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.

     

Thalassemia intermedia: compound heterozygous β∘/β+-thalassemia and co-inherited heterozygous α+-thalassemia

Summary The relative excess of - over -globin chains in the erythroid precursors is the chief pathophysiological factor of homozygous -thalassemia. The clinical picture is usually characterized by a transfusion-dependent dyserythropoietic anemia (thalassemia major). However, some patients present with moderate anemia that does not require regular blood transfusions (thalassemia intermedia). The molecular heterogeneity of -thalassemia mutations and changes of - and -globin gene expression play an important role in modifying the clinical phenotype. We report here on a female Greek patient with homozygous -thalassemia but normal growth and development, excellent exercise tolerance, and no need of blood transfusions. She is thus mildly affected clinically, although there is marked pallor, jaundice, and hepatosplenomegaly. These signs correspond to her marked hypochromic, microcytic anemia with erythroid hyperplasia of the bone marrow. -Globin genotyping shows her to be compound heterozygous for the codon 39 C T -nonsense mutation and for the T C ⁺-mutation at position 6 of the splice consensus at the exon 1/intron 1 junction (CD39 C T/IVS 1–6 T C). -Globin gene mapping demonstrates the presence of a 3.7-kb ⁺-thalassemia deletion on one allele (–^3.7/). Taken together, this study identifies a complex interaction of genetic factors that do not significantly alter the clinical phenotype when present alone but ameliorate the course of homozygous -thalassemia when inherited in combination.Abbreviations Hb hemoglobin - Hct hematocrit - HPFH hereditary persistence of fetal hemoglobin - IVS intervening sequence - MCH mean corpuscular hemoglobin - MCV mean corpuscular volume - PCR polymerase chain reaction     

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.     

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.     

Co-cultivation of Niemann-Pick disease type C fibroblasts belonging to complementation groupsα andβ stimulates LDL-derived cholesterol esterification

Summary Niemann-Pick disease type C (NPC) is a neurovisceral storage disorder with an unknown primary deficiency. Somatic cell hybridization experiments using human cultured fibroblasts have shown that two complementation groups (NPC- and NPC-) are associated with the biochemical and clinical phenotypes comprising NPC. We identified the rarer complementation group NPC- originally using the technique of filipin staining as a marker for complementation. In this study we show that the esterification of cholesterol derived from the LDL pathway can be used as an isotopic assay. However, multinuclear hybrids exhibit a delayed induction in this pathway. Furthermore, we discovered that, in the presence of an LDL source, co-cultivation of fibroblasts belonging to NPC- and NPC- stimulated cholesterol esterification.     

Overproduction of inhibitory hematopoietic cytokines by lipopolysaccharide-activated peripheral blood mononuclear cells in patients with aplastic anemia

The aim of this study was to measure the level of cytokines produced by peripheral blood mononuclear cells (PBMNC) in patients with aplastic anemia (AA) and to determine their effect on the clonal growth of normal bone marrow (BM) cells. Twenty-one patients with AA and 11 normal controls were enrolled in this study. Medium conditioned by PBMNC of AA patients in the presence of lipopolysaccharide (LPS) was found to be suppressive to the colony growth of normal BM cells. Thus, we further determined the presence in the PBMNC-conditioned medium (CM) of both inhibitory cytokines: macrophage inflammatory protein-1 (MIP-1), tumor necrosis factor- (TNF-), transforming growth factor-2 (TGF-2), and interferon- (IFN-), and stimulatory cytokines: interleukin-3 (IL-3) and stem cell factor (SCF). Spontaneous production of MlP-1 was higher in the AA patients than the normal controls (1887±174 pg/ml vs 1643±93 pg/ml), but the difference was not significant. After LPS stimulation, the production of MIP-1 was markedly increased in the AA patients, and its level was significantly higher than that of the normal controls (2360±149 pg/ml vs 1517±92 pg/ml, p=0.0022). The level of TNF was also higher in the AA patients. However, IFN-, TGF-2, SCF, and IL-3 were not detectable in the PBMNC-CM of either AA patients or normals. The myelopoietic suppressing effect of AA-PBMNC-CM from each AA patient was significantly blocked by pretreatment with anti-TNF-, resulting in a colony-forming enhancement of 174%±12%. A similar effect was noted in six of 11 AA patients by pretreatment with anti-MIP-1. We conclude that TNF and MIP-1 can be overproduced by the PBMNC of some AA patients, which may play a role in the progression of AA.     

