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Biomedical subjects

E M Connor

Publications and source records attributed to E M Connor.

28 records · Page 2Linked to original sources

Relationship between HTLV-III neutralizing antibody and clinical status of pediatric acquired immunodeficiency syndrome (AIDS) and AIDS-related complex cases.

To investigate a possible protective role of HTLV-III neutralizing antibodies in individuals exposed to the virus, sera of children with acquired immunodeficiency syndrome or acquired immunodeficiency syndrome-related complex were analyzed for neutralizability of HTLV-IIIB infectivity. Twelve pediatric patients (nine acquired immunodeficiency syndrome, three acquired immunodeficiency syndrome-related complex) were clinically stable and had survived more than 2 yr postonset. Their predominant clinical problems included lymphocytic interstitial pneumonia, candidiasis, recurrent bacterial infections, failure to thrive, and lymphadenopathy. Twelve additional children (all acquired immunodeficiency syndrome) were classified as clinically poor; 10 of them had died. Their median length of survival was less than 2 yr, and their disease spectrum included progressive encephalopathy, thymic depletion or atrophy, and Pneumocystis carinii pneumonia in addition to many of the clinical features of the stable children. All (100%) of the stable patients possessed serum neutralizing antibody in contrast to only one of the 12 (8%) clinically poor patients. A simple decline in immunologic reactivity to HTLV-III antigens with disease progression did not account for this difference, since HTLV-III antibody titers of the clinically poor cases (1 X 10(2) to 1 X 10(7)) ranged as high as those of the stable cases (1 X 10(4) to 1 X 10(7)) when measured by the ELISA technique. Although stable cases possessed a higher geometric mean titer (2.8 X 10(5)) by ELISA than the poor cases (4 X 10(4)), this difference was not statistically significant. Serial serum samples from stable children exhibited continual neutralizing antibody activity while two of three clinically poor cases lacked neutralizing activity in serial specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗

Community-oriented primary care: an examination of the US experience.

Community-oriented primary care (COPC) represents a specific variation on the general primary care model. Seven case studies from vastly different health care settings were examined and this report describes the diversity of expression of the principles of COPC observed. The results suggest that COPC is not limited to publicly funded programs, but can find expression in the private sector as well. The organization of financing and the lack of feasible quantitative tools hinder the full development of the model.

Community Health Services↗

Pathology of opportunistic infections in children with acquired immune deficiency syndrome.

Opportunistic infections (OI) were diagnosed by histology and culture of biopsy and autopsy material in 15 children with the acquired immune deficiency syndrome (AIDS). The opportunistic pathogens included Pneumocystic carinii, Toxoplasma gondii, Candida species, Aspergillus species, Mycobacterium avium-intracellulare, cytomegalovirus, and herpes simplex virus. Seven of 15 patients also had multiple systemic infections with common pathogenic bacteria. Accurate diagnosis of OI in AIDS is of importance in the decision regarding the choice of appropriate antimicrobial therapy. Careful histologic assessment of the biopsy specimens; awareness of unusual features such as paucity of organisms and inflammatory reaction, "histoid" variety of reaction, lack of granuloma formation, and resemblance to Whipple's disease in certain OI; and demonstration of causative organisms by appropriate special stains and/or culture are essential in the evaluation of these patients.

Acquired Immunodeficiency Syndrome↗

Neurologic manifestations of human immunodeficiency virus infection in children.

This report describes the neurologic manifestations of 36 children with human immunodeficiency virus (HIV) infection. In this cohort, in 16 of 21 children with acquired immunodeficiency syndrome (AIDS), three of 12 children with AIDS-related complex, and one of three asymptomatic seropositive children, a progressive encephalopathy developed. Neurologic signs were often detected early but tended to worsen coincident with progression of the immunodeficiency. The presence of progressive encephalopathy correlated with the absence of serum neutralizing antibodies to HIV and with a poor, usually fatal, outcome. The incubation period from initial HIV infection in the perinatal period to the onset of progressive encephalopathy varied from 2 months to 5 years. Intrablood-brain barrier synthesis of HIV-specific antibodies was demonstrated in eight of 14 children with AIDS and AIDS-related complex, indicating active brain infection with HIV. In three cases this was unassociated with progressive neurologic signs. Unique neuropathologic findings in children who died with HIV infection further suggest that the progressive encephalopathy is the result of primary and persistent infection of the brain with this retrovirus. These findings broaden the spectrum of HIV infection in children and have important implications for the development of antiviral therapy.

Acquired Immunodeficiency Syndrome↗

Variable adherence of fimbriated Haemophilus influenzae type b to human cells.

