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Biomedical subjects

M Duca

Publications and source records attributed to M Duca.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Circulation of influenza virus A(H1N1) in Moldavia (Romania) during 1978-1982.

The influenza virus A(H1N1) subtype that reappeared after an absence of 20 years was incriminated as an etiological agent of acute respiratory disease outbreaks in Moldavia (Romania). There were three epidemics in the winter--spring of 1978, 1979, and 1982, that affected mostly school communities and young adults. In 1980-1981 the circulation of A(H1N1) virus was limited. In all the epidemics mentioned the A(H1N1) subtype caused mild influenza cases, with minimal complications and insignificant mortality.

Adolescent↗
PubMedDate not supplied

[The clinical and immunological correlations between the p24 antigenemia levels and those of anti-p24 antibodies in HIV-seropositive children].

The influence of HIV I p24 antigen immune complexing with anti-p24 antibodies of the assessment of their respective levels in HIV-positive sera was studied. ELISA tests were used for evaluating anti-p24 and p24 antigenemia, with or without acid dissociation. We have observed that: 1. p24 antigenemia usually coexisted with low anti-p24 levels, an inverse correlation between these two parameters being traced; acid dissociation increased the percentage of p24 positive sera, especially when anti-p24 titers are low; 2. on contrary, after acid dissociation, p24 Ag remain undetectable in 55.56% of patients presenting high titers and 29.41% of those with low levels of anti-p24; acid dissociation do not increase anti-p24 titers. Whereas the first group of observations suggests that p24 Ag and anti-p24 Ab may be involved in immune complexes, the second set indicates that p24 Ag and Ab were not inevitably linked in such complexes. So, they may be indicative for two distinct biological phenomena.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[The presence in pregnant women of the risk factor of serum antibodies against 9 viruses with significance in materno-infantile pathology and the transfer of these antibodies to the newborns].

Indirect enzyme immunoassay, performed with Labsystems (Helsinki) kits, in 30 mothers and their newborns, revealed that 100% of parturient women present IgG antibody to hepatitis A (HAV), herpes simplex 1, and measles viruses, constantly transferring these antibodies to their newborns. 78.6% of the women had IgG to rubella (German measles) virus, passively transmitting them to their offsprings. Serological markers (HBsAg and anti-HBc) of hepatitis B virus infection were present in 42% of the investigated women, anti-HBc being also present in the serum of the newborns. Between the identified risk factors (in the past obstetrical history, current pregnancy, labor and early postnatal period) and the spectrum of IgG antibodies present in mothers no significant correlations were revealed. The same obvious lack of correlation between IgG antibodies and risk factors in the neonate (prematurity, low birth weight, malformations) was also found. However, the presence of IgG anti-measles (2 case), IgM anti-rubella (1 case) and IgM and HAV (4 cases) was associated, in the same order, with interstitial pneumonia, hepatosplenomegaly and death, icterus neonatorum, cardiovascular and neurologic malformations. Neither mothers nor their offsprings presented anti-HIV antibodies, suggesting that in the investigated patients no perinatal transmission had occurred.

Adult↗
PubMedDate not supplied

[Seroepidemiological data on the circulation of influenza virus in Moldova in 1991-1992].

OBJECTIVES: 1. To establish the predominant circulating antigenic subtypes of influenza viruses in the epidemic season (19911992). 2. To evaluate the efficiency of seroepidemiological method in determining the circulating antigenic subtypes and its practical consequences. METHODS: Our study consist of 1082 patients with acute respiratory disease or their contacts. Antigens prepared at "Cantacuzino Institute", C.D.C. Atlanta and from viral strains isolated in our laboratory were used. Hemagglutination-inhibiting Test was preceded by the elimination of the unspecific inhibitors with IO4K M/90. Significant titers were considered those > 1/10. RESULTS: Were assessed by determining the number of antibody carriers, their ratio and geometrical mean of the reciprocal value of H.I. antibody titers. CONCLUSIONS: 1. In the winter of 1991 and 1992 A/H3N2 infections and in the spring 1991 and 1992 A/H1N1 virus prevailed, while B virus circulated by the end of spring 1992 epidemic season. 2. The decrease in 1992 of A/Iaşi/1/69 (H3N2) activity at the same time with high titers against A/Iaşi/1/76 (H3N2) and A/Iaşi/1/80 (H3N2) suggests a marked antigenic drift occurring in this interval 3. Serological method for determining the presence of hemagglutination inhibiting antibodies seemed enough and compulsory for detecting the etiological agent of acute respiratory disease, and an epidemic outbreak. 4. The circulation of three distinct antigenic subtypes determines the options for composition of anti-influenza vaccine.

