IL-6 induction of protein-DNA complexes via a novel regulatory region of the inducible nitric oxide synthase gene promoter: role of octamer binding proteins

Macrophage inducible nitric oxide synthase (iNOS) catalyzes the synthesis of NO. IL-6-stimulated macrophage differentiation of murine myeloid M1 cells is accompanied by iNOS gene induction and steady-state mRNA expression. Two regions within the iNOS promoter mediate transcriptional responsiveness to LPS and IFN-gamma. Region I contains several essential transcription factor binding motifs and promotes responsiveness to LPS, whereas region II potentiates the LPS response by IFN-gamma. Because region I possesses basal promoter activity and directly mediates iNOS gene activation, we attempted to identify the trans-acting factors involved in IL-6-stimulated induction of the murine iNOS gene through this region. Using an electrophoretic mobility shift assay and methylation interference, we show that IL-6 induced reciprocal changes in the binding activity of POU family members to the candidate nonconsensus octamer sequence of region I that correlated, temporally, with iNOS steady-state mRNA expression. Although DNA-protein binding activity of IL-6-stimulated whole-cell extracts also interacted with a radiolabeled canonical octamer motif, such DNA-protein complexes were not eliminated in competition assays using consensus nuclear factor kappaB or IL-6 oligonucleotides. Specifically, our studies show that octamer binding protein-1-related protein binding activity decreased, while binding of octamer binding protein-2-related proteins increased during differentiation. Mutation of the octamer motif disrupted both binding of the IL-6-induced protein-DNA interactions and transcriptional activation through region I, revealing that this motif is absolutely essential for IL-6 induction of iNOS. Thus, differential activation of octamer binding transcriptional modulators from the POU family may be a novel mechanism of IL-6-mediated iNOS gene regulation.

IL-6 induction of protein-DNA complexes via a novel regulatory region of the inducible nitric oxide synthase gene promoter: role of octamer binding proteins

Macrophage inducible nitric oxide synthase (iNOS) catalyzes the synthesis of NO. IL-6-stimulated macrophage differentiation of murine myeloid M1 cells is accompanied by iNOS gene induction and steady-state mRNA expression. Two regions within the iNOS promoter mediate transcriptional responsiveness to LPS and IFN-gamma. Region I contains several essential transcription factor binding motifs and promotes responsiveness to LPS, whereas region II potentiates the LPS response by IFN-gamma. Because region I possesses basal promoter activity and directly mediates iNOS gene activation, we attempted to identify the trans-acting factors involved in IL-6-stimulated induction of the murine iNOS gene through this region. Using an electrophoretic mobility shift assay and methylation interference, we show that IL-6 induced reciprocal changes in the binding activity of POU family members to the candidate nonconsensus octamer sequence of region I that correlated, temporally, with iNOS steady-state mRNA expression. Although DNA-protein binding activity of IL-6-stimulated whole-cell extracts also interacted with a radiolabeled canonical octamer motif, such DNA-protein complexes were not eliminated in competition assays using consensus nuclear factor kappaB or IL-6 oligonucleotides. Specifically, our studies show that octamer binding protein-1-related protein binding activity decreased, while binding of octamer binding protein-2-related proteins increased during differentiation. Mutation of the octamer motif disrupted both binding of the IL-6-induced protein-DNA interactions and transcriptional activation through region I, revealing that this motif is absolutely essential for IL-6 induction of iNOS. Thus, differential activation of octamer binding transcriptional modulators from the POU family may be a novel mechanism of IL-6-mediated iNOS gene regulation.

[Deviation of size-exclusion chromatographic behavior of tryptophan on TOYOPEARL HW-40S column]

A deviation of size-exclusion chromatographic behavior of amino acids on TOYOPEARL HW-40S column is reported. On the column 18 amino acids were not eluted in the same fraction in the total volume, but separated into 5 fractions with tryptophan as the last one far behind the total volume. Interaction between tryptophan and the matrices was investigated under different conditions in order to elucidate the chemical nature of the deviation. It was found that addition of trifluoroacetic acid and sodium chloride of high concentration in mobile phase, dramatically increased the retention time of trypophan, while addition of acetonitrile, sodium chloride of lower concentration and the hydrogen bond breaker urea reduced the interaction. It is concluded that adsorption of tryptophan on TOYOPEARL HW-40S is basically due to the hydrophobic nature with limited influence of hydrogen bond and ionic interaction. The former factor can be eliminated by keeping acentonitrile concentration over 50% (V/V), while the latter two can be reduced to the minimum by adding 0.17mol/L sodium chloride and 3.51mol/L urea. The results not only lead to better understanding of size-exclusion chromatography of this matrices, but also help to apply hydrophobic chromatography of this matrices to the isolation of amino acids and peptides.

Imaging of pediatric liver tumors

Primary pediatric liver tumors are a unique group of neoplasms. The age at presentation, clinical sigma symptoms, and imaging characteristics provide helpful clues in making a prospective diagnosis and in tailoring a differential diagnosis. The role of imaging is fourfold: characterization, localization, determination of resectability, and follow-up use. MR is usually complementary to ultrasound and CT.

Chemokine receptor usage by human eosinophils. The importance of CCR3 demonstrated using an antagonistic monoclonal antibody

Chemokines bind and signal through G-protein coupled seven transmembrane receptors. Various chemokine receptors are expressed on leukocytes, and these may impart selective homing of leukocyte subsets to sites of inflammation. Human eosinophils express the eotaxin receptor, CCR3, but respond to a variety of CC chemokines apart from eotaxin, including RANTES, monocyte chemotactic protein (MCP)-2, MCP-3, and MCP-4. Here we describe a mAb, 7B11, that is selective for CCR3 and has the properties of a true receptor antagonist. 7B11 blocked binding of various radiolabeled chemokines to either CCR3 transfectants, or eosinophils. Pretreatment of eosinophils with this mAb blocked chemotaxis and calcium flux induced by all CCR3 ligands. In all individuals examined, including allergic and eosinophilic donors, > 95% of the response of eosinophils to eotaxin, RANTES, MCP-2, MCP-3, and MCP-4 was shown to be mediated through CCR3. The IL-8 receptors, particularly CXCR2, were induced on IL-5 primed eosinophils, however these eosinophils responded to CC chemokines in the same manner as unprimed eosinophils. These results demonstrate the importance of CCR3 for eosinophil responses, and the feasibility of completely antagonizing this receptor.

