Posterior Zone Research Articles

Combined intravitreal ranibizumab and zone I sparing laser ablation in infants with posterior zone I retinopathy of prematurity.

Purpose:To evaluate the efficacy of combined intravitreal ranibizumab (IVR) and zone I sparing laser ablation in infants with posterior zone I Retinopathy of Prematurity (ROP).Methods:This was a retrospective, interventional case series including premature infants diagnosed with posterior zone I ROP (n = 24) on ROP screening. Charts and RetCam images of preterm infants with posterior zone I ROP treated with immediate IVR and zone I sparing laser ablation at 4 weeks between April 2016 and September 2019 were reviewed. Data were analyzed and tabulated using frequency and descriptive statistics to describe the demography, morphology, and treatment outcomes. Primary outcome measure was structural outcome at 6 months. It was further categorized as favorable and unfavorable.Results:Twenty-four infants (48 eyes) with a mean gestational age of 28.54 ± 1.98 weeks and birth weight of 1180.33 ± 280.65 grams were analyzed. Thirty-six (75%) eyes had persistent tunica vasculosa lentis and twenty-six (54.1%) eyes had iris neovascularization. All eyes had features of aggressive posterior retinopathy of prematurity (APROP) limited to posterior zone I. The mean duration between IVR and zone I sparing laser ablation was 29.62 ± 6.36 (range: 24-34) days. One infant (2 eyes) received a second IVR treatment for recurrence of plus disease and persistent new vessels close to the fovea. Laser augmentation was done in 13 (27.1%) eyes. A favorable structural outcome was seen in 45 (93.7%) eyes.Conclusion:Posterior zone I ROP presents as APROP. Combined IVR and zone I sparing laser ablation appears effective treatment option in these eyes.

Sinkhole Scanner: A New Method to Detect Sinkhole-Related Spatio-Temporal Patterns in InSAR Deformation Time Series

Sinkholes are sudden disasters that are usually small in size and occur at unexpected locations. They may cause serious damage to life and property. Sinkhole-prone areas can be monitored using Interferometric Synthetic Aperture Radar (InSAR) time series. Defining a pattern using InSAR-derived spatio-temporal deformations, this study presents a sinkhole pattern detector, called the Sinkhole Scanner. The Sinkhole Scanner includes a spatio-temporal mathematical model such as a 2-dimensional time evolving Gaussian function as a kernel, which moves over the study area using a sliding window approach. The scanner attempts to fit the model over deformation time series of Constantly Coherent Scatterers (CCS) intersected by the window and returns the posterior variance as a measure of goodness of fit. In this way, the scanner searches for subsiding regions resembling sinkhole shapes over a sinkhole prone area. It is designed to detect large sinkholes with a high efficiency, and small sinkholes with a lower efficiency. It is tested at four different spatial scales, and on a simulated and real set of deformation data. Real data were obtained from Sentinel-1A SLC data in IW mode, over Ireland where a large sinkhole occurred on 24 September 2018. The Sinkhole Scanner was able to identify a pattern of low posterior variance zones consistent with the simulated set. In case of the real data, it is able to identify significantly low posterior variance zones near the sinkhole area with the lowest value being 51.1% of the maximum value. The results from Sinkhole Scanner over the real sinkhole site were compared with Multiple Hypothesis Testing (MHT), which identifies Breakpoint and Heaviside temporal anomalies in the deformation time series of CCS. MHT was able to identify high likelihood for Heaviside anomalies in deformation time series of CCS near the sinkhole site about 10 epochs before the sinkhole occurrence. We show that the Sinkhole Scanner is efficient in monitoring a large area and search for sinkholes and that MHT can be used successively to identify temporal anomalies in the vicinity of areas detected by the Sinkhole Scanner. Future research may address other Sinkhole shapes whereas the underlying stochastic model may be adjusted. We conclude that the Sinkhole Scanner is important to be applied at different levels of scale to converge on potential sinkhole centers.

The comfort of knitted fabrics: interaction of sportswear and athlete’s body

The properties of the material used for the production of sportswear, as well as the properties of the sportswear, directly affect the heat exchange and sweat transfer that occurs at the interface between the skin and the environment. Thermography is a valuable method that provides insight into the patterns of temperature distribution on the surface of human skin that change during sports training or intense exercise. Such patterns can be further used to improve the design of sportswear. The experiment presented in this paper focuses on studying the changes in body temperature of the participating subjects during two typical types of training in football (condition training and tactical training). The duration of each training session was 60 minutes and measurements were taken after each of the total 10 training sessions. The thermal camera was used to measure the upper body temperatures of the players and the professional software was used for further processing of the thermal images. In the analysis of the thermal data, the average temperatures for 9 anterior and 9 posterior zones of the upper body were obtained. The results related to the changes in average temperature for each observed anterior and posterior zone and two types of football training are presented and discussed.

