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J L Miller

Publications and source records attributed to J L Miller.

At least 91 records · Page 5Linked to original sources
PubMed2000

Effect of WEB 2086 on leukocyte adherence in response to hemorrhagic shock in rats.

BACKGROUND: The pathogenesis of generalized microvascular injury after hemorrhagic shock is known to involve the generation of platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine [PAF]). The release of PAF is manifested in several ways, including by increased vascular permeability, altered vascular reactivity, and increased leukocyte adherence to the endothelium. WEB 2086 is a PAF antagonist that has been shown experimentally to improve survival after hemorrhagic shock. The purpose of this study was to examine the efficacy of WEB 2086 in attenuating leukocyte adherence before, during, and after hemorrhagic shock. METHODS: After a control period, blood was withdrawn to reduce the mean arterial pressure to 40 mm Hg for 30 minutes in urethane-anesthetized rats. Mesenteric venules in a transilluminated segment of the small bowel were examined to quantitate leukocyte adherence using intravital microscopy. RESULTS: In sham-operated rats (control), there was minimal to no leukocyte adherence throughout the experiment. Hemorrhagic shock resulted in a significant increase in leukocyte adherence postshock during resuscitation (10.9 +/- 1.8 cells/100 microm, p < 0.01) when compared with controls. WEB 2086, when given before shock, significantly attenuated leukocyte adherence (0.1 +/- 0.08 cells/100 microm, p < 0.01) when compared with hemorrhagic shock alone. This effect of WEB 2086 on adherence could be demonstrated even when it was given during (3.5 +/- 0.9 cells/100 microm, p < 0.01) and 10 minutes into (5.8 +/- 1.1 cells/100 microm, p < 0.05) hemorrhagic shock. CONCLUSION: Our findings suggest that WEB 2086 may be of therapeutic benefit against the microvascular damage sustained after hemorrhagic shock.

Animals↗
PubMed2000

Effect of LFA-1beta antibody on leukocyte adherence in response to hemorrhagic shock in rats.

The activation and adherence of leukocytes to the venular endothelium are critical steps in the pathogenesis of generalized microvascular injury following hemorrhagic shock. Previous studies have shown that the integrins CD11/CD18 play a significant role in this interaction. The purpose of this study is to examine the efficacy of anti-LFA-1beta, an antibody to CD11a/CD18, in attenuating leukocyte adherence before, during, and after hemorrhagic shock. Following a control period, blood was withdrawn to reduce the mean arterial pressure to 40 mm Hg for 30 min in urethane-anesthetized rats. Mesenteric venules in a transilluminated segment of the small intestines were examined to quantitate leukocyte adherence using intravital microscopy. In sham-operated rats (control), there was minimal to no leukocyte adherence throughout the experiment. Hemorrhagic shock resulted in significant leukocyte adherence during resuscitation (10.8 +/- 1.7 cells/100 microm, P < 0.01) when compared to control. Anti-LFA-1beta, when given before hemorrhagic shock, significantly attenuated leukocyte adherence during resuscitation (1.1 +/- 0.8, P < 0.01) when compared with hemorrhagic shock alone. This protective effect of anti-LFA-1beta on leukocyte adherence was even demonstrated when it was given during (1.6 +/- 0.3, P < 0.01) and 10 min after hemorrhagic shock (5.8 +/- 0.4, P < 0.05). These results suggest that anti-LFA-1beta may be of potential therapeutic benefit against microvascular injury caused by hemorrhagic shock.

Animals↗
PubMed2000

Post-traumatic stress disorder in primary care practice.

PURPOSE: To provide clinicians in primary care settings with guidelines on evaluation, diagnosis, and management of post-traumatic stress disorder (PTSD). DATA SOURCES: Research-based articles in the medical and psychiatric literature, review articles, and diagnostic criteria. CONCLUSIONS: PTSD is a disorder where psychological and physiological reactions are closely related. Populations at risk include survivors of motor vehicle accidents, natural and man-made disasters, torture, and childhood sexual abuse, as well as combat veterans. IMPLICATIONS FOR PRACTICE: Patients with a history of recent trauma should be targeted for early screening and intervention. Effective treatment of PTSD is a three-stage process consisting of stabilization of symptoms, processing of traumatic perceptions, and integration of trauma into the patient's world- and self-view.

Accidents, Traffic↗
PubMed2000

Involvement of the mannose receptor in infection of macrophages by influenza virus.

