Flexible CO2 Laser in Therapeutic Bronchoscopy: Initial Experiences in a Tertiary Center

BACKGROUND

CO2 Laser (CO2L) technology deployable through flexible endoscopes now allows for their use throughout the airway, although published data are limited.

METHODS

Retrospective analysis of CO2L bronchoscopic procedures, excluding glottic and subglottic interventions. Procedural success was defined as >50% visual reduction in airway obstruction in the area treated or resolution of the procedural indication.

RESULTS

Seventy-two procedures were performed on 36 patients. Nonmalignant indications comprised 66%: stent-associated granulation tissue (28%), granulomatosis with polyangiitis lesions (23%), and lung transplant-related granulation tissue (16%) were the most common. Bronchoscopic access was flexible only in 81% and primarily rigid (combined with flexible) in 18%. The site of intervention was the trachea at 19%, the mainstem at 56%, and lobar/segmental airways at 45%. Procedural success was 89%. CO2L was used exclusively in 19%; in 81%, additional techniques were required, most commonly balloon dilation (59%), cryo-debulking (23%), and rigid dilation (16%). Malignant indications had a nonsignificant trend toward requiring adjuvant techniques ( P =0.05). Seventy-six percent of the patients required more than 1 procedure. CO2L exclusive cases had no statistically different needs for subsequent therapeutic bronchoscopies ( P =0.10) or time to reintervention (109 vs. 41 days, P =0.07), and reintervention-free survival was similar ( P =0.10) and difficult to predict. The complication rate attributable to CO2L was 2.7%.

CONCLUSION

CO2L is a safe and useful tool when precise cutting and vaporization are desired. Its use in multi-modality approaches has high levels of success in adequately selected lesions, adding an ablative potential to dilation techniques. Vasculitis-associated scars/webs and granulation tissue (including stent-associated) appear to be ideal targets.

Pulmonary artery pseudoaneurysm arising from primary lung neoplasm: A proposed mechanism

Pulmonary artery pseudoaneurysms (PAPs) are rare and life-threatening occurrences. We present a 57-year-old male patient with squamous cell lung cancer, who presented with hemoptysis. Bronchoscopy did not reveal ongoing bleeding. Imaging showed a left lower lobe tumor, a cavitary lesion communicating with the bronchus, and a pulmonary artery pseudoaneurysm. Successful embolization of the originating segmental branch of the pulmonary artery was performed. The pathogenesis of PAPs associated with primary lung malignancies remains poorly understood. We propose a four-step mechanism involving primary tumor expansion, central cavitary necrosis, direct arterial invasion, inflammatory response, vessel wall damage, pseudoaneurysm formation, and subsequent filling of the former cavitary lesion. This case emphasizes the importance of considering PAPs in primary lung malignancies, particularly in male patients with squamous cell pathology. Understanding the proposed pathogenic mechanism could lead to early detection, prompt intervention, and improved outcomes.

Evaluation of automated sample preparation system for lymph node sampling

Background

Endobronchial ultrasound-guided transbronchial fine needle aspiration (EBUS-FNA) has revolutionized the diagnostic and staging approach to non-small cell carcinoma and thoracic lymphadenopathy. However, obstacles to efficacy of rapid on-site evaluation (ROSE) of the samples include variability in sample quality and slow and cumbersome process in the procedure room leading to extended procedure time. The purpose of this pilot study was to evaluate the feasibility and specimen quality of lymph node biopsies prepared through a novel automated system for automated fixation, drying and staining compared to standard slide preparation method.

Methods

We performed a prospective, single-center pilot feasibility study of patients undergoing EBUS. Samples were split into conventional standard of care (SOC) slide preparation and preparation using the device ("instrument"). Pathologists compared the SOC slides to the slides prepared by the automated system and assessed the following metrics: nuclear and cytoplasmic quality, presence of debris/artifact, staining quality, creation of a monolayer, and ease of adequacy/diagnosis assessment. A score between 1 (lowest quality) and 3 (highest quality) was assigned to the above metrics.

Results

Sixty patients were recruited. One to three lymph nodes were sampled for each patient for a total of 72 samples collected. The mean scores of each assessment category showed no statistical difference between the two preparation techniques except for improved monolayer creation in the instrument samples. Thirty of thirty-one (96.8%) paired samples in the final analysis showed diagnostic equivalency between the automated slides and conventional slides; the discordant pairing was reported to be suspicious on the instrument sample and atypical on the SOC.

