Biomedical subjects

C Cernescu

Publications and source records attributed to C Cernescu.

120 records · Page 7Linked to original sources

PubMedDate not supplied

Syncytium forming capacity of HIV 1 strains in inhibited by pretreatment of CD4 expressing cells with 3'-azido-3'-deoxythymidine but not by alpha interferon.

3'azido-3'deoxythymidine (AZT) inhibits the ability of uninfected CD4 expressing cells to participate in syncytium formation, when cocultured with cells chronically infected with human immunodeficiency virus type 1 (HIV 1). The inhibition of giant cells formation is similar, irrespective of the AZT-sensitive or resistant phenotype of the HIV1 strains. The effect on syncytium formation occurs when the uninfected target cells are pretreated with AZT, the therapeutic index varying between 290 (CEMss, H9 and > 2000 (HeLa CD4 beta gal). The syncytium reducing effect of AZT is an additional antiviral property, distinct from the inhibition of HIV replication. The HIV 1 phenotype (AZT sensitive or resistant) determines differences both in the morphology of syncytia and in the kinetics of syncytium formation. Pretreatment of the target cells with alpha interferon (125-2000 UI/ml) either alone or in combination with AZT, has no effect on the ability of these cells to participate in syncytium formation, probably owing to the basal IFN synthesis in the system.

CD4-Positive T-Lymphocytes↗

PubMedDate not supplied

CD 26--to be or not to be a cofactor for CD 4 receptor of human immunodeficiency viruses.

Earlier work has shown that HIV binding to CD 4 is necessary, but apparently not sufficient, for viral entry into cells. Several molecules have been proposed as potential candidates for coreceptors in HIV infection. Remarkable attention and criticism was raised by the report of Hovanessian group from Pasteur Institute, France, which claimed the role of CD 26, an enzyme also known as dipeptidyl peptidase IV, as cofactor in HIV entry and HIV infection. Present review mentions some reports which support or reject this hypothesis.

CD4 Antigens↗

PubMedDate not supplied

Considerations about the prophylactic role of T cell vaccination in HIV infection.

The AIDS epidemic in Romania has properties that are both common to countries of Eastern Europe and unique to Romania. The unique aspects include the large number of cases in children infected parenterally and a relatively low but steadily increasing number of HIV infected adults. Other groups of children and adults were also exposed at risk to acquire HIV by transfusion with unscreened blood or by multiple parenteral treatments with potentially contaminated needles. Our hypothesis was that a substantial number of people in area of high endemicity was "silently" infected but did not undergo specific immune response or clinical signs. In an attempt to explore the possibility that immunization with autologous proteins (consequence of multiple transfusions) can play a role in the protection from HIV infection or in slowing down the progression of disease, we compared the incidence of autoantibodies (anti-nuclear, smooth muscle and anti-HEp-2) in a group of long survivors children with AIDS, in HIV infected children with rapid evolution and in adults at risk for parenteral acquisition of blood borne viral disease. We analyzed also the incidence of some blood borne viral infections and the presence of anti-HLA antibodies in the same groups of patients. Our results do not support the suggestion that HIV infection or AIDS can be prevented, respectively, delayed by T-cell vaccination.

Adolescent↗

PubMedDate not supplied

Preliminary results of HIV screening in sentinel facilities in Romania.

In the first months of 1994, 393 patients (random consecutive clinic attenders) from three sentinel clinics were tested for anti-V3 loop antibodies in ELISA with a branched synthetic peptide reproducing eight copies of full V3 sequence. Compared with a commercial HIV 1/2 ELISA kit the sensitivity of anti-V3 assay was 97.6% and the specificity 89.7%. The seroprevalence in women attending prenatal clinic was 7.54% and in children with multiple hospitalization record, 3.82%. Both heterosexual and parenteral transmission through unsafe medical practices fuel actual AIDS epidemic in Romania.

Adult↗

PubMedDate not supplied

Relevance of the reactivity of HIV 1 positive sera with synthetic peptides for understanding antigenic differences between circulating strains.

