Gabexate mesilate, a synthetic protease inhibitor, attenuates carbon tetrachloride-induced liver injury in rats

Background Gabexate mesilate, a synthetic protease inhibitor, is used to treat acute pancreatitis and disseminated intravascular coagulation because it inhibits various serine proteases; however, whether gabexate mesilate prevents acute liver failure has not yet been studied. The aim of the present study was to investigate the effect of gabexate mesilate in carbon tetrachloride (CCl₄)-induced liver injury in rats.Methods Acute hepatic failure was induced by administration of CCl₄ intragastrically to male Sprague–Dawley rats. The effects of gabexate mesilate were examined in terms of serum transaminase levels, liver histology, and the prognosis of rats.Results Gabexate mesilate treatment significantly decreased the elevation of serum transaminase levels and improved liver histology 24h after the administration of CCl₄ (0.2ml/100g rat weight). Plasma tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) decreased significantly in the gabexate mesilate-treated rats compared with saline-treated rats. Gabexate mesilate treatment also significantly improved survival rate after a lethal dose of CCl₄ (0.5ml/100g rat weight) from 0% to 20%.Conclusions Gabexate mesilate treatment attenuated CCl₄-induced liver injury via a suppression of proinflammatory cytokine production. In addition, these investigations suggest that gabexate mesilate treatment may provide therapeutic strategies for human acute liver failure.     

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.     

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.     

Der Patient als Keimquelle in der Intensivpflegestation

Zusammenfassung 133 Patienten einer Intensivpflegestation, die bei der Aufnahme keine Symptome bakterieller Infektion zeigten und noch keine Antibiotika erhalten hatten, wurden nach dem Zufallsprinzip zwei Gruppen zugeordnet. Eine Gruppe (+Pat.) erhielt eine Antibiotikaprophylaxe mit Penicillinen oder Cephalosporinen, die zweite Gruppe (–Pat.) erhielt keine Antibiotika. Staph. aureus war bei –Pat. im Trachealsekret und in der Umgebung der häufigste potentiell pathogene Keim. Staph. aureus war im Trachealsekret und in der Umgebung der –Pat. signifikant häufiger als bei +Pat.. Klebsiella spp. standen im Trachealsekret und in der Umgebung von +Pat. an erster Stelle. Sie waren im Trachealsekret von +Pat. signifikant häufiger als bei –Pat.. In der ersten Woche des Stationsaufenthaltes traten bei +Pat. starke Veränderungen in der Keimflora der Trachealsekrete auf: die Besiedelung mit gramnegativen Keimen stieg auf fast 100% an, gleichzeitig ging die Frequenz von Staph. aureus zurück. In den Abklatschuntersuchungen aus der Patientenumgebung traten gramnegative Stäbchen bei +Pat. in signifikant höheren Koloniezahlen auf als bei –Pat.. Die paarweisen Vergleiche von Bakterienstämmen aus den Trachealsekreten und aus der Patientenumgebung ergaben, daß +Pat. gramnegative Keime und –Pat. Staph. aureus signifikant häufiger an die Umgebung abgaben. Auf die Kontamination der Patientenumgebung mit Staph. aureus wirkte sich der Faktor der trachealen Intubation nicht aus. Gramnegative Keime waren im Trachealsekret von intubierten Patienten signifikant häufiger als bei nicht intubierten. Derselbe Trend zeigte sich auch in der Patientenumgebung. Die Antibiotikaprophylaxe konnte, wie die klinischen Ergebnisse der Studie zeigten, die Patienten nicht im erwarteten Ausmaß vor Infektionen schützen. Patienten, insbesondere tracheal-intubierte, die Antibiotika erhalten, sind als Streuquellen für hochresistente gramnegative Keime anzusehen.