Treatment of cat allergy with T-cell reactive peptides

We induced in allergic humans the counterpart of murine experimental T-cell tolerance. T-cell lines from cat-allergic humans were used to map T-cell epitopes for the principal allergen of cat dander, Fel d 1. Two peptides of 27 amino acids each were synthesized to contain the dominant epitopes (ALLERVAX CAT). After a safety trial, we carried out a blinded study of the dose required for efficacy. We randomly divided 95 cat-sensitive patients into placebo, 7.5 micrograms, 75 micrograms, and 750 micrograms groups. Patients received a subcutaneous injection weekly for 4 wk. Before and after treatment, patients were exposed in a room inhabited by live cats and scored by nose and lung symptoms. Baseline nasal and lung scores (+/-SEM) were 6.2 +/- 0.56 and 5.4 +/- 0.73 in the 750 micrograms group; 7.8 +/- 0.53 and 4.7 +/- 0.68 in the placebo group. Six weeks after treatment, scores adjusted for baseline differences were reduced in the 750 micrograms group: -2.3 +/- 4.9 and -2.3 +/- 0.59 compared with -0.84 +/- 0.50 and -0.85 +/- 0.62 in the placebo group. The 75 micrograms group showed intermediate effects and the 7.5 micrograms group no effect. Linear trend analysis indicated a significant dose response effect: p = 0.05 for nose and 0.03 for lung symptoms. Allergic side effects occurred an hour or more after the first 750 micrograms dose in 16 of 24 patients but required little or no treatment with one exception. T-cell reactive treatment peptides safely improved allergic responses to cats.

Increased airway resistance due to surfactant dysfunction can be alleviated with aerosol surfactant

To investigate the contribution of pulmonary surfactant to a low airflow resistance through narrow conducting airways, a system was developed with which it was possible to determine the resistance meeting a steady flow of air at 0.5 mL/min. The airflow, delivered by an infusion pump, entered the extreme periphery of a conducting airway in an excised rat lung and exited through the trachea. The resistance was determined by measuring the pressure of the air entering the lung. If the airway remained open, the pressure was only slightly above zero; when a blocking liquid column formed in the lumen of the airway, the pressure increased rapidly but dropped abruptly as the liquid was pushed away into a wider airway section. When endogenous pulmonary surfactant was removed with a saline lavage, the airway was blocked almost constantly by an endless re-formation of liquid columns. Consequently, during a 4-min period of pressure recording, free airflow was observed only rarely. However, administration of aerosol surfactant increased the duration of free airflow in relation to the volume administered. After an injection of 80 mL of aerosol surfactant, the airway stayed open 89 +/- 3% of the 4-min recording time compared with only 28 +/- 5% when the same volume of air (80 mL) without surfactant had passed through the airway (p < 0.0001). We conclude that surfactant contributes to a free airflow through conducting airways and may have an important role in the maintenance of low airway resistance.

GRB2 and SH-PTP2: potentially important endothelial signaling molecules downstream of the TEK/TIE2 receptor tyrosine kinase

TEK is a newly cloned receptor tyrosine kinase that is expressed predominantly in the endothelium of actively growing blood vessels. Disruption of TEK function in transgenic mice results in a profound defect in vascular development leading to embryonic lethality. These studies show that TEK signaling is indispensable for the development of the embryonic vasculature and suggest that TEK signaling may also be required for the development of the tumor vasculature. Because the ligand for TEK has not been identified, it has been difficult to study signal transduction by this important endothelial receptor. To circumvent this problem, a soluble TEK kinase domain (GTEKH) was developed which could be easily purified, autophosphorylated, and radiolabeled. Using the autophosphorylated, radiolabeled GTEKH to probe a mouse embryo expression library only two candidate signaling molecules were isolated, SH-PTP2 and GRB2. Autophosphorylated GTEKH associated with GRB2 and SH-PTP2 from endothelial lysates and not with PI3 kinase or PLC gamma. The association of GRB2 and SH-PTP2 with TEK was highly dependent on specific tyrosine residues in the TEK c-tail. These studies identify GRB2 and SH-PTP2 as potentially important mediators of TEK signaling that may trigger crucial endothelial responses during embryonic vascular development and during pathologic vascular growth.

A membrane proximal domain of the human interleukin-3 receptor beta c subunit that signals DNA synthesis in NIH 3T3 cells specifically binds a complex of Src and Janus family tyrosine kinases and phosphatidylinositol 3-kinase

The high affinity human interleukin-3 receptor is a heterodimeric protein consisting of an alpha and beta c subunit. The beta c subunit is responsible for receptor signal transduction. We have shown that a membrane proximal domain of the cytoplasmic tail of the human beta c subunit (amino acids 451-517) is minimally required for human IL-3 to signal DNA synthesis in quiescent transfected NIH 3T3 cells. Glutathione S-transferase (GST) fusion proteins of this 451-517 region and another region 451-562 that includes an acidic domain previously shown in other receptors to bind Src family kinases were constructed. Purified Lyn and Lck kinase, but not Fes, could phosphorylate tyrosines in both domains. Adsorption with lysates from the human IL-3-dependent hematopoietic cell line (TF-1) or 3T3 cells and in vitro phosphorylation showed that both these domains were intensely phosphorylated. Phosphoamino acid analysis, however, revealed that the majority of phosphorylation was on serine and threonine rather than tyrosine. Adsorption of these domains with 3T3 or TF-1 cell lysates, followed by immunoblotting, showed that cytoplasmic tyrosine kinases Lyn, Fes, and JAK-2 could also stably associate with both domains; however, Src family kinases are more strongly recognized by both regions than JAK-2 kinase. In addition, phosphatidylinositol 3-kinase from cell lysates was also found stably associated with these domains, but GTPase activating protein, Vav, Sos1, or Grb2 were not.

