Abdominal functional electrical stimulation to improve respiratory function after spinal cord injury: a systematic review and meta-analysis.

This corrects the article DOI: 10.1038/sc.2016.31.

Abdominal functional electrical stimulation to improve respiratory function after spinal cord injury: a systematic review and meta-analysis.

OBJECTIVES: Abdominal functional electrical stimulation (abdominal FES) is the application of a train of electrical pulses to the abdominal muscles, causing them to contract. Abdominal FES has been used as a neuroprosthesis to acutely augment respiratory function and as a rehabilitation tool to achieve a chronic increase in respiratory function after abdominal FES training, primarily focusing on patients with spinal cord injury (SCI). This study aimed to review the evidence surrounding the use of abdominal FES to improve respiratory function in both an acute and chronic manner after SCI. SETTINGS: A systematic search was performed on PubMed, with studies included if they applied abdominal FES to improve respiratory function in patients with SCI. METHODS: Fourteen studies met the inclusion criteria (10 acute and 4 chronic). Low participant numbers and heterogeneity across studies reduced the power of the meta-analysis. Despite this, abdominal FES was found to cause a significant acute improvement in cough peak flow, whereas forced exhaled volume in 1 s approached significance. A significant chronic increase in unassisted vital capacity, forced vital capacity and peak expiratory flow was found after abdominal FES training compared with baseline. CONCLUSIONS: This systematic review suggests that abdominal FES is an effective technique for improving respiratory function in both an acute and chronic manner after SCI. However, further randomised controlled trials, with larger participant numbers and standardised protocols, are needed to fully establish the clinical efficacy of this technique.

Amiodarone and cyclophosphamide: potential for enhanced lung toxicity.

Antineoplastic therapy can be associated with drug-induced lung toxicity. With the increasing use of amiodarone for cardiac dysrhythmias there is an increasing possibility of its combined use with chemotherapies for various malignancies. We report a patient on long-term amiodarone who developed biopsy-proven drug-induced lung toxicity after receiving high-dose cyclophosphamide, at a time-frame much shorter than would have been predicted with cyclophosphamide alone. The potential for enhanced lung toxicity secondary to combination of amiodarone and cyclophosphamide is discussed.

Prevention of influenza-induced lung injury in mice overexpressing extracellular superoxide dismutase.

Reactive oxygen and nitrogen species such as superoxide and nitric oxide are released into the extracellular spaces by inflammatory and airway epithelial cells. These molecules may exacerbate lung injury after influenza virus pneumonia. We hypothesized that enhanced expression of extracellular superoxide dismutase (EC SOD) in mouse airways would attenuate the pathological effects of influenza pneumonia. We compared the pathogenic effects of a nonlethal primary infection with mouse-adapted Hong Kong influenza A/68 virus in transgenic (TG) EC SOD mice versus non-TG (wild-type) littermates. Compared with wild-type mice, EC SOD TG mice showed less lung injury and inflammation as measured by significant blunting of interferon-gamma induction, reduced cell count and total protein in bronchoalveolar lavage fluid, reduced levels of lung nitrite/nitrate nitrotyrosine, and markedly reduced lung pathology. These results demonstrate that enhancing EC SOD in the conducting and distal airways of the lung minimizes influenza-induced lung injury by both ameliorating inflammation and attenuating oxidative stress.

Poly(A) cDNA-specific (PACS) RT-PCR: a quantitative method for the measurement of any poly(A)-containing mRNA not affected by contaminating genomic DNA.

We present a simple and efficient RT-PCR method for the detection and quantitation of any poly(A)-containing mRNA that is not affected by contaminating genomic DNA and does not rely on exhaustive DNase digestion protocols. The technique described here requires the use of an antisense primer designed to contain 6-8 bp cDNA-specific sequence and an additional 17 Ts located on the 5' end to take advantage of the poly(A) tail. A second cDNA-specific sense primer can be used that does not need to be separated by intronic DNA sequence.

Pulmonary toxicity of induction chemotherapy prior to standard or high-dose chemotherapy with autologous hematopoietic support.

