Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
Add more filters










Publication year range
3.
Chest ; 161(4): e233-e240, 2022 04.
Article in English | MEDLINE | ID: mdl-35396057

ABSTRACT

CASE PRESENTATION: A 20-year-old woman presented with dry cough, right-sided thoracic pain, and gradually progressive dyspnea on exertion. She had no hemoptysis or fever. There was no relevant medical history. She was a never smoker and used no medication besides oral contraceptives. There were no other risk factors for a pulmonary embolism. There was a family history of ovarian and breast cancer. Physical examination showed a mildly ill-looking woman, with shallow breathing and normal blood oxygen saturation. Auscultation revealed normal breath sounds without crackles or wheezing. Laboratory testing showed a significantly increased D-dimer (4,560 µg/L [normal, < 500 µg/L]), elevated C-reactive protein (131 mg/L [normal, < 5 mg/L]), normal leucocytes, and elevated lactate dehydrogenase (825 units/L [normal, 50 to 250 units/L).


Subject(s)
Physical Exertion , Tomography, X-Ray Computed , Adult , Chest Pain/diagnosis , Chest Pain/etiology , Diagnosis, Differential , Dyspnea/diagnosis , Dyspnea/etiology , Female , Humans , Young Adult
4.
Lung Cancer ; 166: 143-149, 2022 04.
Article in English | MEDLINE | ID: mdl-35279453

ABSTRACT

OBJECTIVES: Programmed death-ligand 1 (PD-L1) is the only approved predictive biomarker for immunotherapy in non-small cell lung cancer (NSCLC). However, predictive PD-L1 immunohistochemistry is subject to interobserver variability. We hypothesized that a pathologist's personality influences the interobserver variability and diagnostic accuracy of PD-L1 immunoscoring. MATERIALS AND METHODS: Seventeen pathologists performed PD-L1 immunoscoring on 50 resected NSCLC tumors in three categories (<1%;1-49%;≥50%). Also, the pathologists completed a certified personality test (NEO-PI-r), assessing five personality traits: neuroticism, extraversion, openness, altruism and conscientiousness. RESULTS: The overall agreement among pathologists for a series of 47 tumors was substantial (kappa = 0.63). Of these, 23/47 (49%) tumors were entirely negative or largely positive, resulting in a kappa value of 0.93. The remaining 24/47 (51%) tumors had a PD-L1 score around the cutoff value, generating a kappa value of 0.32. Pathologists with high scores for conscientiousness (careful, diligent) had the least interobserver variability (r = 0.6, p = 0.009). Also, they showed a trend towards higher sensitivity (74% vs. 68%, p = 0.4), specificity (86% vs. 82%, p = 0.3) and percent agreement (83% vs. 79%, p = 0.3), although not significant. In contrast, pathologists with high scores for neuroticism (sensitive, anxious) had significantly lower specificity (80% vs. 87%, p = 0.03) and percent agreement (78% vs. 85%, p = 0.03). Also, a trend towards high interobserver variability (r = -0.3, p = 0.2) and lower sensitivity (68% vs. 74%, p = 0.3) was observed, although not significant. Pathologists with relatively high scores for conscientiousness scored fewer tumors PD-L1 positive at the ≥ 1% cut-off (r = -0.5, p = 0.03). In contrast, pathologists with relatively high scores for neuroticism score more tumors PD-L1 positive at ≥ 1% (r = 0.6, p = 0.017) and ≥ 50% cut-offs (r = 0.6, p = 0.009). CONCLUSIONS: This study is the first to demonstrate the impact of a pathologist's personality on the interobserver variability and diagnostic accuracy of immunostaining, in the context of PD-L1 in NSCLC. Larger studies are needed for validation of these findings.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , B7-H1 Antigen , Biomarkers, Tumor , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/pathology , Humans , Immunohistochemistry , Lung Neoplasms/diagnosis , Lung Neoplasms/pathology , Observer Variation , Pathologists , Personality
5.
Mod Pathol ; 35(3): 326-332, 2022 03.
Article in English | MEDLINE | ID: mdl-34389791

