Neonatal group B streptococcal osteomyelitis and suppurative arthritis. Outpatient therapy.
Explore the source record for details and available documents.
Arthritis, Infectious↗
Biomedical subjects
K M Edwards
Publications and source records attributed to K M Edwards.
Diphtheria outbreaks in immunized populations.
Explore the source record for details and available documents.
Adult↗
Laboratory and epidemiologic assessment of a recent influenza B outbreak.
A viral surveillance system in Nashville detected an outbreak of influenza B that occurred between January and March 1986. Paired sera from 32 individuals with culture-documented influenza B illness were tested using three serologic assays. Enzyme-linked immunosorbent assay (ELISA) using purified hemagglutinin-neuraminidase and plaque neutralization detected a seroresponse in 69% and 66% of these individuals, respectively. These assays were superior to hemagglutination inhibition, which detected a 41% seroresponse. ELISA was perferred because of cost and ease of performance. A group of 286 individuals, aged 1-65 years, was studied more extensively including serologic assessment before and after the influenza B outbreak. Historical information and viral throat cultures were obtained from those with influenza-like illness during the epidemic. An influenza B infection rate (seroresponse and/or positive culture) of 31% and illness rate (infection with flu-like symptoms during the epidemic period) of 13% was demonstrated using these methods. Pre-epidemic mean serum ELISA IgG titers were lower in those with, versus those without, evidence of subsequent influenza B illness (1,541 vs. 4,311, P = .0026). Children less than or equal to 15 years of age were infected more frequently than adults (44% vs. 28%, P = .04). Fever greater than or equal to 101 degrees F was reported more frequently with influenza B than non-B illness (43% vs. 18%, P = .03). These data are useful in preparing for future epidemiologic studies of influenza B and demonstrate the value of and need for standardization of ELISA as a serologic assay for influenza B.
Age Factors↗
Poxvirus deletion mutants: virulence and immunogenicity.
Post-vaccinial encephalitis and disseminated vaccinia are major concerns with the use of vaccinia virus recombinants as immunization vectors in man. To identify and characterize possible attenuated poxvirus vectors, rabbitpox virus (RPV) (closely related to vaccinia) and four deletion mutants of RPV were studied for organ tropism, neurovirulence, and protection from wild-type challenge in BALB/c mice. Intraperitoneal (IP) inoculation with 10(7) PFU wild-type (wt) RPV or with two mutants 8 sm and 28 (containing approximately 12 kilobase deletions) showed titers of greater than 10(3) PFU/g tissue in multiple organs. In contrast, IP inoculation of 10(7) PFU of mutants 31 or 23 (containing approximately 30 kilobase deletions) showed markedly reduced growth in all organs. Neurovirulence of wt and mutant RPV was determined by intracerebral (IC) inoculation of mice. Wt and mutants 8 sm, and 28 RPV had LD50 less than 10(2) PFU; in contrast, 31 and 23 had LD50 greater than 10(5) PFU. Finally, 10(6) PFU of mutants 31 or 23, were administered to mice by scarification, the normal route of vaccinia immunization. Both 31 and 23 grew locally in the skin and protected mice challenged IC at 21 days with 100 LD50 of wt RPV, while all unimmunized controls died. We conclude that deletion mutants 31 and 23 demonstrate markedly reduced invasiveness and neurovirulence while retaining immunogenicity. Similar deletion mutations in vaccinia may create avirulent, but effective vaccine vectors for man.
Animals↗
Central venous catheter infections.
When used wisely, central venous catheters are capable of providing vital circulatory access in any patient with a remarkably low risk of infection or major complication. Tunneled silicone catheters are the route of choice for long-term or outpatient use, particularly for oncology or TPN patients; insertion of such a catheter should occur early in the hospitalization of a newly diagnosed patient on chemotherapy. The greatest experience has accrued with the cuffed silicone catheters (for example, Broviac), but the totally implantable devices (for instance, Port-a-cath) may become the device of choice in pediatric outpatients. For infants, small, percutaneously inserted noncuffed silicone catheters appear to offer the greatest safety. Among acute care patients, percutaneous plastic central venous catheters fulfill a vital role but represent an important source of infection. Scrupulous technique, the minimizing of manipulation, and a readiness to replace the catheter at any suggestion of trouble are important to achieving the best results. Within a given design, it is generally best to use the smallest diameter catheter capable of performing the desired tasks. However, on the basis of currently available data, there need be no hesitation to use a multilumen catheter if the care of the patient demands multiple access ports. The various silicone catheters can usually be left in place while infection is treated, although fungal and certain other infections are more likely to require catheter removal. Percutaneous plastic catheters should be removed or changed over a wire if infection is suspected; if tip culture of the removed catheter is positive, and the catheter was replaced over a wire, then the replacement catheter should be promptly removed.
