Echo duration selectivity of the bat varies with pulse–echo amplitude difference

Inverted Pedicled Internal Limiting Membrane Flap Attached to an Optic Disc with Autologous Blood Clot for Large Macular Holes

Purpose

An inverted ILM flap might be accidentally separated from the retina or sucked away during surgery for large macular holes (MHs). This article is to determine the efficacy of a new inverted pedicled internal limiting membrane (ILM) flap attached to an optic disc with an autologous blood clot (ABC) technique for the treatment of large MHs.

Methods

An inverted pedicled ILM flap connected to the optic disc with ABC was used to treat 12 consecutive patients with significant macular holes (>600 m). The ILM was first peeled off around MH as a semidiameter of about 1.5 diameters of the optic disc. The superior residual ILM was used to produce a pedicled ILM flap that was connected to the optic disc and was later inverted to cover the MH. The macular hole was covered with a repositioned flap larger than 2 MH diameters in an inverted way. ABC was used to fasten the flap, followed by fluid-air exchange with air or C3F8 as tamponade. Spectral domain-optical coherence tomography (SD-OCT) and best-corrected visual acuity (BCVA) were performed at each postoperative follow-up.

Results

The mean aperture and base macular hole diameters were 737.9 ± 109.6 µm (range, 607-982 µm) and 1244.3 ± 227.4 µm (range, 975-1658 µm). All macular holes (100%) were closed after a single surgery without intraoperative or postoperative complications related to the ILM transposition technique. At the last postoperative visit, we found one eye with a U-shaped closure, three eyes with W-shaped closures, and eight eyes with V-shaped closures. No postoperative flap closures were noted in all cases. The preoperative mean BCVA was 1.5 ± 0.3 (range, 1.1-2.0). After a mean follow-up of 5.3 ± 4.8 (range, 3-16) months, the postoperative mean BCVA was 0.8 ± 0.2 (range, 0.6-1.1), and the difference was statistically significant (p < 0.05).

Conclusion

This novel technique is safe and suitable for large MHs and can be an alternative option for accidental ILM flap loss during other inverted ILM flap operations.

A mean platelet volume in inflammatory bowel disease: A systematic review and meta-analysis

Background

Inflammatory bowel disease (IBD) is a chronic gastrointestinal tract inflammatory state, which is affecting millions of individuals in the world. It can affect alimentary canals such as colon, rectum, ileum and other parts. In IBD, platelet parameters underwent several changes. Therefore, the aim of this review was determining the estimated pooled mean platelet volume and mean difference in inflammatory bowel disease to elucidate its potential diagnostic value.

Methods

Articles were extensively searched in bibliographic databases using Medical Subject Heading and entry phrases or terms. In addition, articles were directly searched in Google Scholar to account for the studies omission in searching bibliographic databases. Observational (cohort, cross-sectional and case-control) studies, published in English language and conducted on IBD were included. For studies meeting the eligibility criteria, the first author’s name, publication year, population, study design, study area, sample size, mean platelet volume and standard deviation were extracted and entered in to Microsoft-excel. The analysis was done by Stata version 11. In order to estimate the pooled mean platelet volume and mean difference, random effect model was done. The heterogeneity was quantified using Higgin’s I² statistics. Publication bias was determined using Egger’s test statistics and funnel plot. Sub-group analysis based on population carried to reduce heterogeneity.

Results

A total of 17 relevant articles with 2957 participants (1823 IBD cases and 1134 healthy controls) were included to this study. The pooled estimated MPV was 9.29fl; 95% CI: 9.01–9.57 and 9.50fl; 95% CI: 8.81–10.20 in IBD and control groups, respectively. The standardized pooled estimate of mean difference in mean platelet volume was -0.83fl; 95% CI: -1.15, -0.51; I²: 93.1%; P-value < 0.001. In subgroup analysis based on population, the highest estimated mean difference in MPV was observed among patients of CD; -2.30; 95% CI: -3.46, -1.14; I²: 97.8%; P-value < 0.001.

Conclusion

According to the current systematic review and meta-analysis, mean platelet volume was lower in IBD compared to control. The decreased mean platelet volume could be attributed to platelet consumption or sequestration associated with the progression of IBD. As a result, in IBD, mean platelet volume can provide diagnostic and prognostic information.