Conclusions

Study results suggest that slides prepared by the automated system are of adequate quality for adequacy assessment with diagnostic concordance when compared to SOC slides.

Erythrose and Threose: Carbonyl Migrations, Epimerizations, Aldol, and Oxidative Fragmentation Reactions under Plausible Prebiotic Conditions

The prebiotic generation of sugars in the context of origins of life studies is of considerable interest. Among the important intramolecular processes of sugars are carbonyl migrations and accompanying epimerizations. Herein we describe the carbonyl migration-epimerization process occurring down the entire carbon chain of chirally pure d-tetroses sugars under mild conditions. Employing chirally pure 1-¹³ C-erythrose, 4-¹³ C-erythrose and 1-¹³ C-threose, we (1) identify all the species formed as the carbonyl migrates down the four-carbon chain and (2) assess the rates associated with the production of each of these species. Competing aldol reactions and oxidative fragmentation processes were also observed. Further observations of self-condensation of glycolaldehyde mainly yielding 2-keto-hexoses (sorbose and tagatose) and tetrulose also provides a basis for understanding the effect of carbonyl migrations on the product distribution in plausible prebiotic scenarios.

Novel Image-Guided Flexible-Probe Transbronchial Microwave Ablation for Stage 1 Lung Cancer

BACKGROUND

Image-guided percutaneous thermal ablation is an established treatment option for early-stage lung cancer in medically inoperable patients but carries a high risk of pleura-related complications, particularly pneumothorax.

OBJECTIVE

This study aimed to determine if image-guided transbronchial microwave ablation (tMWA) is a feasible approach to treat peripheral stage 1 lung cancer.

METHOD

A prospective, single-arm, multicenter study sought to enroll 40 adults who were medically inoperable or declined surgery for peripheral stage 1 lung tumors (≤20 mm). Ablation was performed using navigational bronchoscopy and a flexible MWA probe, guided by cone-beam CT with augmented fluoroscopy. Follow-up at 1, 6, and 12 months included CT imaging of the ablation zone and possible tumor recurrence, adverse events (AEs), pulmonary function, and quality of life.

RESULTS

Across 2 sites, 11 tumors (10 NSCLC, 1 carcinoid) were treated in 10 enrolled patients. Median tumor diameter was 13 × 14 mm (7-19 mm) and median minimum ablative margin was 11 mm (5-19 mm). Technical success and technique efficacy were achieved in all patients. No tumor recurrence was seen during 12-month follow-up. No pneumothorax, pleural effusion, or bronchopleural fistula were noted. Minor AEs included scant hemoptysis, pain, cough, and dyspnea. Two serious AEs occurred ≤30 days of ablation and included a COPD exacerbation (day 9) and a death of unknown cause (day 15). The death led the sponsor to halt enrollment. Pulmonary function and quality-of-life indices remained stable.

CONCLUSIONS

Image-guided tMWA is a technically feasible approach for peripheral early-stage lung cancer but warrants further evaluation of safety and efficacy in larger cohorts.

Respiratory mucosal immunity against SARS-CoV-2 after mRNA vaccination

SARS-CoV-2 mRNA vaccination induces robust humoral and cellular immunity in the circulation; however, it is currently unknown whether it elicits effective immune responses in the respiratory tract, particularly against variants of concern (VOCs), including Omicron. We compared the SARS-CoV-2 S-specific total and neutralizing antibody responses, and B and T cell immunity, in the bronchoalveolar lavage fluid (BAL) and blood of COVID-19-vaccinated individuals and hospitalized patients. Vaccinated individuals had significantly lower levels of neutralizing antibody against D614G, Delta (B.1.617.2), and Omicron BA.1.1 in the BAL compared with COVID-19 convalescents despite robust S-specific antibody responses in the blood. Furthermore, mRNA vaccination induced circulating S-specific B and T cell immunity, but in contrast to COVID-19 convalescents, these responses were absent in the BAL of vaccinated individuals. Using a mouse immunization model, we demonstrated that systemic mRNA vaccination alone induced weak respiratory mucosal neutralizing antibody responses, especially against SARS-CoV-2 Omicron BA.1.1 in mice; however, a combination of systemic mRNA vaccination plus mucosal adenovirus-S immunization induced strong neutralizing antibody responses not only against the ancestral virus but also the Omicron BA.1.1 variant. Together, our study supports the contention that the current COVID-19 vaccines are highly effective against severe disease development, likely through recruiting circulating B and T cell responses during reinfection, but offer limited protection against breakthrough infection, especially by the Omicron sublineage. Hence, mucosal booster vaccination is needed to establish robust sterilizing immunity in the respiratory tract against SARS-CoV-2, including infection by the Omicron sublineage and future VOCs.

