Biphasic graft preservation for lung transplantation

The standard, most widely applied way of preserving a lung for transplantation is infusion through the pulmonary artery (PA) of a pulmonaryplegic solution. In this prospective study, we analyzed the initial function of the pulmonary and cardiac graft after biphasic infusion of a solution introduced retrograde through the left auricle and antegrade through the PA. Twenty-six heart and lung grafts (9 unilateral and 17 bilateral) were preserved by cardioplegia and pulmonaryplegia (biphasic) between January 1996 and March 1997. Indicators of graft viability recorded were the ratio of arterial oxygen pressure (PaO2) to inspired fraction (FiO2), mean systemic pressure (MSP), mean pulmonary artery pressure (MPAP) cardiac output, pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR). The variables were recorded upon arrival of the grafts in the intensive care unit and in the first 24 h. Morbidity and mortality after heart transplants were recorded throughout a follow-up period of one month. After transplantation, most patients had a oxygenation coefficient (PaO2/FiO2) greater than 252 mmHg in the first 48 h. Hemodynamic parameters were also kept within normal ranges immediately after surgery and 24 h later. Mean ischemic time was 245 min for unilateral transplants, 215 for the first lung in double lung transplants, and 300 min for the second lung. In the early postoperative period, 3 patients suffered lung graft dysfunction, which was treated satisfactorily with nitric oxide (NO). No heart transplant patient suffered primary heart failure or left ventricular dilatation. We conclude that biphasic pulmonary preservation achieves satisfactory initial functional viability of the graft. Heart grafts removed simultaneously functioned successfully in the transplanted patient without additional pharmacological or mechanical support.     

A comparison of the new preservation solution Celsior to Euro-Collins and University of Wisconsin solutions in lung reperfusion injury

BACKGROUND: The lung is particularly susceptible to reperfusion injury, both experimentally and clinically after transplantation. The extracellular-type preservation solution Celsior, which has been predominantly studied in cardiac preservation, has components designed to prevent cell swelling, free radical injury, energy depletion, and calcium overload. Using an isolated blood-perfused rat lung model, we investigated whether Celsior would decrease preservation injury and improve lung function after cold ischemic storage and reperfusion compared to Euro-Collins (EC) and University of Wisconsin (UW) solutions. METHODS: Lewis rat lungs were isolated, flushed with the respective cold preservation solution, and then stored at 4 degrees C for 6 or 12 hr. After ischemic storage, the lung block was suspended from a force transducer, ventilated with 100% O2, and reperfused for 90 min with fresh blood via a cannula in the pulmonary artery. Lung compliance, alveolar-arterial oxygen difference, and outflow oxygen tension were all measured. The capillary filtration coefficient (Kf), a sensitive measure of changes in microvascular permeability, was determined. RESULTS: For 6 hr of cold storage, lungs stored in Celsior had lower Kf values than those stored in EC, indicating decreased microvascular permeability. No other significant differences were noted between Celsior and EC or UW. For 12 hr of cold storage, Celsior provided increased oxygenation, decreased alveolar-arterial O2 differences, increased compliance, and decreased Kf values as compared to both EC and UW. CONCLUSIONS: Celsior provides better lung preservation than EC or UW as demonstrated by increased oxygenation, decreased capillary permeability, and improved lung compliance, particularly at 12-hr storage times. These results are highly relevant, inasmuch as EC and UW are the most common clinically used lung preservation solutions. Further studies of Celsior in experimental and clinical lung transplantation, as well as in other solid organs, are indicated.     

Protective effects of various preservation solutions on cultured endothelial cells

