Biological Activity of a Partially Purified Inhibitor of Vaccinia Virus Hemagglutinin

An inhibitor acting against vaccinia virus hemagglutinin, and producing a hemagglutinin-negative virus, was separated from tumorous ascitic plasma. The finding that the partially purified inhibitor was biologically active strengthens the evidence for a specific role of the inhibitor in altering the virus.     

Model analysis of the contribution of atrial contraction to ventricular filling

We studied the contribution of atrial contraction to ventricular filling by modelling the right heart and the associated vasculature. Right atrial and ventricular contractions were represented by periodically varying volume elastances which are independent of loading conditions. The values of these elastances were experimentally determined. The systemic veins, the tricuspid valve and the pulmonary arteries were all represented by impedance networks. For these impedances we used as much experimentally obtained information as possible. The dynamic pressure and flow waveforms observed in the model under control conditions generally agreed with those reported in the literature. We therefore proceeded to analyze the effects of changing the time interval between atrial systole and ventricular systole, atrial contractility, heart rate, and blood inertance. There was an optimal atrial systole-ventricular systole interval of about 0.1 sec for ventricular filling. Stroke volume of the ventricle was enhanced by an increase in atrial contractility, a decrease in heart rate, and an increase in blood inertance. The effect of changing atrial compliance was found to be dependent on heart rate. Contribution of atrial contraction to ventricular filling was also found to be more significant during exercise than at rest.     

Evaluation of a Selective Transport Medium for Gastric Biopsy Specimens To Be Cultured for Helicobacter pylori

Since the means of culturing Helicobacter pylori may not be available in some laboratories, prolonging the survival of this organism during transportation is a major concern in terms of improving detection rates. A selective transport medium was evaluated for the preservation of H. pylori from 254 gastric biopsy specimens collected from a rural area in China where culturing is not feasible. Gastric biopsy specimens were inoculated in sterile broth consisting of brain heart infusion (BHI) broth, horse serum, and yeast extract supplemented with vancomycin, amphotericin B, and nalidixic acid (VAN). Of the 254 biopsy specimens, 238 were identified by histology to have H. pylori infection. Total rates of recovery of H. pylori from the H. pylori-positive gastric biopsy specimens stored in the BHI-VAN broth ranged from 76 to 46% after storage of specimens for 5 to 9 days. In conclusion, the selective medium is useful for prolonging the survival of H. pylori in gastric biopsy specimens for which immediate culture is not feasible.     

Sexual transmission of hepatitis B infection despite the presence of hepatitis B virus immunity in recipients of allogeneic bone marrow transplantation.

BACKGROUND: After hematopoietic cell transplantation (HCT), hepatitis due to hepatitis B virus (HBV) rarely occurred beyond the initial 12 months after transplantation. OBJECTIVES: We investigated the cause of "late" hepatitis due to HBV infection in two recipients after allogeneic HCT. STUDY DESIGN: Two male patients with acute myeloid leukemia and light chain myeloma, respectively, developed HBV-related hepatitis more than 2 years after HCT. All serum samples collected from the recipients, donors and their respective spouses were tested for HBV DNA by nested PCR, and if positive further quantified by Digene Hybrid Capture assay II. The HBV genotype was determined by PCR and sequencing. RESULTS: Genotypic analysis suggested that the cause of "late" hepatitis was due to acute HBV infection transmitted from their respective spouse. CONCLUSION: Our findings suggested that sexual precautions should be taken in these patients after HCT. Alternatively, or even additionally, active vaccination should be delivered to these patients once they have lost their HBV immunity.     

Wound dressing with sustained anti-microbial capability

Amphiphilic poly(ether ester amide) (PEEA) multiblock copolymers were synthesized by polycondensation in the melt from hydrophilic poly(ethylene glycol) (PEG), 1,4-dihydroxybutane and short bisester-bisamide blocks. These amide blocks were prepared by reaction of 1,4-diaminobutane with dimethyl adipate in the melt. A range of multiblock copolymers were prepared, with PEG contents varying from 23-66 wt %. The intrinsic viscosity of the PEEA polymers varied from 0.58-0.78. Differential scanning calorimetry showed melting transitions for the PEG blocks and for the amide-ester blocks, suggesting a phase separated structure. Both the melting temperature and the crystallinity of the hard amide-ester segments decreased with increasing PEG content of the polymers. The equilibrium swelling ratio in phosphate buffered saline (PBS) increased with increasing amount of PEG in the polymers and varied from 1.7 to 3.7, whereas the polymer that contained 66 wt % PEG was soluble in PBS. During incubation of PEEA films in PBS, weight loss and a continuous decrease in the resulting inherent polymer viscosity was observed. The rate of degradation increased with increasing PEG content. The composition of the remaining matrices did not change during degradation. A preliminary investigation of the protein release characteristics of these PEEA copolymers showed that release of the model protein lysozyme was proportional to the square root of time. The release rate was found to increase with increasing degree of swelling of the polymers.     

Epstein-Barr-virus-transformed lymphoblastoid cell lines derived from patients with X-linked agammaglobulinaemia and Wiskott-Aldrich syndrome: responses to B cell growth and differentiation factors.

