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Jacques SDM, Leynaud O, Strusevich D, Beale AM, Sankar G, Martin CM, Barnes P. Redox Behavior of Fe-Mo-O Catalysts Studied by Ultrarapid In Situ Diffraction. Angew Chem Int Ed Engl 2006; 45:445-8. [PMID: 16323232 DOI: 10.1002/anie.200502897] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Winter R, Messurier DL, Martin CM. Energy-dependentin situsmall-angleX-ray scattering study of nano-ceramics. CRYSTALLOGR REV 2006. [DOI: 10.1080/08893110600688964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Page AJ, Brierley SM, Martin CM, Price MP, Symonds E, Butler R, Wemmie JA, Blackshaw LA. Different contributions of ASIC channels 1a, 2, and 3 in gastrointestinal mechanosensory function. Gut 2005; 54:1408-15. [PMID: 15987792 PMCID: PMC1774697 DOI: 10.1136/gut.2005.071084] [Citation(s) in RCA: 221] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIMS Members of the acid sensing ion channel (ASIC) family are strong candidates as mechanical transducers in sensory function. The authors have shown that ASIC1a has no role in skin but a clear influence in gastrointestinal mechanotransduction. Here they investigate further ASIC1a in gut mechanoreceptors, and compare its influence with ASIC2 and ASIC3. METHODS AND RESULTS Expression of ASIC1a, 2, and 3 mRNA was found in vagal (nodose) and dorsal root ganglia (DRG), and was lost in mice lacking the respective genes. Recordings of different classes of splanchnic colonic afferents and vagal gastro-oesophageal afferents revealed that disruption of ASIC1a increased the mechanical sensitivity of all afferents in both locations. Disruption of ASIC2 had varied effects: increased mechanosensitivity in gastro-oesophageal mucosal endings, decreases in gastro-oesophageal tension receptors, increases in colonic serosal endings, and no change in colonic mesenteric endings. In ASIC3-/- mice, all afferent classes had markedly reduced mechanosensitivity except gastro-oesophageal mucosal receptors. Observations of gastric emptying and faecal output confirmed that increases in mechanosensitivity translate to changes in digestive function in conscious animals. CONCLUSIONS These data show that ASIC3 makes a critical positive contribution to mechanosensitivity in three out of four classes of visceral afferents. The presence of ASIC1a appears to provide an inhibitory contribution to the ion channel complex, whereas the role of ASIC2 differs widely across subclasses of afferents. These findings contrast sharply with the effects of ASIC1, 2, and 3 in skin, suggesting that targeting these subunits with pharmacological agents may have different and more pronounced effects on mechanosensitivity in the viscera.
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Ríos S, Martin CM, Whittle KR. On the nanostructure of radiation-amorphized zircon and pyrochlores: a small-angle x-ray scattering study. Z KRIST-CRYST MATER 2005. [DOI: 10.1524/zkri.220.8.748.67082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Nanoscale structural features of amorphous zircon and pyrochlore produced by self-irradiation induced amorphization have been characterized by small-angle X-ray scattering (SAXS). Electron density fluctuations were observed in the untreated samples and studied as a function of annealing temperature (up to 1300 °C). In untreated zircon, density fluctuations were found to have a characteristic length-scale of approximately 1 nanometer diameter. A clear scattering maximum develops at ∼3 nm–1 as a function of the degree of damage, but only for amorphous fractions higher than 70%. For the untreated pyrochlore sample such a strong signal was not observed in the scattering function. As annealing temperature increases, phase segregation is observed in zircon with a clear nucleation at 850 °C of zirconia grains. The SAXS contribution, however, points towards a lower nucleation temperature, ca. 700 °C. In the pyrochlore structure, at temperatures as low as 300 °C the appearance of a first crystalline phase, Ca2Nb2O7, is observed, with the subsequent crystallization of TiO2 at 800 °C. Observed electron density variations are compared between the two structures and discussed in terms of nanoscale phase segregation phenomena.