We closely followed the pulmonary function of 150 consecutive high-risk breast cancer patients who underwent standard induction CAF (cyclophosphamide, doxorubicin, 5-fluorouracil) chemotherapy, followed by randomization to either standard-dose CPB (cyclophosphamide, cisplatin, bischloroethylnitrosourea [BCNU]) chemotherapy (SDC) or to high-dose CPB chemotherapy (HDC) with autologous bone marrow transplantation (ABMT) and peripheral blood progenitor cell support (PBPCS). Previously, we have described a delayed pulmonary toxicity syndrome (DPTS) which characterizes the pulmonary dysfunction after HDC and ABMT in this patient population. However, little is known concerning the role induction chemotherapy plays in its development. We found that after three cycles of induction CAF, the mean diffusing capacity of the lungs for carbon monoxide (DL(CO)) significantly decreased by 12.6%. Additionally, in patients receiving HDC, the mean DL(CO) further decreased to a nadir of 55.2 +/- 14.1% which was significantly lower than those receiving SDC (nadir: 80.7 +/- 12.3%). DPTS occurred in 72% of patients receiving HDC as compared with only 4% of patients receiving SDC. All individuals diagnosed with DPTS were treated with prednisone and the 2-yr follow-up of pulmonary function revealed a gradual improvement in mean DL(CO) such that there were no differences between HDC and SDC groups at the end of the study. No mortality was attributable to pulmonary toxicity in either group. After induction chemotherapy, but before HDC, bronchoalveolar lavage (BAL) demonstrated significant elevations in interleukin-6 (IL-6), IL-8, neutrophils, and lymphocytes. We conclude that induction CAF produces asymptomatic pulmonary dysfunction and inflammation which may prime the lungs for further injury by HDC and predispose to the development of DPTS. Fortunately, in this specific ABMT patient population, the early and judicious use of prednisone appears to improve pulmonary function in patients who develop DPTS.

Extracellular superoxide dismutase in the airways of transgenic mice reduces inflammation and attenuates lung toxicity following hyperoxia.

Extracellular superoxide dismutase (EC-SOD, or SOD3) is the major extracellular antioxidant enzyme in the lung. To study the biologic role of EC-SOD in hyperoxic-induced pulmonary disease, we created transgenic (Tg) mice that specifically target overexpression of human EC-SOD (hEC-SOD) to alveolar type II and nonciliated bronchial epithelial cells. Mice heterozygous for the hEC-SOD transgene showed threefold higher EC-SOD levels in the lung compared with wild-type (Wt) littermate controls. A significant amount of hEC-SOD was present in the epithelial lining fluid layer. Both Tg and Wt mice were exposed to normobaric hyperoxia (>99% oxygen) for 48, 72, and 84 hours. Mice overexpressing hEC-SOD in the airways attenuated the hyperoxic lung injury response, showed decreased morphologic evidence of lung damage, had reduced numbers of recruited inflammatory cells, and had a reduced lung wet/dry ratio. To evaluate whether reduced numbers of neutrophil infiltration were directly responsible for the tolerance to oxygen toxicity observed in the Tg mice, we made Wt and Tg mice neutropenic using anti-neutrophil antibodies and subsequently exposed them to 72 hours of hyperoxia. Both Wt and Tg neutrophil-depleted (ND) mice have less severe lung injury compared with non-ND animals, thus providing direct evidence that neutrophils recruited to the lung during hyperoxia play a distinct role in the resultant acute lung injury. We conclude that oxidative and inflammatory processes in the extracellular lung compartment contribute to hyperoxic-induced lung damage and that overexpression of hEC-SOD mediates a protective response to hyperoxia, at least in part, by attenuating the neutrophil inflammatory response.

Coronavirus pneumonia following autologous bone marrow transplantation for breast cancer.

Infectious bronchitis virus, otherwise known as coronavirus, can cause mild upper respiratory tract illnesses in children and adults. Rarely has coronavirus been linked, either by serology or nasal wash, to pneumonia. We report a case of a young woman who, following treatment for stage IIIA breast cancer using a high-dose chemotherapy regimen followed by autologous bone marrow and stem cell transplantation, developed respiratory failure and was found to have coronavirus pneumonia as diagnosed by electron microscopy from BAL fluid. We propose that coronavirus should be considered in the differential diagnosis of acute respiratory failure in cancer patients who have undergone high-dose chemotherapy and autologous hematopoietic support.

Physiologic effects of extracellular superoxide dismutase transgene overexpression on myocardial function after ischemia and reperfusion injury.

