Galactosamine alters glucose regulation in ten-day-old rats treated with a low dose of endotoxin

Hypoglycemia develops rapidly during septic shock and is a common and life-threatening problem in the human newborn. In adult animals, galactosamine alter glucose metabolism and increases mortality of endotoxic shock. Galactosamine may alter tissue glucose uptake and induce hypoglycemia in ten-day-old rats. The present study showed that galactosamine induced hypoglycemia and a high mortality without an increase in plasma insulin concentration in ten-day-old rats treated with a low dose of endotoxin. Galactosamine decreased tissue glucose uptake in endotoxin-treated animals. Hypoglycemia induced by galactosamine could be due to decreased gluconeogenesis.

Oxygen intake efficiency slope: a new index of cardiorespiratory functional reserve derived from the relationship between oxygen consumption and minute ventilation during incremental exercise

We investigated the usefulness of the oxygen intake efficiency slope (OIES) as a submaximal measure of cardiorespiratory functional reserve. OIES was derived from the relationship between oxygen consumption (VO2; ml/min) and minute ventilation (VE; l/min) during incremental exercise, which was determined by the following equation: VO2 = a logVE + b, where "a" represents OIES, which shows the effectiveness of ventilation. Maximal oxygen consumption (VO2max) is effort-dependent. There is no standard submaximal measurement of cardiorespiratory reserve that provides generally acceptable results. Exercise tests were performed by 17 normal volunteers on an ergometer using a symptom-limited Ramp protocol. Expired gas was continuously analyzed. OIES was calculated using the first 75%, 90%, and 100% of exercise data. We also determined the following submaximal parameters: the ventilatory anaerobic threshold (VAT), the slope of the minute ventilation-carbon dioxide production relationship (VE-VCO2 slope), and the extrapolated maximal oxygen consumption (EMOC). We analyzed the relationship between OIES, other submaximal parameters and VO2max, and examined the effects of submaximal exercise on OIES. The correlation coefficient of the logarithmic curve-fitting model was 0.991 +/- 0.006. OIES and VO2max were significantly correlated (r = 0.966, p < 0.0001). The correlation between OIES and VO2max was stronger than the correlation between VO2max and VAT, the VE-VCO2 slope and EMOC. OIES values for 100% and 90% of exercise were identical; OIES for 75% of exercise was slightly lower (3%). Our results suggested that OIES may provide an objective, effort-independent estimation of cardiorespiratory functional reserve.

Prolonged survival of rat hepatic allografts pretreated with a single donor-specific blood transfusion: the distribution of donor cells expressing class I major histocompatibility complex antigens in the recipient

We previously reported that a pretransplant transfusion of either ACI strain rat donor blood or PVG.r1 strain blood, which shares only the RT1.A class I major histocompatibility complex (MHC) region with an ACI donor, significantly prolonged the survival of ACI-to-LEW rat hepatic allografts, suggesting that the class I MHC antigens can be immunosuppressive in rat hepatic allografts. The distribution of the donor cells expressing RT1.Aa class I MHC antigens in the recipients was investigated using a MN4-91-6 mouse anti-rat class I (RT1.Aa) MHC monoclonal antibody. The donor class I MHC-positive cells accumulated mainly in the splenic white pulp and lymph nodes at 12 and 24 hr after blood transfusion, while very few cells were seen in the thymus, liver, lungs, and kidneys. The number of cells began to decrease in the splenic white pulp and lymph nodes at 24 hr after transfusion. This may indicate the destruction of donor cells by the recipient cells. Within 48 hr after transfusion, most cells disappeared from the recipient tissue. In an attempt to study the role of the spleen in inducing immunological unresponsiveness, a splenectomy was performed at the time of transplantation and this abrogated the prolongation of hepatic allograft survival in the recipients which received the donor blood. These findings suggest that the presence of class I MHC-positive cells in the splenic white pulp, a T-dependent area, may play an important role in inducing immunological unresponsiveness.

Evaluation of intramyocardial coronary blood flow waveform during intraaortic balloon pumping in the absence or presence of coronary stenosis

Our aim was to evaluate the effects of intraaortic balloon pumping (IABP) on the blood velocity waveform in the absence or presence of coronary artery stenosis. Using anesthetized open-chest dogs, the septal arterial blood flow velocities were measured with a 20 MHz 80-channel ultrasound pulsed Doppler velocimeter in the absence (n = 5) or presence (n = 3) of left main coronary artery stenosis. The blood velocity waveform was analyzed by calculating the systolic retrograde velocity integral (SR) and the diastolic antegrade velocity integral (DA). A slosh ratio was defined as SR/DA. The left anterior descending arterial flow (CBF), aortic pressure (AoP), and poststenotic distal coronary pressure (DiP) were also measured simultaneously. We compared the effect of IABP on the velocity waveforms in the absence and in the presence of coronary artery stenosis. In the absence of stenosis, IABP increased DiP during diastole and augmented DA while it also increased SR. IABP augmented the net CBF because of the greater increase in DA than SR. In the presence of stenosis, however, IABP did not increase DiP and resulted in no significant effect on the net CBF.