Bacterial Infections↗
Protein synthesis by HepG2 cells infected with influenza B virus.
Reye's syndrome is an acute hepatopathy and encephalopathy affecting children during the convalescent period of a viral infection, frequently influenza B. The role of influenza B in the pathogenesis of Reye's syndrome is unknown. To investigate this relationship, an in vitro system was designed to examine the interaction of influenza B virus with a cell line of human hepatocytes (HepG2) which retains many specific hepatic synthetic characteristics. HepG2 was capable of supporting a productive infection by influenza B, although greater virus inputs were required than in fully permissive Madin-Darby canine kidney cells. Because of the recent association of Reye's syndrome with aspirin use, the kinetics of influenza B growth were studied in the presence of acetylsalicylic acid (25 and 100 micrograms/ml) and were not found to be altered. Protein synthesis by HepG2 cells was decreased by 80% in influenza B-infected cells when compared to uninfected controls. Acetylsalicylic acid, 100 micrograms/ml, did not affect the rate of 35S-methionine incorporation by infected or uninfected HepG2 cells. The rates of synthesis of specific proteins (albumin, transferrin, and apoprotein B) by HepG2 cells were determined by immunoprecipitation of 35S-methionine labeled cell lysates. After 12 h of infection, synthesis of all three plasma proteins was decreased by 40-60%. These studies describe a useful system for delineation of mechanisms by which influenza B virus interacts with host hepatocytes and the host-cell protein synthetic machinery. The studies could be pertinent to the pathogenesis of Reye's syndrome.
Aspirin↗
MRI of mumps encephalitis: comparison with CT evaluation.
The evaluation of a patient with mumps encephalitis by computed tomography (CT) and magnetic resonance (MR) imaging is reported. Correlation of findings on MR and CT in relation to clinical symptoms is presented. MR was found to be more sensitive in the number of lesions detected (11) as compared to CT (3). Thus, it seems that MR imaging may be a sensitive diagnostic adjunct in cases of suspected viral encephalitis.
Child, Preschool↗
Syndrome of periodic fever, pharyngitis, and aphthous stomatitis.
A syndrome of periodic fever that resembles human cyclic neutropenia in its clinical presentation has been identified in 12 children observed at two major referral centers. Attacks characterized by abrupt onset of fever, malaise, chills, aphthous stomatitis, pharyngitis, headache, and tender cervical adenopathy occur at 4- to 6-week intervals over periods of years. These episodes of illness resolve spontaneously in 4 to 5 days. Mild leukocytosis and elevation of the erythrocyte sedimentation rate during attacks are the only laboratory abnormalities. Affected children grow normally, are not unusually susceptible to infection, and exhibit no long-term sequelae. Attacks may be aborted by short courses of prednisone but do not respond to nonsteroidal anti-inflammatory agents. This syndrome is sporadic and appears to be much more common than cyclic neutropenia.
Blood Sedimentation↗
Lack of comparability between commonly used serological assays of immune response to Haemophilus influenzae vaccine.
Reliable measures of the serum level of antibody to the capsular polysaccharide (PRP) of Haemophilus influenzae type b (Hib) are essential for evaluating current and future vaccines intended to protect against invasive disease. It was recently noted, however, that certain commonly used assays of antibody to PRP produced incompatible results. To investigate this observation, we analyzed banked sera from four PRP vaccine studies in parallel by several assays. Significant differences were noted, both in absolute titers and in the ratios of post- to prevaccination titers, between the various assays. These differences seemed to be due to the different antigen preparations used in the assays. Unless workers standardize on a single assay, protective levels of antibody to PRP will have to be defined separately for each assay. Serological results of Hib vaccine trials cannot be compared without considering the assay methods used.