ABSTRACT

Companion diagnostic immunohistochemistry (IHC) tests are developed and performed without incorporating the tools and principles of laboratory metrology. Basic analytic assay parameters such as lower limit of detection (LOD) and dynamic range are unknown to both assay developers and end users. We solved this problem by developing completely new tools for IHC-calibrators with units of measure traceable to National Institute of Standards & Technology (NIST) Standard Reference Material (SRM) 1934. In this study, we demonstrate the clinical impact and opportunity for incorporating these changes into PD-L1 testing. Forty-one laboratories in North America and Europe were surveyed with newly-developed PD-L1 calibrators. The survey sampled a broad representation of commercial and laboratory-developed tests (LDTs). Using the PD-L1 calibrators, we quantified analytic test parameters that were previously only inferred indirectly after large clinical studies. The data show that the four FDA-cleared PD-L1 assays represent three different levels of analytic sensitivity. The new analytic sensitivity data explain why some patients' tissue samples were positive by one assay and negative by another. The outcome depends on the assay's lower LOD. Also, why previous attempts to harmonize certain PD-L1 assays were unsuccessful; the assays' dynamic ranges were too disparate and did not overlap. PD-L1 assay calibration also clarifies the exact performance characteristics of LDTs relative to FDA-cleared commercial assays. Some LDTs' analytic response curves are indistinguishable from their predicate FDA-cleared assay. IHC assay calibration represents an important transition for companion diagnostic testing. The new tools will improve patient treatment stratification, test harmonization, and foster accuracy as tests transition from clinical trials to broad clinical use.


Subject(s)
B7-H1 Antigen , Lung Neoplasms , Biomarkers, Tumor , Humans , Immunohistochemistry , Lung Neoplasms/pathology , North America , Technology
7.
Front Pharmacol ; 12: 587003, 2021.
Article in English | MEDLINE | ID: mdl-33692687

ABSTRACT

Background: The process of brain death (BD) leads to a pro-inflammatory state of the donor lung, which deteriorates its quality. In an attempt to preserve lung quality, methylprednisolone is widely recommended in donor lung management. However, clinical treatment doses vary and the dose-effect relation of methylprednisolone on BD-induced lung inflammation remains unknown. The aim of this study was to investigate the effect of three different doses methylprednisolone on the BD-induced inflammatory response. Methods: BD was induced in rats by inflation of a Fogarty balloon catheter in the epidural space. After 60 min of BD, saline or methylprednisolone (low dose (5 mg/kg), intermediate dose (12.5 mg/kg) or high dose (22.5 mg/kg)) was administered intravenously. The lungs were procured and processed after 4 h of BD. Inflammatory gene expressions were analyzed by RT-qPCR and influx of neutrophils and macrophages were quantified with immunohistochemical staining. Results: Methylprednisolone treatment reduced neutrophil chemotaxis as demonstrated by lower IL-8-like CINC-1 and E-selectin levels, which was most evident in rats treated with intermediate and high doses methylprednisolone. Macrophage chemotaxis was attenuated in all methylprednisolone treated rats, as corroborated by lower MCP-1 levels compared to saline treated rats. Thereby, all doses methylprednisolone reduced TNF-α, IL-6 and IL-1ß tissue levels. In addition, intermediate and high doses methylprednisolone induced a protective anti-inflammatory response, as reflected by upregulated IL-10 expression when compared to saline treated brain-dead rats. Conclusion: We showed that intermediate and high doses methylprednisolone share most potential to target BD-induced lung inflammation in rats. Considering possible side effects of high doses methylprednisolone, we conclude from this study that an intermediate dose of 12.5 mg/kg methylprednisolone is the optimal treatment dose for BD-induced lung inflammation in rats, which reduces the pro-inflammatory state and additionally promotes a protective, anti-inflammatory response.

