B were phosphorylated by cyclic AMP-dependent protein kinase with a stoichiometry of one phosphate/molecule of protein. These results indicate that smg p21A and -B coexist in bovine aortic smooth muscle membranes and suggest that smg p21A and -B may serve as intermediates for cyclic AMP actions.

Enzyme immunoassay of the active metabolite (RS-5139) of angiotensin converting enzyme inhibitor (CS-622)

A simple and sensitive enzyme immunoassay (EIA) for determination of the active metabolite (RS-5139) of a new angiotensin converting enzyme inhibitor (CS-622) was developed. The N-succinimmidyl ester of RS-5139 was coupled with bovine serum albumin (BSA) and its conjugate was used as an immunogen. Horse radish peroxidase (HRP; EC 1, 11, 1, 7) was used as a labeled enzyme and 3, 3', 5, 5'-tetramethylbenzidine was used as a substrate. The antiserum was used at a final dilution of 1:10000 and sensitivity was 10 pg in plasma and 20pg in urine. CS-622 exhibited cross-reactivity (22.3%), but other ACE inhibitors didn't exhibit cross-reactivity. The plasma levels determined by EIA and GC/MS was good agreement (y = 6.58e-2 + 1.07x, R - 2 = 0.985, n = 52).

Suicides in active-duty enlisted Navy personnel

Cases of completed suicide among U.S. Navy enlisted personnel occurring from 1974 through 1985 were identified and compared with similar rates in the U.S. general population and in the U.S. Army. Although the Navy suicide rate was the lowest of the three groups, this rate increased between 1976 and 1983. This was in contrast to national and Army trends during the same period. Young white males in the apprentice/recruit and blue-collar occupations had the highest rates of completed suicide in the Navy. Recommendations for prevention and treatment are discussed.

Possible involvement of 3-hydroxymethylglutaryl-CoA reductase in determining the side-chain length of ubiquinone in rat heart

The biosynthetic mechanism for determining the side-chain length of ubiquinone in rat heart mitochondria was investigated. The biosynthesis of nonaprenyl ubiquinone (UQ-9) and decaprenyl ubiquinone (UQ-10) in the mitochondria from rat hearts previously perfused with mevalonolactone was accelerated depending on the concentration of mevalonolactone. Furthermore the synthesis ratio between UQ-10 and UQ-9 (UQ-10/UQ-9) increased in accordance with the increasing concentration of mevalonolactone used. In addition, an enhancement of the synthesis ratio (UQ-10/UQ-9) was observed when the rats were treated with isoproterenol to increase the activity of 3-hydroxymethylglutaryl-CoA (HMG-CoA) reductase, a rate-limiting enzyme which forms mevalonate. Moreover, the addition of isopentenyl pyrophosphate, which is a metabolite of mevalonate, elevated the synthetic ratios UQ-10/UQ-9 in intact mitochondria and decaprenyl pyrophosphate/solanesyl pyrophosphate in the partially purified polyprenyl pyrophosphate synthetase from rat heart. These results suggest that the HMG-CoA reductase could be involved as a determining factor of the side-chain length of ubiquinone in rat heart.

[Studies on Stachys sieboldii MIQ. II. Anti-anoxia action and the active constituents]

During screening for the development of drugs from natural products, methanolic extract of tuber of Stachys sieboldii MIQ. (Labiatae) significantly inhibited the lethal induced by KCN in mice. The methanolic extract was fractionated by column chromatography to identify the active constituents. Acteoside and stachysoside C, phenylethanoid glycoside, have a significant effect on the KCN-induced anoxia model.

[Usefulness for evaluation of the left ventricular disorders by apexcardiographic A-wave ratio in patients with hypertrophic cardiomyopathy]

Usefulness for evaluation of left ventricular disorders by apexcardiographic A-wave ratio was studied in 48 patients with hypertrophic cardiomyopathy. These subjects were divided into 3 groups: A-wave ratio less than or equal to 15% (group 1), 16% less than or equal to A-wave ratio less than or equal to 29% (group 2), and A-wave ratio greater than or equal to 30% (group 3). A-wave ratio was found to have a positive correlation with Time constant T (r = + 0.71), left ventricular end-diastolic pressure (r = +0.46), and left ventricular atrial kick (r = +0.55). During exercise, ejection fraction decreased significantly (p less than 0.05) in group 3 as compared to group 1. During treadmill exercise test, rise of systolic blood pressure was significantly (p less than 0.05) poor, and there was a large number of ST depression (p less than 0.05) in group 3. It was recognized by exercise thallium-201 myocardial scintigraphy, that the frequency of perfusion defect was 30% in group 3. In conclusion, high A-wave ratio may strongly suggest impaired left ventricular diastolic function, and, there was correlated to abnormal hemodynamic state during exercise. Apexcardiographic A-wave ratio proved to be useful in patients with hypertrophic cardiomyopathy. It is useful for evaluation of left ventricular disorders.