Combining Shape-Sensing Robotic Bronchoscopy With Mobile Three-Dimensional Imaging to Verify Tool-in-Lesion and Overcome Divergence: A Pilot Study

Objective

To determine whether CT-to-body divergence can be overcome to improve the diagnostic yield of peripheral pulmonary nodules with the combination of shape-sensing robotic-assisted bronchoscopy (SSRAB) and portable 3-dimensional (3D) imaging.

Patients and Methods

A single-center, prospective, pilot study was conducted from February 9, 2021, to August 4, 2021, to evaluate the combined use of SSRAB and portable 3D imaging to visualize tool-in-lesion as a correlate to diagnostic yield.

Results

Thirty lesions were subjected to biopsy in 17 men (56.7%) and 13 women (43.3%). The median lesion size was 17.5 mm (range, 10-30 mm), with the median airway generation of 7 and the median distance from pleura of 14.9 mm. Most lesions were in the upper lobes (18, 60.0%). Tool-in-lesion was visualized at the time of the procedure in 29 lesions (96.7%). On the basis of histopathologic review, 22 (73.3%) nodules were malignant and 6 (20.0%) were benign. Two (6.7%) specimens were suggestive of inflammation, and the patients elected observation. The mean number of spins was 2.5 (±1.6) with a mean fluoroscopy time of 8.7 min and a mean dose area product of 50.3 Gy cm² (±32.0 Gy cm²). There were no episodes of bleeding or pneumothorax. The diagnostic yield was 93.3%.

Conclusion

This pilot study shows that the combination of mobile 3D imaging and SSRAB of pulmonary nodules appears to be safe and feasible. In conjunction with appropriate anesthetic pathways, nodule motion and divergence can be overcome in most patients.

Trial Registration

https://clinicaltrials.gov Identifier NCT04740047

Respiratory humoral and cellular immune responses following COVID-19 mRNA vaccination

Vaccination is the key for controlling COVID-19 pandemic. SARS-CoV-2 mRNA vaccines have been demonstrated to induce robust and persistent humoral and cellular immunity in the circulation, but the vaccine-induced immune responses in the respiratory tract remain largely elusive. Here, we examined SARS-CoV-2 S-specific antibody, B and T cell immune responses in the bronchoalveolar lavage (BAL) fluid and blood from unvaccinated, COVID-19 vaccinees or COVID-19 convalescents that recovered from prior moderate to severe SARS-CoV-2 infection. We found that mRNA vaccination induced significant SARS-CoV-2 S-specific CD4+ and CD8+ T cell responses in the blood but not in the BAL. Similarly, mRNA vaccination failed to provoke detectable SARS-CoV-2 S RBD-specific B cell responses in the BAL despite marked RBD-specific B cells were observed in the blood of COVID-19 vaccinees. In contrast, robust SARS-CoV-2 S-specific B and T cell responses were present in the BAL of COVID-19 convalescents. Furthermore, significant neutralizing antibody responses were only observed in the BAL from convalescents but not vaccinees, while both COVID-19 vaccinee and convalescent groups mounted marked neutralizing antibody responses in the blood. Thus, despite their induction of robust circulating humoral and cellular immunity, the current COVID-19 vaccines provoke relatively weak cellular and neutralizing antibody responses in the lower respiratory tract. Our results indicate that a mucosal booster vaccine may be needed to establish robust immunity in the respiratory mucosa, which could provide a strong first line of defense against SARS-CoV-2 re-infection.

Predicting malignant pleural effusion during diagnostic pleuroscopy with biopsy: A prospective multicentre study

BACKGROUND AND OBJECTIVE

Pleuroscopy with pleural biopsy has a high sensitivity for malignant pleural effusion (MPE). Because MPEs tend to recur, concurrent diagnosis and treatment of MPE during pleuroscopy is desired. However, proceeding directly to treatment at the time of pleuroscopy requires confidence in the on-site diagnosis. The study's primary objective was to create a predictive model to estimate the probability of MPE during pleuroscopy.