[Clinical characteristics and genetic background of secondary amyloidosis associated with rheumatoid arthritis in Japanese]

In order to examine the clinical characteristics and genetic background of secondary amyloidosis associated with rheumatoid arthritis, we analyzed clinical features and HLA typing of 85 patients in a multicenter study. Eighty-five patients with secondary amyloidosis associated RA were studied. The diagnosis of secondary amyloidosis were made on histological findings by biopsy or autopsy. The most common biopsy site was gastrointestinal tract (79.5%). Clinical symptom and the frequency at the time of diagnosis were; diarrhea (35 cases), abdominal pain (22 cases) and vomiting and nausea (16 cases). Abnormalities and the frequency in a laboratory test included proteinuria (49 cases), increased serum creatinine (32 cases), anemia (30 cases) and hematuria (15 cases). Twenty-eight patients were dead and 57 patients were alive at the time of the study. The average duration between diagnosis of amyloidosis and death was 19.4 +/- 18.5 (SD) months among the dead patients. The average duration after diagnosis of amyloidosis was 24.2 +/- 19.5 (SD) months in surviving patients. The causes of death were renal failure complicated with heart failure (6 patients), heart failure alone (3 patients) and renal failure alone (2 patients). Fifty-nine patients in the control group who were negative to amyloid deposition on biopsies at more than one site in the gastrointestinal tract, were clinically compared with patients in the amyloidosis group. No difference were noted in the age of RA occurrence and the stage between the two groups. As to the class, however, the number of patients with severe functional disorder (class 3 or severe) was larger in the amyloidosis group. There were no significant difference between the two groups in Lansbury's activity index. On hematology, biochemistry and urinalysis, the incidences of increased white blood cell count, anemia, increased platelet count, increased serum creatinine, hypoproteinemia, hypoalbuminemia, increased IgA, and increased urine and blood BMG were statistically significantly higher in the amyloidosis group than in the control group. HLA-A, -B, -C, and DR-locus antigens were compared in the 53 patients in the amyloidosis group and in the 59 subjects in the control group. There were no significant differences in frequency of HLA-A, and -B antigens between two groups. Frequency of CW7 antigen was significantly decreased in the amyloidosis group (13.2%) than in the control group (39.0%). Frequency of DR1 antigen was decreased in the amyloidosis group (3.8%) than in the control group (22.0%), although the difference was not significant. These findings suggest the possible involvement of genetic factors in the occurrence of amyloidosis. It is suggested that the occurrence of amyloidosis is suppressed by some genes which are linked with CW7 antigen.

Microheterogeneity of myocardial blood flow in rabbit hearts during normoxic and hypoxic states

The goal of this study was to evaluate microheterogeneity of myocardial blood flow and its dependence on arterial O2 tension (PaO2). We measured within-layer distribution of regional blood flows in the left ventricles of anesthetized rabbits in both normoxic and hypoxic states with myocardial region sizes in the range of 0.01-1.0 mm2. A novel method of digital radiography combined with the technique of 3H-labeled desmethylimipramine deposition enabled us to visualize and accurately quantitate regional blood flow at such high levels of resolution. To analyze myocardial blood flow patterns, we computed the coefficient of variation (CV) and the correlation between adjacent regional flows (CA). The CA values were larger in the hypoxic state (PaO2 = 26 +/- 5 mmHg) than in the normoxic state (PaO2 = 97 +/- 20 mmHg) at all levels of resolution (P < 0.001). In the normoxic state, there was a transmural difference in CA (P < 0.001); CA increased with depth of the left ventricle (from subepicardium to subendocardium). However, the relation between CA and the depth of the left ventricle was not statistically significant in the hypoxic state. The CV values were smaller in the hypoxic state than in the normoxic state at all levels of resolution (P < 0.001). When the degree of resolution was reduced from 0.01 to 1.0 mm2, CV decreased by 75% in the normoxic and by 69% in the hypoxic state. Thus we conclude that 1) the decrease in PaO2 increases similarity of blood flows in nearby regions and decreases myocardial blood flow heterogeneity, and 2) similarity of regional blood flows increases with depth of the left ventricle in the normoxic state, but this transmural difference disappears in the hypoxic state.