Human IL-3 receptor signaling: rapid induction of phosphatidylcholine hydrolysis is independent of protein kinase C but dependent on tyrosine phosphorylation in transfected NIH 3T3 cells

Although tyrosine kinases are clearly activated after ligand engagement of the human IL-3R in both hematopoietic and nonhematopoietic cytoplasmic environments, a role for phospholipid hydrolysis and protein kinase C in IL-3R signal transduction is emerging. We have used NIH 3T3 cells transiently transfected with human IL-3R alpha- and beta-subunits to study phosphatidylcholine hydrolysis in response to human IL-3. We have found that NIH 3T3 cells expressing the complete human IL-3R respond to human IL-3 with a rapid and sustained increase in sn-1'2'-diacylglycerol. Accompanying this was a rapid increase in intracellular levels of phosphorylcholine. The protein kinase C inhibitor H-7, however, was not effective in inhibiting phosphatidylcholine hydrolysis in response to human IL-3 in NIH 3T3 cells expressing the human receptor. Thus the human IL-3R induces a rapid protein-kinase-C-independent hydrolysis induced by the murine receptor. Simultaneous with the increase in phosphatidylcholine hydrolysis induced by the murine receptor. Simultaneous with the increase in diacylglycerol levels was an increase in membrane-bound protein kinase C enzyme activity. Immunoblotting with isoform-specific Abs against protein kinase C showed that, whereas the zeta-isoform is constitutively membrane bound, the alpha-isoform of protein kinase C is translocated to the membrane in response to IL-3. Activation of phosphatidylcholine hydrolysis and protein kinase C activation required both alpha- and beta-receptor subunits. To determine the relationship of tyrosine phosphorylation to the activation of phosphatidylcholine hydrolysis and protein kinase C translocation, we used the specific and structurally unrelated tyrosine kinase inhibitors genistein and herbimycin. Both inhibitors effectively blocked human IL-3-induced tyrosine phosphorylation. In addition, both inhibitors blocked phosphatidylcholine hydrolysis and protein kinase C translocation. These data, combined with our previous report showing that c-jun induction by IL-3 is dependent on protein kinase C, suggest that, in hematopoietic and nonhematopoietic cells expressing the human IL-3R, phosphatidylcholine hydrolysis and protein kinase C are downstream effectors of tyrosine phosphorylation in the IL-3 signal transduction cascade resulting in immediate early response gene induction.

Human IL-3 receptor signaling: rapid induction of phosphatidylcholine hydrolysis is independent of protein kinase C but dependent on tyrosine phosphorylation in transfected NIH 3T3 cells

Although tyrosine kinases are clearly activated after ligand engagement of the human IL-3R in both hematopoietic and nonhematopoietic cytoplasmic environments, a role for phospholipid hydrolysis and protein kinase C in IL-3R signal transduction is emerging. We have used NIH 3T3 cells transiently transfected with human IL-3R alpha- and beta-subunits to study phosphatidylcholine hydrolysis in response to human IL-3. We have found that NIH 3T3 cells expressing the complete human IL-3R respond to human IL-3 with a rapid and sustained increase in sn-1'2'-diacylglycerol. Accompanying this was a rapid increase in intracellular levels of phosphorylcholine. The protein kinase C inhibitor H-7, however, was not effective in inhibiting phosphatidylcholine hydrolysis in response to human IL-3 in NIH 3T3 cells expressing the human receptor. Thus the human IL-3R induces a rapid protein-kinase-C-independent hydrolysis induced by the murine receptor. Simultaneous with the increase in phosphatidylcholine hydrolysis induced by the murine receptor. Simultaneous with the increase in diacylglycerol levels was an increase in membrane-bound protein kinase C enzyme activity. Immunoblotting with isoform-specific Abs against protein kinase C showed that, whereas the zeta-isoform is constitutively membrane bound, the alpha-isoform of protein kinase C is translocated to the membrane in response to IL-3. Activation of phosphatidylcholine hydrolysis and protein kinase C activation required both alpha- and beta-receptor subunits. To determine the relationship of tyrosine phosphorylation to the activation of phosphatidylcholine hydrolysis and protein kinase C translocation, we used the specific and structurally unrelated tyrosine kinase inhibitors genistein and herbimycin. Both inhibitors effectively blocked human IL-3-induced tyrosine phosphorylation. In addition, both inhibitors blocked phosphatidylcholine hydrolysis and protein kinase C translocation. These data, combined with our previous report showing that c-jun induction by IL-3 is dependent on protein kinase C, suggest that, in hematopoietic and nonhematopoietic cells expressing the human IL-3R, phosphatidylcholine hydrolysis and protein kinase C are downstream effectors of tyrosine phosphorylation in the IL-3 signal transduction cascade resulting in immediate early response gene induction.

Upregulation of NF-kappa B-dependent gene expression mediated by the p75 tumor necrosis factor receptor

Tumor necrosis factor (TNF-alpha) interacts with two transmembrane receptor proteins, p55TNFR and p75TNFR, which are members of a family of cell surface molecules that include the Fas antigen, CD27, CD30, CD40, OX40, a Shope fibroma viral protein, and the low-affinity p75 neurotrophin receptor. Although the p55 TNF receptor has been shown to be primarily responsible for the biologic responses of TNF-alpha, the exact involvement of the p75 TNF receptor in signaling events is unclear. Here we show that expression of a human cDNA clone for p75 in COS-1 and 3T3 cells results in the constitutive activation of an TNF-inducible NF-kappa B-containing promoter. Analysis of a number of chimeric p75 receptor cDNA constructs further suggests that this activity requires the cytoplasmic domain of the p75 receptor. These results therefore indicate that the p75 TNF receptor is capable of mediating signal transduction.

Left ventricular function and coronary artery disease progression early after coronary bypass grafting

To investigate the effects of coronary artery disease progression on left ventricular function in patients who suffer angina early after coronary artery bypass grafting, we studied the progression of coronary stenoses, the occurrence of graft occlusions, and measured left ventricular ejection fraction (regional and global) in 34 consecutive patients who underwent repeat angiography 25.2 +/- 3.5 (standard error of the mean) months postoperatively, from a total population of 550 patients who underwent bypass grafting. Resting left ventricular function and stenosis severity were assessed using a computerized, quantitative analysis system. Coronary stenosis progression was defined as an increase in the percentage of the stenotic occlusion by 30% or more, any increase in lesion severity that resulted in total coronary artery occlusion, or the occurrence of a new stenosis that occluded the artery by 50% or more. Group 1 comprised 21 patients with all grafts patent and group 2 comprised 13 patients with one or more grafts occluded (20 of 34 grafts). Coronary artery disease progressed in all patients in group 1, and this involved 22 of 54 (41%) grafted vessels and 3 of 15 (20%) nongrafted vessels (p < 0.05). Coronary artery disease progressed in 11 patients in group 2, involving 15 of 32 (47%) grafted vessels and 1 of 6 (17%) nongrafted vessels (p < 0.01). An increased collateral circulation was observed in both groups. The left ventricular ejection fraction remained unchanged in both groups (group 1, 0.60 +/- 0.03 versus 0.62 +/- 0.03; group 2, 0.62 +/- 0.05 versus 0.62 +/- 0.04 before and after bypass, respectively; p = not significant) and there was no difference between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Human interleukin-3 stimulates a phosphatidylcholine specific phospholipase C and protein kinase C translocation