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The patient as a source of bacteria in intensive care units: Influence of antibiotics and tracheal intubation

Summary 133 patients in an intensive care unit, who prior to admission had not shown any signs of bacterial infection and had not received antibiotic treatment, were assigned to two groups at random. One group received antibiotic prophylaxis with penicillins or cephalosporins (+Pat.), the other group did not receive antibiotics (–Pat.). Staph. aureus was the most frequent facultative pathogen in tracheal secretions and in the environment of –Pat.. This organism was significantly more frequent in –Pat. than in +Pat. in both the tracheal secretions and the enviroment. Klebsiella spp. outnumbered all other species in +Pat.. They were significantly more frequent in tracheal secretions of +Pat. than of –Pat.. In the first week of hospitalisation marked changes were seen in bacterial flora of tracheal secretions of +Pat.. Colonization with gramnegative bacteria rose to nearly 100%, the frequency of Staph. aureus diminishing at the same time. Monitoring by contact cultures revealed that gramnegative rods were significantly more numerous in the environment of +Pat. than of –Pat.. Matching bacterial strains cultured from tracheal secretions and from the environment of the patients proved that +Pat. spread significantly higher numbers of their gramnegative bacteria into the environment. The same is true of –Pat. for Staph. aureus. Intubation had no noticeable effect on the degree of contamination of the surroundings with Staph. aureus. Gramnegative rods were significantly more frequent in tracheal secretions of patients with intubation than in patients without. The same trend was observed for environmental contamination. As the clinical results of this study have shown, antibiotic prophylaxis does not protect patients from infections to the extent expected. Patients, and particularly intubated patients, receiving antibiotic treatment have to be considered as sources of highly resistant gramnegative organisms.

     

Phase contrast studies on mitotic cycle of pernicious anemia megaloblasts after vitamin B12 treatment

Summary Phase-contrast observations show that the mitotic time in vitro of erythropoietic cells (intermediate erythroblasts) from pernicious anemia patients 36 hours after the onset of Vit. B₁₂ therapy appears consistently longer than in megaloblasts from untreated patients. The duration of mitosis appears unchanged in erythropoietic cells from patients at the 4th day after the onset of treatment (definitive erythroblasts), in respect of intermediate erythroblasts. Both mitotic time of intermediate and definitive erythroblasts do not significantly differ from that of normoblasts from healthy patients. Maturation induces a lengthening of mitosis at a higher degree in intermediate, definitive and normal erythroblasts, than in megaloblasts. In connection with the increase in mitotic time, all mitotic phases are also prolonged, but at a different degree for each phase. These Authors claim that the proliferative potentials of intermediate, definitive, and normal erythroblasts are lower than that of megaloblasts from untreated patients.

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Zusammenfassung Phasenkontrastbeobachtungen zeigen, daß die Dauer der Mitose in vitro von erythropoetischen Zellen (intermediäre Erythroblasten) von Kranken mit perniziöser Anämie 36 Stunden nach Beginn einer Vit.-B₁₂-Behandlung durchwegs länger erscheint, als bei Megaloblasten von unbehandelten Kranken. Die Dauer der Mitose bei erythropoetischen Zellen von Kranken am 4. Tag nach Beginn der Behandlung (definitive Erythroblasten) scheint in bezug auf intermediäre Erythroblasten unverändert zu sein. Die Mitosezeit von intermediäre sowie von definitiven Erythroblasten unterscheidet sich nicht signifikant von der von Normoblasten gesunder Personen. Die Reifung verursacht eine Verlängerung der Mitose in höherem Maße bei intermediären, definitiven und der normalen Erythroblasten, als bei Megaloblasten. In Verbindung mit der Verlängerung der Mitosezeit werden auch alle Mitosephasen verlängert; jedoch in einem für jede Phase verschiedenen Ausmaß. Nach Ansicht der Autoren ist das Vermehrungspotential intermediärer, definitiver und normaler Erythroblasten niedriger, als das von Megaloblasten unbehandelter Kranker.

     

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.     

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.

     

Interferonγ and tumour necrosis factorα induce a synergistic antiproliferative response in human Ewing's sarcoma cells in vitro

