Biomedical subjects

E J Miller

Publications and source records attributed to E J Miller.

At least 19 recordsLinked to original sources

PubMed2004

Mycoplasma arthritidis bacteriophage MAV1 prophage integration, deletions, and strain-related polymorphisms.

Temperate bacteriophage MAV1 is found in certain highly virulent strains of Mycoplasma arthritidis. Integration sites, portions of the right and left prophage ends, and flanking DNA from eight prophages in seven M. arthritidis strains were characterized in this study. attb and attp sites conformed for the most part to the consensus sequence TATTTTT, although minor polymorphisms were noted. Prophages were integrated into similar sites in four strains, suggesting that these strains may have had a common ancestor. Two strains had three prophage copies each, and integration sites were identical. Two strains had two copies each. One of these shared two of the integration sites occupied in the three-copy strains, while the other shared one of these sites and harbored a second prophage in a unique site. Integration sites in the two strains with one prophage each were unique. Four MAV1 copies contained extensive substitutions within a region encoding a putative structural protein and the putative repressor protein. A 3-kb fragment was deleted from the right side of two of these copies. It is proposed that polymorphisms within MAV1 prophage integration sites and within the prophages themselves may help to identify phylogenetic relationships among virulent M. arthritidis strains.

Amino Acid Sequence↗

PubMed2002

Pseudomonas aeruginosa elastase stimulates ERK signaling pathway and enhances IL-8 production by alveolar epithelial cells in culture.

OBJECTIVE AND DESIGN: Bacterial products as well as the host airway inflammatory responses contribute to the pathogenesis of Pseudomonas infections. We sought to determine if Pseudomonas elastase (PE) induces mitogen-activated protein (MAP) kinase activity in association with interleukin-8 (IL-8) production by alveolar epithelial cells. METHODS: We utilized Western blot analysis to detect phosphorylation of signaling intermediates and ELISA was used to measure IL-8 production. RESULTS: We found that PE induces phosphorylation of the extracellular signal-regulated (ERK1/2) proteins of the MAPK pathway in A549 epithelial cells. Similar results were obtained using primary cultures of rabbit alveolar type II epithelial cells. PE also enhanced IL-8 production, which was abolished in the presence of the ERK activation inhibitor U0126. CONCLUSIONS: We conclude that PE activates the ERK1/2 arm of the MAPK pathway and that activation of this pathway results in enhanced IL-8 production. The results demonstrate that PE may augment pulmonary inflammation via cellular signaling that regulates expression of IL-8.

Animals↗

PubMed2002

Antileukinate, a hexapeptide inhibitor of CXC-chemokine receptor, suppresses bleomycin-induced acute lung injury in mice.

A hexapeptide, Ac-RRWWCR-NH(2) (Antileukinate), has been reported to be a potent inhibitor of CXC-chemokine receptor. However, the in vivo anti-inflammatory activity of this agent has not been tested except in a rabbit skin edema model. This study was undertaken to investigate the effect of subcutaneously administered Antileukinate on experimental bleomycin-induced acute lung injury in mice, in which CXC-chemokines have been reported to be involved. Lung injury was assessed on the basis of histopathology, the number of total cells, the percentage of neutrophils, and protein concentration in the bronchoalveolar lavage (BAL) fluid, and the wet lung weight at 7 days after intratracheal instillation of bleomycin. Histopathological studies revealed that treatment with Antileukinate markedly suppressed inflammatory cell infiltration and interstitial lung edema. The neutrophil counts in the BAL fluid were significantly decreased in the Antileukinate-treated group. The suppression of pulmonary edema was further confirmed by the reduction of wet lung weight and total protein concentration in the BAL fluid. These findings suggest that Antileukinate is able to inhibit acute lung injury by suppressing neutrophil mobilization induced by CXC-chemokines.

Animals↗

PubMed2001

Association of IL-8 and MCP-1 with the development of reexpansion pulmonary edema in rabbits.

