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Biomedical subjects

E Cattaneo

Publications and source records attributed to E Cattaneo.

At least 91 records · Page 5Linked to original sources
PubMed1981

Antigenic and biological relationships between human coronavirus OC43 and neonatal calf diarrhoea coronavirus.

Monospecific antisera were prepared in mice to human coronavirus OC43 and neonatal calf diarrhoea coronavirus (NCDCV) which had been previously adapted to growth in suckling mouse brain. Brain suspension from infected suckling mice was used as immunogen. The antigenic relationship between OC43 and NCDCV was studied by the indirect immunoperoxidase antibody technique, by the haemagglutination-inhibition (HI) test and a new infectious centre-reduction neutralization test. In mouse immune sera, a two-way cross-reaction between OC43 and NCDCV was detected. However, the antigenic relationship appeared to be closer for internal (as shown by immunoperoxidase staining) as compared to surface antigens (as shown by HI and neutralization). In primary infections of natural hosts there was a high degree of cross-reactivity between the two coronavirus strains for both surface and internal antigens, and homologous and heterologous titres were consistently within an eightfold dilution difference by all tests. Most human adults and calves had antibody to both OC43 and NCDCV and geometric mean titres of homologous antibody were higher than titres of heterologous antibody. Although OC43 and NCDCV share antigenic determinants, they possessed several different biological properties, including plaque morphology by the infectious centre assay, agglutination of 1-day-old chick erythrocytes and resistance of haemagglutinin to physical and chemical treatments.

Antibodies, Viral↗
PubMed1981

Antibody to human adenovirus early antigens during acute adenovirus infections.

The antibody (Ab) response to human adenovirus (AV) early antigens (EA) in acute AV infections was studied by the immunoperoxidase antibody technique for determining virus-specific immunoglobulin G (IPA-IgG). AV-EA-Ab appeared about 5 days after the onset of clinical symptoms, reached a peak 15 to 30 days later, and declined in titer after a few months. The staining pattern in the IPA-IgG reaction was usually nuclear; however, in most primary infections sera obtained 2 to 3 weeks after the onset of infection also showed cytoplasmic staining. According to the recent deoxyribonucleic acid homology classification of human AV in five groups (A, B, C, D, and E), the EA-Ab response in primary human infections was found to be group specific for groups A to D, with consistent cross-reactions with group E. In AV type 4 (group E) infections, EA-Ab appeared to be directed against all groups, although at different titers. Comparable results were obtained using AV type-specific animal antisera. Thus, it was concluded that group E shares EA with all the other groups. Furthermore, in each individual with remote AV infections, the current infection elicited an anamnestic EA-Ab response to all AV groups responsible for previous infections. In diagnostic virology these findings can be applied to the rapid diagnosis of a current for recent) AV infection on a single serum sample and to the rapid group identification of clinical isolates by using type-specific animal antisera containing EA-Ab (one for each group) or sera from patients with primary AV infections.

Acute Disease↗
PubMed1980

Serodiagnosis of respiratory synctial virus infections in infants and young children by the immunoperoxidse technique.

The immunoperoxidase antibody (IPA) technique was used to develop two new tests for serodiagnosis of respiratory syncytial virus infections: a microneutralization test based on the reduction of the number of infected cells and an IPA test for determination of virus-specific immunoglobulin G (IgG). Neutralizing antibody was determined both in the presence and absence of complement. In a group of 24 infants and young childres, ages less than 1 to 36 months, with acute respiratory syncytial virus infection, serodiagnosis was made by the IPA-IgG test in 20 cases, by neutralization test with addition of complement in 19 cases, and by neutralization test without addition of complement in 17 cases. Complement fixation detected only 12 cases of infection. All four cases not serologically diagnosed were infants less than 1 month old. Neutralization test antibody titers in the presence of complement were usually 4- to 16-fold higher than titers obtained without addition of complement. Both IPA-IgG and neutralization test (in the presence of complement) appear very efficient in serologically detecting respiratory syncytial virus infections in infants older than 1 month and give rapid results (IPA-IgG takes 2 h to complete, and the neutralization test takes 24 h). However, IPA-IgG is simpler to perform.

Antibodies, Viral↗
PubMed1979

Antibody to early antigens of varicella-zoster virus during varicella and zoster.

IgG antibody to the early antigens of varicella-zoster virus (VZV) was studied during both varicella and zoster by the indirect immunoperoxidase antibody technique. In parallel, complement-fixing, immune-adherence hemagglutinating, IgG, and IgM antibodies to VZV were studied. In both varicella and zoster infections, antibody to the early antigens of VZV appeared three to five days after onset of infection, reached a peak during the second week, and progressively decreased in titer until it disappeared, usually within two months. This antibody usually appeared slightly later than IgG or IgM antibody and grossly correlated with IgM antibody in varicella. In zoster infections, IgM antibody to VZV was not found by the immune-adherence hemagglutination assay at a titer of greater than or equal to 1:4, whereas antibody to the early antigens showed a curve similar to that found in varicella. It is suggested that antibody to the early antigens of VZV be considered as a marker of acute VZV infection, which is associated with a specific and significant IgM antibody response in varicella but not in zoster.

Adolescent↗
PubMed1978

Seroepidemiologic study of human coronavirus OC43 infections in Italy.