Expression of interferon-γ and tumor necrosis factor-α in bone marrow T cells and their levels in bone marrow plasma in patients with aplastic anemia

Immune-mediated stem cell damage has been postulated to be responsible for disease initiation and progression in aplastic anemia (AA). It is hypothesized that T lymphocytes play a major role in destroying the bone marrow (BM) stem cells of AA patients by infiltrating the BM and secreting excessive levels of anti-hematopoietic cytokines, interferon-gamma (IFN-), and tumor necrosis factor-alpha (TNF-). We undertook this study to assess the pathogenic significance of anti-hematopoietic cytokines such as IFN- and TNF- in BM T cells and plasma of AA patients. Significantly elevated levels of IFN- and TNF- were found in the BM plasma of AA patients compared to controls (p=0.05 and 0.006, respectively). Intracellular IFN- and not TNF- in BM CD3⁺ T cells of AA patients was significantly higher compared to controls (p=0.04 and p=0.2, respectively). A follow-up analysis of expression of these cytokines in BM T cells and their levels in BM plasma in five AA patients before and 180 days (6 months) after antithymocyte globulin (ATG) and cyclosporin A (CsA) therapy showed a decline 180 days after therapy compared to pre-therapy. We thus conclude that increased production of both IFN- and TNF- in the BM may contribute to disease pathogenesis in AA and ATG therapy may induce hematological remission by suppressing the elevated levels of IFN- and TNF- in AA BM.     

High levels of macrophage inflammatory protein-1α correlate with prolactin in female patients with active rheumatoid arthritis

The relationship between the endocrine immune modulator prolactin and the macrophage activation parameter MIP-1 (macrophage inflammatory protein-1) was investigated in 61 females with rheumatoid arthritis (RA). The chemokine MIP-1 was found to be twice as high in active than in inactive RA. Parallel to the inflammatory activity (acute phase response and joint count) and high levels of MIP-1 there were markable changes of serum prolactin. MIP-1 seems to have an influence on the pituitary hormone secretion. A significant correletion between prolactin and MIP-1 (r=0.67;p0.00001) point out the bidirectional influence of the immune and endocrine system in RA.     

Increased levels of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in tracheal aspirates of newborns with pneumonia

Summary Pneumonia is one of the major sites of infection in ventilated newborns. We investigated whether the cytokines IL-1 and TNF- are detectable in tracheal aspirates of newborns with pneumonia as a diagnostic marker. All 12 infants with pneumonia had elevated levels of IL-1 (range 30–300 pg/ml) and TNF- (range 60–680 pg/ml), whereas control infants (n=21; respiratory distress syndrome, very low birth weight or infants intubated preoperatively) had no detectable levels of IL-1 or TNF-.In vitro investigations with mononuclear cells of umbilical cord blood were performed to rule out that exogenously added surfactant influences IL-1 and TNF- production. It is concluded that IL-1 and TNF- are important and specific mediators of neonatal pneumonia which may be of diagnostic importance.

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Erhöhte Spiegel von TNF- und IL-1 im Trachealsekret von Neugeborenen mit Pneumonie

Zusammenfassung Die Pneumonie ist eine der Hauptlokalisationen von Infektionen bei Neugeborenen. Wir untersuchten, inwieweit die Zytokine IL-1 und TNF- im Trachealsekret von Neugeborenen mit Pneumonie als diagnostischer Marker nachgewiesen werden können. Alle 12 Kinder mit Pneumonie hatten erhöhte Spiegel für IL-1 (30–300 pg/ml) und TNF- (60–680 pg/ml), während die Kontrollen (n=21; Atemnotsyndrom, sehr untergewichtige Neugeborene, präoperativ intubierte Kinder) keine nachweisbaren Spiegel für IL-1 und TNF- hatten. Um auszuschließen, daß exogen appliziertes Surfactant die IL-1 und TNF--Produktion beeinflußt, wurdenIn vitro-Untersuchungen mit mononukleären Zellen von Nabelschnurblut durchgeführt. Wir schließen aus den Ergebnissen, daß IL-1 und TNF- wichtige und spezifische Mediatoren der Neugeborenenpneumonie sind, die von diagnostischer Bedeutung sein können.