BACKGROUND: The aim of this study is to determine the relationships between the cytokines and the inflammatory response in reexpansion pulmonary edema (RPE). METHODS: We examined the cell population, epithelial permeability measured by Evans blue dye (EB), betaglucuronidase and cytokine concentrations in bronchoalveolar lavage fluid (BALF) and/or blood using a rabbit RPE model. RESULTS: We confirmed that RPE is characterized by recruitment of polymorphonuclear leukocytes (PMNs), the release of PMN granular contents into the air spaces, and increased vascular permeability. These findings were highly correlated with increased interleukin-8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) concentrations in the BALF. Growth related oncogene (GRO) was detected in the BALF from only 2 of the 7 reexpanded lungs while TNFalpha was not detected in any rabbits. A similar but less severe inflammatory response to the reexpanded lung was found in the contralateral lung. CONCLUSIONS: IL-8 and MCP-1 may play important roles in the development of RPE; the inflammatory response is independent of TNFalpha and unilateral reexpansion of the lung induces an inflammatory response not only in the reexpanded lung but also in the contralateral lung.

Animals↗

PubMed2001

Pryce's type I pulmonary intralobar sequestration presenting with massive hemoptysis.

Pryce's type I intralobar sequestration, in which a region of lung exhibits tracheobronchial continuity and aberrant systemic arterial supply, is most frequently asymptomatic and discovered incidentally. While hemoptysis may be a common presenting symptom, massive hemoptysis is rarely seen. We document a case of a 58-year-old man, previously asymptomatic, whose initial presentation was that of massive hemoptysis. The radiographic, intraoperative and pathologic findings in our patient confirm that his sequestration was of Pryce's type I. Ann Diagn Pathol 5:91-95, 2001.

Angiography↗

PubMed2000

alpha-Chemokine growth factors for adenocarcinomas; a synthetic peptide inhibitor for alpha-chemokines inhibits the growth of adenocarcinoma cell lines.

PURPOSE: The experiments aimed to determine if alpha-chemokine inhibitors are effective suppressors of the growth of adenocarcinomas, a neoplasm with a high mortality rate. METHODS: Expression of growth-related oncogene (GROalpha) and interleukin-8 (IL-8) was determined by enzyme-linked immunosorbent assay. Inhibition of alpha-chemokine binding to tumor cells was assessed in the presence and absence of the hexapeptide, antileukinate. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were performed to determine the effect of alpha-chemokines, monoclonal antibodies (mAb), and antileukinate on cell proliferation. Finally, antileukinate inhibition of human, lung adenocarcinoma tumor growth, was determined in BALB/c nude mice. RESULTS: All of the adenocarcinomas tested produced either GROalpha or IL-8 or both. Proliferation of lung, stomach and colon adenocarcinoma cells was inhibited by anti-GROalpha mAb and/or anti-IL-8 mAb while recombinant human GROalpha stimulated the proliferation of lung and stomach adenocarcinomas. Antileukinate inhibited GROalpha binding to specific receptors on adenocarcinoma cells and inhibited the proliferation of all adenocarcinomas tested. Colon-derived adenocarcinomas specifically bound IL-8 and this binding was also inhibited by antileukinate. Administration of antileukinate in vivo inhibited the tumor growth of adenocarcinoma A549. CONCLUSIONS: GROalpha and IL-8 are necessary for the growth of lung, stomach and colon adenocarcinomas, and can be inhibited by the hexapeptide, antileukinate. The findings suggest the possibility of using alpha-chemokine receptor inhibitors in the treatment of adenocarcinoma.

Adenocarcinoma↗

PubMed2000

Specific binding of IL-8 to rabbit alpha-macroglobulin modulates IL-8 function in the lung.

OBJECTIVE AND DESIGN: The purpose of this study was to compare chemotactic activity of IL-8 alone with that of IL-8 reacted with rabbit alpha-macroglobulins (alphaM) in vivo. METHODS: Initially the binding of recombinant human IL-8 (rhIL-8) to rabbit alphaM was studied. 125I-labeled rhIL-8 was incubated with alphaM, and electrophoresed on native 5% gels or SDS-polyacrylamide 4-20% gradient gels. Next, rhIL-8 or rhIL-8 bound to alphaM was administered via an endotracheal tube to rabbit's lungs. TREATMENT: An endotracheal tube was wedged into a segment of the lobe of each lung, and a sample instilled through the tube into this segment. After 4 h the lungs were lavaged. RESULTS: rhIL-8 bound to alphaM retained its full chemotactic activity in vitro but exhibited a diminished ability to induce the influx of neutrophils into the rabbit lung. CONCLUSIONS: The data suggest that alphaM may facilitate IL-8 clearance from the lung.

