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Biomedical subjects

M Müller

Publications and source records attributed to M Müller.

At least 253 records · Page 14Linked to original sources

Alterations of norepinephrine levels in plasma and CSF of patients after traumatic brain injury in relation to disruption of the blood-brain barrier.

BACKGROUND: In injured brain tissue with a disrupted blood-brain barrier (BBB) catecholamines such as norepinephrine (NE) are known to enhance glucose consumption and cerebral blood flow but may lead to an energy depletion increasing the risk of ischemia. Therefore it is of great interest whether the exogenous administration of NE used mainly to maintain an adequate cerebral perfusion pressure influences CSF NE levels or not, and whether elevated plasma or CSF levels of NE can influence the actual clinical condition. We addressed this issue by measuring the levels of NE in CSF and plasma and correlating them with the actual clinical condition of the patients. METHODS: In 29 patients with severe TBI (< 8 points on the Glasgow Coma Scale, GCS) NE levels were analysed by high performance liquid chromatography (HPLC) in paired blood and CSF specimens which were collected from days 1 to 14 after severe TBI (total number of pairs = 121). The integrity of the BBB was evaluated by determining the CSF/serum albumin ratio. The clinical condition of the patients was assessed by GCS. RESULTS: Elevated plasma and CSF NE levels were observed in 50% of all samples, most consistently in patients treated with NE. NE elevation in CSF was independent of whether or not the BBB remained intact. There was no correlation between GCS and the levls of NE in CSF or plasma either in samples from the treated or the untreated group. INTERPRETATION: Exogenous administration of NE seems to increase NE levels in plasma and CSF. However, in this group of patients with severe TBI there was no clinical evidence that exogenous administration of NE was detrimental to the traumatized patients.

Adolescent↗

Limits for the detection of (poly-)phosphoinositides by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been recently established as a powerful tool for the analysis of biomolecules. Here, MALDI-TOF MS was used for the detection of (poly-)phosphoinositides (PPI). PPI possess higher molecular weights than other phospholipids and a high phosphorylation-dependent negative charge. Both features affect the MALDI detection limits expressed as the minimum of analyte on the sample plate resulting in a signal-to-noise-ratio of S/N = 5. Using 2,5-dihydroxybenzoic acid (DHB) as matrix the detection limit for phosphatidylinositol (PI) is seven times higher than for phosphatidylcholine (PC) and further increases with increasing phosphorylation or in mixtures with other well-detectable phospholipids. For phosphatidylinositol-tris-phosphate (PIP3) in a mixture with PC, the limit is about 20 times higher than for PI. The consequences for the experimental conditions are discussed. It is advisable to pre-separate PPI from biological lipid mixtures prior to the application of MALDI-TOF MS.

Phosphatidylinositol Phosphates↗

CsCl as an auxiliary reagent for the analysis of phosphatidylcholine mixtures by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is mainly used for protein and peptide analysis. However, there is growing evidence that also phospholipids like phosphatidylcholines (PC) can be easily analyzed by MALDI-TOF MS. In MALDI-TOF methodology, the sample is cationized by the addition of inorganic ions. This process is strongly dependent on the corresponding ion concentration. In biological samples various cations are present (mainly H+, Na+ and K+) and, therefore, a mixture of different adducts is formed. Since phospholipids exhibit a wide distribution of different fatty acid residues a considerable peak overlap may occur. This is a major problem since the peak assignment in a mixture will be often unclear. In this paper we demonstrate that this problem can be easily overcome by mixing the analyte with caesium chloride (CsCl). This yields naturally non-occurring Cs+ adducts that are apparent due to the large shift of the molecular mass. The proposed method facilitates the clear assignment of most peaks. Besides that, we will show that CsCl can also be used for the determination of the relative fatty acid composition of a given PC sample. For this purpose naturally occurring mixtures of PCs as well as organic extracts of human lipoproteins-that are mainly composed of PC and sphingomyeline-are used.

Cesium↗

Evolution of minimally invasive plate osteosynthesis (MIPO) in the femur.

