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Biomedical subjects

C Lane

Publications and source records attributed to C Lane.

15 recordsLinked to original sources
PubMed1992

Induction of VCAM-1 and ICAM-1 on human neural cells and mechanisms of mononuclear leukocyte adherence.

We propose that leukocyte-derived cytokines induce the expression of adhesion molecules on the surface of neural cells that facilitates the subsequent attachment of leukocytes. Leukocyte adherence may contribute to some of the neural cell injury seen with various inflammatory diseases of the nervous system. With an in vitro model system, we have shown that mononuclear leukocytes bind to human neuroblastoma and cortical neuron cells only after the neural cells are stimulated with TNF-alpha. TNF-alpha stimulates expression of vascular cell adhesion molecule-1 (VCAM-1) in both of these neural cell lines. VCAM-1 mRNA is increased and VCAM-1 protein can be identified on the neural cell membranes with a new VCAM-1-specific mAb, CL40/2 F8. TNF-alpha also induces ICAM-1 in both of these neural cell lines. Leukocyte beta 1 (CD29) and beta 2 (CD18) integrins and their respective ligands, ICAM-1 and VCAM-1, on neural cells appear to be the dominant ligands mediating MNL:neural cell adhesive interactions. mAb to CD18 block 32 to 57% of the MNL binding to neural cells; similar inhibition is seen with mAb to ICAM-1. mAb to CD29 block 16 to 17% of the MNL binding to the neural cells suggesting that leukocyte beta 1 integrins and neural VCAM-1 may be a second route for MNL:neural cell interactions. Addition of both anti-CD18 and anti-CD29 mAb have an additive blocking effect; both ligand pairs may participate in MNL adhesion to neural cells, reminiscent of the multiplicity of ligands used by MNL when binding to endothelium.

Antibodies, Monoclonal↗
PubMed1992

How loss affects anger and alienates potential supporters.

The effects of loss of resources and illness symptoms on experienced anger, anger expression, and supporter's anger was studied among patients with severe chronic breathing disorder. Both illness symptoms and resource loss were related to greater anger. Angry feelings, in turn, led to more angry behavior. This angry behavior, in turn, resulted in increased anger of supporters. This process illustrates how chronic stress depletes both personal resources and social resources, making the individual increasingly vulnerable to further stressful experiences, inevitably to be confronted in chronic stress sequences.

Adaptation, Psychological↗
PubMed1992

Effect of an inhaled thromboxane mimetic (U46619) on in vivo pulmonary resistance and airway hyperresponsiveness in dogs.

1. We investigated the role of thromboxane A2 in the airway hyperresponsiveness that follows the inhalation of ozone in dogs by examining the responses to an inhaled thromboxane analogue (U46619). 2. Measurements of pulmonary resistance were made in anaesthetized dogs; the concentration of inhaled agonist causing an increase of 5 cmH2O l-1 s was calculated (provocative concentration). The effect of inhaled U46619 was studied on in vivo canine airway resistance, on airway responsiveness and on airways made hyperresponsive following the inhalation of ozone. 3. Inhaled thromboxane is a potent constrictor of the canine airway. The mean provocative concentration was 2.13 x 10(-4) M, compared to acetylcholine which was 3.23 x 10(-2) M. 4. Inhaled thromboxane did not result in the development of airway hyperresponsiveness to acetylcholine. Following U46619 inhalation the mean provocative concentration to acetylcholine was 3.92 x 10(-2) M. 5. Canine airway was not hyperresponsive to inhaled thromboxane following the inhalation of ozone. This was not due to an inhibition of acetylcholinesterase as the dogs were hyperresponsive to carbachol (a muscarinic agonist not degraded by endplate cholinesterase). 6. These experiments do not support a role for thromboxane in the development of airway hyperresponsiveness following the inhalation of ozone in dogs.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1992

Anoxia/reoxygenation-induced neutrophil adherence to cultured endothelial cells.