Human Coronavirus OC43 from suckling mouse brain (SMB) suspension has been adapted to grow in human embryonic lung fibroblast cell cultures. Complement-fixing and hemagglutinating antigens were prepared from infected cell cultures and used in parallel with the same antigens from SMB for a study of the prevalence of OC43 antibody in Northern Italy as well as for the serodiagnosis of recent OC43 infections and reinfections. Results show (i) a higher sensitivity of the hemagglutination-inhibition as compared to the complement fixation test both for antibody detection in seroepidemiological studies and serodiagnosis of acute infections, (ii) a high prevalence of OC43 antibody in Northern Italy, so that only exceptionally are people older than 12 years seronegative, (iii) a high rate of OC43 reinfections during the winter-spring season 1976/77 in a population sample with preexisting antibody (iv) a good quality of reagents prepared from cell cultures, and hence free of contaminating mouse viruses, such as mouse hepatitis virus.

Adolescent↗
PubMed1978

Immunoglobulin G to virus-specific early antigens in congenital, primary, and reactivated human cytomegalovirus infections.

Immunoglobulin G antibody to human cytomegalovirus (CMV)-specific early antigens (EA-Ab) was determined by the immunoperoxidase antibody technique in several cases of congenital, primary, and reactivated CMV infections. Mothers of congenitally infected infants and a group of leukemic children and pregnant women were also studied. In 11 cases of congenital infection, CMV EA-Ab was always associated with CMV excretion whether immunoglobulin M antibody was present or not. Nine mothers of congenitally infected infants had CMV EA-Ab for several months after delivery, but association with CMV elimination was not established when urine and/or saliva were tested for virus isolation. In all nine cases of primary CMV infection, CMV EA-Ab was present, and in five its detection was associated with CMV isolation. In one case, disappearance of EA-Ab occurred when virus excretion ceased. In five cases of reactivated CMV infections, a consistent association between CMV EA-Ab and virus isolation was found. Six of 31 leukemia children had CMV EA-Ab, and virus was isolated from 3 of these. Four of 28 pregnant women showed EA-Ab in their serum, but tests for isolation were not done. These data suggest that CMV EA-Ab is not a marker of a current primary CMV infection, as previously reported, but a marker of an active CMV replication which can take place in primary as well as in congenital and reactivated CMV infections.

Adult↗
PubMed1976

[Distribution of HB s Ag subtypes in a sample of acute viral hepatitis of type B in Northern Italy].

82 HBsAg from acute hepatitis B patients living in Northern Italy were subtyped. HBsAg has been detected by immunodiffusion (ID), electrosyneresis (ES), complement fixation (CF) and radioimmunoassay (RIA, Kit Ausria I and II, Abbott). Subtyping was performed by ES in 50 and by ID in 30 of the 82 assayed sera. An higher frequency of ayw subtype (83,1%) in comparison with adw subtype (16,9%) has been observed. No difference was found between adw and ayw subtypes analyzed as far as geographic-ethnic characters, incubation time, course and prognosis of the disease or the biohumoral indices. No patient was found to have both y and d specificities and so r determinant was never found.

Acute Disease↗
PubMed1975

[Determination of anti-cytomegalovirus antibodies by the immunoperoxidase method: comparison with the methods of complement fixation and immunofluorescence].

Indirect immunoperoxidase technique (IIP) has been employed for determination of IgG antibody titer to cytomegalovirus (CMV) in sera from 110 blood donors. Titers have been compared with complement fixation (CF) and indirect fluorescent antibody (IFA) technique titers, the latter being applied to determination of all specific antibody classes. Within variability range of the quality of reagents employed in different tests, it seems reasonable to conclude IIP technique is as sensitive as IFA and much more sensitive than CF test. Considering CF test is able to detect only IgG antibody, the advantage of using immunohistochemical techniques is obvious. Moreover IIP does not need fluorescence microscope and results reading is easier and can be delayed. Non-specific staining of Golgi area is shared by both techniques, but endpoint determination has to take into account only the nuclear virus-specific inclusion labelling.

Antibodies, Viral↗
PubMedDate not supplied

Growth hormone regulation of growth hormone-releasing hormone gene expression.

Slot-blot hybridization technique was used to evaluate growth hormone-releasing hormone (GHRH) mRNA levels in the hypothalamus of long-term (14 days) hypophysectomized (HPX) rats treated or not with 125 micrograms hGH/rat, twice daily IP, since the first day postsurgery. In addition, mRNA levels were determined in the hypothalamus of short-term (4 days) GH-treated (250 micrograms hGH/rat, twice daily IP) intact rats. GHRH mRNA levels were increased in HPX rats, and GH treatment partially counteracted this rise. Short-term administration of GH decreased GHRH mRNA levels in intact rats. These results, evaluated together with previous findings showing decreased hypothalamic GHRH-like immunoreactivity in both HPX rats and intact rats given GH (6, 7, 9), indicate that GH exerts a negative feedback action on the synthesis and release of GHRH.

Animals↗
PubMedDate not supplied

Brain cytochromes P-450 are responsive to phenobarbital and tricyclic amines.

Cytochrome P-450 form b has been detected for the first time in rat brain by cross-hybridization of poly(A+) RNA with a radiolabelled cDNA probe. The cross-hybridizable material was easily detectable in rats after treatment with phenobarbital but not in untreated rats. Moreover, treatment of rats with amitriptyline or imipramine, tricyclic antidepressants in wide therapeutic use for depression, markedly increases the amount of RNA species hybridizing with P-450b cDNA probe in comparison to untreated controls. These observations raise the issue of a possible role for brain cytochromes P-450 in the metabolism of drugs such as the tricyclic antidepressants.

Animals↗