Problems with conventional open reduction and internal plate fixation of distal femoral fractures are well established. These problems have been associated with extensile exposures of the fracture site. "Biological plating", like intramedullary nail fixation, of distal femoral fractures preserves the soft tissues about the fracture, and is associated with early fracture consolidation and low rates of infection. Anatomical restoration of the articular surface continues to be the main goal in the treatment of these fractures regardless of the stabilization technique. Submuscular plating techniques, which provide for closed reduction of the diaphyseal/metaphyseal component of the fracture, have improved significantly.

Bone Plates↗

Minimally invasive fracture stabilization of distal femoral fractures with the LISS: a prospective multicenter study. Results of a clinical study with special emphasis on difficult cases.

The LISS-DF (Less invasive stabilization system-distal femur) is a new type of implant system for the treatment of distal femoral fractures according to the principles of "Minimally Invasive Surgery". A plate, pre-contoured to the anatomy, is inserted through a minimally invasive incision into the epiperiosteal space by means of an aiming device after indirect, closed fracture reduction. The implant is stabilized by insertion of screws which lock into the plate holes and prevent tilting. This is performed with the aid of an aiming device and through stab incisions. It is not necessary for a large area to be exposed at the fracture site. As part of an AO prospective multicenter study, the new system was applied to 112 patients with 116 fractures. The time to follow-up was on average 13.7 months (minimum 7 months, maximum 33 months). Fractures treated were distal femoral shaft and supracondylar femoral fractures. Eight patients died during the study of causes unrelated to the implant. Of the remaining 104 patients with 107 fractures, 96 patients with 99 fractures were available for complete follow-up (93% follow-up rate). In 90% of all cases treated and followed up, the fracture had consolidated during the period of observation. Twenty-three revision operations were necessary in 21 patients. In two cases, implant failure occurred as the result of a pseudarthrosis. The complications can be attributed in nearly all cases to the severity of the trauma and/or a lack of experience when applying the new style implant to a wider range of indications. The results of the study show that with a sound knowledge of the operative technique and careful preoperative planning this system represents an excellent, safe procedure for the treatment of almost all distal femoral fracture types including periprosthetic fractures of the distal femur. There is generally no need for primary cancellous bone grafting.

Adolescent↗

Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane.

Bacteria use several routes to target their exported proteins to the plasma membrane. The majority are exported through pores formed by SecY and SecE. Two different molecular machineries are used to target proteins to the SecYE translocon. Translocated proteins, synthesized as precursors with cleavable signal sequences, require cytoplasmic chaperones, such as SecB, to remain competent for posttranslational transport. In concert with SecB, SecA targets the precursors to SecY and energizes their translocation by its ATPase activity. The latter function involves a partial insertion of SecA itself into the SecYE translocon, a process that is strongly assisted by a couple of membrane proteins, SecG, SecD, SecF, YajC, and the proton gradient across the membrane. Integral membrane proteins, however, are specifically recognized by a direct interaction between their noncleaved signal anchor sequences and the bacterial signal recognition particle (SRP) consisting of Ffh and 4.5S RNA. Recognition occurs during synthesis at the ribosome and leads to a cotranslational targeting to SecYE that is mediated by FtsY and the hydrolysis of GTP. No other Sec protein is required for integration unless the membrane protein also contains long translocated domains that engage the SecA machinery. Discrimination between SecA/SecB- and SRP-dependent targeting involves the specificity of SRP for hydrophobic signal anchor sequences and the exclusion of SRP from nascent chains of translocated proteins by trigger factor, a ribosome-associated chaperone. The SecYE pore accepts only unfolded proteins. In contrast, a class of redox factor-containing proteins leaves the cell only as completely folded proteins. They are distinguished by a twin arginine motif of their signal sequences that by an unknown mechanism targets them to specific pores. A few membrane proteins insert spontaneously into the bacterial plasma membrane without the need for targeting factors and SecYE. Insertion depends only on hydrophobic interactions between their transmembrane segments and the lipid bilayer and on the transmembrane potential. Finally, outer membrane proteins of Gram-negative bacteria after having crossed the plasma membrane are released into the periplasm, where they undergo distinct folding events until they insert as trimers into the outer membrane. These folding processes require distinct molecular chaperones of the periplasm, such as Skp, SurA, and PpiD.

Adenosine Triphosphatases↗

Reverse transcriptase-polymerase chain reaction for prostate-specific antigen in the molecular staging of pelvic surgical margins after radical prostatectomy.

