High-flow endobronchial cooled humidified air protects non-heart-beating donor rat lungs against warm ischemia

OBJECTIVE

Lungs from non-heart-beating donors for transplantation require protection against warm ischemic damage. Minimally invasive techniques are required to reduce organ damage during the warm ischemic period because invasive surgical procedures are often not feasible at this time. This study investigated the preservative effect of high-flow endobronchial cooled humidified air during warm ischemia in non-heart-beating donor rat lungs.

METHODS

Fourteen animals were divided into a Cooling group (n = 7), which received cooled air/saline spray during a 2-hour warm ischemic period, and a Control group (n = 7), which received no cooling. After ischemia the lungs were reperfused on an isolated lung perfusion apparatus.

RESULTS

Endobronchial temperatures in the Cooling and Control groups were 8 degrees C and 36 degrees C at 10 minutes, and 5 degrees C and 35 degrees C at 20 minutes, respectively (P < .0001). Lung core and surface temperatures in the Cooling group were also lower than those in the corresponding Control group (P < .0001). After reperfusion, pulmonary arterial pressure (P = .003) and peak airway pressure (P = .002) were lower in the Cooling group than in the Control group. Higher pulmonary venous PO2 (P = .02), higher adenosine triphosphate levels (P = .01), and lower wet/dry lung weight ratio (P = .003) were seen in the Cooling group compared with the Control group.

CONCLUSIONS

High-flow endobronchial cooled humidified air can decrease lung temperature and improve post-ischemic pulmonary function and adenosine triphosphate levels in non-heart-beating donor lungs.

Techniques of Reconstruction for Inadequate Donor Left Atrial Cuff in Lung Transplantation

BACKGROUND

An inadequate donor left atrial (LA) cuff due to an anatomical abnormality of the pulmonary vasculature or technical errors at the time of procurement can exclude the lungs from transplant. This study aims to describe the incidence, efficacy, and various techniques of LA cuff reconstruction in lung transplantation.

METHODS

A total of 637 pulmonary venous anastomosis in 405 consecutive lung transplants from January 1995 to July 2005 were reviewed. Comparison between the patients who required LA cuff reconstruction (reconstruction group) or who did not (no-reconstruction group) was made in posttransplant outcomes.

RESULTS

An overall incidence of requirement of LA cuff reconstruction was 2.7% (4% on the right, 1% on the left, p = 0.03). Seventy-one percent of LA inadequacy was corrected using a pericardial patch on the anterior LA cuff wall; the remainder required complicated reconstruction for separated/short pulmonary veins to create a new LA cuff. There was no significant difference between the reconstruction and no-reconstruction groups, respectively, in oxygenation (329 +/- 28, 337 +/- 10, p = 0.81), duration of intubation and intensive care unit stay (p = 0.54, p = 0.89, respectively), 30-day mortality (12%, 6%, p = 0.30), and 5-year survival (57%, 52%, p = 0.80).

CONCLUSIONS

Inadequate donor LA cuff is an infrequent but potentially serious complication in lung transplantation. Donor LA cuff reconstruction using donor pericardium or pulmonary artery remnant is a useful technique to salvage surgically marginal lungs without affecting early and late posttransplant outcomes. These lungs should not be excluded from transplantation.

Spectroscopic analysis of small organic molecules: A comprehensive near-edge x-ray-absorption fine-structure study of C6-ring-containing molecules

