Indirect ultramicroELISA for the detection of total adenovirus antibodies in human serum

An indirect ultramicroELISA method was normalized for the detection of total antibodies to Adenovirus (AD) (UMELISA AD). The optimum concentration of surface antigen determined was 30 micrograms/mL; serum dilution was of 1:40; and conjugate dilution, of 1:1,000. The UMELISA AD was compared with the complement fixing and indirect immunofluorescence techniques. Results showed accordance by 88% and 96.6%, respectively. The method is valid for the screening of antibodies in seroepidemiological studies as well as for the diagnosis of the infection by paired serum samples.     

Cesium uptake studies on human erythrocytes

We compared the performance of second and third generation ELISA assays to detect antibodies to HIV-1 virus with conventional Western blotting (WB) and radioimmune Western blotting (RIWB). Both sera from commercial seroconversion panels and serial dilutions of a serum for HIV-1 antibodies were tested with Murex HIV Recombinant, Vidas bioMérieux HIV 1/2 (2nd generation ELISA) Murex HIV 1-2 (3rd generation ELISA), as well as with WB and RIWB. In seroconversion panels all ELISA assays were positive for the same serum with the exception of the first serum of Panel D which was negative with both sample Murex assays and borderline with Vidas assay. This serum was negative with WB but evidenced antibodies to gp160 p66, p51, p24 HIV-1 proteins when assayed by RIWB. In only two cases did WB reveal antibodies to HIV-1 proteins before ELISA assays (Panel A and E); not only did RIWB show the same sensitivity as WB in the two last panels, but it also detected antibodies to HIV-1 proteins earlier than WB, ranging from a few days (Panel C) to approximately 12 weeks (Panel D). The results obtained by testing the dilutions of the serum positive for anti HIV-1 antibodies showed the following degrees of sensitivity: Murex HIV 1-2 (the most sensitive), Murex HIV Recombinant and Vidas bioMérieux HIV 1/2. Although WB was more sensitive than the ELISA assays and picked out antibodies to gp160, gp120 and p24 HIV proteins at 1/4000 serum dilution, the most sensitive test was RIWB which at 1/20,000 serum dilution enabled detection of antibodies to gp160, p66 and p24 HIV proteins.     

Prevalence of Neospora caninum and Toxoplasma gondii antibodies in sera from camels from Egypt

Sera from camels from Egypt were examined by the direct agglutination tests incorporating mercaptoethanol for antibodies to Neospora caninum and Toxoplasma gondii. Antibodies to N. caninum were found in 6 of 161 camels in titers of 1:40 (2 camels) and 1:80, 1:160, 1:640, and 1:1280 in 1 camel each, using N. caninum formalin preserved whole tachyzoites as antigen. Antibodies to T. gondii were found in 17.4% of 166 camels in titers of 1:25 (3 camels), 1:50 (18 camels). and > 1:500 (8 camels) using T. gondii tachyzoites. All 6 camels with N. caninum antibodies had no T. gondii antibodies in 1:4 dilution of serum, indicating specificity of the reaction. This is the first report of N. caninum prevalence in Egypt.     

Clinical factors relating to the presence of serum anti-GM1 and GD1b antibodies in demyelinating neuropathy--study using a multivariate analysis

We studied clinical factors relating to the presence of serum anti-GM1 and GD1b antibodies in patients with demyelinating neuropathy using a multivariate analysis. Sera were obtained from 46 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 33 with Guillain-Barré syndrome (GBS) and kept frozen at -20 degrees C until use. Anti-GM1 and GD1b IgM and IgG antibodies were measured by ELISA at serum dilution of 1:100 and considered to be positive when those values were more than the cut off values determined by means and standard deviations in 35 normal controls. Age, sex, duration, prodromal disease, neurological findings, concentration of CSF protein, nerve conduction, treatment, and outcome were investigated in all patients retrospectively. Multivariate logistic models using all those characteristics were used to clarify the clinical factors relating to the presence of anti-GM1 and GD1b antibodies. In CIDP, anti-GM1 antibodies associated with or without anti-GD1b antibodies were frequently seen in patients with motor dominant neuropathy than those with sensory dominant neuropathy (P = 0.007, odds ratio = 11.6). There was significant difference in anti-GM1 IgM antibodies (P = 0.003, odds ratio = 22.2), but no difference in IgG antibodies. Anti-GM1 antibodies were observed 5 (IgM, 5; IgG, 2) of 7 patients with pure motor neuropathy, 9 (IgM, 8; IgG, 4) of 17 with motor dominant neuropathy, 5 (IgM, 2; IgG, 3) of 16 with sensori-motor neuropathy, and none of 6 with sensory dominant neuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Apparent enhancement of perinatal transmission of human immunodeficiency virus type 1 by high maternal anti-gp160 antibody titer