8.
Eur J Clin Invest ; 51(4): e13497, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33482016

ABSTRACT

AIM: Integration of endomyocardial biopsy (EMB) in the diagnostic workup of cardiac sarcoidosis (CS) is under-recognized in current clinical practice, since capturing focal granulomas is challenging. Our aim was to describe our experience with electro-anatomic mapping (EAM)-guided EMB and provide a comprehensive review of the literature. METHODS AND RESULTS: Five patients (age 49.4 ± 11.4) with suspected CS underwent EAM-guided EMB in Isala Heart Center (Zwolle, the Netherlands) between 2017 and 2019. In all patients, a 3D bipolar voltage map (<0.5-1.5 mV) and unipolar voltage map (LV < 8.3 mV, RV < 5.5 mV) was created using a high-density mapping catheter. The bioptome was connected to the mapping system to guide targeted EMB. Biopsy samples (2-9 samples) were taken from both LV and RV sites, guided by EAM and areas with abnormal electrograms, without complications. CS diagnosis was based on EMB in 2/5 patients. A granuloma was captured in one patient at the LV basal septum with normal bipolar and abnormal unipolar voltage. All patients with delayed enhancement on cardiac magnetic resonance, revealed fibrosis in the biopsy sample. In one patient with suspected isolated cardiac sarcoidosis, diagnosis could not be confirmed by histopathology analysis, while unipolar voltage mapping was abnormal and diastolic potentials were present. Literature search revealed 7 reports (18 patients) describing EAM-guided EMB in CS patients, with 100% of the EMB taken form the RV. CONCLUSION: Unipolar voltage mapping may be superior to target active inflamed tissue and should be evaluated in future research regarding EAM-guided EMB in CS.


Subject(s)
Cardiomyopathies/pathology , Sarcoidosis/pathology , Adult , Biopsy , Cardiac Imaging Techniques , Cardiomyopathies/diagnostic imaging , Cardiomyopathies/physiopathology , Electrocardiography , Electrophysiologic Techniques, Cardiac , Humans , Image-Guided Biopsy , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Male , Middle Aged , Positron Emission Tomography Computed Tomography , Sarcoidosis/diagnostic imaging , Sarcoidosis/physiopathology
9.
Cancer Cytopathol ; 129(4): 304-317, 2021 04.
Article in English | MEDLINE | ID: mdl-33108706

ABSTRACT

BACKGROUND: Immunohistochemical staining of programmed death-ligand 1 (PD-L1) is used to determine which patients with non-small cell lung cancer (NSCLC) may benefit most from immunotherapy. Therapeutic management of many patients with NSCLC is based on cytology instead of histology. In this study, concordance of PD-L1 immunostaining between cytology cell blocks and their histologic counterparts was analyzed. Furthermore, the effect of various fixatives and fixation times on PD-L1 immunoreactivity was studied. METHODS: Paired histologic and cytologic samples from 67 patients with NSCLC were collected by performing fine-needle aspiration on pneumonectomy/lobectomy specimens. Formalin-fixed, agar-based or CytoLyt/PreservCyt-fixed Cellient cell blocks were prepared. Sections from cell blocks and tissue blocks were stained with SP263 (standardized assay) and 22C3 (laboratory-developed test) antibodies. PD-L1 scores were compared between histology and cytology. In addition, immunostaining was compared between PD-L1-expressing human cell lines fixed in various fixatives at increasing increments in fixation duration. RESULTS: Agar cell blocks and tissue blocks showed substantial agreement (κ = 0.70 and κ = 0.67, respectively), whereas fair-to-moderate agreement was found between Cellient cell blocks and histology (κ = 0.28 and κ = 0.49, respectively). Cell lines fixed in various alcohol-based fixatives showed less PD-L1 immunoreactivity compared with those fixed in formalin. In contrast to SP263, additional formalin fixation after alcohol fixation resulted in preserved staining intensity using the 22C3 laboratory-developed test and the 22C3 pharmDx assay. CONCLUSIONS: Performing PD-L1 staining on cytologic specimens fixed in alcohol-based fixatives could result in false-negative immunostaining results, whereas fixation in formalin leads to higher and more histology-concordant PD-L1 immunostaining. The deleterious effect of alcohol fixation could be reversed to some degree by postfixation in formalin.