Three human cell lines derived from Ewing's sarcoma (RM-82, VH-64, and WE-68) were investigated to establish the influence of recombinant human interferon (rhIFN) and tumour necrosis factor (rhTNF) on cell proliferation and survival and to characterize IFN and TNF receptor expression. Incorporation of [³H]thymidine into cells was inhibited by rhIFN after 24 h of incubation. Half-maximal inhibition was observed with 10–80 U/ml rhIFN. A maximal effect (50%–70% inhibition of cell proliferation) was achieved by treatment of cells with 250 U/ml rhIFN. The influence of rhTNF on proliferation was found to differ among cell lines and varied with the concentration and the duration of exposure of cells to this cytokine. In WE-68 and VH-64 cells [³H]thymidine incorporation was not affected by rhTNF up to 2000 U/ml after 96 h of incubation, where-as in RM-82 cells the incorporation was inhibited by 35% after 48 h of incubation with 100 U/ml rhTNF. However, all cell lines showed a synergistic antiproliferative response to the combination of rhIFN and rhTNF after 24 h of incubation. The human recombinant cytokines interleukin(IL)-1, IL-1, IL-2, IL-3, IL-4, IL-6 and granulocyte/macrophagecolony-stimulating factor, tested alone and in combination with rhIFN and rhTNF, had no influence on cell proliferation. Binding studies in the cell lines with¹²⁵I-rhIFN revealed a dissociation constant (K _d ) of 160–306 pM and approximately 8000–13500 receptors/cell. Binding experiments with¹²⁵I-rhTNF indicated 430–1250 receptors/cell withK _d ranging from 13 pM to 162 pM. These data indicate that, among various cytokines, only IFN and TNF are capable of potently reducing Ewing's sarcoma cell growth in vitro. Our data suggest that IFN alone or in combination with TNF may be useful in the design of novel strategies in Ewing's sarcoma therapy.     

Bone marrow and peripheral blood globin chain biosynthesis in iron deficiency

Summary Globin chain synthesis was studied in 13 iron-deficient patients. The mean whole-cell globin / ratio in the peripheral blood of 11 patients was 1.05±0.06 which is similar to the value 0.99±0.08 obtained for 10 controls. The ratios odtained for stroma-free globin were not significantly different from those of whole cell preparations. In contrast, the / ratio of bone marrow was 0.73±0.14 in 10 iron deficient patients, which is significantly lower than that of controls. Two other patients had decreased / ratios in the peripheral blood, probably because of the presence of an -thalassemia gene. These results demonstrate a reduced rate of synthesis of chains relative to that of chains in the bone marrow of iron-deficient patients that is not demonstrable in the peripheral blood.This work was partly supported by Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil     

Plasma lysosomal enzyme levels in patients with motor neuron disease

Summary -Hexosaminidase and acid--mannosidase were estimated in 17 adult patients with motor neuron disease. Normal plasma levels of -hexosaminidase ((A+B) and A) were found in all patients studied. Plasma acid -mannosidase levels were normal in all but two patients with the spinal muscular atrophy type of the disorder. In addition, altered biochemical properties of acid -mannosidase (i.e.K _m, thermal stability) were found in the low-activity cases.     

Follow-up of “non-diabetic” relatives of diabetics by retesting oral glucose tolerance after 5 years

Summary Of 743 first degree relatives of diabetics in whom oral glucose tolerance tests had been performed in 1967 488 were re-tested in 1972. Among the original normals (n = 353) 17.6% had developed a subclinical and 1.3% an overt diabetes within 5 years. The original subclinical diabetics (n = 118) showed a remission to normal in 35.6% and a progression to overt diabetes in 13.6%. 3 out of the 17 formerly overt diabetics were found to be normal after 5 years and 3 were subclinical diabetics. Thus the performance of an oral glucose tolerance test is of limited prognostic value in the individual case. In both studies a higher prevalence of abnormal test results occurred in the older age groups and in overweight subjects. Remission or deterioration did not depend, however, on age or on weight changes. The frequency of abnormal tests was higher in males than in females, but the tendency towards the development of diabetes was more pronounced in females, in accordance with a previous observation of a higher age dependance of glucose tolerance in females.     

Cooperative effects of gamma-interferon and 1α, 25-dihydroxyvitamin D3 on in vitro differentiation of the blast cells of RAEB and RAEB-T

Summary We added recombinant human gammainterferon (-IFN) and 1 , 25-dihydroxyvitamin D₃ (1 , 25 (OH)₂D₃) to the bone marrow cells from six patients with RAEB or RAEB-T in liquid suspension cultures. After cultivation for 7 to 9 days, numerical, morphological and functional changes of the cells were assessed. -IFN and 1 , 25 (OH)₂D₃ additively suppressed cell growth, especially the number of blast cells decreased. The expression of -naphthylbutyrate esterase (NBE) activity appeared to be promoted but that of naphthol AS-D chloroacetate esterase (NAE) activity was apparently suppressed by the addition of -IFN and/or 1 , 25 (OH)₂D₃. The percentage of NBT reduction-positive cells and latex-phagocytizing cells was only slightly increased by both agents. These results indicate that -IFN and 1 , 25 (OH)₂D₃ cooperate to induce monocytoid differentiation of the patients' blast cells. Combination therapy with both agents merits further study.     