The presence of antibodies able to enhance infection in vitro in sera from human immunodeficiency virus (HIV)-1-infected patients raises the possibility that antibodies exert a deleterious activity during natural infection. The anti-HIV-1 humoral response and plasma HIV-1 RNA were measured in a cohort of 98 infected mothers, included in the French Prospective Study on Pediatric HIV Infection, 49 of whom transmitted HIV to their children. Transmission from mother to child was associated with antibody responses to the envelope gp160 (P = .009 for serum dilution of 1/400) and to a highly conserved domain of the transmembrane glycoprotein (P = .055 for serum dilution of 1/400) and with plasma HIV-1 RNA levels (P < .0001). Multivariate logistic regression indicated that a high anti-gp160 response and a high plasma virus load are independent risk factors for perinatal transmission of HIV-1 (odds ratio, 3.4; 95% confidence interval, 1.1-9.9 for anti-gp160; odds ratio, 2.8; 95% confidence interval, 1.6-5.0 for virus load).     

Prenatal availability of choline modifies development of the hippocampal cholinergic system

BACKGROUND: Pigeon fanciers' lung (PFL) is a form of extrinsic allergic alveolitis. Affected individuals produce antibodies to various pigeon antigens, and the resulting immune complexes are thought to initiate the disease. However, high antibody titres also occur in some asymptomatic individuals. Previously attention has focused on protein antigens, but we have recently identified pigeon intestinal mucin as a novel antigen in PFL. OBJECTIVE: To determine the relationship between IgG subclass antibodies to pigeon intestinal mucin and the development of pigeon fanciers' lung. METHODS: Sera were collected from 250 pigeon fanciers, who also completed a clinical questionnaire. Sera were screened for precipitating antibodies to pigeon serum and droppings. Individuals with symptoms and precipitating antibodies were considered to have classical PFL. Serum IgG and IgG subclass antibodies to pigeon intestinal mucin and pigeon serum proteins were investigated by quantitative enzyme-linked immunosorbent assay (ELISA). RESULTS: Very high titres of IgG antibodies against pigeon mucin were found in all precipitin-positive individuals. A strong positive correlation was seen between titres of antibodies to mucin and to serum proteins, but this was not due to crossreactivity. No significant differences in IgG titres to either mucin or pigeon serum proteins were found between individuals with PFL and asymptomatic precipitin positive fanciers. IgG1 and IgG2 were the major subclasses of anti-mucin, with lower titres of IgG3. Patients with PFL had significantly higher titres of IgG1 to mucin than asymptomatic, precipitin-positive individuals. In contrast, no significant differences were seen between PFL and asymptomatic precipitin-positive sera with respect to the subclass titres against pigeon serum proteins. CONCLUSION: The high titres of anti-mucin IgG in sera of all individuals with PFL, together with the finding that high IgG1 titres to mucin are associated with the development of disease confirm pigeon intestinal mucin as an important antigen in PFL.     

Effects of autoantibodies to the insulin receptor on isolated adipocytes. Studies of insulin binding and insulin action

