Transient Narrowing Research Articles

A proposal to account for the stimulus, the mechanism, and the mediators released in exercise-induced bronchoconstriction.

Exercise induced bronchoconstriction (EIB) describes the transient narrowing of the airways that follows vigorous exercise. It commonly occurs in children and adults who have asthma and in elite athletes. The primary stimulus is proposed to be loss of water, by evaporation, from the airway surface due to conditioning inspired air. The mechanism, whereby this evaporative loss of water provokes contraction of the bronchial smooth muscle, is thought to be an increase in osmolarity of the airway surface liquid. The increase in osmolarity causes mast cells to release histamines, prostaglandins, and leukotrienes. It is these mediators that contract smooth muscle causing the airways to narrow.

Exercise-induced laryngeal obstruction: a rarely recognized cause of exercise-induced dyspnea. Two case reports

Introduction: Exercise-induced laryngeal obstruction (EILO) is a transient and reversible narrowing of the larynx in response to intense physical effort. The clinical picture of EILO often resembles those of asthma or exercise induced bronchospasm. The gold standard in EILO diagnostics is nasofiberoscopic examination during intense exercise (CLE).Case Description: We present two clinical cases of athletes initially treated for asthma who were diagnosed with EILO after CLE. This allowed the initiation of phoniatric rehabilitation and initial improvement of exercise tolerance.

Abstract 14339: Differences in Clinical and Angiographic Characteristics Following Intracoronary Ergnovine and Acetylcholine Provocation Test for Coronary Artery Spasm

Background: Ergnovine (Erg) and Acetylcholine (Ach) are useful agents for assessing significant coronary artery spasm (CAS). However, comparison studies of the two agents are limited. Methods: A total of 8,093 consecutive patients (pts) who underwent Erg or Ach provocation test between November 2004 and June 2021 were enrolled. Significant CAS was defined as focal or diffuse severe transient luminal narrowing (>70%) with/without chest pain or ST-T change on ECG. We divided into two groups according to provocation agent; 1) the Erg group (n=639), 2) the Ach group (n = 7,454). We investigated whether there are differences in clinical and angiographic characteristics according to intracoronary Erg or Ach provocation test. Results: Baseline clinical characteristics were similar between the two groups except the Erg group were more elderly (58.5 years vs 56.6 years, p < 0.001) and dyslipidemia (36.0% vs 18.6%, p < 0.001) but lower rates of current smokers (16.0% vs 21.1%, p = 0.002) and alcoholics (27.1% vs 32.9%, p = 0.002). During the provocation test, the higher rates of myocardial bridge, ECG change, chest pain, atrioventricular node block, and positive CAS results but lower rates of baseline spastic change were shown in the Ach group. More pts received to lower Ach dose and higher Erg dose during the provocation test. In CAS positive patients, the Ach group had higher rates of spasm in the left anterior descending artery and mid site, but lower proximal site (table). Conclusion: Clinical and angiographic parameters were different between Erg and Ach provocation tests. Further study would be needed to validate the different parameters and different positive rates between the two agents. Table. Angiographic and Procedural Parameters during Ergonovine versus Acetylcholine Provocation Test

Abstract 12018: Coronary Microvascular Dilatory Dysfunction According to the Types of Coronary Functional Abnormalitiescoronarymicrovascular Dilatory Dysfunction According to the Types of Coronary Functional Abnormalities

