Optogenetic Spreading Depression Elicits Trigeminal Pain and Anxiety Behavior

OBJECTIVE

Cortical spreading depression (SD) is an intense depolarization underlying migraine aura. Despite the weight of evidence linking SD to the pain phase of migraine, controversy remains over a causal role of SD in cephalgia because of the invasive nature of previous SD induction methods. To overcome this problem, we used a novel minimally invasive optogenetic SD induction method and examined the effect of SD on behavior.

METHODS

Optogenetic SD was induced as a single event or repeatedly every other day for 2 weeks. End points, including periorbital and hindpaw mechanical allodynia, mouse grimace, anxiety, and working memory, were examined in male and female mice.

RESULTS

A single SD produced bilateral periorbital mechanical allodynia that developed within 1 hour and resolved within 2 days. Sumatriptan prevented periorbital allodynia when administered immediately after SD. Repeated SDs also produced bilateral periorbital allodynia that lasted 4 days and resolved within 2 weeks after the last SD. In contrast, the hindpaw withdrawal thresholds did not change after repeated SDs suggesting that SD-induced allodynia was limited to the trigeminal region. Moreover, repeated SDs increased mouse grimace scores 2 days after the last SD, whereas a single SD did not. Repeated SDs also increased thigmotaxis scores as a measure of anxiety. In contrast, neither single nor repeated SDs affected visuospatial working memory. We did not detect sexual dimorphism in any end point.

INTERPRETATION

Altogether, these data show a clinically congruent causal relationship among SD, trigeminal pain, and anxiety behavior, possibly reflecting SD modulation of hypothalamic, thalamic, and limbic mechanisms. ANN NEUROL 2021;89:99-110.

Intravascular Endothelin-1 does not trigger or increase susceptibility to Spreading Depolarizations

Objectives

Spreading depolarizations (SD) likely manifest as aura in migraineurs. Triggers are unknown although vascular events have been implicated. Direct carotid puncture has been reported to trigger migraine with aura. The potent vasoconstrictor endothelin-1 (ET-1), which can be released from the endothelium under pathological conditions, may play a role. Here, we tested whether intracarotid ET-1 infusion triggers SD and whether systemic ET-1 infusion increases the susceptibility to SD.

Methods

Carotid infusions were performed in mice (C57BL/6, male) through a catheter placed at the carotid bifurcation via the external carotid artery. Intracarotid ET-1 (1.25 nmol/ml) was infused at various rates (2–16 μl/min) with or without heparin in the catheter and compared with vehicle infusion (PBS with 0.01% acetic acid) or sham-operated mice (n = 5). Systemic infusions ET-1 (1 nmol/kg, n = 7) or vehicle (n = 7) infusions were performed in rats (Sprague-Dawley, male) via the tail vein. Electrical SD threshold and KCl-induced SD frequency were measured after the infusion.

Results

Intracarotid infusion of saline (n = 19), vehicle (n = 7) or ET-1 (n = 12) all triggered SDs at various proportions (21%, 14% and 50%, respectively). These were often associated with severe hypoperfusion prior to SD onset. Heparinizing the infusion catheter completely prevented SD occurrence during the infusions (n = 8), implicating microembolization from carotid thrombi as the trigger. Sham-operated mice never developed SD. Systemic infusion of ET-1 did not affect the electrical SD threshold or KCl-induced SD frequency.

Conclusion

Intravascular ET-1 does not trigger or increase susceptibility to SD. Microembolization was the likely trigger for migraine auras in patients during carotid puncture.

Sex and Genetic Background Effects on the Outcome of Experimental Intracranial Aneurysms

BACKGROUND AND PURPOSE

Intracranial aneurysm formation and rupture risk are, in part, determined by genetic factors and sex. To examine their role, we compared 3 mouse strains commonly used in cerebrovascular studies in a model of intracranial aneurysm formation and rupture.

METHODS

Intracranial aneurysms were induced in male CD1 (Crl:CD1[ICR]), male and female C57 (C57BL/6NCrl), and male 129Sv (129S2/SvPasCrl or 129S1/SvImJ) mice by stereotaxic injection of elastase at the skull base, combined with systemic deoxycorticosterone acetate-salt hypertension. Neurological deficits and mortality were recorded. Aneurysms and subarachnoid hemorrhage grades were quantified postmortem, either after spontaneous mortality or at 7 to 21 days if the animals survived. In separate cohorts, we examined proinflammatory mediators by quantitative reverse transcriptase-polymerase chain reaction, arterial blood pressure via the femoral artery, and the circle of Willis by intravascular latex casting.