METHODS

A prospective observational multicentre cohort study of consecutive patients undergoing pleuroscopy was conducted. We used a logistic regression model to evaluate the probability of MPE with relation to visual assessment, rapid on-site evaluation (ROSE) of touch preparation and presence of pleural nodules/masses on computed tomography (CT). To assess the model's prediction accuracy, a bootstrapped training/testing approach was utilized to estimate the cross-validated area under the receiver operating characteristic curve.

RESULTS

Of the 201 patients included in the study, 103 had MPE. Logistic regression showed that higher level of malignancy on visual assessment is associated with higher odds of MPE (OR = 34.68, 95% CI = 9.17-131.14, p < 0.001). The logistic regression also showed that higher level of malignancy on ROSE of touch preparation is associated with higher odds of MPE (OR = 11.63, 95% CI = 3.85-35.16, p < 0.001). Presence of pleural nodules/masses on CT is associated with higher odds of MPE (OR = 6.61, 95% CI = 1.97-22.1, p = 0.002). A multivariable logistic regression model of final pathologic status with relation to visual assessment, ROSE of touch preparation and presence of pleural nodules/masses on CT had a cross-validated AUC of 0.94 (95% CI = 0.91-0.97).

CONCLUSION

A prediction model using visual assessment, ROSE of touch preparation and CT scan findings demonstrated excellent predictive accuracy for MPE. Further validation studies are needed to confirm our findings.

Immune signatures underlying post-acute COVID-19 lung sequelae

[Figure: see text].

Proinflammatory circulating markers: new players for evaluating asymptomatic acute cardiovascular toxicity in breast cancer treatment

PURPOSE

This study aimed to evaluate markers of cardiac damage (total CK, CKMB and CRP), inflammatory markers (free iron, homocysteine and TNF-α) as well as lipidogram in breast cancer patients undergoing acute cycles of doxorubicin (DOX), paclitaxel (PTX) or trastuzumab (TZ) and to verify if there is an association between these markers and the toxicity of the chemotherapeutic treatment. Methods: Included in the study were 120 breast cancer patients and 50 healthy controls. All analyzes were performed on automated systems. For the statistical analysis, each group was compared with the controls according to their normality by Student's t-test and Mann-Whitney test. Results: Our results showed that DOX treatment led to increased hsCRP (4.80 ± 1.23 mg/dL, p = 0.0005), triglycerides (187.6 ± 25.06, p = 0.0231), TNF-α (42.31 ± 17.96 pg/mL, p = 0.01) and Fe levels (138.8 ± 18.6 μg/dL, p = 0.0193). In the meantime, PTX induced changes in CK-MB (8.78 ± 4.2 U/L, p = 0.0361), hsCRP (7.12 ± 1.87 mg/dL, p = 0.0006), cholesterol (201.7 ± 19.54, p = 0.05), triglycerides (201.7 ± 19.54, p = 0.0277), TNF-α (38.27 ± 9.12 pg/mL, p = 0.023), homocysteine (10.95 ± 0, 86 μmol/L, p = 0.005), and free iron (113 ± 18 6 μg/dL, p = 0.045) while TZ augmented CK-MB (6.9 ± 1.97 U/L, p < 0.00), hsPCR (3.12 ± 0.68 mg/dL, p = 0.095), cholesterol (218.3 ± 16.79, p = 0.0317), triglycerides (218.3 ± 16.79, p = 0.0127), TNF-α (89.6 ± 12.11, p = 0.032), homocysteine (9.95 ± 1.15 μmol/L, p = 0.0396), free iron (120.5 ± 4.64 μg/dl, p = 0.0058) as well. Conclusions: Our data demonstrated the existence of a proinflammatory net triggered by breast cancer chemotherapy that could increase cardiomyocytes permeability and allow the leakage of circulating proteins as CK-MB and induce the production of hsCRP.

Executive summary of EPOS 2020 including integrated care pathways

The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012(1-3). The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings.

European Position Paper on Rhinosinusitis and Nasal Polyps 2020

The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise . The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included. The full document can be downloaded for free on the website of this journal: http://www.rhinologyjournal.com.