Subject(s)
B7-H1 Antigen/metabolism , Carcinoma, Non-Small-Cell Lung/metabolism , Formaldehyde/chemistry , Lung Neoplasms/metabolism , Tissue Fixation/methods , Biopsy, Fine-Needle , Carcinoma, Non-Small-Cell Lung/pathology , Female , Humans , Immunohistochemistry , Lung Neoplasms/pathology , Male
10.
J Clin Pathol ; 73(7): 423-430, 2020 Jul.
Article in English | MEDLINE | ID: mdl-31822512

ABSTRACT

AIMS: Investigate the impact of interlaboratory- and interobserver variability of immunohistochemistry on the assessment of programmed death ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC). METHODS: Two tissue microarrays (TMAs) were constructed from 50 (TMA-A) and 51 (TMA-B) resected NSCLC cases, and distributed among eight centres. Immunostaining for PD-L1 was performed using Agilent's 22C3 pharmDx Assay (pharmDx) and/or a 22C3 laboratory developed test (LDT). The interlaboratory variability of staining- and interobserver variability of scoring for PD-L1 were assessed in selected critical samples (samples at the cut-off of positivity) and non-critical samples. Also, PD-L1 epitope deterioration in time in stored unstained slides was analysed. Krippendorff's alpha values (0=maximal, 1=no variability) were calculated as measure for variability. RESULTS: For interlaboratory variability of immunostaining, the percentage of PD-L1 positive cases among centres ranged 40%-51% (1% cut-off) and 23%-30% (50% cut-off). Alpha values at 1% cut-off were 0.88 (pharmDx) and 0.87 (LDT) and at 50% cut-off 0.82 (pharmDx) and 0.95 (LDT). Interobserver variability of scoring resulted in PD-L1 positive cases ranging 29%-55% (1% cut-off) and 14%-30% (50% cut-off) among pathologists. Alpha values were at 1% cut-off 0.83 (TMA-A) and 0.66 (TMA-B), and at 50% cut-off 0.77 (TMA-A) and 0.78 (TMA-B). Interlaboratory variability of staining was higher (p<0.001) in critical samples than in non-critical samples at 50% cut-off. Furthermore, PD-L1 epitope deterioration in unstained slides was observed after 12 weeks. CONCLUSIONS: The results provide insight in factors contributing to variability of immunohistochemical assessment of PD-L1, and contribute to more reliable predictive testing for PD-L1.


Subject(s)
B7-H1 Antigen/metabolism , Carcinoma, Non-Small-Cell Lung/therapy , Lung Neoplasms/pathology , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Epitopes/metabolism , Humans , Immunohistochemistry , Immunotherapy , Lung/pathology , Lung Neoplasms/metabolism , Observer Variation , Pathologists , Predictive Value of Tests , Tissue Array Analysis
11.
Transplantation ; 103(10): 2057-2064, 2019 10.
Article in English | MEDLINE | ID: mdl-30951018

