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Biomedical subjects

W A Jensen

Publications and source records attributed to W A Jensen.

At least 19 recordsLinked to original sources
PubMed1992

Immunodeficiency syndrome associated with wasting and opportunistic infection in juvenile llamas: 12 cases (1988-1990).

Immunodeficiency was diagnosed as the cause of severe debilitating disease characterized by weight loss, failure to grow, and persistent infections that failed to respond to treatment in 12 young llamas. The llamas were affected after maternal-acquired immunity had decreased; failure of passive transfer of immunoglobulins thus was not suspected. Areas of lymph nodes containing T lymphocytes were hypocellular, suggesting T-cell involvement. High serum immunoglobulin concentrations were not found, despite the existence of infectious disease, suggesting at least secondary B-cell involvement. Results of lymphocyte blastogenesis assays were suggestive of B- and T-cell involvement. It was not possible to determine whether the condition was inherited or acquired.

Animals↗
PubMed1992

Seroprevalence of bovine immunodeficiency-like virus and bovine leukemia virus in a dairy cattle herd.

To determine the prevalence of single vs. dual infection with bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV), sera (n = 95) from a dairy cattle herd were analyzed for anti-BIV and anti-BLV antibodies by an enzyme linked immunosorbent assay. Twenty-one percent (20/95) of samples were BIV-seropositive, while 52% (49/95) of the same samples were BLV-seropositive. A significantly greater percentage of BIV-seronegative samples were BLV-seropositive, 57% (43/75), than were BIV-seropositive samples, 30% (6/20). There was no significant correlation between data ranked from least to greatest amount of anti-viral antibody. Five cattle had persistent lymphocytosis (PL); all five were BLV-seropositive and two were BIV-positive. The mean anti-BLV titer was significantly greater in PL cattle, as compared at non-PL cattle, whereas there was no significant difference between the mean anti-BIV titer in PL cattle, as compared with non-PL cattle. These results provide additional information on the seroprevalence of naturally occurring BIV infection, and indicate that BIV can exist independent of other common infectious agents, such as BLV. Further, the results suggest that infection with BIV is not associated with an increased rate of infection with other infectious agents such as BLV.

Animals↗
PubMed1992

Inhibition of protein kinase C results in decreased expression of bovine leukemia virus.

The in vitro expression of bovine leukemia virus (BLV) in short-term cultured bovine peripheral blood mononuclear cells (PBMC) is associated with increased spontaneous lymphocyte blastogenesis. The purpose of this study was to determine whether intracellular pathways responsible for antigen- or mitogen-induced lymphocyte blastogenesis were also responsible for induction of BLV expression. The protein kinase C (PKC) inhibitor 1-(5-isoquinolinylsulfonyl)-3-methylpiperazine dihydrochloride (3-methyl H7) decreased blastogenesis in a dose-dependent manner, as measured by [3H]thymidine incorporation, in unstimulated, lipopolysaccharide-stimulated and phorbol ester (PMA)-stimulated BLV-infected PBMC. Similarly, 3-methyl H7 decreased BLV expression, as measured by production of gp51 envelope antigen or p24gag antigen, in BLV-infected PBMC under the same conditions. Using an RNase protection assay, the inhibition of BLV expression by 3-methyl H7 was shown to be due to decreased transcriptional activity. The cyclic GMP-dependent protein kinase and cyclic AMP-dependent protein kinase inhibitor N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA1004) did not inhibit either BLV expression or blastogenesis of BLV-infected bovine PBMC. Additional evidence for the PKC-dependent expression of BLV was obtained by using a persistently BLV-infected B-lymphocyte cell line, NBC-13. Activation of PKC by PMA in NBC-13 cells increased BLV expression. 3-methyl H7 decreased the PMA-induced expression of BLV in NBC-13 cells in a dose-dependent manner, whereas HA1004 did not inhibit this expression. These results identify a mechanism for the induction of BLV expression through PKC activation and therefore indicate that latency and replication of BLV is controlled by normal B-lymphocyte intracellular signaling pathways.

