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Biomedical subjects

M S Edwards

Publications and source records attributed to M S Edwards.

At least 289 records · Page 16Linked to original sources
PubMed1981

Complications and sequelae of meningococcal infections in children.

Eight-six children with meningococcal meningitis or bacteremia were evaluated prospectively between 1977 and 1979 to determine the incidence of complications and features predictive of their development. The majority (83%) of these infections were caused by serogroup B strains. Twenty-seven percent of survivors experienced one or more suppurative, allergic, or neurologic complications. Hearing loss, noted in 9% of children, occurred significantly more often in patients with admission leukocytosis or leukopenia, or with CSF leukocytosis greater than 10,000/mm3 than in those with an uncomplicated course (P less than 0.01). Ten percent of survivors developed allergic complications manifested as cutaneous vasculitis or arthritis with onset five to eight days after admission. Shock, purpuric skin lesions, and fever persisting longer than five days occurred significantly more often in these children than in those who developed hearing loss or those with an uncomplicated course (P less than 0.05). Resolution of allergic complications occurred within 14 days of their onset. Compared to Neisseria meningitidis groups A and C, group B strains appear to be intermediate in their potential for allergic complications associated with childhood infection.

Adolescent↗
PubMed1981

Intrathecal chemotherapy for leptomeningeal dissemination of medulloblastoma.

Cerebrospinal fluid dissemination of medulloblastoma occurs despite adequate systemic chemotherapy, and unless it is present at the time of initial diagnosis, occurs late in the course of the disease. Intrathecal chemotherapy with an implanted Ommaya reservoir can produce short-term benefit. We report here our protocol for and the results of intrathecal chemotherapy for leptomeningeal dissemination of medulloblastoma.

Adolescent↗
PubMed1981

Delayed sciatic palsy after total hip replacement: case report.

A 33-year-old woman with a 22-year history of juvenile rheumatoid arthritis developed right lower extremity sciatica 32 months after total hip arthroplasty. Physical examination and electromyography localized the abnormality to the sciatic nerve proximal to the midthigh level, involving the branch to the short head of the biceps femoris muscle. At surgical exploration, a sharp spur of methyl methacrylate, used to cement the acetabular prosthesis to the acetabulum, was found to have eroded through the lateral half of the sciatic nerve. The sciatica was relieved by neurolysis. The etiology of sciatic neuropathy after total hip replacement is reviewed.

Adult↗
PubMed1981

Dynamic computed tomography of the brain: techniques, data analysis, and applications.

Rapid sequence computed tomography (CT) scanning has many potential applications in studying intracranial physiologic events. However, visual inspection of these rapid sequence scans fails to extract the large amount of information inherent in the digital data. The concept of corrected mean transit time applied to rapid sequence scans after intravenous bolus injection of contrast material provides quantitative data on relative hemispheric flow. Use of histogram-based areas of interest permits accurate and reproducible identification of anatomic structures including arteries and gray and white matter. Gamma variate curve fit techniques reduce statistical noise. The concept of transit time can be expanded to the creation of functional CT images.

Blood Flow Velocity↗
PubMed1981

Chemotherapy of pediatric brain-stem tumors.

Forty-five children harboring brain-stem tumors were treated at the University of California, San Francisco, between 1969 and 1979. Pathological diagnoses were made in 19 patients. All patients received radiation therapy (RT). Thirteen patients received chemotherapy before, during, or immediately after RT. Twenty-four patients were treated with chemotherapy at the time of tumor progression, after initial treatment with RT alone. No statistically significant difference in time to tumor progression or survival was found for treatment with chemotherapy as an adjuvant to RT compared to treatment with RT alone followed by chemotherapy administered at the time of tumor progression. There were, however, more long-term survivors in the group that was first treated with chemotherapy at the time of tumor progression. There was no statistically significant correlation between survival and tumor pathology or location, although there were more long-term survivors among patients harboring low-grade gliomas and among patients with tumors confined to the midbrain. The authors documented the response of some brain-stem tumors to chemotherapy; however, cooperative controlled studies will be required to determine the optimum treatment for this disease.

