The antigenicity of human hemoglobins

Summary The correlation of the antigenicities among native hemoglobins and their subunit chains were investigated by the absorption of antisera and the combination of urea added immunoelectrophoresis with double diffusion. Alphachain showed identity with Hb-F but partial identity with -chain and Hb-A. Beta-chain showed identity with Hb-A but -chain and Hb-F showed partial identity with this chain. Gamma-chain showed identity only with Hb-F and its antigenicity was considered as being different from those of - or -chains.The lines of -, -and -chains were reconfirmed from the facts that the appearance of them depended always on the existence of anti-Hb-A or anti-Hb-F antibodies in the absorbed antisera and the minor component lines of

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Zusammenfassung Die Zusammenhänge der Antigenität zwischen nativen Hämoglobinen und deren Unterketten wurden mit der Absorption der Antiseren und der Kombination der Harnstoff-Immunelektrophorese und Doppeldiffusion untersucht. Die -Kette zeigte Identität mit Hb-F, aber nur partielle Identität mit der -Kette und Hb-A. Die -Kette war in ihrer Antigenität mit Hb-A identisch, die -Kette und Hb-F waren teilweise identisch mit der -Kette. Die -Kette zeigte die Identität mit Hb-F; es wird angenommen, daß ihre Antigenität verschieden von der -oder -Ketten ist.Für das Auftreten der Linien der -, - und -Ketten müssen Anti-Hb-A-oder Anti-Hb-F-Antikörper in den absorbierten Antiseren vorhanden sein, außerdem fusionieren die schwächeren Linien der Doppeldiffusion nicht mit irgendwelchen Linien der Unterketten. Auch gereinigte - oder -Ketten wurden zur Feststellung ihrer Linien benutzt.

     

Demonstration of a relatively hepatoselective effect of covalent insulin dimers on glucose metabolism in dogs

Summary Insulin analogues with relatively greater effect on hepatic glucose production than peripheral glucose disposal could offer a more physiological approach to the treatment of diabetes mellitus. The fact that proinsulin exhibits this property to a minor degree may suggest that analogues with increased molecular size may be less able than insulin to obtain access to peripheral receptor sites. Covalent insulin dimers have previously been shown to possess lower hypoglycaemic potencies than predicted by their in vivo receptor binding affinities. Reduced rates of diffusion to peripheral target tissues-might be an explanation for the lower in vivo potency compared to insulin. To test the relative hepatic and peripheral effects of covalent insulin dimers, glucose clamp procedures with D-[3-³H] glucose tracer infusions were used in anaesthetised greyhounds to establish dose-response curves for rates of hepatic glucose production and glucose disposal with insulin, N^B1, N^{B 1},-suberoyl-insulin dimer, and N^B29, N^{B 29},-suberoyl-insulin dimer. With N^B1, N^{B 1},-suberoyl-insulin dimer molar potencies relative to insulin were 68%, (34–133) (mean and 95% fiducial limits), for inhibition of hepatic glucose production and 14.7%, (10.3–20.9) for glucose disposal. With N^B29,N^{B 29},-suberoyl-insulin dimer potencies were 75%, (31–184) and 2.5%, (1.5–4.3), for inhibition of hepatic glucose production and for glucose disposal, respectively. The demonstration that both dimers exhibit a significantly greater effect on glucose production than on glucose disposal supports the suggestion that analogues with increased molecular size may exhibit reduced ability to gain access to peripheral target cells.Abbreviations B1-B 1D N^B1,N^{B 1},-suberoyl-insulin dimer - B29-B 29D N^B29,N^{B 29},-suberoyl-insulin dimer - Ra hepatic glucose production rate - Rd peripheral glucose disposal rate - M_r relative molecular weight - MCR metabolic clearance rate - ANOVA analysis of variance     

