Direct demonstration of heterogeneous, sulfated O-linked carbohydrate chains on an endothelial ligand for L-selectin

We have previously identified endothelial ligands for L-selectin as sialylated, fucosylated and sulfated glycoproteins of approximately 50 kDa and 90 kDa (Sgp50 and Sgp90). In this report, we use the beta elimination reaction to demonstrate directly the presence of sulfated O-linked sugar chains on one of these ligands, after metabolic labeling with radiolabeled sulfate or fucose. All of the sulfated and the majority of the fucosylated O-linked sugar chains were shown to be sialylated by affinity chromatography on a Limax agglutinin column. Analyses by anion exchange and gel permeation chromatography revealed a complexity of sugar chains, which were heterogeneous both in charge and size. Charged groups other than sialic acid appeared to exert a predominant influence on the total charge of the sugar chains. The probable existence of a varying number of sulfate modifications per sugar chain is discussed.

[Successful two-staged Jatene operation for severe right ventricular dysfunction and tricuspid regurgitation after Senning operation--a case report]

We report a seven-year-old boy who underwent a successful Jatene procedure seven years after Senning procedure. The modified Senning operation was performed for the treatment of transposition of the great arteries with intact ventricular septum at three years of age. However, he gradually showed the progressive right ventricular failure with tricuspid regurgitation after operation. When he was referred to our hospital, he was in severe right ventricular failure and showed massive tricuspid regurgitation simultaneously with the moderate degree of left ventricular failure. Staged pulmonary artery banding was applied to prepare the left ventricle for Jatene procedure in spite of the presence of left ventricular failure. The systolic pressure ratio of left ventricle to right ventricle was elevated to 0.91 by this banding although the left ventricular ejection fraction decreased from 43% to 30%. And Jatene procedure was successfully performed after three months of preparation period. Catheterization study after Jatene procedure revealed improved right and left ventricular functions with decrease of tricuspid regurgitation. We conclude that the Jatene procedure should be an ideal alternative in patient with right ventricular failure and/or tricuspid regurgitation after an atrial switch operation; the left ventricle could be prepared by an effective pulmonary banding in most instances.

Replacement of Thr-303 of P450 2E1 with serine modifies the regioselectivity of its fatty acid hydroxylase activity

Threonine-303 of rabbit P450 2E1, which is putatively located at the distal heme surface, was replaced by serine and valine via site-directed mutagenesis. In the oxidized state, the Ser-mutated P450 exhibited a low- and high-spin mixed-type (low > high) absorption spectrum, whereas the Val-mutated P450, like the wild-type P450, exhibited a nearly high-spin type spectrum. The reduced CO complexes of the Ser- and Val-mutated P450s, as well as that of the wild-type P450, showed a Soret absorption maximum at 452 nm. Both mutated P450s were active in the hydroxylation of C10 to C18 fatty acids at somewhat lower rates than the wild-type P450. The Val-mutated P450 gave the same two products (the major one is probably the omega-1 hydroxy analog) as the wild-type P450, while additional products were formed on incubation with C11 to C17 fatty acids as substrates of the Ser-mutated P450; a total of four products was detected for each of the C12 to C15 fatty acids, and three for each of the C11, C16, and C17 homologues. The metabolites of laurate were determined by GC-MS analysis to be the omega-1, omega-2, omega-3, and omega-4 hydroxy counterparts. The Ser-mutated P450 hydroxylated drug substrates at almost the same rates as the wild-type P450, while the mutation to valine significantly lowered the drug hydroxylase activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Dihydrolipoic acid protects pancreatic islet cells from inflammatory attack

In vitro models of pancreatic islet cell inflammation are the lysis of isolated islet cells by activated macrophages or by oxygen radicals released by the endothelial enzyme xanthine oxidase. Dihydrolipoic acid protected islet cells in both systems by different modes of action. Macrophage cytotoxicity towards islet cells, which is nitric-oxide-mediated, was suppressed by 2 h of preincubation of macrophages with lipoic acid. Similarly, 2 h of preincubation sufficed to protect islet cells against enzymatically produced oxygen radicals. Dihydrolipoic acid was found by chemiluminescence assay to scavenge directly such radicals. In macrophages dihydrolipoic acid suppressed the production of nitrite as a measure of nitric oxide release. These results suggest that dihydrolipoic acid is an anti-inflammatory agent which at the same time interferes with nitric oxide release from inflammatory macrophages and protects target cells from oxygen radical attack.

