Additive and antagonist effects of therapeutic gene combinations for suppression of HIV-1 infection.

A previously described Moloney-based vector expressing a double copy anti-tat antisense tRNA (DC-tRNA-AT) (Biasolo et al., 1996. J.

Human coronavirus polyadenylated RNA sequences in cerebrospinal fluid from multiple sclerosis patients.

Human coronaviruses, represented by the two prototype strains HCV-OC43 and HCV-229E, are important human respiratory pathogens, also associated with necrotizing enterocolitis. Two previous studies, one describing the electron microscopic observation of doughnut-shaped particles, resembling coronaviruses, in a perivascular inflammatory lesion of brain tissue taken at autopsy from a multiple sclerosis patient, and the other one reporting the isolation of coronaviruses from the brains of two multiple sclerosis patients, suggested the possible association between coronaviruses and human demyelinating diseases. We analysed polyadenylated RNAs extracted from cerebrospinal fluid of twenty randomly selected multiple sclerosis patients and ten patients with other neurological diseases (medullary atrophy, Parkinson's disease, polyneuropathy, senile dementia, headache and toxic polyneuropathy) by reverse transcription and polymerase chain reaction searching for HCV-OC43 and HCV-229E sequences.

DNA probe for the human coronavirus OC43 also detects neonatal calf diarrhea coronavirus (NCDCV).

Human coronaviruses (HCV) OC43 and 229E are the second most frequently isolated agents of common colds, and have also been associated with severe upper respiratory infections in children and with gastroenteritis of unknown etiology, such as infantile necrotizing enterocolitis. While HCV-OC43 and neonatal calf diarrhea coronavirus NCDCV cannot be held responsible for enteric infection in man, serological data suggest the possible existence of a human coronavirus, antigenically related to HCV-OC43 and NCDCV, and responsible for enteric infections. We developed a rapid and sensitive method for the diagnosis of the human respiratory coronavirus infections, and for detecting these viruses in suspect coronavirus infections.

Pseudomonas aeruginosa proteases: purification procedures for an enzymatic standard.

Pseudomonas aeruginosa may cause severe infections in debilitated patients. Strains of this microorganism produce several extracellular space proteins, some of which are believed to be virulence factors. There are experimental correlations between the ability to produce proteases and virulence.

HIV type 1 intraperitoneal infection of rabbits permits early detection of serum antibodies to Gag, Pol, and Env proteins, neutralizing antibodies, and proviral DNA from peripheral blood mononuclear cells.

The aim of this study is the development of an animal model useful for studying HIV-1 pathogenesis, candidate vaccines, and antiviral drugs. Aseptic thioglycolate peritonitis was induced in six rabbits. After 4 days, four rabbits were infected with 1 ml of HIV-1 stock containing 100 times the MID50.

Systemic hyperthermia in the treatment of HIV-related disseminated Kaposi's sarcoma. Long-term follow-up of patients treated with low-flow extracorporeal perfusion hyperthermia.

Treatment of HIV and related malignancies with pharmacologic and biologic agents has not appreciably modified the course of disease. Immunologic impairment remains the critical factor in response. We report the long-term results of a single session of low-flow (0.

Booster PCR: evaluation of an improved method for amplification of a few HIV-1 proviral DNA sequences.

A biphasic polymerase chain reaction designed as booster PCR for the detection of human immunodeficiency virus type-1 (HIV-1) was evaluated in samples containing a very low number of target DNA. We examined DNA samples obtained from chronically infected H9/HTLV-III B cells and purified plasmidic DNA containing the entire HIV-1 genome. By using booster PCR we detected HIV-1 DNA sequences up to 5 infected cells in samples containing about 2 micrograms of genomic DNA, and up to 1 copy of plasmidic DNA in samples containing about 0.

Mice infection with HIV-1: a new mouse model for HIV-1 in vivo research.

In mice experimentally infected with 1 x 10(5) UI/mouse of HTLV-IIIB IgM antibodies were detected 10-12 days after the infection, reaching peak values two weeks later; the IgM seratiter progressively decreased thereafter and was negative at ten-eleven weeks. HIV p24 antigen was detected ten-fifteen days after infection and reached peak values five-six weeks later. Antigenemia subsequently decreased and showed an oscillating course with a progressive decrease which persisted throughout the observation period.

Endocytosis constitute the infectious route of HIV-1 entry in human and rabbit monocytes lacking the CD4 receptor.

To obtain "functionally" CD4 negative human monocytes (0-5 CD4 +/1 x 10(6)/cells), 50 ng/5.10(5) cells of OKT4A were added daily after a pre-incubation with OKT4A (100 ng/5.10(5) cells.

Kinetics of p24 antigenemia, IgM, IgG antibodies to p24 and p41 and Ig virus isolation in rabbits experimentally infected with HIV-1.

In rabbits experimentally infected with 1.10(5) u.i.

Modification of norfloxacin inhibition of DNA gyrase induced by a 28 KDal DNA binding protein.

We have previously studied a clinical isolate of Providencia stuartii which showed high levels of resistance to 4-quinolones, aminoglycoside and beta-lactam antibiotics (Landini et al., 1987). DNA gyrase from this isolate was inhibited for 50% of activity at a concentration of 15 microM of norfloxacin, which is about 5-fold higher compared to the 50% inhibitory concentration for a standard DNA gyrase.

Detection of IgG anti-HIV antibodies in mice experimentally infected with HIV-1.

In the present work we report our preliminary data demonstrating the susceptibility of mouse to HIV infection. IgG antibodies were found in mice intraperitoneally inoculated with H9/HTLV-IIIB infected cells. Infected mice showed a humoral response and the antibodies detection includes specific immunoglobulin directed against the major gene product of HIV.