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Murphy N, Ring M, Heffron CCBB, King B, Killalea AG, Hughes C, Martin CM, McGuinness E, Sheils O, O'Leary JJ. p16INK4A, CDC6, and MCM5: predictive biomarkers in cervical preinvasive neoplasia and cervical cancer. J Clin Pathol 2005; 58:525-34. [PMID: 15858126 PMCID: PMC1770660 DOI: 10.1136/jcp.2004.018895] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To analyse and compare expression patterns of three potential biomarkers-p16(INK4A), CDC6, and MCM5-and evaluate their use as predictive biomarkers in squamous and glandular cervical preinvasive neoplasia. METHODS Immunocytochemical analysis of p16(INK4A), MCM5, and CDC6 expression was performed on 20 normal, 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, 10 squamous cell carcinoma, 19 cervical glandular intraepithelial neoplasia (cGIN), and 10 adenocarcinoma samples. Staining intensity was assessed using a 0-3 scoring system. p16(INK4A), MCM5, and CDC6 expression was also examined in ThinPrep slides exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) was detected using a modified SYBR green assay. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing. RESULTS All three markers showed a linear correlation between expression and grade of dysplasia. p16(INK4A) and MCM5 protein expression was upregulated in all grades of squamous and glandular dysplasia. CDC6 protein was preferentially expressed in high grade lesions and in invasive squamous cell carcinoma. CONCLUSION p16(INK4A) expression was closely associated with high risk HPV infection-all grades of squamous and glandular cervical lesions were immunohistochemically positive. MCM5 staining intensity was independent of high risk HPV infection, highlighting its potential as a biomarker in both HPV dependent and independent cervical dysplasia. CDC6 may be a biomarker of high grade and invasive lesions of the cervix, with limited use in low grade dysplasia. p16(INK4A) was the most reliable marker of cervical dysplasia. Combinations of dysplastic biomarkers may be useful in difficult diagnostic cases.
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Goodwin CS, Raftery EB, Goldberg AD, Skeggs H, Till AE, Martin CM. Effects of rate of infusion and probenecid on serum levels, renal excretion, and tolerance of intravenous doses of cefoxitin in humans: comparison with cephalothin. Antimicrob Agents Chemother 2005; 6:338-46. [PMID: 15830485 PMCID: PMC444649 DOI: 10.1128/aac.6.3.338] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using a randomized crossover design, 1-g intravenous doses of cephalothin and cefoxitin, a cephalosporinase-resistant cephamycin, were infused into 12 normal adult males over periods of 120, 30, and 3 min, the last with and without prior intravenous infusions of probenecid (1 g). Mean peak serum concentrations of antibiotic activity after cephalothin infusions were 23, 56, 103, and 102 mug/ml, respectively, and after cefoxitin infusions they were 27, 74, 115, and 125 mug/ml, respectively. Probenecid treatment prolonged the terminal serum half-life of cephalothin-like activity from 0.52 to 1.0 h, and of cefoxitin from 0.68 to 1.4 h. In contrast to cephalothin, which was found to be metabolized about 25% to the less active desacetyl form, cefoxitin was metabolized less than 2% to the virtually inactive descarbamyl form, as judged from urinary recoveries. Neither antibiotic displayed detectable organ toxicity. Of 300 recent clinical isolates of gram-negative bacilli other than Pseudomonas spp., 83% were susceptible to cephalothin but 95% were susceptible to cefoxitin. Organisms resistant to cephalothin but susceptible to cefoxitin included strains of Escherichia coli, Proteus vulgaris, Klebsiella spp., Serratia marcescens, Enterobacter spp., and Bacteroides spp.