Association between interleukin-1 receptor antagonist (IL-1ra) VNTR, gene polymorphism and breast cancer susceptibility in Iranian population: Experimental and web-based analysis

Breast cancer is one of the leading causes of cancer mortality. Growing evidence indicates that interleukins and its polymorphisms are involved in the pathogenesis of breast cancer. Variable number of tandem repeat (VNTR) polymorphism can affect transcription rate, mRNA stability and also the resulting protein expression and activity. Hence, present study aimed to assess the possible association between interleukin-1 receptor antagonist (IL-1Ra) VNTR polymorphism, and breast cancer susceptibility in Iranian population. A total of 300 Iranian individuals, 150 breast cancer patients and 150 age-matched healthy women, were included in this study. DNA extracted by salting out method and genotyping was done using the polymerase chain reaction. The frequency of the allele 2(5% vs. 22%) and the 2/2 genotype (22% vs. 46%) of IL-1Ra VNTR polymorphism was significantly higher in healthy control compared to breast cancer patient: therefore, A2 allele may play a protective role against breast cancer and its progression (p = .0001 and OR = 0.105, 95% CI: [0.044-0.248]). The allele 2 and 2/2 genotype of the IL-Ra VNTR polymorphism can be a protective factor against breast cancer susceptibility.

Tafasitamab Plus Lenalidomide Versus 3 Rituximab-Based Treatments for Non-Transplant Eligible Relapsed/Refractory Diffuse Large B-Cell Lymphoma: A Matching-Adjusted Indirect Comparison

INTRODUCTION

Tafasitamab plus lenalidomide (TAFA + LEN) received accelerated US Food and Drug Administration approval and conditional European Medicines Agency approval for treatment of adults with relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL) not eligible for autologous stem cell transplant. This study investigates the relative efficacy of TAFA + LEN versus comparator treatments.

METHODS

Matching-adjusted indirect comparisons (MAICs) of TAFA + LEN were performed using data from L-MIND, and comparator studies assessing rituximab-based combination therapies, including polatuzumab vedotin + bendamustine + rituximab (POLA + BR) bendamustine + rituximab (BR), and gemcitabine + oxaliplatin + rituximab (R-GEMOX) to provide relative efficacy estimates for overall survival (OS), progression-free survival (PFS), duration of response (DOR), objective response rate (ORR), and complete response rate (CRR). Patient-level data from L-MIND were weighted to match reported distributions of clinically validated prognostic factors and effect modifiers in comparator trials. MAIC results versus multiple BR studies were pooled using meta-analysis.

RESULTS

MAICs were feasible versus POLA + BR and BR. Compared to POLA + BR, TAFA + LEN was associated with significantly longer DOR [hazard ratio (HR) 0.34 (95% CI 0.12, 0.98); p = 0.045]. Due to concerns about the proportional hazard assumption for OS and PFS, separate HRs were estimated before and after 4 months of follow-up. OS after 4 months, was significantly greater for TAFA + LEN versus POLA + BR [HR 0.41 (95% CI 0.19, 0.90); p = 0.026]. Compared with BR, TAFA + LEN was associated with significantly improved OS [GO29365 comparator trial: HR 0.39 (95% CI 0.18, 0.82); p = 0.014], PFS (pooled data: HR 0.39 (95% CI 0.29, 0.53); p < 0.001], DOR [pooled data: HR 0.35 (95% CI 0.25, 0.50); p < 0.001], and CRR [pooled data: odds ratio 2.43 (95% CI 1.33, 4.41); p = 0.004].

CONCLUSION

In MAIC analyses, treatment with TAFA + LEN for R/R DLBCL provided better OS and PFS outcomes than standard treatment regimens. Validation from large, randomized, phase 3 clinical trials is required to confirm these results.

Synthesis of benzimidazolones by immobilized gold nanoparticles on chitosan extracted from shrimp shells supported on fibrous phosphosilicate

We demonstrate the synthesis of benzimidazolones from o-phenylenediamines and CO₂ in the presence of gold nanoparticles supported on a composite material based on microcrystalline chitosan from shrimp shells and fibrous phosphosilicate.