Human interleukin-3 binds to a high affinity receptor composed of alpha- and beta-subunits. The beta-subunit is responsible for signal transduction but does not contain any intrinsic tyrosine kinase activity or other consensus motifs related to intracellular signaling. Previous work using IL-3 dependent MO7E cells has suggested a major role only for non-receptor tyrosine kinase activation in IL-3 signal transduction. We have shown, however, that engagement of the human interleukin-3 receptor induces the translocation of protein kinase C from the cytosol to the cell membrane in MO7E cells. This translocation is accompanied by rapid (2-5 min) accumulation of 1'2'-diacylglycerol (twice control values) in the absence of an increase in intracellular Ca2+. Prelabeling cells with [3H]glycerol or [3H]-choline demonstrated rapid release of [3H]phosphorylcholine and a decrease in [3H]glycerol-labeled phosphatidylcholine in response to IL-3 stimulation. In addition, IL-3 did not induce phosphatidic acid accumulation, and the IL-3 induced diacylglycerol accumulation was blocked by p-bromophenacylbromide (a phospholipase C inhibitor). It is thus likely that interleukin-3 is activating a phosphatidylcholine specific phospholipase C rather than a phospholipase D. Finally, genistein and herbimycin, specific tyrosine kinase inhibitors, inhibited both IL-3 induced protein kinase C translocation and the accumulation of diacylglycerol. Thus, IL-3 induced tyrosine phosphorylation may result in activation of a phosphatidylcholine phospholipase C and protein kinase C.

Neisseria gonorrhoeae possesses two nicotinamide adenine dinucleotide-independent lactate dehydrogenases

An important metabolic capability of Neisseria gonorrhoeae is the utilization of host-derived lactate. Two isoenzymes of the membrane-associated, pyridine dinucleotide-independent type of lactate dehydrogenase (iLDH) participate in lactate assimilation, but exhibit distinctive properties. Isoenzyme iLDH-I utilized lactate exclusively as substrate, exhibiting a preference for the D-isomer. In contrast, isoenzyme iLDH-II exhibited broad substrate specificity (lactate, phenyllactate, and 4-hydroxyphenyllactate), but was stereospecific for the L-isomers. These results explain the difficulty in isolating mutants unable to utilize lactate.

Interleukin-3 inhibits cycloheximide induction of C-jun mRNA in human monocytes: possible role for a serine/threonine phosphatase

Cycloheximide is a strong inducer of the c-jun protooncogene mRNA at concentrations (< or = 50 ng/ml) that do not inhibit protein synthesis in human monocytes. This induction is transient lasting 30-60 min in contrast to the sustained induction obtained with concentrations that inhibit protein synthesis. The pluripotent colony stimulating factor interleukin-3 (IL-3) (10 ng/ml) is also a modest inducer of the c-jun gene in these cells; however, in combination with cycloheximide, IL-3 dramatically reduces the c-jun induction below levels induced by cycloheximide alone. This is a true inhibition and is not due to a change in temporal kinetics of induction because the suppression in the presence of IL-3 is observed at both 30 and 60 min after simultaneous addition of both IL-3 and cycloheximide. Preincubation of monocytes with 12.5 nM okadaic acid (a potent inhibitor of protein phosphatases 1 and 2A) and cycloheximide prior to addition of IL-3 restored the level of c-jun induction to that mediated by cycloheximide alone. This concentration of okadaic acid inhibited almost 70% of the phosphorylase phosphatase activity in monocyte lysates. These observations suggest that activation of protein serine/threonine phosphatase(s) underlies the ability of IL-3 to inhibit cycloheximide induction of c-jun in monocytes.

Response of normal and reperfused livers to glucagon stimulation: NMR detection of blood flow and high-energy phosphates

The effects of glucagon on blood flow and high-energy phosphates in control and in rat livers damaged by ischemia were studied using in vivo nuclear magnetic resonance (NMR) spectroscopy. Normal livers and livers which had been made ischemic for 20, 40, and 60 min followed by 60 min of reperfusion were studied. Ischemia led to a loss in adenosine triphosphate (ATP) within 30 min. Reperfusion after 20 min of ischemia led to complete recovery of ATP. 60 min of reperfusion after 40 or 60 min of ischemia led to only a 76% and 48% recovery of ATP, respectively. Glucagon, at doses up to 2.5 mg/kg body weight, caused no changes in the inorganic phosphate (P(i)) to ATP ratio in normal livers as measured by 31P-NMR spectroscopy. In livers which had been made ischemic for 20, 40, or 60 min, glucagon caused an increase in the P(i)/ATP ratio of 18%, 40%, and 40%, respectively. 19F-NMR detection of the washout of trifluoromethane from liver was used to measure blood flow. Glucagon-stimulated flow in the normal liver in a dose-dependent manner, with 2.5 mg glucagon/kg body weight leading to a 95% increase in flow. Ischemia for 20, 40, and 60 min followed by 60 min of reperfusion led to hepatic blood flows which were 63%, 68%, and 58% lower than control liver. In reperfused livers, blood flow after glucagon-stimulation was reduced to 56%, 43%, and 48% of control glucagon-stimulated flow after 20, 40, and 60 min of ischemia. These results indicate that ischemia followed by reperfusion leads to decreases in hepatic blood flow prior to alterations in ATP and the response of the liver to glucagon is altered in the reperfused liver.

Aniridia-Wilms' tumour syndrome--a case report

Wilms' tumour is rarely associated with sporadic non-familial congenital aniridia. A child with sporadic aniridia has a 25% chance of subsequently developing Wilms' tumour. Unawareness of this association can lead to a delayed diagnosis of Wilms' tumour. One such case in a 2 year old is reported. Wilms' tumour, one of the common childhood malignancies, is associated with other congenital anomalies in about 15% of cases. These include hemihypertrophy, genitourinary abnormalities, mental retardation, aniridia etc. Sporadic non-familial aniridia was noted in only 1.1% of 547 children with Wilms' tumours evaluated by the National Wilms' Tumour study group. Unawareness on the part of a clinician about these associated anomalies can lead to an avoidable delay in diagnosing Wilms' tumour. One such case in a two year old girl is being reported.