Animals↗
PubMed1992

Analysis of induced sputum for the diagnosis of recurrent Pneumocystis carinii pneumonia.

We studied the sensitivity of ISA for diagnosis of second-episode PCP in AIDS patients. We induced sputum in 218 patients who had known or suspected AIDS and who had a presentation suggestive of PCP. All patients with negative sputum smear for PCP underwent BAL. Twenty-five patients were identified who had second-episode PCP at least 30 days after initial diagnosis. Chest roentgenographic infiltrate patterns for these 25 patients were blindly scored as normal, diffuse, upper lobe or focal non-upper lobe. The sensitivity of ISA was 72 percent for the first episode of PCP, 72 percent for the second episode of PCP, 72 percent for patients with second-episode PCP who had initial PCP detected by ISA and 71 percent for patients with second-episode PCP whose first episode of PCP was missed by ISA. Of the ten patients who were treated with AP, only one had a false-negative sputum analysis. A comparison of patients who had second-episode PCP diagnosed by ISA with those who had false-negative sputum analysis showed no difference in time to relapse, chest x-ray film pattern (all diffuse) or use of AP.

AIDS-Related Opportunistic Infections↗
PubMed1991

Case report: hepatic hydrothorax without ascites.

Pleural effusion due to hepatic cirrhosis and ascites is well known. We describe three patients with right-sided hepatic hydrothorax in the absence of ascites. The formation of pleural fluid in these patients is probably a result of fluid movement from peritoneal to pleural space across diaphragmatic defects before ascites can form. The differential diagnosis of a right-sided transudative pleural effusion in a patient with chronic liver disease with or without ascites includes congestive left ventricular failure and nephrotic syndrome. These diseases are usually ruled out with standard clinical tests. Patients with hepatic hydrothorax should be treated with fluid restriction and diuretics. Patients with severe symptoms due to refractory hepatic hydrothorax might benefit from pleural sclerosis and surgical closure of diaphragmatic defects.

Adult↗
PubMed1991

In vivo transcription of the bovine leukemia virus tax/rex region in normal and neoplastic lymphocytes of cattle and sheep.

Expression of bovine leukemia virus (BLV) has been considered to be blocked at the transcriptional level in vivo, since viral RNA species are not readily detected in freshly isolated leukocytes from BLV-infected animals. However, the presence of a persistent antiviral antibody response in infected animals suggests that some degree of virus expression must occur in vivo. The purpose of this study was to determine whether BLV RNA species could be detected by using the polymerase chain reaction in normal or neoplastic lymphoid cells freshly isolated from naturally or experimentally BLV-infected cattle and sheep, respectively. Primers designed to detect a 2.1-kb doubly spliced BLV tax/rex-specific mRNA were used to amplify cDNA copies of RNA derived from infected animals. The amplified viral product was then detected with a radiolabeled BLV tax/rex-specific probe. BLV-specific RNA was detected readily in freshly isolated peripheral blood leukocytes derived from BLV-seropositive cattle or sheep with persistent lymphocytosis and less readily in peripheral blood leukocytes from BLV-seropositive but hematologically normal animals. BLV-specific RNA was also detected in fresh samples of BLV-induced lymphosarcomas. Normal and neoplastic lymphoid cells from BLV-seronegative animals were uniformly negative under similar conditions. These primers also amplified the same viral product from genomic DNA derived from BLV-seropositive animals, providing further evidence for in vivo transcription and suggesting that BLV RNA-dependent DNA polymerase is capable of reverse transcribing the 2.1-kb mRNA in vivo. The demonstration of transcriptional products of BLV in vivo proves that viral latency in BLV infection is incomplete.

Animals↗
PubMed1990

In vitro expression of bovine leukemia virus in isolated B-lymphocytes of cattle and sheep.