     

Changes in expression levels of genes involved in fatty acid metabolism: upregulation of all three members of the PPAR family (α, γ, δ) and the newly described adiponectin receptor 2, but not adiponectin receptor 1 during neonatal cardiac development of the rat

During neonatal cardiac development, the heart changes its substrate preference from glucose to fatty acids. The aim of this study was to investigate the changes in mRNA expression levels of genes involved in the control of cardiac fatty acid metabolism in the transition from neonatal to adult life. Methods mRNA expression levels for peroxisome proliferator activated receptor (PPAR) , and , PPAR co–factor 1 and (PGC–1 and ), 9–cis retinoc–acid–activated receptor , and (RXR , , ), 5–AMP activated protein kinase (AMPK) 1 and 2, adiponectin receptor 1 and 2 (AR 1 and AR 2) were measured in heart tissue of neonatal 0–day, 7–day and 21– day old rats. Results mRNA expression of all three members of the PPAR family were upregulated significantly from day 0 to day 21 ( +117%, +133%, +203%). In addition, m–RNA expression of all RXR isoforms increased from day 0 to day 7 ( +125%, +69%; +41%). AR 2 exhibited a small but significant increase in mRNA expression (+ 46%). Conclusions We were able to demonstrate for the first time that in addition to PPAR, also PPAR and , as well as all RXR isoforms and AR 2 are upregulated in the heart during neonatal development.Drs. Steinmetz and Quentin contributed equally to this publication     

Glucokinase is not the pancreatic B-cell glucoreceptor

Summary A series of recent experimental findings are reviewed to indicate that glucokinase does not represent the pancreatic B-cell glucoreceptor. (1) Whether in liver, pancreatic islet or insulin-producing tumoral cell homogenates, glucokinase fails to yield a higher reaction velocity with -than -D-glucose. (2) At a high glucose concentration (40 mmol/l), when the phosphorylation of glucose by glucokinase is indeed higher with - than -D-glucose, no preference for -D-glucose is observed in intact islets, as judged from the utilization of D-[5-³H]glucose, production of lactic acid, oxidation of D-[U-¹⁴C] glucose, net uptake of ⁴⁵Ca or release of insulin. (3) The glucose 6-phosphate content of intact islets is higher in the presence of - than -D-glucose. (4) At a low glucose concentration (3.3 mmol/l), when the participation of glucokinase to hexose phosphorylation is minimal, -D-glucose is still better metabolized and stimulates both ⁴⁵Ca net uptake and insulin release more efficiently than -D-glucose, despite the fact that hexokinase yields a higher reaction velocity with - than -D-glucose. (5) In intact islets, -D-glucose is used preferentially to -D-glucose in the pentose cycle pathway as judged from the oxidation of - or -D-[1-¹⁴C]glucose relative to that of - or -D-[6-¹⁴C]glucose. (6) In islets removed from fasted rats, the rate of glycolysis is more severely decreased than expected from the repression of glucokinase. (7) The metabolism of glucose in tumoral insulin-producing cells differs, in several respects, from that in normal pancreatic islets, although the pattern of hexokinase and glucokinase activities is similar in these two types of cells. All these observations point to the participation of regulatory sites distal to glucose phosphorylation in the control of glucose metabolism in islet cells.     