RESULTS

We found striking differences in aneurysm formation, rupture, and postrupture survival rates among the groups. 129Sv mice showed the highest rates of aneurysm rupture (80%), followed by C57 female (36%), C57 male (27%), and CD1 (21%). The risk of aneurysm rupture and the presence of unruptured aneurysms significantly differed among all 3 strains, as well as between male and female C57. The same hierarchy was observed upon Kaplan-Meier analysis of both overall survival and deficit-free survival. Subarachnoid hemorrhage grades were also more severe in 129Sv. CD1 mice showed the highest resistance to aneurysm rupture and the mildest outcomes. Higher mean blood pressures and the major phenotypic difference in the circle of Willis anatomy in 129Sv provided an explanation for the higher incidence of and more severe aneurysm ruptures. TNFα (tumor necrosis factor-alpha), IL-1β (interleukin-1-beta), and CCL2 (chemokine C-C motif ligand 2) expressions did not differ among the groups.

CONCLUSIONS

The outcome of elastase-induced intracranial aneurysm formation and rupture in mice depends on genetic background and shows sexual dimorphism.

Translating Idiopathic pulmonary fibrosis guidelines into clinical practice

INTRODUCTION AND OBJECTIVES

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrotic interstitial lung disease of unknown cause, which predominantly manifests in older males. IPF diagnosis is a complex, multi-step process and delay in diagnosis cause a negative impact on patient survival. Additionally, a multidisciplinary team of pulmonologists, radiologists and pathologists is necessary for an accurate IPF diagnosis. The present study aims to assess how diagnosis and treatment of IPF are followed in Portugal, as well as the knowledge and implementation of therapeutic guidelines adopted by the Portuguese Society of Pulmonology.

MATERIALS AND METHODS

Seventy-eight practicing pulmonologists were enrolled (May-August 2019) in a survey developed by IPF expert pulmonologists comprised of one round of 31 questions structured in three parts. The first part was related to participant professional profile, the second part assessed participant level of knowledge and practice agreement with national consensus and international guidelines for IPF as well as their access to radiology and pathology for IPF diagnosis, and the third part was a self-evaluation of the guidelines adherence for diagnosis and treatment in their daily practice.

RESULTS

Participants represented a wide spectrum of pulmonologists from 14 districts of Portugal and autonomous regions of Azores and Madeira. The majority were female (65%), with 5-19 years of experience (71%) and working in a public clinical center (83%). Importantly, the majority of pulmonologists follow their IPF patients (n=45) themselves, while 26% referred IPF patients to ILD experts in the same hospital and 22% to another center. Almost all pulmonologists (98%) agreed or absolutely agreed that multidisciplinary discussion is recommended to accurately diagnose IPF. No pulmonologists considered pulmonary biopsy as absolutely required to establish an IPF diagnosis. However, 87% agreed or absolutely agree with considering biopsy in a possible/probable UIP context. If a biopsy is necessary, 96% of pulmonologists absolutely agree or agree with considering criobiopsy as an option for IPF diagnosis. Regarding IPF treatment, 98% absolutely agreed or agreed that antifibrotic therapy should be started once the IPF diagnosis is established. Finally, 76% stated that 6 months is the recommended time for follow-up visit in IPF patients.

CONCLUSIONS

Portuguese pulmonologists understand and agree with national consensus and international guidelines for IPF treatment but their implementation in Portugal is heterogeneous.

The role of interventional bronchoscopy in the management of post-intubation tracheal stenosis: A 20-year experience

PURPOSE

Benign tracheal stenosis management is still controversial, and there is no international consensus on the best treatment option. Thus, we aimed to look into the history of PITS and the different strategies used in its treatment. The importance of bronchoscopic treatment was also defined, and its effectiveness and safety were assessed.

METHODS

Retrospective study of patients diagnosed with PITS, who were referred to the Bronchology Department between January 1996 and December 2016.