The purpose of this study was to determine the effect of T-lymphocytes and phytohemagglutinin (PHA), a T-cell mitogen, on the expression of bovine leukemia virus (BLV) in cultured B-lymphocytes from BLV-infected cattle and sheep. Bovine B-lymphocytes were isolated by negative selection via complement-mediated lysis of T-lymphocytes. Additionally, bovine and ovine B-lymphocytes were positively selected using fluorescence activated cell sorting. Expression of BLV in cultured bovine and ovine B-lymphocytes occurred in the absence of T-lymphocytes and without PHA stimulation. The results of this study demonstrate that BLV replication in cultured B-lymphocytes is T-cell independent. This finding may have implications for the mechanism of viral latency within infected B-lymphocytes.

Animals↗
PubMed1990

Analysis of induced sputum in the diagnosis of Pneumocystis carinii pneumonia.

Sixty-two patients with possible AIDS-associated Pneumocystis carinii pneumonia (PCP) were studied to determine the diagnostic usefulness of sputum analysis and whether or not the results of sputum analysis are related to severity of disease. Induced sputum was stained with Gomori Methenamine silver and modified Wright Giemsa stains. Indicators of disease severity were: extent of chest roentgenographic infiltrate, serum lactic dehydrogenase activity, alveolar-arterial oxygen tension difference, and total blood lymphocyte count. All patients with sputum negative for Pneumocystis underwent bronchoscopy with bronchoalveolar lavage. Sputum analysis was 71% sensitive and 100% specific for the diagnosis of PCP. The negative predictive value of sputum analysis was 48%. There was no relationship between sputum results and the severity of PCP. This study led to the conclusions that sputum analysis is a sensitive, specific, rapid, and low-cost technique for the diagnosis of PCP, and that the sensitivity of sputum analysis for the detection of PCP is not affected by the severity of PCP.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Cell organelle motions in bronchoalveolar lavage macrophages from smokers and nonsmokers.

The migratory and phagocytic capabilities of pulmonary macrophages are important elements in lung defense against particles and pathogens deposited on alveolar surfaces. Both functions rely on macrophage cytoplasmic movements. We examined how a common respiratory exposure, cigarette smoking, affects intracellular motions in human pulmonary macrophages (HPM phi). We observed that HPM phi isolated by bronchoalveolar lavage from human volunteers and cultured in vitro were capable of ingesting unopsonized magnetic iron oxide particles localized within phagosomes and phagolysosomes. Upon magnetization, the particles collectively produced a remanent magnetic field (RMF). Motions of particle-containing organelles caused a decay of the RMF, or "relaxation." We applied this technique, which is an alternative to optical microscopy, for evaluating both movement and viscosity of macrophage cytoplasm. In our in vitro studies, we found that HPM phi isolated from smokers exhibited more rapid RMF decay than did HPM phi isolated from nonsmokers. Rotating the intracellular magnetic particles with external fields showed that the HPM phi cytosol was highly viscous in both smoker and nonsmoker cells. In both cell groups, resistance to particle rotation was increased by 2.6 ng/ml phorbol myristate acetate. Our in vitro magnetometric quantification of intracellular particle movement in isolated HPM phi suggests that lung macrophage cell organelle motions are increased in smokers; this may be the mechanism for the enhanced in vivo magnetic-particle motion reported previously in magnetometric studies of human subjects who are smokers.

Bronchoalveolar Lavage Fluid↗
PubMed1990

Myasthenia gravis presenting as isolated respiratory failure.

A patient with myasthenia gravis presenting as respiratory failure was unusual in his lack of peripheral neuromuscular involvement, negative results on many commonly used diagnostic tests, and lack of response to firstline therapeutic measures. Review of the pertinent literature revealed no previously described presentation of myasthenia gravis in this manner.

Humans↗
PubMed1990

Pleuropulmonary manifestations of hepatic amebiasis.