Antibodies, Bacterial↗
Role of respiratory tract proteases in infectivity of influenza A virus.
Proteolytic cleavage of influenza virus hemagglutinin (HA) glycoprotein into subunits designated HA1 and HA2 is required for penetration of virus into the cell. It is generally assumed that this cleavage is an intracellular function of the host cell. Human adenoid fibroblast (HAF) lines, which support the growth of influenza A virus but release virus with an uncleaved HA, provide a model system that has allowed exploration of mechanisms of cleavage in vivo. Exposure of HAF-grown influenza virus to nasal secretions from children with respiratory tract symptoms induced HA cleavage and rendered virus fully infectious. Characterization of this proteolytic enzyme, present in the extracellular environment of the respiratory tract, suggests that it is a serine endopeptidase.
Cathepsin D↗
Sporadic congenital Caffey's disease.
Caffey's disease is an inflammatory skeletal disorder of infancy manifested clinically by fever, soft-tissue swelling, and constitutional signs with radiographic evidence of periosteal new bone formation. Although prevalent between 1940 and 1960, nonfamilial cases have become extraordinarily rare. The authors report the sporadic occurrence of congenital Caffey's disease in a premature infant and note an interesting association with maternal herpes zoster early during gestation. The etiology of this mysterious disease is likely to remain elusive as new cases become scarce.
Adult↗
Diphtheria, tetanus, and pertussis vaccine. A comparison of the immune response and adverse reactions to conventional and acellular pertussis components.
Although the conventional Bordetella pertussis vaccine, which consists of killed whole organisms, has been shown to be effective in preventing disease, it has been associated with transient local and systemic reactions and may produce encephalopathy, though rarely. A new acellular pertussis vaccine containing partially purified protein antigens, filamentous hemagglutinin, and lymphocytosis-promoting factor hemagglutinin has been developed for use in Japan. We compared the immunogenicity and reactogenicity of conventional and acellular pertussis vaccine. Forty children aged 4 to 6 years and 40 children aged 18 to 24 months, all previously immunized at appropriate times with conventional diphtheria and tetanus toxoids and pertussis vaccine, were enrolled. We randomly assigned children to receive either conventional pertussis vaccine or acellular pertussis vaccine in a double-blind fashion. The diphtheria and tetanus components in both preparations were identical. Equivalent rises in pertussis agglutinin titers and antibodies to filamentous hemagglutinin and lymphocytosis-promoting factor hemagglutinin were measured in both vaccine groups at both ages that we studied. However, reaction rates to the two vaccines in both age groups were strikingly different. Acellular pertussis vaccine was significantly less reactogenic for fever, pain, fretfulness, abnormal gait, and local reactions at the vaccine administration site. If studies in progressively younger children confirm its reduced reactogenicity and equal immunogenicity, and if large-scale trials indicate its efficacy, the acellular pertussis vaccine may be a more appropriate candidate than the current vaccine.
Child↗
Complement activation by respiratory syncytial virus-infected cells.
Respiratory syncytial virus (RSV), a major respiratory pathogen of children, has been speculated to cause disease by immunologic mechanisms. Although circulating levels of complement (C) are normal during RSV infections, the role of C in respiratory tract secretion is unclear. Since epithelial cells of the respiratory tract of children infected with RSV express viral surface antigens, the ability of RSV infected human cells to activate C was studied. RSV infected human cells (HeLa) were found to activate both the classical and alternative C pathways as measured by the cleavage of native C3 into its breakdown products. Increased C activation occurred in the presence of antibody. Cytolysis of RSV infected cells was then studied using a chromium release assay. Both the classical and alternative C pathways in the presence of antibody participated in the lysis of RSV infected cells. The combined effects of activation of C and the lysis of RSV infected cells by C and antibody may contribute to the pathogenesis of disease.
Antibodies, Viral↗
In vitro production of anti-influenza virus antibody after simultaneous administration of H3N2 and H1N1 cold-adapted vaccines in seronegative children.