Animals↗

PubMed2000

Virulence factors from Pseudomonas aeruginosa increase lung epithelial permeability.

Pseudomonas aeruginosa infection frequently complicates lung injury and can be fatal in immunocompromised or debilitated individuals. Previous studies from our laboratory indicate that elastase from P. aeruginosa increases epithelial permeability by disrupting tight junctions between epithelial cells. Because the inflammatory reaction of the host is a prominent feature of bacterial infection, we reasoned that additional virulence factors from this organism could extend and augment the initial pulmonary injury by prompting accumulation of neutrophils. To test this hypothesis, we compared responses of guinea pigs to aerosols of elastase (PE) and lipopolysaccharide (LPS) from P. aeruginosa. After each treatment, we measured epithelial permeability and accumulation of neutrophils, interleukin 8 (IL-8), and beta-glucuronidase in epithelial lining fluid (ELF). We found that PE increased epithelial permeability, as measured by both the clearance of aerosolized radiolabeled albumin from the air spaces and the concentration of plasma albumin in epithelial lining fluid, but it was less effective than LPS at recruiting neutrophils into the lungs. In contrast, LPS had no significant effect on epithelium, but it increased the concentration of neutrophils, IL-8, and beta-glucuronidase in ELF. Increased epithelial permeability induced by PE does not cause lung inflammation, but it may facilitate the LPS-induced influx of neutrophils.

Animals↗

PubMed2000

Nutritional status of substance abusers with mandible fractures.

PURPOSE: The purposes of this study were 1) to assess the validity of patient self-report in identifying illegal substance abuse and 2) to identify nutritional deficiencies in substance abusers presenting for treatment of mandible fractures. PATIENTS AND METHODS: To address the research purposes, a prospective cohort study was conducted of patients presenting for treatment of mandible fractures. A urine drug screen was used to determine the validity of patient self-report of substance abuse. For purposes of assessing nutritional status, 2 categories of substance abusers were identified: illegal and legal (alcohol). The nutritional status was measured using various laboratory markers. RESULTS: The sample was composed of 93 subjects. Urine drug studies were available for 32 patients. Of the 22 patients who denied illegal drug use, 12 (55%) had a positive drug screen. Of the 10 patients reporting a positive history of illicit drug use, 7 (70%) had a positive urine drug screen (P = .47). A positive correlation was found between alcohol exposure and serum aspartate aminotransferase, mean corpuscular volume, and lactate dehydrogenase. Positive drug screens also were associated with increased serum ferritin levels. CONCLUSIONS: The results of this study suggest that patient self-report of illicit drug use may be unreliable. The findings also suggest that legal and illegal substance abusers presenting for treatment of mandible fractures have minimal nutritional deficiencies.

Adult↗

PubMed2000

Power frequency magnetic field exposure and gap junctional communication in Clone 9 cells.

Exposure to a power-frequency magnetic field has been reported to produce a statistically significant inhibition of gap junctional communication (GJC) in Clone 9 cells that have been pre-stressed by treatment with low concentrations of chloral hydrate (CH) [C.F. Blackman, J.P. Blanchard, S.G. Benane, D.E. House, J.A. Elder, Double blind test of magnetic field effects on neurite outgrowth, Bioelectromagnetics, 19 (1998) 204-209]. This observation might provide mechanistic insight into the possible role of electromagnetic fields (EMFs) in the carcinogenic process, since cancer cells frequently show decreased or absent GJC, and tumor promoting chemicals have been observed to inhibit GJC. Magnetic field exposure conditions were 45 Hz, 23.8 microT rms + parallel DC 36.6 microT, for 30 min of exposure. The responses of Clone 9 cells to the GJC-inhibiting effects of the tumor promoter 12-O-tetradecanoylphorbol 13-acetate and the chemical CH were evaluated and compared to reported results [S.G. Benane, C.F. Blackman, D.E. House, Effects of perchloroethylene and its metabolites on intercellular communication in Clone 9 rat liver cells, J. Toxicol. Environ. Health, 48 (1996) 427-437]. Before magnetic field exposure, cells were exposed for 24 h to either 3 (nine experiments) or 5 mM (11 experiments) CH to produce GJC of 67% or 50%, respectively, relative to unexposed controls. GJC was assessed microscopically using the scrape-loading technique and a blinded protocol. No statistically significant effect was observed due to magnetic field exposure with either CH concentration.