International Classification of Retinopathy of Prematurity, Third Edition

The International Classification of Retinopathy of Prematurity is a consensus statement that creates a standard nomenclature for classification of retinopathy of prematurity (ROP). It was initially published in 1984, expanded in 1987, and revisited in 2005. This article presents a third revision, the International Classification of Retinopathy of Prematurity, Third Edition (ICROP3), which is now required because of challenges such as: (1) concerns about subjectivity in critical elements of disease classification; (2) innovations in ophthalmic imaging; (3) novel pharmacologic therapies (e.g., anti-vascular endothelial growth factor agents) with unique regression and reactivation features after treatment compared with ablative therapies; and (4) recognition that patterns of ROP in some regions of the world do not fit neatly into the current classification system. Review of evidence-based literature, along with expert consensus opinion. International ROP expert committee assembled in March 2019 representing 17 countries and comprising 14 pediatric ophthalmologists and 20 retinal specialists, as well as 12 women and 22 men. The committee was initially divided into 3 subcommittees-acute phase, regression or reactivation, and imaging-each of which used iterative videoconferences and an online message board to identify key challenges and approaches. Subsequently, the entire committee used iterative videoconferences, 2 in-person multiday meetings, and an online message board to develop consensus on classification. Consensus statement. The ICROP3 retains current definitions such as zone (location of disease), stage (appearance of disease at the avascular-vascular junction), and circumferential extent of disease. Major updates in the ICROP3 include refined classification metrics (e.g., posterior zone II, notch, subcategorization of stage 5, and recognition that a continuous spectrum of vascular abnormality exists from normal to plus disease). Updates also include the definition of aggressive ROP to replace aggressive-posterior ROP because of increasing recognition that aggressive disease may occur in larger preterm infants and beyond the posterior retina, particularly in regions of the world with limited resources. ROP regression and reactivation are described in detail, with additional description of long-term sequelae. These principles may improve the quality and standardization of ROP care worldwide and may provide a foundation to improve research and clinical care.

GROWTH OF THE PEDIATRIC KNEE MENISCUS: A CADAVERIC STUDY

Background:The menisci of the knee play a critical role in maintaining structural integrity, as well as in load bearing and shock absorption. In adolescent patients, meniscal tear is a very common sports injury, and is frequently associated with concomitant traumatic injuries including tibial eminence fracture or ACL tear. The incidence of pediatric meniscal tears is increasing, and anatomic studies to guide repair, saucerization and transplantation do not exist.Hypothesis/Purpose:This study’s purpose was to evaluate meniscus dimensions in the developing meniscus and provide anatomic parameters for repair, saucerization, resection, transplantation.Methods:From images of 29 dissected cadaveric knee specimens between 1 month and 132 months of age obtained on a copy stand (14 left knee, 15 right knee), we made direct length measurements from the inner to outer meniscus rim at 45 degree intervals (12, 1:30/10:30, 3:00/9:00, 4:30/7:30 o’clock, 6 o’clock) using Autodesk Fusion 360 software (Figure 1.1). We also measured width between the outer medial and lateral meniscus rims, as well as CT measurements of coronal and sagittal width of the tibial plateau using OsiriX DICOM software. Generalized linear models were used to evaluate the associations of meniscal length measurements with age, tibial width, and meniscal width measurements. All statistical analyses were completed with a two-sided level of significance of 0.05.Results:All radial length measurements were predicted to increase significantly with age (p < 0.01), as coronal tibial width increases (p < 0.05), and as lateral-medial meniscal width increases (p < 0.001) (Figure 1.2). Other than the lateral 3 o’clock measurement (p = 0.119), all radial measurements were predicted to increase significantly as sagittal tibial width increases (p < 0.05). The posterior zones of the medial meniscus (6:00, 4:30/7:30) were found to increase in radial length at a faster rate than the anterior zones. The anterior zones of the medial meniscus (12:00, 1:30/10:30) had the slowest rate of growth.Discussion/Conclusion:Meniscus radial length is related to age, tibial plateau width, and lateral-medial meniscus width. Radial dimensions from normal lateral menisci may allow the surgeon to obtain ideal size of resection, saucerization of discoid menisci. The growth of medial meniscus posterior zones is greater than the anterior zones. This may be attributed to increased posterior region load bearing which increases with ambulation in the developing child. Improved anatomic understanding may help surgeons plan for discoid resection/saucerization/repair, and also support appropriate selection of meniscus allograft for transplantation.Figure 1.1.Figure 1.2.