Vascular endothelium represents the first target in organ preservation and plays an important role in reperfusion injury. Bovine aortic endothelial cells were cultivated and the most commonly used preservation solutions, such as University of Wisconsin HTK (Brettschneider's histidine-tryptophane-ketoglutarate), and Euro-Collins solutions were tested on the endothelial monolayer. In addition, one group of cultivated cells was preserved with cold saline solution, and endothelial monolayers grown in culture medium were used as controls. The quality of preservation was assessed after 24, 48, and 72 hours of cold storage. Reperfusion was simulated and its effects were observed by reincubation in culture medium at 37 degrees C for 6 hours. The total number of cells, cell viability (determined using trypan blue exclusion), and morphologic alterations were determined. Prostacyclin release was evaluated as a biochemical marker. University of Wisconsin solution maintains more than 99% cell viability after rewarming after both 24 and 48 hours of cold storage. After 72 hours, 86.7% of cells were still viable. Preservation with HTK and Euro-Collins solution allowed cell survival for only 24 hours (96.7%, HTK; 49.9%, Euro-Collins), with no viable cells seen after 48 hours. The cold saline-preserved sample showed 57.8% viable cells after 24 hours and 29.7% after 48 hours. No viable cells were detectable after 72 hours. Light microscopy revealed several patterns of both structural damage and intracellular change (nucleus and cytoplasm) in the endothelial monolayer after preservation with HTK, Euro-Collins solution, and cold saline solution. No morphologic alterations were seen in the University of Wisconsin solution group for as long as 72 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ischemic preconditioning enhances donor lung preservation in the rat

BACKGROUND: Ischemic preconditioning achieved by brief periods of ischemia and reperfusion before a prolonged period of ischemia can significantly reduce the extent of cardiac damage in many mammalian species and human beings. In this study we used a rat model of single lung transplantation to show that ischemic preconditioning also occurs in the lung. METHODS: Rats randomly selected for ischemic preconditioning had their left main bronchus and pulmonary artery occluded for 5 minutes, followed by 10 minutes of reperfusion and ventilation. Lungs of control rats were ventilated for 15 minutes. The lungs were perfused with University of Wisconsin solution, then heart and lungs were excised en bloc and stored in University of Wisconsin solution at 0 degree C for 6 or 12 hours. After left pneumonectomy, the left lung of the donor was then implanted into the recipient via left thoracotomy. After 1 hour of ventilation and reperfusion, a right pneumonectomy was performed making the animal completely dependent on the transplanted lung. Samples of arterial blood from the left ventricle were then taken for arterial oxygen tension and arterial carbon dioxide tension determination. Water contents of the donor lungs were measured before and after reperfusion. Thiobarbituric acid reactive substances were measured in the right donor lung after storage. RESULTS: Lungs transplanted after 12 hours of storage had profoundly impaired gas exchange (arterial oxygen tension = 34 +/- 5; arterial carbon dioxide tension = 69 +/- 7 mm Hg) compared with the normal levels in the 6-hour storage group (arterial oxygen tension = 308 +/- 22; arterial carbon dioxide tension = 17 +/- 1 mm Hg). Ischemic preconditioning significantly improved gas exchange in the 12-hour storage group (arterial oxygen tension = 83 +/- 11; arterial carbon dioxide tension = 40 +/- 4 mm Hg). Ischemic preconditioning also significantly decreased thiobarbituric acid reactive substances formation at both 6- and 12-hour storage. CONCLUSIONS: These results show that the phenomenon of ischemic preconditioning occurs in the lung and that it may reduce injury to the donor lung during prolonged cold ischemic storage.     

Enhancement of extended lung preservation with a vasoactive intestinal peptide-enriched University of Wisconsin solution

Vasoactive intestinal peptide (VIP) is a known pulmonary and bronchial vasodilator as well as an oxygen free radical scavenger. Since its effect as an additive to University of Wisconsin (UW) solution for lung preservation has been shown previously, the aim of this study was to determine the ability of VIP to improve lung preservation followed by reperfusion. Four groups of excised Sprague-Dawley rat lungs (n = 24) were studied using an isolated blood perfused working lung model. The first 3 groups of lungs were flushed and stored in UW solution at 4 degrees C for: (1) 4 hr, (2) 18 hr, and (3) 24 hr. Group 4 lungs were flushed with UW solution + VIP (1 microgram/ml) and stored in UW solution + VIP (0.5 microgram/ml) for 24 hr. After preservation, the lungs were reperfused to evaluate their functions for 2 hr or until lung failure occurred (arterial oxygen saturation less than 90% and/or appearance of bronchial fluid in the bronchial cannula). In the lungs stored in UW solution for 24 hr, failure occurred after 10 min of reperfusion and all functions were significantly altered. The addition of VIP to UW solution maintained the functional capacity of the lungs, recorded by lung resistance, lung compliance, elastic work, flow resistive work, shunt fraction, and blood oxygen tension. No statistical difference in these parameters other than shunt fraction was found when the VIP group was compared with the group preserved for 4 hr in UW solution. We conclude that lung preservation can be extended to 24 hr with the maintenance of lung functional capacity if VIP is added to UW solution.     