Animals↗

PubMed2000

Modulation by pentobarbital of neutrophil responses to inhaled E. coli endotoxin in sheep: role of lung epithelium.

Neutrophils (PMNs) are implicated in the pathogenesis of acute respiratory distress syndrome (ARDS). The role of the epithelium in the modulation of PMN migration within the lungs was examined. Epithelial integrity and PMN concentrations in the lung air spaces and lymph were measured in sheep anaesthetized with either halothane (1-2.5%) or intravenous pentobarbital (12+/-4 mg x kg(-1) x h(-1)). Ventilation with an aerosol containing 25 mg Escherichia Coli endotoxin (lipopolysaccharide; LPS) effected neutrophil recruitment to the air spaces. Lymphatic clearance of aerosolized 99mTc-DTPA provided an index of epithelial integrity. Three hours after the deposition of LPS, the lung lining fluid of sheep anaesthetized with halothane (n=7) had 4.9+/-3.2x10(6) PMN.mL(-1), but the lung lymph had almost no PMNs (3+/-8%). Sheep anaesthetized with pentobarbital (n=6) had fewer PMNs in the air spaces (2.4+/-1.2X10(6) mL(-1)) and more PMNs in the lung lymph (30+/-20%). Control sheep (n=5) that received no LPS had almost no PMNs in the airspaces or lung lymph, regardless of the anaesthesia. Three additional sheep that remained awake after receiving LPS also had no PMNs in the lung lymph. The PMN fraction in the lung lymph correlated well with the extra-alveolar epithelial permeability measured by lymphatic clearance of aerosolized diethylenetriamine penta-acetic acid (r=0.81, p<0.001). Aerosolized lipopolysaccharide recruits neutrophils into the lungs of sheep, but they appear to remain in the airspaces unless extra-alveolar permeability is increased by agents such as pentobarbital.

Analysis of Variance↗

PubMed2000

Molecular characterization of Mycoplasma arthritidis membrane lipoprotein MAA1.

Genes encoding the Mycoplasma arthritidis surface-exposed lipoprotein MAA1 were cloned and sequenced from MAA1-expressing strains 158p10p9 and PG6, from a low-adherence (LA) variant derived from 158p10p9 that expresses a truncated version of MAA1 (MAA1Delta) and from two MAA1-negative strains, 158 and H39. The deduced amino acid sequences of maa1 from 158p10p9 and PG6 predicted, respectively, 86.5- and 86.4-kDa basic, largely hydrophilic lipoproteins with 29-amino-acid signal peptides and predicted cleavage sites for signal peptidase II (Ala-Ala-Ala downward arrowCys). The truncation in the LA variant resulted from a G-->T substitution at nucleotide 695, which created a premature stop codon. This, in turn, generated a predicted 26.6-kDa prolipoprotein (23.6 kDa after processing), consistent with an M(r) of approximately 24,000 calculated for MAA1Delta. Similarly, absence of MAA1 expression in H39 and 158 resulted from C-->A substitutions at nucleotide 208, generating premature stop codons at that site in both strains.

Amino Acid Sequence↗

PubMed1999

Inhibition of GROalpha-induced human endothelial cell proliferation by the alpha-chemokine inhibitor antileukinate.