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Page AJ, Brierley SM, Martin CM, Martinez-Salgado C, Wemmie JA, Brennan TJ, Symonds E, Omari T, Lewin GR, Welsh MJ, Blackshaw LA. The ion channel ASIC1 contributes to visceral but not cutaneous mechanoreceptor function. Gastroenterology 2004; 127:1739-47. [PMID: 15578512 DOI: 10.1053/j.gastro.2004.08.061] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Visceral mechanoreceptors are critical for perceived sensations and autonomic reflex control of gastrointestinal function. However, the molecular mechanisms underlying visceral mechanosensation remain poorly defined. Degenerin/epithelial Na+ channel (DEG/ENaC) family ion channels are candidate mechanosensory molecules, and we hypothesized that they influence visceral mechanosensation. We examined the influence of the DEG/ENaC channel ASIC1 on gastrointestinal mechanosensory function, on gastric emptying, and on fecal output. We also compared its role in gastrointestinal and somatic sensory function. METHODS To assess the role of ASIC1 we studied wild-type and ASIC1-/- mice. Reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis determined expression of ASIC1 messenger RNA and protein in vagal and spinal sensory ganglia. Colonic, gastroesophageal, and cutaneous afferent fibers were characterized by functional subtype and their mechanical stimulus-response relationships were determined. Gastric emptying was determined by using a 13CO2 breath test. Behavioral tests assessed somatic mechanical and thermal sensitivity. RESULTS ASIC1 was expressed in sensory ganglia and was lost after disruption of the ASIC1 gene. Loss of ASIC1 increased mechanosensitivity in all colonic and gastroesophageal mechanoreceptor subtypes. In addition, ASIC1-/- mice showed almost double the gastric emptying time of wild-type mice. In contrast, loss of ASIC1 did not affect function in any of the 5 types of cutaneous mechanoreceptors, nor did it affect paw withdrawal responses or fecal output. CONCLUSIONS ASIC1 influences visceral but not cutaneous mechanoreceptor function, suggesting that different mechanisms underlie mechanosensory function in gut and skin. The role of ASIC1 is highlighted by prolonging gastric emptying of a meal in ASIC1-/- animals.
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d'Almeida MS, White M, Martin CM, Sibbald WJ, Chin-Yee IH. Effect of haemodilution with diaspirin cross-linked haemoglobin on the oxygen reserve in a rodent model of surgical blood loss. Transfus Med 2003; 13:293-301. [PMID: 14617340 DOI: 10.1046/j.1365-3148.2003.00456.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The efficacy of pre-operative haemodilution is limited by the reduction in haemoglobin concentration. Acellular haemoglobin-based oxygen carriers provide an alternative to colloid as a haemodiluent, potentially extending the safe limits of this procedure. The aim of this investigation was to determine whether haemodilution with a cross-linked haemoglobin solution, diaspirin cross-linked haemoglobin solution (DCLHb), would enhance the oxygen reserve compared to pentastarch. Sprague Dawley rats were placed in a metabolic box to directly measure systemic oxygen consumption (VO2). Rats were randomized to be haemodiluted to a cellular haemoglobin of 80 g L(-1) with either DCLHb or pentastarch. Oxygen reserve was assessed during isovolemic haemorrhage by determining the critical oxygen delivery (DO2crit) and haemoglobin concentration at the point of oxygen supply dependency (OSD). Following haemodilution and for the duration of the experiment, cardiac index (CI) was significantly lower and systemic vascular resistance was significantly higher in the DCLHb than the pentastarch group. The DO2crit (3.2 +/- 0.4 mL minAg(-1) and 3.4 +/- 0.5 mL minAg(-1), DCLHb versus pentastarch) and cellular haemoglobin concentration (51 +/- 9 g L(-1) and 48 +/- 9 g L(-1)), at which rats entered OSD were similar in both groups. Total haemoglobin concentration (cellular and plasma DCLHb) and arterial oxygen content were significantly higher in the DCLHb group (total haemoglobin, 66 +/- 8 g L(-1) and arterial content, 9.2 +/- 1.4 mL dL(-1)) compared to the pentastarch group (total haemoglobin, 48 +/- 9 g L(-1) and arterial content, 7.3 +/- 1.4 mL dL(-1)). Oxygen extraction ratios increased from baseline levels to 0.53 +/- 0.07 and 0.56 +/- 0.1, for the DCLHb and pentastarch groups, respectively, and were not significantly different. The increase in arterial oxygen content from DCLHb in plasma was offset by the decrease in CI observed in this group. Plasma DCLHb did not extend the limits of haemodilution beyond the capacity of the cellular haemoglobin concentration.