Capsular and ‘O’ serotype determinants of Bacteroides fragilis

Summary Forty-one strains ofBacteroides fragilis, 20 strains of otherBacteroides species and 14 strains of other genera were examined by the indirect immunofluorescent assay (IFA) using anticapsular serum. The sixty-oneBacteroides strains were O serotyped by direct agglutination tests using absorbed antisera raised against 23 strains, each with a different O antigenic determinant. All 41B. fragilis strains tested were positive by IFA with the anticapsular serum, but apart from one strain ofB. distasonis, none of the remaining 19 strains of other bacteroides, i. e.B. thetaiotaomicron, B. distasonis, B. vulgatus, B. ovatus, B. melaninogenicus group andB. ureolyticus, and none of the 14 other bacterial species examined were positive. The majority of strains of saccharolytic bacteroides tested reacted with one of the 23 O antisera and were designated as a specific O serotype; a fewBacteroides strains had multiple agglutination reactions indicating the presence of multiple antigenic determinants. All O serotypes gave positive IFA tests with their homologous O antisera. Common capsular determinants and O antigenic determinants appear to exist on the same strains ofB. fragilis. Serological typing ofB. fragilis and related species would be useful in epidemiological studies.

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Kapsel- und O-Determinanten von Bacteroides fragilis

Zusammenfassung 41 Stämme vonBacteroides fragilis, 20 Stämme andererBacteroides-Spezies und 14 Stämme anderer Genera wurden unter Verwendung von Kapsel-Antiserum mit dem indirekten Immunfluoreszenztest (IFA) untersucht. Die O-Serotypisierung der 61Bacteroides-Stämme erfolgte mit dem indirekten Agglutinationstest; dabei wurden absorbierte Antiseren gegen 23 Stämme verwendet, von denen jeder eine unterschiedliche O-Determinante aufwies. Alle untersuchten 41 Stämme vonB. fragilis waren im IFA mit Kapsel-Antiseren positiv; hingegen war mit Ausnahme eines Stammes vonB. distasonis keiner der übrigen Stämme andererBacteroides-Spezies positiv, das heißt der GruppeB. thetaiotaomicron, B. distasonis, B. vulgatus, B. ovatus, B. melaninogenicus undB. ureolyticus; von den anderen geprüften 14 Bakterienspezies war ebenfalls keine positiv. Die Mehrzahl der Stämme der untersuchten saccharolytischenBacteroides reagierte mit einem der 23 O-Antiseren und wurde einem spezifischen O-Serotyp zugeordnet; einigeBacteroides-Stämme wiesen mehrfache Agglutinations-reaktionen auf, was für das Vorliegen mehrerer Antigendeterminanten spricht. Bei denselben Stämmen vonB. fragilis scheinen gemeinsame Kapsel- und O-Antigendeterminanten vorzukommen. Für epidemiologische Untersuchungen dürfte die Serotypisierung vonB. fragilis und verwandten Spezies von Nutzen sein.

     

Immunolocalization of Transforming Growth Factor-α and Epidermal Growth Factor Receptor in the Rat Gastroduodenal Area

The maintenance of gastrointestinal epitheliumintegrity requires a fine balance between proliferationand differentiation as well as protection againstgastric acid secretion. Transforming growthfactor- (TGF-) regulates these functions bybinding to epidermal growth factor receptor (EGF-R).This study was designed to identify the localization ofTGF- and EGF-R in the rat gastroduodenal region. In the stomach, the surface and gastric pitcells showed staining for TGF- antibodies in thecytoplasm and basolateral and apical membranes.TGF- and EGF-R were observed in the supranuclearregion of the cells lining the gland. In the duodenum,the enterocytes coexpressed both TGF- and EGF-Rin the supranuclear area. The EGF-R was also observed inthe apical membrane. Brunner's glands were positive for both TGF- and EGF-R antibodies. Ourresults demonstrate the coexpression of TGF- andEGF-R in the rat gastroduodenal area, which suggests afunctional role for them in the establishment and maintenance of the epithelialrenewal.     

