Intraoperative tissue oximetry in the human gastrointestinal tract

Sheridan, W. G.; Lowndes, R. H.; Young, Honor

doi:10.1016/s0002-9610(05)81226-7

Cited by 98 publications

(71 citation statements)

References 29 publications

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“…O 2 sensititivity is also enhanced by the fact that Giardia lacks the conventional ROS scavenging systems (26). Despite its O 2 sensitivity, in vivo the parasite is exposed to significant levels of O 2 in the luminal portion of duodenum and jejunum, where up to 50 M O 2 is present (43). Therefore, the occurrence of an efficient O 2 scavenging system is strictly required for survival and pathogenicity of Giardia.…”

Section: Discussionmentioning

confidence: 99%

The O2-scavenging Flavodiiron Protein in the Human Parasite Giardia intestinalis

Matteo

Scandurra

Testa

et al. 2008

Journal of Biological Chemistry

106

142

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The flavodiiron proteins (FDP) are widespread among strict or facultative anaerobic prokaryotes, where they are involved in the response to nitrosative and/or oxidative stress. Unexpectedly, FDPs were fairly recently identified in a restricted group of microaerobic protozoa, including Giardia intestinalis, the causative agent of the human infectious disease giardiasis. The FDP from Giardia was expressed, purified, and extensively characterized by x-ray crystallography, stopped-flow spectroscopy, respirometry, and NO amperometry. Contrary to flavorubredoxin, the FDP from Escherichia coli, the enzyme from Giardia has high O 2 -reductase activity (>40 s ؊1 ), but very low NO-reductase activity (ϳ0.2 s ؊1 ); O 2 reacts with the reduced protein quite rapidly (milliseconds) and with high affinity (K m < 2 M), producing H 2 O. The three-dimensional structure of the oxidized protein determined at 1.9 Å resolution shows remarkable similarities with prokaryotic FDPs. Consistent with HPLC analysis, the enzyme is a dimer of dimers with FMN and the nonheme di-iron site topologically close at the monomer-monomer interface. Unlike the FDP from Desulfovibrio gigas, the residue His-90 is a ligand of the di-iron site, in contrast with the proposal that ligation of this histidine is crucial for a preferential specificity for NO. We propose that in G. intestinalis the primary function of FDP is to efficiently scavenge O 2 , allowing this microaerobic parasite to survive in the human small intestine, thus promoting its pathogenicity.The flavodiiron proteins (FDP, 2 originally named A-type flavoproteins (1)) are widespread among Bacteria and Archaea, either strict or facultative anaerobes, where they have been proposed to play a role in the response to nitrosative and/or oxidative stress (2, 3). A few prokaryotic FDPs have been characterized to date, namely those from the bacteria Desulfovibrio gigas (originally named rubredoxin:oxygen oxidoreductase, ROO (4 -7), and hereafter denoted FDP Dg ), Escherichia coli (named flavorubredoxin, FlRd, 3 Refs. 2, 8 -11), Desulfovibrio vulgaris (12), Moorella thermoacetica (FDP Mt , (13, 14)), and the homologous enzyme from the methanogenic archaeon Methanothermobacter marburgensis (FDP Mm , Refs. 15, 16). The FDPs contain two redox centers: a FMN, the electron entry site into the enzyme, and a non-heme Fe-Fe center, the active site (13). They are cyanide-insensitive enzymes able to catalyze the reduction of O 2 (to H 2 O) and/or NO (to N 2 O). Some of these enzymes are almost exclusively reactive toward NO (such as E. coli FlRd, Refs. 2, 9), 4 others toward O 2 (such as the M. marburgensis enzyme, (15)), whereas some FDPs catalyze the reduction of both gases, though with different efficiency (7,12,13). These enzymes are expected to play a protective role in anaerobic or microaerobic microorganisms that need to survive under O 2 and cope with NO produced by the host defense system to counteract infection (17,18).Surprisingly, a few years ago, genes coding for FDPs were identified also in the geno...