Changes in alveolar oxygen and carbon dioxide concentration and oxygen consumption during lung preservation. The maintenance of aerobic metabolism during lung preservation

Adult human liver microsomes supplemented with NADPH catalyzed the regioselective N-oxygenation of the aliphatic tertiary amine and S-oxidation of the phenothiazine sulfur atom of several 10-(N,N-dimethylaminoalkyl)phenothiazines. In addition, (+)- and (-)-4-bromophenyl-1,3-oxathiolane were converted to the corresponding S-oxides in the presence of NADPH and adult human liver microsomes. The (+) and (-) enantiomers of 4-bromophenyl-1,3-oxathiolane were converted to the S-oxides with low and high stereoselectivity, respectively. Studies on the biochemical mechanism for N-oxygenation of 10-(N,N-dimethylaminoalkyl)phenothiazines suggested that this reaction was catalyzed by the flavin-containing monooxygenase (form II), although cytochrome P-450 2D6 may also have contributed to N-oxide formation. S-Oxidation of chlorpromazine was catalyzed mainly by cytochrome P-450 3A. S-Oxidation of 10-(N,N-dimethylaminoalkyl)phenothiazines was catalyzed by a number of cytochromes P-450, including cytochromes P-450 2A6, 2C8, and 2D6. S-Oxygenation of (+)-4-bromophenyl-1,3-oxathiolane produced a mixture of the cis- and trans diastereomers in a process probably dependent on both hepatic monooxygenase systems. (-)-4-Bromophenyl-1,3-oxathiolane was converted almost exclusively to the trans-S-oxide in a process likely dependent on the adult human liver flavin-containing monooxygenase (form II). Development of regio- and stereochemical probes of adult human liver flavin-containing monooxygenase (form II) and cytochromes P-450 activity may be useful for eventual in vitro-in vivo correlations, but may require approaches quite distinct from that currently used for animal monooxygenases.     

Reflections on screening tests for lung cancer

Screening for lung cancer is a controversial issue. Much needs to be done in the area of primary prevention of lung cancer. Predictions of lung cancer mortality in Europe indicate further increases in the coming 20 years, due to the extensive number of individuals having long periods of exposure to carcinogens. The treatment of lung cancer is not solved, either, and the global epidemiological situation of lung cancer raises great concerns. Due to these reasons, it seems to be necessary to revise the issue of lung cancer screening. In Hungary, annual minimal mass roentgen screening has been done for decades. The data of more than 4.3 million individuals were analysed in 1996. Out of the symptomless patients detected, 21.4% fell into oncological stage 1, 33.7% into stage 2 and 29% into stage 3. Those patients who were not screened, but who presented with symptoms and were detected as such, can be classified into stages as follows: Stage 1: 8.7%, stage 2: 21.5% and stage 3: 36.3%. The resection rate in the screened group versus non-screened group was 34.3% and 13.7% respectively. Minimal mass roentgen screening allows the detection of lung cancer patients in an earlier stage; with improved treatment possibilities, survival rates and patients' quality of life will shift to a positive direction. It is suggested that the effectiveness of minimal mass roentgen screening of lung cancer should be revised.     

Pneumocytes type II ultrastructural modifications after storage in preservation solutions for transplantation

Although lung transplantation represents a real therapeutic opportunity, the problem of preserving the organ for a prolonged period (> 10 h) still remains unsolved. Further studies are necessary to fully understand the behavior of different lung cell types during the ischemic period. As ultrastructural modifications of cells of lung samples stored in different means of preservation represent an index of the integrity and therefore of cellular viability, in the present work we have compared the time-related ultrastructural changes in human pneumocytes type II cells after hypothermic (10 degrees C) storage for 6 and 12 h in University of Wisconsin (UW) solution and in low potassium dextran (LPD) solution. An ultrastructural grading scale was used to quantify the damage and the results confirmed what was observed microscopically. Statistical analysis (t test) of the data showed that after 6 h in LPD solution, pneumocytes type II were less damaged than those stored in UW solution; these differences were statistically significant (p < 0.05). In our opinion, ultrastructural studies should be considered among the methods presently used to assess the effectiveness of different storage fluids.     

