Effect of ligand orientation on hepatocyte attachment onto the poly(N-p-vinylbenzyl-o-beta-D-galactopyranosyl-D-gluconamide) as a model ligand of asialoglycoprotein

The orientation effect of galactose ligand on hepatocyte attachment was investigated. Poly(N-p-vinylbenzyl-o-beta-D-galactopyranosyl-D-gluconamide )(PVLA), a beta-galactose-carrying styrene homopolymer, was used as a model ligand for the asialoglycoprotein receptors on hepatocytes. PVLA was transferred onto the poly(gamma-benzyl L-glutamate) (PBLG) or PBLG/poly(ethylene glycol) (PEG)PBLG Langmuir-Blodgett (LB) films as the monolayer level. The dichroic fluorescence values of the confocal microscope indicated that the PVLA transferred onto the LB films was located with a preferential orientation of its molecular axes with regard to the direction of the alpha-helix of polypeptide. Hepatocyte recognized well-oriented galactose moieties of the surface of PVLA through asialoglycoprotein receptors.

Assignment of the E4TF1-60 gene to human chromosome 21q21.2-q21.3

The gene encoding human transcription factor E4TF1-60 was previously mapped to chromosome 21q21. We analyzed the localization of the E4TF1-60 gene in more detail by genomic Southern hybridization and determined the sequence of the exons and the regions surrounding the intron boundaries. We report here that E4TF1-60 locates in the long arm of chromosome 21 at q21.2-q21.3 and contains a total of ten exons.

Structural effect of galactose residue in synthetic glycoconjugates on interaction with rat hepatocytes

N-p-Vinylbenzyl-O-beta-D-galactopyranosyl-(1,4)-D-gluconamide++ + (PVLA) has been used as an asialoglycoprotein model polymer. Rat hepatocytes expressing asialoglycoprotein receptors are capable of binding to hydrophobic plastic dishes coated with PVLA. PVLA, water-soluble polystyrene derivatives bearing galactose residues preferentially adsorb to plastic plates made of polystyrene rather than those of poly(methyl methacrylate). Hence, we modified chitosan beads with linear chains composed of a long alkyl or phenyl moiety to study the effect of structural variations of adsorbed PVLA, and investigated the extent of hepatocyte attachment to the hydrophobic beads coated with PVLA. The attachment was independent of the amount of immobilized PVLA; rather, it was dependent on the hydrophobicity of the beads with PVLA. To simplify the surface of the hydrophobic beads with PVLA, galactopyranoses were covalently linked to chitosan beads via hydrophobic spacer arms, and hepatocyte attachment was compared among the prepared beads. The beads with spacer arms containing phenylalanine and a phthalic moiety showed increased hepatocyte attachment, which was elicited by galactose residues on the beads. These results suggest that rotational restriction or stiffness and hydrophobicity due to the phenyl moiety are essential to enhance the specificity of terminal galactose in PVLA. This analysis contributes to the design and optimization of an artificial ligand for cellular receptors recognizing sugar moieties.

KatG sequence deletion is not the major cause of isoniazid resistance in Japanese and Yemeni Mycobacterium tuberculosis isolates

One of the mechanisms of isoniazid resistance to Mycobacterium tuberculosis has been proved to be the chromosomal deletion of katG. Based on this finding, 22 isoniazid-resistant isolates of M. tuberculosis obtained in Japan and Yemen were analysed for katG by polymerase chain reaction and catalase activity. Only six (27%) of the 22 isolates were compatible with the mechanism (lack of amplification of katG and loss of catalase activity). In contrast, eight isolates (36%) were katG positive but catalase activity-negative and eight (36%) were positive for both factors, indicating that isoniazid resistance is multifactorial and the deletion of katG was not the major cause of resistance in the isolates examined in this study.