We report high-resolution C 1s near-edge x-ray-absorption fine-structure (NEXAFS) spectra of the C6-ring-containing molecules benzene (C6H6), 1,3- and 1,4-cyclohexadiene (C6H8), cyclohexene (C6H10), cyclohexane (C6H12), styrene (C8H8), and ethylbenzene (C8H10) which allow us to examine the gradual development of delocalization of the corresponding pi electron systems. Due to the high experimental resolution, vibrational progressions can be partly resolved in the spectra. The experimental spectra are compared with theoretical NEXAFS spectra obtained from density-functional theory calculations where electronic final-state relaxation is accounted for. The comparison yields very good agreement between theoretical spectra and experimental results. In all cases, the spectra can be described by excitations to pi*- and sigma*-type final-state orbitals with valence character, while final-state orbitals of Rydberg character make only minor contributions. The lowest C 1s-->1pi* excitation energy is found to agree in the (experimental and theoretical) spectra of all molecules except for 1,3-cyclohexadiene (C6H8) where an energy smaller by about 0.6 eV is obtained. The theoretical analysis can explain this result by different binding properties of this molecule compared to the others.

Extracorporeal membrane oxygenation after lung transplantation: evolving technique improves outcomes

BACKGROUND

Severe pulmonary graft failure (PGF) is the most common cause of death within the first 30 days after lung transplantation. Extracorporeal membrane oxygenation (ECMO) may provide lifesaving temporary support; however, its longer-term efficacy is controversial.

METHODS

We reviewed the use of ECMO for severe PGF after lung transplantation, and compared the outcomes between our early (1990 to 1999) and recent (2000 to 2003) experience utilizing improved initiation timing, oxygenator technology, and surgical technique.

RESULTS

Ten transplant recipients from a total of 481 (2.1%) were managed for PGF on ECMO by a multidisciplinary team at The Alfred Hospital. Four single-lung, 3 bilateral single-lung, and 3 heart-lung recipients were supported for a mean of 96 hours (range 14 to 212 hours). In the early group (operation from 1990 to 1999, n = 4) ECMO was initiated 21 days (range 7 to 40 days) after lung transplantation and in the recent group (operation from 2000 to 2003, n = 6) after 0 to 2 days (p = 0.01). Radial-arterial blood gas analysis 12 hours after initiation of ECMO showed significantly better oxygenation in the recent group (341 +/- 90 mm Hg) than in the early group (90 +/- 23 mm Hg, p = 0.03). Four deaths occurred as a result of bleeding (two in each group). In the early group only 1 patient was weaned from ECMO but died. In the recent group 3 were successfully weaned and were discharged from the intensive care unit; of these patients, 2 were discharged from hospital.

CONCLUSIONS

Extracorporeal membrane oxygenation results have improved with advances in oxygenator technology and surgical techniques. The procedure can allow resolution of early PGF after lung transplantation.

133Xenon ventilation scintigraphy applied to bronchoscopic lung volume reduction techniques for emphysema: relevance of interlobar collaterals

BACKGROUND

133Xenon ventilation scintigraphy and (99m)Tc-MAA perfusion scintigraphy can be used to assess dynamic ventilation patterns in patients with severe emphysema.

AIM

To describe the scintigraphic features of attempted bronchoscopic lung volume reduction (BLVR), exploring mechanisms that might explain the unexpected lack of postoperative atelectasis.

METHODS

Five patients with heterogenous severe upper lobe emphysema were evaluated with 133Xenon ventilation and (99m)Tc-MAA perfusion scintigraphy, chest radiography, bronchoscopy and high resolution computed tomography before and up to 1 month after endoscopic placement of bronchial prostheses (BLVR). Ex vivo assessment of the lungs of two further patients with severe upper lobe emphysema was performed.

RESULTS

No significant subsegmental or lobar collapse was evident on post-procedure chest radiography or high resolution computed tomography, despite bronchoscopic confirmation of adequate position and functioning of prostheses. 133Xenon ventilation scintigraphy confirms significantly decreased upper lobe wash-in (P < 0.023), unchanged lower lobe wash-in and significantly increased lower lobe wash-out rates (P < 0.005) after BLVR. Significant redistribution of perfusion to the lower lobes occurred after BLVR (P < 0.025). Ex vivo experiments on explanted emphysematous lungs demonstrated that these findings could best be explained by collateral interlobar ventilation, which was calculated in one specimen to be as high as 15% of total lower lobe ventilation. Peri-valvular leak is a much less likely possibility.