The F(ab')2 fragment of an anti-ICAM-1 monoclonal antibody attenuates liver injury after orthotopic liver transplantation

Long-term storage of liver grafts results in increased adhesion of leukocytes onto the sinusoidal walls. This eventually leads to posttransplant graft damage through disturbances of hepatic microcirculation. Intracellular adhesion molecule-1 (ICAM-1) is known to be involved in attachment of leukocytes. This study was designed to examine whether ICAM-1 participated in the pathogenesis of posttransplant liver injury. Inbred Lewis rats were used as both donors and recipients to avoid immunoreactivity. Donor livers were stored for either 1 or 6 hr in ice-cold Euro-Collins solution and subsequently implanted. Expression of ICAM-1 was examined immunohistochemically. In some rats that received livers stored for 6 hr, the intact IgG (1.0 mg/kg) or the F(ab')2 fragment (0.5 mg/kg) of an anti-ICAM-1 mAb (1A29) was administered via the tail vein immediately after reperfusion of portal blood. In the group receiving livers stored for 6 hr, ICAM-1 began to be expressed on the sinusoidal endothelial cells as early as 15 min after reperfusion of the portal blood. Strong ICAM-1 expression was observed from 2 hr up to 24 hr after reperfusion. In contrast, expression of ICAM-1 was not evident at any time point after surgery in the 1-hr storage group as well as in untransplanted, normal livers. Serum alanine aminotransferase (ALT) levels were significantly higher in the 6-hr storage group compared with those of the 1-hr storage group (1-hr: 171 +/- 9 IU/L; 6-hr: 825 +/- 109 IU/L, P < 0.05; mean +/- SEM) 24 hr after transplantation. Serum ALT levels were markedly reduced by treatment with the F(ab')2 fragment of 1A29 (247 +/- 34 IU/L, P < 0.05 vs. 6-hr storage group). This was associated with reduced accumulation of leukocytes in the liver. In marked contrast, treatment with the intact IgG of 1A29 increased serum ALT levels dramatically (5297 +/- 634 IU/L, P < 0.05 vs. 6-hr storage group) and reduced serum complement. Histological examination revealed focal hepatocellular necrosis 24 hr after surgery in the 6-hr storage group. Treatment with the F(ab')2 fragment decreased the liver damage; in marked contrast, treatment with the intact IgG strikingly aggravated the injury, as characterized by massive necrosis throughout the liver. Liver damage caused by the intact IgG might be related to activation of the complement system by the Fc portion of the antibody. Taken together, these results indicate that ICAM-1 is involved in the mechanism of postoperative liver injury following liver transplantation.

Suppression of hepatic allograft rejection in the rat by mitomycin C-treated donor splenocytes: in situ splenic distribution of donor class I major histocompatibility complex antigen-positive cells in the recipient

A single intravenous injection of 3 x 10(6) donor splenocytes treated with mitomycin C (MMC) 7 days before hepatic transplantation prolongs survival of hepatic allografts in the ACI(RT1a) to LEW(RT1(1)) rat combination. This effect is donor specific. The in situ distribution in the recipient of the donor cells administered preoperatively was investigated using intracellularly fluorescence-labeled donor splenocytes. The donor cells were accumulated mainly in the splenic white pulp and lymph nodes at 12 and 24 hr after injection. Contrarily, very few cells were seen in the thymus, liver, kidney, and lung. The number of cells with dull and weak fluorescence began to increase in the splenic white pulp and lymph nodes at 24 hr after injection. This may indicate the breakdown of donor cells by recipient cells. In contrast, a number of donor cells could be detected even after 48 hr and a few cells at 7 days after splenocyte injection in the LEW-to-LEW isogeneic combination. As we previously revealed the role of class I major histocompatibility complex (MHC) antigens in prolonging hepatic allograft survival in the rat, the splenic distribution of donor class I MHC-positive cells in the recipient after intravenous administration of MMC-treated donor splenocytes was studied using immunostaining with a MN4-91-6 mouse anti-rat RT1.Aa class I MHC monoclonal antibody. The donor class I-positive cells accumulated mainly in the splenic white pulp at 12 and 24 hr after injection. This is similar to that observed in the fluorescence study. Within 48 hr after injection, most cells had disappeared from the recipient tissue. These findings suggest that the splenic white pulp, a T-dependent area, may play an important role in inducing immunological unresponsiveness.

Cytokine production by SV40-transformed adherent synovial cells from rheumatoid arthritis patients

We examined the mRNA levels for various cytokines, including IL-1 alpha, IL-1 beta, TNF alpha, TGF-beta 1, GM-CSF, IL-6, IL-8, bFGF, PDGF-A, PDGF-B and IL-1ra, and IL-1 beta converting enzyme, and the protein levels of some of these cytokines in 19 SV40-transformed synovial cell clones. Among those tested, the mRNA levels for IL-6, bFGF and PDGF-A in rheumatoid arthritis (RA) cell clones were greater than those in non-RA cell clones. Moreover, except for one osteoarthritis (OA) cell clone, the mRNA levels for IL-8 in RA cell clones were also greater than those in non-RA cell clones. Although the protein levels were not always correlated with the mRNA levels, the exception being the same OA cell clone, the protein levels of cytokines, such as IL-1 alpha, IL-1 beta, IL-6 and IL-8, in RA cell clones were greater than those in non-RA cell clones. TNF-a was not detected in any cells tested at either the mRNA or the protein level. TNF-alpha upregulated the expression of GM-CSF mRNA in both RA cell clones and one OA cell clone, but not in the other OA cell clone or the normal cell clone. Taken together, these SV-40 transformed synovial cell clones retained many of the original characteristics in terms of cytokine production.

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.