Altered gene expression of natriuretic peptide receptor subtypes in the kidney of stroke-prone spontaneously hypertensive rats

1. To elucidate the physiological and pathophysiological role of the natriuretic peptide system in the progression of hypertensive renal disease, we examined the gene expression of natriuretic peptide receptor subtypes, guanylate cyclase-A (GC-A), guanylate cyclase-B (GC-B) and clearance receptor (C receptor), in the kidney of stroke-prone spontaneously hypertensive rats (SHRSP) at 8 and 20 weeks of age, and compared them with their gene expression in age-matched Wistar-Kyoto (WKY) rats. 2. Northern blot analyses revealed that messages for three natriuretic peptide receptor subtypes were expressed in the kidney, and their expressions were higher in the glomeruli than in the whole kidney in each strain. 3. In 20 week old rats with established hypertension, the glomerular concentration of GC-A mRNA was significantly higher in SHRSP than in WKY. The concentrations of GC-B and C receptor mRNA in the glomeruli tended to increase and decrease, respectively, but they were not statistically significant in SHRSP. 4. In 8 week old rats, the glomerular concentrations of GC-A, GC-B and C receptor mRNA were not significantly different between SHRSP and WKY. 5. This study demonstrates that in the progression of hypertension, the expression of GC-A, which mediates biological actions of natriuretic peptides, is enhanced in the kidney of SHRSP compared to that of WKY. Together with the augmented secretion of the ligands previously revealed, altered expression of natriuretic peptide receptor subtypes in SHRSP may have a deterrent role in the development of hypertension and its renal complications.

Preparation of a monoclonal antibody against mouse brain natriuretic peptide (BNP) and tissue distribution of BNP in mice

1. In order to explore the significance of brain natriuretic peptide (BNP), a cardiac hormone secreted from the ventricle, in mice, we prepared a monoclonal antibody against mouse BNP (mBNP) and established a specific radioimmunoassay (RIA) for mBNP. 2. A monoclonal antibody, KY-mBNP-I, was prepared by the fusion of mouse myeloma cells X63-Ag8.653 with spleen cells of the BALB/c mouse immunized with synthetic mBNP[108-121] conjugated to bovine thyroglobulin. KY-mBNP-I belonged to an IgG2a subclass and showed a high affinity for mBNP (Ka = 1.8 x 10(11) mol/L-1). 3. The RIA established that using KY-mBNP-I was highly sensitive and specific for mBNP, with an IC50 value of 3 fmol/tube and cross-reactivities of less than 0.003% with related natriuretic peptides. mBNP-like immunoreactivity (mBNP-LI) was detected in the mouse atrium (0.35 +/- 0.02 nmol/g), ventricle (20.5 +/- 0.5 pmol/g) and kidney (0.50 +/- 0.05 pmol/g), but not in other tissues including brain. 4. Gel filtration analysis revealed that the major component of tissue mBNP-LI was co-eluted with synthetic mBNP[77-121], a 45-amino acid mature peptide. 5. The monoclonal antibody and RIA for mBNP established here will provide useful tools to investigate the functional significance of BNP in mice, coupled with the genetic engineering approach.

[A case of Sjögren's syndrome and systemic lupus erythematosus complicated with necrotizing angiitis of the gallbladder]

A 71 year-old man with Sjogren's syndrome and systemic lupus erythematosus was admitted to our hospital because of abdominal pain and fever. Laboratory investigation showed an ESR of 76 mm/hr, elevation of CRP and marked leukocytosis. Abdominal ultrasound and CT scan showed enlargement of the gallbladder and intravesicular sludge without stones. With a clinical diagnosis of acute cholecystitis and pan-peritonitis, the surgical procedures including cholecystectomy were performed. Histological examination of the gallbladder showed a presence of necrotizing angiitis of small arteries. The postoperative course was uneventful with daily administration of 10 mg of prednisolone.

