Plasma levels of human granulocytic elastase α1-proteinase inhibitor complex (E-α1-PI) in leukemia

Summary There is evidence that polymorphonuclear granulocytes release neutral proteinases such as elastase (E) and cathepsin G in the course of acute leukemia. These proteinases may inactivate clotting factors by unspecific degradation before they are eliminated via complex formation with endogenous inhibitors, e. g. the ₁-proteinase inhibitor (₁-PI). In this study it was attemped to correlate plasma levels of the E-₁-PI complex with factor XIII and antithrombin III in acute leukemia. Using a newly developed, sensitive enzyme-linked immunoassay the concentration of E-₁-PI in patients with various types of leukemia, malignant lymphoma or multiple myeloma was determined. Only patients with acute myelocytic or promyelocytic leukemia (AML, APL) and chronic myelocytic leukemia with and without blastic transformation (CML) showed moderate to high levels of E-₁-PI (2- to 20-fold of normal). However, coagulation factor concentration observed in the different types of leukemia seemed to be independent of elastase liberation. Most of the AML-patients with elevated E-₁-PI levels showed peroxidase positive blood cell smears.     

Serum Levels of α1-Antitrypsin Predict Phenotypic Expression of the α1-Antitrypsin Gene

We conducted a retrospective analysis to determine if both ₁-antitrypsin serum level and phenotype need be studied when evaluating children for ₁-AT deficiency. We collected data from patients less than 19 years old who had both serum ₁-AT level and phenotype determined over a 9-year period (January 1992–December 2000). Eighty-eight patients were identified and 15 had the PiZZ phenotype. The serum ₁-AT level was below normal (normal 85–215 mg/dl) in all 15 PiZZ patients. Seventy-two of 73 non-PiZZ patients had normal or above normal serum levels. The sensitivity of the serum ₁-AT level was 100%, and the specificity was 99%. The serum ₁-AT level had a positive predictive value of 94% and a negative predictive value of 100%. We conclude that serum ₁-AT levels are highly predictive of the PiZZ phenotype. Determination of the serum ₁-AT level alone should be the initial test when evaluating for ₁-AT deficiency.     

Expression and secretion of alpha1-proteinase inhibitor are regulated by proinflammatory cytokines in human pancreatic islet cells

Aims/hypothesis Alpha1-proteinase inhibitor (1-PI) has been considered a key player in inflammatory processes. In humans, the main production site of 1-PI is the liver, but other tissues, including pancreatic islets, also synthesise this molecule. The aims of this study were to assess the islet cell types that produce 1-PI, to determine whether 1-PI is actually secreted by islet cells, and to assess how its production and/or secretion are regulated.Methods Expression of 1-PI in human islet cells was assessed by immunofluorescence, electron microscopy and western blotting. Release of 1-PI was analysed by reverse haemolytic plaque assay and ELISA. The effects of cytokines on 1-PI synthesis and secretion were tested.Results Immunofluorescence showed that alpha and delta cells do express 1-PI, whereas beta cells do not. By electron microscopy, we demonstrated a colocalisation of 1-PI with glucagon and somatostatin within secretory granules. Immunolabelling also revealed localisation of 1-PI within the Golgi apparatus, related vesicles and lysosomal structures. The expression of 1-PI in islet cells was also demonstrated by western blotting and ELISA of protein extracts. ELISA and reverse haemolytic plaque assay showed that 1-PI is secreted into the culture medium. Treatment of islet cells with IL-1 and oncostatin M for 4 days increased the production and release of 1-PI.Conclusions/interpretation Our results demonstrate that 1-PI is expressed by the alpha and delta cells of human islets, and that proinflammatory cytokines enhance the production and release of this inhibitor.     

Triplication (/ααα<Superscript>Anti3.7</Superscript>) or deletion (-α<Superscript>3.7</Superscript>/) association in Argentinian β-thalassemic carriers

Prevalence of alpha gene triplication or deletion in -thalassemia carriers was studied in 109 unrelated individuals in Rosario, Argentina. In different populations -^3.7 allele presents a higher prevalence than ^anti3.7; thus, -thalassemia associated with -thalassemia is more frequently observed. Nevertheless, this event was detected in only one case (0.9%), while the association with alpha triplication was present in two subjects (1.8%).     