Introduction: Recently, there has been an increasing interest in coronary functional abnormalities (CFA), which include epicardial coronary spasm (ECS), microvascular spasm (MVS) and microvascular vasodilatory dysfunction (MVD). However, the frequency of MVD according to the types of CFA remains unclear. Hypothesis: Thus, this study aimed to investigate the frequency of MVD according to the types of CFA in patients with ischemia with non-obstructive coronary arteries (INOCA). Methods: This study included 63 patients with INOCA who underwent coronary angiography (CAG) and coronary function tests (CFT) to evaluate chest pain. In CFT, acetylcholine was first administered intracoronarily in a stepwise manner, followed by chest symptoms, electrocardiographic ST-T changes and CAG. ECS was defined as coronary vasoconstriction of >90% on CAG accompanied by chest symptoms or electrocardiographic ST-T changes. Additionally, a focal spasm was defined as a transient vessel narrowing of >90% within the borders of one isolated coronary segment (as defined by the American Heart Association), and a diffuse spasm was defined as a 90% diffuse vasoconstriction in ≥2 adjacent coronary segments of the coronary artery. Moreover, MVS was defined as the presence of both chest symptoms and ST-T changes with non-significant coronary vasoconstriction (<90%) on CAG. After nitroglycerin administration, coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) were subsequently obtained by transvenous adenosine triphosphate infusion using a pressure wire. MVD was defined as CFR of <2.0 or IMR of ≥25 units. Results: CAG and CFT were performed on 91 coronary arteries in 63 patients with INOCA, the results of which are shown below. Conclusions: These findings suggest that the frequency of MVD differs according to the types of CFA. Properly evaluating the MVD and reflecting this in the therapeutic strategy in patients with INOCA is desirable in clinical settings.

Inactivated COVID-19 vaccine induced acute stroke-like focal neurologic symptoms: a case series

BackgroundA subgroup of individuals experienced stroke-like symptoms after receiving an inactivated COVID-19 vaccine. We present clinical characteristics, neuroimaging, and outcome of these patients.MethodsMedical personals who had neurological symptoms after receiving inactivated COVID-19 vaccine were enrolled. Clinical, laboratory investigation and neuroimaging were collected. Subjects were prospectively followed-up on clinical and neuroimaging to detect brain parenchymal or cerebrovascular abnormality.ResultsNineteen out of 385 subjects (4.9%) developed neurological symptoms after vaccination. There was a female predominance (89.5%) with mean age of 34 ± 7.5 years. Majority of patients (52.6%) had symptoms within 60 min after vaccination. The most common neurological symptoms were numbness (94.7%) followed by headache (52.6%) and weakness (47.4%). The most common neurological signs were sensory deficit (79%) followed by motor weakness (52.6%) and tongue deviation (26.3%). Recurrent headache was observed in most patients (89.5%) during followed up. Serial brain imaging was done in all patients with median follow-up interval of 18 days. There was no evidence of acute brain infarction in any of the patients, 84.2% had no vascular abnormality, 15.8% had transient focal narrowing of cerebral vessels. Outcome was favorable, modified ranking scale 0–1 for all patients at 4 weeks after vaccination.ConclusionsTransient focal neurological symptoms and deficits can be found after COVID-19 vaccination. However, benefit to stop COVID-19 pandemic by vaccination is outweighed by these seemingly reversible side effects. The pathophysiology underlined these phenomena should be further investigated.

Ultra-slow electron spin-lattice relaxation in a low magnetic field enables massive optical spin polarization in the 4A2 ground state of Cr3+ in ruby* *This paper is dedicated to my late friend and mentor Dr Alex Szabo, the originator of transient spectral hole-burning and fluorescence line narrowing in the solid state, whose knowledge of the spectroscopy of ruby is unsurpassed.

Ruby (α-Al2O3 doped with Cr3+) has been an archetypal material in the development of optical spectroscopy of the solid state for the last 150 years and was the first material that was demonstrated to lase. Notwithstanding the vast literature on ruby, one effect was somehow missed: in a magnetic field B ∥c ∼ 235 mT, the spin-lattice relaxation time T 1 for the |+3/2⟩ level in the 4A2 ground state is massively lengthened to ∼12 s at 1.4 K as demonstrated in this study. This very long relaxation time enables optical pumping of the |+3/2⟩ level via the R 1(±1/2) lines and a considerable +3/2 spin polarization of ∼95% is readily achieved. The observed magnetic field dependence can be quantitatively described using the one-phonon relaxation process.