Infection of rabbits with human immunodeficiency virus.

An important requirement for the development of a vaccine against the human immunodeficiency virus (HIV-1), the causative agent of AIDS, is a readily available animal model that would allow possible immunogens to be evaluated. The only species to have been infected with HIV-1 so far is the chimpanzee. However, the scarcity of this animal and its designation as an endangered species place severe restrictions on its use as an animal model.

Antiviral activity of Chamaecyparis lawsoniana extract: study with herpes simplex virus type 2.

Ethanolic extract of the green part of Chamaecyparis Lawsoniana was tested for antiviral activity and toxicity in tissue culture. All experiments were carried out in confluent human embryo lung fibroblasts. Treatment of fibroblast cells with extracts after viral inoculation was effective in inhibiting the replication of herpes simplex virus type 2 (HSV-2).

Beta-lactam resistant Pseudomonas aeruginosa strains emerging during therapy: synergistic resistance mechanisms.

The emergence of beta-lactam resistant strains of Pseudomonas aeruginosa during treatment was studied. Three different strains present before treatment persisted with changes in their beta-lactam resistance during treatment. The isolates before and after therapy were studied for beta-lactamase production and permeability barrier.

The morphogenesis of BLV (bovine leukemia virus) cultivated on FLK (fetal lamb kidney): an ultrastructural study.

A new cell line, obtained by co-cultivation of fetal lamb kidney cells and lymphocytes collected from an adult calf affected by enzootic bovine leukemia, was studied for bovine leukemia virus (BLV) morphogenesis. In this new cell line, called FLK-BLV, persistently infected with BLV, we identified extracellular and intracellular BLV particles. We never observed "budding" particles along the cell surface, and therefore assumed it was a new BLV maturation process in the cell vacuoles.

Modifications of DNA-gyrase and of permeability in a norfloxacin-resistant clinical isolate of Providencia stuartii.

We obtained a clinical isolate of Providencia stuartii showing a high level of resistance to norfloxacin and to other 4-quinolones, whose target is the enzyme DNA-gyrase. This strain showed resistance also to beta-lactam and aminoglycoside antibiotics. In order to detect modification of DNA-gyrase, we performed supercoiling assays in vitro in presence of norfloxacin and ciprofloxacin.

Preliminary characterization of an inhibitory activity of fetal bovine serum on the infectivity of rotavirus strain SA-11.

In the present work we studied non antibody inhibiting activity present in fetal bovine serum and active to Rotavirus infectivity and growth in cell cultures. This inhibitor was revealed by an in vitro neutralization test and characterized by gel filtration and chemical and enzymatic treatments. Furthermore, commercial preparations of bovine serum proteins were tested for inhibitory activity.

Human immunodeficiency virus (HIV): an ultrastructural study.

H-9 cells producing HIV were examined by electron microscopy to value the virus-host cell relationships. HIV fine structure was also studied. HIV induces little cellular damages and it can penetrate into the cytoplasm by phagocytosis.

Occurrence of antipseudomonal beta-lactams and aminoglycosides resistance in Pseudomonas aeruginosa during therapy.

Four strains of Pseudomonas aeruginosa clinical isolates were studied for resistance to antipseudomonal beta-lactams and aminoglycosides. Two of these strains were isolated from two different patients before antibiotic treatment, the other two strains, isolated during therapy, developed resistance to many of antipseudomonal beta-lactams and, in addition, to aminoglycoside antibiotics. All the strains produced a constitutive chromosomal beta-lactamase, while the latter two showed a significant reduction in permeability coefficient.

Prevalence of antibody to human coronaviruses 229E, OC43 and neonatal calf diarrhea coronavirus (NCDCV) in patients of Northern Italy.

A seroepidemiological study for detection of antibody to human coronaviruses OC43, 229E, and neonatal calf diarrhea coronavirus (NCDCV), has been carried out using sera collected from hospitalized patients or healthy persons through routine laboratory tests in Northern Italy. Patients tested were children and adults with different pathological diseases. Antibody detection was performed by using an indirect immunoperoxidase staining technique (for all viruses) and, in the case of OC43 and NCDCV, antibody detection was obtained even with a hemagglutination inhibition test and a plaque reduction neutralization assay.

Third-generation cephalosporins resistance in clinical isolates of Enterobacteriaceae.

Seven clinical isolates of Enterobacteriaceae resistant to third-generation cephalosporins were investigated in order to assess the role played in resistance by permeability barrier and by beta-lactamase production. The addition of subinhibitory concentrations of EDTA increased susceptibility to ceftriaxone in five strains showing that the permeability barrier is involved. All strains produced different amounts of beta-lactamases that were always increased by cefoxitin induction.

Serum inhibitor of coronaviruses OC43 and NCDCV: a study in vivo.

It is well known that some strains of coronaviruses, such as human OC43 and bovine NCDCV, are highly inhibited by non antibody factors present in sera of different mammalian species and sensitive to phospholipase-C treatment. So far this inhibitor has only been revealed in vitro experimental procedures with coronavirus strains adapted to growth in human lung fibroblast cell cultures. The purpose of this work was to ascertain whether this inhibiting activity was also effective "in vivo".

Coronavirus inhibitor in human sera: age distribution and prevalence.

We studied the distribution, in human sera, of non antibody serum inhibitor active towards human OC43 and bovine NCDCV coronaviruses. Antibodies to coronaviruses, present with high prevalence in human sera, were filtered by Protein A Sepharose CL 4B column. In the present work we tested sera of newborns, infants, young children and adults.