Systemic lupus erythematosus complicated with liver cirrhosis in a patient with Papillon-Lefèvre syndrome.

We report the first case of a girl who presented with Papillon-Lefèvre syndrome (PLS) and subsequently developed systemic lupus erythematosus and liver cirrhosis. This indicates that autoimmune diseases can be a complication in patients with PLS. Cathepsin C gene mutations were not found in our patient or her mother. Thus, other genetic factors may have been involved in this patient.

Properties of the strongly immobilized signal observed in spin-labeled erythrocytes.

A strongly immobilized signal from fatty acid spin labels was observed in human erythrocytes treated with oxidizing agents such as glutaraldehyde, hydrogen peroxide, phenylhydrazine and copper-ortho-phenanthroline. This signal was also observed in freshly prepared ghosts treated with potassium superoxide and in old erythrocyte ghosts. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of these samples demonstrated the diffuse, nondiscrete bands of high molecular weight due to the cross-linking of membrane proteins. The temperature and pH dependences of the outer hyperfine splitting of this signal were very similar to those of bovine serum albumin. We propose that the strongly immobilized signal reflects the interaction of the lipids with the cross-linked products of membrane proteins.

Role of the antibody Fc in the immune clearance of Trypanosoma cruzi.

Passive transfer of immune serum obtained from mice chronically infected with Trypanosoma cruzi to mice containing circulating bloodstream trypomastigotes induces a very fast clearance of the parasites. Comparison of trypomastigotes clearance in normocomplementemic and C5-deficient mice showed no difference. IgG fraction obtained from immune serum was very efficient at inducing complement-mediated lysis and immune clearance of bloodstream trypomastigotes, whereas its Fc-missing F (ab') 2 fragments, although able to induce lysis, were unable to induce clearance. It is suggested that the immune clearance of bloodstream trypomastigotes is dependent on the antibody Fc region and that complement-mediated lysis is not a prerequisite for elimination of the parasites from circulation.

Isotype of antibodies responsible for immune lysis in Trypanosoma cruzi infected mice.

Serum obtained from mice infected with Trypanosoma cruzi have antibodies able to induce immune lysis in presence of complement. Gel filtration in Sephadex G-200 and affinity chromatography with rabbit anti-mouse IgG and protein A-Sepharose showed that the antibodies responsible for the immune serum lytic activity are exclusively located in Ig of IgG isotype, including IgG1, IgG2a, IgG2b and probably IgG3. It is suggested that antibodies responsible for protection against T. cruzi infection and antibodies responsible for immune lysis are the same.

Characterization of antibody isotype responsible for immune clearance in mice infected with Trypanosoma cruzi.

Humans and mice chronically infected with Trypanosoma cruzi present a strong humoral immune response mediated by specific antibodies. Passive transfer of homologous immune serum to normal mice containing circulating bloodstream trypomastigotes (Bts) induces a very fast clearance of the parasites. In order to find out the role of the different immunoglobulin classes in the clearance, mice containing a known number of these parasite forms in circulation were injected with total immune serum, IgG-free serum, IgG1, or IgG2 fractions and the speed of removal of the parasites from circulation was determined. The results of these experiments suggest that the immune clearance of T. cruzi is due to antibodies located in the IgG isotype, particularly in the IgG2 subclass.

A comparative study of anti-Trypanosoma cruzi serum obtained in acute and chronic phase of infection in mice.

The IgG antibody content, specificity, lytic activity, clearance capacity and protective ability of mouse anti-Trypanosoma cruzi serum was determined during the course of infection. The IgG antibody content increased during the course of infection, reaching its highest level in the serum collected in the chronic phase of the infection. The T. cruzi antigens recognized by antibodies using the protein transfer technique also increased with time of infection. Antibodies present in day 22 post-infection (p.i.) serum were already able to recognize all the antigens detected by antibodies present in serum from the chronic phase. The lytic and clearance ability were not detected on day 7 p.i., but appeared on day 14 p.i. and reached their highest level on day 45 p.i. The protective ability was present in serum of the chronic phase, but was absent from the acute serum. The IgG antibody content of the acute serum was four times less than that of the chronic serum. When the IgG antibody concentration of the acute serum was equalized to that of the chronic serum, the acute serum was as able to protect the infected animals as the chronic serum. It is suggested that the disagreement between the protective ability of anti-T. cruzi antisera collected in the acute or in the chronic phase of the infection is due to a quantitative rather than a qualitative difference.