New chronic pancreatitis model with diabetes induced by cerulein plus stress in rats

To establish a new experimental model of chronic pancreatitis (CP) with diabetes, we investigated pancreatic endocrine function, blood flow, and histopathology in CP induced by repetition of cerulein injection plus water immersion stress in rats. CP rats were treated with water immersion stress for 5 hr and two intraperitoneal injections of 20 micrograms/kg body weight of cerulein once a week for 16 weeks. In the CP group, pancreatic contents of protein, amylase, elastase, and lipase significantly decreased to 64, 38, 23, and 68% of the control group, respectively. In oral glucose tolerance test (glucose 2 g/kg body wt), blood glucose level in the CP group was 212.1 +/- 97.8 mg/dl (mean +/- SD) at 30 min and was significantly higher than the control group (126.3 +/- 15.4 mg/dl)(P < 0.05). Two of seven rats in the CP group showed an obvious diabetic insulin in the CP group was 640.1 +/- 148.7 pM, significantly lower than in the control group (1133.4 +/- 242.0 pM)(P < 0.001). However, insulin content in the pancreas was 12.37 nmol/pancreas). In CP rats, winding and dilatation of surface blood vessels and gland atrophy were evident. Marked fibrosis, fatty changes, and destruction of lobular architecture were also demonstrated microscopically, although the structure of each pancreatic islet was preserved and each islet was fully stained with anti-insulin antibody. In the CP group, pancreatic blood flow by the hydrogen gas-clearance method was 197.6 +/- 33.0 ml/min/100 g, which was significantly less than the control group (276.2 +/- 19.1 ml/min/100 g) (P < 0.001). Thus, we conclude that the CP model induced by cerulein plus stress is a new CP model with diabetes in rats, in which the glucose tolerance was impaired without loss of insulin reserve.

Crystal structure of a mixed chain diacylglycerol, 1-stearoyl-3-oleyl-glycerol

Diacylglycerols composed of one saturated and one unsaturated chain make up the hydrophobic core of many biological membranes. We report here the first crystalline structure of such a mixed chain diacylglycerol. The mixed chain diacylglycerol, 1-stearoyl-3-oleyl-glycerol (1,3-SODG) was produced by solution isomerization of 1-stearoyl-2-oleyl-sn-glycerol. 1,3-SODG was isolated by flash chromatography and crystallized by slow evaporation in ethyl acetate at 4 degrees C. The melting point was 42.5 degrees C and the enthalpy was 18.0 kcal/mol. The crystal structure was determined to a final R factor of 0.127. Four molecules are present in the monoclinic unit cell: space group Cc, a = 9.362(2), b = 5.495(2), c = 77.92(3)A, beta = 91.46(2), V = 4007(4)A3, Z = 4, D = 1.032 g/cm3. The molecule forms an extended V-shaped conformation with the oleate and stearate chains coming off the two ends of the glycerol with an angle between their planes of 94 degrees. The two chains pack separately in individual layers and do not interact. The hydrogen bonds between the free hydroxyl group on the glycerol-2 position and the carbonyl oxygen on the oleyl chain of an adjacent molecule are 2.78 A in length and stabilize the glycerol layers. The stearoyl chain is roughly straight and packed in a triclinic parallel subcell. Both portions of the oleyl chain also pack in triclinic parallel packing. The torsion angle sequence along the double bond extending from the oleyl carbons C7 to C13 is tscsst (173 degrees, -152 degrees, -17 degrees, -157 degrees, -163 degrees, -178 degrees). This sequence is different from other monounsaturates. The torsion angle sequence around the glycerol region shows that the glycerol conformation is quite similar to the A conformer of racemic alpha monolaurin, and to 1,3-di-11-bromoundecanoyl glycerol, but completely unlike 1,2-diacyl-sn-glycerols. Thus the glycerol conformation appears to be driven by the hydrogen bond formation, which in turn determines whether chains interact or are segregated. In 1,3-diacylglycerols the two acyl chains point in different directions and are segregated. In 1,2-diacylglycerols the acyl chains lie side by side and must interact. When the two chains are quite different, then serious problems in packing occur, giving rise to disordered crystal packing. Probably as a result of the disordered chain packing in 1-stearoyl-2-oleyl-sn-glycerol (Di, L. and D.M. Small. 1993. J. Lipid Res. 34: 1611-1623) we were not successful in growing adequate crystals suitable for crystallographic structure determination of this 1,2 mixed chain diacylglycerol.