Previous studies have shown enhanced neutrophil adhesion to endothelial cells exposed to anoxia and then reoxygenated (A/R). To define the molecular basis for these observations, we evaluated the relative roles of CD11/CD18 determinants (CD11a and CD11b) of neurtrophils and the endothelial adhesion proteins intercellular adhesion molecule 1 (ICAM-1) and endothelial-leukocyte adhesion molecule 1 (ELAM-1). Human umbilical vein endothelial cell (HUVEC) monolayers were exposed to anoxia for 30 min, reoxygenated, and then reacted with 51Cr-labeled neutrophils in adhesion assays. Neutrophil adhesion to HUVEC exposed to A/R was significantly increased (2.7-fold) as compared with that observed with normoxic (control) HUVEC. This A/R-induced hyperadherence was significantly diminished by monoclonal antibodies (MAb) directed at CD11a, CD11b, CD18 or ICAM-1, but not by MAb directed at ELAM-1. The inhibitory effects of anti-CD11a and anti-CD11b were additive and equivalent to that of anti-CD18 MAb. A/R did not elicit increased levels of ICAM-1 or ELAM-1 mRNA or surface protein. However, immunofluorescence flow cytometry indicated that incubation of neutrophils in supernatants of A/R-conditioned HUVEC elicited an increase of surface CD11b and CD18, but not CD11a. Supernatants from A/R-conditioned HUVEC promoted neutrophil adherence to naive HUVEC, and this hyperadhesivity was diminished by a platelet-activating factor (PAF) receptor antagonist and catalase but not by a 5-lipoxygenase inhibitor, a leukotriene B4 receptor antagonist, or superoxide dismutase. These studies indicate that A/R promotes neutrophil adherence via CD11a/CD18- and CD11b/CD18-dependent interactions with ICAM-1 that appear to be mediated by hydrogen peroxide and PAF.

Antibodies, Monoclonal↗
PubMed1991

Antibodies against human neutrophil LECAM-1 (LAM-1/Leu-8/DREG-56 antigen) and endothelial cell ELAM-1 inhibit a common CD18-independent adhesion pathway in vitro.

Neutrophil adhesion to interleukin-1 (IL-1)-stimulated human umbilical vein endothelial cells (HUVEC) involves the CD18 family of leukocyte integrins (lymphocyte function-associated antigen-1 [LFA-1], Mac-1, and p150,95) and LECAM-1 (DREG-56/LEU-8/LAM-1 antigen) on neutrophils and intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1) on the endothelium. In this study, we compare CD18-independent adhesion pathways mediated by neutrophil LECAM-1 and endothelial ELAM-1 and find that these two pathways overlap in a variety of assays: (1) anti-LECAM-1 and anti-ELAM-1 monoclonal antibody (MoAb) inhibit neutrophil binding to HUVEC, and the inhibitory effect is not additive; (2) anti-LECAM-1 MoAb, like anti-ELAM-1 MoAb, inhibits neutrophil binding to HUVEC stimulated for 3 hours with IL-1, but not to HUVEC stimulated for 8 hours, by which time ELAM-1 expression is downregulated; (3) anti-ELAM-1 MoAb has no effect on transendothelial migration, a CD18-dependent, LECAM-1-independent neutrophil function. Interestingly, anti-ELAM MoAb has a reduced but significant inhibitory effect on the adhesion of activated neutrophils that have shed their cell-surface LECAM-1. We also show that neutrophil binding to ELAM-1-transfected L cells is inhibited not only by anti-ELAM-1 but also by anti-LECAM-1 MoAb. These results suggest that LECAM-1 and ELAM-1 can operate in the same adhesion pathway, possibly as a receptor-counterreceptor pair. LECAM-1 and ELAM-1 are likely to interact with other ligands as well, perhaps through carbohydrate determinants that modify more than one glycoprotein.

Animals↗
PubMed1991

Development of two new monoclonal antibodies reactive to a surface antigen present on human ovarian epithelial cancer cells.

Monoclonal antibodies which bind selectively to cancer cells are currently used for tumor localization and for targeting cytotoxic reagents. The success of these approaches depends on the specificity of the antibody and its reactivity to a majority of the tumor samples. Frequently, monoclonal antibodies are generated by immunizing mice with antigenic preparations from a single tumor cell line. Antibodies generated under these conditions often react to a narrow range of tumors. In the present study, mice were immunized with multiple ovarian cancer cell lines in a sequential manner to amplify the immune response against common antigenic determinants expressed in these cell lines. Spleen cells from the immunized mice were then fused with NS-1 myeloma cells to establish hybridomas. Two cell lines were selected on the basis of their selective reactivity to ovarian cancer cells after extensive screening. Monoclonal antibodies OVX1 and OVX2 bound to all 5 ovarian carcinoma cell lines tested and did not bind to normal fibroblast cells. These antibodies recognized a unique antigenic determinant present in ovarian and breast cancer cells. Cross-blocking studies showed that the binding of OVX1 and OVX2 is not displaceable by 10 other previously described anti-ovarian antibodies including OC125. In immunocytochemical studies, OVX1 reacted to a majority of ovarian cancer tissues (17 of 20) and did not bind to normal ovarian tissues. Preliminary results indicate that OVX1 and OVX2 antibodies are directed to a high molecular weight antigen. These antibodies could be used in the preparation of cytotoxic conjugates.

