Romanian journal of virology最新文献

In order to obtain information on neurologic AIDS, 54 white caucasian children infected by nosocomial route with a median age of 46.2 +/- 7 months were followed up prospectively for a median of 12 months with three months Denver tests neurologic evaluation and six months serologic investigations in CSF and sera. Paired CSF and serum samples, collected on the same day, from children with AIDS encephalopathy, were analysed for the permeability of the blood brain barrier (BBB) and for intrathecal production of anti HIV specific antibodies. A prospective follow-up and repeated comparison of WB profiles and the presence of anti V3 antibodies in CSF and sera was done, as well as an evaluation of the modification in the CSF antibody specificity (anti gag Western Blot scoring) with disease progression. An increased intrathecal synthesis of IgG was recorded in all subjects, in spite of an unaltered BBB permeability. No significant differences were recorded for the anti gag score in the serum samples, which was stable between 9.1-10.4. By contrast, the score for CSF samples decreases significantly with disease progression, from 8.7 in children without encephalopathy, to 6.5 in those with stationary disease and 3.6 in the progressive encephalopathy group. A strong correlation was found between the level of anti p24 antibodies determined by ELISA and the anti gag score quantified by WB for the same CSF samples. The p24 antigen was found to be positive only in 3 cases, even after immune complex dissociation. Anti V3 antibodies were not detected in CSF samples from patients with functional BBB. The decline in anti-gag antibody reactivity in CSF is an early indicator of disease progression, reflecting a severe course of neurological impairments. The absence of anti V3 antibodies in the CSF samples suggests that the PND of neurotropic strains mapped in distinct positions into the V3 loop. These results reflect the selection of antigenic escape mutants which evolve in the CNS, distinct from the blood lymphotropic isolates.

Mice distributed in groups were inoculated with the herpes virus simplex type 1 and type 2 strains in various dilutions (10(-1)-10(-7)), which had been maintained on primary human embryo cell cultures. The animals were killed and homogenates were prepared of their brains, which were used for testing the infective titre in vivo and for the isolation of nuclei, by means of the Hymer-Kuff technique. For the cytokaryological examinations, smears were prepared from the homogenate, which were stained by May-Grünwald-Giemsa and Mann methods. The cell and nucleus types were evaluated morphologically, descriptively, according to the size and structure. On the basis of three criteria the following groups were set up: large sized cells with bulky nuclei; middle sized cells with nuclei of a medium size; small sized cells with small nuclei and visible nucleoli; small sized cells with small, tachychromatic nuclei; cells exhibiting karyolysis. In both the infection with herpes virus simplex type 1 and type 2, the small sized cells with small tachychromatic nuclei represent the highest rate. Between the variants of the elaborated models no significant differences regarding the cell and nucleus types are recorded. On the whole, the cytokaryological picture does not exhibit notable differences, but rather resemblances with respect to the proportionality of the nucleus types in the experimental variants studied, in the case of herpes simplex virus type 1 and 2 induced infections.

Experimental infections were induced in white mice by intranasal administration of parainfluenza virus type 3, 739-2D strain, to which influenza virus A/Beijing, 353/89 (H3N2) strain, and respiratory syncytial virus, Long strain, were associated. The model was organized so as to obtain a triassociated infection, parainfluenza virus type 3 being inoculated the first and the other two viruses, in the following stages-II and III-, alternately. The infections were revealed by the presence of positive immunofluorescence reactions in the pulmonary tissue, of histological, histochemical and histoenzymatic lesions at the level of the respiratory apparatus, as well as of pathomorphological changes in other organs. At the pulmonary parenchyma level the inflammatory lesion had a 100% frequency. The severest pathomorphological picture was the diffuse, lymphohistiocytic and macrophagic bronchopneumonia. The cytoinfiltrate was characterized by a proportionality between lymphocytes and histiocytes and the lower but not insignificant presence of macrophages. The prevalent lesion was the thickening of interparietoalveolar septa, as a consequence of stasis hyperemia, oedema and lymphohistiomacrophagocytic infiltrate, to which dystrophic lesions, especially of biocytes, are often added. Different lesions are present in other organs, such as: in the liver-inflammatory, dystrophico-inflammatory and dystrophic lesions; in the kidney, pancreas, cerebellum and thymus--vascular changes, stasis hyperemia; in the spleen--hyperplasia of megakaryocytes. Generally, the type and severity of lesions vary from one viral-association-induced infection to another.