Plasma concentrations of immunoreactive-endothelin in patients with chronic renal failure treated with recombinant human erythropoietin

1. Elevation of blood pressure is one of the major side effects of recombinant human erythropoietin therapy in haemodialysis patients. 2. We investigated the possible involvement of endothelin in the pathogenesis of this recombinant human erythropoietin-induced blood pressure elevation in 51 patients undergoing maintenance haemodialysis. 3. Blood haemoglobin level increased from 7.1 +/- 0.1 to 8.8 +/- 0.1 g/dl (means +/- SEM) after 8 weeks of treatment with recombinant human erythropoietin (3000-4500 units/week). An increase in mean blood pressure was found in 19 patients (37%) (n = 9, by 0-10 mmHg; n = 10, by > 10 mmHg). 4. Plasma immunoreactive-endothelin concentration significantly increased from 2.26 +/- 0.18 to 3.14 +/- 0.31 pmol/l in the 10 patients whose mean blood pressure increased by more than 10 mmHg (P < 0.05), but not in the other patients. Moreover, the increase in plasma immunoreactive-endothelin concentration showed a significant positive correlation with the change in mean blood pressure in 19 patients with elevated mean blood pressure (r = 0.47, P < 0.05). 5. There was no significant correlation between the change in plasma immunoreactive-endothelin concentration and the change in blood haemoglobin level or the change in body weight. 6. These results suggest the possibility that endothelin may contribute to the recombinant human erythropoietin-related rise in blood pressure in some haemodialysis patients.

Schizosaccharomyces pombe map3+ encodes the putative M-factor receptor

A defect in the map3 gene of the fission yeast Schizosaccharomyces pombe causes h+ mating-type-specific sterility. This gene was cloned by complementation. Nucleotide sequence analysis showed that it has a coding capacity of 365 amino acids. The deduced map3 gene product is a putative seven-transmembrane protein and has 20.0% amino acid identity with the a-factor receptor of Saccharomyces cerevisiae, encoded by STE3. It is also homologous with the Ustilago maydis mating pheromone receptors. The map3 gene is expressed in h+ cells but not in h- cells, and the transcripts are induced in response to nitrogen starvation. h+ cells defective in map3 do not respond to purified M-factor. When map3 is expressed ectopically in h- cells, they apparently acquire the ability to respond to the M-factor produced by themselves. The gpa1 gene, which encodes the alpha-subunit of a G-protein presumed to couple with the mating pheromone receptors, is essential for this function of map3. These observations strongly suggest that map3 encodes the M-factor receptor. Furthermore, this study provides strong support for the notion that pheromone signaling is essential for initiation of meiosis in S. pombe and that either M-factor signaling or P-factor signaling alone is sufficient.

Exocytosis in the lingual mucus cells of Rana esculenta evoked by acetylcholine: observation of living cells by confocal laser scanning microscopy

Exocytosis of a secretory cell is believed to occur when a part of the limiting membrane of the secretory granules fuses with the luminal plasma membrane to release their contents. Using a confocal laser scanning microscope, we have studied these events in living frog lingual gland cells. In a differential interference contrast (DIC) mode, secretory granules were found to be stable in general, but after stimulation with acetylcholine chloride (ACh) of more than 1 microM concentration, there were abrupt changes in the light intensity of granules as described in other cells. We found that with the same stimulation, two different types of secretion occurred. In the first type, a small vacuole was formed and granule contents were released from various regions of the cell. In the second type, a large vacuole was formed and granule contents were released all at once. Using two fluorescent dyes BCECF and Lucifer Yellow, we were able to perform positive and negative staining of the cell as well as its granules. Confocal images of the fluorescence mode clearly demonstrated the release process which corresponded to the DIC image observed simultaneously. The electron microscopic image also showed two different types of secretion.

