Characterization of integrin subunits,cellular adhesion and tumorgenicity of four human prostate cell lines

Cellular adhesion to extracellular matrix proteins via integrin molecules is a major factor in the process of invasion and metastasis of human tumor cells. Four human prostate cell lines were characterized according to the presence and quantity of integrin subunits, the ability of the cells to attach to extracellular substrates and the capacity of the cells to form tumors in severe combined immunodeficient (SCID) mice. All four human prostate cell lines expressed three to five integrins on their cell surfaces. The DU145, PC3 and 431P cells expressed primarily ₃, ₅, and ₆ integrin at similar levels. These cell lines expressed the subunits ₁, ₃ and ₄ with ₁ predominant. The DU145 cells preferred attachment to fibronectin, followed by laminin and vitronectin. Approximately 50%–60% of the binding of DU145 cells to fibronectin and laminin was dependent on the function of ₅₁ and ₆ respectively. The cell line LNCaP differed in its low expression of the ₃ subunit, 95% of cellular adhesion to fobronectin and laminin being integrin-dependent and its inability to attach to vitronectin, in spite of surface expression of _v3. All the cell lines except for LNCaP readily formed tumors within SCID mice and the expression of ₃, ₆, ₁, and ₄ integrin subunits was preserved in the resulting tumor tissue. The altered adhesion properties of the LNCaP cells may explain their altered tumorigenicity.Abbreviations SCID severe combined immunodeficiency - FITC fluorescein isothiocynate - FACS fluorescence-activated cell sorting - PBS phosphate-buffered saline - FBS fetal bovine serum This work was supported in part by a grant from the Friends of the Arizona Cancer Center, Phoenix Chapter, is ACS grant PDT-388 and CH-467 and CA 56666     

α1-antitrypsin deficiency and liver disease

Summary ₁-Antitrypsin (₁AT) deficiency, one of the most common lethal hereditary disorders among Caucasians, is associated with emphysema in adults, while in children it is associated with liver disease. Produced in the liver and released into the plasma, ₁AT serves as the body's major inhibitor of neutrophil elastase, a powerful proteolytic enzyme capable of degrading extracellular structural proteins. The pathogenesis of the liver disease associated with ₁AT deficiency is not as well understood, but is clearly linked to specific mutations in coding exons of the ₁AT gene, and the resulting accumulation of ₁AT within hepatocytes. At present, therapy for the liver disease associated with ₁AT deficiency is symptomatic, with liver transplantation as a last resort. New strategies are being developed to suppress the accumulation of ₁AT by transferring the normal gene into the liver.     

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.     

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%).     

A fluorimetric enzyme assay for the diagnosis of sanfilippo disease type A (MPS IIIA)

Summary 4-Methylumbelliferyl--d-N-sulphoglucosaminide (MU--GlcNS) was synthesized and shown to be a substrate for the lysosomal heparin sulphamidase. Sanfilippo A patients' fibroblasts (n=42) and lymphocytes (n=1) showed 0–3% of mean normal heparin sulphamidase activity; in total leukocytes from patients (n=8) sulphamidase activity was clearly deficient. In fibroblasts from obligate heterozygotes for Sanfilippo A, the sulphamidase activity was reduced in 9 out of 10 cases. Heparin sulphamidase desulphates MU-GlcNS to MU-GlcNH₂ and further hydrolysis during a second incubation is required to liberate 4-methylumbelliferone, which can be measured. Yeast-glucosidase, which has low but sufficient-glucosaminidase activity, was used to hydrolyse the reaction intermediate MU-GlcNH₂ to release 4-methylumbelliferone and free glucosamine.     

α-Adrenergic responses of isolated canine coronary microvessels

Although -adrenergic activation is known to increase coronary microvascular resistance in vivo, the magnitude of its segmental microvascular consequences is not well understood. Quantification of these effects in vivo is hindered by escape mechanisms that minimize the influences of constrictors, and alterations in flow and pressure, which effect microvascular tone by shear stress-dependent and myogenic mechanisms, respectively. To eliminate these confounding influences, we have studied responses in vitro under conditions with these variables controlled. We evaluated the diameter changes of isolated canine coronary arterioles (110±12 m, n=35) and venules (98±7 m, n=9) in response to -adrenergic activation by norepinephrine (10^–10 to 10^–4 M) in the presence of -adrenergic blockade by alprenolol (10^–6 M). In contrast to the situation in vivo, -adrenergic activation did not constrict isolated coronary arterioles, but constricted isolated coronary venules in a dose-dependent manner over a range of 10^–10 to 10^–4 M (–27 ±3% maximum diameter change). Coronary arteriolar -adrenergic constriction was not promoted by 1) subthreshold or vasoactive doses of the vasoconstrictors KCl, angiotensin II, U46619, endothelin-1, neuropeptide Y or arginine vasopressin, 2) inhibition of the presynaptic uptake of norepinephrine by imipramine (10^–6 M), 3) inhibition of EDRF synthesis by N^g-monomethyl-L-arginine (10^–5 M) or 4) inhibition of prostaglandin synthesis by indomethacin (10^–5 M). Furthermore, -adrenergic activation did not modify microvascular dilatation by adenosine (10^–9 to 10^–4 M) or nitroglycerin (10^–9 to 10^–4 M), suggesting that -adrenergic constriction in vivo is not due to attenuation of cAMP or cGMP-dependent mechanisms of coronary dilatation. In contrast to the lack of constriction in coronary arterioles, canine skeletal muscle arterioles exhibited significant -adrenergic constriction (–80±4%), maximum diameter change). The coronary venular -adrenergic constriction was significantly inhibited by both the ₁-and ₂-adrenergic receptor antagonists, prazosin (10^–8 M) and rauwolscine (10^–7 M), indicating a mixed population of ₁-and ₂-adrenergic receptors. These results suggest that coronary arterioles, but not venules, lose -adrenergic responsiveness during isolation and cannulation, or that the primary coronary microvascular response to -adrenergic activation is venular constriction.     