NMR monitoring of rheumatoid arthritis patients receiving anti-TNF-α monoclonal antibody therapy

The aim of this study was to investigate if dynamic gadolinium-DTPA-supported magnetic resonance (MR) imaging can monitor the therapeutic effect of a fast-acting immuno-modulating drug like anti-tumour necrosis factor alpha (anti-TNF-) monoclonal antibody (moab) in patients with rheumatoid arthritis (RA). Dynamic MR imaging was performed on 64 joints in a total of 18 patients before and after infusion with either a placebo or 1 or 10 mg/kg of anti-TNF- moab. Additionally, treating the placebo group and reinfusing the verum group with either 3 or 10 mg/kg was monitored by quantitative nuclear magnetic resonance (NMR). Time-dependent signal intensity changes were then correlated with a total of five Paulus criteria and with ESR and C-reactive protein (CRP). No changes in either the gadolinium uptake or clinical parameters were seen after the infusion of a placebo. Therapy with 1 mg/kg anti-TNF- moab resulted in a significant decrease in clinical disease activity, as well as in gadolinium-DTPA uptake in dynamic NMR studies. However, correlations between signal intensity changes and Paulus criteria were only demonstrated for the variable doctor's evaluation of disease activity. Patients given 10 mg/kg moab demonstrated a very significant improvement in all clinical manifestations of their disease, as well as a high significant reduction in gadolinium uptake (P=0.004). In addition, the latter group showed significant correlations between time-dependent signal intensity changes and five Paulus criteria: number of swollen joints, number of painful joints, duration of morning stiffness, doctor's evaluation of disease activity and patient's evaluation of disease activity. No differences and correlations were seen for ESR and CRP. We concluded that dynamic NMR studies are suitable to monitor inflammatory activity in RA patients under therapy with biological response modifiers such as anti-TNF- moab.     

Spontaneous interferon-α antibodies in a patient with pure red cell aplasia and recurrent cutaneous carcinomas

Summary High-titered spontaneous interferon (IFN) antibodies were detected in a patient with pure red cell aplasia (PRCA), a benign mediastinal tumor, and recurrent cutaneous carcinomas. The circulating IFN antibodies reacted broadly with various human IFN- subtypes (20–140×10³ neutralizing units/ml serum) but not with IFN- or IFN-, and they neutralized the antiviral activity of the patient's endogenous IFN-. The IFN-binding activity was restricted to the IgG₁ subclass in a nonmonoclonal manner. Whereas the PRCA repeatedly responded to immunosuppression with high-dose cyclosporin A (CSA) and CSA plus plasmapheresis, IFN antibody production continued during treatment with cyclophosphamide and CSA. Serological analysis revealed past infection with parvovirus B19 and persistent B19 IgM titers. Antibody-mediated impairment of the IFN- system might have favored the development of both PRCA and the various cutaneous carcinomas in this patient.     

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     

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      

Inborn errors of bile acid metabolism

Summary Cholesterol is converted to cholic acid and chenodeoxycholic acid by a series of reactions involving modifications to the steroid nucleus and oxidation of the side chain. These reactions can be affected by a number of inborn errors of metabolism. When this happens unusual bile acids or bile alcohols are synthesized; these can be identified using gas chromatography-mass spectrometry and fast atom bombardment mass spectrometry techniques. Two defects affecting the modifications to the steroid nucleus have been described; both present with cholestatic liver disease of neonatal onset. The better characterized of the two — 3-hydroxy-5-C27-steroid dehydrogenase deficiency — leads to excretion of 3-7-dihydroxy-5-cholenoic acid and 3,7,12-trihydroxy-5-cholenoic acid in the urine. The liver disease improves dramatically on treatment with chenodeoxycholic acid. Deficient activity of 3-oxo-4-steroid 5-reductase is thought to be the cause of familial liver disease in some infants who excrete 7-hydroxy-3-oxo-4-cholenoic acid and 7,12-dihydroxy-3-oxo-4-cholenoic acid in the urine. However, diagnosis of this disorder is problematical; a similar pattern of metabolite excretion can occur as a result of liver damage caused by viruses or inborn errors of pathways unrelated to bile acid synthesis. Defective side chain oxidation in patients with cerebrotendinous xanthomatosis (CTX) leads to synthesis of bile alcohols such as 5-cholestane-3,7,12,25-tetrol and 5-cholestane-3,7,12,23,25-pentol. Patients with CTX do not have cholestatic liver disease. Their major problems (neurological disease, atherosclerosis and xanthomata) are caused by accumulation of cholestanol and cholesterol in the tissues. Bile acid precursors are probably diverted into synthesis of cholestanol. Chenodeoxycholic acid suppresses the production of abnormal metabolites from cholesterol (by inhibition of cholesterol 7-hydroxylase) and leads to improvement in the neurological disease. Defective side chain oxidation also occurs in peroxisomal disorders but this time it leads to accumulation of C27 bile acids such as 3,7,12-trihydroxy-5-cholestanoic acid (trihydroxycoprostanic acid, THCA). This compound is readily detected in the bile and plasma of patients with defects of peroxisome biogenesis. In patients with defects of a single peroxisomal-oxidation enzyme (the 3-hydroxyacyl-CoA component of the bifunctional protein or the thiolase), the major C27 bile acid in bile may be 3,7,12,24-tetrahydroxy-5-cholestanoic acid (varanic acid). In addition to the above inborn errors, others which are less well characterized undoubtedly exist, as do defects of bile acid transport across membranes.     