Autoantibodies to the insulin receptor have been detected in the sera of several patients with the Type B syndrome of insulin resistance and acanthosis nigricans. In this study we have used three of these sera (B-1, B-2, and B-3) as probes of the insulin receptor in isolated rat adipocytes. Preincubation of adipocytes with each of the three sera resulted in an inhibition of subsequent [(125)I]insulin binding. 50% inhibition of binding occurred with serum dilutions of 1:5 to 1:7,500. As in our previous studies with other tissues, Scatchard analysis of the insulin-binding data was curvilinear consistent with negative cooperativity. Computer analysis suggested that in each case the inhibition of binding was due to a decrease in receptor affinity rather than a change in available receptor number. In addition to the effects on insulin binding, adipocytes pretreated with antireceptor sera also showed alterations in biological responses. All three sera produced some stimulation of basal glucose oxidation. With serum B-3, maximal stimulation of glucose oxidation occurred at a serum concentration that inhibited binding by only 10-15%, whereas with serum B-2 the dilution curves for inhibition of binding and stimulation of glucose oxidation were superimposable. Serum B-1 behaved as a partial agonist; that is, it inhibited binding more effectively than it stimulated glucose oxidation. Cells pretreated with this serum in a concentration which inhibited binding by 80% also showed a five-fold shift to the right in the dose response of insulin-stimulated glucose oxidation, whereas spermine-stimulated glucose oxidation was unaffected. Serum B-2, which contained the highest titer of antireceptor antibodies, also stimulated 2-deoxy-glucose transport, as well as glucose incorporation into lipid and glycogen. Both the ability of the serum to inhibit binding and stimulate glucose utilization were enriched in purified immunoglobulin fractions and retained in the F(ab')(2) fragment of the IgG. In addition, the bioactivity was blocked by antihuman IgG but not by anti-insulin antibodies. Enzymatic digestion of adipocytes with trypsin resulted in a complete loss of insulin-stimulated bioactivity of serum B-3, but had only minor effects on the glucose oxidation produced by serum B-1 or B-2.These data suggest that the antibodies present in these three sera bind to different determinants on the insulin receptor. Thus, these antibodies may be useful probes of receptor structure and function.     

Antineutrophil cytoplasmic antibodies (ANCA) in rheumatoid arthritis: a prospective study

To investigate a possible relationship between the presence of antineutrophil cytoplasmic antibodies (ANCA), rheumatoid factor (RF), antinuclear antibodies (ANA), complement, disease activity and disease severity, 111 clinically well-documented RA patients were studied prospectively for ANCA, RF, ANA, C-reactive protein (CRP), total haemolytic complement (CH50) and complement split product C3d. Disease activity and severity were also assessed clinically, as well as anamnestically, using the Hannover Activity of Daily Living Questionnaire, the functional Steinbrocker grades, and numeric and verbal rating scales. At a serum dilution of 1:50, 20% of the 111 sera showed predominantly an atypical perinuclear staining pattern. There was no correlation between ANCA positivity and serological markers, disease activity and disease severity. Regarding previous therapies with disease-modifying antirheumatic drugs, ANCA+ patients took sulphasalazine significantly more often than ANCA- patients.     

Antibodies to myelin basic protein in children with autistic behavior

Based on a possible pathological relationship of autoimmunity to autism, antibodies reactive with myelin basic protein (anti-MBP) were investigated in the sera of autistic children. Using a screening serum dilution of 1:400 in the protein-immunoblotting technique, approximately 58% (19 of 33) sera of autistic children (< or = 10 years of age) were found to be positive for anti-MBP. This result in autistics was significantly (p < or = .0001) different from the controls (8 of 88 or only 9% positive), which included age-matched children with normal health, idiopathic mental retardation (MR) and Down syndrome (DS), and normal adults of 20 to 40 years of age. Since autism is a syndrome of unknown etiology, it is possible that anti-MBP antibodies are associated with the development of autistic behavior.     

Characterization of the neutrophil molecules identified by quinine-dependent antibodies from two patients

BACKGROUND: Two patients with episodic pancytopenia and renal failure associated with quinine (Qn) ingestion were previously found to have Qn-dependent antibodies that reacted with red cells, platelets, and neutrophils. The purpose of these studies was to characterize the neutrophil antigens recognized by Qn-dependent antibodies from these two patients. STUDY DESIGN AND METHODS: The neutrophil molecules recognized by the Qn-dependent antibodies in the sera from the two patients were analyzed by immunoprecipitation using 125I-labeled neutrophils. Neutrophils from 13 different donors were tested. RESULTS: The Qn-dependent antibodies from Patient 1 immunoprecipitated a 60-kDa molecule on neutrophils from seven donors and an 85-kDa molecule on neutrophils from three donors. The Qn-dependent antibodies from Patient 2 reacted with a 32-kDa molecule on neutrophils from 5 donors, a 60-kDa molecule on neutrophils from 9 donors, and an 85-kDa molecule on neutrophils from 10 donors. Neutrophil-specific antigen NB1 is also located on a 60-kDa glycoprotein (GP). While the antibody in serum from Patient 1 did not show specificity for NB1, the antibody from Patient 2 detected the 60-kDa molecule on NB1-positive neutrophils from 9 of 11 donors tested and did not detect the 60-kDa molecule on NB1-negative neutrophils from 2 donors. In a monoclonal antibody immobilization of granulocyte antigens assay, the Qn-dependent antibody from both patients reacted with the 60-kDa molecule carrying NB1. The Qn-dependent antibody from a third patient, Patient 3, was previously found to react with an 85-kDa GP and the 60-kDa NB1 GP. To determine if the Qn-dependent antibodies from Patients 2 and 3 recognized the same 85-kDa GP, neutrophils were treated with serum from Patient 3 plus Qn to remove the 85-kDa GP. Then, serum from Patient 2 plus Qn no longer immunoprecipitated the 85-kDa GP. CONCLUSION: The antigens recognized by Qn-dependent neutrophil antibodies were located on molecules of 85, 60, and 32 kDa. Qn-dependent antibodies from two patients reacted with the same 85-kDa GP and those from three patients reacted with the same 60-kDa GP. The 60-kDa molecule recognized by the Qn-dependent antibodies carried the NB1 antigen.     