OBJECTIVE: Myocardial injury after ischemia and reperfusion may be mediated, in part, by oxygen-derived free radicals. In this study the protective effects of extracellular superoxide dismutase overexpression were directly assessed in the hearts of transgenic mice, after ischemia and reperfusion injury, using an isolated work-performing murine heart preparation and computerized analysis of functional data. METHODS: A blinded study was performed to compare cardiac function in the hearts of both transgenic mice with a 3.5-fold overexpression of myocardial extracellular superoxide dismutase (n = 6, 22 to 26 gm) and littermate controls (n = 8, 22 to 26 gm). Preload-dependent cardiac output, contractility, heart rate, stroke work, and stroke volume were evaluated in the two groups before and after a 6-minute period of normothermic ischemia. RESULTS: No differences were found between extracellular superoxide dismutase hearts and control hearts in any parameter of myocardial function before ischemia. After ischemia, decreases in cardiac output occurred in both groups; however, this decrease was larger in control mice compared with extracellular superoxide dismutase mice. A higher percentage of recovery was also observed in the contractility, heart rate, stroke work, and stroke volume of extracellular superoxide dismutase hearts compared with control hearts. CONCLUSION: After global normothermic ischemia and subsequent reperfusion, decreases in cardiac function occurred in both extracellular superoxide dismutase and control mice; however, a higher percentage of recovery was observed in the extracellular superoxide dismutase overexpressed hearts. These data suggest that extracellular superoxide dismutase transgene overexpression significantly improves preservation of myocardial function after ischemia and reperfusion injury.

Delayed pulmonary toxicity syndrome following high-dose chemotherapy and bone marrow transplantation for breast cancer.

We have intensely followed 45 consecutive women who underwent high-dose chemotherapy (cyclophosphamide/cisplatin/BCNU) and autologous bone marrow transplant (HDC/ABMT) for primary breast cancer with pulmonary function testing and computed tomography at regular intervals up to 126 wk (median follow-up, 72 wk). Our results show a high incidence of interstitial pneumonitis requiring steroids (64%), but no deaths due to pulmonary toxicity. The DL(CO) reaches a nadir of 58.2 +/- SEM 3.4 (expressed as a percent of baseline value) 15-18 wk following HDC/ABMT, and marginally improves with time. To a much lesser extent, vital capacity is reduced with a parallel drop in FEV1, suggesting mild restrictive changes without significant obstruction. Patients who develop pulmonary symptoms of cough or dyspnea have a corresponding significantly greater and earlier decline in DL(CO). Chest computed tomography was neither sensitive nor specific for diagnosing pulmonary toxicity. For patients who received steroids for pulmonary toxicity, there was a subsequent improvement in DL(CO) of 17.1% (p = 0.0001). Because our patients do not fit with the recent definition of idiopathic pulmonary syndrome (IPS), we propose the term delayed pulmonary toxicity syndrome (DPTS) to better describe the milder form of lung toxicity seen in our patient population. We were unable to correlate the severity of DPTS with age, tobacco use, baseline pulmonary function, or systemic exposure to BCNU, cyclophosphamide, or cisplatin. These data suggest that factor(s) other than, or in addition to, chemotherapy systemic exposure can contribute to DPTS. Furthermore, early identification and institution of systemic corticosteroids may improve lung function.

Mouse extracellular superoxide dismutase: primary structure, tissue-specific gene expression, chromosomal localization, and lung in situ hybridization.

Extracellular superoxide dismutase (EC-SOD) is the major extracellular antioxidant enzyme. We have determined the primary structure of mouse EC-SOD by characterization of complementary DNA (cDNA) clones and by amino-acid sequence analysis of purified protein. cDNA sequence analysis indicates that mouse EC-SOD is synthesized as a 251-amino-acid precursor protein with a predicted molecular weight of 27,400 D. Amino-terminal micro sequence analysis of purified mature mouse lung EC-SOD demonstrated the sequence to begin with SSFDLADRLDPV-. These results indicate that EC-SOD as initially synthesized contains a 24-amino-acid precursor peptide, and that the mature protein is 227 amino acids in length. Computer algorithms that predict the most likely site of cotranslational signal peptidase cleavage suggest that processing will occur between amino acids 18 and 19 or 20 and 21, which implies that EC-SOD may be initially synthesized as a pre-pro-protein. Like human EC-SOD, mature mouse EC-SOD is glycosylated. The full-length mouse EC-SOD cDNA is 1,834 base pairs long and is 82% (79% for protein) identical to rat EC-SOD, but only 60% (60% for protein) identical to human EC-SOD. The mouse EC-SOD gene locus (Sod3) was mapped by interspecific backcross haplotype analysis as being 0.9 +/- 0.9 centimorgans distal to the Qdpr locus on mouse Chromosome 5, a position suggesting that the human homologue of EC-SOD will map close to the human QDPR locus (4p15.3). Of nine tissues examined by Northern blot analysis, those of the kidney and lung are by far the major tissues that express EC-SOD messenger RNA. Using in situ hybridization in the mouse lung, we demonstrate EC-SOD gene expression to be highly localized to alveolar Type II epithelial cells. These data suggest that alveolar Type II cells play a central role in mediating EC-SOD antioxidant function in the lung.