The effect of dbcAMP on the lysolecithin induced hemolysis of calf and adult cattle erythrocytes

Summary The calf erythrocytes have an increased sensitivity against lysolecithin as compared to their adult counterparts. 10^–3M dbcAMP increases the hemolysis induced by 5g of lysolecithin in 0.15 M NaCl containing 10 mM phosphate buffer (pH 7.4). By increasing the level of phosphate buffer (75 mM) in the incubation mixture, 10^–3M dbcAMP decreases the hemolysis induced by 5g of lysolecithin. These data suggest a dual effect exerted by dbcAMP: the relatively labilizing or stabilizing effect prevails as a function of exogenous inorganic phosphate level.10-⁶M dbcAMP also has a relative protective effect against lysolecithin.The combined addition of cAMP (10^–3) and theophyllin (10^–4M) does not stabilize the membrane.By increasing the level of lysolecithin to 20g/ml the stabilizing effect of dbcAMP disappears.DbcAMP (10^–3) as well as cAMP (10^–3M) and theophyllin (10^–4M) have a minimum increasing effect on hemolysis in the absence of lysolecithin, too.

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Abbreviations dbcAMP N⁶-20-dibutyryladenosine 35-monophosphate - cAMP cyclic 35-adenosine monophosphate     

Oxidative stress induces insulin resistance by activating the nuclear factor-κB pathway and disrupting normal subcellular distribution of phosphatidylinositol 3-kinase

Aims/hypothesis Oxidative stress is associated with diabetes, hypertension and atherosclerosis. Insulin resistance is implicated in the development of these disorders. We tested the hypothesis that oxidative stress induces insulin resistance in rats, and endeavoured to identify mechanisms linking the two.Methods Buthionine sulfoximine (BSO), an inhibitor of glutathione synthase, was administered to Sprague-Dawley rats and 3T3-L1 adipocytes. Glucose metabolism and insulin signalling both in vivo and in 3T3-L1 adipocytes were examined. In 3T3-L1 adipocytes, the effects of overexpression of a dominant negative mutant of inhibitory B (IB), one role of which is to block oxidative-stress-induced nuclear factor (NF)-B activation, were investigated.Results In rats given BSO for 2 weeks, the plasma lipid hydroperoxide level doubled, indicating increased oxidative stress. A hyperinsulinaemic-euglycaemic clamp study and a glucose transport assay using isolated muscle and adipocytes revealed insulin resistance in BSO-treated rats. BSO treatment also impaired insulin-induced glucose uptake and GLUT4 translocation in 3T3-L1 adipocytes. In BSO-treated rat muscle, adipose tissue and 3T3-L1 adipocytes, insulin-induced IRS-1 phosphorylation in the low-density microsome (LDM) fraction was specifically decreased, while that in whole cell lysates was not altered, and subsequent translocation of phosphatidylinositol (PI) 3-kinase from the cytosol and the LDM fraction was disrupted. BSO-induced impairments of insulin action and insulin signalling were reversed by overexpressing the dominant negative mutant of IB, thereby suppressing NF-B activation.Conclusions/interpretation Oxidative stress induces insulin resistance by impairing IRS-1 phosphorylation and PI 3-kinase activation in the LDM fraction, and NF-B activation is likely to be involved in this process.Abbreviations BSO buthionine sulfoximine - GMSA gel mobility shift assay - IB inhibitory B - IKK IB kinase - LDM low-density microsome - NF-B nuclear factor-B - PI phosphatidylinositol     

Comparative and combined effects of transforming growth factors α and β, interleukin-1 and interferon-γ on rheumatoid synovial cell proliferation,glycolysis and prostaglandin E production

Summary Enhanced cell proliferation, glycolysis and prostaglandin E production are all characteristic features of rheumatoid synovial tissue. The interrelationships of these three cellular parameters have been examined using rheumatoid synovial fibroblasts and their responses to specific cytokines in vitro. Transforming growth factor (TGF) caused a more than threefold increase in synovial cell proliferation whilst transforming growth factor (TGF), interleukin-1 (IL-1) and interferon- (IFN-) produced only marginal changes. The combined addition of IL-1 with TGF resulted in an enhanced proliferative response comparable with that produced by TGF. Glycolysis, estimated by glucose utilisation and measurements of the glycolytic regulatory metabolite fructose 2,6-bisphosphate was significantly stimulated by TGF, IL-1 and IFN-, but less so by TGF. Prostaglandin E production was significantly increased by IL-1 to an extent much greater than that produced by TGF or TGF, although the combined addition of IL-1 with either TGF or resulted in a synergistic increase in PGE production, a response partly diminished by the addition of IFN-. These findings suggest that the extent to which a cytokine stimulates glycolysis is not consistently related to its mitogenicity, and that cytokine combinations which stimulate high levels of PGE production (a growth inhibitor) will not necessarily be associated with a reduced rate of cellular proliferation in cultured, adherent, rheumatoid synovial fibroblasts.     