CONCLUSION

133Xenon ventilation scintigraphy indicated the presence of significant interlobar collateral ventilation in patients with severe emphysema that may have major relevance to these novel alternative techniques to lung volume reduction surgery. 133Xenon scintigraphy can be used in the evaluation of severe emphysema before and after novel therapeutic interventions.

Probing the molecular environment using spin-resolved photoelectron spectroscopy

Angle- and spin-resolved photoelectron spectroscopy with linearly and circularly polarized synchrotron radiation were used to study the electronic structure of model triatomic molecules, hydrogen sulfide, and carbonyl sulfide. The spin-polarization measurements of the molecular field split components of the S 2p photolines revealed a strong effect of the different molecular environments. The validity of simple atomic models to explain the results is discussed.

Economic considerations and future directions for lung volume reduction surgery

Chronic obstructive pulmonary disease is a major cause of morbidity and mortality throughout the world. Standard management includes avoidance of causative factors such as smoking, and pharmacological therapy with combinations of inhaled and/or oral bronchodilators and corticosteroids. Lung transplantation is an established but infrequent option due to donor shortages. The nonevidence-based application of lung volume reduction surgery as palliation for patients with severe emphysema culminated in the US federally approved multicenter National Emphysema Treatment Trial published in 2003. This article reviews recent guidelines concerning chronic obstructive pulmonary disease management as outlined in the 2002 Global Initiative for Obstructive Lung Disease Workshop Report, focuses on published data regarding the cost-effectiveness of lung volume reduction surgery and outlines some less invasive techniques that are on the horizon.

Experimental evidence of a dynamic Jahn-Teller effect in C60(+)

Detailed analysis of the highest occupied molecular orbital band shape in the photoelectron spectrum of gaseous C60 reveals a dynamic Jahn-Teller effect in the ground state of C60(+). The direct observation of three tunneling states asserts a D(3d) geometry for the isolated cation, originating from a strong vibronic coupling. These results show that the ionic motion plays an important role in the electron-phonon interaction.

Bronchoalveolar lavage macrophage and lymphocyte phenotypes in lung transplant recipients

Recent publications have demonstrated potentially pathologic changes in bronchoalveolar lavage (BAL) from clinically stable lung transplant recipients (SLTRs), but there are few available data on alveolar macrophages (AMs). We formulated the hypothesis that changes in BAL AM and lymphocyte phenotypes would be apparent even in SLTRs.A cross-sectional study using a standardized 3 x 60 ml BAL, investigating lymphocyte and AM phenotypes in 19 SLTRs, 5 subjects with bronchiolitis obliterans syndrome (BOS) and 18 normal control volunteers. BAL lymphocyte and AM markers were assessed using flow cytometry. We confirmed a significant elevation of neutrophils in all lung transplant recipients with a more marked elevation in the BOS subjects. Flow-cytometric analysis showed increased numbers of natural killer (NK; CD56/CD16-positive) cells, increased CD11b- and CD11c-positive CD3 lymphocytes, increased CD8-positive lymphocytes and increased HLA-DR expression in CD8 cells from the lung transplant recipients, when compared with normals (p <.005). In contrast, the expression of a number of AM surface markers, associated with a range of host defense functions against bacteria, fungi and viruses (CD11a, CD11b, CD11c, HLA-DR, CD14), was lower in both SLTRs and those with BOS (p <.05). These novel findings are consistent with complex lymphocyte and macrophage changes that may result from clinically silent infection, partially suppressed rejection, or both.