New consecutive high-dose chemotherapy modality with fractionated blood stem cell support in the treatment of high-risk pediatric solid tumors: a feasibility study.

For the treatment of childhood solid tumors, we performed a pilot feasibility study of consecutive high-dose therapies, in which each course was followed by transplantation with granulocyte colony-stimulating factor-mobilized peripheral blood cells which had been separated into CD34-positive and -negative fractions by an Isolex system (Baxter). Positive selection of CD34+ cells has been associated with inevitable cell loss. To overcome this loss, CD34+ cells that had migrated into the negative fraction were saved and used for the first transplant, which was followed by a second transplant after a 3- to 5-month interval. In this phase I feasibility study, the results in six children were evaluated for safety and engraftment. Multi-drug cytoreductive regimens using ranimustine (MCNU), melphalan, thiotepa, carboplatin, cyclophosphamide or VP-16 were comparable between the two transplant procedures in terms of their intensity. The number of CD34+ cells in the 'CD34(+) fraction' was 3.31 x 10(6)/kg (0.63-4.3 x 10(6)/kg), while this number in the 'CD34(-) fraction' could not be evaluated correctly due their scarcity (<0.1%). The median numbers of infused MNC and CFU-GM were, respectively, 4.2 x 10(6)/kg and 1.75 x 10(5)/kg in the CD34(+) fraction, and 4.8 x 10(8)/kg and 3.35 x 10(5)/kg in the CD34(-) fraction. The number of days required to achieve an ANC >0.5 x 10(9)/l and a platelet count >20 x 10(9)/l and >50 x 10(9)/l were, respectively, 14.5, 15.0 and 19.5 in the first transplant with CD34- cells, and 13.5, 18.0 and 25.0 in the second transplant with CD34+ cells, with no essential difference between the two treatments. Although the small number of patients, the variation in clinical status and treatment, and the short follow-up invalidate any evaluation of the therapeutic benefit of this strategy, the encouraging results support the feasibility of this strategy, which enables an escalation of dose intensity with an improved cost/benefit ratio.

Reduced muscle amino acid uptake in sepsis and the effects in vitro of septic plasma and interleukin-1.

Inhibited amino acid transport in skeletal muscle during sepsis has been demonstrated previously. In the present study we investigated the effects in vitro of plasma from septic animals or fractions of septic plasma that contain solutes with a molecular weight less than 30,000 daltons or less than 2000 to 3000 daltons on amino acid transport in incubated rat soleus (SOL) muscles. The influence of interleukin-1 (IL-1), prostaglandin E2 (PEG2), and the "catabolic" hormones corticosterone, glucagon, and epinephrine on muscle amino acid uptake was also investigated. Amino acid transport was studied with 3H-alpha-aminoisobutyric acid (AIB). Whole-septic plasma and the two low molecular-weight fractions of the septic plasma reduced muscle amino acid uptake by about 20%. IL-1 or PGE2 did not affect amino acid transport. When the catabolic hormones were added individually to incubated SOL muscles, no changes in AIB uptake were noticed. When glucagon or epinephrine was added in combination with corticosterone or when all three hormones were added together, amino acid transport was reduced by 10% to 15%. The results suggest that inhibited muscle amino acid uptake in sepsis is caused by a circulating factor(s) with a molecular weight less than 2000 to 3000 daltons. A synergistic action among the catabolic hormones may be one important factor for reduced muscle amino acid transport in sepsis.

Effect of insulin on amino acid uptake and protein turnover in skeletal muscle from septic rats. Evidence for insulin resistance of protein breakdown.

