Probing the role of lysines and arginines in the catalytic function of cytochrome P450d by site-directed mutagenesis. Interaction with NADPH-cytochrome P450 reductase

To identify amino acids of cytochrome P450d (P450d) which participate in the interaction with NADPH-cytochrome P450 reductase, we changed conserved ionic amino acids of P450d to others by site-directed mutagenesis. Turnover numbers (0.032-0.008 min-1) of purified mutants Lys94-Glu, Lys99-Glu, Lys105-Glu, Lys440-Glu, Lys453-Glu, Arg455-Glu, and Lys463-Glu toward 7-ethoxycoumarin were much lower than that (0.380 min-1) of the wild type at 25 degrees C. Reduction rates (less than 0.054 s-1) of the heme of all mutants (0.1 microM) in the presence of NADPH and the reductase (0.3 microM) were much lower than that (5.9 s-1) of the wild type. Furthermore, a turnover number (0.042 min-1) of a microsomal triple mutant (Arg135-Leu + Arg136-Leu + Arg137-Leu) of a conserved Arg cluster was much lower than that (0.674 min-1) of the wild type at 37 degrees C. Thus, we suggest that Lys94, Lys99, Lys105, Lys440, Lys453, Arg455, Lys463, and perhaps the Arg cluster Arg135-Arg136-Arg137 of P450d will participate in the intermolecular electron transfer process by forming ionic bridges between the two proteins and/or by orienting appropriate geometry for electron transfer on the interfacial surface between the two proteins.

Transforming growth factor beta 1 differentially regulates alpha-fetoprotein and albumin in HuH-7 human hepatoma cells

Transforming growth factor beta 1 (TGF-beta 1) is known to inhibit hepatocyte growth in vitro and in vivo. In this study, we analyzed the effect of TGF-beta 1 on alpha-fetoprotein (AFP) and albumin gene expression in HuH-7 human hepatoma cells. TGF-beta 1 inhibited cell growth in a dose dependent manner. The cellular secretion rate of AFP but not albumin was suppressed significantly by TGF-beta 1. TGF-beta 1 caused a significant reduction in the level of AFP mRNA. In contrast, the levels of albumin mRNA or beta-actin mRNA were not changed by TGF-beta 1. In transient transfection experiments, TGF-beta 1 resulted in selective repression of AFP promoter activity. These results suggest that TGF-beta 1 is one of the key factors involved in the differential regulation of the AFP gene and the albumin gene.

Ligand binding studies of engineered cytochrome P-450d wild type, proximal mutants, and distal mutants

Interactions of various axial ligands with cytochrome P-450d wild type, proximal mutants (Lys453Glu, Ile460Ser), and putative distal mutants (Glu318Asp, Thr319Ala, Thr322Ala) expressed in yeast were studied with optical absorption spectroscopy. P-450d wild type and all five mutants were purified essentially as the high-spin form, but the putative distal mutants contained about 5% low-spin form. Bindings of metyrapone and 4-phenylimidazole to the wild type and all mutants formed nitrogen-bound low-spin forms. In contrast, binding of 2-phenylimidazole to the wild type and most of mutants formed oxygen-bond low-spin forms except for the mutant Glu318Asp in which the nitrogen-bound low-spin form was formed. By analogy with the distal structure of P-450cam, it was thus suggested that Glu318 of P-450d, which corresponds with Asp251 of P-450cam, somehow interacts with 2-phenylimidazole over the heme plane. Addition of 1-butanol and acetanilide, a substrate of P-450d, to the wild type and mutants caused the spin change to the low-spin form. The order of dissociation constants of these oxygen ligands to P-450d was wild type greater than proximal mutants greater than putative distal mutants. Spectral analyses showed that the binding of acetanilide is the same as that of another substrate, 7-ethoxycoumarin, in the putative distal mutants but is not the same in the wild type and proximal mutants. From these findings together with other spectral data, it was suggested that the region from Glu318 to Thr322 is located at the distal region of the heme in membrane-bound P-450d as suggested from the X-ray crystal structure of water-soluble P-450cam and amino acid alignments of P-450s.

[Platelet aggregation in chronic renal failure--whole blood aggregation and effect of guanidino compounds]

Studies were performed on the platelet aggregation (PA) in patients with chronic renal failure (CRF) and normal subjects (NS). The PA was investigated in the whole blood by the electrical impedance method. The concentrations of plasma (P-) and erythrocyte (E-) guanidinosuccinic acid (GSA) and methylguanidine (MG) in uremic patients with CRF were determined by high performance liquid chromatography. GSA and MG are guanidino compounds (GC) and have been widely shown to act as uremic toxins. The effects of GSA and/or MG on the PA of NS were also investigated. The results showed that the PA of conservative therapy patients with CRF was significantly lower than that of NS, while the PA of hemodialysis (HD) patients was improved. The PA of continuous ambulatory peritoneal dialysis (CAPD) patients was rather high and the possibility of sugar and lipid metabolic disorders was suggested as the cause. The concentrations of P- and E-GSA and MG in uremic patients with CRF were increased. But there were no significant correlations between the PA and the concentrations of GSA and MG. In vitro, GSA and/or MG at a high concentration exerted a significant inhibitory effect, while at a low concentration they showed a lesser inhibitory effect on the PA. In conclusion, based on their inhibition of the PA in patients with CRF, the dialyzable materials, GSA and MG, are considered to represent active uremic toxins.

