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Biomedical subjects

E Rossier

Publications and source records attributed to E Rossier.

At least 37 records · Page 2Linked to original sources

Antibodies to human cytomegalovirus structural polypeptides during primary infection.

This study aimed at broadening the understanding of the immunogenic potential of cytomegalovirus (CMV) structural polypeptides during natural infection and to ascertain their possible use in serological diagnosis. Immunoblotting was used to analyse the appearance and development of serum IgG and IgM against human CMV structural polypeptides in sequential sera from renal transplant recipients during the first 1-3 months of primary CMV infection. The results showed that the first IgG to appear is specific for a polypeptide of 66 kDa and these antibodies appear either alone or together with others against another polypeptide of 82 kDa. IgG to the 150 kDa protein appears at least one week later. The first IgM to appear reacts preferentially with a 38 and 66 kDa polypeptide. The early detection of antibody against the major viral antigenic proteins in the diagnosis of CMV primary infection is discussed.

Antibodies, Viral↗

Mycoplasma pneumoniae infections in a rural setting in Canada.

Mycoplasma pneumoniae infection was monitored in patients with symptoms of acute respiratory tract infection in a village in southeastern Ontario from April 1983 to April 1984. M. pneumoniae was isolated from 51 (48%) of the 106 patients. The incidence began to increase in May 1983, reached a peak in July and declined to normal by mid-August. During the epidemic period M. pneumoniae was detected in 36 of the 43 symptomatic patients. The most prominent features of the outbreak were the considerable intrafamilial attack rate and the high frequency of pneumonia among infected patients. Treatment with tetracyclines and erythromycin reduced the duration of the illness and accelerated the resolution of symptoms.

Adolescent↗

Sensitivity and specificity of enzyme immunofiltration and DNA hybridization for the detection of HCMV-infected cells.

The sensitivity and specificity of enzyme immunofiltration and DNA hybridization were compared in human cytomegalovirus (HCMV) (AD 169)-infected MRC-5 cells. The enzyme immunofiltration was carried out on glass fiber filters in microplates, using an HCMV (AD 169) monoclonal antibody and a peroxidase conjugate. The DNA hybridization was carried out with a microfiltration apparatus, using a 32P-labelled HCMV (AD 169) Eco R1 D fragment probe. The sensitivities of enzyme immunofiltration and DNA hybridization were 1.82 X 10(3) and 1.13 X 10(3) infected cells, respectively. Both methods were highly specific, but enzyme immunofiltration was faster and simpler.

Antibodies, Monoclonal↗

Role of respiratory viruses in exacerbations of primary nephrotic syndrome.

To determine whether respiratory virus infections (URI) are associated with exacerbation of nephrotic syndrome (NS) in childhood, a prospective two-winter study of 32 children with NS was done. We obtained pre- and post-season viral serologic studies, biweekly nose and throat viral cultures, daily urinalysis, biweekly telephone follow-up for URI and renal complaints, and clinical assessments as indicated. When a URI occurred, viral cultures were done weekly if the child was at home and twice weekly if hospitalized. Sixty-one URIs occurred; the agent was identified in 33 (51.6%) (respiratory syncytial virus 14, influenza virus five, parainfluenza virus five, varicella zoster virus four, adenovirus three, Mycoplasma pneumoniae one, and Chlamydia trachomatis one). Forty-one exacerbations occurred, 71% with URI; 29% had no URI during the preceding 10 days (P less than 0.01). Total relapse occurred in 29 of 41 exacerbations, 69% with URI and 31% without URI (P less than 0.01). Patients with unstable NS had more exacerbations than those with stable NS (15 of 19 (79%) vs four of 13 (31%), P less than 0.001) and more URI (2.32 vs 1.46 per child, P less than 0.05). Exacerbations in patients with minimal change, mesangioproliferative, and focal glomerulosclerosis occurred in 40%, 60%, and 64%, respectively. We conclude that exacerbations and relapses of childhood NS are temporally related to URI. Inasmuch as multiple viral agents were associated with exacerbations, nonspecific host response to infection, not viral antigen or antibody response, may be the link to NS.

Adolescent↗

Studies on fastidious adenoviruses in Ontario: a distinct strain associated with gastroenteritis.

From 100 cases of gastroenteritis among children caused by adenovirus infection in Ontario, 33 virus isolates were divided into three categories according to their biological behavior in tissue cultures. So far, the results of neutralization tests, structural protein analysis, and DNA restriction patterns showed that the virus of category 1 was similar to adenovirus type 40. However, the adenovirus of category 2 was a distinct adenovirus which shared some similarities with adenovirus type 5. Viruses of category 3 are still under investigation.

Adenoviridae Infections↗

Microcarriers in combination with enzyme immunofiltration and immunofluroescence for the detection of herpes simplex virus antigens in culture.

A microcarrier culture system in combination with enzyme immunofiltration with a herpes simplex virus (HSV) group monoclonal antibody was found to be as sensitive as immunofluorescence for the detection of HSV type 1 (HSV-1) in cell cultures and to give specific identification at the same time as the appearance of the cytopathic effect with very high infectious inocula and within 10 to 24 h of the appearance of the cytopathic effect with very high infectious inocula and within 10 to 24 h of the appearance of the cytopathic effect with low to high inocula. Multiplicities of infection from 10(-5) to 10(1) were tested at 8 to 96 h postinfection. When applied to the identification of HSV-1 and HSV-2 in cultures of clinical samples, the system detected HSV antigens in 50% of the samples after 2 days and in 100% of the samples after 3 days. With 2 ml of microcarrier suspension and with 50 to 300 microliter per sample, several portions are available for replicate and sequential sampling without destroying the culture. The system requires only that 2 X 10(5) microcarriers be added to the culture tube at the time or before it is seeded with cells, at an extra cost of 6 cents (U.S.) per tube and little extra labor.