OBJECTIVES: To examine the application of reverse transcriptase-polymerase chain reaction (RT-PCR) to assist in prostate-specific antigen (PSA) detection in the surgical margins after radical prostatectomy (RP). The risk of local recurrence increases considerably in the presence of extracapsular tumor growth and/or positive surgical margins at RP. Although this makes it possible to identify patients with an increased risk of local recurrence, precise predictions cannot be made. A more precise assessment is desirable mainly for early planning of adjuvant therapy. METHODS: Ninety-five patients with clinically organ-confined prostate cancer (CaP) underwent RP. After removing the gland, biopsies were obtained from four defined areas of the prostatic fossa and processed for RT-PCR for PSA detection. Sixteen patients with muscle-invasive bladder carcinoma who underwent radical cystoprostatectomy served as controls. RESULTS: Thirty-two of 95 patients with CaP (35%) had at least one positive molecular margin indicating an expression for PSA; 19 of 48 (39%) of these had an organ-confined tumor stage according to conventional histology and 13 of 47 (28%) had tumor growth beyond the prostate. A statistically significant correlation between the frequency of positive molecular margins and clinical data was only observed in the group with disease greater than Stage pT2. All controls had negative molecular margins (P = 0.012). CONCLUSIONS: On the basis of the results obtained, molecular diagnostic RT-PCR for PSA detection in the surgical margins after RP seems to be an interesting supplementary tool for monitoring the course and establishing the prognosis. Long-term follow-up of these patients is needed to demonstrate the clinical value of molecular diagnostics of surgical margins during RP.

Adenocarcinoma↗

DNA-based detection of prostate cancer in urine after prostatic massage.

OBJECTIVES: Promoter hypermethylation of the glutathione-S-transferase P1 (GSTP1) gene is a specific feature of prostate cancer. This epigenetic DNA alteration served as the target for molecular detection of prostate cancer cells in urine sediments after prostatic massage. METHODS: Bisulfite treatment followed by methylation-specific polymerase chain reaction was used to detect GSTP1 promoter hypermethylation in DNA isolated from urine sediments obtained after prostatic massage of men with and without prostate cancer. RESULTS: GSTP1 promoter hypermethylation was demonstrated in the sediments of 1 (2%) of 45 patients diagnosed with benign prostatic hyperplasia, 2 (29%) of 7 patients with prostatic intraepithelial neoplasia, 15 (68%) of 22 patients with early, intracapsular cancer, and 14 (78%) of 18 patients with locally advanced or systemic prostate cancer, resulting in a specificity of 98% and an overall sensitivity of 73% for the detection of prostate cancer. CONCLUSIONS: Urinalysis for GSTP1 promoter hypermethylation constitutes a sensitive and highly specific DNA-based marker for molecular detection of prostate cancer, including early stages.

Adenocarcinoma↗

Detection of prostate-specific antigen RNA before and after radical retropubic prostatectomy and transurethral resection of the prostate using "Light-Cycler"-based quantitative real-time polymerase chain reaction.

OBJECTIVES: To report our initial experience gained in establishing real-time reverse transcriptase-polymerase chain reaction (RT-PCR) detection of prostate-specific antigen (PSA) mRNA using the quantitative online PCR system LightCycler. Many studies have thus far failed to provide the desired proof that the detection of circulating PSA-expressing tumor cells with RT-PCR in the blood samples of patients with prostate cancer (PCa) is a highly sensitive prognostic and course marker. One of the possible reasons is the lack of reliable quantification methods. METHODS: Blood samples before and after surgery were obtained from 87 patients who underwent radical prostatectomy for locally confined PCa and 27 patients who underwent transurethral resection of the prostate for benign prostatic hyperplasia. Eight days postoperatively, additional blood samples were obtained from the patients with PCa. Quantitative no-nested RT-PCR for PSA mRNA (291 bp) was performed using the LightCycler system applying the SYBR Green protocol. The number of circulating LNCaP tumor cell-equivalents per sample was estimated from the mean amplification value measured in a given number of LNCaP cells. RESULTS: PSA mRNA was detected preoperatively in 19 patients with Stage pT2 tumor (40%) and in 28 patients with tumor greater than Stage pT2 (72%), but in only 2 patients with benign prostatic hyperplasia (8%; analysis of variance, P <0.001). Significant quantitative differences were observed among Stage pT2 disease (1034 LNCaP tumor cell-equivalents/mL), greater than Stage pT2 disease (7830 cells/mL), and benign prostatic hyperplasia (58 cells/mL; analysis of variance for all groups, P <0.001). The correlation between the detection of PSA expression by RT-PCR and the Gleason score and serum PSA value was statistically significant. CONCLUSIONS: Our results show that the initial experience with the LightCycler system for PSA-assisted detection of circulating PSA mRNA in PCa by RT-PCR may be a promising preoperative prognostic marker for organ-confined or locally advanced PCa. Long-term follow-up of these patients with PCa must demonstrate the clinical value of molecular diagnostics with quantitative RT-PCR systems.