Canine lung transplantation after more than twenty-four hours of normothermic preservation

BACKGROUND: Consistent clinical results have not been achieved when lung preservation times exceed 6 hours. The aim of this study was to use an alternative normothermic autoperfusion technique for lung preservation and transplantation. METHODS: In six paired dogs, donor lungs were removed, along with the heart, liver, pancreas, duodenum, and both kidneys, and were preserved for 24 to 33 hours in a normothermic autoperfused multiple organ block. Orthotopic left lung transplantation was performed at the end of the preservation period. RESULTS: Lung function was good during the preservation period. With a gas mixture of 50% O2 + 3% CO2 + 47% N2 delivered to the multiorgan block, arterial oxygen tension ranged from 331 +/- 19 to 383 +/- 8 mm Hg; carbon dioxide tension ranged from 18 +/- 5 to 32 +/- 5 mm Hg; and pH ranged from 7.36 +/- 0.02 to 7.45 +/- 0.08. After transplantation, the dogs were kept anesthetized and ventilated for 24 hours with the same gas mixture. The opposite pulmonary artery was occluded 0 to 6 hours after transplantation. Arterial blood pressures were stable after surgery. Arterial oxygen tension was maintained between 205 +/- 39 and 320 +/- 57 mm Hg, and arterial carbon dioxide tension was maintained between 23 +/- 2 and 34 +/- 2 mm Hg. Lung tissue wet/dry weight ratio was 4.94 +/- 0.17 after preservation; this ratio did not differ from that found in normal controls (4.91 +/- 0.10). CONCLUSIONS: This study shows that the lungs were well preserved for more than 24 hours of preservation when the normothermic multiorgan block preparation was used. The transplanted left lung was able to support the anesthetized dog after the opposite pulmonary artery was occluded.     

Helical CT for secondary screening of lung cancer

Helical CT was used on a trial basis for secondary screening of lung cancer, and its clinical usefulness is discussed in this report. The subjects 157 patients with abnormal shadows on plain chest X-ray images acquired between November 1993 and August 1994. Imaging parameters used for screening CT were as follows: 50 mA, 120 kV, a couch-top movement speed of 20 mm/s, and a beam width of 10 mm. The entire lung field was scanned during a single breath-hold. Reconstructed images were generated at 10-mm intervals by the 180 degree interpolation method, and films were produced. Images of the entire lung field were made during a single breath-hold in all patients. Abnormal shadows were detected in 73 of 157 patients by screening CT. These 73 patients included 14 with lung cancer, 53 with benign lesions, one under observation, and five others. The average diameter of the tumors was 11.1 mm. The lung cancers detected all arose in the periphery, and were classified into stage I (10 paeitents), stage IIIA (3 patients), and stage IV with bone metastases (1 patient). Lung cancers in clinical stage I (3 patients) and stage IV (1 patient) were difficult to see on plain chest X-ray films. We conclude that screening CT is useful for early diagnosis of lung cancer because the entire lung field can be imaged during a single breath-hold. Therefore, helical CT can be expected to be useful in screening for lung cancer.     

