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Biomedical subjects

J M Lombardo

Publications and source records attributed to J M Lombardo.

10 recordsLinked to original sources

Anonymous human immunodeficiency virus surveillance and clinically directed testing in a Newark, NJ, hospital.

From September 1988 to August 1989, in a university hospital in Newark, NJ, 3529 serum and plasma specimens from patients with admitting conditions presumably not associated with human immunodeficiency virus (HIV) infection (Centers for Disease Control, Atlanta, Ga, Sentinel Hospital Surveillance System criteria) were tested anonymously for the presence of type 1 HIV (HIV-1) antibody. Of these specimens, 269 (7.6%) were confirmed HIV-1 seropositive. Overall, 10.3% of male patients and 4.8% of female patients were seropositive. Persons 25 to 44 years old had the highest HIV-1 seroprevalence- 20.9% for male and 7.5% for female patients. Based on this anonymous testing, the number of HIV-infected hospitalized patients discharged in 1988 was estimated. Data on hospital-confirmed HIV-infected patients tested on the basis of clinical suspicion suggest that only 40% of HIV-infected patients were actually tested for HIV-1 infection as part of their medical care in this hospital. These data demonstrate a high prevalence of HIV infection in this patient population and suggest that hospitals serving populations with a high HIV seroprevalence offer routine screening for HIV infection as part of good medical care.

Adolescent

Evaluation of an atypical HIV type 1 antibody. Serologic pattern leading to detection of HIV type 2 infection in North America.

The variability and discordance of human immunodeficiency virus type 1 (HIV-1) antibody enzyme immunoassay determinations on serial specimens derived, to our knowledge, from the first documented case of HIV-2 infection in North America are described. The initial specimen was weakly reactive, but two subsequent serum specimens were both nonreactive by enzyme immunoassay. All specimens were indeterminate for HIV-1 antibody by HIV-1 Western blot analysis. Serum HIV-2 antibody was demonstrated by enzyme immunoassay using whole virus lysate, HIV-2-specific synthetic peptide assays, and HIV-2 Western blot analysis. Human immunodeficiency virus type 2 genomic sequences were demonstrated in peripheral blood mononuclear cells using gene amplification technology. Human immunodeficiency virus type 2, isolated from peripheral blood lymphocytes, had typical morphologic features of lenti-virus by electron microscopy. Western blot analysis and other specific assays should be considered in individuals with clinical evidence suggesting HIV infection who are nonreactive for HIV-1 antibody by enzyme immunoassay or who have atypical reactivity patterns.

Acquired Immunodeficiency Syndrome

Chlamydia trachomatis.

The frequency of positive serological tests for Chlamydia trachomatis, the most common sexually transmitted pathogen in the United States, was assessed in 18,622 specimens derived from New Jersey clinics. From the results, 13 percent female patients and 17 percent male patients were reactive for chlamydial antigen.

Adolescent

HIV-2-associated AIDS in the United States. The first case.

A 41-year-old woman from the Cape Verde Islands, Africa, who had been residing in the United States for 11 months was found to have human immunodeficiency virus type 2 (HIV-2)-associated acquired immunodeficiency syndrome (AIDS). Antibody to HIV-2 was found by enzyme immunoassay and was verified by radioimmunoprecipitation. The patient was being treated for pulmonary tuberculosis at the time of her admission to our institution. Further laboratory and clinical evaluation at our facility revealed depressed CD4 lymphocytes, oral candidiasis, and cryptococcal meningitis with indeterminate results on serologic testing for HIV type 1 (HIV-1). The biopsy specimen of a lesion in the right occipital lobe of the brain documented Toxoplasma gondii, indicating a clinical diagnosis of AIDS. To our knowledge, our study presents the first known patient with HIV-2-associated AIDS in the United States. Our patient provides further evidence that HIV-2 causes severe immunodeficiency and opportunistic infection. The condition should be suspected in the face of normal or repeatedly equivocal HIV-1 antibody test results in the presence of clinically documented AIDS.

Acquired Immunodeficiency Syndrome

Elimination of the M. hyorhinis from murine neuroblastoma cell lines by in vivo passage.

Cell lines derived from a murine neuroblastoma, Clone N18, were cured of their M. hyorhinis infection by in vivo passage. The major variable determining success of this method was found to be the incubation time in vivo. Infected cells maintained in vivo for 27 d or more and then placed in culture were free of mycoplasma whereas those maintained in vivo for 7 or 14 d were found to still be infected. This approach to eliminating mycoplasma infection may be successful using other tumor cell lines.

Animals

Clonal variation in cultured neuroblastoma cells. I. Isolation and characterization of variants.

Two spontaneously arising variant clones were selected from the N18 neuroblastoma cell line solely on the basis of their flattened morphology and tight adherence to the culture flask. Two other clones having the round loosely adherent morphology typical of the parent line were also selected, and flat variants were shown to arise in them upon prolonged cultivation. The flat variant clones have slower growth rates in culture, lower cloning efficiencies in suspension, and reduced acetylcholinesterase inducibility when compared with either the parent N18 line or the round cell clones. Cells of both morphologic types have high levels of plasminogen activator and are tumorigenic, although the variants have a slower growth rate in vivo, consistent with their slower growth rate in culture. SDS-polyacrylamide gel electrophoresis of total protein from the two cell types shows that the flat variants have increased amounts of a 200,000 molecular weight polypeptide that has tentatively been identified as the heavy chain of myosin. Round morphological revertants from one of the flat variant clones exhibited growth characteristics typical of the parent N18 line, but their content of myosin heavy chain, although reduced, was not so low as that in the round cell clones originally isolated. The possibility of a causal relationship between flat morphology, reduced suspension cloning efficiency, and increased content of myosin heavy chain is discussed.

Acetylcholinesterase

Clonal variation in cultured neuroblastoma cells. II. The relationship of increased intracellular cyclic AMP content to increased anchorage requirement for growth and flattened morphology.

Flat variant clones were isolated from both the N18 neuroblastoma cell line and from a subclone of the parent line exhibiting the typical round cell morphology. Several revertant clones exhibiting the round parental morphology were also isolated from one of the flat variant clones. The flat variants exhibit decreased cloning efficiency in suspension and increased amounts of myosin heavy chain when compared to the round cell clones. Intracellular cAMP levels were increased from two- to fivefold over those in clones representative of the parent line and in the round cell revertants. Treatment with the phosphodiesterase inhibitor RO20-1724 increased cAMP levels and reduced suspension cloning efficiency without altering doubling time or attached cloning efficiency. Increasing cAMP levels of two of the round cell clones by treatment with the phosphodiesterase inhibitor caused increased flattening of the cell body and increased myosin heavy chain content. Thus, even though increased cAMP level may be sufficient to explain the reduced cloning efficiency of the flat variants, it is not the sole cause of the flat morphology.

Cell Adhesion