Prognostic relevance of histological findings on bone marrow biopsy in myelodysplastic syndromes

Summary Bone marrow biopsy (BMB) has aroused growing interest as a possible aid in the diagnostic and prognostic evaluation of myelodysplastic syndromes (MDS). Previous reports have pointed out that MDS patients with blastic aggregates or severe bone marrow (BM) fibrosis are characterized by a worse clinical outcome. BMBs of 106 MDS patients were retrospectively reviewed, and relationships among the different histological parameters as well as clinicopathological correlations were looked for. Three patterns of BM blastic infiltration (diffuse, cluster, and large) were recognized. Overt leukemic transformation and overall survival were selected as prognostic end points. BM infiltration was diffuse in 18, cluster in 48, and large in 40 cases. RAEB-t patients accounted for about half of the large cases, and none had a diffuse pattern (p<0.01). Nineteen patients showed extensive BM fibrosis; most of them were characterized by cluster blastic infiltration and megakaryocyte hyperplasia. Leukemic transformation occurred in 67% of large cases (p<0.001) and in none of the cluster cases with severe BM fibrosis (p<0.01); however, survival was equally poor in these two groups because of early leukemic transformation (large cases) and BM failure (cluster cases). The FAB classification did not significantly correlate with prognosis. Patients with cluster BM infiltration and severe fibrosis can be regarded as a true separate MDS subset characterized by unique clinicopathological and prognostic features. Because of the subacute clinical behavior of most cases, and the poor performance status of many elderly patients, there is still controversy as to the best therapeutic approach in MDS. Histological analysis allowed two groups of MDS patients to be identified, both characterized by poor life expectancy, who could benefit from early aggressive chemotherapy.     

Local and Systemic Liberation of Proinflammatory Cytokines in Ulcerative Colitis

Determination of plasma and tissue cytokinelevels in inflammatory bowel disease have frequentlyresulted in conflicting data. In the present study wedetermined in patients with ulcerative colitis (UC), the levels of the proinflammatory cytokinesinterleukin (IL)-1, IL-6, interferon(IFN)-, and tumor-necrosis factor (TNF)-liberated by peripheral blood mononuclear cells (PBMC)and lamina propria mononuclear cells (LPMC) after 48-hrculture with pokeweed mitogen (PWM). IL-1, IL-6,IFN- and TNF- in the supernatant weredetected by ELISA. Results show low basal levels ofIL-1 secretion by PBMC and LPMC, and a considerableincrease after mitogen stimulation. Basal IL-6production by PBMC was higher in UC patients than incontrols [2029 pg/ml, CI₉ (–165 to4223) vs 572 pg/ml (–383 to 1527) respectively, P = 0.05] and also afterPWM activation [14,995 pg/ml (7759 -22230) vs 6598 pg/ml(3240-9956), respectively, P = 0.05]. In LPMC, nodifferences in IL-6 secretion were observed. TNF- in activated PBMC of patients with UC was notsignificantly increased in relation to control (P =0.09). No constitutive secretion of IFN- wasobserved in mononuclear cells. IFN- levelssecreted by activated LPMC were lower in patients withUC than in controls [1571 pg/ml (–108 to 3251) vs7953 pg/ml (3851-12,055), respectively, P = 0.03]. Theseresults suggest that IL-6, IL-1, and TNF- participate as mediators in the inflammatoryphenomena observed in UC. Further studies are necessaryto evaluate the role of IFN- in thiscondition.     