Antigens, Viral↗

Comparison of five methods of cytomegalovirus antibody screening of blood donors.

A group of 120 sera from blood donors was screened by complement fixation and commercially available immunofluorescence, solid-phase fluorescence immunoassay, enzyme-linked immunosorbent assay, and indirect hemagglutination tests. Twenty-four of the sera were positive by three or more of the five tests and judged to be true positives; 89 were negative by three or more of the tests and considered to be true negatives. The tests were ranked for accuracy, sensitivity, specificity, false-positive rate, and false-negative rate. The indirect hemagglutination test scored best, followed by enzyme-linked immunosorbent assay, solid-phase fluorescence immunoassay, complement fixation, and immunofluorescence, in that order. When the tests were ranked on the basis of technical demands, turnaround time, requirement for special equipment, and subjectivity in reading, the indirect hemagglutination test again scored best, followed by solid-phase fluorescence immunoassay, enzyme-linked immunosorbent assay, immunofluorescence, and complement fixation in that order. Our findings suggest that the indirect hemagglutination test is the most reliable and effective commercially available test for the identification of those donors who are very unlikely to transmit cytomegalovirus to recipients.

Antibodies, Viral↗

Persistence of naturally acquired cell-mediated immunity to rubella virus during the first trimester of pregnancy.

We studied the persistence of naturally acquired cell-mediated immunity to rubella during early pregnancy. We compared lymphocyte transformation responses to phytohemagglutinin and rubella virus in 35 naturally immune women aged 17-37 years, in the first trimester of pregnancy, with 49 naturally immune age-matched nonpregnant controls. A significant lower lymphocyte transformation response to phytohemagglutinin was observed during the first trimester of pregnancy (P = 0.008), but lymphocyte transformation responses to rubella virus were not significantly different (P = 0.901). These data indicate that, in naturally immune women, cell-mediated immunity to rubella virus is not significantly altered by the physiological changes in early pregnancy.

Adult↗

Persistence of humoral and cell-mediated immunity to rubella virus in cloistered nuns and in schoolteachers.

Humoral and cell-mediated immunity to rubella virus after naturally acquired infection were compared in 19 cloistered nuns (29-79 years of age), 18 female schoolteachers (21-61 years of age), and 21 female control subjects (20-30 years of age), who were all seropositive for rubella virus, by use of a hemagglutination-inhibition test, a passive hemagglutination test, a hemolysis-in-gel test, a radioimmunoassay, an enzyme-linked immunosorbent assay, and lymphocyte transformation tests. No significant differences were found among the groups by the radioimmunoassay, the hemolysis-in-gel test, and the enzyme-linked immunosorbent assay. The cloistered nuns had significantly lower cell-mediated immunity to rubella virus than did the teachers and the control subjects but nonetheless showed protective levels of antibody to rubella virus and significant lymphocyte transformation responses, which persisted until age 79 in the probable absence of reinfection.

Adult↗

Bordetella pertussis in the National Capital Region: prevalent serotype and immunization status of patients.

Over a 2-year period 67 strains of Bordetella pertussis were identified in 231 single specimens of nasopharyngeal secretions submitted from patients suspected to have whooping cough in the National Capital Region; 89.5% of the identifications were made by culture. Serotype 1,3 was predominant. At least 75% of the patients with bacteriologically confirmed whooping cough had not been fully immunized. There was no evidence that adenoviruses or other viruses played any important etiologic role in the 204 cases of whooping cough or whooping cough syndrome studied virologically.

Bordetella pertussis↗

Absence of cell-mediated immunity to rubella virus 5 years after rubella vaccination.

The long-term effectiveness of rubella vaccination in childhood is particularly important because the ultimate goal of immunization is the prevention of infection during pregnancy. Of 25 healthy children tested 4 to 5 years after rubella vaccination, 19 showed no evidence of cell-mediated immunity (CM) to rubella virus despite the presence of hemagglutination-inhibition or complement-fixation antibodies or both. Twenty-two of 25 seropositive, naturally infected young adults showed evidence of CMI. These results indicate that fetuses of women who have been vaccinated against rubella may not be protected against damage by wild rubella infection during the pregnancy, when CMI is physiologically depressed.

Adult↗

The relative ability of four rubella antigens to elicit blast cell transformation of lymphocytes from immune individuals.

The ability of crude, semi-purified, and purified rubella antigens to elicit a specific and significant blast cell transformation of lymphocytes from immune individuals was investigated in 25 seronegative and 25 seropositive young adults. The type of preparation and the purity of the antigens were critical. Titration of the antigens by complement fixation or hemagglutination was of little value for selecting the best antigen which was a whole virion-purified antigen.

Adult↗

A case of Powassan virus encephalitis.

A case of encephalitis due to Powassan virus, probably transmitted through tick-bite, is reported in an 8-year-old boy. There was a 50-fold increase in neutralization titre against Powassan virus, but the virus could not be isolated. Other virological investigations were negative.The patient survived and early physiotherapy and speech re-education could be instituted. Nine months after onset of illness the patient showed moderate sequelae, despite a very severe illness.

Child↗