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.     

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.     

Autocrine growth stimulation of SW403 colon carcinoma cell line is caused by transforming-growth-factor-α-mediated epidermal growth factor receptor activation

Results of recent studies indicate that some cultured human carcinoma cell lines are capable of proliferating autonomously in serum-free medium as a result of the synthesis and secretion of transforming growth factor (TGF). TGF interacts with epidermal growth factor receptor (EGFR) and induces its activation. In an attempt to extend these observations, we evaluated TGF-mediated autonomous growth and constitutive EGFR activation in the human adenocarcinoma cell line SW403. The cell line shows synthesis of EGF receptors and TGF but not EGF, and exhibits constitutive phosphorylation of the 170-kDa EGFR. Use of blocking anti-EGFR monoclonal antibodies (mAb) inhibits autonomous growth of SW403 cells and leads to a significant reduction of receptor phosphorylation. The inhibitory effect of the blocking anti-EGFR mAb is reversible upon addition of TGF. In contrast, autonomous proliferation of SW403 cells is not inhibited by addition of neutralizing anti-EGF mAb. Our findings suggest that the proliferation of cells of the human SW403 adenocarcinoma cell line is regulated by an autocrine TGF loop and that this regulatory pathway can be interrupted by using anti-EGFR mAb.Abbreviations EGF epidermal growth factor - EGFR epidermal growth factor receptor - mAb monoclonal antibody - TGF transforming growth factor      

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.     

The importance of granulocyte elastase in haematological diagnosis

Summary PMN elastase is a useful additional parameter in the differential diagnosis of the leukaemias. In all patients with myelocytic leukaemias there were elevated levels of elastase-₁-proteinase inhibitor (E-₁PI), while in the lymphatic leukaemias complexed elastase levels were decreased. The highest values were found in the peripheral blood plasma and bone marrow plasma of patients with CML. Despite high E-₁PI concentrations there were no signs of bleeding or consumption of plasmatic coagulation factors. In AML a wide range of E-₁PI levels was observed, extending from slightly elevated to four hundred-fold increased. In myeloblastic leukaemias without maturation (FAB M1) the concentrations of complexed elastase remained below 150 ng/ml. In myeloblastic leukaemias with maturation (FAB M2) the E-₁PI values ranged between 214 ng/ml and 850 ng/ml (x= 402 ± 69), and in myelo-monoblastic leukaemias (FAB M4) between 450 ng/ml and 720 ng/ml (x = 663 ± 72). The only case of promyelocytic leukaemia (FAB M3) exhibited an extremely high value of 4,550 ng/ml, while a monocytic leukaemia (FAB M5) showed an extremely low value of 5 ng/ml. During cytostatic therapy there was a rapid decrease in levels of complexed elastase, with E-₁PI values returning to normal in remission. In recidivating cases there was an increase of E-₁PI levels in AML and a decrease in ALL. There was a correlation between the E-₁PI concentrations in peripheral plasma and leukaemic bone marrow infiltration, so providing a good basis for monitoring remission from leukaemia and indicating relapse. It was also interesting to observe an extremely low E-₁PI level (5 ng/ml) in patients with myelodysplasia. Under Decortin/Plenastril therapy the concentration rose to 50 ng/ml. An E-₁PI level of 10 ng per ml was observed in one case of Ranitidine agranulocytosis. Under corticoid therapy the value returned to normal within eight days.     

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.     

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.     

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.     