RESULTS

Of 115 patients enrolled (mean age 48.5±17.6 years, 53% males), 66.1% had complex stenosis. The most common causes of intubation were respiratory (29.9%), neurological (26.8%) and surgical (19.6%). Complex stenosis was caused by longer intubation, and was more frequent among previously tracheostomized patients. The most common location was the upper third of trachea (60.9%). Most cases were initially treated by interventional bronchoscopy, and although serial dilations were effective in some complex PITS, a higher proportion of simple stenosis was successfully managed with this treatment option. Long-term recurrence after serial dilation was observed in 25.0% of cases. Stent placement was required (19.1%) only for complex PITS. Stent-related complications were frequent (61.9%) and linked to the stenting time (p<0.001). Overall, there were no procedure-related complications. Surgical intervention was also performed (30.0%), always with complex PITS. Post-surgical recurrences were observed in 24.2% of cases.

CONCLUSIONS

Interventional bronchoscopy is an efficient and safe modality in PITS management. Further studies are needed for better classification and improved knowledge of PITS pathogenesis, and to achieve international consensus of definition to guide clinicians in their practice.

Effect of an aerobic exercise session combined with abdominal radiofrequency on lipolytic activity in women: Randomized control trial

BACKGROUND

Abdominal adiposity is a cardiovascular risk factor; it is assumed that the combination of radiofrequency and physical exercise may decrease this excess of adipose tissue.

PURPOSE

To understand whether an aerobic physical exercise session associated with abdominal radiofrequency increases the level of lipolytic activity.

METHODOLOGY

The study analyzes the effect of a combined aerobic exercise session with radiofrequency. Participants were 30 healthy female volunteers, aged 18-28 years, randomly assigned to an experimental group and placebo group. They were characterized by a sociodemographic questionnaire, the International Physical Activity Questionnaire and the Food Frequency Questionnaire. The groups performed an abdominal radiofrequency session followed by moderate aerobic exercise, assessing glycerol concentration and lipid profile values before and after the intervention. In the experimental group, a percentage of potency was used that allowed to maintain the temperature between 40º C and 42º C to the epidermis. In the placebo group, the power of the radiofrequency was 0 Watt. To compare results, Student's t test was used for a significance level of 0.05.

RESULTS

There were no significant changes in glycerol concentrations between groups (P > 0.05). There were no changes in the lipid profile of both groups after the intervention (P > 0.05).

CONCLUSION

The association of exercise with radiofrequency did not present an increased effect on lipolytic activity when compared to the isolated exercise. The application of this technique is a safe intervention.

Effect of four sessions of aerobic exercise with abdominal radiofrequency in adipose tissue in healthy women: Randomized control trial

BACKGROUND

Abdominal adiposity is a cardiovascular risk factor; it is assumed that the combination of radiofrequency and physical exercise may decrease this excess of adipose tissue.

PURPOSE

To analyze the effect of four intervention sessions on abdominal adipose tissue.

METHODOLOGY

The study analyzes the effect of four sessions of aerobic exercise combined with radiofrequency. Participants were 28 healthy female volunteers, aged 18-28 years, randomly assigned to an experimental group and a placebo group. They were characterized by a sociodemographic questionnaire, the International Physical Activity Questionnaire and the Food Frequency Questionnaire. The groups performed four sessions of abdominal radiofrequency followed by moderate aerobic exercise, assessing body mass, body mass index, fat mass, waist circumference, waist/height ratio, subcutaneous adipose thickness, and horizontal abdominal adipose fold at the first and fourth sessions. In the experimental group, a percentage of potency was used that allowed to maintain the temperature between 40°C and 42°C to the epidermis. In the placebo group, the power of the radiofrequency was 0 W. To compare results, Student's t test was used for a significance level of 0.05.

RESULTS

There was a statistically significant decrease in waist circumference, abdominal subcutaneous adipose thickness, and horizontal abdominal fold in the experimental group compared to the placebo group (P < 0.05).

CONCLUSION

Combined exercise intervention with radiofrequency has been shown to be effective in reducing abdominal adiposity.