Influenza viruses A/PR/8/34 (PR8; H1N1), A/Aichi/68 X-31 (HKx31; H3N2), and A/Beijing/89 X-109 (BJx109; H3N2) show marked differences in their ability to infect murine macrophages, including resident alveolar and peritoneal macrophages as well as the macrophage-derived cell line J774. The hierarchy in infectivity of the viruses (PR8 < HKx31 < BJx109) resembles that of their reactivity with mannose-binding lectins of the collectin family. Since the macrophage mannose receptor recognizes the same spectrum of monosaccharides as the collectins do, we investigated the possible involvement of this receptor in infection of macrophages by influenza virus. In competitive binding studies, the binding of (125)I-labeled mannosylated bovine serum albumin to macrophages was inhibited by the purified hemagglutinin and neuraminidase (HANA) glycoproteins of influenza virus but not by HANA that had been treated with periodate to oxidize its oligosaccharide side chains. The inhibitory activity of HANA from the three strains of virus differed markedly and correlated with the infectivity of each virus for macrophages. Infection of macrophages, but not MDCK cells, by influenza virus was inhibited by yeast mannan. A variant line of J774 cells, J774E, which expresses elevated levels of the mannose receptor, was more readily infected than J774, and the sensitivity of J774E cells to infection was greatly reduced by culture in the presence of D-mannose, which down-modulated mannose receptor expression. Together, the data implicate the mannose receptor as a major endocytic receptor in the infectious entry of influenza virus, and perhaps other enveloped viruses, into murine macrophages.

Animals↗
PubMed2000

Scavenger-receptor targeted photodynamic therapy.

Covalent conjugation of a photosensitizer to a ligand that specifically recognized and internalized by a cell-surface receptor may be a way of improving the selectivity of photodynamic therapy (PDT). The class A Type-I scavenger receptor of macrophages, which among other ligands recognizes maleylated serum albumin and has a high capacity is a good candidate for testing this approach. Chlorin(e6) was covalently attached to bovine serum albumin to give conjugates with molar substitution ratios of 1:1 and 3:1 (dye to protein), and these conjugates could then be further modified by maleylation. A novel way of purifying the conjugates by acetone precipitation was developed in order to remove traces of unbound dye that could not be accomplished by size-exclusion chromatography. Conjugates were characterized by polyacrylamide gel electrophoresis and thin-layer chromatography. Photosensitizer uptake was measured by target J774 murine macrophage-like cells and nontarget OVCAR-5 human ovarian cancer cells, and phototoxicity was examined after illumination by a 660 nm diode laser by a tetrazolium assay. All of the purified conjugates were taken up by and after illumination killed J774 cells while there was only small uptake and no phototoxicity toward OVCAR-5 cells. The higher dye:protein ratio and maleylation of the conjugates both produced higher uptakes and lower survival ratios in J774 cells. The uptake and phototoxicity by J774 cells were decreased after incubation at 4 degrees C demonstrating internalization, and confocal microscopy with organelle-specific green fluorescent probes showed largely lysosomal localization. Uptake and phototoxicity by J774 cells could both be competed by addition of the scavenger receptor ligand maleylated albumin. These data show that scavenger receptor-targeted PDT gives a high degree of specificity toward macrophages and may have applications in the treatment of tumors and atherosclerosis.

Animals↗
PubMed2000

Motivators of health seeking behavior in urban African-American men: an exploration of triggers and barriers.

A health crisis exists with African-American men. Morbidity and mortality are higher among African-American men than any other racial/ethnic group. This disparity may be partially related to health seeking behavior in African-American men. Health seeking behavior is influenced by both internal and external motivators. Using the Health Belief Model as a guiding theoretical framework, a qualitative study using focus group methodology was conducted with adult urban African-American men in a large northeastern metropolitan area to explore motivators of health seeking behavior. A total of 38 men were interviewed. Sessions were audiotaped, transcribed verbatim, and analyzed using thematic content analysis techniques. External motivators were identified as resource availability and significant others to include family and associates. Internal motivators were identified as perceived disability and death from an illness and unrelieved symptoms. For most men, seeking care was done after all other measures failed to relieve symptoms. Interventions that will facilitate health seeking behavior in African-American men are needed in order to impact the health disparity. This study identified motivators needed to encourage health seeking behavior in African-American men. The results can be used to develop programs specifically targeting African-American men. Additionally, the study identified key variables for further investigation.

Adult↗