Second-look arthroscopy after meniscus repair and synovial mesenchymal stem cell transplantation to treat degenerative flaps and radial tears of the medial meniscus: A case report

BackgroundThe purpose of this study was to compare arthroscopic findings of a degenerative flap and radial tear of the medial meniscus (MM) before and one year after treatment by meniscus repair and synovial mesenchymal stem cell (MSC) transplantation. MethodsPatients with a degenerative flap and radial MM tear that would generally be treated by meniscectomy were included. The patients ranged in age from 45 to 62 years and all underwent meniscus repair and synovium harvest at time 0. The digested synovium was cultured with autologous serum for 12 days, and an average of 4 × 107 MSCs were transplanted at two weeks. A second-look arthroscopy was performed at 52 weeks (n = 6). The average duration of symptoms was 24 months. For flap tears, arthroscopic findings were quantified in terms of the presence, stability, and smoothness of the meniscus at each zone and area. The Lysholm score was evaluated throughout the 52 week follow-up. ResultsFour patients with MM flap tears showed deficiencies in the central area at the posterior junctional zone before treatment, but this zone was completely restored to a stable and smooth condition in two patients and partially restored in the other two patients. The arthroscopy score for a flap tear at the central area of the posterior junctional zone was 0.3 ± 0.5 before treatment and 4.3 ± 2.1 after treatment. The score was significantly higher after treatment (p < 0.05, n = 4). The original radial MM tears in two patients were healed one year after treatment. Lysholm scores were significantly higher at 4 and 52 weeks after treatment than before treatment (n = 6). ConclusionsArthroscopic findings for a degenerative flap and radial tear of the MM were improved at the central area of the posterior junctional zone one year after meniscus repair and MSC transplantation.

Spatial Distribution and Quantification of Mammographic Breast Density, and Its Correlation with BI-RADS Using an Image Segmentation Method.

(1) Background: Mammographic breast density (MBD) and older age are classical breast cancer risk factors. Normally, MBDs are not evenly distributed in the breast, with different women having different spatial distribution and clustering patterns. The presence of MBDs makes tumors and other lesions challenging to be identified in mammograms. The objectives of this study were: (i) to quantify the amount of MBDs—in the whole (overall), different sub-regions, and different zones of the breast using an image segmentation method; (ii) to investigate the spatial distribution patterns of MBD in different sub-regions of the breast. (2) Methods: The image segmentation method was used to quantify the overall amount of MBDs in the whole breast (overall percentage density (PD)), in 48 sub-regions (regional PDs), and three different zones (zonal PDs) of the whole breast, and the results of the amount of MBDs in 48 sub-regional PDs were further analyzed to determine its spatial distribution pattern in the breast using Moran’s I values (spatial autocorrelation). (3) Results: The overall PD showed a negative correlation with age (p = 0.008); the younger women tended to have denser breasts (higher overall PD in breasts). We also found a higher proportion (p < 0.001) of positive autocorrelation pattern in the less dense breast group than in the denser breast group, suggesting that MBDs in the less dense breasts tend to be clustered together. Moreover, we also observed that MBDs in the mature women (<65 years old) tended to be clustered in the middle zone, while in older women (>64 years old) they tended to be clustered in both the posterior and middle zones. (4) Conclusions: There is an inverse relationship between the amount of MBD (overall PD in the breast) and age, and a different clustering pattern of MBDs between the older and mature women.

Clinical Characteristics of Preterm Neonates with Aggressive Posterior Retinopathy of Prematurity.