Tissue engineered vascular grafts transform into autologous neovessels capable of native function and growth

BackgroundTissue-engineered vascular grafts (TEVGs) have the potential to advance the surgical management of infants and children requiring congenital heart surgery by creating functional vascular conduits with growth capacity.MethodsHerein, we used an integrative computational-experimental approach to elucidate the natural history of neovessel formation in a large animal preclinical model; combining an in vitro accelerated degradation study with mechanical testing, large animal implantation studies with in vivo imaging and histology, and data-informed computational growth and remodeling models.ResultsOur findings demonstrate that the structural integrity of the polymeric scaffold is lost over the first 26 weeks in vivo, while polymeric fragments persist for up to 52 weeks. Our models predict that early neotissue accumulation is driven primarily by inflammatory processes in response to the implanted polymeric scaffold, but that turnover becomes progressively mechano-mediated as the scaffold degrades. Using a lamb model, we confirm that early neotissue formation results primarily from the foreign body reaction induced by the scaffold, resulting in an early period of dynamic remodeling characterized by transient TEVG narrowing. As the scaffold degrades, mechano-mediated neotissue remodeling becomes dominant around 26 weeks. After the scaffold degrades completely, the resulting neovessel undergoes growth and remodeling that mimicks native vessel behavior, including biological growth capacity, further supported by fluid–structure interaction simulations providing detailed hemodynamic and wall stress information.ConclusionsThese findings provide insights into TEVG remodeling, and have important implications for clinical use and future development of TEVGs for children with congenital heart disease.

Differential effects of intense exercise and pollution on the airways in a murine model

BackgroundExercise-induced bronchoconstriction (EIB) is a transient airway narrowing, occurring during or shortly after intensive exercise. It is highly prevalent in non-asthmatic outdoor endurance athletes suggesting an important contribution of air pollution in the development of EIB. Therefore, more research is necessary to investigate the combination of exercise and pollutants on the airways.MethodsBalbc/ByJ mice were intranasally challenged 5 days a week for 3 weeks with saline or 0.2 mg/ml diesel exhaust particles (DEP), prior to a daily incremental running session or non-exercise session. Once a week, the early ventilatory response was measured and lung function was determined at day 24. Airway inflammation and cytokine levels were evaluated in bronchoalveolar lavage fluid. Furthermore, innate lymphoid cells, dendritic cells and tight junction mRNA expression were determined in lung tissue.ResultsSubmaximal exercise resulted in acute alterations of the breathing pattern and significantly improved FEV0.1 at day 24. DEP exposure induced neutrophilic airway inflammation, accompanied with increased percentages of CD11b+ DC in lung tissue and pro-inflammatory cytokines, such as IL-13, MCP-1, GM-CSF and KC. Occludin and claudin-1(Cldn-1) expression were respectively increased and decreased by DEP exposure. Whereas, exercise increased Cldn-3 and Cldn-18 expression. Combining exercise and DEP exposure resulted in significantly increased SP-D levels in the airways.ConclusionDEP exposure induced typical airway neutrophilia, DC recruitment and pro-inflammatory cytokine production. Whereas, intensive exercise induced changes of the breathing pattern. The combination of both triggers resulted in a dysregulation of tight junction expression, suggesting that intensive exercise in polluted environments can induce important changes in the airway physiology and integrity.

Sleep-disordered breathing and comorbidities: role of the upper airway and craniofacial skeleton.

Obstructive sleep-disordered breathing (SDB), which includes primary snoring through to obstructive sleep apnea syndrome (OSAS), may cause compromise of respiratory gas exchange during sleep, related to transient upper airway narrowing disrupting ventilation, and causing oxyhemoglobin desaturation and poor sleep quality. SDB is common in chronic disorders and has significant implications for health. With prevalence rates globally increasing, this condition is causing a substantial burden on health care costs. Certain populations, including people with sickle cell disease (SCD), exhibit a greater prevalence of OSAS. A review of the literature provides the available normal polysomnography and oximetry data for reference and documents the structural upper airway differences between those with and without OSAS, as well as between ethnicities and disease states. There may be differences in craniofacial development due to atypical growth trajectories or extramedullary hematopoiesis in anemias such as SCD. Studies involving MRI of the upper airway illustrated that OSAS populations tend to have a greater amount of lymphoid tissue, smaller airways, and smaller lower facial skeletons from measurements of the mandible and linear mental spine to clivus. Understanding the potential relationship between these anatomical landmarks and OSAS could help to stratify treatments, guiding choice towards those which most effectively resolve the obstruction. OSAS is relatively common in SCD populations, with hypoxia as a key manifestation, and sequelae including increased risk of stroke. Combatting any structural defects with appropriate interventions could reduce hypoxic exposure and consequently reduce the risk of comorbidities in those with SDB, warranting early treatment interventions.