Garrod's foresight; our hindsight

Archibald Edward Garrod introduced a paradigm, new for its day, in medicine: Biochemistry is dynamic and different from the static nature of organic chemistry. It led him to think about metabolic pathways and to recognize that variation in Mendelian heredity could explain an inborn error of metabolism. At the time, Garrod had no idea about the nature of a gene. Genes are now well understood, genomes are being described for one organism after another (including H. sapiens) and it is understood that genomes speak biochemistry (not phenotype). Accordingly, in the era of genomics, biochemistry and physiology become the bases of functional genomics and it is possible to appreciate why nothing in biology makes sense without evolution (and nothing in medicine will make sense without biology). Mendelian, biochemical and molecular genetics together have revealed what lies behind the four canonical inborn errors described by Garrod (albinism, alkaptonuria, cystinuria and pentosuria). Both older and newer ideas in genetics, new tools for applying them, and renewed respect for the clinician-scientist will enhance our understanding of the human biological variation that accounts for variant states of health and overt disease; an unsimple phenotype (phenylketonuria) is used to illustrate in some detail. What can be known and what ought to be done with knowledge about human genetics to benefit individuals, families and communities (society) is both opportunity and challenge.     

Influence of insulin on cyclic 3′,5′-AMP phosphodiesterase activity in liver,skeletal muscle,adipose tissue,and kidney

Summary Influence of insulin on liver glycogen metabolism and on lipolysis appears to be mediated by a decreased intracellular 3,5-AMP concentration. Reduced formation of 3,5-AMP had been shown in adipose tissue incubated with insulin. The influence of insulin on 3,5-AMP degradation has been investigated. — 3,5-AMP phosphodiesterase (PDE) activity was reduced in liver, adipose tissue and, insignificantly, in skeletal muscle of insulin deficient, i.e. alloxan diabetic or starved rats. I.V. injection of a low dose of insulin (0.5 U/kg) or stimulation of endogenous insulin secretion by injection of glucose led to a rapid increase of PDE activity in these tissues. 15 min after insulin injection liver PDE activity was increased. The maximal effect occurred after 30–45 min. Renal PDE activity was not decreased in alloxan diabetes, insulin injection has been found ineffective. —In vitro, there was an activating effect of crystalline insulin on PDE purified from beef heart. Insulin concentration required for duplication of enzyme activity was of the order of 2 · 10^–5 M. Treatment with actinomycin D nearly prevented stimulation of liver PDE by insulin. This may indicate that the action of insulin on PDE activity is essentially based on an increased enzyme synthesis. — Owing to the influence of insulin secretion on liver and adipose tissue 3,5-AMP concentration, glycogen metabolism and lipolysis can be quickly adapted to food intake.

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Der Einfluß von Insulin auf die 3,5-AMP-Phosphodiesterase-Aktivität in Leber, Skeletmuskulatur, Fettgewebe und Niere