2-Bromopalmitoyl-CoA and 2-bromopalmitate: promiscuous inhibitors of membrane-bound enzymes

2-Bromopalmitate and 2-bromopalmitoyl-CoA have been shown to inhibit a variety of enzymes and proteins associated with lipid metabolism. We found that both of the brominated compounds were non-competitive inhibitors of two microsomal activities of triacylglycerol biosynthesis, the mono- and diacylglycerol acyltransferases. With both compounds, the calculated Ki values were lower than the Km value for the palmitoyl-CoA substrate. In addition to inhibiting two other lipid synthetic activities, fatty acid CoA ligase and glycerol-3-P acyltransferase, 2-bromopalmitate and 2-bromopalmitoyl-CoA also inhibited two microsomal enzyme activities that are not related to lipid metabolism, NADPH cytochrome-c reductase and glucose-6-phosphatase. Inhibition of the three acyltransferases and fatty acid CoA ligase could be overcome by the addition of phospholipid vesicles, and 2-bromo[14C]palmitate readily labeled a large number of membrane-bound proteins as well as cytosolic proteins that had been solubilized in SDS. Thus, it appears likely that the inhibitory properties of the brominated compounds strongly depend on the effective concentration of the inhibitor within membranes rather than on any specific affinity for an acyl-chain binding region of the enzyme.

Quinone induced stimulation of hexose monophosphate shunt activity in the guinea pig lens: role of zeta-crystallin

The response of the hexose monophosphate shunt (HMS) in organ-cultured guinea pig lens to 1,2-naphthoquinone and 5-hydroxy-1,4-naphthoquinone (juglone) has been investigated. Both these compounds, which are substrates of guinea pig lens zeta-crystallin (NADPH:quinone oxidoreductase), were found to cause increases in the rate of 14CO2 production from 1-14C-labelled glucose. Exposure of lenses to 15 microM 1,2-naphthoquinone or 20 microM juglone yielded 5.9- and 7-fold stimulation of HMS activity, respectively. Unlike hydrogen peroxide-induced stimulation of HMS activity, these effects were not abolished by preincubation with the glutathione reductase inhibitor, 1,3-bis(2-chloroethyl)-1 nitrosourea (BCNU). While hydrogen peroxide produced substantial decrements in lens glutathione (GSH) levels, incubation with quinones was not associated with a similar reduction in GSH concentration. Protein-bound NADPH content in quinone-exposed guinea pig lenses was decreased, with a concomitant increase in the amounts of free NADP+. This finding supported the involvement of zeta-crystallin bound NADPH in the in vivo enzymic reduction of quinones. Hydrogen peroxide, on the other hand, caused decreases in the level of free NADPH alone, serving to confirm our earlier inference that quinone stimulated increases in the guinea pig lens HMS could be mediated through zeta-crystallin NADPH:quinone oxidoreductase activity.

Salmonella typhimurium isolated from bacteraemia

During a two year period, a total of 15 strains of S. typhimurium were isolated and analysed by phage typing. Of these, 13 were found untypable, while two strains belonged to phage 76 and 22. All the strains were sensitive to Gentamicin and Cephaloridine. All but one showed multiple drug resistance.

Management options in penetrating rectal injuries

A retrospective analysis of 54 patients (1976-1989) with penetrating rectal injuries was carried out to evaluate the options in management. The diagnosis was made on proctosigmoidoscopy in 39 patients and at laparotomy in 15. Three patients died within 24 hours from extensive associated trauma (Abdominal Trauma Index [ATI] 39.2). In the remaining 51 patients, rectal wound repair was performed in seven patients, four without proximal colostomy (mean ATI 16.5) and three with colostomy (mean ATI 24.8) without complications. Colostomy and presacral drainage with or without repair were employed in 43 patients. Twenty-one of these patients had rectal washout in addition. The other 22 patients did not have this procedure. The incidence of pelvic abscess in these two groups, who had comparable mean ATI, was identical (4.7% and 4.5%, respectively). One other patient with an extraperitoneal rectal injury had a colostomy alone without presacral drainage and subsequently developed pelvic abscess. The overall incidence of abscess was three of 51 patients or 5.8%. There were no late deaths from sepsis. It is concluded that colostomy (loop or end) and presacral drainage are the most important components of rectal injury management. Small and isolated rectal or rectosigmoid perforations may be repaired primarily without fecal diversion. The value of distal rectal irrigation remains to be proven, but it may be indicated in high-energy injuries of the rectum.

Further studies on the mechanism of phenol-sulfuric acid reaction with furaldehyde derivatives

Even though the chromogens formed from mannose and galactose showed comparable absorbances at 480 nm in the conventional (developer present during heat of dilution) and modified (developer reacted at room temperature after cooling; epsilon mannose = 13,700, galactose = 14,000) phenol-sulfuric acid reactions, shoulders in the region 420-430 nm were prominent in the former method. Fucose was 10 times less reactive in the modified method (epsilon = 800) than in the conventional method. 2-Formyl-5-furan sulfonic acid reacted equally efficiently in the two methods (epsilon = 40,800). 5-Methyl-2-furaldehyde, unlike the sulfonate derivative or 5-hydroxymethyl-2-furaldehyde, required heat for condensation with phenol. 2-Furaldehyde dimethylhydrazone reacted 25 times better to form a chromogen (epsilon = 40,500) in the modified phenol-sulfuric acid method. The possible roles of intermediates between hexoses and furaldehydes in forming chromogens and the effect of substitution at the 2- and 5-positions of furaldehyde on the rates of condensation with phenol for the observed differences between the conventional and the modified methods are discussed.