Hypotensive effect of losartan, a nonpeptide angiotensin II receptor antagonist, in essential hypertension

We examined the chronic effects of losartan (DuP 753), a novel orally active angiotensin II receptor antagonist, on blood pressure and renal function in eight hospitalized patients with essential hypertension. After a control period of 1 week, losartan was administered orally once a day for 2 to 4 weeks in increasing doses of 12.5, 25, 50, and 100 mg, until blood pressure in the supine position decreased more than 20 mm Hg (systolic) and 10 mm Hg (diastolic) (or 13 mm Hg in mean blood pressure). The average dose of losartan was 59.4 +/- 43.7 (mean +/- SD) mg/day. Systolic, diastolic, and mean blood pressures, according to 24 h monitoring, fell significantly, from 151.9 +/- 6.8 to 137.2 +/- 7.9 mm Hg, from 90.6 +/- 3.7 to 81.0 +/- 3.7 mm Hg, and from 111.1 +/- 4.6 to 99.7 +/- 5.0 mm Hg, respectively (mean +/- SE, P < .01 for each), with no change in circadian rhythm or variability of blood pressure. Reduction in blood pressure was slightly greater during daytime than during sleep time. Unlike peptide angiotensin II antagonists, losartan did not exert pressor action. No significant alterations were observed in body weight, serum electrolytes, creatinine clearance, urine volume, or urinary excretion of sodium. Losartan significantly lowered serum uric acid concentration from 5.5 +/- 0.4 to 4.8 +/- 0.3 mg/dL (P < .05). Urinary excretion of uric acid increased significantly from 498.9 +/- 64.4 to 540.6 +/- 66.6 mg/day (P < .05). Plasma renin activity rose significantly but plasma aldosterone concentration did not change with the losartan treatment. These results suggest that losartan has a long-acting hypotensive effect with a hypouricemic action in essential hypertension.

Bond strength of resin to dentin treated with calcium phosphate desensitizer

In a previous study we proposed a new method utilizing immediate precipitation of calcium phosphate (CaP) in situ for treatment of dentin hypersensitivity. Sequential application of 5% disodium phosphate followed by 10% calcium chloride on patent dentin surface resulted in instant occlusion of dentin tubules and immediate relief from the hypersensitivity. To guarantee long-lasting effectiveness of the CaP treatment, resin coverage of the treated dentin surface will be the next practical approach. However, the CaP covering the surface may possibly affect bonding of resins. This study determined the effect of the CaP treatment on tensile bond strength of adhesive resins to dentin. Independent of the type of resin used, a bond strength of 4-5 MPa was obtained; cohesive failure occurred within the resin-CaP hybridized composite layer rather than at the dentin surface. The CaP treatment produced a significant increase in the bond strength of one resin.

A Japanese pedigree of autosomal dominant congenital stationary night blindness with variable expressivity

Three cases in three successive generations of one family with autosomal dominant congenital stationary night blindness are presented. Case 1, the proband, and Case 3, his grandfather had the same electroretinographic responses: nonrecordable scotopic electroretinogram (ERG), normal but slightly diminished flicker ERG, and negative-shaped single bright-flash ERG. Their dark adaptation curves were monophasic with no rod segment. However, Case 2, the proband's father, showed different ERG findings; a moderately diminished scotopic ERG, a normal flicker ERG, and a biphasic dark adaptation curve with an elevated final rod threshold. The authors believe that these differences reflect variations in the expressivity of a single gene mutation with the lowest expressivity being seen in Case 2.

Konno procedure for congenital aortic stenosis with a single coronary artery from the left coronary sinus

A right coronary artery originating from the left coronary sinus and traversing anteriorly is thought to be one of the contraindications for a Konno aortoventriculoplasty in congenital aortic stenosis because this procedure necessitates incision of the right ventricular outflow tract. The case of a 5-year-old girl with congenital aortic stenosis associated with a single coronary artery, successfully treated surgically by the Konno procedure and right coronary artery reimplantation, is reported. Preoperatively there was a pressure gradient between the left ventricle and the ascending aorta of 109 mmHg, which disappeared postoperatively. A postoperative angiography showed a patent right coronary artery.