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Martin CM, Uhlmann V, Killalea A, Sheils O, O'Leary JJ. Detection of measles virus in children with ileo-colonic lymphoid nodular hyperplasia, enterocolitis and developmental disorder. Mol Psychiatry 2003; 7 Suppl 2:S47-8. [PMID: 12142949 DOI: 10.1038/sj.mp.4001179] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Page AJ, Martin CM, Blackshaw LA. Vagal mechanoreceptors and chemoreceptors in mouse stomach and esophagus. J Neurophysiol 2002; 87:2095-103. [PMID: 11929927 DOI: 10.1152/jn.00785.2001] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We used a novel in vitro mouse vagus-gastro-esophageal preparation to study the properties of peripheral vagal afferent endings. We found two types of mechanoreceptive fiber, mucosal receptors and tension receptors. These were distinguished by their sensitivity to mucosal stroking with von Frey hairs and circular tension applied via a claw-cantilever system. A comparison was made with gastro-esophageal afferents found in a similar preparation of ferret tissue. Responses of mouse tension receptors to circular tension were significantly greater than ferret tension and tension/mucosal receptors. Similarly the responses of mouse mucosal receptors to mucosal stroking were significantly greater than ferret mucosal and tension/mucosal receptors. Forty-seven percent of mouse mucosal receptors and 50% of tension receptors responded to one or more drugs or chemical stimuli applied to the receptive field. These included alpha,beta-methylene ATP (10(-6) to 10(-3) M), 5-hydroxytryptamine (10(-6) to 10(-3) M), and hydrochloric acid (10(-2) to 10(-1) M). Drug responses were concentration dependent. One hundred percent of mucosal receptors and 61% of tension receptors tested responded to bile (1:8 to 1:1 dilution). A third type of fiber was recruited by bile. These fibers were mechanically insensitive and silent prior to bile exposure. In conclusion, we have shown three types of gastro-esophageal vagal afferent fibers in the mouse: mucosal mechanoreceptors, tension receptors, and specific chemoreceptors activated by bile.
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Uhlmann V, Martin CM, Sheils O, Pilkington L, Silva I, Killalea A, Murch SB, Walker-Smith J, Thomson M, Wakefield AJ, O'Leary JJ. Potential viral pathogenic mechanism for new variant inflammatory bowel disease. Mol Pathol 2002; 55:84-90. [PMID: 11950955 PMCID: PMC1187154 DOI: 10.1136/mp.55.2.84] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS A new form of inflammatory bowel disease (ileocolonic lymphonodular hyperplasia) has been described in a cohort of children with developmental disorder. This study investigates the presence of persistent measles virus in the intestinal tissue of these patients (new variant inflammatory bowel disease) and a series of controls by molecular analysis. METHODS Formalin fixed, paraffin wax embedded and fresh frozen biopsies from the terminal ileum were examined from affected children and histological normal controls. The measles virus Fusion (F) and Haemagglutinin (H) genes were detected by TaqMan reverse transcription polymerase chain reaction (RT-PCR) and the Nucleocapsid (N) gene by RT in situ PCR. Localisation of the mRNA signal was performed using a specific follicular dendritic cell antibody. RESULTS Seventy five of 91 patients with a histologically confirmed diagnosis of ileal lymphonodular hyperplasia and enterocolitis were positive for measles virus in their intestinal tissue compared with five of 70 control patients. Measles virus was identified within the follicular dendritic cells and some lymphocytes in foci of reactive follicular hyperplasia. The copy number of measles virus ranged from one to 300,00 copies/ng total RNA. CONCLUSIONS The data confirm an association between the presence of measles virus and gut pathology in children with developmental disorder.
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Ostermann M, Alvarez G, Sharpe M, Martin C. Crit Care 2002; 6:P177. [DOI: 10.1186/cc1637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Morita Y, Yu P, Martin CM. An alternative thermodilution method to measure cardiac output in a rat model of stagnant hypoxia. Shock 2000; 14:550-4. [PMID: 11092688 DOI: 10.1097/00024382-200014050-00009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Rats are often used to study hemodynamics in animal research. We have established an alternative method to measure cardiac output in a conscious rat using a thermodilution technique via a left ventricular injection. The validity of this method was evaluated in conscious rats and compared with the results obtained using the radiolabeled microspheres (reference sample method). Using 20 male Sprague-Dawley rats, a baseline cardiac index was measured by thermodilution to determine the baseline cardiac index and to evaluate between animal variability. The baseline cardiac index was compared to the reference sample method with 6 rats. Following baseline measurements, an intra-atrial balloon was inflated in a stepwise manner to create 2 to 3 different cardiac outputs, and the cardiac index was computed. For each measurement, the cardiac index was first measured by thermodilution and immediately followed by the reference sample method. A total of 21 measurements were obtained, and the results were analyzed by a Bland-Altman plot and the correlation coefficient was calculated. Although the agreement between the two methods was poor, both methods had a good correlation (r2 = 0.59). With the thermodilution technique, we demonstrated a small coefficient of variation in each measurement, with a low intra-animal and inter-animal variability. As there is no gold standard method to measure cardiac output in rats, we believe that left ventricular thermodilution is a reliable method, and overcomes several technical difficulties such as heat loss, one of the significant limitations of the conventional thermodilution method (via right atrial injection). This new thermodilution technique (via the left ventricle) is therefore an attractive alternative method to measure cardiac output in rats.