Quantitative nephelometric assay for determining alpha-foetoprotein evaluated

A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of alpha-foetoprotein in serum and amniotic fluid was evaluated with the Behring Nephelometer analyser II. Method stability was good: reconstituted reagents and calibration curve were stable for at least one week. The intra-assay CV varied between 2.3% and 4.0%. The inter-assay CV varied between 3.5% and 4.6%. Samples with alpha-foetoprotein concentrations up to 273000 micrograms/l were analysed without high-dose "hook" effect after automatic dilution. No significant interference from haemoglobin, bilirubin, rheumatoid factors, or human anti-mouse antibodies was detected up to concentrations of 0.15 mmol/l haemoglobin, 268 mumol/l bilirubin, 470 int, units/l rheumatoid factor and a titre of 1/1000 human anti-mouse antibodies. Interference due to triacylglycerols depended on the size of triacylglycerol containing particles: for VLDL, interference did not occur up to triacylglycerol levels of 6.0 mmol/l, for chylomicrons interference was already noted at triacylglycerol levels of 1.0 mmol/l. Correlation with a commercial RIA (Kabi Pharmacia) was excellent both for serum (n = 65) and amniotic fluid (n = 100). The effect of the molecular variation of the carbohydrate moiety of alpha-foetoprotein on the test results was studied using concanavalin A affinity chromatography. The detection of both concanavalin A-reactive and concanavalin A-non-reactive alpha-foetoprotein was equivalent by both methods. Multimeric forms of alpha-foetoprotein were prepared by gel permeation chromatography. The effect of autopolymerization of alpha-foetoprotein on the nephelometric determination of alpha-foetoprotein was negligible. We conclude that latex-enhanced immunonephelometry is a rapid, practical, and reliable method for measuring alpha-foetoprotein in serum and amniotic fluid.     

Anti-bacterial activity of the fluid contents of spermatoceles and epididymal cysts

OBJECTIVE: To show that the fluids obtained from spermatoceles and epididymal cysts are not infected, even though they may be present for long periods, and that these fluids have bactericidal activity. MATERIALS AND METHODS: Sixteen patients, 13 with a spermatocele and three with an epididymal cyst, were included in the study. Protein, glucose, chloride, inorganic phosphorus, calcium and magnesium contents were measured and cultures of the fluids were carried out. Bactericidal activity against the Escherichia coli NTCC 10418 clone was tested in different dilutions. RESULTS: Biochemical analysis showed that the protein, glucose and ionic content of the fluids was lower than that of serum, except for chloride. Microbiological cultures were negative for all samples. A significant bactericidal effect was obtained with 1/1 dilution and no reproduction was seen with this dilution. CONCLUSION: These findings indicate that the fluids within spermatoceles and epididymal cysts do not become infected under normal circumstances.     