We investigated the effect of different concentrations of insulin (0, 10, 1 X 10(2), 1 X 10(3), 1 X 10(4), and 1 X 10(5) mU/L [0, 70, 7 X 10(2), 7 X 10(3), 7 X 10(4), and 7 X 10(5) pmol/L]) on amino acid (alpha-aminoisobutyric acid) uptake and protein synthesis and breakdown in incubated extensor digitorum longus (EDL) and soleus muscles of rats. We studied three groups: untreated, fed rats; sham-operated rats; and septic rats. Sepsis was induced by cecal ligation and puncture. The alpha-aminoisobutyric acid uptake was increased by insulin in all three groups. Protein synthesis was maximally stimulated by 30% to 40% by 1 X 10(2) mU/L (7 X 10(2) pmol/L) of insulin in all three groups. Protein degradation in soleus muscle was not affected by insulin. In EDL muscles from untreated and sham-operated rats, protein breakdown was reduced by 15% to 20% by 1 X 10(2) mU/L (7 X 10(2) pmol/L) of insulin. In contrast, protein breakdown was not inhibited by insulin in septic EDL muscle until the concentration of the hormone was increased to 1 X 10(4) mU/L (7 X 10(4) pmol/L), at which concentration the hormonal effect was less than half that in nonseptic muscle. The results suggest a postreceptor insulin resistance of protein breakdown in septic muscle, while the response to the hormone of amino acid transport and protein synthesis was not altered in sepsis.

Trypanosoma cruzi: advantages of isolating bloodstream trypomastigotes by the carboxy methyl cellulose method.

Bloodstream trypomastigotes were isolated from blood of A/Sn mice 7 d after infection with 10(5) Trypanosoma cruzi Y strain. Red blood cells were removed by centrifugation and hypotonic shock and platelets and leucocytes by passage through a carboxy methyl cellulose column. Binding of trypomastigotes to the resin was prevented by including 10% normal mouse serum in the eluting buffer. In such conditions, more than 90% of the parasites applied to the column were recovered, free of white blood cells and platelets. A comparative study of the pre- and post-separation trypomastigotes showed that both had the same infecting capacity, ability to evade destruction by the complement system, and antigenic profile.

Isolation of IgGT from hyperimmune horse anti-snake venom serum: its protective ability.

Hyperimmune horse anti-bothropic serum, used in serum therapy, was analyzed for its IgGT content and protective ability. IgGT was isolated through a combination of salt-mediated hydrophobic chromatography and protein A affinity chromatography. The chromatographic fractions obtained were analyzed with regard to their isotype content and protective ability. The results suggest that the protective ability of hyperimmune anti-venom serum is located mainly in the IgGT subclass.

Neutralization of bothropic and crotalic venom toxic activities by IgG(T) and IgGa subclasses isolated from immune horse serum.

IgG(T) and IgGa isotypes were isolated from horse hyperimmune anti-bothropic and anti-crotalic sera using a combination of two affinity chromatographic processes. IgG(T) and IgGa isotypes were isolated from these sera by chromatography on protein A-Sepharose followed by separation of the two isotypes by chromatography on a column of anti-IgG(T)-Sepharose. LO-HoGT-1, a rat anti-horse IgG(T) monoclonal antibody, was used. A comparative study of the efficiency of these isotypes in neutralizing the main toxic activities of the homologous venoms was carried out. It was found that IgG(T) was about three-fold and seven-fold more protective than IgGa for neutralization of the lethal activity of B. jararaca and C. d. terrificus venoms, respectively. IgG(T) was also more effective than IgGa for the neutralization of the haemorrhagic activity induced by B. jararaca venom, while both isotypes neutralized equally well the blood incoagulability induced by this venom. The results suggest that IgG(T) is the most protective isotype present in both anti-bothropic and anti-crotalic sera, followed by IgGa. Owing to their very low concentration in the serum, other IgG isotypes are not likely to be important in neutralizing the venoms' toxic activities.

Efficacy of bothropic antivenom and its IgG(T) fraction in restoring fibrinogen levels of Bothrops jararaca envenomed mice.