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     

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.     

Rapid detection of −α 4.2 deletion of α-thalassemia-2 by polymerase chain reaction

Summary We sequenced part of the X boxes of-thalassemia-1 of Southeast Asia type (- -SEA) with– ^4.2,– ^3.7,– ^G-Taichung, and ^CS. We found the X box of– ^3.7 belonged to the X box of 2 globin gene and the X box of ^cs contained X boxes of both al and2 globin gene, whereas the X box of– ^4.2 and– ^G-Taichung was a hybrid of X boxes of 2 and 1 globin gene. We also found there are two types of– ^4.2 deletion; type 1 is a common type of– ^4.2 deletion and type 2 is linkage to– ^G-Taichung. We used a combination of two methods, the amplification refractory mutation system (ARMS) and the amplified created restriction sites (ACRS), to amplify the hybrids of X boxes specifically. The upstream primer for X box of2 globin gene was designed following the standard ARMS procedure to amplify the X segment of the-globin gene. The downstream primer was designed according to the ACRS method to check the specificity of PCR products. Using this approach, we can diagnose the different types of– ^4.2 deletion. This kind of approach can also be used to amplify the specific region from the cluster of highly homologous genes.     

Expression and prognostic roles of integrins and interleukin-1 receptor type I in patients with ductal adenocarcinoma of the pancreas

To Investigate the prognostic indicator, we examined the expression of ₆- and ₅- integrin and interleukin-1 receptor type I (IL-1RI) immunohistochemically, and analyzed the correlation between immunohistochemical findings and clinicopathological factors in pancreatic cancer. In patients with a strongly expressing ₆- integrin subunit or weakly expressing ₅₁-integrin in pancreatic cancer tissues there was a significant association with advanced TNM stage (P = 0.027 and 0.014, respectively), presence of liver metastases (P = 0.032 and 0.002, respectively), and poor prognosis (P = 0.0155 and 0.0056, respectively). In patients with a weakly expressing ₆ integrin subunit or weakly expressing ₅₁-integrin in noncancerous pancreatic tissues there was a significant association with poor prognosis (P = 0.0324 and 0.0396, respectively). Multivariate analysis demonstrated that strong expression of ₆- and weak expression of ₅₁-integrin were found to be independent prognosticators in pancreatic cancer patients. Our present results indicate that ₆₁- and ₅₁-integrin expression can be a significant prognostic indicator in pancreatic cancer.     

Lack of α2-Antiplasmin Enhances ADP Induced Platelet Micro-Aggregation through the Presence of Excess Active Plasmin in Mice

Background: The role of 2-antiplasmin (2-AP) on platelet aggregation was investigated using mice deficient in 2-AP (2-AP^–/–) or using wild type mice (2-AP^+/+). Methods: Blood samples were taken from each mouse under anesthesia with ether and platelet rich plasma (PRP) was prepared. Platelet aggregation induced by various doses of ADP (0.3–30 M) was detected using a laser-light scattering (LS) system. Aggregated forms were observed using a scanning electron microscopy (SEM). Results: Dose-dependent platelet aggregation was not different in both types of mice. However, platelet micro-aggregate formation in 2-AP^–/– mice induced by low dose of ADP (1.0 M) markedly increased compared to the situation in wild type mice. Aggregated form detected by SEM showed supported data from LS analysis. When washed platelets of 2-AP^+/+ mice were resuspended in plasma of 2-AP^–/– mice, platelet micro-aggregation was also increased. On the contrary, when washed platelets of 2-AP^–/– mice were suspended in plasma of 2-AP^+/+ mice, platelet micro-aggregation did not change. In separate experiments, tPA (1.0 g/ml) was added to PRP before the stimulation of ADP. tPA had no effect on platelet aggregation in 2-AP^+/+ mice, however platelet micro-aggregation in 2-AP^–/– mice was markedly increased by the treatment with tPA. Moreover, the amount of released ATP from stimulated platelets was increased in 2-AP^–/– mice treated with tPA. Conclusion: Lack of 2-AP increased platelet micro-aggregation, and plasmin plays an important role in the formation of platelet aggregation when 2-AP knockout mice are used. Consequently, the reduction of 2-AP could be a risk factor for the activation of platelets resulting in thrombus formation.     