Presence of Two Signaling TGF-β Receptors in Human Pancreatic Cancer Correlates with Advanced Tumor Stage

Transforming growth factor- (TGF-)signal transduction is mediated via specific cellsurface signaling TGF- receptors, most notably thetype I ALK5 (TR-I_ALK5)and the type II(TR-II). We evaluated TR-I_ALK5 andTR-II expression in 41 human pancreatic cancertissue samples and correlated these findings withclinical data of the patients. Northern blot analysisindicated that, in comparison with the normal pancreas,pancreatic adenocarcinomas exhibited 8.0-fold and4.5-fold increases (P < 0.01), respectively, in mRNAlevels encoding TR-I_ALK5 andTR-II. In situ hybridization showed that both TR-I_ALK5 mRNAwere highly expressed in the majority of pancreaticcancer cells. Immunohistochemical analysis ofTR-I_ALK5 and TR-II revealedpositive immunostaining in 73% and 56% of the tumors, respectively. Both receptorswere concomitantly present in 54% of the pancreaticcancer samples. The presence ofTR-I_ALK5 or TR-II and theconcomitant presence of TR-I_ALK5 and TR-II in the cancer cells was associatedwith advanced tumor stage (P < 0.01). These findingsshow that in many human pancreatic cancers, increasedlevels of the two signaling TRs are present. The presence of the signaling TRs inadvanced tumor stages indicates a role in diseaseprogression.     

Regulation of the release of tumour necrosis factor (TNF)α and soluble TNF Receptor by γ irradiation and interferon γ in Ewing's sarcoma/peripheral primitive neuroectodermal tumour cells

This study analyses the production of tumour necrosis factor (TNF) and soluble TNF receptor (sTNF-R) before and after exposure to irradiation and interferon (IFN) in 12 cell lines derived from Ewing's sarcoma (ES)/peripheral primitive neuroectodermal tumours (pPNET). Supernatants from ES/pPNET cell cultures were tested in a TNF-specific amplified enzyme-linked immunosorbent assay (ELISA), a bioassay, and sTNF-R_p55 and sTNF-R_p75 ELISA. The tumour cell lines released minimal amounts of TNF, prominent amounts of sTNF-R_p55 (7/12 cell lines) and no sTNF-R_p75. Exposure to irradiation (5 Gy) either induced (3/12) cell lines) or up-regulated (3/12 cell lines) TNF release without changing sTNF-R_p55 and sTNF-R_p75 levels. Priming of cultures with recombinant human IFN (rhIFN) markedly enhanced TNF secretion in the radiation-responsive cell lines and had no influence on sTNF-R_p55 and sTNF-R_p75 levels. rhIFN affected the magnitude rather than the sensitivity of the radiation response. The TNF secreted was bioactive, as shown by its cytotoxic effect of WEHI-164 cells, and neutralization of its activity by anti-TNF monoclonal antibody. Herbimycin A (a tyrosine-specific protein kinase inhibitor) but not calphostin C (a protein kinase C inhibitor), H89 (a protein kinase A inhibitor), AACOCF3 (a specific inhibitor of phospholipase A₂) and MK-886 (a specific inhibitor of 5-lipoxygenase) abrogated -irradiation-stimulated TNF release. The antioxidantsN-acetylcysteine, nordihydroguaiaretic acid and mepacrine dose-dependently inhibited -irradiation-mediated TNF production. Collectively our findings indicate that IFN priming potentiates the secretion of bioactive TNF by ES/pPNET cells in response to irradiation without affecting sTNF-R release. The data suggest a requirement for protein tyrosine kinase activity and a role for reactive oxygen species in the -irradiation-mediated intracellular signalling pathway leading to TNF production.     

Heterophilic interactions between cell adhesion molecule L1 and α<Subscript>v</Subscript> β<Subscript>3</Subscript>-integrin induce HUVEC process extension <Emphasis Type="Italic">in vitro</Emphasis> and angiogenesis <Emphasis Type="Italic">in vivo</Emphasis>