Apoptosis and delayed neuronal damage after carbon monoxide poisoning in the rat.

Delayed neurological damage after CO hypoxia was studied in rats to determine whether programmed cell death (PCD), in addition to necrosis, is involved in neuronal death. In rats exposed to either air or CO (2500 ppm), microdialysis in brain cortex and hippocampus was performed to determine the extent of glutamate release and hydroxyl radical generation during the exposures. Groups of control and CO-exposed rats also were tested in a radial maze to assess the effects of the CO exposures on learning and memory. At 3, 7, and 21 days after CO exposure brains were perfusion-fixed and hematoxylin-eosin (H&E) was used to assess injury and to select regions for further examination. DNA fragmentation was sought by examining cryosections with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) reaction. We found significant increases in glutamate release and .OH generation during and immediately after CO hypoxia. CO-exposed rats showed learning and memory deficits after exposure associated with heterogeneous cell loss in cortex, globus pallidus, and cerebellum. The frontal cortex was affected most seriously; the damage was slight at Day 3, increased at Day 7, and persistent at Day 21 after CO exposure. TUNEL staining was positive at all three time points, and TUNEL-labeled cells were distributed similarly to eosinophilic cells. The number of cells stained by TUNEL was less than by H&E and amounted to 2 to 5% of all cell nuclei in regions of injury. Ultrastructural features of both neuronal necrosis and apoptosis also were observed readily by electron microscopy. These findings indicate that both necrosis and apoptosis (PCD) contribute to CO poisoning-induced brain cell death.

Sequence analysis, tissue expression and chromosomal localization of a mouse secreted superoxide dismutase gene.

Using a reverse transcriptase polymerase chain reaction (RT-PCR), a complement DNA encoding secreted superoxide dismutase (s-SOD) of a mouse kidney has been isolated and the nucleotide sequence was determined. The deduced amino acid sequence of mouse s-SOD cDNA shares 79% identity with the rat seminal SOD sequence and 61% identity with the human SOD3 sequence. Northern blot analysis showed that mouse s-SOD is intensely expressed in the kidney and lung tissues and detectable in other tested tissues, including the brain. The mouse s-SOD gene was assigned to chromosome 5 using fluorescence in situ hybridization analysis and PCR analysis of mouse/hamster hybrid cells.

Extracellular superoxide dismutase transgene overexpression preserves postischemic myocardial function in isolated murine hearts.

BACKGROUND: Myocardial injury after ischemia and reperfusion may be mediated, at least in part, by oxygen-derived free radicals; this supposition is supported by the observation that significant quantities of these radicals are generated during reperfusion. To directly assess the protective effect of extracellular superoxide dismutase (EC-SOD), this study was designed to investigate the ability of EC-SOD overexpression in the hearts of transgenic mice to protect myocardial tissue against ischemiareperfusion injury by use of an isolated work performing murine heart preparation and functional analysis. METHODS AND RESULTS: Ten transgenic mice (EC.SOD, 28 to 31 g) were studied and compared with 10 control mice (Ctl, 28 to 31 g) in terms of preischemic and postischemic myocardial function. All hearts underwent cardiac harvest and arrest, followed by instrumentation and subsequent reperfusion with warm Krebs-Henseleit solution. Preload-dependent functional analysis was then performed to evaluate cardiac output, contractility (dP/dt), heart rate, stroke work, and stroke volume before and after a 7-minute period of warm ischemia. Results are expressed as mean +/- SEM (ANOVA, paired unpaired t tests). There was no significant difference in preischemic myocardial performance for Ctl and EC-SOD mice. After warm ischemia, cardiac output in EC-SOD was significantly improved compared with Ctl (EC-SOD, 4.55 +/- 0.37 mL/min; Ctl, 2.55 +/- 0.28 mL/min; P < .05). Postischemic dP/dt, stroke work, and stroke volume were also significantly improved in EC-SOD compared with Ctl mice (EC-SOD, 1808 +/- 39 mm Hg/s, 745 +/- 67 dyne.cm, and 13.1 +/- 1.2 microL, respectively; Ctl, 1497 +/- 87 mm Hg/s, 472 +/- 83 dyne.cm, and 8.2 +/- 1.5 microL; P < .05). CONCLUSIONS: EC-SOD overexpressed mice showed significant improvement in postischemic cardiac function compared with Ctl mice. Thus, EC-SOD overexpressed hearts are less susceptible to mild degrees of ischemia-reperfusion injury than normal hearts.