Enhanced Expression of Transforming Growth Factor (TGF) -α Precursor and TGF-β1 During Paneth Cell Regeneration

An intravenous injection of diphenylthiocarbazone (dithizone), a zinc chelator, induces selective killing and rapid regeneration of Paneth cells, which have a large amount of zinc in their cytoplasmic granules. We examined the expression pattern of transforming growth factor (TGF) - and TGF-₁ in this regenerative process. Messenger RNA expression of TGF- and TGF-₁ reached their peaks at 12 and 24 hr after dithizone injection, respectively. Protein expression of TGF- precursor and TGF-₁ increased to a maximum at 24 and 72 hr, respectively. Their immunoreactivities were localized in the epithelial cells in the vicinity of Paneth cells, whereas they were prominent in the upper half of the crypts in control rats. In conclusion, destruction of Paneth cells induced TGF- precursor expression, followed by an increase of TGF-₁ especially in the crypt bases. This unique expression pattern of two growth factors may be involved in rapid regeneration of Paneth cells.     

Selective A2A adenosine agonist ATL-146e attenuates acute lethal liver injury in mice

Background d-Galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury is an experimental model of fulminant hepatic failure in which tumor necrosis factor- (TNF-) plays a pivotal role. We examined the effects of a highly selective adenosine A_2A receptor agonist (ATL-146e) on GalN/LPS-induced fulminant hepatic failure.Methods Mice were given an intraperitoneal dose of GalN (800mg/g body weight)/LPS (100ng/g body weight) with and without ATL-146e (0.01µg/kg) treatment. Liver injury was assessed biochemically and histologically. Also, TNF- levels in the serum were determined.Results The serum liver enzyme (ALT) level in vehicle-treated mice was 20960 ± 2800IU/ml and was reduced by 63% to 7800 ± 1670IU/ml by treatment with 0.01µg/kg per minute ATL146e, P < 0.05. Treatment with ATL-146e significantly reduced serum TNF- and greatly reduced inflammation assessed by histopathologic examination compared with control mice treated with GalN/LPS. ATL-146e also reduced lethality at 12h from 65% to 13%.Conclusion The present findings suggest that the highly selective adenosine A_2A receptor agonist (ATL-146e) prevents endotoxin-induced lethal liver injury by suppression of TNF- secretion.     

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.     

Effect of recombinant human transforming growth factor beta and tumor necrosis factor alpha on bone marrow progenitor cells of HIV-infected persons

Summary With progressive disease, the majority of patients with human immunodeficiency virus (HIV) infection develop bone marrow failure with anemia, leukopenia, and thrombocytopenia, the cause of which has not yet been clarified. Besides direct infection of bone marrow progenitor cells and immune-mediated cytolysis, the action of inhibitory cytokines, like transforming growth factor beta (TGF-) and tumor necrosis factor alpha (TNF-), has to be discussed with regard to their pathophysiological role in HIV-induced bone marrow failure. Therefore, the influence of recombinant human TGF- and TNF- on colony growth of pluripotent (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells from the bone marrow of HIV-1-infected persons and normal controls was assessed in methylcellulose cultures. Both cytokines inhibited the colony formation of hematopoietic progenitor cells from HIV-positive persons. When added to unseparated bone marrow cells from HIV-infected persons and normal controls, the 50% inhibition (ID₅₀) of BFU-E by TGF- occurred at 1.3 ng/ml and 3.7 ng/ml, respectively, while the ID₅₀ of CFU-GM occurred at 15.5 ng/ml and 142.7 ng/ml. Concentrations of TNF-, causing 50% inhibition of colony formation by bone marrow cells from HIV-infected or noninfected individuals were 6.3 U/ml and 17.0 U/ml for BFU-E, and 24.4 U/ml and >3,000 U/ml for CFU-GM, respectively. The ID₅₀ of the CFU-GEMM growth was below the lowest concentration of both cytokines tested. The suppressive effects were specifically abolished by antibodies against TGF- and TNF-, thus confirming that the inhibitory activities were due to the cytokine preparation used.The study was supported by a grant from theBundesgesundheitsamt     

