Rapid induction of apoptosis in B-cell lymphoma by functionally isolated human antibodies

Novel panning and screening methodology was devised to isolate high affinity human recombinant scFv antibody fragments with functionally associated properties in B lymphoma cells. The approach was used to generate a panel of apoptosis‐inducing antibodies specific for antigens differentially expressed in B lymphoma vs. T leukaemia cells. The selections resulted in an antibody pool with near perfect selectivity (>99%) for the B lymphoma target cells. Randomly picked clones (72) revealed 7 unique antibody genotypes. Six of these rapidly induced apoptosis in target cells. Following the conversion to full IgGs, the antibodies were shown to be specific for HLA‐DR/DP, the B‐cell receptor μ chain and for CD54/ICAM‐1. The latter receptor was not previously associated with apoptotic properties in B‐cell lymphomas. Anti‐ICAM‐1 IgG induced apoptosis in a broad range of B lymphoma cell lines and were shown by immunohistochemistry to bind strongly to B lymphoma tissue obtained from 5 different B lymphoma patients. The recombinant IgG antibodies had affinities in the subnanomolar (0.3 nM) to nanomolar (3 nM) range. The described technology is generally applicable for the rapid isolation of high affinity human antibodies with specificity for differentially expressed cell surface receptors with intrinsic negative or positive signalling properties from naïve phage libraries. © 2006 Wiley‐Liss, Inc.     

Myopericarditis following smallpox vaccination among vaccinia-naive US military personnel

Context  In the United States, the annual incidence of myocarditis is estimated at 1 to 10 per 100 000 population. As many as 1% to 5% of patients with acute viral infections involve the myocardium. Although many viruses have been reported to cause myopericarditis, it has been a rare or unrecognized event after vaccination with the currently used strain of vaccinia virus (New York City Board of Health). Objective  To describe a series of probable cases of myopericarditis following smallpox vaccination among US military service members reported since the reintroduction of vaccinia vaccine. Design, Setting, Participants  Surveillance case definitions are presented. The cases were identified either through sentinel reporting to US military headquarters surveillance using the Defense Medical Surveillance System or reports to the Vaccine Adverse Event Reporting System using International Classification of Diseases, Ninth Revision. The cases occurred among individuals vaccinated from mid-December 2002 to March 14, 2003. Main Outcome Measure  Elevated serum levels of creatine kinase (MB isoenzyme), troponin I, and troponin T, usually in the presence of ST-segment elevation on electrocardiogram and wall motion abnormalities on echocardiogram. Results  Among 230 734 primary vaccinees, 18 cases of probable myopericarditis after smallpox vaccination were reported (an incidence of 7.8 per 100 000 over 30 days). No cases of myopericarditis following smallpox vaccination were reported among 95 622 vaccinees who were previously vaccinated. All cases were white men aged 21 years to 33 years (mean age, 26.5 years), who presented with acute myopericarditis 7 to 19 days following vaccination. A causal relationship is supported by the close temporal clustering (7-19 days; mean, 10.5 days following vaccination), wide geographic and temporal distribution, occurrence in only primary vaccinees, and lack of evidence for alternative etiologies or other diseases associated with myopericarditis. Additional supporting evidence is the observation that the observed rate of myopericarditis among primary vaccinees is 3.6-fold (95% confidence interval, 3.33-4.11) higher than the expected rate among personnel who were not vaccinated. The background incidence of myopericarditis did not show statistical significance when stratified by age (20-34 years: 2.18 expected cases per 100 000; 95% confidence interval [CI], 1.90-2.34), race (whites: 1.82 per 100 000; 95% CI, 1.50-2.01), and sex (males: 2.28 per 100 000; 95% CI, 2.04-2.54). Conclusion  Among US military personnel vaccinated against smallpox, myopericarditis occurred at a rate of 1 per 12 819 primary vaccinees. Myopericarditis should be considered an expected adverse event associated with smallpox vaccination. Clinicians should consider myopericarditis in the differential diagnosis of patients presenting with chest pain 4 to 30 days following smallpox vaccination and be aware of the implications as well as the need to report this potential adverse advent.      

Targeted disruption of the VH 81X gene: Influence on the B cell repertoire

We have generated a mutant mouse in which the most D-proximal V_H gene (V_H81X) has been disrupted by introducing a neomycin-resistance gene into the V_H81X exon by means of gene targeting in embryonic stem cells. The mutant mice generated are unable to express the V_H81X gene but appear to display a normal pattern of B cell differentiation as well as normal numbers of bone marrow and peripheral B cells from fetal life all through ontogeny. They mount normal immune responses to several different antigens tested. In contrast, the distribution of V_H gene rearrangements in the V_H7183 family is altered in homozygous mutant mice. Thus, the antibody repertoire of the targeted mice is modified, at least as far as the expression of V_H7183 genes is concerned.     