Protective effect of nitric oxide on development of acute pancreatitis in rats

Nitric oxide (NO) has been implicated to regulate pancreatic circulation, promote capillary integrity, and inhibit leukocyte adhesion. We investigated the role of NO in the development of pancreatitis. Nitro-L-arginine, an inhibitor of NO synthase, in total dose of 35 mg/kg body wt was infused in the rats with edematous pancreatitis induced by two intraperitoneal injections of cerulein (20 micrograms/kg). L-Arginine (125 or 250 mg/kg), a NO donor was intravenously administered twice in the rats with hemorrhagic pancreatitis induced by water-immersion stress plus two intraperitoneal injections of cerulein (40 micrograms/kg). The degree of pancreas edema, serum amylase levels, and histologic alterations were investigated. Nitro-L-arginine exacerbated cerulein-induced pancreatitis and caused a decrease in pancreatic blood flow. L-Arginine ameliorated the severity of hemorrhagic pancreatitis dose dependently and improved the pancreatic blood flow. These findings suggest that NO could confer protection against the development of hemorrhagic pancreatitis, probably through improvement of the pancreatic microcirculation.

Receptor-mediated interaction of the low-density lipoprotein complex with dextran sulfate: potential as a multi-biological coupler

We have investigated the receptor-mediated binding and uptake of low-density lipoprotein (LDL) and its insoluble complex with dextran sulfate to determine the contribution of positively charged sites in LDL to receptor-mediated interactions. Rabbit plasma LDL derivatized with FITC retained its sedimentation ability with dextran sulfate, as well as intact LDL, and binding of fluorescent LDL and its complex to liver cells was assayed by flow cytometry. Flow cytometry revealed that the binding of complex LDL with dextran sulfate, as well as that of pure LDL, increased on rat liver parenchymal cells treated with estrogen, which enhanced the expression of LDL receptors, and decreased on Hep G2 and Chang Liver cells treated with a monoclonal antibody against LDL receptors. The binding of pure LDL and complex LDL to hepatocytes was depressed by pretreatment with unlabeled LDL in a similar manner, but not with asialoglycoprotein, a ligand of asialoglycoprotein receptors on liver cells. Furthermore, we carried out a stable primary culture of rat hepatocytes, and then pure LDL and complex LDL were applied to the cultured hepatocytes. Hepatic-differentiated functions such as albumin and bile acid secretion decreased on the uptake of pure LDL and complex LDL in a similar manner. Consequently, comparative studies using pure LDL and complex LDL allowed us to determine that the complex formation with dextran sulfate had no influence on the receptor-mediated binding or uptake of LDL, and that LDL possessed binding domains for LDL receptors and sulfonic carbohydrates, containing positively charged amino acids.

Long-term follow-up of idiopathic ventricular arrhythmias in otherwise normal children

Clinical characteristics and long-term prognosis of 163 children with ventricular arrhythmias without underlying heart diseases (78 with ventricular premature contractions (VPC group), 39 with ventricular couplets (CPLT group), and 46 with ventricular tachycardia (VT group)) were studied by Holter electrocardiographic monitoring (Holter ECG) and treadmill exercise testing. The age of the subjects at the initial examination was 8.9 +/- 3.4 years in the VPC group, 9.9 +/- 3.5 years in CPLT group, and 9.4 +/- 3.1 years in the VT group. The duration of the follow-up was 71.7 +/- 32.1 months in the VPC group, 65.9 +/- 32.8 months in the CPLT group, and 84.0 +/- 31.9 months in the VT group. VPC's disappeared during the follow-up period in 22 (28%) of the 78 children in the VPC group. CPLT's disappeared in 15 (38%) and VPC's disappeared in 9 (23%) of the 39 children in the CPLT group. In the 46 children in the VT group, VT disappeared in 30 (65%), and VPC's disappeared in 17 (37%). One child (2%) in the VT group died of heart failure due to drug-resistant sustained VT. The mean time until the disappearance of VPC's in the 163 patients was estimated to be 115.2 +/- 4.3 months. The mean time until the disappearance of VT in the 46 children in the VT group was estimated to be 89.0 +/- 4.9 months. Multivariate analysis of prognostic factors related to the disappearance of VPC's indicated that nighttime VPC's were significantly more likely to disappear (p = 0.018), and that symptomatic VT was significantly more likely to disappear than asymptomatic VT (p = 0.032), probably because more symptomatic cases received antiarrhythmic therapy. Ventricular arrhythmias in children without underlying diseases often disappeared, and the prognosis was generally favorable. However, appropriate treatment and follow-up were required in children with sustained VT, symptomatic VT, or VT with a high rate of VT.