Zusammenfassung An der Steigerung der Glykogensynthese der Leber und der Verminderung der Lipolyse durch Insulin ist eine Abnahme der 3,5-AMP-Konzentration wesentlich beteiligt. Die 3,5-AMP-Bildung ist in Fettgewebe, das mit Insulin inkubiert wird, vermindert. Insulin beeinflußt jedoch auch den 3,5-AMP-Abbau. -Die 3,5-AMP-Phosphodiesterase (PDE)-Aktivität des Fettgewebes, der Leber und, in geringerem Grade, der Skeletmuskulatur ist im Insulinmangel vermindert, d.h. bei alloxandiabetischen oder hungernden Ratten. I.v. Injektion von 0,5 E/kg Insulin oder eine erhöhte Abgabe von Insulin aus dem Pankreas nach Glucoseinjektion führen in diesen Geweben zu einem raschen Anstieg der PDE-Aktivität. Dieser ist in der Leber schon 15 min nach Insulingabe nachweisbar und erreicht nach 30–45 min sein Maximum. In der Niere ist kein Einfluß von Insulin auf die PDE-Aktivität nachweisbar. — Aus Rinderherz isolierte PDE wirdin vitro durch Insulin aktiviert, jedoch werden2 · 10^–5 M zur Verdopplung der Aktivität benötigt. Actinomycin D verhindert die Steigerung der Leber-PDE-Aktivität nach Insulininjektion. So kann die Wirkung des Hormons im wesentlichen auf eine gesteigerte PDE-Synthese zurückgeführt werden. — Durch diesen Einfluß der Insulininkretion auf die 3,5-AMP-Konzentration in Leber und Fettgewebe können Glykogenstoffwechsel und Lipolyse rasch an die Nahrungsaufnahme angepaßt werden.

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Influence de l'insuline sur l'activité de la 3,5-AMP-phosphodiestérase dans le foie, le muscle strié, le tissu adipeux et le rein

Résumé L'influence de l'insuline sur le métabolisme du glycogène hépatique et sur la lipolyse semble s'exercer par l'intermédiaire d'une diminution de la concentration de 3,5-AMP intracellulaire. Onamontré une diminution de la formation de 35-AMP dans le tissu adipeux incubé avec de l'insuline. L'influence de l'insuline sur la dégradation du 3,5-AMP est étudiée. — L'activité de la 3,5-AMP-phos-phodiestérase (PDE) est diminuée dans le foie, le tissu adipeux et, de façon non-significative, dans le muscle strié des rats qui manquent d'insuline, c-à-d les rats rendus diabétiques par l'alloxane ou les rats privés de nourriture. L'injection intraveineuse d'une faible dose d'insuline (0.5 U/kg) ou la stimulation de la sécrétion d'insuline endogène par une injection de glucose provoquent une augmentation rapide de l'activité de la phosphodiestérase dans ces tissus. 15 min après l'injection d'insuline, l'activité de la phosphodiesterase du foie est augmentée. L'effet maximum est atteint après 30–45 min. L'activité de la phosphodiestérase rénale n'est pas diminuée dans le diabète alloxanique, l'injection d'insuline s'est avérée inefficace.In vitro, l'insuline cristalline a un effet activant sur la phosphodiestérase purifiée du coeur de boeuf. La concentration d'insuline requise pour doubler l'activité de l'enzyme est de l'ordre de 2 · 10^–5 M. Le traitement avec actinomycin D empêche la stimulation par l'insuline de la PDE dans le foie. Ceci peut indiquer que l'action de l'insuline sur l'activité de la phosphodiestérase est essentiellement basée sur une synthèse accrue de l'enzyme. A cause de l'influence de la sécrétion d'insuline sur la concentration en 3,5-AMP du foie et du tissu adipeux, le métabolisme du glycogène et la lipolyse peuvent s'adapter rapidement à la prise de nourriture.

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Non-Standard Abbreviations G 6 P Glucose-6-phosphate - UDPG UDP-glucose - FFA non-esterifled, free fatty acids - 3,5-AMP cyclic adenosine-3,5-monophosphate - PDE 3,5-AMP phosphodiesterase This study was supported by the Deutsche Forschungsgemeinschaft.Deceased October 31, 1967.     

Neutrophil-mediated cartilage injury in vitro is enhanced by tumour necrosis factor alpha

Summary Neutrophil functions relevant to tissue damage are altered by cytokines such as tumour necrosis factor alpha (cachectin, TNF), known to be present in inflammatory foci. In this study we examined the effect of TNF on neutrophil-mediated cartilage damage in vitro. Human neutrophils were able to injure both human and bovine articular cartilage slices by degrading proteoglycan and inhibiting its synthesis. Recombinant human TNF enhanced neutrophil-mediated degradation of proteoglycan, even when neutrophils were preincubated with TNF and washed before incubating with cartilage. TNF alone degraded proteoglycan and inhibited its synthesis. Neutrophil-mediated inhibition of proteoglycan biosynthesis was increased after incubating cartilage together with neutrophils and TNF, but was unaltered when neutrophils were preincubated with TNF. We conclude that TNF enhances neutrophil injury to articular cartilage.     