Human monocytes CD36 and CD16 are signaling molecules. Evidence from studies using antibody-induced chemiluminescence as a tool to probe signal transduction

A panel of monoclonal antibodies (mAb) directed against human monocyte surface antigens was tested for their capacity to mediate signal transduction by measuring luminol-enhanced chemiluminescence (CL). The response patterns fell into three categories. The mAb Mo4, OKM3, OKM6 and antibodies specific for Fc receptor (FcR) type I and II did not mediate signal transduction directly or were weak triggers, but upon second-order cross-linking by goat anti-mouse immunoglobulin (Ig) F(ab')2 or rabbit anti-mouse Ig, a strong CL response was induced. The mAb recognizing different epitopes on CD11b (complement receptor type III alpha chain) were unique in their ability to induce a CL response either by direct stimulation or by second-order cross-linking. The mAb 3G8 recognizing FcR type III (FcRIII; CD16) on a monocyte subpopulation and CD36-specific monoclonals directly elicited a CL response. A response of similar magnitude was obtained with 3G8 F(ab')2 or with intact 3G8. Furthermore, elutriation-centrifugation-purified monocytes were stimulated by 3G8 to a similar extent as unseparated mononuclear cells, whereas lymphocytes did not respond. This suggests that a FcRIII-expressing monocyte subpopulation may mediate effector functions, including the generation of reactive oxygen species, via FcRIII triggering. Our finding that anti-CD36 F(ab')2 directly induces an oxidative burst is the first evidence that CD36 itself is a trigger molecule. CD36, which is thought to interact with erythrocytes infected with Plasmodium falciparum and with thrombospondin, may constitute a signal-transducing element and thus may have functions extending beyond mediation of adherence. The present CL system constitutes a simple assay for detecting mAb directed against monocyte surface signalling elements. Probing mAb for signal transduction requires suspended cells and antibodies in the fluid phase in order to avoid inadvertent FcR triggering, which may occur when cells are stimulated by surface-adherent whole antibodies.

Penetrating pancreatic injuries. Analysis of 103 consecutive cases

The optimal management of penetrating pancreatic injuries continues to be a matter of debate and controversy. The present study analyzes 103 consecutive patients with these wounds treated at a level I Trauma Center in a 14-year period (1975-1988). Twenty-seven patients died within 48 hours from extensive associated trauma (Abdominal Trauma Index [ATI] 46.7). The majority of the remaining 76 patients were treated by debridement and drainage. Nineteen patients with grade III injuries had distal pancreatectomy. Six patients with extensive combined pancreatoduodenal injuries had pancreatoduodenectomy. Pancreatoenteric anastomoses or duodenal diversion procedures rarely were used. Pancreatic complications included major fistulas in four patients (5%) and pancreatic abscess in nine patients (11%). Only one of the fistulas required subsequent fistulojejunostomy. Intra-abdominal abscesses occurred in 18 patients (23.6%), mostly in patients with associated colon injury (P less than 0.001). It is concluded that a conservative approach to penetrating pancreatic injuries yields optimal results and that associated colon injury is an important predeterminant for abscess formation.

Taurine lowers blood pressure in the spontaneously hypertensive rat by a catecholamine independent mechanism

Taurine, a sulfur aminoacid, has been studied for a role in blood pressure regulation since it functions as a generalized inhibitory neurotransmitter and is found in high concentrations in the myocardium. We reinvestigated the magnitude of the hypotensive effect of chronic taurine administration to the spontaneously hypertensive rat (SHR) and the role of catecholamines in such an action. The SHR received either a 1% taurine solution or tap water to drink for 16 weeks. Taurine treatment caused a significant persistent reduction in blood pressure by 4 weeks that was maximal at 16 weeks (146 +/- 6 [exp.] v 182 +/- 5 [control] mm Hg, P less than .01). While this taurine-induced decline in blood pressure in the SHR was not accompanied by alterations in plasma epinephrine levels, there was a steady 235% increment in the norepinephrine concentration from 231 +/- 31 pg/mL initially to 542 +/- 126 pg/mL at completion of the study, P less than .02. The reduction in blood pressure was associated with decreased proteinuria in the taurine-treated SHR (9.6 +/- 4 [exp.] v 21.5 +/- 7 [control] mg/24 h, P less than .02) and less cardiac and renal hypertrophy. We conclude that taurine administration results in a 20 to 25% reduction in blood pressure in the SHR. The mechanism of this hypotensive action requires further study but is independent of changes in plasma catecholamine levels. The vasodepressor effect of taurine leads to less hypertensive injury to the kidney and heart in the SHR.

Fluorescence studies on binding of amphiphilic drugs to isolated lamellar bodies: relevance to phospholipidosis

Lysosomal phospholipid storage disorder in lung tissue was observed during chronic treatment with amphiphilic amine drugs. The prevailing and widely accepted mechanism of phospholipidosis is that amphiphilic drugs bind to phospholipids and make the phospholipids unsuitable substrates for the action of phospholipases. We investigated hydrophobic and hydrophilic binding of fifteen drugs to the phospholipid storage organelle, lung lamellar bodies, isolated from male Sprague-Dawley rats. Hydrophobic interactions were studied using 1,6-diphenyl-1,3,5-hexatriene as a fluorescent probe and hydrophilic binding was studied using 1-anilino-8-naphthalene sulfonate as a fluorescent probe. The binding parameters were calculated using Scatchard equations. Of the fifteen drugs used, nine drugs bound to the hydrophobic moiety of lamellar bodies. The order of binding capacities was promethazine greater than chloramphenicol greater than amiodarone = desethylamiodarone greater than promazine greater than chlorpromazine greater than trimipramine greater than propranolol greater than imipramine much greater than chlorphentermine, phentermine, chloroquine, chlorimipramine, cyclizine and chlorcyclizine. Two binding affinities were calculated for all the bound drugs. Binding affinities to hydrophilic sites of lamellar bodies were calculated in terms of emission coefficients for 1-anilino-8-naphthalene sulfonate in the presence of drugs. Hydrophilic binding was in the order chlorpromazine greater than chlorimipramine greater than promazine greater than trimipramine greater than imipramine greater than chlorcyclizine greater than propranolol greater than promethazine greater than chlorphentermine greater than cyclizine greater than phentermine greater than chloroquine much greater than chloramphenicol, amiodarone and desethylamiodarone. The binding affinities of chlorinated analogs were stronger to hydrophilic sites when compared to the parent compound. Amiodarone, which is known to induce pulmonary phospholipidosis and its major non-polar metabolite, desethylamiodarone, bound strongly to lamellar bodies. These two drugs also inhibit phospholipases in vitro. The drugs with weak phospholipidosis-inducing capacity and extensive in vivo metabolism, namely, imipramine, chlorpromazine and promazine, also bound strongly to lamellar bodies with hydrophilic as well as hydrophobic interactions. On the other hand, chloroquine, which is known to induce phospholipidosis and to inhibit phospholipases, did not bind to lamellar bodies. Two major conclusions could be drawn from this study: one is that the drug interactions with isolated lamellar bodies could be studied using membrane fluorescence probes, 1,6-diphenyl-1,3,5-hexatriene and 1-anilino-8-naphthalene sulfonate; second is that the amphiphilic drugs bind to lamellar bodies, as reported for phospholipid vesicles, and the binding of drugs to lamellar bodies could be correlated with their phospholipidosis-inducing capacity only if