Role of bradykinin in protection of ischemic preconditioning in rabbit hearts

Bradykinin receptor activation has been proposed to be involved in ischemic preconditioning. In the present study, we further investigated the role of this agent in preconditioning in both isolated and in situ rabbit hearts. All hearts were subjected to 30 minutes of regional ischemia followed by reperfusion for 2 hours (in vitro hearts) and 3 hours (in situ hearts). Infarct size was measured by tetrazolium staining and expressed as a percentage of the size of the risk zone. Preconditioning in situ hearts with 5 minutes of ischemia and 10 minutes of reperfusion significantly reduced infarct size to 10.2 +/- 2.2% of the risk region (P < .0005 versus control infarct size of 36.7 +/- 2.6%). Pretreatment with HOE 140 (26 micrograms/kg), a bradykinin B2 receptor blocker, did not alter infarct size in nonpreconditioned hearts (40.6 +/- 5.3% infarction) but abolished protection from ischemic preconditioning (34.1 +/- 1.6% infarction). However, when HOE 140 was administered during the initial reflow period following 5 minutes of ischemia, protection was no longer abolished (15.6 +/- 3.9% infarction versus 13.3 +/- 3.8% without HOE 140, P = NS). Bradykinin infusion in isolated hearts mimicked preconditioning, and protection was not affected by pretreatment with the nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester or the prostaglandin synthesis inhibitor indomethacin but could be completely abolished by the protein kinase C (PKC) inhibitors polymyxin B and staurosporine as well as by HOE 140. HOE 140 could not block the protection of ischemic preconditioning in isolated hearts. That failure was apparently due to the absence of blood-borne kininogens rather than autonomic nerves. When the preconditioning stimulus in the in situ model was amplified with four cycles of 5-minute ischemia/10-minute reperfusion, HOE 140 pretreatment could no longer block protection (infarct size was 10.7 +/- 3.5% versus 6.4 +/- 2.0% without HOE 140, P = NS). We propose that bradykinin receptors protect by coupling to PKC as do adenosine receptors, and blockade of either receptor will diminish the total stimulus of PKC below threshold and prevent protection. A more intense preconditioning ischemic stimulus can overcome bradykinin receptor blockade, however, by simply enhancing the amount of adenosine and possibly other agonists released.

Apoptosis: a new mechanism of endothelial and Kupffer cell killing

Kupffer cells (KC) become activated in response to lipopolysaccharide (LPS) and produce a variety of mediators. Among them, TNF alpha is known to injure the liver. Here we report that TNF alpha mediates apoptosis in KC and sinusoidal endothelial cells. After stimulation for 24 h with LPS (0-10 micrograms/mL), apoptosis in KC detected by TUNEL TdT-mediated dUTP-biotin nick end labelling (TUNEL) increased in a concentration-dependent manner (0 micrograms/mL, 12 +/- 4%; 0.1 microgram/mL, 36 +/- 11%; 1.0 micrograms/mL, 65 +/- 9%; 10 micrograms/mL, 78 +/- 15%). In contrast, co-incubation of endothelial cells with LPS-stimulated KC resulted in a marked increase in TUNEL-positive endothelial cells. TNF alpha antibody blocked apoptosis in both KC and endothelial cells. Apoptosis was observed in cells adjacent to or in contact with KC. Reducing transmembrane TNF alpha expressed on KC also led to a decrease in endothelial cell apoptosis, suggesting that transmembrane TNF alpha is implicated in the cell-to-cell contact mechanism of induction of apoptosis. Thus, TNF alpha mediates apoptosis in KC and endothelial cells.

