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Biomedical subjects

L Pulliam

Publications and source records attributed to L Pulliam.

At least 37 records · Page 2Linked to original sources
PubMed1992

Effects of dimethyl prostaglandin A1 on herpes simplex virus and human immunodeficiency virus replication.

We have investigated the direct effect of dimethyl prostaglandin A1 (dmPGA1) on the replication of herpes simplex virus (HSV) and human immunodeficiency virus type 1 (HIV-1). dmPGA1 significantly inhibited viral replication in both HSV and HIV infection systems at concentrations of dmPGA1 that did not adversely alter cellular DNA synthesis. The 50% inhibitory concentration (ID50) for several HSV type 1 (HSV-1) strains ranged from 3.8 to 5.6 micrograms/ml for Vero cells and from 4.6 to 7.3 micrograms/ml for human foreskin fibroblasts. The ID50s for two HSV-2 strains varied from 3.8 to 4.5 micrograms/ml for Vero cells; the ID50 was 5.7 micrograms/ml for human foreskin fibroblasts. We found that closely related prostaglandins did not have the same effect on the replication of HSV; dmPGE2 and dmPGA2 caused up to a 60% increase in HSV replication compared with that in untreated virus-infected cells. HIV-1 replication in acutely infected T cells (VB line) and chronically infected macrophages was assessed by quantitative decreases in p24 concentration. The effective ID50s were 2.5 micrograms/ml for VB cells acutely infected with HIV-1 and 5.2 micrograms/m for chronically infected macrophages. dmPGA1 has an unusual broad-spectrum antiviral activity against both HSV and HIV-1 in vitro and offers a new class of potential therapeutic agents for in vivo use.

Animals↗
PubMed1991

Purified trichosanthin (GLQ223) exacerbation of indirect HIV-associated neurotoxicity in vitro.

A formulated preparation of trichosanthin (GLQ223, Pharmaceutical Development Group, Genelabs Inc., Redwood City, California, USA) has been shown to selectively inhibit HIV replication in vitro in lymphocytes and macrophages. In view of recent anecdotal reports of central nervous system (CNS) complications associated with trichosanthin use in some HIV-infected patients, we evaluated any potential drug effects leading to neurotoxicity using a human brain cell aggregate model. Brain cell aggregate cultures were incubated with dilutions of purified trichosanthin alone (trichosanthin), supernatants of HIV-infected macrophage cultures (S-HIV), supernatants of uninfected macrophage cultures (S-U), supernatants of purified trichosanthin-treated uninfected macrophage cultures (S-trichosanthin), or supernatants of purified trichosanthin-treated HIV-infected macrophage cultures (S-HIV-trichosanthin). Treatment with purified trichosanthin alone at up to 2 micrograms/ml, with S-U or with S-trichosanthin, produced no morphological signs of toxicity to brain cell aggregate cultures. S-trichosanthin treatment at 2 micrograms/ml did not result in a significant change in cyclic nucleoside phosphorylase (CNP) activity. Treatment of the brain aggregates with S-HIV and S-HIV-trichosanthin did, however, result in morphological alteration of the brain aggregates, with S-HIV-trichosanthin-treated brain aggregates showing the most severe damage. Although purified trichosanthin did not appear to be directly toxic to human brain aggregate cultures, trichosanthin treatment of infected macrophages may have increased the morphological alterations caused by supernatants of HIV-infected macrophages. These experimental observations may explain anecdotal reports of adverse CNS reactions in association with trichosanthin treatment of HIV-infected patients and emphasize the neurotoxic potential of any therapy targeted at HIV-infected macrophages.

Brain↗
PubMed1991

Cytomegalovirus preferentially infects a monocyte derived macrophage/microglial cell in human brain cultures: neuropathology differs between strains.