Correlation of axenic linkage groups with the position of the microtubule-organizing center in aggregating Dictyostelium

Positioning of the microtubule-organizing center (MTOC) in Dictyostelium discoideum was found to be genetically regulated. We examined the wild-type strain NC-4 cells independently maintained in different laboratories, freshly recovered cells from spores stocked for over 20 years, the temperature-sensitive growth mutant HU49 isolated from NC-4, as well as strain V-12 which is the opposite mating-type to NC-4. During aggregation on nonnutrient agar plates, all these strains showed similar cell polarity, as defined by the alignment of the nucleus ahead of the MTOC. By contrast, in Ax2 and Ax3, axenic strains carrying axenic mutations on linkage groups II and III, the MTOC was usually positioned ahead of the nucleus. Cells containing axenic linkage group II but not III positioned the MTOC ahead of the nucleus. Conversely cell polarity of strains including axenic linkage group III but not II was similar to that of wild-type cells. Thus axenic linkage group II, probably axeC or other linked gene(s) not yet identified, is responsible for the location of the MTOC anterior to the nucleus during aggregation. The anterior positioning of the MTOCs was prevented by growth on bacteria in cells carrying both axenic linkage groups, but not in those carrying only axenic linkage group II.

Bladder tumor staging: comparison of conventional and gadolinium-enhanced dynamic MR imaging and CT

With computed tomography (CT) and unenhanced magnetic resonance (MR) imaging, stage pT3b extravesical extension and beyond can be diagnosed, but tumors confined to the bladder wall (stages pT1-pT3a) are poorly delineated. To determine whether visualization of such tumors could be improved with gadolinium-enhanced MR imaging, dynamic breath-hold T1-weighted MR images were obtained after intravenous infusion of 0.1 mmol/kg gadopentetate dimeglumine in 79 patients (86 tumors). Conventional MR images, CT scans, and histologic correlation were available in all cases. With dynamic gadolinium-enhanced MR imaging, the mucosa could be distinguished from the muscular layers of the bladder wall. Staging accuracy with this technique was 85% (73 of 86), which was significantly better than with CT (55%; 47 of 86) (P < .005) or conventional MR imaging (58%; 50 of 86) (P < .05). The accuracy of staging the intramural extent (pT1-pT3a) of bladder tumors was thus improved with gadolinium-enhanced dynamic MR imaging.

Effect of slow release nifedipine tablets in patients with essential hypertension

The antihypertensive effect of slow release nifedipine (CAS 21829-25-4) tablets (20 mg, Adalat) administered once or twice daily was studied in patients with essential hypertension of WHO stage I or II. Ambulatory blood pressure was monitored by a finger volume oscillometric device every 5 min for 24 h before and during the treatment with nifedipine. Whether administered once or twice daily, nifedipine tablets dit not change the pattern of circadian blood pressure variation; i.e. diurnal rise and nocturnal fall. Twice daily administration induced a significant downward shift in the blood pressure pattern. In other words, further hypotensive effect was observed during the night when the blood pressure was already low. On the other hand, administration once daily in the morning lowered daytime blood pressure without affecting blood pressure during the night. The duration of action of nifedipine tablets administered once daily was 12 h or more. In the acute experiment using 20 mg tablets of nifedipine, plasma concentration of nifedipine was well correlated with the percentage change in mean blood pressure. The minimal effective plasma concentration of nifedipine was estimated to be 13.4 ng/ml. However, in chronic treatment, nifedipine lowered blood pressure at the plasma concentration of 10 ng/ml. The results indicate that nifedipine tablets administered once daily provide an effective antihypertensive regimen for controlling daytime hypertension with minimal antihypertensive effect during the night.

Enhanced production of platelet-activating factor in stimulated rat leukocytes pretreated with triacsin C, A novel acyl-coA synthetase inhibitor

Triacsin C, a product of Streptmyces sp. SK-1894, was previously reported as an inhibitor of long chain acyl-CoA synthetase. Pretreatment with triacsin C (500 nM) for 1h enhanced production of platelet-activating factor in rat neutrophils, followed by stimulation with A23187 or fMLP. Amount of lyso-PAF was also augumented. Triacsin C alone did not increase PAF content and did not modulate enzymatic activities of acytransferase, cholinephosphotransferase, acetylhydrolase, acetyltransferase or phospholipase A2. These results suggest that triacsin C might enhance supply of substrate for PAF synthesis, i.e. accumulation of lyso-PAF by interfering reacylation pathway.