Direct in vivo observation of subendocardial arteriolar response during reactive hyperemia

To study the vasodilatory capacity of subendocardial (ENDO) arterioles, we evaluated the reactive hyperemic responses of ENDO as well as subepicardial (EPI) arterioles in 40 dogs by our needle-probe intravital microscope. We also examined the individual and combined effects of an ATP-sensitive K+ channel blocker (glibenclamide, 200 micrograms/kg), an inhibitor of nitric oxide synthase (NG-monomethyl-L-arginine [L-NMMA], 2 mumol/min, 20 minutes), and an adenosine-receptor antagonist (8-phenyltheophylline [8PT], 0.75 mumol/min, 15 minutes). The percent increase in end-diastolic diameter of ENDO arterioles was larger (P < .01) than that of EPI arterioles during reactive hyperemia, especially for the arterioles larger than 120 microns (P < .01). The diastolic-to-systolic vascular pulsation amplitude at the peak flow was greater in ENDO than EPI arterioles (25% versus 6%, P < .05). Compared with control conditions, the presence of both glibenclamide and L-NMMA suppressed the vasodilation responses of ENDO arterioles (P < .01 for both) and EPI arterioles (P < .05 for both). The effect of L-NMMA was greater in ENDO arterioles (P < .01), but that of glibenclamide was not different between ENDO and EPI arterioles. 8PT influenced the hyperemic response, although statistical significance was found only in the flow response. The effect of combined infusion of L-NMMA and glibenclamide with or without 8PT was greater than that of individual infusions in both ENDO and EPI arterioles. Conclusions are as follows: (1) The vasodilatory response of ENDO arterioles was even larger than that of EPI arterioles. Thus, the smaller flow reserve of ENDO arterioles may be caused by other factors, including the greater effects of myocardial compression and nitric oxide on the ENDO arterioles. (2) The vascular responses of ENDO and EPI arterioles were modulated by both endothelium-independent and -dependent vasodilative factors, and the effect of each factor including adenosine was associated with the effects of others.

Transient inhibition of glucose uptake mimics ischemic preconditioning by salvaging ischemic myocardium in the rabbit heart

The aim of this study was to test whether transient inhibition of glucose uptake could precondition the rabbit heart. Rabbit hearts experienced 30 min regional ischemia followed by either 120 min (isolated heart protocol) or 180 min (in situ protocol) reperfusion. Infarct size was determined by tetrazolium staining. In isolated heart experiments, 15 min perfusion with glucose-free Krebs buffer starting 30 min prior to ischemia significantly limited infarct size to 9.9 +/- 2.6% of the risk zone as compared with 29.4 +/- 1.7% infarction in controls. This protection could be blocked (30.8 +/- 3.4%) by polymyxin B (50 microM), a protein kinase C inhibitor, but not by 8-(p-sulfophenyl)theophylline, an adenosine receptor inhibitor, suggesting the mechanism was similar to that of ischemic preconditioning but without involvement of adenosine receptors. Pyruvate and acetate inhibit glucose uptake without incurring a metabolic deficit. When 20 mM pyruvate or 1 mM acetate was added to the glucose-containing buffer for 15 min prior to ischemia, protection was evident (12.0 +/- 3.0% and 10.0 +/- 3.7% infarction, respectively). However, when acetate (1 mM) was present in the perfusate throughout the experiment, neither omission of glucose nor addition of pyruvate caused protection (26.1 +/- 2.2% and 28.9 +/- 4.7% infarction, respectively). Furthermore, when in situ hearts which preferably utilize lipid substrates were treated with pyruvate (2 g/kg i.v. 20 min before ischemia), infarct size was 40.3 +/- 3.0%, which did not differ from that in untreated hearts (38.6 +/- 3.2%). Hence transient inhibition of glucose uptake can precondition the heart, but only if other substrates which are utilized in preference to glucose are absent.