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Section: Discussionmentioning

confidence: 99%

The O2-scavenging Flavodiiron Protein in the Human Parasite Giardia intestinalis

Matteo

Scandurra

Testa

et al. 2008

Journal of Biological Chemistry

106

142

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“…Sheridan et al [5] reported PtC>2 measure ment from the serosal surface of the human gastrointestinal tract using a polographic oxy gen electrode. They found that relative tissue hypoxia played an important role in the pre diction of the viability of tissue and the devel opment of postoperative leakage in colonic anastomosis [6].…”

Section: Introductionmentioning

confidence: 99%

Anastomotic Tissue Oxygen Tension during Esophagectomy in Patients with Esophageal Carcinoma

et al. 1996

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Submucosal tissue oxygen tension (PtO₂) was measured in 20 patients with cervical esophagogastrostomy after resection of esophageal carcinoma, using a Clark-type oxygen electrode. The mean gastric baseline PtO₂ was 54.6 ± 10.7 mm Hg. Following ligature of the vasa brevia and the left gastroepiploic artery PtO₂ decreased to 45.8 ± 9.9 mm Hg, ligature of the left gastric artery caused a decrease to 34.2 ± 9.7 mm Hg and resection of the lesser curvature and pulling up of gastric tube led to 25.5 ± 9.0 mm Hg. Clinical value and practicability of intraoperative PtO₂ measurements could be proven.

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“…In the gastrointestinal (GI) tract, tissue oxygen tension has been used to assess intestinal function and viability (1,2). Oxygen tension varies in bowel ischemia where there is limited perfusion and in inflammatory bowel disease (3).…”

mentioning

confidence: 99%

“…Oxygen tension varies in bowel ischemia where there is limited perfusion and in inflammatory bowel disease (3). Past techniques for measurement of oxygen tension in the GI tract have been based primarily on modified Clark electrodes with surgical laparotomy or endoscopy (1,4,5). The invasive nature of these methods has limited greatly the ability to perform measurements of oxygen in the clinical diagnosis and treatment of disease, as well as in animal models of the pathogenesis of disease (6)(7)(8)(9).…”

mentioning

confidence: 99%

Noninvasive measurement of anatomic structure and intraluminal oxygenation in the gastrointestinal tract of living mice with spatial and spectral EPR imaging

Shankar

Chzhan

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

348

293

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EPR imaging has emerged as an important tool for noninvasive three-dimensional (3D) spatial mapping of free radicals in biological tissues. Spectral-spatial EPR imaging enables mapping of the spectral information at each spatial position, and, from the observed line width, the localized tissue oxygenation can be mapped. We report the development of EPR imaging instrumentation enabling 3D spatial and spectral-spatial EPR imaging of small animals. This instrumentation, along with the use of a biocompatible charcoal oximetry-probe suspension, enabled 3D spatial imaging of the gastrointestinal (GI) tract, along with mapping of oxygenation in living mice. By using these techniques, the oxygen tension was mapped at different levels of the GI tract from the stomach to the rectum. The results clearly show the presence of a marked oxygen gradient from the proximal to the distal GI tract, which decreases after respiratory arrest. This technique for in vivo mapping of oxygenation is a promising method, enabling the noninvasive imaging of oxygen within the normal GI tract. This method should be useful in determining the alterations in oxygenation associated with disease.

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Intraoperative tissue oximetry in the human gastrointestinal tract

Cited by 98 publications

References 29 publications

The O2-scavenging Flavodiiron Protein in the Human Parasite Giardia intestinalis

The O2-scavenging Flavodiiron Protein in the Human Parasite Giardia intestinalis

Anastomotic Tissue Oxygen Tension during Esophagectomy in Patients with Esophageal Carcinoma

Noninvasive measurement of anatomic structure and intraluminal oxygenation in the gastrointestinal tract of living mice with spatial and spectral EPR imaging

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