Catheter based treatments for fibrosing mediastinitis

Fibrosing mediastinitis is a rare, often debilitating and potentially lethal disease characterized by an exuberant fibroinflammatory response within the mediastinum. Patients typically present with insidious symptoms related to compression of adjacent structures including the esophagus, heart, airways, and cardiac vessels. Fibrosing mediastinitis is most often triggered by Histoplasmosis infection; however, antifungal and anti-inflammatory therapies are largely ineffective. While structural interventions aimed at alleviating obstruction can provide significant palliation, surgical interventions are challenging with high mortality and clinical experience with percutaneous interventions is limited. Here, we will review the presentation, natural history, and treatment of fibrosing mediastinitis, placing particular emphasis on catheter-based therapies.

Diffuse large B cell lymphoma with superimposed lung abscess: potential role for intracavitary fibrinolytic therapy through a percutaneous drain to facilitate lung abscess drainage

This is a case of primary pulmonary lymphoma presenting concurrently with superimposed lung abscess, managed with the assistance of intracavitary fibrinolytic therapy. A 28-year-old man presented with 2 months of persistent cough. He had a large lung abscess involving almost the entire right upper lobe. The mass continued to progress in spite of appropriate antibiotic administration. Given the extent of involvement, he was not a surgical candidate. A bronchoscopy with bronchoalveolar lavage and transbronchial biopsies demonstrated diffuse large B cell lymphoma. Initial cultures were positive for Group G Streptococci A CT-guided percutaneous drain was placed with initial purulent drainage that grew Prevotella and Streptococcus mitis; however, drainage quickly abated without adequate evacuation of the abscess cavity. To further optimise drainage in anticipation of chemotherapy administration, intracavitary fibrinolytic therapy including tissue plasminogen activator and deoxyribonuclease was attempted to better evacuate the infected space.

Indwelling Tunneled Pleural Catheters for Refractory Hepatic Hydrothorax in Patients With Cirrhosis: A Multicenter Study

BACKGROUND

The outcome of indwelling pleural catheter (IPC) use in hepatic hydrothorax (HH) is unclear. This study aimed to review the safety and feasibility of the IPC in patients with refractory HH.

METHODS

A retrospective multicenter study of patients with HH from January 2010 to December 2016 was performed. Inclusion criteria were refractory HH treated with an IPC and an underlying diagnosis of cirrhosis. Records were reviewed for patient demographics, operative reports, and laboratory values. The Kaplan-Meier method was used to estimate catheter time to removal. The Cox proportional hazard model was used to evaluate for independent predictors of pleurodesis and death.

RESULTS

Seventy-nine patients were identified from eight institutions. Indication for IPC placement was palliation in 58 patients (73%) and bridge to transplant in 21 patients (27%). The median in situ dwell time of all catheters was 156 days (range, 16-1,978 days). Eight patients (10%) were found to have pleural space infection, five of whom also had catheter-site cellulitis. Two patients (2.5%) died secondary to catheter-related sepsis. Catheter removal secondary to spontaneous pleurodesis was achieved in 22 patients (28%). Median time from catheter insertion to pleurodesis was 55 days (range, 10-370 days). Older age was an independent predictor of mortality on multivariate analysis (hazard ratio, 1.05; P = .01).

CONCLUSIONS

We present, to our knowledge, the first multicenter study examining outcomes related to IPC use in HH. Ten percent infection risk and 2.5% mortality were identified. IPC placement may be a reasonable clinical option for patients with refractory HH, but it is associated with significant adverse events in this morbid population.

Creation of a Balloon-Expandable Bifurcated Covered Stent to Treat a Complex Left Anastomotic Stricture in a Lung Transplant Recipient

Airway complications after lung transplant occur in approximately 10-15% of the recipients and often occur at the anastomosis, largely due to ischemia. To decrease anastomotic ischemia, surgeons minimize the length of the donor bronchus. However, a shortened donor bronchus creates technical challenges if a stent is required to treat an airway complication. We present a case of a lung transplant recipient with the combination of left main stem bronchial malacia and a triad of severe strictures at the left anastomosis, entrance to the left upper lobe, and left lower lobe. After failing several attempts using other modalities, success was achieved with in situ creation of a bifurcated fully covered balloon-expandable metallic stent. We describe a novel technique of punching a side branch hole through the wall of the stent to allow a left upper lobe stent to be placed through a stent directed into the left lower lobe in a Y configuration with a good clinical outcome.