Pharmacological evidence for beta3 adrenoceptors in the control of rat gastric acid secretion

The effect of the ₃-adrenoceptor agonist BRL37344 on gastric acid secretion evoked by different secretory stimuli was investigated in anaesthetized rats with lumen-perfused stomachs in comparison with the ₂-adrenoceptor agonist clenbuterol. Intravenous injections of BRL37344 (1–10 mol/kg) and clenbuterol (0.01–1 mol/kg) dose-dependently reduced 2-deoxy-D-glucose-induced acid secretion, with BRL37344 about forty times less potent than clenbuterol. BRL37344 (0.1–3 mol/kg) inhibited pentagastrin-induced acid output, whereas clenbuterol was effective only at high doses (10–100 mol/kg). The inhibitory effect of BRL37344 on pentagastrin-induced acid secretion was not modified by the nonselective –adrenoceptor antagonist propranolol, but it was prevented by bupranolol, a ₃-adrenoceptor antagonist. Furthermore, neither BRL37344 (10 mol/kg) nor clenbuterol (100 mol/kg) modified the acid secretion induced by histamine. These data suggest that ₃ adrenoceptors have an inhibitory role in the control of rat gastric acid secretion induced by indirect stimuli.     

Human Plasma Fibronectin Mediates Adhesion of U937 Cells by RGD and CS1

Fibronectin specifically binds to U937 cells (monocytic cell line) in a dose-dependent manner. The specific receptors for the RGD sequence have been identified as ₅₁ and _IIb3, and that for CS1 has been defined as ₄₁. RGDS, CS1 peptide, and two peptides together showed similar inhibitory activities on this adhesion, while the 29-kD dispase-digested fragment of the C-terminal heparin-binding domain did not. Thus, the adhesion of fibronectin to U937 cells is mainly mediated by RGDS in the cell-binding domain and CS1 in the alternatively spliced region. Flow cytometry using monoclonal antibodies revealed expressions of ₃₁, ₄₁, and ₅₁, and not expression of ₂₁. Adhesion of U937 cells to fibronectin-coated wells is specific and is inhibited by anti-₄₁ and anti- ₅₁ monoclonal antibodies. The IC-50 for anti-₅₁ antibody was almost a log lower than the value for anti-₄₁ antibody. These results demonstrated that interactions of RGDS and CS1 sequence of fibronectin with ₅₁ and ₄₁ on U937 cells were required for the adhesion of U937 cells to fibronectin. These results may provide further information to understand the mechanism(s) of tumor cell adhesion and atherogenesis.     

A deletion of 11 bp (CD 131–134) in exon 3 of the β-globin gene produces the phenotype of inclusion body β-thalassemia

Dominant inherited -thalassemias describe those -thalassemia variants that result in a thalassemia intermediate phenotype in individuals who have inherited only a single copy of the abnormal gene. This form of thalassemia is characterized by moderately severe anemia with jaundice and splenomegaly; it is also characterized by the presence of inclusion bodies in the red blood cell precursors and has, therefore, previously been referred to as inclusion body -thalassemia. We describe a case of inclusion body -thalassemia in a 51-year-old Spanish male caused by a deletion of 11 bp (CD 131–134) in exon 3 of the -globin gene. The deletion of 11 bp in exon 3 of the -globin chain is predicted to produce an anomalous chain of 134 amino acids instead of the normal 146 with an extremely altered amino acid sequence from residues 131–134. Although this shortened variant would lead to a missing H helix, which is involved in ₁₁ contact and ₁₂ subunit interactions, the variant chain can still be bound to the heme group and acquire a secondary structure that is not suitable for the formation of stable dimers or tetramers and also less susceptible to proteolytic degradation. This is the first report of such a -thalassemia mutation.     