Several problems have arisen concerning the detection methodology of sources and chains of HIV transmission based on molecular and antigenic relatedness of HIV isolates. Great progress in mapping virus genome or provirus, especially in identifying the changes in the env gene provides interesting data for molecular epidemiology. We address the same problem by the investigation of the reactivity of sera from HIV 1 seropositive children with two panels of synthetic peptides mimicking immunoreactive fragment of HIV1 glycoproteins in solid phase EIA. The samples proceed from two distinct settings: an orphanage in which nosocomial transmission was highly suspected and from different hospitals caring for HIV infected children. The synthetic peptides have sequences which reproduce two target regions: one in the principal neutralization domain of gp 120 (V3 loop) and the other at the COOH end of gp 41. Our results indicate that minimal differences in aminoacids flanking central conserved GPGRA region in V3 loop of gp 120 evidence strain specific antibodies while the COOH end of gp 41 reveals antibodies which link HIV 1 strains in a broad fashion. Sera from HIV infected children collected in different settings recognize the same synthetic peptides panel with distinct frequencies suggesting circulation of different antigenic strains.

Amino Acid Sequence↗

PubMedDate not supplied

Neuroophthalmological examination in children with AIDS.

Evaluation of HIV disease status includes physical examination (anthropomorphic measurements, neurological assessment, etc.) and laboratory examination. Consideration should be given to changes from baseline values, age adjusted normal values and the rapidity of changes. Here we compare results of neuroophthalmologic assessment with Western Blo (WB) profiles in cerebrospinal fluids (CSF) of 54 children with AIDS. Children were classified by Denver Developmental Screening Test (DDST) administration in encephalopathy positive (n = 44) and encephalopathy negative (n = 10) groups. Neuroophthalmological examination which included nine items with good test-retest reliability showed that two of them (nystagmus on following and visual memory impairment) appeared early in the encephalopathy free group and correlated with the loss of some gag band in Western Blot (lower gag score). No correlation was however, found with respect to p24 antigen level in cerebrospinal fluid, a marker which reflects CNS viral load.

AIDS Dementia Complex↗

PubMedDate not supplied

[A seroprevalence study of the hepatitis C virus among multiply transfused patients].

A study was conducted on 61 polytransfused patients, 24 patients submitted to long lasting parenteral treatments, 116 blood donors and 132 controls. Immuno-enzymatic tests were used for detection of antibodies against hepatitis C virus (HCV). They were found in 56 (91.8%) out of the 61 polytransfused patients, in 5 (4.3%) of the donors, in 5 (20.8%) of the patients with multiple treatments and in 5 (3.7%) controls. The VHB markers were detected at variable rates in all investigated groups. The high rate of seropositivity indicates that hepatitis C is becoming an important public health problem in Romania.

Adult↗

PubMedDate not supplied

Immunological disorders of increased severity in children with AIDS associated with hepatitis B and C infections.

Two groups of children were set up: children infected with HIV and hepatitis viruses and children infected with HIV, but not with hepatitis viruses, too. The immunological aspects investigated referred to the Ig serum value, the absolute number of T CD4 lymphocytes and the T CD4/T CD8 ratio. The subjects of the first group (in whom hepatitis markers were present) displayed increased IgA and IgM values at a higher rate than those of the second group (54.87% against 32%, 83.3% against 53%), as well as a lowering below 300/ml of the number of T CD4 lymphocytes (50% against 29.4%). On the other hand, increased IgG levels and values below 0.8 of the T CD4/T CD8 ratio were found at similar rates in the two groups of children (77.4% against 80% and 70.5% against 70% respectively). By means of the data obtained, the authors try to point out one of the ways by which hepatitis viruses, considered as a potential cofactor in the AIDS development, contribute to the course of this disease, namely by intensifying the immunological disorders.

AIDS-Related Opportunistic Infections↗

PubMedDate not supplied

Nucleic acid vaccines.