Analysis of Variance↗

Pharmacokinetics of levormeloxifene in young versus elderly postmenopausal women.

BACKGROUND: Physiologic changes of aging may affect processes of drug absorption and distribution, in some cases necessitating age-dependent dose adjustment. OBJECTIVE: The possibility of age dependence in the pharmacokinetic behavior and tolerability of levormeloxifene was investigated in a single-center, open-label study. METHODS: The study comprised 2 groups of healthy postmenopausal women: group A included younger subjects (50-60 years) and group B included elderly subjects (> or = 66 years). All subjects received a single 40-mg tablet of levormeloxifene base. Blood samples were collected immediately before drug intake and at several points after administration, through day 34. Peak plasma concentration, time to maximum plasma concentration, area under the plasma concentration-time curves from zero to the last quantifiable value and to infinity, and terminal half-life were calculated for levormeloxifene and compared between age groups. RESULTS: Of 29 subjects enrolled, 28 (15 group A, 13 group B) completed the study. The ages of the women in group A ranged from 50 to 58 years and in group B from 66 to 79 years. No serious adverse events were reported. Ten subjects experienced 17 adverse events, of which 2 (abdominal pain and vaginal hemorrhage) were judged to be possibly related to study drug. There was no noticeable difference between age groups in the frequency of adverse events or laboratory abnormalities. The plasma concentration-time curves of levormeloxifene were indistinguishable between age groups up to 48 hours after dosing. From 72 hours onward, the mean plasma concentration-time curve was approximately 20% higher and the area under the curve was approximately 19% greater in the older subjects compared with the younger subjects. However, no statistically significant differences were observed between groups in any of the pharmacokinetic parameters, except for the elimination rate constant. The difference in mean elimination half-life was 25 hours (group A, 126 hours; group B, 151 hours). CONCLUSION: The findings suggest that it is not necessary to adjust the dose of levormeloxifene on the basis of age in postmenopausal women. However, these results need confirmation in a multiple-dose setting under steady-state conditions--that is, as the drug is intended to be used clinically.

Age Factors↗

Function and regulation of ATP-binding cassette transport proteins involved in hepatobiliary transport.

Hepatobiliary transport of endogenous and exogenous compounds is mediated by the coordinated action of multiple transport systems present at the sinusoidal (basolateral) and canalicular (apical) membrane domains of hepatocytes. During the last few years many of these transporters have been cloned and functionally characterized. In addition, the molecular bases of several forms of cholestatic liver disease have been defined. Combined, this has greatly expanded our understanding of the normal physiology of bile formation, the pathophysiology of intrahepatic cholestasis, as well as of drug elimination and disposition processes. In this review recent advances, with respect to function and regulation of ATP binding cassette transport proteins expressed in liver, are summarized and discussed.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Cerebral blood flow velocity and inflammatory response after severe traumatic brain injury.