Cyclosporin A protects pancreatic islet cells from nitric oxide-dependent macrophage cytotoxicity

It has been shown earlier in an in-vitro model of inflammatory islet cell death that activated macrophages lyse islet cells via the release of nitric oxide. Here we report that cyclosporin A suppresses macrophage cytotoxicity. Control experiments showed that the immunosuppressive drug does not improve the defences of islet cells against nitric oxide but inhibits the release of nitric oxide from LPS-stimulated macrophages. This property of cyclosporin A may contribute to the preservation of beta cell function seen in cyclosporin A-treated patients with recent onset type I diabetes.

[Inhibition of acute rejection of heart graft in rats without immunosuppressants after intrathymic myocardial cell inoculation in the neonatal period]

There have been no successful cases reported of organ transplantation in application of neonatal immunological tolerance. Isolated myocardial cells from Lewis (LEW/Crj) rat hearts were inoculated into the thymus of incompatible King (WKAH/Hkm) rats. Ten weeks later the heart from LEW donor was transplanted heterotopically to the WKAH rat that had inoculated intrathymic myocardial cells without immunosuppression (n = 4, Group 1). Group 2 was made up of 4 isografts of heart transplantation (nontreated isograft). Group 3 was made up 4 allografts of heart transplantation (nontreated allograft). The animals were killed 7 days after transplantation, and early rejection was evaluated by accumulation of iodine-125 (125I)-labeled antimyosin antibody (AMA) uptake and confirmed by histological examination. In Group 1 & 2, the value of I-125 AMA uptake ratio was small (Group 1; RV: 1.28 +/- 0.28, IVS: 1.29 +/- 0.28, LV: 1.43 +/- 0.25, Group 2: RV: 1.14 +/- 0.07, IVS: 0.95 +/- 0.06, LV: 1.16 +/- 0.21). This level of the value indicates that the rejection does not occur. On the other hand, in Group 3, the value was high (RV: 4.63 +/- 1.92, IVS: 4.42 +/- 1.75, LV: 4.45 +/- 1.73) compared with Group 1 & 2. This level indicate that the rejection is severe. In the histological studies, Group 3 showed necrosis of myocardial cells, while Group 1 with neonatal immunological tolerance showed only very mild lymphocytic infiltration. The histology of thymic tissue in Group 1, the LEW myocardial cells are surviving in the WKAH rat thymus.

Role of the septal leaflet in tricuspid valve closure. Consideration for treatment of complete atrioventricular canal

A septal leaflet of the tricuspid valve is thought to work differently from other anterior and posterior leaflets. We studied its role in valve closure in dogs by means of a dynamic area meter. During the control state, the tricuspid valve orifice area increased twice in diastole coincidentally with either atrial systole or rapid ventricular filling. We observed several findings after the septal leaflet resection: (1) two peak area patterns of the tricuspid valve orifice in diastole, (2) no elevation of right atrial pressure on ventricular systole (there was no V wave), (3) no tricuspid valve regurgitation on right ventriculography. These findings suggest that a complete valve closure occurred without the septal leaflet in regular sinus rhythm. An elevation of the right ventricular pressure produced by pulmonary artery stenosis without septal leaflet, however, easily caused tricuspid valve regurgitation in contrast to the same pressure of the right ventricle with the normal tricuspid valve. The right ventricular pacing caused severe valve regurgitation without the septal leaflet. Results indicate that in the repair of the complete atrioventricular canal defect and other tricuspid valve lesions, the septal leaflet of the tricuspid valve rarely requires attention. An atrioventricular block should be avoided, however, because electrical cardiac pacing on the right ventricle causes severe valve regurgitation without the septal leaflet.