Perceptions on the value of bodily functions in multiple sclerosis

BACKGROUND

In neurological diseases presenting with a plethora of symptoms, the value of bodily functions for a given patient might be a guide for clinical management. Multiple sclerosis (MS) is paradigmatic in this respect, and little is known about the value of different bodily functions of patients and their physicians' perceptions.

METHODS

In a multicenter study, 171 patients with relapsing-remitting multiple sclerosis (RRMS), 61% with a clinically active disease within the last 2 years were followed over up to 3 years and yearly patients and their study physician rated on the perceived value of 13 bodily functions via a priority list. Differences between patients and physicians as well as modulating disease demographic factors were analyzed.

RESULTS

Patients with RRMS rated visual function followed by thinking and memory and walking highest while physicians stressed mobility, followed by thinking and memory and alertness most. Ratings were independent from disease duration or disability. Strongest value judgment differences were seen in swallowing regarded more relevant by patients and hand function regarded more relevant by physicians. In general, patients' and physicians' ratings through time were quite stable. Collapsing physical items into a physical functioning scale and mental items in a mental function scale, both dimensions were regarded equally important by patients while physicians underscored physical functioning (P = .016).

CONCLUSION

There are differences between patients and physicians in value statements of bodily functions in MS. In particular, visual functioning is under-recognized by physicians.

Belatacept for Maintenance Immunosuppression in Lung Transplantation

Belatacept is a novel immunosuppressant that blocks a T-cell costimulation pathway and is approved for use in adult kidney transplant recipients. Its safety and efficacy have not been established after lung transplantation. We present a case of a lung transplant recipient treated with belatacept. A 56-year-old man underwent bilateral lung retransplantation for bronchiolitis obliterans syndrome (BOS). In the third year posttransplant, he developed hemolytic uremic syndrome (HUS) attributed to tacrolimus. Tacrolimus was changed to sirolimus. One month later, he presented with worsening renal function and HUS attributed to sirolimus. Plasmapheresis and steroid pulse were initiated with clinical improvement, and sirolimus was switched to belatacept. He experienced no episodes of cellular rejection but developed recurrent BOS. Complications during treatment included anemia and recurrent pneumonias. The safety and efficacy of belatacept in lung transplantation remains unclear; further studies are needed.

A randomized trial of the effects of nebulized albuterol on pulmonary edema in brain-dead organ donors

Donor lung utilization rates are persistently low primarily due to donor lung dysfunction. We hypothesized that a treatment that enhances the resolution of pulmonary edema by stimulating the rate of alveolar fluid clearance would improve donor oxygenation and increase donor lung utilization. We conducted a randomized, blinded, placebo-controlled trial of aerosolized albuterol (5mg q4h) versus saline placebo during active donor management in 506 organ donors.The primary outcome was change in oxygenation arterial partial pressure of oxygen/fraction of inspired oxygen [PaO2/FiO2] from enrollment to organ procurement.The albuterol (n¼260) and placebo (n¼246)groups were well matched for age, gender, ethnicity,smoking, and cause of brain death. The change in PaO2/FiO2 from enrollment to organ procurement did not differ between treatment groups (p¼0.54) nor did donor lung utilization (albuterol 29% vs. placebo 32%,p¼0.44). Donors in the albuterol versus placebo groups were more likely to have the study drug dose reduced (13% vs. 1%, p<0.001) or stopped (8% vs. 0%,p<0.001) for tachycardia. In summary, treatment with high dose inhaled albuterol during the donor management period did not improve donor oxygenation or increase donor lung utilization but did cause tachycardia.High dose aerosolized albuterol should not be used in donors to enhance the resolution of pulmonary edema.

Does the Cyanophora paradoxa genome revise our view on the evolution of photorespiratory enzymes?