Epstein-Barr-virus-transformed B lymphoblastoid cell lines (EBV-transformed LCL) from three patients with X-linked agammaglobulinaemia (XLA), six patients with Wiskott-Aldrich Syndrome (WAS), and seven normal donors, were tested for growth and differentiation in response to human recombinant IL-4, a commercially available, low molecular weight B cell growth factor (BCGFlow), and B cell differentiation factor (BCDF) secreted by the T24 cell line, now known to be IL-6. Proliferation (3H-TdR uptake) by EBV-transformed LCL from both XLA and WAS patients in response to BCGFlow was similar to that obtained with the normal cell lines. In addition, three normal and three WAS, but none of the XLA EBV-transformed LCL, proliferated a little in response to IL-4. All the normal B cell lines secreted IgM, and six out of the seven secreted IgG in response to BCGFlow and BCDF. A similar pattern of response was obtained with the WAS EBV-transformed LCL (6/6 secreted IgM and 4/6 secreted IgG). Several of the normal and WAS EBV-transformed LCL also secreted IgM and IgG in response to IL-4. In contrast, the lines from the XLA patients were abnormal. One secreted large amounts of IgM and two secreted small amounts, but none of the XLA lines secreted IgG constitutively or in response to any of the factors (IL-4, BCDF). The lack of detectable IgG secretion by the XLA lines was probably due to an absence of precommitted IgG B cell precursors transformed by EBV rather than an intrinsic inability to respond to BCGF and BCDF. All of the lines, including those derived from XLA patients, were shown to secrete B cell growth and differentiation factors detected on indicator B cell lines. These results suggest that the abnormal X-linked genes responsible for XLA and WAS do not interfere with B cell responses to B cell growth and differentiation factors.     

Febrile-range hyperthermia augments pulmonary neutrophil recruitment and amplifies pulmonary oxygen toxicity

Febrile-range hyperthermia (FRH) improves survival in experimental infections by accelerating pathogen clearance, but may also increase collateral tissue injury. We hypothesized that FRH would worsen the outcome of inflammation stimulated by a non-replicating agonist and tested this hypothesis in a murine model of pulmonary oxygen toxicity. Using a conscious, temperature-controlled mouse model, we showed that maintaining a core temperature at FRH (39 degrees C to 40 degrees C) rather than at euthermic levels (36.5 degrees C to 37 degrees C) during hyperoxia exposure accelerated lethal pulmonary vascular endothelial injury, reduced the inspired oxygen threshold for lethality, induced expression of granulocyte-colony stimulating factor, and expanded the circulating neutrophil pool. In these same mice, FRH augmented pulmonary expression of the ELR(+) CXC chemokines, KC and LPS-induced CXC chemokine, enhanced recruitment of neutrophils, and changed the histological pattern of lung injury to a neutrophilic interstitial pneumonitis. Immunoblockade of CXC receptor-2 abrogated neutrophil recruitment, reduced pulmonary vascular injury, and delayed death. These combined data demonstrate that FRH may enlist distinct mediators and effector cells to profoundly shift the host response to a defined injurious stimulus, in part by augmenting delivery of neutrophils to sites of inflammation, such as may occur in infections. In certain conditions, such as in the hyperoxic lung, this process may be deleterious.     

TGF-β1 Null Mutation Leads to CD154 Upregulated Expression in Affected Tissues

The TGF-1(–/–) mouse is a murine model for systemic autoimmune disease. The aim of this study is to elucidate the immunological mechanism that leads to multifocal tissue inflammation and autoantibody production in TGF-1(–/–) mice. Heart, lung, liver, and salivary gland from TGF-1(–/–) were assessed for CD154 expression by RT-PCR and immunohistochemistry. Compared to wild-type littermates, CD154 expression was elevated in all tissues studied. Furthermore, IL-12 mRNA was expressed in the salivary gland and heart of TGF-1(–/–) mice and not in wild-type littermates. This suggests that the CD154 pathway is activated in these tissues. This shows that TGF-1 regulates CD154 expression leading to spontaneous IL-12 production and autoimmunity.     

Use of pulsed-field gel electrophoresis to investigate an outbreak of Serratia marcescens.

Pulsed-field gel electrophoresis (PFGE) typing was applied to the epidemiological investigation of 20 Serratia marcescens isolates collected from urine specimens of 17 patients and three urinals over a 2-month period. Twenty-five epidemiologically unrelated strains were also tested to determine the discriminatory power of PFGE. The PFGE fingerprints of each isolate were consistent in three different tests. The 20 outbreak isolates had an identical PFGE fingerprint pattern, while the epidemiologically unrelated strains demonstrated unique PFGE fingerprint patterns. The source of the outbreak was inadequately disinfected urinals. We conclude that PFGE served as a highly discriminatory and reproducible method for the epidemiological investigation of the outbreak of S. marcescens infection addressed by this study.     

Chemiluminescent response to pathogenic organisms: normal human polymorphonuclear leukocytes

Chemiluminescence (CL) is a sensitive indicator of phagocytosis and intracellular killing; however, little is known of the normal CL response by human polymorphonuclear leukocytes to different pathogenic microorganisms. We investigated the luminol-enhanced CL response of normal polymorphonuclear leukocytes to a number of common bacterial pathogens and two yeasts. We analyzed the CL response to viable and heat-killed microorganisms at 25 and 37 degrees C. The CL response to all microorganisms was greater and more rapid at 37 degrees C. Variable responses were observed with viable and heat-killed microorganisms; some were unaffected, whereas other demonstrated reduced CL. Each microorganism caused a reproducible response pattern, which could be placed into two general categories. In the first category were those which caused a rapid exponential rise and decay in CL: Enterobacter cloacae, Salmonella typhimurium, Shigella flexneri, Staphylococcus aureus, Candida albicans, and zymosan. In the second category were those which rose slowly over a longer time course to a poorly defined peak: Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Streptococcus pyogenes. The CL response also reflected serum opsonic activity. The effect of inactivated complement, factor B, and removal of specific antibody were investigated. Increasing the concentration of zymosan gave a proportional rise in peak CL; however, a strain of E. coli caused a variation in peak time rather than peak height. Different CL kinetics were shown for three strains of K. pneumoniae, possibly a result of each having different membrane or cell wall characteristics. This study defines the nature and factors affecting the normal CL response to a variety of common pathogenic microorganisms.