Bothropic antivenom and its IgG(T) fraction, administered 4 h after experimental envenoming by Bothrops jararaca in Swiss mice, were compared for their abilities to restore fibrinogen 24 or 48 h after treatment. IgG(T) was able to normalise fibrinogen levels as efficiently as conventional antivenom. As IgG(T) also neutralises most anti-toxic activities of Bothrops venom, our results suggest that IgG(T) could be a better alternative treatment for envenoming due to the reduced amount of extraneous proteins, which may facilitate the induction of early adverse reactions.

Neutralization of Thalassophryne nattereri (niquim) fish venom by an experimental antivenom.

T. nattereri (niquim) is a venomous fish involved in many human accidents in Brazil. The clinical picture includes mild local erythema, severe edema, intense pain and rapid progression to necrosis. The present therapy with anti-inflammatory and analgesic drugs is ineffective and, therefore, we decided to assess serum therapy as an alternative treatment using an experimental antivenom. The antivenom used was raised in rabbits showing an ELISA antibody titer of 1:8,192,000 and its ability to neutralize lethality, necrosis, nociception and edema was evaluated both by pre-incubating the venom with antivenom before injection into mice or by independent injections of venom and antivenom. Lethality was completely neutralized by pre-incubation (ED(50)=141.5 microl/mg) while necrosis and nociception were neutralized by pre-incubation or the independent injection of antivenom. Edema was only partially prevented even when large amounts of antivenom were used. These data suggest that antivenom may be a promising treatment for patients stung by T. nattereri and suggest the viability of producing a horse antivenom for use in clinical trials.

Tolerance to the antinociceptive effect of Crotalus durissus terrificus snake venom in mice is mediated by pharmacodynamic mechanisms.

Crotalus durissus terrificus venom exerts central and peripheral antinociceptive effect mediated by opioid receptors. The present work investigated the tolerance to the antinociceptive effect of the venom and characterised the mechanisms involved in this phenomenon. The hot plate test, applied in mice, was used for pain threshold determination. The venom (200 microg/kg) was administered by oral route, daily, for 14 days, and the nociceptive test was applied before and on days 1, 7 and 14 of the treatment. Prolonged treatment with venom lead to the development of tolerance to the antinociceptive effect. Tolerant animals exhibited increased sodium pentobarbital-induced sleeping time, although total hepatic microsomal cytochrome P450 was not altered. The antinociceptive effect of a single dose of venom (200 microg/kg) is mediated by kappa opioid receptors. Mice long-term-treated with venom showed cross-tolerance to U-TRANS, an agonist of kappa-opioid receptor, but not to morphine or DAMGO, two mu-opioid receptor agonists. Prolonged administration of venom did not cause symptoms of abstinence syndrome. These data indicate that prolonged treatment with C. durissus terrificus venom induces tolerance to the antinociceptive effect and that pharmacodynamic mechanisms are involved in the genesis of this phenomenon.

Horse IgG isotypes and cross-neutralization of two snake antivenoms produced in Brazil and Costa Rica.

Horse IgG isotypes and cross-neutralization of two snake antivenoms produced in Brazil and Costa Rica. Toxicon 000-000. This work compared the specificity, ELISA titers and IgG subclass content of the polyvalent antivenom (anti-Bothrops asper, Crotalus durissus durissus and Lachesis muta stenophrys) of Instituto Clodomiro Picado (Costa Rica) and the bothropic antivenom (anti-Bothrops jararaca, B. jararacussu, B. moojeni, B. neuwiedi and B. alternatus) of Instituto Butantan (Brazil). The role of IgG(T) and IgGa subclasses in neutralization of some venom toxic activities and the cross neutralization of the antivenoms against B. jararaca and B. asper venoms were also evaluated. Both antivenoms were able to recognize B. asper and B. jararaca venoms by immunoblotting and presented similar antibody titers when assayed by ELISA. IgG(T) was highest, followed by IgGa, IgGb and IgGc. IgGa and IgG(T) isotypes isolated from both antivenoms by affinity chromatography were tested for neutralization of lethal, hemorrhagic, coagulant and phospholipase A2 activities of the homologous venoms. In both antivenoms, IgG(T) was the major isotype responsible for neutralization of all the tested activities, followed by IgGa. These results suggest that Instituto Butantan and Instituto Clodomiro Picado antivenoms have the same IgG profile and their neutralizing ability is due mostly to the IgG(T) isotype. Also, they neutralize lethality in mice induced by homologous and heterologous venoms, the bothropic antivenom of Instituto Butantan being more effective.