[Thyroid hormones in patients with acute exacerbations of pneumoconiosis]

Thyroid hormone levels in serum were measured in 34 patients with acute exacerbations of pneumoconiosis. Levels of free T3 were below the normal range in 26 patients, and 12 of those patients (46.2%) died. Levels of free T3 were within the normal range in 8 patients, and only of those patients died. Having a T3 level within the normal range was associated with a good outcome. Levels of free T3 measured during acute exacerbations were significantly lower than those measured when the disease was clinically stable. Patients who died tended to have lower levels of free T3 than did those who survived. These results suggest that levels of free T3 in serum samples taken during an acute exacerbation can helpful in predicting the outcome of pneumoconiosis.

Functional analysis of the threonine- and serine-rich Gp-I domain of glucoamylase I from Aspergillus awamori var. kawachi

Glucoamylase I (GAI) from Aspergillus awamori var. kawachi hydrolyzes raw starch efficiently and is composed of three functional domains: the amino-terminal catalytic GAI' domain (A-1 to V-469), the threonine- and serine-rich O-glycosylated Gp-I domain (A-470 to V-514), and the carboxy-terminal raw starch-binding Cp domain (A-515 to R-615). In order to investigate the role of the Gp-I domain, an additional repeat of Gp-I and internal deletions of the entire Gp-I sequence or parts of the Gp-I sequence were introduced within Gp-I. All mutant genes as well as the wild-type gene were inserted into a yeast-secretion vector, YEUp3H alpha, and expressed in Saccharomyces cerevisiae. Wild-type GAI expressed in yeast cells (GAY), GAGpI, having an extra Gp-I, and GA delta 470-493, lacking the A-470-to-T-493 sequences of Gp-I, were successfully secreted into the culture medium. On the other hand, GA delta 470-507, lacking A-470 to S-507, and GA delta GpI, lacking the entire Gp-I (A-470-to-V-514) sequence, failed to be secreted and remained in the yeast cells. The carbohydrate content of GAGpI was 1.2 times higher than that of GAY and 2.4 times higher than that of the original GAI. The raw starch digestibility of GAGpI was almost the same as that of GAY but was 1.5 times faster than that of GAI.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoxia preconditions rabbit myocardium via adenosine and catecholamine release

It has been proposed that brief hypoxia can substitute for ischemia in the preconditioning of cardiac tissue and salvage of ischemic myocardium. To elucidate a possible mechanism isolated rabbit hearts were subjected to a 30-min period of regional ischemia by occluding a previously snared coronary artery. Following 2 h of reperfusion infarct size was measured by staining left ventricular slices with triphenyltetrazolium chloride. In control hearts infarction averaged 28.7 +/- 1.9% of the risk zone. If the hearts were preconditioned with 5 min global ischemia/10 min reperfusion prior to the regional ischemia, then infarction was significantly reduced to 7.2 +/- 2.0% (P < 0.01). When global hypoxia (pO2 of perfusate 42.0 +/- 2.1 mmHg) for ten min substituted for the five min period of global ischemia, protection was comparable to that observed after ischemic preconditioning (10.2 +/- 1.5% infarction, P< 0.01 v control). During hypoxic perfusion adenosine release increased 16-fold over baseline levels. This protection could not be blocked by adding levels either the adenosine antagonist 8-(p-sulfophenyl)theophylline or the alpha 1-adrenergic blocker phenoxybenzamine to the hypoxic perfusate. However, co-administration of both agents to the hypoxic perfusate successfully aborted protection (22.6 +/- 2.9% infarction, P N.S. v control). Therefore, 10 min of hypoxia releases both norepinephrine and adenosine in sufficient quantities such that either can completely precondition the heart.