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Sielenkämper AW, Yu P, Eichelbrönner O, MacDonald T, Martin CM, Chin-Yee IH, Sibbald WJ. Diaspirin cross-linked Hb and norepinephrine prevent the sepsis-induced increase in critical O(2) delivery. Am J Physiol Heart Circ Physiol 2000; 279:H1922-30. [PMID: 11009481 DOI: 10.1152/ajpheart.2000.279.4.h1922] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We hypothesized that support of arterial perfusion pressure with diaspirin cross-linked Hb (DCLHb) would prevent the sepsis-induced attenuation in the systemic O(2) delivery-O(2) uptake relationship. Awake septic rats were treated with a chronic infusion of DCLHb or a reference treatment [norepinephrine (NE)] to increase mean arterial pressure by 10-20% over 18 h. Septic and sham control groups received normal saline. Isovolemic hemodilution to create anemic hypoxia was then performed in a metabolic box during continuous measurement of systemic O(2) uptake. O(2) delivery was calculated from hemodynamic variables, and the critical point of O(2) delivery (DO(2 crit)) was determined using piecewise regression analysis of the O(2) delivery-O(2) uptake relationship. Sepsis increased DO(2 crit) from 4.99 +/- 0.17 to 6.69 +/- 0.42 ml x min(-1) x 100 g(-1) (P < 0.01), while O(2) extraction capacity was decreased (P < 0.05). DCLHb and NE infusion prevented the sepsis-induced increase in DO(2 crit) [4.56 +/- 0.42 ml x min(-1) x 100 g(-1) (P < 0.01) and 5.04 +/- 0.56 ml x min(-1) x 100 g(-1) (P < 0.05), respectively]. This was explained by a 59% increase in O(2) extraction capacity in the DCLHb group compared with septic controls (P < 0.05), whereas NE treatment decreased systemic O(2) uptake in anemic hypoxia (1.51 +/- 0.08 vs. 1.87 +/- 0.1 ml x min(-1) x 100 g(-1) in septic controls, P < 0.05). We conclude that DCLHb ameliorated O(2) extraction capacity in the septic microcirculation, whereas NE decreased the metabolic demands of the tissues.
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Eastham JA, Grafton W, Martin CM, Williams BJ. Suppression of primary tumor growth and the progression to metastasis with p53 adenovirus in human prostate cancer. J Urol 2000; 164:814-9. [PMID: 10953161 DOI: 10.1097/00005392-200009010-00055] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE Numerous advances have been made in gene therapy approaches for the treatment of solid tumors, including prostate cancer. While treatment of the primary tumor has been well investigated, little information is available regarding gene therapy techniques which might impact on the progression to metastatic disease. We investigate the ability of p53 adenovirus to suppress not only primary tumor growth, but also the progression to metastatic disease. Mutation of the p53 tumor suppressor gene has been associated with the progression of prostate cancer. In this study, we utilized a metastatic model for human prostate cancer to determine if introduction of the wild-type p53 gene using an adenoviral vector (rAd-p53) impacted on primary tumor growth as well as the progression to metastatic disease. MATERIALS AND METHODS For our studies, we used the human prostate cancer cell line PC-3, which has a homozygous loss of p53 expression. Expression of exogenous p53 as well as p21 induction at various time points after infection with rAd-p53 was determined in vitro. In vivo studies were performed in nude mice following orthotopic (intraprostatic) injection of PC-3 cells. Primary tumor growth as well as the progression to metastatic disease was assessed following rAd-p53 treatment. RESULTS In vitro studies demonstrated high levels of p53 gene expression as well as the induction of p21 gene expression. Infection of PC-3 cells with rAd-p53 resulted in marked growth inhibition, as well as wide-spread fragmentation of nuclei and secretion of nuclear matrix proteins into the culture medium consistent with the process of apoptosis. In vivo studies demonstrated that a single injection of rAd-p53 into an established orthotopic prostate tumor resulted not only in primary tumor growth suppression (treated = 97.5 +/- 25.3 mm.3 versus control = 393.4 +/- 67.2 mm.3; p = 0.0002) but also reduced the frequency of progression to metastatic disease (treated = 8 of 19 versus control = 18 of 19; p = 0.001). CONCLUSION These experiments demonstrate that a single injection of rAd-p53 into an established orthotopic prostate tumor results not only in suppression of primary tumor growth, but also in a reduction of the frequency of progression to metastatic disease. These results suggest that a rAd-p53 gene therapy strategy may be useful in the treatment of human prostate cancer.