In the present work there are described some spectral characteristics in the ultraviolet and infrared region under various environment conditions for a series of synthetic analogues of deoxyguanosine, substances possessing antiviral properties. The study is performed on the Acyclovir compounds and on its Na, K and Li salts, synthetized in Romania, in comparison with the similar product Zovirax, of the "Wellcome" firm (England), used in the clinical practice for several years. The results show a very marked resemblance of the spectral behavior for all these products, a conclusion confirmed by the similar biological effects in the herpetic infection.

Four prostaglandin compounds synthetized at ICCF [chloprostenol triacetate (a), the isopropylic ester of the chloprostenol analogue (b), a PGA2 sulprostone analogue (c) and a PGE2 analogue (d)] were tested with respect to the cytotoxic effect, by successive studies on chicken embryo fibroblasts (CEF) and on human cells (HeLa). It was established that (b) and (d) display a high cytotoxicity, while (a) and (c) were relatively well tolerated by the cell layer. The spectrofluorometric determinations showed that these drugs did not induce modifications at the cell membrane level. The treatment with 4 micrograms/ml PGs (a) and (c) of HeLa cells inoculated with Sendai virus produced a significant decrease of TCID50/ml 24 hrs after drug introduction into the culture medium, from 10(6.5) to 10(4.5) and to 10(3.25), respectively.

The human immunodeficiency virus (HIV) infection produces a gradual depletion of T-helper CD4+ lymphocytes as, surprisingly, a consequence of apoptosis of the uninfected lymphocytes. We suggested that this is the result of the action exerted by HIV inductors of apoptosis (for example, gp 120) in the absence of viral apoptosis suppressor, which confers protection to the infected cell. We intended to demonstrate this hypothesis within the framework of a complex study regarding the apoptosis mechanisms in HIV infection. We started this study by setting up an apoptosis model on HIV-negative peripheral blood lymphocytes (PBLs)* cultivated in vitro in the presence of dexamethasone (Dex). In this work we characterize this model morphologically and biochemically. Three unreported morphological changes observed by us--namely: I) fringing of nucleus with advancement of fringes up to the plasma membrane; II) segmentation and peripheral migration of condensed chromatin through a rotation movement; III) "flowering of the cell" consisting in the radial separation of the lymphocyte into centrally united "petals" with the tendency to form apically multiple apoptotic bodies--completed the classical morphology of the apoptosis phenomenon. The apoptotic death was confirmed by the oligonucleosomal (multiples of 200 bp) and mononucleosomal fragmentation of DNA isolated from lymphocytes.

During the summer of 1996 an unusual clustering of meningoencephalitis cases was recorded in the Capital City, Bucharest, and in some areas from South-East Romania. After an initial suspicion of an enteroviral etiology was discarded, the West Nile etiology was confirmed by specific antibodies demonstration through hemagglutination-inhibition and ELISA tests. This study included 251 patients with the diagnoses of West Nile acute encephalitis (166 cases), acute meningitis (57 cases) and acute febrile disease (33 cases). The patients' age ranged from 1 to 89 years (mean 51.1 years). The most frequent clinical manifestations were: fever (95.7% of cases), cephalalgia (92.6%), stiffness of the neck (89.1%), vomiting (62.5%), marked asthenia (46.5%), myalgia (28.9%). In addition, patients with encephalitis exhibited: alteration of consciousness (89.2% of cases), tremor of extremities (40.4%), ataxia (44%), paralysis (15.1%). The fatality rate was 15.1% in acute encephalitis, 1.8% in acute meningitis and 0% in the acute febrile disease.

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).

Human papillomaviruses (HPVs) are considered the main etiological agent of cervical cancer and of its precursory lesions (CIN). The HPV transformation potential consists in the presence of two oncogenes, E6 and E7, which inactivate the tumour-suppressor proteins p53 and pRB of the host cell, inducing uncontrolled transformation and proliferation mechanisms. These effects were demonstrated by in vitro experiments.

Experimental data on bichromatic multiple light scattering enhanced absorbance (MLSEA) photometry at 260 and 350 nm of nucleic acid chromophores on dried chromatography paper disks, previously impregnated with RNA solutions are analyzed. The extrapolated X(O) value of the adsorbed chromophore mole fraction X (9, 10) and mainly its slope dX(O)/dlogD in terms of the logarithmic plot of Debye length D (A), are strongly dependent upon the polynucleotide degree of polymerization P, providing a new ultramicroanalytical, rapid and simple parameter for relative P measurements. New experimental evidence is brought for the two-step adsorption model of polyelectrolytes at charged interfaces.