Addition of an osmotic agent to liver preservative solutions in a model of in vitro preservation of hepatocytes

To avoid hypoxic cell swelling during liver preservation followed by reduced perfusion in the reoxygenation period, osmotic substances such as mannitol, sucrose and raffinose, and the impermeant anion lactobionate are used in established liver preservation solutions. The various osmotic agents were investigated at concentrations of 60, 140, 260 and 300 mM, the solutions being kept isotonic by substitution with sodium and potassium chloride to 300 mosmol/l. Cultures of adherent pig hepatocytes were incubated in an in vitro model of cold hypoxia (4 degrees C, PO2 < 0.1 mmHg) for 24 h and reoxygenated with standard culture medium for 3 h. After each incubation period, light microscopy was performed to estimate cell viability and detachment rate. LDH and GOT liberation were also measured. To estimate the change in cell volume, isolated hepatocytes were incubated in suspension for 24 h of cold hypoxia. The cell volumes were compared after centrifugation and measurement of the pellet and the solute levels. Rising concentrations of osmotic substances resulted in increasing liberation of LDH and GOT. The levels of LDH and GOT release from cultures incubated with 60 mmol/l sucrose or raffinose were comparable to those in a preservation solution of "extracellular" ion composition. Addition of mannitol to the preservation solution resulted in cell damage. At high concentrations, sucrose did not affect the hepatocytes as much as raffinose. While mannitol can permeate the hepatocytes and lead to cell swelling, a cell-shrinking effect was observed when sucrose was used, and even more pronounced cell shrinking was seen with raffinose, to which the hepatocyte membrane is known to be permeable.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of compulsive rituals with visual screening: a case study with long-term follow-up

The present study reports on the use of visual screening, a mildly aversive response suppression procedure, as a treatment for reducing compulsive behaviors in a four and one-half year-old developmentally disabled boy. Two distinct patterns of compulsive responding were observed: repetitive (stereotyped) shoe-related behaviors and a ritualistic shoe-related act. The effect of visual screening on repetitive shoe-related responses was initially evaluated in a laboratory setting under A-B-A-B-B1 experimental conditions and systematically extended to the classroom setting in multiple baseline fashion. Visual screening was also contingently applied as treatment for the shoe-related ritual, with the effects analyzed using a similar multiple baseline format across hospital residential unit and natural home settings. Results of the study indicated that visual screening was an effective treatment for suppressing both forms of the subject's compulsive responding and that it was an easily learned and administered procedure from both staff and parent perspectives. Follow-up data across 12 months were obtained and indicated that the effect of treatment was exceptionally durable.     

Rapid screening for psychologic distress in men with prostate carcinoma: a pilot study

BACKGROUND: As more oncology care is moved to the outpatient setting, the need for a rapid means for oncologists to identify patients with significant distress has increased. Concurrent with this move has been the pressure to reduce time spent with each patient, adding to the likelihood that a distressed patient will not be recognized and will remain untreated in the current health care environment. METHODS: A pilot program was conducted in a prostate carcinoma oncology clinic to test the feasibility of a two-stage approach that identifies patients in significant distress and refers them for treatment. Two pencil and paper self-report measures were used to detect psychologic distress in patients over the previous week: 1) The Hospital Anxiety and Depression Scale (HADS) and 2) "The Distress Thermometer." Patients who scored above an agreed upon cutoff score on either measure (HADS = 15+; Thermometer = 5+) were referred to the psychiatric liaison in the clinic for evaluation. RESULTS: Compliance in filling out the measures was excellent; only 8 of 121 patients (6.6%) refused. Thirty-one percent of evaluable patients were referred based on elevated scores. Seventeen of 29 patients actually were evaluated. Eight of 17 patients met Diagnostic and Statistical Manual (of Mental Disorders)-IV criteria for a psychiatric disorder. CONCLUSIONS: This approach for rapid screening for distress was acceptable in prostate carcinoma patients, although these older men were reluctant to agree to evaluation and treatment. This simple screening method needs further testing and the identification of barriers on the part of the patient and oncologist that impede the identification of the most distressed patients.     

The effects of saline solutions on red cell shape: a scanning-electron- microscope-based study

Red cells appear to change shape in response to alterations in their environment both in vitro and in vivo. To investigate the qualitative aspects of this phenomenon, five drops of a venous blood sample were fixed in buffered glutaraldehyde for baseline observations and 0.5 ml of blood added to 4 ml of four different saline solutions. Triplicated 10-drop samples from the suspensions were fixed in the glutaraldehyde solution after 2.5, 5, 10, 20 and 40 min and prepared for scanning electron microscopy. Red cell shape analysis of the resulting micrographs showed that the cells had changed shape, although no two patterns of change were the same.