Adolescent↗
PubMedDate not supplied

Hypothesis of transition in two ways from atrial fibrillation to sinus rhythm.

A hypothesis of transition from atrial fibrillation to sinus rhythm in close relation with monophasic action potential duration is proposed. The first way: the prolongation of the right atrial refractoriness reduces the wave fronts below a critical number and their collision terminates the arrhythmia. The second way: progressive shortening of refractoriness at a critical level with block and collision of wave fronts.

Atrial Fibrillation↗
PubMedDate not supplied

[The specific serological profile in hepatitis B virus infection in children].

UNLABELLED: Hepatitis B virus infection (HBV) has a very well known specific serologic profile. In the last years the molecular biology methods reveal some "particular serological profiles" by genomic mutation. One particular profile consists in the absence of anti-HBc total antibodies simultaneously with the presence of HBsAg. Our tested group consists of 372 children aged 0.1 to 15 years. The presence of HBsAg was determined by ELISA "sandwich" and confirmed by neutralisation test. For HIV infection we used two ELISA tests (competitive and indirect) and the Western Blot test for confirmation. Of the total, there were 13 children HBsAg positive and without anti-HBc antibody (3.49% respectively), 7 of the 13 children (53.8%) were dystrophic and 4 were HIV positive (30.76%). From 372 cases, 104 were HBsAg positive (27.9%) and 53 (14.2%) of them had chronic hepatitis. CONCLUSIONS: 1. The particular serologic profile requires the testing of all serological markers specific for HBV. 2. This particular serologic profile is correlated with HIV positive status and dystrophy.

Adolescent↗
PubMedDate not supplied

[The prevalence of HBsAg in hospitalized children as a marker of hepatitis B virus infection].

UNLABELLED: The aim of this study was to determine the prevalence of hepatitis B surface antigen (HBsAg) in hospitalised children, as specific marker for hepatitis B virus (HBV) infection. Our study group consists of 517 children, 68 of them diagnosed with chronic hepatitis. For HBsAg determination we used an ELISA test (Labsystems); for some children we also tested by ELISA the following markers: the antibodies and anti-hepatitis C virus (HCV) antibodies. From 517 children 24.28% were HBSAg positive and 75% of children with chronic hepatitis were positive for the same marker. Almost 100% of chronic active hepatitis (CAH) patients was positive for HBSAg. CONCLUSIONS: 1. The prevalence of HBsAg was much higher as compared with the healthy population prevalence; it is a clear prove that HBV infection has an important role in chronic hepatitis appearance. 2. For all HBsAg positive patients, it is necessary to determine other markers like HBeAg-anti-HBe antibodies system as well as markers for other viral hepatitis (HDV, HCV). 3. The anti-HBV infection vaccine will reduce significantly the prevalence of HBV and HDV infections; 4. Biological molecular technique, like PCR will be necessary in our country, in the future, even the price is so high, to monitoring the IFN treatment for chronic infection as unique solution for these patients.

Adolescent↗
PubMedDate not supplied

Multiple false-positive reactions in anti-CD4 ELISA testing of dystrophic children.