Processing of Natural Echolocation Sequences in the Inferior Colliculus of Seba's Fruit Eating Bat, Carollia perspicillata

For the purpose of orientation, echolocating bats emit highly repetitive and spatially directed sonar calls. Echoes arising from call reflections are used to create an acoustic image of the environment. The inferior colliculus (IC) represents an important auditory stage for initial processing of echolocation signals. The present study addresses the following questions: (1) how does the temporal context of an echolocation sequence mimicking an approach flight of an animal affect neuronal processing of distance information to echo delays? (2) how does the IC process complex echolocation sequences containing echo information from multiple objects (multiobject sequence)? Here, we conducted neurophysiological recordings from the IC of ketamine-anaesthetized bats of the species Carollia perspicillata and compared the results from the IC with the ones from the auditory cortex (AC). Neuronal responses to an echolocation sequence was suppressed when compared to the responses to temporally isolated and randomized segments of the sequence. The neuronal suppression was weaker in the IC than in the AC. In contrast to the cortex, the time course of the acoustic events is reflected by IC activity. In the IC, suppression sharpens the neuronal tuning to specific call-echo elements and increases the signal-to-noise ratio in the units' responses. When presenting multiple-object sequences, despite collicular suppression, the neurons responded to each object-specific echo. The latter allows parallel processing of multiple echolocation streams at the IC level. Altogether, our data suggests that temporally-precise neuronal responses in the IC could allow fast and parallel processing of multiple acoustic streams.

Sharp temporal tuning in the bat auditory midbrain overcomes spectral-temporal trade-off imposed by cochlear mechanics

In the cochlea of the mustached bat, cochlear resonance produces extremely sharp frequency tuning to the dominant frequency of the echolocation calls, around 61 kHz. Such high frequency resolution in the cochlea is accomplished at the expense of losing temporal resolution because of cochlear ringing, an effect that is observable not only in the cochlea but also in the cochlear nucleus. In the midbrain, the duration of sounds is thought to be analyzed by duration-tuned neurons, which are selective to both stimulus duration and frequency. We recorded from 57 DTNs in the auditory midbrain of the mustached bat to assess if a spectral-temporal trade-off is present. Such spectral-temporal trade-off is known to occur as sharp tuning in the frequency domain which results in poorer resolution in the time domain, and vice versa. We found that a specialized sub-population of midbrain DTNs tuned to the bat's mechanical cochlear resonance frequency escape the cochlear spectral-temporal trade-off. We also show evidence that points towards an underlying neuronal inhibition that appears to be specific only at the resonance frequency.

Echo amplitude sensitivity of bat auditory neurons improves with decreasing pulse-echo gap

During hunting, insectivorous bats systematically vary the parameters of emitted pulses and analyze the returning echoes to extract prey features. As such, the duration of the pulse (P) and echo (E), the P-E gap, and the P-E amplitude difference progressively decrease throughout the prey-approach sequence. Our previous studies have shown that most inferior collicular neurons of bats discharge maximally to a best duration, and they have the sharpest echo frequency and amplitude sensitivity when stimulated with P-E pairs with duration the same as the best duration. Furthermore, their echo duration and frequency sensitivity improves with decreasing P-E duration and P-E gap. The present study shows that this is also true in the amplitude domain. Thus, all these data indicate that bats can better extract multiple parameters of expected rather than unexpected echo after pulse emission. They also support the hypothesis that a bat's inferior collicular neurons improve the response sensitivity in multiple parametric domains as the prey is approached to increase the success of hunting.

Dynamic temporal signal processing in the inferior colliculus of echolocating bats