Antibodies to beta 2-glycoprotein-I: urea resistance, binding specificity, and association with thrombosis

The aim of the present study was to evaluate the urea resistance and binding characteristics of anti-beta 2-glycoprotein I (anti-beta 2GPI) antibodies using standard anticardiolipin (aCL) and anti-beta 2GPI enzyme immunosorbent assays (ELISAs). Sera from patients with antiphospholipid syndrome (APS) (n = 22) and non-APS (n = 24), positive in a standard aCL ELISA, were tested in an anti-beta 2GPI ELISA performed in polystyrene-irradiated ELISA plates. Urea resistance aCL and anti-beta 2GPI ELISAs were performed by measuring the ability of antibodies to recognize antigen in the presence of 2 M urea. The serum dilution after urea treatment (D) expressed as a percentage of the serum dilution without urea treatment (D(o)) corresponding to the same optical density was defined as residual activity (RA = 100 D/D(o)). The higher the RA, the higher the resistance of the antibodies to urea. APS compared to non-APS sera had higher aCL binding (absorbance values ranging between 0.180 and 1.400; median, 0.717 vs 0.120-1.273; median, 0.250, respectively; P < 0.004). Six APS patients' sera had low aCL levels but they expressed RA > or = 30%. Anti-beta 2GPI antibodies were detected in 15 of 22 APS vs 3 of 24 non-APS patients (P < 0.03); RA > or = 30% was detected in 15 of 22 APS vs 1 of 23 non-APS patients (P < 0.004). Using a CL affinity column, antibodies were purified from three APS anti-beta 2GPI negative and three non-APS anti-beta 2GPI-positive patients and tested in a aCL ELISA, using highly purified bovine serum albumin (BSA) as a blocking agent (modified ELISA); reactivity was not detected in two APS and one non-APS sera. On the contrary, the reactivity of the purified antibodies was high when beta 2GPI was incubated with CL in the ELISA plates; thus some anti-beta 2GPI negative sera from APS patients recognized the CL/beta 2GPI complex, rather than CL or beta 2GPI alone. In conclusion, anti-beta 2GPI antibodies are common in the APS patients, but a number of such patients recognize the CL/beta 2GPI complex and not CL or beta 2GPI. Antibodies to either beta 2GPI or the CL/beta 2GPI complex derived from APS sera present a high resistance to urea. Anti-beta 2GPI antibodies of low urea resistance exist in a minority of non-APS patients with autoimmune disease.     

Immunological evaluation of a 26-kDa antigen from Taenia solium larvae for specific immunodiagnosis of human neurocysticercosis

Human neurocysticercosis, due to infection of the central nervous system by cysticerci of Taenia solium, is a severe form of neurologic disease occurring in Central and South America. Specific proteins from scolex antigen from cysticerci were purified by polyacrylamide gel electrophoresis and electroelution and recognized in Western blots by antibodies present in sera from patients with neurocysticercosis. The proteins appeared as 13-, 17-, and 26-kDa bands on Coomassie blue-stained gels and proved to be specific to cysticerci of T. solium. No cross-reactivity with sera from patients with taeniasis or hydatidosis was observed. Enzyme-linked immunosorbent assay using the purified proteins of 13, 17, and 26 kDa demonstrated rates of 53%, 88%, and 100% specificity, respectively, at the cutoff serum dilution of 1:32 for the specific immunodiagnosis of human neurocysticercosis.     

Spontaneous spermagglutination in ejaculates from men with head-to-head or tail-to-tail spermagglutinating antibodies in serum

Weak or sometimes up to moderate spermagglutination was encountered in ejaculates from a group of men without spermagglutinating antibodies in serum. A similar pattern of spermagglutination was seen in ejaculates from men with head-to head (H-H) spermagglutinating antibodies in serum, even when a high titer (greater than or equal to 1:64) of antibodies was present. In contrast, men with high titers of tail-to-tail (T-T) sperm agglutinating antibodies in serum showed very marked or complete spermagglutination in the ejaculates. The agglutination in ejaculates from men with low titers (less than or equal to 1:32) of T-T spermagglutinating antibodies in serum was much less conspicuous and equaled that in ejaculates from men without such antibodies. This indicates that only a high titer of T-T spermagglutinating antibodies is associated with marked or complete spermagglutination in ejaculates.     