Picoprep-3™ Is a Superior Colonoscopy Preparation to Fleet™: A Randomized,Controlled Trial Comparing the Two Bowel Preparations

PURPOSE: Bowel preparations for colonoscopy have to balance the demand for adequate cleansing action of the bowel and patient acceptability. There has been no study comparing Picoprep-3 (sodium picosulfate), a relatively new product, to Fleet (sodium phosphate), a well-studied and widely used preparation. This study was designed to compare the efficacy and patient tolerance of these two bowel preparations for colonoscopy. METHODS: A randomized, single-blinded, prospective trial was conducted. A total of 400 consecutive patients presenting for elective colonoscopy at St George Private Hospital during a 20-week period were randomly assigned to receive Picoprep-3 or Fleet. Patients were asked to record the effects of the preparation, noting tolerability, taste, and side effects. Two hundred patients were assigned to the Picoprep-3 group and 200 to the Fleet group. Surgeons were blinded to the preparation used and rated the quality of the bowel preparation on a scale of 1 to 5 (1 being the optimal score). RESULTS: Picoprep-3 was found to be better tolerated (P < 0.0001) and better tasting (P < 0.0001) than Fleet. Patients in the Picoprep-3 group reported significantly less nausea (P < 0.001), vomiting (P < 0.004), dizziness (P < 0.01), abdominal pains (P = 0.0005), and thirst (P < 0.0001) associated with the preparation. There was no significant difference in visualization of the colon between the two groups as judged by the two colonoscopists (P = 0.06). CONCLUSIONS: Colonoscopy preparation with Picoprep-3 has similar efficacy but superior taste and tolerability compared with Fleet. Picoprep-3 caused less adverse side effects in the study population.     

Synergistic cytotoxicity of human recombinant tumour necrosis factor α combined with microtubule effectors

Summary Combinations of human recombinant tumour necrosis factor (rhTNF) with each of four different agents disturbing the microtubule system of the cellular cytoskeleton were tested for synergistic cytotoxic action against murine melanoma B16K and L-M(S) cells. In addition to the known microtubule effectors colchicine, vincristine, and taxol, the influence of the fluorenone-azomethine derivative-diphenylene-N-{p-[bis-(-hydroxyethyl)-amino]-phenyl}-nitrone (DHPN) on the rhTNF cytotoxicity was studied. Applying a novel computerbased isobole method [Suehnel J (1990) Antiviral Res 13:23–40] concentration ranges of synergistic, zero, and antagonistic interaction were found after in vitro combination of rhTNF with each of the drugs tested in a 72-h cytotoxicity assay. In contrast, a 24-h exposure of B16K cells to these combinations still did not inhibit in vitro colony formation to a greater extent than either drug alone. A preliminary in vivo experiment revealed an increased antitumour effect after treatment of established subcutaneous melanoma B16 tumours with a combination of rhTNF and DHPN.Abbreviations rhTNF human recombinant tumour necrosis factor - DHPN -diphenylene-N-{p-[bis-(-hydroxyethyl)-amino]-phenyl}-nitrone     

A Czechoslovakian teenager with Hb E-β∘-thalassemia [IVS-I-1 (G → A)] complicated by the presence of an α-globin gene triplication

Summary We have examined the molecular basis of three inherited hemoglobin (Hb) disorders present in a Czechoslovakian girl with a severe, transfusion-dependent, hemolytic anemia. She is heterozygous for Hb E (on a genetic background specific for Czechoslovakian families), heterozygous for the -thalassemia (thal) allele IVS-I-1 (G A), and heterozygous for an -globin gene triplication. The combination of these three undesirable traits results in a severe chain imbalance that is the basis of the serious hemolytic disorder observed in this teenager.This study was supported in part by USPHS Research Grant HLB-41544. This is contribution 1282 from the Department of Cell and Molecular Biology at the Medical College of Georgia in Augusta     

Nuclear factor-kappaB and TNF-alpha mediate gastric ulceration induced by phorbol myristate acetate

Phorbol esters induce inflammation in rodents by activating protein kinase C. We determined whether nuclear factor-B (NF-B) and tumor necrosis factor- (TNF-) play role in the formation of gastric ulcer induced by phorbol-12-myristate-13-acetate (PMA) in rats. Subserosally injected PMA dose-dependently induced gastric mucosal ulcer. Activation of NF-B in the gastric mucosa corresponding to the PMA injection sites was observed before the ulcers became obvious as assessed by an in situ fluorescence DNA binding assay and electrophoretic mobility shift assay. The NF-B activation and subsequent ulcer formation were significantly inhibited by injection of pyrrolidine dithiocarbamate, proteasome inhibitor (MG132), or NF-B decoy. Antibody against TNF- significantly inhibited ulcer formation without attenuating NF-B activation. These results suggest that both NF-B activation followed by TNF- release contribute to tissue damage in PMA-induced gastric ulcer formation.     