Distribution of carotenoids in the eggs from four species of salmonids

1. The distribution of carotenoids in unfertilized ovulated eggs from chum salmon, kokanee (natural and cultured), masu salmon and cultured rainbow trout was examined from the comparative biochemical point of view. 2. The carotenoid contents in the eggs from cultured salmons such as kokanee and rainbow trout were low, whereas those from natural salmons were high. 3. The carotenoids were distributed in both chylomicra particles with high levels of triglyceride and lipovitellin. The carotenoids in the eggs of cultured kokanee and masu salmon were mostly distributed in lipovitellin, whereas those of the other salmons were equally contained in both chylomicra particles and lipovitellin. 4. Comparison of carotenoid distribution in the eggs from immature and mature chum salmon indicated that the carotenoids were bound to lipovitellin, as well as to chylomicra particles, during vitellogenesis.

Three-quarters nephrectomy in rats as a model of early renal failure

To produce a compatible model of early renal failure easily, we prepared three-quarters nephrectomized animal. 20 Sprague-Dawley rats were divided into the following two groups: 10 rats which received three-quarters nephrectomy (Nx group), assuming the weight of both kidneys to be equal, and another 10 rats which underwent sham operations (S group). The levels of creatinine clearance in Nx group and S group were 286.5 +/- 33.5 vs. 431.1 +/- 55.9 microliters/min/100 g BW (P less than 0.001) on week 2, and 233.0 +/- 16.7 vs. 562.3 +/- 62.9 microliters/min/100 g BW (P less than 0.001) on week 10, respectively. The indirect and direct systolic blood pressure (SBP) values of Nx group and S group at the 10th week were 154.5 +/- 5.5 vs. 131.1 +/- 3.6 mmHg (P less than 0.01), and 148.2 +/- 4.8 vs. 130.7 +/- 6.6 mmHg (P less than 0.01), respectively. Significant changes in the levels of urinary protein excretion, urinary sodium output, urinary epinephrine, urinary norepinephrine and plasma renin activity between both groups were recognized on the 10th week. The planar area of Nx group was significantly increased as compared to that of S group (11.0 +/- 0.3 vs. 7.2 +/- 0.1 x 10(-3) mm2, P less than 0.001). It is concluded that this model resembles early renal failure in humans because slow progression of renal dysfunction occurred with mild elevation of SBP, and that it is adequate for evaluating the influence of glomerular hypertrophy, resulting in glomerulosclerosis.

Sudden appearance of coronary thrombus observed by angiography--a case report

A sudden coronary thrombus formation was documented by chance during cardiac catheterization in a patient with postinfarction angina. The thrombus was successfully treated with intravenous urokinase and heparin infusions, and thereafter, coronary angioplasty was performed without any complication.

Renal tubular epithelial antigen-containing immune complexes stimulate interleukin-1 production by cultured rat glomerular mesangial cells

The ability of immune complexes (IC) derived from rat renal tubular epithelial (RTE) antigen to trigger the production of interleukin-1 (IL-1) was investigated. When cultured rat mesangial cells (MC) were activated by the IC, substantial amounts of IL-1 could be detected in the culture supernatants as measured by the mouse thymocyte assay. To avoid the effect of prostaglandins on the IL-1 assay, we cultured the MC with addition of indomethacin and assayed IL-1 activity in the culture supernatants. This cyclooxygenase inhibitor augmented IC-induced IL-1 production. These biological activities were neutralized by a specific antibody to IL-1. These findings suggest that IC may participate in local inflammatory responses in the kidney partly due to their capacity to induce the synthesis of MC IL-1.

Soluble immune complexes stimulate production of interleukin-1 by cultured rat glomerular mesangial cells

Interleukin-1 (IL-1) is a pleiotropic factor, eliciting a broad set of immunologic and inflammatory events. We have previously shown that IL-1 is present in inflamed glomeruli. To evaluate factors that might regulate of IL-1 production, we tested the effects of substances accessible to mesangial cells (MC): immune complexes (IC) are known to modulate MC function. We have attempted to assess the ability of soluble IC derived from rat glomerular basement membrane to induce the production of IL-1. When isolated MC were incubated with the soluble IC, substantial amount of IL-1 could be detected in the supernatants as measured by the mouse thymocyte assay. To block the effect of prostaglandins on the IL-1 assay, we cultured the MC with the addition of indomethacin and assayed IL-1 activity in the culture supernatants. The use of indomethacin resulted in a further increase in IL-1 production. These biological activities were neutralized by a specific antibody to IL-1. In the present report, we show that IC represent important sources of stimulation of MC for the production of IL-1. We speculate that IC could augment local inflammatory responses in the kidney partly due to their capacity to induce the production of IL-1.