The attachment of isogenic fimbriated and nonfimbriated Haemophilus influenzae type b variants to human cells was studied by using a radioactive assay and an indirect immunofluorescent assay. As described previously, fimbriated H. influenzae variants adhered to a greater extent than nonfimbriated variants to human buccal epithelial cells (2.1 and 0.29 bacteria per cell, respectively, as determined by the radioactive assay [P less than 0.05]; 7.6 and 1.6 bacteria per cell, respectively, as determined by the immunofluorescent assay [P less than 0.01]). As the concentration of fimbriated bacteria was increased, so were the numbers of adherent bacteria; in contrast, increasing the bacterial concentration had a much smaller effect on adherence of nonfimbriated H. influenzae type b. The distribution of bacteria on the buccal cells also differed. Whereas 37% of the buccal cells failed to bind nonfimbriated H. influenzae type b, failure to bind was observed for only 4% of the buccal cells exposed to fimbriated H. influenzae. In contrast, adherence to human foreskin fibroblasts was low regardless of the presence of fimbriae. On the other hand, fimbriated H. influenzae type b adhered less well than nonfimbriated variants to HEp-2 cells (1.6 and 3.8 bacteria per cell, respectively, as determined by the radioactive assay [P less than 0.05]; 1.3 and 4.8 bacteria per cell, respectively, as determined by the immunofluorescent assay [P less than 0.02]). Whereas adherence to HEp-2 cells increased considerably as the concentration of nonfimbriated bacteria was increased, there was only a small enhancement of adherence with an increase in the concentration of fimbriated H. influenzae type b. Furthermore, only 16% of the HEp-2 cells failed to bind nonfimbriated H. influenzae type b, whereas 50% failed to bind fimbriated H. influenzae type b. These data indicate that H. influenzae type b may contain two adhesins. One is associated with fimbriae and enables adherence to buccal cells, whereas the other is nonfimbrial and is associated with adherence to HEp-2 cells. It is not known whether either of these adhesins plays a role in pathogenesis.

Adhesiveness↗

Enhanced nasopharyngeal colonization of rats by piliated Haemophilus influenzae type b.

Piliated Haemophilus influenzae type b strains display an enhanced adherence to human epithelial cells in vitro. However, clinical isolates, even from mucosal sites, are seldom piliated, although piliated populations can be selected from them. Experiments with rats have led some authors to suggest that piliation does not implement colonization by H. influenzae type b. Piliated populations were obtained from 35 strains by selection for adherence to human erythrocytes. One strain, H. influenzae H305, simultaneously acquired an increased adherence to rat erythrocytes and buccal epithelial cells. In contrast to other strains, H. influenzae H305 in piliated form was more effective than in nonpiliated form in the colonization of rats by intranasal inoculation. After the piliated inoculum, however, the colonies cultured from the nasal washes were negative for erythrocyte adherence. Thus, piliated H. influenzae type b strains have an apparent advantage to initiating colonization in the rat model but may give rise to nonpiliated progeny that are more readily cultivable from the mucosal surface.

Adhesiveness↗

A hemadsorption method for detection of colonies of Haemophilus influenzae type b expressing fimbriae.

Although fimbriated variants of Haemophilus influenzae type b have recently been described, cultures of most clinical isolates contain only a small proportion of fimbriated forms. Because colonies of fimbriated and nonfimbriated cells are visually indistinguishable, a rapid, simple method was developed for the identification and quantitation of colonies of fimbriated H influenzae. This procedure, also applicable to other bacteria (for example, Escherichia coli), involves transferring the colonies from agar to nitrocellulose disks and incubating the disks in a suspension of red blood cells. Colonies that contain predominantly fimbriated bacteria bind the red blood cells and appear as red dots on the nitrocellulose. This nitrocellulose hemadsorption method is described, as well as its applicability for determining the proportion of fimbriated cells in a culture, the kinetics of enrichment of fimbriated forms during enrichment procedures, and the transition rate from the nonfimbriated to the fimbriated state.

Bacteriological Techniques↗

Severe gastrointestinal involvement in children with the acquired immunodeficiency syndrome.

Five children with the acquired immunodeficiency syndrome (AIDS) and unusual gastrointestinal disease are described. Two children presented with malnutrition, abdominal distention, and diarrhea. One was found to have moderately severe villus atrophy on jejunal biopsy and was initially thought to have celiac disease. Jejunal biopsy from the second child revealed infiltration of the mucosa with acid-fast bacilli-laden macrophages. A third child suffered recurrent abdominal pain, progressive weight loss, diarrhea, and severe gastrointestinal hemorrhage secondary to infection with cytomegalovirus. Pseudomembranous necrotizing jejunitis associated with overgrowth of Klebsiella pneumoniae in the duodenal fluid occurred in one patient. The fifth child presented in the newborn period with Serratia marcescens cholecystitis. Gastrointestinal disease in children with AIDS may be due to idiopathic villus atrophy and bacterial or opportunistic infection.

Acquired Immunodeficiency Syndrome↗