GROalpha, an autocrine mitogenic factor for melanoma cell lines, belongs to the superfamily of alpha-chemokines. Here, we report that GROalpha stimulates the growth of human umbilical vein endothelial cells (HUVEC) in vitro, with proliferation being significantly stimulated by 100 nM recombinant human (rh) GROalpha. Proliferation was significantly inhibited by 100 microg/ml anti- human GROalpha monoclonal antibody (mAb), while excess GROalpha restored the growth. The addition of rhIL-8, rhIP-10, anti-human IL-8 or anti-human ENA-78 mAbs did not alter HUVEC proliferation. [125I]IL-8 binding to HUVEC was saturable and inhibited by non-radioactively iodinated IL-8, but not non-iodinated IL-8. [125I]GROalpha binding was also inhibited by iodinated IL-8. Since these data suggested specific binding sites for alpha-chemokines on HUVEC, we tested the effect of antileukinate, a potent alpha-chemokine receptor inhibitor, on [125I]GROalpha binding. Antileukinate inhibited GROalpha binding and suppressed HUVEC proliferation in a dose-dependent manner. Antileukinate was not cytotoxic, with no decrease in cell viability in the presence of 100 microM antileukinate. These findings suggest that GROalpha is essential for HUVEC growth factor and that antileukinate inhibits growth by preventing autocrine GROalpha receptor binding. This raises the interesting possibility of alpha-chemokine receptor inhibitors, such as antileukinate, in the treatment of cancer where angiogenesis is an important factor for tumour growth.

Antibodies, Monoclonal↗

PubMed1999

A synthetic peptide inhibitor for alpha-chemokines inhibits the tumour growth and pulmonary metastasis of human melanoma cells in nude mice.

Growth-related oncogene-alpha (GROalpha) was first described as an autocrine mitogen and growth factor for melanoma cells. More recent studies show that GROalpha, interleukin-8 (IL-8) and other members of the alpha-chemokine superfamily are also angiogenic. Therefore, we sought to determine if inhibitors of the alpha-chemokine receptor would be effective in inhibiting the tumour growth and pulmonary metastasis of human melanoma cells. We determined that melanocytes and 12 human melanoma cell lines produce both GROalpha and IL-8. The proliferation of A375SM, a highly metastatic cell line, and C8161-C were significantly increased by human recombinant GROalpha and inhibited by anti-human GROalpha monoclonal antibody. Antileukinate, a potent inhibitor of alpha-chemokine receptor binding, inhibited the binding of GROalpha to its receptors in melanocytes and all 12 melanoma cell lines tested. Antileukinate also suppressed proliferation of A375SM and C8161-C cells in a dose-dependent manner, and the suppression was not due to cytotoxic effects. Furthermore, continuous administration of antileukinate inhibited the tumour growth and pulmonary metastasis of A375SM cells in athymic BALB/c nude mice. These findings suggest that antileukinate inhibits the growth of melanoma cells by preventing GROalpha from binding to its receptors. This suggests a possible use of alpha-chemokine receptor inhibitors such as antileukinate in the treatment of malignant melanoma.

Animals↗

PubMed1999

Chemokine involvement in tetracycline-induced pleuritis.

Sclerosants such as tetracycline (TCN) have often been used in the control of malignant pleural effusions. Although the resultant inflammatory response is probably important in the ensuing pleural fibrosis, the signals responsible for the cellular influx into the pleural space following TCN instillation are not well understood. This study, therefore, sought to determine whether the chemokines interleukin-8 (IL-8), growth-related protein (Gro), and monocyte chemotactic protein-1 (MCP-1) were locally elaborated within the first 72 h following intrapleural TCN administration. TCN induced an exudative effusion with high lactate dehydrogenase activity. Although there was no significant change in the pleural fluid total leukocyte content, the median polymorphonuclear neutrophil concentration decreased from 1.067x10(6) to 2.03x10(5) cells x mL(-1) between 24 and 72 h, whereas the median macrophage concentration increased from 1.44x10(5) to 5.98x10(5) cells x mL(-1) over the same period. Furthermore, IL-8, Gro and MCP-1 concentrations decreased between 24 and 72 h. Immunocytochemistry indicated expression of IL-8 by pleural mesothelial cells 24 h, but not 72 h, following TCN administration. The data suggest that local elaboration of interleukin-8 and growth-related protein, in part of mesothelial origin, may influence neutrophil recruitment in tetracycline-induced pleuritis.