In the present-day O2 -rich atmosphere, the photorespiratory pathway is essential for organisms performing oxygenic photosynthesis; i.e. cyanobacteria, algae and land plants. The presence of enzymes for the plant-like 2-phosphoglycolate cycle in cyanobacteria indicates that, together with oxygenic photosynthesis, genes for photorespiratory enzymes were endosymbiotically conveyed from ancient cyanobacteria to photosynthetic eukaryotes. The genome information for Cyanophora paradoxa, a member of the Glaucophyta representing the first branching group of primary endosymbionts, and for many other eukaryotic algae was used to shed light on the evolutionary relationship of photorespiratory enzymes among oxygenic phototrophs. For example, it became possible to analyse the phylogenies of 2-phosphoglycolate phosphatase, serine:glyoxylate aminotransferase and hydroxypyruvate reductase. Analysis of the Cyanophora genome provided clear evidence that some photorespiratory enzymes originally acquired from cyanobacteria were lost, e.g. glycerate 3-kinase, while others were replaced by the corresponding enzymes from the α-proteobacterial endosymbiont, e.g. serine:glyoxylate aminotransferase. Generally, our analysis supports the view that many C2 cycle enzymes in eukaryotic phototrophs were obtained from the cyanobacterial endosymbiont, but during the subsequent evolution of algae and land plants multiple losses and replacements occurred, which resulted in a reticulate provenance of photorespiratory enzymes with different origins in different cellular compartments.

Evolution of the biochemistry of the photorespiratory C2 cycle

Oxygenic photosynthesis would not be possible without photorespiration in the present day O2 -rich atmosphere. It is now generally accepted that cyanobacteria-like prokaryotes first evolved oxygenic photosynthesis, which was later conveyed via endosymbiosis into a eukaryotic host, which then gave rise to the different groups of algae and streptophytes. For photosynthetic CO2 fixation, all these organisms use RubisCO, which catalyses both the carboxylation and the oxygenation of ribulose 1,5-bisphosphate. One of the reaction products of the oxygenase reaction, 2-phosphoglycolate (2PG), represents the starting point of the photorespiratory C2 cycle, which is considered largely responsible for recapturing organic carbon via conversion to the Calvin-Benson cycle (CBC) intermediate 3-phosphoglycerate, thereby detoxifying critical intermediates. Here we discuss possible scenarios for the evolution of this process toward the well-defined 2PG metabolism in extant plants. While the origin of the C2 cycle core enzymes can be clearly dated back towards the different endosymbiotic events, the evolutionary scenario that allowed the compartmentalised high flux photorespiratory cycle is uncertain, but probably occurred early during the algal radiation. The change in atmospheric CO2 /O2 ratios promoting the acquisition of different modes for inorganic carbon concentration mechanisms, as well as the evolutionary specialisation of peroxisomes, clearly had a dramatic impact on further aspects of land plant photorespiration.

Brain imaging in patients with transient ischemic attack: a comparison of computed tomography and magnetic resonance imaging

BACKGROUND

Brain imaging in stroke aims at the detection of the relevant ischemic tissue pathology. Cranial computed tomography (CT) is frequently used in patients with transient ischemic attack (TIA) but no data is available on how it directly compares to magnetic resonance imaging (MRI).

METHODS

We compared detection of acute ischemic lesions on CT and MRI in 215 consecutive TIA patients who underwent brain imaging with either CT (n = 161) or MRI (n = 54). An MRI was performed within 24 h in all patients who had CT initially.

RESULTS

An initial assessment with CT revealed no acute pathology in 154 (95.7%) and possible acute infarction in 7 (4.3%) patients. The acute infarct on CT was confirmed by diffusion-weighted imaging (DWI) in only 2 cases (28.6%). DWI detected an acute infarct in 50 of the 154 patients with normal baseline CT (32.5%). Among 54 patients without baseline CT, DWI showed acute ischemic lesions in 19 (35.2%). The ischemic lesions had a median volume of 0.87 cm(3) (range: 0.08-15.61), and the lesion pattern provided clues to the underlying etiology in 13.7%.

CONCLUSION

Acute MRI is advantageous over CT to confirm the probable ischemic nature and to identify the etiology in TIA patients.

Diffusion-weighted imaging for the differential diagnosis of disorders affecting the hippocampus

BACKGROUND

The human hippocampus can be affected in a large variety of very different neurological diseases, of which acute ischemic stroke, transient global amnesia, epilepsy, and limbic encephalitis are the most common. Less frequent etiologies include various infections and encephalopathy of different origins. Clinical presentation notably comprises confusional state, altered vigilance, memory deficits of various extent and seizures. While in hypoxic or hypoglycemic encephalopathy, clinical presentation and surrounding circumstances provide some clues to reach the correct diagnosis, in the above-listed more common disorders, signs and symptoms might overlap, making the differential diagnosis difficult. This review presents recent studies using the diffusion-weighted imaging (DWI) technique in diseases involving the hippocampus.