Sixteen doubly seronegative (H3N2 and H1N1) young children were recently enrolled in a study of live, attenuated cold-adapted influenza A vaccines. Twelve children received simultaneously H3N2 and H1N1 live, attenuated influenza vaccine intranasally and four received saline as placebo controls. Peripheral blood lymphocytes (PBL) were obtained sequentially from all children and the in vitro production of anti-influenza H3N2 and H1N1 antibody from unstimulated and influenza stimulated cells was measured by ELISA. In vitro antibody studies were performed at 0, 2, 4, and 12 weeks after immunization. PBL from six of 12 children spontaneously produced H3N2 antibody and eleven of 12 produced H1N1 antibody. Influenza stimulation of PBL induced antibody production in 8/12 for H3N2 and 12/12 for H1N1. PBL from all four placebo immunized children failed to produce specific influenza antibody in vitro at any time studied. In vitro antibody produced after immunization was primarily of the IgG isotype with peak production occurring at 4-12 weeks, supporting the primary nature of the response. The correlation between the presence of positive serum HAI and ELISA titres, and the production of in vitro antibody was good for both H3N2 and H1N1 vaccines. In summary, the simultaneous administration of two attenuated influenza A vaccines into the upper respiratory tract of seronegative children resulted in the stimulation of PBL capable of secreting both H3N2 and H1N1 influenza specific antibody in vitro.
Antibodies, Viral↗
Human adenoid organ culture: a model to study the interaction of influenza A with human nasopharyngeal mucosa.
Previous studies of infections with influenza A in animal models have stressed the tropism of this virus for the upper respiratory tract. To assess the interaction of influenza A virus with human respiratory tissue, we maintained adenoids, consisting of ciliated epithelium with underlying lymphoid follicles, in organ culture. When the organ cultures were inoculated with wild-type influenza A/Alaska (H3N2), epithelial damage and migration of inflammatory cells from the follicles into the lamina propria were seen. Growth of the virus and ciliary damage in infected organ cultures from seronegative donors were significantly greater than that seen in organ cultures from seropositive donors. Adenoidal lymphocytes were then studied to determine which factors might modulate infectivity. Specific in vitro production of antibody to influenza A/Alaska was demonstrated by adenoidal lymphocytes from seropositive donors, whereas lymphocytes from seronegative donors did not produce antibody. The human adenoid organ culture provides an attractive model to study the pathogenesis of influenza A infections and the resultant local immune response.
Antibodies, Viral↗
Frequency of broviac catheter infections in pediatric oncology patients.
Indwelling, right atrial catheters are important in the care of children with cancer, despite the risk of infection. We have reviewed the records of 64 pediatric oncology patients with 70 Broviac catheters. Fifty infections (17 exit site, 25 septic, and 8 combined) occurred during 17,581 catheter-days, a crude rate of 2.8 infections/1,000 catheter-days. The risk of infection correlated most strongly with age; for example, only children aged one through four years had multiple infections. Overall, 70% of infections were cured without removing the catheter, including 83% of septic infections. However, as compared with newly inserted catheters, the subsequent mean infection-free interval was greatly reduced for catheters associated with a previous, cured infection. Thus, although most Broviac catheter infections can be cured without catheter removal, insertion of a new catheter may nonetheless be necessary in patients who may need prolonged intravenous therapy.
Adolescent↗
Failure of intraventricular gamma globulin to eradicate echovirus encephalitis in a patient with X-linked agammaglobulinemia.
Explore the source record for details and available documents.
Agammaglobulinemia↗
Reye's syndrome associated with adenovirus infections in infants.
The isolation of adenovirus from the liver of an infant with Reye's syndrome prompted a retrospective review to determine the role of this group of viruses in the cause of Reye's syndrome. A total of 34 patients with Reye's syndrome who were admitted to Vanderbilt University, Nashville, Tenn, during a ten-year period were identified. Six of the patients were younger than 1 year, and positive adenoviral cultures and increased serological responses were obtained in three of these children. The clinical and pathologic data from these three children suggest that adenovirus may be an important agent in initiating Reye's syndrome in the very young child. Further, the mitochondrial abnormalities present in the livers of the patients with adenovirus-associated disease tended to be mild in spite of severe clinical disease.
Adenoviridae Infections↗