Cell adhesion molecule L1 was implicated in angiogenic processes, tumor formation and metastasis. Here, we provide evidence that the sixth Ig-like domain of L1 (L1Ig6) interacts with _{v 3} to induce process extension of human umbilical vein endothelial cells (HUVECs) in vitro and angiogenesis in vivo. HUVECs formed network-like structures on full-length L1 or L1Ig6 substrates comparable to structures found on matrigel. In the presence of mab _{v 3} or cyclic RGD, apoptosis was induced. In fibrin matrices where L1Ig6 was covalently incorporated, HUVECs formed multicellular and hollow processes through interactions between cell-surface _{v 3} and RGD-sites of matrix-immobilized L1Ig6. No such processes were induced by L1Ig6 having non-functional RDG-sites, or in the presence of mab _{v 3} or cyclic RGD. In those matrices, increased apoptosis was found. Co-immunoprecipitation of L1 or L1Ig6 with _{v 3} suggests close interactions. Furthermore, L1Ig6 stimulated HUVECs showed increased tyrosine phosphorylation of _{v 3} and phosphorylation of MAP kinases (ERK1 and ERK2) but not AKT indicating specific activation of _v and _{v 3} followed by activation of downstream kinases. Application of L1Ig6-modified fibrin matrices on CAMs induced 50–60% increased _v and _v3 protein expression and in vivo angiogenesis indicated by ~50% increased mean vascular length density. The results demonstrate angiogenic potential of L1Ig6 involving ligation and activation of _v3     

Differential expression of cell surface integrins on human mast cells and human basophils

Summary Integrins are multifunctional recognition molecules and are expressed on various hematopoietic cells. In the present study expression of integrins on the cell surface of human mast cells and human basophils was investigated by using monoclonal antibodies (mAbs) and indirect immunofluorescence. Human mast cells were obtained from lung (n = 5), uterus (n = 5) and skin (n = 4). Human blood basophils were obtained from normal donors (n = 2). In addition, HMC-1 cells (human mast cell line) and KU-812 cells (a basophil cell line) were analyzed. Primary mast cells were found to react with mAbs directed against the common chain of 1 integrins (CD 29), the chain of VLA-4 (CD49d) and VLA-5 (CD49e), the chain of 3 integrins (CD 61), and the chain of the vitronectin receptor (VNR) (CD 51). Mast cells were not recognized by mAbs to 2 integrins (CD 18, CD 11 a, CD 11b, CD 11c), the chain of VLA-2 (CD 49 b), and VLA-6 (CD 49 f). No differences in expression of integrins on human mast cells obtained from different organs were found. HMC-1 cells and primary mast cells expressed an almost identical pattern of integrins. Human basophils and KU-812 cells were found to react with mAbs directed against 1-integrins (CD 29, CD 49 b, CD 49 d, CD 49 e) and 2-integrins (CD 18, CD 11 a, CD 11 b, CD 11 c). Together, mast cells and blood basophils express a unique pattern of integrins. These cell surface structures may be involved in the distribution of basophils and tissue mast cells and their accumulation and function in inflammed tissues.Supported by theFonds zur Förderung der Wissenschaftlichen Forschung in Österreich, grant no. P-7891     

Variation of lysosomal enzyme activity with gestational age in chorionic villi

Summary The activities of 14 lysosomal enzymes in chorionic villi at gestational ages of 6–12 weeks were assayed.Arylsulphatases A and B, -glucosidase and -glucuronidase activities increased with advancing gestational age. When compared with the activity in cultured amniotic fluid cells, arylsulphatase A, -galactosidase, -glucosidase, heparan N-sulphatase, -l-iduronidase, -mannosidase, neuraminidase and sphingomyelinase showed significant differences. All except -glucuronidase showed lower activity in chorionic villi than in cultured amniotic fluid cells. Prenatal diagnosis using chorionic villi was possible except for -l-iduronidase.Storage at –20°C up to 42 days did not significantly affect activity. The results emphasize the importance of using fresh or frozen age-matched control tissue for diagnosis.     

Serum cytokines in patients with rheumatoid arthritis

Serum cytokines such as interleukin 1 (IL-1), interferon (IFN-), and tumor necrosis factor (TNF) were measured in 40 patients with rheumatoid arthritis (RA). In the 40 patients studied, serum IL-1 was detected in 5 patients, IFN- in 10 patients, and TNF in 20 patients. The IL-1-positive group showed increased values of activity indices compared to the IL-1-negative group. Values of serum IFN- correlated well with the number of peripheral blood lymphocytes and CD3⁺ cells and with the percentage of CD3⁺ CD26⁺ cells. Values of serum TNF correlated positively with the number of peripheral blood monocytes and the percentage of CD3⁺ HLA-DR⁺ and CD3⁺ CD25⁺ cells. These results indicated that serum IL-1 in RA patients reflects the activity of RA, while the serum IFN- and TNF in RA patients may be related to circulating activated lymphocytes and monocytes, respectively.