Reevaluation of the phenol-sulfuric acid reaction for the estimation of hexoses and pentoses

Evidence is provided to show that in the conventional phenol-sulfuric acid reaction procedure, phenol underwent sulfonation in situ and the phenolsulfonic acid formed decreased the color intensity for hydroxymethyl furfural (HMF), furfural, and many hexoses and pentoses tested. A modified method is described to overcome this problem in which phenol was added after the dehydration of carbohydrates by sulfuric acid and after cooling the system. The color intensity around 475-485 nm for different compounds was fairly proportional to the amount of furfural derivatives (absorption at 310-320 nm) formed from the sugars in the modified method unlike in the conventional procedure. The studies also show that for condensation of HMF derivatives with phenol, heat is not necessary. The color intensity in the modified method also increased compared to that in the conventional method. The increase in the modified method compared to that in the conventional method was 6.0-fold for furfural, 9.1-fold for hydroxymethyl furfural, 3.7-fold for fructose, 2.3-fold for xylose, and 2.0-fold for glucose and arabinose. The possible reasons for this differential increase are discussed.

A colorimetric method for the estimation of serum glycated proteins based on differential reduction of free and bound glucose by sodium borohydride

A new colorimetric method based on the phenol-sulfuric acid reaction is described for the estimation of serum glycated proteins by the differential reduction of free glucose and hexose bound nonenzymatically with 2.0 and 20 mg of NaBH4 in 0.02 ml of serum, respectively, at room temperature for 15 min. The values (microgram hexose/mg protein) in control subjects (n = 60) and diabetics (n = 90) were estimated to be 5.60 +/- 0.85 and 10.8 +/- 1.6, respectively. The increase was highly significant (P less than 0.001) in diabetics. The serum glycated protein levels correlate well with fasting blood sugar values (r = 0.77, P less than 0.001, n = 25). There was also a highly significant correlation between glycated protein level and glycated albumin value in individual serum samples (r = 0.85, P less than 0.001, n = 25). Values of borohydride reducible glyco-groups bound to serum proteins also correlated well with serum glycated protein levels (r = 0.96, p less than 0.001, n = 20) determined by the thiobarbituric acid assay method. The method is found to be simple and rapid, with a coefficient of variations of +/- 3.8%.

Flow cytometric resonance energy transfer measurements support the association of a 95-kDa peptide termed T27 with the 55-kDa Tac peptide

Two monoclonal antibodies (OKT27 and OKT27b) have been produced that react with distinct epitopes of a 95-kDa peptide. The T27 antigen is widely distributed, being expressed on B lymphocytes, monocytes, and adult T-leukemic cells but not on polymorphonuclear leukocytes or platelets. There was a low level of T27 expression on resting T cells that increased on T-cell activation. In preliminary studies, the OKT27b antibody coprecipitated a 55-kDa peptide, as well as the 95-kDa peptide, from the radiolabeled cells of the HuT 102B2 cell line. Preclearance with anti-Tac, a monoclonal antibody to the 55-kDa peptide of the multichain interleukin 2 receptor, removed the 55-kDa but not the 95-kDa peptide from subsequent OKT27b immunoprecipitates of HuT 102B2 extracts, suggesting the possibility that the T27 peptide was associated with the Tac peptide. However, the precipitation of the p55 Tac peptide by OKT27b was quite inconsistent. Thus, additional information was sought using a flow cytometric energy transfer technique to provide a physical estimation of the proximity between the Tac and the T27 peptides. The flow cytometric version of the fluorescence resonance energy transfer technique permits the determination of inter- and intramolecular distances at 2- to 10-nm levels on a cell-by-cell basis. Using this approach, there was a mean energy transfer of 7.3% with HuT 102B2 cells when fluorescein isothiocyanate anti-Tac served as the donor and tetramethylrhodamine isothiocyanate OKT27 served as the acceptor. In contrast, there was no energy transfer in comparable studies observed when fluorescein anti-Tac and rhodamine anti-transferrin receptor antibodies were used. These observations support the conclusion that there is a close nonrandom proximity in HuT 102B2 cells between the 95-kDa peptide identified by the OKT27 monoclonal antibody and the p55 Tac peptide of the multichain interleukin 2 receptor.

An endogenous inducer of sexual development in Aspergillus nidulans

During development of the homothallic ascomycete Aspergillus nidulans, asexual sporulation is followed by sexual sporulation. We report here the detection of a solvent-extractable activity which inhibits asexual sporulation and stimulates premature sexual sporulation. This activity, called precocious sexual inducer (psi), is overproduced by certain mutants that are blocked in both modes of sporulation. Using partially purified preparations of psi, biological response could be elicited with as little as 50 ng of material. We suggest that psi is a hormone-precursor which is converted to a hormone by normal sporulating strains that respond to psi, but not by the asporogenous mutants that overproduce psi. The stability of psi activity gives promise that the compound can be purified and identified.

Null cell identification and characterization with OKT16: an anti-p40 monoclonal antibody

A murine monoclonal antibody, OKT16, specific for human lymphocytes of T lineage, was isolated by standard immunization and hybridization techniques. The distribution of the antigen defined by OKT16 was similar to the antigen reactive with monoclonal antibodies 3A1 and WT1. This identity of antigen targets was confirmed in an enzyme-linked immunosorbent assay system and by sequential immunoprecipitation. Under reducing conditions, OKT16 reacted with an antigen of 40K daltons; however, under nonreducing conditions this antigen appeared as an 84K-dalton molecule, which suggests that the p40 antigen exists as a disulfide-linked dimer. By indirect immunofluorescence, OKT16 reacted with a greater fraction of nonrosetting, non-B (null) lymphocytes than with antibodies to other T cell-specific proteins. Two-color immunofluorescence demonstrated the coexpression of the T16 antigen and the C3bi receptor on most null cells. The T10 antigen (found on cortical thymocytes and activated peripheral T cells) was restricted to most T16-bearing null cells and expression of the Fc receptor for aggregated IgG (defined by monoclonal antibody 73.1) was restricted to a major subset of T16-bearing null cells. The T cell-specific markers defined by OKT8, OKT11, and OKT17, as well as the monocyte marker defined by OKM5, were expressed by smaller subsets of OKT16-reactive null cells. These studies support by phenotypic analysis the functional heterogeneity ascribed to null cells. The 40K-dalton T16 antigen has the most extensive null cell representation of all the T lineage markers described to date.