M018 MULTIPLE INTUBATIONS FOR "ANAPHYLAXIS": ANOTHER PRESENTATION FOR INDUCIBLE LARYNGEAL OBSTRUCTION

Inducible laryngeal obstruction (ILO) refers to a transient narrowing of the larynx due to paradoxical adduction of the vocal folds, false vocal cords or supraglottic tissue leading to periodic laryngeal obstruction. ILO is associated with exercise, reflux, inhaled irritants, and stress. Common symptoms include subjective throat tightness, choking sensation, cough and occasionally stridor or dysphonia. Recurrent intubations for a history of repeated anaphylactic events should trigger a thorough evaluation for ILO, especially in patients who present with atypical histories.

Does The Mixed Relay Triathlon Affect Respiratory Function In Healthy Junior Triathletes?

Exercise-induced bronchoconstriction (EIB) is a transient narrowing of the airway that can be attributed to heavy ventilation associated with sustained high intensity exercise greater than 8 min. High aerobic and ventilatory training demands can exacerbate the EIB response and lead to prevalence of EIB in endurance athletes like triathletes. The mixed relay triathlon, due to its high intensity and short duration format, will induce heavy ventilation that could lead to EIB. However, no research at present has determined the influence of a mixed relay on respiratory function and baseline spirometry measures which influence EIB. PURPOSE: To determine severity and prevalence of EIB in healthy triathletes competing in a mixed relay and understand if baseline spirometry is predictive of the EIB response and race performance. METHODS: Seven males (17.7 ± 0.4 years, 183.7 ± 3.0 cm) and 5 females (17.6 ± 0.6 years, 171.1 ± 2.7 cm) competed in the Canadian Championships (300m swim, 6km bike, 1.6km run). Spirometry measures of Forced Expiratory Volume in 1 sec (FEV1), Forced Vital Capacity (FVC), FEV1/FVC (%), Forced Expiratory Flow at 50% FVC (FEF50), FEF 25-75% and Peak Expiratory Flow (PEF) was performed before warm up and 5 min post-race. Measures were calculated as % delta change (for EIB determination) and in raw units to determine pre-post differences in measures via paired sample t-tests. RESULTS: Mean race time was 22.4 ± 1.5 min including transitions (swim 4.5 ± 0.5 min, bike 10.4 ± 0.7 min, run 6.1 ± 0.6 min). No spirometry measure was significantly decreased post-race. One athlete had mild EIB (% decrease in FEV1 between 10 and 25%) and 2 athletes had a baseline FEV1/FVC ratio <0.7. Percent delta change in PEF and FEF 25-75% were correlated to finish time (r=-0.78, r=-0.83, p<0.05 respectively). CONCLUSION: An all-out 20 min ultra-short triathlon does not negatively affect respiratory function in young healthy junior triathletes. It maybe that the decrease in PEF and FEF 25-75 affected finish time due to reduced airway function affecting exercise intensity. The low prevalence of EIB compared to older endurance athletes supports the late onset of EIB in endurance athletes (> 25 years) although the 2 athletes with <0.7 resting FEV1/FVC ratios show signs of underlying airway obstruction.

Transient narrowing of a wide QRS tachycardia. What is the mechanism?

Electrocardiogram showing a regular wide QRS tachycardia with left branch block (LBBB) like in morphology at 200 beats per minute (bpm). During electrophysiology study, it suddenly gets narrow and faster. What is the mechanism of the switch from a broad complex to a narrow complex tachycardia?