Animals↗
PubMed1990

Inhibition of microvascular endothelial cell proliferation by vitreous following retinal scatter photocoagulation.

Laser photocoagulation of pig retina induced breakdown of the blood-retinal barrier, with the appearance of serum proteins in the vitreous as determined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting techniques. Vitreous from lasered eyes inhibited the proliferation of cultured retinal microvascular endothelial cells in comparison with vitreous from non-lasered control eyes, and the inhibitory effect in the lasered eyes persisted for at least seven days. Inhibition was specific for endothelial cells, since no effect was observed when retinal pericytes or Tenon's fibroblasts were the target cells. These results suggest that indirect scatter photocoagulation may induce regression of neovascularisation by causing breakdown of the blood-retinal barrier and thus releasing into the vitreous serum components which result in inhibition of retinal microvascular endothelial cell growth.

Animals↗
PubMed1986

Stimulation and expansion of a human T-cell subpopulation by a monoclonal antibody to T-cell receptor molecule.

A murine monoclonal antibody (MAb) was obtained that showed unique specificity for the immunizing T-cell line HPB-ALL. This antibody, C37 (an IgG1,K) also reacted with a small (2-5%) population of normal peripheral blood T (PBL-T) cells. These C37-positive (C37+) cells were found in both the T4/Leu3+ and T8/Leu2+ subsets. Like OKT3 antibody, C37 induced T-cell mitogenesis with a peak proliferative response at day 3. In long-term cultures containing irradiated autologous feeder cells and IL-2, C37 antibody caused the selective expansion of C37+ T cells. On HPB-ALL cells C37 induced comodulation of the T3 molecule. C37 precipitated a disulfide-linked dimer characteristic of the T-cell antigen receptor consisting of an alpha-subunit (45-48 kD) and a beta-subunit (38-42 kD) from both C37+ T-cell blasts of a normal individual and HPB-ALL cells that were surface radioiodinated. However, the precipitated molecule isolated from C37 antibody-activated T-cell blasts exhibited a different pI from that isolated from HPB-ALL cells. Our studies indicate that C37 recognizes an epitope on the T-cell receptor molecule that is shared by a subpopulation of human T cells, which raises the possibility that multiple variable-region associated and/or framework-like determinants of the T-cell antigen receptor can be defined serologically and used in functional and molecular studies of T-cell subsets.

Antibodies, Monoclonal↗
PubMed1979

Sequestration and turnover of guinea-pig milk proteins and chicken ovalbumin in Xenopus oocytes.

The stability and distribution of proteins within the living cell can be studied using Xenopus laevis oocytes. Microinjection of messenger RNAs and secretory proteins, followed by cell fractionation, shows that transfer of ovalbumin and milk proteins across intracellular membranes of the oocyte only occurs during their synthesis. Thus milk protein primary translation products, made in the wheat germ cell-free system, when injected into oocytes remain in the cytosol and are not recovered within membrane vesicles. Such miscompartmentalized primary milk proteins are rapidly degraded (t 1/2 0.6 +/- 0.1 h). In contrast, processed milk proteins, extracted from oocytes injected with mammary gland RNA, are relatively stable when introduced into the cytosolic compartment (t 1/2 alpha-lactalbumin 20 +/- 8 h, casein A 6 h, casein B 4 h, casein C 8.3 h). The primary ovalbumin product is also stable (t 1/2 22 +/- 9 h). Indirect evidence that rapid degradation of miscompartmentalized milk protein primary translation products may occur in vivo was obtained by the injection of massive amounts of ovalbumin and milk protein mRNA. Under these conditions there is no accumulation of primary milk protein translation products, but a polypeptide resembling the unglycosylated ovalbium wheat germ primary product can be detected in the cytosol. Only the glyclosylated forms of ovalbumin are found in the oocyte membrane vesicle fraction. We discuss the roles played by the presence of detachable signal sequences and the absence of secondary modifications in determining the rate of degradation of primary translation products within the cytosol.