In nature, communication sounds among animal species including humans are typical complex sounds that occur in sequence and vary with time in several parameters including amplitude, frequency, duration as well as separation, and order of individual sounds. Among these multiple parameters, sound duration is a simple but important one that contributes to the distinct spectral and temporal attributes of individual biological sounds. Likewise, the separation of individual sounds is an important temporal attribute that determines an animal's ability in distinguishing individual sounds. Whereas duration selectivity of auditory neurons underlies an animal's ability in recognition of sound duration, the recovery cycle of auditory neurons determines a neuron's ability in responding to closely spaced sound pulses and therefore, it underlies the animal's ability in analyzing the order of individual sounds. Since the multiple parameters of naturally occurring communication sounds vary with time, the analysis of a specific sound parameter by an animal would be inevitably affected by other co-varying sound parameters. This is particularly obvious in insectivorous bats, which rely on analysis of returning echoes for prey capture when they systematically vary the multiple pulse parameters throughout a target approach sequence. In this review article, we present our studies of dynamic variation of duration selectivity and recovery cycle of neurons in the central nucleus of the inferior colliculus of the frequency-modulated bats to highlight the dynamic temporal signal processing of central auditory neurons. These studies use single pulses and three biologically relevant pulse-echo (P-E) pairs with varied duration, gap, and amplitude difference similar to that occurring during search, approach, and terminal phases of hunting by bats. These studies show that most collicular neurons respond maximally to a best tuned sound duration (BD). The sound duration to which these neurons are tuned correspond closely to the behaviorally relevant sounds occurring at different phases of hunting. The duration selectivity of these collicular neurons progressively increases with decrease in the duration of pulse and echo, P-E gap, and P-E amplitude difference. GABAergic inhibition plays an important role in shaping the duration selectivity of these collicular neurons. The duration selectivity of these neurons is systematically organized along the tonotopic axis of the inferior colliculus and is closely correlated with the graded spatial distribution of GABA_A receptors. Duration-selective collicular neurons have a wide range of recovery cycle covering the P-E intervals occurring throughout the entire target approaching sequences. Collicular neurons with low best frequency and short BD recover rapidly when stimulated with P-E pairs with short duration and small P-E amplitude difference, whereas neurons with high best frequency and long BD recover rapidly when stimulated with P-E pairs with long duration and large P-E amplitude difference. This dynamic variation of echo duration selectivity and recovery cycle of collicular neurons may serve as the neural basis underlying successful hunting by bats. Conceivably, high best frequency neurons with long BD would be suitable for echo recognition during search and approach phases of hunting when the returning echoes are high in frequency, large in P-E amplitude difference, long in duration but low in repetition rate. Conversely, low best frequency neurons with shorter BD and sharper duration selectivity would be suitable for echo recognition during the terminal phase of hunting when the highly repetitive echoes are low in frequency, small in P-E amplitude difference, and short in duration. Furthermore, the tonotopically organized duration selectivity would make it possible to facilitate the recruitment of different groups of collicular neurons along the tonotopic axis for effective processing of the returning echoes throughout the entire course of hunting.

Echo frequency selectivity of duration-tuned inferior collicular neurons of the big brown bat, Eptesicus fuscus, determined with pulse-echo pairs

During hunting, insectivorous bats such as Eptesicus fuscus progressively vary the repetition rate, duration, frequency and amplitude of emitted pulses such that analysis of an echo parameter by bats would be inevitably affected by other co-varying echo parameters. The present study is to determine the variation of echo frequency selectivity of duration-tuned inferior collicular neurons during different phases of hunting using pulse-echo (P-E) pairs as stimuli. All collicular neurons discharge maximally to a tone at a particular frequency which is defined as the best frequency (BF). Most collicular neurons also discharge maximally to a BF pulse at a particular duration which is defined as the best duration (BD). A family of echo iso-level frequency tuning curves (iso-level FTC) of these duration-tuned collicular neurons is measured with the number of impulses in response to the echo pulse at selected frequencies when the P-E pairs are presented at varied P-E duration and gap. Our data show that these duration-tuned collicular neurons have narrower echo iso-level FTC when measured with BD than with non-BD echo pulses. Also, IC neurons with low BF and short BD have narrower echo iso-level FTC than IC neurons with high BF and long BD have. The bandwidth of echo iso-level FTC significantly decreases with shortening of P-E duration and P-E gap. These data suggest that duration-tuned collicular neurons not only can facilitate bat's echo recognition but also can enhance echo frequency selectivity for prey feature analysis throughout a target approaching sequence during hunting. These data also support previous behavior studies showing that bats prepare their auditory system to analyze expected returning echoes within a time window to extract target features after pulse emission.

The recovery cycle of bat duration-selective collicular neurons varies with hunting phase

During hunting, duration selectivity and recovery cycle underlie a bat's ability to determine echo duration and target distance (echo ranging). This study shows that the recovery cycle of most duration-selective neurons in the bat central nucleus of the inferior colliculus neurons varies with biologically relevant pulse-echo (P-E) duration and amplitude. As such, neurons with short best duration recover rapidly when stimulated with P-E pairs with short duration and small P-E amplitude difference, whereas neurons with long best duration recover rapidly when stimulated with P-E pairs with long duration and large P-E amplitude difference. These data indicate that different groups of duration-selective neurons underlie the bat's ability to effectively perform echo recognition and ranging during different phases of hunting.