Cytomegalovirus (CMV) has been shown through pathologic examination to infect many cell types of the brain; however, neuropathology specific for CMV has been difficult to prove in the absence of classic cytomegalic cells or demonstration of CMV antigens. In an effort to further understand CMV infection of brain tissue, a human brain cell aggregate system was infected with several strains of CMV. Different neuropathologic changes were observed that were related to CMV strain and multiplicity of infection. These changes were consistent with those considered characteristic for human immunodeficiency virus (HIV) infection, including a nodular and multinucleated giant cell formation. By electron microscopy, only a few cells throughout the aggregates demonstrated intranuclear virions. These cells were identified by ultrastructural morphology as either monocyte derived macrophages or microglial cells (M/M). Antigen expression was observed in these cells with and without neuropathologic changes. Infection progressed in either a diffuse fulminant manner or a more focal cell to cell spread. These studies demonstrate that CMV selectively infects M/M in normal human brain cultures and suggests differences in neuropathology based on multiplicity of infection and strain variation.

Brain↗
PubMed1991

Human immunodeficiency virus-infected macrophages produce soluble factors that cause histological and neurochemical alterations in cultured human brains.

We wanted to establish an in vitro human model for AIDS-associated dementia and pursue the hypothesis that this disease process may be a result of soluble factors produced by HIV-infected macrophages. Human brain aggregates were prepared from nine different brain specimens, and were treated with supernatants from in vitro HIV-infected macrophages (SI), uninfected macrophages (SU), infected T cells, or macrophage-conditioned media from four AIDS patients. Seven of nine treated brains exposed to SI showed peripheral rarefaction after 1 wk of incubation that by ultrastructural analysis showed cytoplasmic vacuolation. Aggregates from two of three brain cultures treated with SI for 3 wk became smaller, an approximately 50% decrease in size. The degree of apparent toxicity in brains exposed to patient-derived macrophage supernatants paralleled the proportion of macrophages found to be expressing HIV p24. Ultrastructural abnormalities were not observed in brains treated with supernatants from HIV-infected T cells, uninfected macrophages, or LPS-activated macrophages. Levels of five neurotransmitter amino acids were decreased in comparison to the structural amino acid leucine. These findings suggest that HIV-infected macrophages, infected both in vitro as well as derived from AIDS patients' peripheral blood, produce factors that cause reproducible histochemical, ultrastructural, and functional abnormalities in human brain aggregates.

AIDS Dementia Complex↗
PubMed1991

Client satisfaction with a nurse-managed clinic.

To survive and thrive in today's competitive health-care market, health-care providers must evaluate outcomes of their services, including client satisfaction, then use this information to set standards. In the past, standards of care for the elderly were based on tradition rather than evaluation of their effect on outcomes (Thorsland, 1986). There are, therefore, few guidelines for evaluating outcomes of care in any setting and almost none for care of the elderly in nurse-managed centers. As a first step in evaluating client satisfaction in a nurse-managed clinic a focus group discussion was conducted with nine clients of the Nurse Education Link to Aged (NELA) Wellness Center. The focus group participants indicated that the Center had done an excellent job of meeting physical and emotional health needs of clients. Participants especially liked the location of the clinic in the apartment building where they live. Additional services requested by participants included programs for coping with depression and stress, alcoholism, and arthritis, and for increasing social interaction between men and women.

Aged↗
PubMed1990

Comparison of four methods for rapid detection of Pneumocystis carinii in respiratory specimens.

Four stains for the detection of Pneumocystis carinii in respiratory specimens were compared for sensitivity, specificity, preparation time, and ease of interpretation. One hundred specimens were collected. Of these, 50 were induced sputum specimens and 50 were bronchoalveolar lavage fluid. All specimens were stained with Diff-Quik (DQ) (a modified Giemsa stain), a quick silver stain, and direct and indirect immunofluorescence stains. A positive specimen was defined as any smear positive by two or more of the methods. Fifty-eight percent of specimens were positive. Seventy-four percent of the sputum specimens and 42% of the bronchoalveolar lavages were positive. The sensitivities for detection of P. carinii in sputum were 92% with silver stain, 97% with direct immunofluorescence assay (DFA), 97% with indirect immunofluorescence assay (IFA), and 92% with DQ. The sensitivities for detection in bronchoalveolar lavage were 86% with silver stain, 90% with DFA, 86% with IFA, and 81% with DQ. Preparation times varied from 90 min for the silver stain and IFA to 3 min for DQ. Costs of the tests varied from $1.50 per slide for DQ to $10.00 per slide for the silver stain and DFA. Reading times varied from 10 to 30 min for the silver stain and DQ to less than 5 min for the immunofluorescence assays. We conclude that all of these tests are viable options for the clinical laboratory, and the choice will be influenced by factors such as clinical volume, ability to batch specimens, and expertise of technological support. A reasonable option may be to use the quick and inexpensive DQ as a screening test and to confirm negative smears with a more sensitive assay.