Animals↗
PubMed1978

Requirement for 7-methylguanosine in translation of globin mRNA in vivo.

The 7-methylguanosine (m7G) residue present in the m7G5' ppp5'X-"CAP" structure of rabbit globin mRNA was removed quantitatively by periodate oxidation followed by beta-elimination in the presence of cyclohexylamine. The RNA thus treated was intact and exhibited no signs of degradation as examined by polyacrylamide gel electrophoresis in formamide. Assay for protein synthesis using a wheat germ cell-free system showed that the globin mRNA lacking m7G had lost most of its messenger activity. Identical treatment, of satellite tobacco necrosis virus (STNV) RNA, which does not contain the 5'-terminal "CAP" structure, resulted in no loss of its mRNA activity. Since the importance of the m7G residue in eukaryotic mRNA has not yet been shown essential for translation in vivo, both untreated and treated globin mRNAs were injected into frog oocytes and their translation into globin was measured at intervals over a ninety-six hour period. Globin mRNA either treated with periodate alone or lacking in m7g altogether were both found to have lost more than 90% of their activity in vivo.

Animals↗
PubMed1977

Subcellular compartmentation of albumin and globin made in oocytes under the direction of injected messenger RNA.

The Xenopus oocyte can be used to study the nature and specificity of the translational and post-translational systems of a normal living cell. We describe experiments combining messenger RNA microinjection and subcellular fractionation. Total Xenopus liver RNA directs the synthesis of albumin and vitellogenin contained within membrane vesicles; similarly, guinea pig mammary gland mRNA codes for membrane-bound protease-resistant milk proteins. In contrast, iodinated albumin protein injected into oocytes remains in the supernatant fraction, as does globin made on mRNA. The information encoded in the albumin messenger is therefore sufficient to specify synthesis of a membrane-bound product; moreoever, this highly efficient coupled translation-processing system may be of use in the study of the transfer of newly made proteins across membranes. A significant proportion (up to 20%) of newly made oocyte proteins enter a light membrane fraction, and many remain there. We speculate that these vesicles represent part of an important storage system.

Albumins↗
PubMed1977

Modified semiautomated method for free fatty acids in serum.

Modifications have been made to the reagent system of the semiautomated method for the determination of plasma free fatty acids by Baird et al. (1967), and results are reported of investigations into parameters affecting sensitivity and analytical range.

Animals↗
PubMed1975

Surveillance of some infectious diseases among aircrew personnel in Southeast Asia.

A 2-year analysis of specimens among aircrew personnel in Southeast Asia is reported. Stool specimens were examined for intestinal parasites and enteric bacteria, blood smears for blood parasites, and sera tested for transaminases (SGOT) and antibodies to Entamoeba histolytica, Toxoplasma gondii, Chikungunya and Japanese encephalitis viruses, Rickettsia tsutsugamushi, Leptospira sp. and Pseudomonas pseudomallei. One to four specimens each were obtained from 537 adult males and 20 females. There were 56 subjects with intestinal parasites as follows: Giardia lamblia (3.8%), Endolimax nana (2.6%), Entamoeba histolytica (1.4%), Entamoeba hartmanni (0.9%), Entamoeba coli (0.7%), Trichiuris trichiura (1.7%), Ascaris lumbricoides (1.4%), hookworm (0.9%), and Clonorchis sinensis (1.2%). Two individuals had malaria, Plasmodium vivax (0.6%). Pathogenic enteric bacteria were isolated from seven stool specimens; Shigella groups B and D (0.9%), Salmonella paratyphi (0.3%), and Arizona group (0.9%). Significantly elevated SGOT levels were found in 0.9% and antibodies to Japanese encephalitis virus in 1.5%, to Rickettsia tsutsugamushi in 1.2%, to Pseudomonas pseudomallei in 0.3%, to Entamoeba histolytica in 0.9% and to Toxoplasma gondii in 10.1%. No antibodies were found to Chikungunya virus or Leptospira sp.

Aerospace Medicine↗