Heterozygous TERT gene mutation associated with familial idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown cause that occurs sporadically, but it can also occur in families and so named as Familial Pulmonary Fibrosis (FPF). Some forms of FPF overlaps IPF features, namely the radiological and histological pattern of usual interstitial pneumonia (UIP). Genetic and environmental factors commonly play an important role in the pathogenesis of FPF and the most commonly identified mutations involve the telomerase complex. Here, we report a rare case of FPF in a male at the age of 44, in whom genetic testing showed heterozygous variants for the telomerase reverse transcriptase gene (TERT). Our report highlights the importance of compiling a thorough family history in younger patients identified with UIP serving as a resource for identifying the current and future genetic links to disease. Families with UIP hold a great promise in defining UIP pathogenesis, potentially suggesting targets for the development of future therapies.

Organizing pneumonia revisited: insights and uncertainties from a series of 67 patients

Background: Organizing pneumonia (OP) is classified as an acute/subacute pneumonia according to the American Thoracic Society/European Respiratory Society statement (2013 update). Although its clinical presentation, radiologic and histologic features are well established, data on the relevance of potential causes, corticosteroid doses and length, or management of relapses are based on heterogeneous series of patients. Objectives: The aims of this study were to describe clinical presentation, diagnosis and treatment of OP, explore potential causes, discuss strategies for managing relapses, and analyze prognostic factors. We also discuss our findings in relation to relevant data in the literature. Methods: We performed a cross-sectional study of all patients diagnosed with OP at a tertiary referral center in northern Portugal between 2008 and 2015. Results: Sixty-seven patients were diagnosed with OP over the 7-year study period. Dyspnea and cough were the most common presenting symptoms and approximately 30% of patients were hospitalized at the time of diagnosis. Approximately half of the patients were receiving drugs described as potential causes of OP. Microorganisms were isolated in approximately one-third of patients. Other potential causes identified were hematologic disorders, neoplasms, connective tissue diseases, myelodysplastic syndromes, immunodeficiencies, radiotherapy, and bird exposure. Cryptogenic OP was diagnosed in just 16 patients (23.8%). Corticosteroids were the most common treatment and 11 patients (16.4%) experienced relapse. Conclusions: The findings for this series of patients confirm the extreme variability of the contexts in which OP can occur and suggest that rather than a distinct, homogeneous clinicopathologic entity, OP is a non-specific reaction whose outcomes are dependent on the cause. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 129-138).

Learning curve for transbronchial lung cryobiopsy in diffuse lung disease

INTRODUCTION

Transbronchial lung cryobiopsy (TBLC) is increasingly used in the diagnosis of diffuse lung disease (DLD), but no data have yet been published on the learning curve associated with this technique.

AIM

To evaluate diagnostic yield, lung tissue sample length and area, and procedure-related complications in a cohort of TBLC procedures to define the learning curve and threshold for proficiency.

METHODS

Retrospective analysis of the first 100 TBLCs performed in different segments of the same lobe in patients with suspected DLD. We compared diagnostic yield, sample length and area, and complications between consecutive groups of patients.

RESULTS

The overall diagnostic yield for TBLC was 82%. Median sample length was 5.4mm (IQR, 5-6) and median area was 19.5mm2 (IQR, 13.3-25). Pneumothorax was the most common complication (18%). On comparing the two groups of 50 consecutive patients, a significant difference was found for diagnostic yield (74% vs 90%; p=0.04), sample length (5.0mm [2.5-16] vs 6.0mm [4-12;] p<0.01) and area (17.5mm2 [6-42] vs 21.5mm2 [10-49]; p<0.01). Logarithm regression was applied to median diagnostic yield and sample length and area for groups of 10 consecutive patients to define the learning curve, which plateaued after approximately 70 procedures.

CONCLUSIONS

Our findings suggest that proficiency in TBLC is achieved at approximately the 70th procedure; however they need to be validated in more series and cohorts.

Four Years' Experience in the Diagnosis of Very Long-Chain Acyl-CoA Dehydrogenase Deficiency in Infants Detected in Three Spanish Newborn Screening Centers