Maxillary growth after two-stage palatal closure in complete (unilateral and bilateral) clefts of the lip and palate from infancy until 10 years of age

The purpose of the study is to clarify the maxillary growth effects following different types of palatal closure in complete clefts of the lip and palate from infancy to 10 years of age. Lip repair, carried out at 5 months in one stage, was accomplished by Tennison's procedure. These patients were then assigned randomly to each of the 4 experimental groups according to the types of clefts and of palatal closure. One group of 14 patients in unilateral cases (Unil-S) and another group of 8 patients in bilateral cases (Bil-S) received mucoperiosteal palatal push-back procedure in a single stage at 20 months. The third group of 16 patients in unilateral cases (Unil-T) and the fourth group of 7 patients in bilateral cases (Bil-T) received the two-stage palatal closure based on Perko technique in which primary veloplasty was accomplished at 20 months and hard palate closure at 5 year 10 months. Non-cleft subjects were served as Controls. A longitudinal maxillary growth was monitored by the measurements of maxillofacial cast models obtained from each of the subjects. The results showed that the growth in depth and height of the maxilla of the Unil-T showed catch-up growth after primary veloplasty and resulted in no significant differences compared to that of the Control in the later phases, however, the Unil-S did not. The maxillary growth inhibition in height was characteristic in both Bil-S and Bil-T after palatal closure. There were no differences between the Bil-S and Bil-T in any dimensions and observation phases. The results indicate that the employment of the two-stage palatal closure is more beneficial for the unilateral cases, however, careful consideration is needed in bilateral cases.

Prospective study of late potentials to predict cardiac sudden death and ventricular tachycardias in patients with myocardial infarction surviving over 4 weeks

We studied, prospectively, the predictive value of late potentials to cardiac sudden death and sustained ventricular tachycardias in 385 patients with myocardial infarction surviving over 4 weeks. Signal averaged electrocardiogram was performed over a 4 week period from the onset of acute myocardial infarction in all patients. Late potentials were observed in 118 of 385 patients. During the mean follow up period of 24.3 months, 17 patients had cardiac sudden death and 15 patients had symptomatic sustained ventricular tachycardias. In 16 of 17 patients with cardiac sudden death and 14 of 15 patients with sustained ventricular tachycardias, late potentials were observed. Sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy of late potentials to cardiac sudden death in these 385 patients were 94.1%, 72.3%, 13.6%, 99.6% and 73.2% respectively. Also, these predictive values of late potentials to sustained ventricular tachycardias in the group of patients were 93.3%, 71.9%, 11.9%, 99.6% and 72.7%, respectively. We concluded that the clinical usefulness of late potentials in patients with myocardial infarction surviving over 4 weeks in the negative predictive value to cardiac sudden death and sustained ventricular tachycardias is superior to that of positive predictive value. Sensitivity of late potentials to these events is also higher.

Two types of C3 nephritic factor: properdin-dependent C3NeF and properdin-independent C3NeF

The IgG fraction of serum from patients with membranoproliferative glomerulonephritis (MPGN) types I and II or partial lipodystrophy (PLD) was found to contain C3 nephritic factor (C3NeF) which reacts with the alternative pathway C3 convertase C3bBb and stabilizes it. Two types of C3NeF were detected, of which one was heat sensitive (56 degrees C for 30 min) and properdin dependent (C3NeF:P) but the other was heat stable and properdin independent (C3NeF:nP). C3NeF:P was found in sera from patients with MPGN types I and II and it displayed the properties of properdin and IgG. C3NeF:P was observed in patients with reduced serum concentrations of C3 and terminal complement components (TCC), and the generation of SC5b-9 complex was increased in mixtures with normal human serum. C3NeF:nP was found in sera from patients with MPGN type II and PLD, whose sera revealed a selective decrease in C3 concentrations.

Preventive effect of angiotensin I on weight reduction in the adrenal glands of DOCA/salt hypertensive rats

We examined the effect of angiotensin I (AI), without the effect of angiotensin II (AII) converted from AI, on the weight of the adrenal glands, adrenal corticosterone (B) and adrenal aldosterone under conditions where the renin-angiotensin system was suppressed, since a reduction in the size of the adrenal glands is often observed in DOCA/salt hypertensive rats. Sixty male Wistar rats fed on a 1% NaCl solution were divided into 6 groups as follows: a) Salt group: received sesame oil and vehicle, b) Salt + C group: received sesame oil and MK422 (0.14 mg/day), an angiotensin converting enzyme inhibitor (CEI), c) DOCA group: received DOCA (30 mg/week) and vehicle, d) DOCA + A group: received DOCA and AI (0.5 mg/kg/day), e) DOCA + A + C group: received DOCA and AI with MK422, and f) DOCA + C group: received DOCA and MK422. After 4 weeks, the rats were sacrificed to sample their blood and remove their adrenal glands. There was no significant difference in adrenal B among the groups apart from the DOCA + C group. Adrenal aldosterone was lower in the groups of DOCA/salt hypertensive rats than in the Salt group and Salt + C group. Furthermore, the DOCA + A + C group and DOCA + C group had lower adrenal aldosterone levels than the DOCA group and DOCA + A group.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration of calcium carbonate with adequate doses of vitamin D metabolite to patients on hemodialysis improves mild secondary hyperparathyroidism

The effects of CaCO3 with vitamin D metabolite and without vitamin D metabolite on secondary hyperparathyroidism were investigated in 18 patients undergoing maintenance hemodialysis. 9 patients (Group 1) were treated with 1 microgram/day 1 alpha (OH)D3 and 2 g/day Al(OH)3, and the other 9 patients (Group 2) received 2 g/day Al(OH)3 without vitamin D metabolite. CaCO3 at amounts of 3 g/day was subsequently administered to all patients instead of Al(OH)3. The levels of mid portion-parathyroid hormone (M-PTH) in Group 2 and of 1,25-dihydroxyvitamin D3 in Group 1 during the baseline period were significantly increased as compared to those in the other group, respectively. In Group 1 only, the level of serum ionized calcium was appreciably elevated at the 4th and 12th weeks as compared to the baseline value, and the level of M-PTH was significantly decreased at the 4th and 12th weeks as compared to the baseline value. The levels of serum phosphate, calcitonin, magnesium and bicarbonate in both groups at the 4th and 12th weeks were not appreciably different from the baseline values. The level of serum aluminum in all patients of both groups were reduced at the 12th week as compared to the baseline values. A close correlation was recognized between M-PTH and the level of intact parathyroid hormone. It is concluded that prescription of 3g/day CaCO3, together with adequate doses of vitamin D metabolite, can ameliorate mild secondary hyperparathyroidism.