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Yu P, Martin CM. Increased gut permeability and bacterial translocation in Pseudomonas pneumonia-induced sepsis. Crit Care Med 2000; 28:2573-7. [PMID: 10921597 DOI: 10.1097/00003246-200007000-00065] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Gut injury and barrier dysfunction may contribute to the pathogenesis of sepsis and multiple organ dysfunction syndrome. The objective of this study was to determine whether gut injury could be demonstrated in hyperdynamic, normotensive sepsis induced by Pseudomonas pneumonia. DESIGN Randomized animal study. SETTING University laboratory. SUBJECTS Adult male Sprague-Dawley rats. INTERVENTIONS Sepsis was induced by intratracheal instillation of Pseudomonas aeruginosa. MEASUREMENTS AND MAIN RESULTS We measured gut mucosal and microvascular injury. In the first experiment, gut mucosal permeability was measured by 51Cr-EDTA uptake in control (n = 6), pneumonia 20-hr (n = 4), and pneumonia 40-hr (n = 4) groups. In the second experiment, microvascular permeability was measured by albumin extravasation, and morphologic abnormalities were scored in control (n = 6), pneumonia 20-hr (n = 9), and pneumonia 40-hr (n = 11) groups. Bacterial translocation to mesenteric lymph nodes was determined in both experiments. Cardiac index increased significantly in the pneumonia compared with control rats (64+/-2.1, 68+/-1.3, vs. 46+/-2 mL/min/100 g, p < .05; all results are listed in the order of pneumonia 20-hr, pneumonia 40-hr, and control groups as mean +/- SEM). Mean blood pressure was normal and was not different between groups (112+/-3, 111+/-2, vs. 118+/-2 mm Hg). 51Cr-EDTA recovery in urine 6 hrs after gavage increased significantly in both pneumonia groups vs. controls (17.5+/-2.2%, 17.9+/-7%, vs. 4+/-0.7%; p < .05). Albumin leak (tissue/plasma ratio) increased significantly in the middle and distal small intestine in the pneumonia 40-hr group vs. controls (0.68+/-0.05, 0.76+/-0.07, vs. 0.45+/-0.04, p < .05 in the middle small gut; 0.75+/-0.09, 0.85+/-0.07, vs. 0.51+/-0.05, p < .05 in the distal small gut). Bacterial translocation to mesenteric lymph nodes increased significantly in pneumonia 40-hr rats vs. controls (positive culture 67% vs. 8%; p < .05). CONCLUSIONS This study demonstrates gut mucosal and microvascular injury and gut barrier dysfunction in normotensive sepsis secondary to bacterial pneumonia. The mechanism and significance of the injury need to be determined.