ABSTRACT

BACKGROUND: Hypothermic machine perfusion (HMP) has become standard care in many center's to preserve kidneys donated after circulatory death (DCD). Despite a significant reduction in metabolism at low temperatures, the remaining cellular activity requires oxygen. Because of the role and safety of oxygen during HMP has not been fully clarified, its supply during HMP is not standard yet. This study investigates the effect of administering oxygen during HMP on renal function in a porcine DCD model. METHODS: After 30 minutes of warm ischemia, porcine slaughterhouse kidneys were preserved for 24 hours by means of cold storage (CS), or HMP with Belzer Machine Perfusion Solution supplemented with no oxygen, 21% or 100% oxygen. Next, kidneys were reperfused for 4 hours in a normothermic machine perfusion setup. RESULTS: HMP resulted in significantly better kidney function during normothermic machine perfusion. Thiobarbituric acid-reactive substances, markers of oxidative stress, were significantly lower in HMP preserved kidneys. HMP preserved kidneys showed significantly lower aspartate aminotransferase and lactate dehydrogenase levels compared with kidneys preserved by CS. No differences were found between the HMP groups subjected to different oxygen concentrations. Adenosine triphosphate levels significantly improved during HMP when active oxygenation was applied. CONCLUSIONS: This study showed that preservation of DCD kidneys with HMP is superior to CS. Although the addition of oxygen to HMP did not result in significantly improved renal function, beneficial effects were found in terms of reduced oxidative stress and energy status. Oxygen addition proofed to be safe and did not show detrimental effects.


Subject(s)
Hypothermia, Induced/methods , Organ Preservation/methods , Oxygen/administration & dosage , Perfusion/methods , Reperfusion Injury/prevention & control , Tissue and Organ Harvesting/adverse effects , Adenosine/administration & dosage , Allografts/blood supply , Allografts/drug effects , Allografts/pathology , Allopurinol/administration & dosage , Animals , Biopsy , Disease Models, Animal , Glutathione/administration & dosage , Humans , Hypothermia, Induced/instrumentation , Insulin/administration & dosage , Kidney/blood supply , Kidney/drug effects , Kidney/pathology , Organ Preservation/instrumentation , Organ Preservation Solutions/administration & dosage , Oxidative Stress , Perfusion/instrumentation , Raffinose/administration & dosage , Reperfusion , Reperfusion Injury/etiology , Reperfusion Injury/pathology , Swine , Tissue and Organ Harvesting/methods , Warm Ischemia/adverse effects
12.
Front Oncol ; 9: 1521, 2019.
Article in English | MEDLINE | ID: mdl-32039011

ABSTRACT

The diagnostic landscape of non-small cell lung cancer (NSCLC) is changing rapidly with the availability of novel treatments. Despite high-level healthcare in the Netherlands, not all patients with NSCLC are tested with the currently relevant predictive tumor markers that are necessary for optimal decision-making for today's available targeted or immunotherapy. An expert workshop on the molecular diagnosis of NSCLC involving pulmonary oncologists, clinical chemists, pathologists, and clinical scientists in molecular pathology was held in the Netherlands on December 10, 2018. The aims of the workshop were to facilitate cross-disciplinary discussions regarding standards of practice, and address recent developments and associated challenges that impact future practice. This paper presents a summary of the discussions and consensus opinions of the workshop participants on the initial challenges of harmonization of the detection and clinical use of predictive markers of NSCLC. A key theme identified was the need for broader and active participation of all stakeholders involved in molecular diagnostic services for NSCLC, including healthcare professionals across all disciplines, the hospitals and clinics involved in service delivery, healthcare insurers, and industry groups involved in diagnostic and treatment innovations. Such collaboration is essential to integrate different technologies into molecular diagnostics practice, to increase nationwide patient access to novel technologies, and to ensure consensus-preferred biomarkers are tested.