Analysis of Variance↗

PubMed1998

Staphylococcal enterotoxin A-induced injury of human lung endothelial cells and IL-8 accumulation are mediated by TNF-alpha.

Staphylococcal enterotoxin A (SEA), a superantigen produced by some strains of Staphylococcus aureus, causes a variety of clinical manifestations ranging from food poisoning to shock. S. aureus can also be associated with the development of acute respiratory distress syndrome, and SEA has been shown to cause an inflammatory reaction in the lung. Therefore, we examined possible interactions between SEA, PBMCs, polymorphonuclear cells (PMNs), and normal human lung microvascular endothelial cells (HMVEC-L), as well as the role of these interactions on the secretion of IL-8. Injury to HMVEC-L, as measured by the release of 51Cr, increased significantly when HMVEC-L were incubated with SEA and PBMCs. IL-8 was secreted by both PBMCs and HMVEC-L. The accumulation of IL-8 in the culture medium of HMVEC-L was increased by SEA in a dose-dependent manner and was directly related to the number of PBMCs present. Although neither anti-human IL-8 nor IL-1 mAb inhibited HMVEC-L cytotoxicity, anti-human TNF-alpha mAb inhibited both the cytotoxicity and IL-8 accumulation completely. When HMVEC-L were incubated with supernatants from SEA-treated PBMCs, HMVEC-L cytotoxicity was comparable with HMVEC-L incubated with SEA and PBMCs at the same time. Although high concentrations of purified PMNs induced HMVEC-L lysis in a dose-dependent manner, the effect of PMNs was not changed in the presence of SEA. These findings suggest that TNF-alpha secreted by SEA-stimulated PBMCs plays a leading role in HMVEC-L injury.

Antibodies, Monoclonal↗

PubMed1998

The risk of serious odontogenic infections in HIV-positive patients: a pilot study.

OBJECTIVE: The purpose of this study was to perform a preliminary test of the hypothesis that patients infected with the human immunodeficiency virus (HIV) have an increased risk for serious odontogenic infections in comparison with HIV-negative patients. STUDY DESIGN: To address the research purpose, we used a case-control study design. A case was a serious odontogenic infection requiring inpatient management. A control was a nonserious odontogenic infection that could be managed on an outpatient basis. The ratio of controls to cases was 2:1. HIV status was determined by record review. RESULTS: The sample was composed of 300 patients. Sixteen patients (5%) were HIV-positive. Overall, 37.5% of the HIV-positive patients had serious infections; this compared with 33% of the HIV-negative patients (odds ratio = 1.21; 95% confidence interval = 0.43-3.44; P = .79). CONCLUSIONS: The results of this pilot study suggest that HIV-positive patients do not have an increased risk for developing serious odontogenic infections.

Adult↗

PubMed1998

Growth characteristics and metastatic properties of human breast cancer xenografts in immunodeficient mice.

We evaluated the growth and metastatic potential of two human breast cancer cell lines and 16 patient-derived biopsy specimens, representing the most common histological types of breast carcinomas, upon subcutaneous implantation into severe combined immunodeficient (SCID) mice. The method of engraftment we used, based on implantation of intact tissue specimens and complete immunosuppression of the host, provided an easier system to grow human breast carcinoma specimens in mouse models and resulted in a 50% success rate of tumor take. No correlation was found between growth in SCID mice and pathological diagnosis, grading, or estrogen/progesterone receptor expression by the tumor biopsy specimen. Serial passage of the tumor fragments in SCID mice resulted in increased metastasis rates and more rapid emergence of a palpable tumor mass. A tumor from a patient with infiltrating ductal carcinoma, which grew aggressively and metastasized in 100% of the female SCID mice, was also successfully engrafted in 100% of nonobese diabetic (NOD)/SCID female mice, but systemic spread was minimal. Fragments of the same tumor grew in only 33% of male SCID mice with very limited metastases. A strong correlation (r = 0.997) was observed between tumor burden and the presence of soluble (serum) interleukin-2 receptor, a marker associated with a subset of human breast tumors. All together, these data indicate the usefulness of SCID/human breast tumor xenografts for measuring tumor progression and evaluating novel therapeutic approaches to breast cancer.

Adenocarcinoma↗