Detection of C3bBb-stabilizing activity (C3 nephritic factor) in the serum from patients with membranoproliferative glomerulonephritis

It is known that membranoproliferative glomerulonephritis (MPGN), hypocomplementaemia and C3 nephritic factor (C3NeF) are closely related to each other, and the presence or absence of C3NeF in the serum is important for evaluating the nature of MPGN. However, some difficulties have been encountered in detecting this factor and therefore a new assay permitting the direct detection of C3NeF without purifying IgG from the patient's serum has been devised. Using this assay method, C3bBb-stabilizing activity was observed even in sera from MPGN patients who were non-hypocomplementaemic. Furthermore, among 98 cases with hypocomplementaemia. C3NeF was found to be absent in 66 cases.

19F-n.m.r. study of trifluoperazine-S100 protein interaction: effects of Ca2+ and Zn2+

19F-n.m.r. spectra were measured to investigate the effects of Ca2+ and Zn2+ on the interaction of trifluoperazine (TFP) with three S100 proteins. It was found that TFP binds to S100a and S100ao proteins irrespective of the presence of Ca2+ and Zn2+, while in the presence of Ca2+ the apparent affinity of TFP to the proteins was greater than that in its absence or in the presence of Zn2+. In contrast, the binding affinity of TRP to S100b protein in the presence and absence of metal ions was lower than to S100a and S100ao proteins. These results suggested that TFP binds to each S100 protein in two ways: one is Ca2(+)- or Zn2(+)-dependent specific manner and another is Ca2(+)- or Zn2(+)-independent non-specific manner.

[Production of C3 nephritic factor by cultured lymphocytes derived from glomerulonephritic patients]

C3 nephritic factor (C3 NeF) has been found mainly in the sera of patients with membranoproliferative glomerulonephritis (MPGN) and partial lipodystrophy (PLD). We examined whether peripheral blood mononuclear cells (PBMC) from patients with PLD and MPGN could produce C3 NeF. We investigated the in vitro immunoglobulin synthesis of PBMC with mitogen. We further studied whether or not C3 NeF was included in the IgG of the culture supernatants by the C3bBb stabilizing activity and agglutination assay. The IgG of PLD patient was able to agglutinate only EAC4bBb cells and none of the other intermediate cells. We thus demonstrated that C3 NeF could be produced in vitro by PBMC derived from the patient with PLD. However, as regard case of C3 NeF weakly positive and C3 NeF negative patients, C3 NeF couldn't be produced in vitro by PBMC derived from the patients.

L-NG-monomethyl arginine inhibits the vasodilating effects of low dose of endothelin-3 on rat mesenteric arteries

We have reported that low doses of endothelin-3 (ET-3) elicited continuous vasodilation of rat mesenteric arteries, which is possibly related to endothelium-derived relaxing factor (EDRF). In order to clarify whether or not the vasodilating effects of ET-3 are associated with EDRF, we examined the effects of L-NG-monomethyl arginine (L-NMMA), an analog of L-arginine, on low-dose ET-3 induced vasodilation of rat mesente-Hc arteries. Infusion of 50 microM L-NMMA inhibited the vasodilation induced by 10(-13) M ET-3 and rather elicited an increase in perfusion pressure, which itself was decreased by infusion of 150 microM L-arginine. In the presence of 50 microM L-NMMA, 10(-13) M ET-3 did not elicit any vasodilation of the mesenteric arteries preconstricted with NE, in which 150 microM L-arginine, but not D-arginine, caused considerable vasodilation. These data suggest that the vasodilating effects of low doses of ET-3 are associated with EDRF as an endothelium-derived nitric oxide.

Effect of atrial natriuretic peptide on adrenal renin and aldosterone

The effect of atrial natriuretic peptide (ANP) on adrenal renin and aldosterone was investigated in anesthetized rats. Under pentobarbital anesthesia 40 mg/kg), intravenous infusion of ANP (0.25 micrograms/kg/min) for 45 min failed to alter the adrenal renin, adrenal aldosterone, and plasma aldosterone (PA). In this condition, intraperitoneal injection of ACTH (10 micrograms/kg) significantly increased the adrenal renin (from 2.4 +/- 0.1 to 5.0 +/- 0.08 ng/mg protein/h, P less than 0.05), adrenal aldosterone (from 13.6 +/- 1.3 to 22.7 +/- 2.3 ng/mg protein, P less than 0.01) and PA (from 59.8 +/- 5.8 to 75.5 +/- 7.4 ng/dl, P less than 0.05), respectively. Under ACTH stimulation, ANP infusion induced significant decreases in adrenal renin (from 5.0 +/- 0.08 to 2.8 +/- 0.2 ng/mg protein/h, P less than 0.05), adrenal aldosterone (from 22.7 +/- 2.3 to 16.2 +/- 1.8 ng/mg protein, P less than 0.05) and PA (from 75.5 +/- 7.4 to 61.6 +/- 4.9 ng/dl). These results suggest a possible role for adrenal renin in the mechanism underlying the inhibitory effect of ANP on aldosterone production in vivo.