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.     

Reflex adrenergic inhibition of colonic motility in anesthetized rat caused by nociceptive stimuli of peritoneum

Nociceptive stimulation of the peritoneum inhibits colonic motility via a sympathoadrenergic reflex. This sympathetic reflex most probably induces the inhibition indirectly via a presynaptic blockade of cholinergic transmission. To further clarify this reflex, colonic motility was continuously recorded by a volume method in rats exposed to nociceptive abdominal stimulation and intravenous drug administration. Intraabdominally applied HCl inhibited colonic motility, which was unaffected by nonselective -adrenoceptor blockade (propranolol). However, the nonselective -adrenoceptor antagonist phentolamine and the selective ₂-adrenoreceptor antagonist yohimbine restored motility. Spontaneous colonic motility was unaffected by the nonselective -adrenoceptor agonist (isoproterenol) and the selective ₂-adrenoreceptor agonist (l-phenylephrine). On the other hand, a nonselective -agonist (noradrenaline) and a selective ₂-adrenoreceptor agonist (clonidine) inhibited spontaneous colonic motility. It is suggested that in the rat sympathetic reflex inhibition of colonic motility caused by abdominal nociception is mediated via presynaptic ₂-adrenoreceptor inhibiting the excitatory cholinergic nuerons.This study was supported by grants from the Eriksson Brothers Foundation for medical research, Vanersborg, Sweden. ICI and Ciba-Geigy generously supplied us with Inderal and Regitin, respectively.     

Hb Cemenelum [α92 (FG4) Arg→Trp]: A hemoglobin variant of theα1/β2 interface that displays a moderate increase in oxygen affinity

Summary Hb Cemenelum [92 (FG4) ArgTrp] carries a structural modification at the same position as Hb Chesapeake, a very high oxygen affinity variant. Hb Cemenelum was found in a French diabetic patient with no abnormal hematological features. The purified abnormal hemoglobin, like Hb J Cape Town, another variant of position 92(FG4), displayed only a 1.5-to 2-fold increased oxygen affinity and a reduced cooperativity. This hemoglobin demonstrates that, even for some key residues of the1/2 interface, the degree at which the functional properties are altered depends upon the specific residue occupying this position.     

Diagnosis of the mucopolysaccharidoses using cultured skin fibroblasts and amniotic fluid cells

Assay of-L-iduronidase, heparin sulphamidase,N-acetyl--D-glucosaminidase, arylsulphatase B,-L-fucosidase,-glucuronidase,-galactosidase and-D-mannosidase in cultured cells is described. Activities in deficient fibroblast strains are compared to control fibroblast strains. The first case of Sanfilippo B in the United Kingdom is reported. A comparison of enzyme activities in cultured fibroblasts and amniotic fluid cells is made.