Contractile activity and prostacyclin generation in isolated coronary arteries from diabetic dogs

Summary The present study was aimed at determining the generation of prostacyclin (PGI₂)-like-material in coronary arteries from normal and diabetic (pancreatectomized) dogs as well as the contractile responses to prostacyclin of preparations from normal, diabetic and insulin-treated diabetic animals. PGI₂ produced a dose-dependent relaxation of coronary arteries from normal dogs. In contrast, those from diabetic animals were not relaxed; indeed, at low concentrations PGI₂ failed to evoke any effect but at higher ones it induced a distinct contraction. In arteries from diabetic animals treated with insulin, PGI₂ induced a biphasic contractile effect, which lay between that of normal controls and untreated diabetics. In addition the basal generation of PGI₂-like-material by coronary arteries was significantly higher in the diabetic (141±0.2 pg/mg, mean±SEM) than in normal dogs (59±0.2 pg/mg). The present experiments demonstrate that the generation of PGI₂-like-substance is significantly increased in coronary arteries from diabetic dogs, but the same vessels are unable to respond to added authentic PGI₂ with relaxation; on the contrary they react with a distinct positive contractile response.     

Detection of anti-bovine β2-glycoprotein I antibody in sera from patients with antiphospholipid syndrome

We studied and characterized anti-bovine ₂ I antibodies (aB₂-GPI) in sera from patients with antiphospholipid syndrome (APS) by ELISA. Bovine ₂-glycoprotein I ₂-GPI was purified by heparin affinity and DEAE ion-exchange chromatography, and identified on immunoblots using a monoclonal antibody against human ₂-GPI and by amino acid sequence analysis. aB₂-GPI levels in the sera from 36 APS patients were measured by ELISA using purified bovine ₂-GPI as an antigen. The mean±standard deviation level of aB₂-GPI was 17.4±22.0 units in the 58% of APS patients who were positive. There was a significant correlation (P=0.003) between aB₂-GPI and anticardiolipin antibody (aCL) levels. aB₂-GPI from the sera of patients with APS was inhibited by bovine ₂-GPI itself. Purified IgG from the sera of patients with APS showed that bovine ₂-GPI was capable of acting as a cofactor for aCL. Purified bovine ₂-GPI was useful antigen for conventional ELISA. aB₂-GPI may contribute to the further development of aCL analysis and to the understanding of the pathogenesis of APS.     

Anatomical structure of the isthmus between the inferior vena cava and tricuspid annulus investigated with a three-dimensional electroanatomical mapping system

We studied the anatomical structure of the isthmus between the inferior vena cava and tricuspid annulus in humans with a three-dimensional electroanatomical mapping system (CARTO, Biosense, Haifa, Israel). Fifteen patients with atrial flutter were studied. Thirteen patients had underlying heart disease. We investigated the anatomical structure of the isthmus with cross sections made from the three-dimensional right atrial map. The cross sections of the isthmus showed a concave shape in 7 patients (47%: group A), convex shape in 2 (13%: group B), and complex shape in 6 (40%: group C). The distance between the IVC and TA was 34 ± 17mm (group A), 25 ± 2mm (group B), 34 ± 16mm (group C), and 32 ± 15mm (Total), respectively. The distance between the top and bottom was 6 ± 5mm (group A), 3mm (group B), 6 ± 3mm (group C), and 6 ± 4mm (total), respectively. Seven of 15 patients exhibited an uneven surface of more than 5mm in depth and 4 of 15 patients had one of more than 10mm. The anatomical structure of the isthmus varies. To carry out precise catheter ablation, these variations should be taken into consideration to ensure an effective procedure.