14.
Transplant Direct ; 4(10): e388, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30498765

ABSTRACT

BACKGROUND: Transplantation of beta cells by pancreas or islet transplantation is the treatment of choice for a selected group of patients suffering from type 1 diabetes mellitus. Pancreata are frequently not accepted for transplantation, because of the relatively high vulnerability of these organs to ischemic injury. In this study, we evaluated the effects of hypothermic machine perfusion (HMP) on the quality of human pancreas grafts. METHODS: Five pancreata derived from donation after circulatory death (DCD) and 5 from donation after brain death (DBD) donors were preserved by oxygenated HMP. Hypothermic machine perfusion was performed for 6 hours at 25 mm Hg by separate perfusion of the mesenteric superior artery and the splenic artery. Results were compared with those of 10 pancreata preserved by static cold storage. RESULTS: During HMP, homogeneous perfusion of the pancreas could be achieved. Adenosine 5'-triphosphate concentration increased 6,8-fold in DCD and 2,6-fold in DBD pancreata. No signs of cellular injury, edema or formation of reactive oxygen species were observed. Islets of Langerhans with good viability and in vitro function could be isolated after HMP. CONCLUSIONS: Oxygenated HMP is a feasible and safe preservation method for the human pancreas that increases tissue viability.

15.
Front Oncol ; 8: 176, 2018.
Article in English | MEDLINE | ID: mdl-29872644

ABSTRACT

A 62-year-old man was referred to our university hospital for treatment of advanced adenocarcinoma of the lung after disease progression on two lines of EGFR TKI and one line of chemotherapy. Fluorescent in situ hybridization analysis upon progression showed an HER2 amplification. At our weekly Molecular Tumor Board (MTB), a decision was made to treat this patient with afatinib, which resulted in a partial response. However, progression was observed with a facial nerve paresis due to a metastasis in the skull. A biopsy of a location in the thorax revealed the presence of an EGFR-T790M mutation associated with acquired resistance, after which treatment with osimertinib was started. After 6 months, disease progression was observed, and a new biopsy was taken from the pelvic bone, which revealed the original amplification of HER2 together with the EGFR-L858R mutation, the EGFR-T790M mutation was not detected. The MTB decided to treat the patient with trastuzumab/paclitaxel. A partial response was observed in different bone lesions, while the skull metastasis with ingrowth in the brain remained stable for 6 months. Because of progression of the bone metastases after 6 months, a biopsy of a lesion in the thorax wall was taken. In this lesion, the EGFR-T790M mutation could be detected again. The MTB advised to start treatment with a combination of osimertinib and afatinib. This resulted in an impressive clinical improvement and a partial response of the bone metastases on the most recent 18-fluorodeoxyglucose positron emission tomography and computer tomography-scan. In conclusion, adjusting treatment to the mutational make-up of the tumor is a great challenge. For optimal treatment response multiple biopsies and re-biopsy upon progression are imperative. As more genes are investigated, treatment decision becomes increasingly difficult, therefore, expert opinions from an MTB is essential.

16.
Transplantation ; 86(1): 148-54, 2008 Jul 15.
Article in English | MEDLINE | ID: mdl-18622292

ABSTRACT

BACKGROUND: Brain death donors are frequently used for transplantation. Previous studies showed that brain death (BD) negatively affects the immunological and inflammatory status of both liver and kidney. Because the intestine is increasingly used as a donor organ and no information on effects of BD on small intestine is available we performed this study. METHODS: We studied the inflammatory and apoptotic changes in donor intestine after BD induction. Brain death was induced in rats by inflation of a balloon catheter. Three groups (n=6) were compared: 1-hr BD, 4-hr BD, and sham-operated controls. RESULTS: An increased polymorphonuclear cell influx in ileum, as a measure of inflammation, was observed in 1- and 4-hr BD group compared with controls. Jejunum showed a significant increase at the 4-hr BD group compared with the control group. Intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and interleukin-6 were upregulated after 1- and 4-hr BD. Caspase-3 positive cells were found in jejunum and ileum after 4-hr BD on the top of the villi. Serum interleukin-6 was severely elevated in the 1- and 4-hr brain dead rats. CONCLUSION: These data show the early occurrence of intestinal inflammation and apoptosis after BD induction. These events may ultimately have a negative influence on the outcome of intestinal transplantation.