Activated human B cells display a functional IL 2 receptor

These studies deal with the expression of a functional IL 2 receptor on activated primary human B cells. Antibody against the receptor (alpha-TAC) reacted with 25 to 65% activated B cells, inhibited B cell proliferation by 50% and inhibited B cell secretion of Ig by greater than 90%. These effects were shown to be independent of contaminating T lymphocytes. Anti-TAC immunoprecipitated a molecule of identical size (65,000 daltons) from T and B lymphocytes; B cells were also shown to actively synthesize the IL 2 receptor. The chymotryptic peptide chromatograms of TAC antigen from T and B cells show these molecules to be indistinguishable.

The mechanism of dysrhythmias in variant angina pectoris: occlusive versus reperfusion

Thirty-six patients with variant angina pectoris (VAP) were analyzed to investigate whether the mechanism underlying dysrhythmia is related to coronary occlusion or reperfusion. Fifteen of the 36 patients demonstrated dysrhythmias (42%). Twelve of 15 patients (80%) experienced dysrhythmia prior to the acme of ST-segment elevation (occlusive dysrhythmia), and those of tachyarrhythmia type were characterized by the presence of ventricular premature beats initially isolated, increasing in frequency, and preceding the more malignant forms of dysrhythmias, such as ventricular tachycardia or ventricular fibrillation. The occlusive dysrhythmias included ventricular dysrhythmia (ventricular premature beats, ventricular tachycardia, slow ventricular tachycardia, ventricular fibrillation) in eight patients and conduction abnormalities (second- and third-degree AV block, left posterior fascicular block) in four patients. Thirteen episodes of VAP were fully recorded electrocardiographically. The average time to onset of dysrhythmia, after the beginning of ST-segment elevation, was 4.94 minutes +/- 1.52. The duration of the episodes without dysrhythmia was 0.86 minute +/- 0.53. The "reperfusion dysrhythmia" occurred in three patients (20%) and was characterized by the appearance of isolated couplets of ventricular premature beats, ventricular tachycardia, or ventricular fibrillation without prodromal ectopic activity. The dysrhythmia occurred in one patient during the resolution of ST-segment elevation and in two patients within seconds of ST-segment normalization. We conclude that the occlusive related dysrhythmias are the most important mechanism in VAP. They are dependent on the duration of the ischemic episode.

Blood levels of glucose and insulin in Meniere's disease

It has been reported that a very commonly overlooked cause of vertigo is disorder of glucose metabolism. This may not be reflected in the glucose tolerance test alone, but becomes obvious when the insulin levels in blood are evaluated simultaneously. Thirty-one patients with Meniere's disease underwent a 5-hour glucose tolerance test with radioimmune assay of insulin. The results were compared with the normal and abnormal patterns suggested by Kraft. On this basis, it was found that 67.7% of our patients showed some abnormality in the relationship between the blood levels of glucose and insulin. These patients were put on a special diet with a limited carbohydrated content prescribed by a qualified dietitian. The effect of this diet was highly variable and the possible reasons for this are also discussed.

Prinzmetal's variant angina: electrocardiographic and angiographic correlations

Thirty patients with variant angina pectoris (VAP) were analyzed for electrocardiographic features during episodes of VAP. Twenty-nine of these patients had cardiac catheterization, and an autopsy study was performed in one. The patients showed predominantly concave upright T-waves during pain. An increase of R wave amplitude (expressed as delta R) of more than 10% was seen in 17/30 patients (57%). The primary ST-T changes produced by the VAP episodes were conspicuous in two patients with pre-existent complete left and right bundle branch block. Serious dysrhythmias, including ventricular fibrillation (VF), ventricular tachycardia (VT), ventricular premature beats (VPBs) (more than five/min, multifocal and R on T phenomenon), and 2 degrees atrioventricular block were found in thirteen patients (43%). The development of dysrhythmias was related to the duration of VAP episodes. The average time to onset of dysrhythmias was 3.54 min. The dysrhythmias were not contingent upon pre-existing coronary artery anatomy (defined by Friesinger's coronary score), left ventricular ejection fraction or left ventricular segmental abnormalities. The location of the ST-segment elevation and the presence of dysrhythmias during the episodes of VAP (A-V blocks, ventricular tachycardia and fibrillation) were not predictive factors of the coronary anatomy. Eight patients (27%) developed myocardial infarction (MI). Five of them had nontransmural MIs and three developed transmural MIs. The development of MI was not related to the severity of the VAP attacks (appreciated by the magnitude of ST-segment elevation and R wave changes) but showed a relation to the development of an unstable pattern which preceded the infarction. Sixteen patients underwent exercise testing. In eight of them, the coronary arteriograms were normal (Group I); in the remaining eight, significant proximal coronary artery obstructive disease was found (Group II). Group I patients displayed a normal ST-segment response and functional aerobic capacity (FAI = 4.4 +/- 14) as well as normal heart rate (HR) and double product (SBP X HR) responses (HR = 154 +/- 21; SBP X 21; SBP X HR = 290 +/- 71). During exercise, a normal delta R was observed. With one exception, Group II patients showed an abnormal ST-segment response with an overall low exercise capacity (FAI = 57 +/- 17) and decreased hemodynamic response (HR = 27; SBP X HR = 130 +/- 40). FAI, HR, SBP X HR Group I vs. Group II = P less than .005/less than .02/less than .005. The abnormal ST-segment response included elevation in four patients and depression in three. During exercise, Group I with ST-elevation displayed a normal (negative) delta R response; while Group II with ST-depression displayed an abnormal delta R response (positive or no change). There was no difference in the coronary score between Group II patients with ST-segment elevation or depression.