Dynamical relativistic effects in photoionization: spin-orbit-resolved angular distributions of xenon 4d photoelectrons near the Cooper minimum

Two decades ago, it was predicted [Y. S. Kim et al., Phys. Rev. Lett. 46, 1326 (1981)] that relativistic effects should alter the dynamics of the photoionization process in the vicinity of Cooper minima. The present experimental and theoretical study of the angular distributions of Xe 4d(3/2) and 4d(5/2) photoelectrons demonstrates this effect for the first time. The results clearly imply that relativistic effects are likely to be important for intermediate- Z atoms at most energies.

Iron overload and nitric oxide-derived oxidative stress following lung transplantation

BACKGROUND

Reactive oxygen species (ROS) may contribute to airway injury and the development of the bronchiolitis obliterans syndrome (BOS) following lung transplantation (LT). Chemically active iron released from ferritin stores and nitric oxide (NO)-derived radicals may add to the oxidative burden.

METHODS

We determined the concentrations of ferritin and the aqueous NO derivative nitrite (NO2(-)) within bronchoalveolar lavage fluid (BALF) of 14 stable LT recipients (ST) and 7 subjects with BOS and 21 normal controls. We also assessed the relationship between BALF ferritin and hemosiderin-laden macrophages (HLMs) using a hemosiderin score (HS) and determined BALF albumin concentration as a marker of microvascular leakage.

RESULTS

BALF ferritin concentrations and HSs were significantly elevated in LT recipients overall compared with normal controls (p < 0.05). BALF NO2(-) levels were elevated in BOS subjects and STs compared with normal controls (p = 0.002 and p = 0.09, respectively), but there was no difference between transplant groups. BALF albumin concentrations were elevated in BOS patients compared with normal controls (p = 0.02) and ST (p = 0.05), but there was no difference between STs and controls. There was a significant relationship between BALF ferritin concentration and HS in LT recipients overall (r(s) = 0.7, p < 0.001). In BOS subjects, but not ST, BALF ferritin was significantly related to BALF albumin (r(s) = 0.8, p = 0.05) and there was a weak relationship with NO2(-) concentration (r(s) = 0.6, p = 0.1). BALF NO2(-) was strongly related to BALF % neutrophils in BOS subjects (r(s) = 0.9, p < 0.01), but there was no such relationship in STs.

CONCLUSIONS

Our findings suggest that the allograft could be subject to significant iron-generated oxidative stress, which may be exacerbated by NO and neutrophil-derived ROS, particularly in BOS. Microvascular leakage may be a feature of established chronic rejection, which potentiates the iron overload and contributes to further airway damage and remodeling.

Bronchoalveolar lavage cellular profiles in lung transplantation: the effect of inhaled corticosteroids

Bronchiolitis Obliterans Syndrome (BOS) remains a major cause of long term morbidity and mortality in lung transplantation, and occurs despite significant immunosuppression. Airway inflammation is thought to precede the development of BOS.

OBJECTIVES

To examine the effect of inhaled corticosteroids on airway inflammation and the development of BOS in lung transplant recipients.

METHODS

30 patients were recruited and randomised in a double blind fashion to receive either 750 micrograms Fluticasone propionate (FP) twice daily or an identical appearing placebo for 3 months. BAL cell counts and differentials were performed at time 0 and after 3 months treatment. Lung function was assessed at each time point using spirometry.

RESULTS

24 patients were felt to be stable and free from infection at both time points and thus included in the analysis. There was a significant reduction in total cell count in BAL fluid after treatment with 3 months FP compared to 3 months placebo, however no change in cell differentials nor lung function was found.

DISCUSSION

Despite a reduction in total cell numbers in BAL fluid, lung function was not altered over the 3 months of treatment. It may be that longer treatment is required to see an effect.

Preliminary experience with inhaled nitric oxide for acute pulmonary hypertension after heart transplantation

BACKGROUND

Substantial interest has developed in the physiologic and therapeutic role of nitric oxide in the last few years. In patients with pulmonary hypertension it appears to be a useful selective pulmonary vasodilator; however, many issues of both staff and patient safety remained unanswered.