Significance of administration of fat emulsion: hepatic changes in infant rats receiving total parenteral nutrition with and without fat.

Total parenteral nutrition (TPN) is associated with cholestasis and hepatic steatosis, which can be lethal in infants who cannot be fed orally. The present animal study focused on the metabolic complications in the liver that may occur due to the excessive administration of fat-free TPN. Thirty infant (3-week-old) male SD rats weighing 60-70 g were randomly allocated to five groups (n = 6): the OD group received an oral diet, the FT group received an oral diet and was fasted overnight on the last day of experiment before sacrifice, the 0% fat group received TPN without fat, the 20% fat group received TPN with 20% of calories from fat emulsion, and the 40% fat group received TPN with 40% of calories from fat emulsion. All TPN regimens were isocaloric, isonitrogenic, and administered for 4 days. In the 0% fat group, plasma levels of liver enzymes were significantly higher than in the other groups. Pathological examination showed hepatomegaly and severe fatty changes without cholestasis in the 0% fat group. The results of this study in infant rats indicate the importance of including fat in the TPN regimen in order to prevent the abnormal hepatic changes associated with the excessive administration of fat-free TPN.

Phospholipids from the free-living nematode Caenorhabditis elegans.

The phospholipid and the fatty chain compositions of diacyl, alkylacyl and alkenylacyl glycerophospholipids of the free-living nematode, Caenorhabditis elegans, were investigated. The phospholipids were comprised of 54.5% ethanolamine glycerophospholipid (EGP), 32.3% choline glycerophospholipid (CGP), 8.1% sphingomyelin and 5.1% others. The most abundant fatty acid in CGP was eicosapentaenoic acid (20:5n-3). The fatty acids in CGP were more unsaturated than those in EGP. Alkenylacyl and alkylacyl subclasses accounted for 1.0 and 2.6%, respectively, of CGP and 14.0 and 19.6%, respectively, of EGP. At least 80% of the alkenyl and alkyl groups were 18:0 chains and the remaining were odd numbered chains. The potential presence of platelet-activating factor (PAF) was examined by bioassay, but PAF-like activity was not detected in the extracts of this nematode.

The possible mechanism of action of IgG antibodies and platelets protecting against Trypanosoma cruzi infection.

1. The role of IgG antibody and platelets in the mechanism of defense against Trypanosoma cruzi infection is reviewed. 2. Experimental data showing the participation of the different IgG subclasses in the immune lysis and immune clearance of the parasites are discussed. 3. The involvement of the platelets in the removal of the parasites from the circulation is considered. 4. It is suggested that IgG anti-T. cruzi antibodies interact with circulating parasites leading to formation of microaggregates, activation of C3 and deposition of C3b on the immune aggregates followed by adherence of platelets through C3b receptors. The immune aggregates would then be taken up by cells of the mononuclear phagocytic system.

Isolation of horse IgG with protein A.

Horse immunoglobulins were obtained from normal serum defatted with dextran sulfate and precipitated with ammonium sulfate. Eight mg of this preparation was submitted to affinity chromatography with protein A-Sepharose CL-4B. Low temperature (4 degrees C) and a starting buffer at pH 8.0 were conditions required for all IgG subclasses to bind to protein A, even those with low affinity. The IgGs bound to protein A were eluted with glycine buffer at pH 2.8. The yield was about 90%. It is suggested that isolated IgG, instead of whole Igs, be used in serum therapy, reducing the amount of Igs and diminishing serum-related reactions.