[A comparative study of C19 steroid-induced hypertension and deoxycorticosterone acetate (DOCA)-salt hypertension]

In order to evaluate the hypertensinogenic action of 19-hydroxyandrostenedione (19-OH-AD), which has been reported to be an amplifier of mineralocorticoid, the changes in several humoral factors were observed in 19-OH-AD treated rats as compared to those in DOCA hypertensive rats. Twenty-five male Wistar rats were castrated at 11 weeks of age, and the experiments were begun at 12 weeks of age. The rats were divided into 3 groups. The control group (n = 8) was given an s.c. injection of 0.2 ml of sesame oil. The 19-OH-AD group (n = 10) was injected s.c. with 10 mg of 19-OH-AD dissolved in 0.2 ml of sesame oil, and the DOCA group (n = 8) was injected s.c. with 10 mg of DOCA dissolved in 0.2 ml of sesame oil three time weekly. The urine was collected for a period of 24 hours, and the urine volume, and urinary excretions of electrolytes, prostaglandin E2 (PGE2), kinin and catecholamine were measured before and after the start of the experiment. The systolic blood pressure (S.B.P.) was measured by the tail-cuff method. The S.B.P. values before and at 9 weeks after the start of the experiments were 136.7 +/- 3.8 and 156.0 +/- 2.6 mmHg in the 19-OH-AD group, and 140.6 +/- 5.6 and 179.3 +/- 5.5 mmHg in the DOCA group, respectively. Body weight, which was elevated in both groups, was higher in the 19-OH-AD group than in the DOCA group. Water intake and urine volume were significantly (p less than 0.001) increased only in the DOCA group. The urinary Na/K ratio was significantly (p less than 0.001) elevated in the DOCA group as compared to that in the other two groups. However, there was no significant difference in urinary Na/K ratio between the control and 19-OH-AD groups. The urinary PGE2 and kinin excretions were significantly (p less than 0.01) increased in the DOCA group but did not change appreciably in the 19-OH-AD group. The urinary catecholamine excretion was significantly increased in the DOCA group. However, there were no differences in the catecholamine excretion between the control and 19-OH-AD groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Electron spin resonance studies of wild-type and mutant cytochromes P-450d: effects of mutations at proximal, aromatic and distal sites on g values

Low-temperature (6-40 K) electron spin resonance (ESR) spectra of cytochrome P-450d (P-450d) and its 17 mutants have been measured. The spectra of the wild-type and all mutant P-450ds showed signals at around g = 8, 3.7 and 1.7, while they didn't show any signal at around g = 2 up to 40 K. It was thus suggested that all of these P-450ds essentially take the ferric high-spin form. The g values of the proximal mutants were closer to those of the wild-type than those of the distal and aromatic mutants, suggesting that mutations at the distal and aromatic sites influence the electronic state of the heme more profoundly than those of the proximal site. The distal multiple mutants whose distal sequences are the same as those of the low-spin type P-450s such as rat P-450c, mouse P1-450 and P3-450 showed only high-spin ESR signals. Thus the spin state of P-450ds (the wild-type and all mutants) may not be solely due to specific characteristics of the distal site, but to the unique nature of the whole heme environment of P-450d. It is also suggested that the amino acids at the distal region of P-450d may be located close to the heme, so that the water molecule cannot bind to the heme, thus taking the high-spin state. Both the aromatic mutants showed rather large deviations of the g values from those of wild-type P-450d, suggesting that the aromatic region somehow interacts with the heme.

[Valvular regurgitation in patients with complete heart block by color Doppler echocardiography]

We studied valvular regurgitation (pulmonary, aortic, tricuspid and mitral regurgitation) in 30 patients with complete heart block by color Doppler echocardiography, pulse Doppler and continuous wave Doppler echocardiography. The prevalence rate of multivalvular regurgitation of these subjects was 83.3%. Regurgitation involving all four valves appeared in 30.0% of these patients. The prevalence rate of pulmonary, aortic, tricuspid and mitral regurgitation was 56.7%, 33.3%, 100%, and 76.7% respectively. Pulmonary regurgitation (PR) was observed in patients with complete heart block without pulmonary hypertension. PR velocity was slow and interrupted by atrial contraction. It might be possible to evaluate atrial pressure from the interruption of PR. Tricuspid regurgitation (TR) during systole was often present in patients with right ventricular endocardial pacing. Systolic TR was influenced by atrial contraction. When atrial contraction occurred during systole, TR was interrupted, or shortened. Diastolic TR and MR were easily detected by M mode color Doppler echocardiography. The diastolic TR and MR were of slow velocity and appeared 240-290 msec after P wave. These atypical valvular regurgitation in patients with complete heart block reflect of the inverse atrial-ventricular pressure gradient across the atrio-ventricular valve.