OBJECTIVES: The cerebral blood flow velocity (CBVF) was measured by transcranial Doppler sonography in patients with severe traumatic brain injury (TBI) in order to determine, whether it depends on the posttraumatic inflammatory response. MATERIAL AND METHODS: CBVF in both middle cerebral arteries (MCA) was recorded in 25 comatous TBI patients (male 20; female five; mean age +/- standard deviation (S.D.), 41 +/- 20 years) and correlated to the levels of interleukine-(IL) 6, IL-8 and IL-10 in corresponding CSF/plasma samples, to PaCO2 and to intracranial (ICP), mean arterial (MAP) and cranial perfusion pressure (CPP). RESULTS: CSF IL-6 and IL-8 were clearly higher than the corresponding plasma levels (mean CSF/plasma quotient for IL-6: 159 +/- 582; for IL-8: 143 +/- 311). CBVF did not show large side-to-side differences at each examination indicating that CBFV in both MCAs was determined mostly by systemic conditions and not by severe regional abnormalities. Since all other evaluated variables including interleukines represent also systemic conditions we used the mean value (MCBFV) of both CBFVs for analysis. By stepwise regression analysis between MCBVF (mean +/- S.D., 80 +/- 26 cm/s) and the variables PaCO2 (33 +/- 4 mmHg), MAP (86 +/- 12 mmHg), ICP (20 +/- 11 mmHg), CPP (70 +/- 14 mmHg) and CSF or plasma IL-6, IL-8 and IL-10, it turned out that MCBFV correlated significantly with PaCO2 (r = 0.478; P < 0.01) and CSF IL-8 (r = -0.361; P < 0.05). CONCLUSIONS: When CPP is adequate for brain perfusion, CBFV in large brain supplying arteries depends predominantly on PaCO2 and shows only a slight association to intrathecal IL-8 levels. For clinical interpretation of CBFV data, the inflammatory response seems to be of minor relevance.

Adult↗

Orientation of alpha-helical poly(L-lysine) in consecutively adsorbed polyelectrolyte multilayers on texturized silicon substrates.

Alternate polyelectrolyte multilayers composed of poly(L-lysine) (PLL) in the alpha-helical state and poly(maleic acid-co-alpha-methylstyrene) (PMA-MS) were deposited by consecutively adsorbing from aqueous solutions on both unmodified and unidirectionally scratched silicon substrates. Thereby, the alpha-helical PLL rods formed in the presence of NaClO(4) were found to be significantly aligned along the scratching direction of the substrate. From the dichroic ratios of the amide I and amide II band, obtained by ATR-FTIR spectroscopy, order parameters with respect to uniaxial orientation were determined using a cone distribution model and the known angles of the transition dipole moments relative to the helix axis. They ranged from S = 0.5-0.7 for the PLL rods oriented on the texturized Si substrate and S = 0.0-0.2 (S = 1 for perfect ordering) for the unoriented PLL rods in the dry and wet states, respectively. Additionally, multilayers composed of PLL and poly(vinyl sulfate) showed similar uniaxial alignment on texturized Si substrates (S = 0.6). Generally, drying the multilayers caused a certain loss of order. Surfaces of anisotropically oriented alpha-helical polypeptides could be interesting for biomimetic purposes.

Adsorption↗

Organotin-induced caspase activation and apoptosis in human peripheral blood lymphocytes.

In the present study, we show that the immunotoxicant, tributyltin (TBT), induces a dose-dependent activation of caspases followed by typical apoptotic morphology in resting human peripheral blood lymphocytes. TBT also caused an early loss of mitochondrial membrane potential (Delta(Psi)(m)) and release of cytochrome c, suggesting that apoptosis was triggered by the mitochondrial pathway. When CD4+ T-cells were sorted from peripheral blood and exposed to TBT for 30 min, caspase activation and apoptosis were induced. Interestingly, in the sorted CD8+ T-cell population, caspase activation was not observed until 2 h of TBT exposure, suggesting that these cells were more resistant toward TBT. Moreover, a time-dependent induction of caspase activity was also detected in CD3-stimulated peripheral blood lymphocytes. This caspase activation was not associated with cytochrome c release or loss of mitochondrial Delta(Psi) and did not lead to apoptotic morphology, although it did lead to both PARP and DFF cleavage. We also noticed a concomitant induction of Hsp27, and it awaits to be seen if this chaperone may interfere with the processing of nuclear protein substrates downstream from these primary caspase-3 substrates. Moreover, no increase in caspase activation or induction of apoptosis was observed after TBT treatment in these cells. Instead, the cells were directed toward necrotic deletion. Taken together, these data suggest that TBT-induced deletion of peripheral lymphocytes is likely to be a component in the overall risk for immunotoxic responses in exposed humans.