Comparison of casual blood pressure and twenty-four-hour ambulatory blood pressure in high school students

OBJECTIVE

To perform ambulatory blood pressure monitoring (ABPM) in high school students and to compare the 24-hour values with casual blood pressure (BP).

METHODS

Ambulatory BP monitoring was carried out in 190 high school students, 15 or 16 years of age, with elevated casual BP during the first examination at school for hypertension; 66 had elevated casual BP at both the first and the second examinations (group H1), and 124 students were normotensive at the second examination (group H2). Sixty-two students who were consistently normotensive served as control subjects (group N). Average BPs for the 24-hour period, the awake period (10 AM to 10 PM), and the sleeping period (1 AM to 6 AM) were calculated.

RESULTS

Average BP for each period was significantly higher in group H1 than in group N. Average BP in group H2 for these periods was intermediate between those of group H1 and of group N. The casual BP had a significant positive correlation with the average BP during the awake period (r = 0.55, p < 0.01 for systolic BP; r = 0.37, p < 0.01 for diastolic BP). In most subjects the casual BP readings were higher than BP during ABPM.

CONCLUSIONS

Casual BP measurements correlated with 24-hour BP, but they tended to be higher than the measurements obtained during 24-hour ABPM.

Tumor necrosis factor alpha-induced up-regulation of interleukin-3 receptor mRNA expression in a CD34-positive hematopoietic cell line

Regulation of interleukin-3 receptor (IL-3R) gene expression by tumor necrosis factor alpha (TNF alpha) was investigated using an IL-3-dependent CD34-positive hematopoietic cell line (KMT2) and a human megakaryocytic cell line (CMK). KMT2 expressed IL-3R alpha-subunit mRNA, whereas the level of expression of IL-3R beta-subunit mRNA was low. CMK expressed IL-3R beta-subunit mRNA more strongly. The expression of IL-3R mRNA varied in the progenitor cells of different lineages. TNF alpha markedly enhanced expression of IL-3R beta-subunit mRNA in KMT2, whereas it only slightly augmented IL-3R alpha-subunit mRNA level. TNF alpha weakly augmented IL-3R mRNAs in CMK. However, the enhancement of IL-3R beta-subunit mRNA in CMK was hardly detectable. The effects of TNF alpha on IL-3R mRNA expression were completely different in a primitive and in a more committed hematopoietic cell line. Addition of TNF alpha to KMT2 resulted in increased numbers of IL-3R on the cell surface without increased IL-3R affinity. The combination of IL-3 with TNF alpha abolished TNF alpha-induced inhibition of proliferation of KMT2. These results indicate that TNF alpha modulates the IL-3-responsiveness of primitive hematopoietic cells through up-regulation of the expression of IL-3R mRNAs, especially that of IL-3R beta-subunit mRNA. Phorbol ester (TPA) enhanced the IL-3R mRNA expression in KMT2.(ABSTRACT TRUNCATED AT 250 WORDS)

A bioassay for bovine interleukin-1 by the A375 cell growth inhibition

Usefulness of a human melanoma cell line A375 was evaluated for detecting bovine interleukin-1 (IL-1). The A375 cell growth was inhibited by culture supernatant of lipopolysaccharide-stimulated bovine peripheral blood mononuclear cells (LPSsup) in a dose dependent manner. A mixture of anti-human IL-1 alpha and beta antibodies suppressed 60% of this inhibitory activity and was confirmed to bind to about 23 k dalton peptides in the LPSsup by Western blotting. Although serum and bronchoalveolar lavage fluid from a healthy cow showed a low inhibitory activity, those from pneumonic cows showed the higher activities. These activities were also suppressed by anti-human IL-1 antibodies. These findings show the A375 cell growth inhibition assay can be a useful bioassay for bovine IL-1 (like) activity.