Adolescent↗
PubMed1981

Role of antibody to native type III polysaccharide of group B Streptococcus in infant infection.

The role of maternally acquired antibody to native type III polysaccharide of group B Streptococcus as a determinant of susceptibility for infant systemic infection was investigated. Sera from 111 acutely ill infants with type III group B streptococcal bacteremia and/or meningitis and their mothers, and cord sera from 45 healthy neonates and their mothers who had type III group B streptococcal vaginal colonization at delivery were studied. Sera from each of 111 acutely ill infants contained very low levels of antibody (less than 1.7 microgram/ml, median 0.4 microgram/ml), and a significant correlation with maternal levels was tested for early onset infection (median 0.6 microgram/ml; 4 = .76; P less than .01). Women whose infants remained well had antibody levels greater than 2 microgram/ml in their sera (73%) more often than those whose infants developed symptomatic infection (17%) (P less than .001), and the median level in their sera (12.6 microgram/ml) was considerably higher. Study of sera obtained during convalescence from 86 surviving infants indicated a poor antibody response to infection. In contrast, high levels of antibody were detected in sera from each of five convalescent women with postpartum bacteremia. These data extend earlier observations suggesting the correlation between low levels of type-specific antibody in serum and risk for systemic infection with type III strains of group B streptococci.

Antibodies, Bacterial↗
PubMed1980

Influence of preimmunization antibody levels on the specificity of the immune response to related polysaccharide antigens.

We studied the influence of preimmunization antibody level on the immune response of adults to one of two structurally related yet immunologically distinct type-specific polysaccharides from Type III Group B streptococcus and Type 14 pneumonococcus. Four weeks after immunization with multivalent pneumococcal vaccine, 20 subjects with low levels of antibody to Type III Group B streptococcus antigen had no significant increase in antibody to this antigen (P greater than 0.05), but all volunteers with moderate to high preimmunization antibody levels who were immunized with Pneumovax had significant increases (P less than 0.01). However, the streptococcal antibody response to pneumococcal Type 14 antigen was weaker and briefer than that in 10 adults given Type III Group B streptococcus vaccine(P less than 0.05). Preimmunization antibody levels influenced the immune response to a structurally similar polysaccharide antigen, but specific Type III polysaccharide antigen appeared necessary to induce a primary antibody response in "nonimmune" adults. We conclude that immunization of mothers with pneumococcal vaccine is not likely to prevent neonatal Type III Group B streptococcal infection, despite immunologic similarities between the two organisms.

Adult↗
PubMed1980

The role of specific antibody in alternative complement pathway-mediated opsonophagocytosis of type III, group B Streptococcus.

The native capsular polysaccharide antigen of type III, group B Streptococcus contains a terminal sialic acid residue on each repeating unit that masks all end-group galactopyranose residues and prevents alternative pathway complement activation by adult human sera in the absence of type-specific antibody. The critical role of the sialic acid residues in allowing the organism to evade activating the alternative complement pathway was shown when neuraminidase treatment of the organism converted the bacteria to activators of the alternative pathway as assessed in agammaglobulinemic serum. The requirement for specific antibody in permitting alternative pathway activation by the fully sialated bacteria was shown when sera that contained low levels of specific antibody failed to activate this pathway, and when prior absorption of serum that contained higher type-specific antibody levels with the capsular antigen failed to activate this pathway. The use of C2-deficient sera showed that the calssical pathway was not required for antibody-dependent alternative pathway activation. The use of isotonic, pH 7.5, veronal-NaCl buffer that contained 1% gelatin and that was supplemented to 4 mM Mg++ and 16 mM EGTA and adjusted to pH 7.5 (MgEGTA) ruled out the participation of the C1-bypass pathway. The presence of sialic acid on the bacterial surface is one means of evading an important mechanism of natural immunity, namely activation of complement by the alternative pathway. Only specific antibody, i.e., acquired immunity, can overcome this virulence factor.

Antibodies, Bacterial↗
PubMed1980

Luminol-enhanced chemiluminescence for evaluation of type III group B streptococcal opsonins in human sera.