Interleukin-2-activated killer cell activity in colorectal tumor patients: evaluation of in vitro effects by prothymosinα1

The effects of prothymosin 1 (Pro 1) in combination with interleukin-2 (IL-2) on peripheral blood lymphocytes from 50 colorectal tumor patients at different stages were studied with respect to immunocytotoxicity, adhesion to cultured SW620 colon carcinoma cells, secretion of cytokines and expression of adhesion and surface marker molecules. On average, the patients showed lower natural killer (NK) cell activity than healthy donors, which was associated with a lower adhesion capacity to the tumor target cells. The NK cell activity of the patients was inversely related to the tumor stage. The generation of lymphokine(IL-2)-activated killer (LAK) cell activity was found to be comparable on lymphocytes from healthy individuals and patients and was not correlated to tumor stage. Pro 1 stimulated patients' LAK cell activity only, primarily at the early stage (Dukes A/B). The Pro 1 effect was associated with an increased adhesion of lymphocytes to tumor target cells and an increased secretion of the deficient IL-2-induced IFN secretion. No significant effects on the low level of TNF secretion was noted. By flow cytometry, Pro 1 in combination with IL-2 augmented the expression of the NK cell markers CD56, CD16/56, the subset CD3/16/56 and CD25 on lymphocytes of the patients. In contrast, Pro 1 was equally effective by increasing the expression of CD18 and CD11a, on lymphocytes from the patients and from normal controls. In conclusion, Pro 1, in combination with IL-2, can partially normalize lymphocyte deficiencies of colon cancer patients in vitro. This potential might provide an experimental basis for applying Pro 1 or related thymic peptides in selected immunotherapies against colorectal tumors.Abbreviations Pro 1 prothymosin 1 - NK natural killer - LAK lymphokine-activated killer - IL-2 interleukin-2 - TNF tumor necrosis factor - IFN interferon - PBL peripheral blood lymphocytes - ELISA enzyme-linked immunosorbent assay     

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     

Alterations of GTP-binding Proteins (Gsα and Gq/11α) in Gastric Smooth Muscle Cells from Streptozotocin-Induced and WBN/Kob Diabetic Rats

We investigated possible impairment of the signal transduction system in gastric myocytes of streptozotocin-induced diabetic (STZ) and spontaneous diabetic WBN/Kob (WBN/Kob) rats. Gastric motility 10 weeks after the onset of diabetes mellitus was significantly reduced in both diabetic rats compared with control, and the decreased motility was not recovered by the administration of insulin to maintain normal blood glucose levels. There was no significant difference between both types of diabetic rats and control rats in total number of [³H]quinuclidinyl benzilate ([³H]QNB) binding sites (B _max: 545–587 fmol/mg protein) on gastric smooth muscle cell membranes or in the affinity of [³H]QNB for the binding sites(K _d : 0.06–0.07 nM). Immunoblot analysis using polyclonal anti-G-protein antibodies indicated increased expression of G_s in gastric smooth muscle cell membranes, but no significant change in G_i or G_q/₁₁ expression in STZ rats, and decreased expression of G_q/₁₁ with no significant change in G_s and G_i in WBN/Kob rats. The cAMP production in gastric smooth muscle cell membranes was augmented in the absence and presence of 100 M isoproterenol, and 100 M forskolin in STZ rats, whereas no significant change of cAMP production was observed in WBN/Kob rats irrespective of the presence of the stimulants. These findings suggest that long-standing diabetes may induce alterations in signal transduction at downstream receptors in gastric myocytes, resulting in the impairment of gastric motility, although the mechanism of reduced contractile activity may differ between STZ and WBN/Kob rats.     

Rapid molecular characterization of Hb H disease in Chinese by polymerase chain reaction

Summary We have developed a rapid method to molecularly distinguish different types of Hb H disease. The study depended on (a) most of the Hb H disease in Taiwan having an-thalassemia-1 of the Southeast Asia type (-SEA) in one allele and (b) the differences of X box of-globin gene cluster in the other allele. To detect the -SEA allele, we utilized the primers located on either side of the breakpoint to do PCR, then characterized the amplified products. For the other allele, we sequenced part of the X box, and found that bases –2803 to –2461 of the X box of – ^3.7 belonged to the X box of ₂ globin gene. In – ^4.2, the bases belonged to the X box of ₁ globin gene, whereas in ^cs it contained both X boxes of ₁ and ₂ globin genes. There was anMboII site at this region of the X box of ₂ globin gene. We utilized PCR to amplify this region and digested it with restriction enzymeMboII, then combined it with another PCR of different primer pairs to molecularly diagnose different types of Hb H disease. One hundred and one cases of Hb H disease from different families were studied: all of the cases had one allele of -SEA deletion, while the other allele showed that 52/101 were – ^3.7, 41/101 were ^cs , 7/101 were – ^4.2, and 1/101 was – ^G.Taichung. Of 52 cases of Hb H with – ^3.7, 47 were type-I deletion and five were type-II deletion.     

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     

α2-Macroglobulin as an inclusion in synovial fluid monocytes

Summary By the immunofluorescence method, inclusions of ₂-macroglobulin (₂M) were demonstrated in synovial fluid monocytes but not neutrophils. They were more frequent in more inflammatory fluids. By in vitro experiments using both mouse peritoneal cells and human peripheral mononuclear cells, it was demonstrated that these inclusions probably correspond to ₂M-protease complexes, which are specifically taken up and destroyed by macrophages in exudates.