Can Pediatricians Assess Exercise-Induced Bronchoconstriction From Post-exercise Videos?

Objective: Exercise-induced bronchoconstriction (EIB) is a highly prevalent morbidity of childhood asthma and defined by a transient narrowing of the airways during or after physical exercise. An exercise challenge test (ECT) is the reference standard for the diagnosis of EIB. Video evaluation of EIB symptoms could be a practical alternative for the assessment of EIB. We studied the ability of pediatricians to assess EIB from post-exercise videos.Methods: A clinical assessment was performed in 20 asthmatic children (mean age 11.6 years) and EIB was measured with a standardized ECT performed in cold, dry air. EIB was defined as a fall in forced expiratory volume in 1 s (FEV1) of ≥10% post-exercise. Children were filmed before and after exercise in frontal position and bare chested. The clinical assessment results and videos were shown to 20 pediatricians (mean experience 14.4 years). Each assessed EIB severity in 5 random children providing 100 assessments, scored on a continuous rating scale (0–10) and in severity classifications (no, mild, moderate, severe) using a scoring list including physical asthma symptoms. Correlations between predicted scores and objective scores were calculated with Spearman's rho and Cohen's Kappa. A generalized linear model was used to assess the relationship between physical symptoms and fall in FEV1.Results: Median fall in FEV1 after exercise was 15.1% (IQR 1.2–65.1). Pediatricians detected EIB with a sensitivity of 78% (95% CI 66–87%) and a specificity of 40% (95% CI 27–55%). The positive predictive value for a pediatricians' diagnosis of EIB was 61% (95% CI 50–72%). The negative predictive value was 60% (95% CI 42–76%). The agreement between predicted EIB severity classifications and the validated classifications based on the ECT's, was fair [Kappa = 0.36 (95% CI 0.23–0.48)]. The correlation between predicted EIB severity scored on a continuous rating scale and fall in FEV1 after exercise was weak (rs = 0.39, p < 0.001). Independent predictive variables for fall in FEV1 were wheezing (−11%), supraclavicular retractions (−8.4%) and a prolonged expiratory phase (−8.8%).Conclusion: The ability of pediatricians to assess EIB from post-exercise videos is fair at best, implicating that standardized ECT's are still vital in the assessment of EIB.

Exercise-induced bronchospasm and its associated factors among secondary school students in an urban community

ABSTRACT Introduction: Exercise-induced bronchospasm (EIB) is a transient narrowing of the airway that usually occurs shortly after exercise. It occurs commonly in people with asthma; however EIB has also been reported in individuals without clinical asthma. The study aimed to determine the prevalence and factors associated with EIB among secondary school students. Methods: It was a descriptive cross-sectional school- based study involving secondary school students aged between 10 and 17 years without previous history of asthma. Subjects undertook a six-minute running test, spirometry was done and the best of three FEV1 readings were obtained pre-exercise, at 5, 10, 15 and 30 minutes post exercise. The diagnosis of EIB was made when there was a decrease in FEV1 of ≥10% from baseline after exercise. Results: Of the 265participants studied, 34 (12.8%) had EIB at 5 minutes post exercise. EIB was significantly more in the 10–13 years age group (χ2 = 18.416, p = <0.001), there was no significant gender difference. The presence of allergic (vernal) conjunctivitis and rhinitis were both significantly associated with the development of EIB (χ2 = 13.574, p < 0.001 and 0.011 respectively). There was no significant association with previous history of wheeze and exposure to indoor air pollution such as cooking with biomass fuel and parental cigarette smoking. Conclusion: EIB exist among non-asthmatic school children, and it is more frequent in the early adolescent age-group. Students with allergic conjunctivitis and rhinitis are more likely to manifest exercise induced bronchospasm.