Adenylate cyclase activities of vascular smooth muscle in early and established DOCA/salt hypertensive rats

It has been demonstrated that the adenylate cyclase activity of vascular smooth muscle regulates its tonus. The present study was undertaken to examine adenylate cyclase activity in early and established deoxycorticosterone acetate (DOCA)/salt hypertensive rats. Early and established DOCA/salt hypertensive rats were prepared by injecting 30 mg of DOCA weekly for 3 and 10 weeks, respectively, into male Wistar rats given drinking water with 1% saline. The membrane protein fraction medium containing the protein, 50 microM isoproterenol, 100 microM GTP, 50 microM forskolin or 25 microM calmodulin was applied. The adenylate cyclase activity was determined by a modified method developed in our laboratory using double isotope counting. The adenylate cyclase activity in the early DOCA/salt hypertensive rats was significantly higher (p less than 0.05) than that in the control rats in the basal condition, which was unaffected by additions of isoproterenol, GTP or forskolin. There was no significant difference in basal adenylate cyclase activity between the established DOCA/salt hypertensive and control rats. The adenylate cyclase activities in the established DOCA/salt hypertensive rats were significantly lower with GTP (p less than 0.02) and forskolin (p less than 0.01) as compared with the control rats. Calmodulin elevated the adenylate cyclase activity significantly (p less than 0.05) in the established DOCA/salt hypertensive rats as well as in the control rats. However, enzyme activity with calmodulin in the established DOCA/salt hypertensive rats was significantly lower (p less than 0.05) than that in the control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal anti-human C3d antibodies: stabilization of the alternative pathway C3 convertase

IgG mouse monoclonal antibody (mAb) was prepared by fusion of spleen cells from mice immunized with human C3d (mAb:C3d) using syngeneic thymocytes as feeder cells. mAb:C3d was assessed for its effect on the stabilization of the cell-bound alternative pathway C3 convertase EAC3bBb. It bound to cell-bound C3b and stabilized C3bBb at 30 degrees in the presence of EDTA-GVB. The plasma protein H reduced the stabilization effect of the stabilized C3 convertase. These results suggest that binding of antibody to C3d may stabilize C3bBb. It seems likely that such antibody induces in C3b conformational change, which increases the C3bBb complex stability.

[Silent myocardial ischemia evaluated by ambulatory left ventricular function monitoring]

To determine whether left ventricular function is less disturbed in asymptomatic ischemia than in symptomatic ischemia, exercise-induced left ventricular function was measured in beat-to-beat using an ambulatory left ventricular function monitoring system. The study subjects were 22 patients with coronary artery disease. Supine and sitting ergometer exercise tests were performed. Of 44 exercise tests, 33 showed significant ST depression on electrocardiograms. Among these 33, 17 were asymptomatic: 16, symptomatic. The left ventricular functions during exercise of these 33 were analyzed and compared with those of five normal controls. The changes in end-diastolic volume were not so significant either in controls or in the asymptomatic and symptomatic groups, but the changes in end-systolic volume were reversed in the diseased groups, particularly in the symptomatic group. The changes in ejection fraction (EF), therefore, were significantly negative in the diseased group, particularly in the symptomatic group. The correlation between exercise-induced left ventricular dysfunction and symptoms was evaluated among the 33 patients. Symptoms were present in 35% (6/17) in less than 10% decrease in EF, 44% (4/9) in 10-15% decrease, and 85% (6/7) in greater than or equal to 15% decrease, respectively. Thus, asymptomatic ischemia represents a lesser degree of myocardial ischemia as indicated by mild left ventricular dysfunction, compared with symptomatic ischemia. However, some cases of severe myocardial ischemia did not develop symptoms. We concluded that silent myocardial ischemia is responsible for a lesser degree of myocardial ischemia and decreased pain perception.

Metastatic small cell carcinoma to the pineal body: case report

A case of metastatic small cell carcinoma to the pineal body is reported and the clinical and radiological features of this rare tumor are discussed. A 66-year-old man presented with progressive dementia, gait disturbance, vertical gaze palsy, and convergence retraction nystagmus. Computed tomographic scan revealed a 2 X 3-cm high-density mass in the pineal region, which showed strong contrast enhancement. The tumor was resected through a right occipital transtentorial approach. The pathological diagnosis of the surgical specimens was small cell carcinoma. A systemic workup for the primary lesion subsequently revealed small cell carcinoma of the lung. Although occurring rarely, metastatic tumor should be considered in the differential diagnosis of pineal tumor in elderly patients.

[Significance of "overshoot" elevation of ejection fraction in early recovery period after exercise in patients with coronary artery disease]

To investigate the relationship between "overshoot" elevation of left ventricular (LV) ejection fraction (EF) in the early recovery period after exercise and myocardial ischemia, LV function was measured in 5 healthy volunteers and 47 pts with coronary artery disease (CAD) using supine ergometer. EF at rest (EFRE), at peak exercise (EFEX), at peak of overshoot (EFOS) and time from cessation of exercise to peak of overshoot (T-OS) were measured using an ambulatory LV function monitor system with a high sensitive CdTe detector. The patients were classified into 3 groups according to EF depression (EFRE-EFEX) by exercise, i.e., D1 (EF decreases less than 5%): 15 pts, D2 (EF decreases 5-10%): 12 pts, D3 (EF decreases greater than or equal to 10%): 20 pts. Degree of overshoot which shows difference in EF between rest and peak of overshoot was 23.8 +/- 2.13% (mean +/- SD) in the normal group, 11.72 +/- 5.12% in D1, 9.56 +/- 6.51 in D2 and 6.12 +/- 4.15% in D3, respectively. T-OS was 1.4 +/- 0.48 in the normal group, 2.8 +/- 0.54 in D1, 4.5 +/- 2.36 in D2 and 5.6 +/- 1.93 min in D3, respectively. We conclude that left ventricular dysfunction was proportionally related to time-lapse from cessation of exercise to peak of overshoot while inversely related to degree of overshoot.