METHODS

This study examines further safety issues and also presents preliminary clinical experience in patients after orthotopic heart transplantation with pulmonary hypertension and right-sided ventricular failure.

RESULTS

Atmospheric levels of nitric oxide and nitrogen dioxide are 100 times less than occupational health standards. When nitric oxide is used at 70 parts per million in the presence of a fraction of inspired oxygen greater than 0.60, nitrogen dioxide levels in the circuit exceed the published short-term exposure limit of the American Conference of Government Industrial Hygienist of 5 parts per million.

CONCLUSION

Staff safety appears confirmed, but despite encouraging clinical results, further longer term safety and efficacy studies are indicated.

Multi-organ donor transmission of hepatitis C virus to five solid organ transplant recipients and lack of transmission to corneal transplant recipients

BACKGROUND

A multi-organ donor seronegative for hepatitis C virus (HCV) by 1st generation enzyme immunoassay (EIA) supplied 5 solid organs and 2 corneas to 7 recipients. This donor was retrospectively shown to be 2nd generation HCV EIA-positive and polymerase chain reaction (PCR)-positive. All 5 solid organ recipients but none of the corneal recipients developed HCV infection.

OBJECTIVES

To demonstrate the discordance between serological and PCR-based HCV detection in solid organ transplant recipients and the lack of transmission of HCV to the two corneal transplant recipients.

STUDY DESIGN

All 5 solid organ recipients were retrospectively shown to be HCV PCR-negative and -seronegative pre-transplant and HCV PCR-positive post-transplant. Serial serum samples on 3 recipients were evaluated by 2nd generation EIA, a prototypic structural and non-structural dual bead assay (EIA-SA, Abbott), the Chiron Recombinant Immunoblot Assay, 2nd generation (RIBA-2), and the Chiron RIBA HCV Test System Strip Immunoblot Assay 3.0 (RIBA-3, Chiron).

RESULTS

The dual bead EIA-SA and RIBA-3 were able to detect HCV seroconversion approximately 6 months earlier than the 2nd generation EIA in 2 recipients, and in 1 recipient only PCR detected infection within the first 10 months. There was no evidence of HCV transmission to the corneal recipients.

CONCLUSIONS

Although third generation assays such as the RIBA-3 and EIA-SA narrowed the window of HCV seronegativity in transplant recipients compared with the 2nd generation EIA, PCR was the most sensitive method of detecting acute HCV infection. Despite transmission of HCV to all of the solid organ recipients HCV was not transmitted to the corneal transplant recipients.

Akv murine leukemia virus enhances bone tumorigenesis in hMT-c-fos-LTR transgenic mice

hMt-c-fos-LTR transgenic mice (U. Rüther, D. Komitowski, F. R. Schubert, and E. F. Wagner. Oncogene 4, 861-865, 1989) developed bone sarcomas in 20% (3/15) of females at 448 +/- 25 days and in 8% (1/12) of males at 523 days. After infection of newborns with Akv, an infectious retrovirus derived from the ecotropic provirus of the AKR mouse, 69% (20/28) of female animals and 83% (24/29) of males developed malignant fibrous-osseous tumors. The tumors in infected transgenics developed with higher frequency and a 200-days shorter mean tumor latency period. The hMt-c-fos-LTR transgene was expressed in all the fibrous-osseous tumors. They also showed newly integrated Akv proviruses, but in most tumors Akv was detected and expressed in only a small number of the tumor cells. Wild-type C3H mice infected with Akv developed benign osteomas with an incidence of 33% and a latency period of 474 days. The data indicate that Akv exerts distinct pathogenic effects on the skeleton. In hMt-c-fos-LTR transgenic mice, predisposed to bone sarcomagenesis, Akv acts synergistically with the fos transgene, resulting in the development of fibrous-osseous tumors.