BACKGROUND: Anti-CD4 autoantibodies are present in up to 10% of HIV infected patients and, until present, they were not recorded in other pathological circumstances. AIM: To test the presence of anti-CD4 autoantibodies in HIV-infected children, using an indirect ELISA test. DESIGN: Cross-sectional controlled study. PATIENTS AND METHODS: The study group: 9 HIV infected dystrophic children--3 AIDS (P2A), 6 P1C. Control groups: 9 HIV seronegative dystrophic children; 14 HIV seronegative eutrophic patients presenting chronic hepatopathies, or dialysed patients. METHODS: 1. Indirect ELISA using as antigen sCD4 molecules; 2. Western blot (sCD4); 3. "Antigenic displacement": sera preincubation with sCD4, followed by indirect ELISA. RESULTS: Indirect ELISA revealed anti-CD4 reactivities in all the dystrophic patients (9 HIV+ and 9 HIV-). WB sCD4 did not confirmed none of these reactivities. Sera preincubation with sCD4 did not significantly modified ELISA CD4 reactivities. CONCLUSIONS: False positive results (FPR) rate following testing of the presence of anti-CD4 in dystrophic children recommends prudence for the interpretation of such tests. "Antigenic displacement" could be an accessible and easy to perform method in order to eliminate the FPR.

Antibody Specificity↗
PubMedDate not supplied

[HIV infection in a seronegative child diagnosed by isolation of the virus. The significant immunological and epidemiological signs].

HIV-1, subtype F was isolated from a seronegative child aged 2.5 yr. ELISA tests (Behring HIV-1 + 2, Abbott HIV-1 + 2, Wellcozyme HIV-1 Recombinant, Clonatec HIV-1 + 2, Genelavia Mixt), and also rapid tests (Abbott Pack, Serodia) were all negative, although some of them presented borderline reactivities. Western Blot (Cambridge Biotech) revealed an undetermined profile (traces of anti-gp160 plus anti-p24). A new WB test (Sanofi Dg. Pasteur) performed at a higher serum concentration (1/25) revealed a complete antibody profile, despite the very low intensity of bands. A new serum sample prelevated 6 month later was completely negative on all tests used. Both samples, were negatives in WB for HIV2 and HTLVs. A heparinised blood sample was used for the co-cultivation of PBMC and was proven to be positive in the 14th day of culture. The isolated DNA from end-culture cells was subjected to PCR amplifications for Heteroduplex Mobility Assay direct subtyping (primers ES7 and ES8) and for the investigation of genotypic sensitivity to AZT (primers A/NE1). Lymphocyte populations phenotyping revealed leukocytosis (> 15,000/mL) with a predominance of the CD8+ subset CD4/CD8 ratio was < 1. Plasmatic HIV-1 load (measured by bDNA--Chiron) did not reached detectable levels of HIV-1 RNA. p24 Ag assay (EIA-Coulter) revealed a detectable p24 antigenemia only in the first serum sample and only after acid dissociation. So, this patient may present an integrated HIV-1 infection until now "silent".

AIDS Serodiagnosis↗
PubMedDate not supplied

[The prevalence of anti-hepatitis C virus antibodies in children from social assistance units in the county of Iaşi].

UNLABELLED: The aim of this study was to determine the prevalence of anti-HCV antibody (Ab) in association with specific markers for hepatitis A virus (HAV) and hepatitis B virus (HBV). We investigated 127 children from two orphanages from Iaşi District (77 males--60.6%). An ELISA kit, IInd generation (Diagnostic Pasteur) was used for anti-HCV determination. Hepatitis B surface antigen (HBsAg) and anti-HAV/total antibodies were diagnosed by ELISA competitive and "sandwich" type respectively (Wellcome-Murex). 16.8% from all children was "repeated reactive" for anti-HCV Ab test; majority of them (88.9%) had a positive result for anti-HAV/total Ab and 30.7% were "carriers" for HBsAg. IN CONCLUSION: (1) the prevalence of anti-HCV Ab is more than 3 fold, comparative with the 4.5% value from blood donors in our region; (2) the high level for HBsAg as marker for an HBV infection requires to test the children's liver function to select and monitor them for IFN treatment purposes; (3) for HAV, which is never involved in chronic infection, even if the vaccination is now available, the cost/benefit ration, suggests that the unspecific prevention methods still keep their value.

Adolescent↗