Subject(s)
Brain Death/immunology , Enteritis/immunology , Ileum/immunology , Inflammation Mediators/metabolism , Jejunum/immunology , Organ Transplantation , Animals , Apoptosis , Brain Death/pathology , Caspase 3/metabolism , Cytokines/metabolism , Disease Models, Animal , Enteritis/pathology , Ileum/pathology , Ileum/transplantation , Immunohistochemistry , Inflammation Mediators/blood , Jejunum/pathology , Jejunum/transplantation , Male , Neutrophils/immunology , RNA, Messenger/metabolism , Rats , Rats, Inbred F344 , Reverse Transcriptase Polymerase Chain Reaction , Time Factors
17.
Ann Surg ; 246(6): 982-8; discussion 989-91, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18043100

ABSTRACT

OBJECTIVE: To study graft function and ischemia/reperfusion injury of porcine kidneys after preservation with the new Groningen Machine Perfusion (GMP) system versus static cold storage (CS). INTRODUCTION: The increasing proportion of marginal and nonheart beating donors necessitates better preservation methods to maintain adequate graft viability. Hypothermic machine preservation (HMP) is a promising alternative to static CS. We have therefore developed and tested an HMP device, which is portable and actively oxygenates the perfusate via an oxygenator. The aim of the present study was to examine the efficacy of the GMP system in a transplantation experiment. MATERIALS AND METHODS: In a porcine autotransplantation model, kidneys were retrieved and either cold stored in University of Wisconsin CS for 20 hours at 4 degrees C or subjected to HMP using University of Wisconsin machine perfusion at 4 degrees C with 2 different pressure settings: 30/20 mm Hg or 60/40 mm Hg. RESULTS: HMP at 30/20 mm Hg was found to better preserve the viability of kidneys reflected by improved cortical microcirculation, less damage to the proximal tubule, less damage mediated by reactive oxygen species, less proinflammatory cytokine expression, and better functional recovery after transplantation. However, high perfusion pressures (60/40 mm Hg) resulted in higher expression of von Willebrand factor and monocyte chemotactic peptide-1 in postpreservation biopsies and subsequent graft thrombosis in 2 kidneys. CONCLUSIONS: It is concluded that the GMP system improves kidney graft viability and perfusion pressures are critically important for outcome.


Subject(s)
Hypothermia, Induced/instrumentation , Kidney Transplantation/physiology , Organ Preservation/methods , Perfusion/instrumentation , Recovery of Function/physiology , Animals , Biopsy , Disease Models, Animal , Equipment Design , Female , Kidney Cortex/pathology , Microcirculation/physiology , Renal Circulation/physiology , Reperfusion Injury/prevention & control , Swine , Transplantation, Autologous , Treatment Outcome
18.
Lab Anim ; 41(3): 363-71, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17640464

ABSTRACT

Organs used for transplantation are usually derived from heart-beating brain dead donors. However, brain death is known to have negative effects on donor organ quality, previously studied using a difficult to control sudden onset experimental model. We have now developed a reproducible gradual onset brain death model in rats without requiring inotropic support. Fisher inbred rats weighing 260-300 g were used. Brain death was induced by a gradual inflation of a subdurally placed balloon catheter. During induction and the period following brain death, the animals were mechanically ventilated and blood pressure was continuously monitored. The blood pressure registration showed a characteristic pattern during brain death induction, in which a decrease in blood pressure, a hypotensive period in which the Cushing response occurred, and a sharp peak were consistent findings. After brain death was induced, blood pressure was maintained at normotensive levels up to 4 h. After the experiments, neuropathological evaluation of the brain located haemorrhagic cerebral parenchyma, and immunocytochemistry of liver tissue revealed a significant influx of polymorph nuclear cells, as was previously observed as well. This improved model allows the study of brain death on donor organ quality without the use of inotropic support.