Bacteriological Techniques↗
PubMed1986

Effect of antiviral agents on replication of herpes simplex virus type 1 in brain cultures.

An in vitro tissue culture system consisting of reaggregated embryonic brain cells was used to evaluate the inhibition of herpes simplex type 1 (HSV-1) by several antiviral compounds. The efficacy of acyclovir, vidarabine, bromovinyldeoxyuridine, and 9-(1,3-dihydroxy-2-propoxymethyl) guanine in HSV-1-infected Vero cell monolayer cultures was compared with that seen with brain cell aggregates. At a mean 50% inhibitory dose with Vero cells, acyclovir showed a 99% reduction of virus titer in brain cell aggregates. Vidarabine and 9-(1,3-dihydroxy-2-propoxymethyl) guanine gave a dose-dependent reduction in virus titer with Vero cells; however, in aggregate cultures treated with the same drugs a dose-dependent decrease at 24 h was followed by an increase to a point of no inhibition at 72 h postinfection. Pretreatment of brain cell aggregates with a hybrid human leukocyte interferon (Le IF-AD) reduced virus titers at 48 h postinfection but did not maintain this reduction at 72 h. In contrast, infected Vero cell monolayer cultures demonstrated a dose-dependent reduction in virus titers with Le IF-AD. Postinfection treatment with Le IF-AD did not reduce plaque formation in Vero cells but was effective in reducing virus titer in HSV-1-infected brain cell aggregates at 48 h postinfection. Antiviral concentrations of up to 200 micrograms or 200,000 IU/ml for interferon did not appear morphologically toxic to brain cells. Antiviral therapy of HSV-1-infected brain cell aggregates may more closely mimic in vivo responses than monolayer cultures.

Acyclovir↗
PubMed1985

Effects of exopolysaccharide production by viridans streptococci on penicillin therapy of experimental endocarditis.

The influence of exopolysaccharide production by viridans streptococci on penicillin therapy of endocarditis was studied in rabbits with experimental aortic-valve endocarditis. Animals were first infected with penicillin-susceptible streptococci known to produce varying amounts of exopolysaccharide in cardiac vegetations. Treatment with procaine penicillin, 300,000 U every 12 hr, was begun one to two days after infection. After five days of therapy, animals infected with Streptococcus sanguis II and Streptococcus morbillorum, both vigorous exopolysaccharide producers, continued to have infected vegetations, while animals infected with Streptococcus salivarius and a different Streptococcus sanguis II, both deficient in exopolysaccharide production, had sterile vegetations. These findings indicate that failure to eradicate streptococci from vegetations correlates with exopolysaccharide production and that this property may be important in determining outcome of therapy.

Animals↗
PubMed1984

Use of aggregating brain cultures to study the replication of herpes simplex virus types 1 and 2 in central nervous system tissue.

A novel tissue culture system consisting of reaggregated embryonic mouse brain cells was used to examine the replication of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) within central nervous system tissue. Brain aggregates cultured 30-40 days in vitro demonstrated progressive maturation and differentiation into cells recognizable as neurons, astrocytes and oligodendrocytes, with the latter cell type exhibiting myelin production. Mature aggregates were infected with HSV and sampled at timed intervals postinfection for morphological, virological, and biochemical assays. By electron microscopy mature nucleocapsids were observed in the nucleus of peripheral cells at 9 h and in all cell types by 33 h. Virus-specific antigens were observed, using the immunoperoxidase test, within peripheral cells at 12 h postinfection (p.i.). By 24 h p.i., antigen production had progressed throughout the infected aggregates. Growth curves of HSV-1 and HSV-2 for intracellular and extracellular infectious virus production correlated well with virus-induced morphological changes and antigen production. SDS-polyacrylamide slab gel electrophoresis of isotopically-labelled proteins and glycoproteins synthesized from 4 to 24 h p.i. in virus-infected aggregates revealed typical HSV-1 polypeptide profiles and HSV-1 and HSV-2 glycoprotein profiles. Our results suggest that aggregating brain cultures may provide a useful and more accurate in vitro model for the study of HSV-induced neurological disease.