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Lacomba MS, Martin CM, Chamond RR, Galera JM, Omar M, Estevez EC. Aqueous and serum interferon gamma, interleukin (IL) 2, IL-4, and IL-10 in patients with uveitis. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2000; 118:768-72. [PMID: 10865312 DOI: 10.1001/archopht.118.6.768] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To determine the cytokine profile in aqueous humor and peripheral blood from patients with uveitis. METHODS Cytokines (interferon [IFN]-gamma, interleukin [IL] 2, IL-4, and IL-10) were measured in aqueous humor and peripheral blood samples from 23 patients with uveitis and 16 patients undergoing operation for uncomplicated cataracts (control group) by means of an enzyme-linked immunosorbent assay. RESULTS Aqueous and serum samples from patients with uveitis showed higher levels of IFN-gamma and IL-2 than those of controls (P<.001). Similarly, serum IL-10 levels were slightly higher in the uveitis group (P=.002). No differences were found between uveitis and control groups for aqueous and serum IL-4 or aqueous IL-10 levels. In patients with uveitis, IFN-gamma levels were significantly higher in serum than aqueous (P<.001), whereas IL-2 levels were higher in aqueous than in serum (P<.001). Serum IFN-gamma levels correlated with severe visual damage (r=0.44; P=. 03). CONCLUSIONS Aqueous and serum levels of IFN-gamma and IL-2 were elevated in patients with uveitis, suggesting a predominantly type 1 response (high IFN-gamma and low IL-4 levels). Elevated serum IFN-gamma level seems to predispose the patient to more serious loss of vision. Arch Ophthalmol. 2000;118:768-772
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Geng NF, Goh PG, Johnson BF, Martin CM, Shephard DS, Zhou W. Nanoscale Super Clusters of Clusters Assembled around a Dendritic Core We thank the Royal Society (Smithson Research Fellowship at Peterhouse to D.S.S.), The Singapore Government (P.G.G.), and ICI Wilton for financial support, and Dr. S. J. Teat at the Daresbury SRS (UK) for assistance in crystallography. Angew Chem Int Ed Engl 2000; 39:1661-1664. [PMID: 10820469 DOI: 10.1002/(sici)1521-3773(20000502)39:9<1661::aid-anie1661>3.0.co;2-h] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Martin CM, Lacomba MS, Molina CI, Chamond RR, Galera JM, Estevez EC. Levels of soluble ICAM-1 and soluble IL-2R in the serum and aqueous humor of uveitis patients. Curr Eye Res 2000; 20:287-92. [PMID: 10806443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
PURPOSE To study the ocular and systemic behaviour of the immune activation markers soluble ICAM-1 and soluble IL-2R in patients with active uveitis. METHODS We determined the levels of soluble ICAM-1 and soluble IL-2R in the aqueous humor and peripheral blood of 23 patients with active uveitis and 16 age and gender matched controls (who were to undergo cataract extraction) by means of ELISA enzyme immunoanalysis. RESULTS Patients with uveitis presented higher levels of soluble ICAM-1 and soluble IL-2R in the aqueous humor and peripheral blood. Comparison of the aqueous humor and peripheral blood revealed higher levels of soluble ICAM-1 in the aqueous humor, while we found no differences for soluble IL-2R. Analysis of the clinical characteristics of the uveitis we studied showed no differences in the levels of these markers in either blood or aqueous humor. CONCLUSIONS The finding of elevated levels of soluble IL-2R and soluble ICAM-1 in the aqueous humor and peripheral blood of patients with uveitis suggests the local and systemic participation of these markers in the pathogenesis of uveitis.
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Sielenkämper AW, Eichelbrönner O, Martin CM, Madorin SW, Chin-Yee IH, Sibbald WJ. Diaspirin cross-linked hemoglobin improves mucosal perfusion in the ileum of septic rats. Crit Care Med 2000; 28:782-7. [PMID: 10752830 DOI: 10.1097/00003246-200003000-00029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the effect of a bolus infusion of diaspirin cross-linked hemoglobin (DCLHb or hemoglobin crosfumaril) on the ileal mucosal microcirculation in septic rats. DESIGN Prospective, randomized, single-blinded study. SETTING University-affiliated animal research laboratory. SUBJECTS Twenty-four male Sprague-Dawley rats, weighing 320-380 g. INTERVENTIONS Under inhalational anesthesia, arterial and venous catheters were inserted and sepsis was created by cecal ligation and perforation (CLP). Twenty-four hours later, animals were reanesthetized and ventilated. Via midline abdominal incision, the ileum was mobilized and prepared for intravital microscopy. Post-CLP hemodynamic values were obtained, and videomicroscopy was performed on four to ten villi. Animals were then randomized to receive 2 mL of DCLHb solution (100 mg/mL; n = 12) or pentastarch (n = 12) intravenously, and measurements were repeated after 20 mins. Rats treated with DCLHb then received nitroprusside to restore mean arterial pressure to post-CLP levels, and final measurements were obtained 15 mins later. MEASUREMENTS AND MAIN RESULTS Cardiac index increased with both treatments (p < .001), whereas systemic vascular resistance index and mean arterial blood pressure were augmented only with DCLHb (p < .0001 compared with pentastarch). Intercapillary areas (ICA; inversely related to capillary density) were determined using computerized image analysis. ICA size decreased after treatment, from 974 +/- 79 to 791 +/- 106 microm2 with DCLHb and from 1044 +/- 90 to 840 +/- 82 microm2 with pentastarch (both p < .05). Red blood cell velocity in terminal arterioles, as assessed by velocimetry from the recorded images, increased by 15% with both treatments (p < .05). Restoration of mean arterial pressure to post-CLP levels in DCLHb animals by nitroprusside infusion abolished the effects of the hemoglobin solution on ICA size and red blood cell velocity. CONCLUSION Both DCLHb and pentastarch infusion improved microcirculatory perfusion in the ileum of septic rats. In addition, DCLHb also exhibited vasopressor properties, which in combination with improved perfusion may be particularly useful in the treatment of sepsis.