Apoptosis↗

The mechanism of action of multidrug-resistance-linked P-glycoprotein.

P-glycoprotein (Pgp), the ATP-binding cassette (ABC) transporter, confers multidrug resistance to cancer cells by extruding cytotoxic natural product amphipathic drugs using the energy of ATP hydrolysis. Our studies are directed toward understanding the mechanism of action of Pgp and recent work deals with the assessment of interaction between substrate and ATP sites and elucidation of the catalytic cycle of ATP hydrolysis. The kinetic analyses of ATP hydrolysis by reconstituted purified Pgp suggest that ADP release is the rate-limiting step in the catalytic cycle and the substrates exert their effect by modulating ADP release. In addition, we provide evidence for two distinct roles for ATP hydrolysis in a single turnover of Pgp, one in the transport of drug and the other in effecting conformational changes so as to reset the transporter for the next catalytic cycle. Detailed kinetic measurements determined that both nucleotide-binding domains behave symmetrically and during individual hydrolysis events the ATP sites are recruited in a random manner. Furthermore, only one nucleotide site hydrolyzes ATP at any given time, causing (in this site) a conformational change that drastically decreases (>30-fold) the affinity of the second site for ATP-binding. Thus, the blocking of ATP-binding to the second site while the first one is in catalytic conformation appears to be the basis for the alternate catalytic cycle of ATP hydrolysis by Pgp, and this may be applicable as well to other ABC transporters linked with the development of multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Penetration of cefaclor into the interstitial space fluid of skeletal muscle and lung tissue in rats.

PURPOSE: To measure and compare the penetration of cefaclor from the plasma compartment into the interstitial space of lung and skeletal muscle in rats and to integrate the data in a pharmacokinetic model. METHODS: Unbound interstitial concentrations in muscle and lung were measured by in vivo microdialysis following i.v. bolus doses of 50 and 75 mg/kg cefaclor. Unbound muscle concentrations were also measured after a primed, continuous i.v. infusion at an infusion rate of 0.3 mg/kg/min. RESULTS: The cefaclor half-life in plasma, muscle and lung was approximately 1 h. Unbound cefaclor concentrations in muscle and lung were found to be virtually identical. A 2-compartment body model was fitted to the data with a tissue penetration factor (AUC(tissue(unbound)))/AUC(plasma(unbound))) of approximately 0.26 independent of dose, tissue and mode of administration. CONCLUSIONS: Unbound concentrations of cefaclor in the interstitial space fluid of lung and skeletal muscle are of similar magnitude and lower than those in plasma. Using total plasma concentrations would overestimate the antibacterial activity of the drug and therefore its clinical efficacy. Instead, therapeutically active levels of cefaclor at the site of action should be taken into account. Microdialysis allows direct measurement of these unbound concentrations.

Algorithms↗

Controlled hypercapnia during one-lung ventilation in patients undergoing pulmonary resection.

BACKGROUND: In a pilot study, the haemodynamic and gas exchange effects of acute hypercapoia during one-lung ventilation in thoracotomy patients were investigated. The effects of normocapnic one-lung ventilation (OLV-N) on haemodynamics and pulmonary gas exchange were compared with those of hypercapnic one-lung ventilation (OLV-H) in 14 patients undergoing pulmonary lobectomy. METHODS: Hypercapnia was induced by decreasing tidal volume until PaCO2 increased to 8-9 kPa. During OLV, minute ventilation was reduced from 8.8+/-1.7 to 4.2+/-0.7 l min(-1). RESULTS: Cardiac index (from 3.3+/-0.6 to 3.9+/-0.6 l min(-1), P<0.01) and pulmonary vascular resistance index (from 245+/-96 to 347+/-125 dyn s cm(-5) m(-2), P<0.05) increased during OLV-H, whereas systemic vascular resistance index decreased from 1952+/-403 to 1636+/-361 dyn s cm(-5) m(-2) (P<0.01). Pulmonary oxygenation remained unchanged. CONCLUSIONS: All patients had an uneventful course during OLV-H. The determinants of pulmonary oxygenation during hypercapnic one-lung ventilation remain to be further elucidated.

Blood Gas Analysis↗