[Murine leukemia virus Akv promotes bone tumor development in fos-transgenic mice]

Newborn hMT-fos-LTR transgenic C3H mice and their non-transgenic siblings were infected with Akv, derived from the ecotropic provirus of the AKR mouse. Bone sarcomas in non-infected transgenics were observed in 20% (3/15) of females at 448 +/- 25 days and in 8% (1/12) of males at 523 days. Akv-infected transgenics developed bone tumors with higher frequency and at younger age: Females in 69% (20/28) at 268 +/- 122 days, males in 83% (24/29) at 279 +/- 109 days. In the majority of the bone tumors of Akv-infected transgenics (70% in females, 59% in males) cellular atypia was lacking and the histological pattern resembled human parosteal osteosarcoma. Only 50% (12/24) of bone tumors in Akv-infected transgenics revealed newly integrated virus sequences by Southern analysis. PCR analysis detected Akv sequences in DNAs of all tumors. Obviously, the insertion of Akv in a few cells induced the considerably accelerated bone tumor growth.

Preoperative prediction for the use of cardiopulmonary bypass in lung transplantation

Cardiopulmonary bypass has been widely used in the management of isolated single and double lung transplantations. Although there are certain clear-cut preoperative indications for cardiopulmonary bypass, in many patients the decision to use this modality is based on the hemodynamic consequences of intraoperative pulmonary artery clamping. We have performed 109 isolated lung transplantations. In 69 patients (38 single lung transplantations and 31 double lung transplantations) cardiopulmonary bypass was initiated only on the basis of intraoperative hemodynamics. We have analyzed preoperative data from these 69 patients to determine whether an intraoperative requirement for cardiopulmonary bypass can be predicted. Of 38 single lung transplantations, 12 necessitated cardiopulmonary bypass (all patients had restrictive lung disease). No patients with obstructive lung disease who underwent single lung transplantation required cardiopulmonary bypass (p < 0.001). For single lung transplantations, 6-minute walk, the arterial desaturation/oxygen requirements on exercise, and the right ventricular ejection fraction were all significantly different between the cardiopulmonary bypass and noncardiopulmonary bypass groups (p < 0.001). Of 31 double lung transplantations, 10 patients required cardiopulmonary bypass (seven had bronchiectasis, two had obstructive lung disease, and one had restrictive lung disease). For obstructive lung disease, no preoperative parameters predicted cardiopulmonary bypass. In conclusion, cardiopulmonary bypass is not necessary for most patients undergoing lung transplantation (in the absence of an absolute preoperative indication). Obstructive lung disease rarely necessitates cardiopulmonary bypass. In single lung transplantations, the subsequent requirement for cardiopulmonary bypass can be predicted from preoperative cardiopulmonary performance. For double lung transplantations, the requirement for cardiopulmonary bypass is usually dependent on unpredictable intraoperative factors.

Pulp response to the combined effects of cavity preparation and periodontal ligament injection

Thirteen random-source dogs provided 54 experimental and 50 control teeth. Controls received either a periodontal ligament (PDL) injection only, or no injection, with deep cavities prepared and restored. Experimental teeth received both a PDL injection and the deep cavity preparation and were then restored with an IRM base and acid-etched composite. Teeth were surgically removed for observation periods of one and 18 weeks and prepared for histologic evaluation. Results indicated that, in this model system, there was little additive effect to the pulpal reaction due to the PDL injection. Controls that were prepared had essentially the same pulpal response as did the experimental teeth (PDL injection/preparation). In both experimental and control pulps, the effects were primarily related to the depth of the cavity preparation.

Relationship between process and outcome in ambulatory care

The outcomes of a series of some 410 acute episodes from two family practice centers were rated on the degree to which the patient regained his usual functional status and his satisfaction with the outcome and the process of care. A portion of outcomes (251) were then compared to process scores obtained using explicit criteria and the rest to implicit process ratings based on the problem-oriented record. In both instances those cases with good outcomes had better process scores than those with bad outcomes; neither measure of satisfaction had a consistent relationship with either process measure.