Genetic control of the immune response: ability of antigens of defined amino acid sequence to be recognized by the Ir-1 gene system

Mice were injected with a series of (T,G)-A--L[poly (L Tyr, L Glu)-poly DL Ala)--poly (L Lys)]-like compounds with side chains of homogeneous sequences: T-A--L, GT-A--L, GGT-A--L, and TG-A--L. T-A--L was not immunogenic. However, T-A--L was able to bind antibodies to (T, G)-A--L 509, and this binding could not be blocked by A--L. When complexed with bovine serum albumin, T-A--L, was immunogenic in both responder and nonresponder strains of mice. GT-A--L and GGT-A--L were both immunogenic and elicited the characteristic responder-nonresponder difference induced by (T,G)-A--L. TG-A--L was also immunogenic, but there was considerable overlap in the response of responder and nonresponder strains. On the average, responder mouse serum had a slightly higher antigen-binding capacity than nonresponder mouse serum. In contrast to antibodies against GGT-A--L, antibodies against TG-A--L bound heterologous antigens poorly. These data, along with the results of other investigators, are consistent with the hypothesis that there are multiple Ir- 1 genes which recognize different sequences. The specificity of the Ir- 1 genes is extraordinary. The polypeptides TG-A--L, TGTG-A--L and GTTG-A--L do not appear to be recognized by these genes.     

Mycophenolate mofetil, together with cyclosporin A, prevents anti-OKT3 antibody response in kidney transplant recipients

OKT3 monoclonal antibody, a murine IgG2a monoclonal antibody targeting the T cell CD3 antigen, elicits a neutralizing humoral response in 20 to 50% of kidney transplant recipients when the concomitant immunosuppression consists of CsA-Sandimmun (SAND) and azathioprine (AZA). In the present study, we investigated the impact of the newer agents, CsA-Neoral (NEO) and mycophenolate mofetil (MMF) on OKT3 sensitization. Sixty-two consecutive kidney transplant recipients received prophylactic OKT3 (5 mg/d) from days 0 to 13, together with steroids. Concomitant immunosuppression consisted of either AZA + SAND (n=20), AZA + NEO (n=31), or MMF + NEO (n=11). The following doses were used: AZA, 2 mg/kg per d from days 0 to 13, then 1 mg/kg per d; MMF, 2 g/d starting on day 1; and CsA, either SAND or NEO, 6 mg/kg per d from day 6. At least two serum samples per month were available during the initial 3 mo for each patient. IgG anti-OKT3 antibodies were first evaluated by enzyme-linked immunosorbent assay. Patients were considered sensitized if their serum scored positive at a dilution > or = 1/1000. Peak titers of IgG anti-OKT3 antibodies and the incidence of patients harboring neutralizing anti-idiotypic antibodies were also determined. A first reduction in OKT3 sensitization was seen in patients receiving Neoral instead of Sandimmun (AZA + SAND: 10 of 20 [50%] patients sensitized versus 6 of 31 [19%] in the AZA + NEO group; P=0.03). This was probably related to the achievement of higher mean CsA trough blood levels in the NEO group during the first month (253+/-44 versus 186+/-49 ng/ml in SAND patients). Peak antibody titers and the proportion of patients with anti-idiotypic antibodies were similar in the AZA + SAND and AZA + NEO groups. A further reduction in the sensitization rate was observed with the replacement of AZA by MMF (MMF + NEO: 0% sensitized patients; P=0.0013). It is concluded that the combination of CsA-Neoral and MMF efficiently prevents sensitization against OKT3.     

The reinforced laryngeal mask airway (LMA) as an alternative airway device to manage the difficult airway

BACKGROUND: Infection with human parvovirus B19 (B19) has been reported in a few patients with various vasculitis syndromes. Mixed cryoglobulinaemia (MC), a model of small vessel size vasculitis, may result from numerous infectious diseases, particularly hepatitis C virus (HCV) infection. AIM: To assess the prevalence of seric B19 infection markers in a large series of patients with MC, with or without HCV infection. PATIENTS AND METHODS: Sixty-four patients were studied: essential MC (EMC, n = 19), MC associated with non-infectious diseases (non-essential MC, n = 9), and patients with HCV infection with (HCV-MC, n = 18) or without MC (HCV-no-MC, n = 18). Patients were considered to have MC if two successive determinations of their serum cryoglobulin concentration were above 0.05 g/l. Serum samples were analysed for specific IgG and IgM antibodies to B19 by enzyme immunoassay. B19 DNA detection was performed by polymerase chain reaction using a set of primers located in the VP1 gene, separately in serum and in cryoprecipitates to investigate a possible capture of B19 DNA in cryoprecipitate. The study also looked for a possible enrichment for of IgG antibodies to B19 in MC. RESULTS: The presence of specific IgG antibodies to B19 was found in 68% EMC, 56% non-essential MC, 78% HCV-MC, and 78% HCV-no-MC. No patient of either group had specific IgM antibodies to B19, or B19 DNA in serum or in cryoprecipitate. Overall, IgG antibodies to B19 were found in 46 of 64 (72%) serum samples, a prevalence quite similar to the prevalence in general adult population (> 60%). A specific enrichment of IgG antibodies to B19 in the MC was not found. CONCLUSION: These results suggest that B19 infection is neither an aetiological factor of EMC, nor a cofactor that may lead to MC production in patients with chronic HCV infection.     