An outbreak of gastroenteritis associated with acute rotaviral infection in schoolchildren

In April 1988 a large outbreak of group C rotavirus infection associated with acute gastroenteritis occurred among schoolchildren and their teachers simultaneously at seven elementary schools in Fukui city, Japan. Of 3,102, 675 (21.8%) became ill. Clinical symptoms were mild, predominantly abdominal pain and vomiting, with diarrhea reported in only 27.6%. The outbreak subsided within 2 d. No pathogenic bacteria were found in fecal specimens; the virus particles detected by electron microscopy were morphologically indistinguishable from conventional infantile rotavirus. Immune electron microscopy showed that these virions formed large aggregates with convalescent serum and with the reference serum specific to group C rotavirus. Polyacrylamide gel electrophoresis showed similar RNA patterns for virus from this outbreak and typical group C rotavirus.

Treatment of secondary hyperparathyroidism in patients on maintenance hemodialysis

The effects of CaCO3 were investigated in 7 patients undergoing maintenance hemodialysis who had been treated with 1 microgram/day 1 alpha (OH)D3 and 2 g/day Al(OH)3. CaCO3 (3 g/day) was administered instead of Al(OH)3. The levels of serum total calcium and ionized calcium were significantly increased, the level of C-terminal parathyroid hormone was appreciably decreased and the levels of serum aluminum in all patients were reduced. There were no significant changes in the levels of serum phosphate, calcium x phosphate product, alkaline phosphatase, calcitonin, magnesium and bicarbonate. It is concluded that 3 g/day CaCO3 is equivalent to 2 g/day Al(OH)3 in terms of its phosphate-binding effect, and the prescription of CaCO3 together with 1 alpha (OH)D3 ameliorates secondary hyperparathyroidism.

[Changes in complement breakdown products and terminal complement complex in patients with acute glomerulonephritis]

In this study we examined the role of the complement system in acute glomerulonephritis (AGN). Breakdown products of complements (iC3b, C4d and Bb) and Terminal complement complex (TCC, SC5b-9 complex) in plasma samples were measured by ELISA. The microassay plates were coated with monoclonal antibodies which bind specifically to human iC3b, C4d, Bb and SC5b-9 complex. This assay accurately quantitates small amounts of in vivo complement activation. The plasma samples were drawn from patients with AGN and other glomerulonephritis. There were some patients with various glomerulonephritis whose plasma iC3b, C4d and Bb concentrations were higher than those in normal human. However specificity was not found. The ratios iC3b/C3 and C4d/C4 were increased in the early stages of AGN, but plasma Bb concentrations revealed no significant changes. Plasma SC5b-9 complex concentrations were increased in the early stages of AGN. C3c, C3d, C4d and SC5b-9 were found to be localised in the glomeruli of those AGN patients. It is suggestive that in these cases of AGN (especially case 2) complement activation is predominantly mediated through the classical pathway and TCC is formed by this activation. This complement activation in the blood and the renal tissue is presumed to be involved in the initiation and progression of AGN.

Effects of Ca2+ and Zn2+ on trifluoperazine-S100 proteins interactions: induced circular dichroism and fluorescence spectra

Interactions of trifluoperazine (TFP) with S100 proteins, EF-hand type Ca2+-binding proteins, in the presence of Ca2+ and Zn2+ were studied with induced circular dichroism (CD) and fluorescence spectra. The positive CD bands of TFP were induced at around 265 nm by adding either S100a or S100a0 protein in the presence of Ca2+. No CD band of TFP was, however, induced by adding S100b protein in the presence of Ca2+. Addition of Zn2+ to the TFP/S100 protein solutions did not induce any CD band at all. The fluorescence intensity of 2-p-toluidinylnaphthalene 6-sulfonate (TNS) bound to S100a or S100a0 protein decreased by adding TFP in the presence of Ca2+, while that bound to S100b protein decreased by adding TFP in the presence of Zn2+, indicating that TFP binds to S100a protein and S100a0 protein in a Ca2+-dependent manner and to S100b protein in a Zn2+-dependent manner. From these results together with other experimental findings it was suggested that (1) TFP binds to S100a protein and S100a0 protein in the presence of Ca2+, with half-saturation points of 18 and 3 microM, respectively, (2) TFP binds to S100b protein only in the presence of Zn2+, (3) alpha-subunit of S100 protein binds to TFP specifically in a Ca2+-dependent manner and beta-subunit in a Zn2+-dependent manner.

Site-directed mutageneses of rat liver cytochrome P-450d: catalytic activities toward benzphetamine and 7-ethoxycoumarin