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure monitoring device based on the cuff-oscillometric method and the Korotkoff sound technique

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure (BP) monitoring device using both the cuff-oscillometric method (O) and the Korotkoff sound method (K) were evaluated. The device was tested for accuracy under static and dynamic conditions by simultaneous comparison with two observers using a standard mercury column sphygmomanometer (standard method) and by the objective recording method (ORM). The performance of the device was also evaluated under ordinary ambulatory conditions. The mean differences in BP of standard method from K-method were -1.2 +/- 4.7 mm Hg systole and 1.3 +/- 4.7 mm Hg diastole (n = 323, mean +/- SD) and those of standard method from O-method were -0.4 +/- 5.3 mm Hg systole and 1.4 +/- 5.1 mm Hg diastole (n = 323). The agreement between each of the two methods of the device and the standard method was within 10 mm Hg for more than 90% of both systolic and diastolic readings. During bicycle exercise, the mean differences in BP of standard method from K-method were -3.4 +/- 4.8 mm Hg systole and 1.8 +/- 5.2 mm Hg diastole (n = 71) and those of standard method from O-method were -1.1 +/- 7.3 mm Hg systole and 1.7 +/- 7.8 mm Hg diastole (n = 67). There was a greater scatter in the individual comparisons of the device and the standard method during exercise, especially in diastolic BP. The relation between the device and ORM was almost similar to that between the device and the standard method.(ABSTRACT TRUNCATED AT 250 WORDS)

Selective inhibition of T-cell-dependent immune responses by bisbenzylisoquinoline alkaloids in vivo

The bisbenzylisoquinoline (BBI) alkaloids, chondocurine, tetrandrine, isotetrandrine and cepharanthine, were tested for immunosuppressive activity in mice. A plaque-forming cell (PFC) response to a T-cell-dependent antigen, sheep red blood cell, was significantly suppressed by a 7 day treatment of chondocurine or tetrandrine at 1 mg/kg/day and of isotetrandrine at 50 mg/kg/day, but not suppressed by cepharanthine treatment. The suppressive effect of chondocurine was greater when it was given after immunization rather than before or concurrently. However, it did not affect the PFC response to a T-cell-independent antigen, lipopolysaccharide. A delayed-type hypersensitivity was also suppressed by chondocurine treatment. There was no significant change in lymphocyte number and proportion of T-cell subsets in the BBI alkaloid-treated mice. These data suggest that there is selective inhibition by chondocurine and tetrandrine of the T-cell-dependent immune reactions.

[Two-stage Jatene procedure after Mustard or Senning operation]

We have successfully performed a two-stage Jatene procedure in four patients who showed severe anatomical right ventricular dysfunction after atrial switch (Mustard or Senning) operation for transposition of the great arteries. All four patients developed an adequate left ventricular pressure for the arterial switch operation by one or two-stage pulmonary artery banding. Left ventricular posterior wall thickness increased sufficiently enough after the banding although left ventricular ejection fraction showed significant decrease. After Jatene procedure left ventricular ejection fraction recovered, and RV end-diastolic volume which had been prominently enlarged preoperatively was dramatically normalized. Cardiac index increased from 3.6 +/- 1.6 l/min/m2 preoperatively to 5.3 +/- 6.1 l/min/m2 postoperatively with the decrease in left atrial pressure. Postoperative electrophysiological study revealed the recovery of sinus node function and atrial conduction by means of the take-down of atrial switch operation previously performed. We conclude that the Jatene procedure should be an ideal alternative in patients with right ventricular dysfunction after atrial switch operation. The left ventricle could be prepared by an effective pulmonary artery banding in most instances.

[Surgical treatment of total anomalous pulmonary venous connection Darling type Ib using pedicled right atrial flap]

A one-month-old baby with total anomalous pulmonary venous connection (TAPVC) type Ib underwent a total correction with a pedicled right atrial (RA) flap, which was made by incising the RA wall in a quadrangular configuration. The common pulmonary vein (PV) was cut back into the left atrium (LA). Then the RA flap was sutured along the limbus of PV recess and atrial septal defect (ASD) to create a new pulmonary venous channel. The defect in the RA wall was directly closed without any prosthetic patch. Absorbable sutures (# 6-0 PDS) were used throughout. Postoperative course was uneventful and echocardiogram showed widely opened PV channel draining into the LA. We think that this procedure could be applied in various types of total and partial anomalous pulmonary venous connection, avoiding pulmonary venous obstruction on the assumption that the RA flap should grow.