Expression of complement factor H binding immunoevasion proteins in Borrelia garinii isolated from patients with neuroborreliosis

The Lyme disease-pathogen Borrelia burgdorferi binds the complement inhibitor factor H (FH) to its outer surface protein E- (OspE) and BbA68-families of lipoproteins. In earlier studies, only serum-resistant strains of the genospecies B. burgdorferi sensu stricto or B. afzelii, but not serum-sensitive B. garinii strains, have been shown to bind FH. Since B. garinii often causes neuroborreliosis in man, we have readdressed the interactions of B. garinii with FH. B. garinii 50/97 strain did not express FH-binding proteins. By transforming the B. garinii 50/97 strain with an OspE-encoding gene from complement-resistant B. burgdorferi (ospE-297), its resistance to serum killing could be increased. OspE genes were detected and cloned from the B. garinii BITS, Pistoia and 40/97 strains by PCR and sequencing. The deduced amino acid sequences differed in an N-terminal lysine-rich FH-binding region from OspE sequences of resistant strains. Recombinant B. garinii BITS OspE protein was found to have a considerably lower FH-binding activity than the B. burgdorferi sensu stricto 297 OspE protein P21 (P21-297). Unlike bacteria that had been kept in culture for a long time, neurovirulent B. garinii strains from neuroborreliosis patients were found to express approximately 27-kDa FH-binding proteins. These were not recognized by polyclonal anti-OspE or anti-BbA68 antibodies. We conclude that B. garinii strains carry ospE genes but have a decreased expression of OspE proteins and a reduced ability to bind FH, especially when grown for prolonged periods in vitro. Recently isolated neuroinvasive B. garinii strains, however, can express FH-binding proteins, which may contribute to the virulence of neuroborreliosis-causing B. garinii strains.     

Head‐to‐head comparison between Actigraph 7164 and GT1M accelerometers in adolescents

We compared, head‐to‐head, the old generation Actigraph model 7164 with the new generation Actigraph GT1M accelerometer. A total of 15 randomly selected teenagers (eight girls and seven boys) were investigated. They performed a treadmill test wearing the two kinds of accelerometers around the waist simultaneously. The treadmill test consisted of three different levels of speed 4, 6 and 8 km h^?1 for four consecutive minutes. Accelerometer counts per 1 sec epoch for the Actigraph GT1M versus the Actigraph 7164 were at 4 km h^?1 21·6 ± 12·9 versus 26·5 ± 11·5 counts, at 6 km h^?1 56·0 ± 23·2 versus 62·9 ± 25·6 counts and at 8 km h^?1 142·6 ± 37·2 versus 156·4 ± 34·9 counts (P<0·01 for all levels of speed). Data from the old generation Actigraph 7164 and the new generation Actigraph GT1M accelerometers differ, where the Actigraph GT1M generates 10‐23% lower values. Correction equation for Actigraph GT1M was Actigraph 7164 = 5·2484 +  Actigraph GT1M counts × 1·0448. These results need to be taken into consideration when using these devices.     

Regulation of B Lymphocyte Development by the Truncated Immunoglobulin Heavy Chain Protein Dμ

The development of B lymphocytes from progenitor cells is dependent on the expression of a pre–B cell–specific receptor made up by a μ heavy chain associated with the surrogate light chains, immunoglobulin (Ig)α, and Igβ. A variant pre–B cell receptor can be formed in which the μ heavy chain is exchanged for a truncated μ chain denoted Dμ. To investigate the role of this receptor in the development of B cells, we have generated transgenic mice that express the Dμ protein in cells of the B lineage. Analysis of these mice reveal that Dμ expression leads to a partial block in B cell development at the early pre–B cell stage, probably by inhibiting V_H to D_HJ_H rearrangement. Furthermore, we provide evidence that Dμ induces V_L to J_L rearrangements.     

Preoperative Anemia Independently Predicts Significantly Increased Odds of Short-Term Complications Following Aseptic Revision Hip and Knee Arthroplasty

BackgroundPreoperative anemia is an important risk factor for developing complications following revision hip (rTHA) and knee (rTKA) arthroplasty. We aim to determine the effect of anemia severity on 30-day postoperative complications following revision hip and knee arthroplasty.MethodsA retrospective cohort study was conducted using the American College of Surgeons National Quality Improvement Program Database. All patients who underwent revision joint arthroplasty (rTJA) between 2006 to 2017 were identified and grouped based upon the hematocrit (Hct) level. Anemia was defined as Hct <36% for women and <39% for men, and further stratified into mild anemia (Hct 33% to 36% for women, Hct 33% to 39% for men), and moderate to severe anemia (Hct <33% for both men and women). Univariate and multivariate analysis were used to evaluate the incidence of multiple adverse events within 30 days after TJA.ResultsA total of 8932 patients undergoing rTHA and 13,313 patients undergoing rTKA were included for analysis. On multivariate adjustment, patients undergoing rTHA with moderate to severe anemia had an increased odds of 5.437 (95% Confidence Interval (CI) 4.604 to 6.421; P < .001) of developing any postoperative complication. On multivariate adjustment, patients undergoing rTKA with moderate to severe anemia had increased odds of 6.731 (95% Confidence Interval (CI) 5.540 to 8.179; P < .001) of developing any postoperative complication.ConclusionThe increasing severity of anemia was associated with an increasing risk of developing any postoperative complication and death following revision hip and knee arthroplasty. There is a significant trend between diminishing preoperative hematocrit levels and increasing odds of postoperative complication.     

On Diffuse Interface Modeling and Simulation of Surfactants in Two-Phase Fluid Flow

An existing phase-field model of two immiscible fluids with a single soluble surfactant present is discussed in detail. We analyze the well-posedness of the model and provide strong evidence that it is mathematically ill-posed for a large set of physically relevant parameters. As a consequence, critical modifications to the model are suggested that substantially increase the domain of validity. Carefully designed numerical simulations offer informative demonstrations as to the sharpness of our theoretical results and the qualities of the physical model. A fully coupled hydrodynamic test-case demonstrates the potential toalso capture non-trivial effects on the overall flow.