A luminol-enhanced chemiluminescence (CL) assay was developed to evaluate type III group B streptococcal opsonins. Sera from 11 adults that contained high (greater than 25 microgram/ml), intermediate (3-24 microgram/ml), or low (less than 2 microgram/ml) antibody concentrations were assessed by CL, indirect immunofluorescence (IF), and bactericidal assays. Total CL activity correlated with antibody concentration (P less than 0.005), IgG- and C3-IF values, and phagocytic and bactericidal indices. Heat-stable CL activity correlated with antibody concentration (P less than 0.0001) and was related to IgG-IF values and phagocytic indices. Significant bactericidal activity was demonstrated in all sera containing greater than 2 microgram of antibody/ml, but no bactericidal activity was observed in heat-inactivated sera. Adsorption of heated sera with type III group B Streptococcus abolished CL activity, whereas CL values of MgEGTA-chelated sera were approximately 80% of untreated sera. Thus, type-specific antibody in addition to heat-labile serum factors, including those of the alternative complement pathway, contribute to opsonization of type III group B Streptococcus.

Antigen-Antibody Reactions↗
PubMed1980

Comparison of slide coagglutination test and countercurrent immunoelectrophoresis for detection of group B streptococcal antigen in cerebrospinal fluid from infants with meningitis.

The usefulness of Phadebact streptococcus reagents for the detection of group B streptococcal antigen in cerebrospinal fluid was evaluated in 54 infants with meningitis and in 22 normal infants. Antigens was detected by slide coagglutination in 19 (82.6%) and by countercurrent immunoelectrophoresis in 20 (87.0%) of 23 cerebrospinal fluid specimens from infants with group B streptococcal meningitis at admission. After initiation of antimicrobial therapy, antigen could be detected in 11 of 19 (by slide coagglutination) and 7 of 18 (by countercurrent immunoelectrophoresis) cerebrospinal fluids. False-positive reactions were noted by slide coagglutination in one infant with S. bovis meningitis and one with group B streptococcal bacteremia without meningitis; none occurred with countercurrent immunoelectrophoresis. The commercial availiability, simplicity, sensitivity (82.6%), and specificity (96.4%) of the Phadebact slide coaggluatination test for detecting group B streptococcal antigen in cerebrospinal fluid suggest that it may be useful for the early and rapid diagnosis of group B streptococcal meningitis.

Agglutination Tests↗
PubMed1980

Chemotherapy of pediatric posterior fossa tumors.

Results of chemotherapy of recurrent posterior fossa tumors in children are presented. Cerebellar astrocytoma, ependymoma, and brain stem glioma have all shown objectively determined responses to treatment with nitrosourea compounds (BCNU or CCNU). Medulloblastoma has shown objectively determined response to various chemotherapeutic agents; but in our experience the best responses have been obtained with a combination of a nitrosourea (CCNU), vincristine, and procarbazine. Although chemotherapy after recurrence has significantly prolonged the life of the patients, cure has not been achieved. Theoretical considerations regarding the failure of initial therapy and the inadequacy of subsequent chemotherapy are discussed.

Astrocytoma↗
PubMed1980

Countercurrent immunoelectrophoresis in the evaluation of infants with group B streptococcal disease.

Admission specimens of CSF, serum, and urine from 67 patients with proved group B streptococcal (GBS) bacteremia and/or meningitis were evaluated by countercurrent immunoelectrophoresis (CIE). Group B and type-specific antigens were detected in 81% of CSF, 63% of serum, and 96% of concentrated urine specimens by CIE. Each of 26 infants with meningitis from whom all three body fluids were available and ten with bacteremia from whom both serum and urine were collected at admission had GBS antigens detected by CIE in at least one specimen. No false positive reactions were observed. Among patients with type III, GBS meningeal infection, fatal outcome or neurologic sequelae were significantly correlated with concentration of type III antigen in admission CSF and duration of antigenuria when compared to normal survivors (P = less than .05, Mann-Whitney U tests). CIE appears to be a useful diagnostic and prognostic tool for infants with GBS infection if admission specimens from more than one source are examined and appropriately high-titered antisera are employed for testing.

Antigens, Bacterial↗