Catalytic activities toward benzphetamine and 7-ethoxycoumarin of 11 distal mutants, 9 proximal mutants, and 3 aromatic mutants of rat liver cytochrome P-450d were studied. A distal mutant Thr319Ala was not catalytically active toward benzphetamine, while this mutant retained activity toward 7-ethoxycoumarin. Distal mutants Gly316Glu, Thr319Ala, and Thr322Ala displayed higher activities (kcat/Km) toward 7-ethoxycoumarin that were 2.4-4.7-fold higher than that of the wild-type enzyme. Although kcat/Km values of four multiple distal mutants toward benzphetamine were less than half that of the wild type, activities of these mutants toward 7-ethoxycoumarin were almost the same as or higher than the wild-type activity toward this substrate. The distal double mutant Glu318Asp, Phe325Tyr showed 6-fold higher activity than the wild-type P-450d toward 7-ethoxycoumarin. Activities of the proximal mutants Lys453Glu and Arg455Gly toward both substrates were much lower (less than one-seventh) than the corresponding wild-type activities. Catalytic activities of three aromatic mutants, Phe425Leu, Pro427Leu, and Phe430Leu, toward benzphetamine were less than 7% of that of the wild type, while the activities of these aromatic mutants toward 7-ethoxycoumarin were more than 2.5 times higher than the wild-type activity toward this substrate. From these findings, in conjunction with a molecular model for P-450d, we suggest that (1) the relative importance to catalysis of various distal helix amino acids differs depending on the substrate and that these differences are associated with the size, shape, and flexibility of the substrate and (2) the proximal residue Lys453 appears to play a critical role in the catalytic activity of P-450d, perhaps by participating in forming an intermolecular electron-transfer complex.

Influence of 1 alpha-hydroxy vitamin D3 (0.25 micrograms/day) and calcium carbonate on patients with chronic renal failure at the predialytic stage

The influence of a small amount of 1 alpha (OH)D3 on patients with chronic renal failure at the predialytic stage (CRFPS patients) receiving CaCO3 was investigated. 7 patients given CaCO3 (3 g/day) were administered 1 alpha (OH)D3 (0.25 micrograms/day) over a period of 12 weeks. 2 patients were eliminated from the study because of obvious deterioration of renal function. The others revealed no significant changes in levels of serum creatinine, adjusted calcium, phosphate, calcium x phosphate product, alkaline phosphatase, C-terminal parathyroid hormone, pH and bicarbonate. Our results indicated that even 0.25 micrograms/day 1 alpha (OH)D3 should not be prescribed to CRFPS patients given 3 g/day CaCO3. We recommend a little sole use of CaCO3 in CRFPS patients, paying attention to any exacerbation of renal function due to a rise in serum calcium concentration, when therapy for secondary hyperparathyroidism is required.

Mutations at the distal and proximal sites of cytochrome P-450d changed regio-specificity of acetanilide hydroxylations

Regio-specificities of acetanilide hydroxylations were studied for 11 distal, 9 proximal and 3 aromatic mutants of cytochrome P-450d. Ratios of turnover numbers among these products were remarkably changed depending on the mutants. For example, the ratio of turnover number, para:ortho:meta = 7:0.1:0.3 for the wild type changed to 11:4:3 for a distal mutant, Thr322Ala, or to 13:13:1 for a proximal mutant, Arg455Gly. It was suggested that regio-specificities of microsomal P-450 enzymes are controlled cooperatively by the whole structure of the protein molecules which influences the tertiary structure of the distal environment.

Bindings of axial ligands to cytochrome P-450d mutants: a difference absorption spectral study

By site-directed mutagenesis, we made several cytochrome P-450d (P-450d) mutants as follows: Asn310Phe (D13), Ile312Leu (D14), Glu318Asp (D15), Val320Ile (D16), Phe325Thr (D19), Asn310Phe,Ile312Leu (M6), Glu318Asp,Val320Ile (M7), Phe325Thr, Glu318Asp (M3). This region (Asn-310-Phe-325) is supposed to be located in the distal helix above the heme plane in P-450d, being conjectured from the structure of P-450cam. We studied Soret spectral changes of those mutants by adding several axial ligands such as aniline, pyridine, metyrapone, 2-phenylimidazole and 4-phenylimidazole. Binding constants (Kb) of aniline and pyridine to the single and double mutants were higher than those to the wild type by 2-10-times. The double mutations did not additively increase the Kb values compared with those to the single mutants. In contrast, Kb value (1.0.10(5) M-1) of metyrapone to the double mutant M3 was much higher than that (2.0.10(3) M-1) of the wild type and those of the single mutants, D15 (4.5.10(4) M-1) and D19 (1.6.10(4) M-1). The increased affinity of metyrapone to the mutant M3 may be attributed to an interaction of the hydrophobic group of metyrapone with nearby hydrophobic group(s) produced cooperatively by the double mutation of P-450d. Kb values of 2-phenylimidazole and 4-phenylimidazole to the mutant M3 were also the highest among those of the mutants and the wild type. Therefore, it was suggested that this region (from Asn-310 to Phe-325) must be located at the distal region of the heme moiety and form, at least, a substrate-binding region of membrane-bound P-450d.

Solvent effect on MCD of Fe(III) heme complexes: magnetic circular dichroism spectra of five-coordinated high-spin iron(III) protoporphyrin-IX-dimethylester in the visible region and their environmental effect. A characterization of the visible electronic transitions in Fe(III) high-spin porphyrins

Magnetic circular dichroism (MCD) spectra were observed to characterize the nature of the visible bands for high-spin Fe(III) protoheme derivatives with p-nitrothiophenolate, p-nitrophenolate, and methoxy anion as the fifth ligands in several solvents. The visible MCD bands for p-nitrophenolate heme were very sensitive to the solvent polarity, but that those for p-nitrothiophenolate heme and methoxy heme were not dependent on solvent polarity. Thus, both the two visible MCD band positions and the magnitudes were dependent on ET value (a solvent polarity parameter) in the former complex, but not in the latter two complexes. The results are consistent with previously proposed electronic structures of high-spin Fe(III) heme complexes.