Pleuropulmonary manifestations of hepatic amebiasis occurred in 30 patients; 18 (60%) presented with at least 1 pulmonary complaint and 10 (33%) had multiple pulmonary symptoms. In 14 patients (47%), abnormalities were found on examination of the chest. In 16 chest roentgenograms (53%), there was at least 1 abnormality: right-sided pleural effusion (9 patients) and elevated right hemidiaphragm (8 patients) were the most common. All patients were treated with metronidazole (Flagyl) and had resolution of the amebic liver abscess and pulmonary disease. Pleuropulmonary disease is a common complication of amebic liver abscess. The clinical presentation and chest roentgenograms are virtually diagnostic and obviate the need for invasive procedures to confirm the diagnosis. Pleuropulmonary disease resolves with amebicidal treatment of the hepatic abscess.

Abdominal Pain↗
PubMed1990

Clarification.

Explore the source record for details and available documents.

Humans↗
PubMed1990

Respiratory failure due to a massive rheumatoid pleural effusion.

A patient with rheumatoid arthritis (RA) and chronic obstructive lung disease was admitted with respiratory failure due to a massive pleural effusion. An extensive evaluation proved the effusion to be of rheumatoid origin. The effusion resolved with prednisone and penicillamine therapy. Although pleural effusions associated with RA are common, massive effusions are rare and respiratory failure from a rheumatoid pleural effusion has not been reported.

Arthritis, Rheumatoid↗
PubMed1988

Cytokine activation of antibacterial activity in human pulmonary macrophages: comparison of recombinant interferon-gamma and granulocyte-macrophage colony-stimulating factor.

We examined the ability of two recombinant human cytokines, granulocyte-macrophage colony-stimulating factor (rHu-GM-CSF) and interferon-gamma (rHu-IFN-gamma) to activate antibacterial mechanisms in human pulmonary macrophages (PM) and peripheral blood monocytes (PBM). Growth of Legionella pneumophila (LP) was assessed in PM or PBM which had been exposed to either rHu-IFN-gamma (500-1000 u/ml) or rHu-GM-CSF (1 to 10,000 u/ml). In both PM and PBM exposed to 500 u/ml rHu-IFN-gamma, growth of LP was reduced compared to cells exposed to media alone. By comparison, exposure of these cell types to rHu-GM-CSF had no detectable effect on bacterial replication. In order to investigate potential mechanisms accounting for this observation, the effect of these cytokines on the hydrogen peroxide (H2O2)-releasing capacity of cells was studied. Exposure of PM and PBM to rHu-IFN-gamma (500 to 1000 u/ml) resulted in increased production of H2O2 triggered by phorbol myristate acetate; when subjected to the same experimental conditions, rHu-GM-CSF-exposed cells exhibited no increase in H2O2 production. To further clarify the role of rHu-IFN-gamma-induced augmentation of oxidative metabolism on cellular inhibition of bacterial growth, an amount of catalase capable of completely neutralizing extracellular H2O2 was added to cells before and during infection. This did not abrogate the antibacterial activity of rHu-IFN-gamma. These studies demonstrate that rHu-IFN-gamma but not rHu-GM-CSF is capable of augmenting the capacity of PM and PBM to restrict LP growth. These data suggest that the antibacterial activity of rHu-IFN-gamma in this system may involve oxidative as well as nonoxidative mechanisms.

Bacteria↗
PubMed1988

Abnormal airway function in individuals with the acquired immunodeficiency syndrome.

Pulmonary function test results of individuals with the acquired immunodeficiency syndrome (AIDS) were analyzed to determine the prevalence of abnormally low forced expiratory flow rates and bronchial hyperreactivity. Of 99 individuals with AIDS, a total of 44 (44 percent) had either low forced expiratory flow rates or a significant response to inhaled bronchodilator. Thirty-one (31 percent) individuals exhibited significant improvement in airflow rates after bronchodilator inhalation, while 33 (33 percent) had low flow rates. Twenty (20 percent) individuals had both low flow rates and a significant response to bronchodilator. In 83 percent of symptomatic individuals treated with bronchodilators there was clinical improvement. Thus, we conclude that abnormally low forced expiratory flow rate with or without bronchial hyperreactivity is a common and treatable complication of AIDS.

Acquired Immunodeficiency Syndrome↗