Involvement of α2-Adrenoceptors in mechanism of intragastric nicotine protection against ethanol injury in rat stomach

To elucidate the role of - and -adrenoceptors in the mechanism of intragastric nicotine protection against ethanol-induced gastric mucosal injury, the following studies were performed. At 0.5-hr prior to the injury study, rats were pretreated with: subcutaneous control, prazosin (0.5 mg/kg) or yohimbine (5 mg/kg) to block ₁- or ₂-adrenoceptors; or intraperitoneal control, metoprolol (2 mg/kg) or butoxamine (4 mg/kg) to block ₁- or ₂-adrenoceptors, respectively. At 1-hr intervals, rats received intragastric vehicle or nicotine (4 mg/kg) and 40% ethanol (10 ml/kg). Total lengths of the linear gastric corpus mucosal lesions were measured by an unbiased observer using a caliper. In a separate study, 0.5-hr after subcutaneous control or yohimbine (5 mg/kg), rats were treated with intragastric vehicle or nicotine (4 mg/kg). One hour later, gastric mucus volume, gastric juice volume and pH, and titratable acid in the gastric juice were measured. In the rat stomach, the intragastric nicotine protection against 40% ethanol-induced mucosal injury was not blocked by selective ₁-(prazosin), ₁-(metoprolol), or ₂-(butoxamine) adrenoceptor antagonists. The protection was significantly reduced although not completely abolished by selective ₂-(yohimbine) adrenoceptor antagonist. Yohimbine also significantly reduced basal and nicotine-stimulated increase in gastric mucus volume. These data suggest that ₂-adrenoceptors are involved in the protective effect of intragastric nicotine against 40% ethanol-induced gastric mucosal injury possibly by a mucus-dependent mechanism.Supported by Veternas Administration Medical Research Funds, and in part by research grants (0162-01, 02, and 291-01) from the Smokeless Tobacco Research Council, Inc., and by funds (1RT 80) provided by the Cigarette and Tobacco Surtax Fund of the State of California through the Tobacco-Related Disease Research Program of the University of California to F.W.L. Dr. Endoh is a recipient of the University of California Tobacco-Related Disease Research Program Research Fellowship Award (FT 37).     

Mechanisms of transforming growth factor-alpha (TGF-alpha) induced gastroprotection against ethanol in the rat: roles of sensory neurons,sensory neuropeptides,and prostaglandins

The mechanisms by which transforming growth factor- (TGF-) protects the stomach against mucosal injury are incompletely understood. The aim of this study was to examine the roles of sensory neurons, sensory neuropeptides and prostaglandins in TGF gastroprotection against ethanol. Fasted rats received TGF- (50 g/kg, intraperitoneally) prior to orogastric ethanol (75% v/v, 1 ml). Gastric injury was quantitated 30 min after ethanol. Involvement of sensory neurons and the sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), were examined by capsaicin deafferentation and specific receptor antagonist infusion, respectively. Indomethacin (10 mg, intragastrically) was used to determine the role of prostaglandins in TGF--mediated gastroprotection. TGF- significantly diminished ethanol-induced gastric lesion area to 5.7 ± 0.8 mm² vs 4l.1 ± 5.2 mm² (P < 0.001). Sensory denervation and CGRP-receptor blockade abolished the TGF- protective effect. In contrast, SP antagonist and indomethacin did not alter TGF- gastroprotection. In conclusion, TGF--mediated gastroprotection involves sensory neuron activation and CGRP release and this protective effect did not involve substance P or prostaglandin generation.     

Serumglykoproteine beim Diabetes mellitus; quantitative immunologische Bestimmung von saurem α1-Glykoprotein,Gc, α2-Makroglobulin und Hämopexin bei Diabetikern mit und ohne Angiopathien