METHODS

References for the review were identified through searches of PubMed from 1965 to January 2011. Only papers published in English were reviewed. Full articles were obtained and references were checked for additional material where appropriate.

RESULTS

All pathologies affecting the hippocampus are associated with distinct lesion patterns on magnetic resonance imaging, and especially DWI has the ability to demonstrate even minute and transient hippocampal lesions. In acute ischemic stroke in the posterior cerebral artery territory, involvement of the hippocampal formation occurs in four distinct patterns on DWI that can be easily differentiated and correspond to the known vascular anatomy of the hippocampus. In the subacute phase after transient global amnesia (TGA), dot-like hyperintense lesions are regularly found in the lateral aspect of the hippocampus on DWI. The DWI lesions described after prolonged seizures or status epilepticus include unilateral or bilateral hippocampal, thalamic, and cortical lesions of various extent, not restricted to vascular territories. In limbic encephalitis, DWI lesions are only infrequently found and usually affect the hippocampus, uncus and amygdala. Furthermore, in some rare cases DWI lesions of different etiology may coexist.

CONCLUSION

In patients with diseases affecting the hippocampus, DWI appears to be useful in differentiating between underlying pathologies and may facilitate a definite diagnosis conducive to an optimal treatment. With a careful clinical examination, experience with the interpretation of DWI findings and knowledge of associated phenomena, it is indeed possible to differentiate between ischemic, ictal, metabolic, and TGA-associated findings.

Clinical and MRI characteristics of acute migrainous infarction

OBJECTIVE

Migrainous infarction is considered a rare complication of migraine. Although several studies reported silent brain lesions on neuroimaging in patients with migraine with aura, knowledge about lesion patterns in acute migrainous infarction is scarce. We investigated clinical and MRI characteristics in a series of patients with migraine-associated acute cerebral ischemia.

METHODS

Seventeen patients among 8,137 stroke patients over an 11-year period were included. All had undergone a dedicated stroke workup including diffusion-weighted imaging (DWI) and a detailed assessment of clinical features and of vascular risk factors.

RESULTS

The majority of patients presented with prolonged aura symptoms (visual aura 82.3%, sensory dysfunction 41.2%, and aphasia 5.9%; median NIH Stroke Scale score 2). Presentation at hospital was significantly delayed after symptom onset (mean 33 hours). A total of 70.6% had acute ischemic lesions in the posterior circulation; the middle cerebral artery territory was affected in 29.4%. Small lesions were present in 64.7%; multiple lesions were found in 41.2%. No overlapping ischemic lesions of different vascular territories were found. The prevalence of a patent foramen ovale was high (64.7%).

CONCLUSIONS

This study supports previous observations that migrainous infarction mostly occurs in the posterior circulation, and in younger women with a history of migraine with aura. Acute ischemic lesions were often multiple and located in distinct arterial territories. As there were no overlapping ischemic lesions, hemodynamic compromise during the development of migraine is unlikely the cause of infarction. Differentiation between migrainous infarction and prolonged migraine aura is difficult and associated with delayed admission of patients.

MR imaging-guided intravenous thrombolysis in posterior cerebral artery stroke

PCA stroke was under-represented in or excluded from the clinical trials examining thrombolysis based on the PWI-DWI mismatch concept. We present 6 patients with PCA stroke treated with thrombolysis in an extended time window by using MR imaging criteria. Symptoms included aphasia, sensorimotor hemiparesis, hemineglect, and homonymous hemianopia. Initial MR imaging demonstrated circumscribed ischemic lesions in the thalamus or hippocampus; MR angiography showed PCA occlusion with corresponding hypoperfusion. Follow-up MR imaging showed partial/complete recanalization in 4 patients with minor infarction growth, while in 1 patient, PCA occlusion persisted, resulting in a large PCA infarction. Three patients improved within 2 hours; at discharge, homonymous hemianopia had resolved in 3 patients. At 3-month follow-up, 4 patients had an mRS score of 0 or 1. These results support the approach to treat patients with PCA stroke with thrombolysis based on the mismatch concept. Because rehabilitation options for hemianopia are limited, thrombolysis may enhance the chance of a favorable outcome.