Identification of very long-chain acyl-CoA dehydrogenase deficiency is possible in the expanded newborn screening (NBS) due to the increase in tetradecenoylcarnitine (C14:1) and in the C14:1/C2, C14:1/C16, C14:1/C12:1 ratios detected in dried blood spots. Nevertheless, different confirmatory tests must be performed to confirm the final diagnosis. We have revised the NBS results and the results of the confirmatory tests (plasma acylcarnitine profiles, molecular findings, and lymphocytes VLCAD activity) for 36 cases detected in three Spanish NBS centers during 4 years, correlating these with the clinical outcome and treatment. Our aim was to distinguish unambiguously true cases from disease carriers in order to obtain useful diagnostic information for clinicians that can be applied in the follow-up of neonates identified by NBS.Increases in C14:1 and of the different ratios, the presence of two pathogenic mutations, and deficient enzyme activity in lymphocytes (<12% of the intra-assay control) identified 12 true-positive cases. These cases were given nutritional therapy and all of them are asymptomatic, except one. Seventeen individuals were considered disease carriers based on the mild increase in plasma C14:1, in conjunction with the presence of only one mutation and/or intermediate residual activity (18-57%). In addition, seven cases were classified as false positives, with normal biochemical parameters and no mutations in the exonic region of ACADVL. All these carriers and the false positive cases remained asymptomatic. The combined evaluation of the acylcarnitine profiles, genetic results, and residual enzyme activities have proven useful to definitively classify individuals with suspected VLCAD deficiency into true-positive cases and carriers, and to decide which cases need treatment.

Idiopathic pulmonary fibrosis in the era of antifibrotic therapy: Searching for new opportunities grounded in evidence

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease that up to now has been associated with a poor prognosis. However, the results of the INPULSIS and ASCEND trials and the approval of nintedanib and pirfenidone have marked the beginning of a new era for IPF patients. Questions remain, however. Should these drugs be used earlier? What effect will they have on more severe disease? Will their effects last beyond the trial period? This manuscript is the outcome of a multidisciplinary meeting between pulmonology, radiology, and pathology clinicians on the use of antifibrotic agents in IPF. In our opinion, the existing data show that pirfenidone and nintedanib slow functional decline in early stages of disease. These drugs also appear to result in therapeutic benefits when administered to patients with advanced disease at diagnosis and maintain effective over time. The data also suggest that continuing antifibrotic therapy after disease progression may confer benefits, but more evidence is needed. Early diagnosis and treatment are crucial for reducing functional decline, slowing disease progression, and improving quality of life.

Analysis of sarcoidosis in the Oporto region (Portugal)

BACKGROUND

Sarcoidosis is a systemic granulomatous disease of unknown etiology. Epidemiological studies of different populations are essential because clinical presentation, organ involvement, disease severity, and prognosis vary significantly according to region and population. The aim of this study was to assess epidemiological and clinical characteristics, staging factors, and clinical course in patients with sarcoidosis from a tertiary hospital in Oporto, Portugal.

METHODS

A retrospective analysis of patients with sarcoidosis and at least 2 years of follow-up evaluated at the Centro Hospitalar de São João between 2000 and 2014.

RESULTS

We identified 409 patients with sarcoidosis (females, 58.9%; mean age at diagnosis, 38.9±13.4 years; smokers, 14.4%]. All the patients were diagnosed according to the ERS/ATS/WASOG consensus statement and 64.1% had evidence of noncaseating epithelioid cell granulomas in biopsy specimens. Bronchoalveolar lavage was performed as part of the diagnostic work-up in 289 patients and 90.2% had lymphocytosis (CD4/CD8 ratio ≥3.5 in 60.9% of cases). Exertion dyspnea, cough, and constitutional symptoms were the most common presenting symptoms; 10.1% of patients were asymptomatic, 22.8% had Löfgren syndrome, and 50.5% had extrathoracic involvement. Radiographic stages of disease according to the Scadding criteria were as follows: stage 0 (5.2%), stage I (33.7%), stage II (47.0%), stage III (8.4%), and stage IV (5.7%). Impaired respiratory function was observed in 45.6% patients and was mostly mild. Systemic treatment was administered in 58.6% of cases. Overall, 45.3% of patients experienced disease resolution.

CONCLUSION

The epidemiological and clinical characteristics of this cohort of patients with sarcoidosis from the Oporto region in northern Portugal revealed epidemiological and clinical characteristics that were generally similar to those described in other Western Europe populations and in the US ACCESS study. However, we found a higher proportion of patients who progressed to chronic forms.

Nanocrystalline anatase TiO2/reduced graphene oxide composite films as photoanodes for photoelectrochemical water splitting studies: the role of reduced graphene oxide

Schematic of a photoelectrochemical cell using TiO₂/RGO film as the photoanode.