Zusammenfassung 1. Bei Diabetikern mit und ohne Gefäßkomplikationen wurden die Serumkonzentrationen des sauren ₁-Glykoproteins, der gruppen-spezifischen Komponente (Gc), des ₂-Makroglobulins und des Hämopexins mit der Immuno-Diffusions-Methode nachMancini und Mitarb. quantitativ bestimmt. — 2. Das ₂- Makroglobulin ist bei Diabetikern vermehrt, bei 276 Patienten fand sich ein Mittelwert von 242 mg% gegenüber einem Mittelwert von 186 mg% bei 98 nicht-diabetischen Blutspendern. Diese Differenz ist statistisch hochsignifikant. Der Konzentrationsanstieg ist bei jugendlichen Diabetikern stärker ausgeprägt als bei Altersdiabetikern. Bei Patienten mit Retinopathie findet sich eine deutlichere Vermehrung als bei Patienten ohne Retinopathie. Auch geht der Anstieg des ₂-Makroglobulins mit dem Schweregrad arteriosklerotischer Veränderungen der peripheren Gefäße parallel. — 3. Die Konzentrationen des sauren ₂-Glykoproteins und der gruppen-spezifischen Komponente sind in Seren von Diabetikern gegenüber gesunden Blutspendern nur unwesentlich vermehrt. — 4. Die Hämopexin Konzentration ist bei Diabetikern mit einem Mittelwert von 92 mg% gegenüber gesunden Blutspendern mit einem Mittelwert von 77 mg% gering erhöht; dieser geringe Unterschied ist statistisch hochsignifikant.

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Serum, glycoproteins in diabetes mellitus; quantitative immunological determination of acid ₁-glycoprotein, Gc, ₂-macroglobulin and haemopexin in diabetics with and without angiopathy

Summary 1. Serum concentrations of acid ₁-glycoprotein, Gc, ₂-macroglobulin and haemopexin were determined in diabetics with and without vascular complications by the immunological assay method ofMancint and co-workers. — 2. ₂-macroglobulin concentrations were increased in sera of diabetics. The mean value was 242 mg% in 276 patients compared with the mean value of 186 mg% in a sample of 98 healthy blood-donors. This difference is statistically highly significant. The increase was more pronounced in juvenile diabetes than in late-onset diabetes. The increase was also more pronounced in patients with retinopathy than in patients without retinopathy. There was also an increase of ₂- macroglobulin concentrations in relation to the degree of arteriosclerotic changes of the peripheral vessels. — 3. Serum concentrations of acid ₁-glycoprotein and Gc were only slightly increased in diabetics compared with blood-donors. — 4. There was a small, but statistically highly significant increase of haemopexin concentrations in sera of diabetics. The mean value in 243 diabetics was 92 mg%, in 15 healthy blood-donors a mean value of only 77 mg% was found.

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft     

Calcium channel blocker treatment of tumor cells induces alterations in the cytoskeleton,mobility of the integrin αIIbβ3 and tumor-cell-induced platelet aggregation

Summary Calcium channel blockers of the phenylalkylamine (i.e. verapamil), benzothiazepine (i.e. diltiazem) and dihydropyridine (i.e. nifedipine) classes were evaluated for effects on the tumor cell/platelet interactions using Walker 256 carcinosarcoma cells (W256 cells). When W256 cells were pretreated for 15 min with channel blockers at concentrations of 50–200 M, macroscopic tumor-cell-induced platelet aggregation was inhibited (order of potency; nifedipine>diltiazemverapamil). However, ultrastructural analysis revealed limited, focal platelet aggregates associated with tumor cell plasma membranes of verapamil- and diltiazem-treated cells. There was no evidence of platelet activation or platelet association with the tumor cell membrane in cells pretreated with nifedipine. Walker 256 cells possess the integrin _IIb3. Tumor cell _IIb3 was shown to mediate tumor cell/platelet interactions in vitro [Chopra et al. (1988) Cancer Res. 48:3787]. Patching and capping of surface _IIb3 were inhibited by nifedipine>diltiazemverapamil. The degree of inhibition of _IIb3 receptor mobility parallels the inhibition of tumor-cell-induced platelet aggregation. W256 cells are characterized by a well-developed microfilament and intermediate filament network and by the absence of a distinct microtubular network. Calcium channel blockers had no effect on the low polymerization level of tubulin. However, they induced rearrangement of microfilament stress fibers. Intermediate filaments were also rearranged but to varying degrees. The order of effectiveness for alteration of intermediate filament organization was nifedipine>diltiazem while verapamil was ineffective. We propose that the previously reported inhibition of tumor cell/platelet interaction and tumor cell metastasis by calcium channel blockers [Honn et al. (1984) Clin Exp Metastasis 1:61] is due not only to the effects of the Ca²⁺ channel blockers on platelets, but also to their effect on the tumor cell cytoskeleton resulting in an inhibition of the mobility and function of the _IIb3 receptor.Abbreviations CCB calcium channel blocker - _IIb3 platelet glycoprotein IIb/IIIa complex - TCIPA tumor cell induced platelet aggregation - W256 Walker 256 carcinosarcoma This work was supported by Public Health Service grant CA-47115, a grant from Harper Hospital and a grant from the Veterans Administration     