Cerebral and systemic embolization during left ventricular support with the Novacor N100 device

To clarify the nature of serum anti-hypervariable region 1 (HVR1) antibodies in patients infected with hepatitis C virus (HCV), we assessed the reactivity of 21 patients' sera with 42 HVR1 proteins by Western blot. HVR1 was expressed as fusion proteins with glutathione S-transferase (GST). The patients' sera reacted with variable percentages of the HVR1 proteins, and always reacted with HVR1 proteins of the different genotype. In the genotype-1b-infected patients, the percentage of genotype-1b HVR1 proteins reactive with serum correlated significantly with viral loads; the sera reactive with the higher percentages of HVR1 proteins contained the larger viral loads. In addition, it was significantly lower in the responders of interferon (IFN) therapy than in nonresponders. The competition assays indicated that multiple fractions of anti-HVR1 antibodies with different specificity in a serum reacted with different HVR1 proteins, and that, additionally, a single fraction of antibodies often reacted with more than one HVR1 protein through a similar amino acid sequence. In conclusion, serum anti-HVR1 antibodies were broadly reactive by the mechanism of both the cross-reactivity of a single fraction of anti-HVR1 antibodies with more than one HVR1 protein and the presence of multiple fractions of anti-HVR1 antibodies with different specificity in a serum. In genotype-1b-infected patients, the broad reactivity of serum anti-HVR1 antibodies correlated with viral loads and response to IFN. Further studies are necessary to elucidate the correlation among the broad reactivity of sera with multiple HVR1 proteins and clinical features of chronic hepatitis C patients.     

The mechanisms, intensity of treatment, and outcomes of hospitalized burns: issues for prevention

Our previous study revealed that passive cutaneous anaphylaxis (PCA) can be produced in congenitally mast cell-deficient WBB6F1-W/Wv (abbreviated as W/Wv) mice on sensitization with undiluted or slightly diluted allogeneic and xenogeneic antisera but not on sensitization with allogeneic monoclonal immunoglobulin (Ig)E and IgG1 antibodies regardless of the antibody concentration [1]. In view of these findings, the present study was conducted to characterize PCA in this strain from its drug susceptibilities using mast cell-bearing WBB6F1-(+)/+ (abbreviated as +/+) and B6D2F1 mice as references. PCA in W/Wv mice mediated by a low dilution (1:4) of hyperimmune serum to bovine serum albumin of the B6D2F1 mouse origin was markedly suppressed by CV-6209, an antagonist of platelet-activating factor (PAF), but not by antihistamines such as cyproheptadine and oxatomide. In contrast, PCA in +/+ and B6D2F1 mice mediated by a high dilution (1:128) of the anti-serum (virtually by IgG1 antibody) was nearly completely suppressed by antihistamines but not by CV-6209. A remarkable difference between PCA in W/Wv and reference mice was also observed in the susceptibility to monoclonal anti-mouse granulocyte (Gr-1) antibody: PCA in W/Wv mice was potently suppressed by the 1- to 3-day pretreatment with this antibody but that in references was not at all. Putting these present results together with the previous finding that anti-granulocyte antibody greatly reduces circulatory Gr-1+ leukocytes, 1 to 3 days after the treatment [2], it is highly probable that PCA in W/Wv mice mediated by some antibody isotypes other than IgE and IgG1 is produced by PAF mainly released from Gr-1+ cells, while IgG1 antibody-mediated PCA in mast cell-bearing reference mice is evoked by histamine derived from mast cells. PCA homologous to that in W/Wv mice could also be produced in the reference mice on sensitization with undiluted or slightly diluted antiserum, when generalized blueing due to excess IgG1 antibody was removed by the oxatomide treatment before the antigen challenge.