EXERCISE INDUCED BRONCHOCONSTRICTION IN MEDICAL STUDENTS

INTRODUCTION: Exercise induced bronchoconstriction (EIB) is transient narrowing of lower respiratory tract airways after exercise. It affects about 5 to 20 % of healthy individuals and 80% of Asthmatics. Obesity has been considered as one of the risk factor to the development of EIB. Symptoms of EIB are nonspecific and can be seen in a variety of disorders and studies have shown a lack of diagnosis specificity and sensitivity based on symptoms. AIM: The aim of this study was to evaluate frequency of EIB in Medical students of Govt. Medical College Miraj. We also tried to find out association of body mass index (BMI) with EIB. We also tried to find out correlation of subjective feeling of breathlessness (symptom of EIB) with actual findings of spirometry tests used to asses EIB. METHOD: This cross-sectional observational study was conducted on 80 male medical students. Exercise challenge test was conducted for participants. Pre and post-test values of Forced expiratory volume in one second (FEV1) and Peak expiratory flow rate (PEFR) were compared and students with ≥ 10% decrease in post-test FEV1 &amp; PEFR were considered positive cases of exercise induced bronchoconstriction. Statistical analysis was done by using software, IBM-SPSS VER 20. RESULT:In our study frequency of EIB in medical students was 6.4%. Decrease in post-test FEV1 and PEFR values were statistically significant with Pvalue &lt; 0.001. Our findings show that there was no association between BMI and EIB. Our study results also reveal strong correlation between subjective feeling of breathlessness measured in terms of visual analogue scale (VAS) and objective spirometry tests used to assess EIB. CONCLUSION: EIB is one of the major problems to be addressed as increasing frequency of EIB in healthy population could pose a threat when people attempt exercise training for their health benefits. Proper care with physician's consultation can minimize undue risks associated with EIB in healthy people.

EXERCISE INDUCED BRONCHOCONSTRICTION IN MEDICAL STUDENTS

INTRODUCTION: Exercise induced bronchoconstriction (EIB) is transient narrowing of lower respiratory tract airways after exercise. It affects about 5 to 20 % of healthy individuals and 80% of Asthmatics. Obesity has been considered as one of the risk factor to the development of EIB. Symptoms of EIB are nonspecific and can be seen in a variety of disorders and studies have shown a lack of diagnosis specificity and sensitivity based on symptoms. AIM: The aim of this study was to evaluate frequency of EIB in Medical students of Govt. Medical College Miraj. We also tried to find out association of body mass index (BMI) with EIB. We also tried to find out correlation of subjective feeling of breathlessness (symptom of EIB) with actual findings of spirometry tests used to asses EIB. METHOD: This cross-sectional observational study was conducted on 80 male medical students. Exercise challenge test was conducted for participants. Pre and post-test values of Forced expiratory volume in one second (FEV1) and Peak expiratory flow rate (PEFR) were compared and students with ≥ 10% decrease in post-test FEV1 &amp; PEFR were considered positive cases of exercise induced bronchoconstriction. Statistical analysis was done by using software, IBM-SPSS VER 20. RESULT:In our study frequency of EIB in medical students was 6.4%. Decrease in post-test FEV1 and PEFR values were statistically significant with Pvalue &lt; 0.001. Our findings show that there was no association between BMI and EIB. Our study results also reveal strong correlation between subjective feeling of breathlessness measured in terms of visual analogue scale (VAS) and objective spirometry tests used to assess EIB. CONCLUSION: EIB is one of the major problems to be addressed as increasing frequency of EIB in healthy population could pose a threat when people attempt exercise training for their health benefits. Proper care with physician's consultation can minimize undue risks associated with EIB in healthy people.