Direct DNA delivery in vivo can be utilized for the production of proteins as well as for the induction of specific cellular and hunoral immune response against a large number of viral pathogens (influenza, hepatitis B, HIV, etc.). Immunogenic levels of gene expression can be achieved in vivo or, alternatively, facilitated DNA inoculation methods have been described for efficient induction of protective immunity. DNA immunization of a number of viral target proteins has been accomplished in a variety of species including non human primates. Our review focuses on the use of this novel technology for the prevention of human retroviruses infections. Some safety considerations for viral nucleic acid vaccines and regulatory requirements are also discussed.

Animals↗

PubMedDate not supplied

Serological profile assessment of the infection with hepatitis C virus (HCV) in haemophiliacs and thalassemic patients.

Polytransfused patients represent a major risk group for hepatitis C (HCV) acquirement. Haemophiliacs and thalassemic patients treated with virus contaminated blood or blood derivatives frequently exhibit anti-HCV antibodies and signs of chronic hepatitis. The serological profile for the HCV infection was investigated in 13 haemophiliacs, 18 cases of thalassemia and in 14 polytransfused patients affected by other diseases. The presence of anti-HCV antibodies was detected by means of the ORTHO HCV 3.0 ELISA kit and confirmed by Western-blot Murex. The serotyping used synthetic peptides mimicking the immunodominant epitopes in the NS4 region, characteristic of each of the six HCV genotypes in an ELISA blocking reaction (Murex). Serotype 1 was prevalent (51.1%), while serotype 2 was detected in 13.3% of patients, with a higher frequency in thalassemia cases. The remaining samples were multireactive, and serotype 3 alone was not detected. The profile of Western-blot bands was distinct for the monoreactive samples belonging to serotype 1 or 2. The analysis of the multireactive samples in young (thalassemic, age mean 15.17 +/- 6.5) and aged patients (haemophiliacs, age mean 32.64 +/- 13.5) allows us to suggest a different succession of reinfection acquirements. The infection with one of the subtypes does not confer protection against the reinfection with others. However, a certain attenuation of the symptomatology is obvious in the case of reinfections, indicating the existence of crossantigenic reactivities which contribute to protection. This protection is more evident in the case of primary infection with type 2 and is partially due to antigens coded by the NS4 genomic segment.

Adolescent↗

PubMedDate not supplied

[Seroprevalence of hepatitis C virus among the multiply transfused].

Adult↗

PubMedDate not supplied

A high number of severe neurologic clinical forms during an epidemic of West Nile virus infection.

The serologic confirmation of more than 800 cases hospitalized during the viral meningoencephalitis epidemic caused by the West Nile virus (WNV) that affected the South-East of Romania during the summer of 1996 consolidated the case definition in over 80% of the patients admitted to the hospital with neurological impairments. Other clinical forms of the WN infection were reported only scarcely during the epidemic and were seroconfirmed at a lower rate (60%). IgM capture ELISA (MAC-ELISA) is a test of choice for the rapid diagnosis. The major advantage of MAC-ELISA procedure is the high probability of accurate diagnosis of WN infection when the test is performed only with acute serum or cerebrospinal fluid (CSF) specimens obtained while the patient is still hospitalized. Rapid diagnosis by MAC-ELISA is important for the institution of public health control, but the results obtained have also some predictive values. We report the serological patterns of 65 pairs of CSF and serum samples collected in the early days of neuroinfection for diagnostic purposes. An unexpected onset of the intrathecal specific humoral immune response before serum immunoglobulins synthesis was recorded in 25% of cases. For 14 patients with intrathecal onset of IgM synthesis, their records evaluated retrospectively showed a severe evolution. The presence of only IgM antibodies in CSF is a characteristic which matched with other laboratory variables described which predict poor evolution in viral encephalitis: pleocytosis, elevated protein concentration in CSF (> 100 mg per deciliter), hyponatremia (< 130 mmol per liter).

Antibodies, Viral↗