Animals↗
PubMed1984

Exopolysaccharide production by viridans streptococci in experimental endocarditis.

Light and electron microscopy with histochemical staining were used to estimate exopolysaccharide production by strains of viridans streptococci recovered from patients with endocarditis. Six strains were selected for study because they represented a wide range of in vitro polysaccharide production. By light microscopy, there was good agreement between three polysaccharide stains (ruthenium red, periodic acid-Schiff and calcifluor white) in the amount of glycocalyx produced, which ranged from minimal (0 to 1+) to maximal amounts (4+). Two strains selected for minimal (strain 1) and maximal (strain 6) in vitro exopolysaccharide production were studied after we used them to experimentally infect cardiac vegetations. Glycocalyx could be demonstrated surrounding organisms in cardiac vegetations, and the relative amounts produced were similar to those seen in vitro. Vegetations formed by glycocalyx-producing strains were also larger than those formed by glycocalyx-deficient strains. Viridans group streptococci which produce exopolysaccharide in vitro also do so within cardiac vegetations. The relationship of exopolysaccharide production to maintenance of endocardial infection is discussed.

Animals↗
PubMed1982

Penicillin-resistant Streptococcus constellatus as a cause of endocarditis.

Endocarditis in a 2-year-old child was caused by a penicillin-resistant Streptococcus constellatus. Viridans streptococci in general and those associated with endocarditis in particular are usually believed to be penicillin sensitive. Although the patient did not receive prophylactic antibiotics, the child had recently been treated with an oral penicillin. Penicillin-resistant viridans streptococci are usually sensitive to the synergistic effects of penicillin and an aminoglycoside, but this organism was not. Clindamycin was ultimately shown to demonstrate admirable bactericidal activity against this patient's S constellatus.

Clindamycin↗
PubMed1980

Biochemical properties of CO2-dependent streptococci.

A total of 153 clinical isolates and 10 reference strains were employed in an investigation of CO2-dependent streptococci. Their selection was based on a lactic acid homofermentative end product. This group of organisms grew best in 5 to 10% CO2, and several species, including Streptococcus mutans, S. intermedius, Streptococcus MG, S. anginosus, and S. constellatus, required increased CO2 for primary recovery. A basal medium of thioglycolate with 0.1% Tween 80 and phenol red was prepared and used with selected carbohydrates. This media provided luxuriant growth. Serological testing failed to give any definitive correlation with species identification. A shortened differentiation scheme, combined from previous studies, was proposed.

Carbohydrate Metabolism↗
PubMedDate not supplied

A normal human brain cell aggregate model for neurobiological studies.

A new in vitro model of normal human brain has been developed in which fetal human brain cells form three-dimensional aggregates that can be maintained for up to 60 days in culture. Cells appear fully differentiated at the time of initiation in culture; the predominant cells identified were astrocytes, neurons, and oligodendrocytes with myelin, with occasional ependymal cells and macrophages. The specific arrangement and numbers of neural cells within aggregates differed among brain specimens. Cell kinetics studies detected DNA synthesis throughout the culture interval. Aggregates cocultured with a human malignant glioma cell line (U251-MG) were progressively invaded by tumor cells. In aggregates infected with human cytomegalovirus (CMV), intracellular viral replication and morphologic changes characteristic of human brain infection with this pathogen were seen. This model of brain aggregates should prove valuable for multidisciplinary studies in human neurobiology, particularly in the fields of developmental neurobiology, neuro-oncogenesis, tumor cell invasion, and species-specific viral infection of the central nervous system.

Astrocytes↗
PubMedDate not supplied

Implementation of a computerized information system in a long-term care facility.

The successful implementation of computerized nursing information systems requires the completion of many tasks and the participation of many persons. In 1989, Pulliam and Boettcher described a six-step process for introducing computerized information systems into long-term care facilities. This article describes the process, particularly the implementation phase, as it actually happened in a 124-bed facility in a mid-Atlantic state. This facility found that successful implementation requires a systems coordinator who is a professional nurse who understands the needs of the patients, can integrate information with the computer system, and can provide on-going support for the users.

Delaware↗