Interferon Alfacon-1 and Ribavirin Versus Interferon α-2b and Ribavirin in the Treatment of Chronic Hepatitis C

Despite advances in the therapy of chronic hepatitis C, a large number of patients do not respond to current therapies. The study objective was to assess whether a combination of interferon (IFN) alfacon-1 and ribavirin improves the response rate compared with a combination of INF -2b and ribavirin in chronic hepatitis C subjects. The study was designed as an open-label, prospective, randomized, controlled study; 128 subjects with chronic hepatitis C were randomized to INF alfacon-1, 15 g three times per week, plus ribavirin, 1 g/day, or IFN-2b, 3 million units three times per week, plus ribavirin, 1 g/day for 48 weeks. The end point of the study was a sustained viral response, defined as undetectable HCV RNA at 24 weeks post 48 weeks of treatment. Overall, 57% of subjects in the INF alfacon-1/ribavirin group achieved a sustained antiviral response, compared with 40% of subjects in the IFN-2b/ribavirin group (P = 0.052). In the subset of subjects with a high viral load, HCV RNA was successfully eradicated in more individuals who received INF alfacon-1/ribavirin than subjects who received IFN-2b/ribavirin (57 versus 31%; P = 0.025). Among individuals with genotype 1 and a high viral load, the sustained antiviral response was significantly higher with INF alfacon-1/ribavirin than with IFN-2b/ribavirin (46 versus 14%; P = 0.019). Adverse events were similar in both treatment groups. In conclusion, this study demonstrated that the combination of INF alfacon-1 and ribavirin provides a significantly better treatment response compared with the combination of IFN- 2b and ribavirin in chronic HCV subjects infected with genotype 1 and a high viral RNA load.     

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.     

Interactive influences of peroxisome proliferator-activated receptor α activation and glucocorticoids on pancreatic beta cell compensation in insulin resistance induced by dietary saturated fat in the rat

Aims/hypothesis We sought to elucidate whether excess glucocorticoids and increased dietary lipids act synergistically to impair glucose tolerance and, if so, whether activation of peroxisome proliferator-activated receptor (PPAR) has an adverse or beneficial effect on glucose tolerance.Methods Dexamethasone (100 g kg^–1 body weight day^–1; 5 days) was administered to insulin-resistant rats fed a high-saturated-fat (HF) diet for 4weeks. The PPAR agonist WY14643 was administered (50 mg kg^–1 body weight intraperitoneally) 24 h before sampling. Glucose-stimulated insulin secretion (GSIS) was assessed in vivo after an acute glucose bolus injection, and in vitro using step-up and step-down islet perifusions.Results Although neither PPAR activation nor dexamethasone alone affected fasting glycaemia in the HF group, dexamethasone in combination with PPAR activation elicited marked postabsorptive hyperglycaemia. Dexamethasone treatment of HF rats had little effect on GSIS after an acute glucose challenge in vivo, but induced glucose intolerance. PPAR activation augmented GSIS in dexamethasone-treated HF rats in vivo, restoring glucose tolerance. Contrasting with data obtained in vivo, greatly enhanced peak rates of GSIS were observed ex vivo in perifusions of islets from dexamethasone-treated HF rats compared with those from untreated HF rats, an effect attenuated by antecedent PPAR activation.Conclusions/interpretation The study demonstrates that glucocorticoid excess precipitates the development of glucose intolerance in rats maintained on a high-saturated-fat diet. It does this by interrupting the negative feedback loop between insulin sensitivity and secretion in vivo, such that further enhancement of compensatory insulin secretion is not possible. PPAR activation restores the coupling between insulin secretion and action.