Subject(s)
Brain Death/physiopathology , Disease Models, Animal , Organ Preservation , Organ Transplantation/methods , Tissue Donors , Animals , Biomarkers/metabolism , Blood Pressure , Brain/pathology , Brain Death/pathology , Immunoenzyme Techniques , Liver/metabolism , Liver/pathology , Male , Rats , Rats, Inbred F344 , Respiration, Artificial
19.
Transpl Int ; 20(4): 343-52, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17326775

ABSTRACT

Hypothermic machine perfusion (HMP) provides better protection against ischemic damage of the kidney compared to cold-storage. The required perfusion pressures needed for optimal HMP of the liver are, however, unknown. Rat livers were preserved in University of Wisconsin organ preservation solution enriched with acridine orange (AO) to stain viable cells and propidium iodide (PI) to detect dead cells. Perfusion pressures of 12.5%, 25% or 50% of physiologic perfusion pressures were compared. Intravital fluorescence microscopy was used to assess liver perfusion by measuring the percentage of AO staining. After 1-h, the perfusion pressure of 12.5% revealed 72% +/- 3% perfusion of mainly the acinary zones one and two. The perfusion pressure of 25% and 50% showed complete perfusion. Furthermore, 12.5% showed 14.7 +/- 3.6, 25% showed 3.7 +/- 0.9, and 50% showed 11.2 +/- 1.4 PI positive cells. One hour was followed by another series of experiments comprising 24-h preservation. In comparison with 24-h cold-storage, HMP at 25% showed less PI positive cells and HMP at 50% showed more PI positive cells. In summary, perfusion at 25% showed complete perfusion, demonstrated by AO staining, with minimal cellular injury, shown with PI. This study indicates that fine-tuning of the perfusion pressure is crucial to balance (in)complete perfusion and endothelial injury.


Subject(s)
Hypothermia, Induced , Liver/physiopathology , Organ Preservation/methods , Perfusion/methods , Acridine Orange , Animals , Cell Survival , Male , Microscopy, Fluorescence , Pressure , Propidium , Rats , Staining and Labeling
20.
Liver Transpl ; 11(11): 1403-11, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16237692

ABSTRACT

Hypothermic machine perfusion (HMP) of abdominal organs is shown to be superior compared to cold storage. However, the question remains if oxygenation is required during preservation as oxygen is essential for energy resynthesis but also generates toxic reactive oxygen species (ROS). To determine if oxygenation should be used during HMP, urea-synthesis rate, adenosine triphosphate (ATP), and generation of ROS were studied in an in vitro model, modeling ischemia-reperfusion injury. Furthermore, expression of uncoupling protein-2 (UCP-2) mRNA was assessed since UCP-2 is a potentially protective protein against ROS. Rat liver slices were preserved for 0, 24, and 48 hr in University of Wisconsin machine perfusion solution (UW-MP) with 0%, 21%, or 95% oxygen at 0-4 degrees C and reperfused for 24 hours. In the 0% and 95% groups, an increase of ROS was found after cold storage in UW-MP. After slice reperfusion, only the 0% oxygen group showed higher levels. The 0% group showed a lower urea-synthesis rate as well as lower ATP levels. mRNA upregulation of UCP-2 was, in contrast to kidney mRNA studies, not observed. In conclusion, oxygenation of UW-MP gave better results. This study also shows that ROS formation occurs during hypothermic preservation and the liver is not protected by UCP-2. We conclude that saturation of UW-MP with 21% oxygen allows optimal preservation results.


Subject(s)
Liver/pathology , Organ Preservation Solutions/pharmacology , Organ Preservation/methods , Oxygen Consumption/physiology , Analysis of Variance , Animals , Base Sequence , Cell Respiration/physiology , Disease Models, Animal , Graft Rejection , Graft Survival , Hepatectomy , Hepatocytes/physiology , In Vitro Techniques , Liver Transplantation/adverse effects , Liver Transplantation/methods , Male , Molecular Sequence Data , Probability , RNA/analysis , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...