The effect of diurnal variation in exercise-induced bronchoconstriction

Objective: Exercise-induced bronchoconstriction (EIB) is an acute, transient narrowing of the airway as a result of exercise. Diurnal variation in asthma is well-established, however, few studies have investigated diurnal variability in EIB; no study has used eucapnic voluntary hyperpnea (EVH). The aim of this study was to examine circadian variability in EIB using EVH.Methods: Fourteen recreationally-active males with mild to moderate asthma and nine healthy controls were randomized to first complete either an AM (07:00–08:00) or PM (17:00–18:00) EVH challenge, followed by the alternate test 34 h to 7 days later. The EVH protocol comprised of six-minutes of hyperventilation of a 5% CO2 gas at a minimum ventilation rate of 21 × FEV1 min−1. The primary outcome measure was FEV1 pre- and post-EVH.Results: We observed no diurnal effect on EIB in the asthma group. The minimum observed post-EVH FEV1 in the asthma cohort was 3.58 ± 0.95 L in AM and 3.62 ± 0.87 L in PM tests, corresponding to a 15.0 ± 15.3% vs. 14.9 ± 14.7% reduction from baseline, respectively. The asthma group showed similar baseline FEV1 before AM (4.21 ± 0.79 L) and PM (4.25 ± 0.65 L) tests. No difference was observed in minute ventilation between AM (26.1 ± 3.4 × FEV1 min−1) and PM (25.6 ± 3.8 × FEV1 min−1) tests for the asthma cohort. Controls displayed no significant changes in FEV1 or minute ventilation between tests.Conclusions: When baseline pulmonary function is similar, this study suggests that time-of-day has no effect on EIB in mild to moderate asthma.

Transient Aortoiliac Narrowing during Voluntary Valsalva Maneuver

A 54-year-old male presented to the outpatient surgery clinic with chronic intermittent right inguinal pain. An unenhanced computed tomography (CT) scan during Valsalve maneuver was performed, which demonstrated aortoiliac narrowing. Kinking of the duodenum and renal vasculature, and flattening of the inferior vena cava and iliac vasculature were also noted. A CT angiogram was subsequently performed without Valsalva maneuver which demonstrated complete resolution of the vascular and enteric findings. The case demonstrates that transient aortoiliac narrowing can also occur during voluntary Valsalva maneuver. Awareness of this entity is important so that patients can be reassured about the transient physiologic nature of these findings.

Intravitreal bevacizumab versus ranibizumab: Effects on the vessels of the fellow non-treated eye

PurposeTo evaluate the effects of anti-vascular endothelial growth factors (anti-VEGF) on the vessels of the non-treated eyes following intravitreal injections. MethodsIn this prospective, non-randomized trial, a total of 38 patients were recruited. 21 patients received ranibizumab, and 17 patients received bevacizumab. Fundus photography was carried out at baseline immediately before injection and at 3 days, 7 days, and one month after the injections. Using image analysis software, measurements were summarized as the central retinal artery equivalent (CRAE) and central retinal vein equivalent. ResultsIn non-treated eyes, CRAE decreased significantly from 153.23 ± 15.20 μm before injection to 148.77 ± 17.21 μm 3 days after intravitreal bevacizumab (P = 0.004). There was no significant difference in CRAE, between the pre-injection baseline, one week, and one month after intravitreal bevacizumab injection in non-treated eyes (P > 0.05). No significant difference was noted in CRAE in the non-treated eyes of the ranibizumab group at any post-injection visit (P = 0.1). ConclusionA significant transient narrowing effect of bevacizumab on retinal arterioles in the fellow non-treated eyes on the third day after intravitreal injection may show that plasma concentrations of these drugs are sufficient to spread the effect to the other eye.

Transient Magnetic Field Effect of Photoexcitations in Donor-Acceptor Organic Semiconductors.

We report transient photoinduced absorption (t-PA) and magnetic field ( B)-dependent t-PA (t-MPA( B)) in a pristine low band gap π-conjugated copolymer composed of donor and acceptor moieties, namely, the poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thi-eno[3,4- b]thiophenediyl]]) (or PTB7) used in photovoltaic applications. Unlike traditional π-conjugated polymers in which the primary photoexcitations are singlet excitons (SE), in pristine PTB7 we find at short times coexistence of two primary photoexcitation species, namely, SE and triplet-triplet (TT) pair. Both species are photogenerated directly from the ground state and are spin-correlated. Although the TT pair decomposes into two separate triplet excitons (TEs) in ∼100 ps, the separated TE spins are still entangled up to ∼6 μs. At longer times, the t-MPA( B) response of the surviving TEs shows transient narrowing effect, which is attributed to a distribution of the TE size.