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Keenan SP, Martin CM, Kossuth JD, Eberhard J, Sibbald WJ. The Critical Care Research Network: a partnership in community-based research and research transfer. J Eval Clin Pract 2000; 6:15-22. [PMID: 10807020 DOI: 10.1046/j.1365-2753.2000.00214.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The objectives of this study were to present a short history of the Critical Care Research Network (CCR-Net), describe its approach to health services research and to summarize completed and current research projects. In doing this, we explored the question is this research network accomplishing its goals? We reviewed the medical literature to identify studies on similar types of Networks and also the evidence supporting the methodology used by CCR-Net to conduct research using MEDLINE, HEALTHSTAR, CINAHL and the keywords network and health care or healthcare, benchmarking and health care or healthcare, and research transfer or research utilization. We also reviewed the bibliographies of retrieved articles and our personal files. In addition, we summarized the results of studies conducted by CCR-Net and outlined those currently in progress. A review of the literature identified studies on two similar networks that appeared to be succeeding. In addition, the literature was also supportive of the general process used by CCR-Net, although the level of evidence varied. Finally, the studies conducted to date within CCR-Net follow the suggested methodology. At the time of this preliminary communication CCR-Net appears to have adopted a valid approach to health services research within the area of Critical Care Medicine. Further direct evidence is required and appropriate studies are planned.
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Martin CM. Consultation length and chronic illness care in general practice. Med J Aust 2000; 172:94-6. [PMID: 10738488 DOI: 10.5694/j.1326-5377.2000.tb139216.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Bloos F, Martin CM, Ellis CG, Sibbald WJ. Effects of modest anemia on systemic and coronary circulation of septic sheep. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:H2195-204. [PMID: 10600837 DOI: 10.1152/ajpheart.1999.277.6.h2195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although a lower transfusion trigger is generally recommended, little evidence is available about the physiological mechanisms of mild anemia in diseases with an imbalance between O2 supply and O2 demand such as sepsis. This study was undertaken to describe the systemic and coronary metabolic O2 reserve in an awake sheep model of hyperdynamic sepsis comparing two different hemoglobin levels. Twenty-four hours after sheep were rendered septic by cecal ligation and perforation (CLP), blood transfusion (n = 7, hemoglobin = 120 g/l) and isovolemic hemodilution (n = 8, hemoglobin = 70 g/l), respectively, were performed. Another 24 h later, we measured hemodynamics, organ blood flows, and systemic and myocardial O2 metabolism variables at baseline and through four stages of progressive hypoxia. Maximum coronary blood flow was 766.3 +/- 87.4 ml. min(-1). 100 g(-1) in hemodiluted sheep group versus 422.7 +/- 53.7 ml. min(-1). 100 g(-1) in the transfused sheep (P < 0.01). Myocardial O2 extraction was higher in the transfusion group (P = 0.03) throughout the whole hypoxia trial. In the hemodilution group, coronary blood flow increased more per increase in myocardial O(2) uptake than in transfused sheep (P < 0.01). This was accompanied by a lower left ventricular epicardial-to-endocardial flow ratio in hemodiluted sheep (1.13 +/- 0.07) than in transfused sheep (1.34 +/- 0.02, P < 0.05). We conclude that the lower coronary blood flow and greater myocardial O2 extraction in transfused septic sheep preserves transmyocardial O2 metabolism better in comparison to hemodiluted sheep.
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