PurposeWe aimed to identify the risk factors that may predispose preterm neonates to develop aggressive posterior retinopathy of prematurity (APROP).MethodsThis retrospective case control study included 16 infants with APROP in zone 1 or posterior zone 2. Thirty-four gestational age and birth weight-matched controls with stage 2 or less ROP were included. We reviewed medical records on infant birth and postnatal characteristics.ResultsPatients who developed APROP had a significantly longer duration of caffeine therapy, were significantly more likely to be small for gestational age (SGA), and were more likely to have a positive blood culture than patients who developed less severe ROP. Patients with APROP who required retreatment had received inotropes for a longer duration of time, had received more plasma transfusions, were more likely to have IVH, and had a greater decrease in the serum hemoglobin during hospitalization.ConclusionBeing SGA, receiving caffeine for a longer duration, and having culture-proven sepsis were associated with APROP. IVH, a low serum hemoglobin, the need for more plasma transfusions, and a longer duration of inotropes were associated with APROP which required retreatment.

Application of Magnetic Resonance-Ultra Time Echo (MR-UTE) Imaging in the Analysis of the Degree of Degeneration of the Intervertebral Disc Cartilage Endplate

Magnetic resonance imaging (MRI) is the most widely used imaging method in clinical lumbar spine examination. Because of its advantages of non-radiation and good tissue contrast, magnetic resonance imaging provides rich and effective diagnostic information for clinic. The most commonly used sequence is type 2 (T2) sequence, which has a longer time (usually longer than 2000 ms). It shows well in long T2 tissues such as nucleus pulposus, cerebrospinal fluid and adipose tissue, showing moderator high signal in images, while for short T2 tissues such as cartilage endplate and anterior and posterior longitudinal zone, it is often no signal and low signal because of its short attenuation time, thus forming obvious tissue contrast. But at the same time, because the time is too long, for short T2 tissue, the signal has been attenuated to zero before sequence acquisition, so the complete structure can not be displayed directly. In this paper, the normal human lumbar intervertebral disc was studied by conventional magnetic resonance type 1 (T1), T2 and double-echo-UTE imaging techniques. Each part of lumbar intervertebral disc and the semi-quantitative analysis of anatomical structure in images were compared, and the advantages and characteristics of each sequence for each anatomical structure of lumbar intervertebral disc and the advantage of MR-UTE in intervertebral disc display were discussed. It has been found that UTE, as a new sequence which can effectively image short T2 tissue, is gradually applied from experiment to clinic in bone and joint system because of its shorter time. In the gross specimens of lumbar intervertebral disc, sequence can directly display the cartilage endplate and the short T2 tissue of the anterior and posterior longitudinal ligament.

Obtaining optimum screw placement for revision acetabular prostheses using the sciatic notch as reference

BackgroundThe use of transacetabular screws aid greatly in attaining acetabular component stability during acetabular revision surgery. There are, however, definite risks involved when using this technique. Inserting screws in the posterior superior safe zone has been advocated as a way to do this safely, but recent studies have shown that this does not hold true in conditions where acetabular anatomy is distorted or where the hip centre of rotation has moved. A method to insert these screws more accurately and safely is proposed. Questions/Purposes(1) Can using the greater sciatic notch as reference point when inserting transacetabular screws for revision acetabular cups ensure accurate and safe placement of screws? (2) How does this proposed new method compare with the posterior superior safe zone method? MethodsWith the use of an observational anatomic study we have developed a new method for the insertion of long transacetabular screws. This method uses the greater sciatic notch as a reference point. Our method was tested on 16 cadaveric hips (reamed to simulate revision conditions) and compared to the safe zone method. ResultsOur method achieved placement of 1–3 screws in the target area in all hips without penetration into the pelvis or sciatic notch. With the use of the safe zone only as reference the pelvis was penetrated 7 times and the sciatic notch twice. ConclusionUsing the greater sciatic notch as a reference guide enables the surgeon to engage a supportive bar of bone for one or more long home run screws whilst minimizing penetration of the pelvis and sciatic notch. In this study our method was superior to using the safe zone in isolation.

Histological Studies on Ageing Changes in the Cornea of Indian Buffaloes (Bubalus bubalis)

Background: Affections of eye commonly encountered in all the species of animals. If these not treated in time, the vision may be hampered, this may impair the physical ability, utility and productivity of animals leading to economic loss to the animal owners. Corneal dystrophies like basement membrane dystrophy, stromal dystrophy, endothelial dystrophy, corneal erosions and corneal ulcerations etc., seen in the aged buffaloes. The current study was carried out to establish basic data and to provide authentic information to the clinicians on ageing changes in eyes of buffaloes.Methods: The study on age related changes in the cornea was conducted on 63 eye balls of locally available buffaloes of different breeds in and around Proddatur. These buffaloes were categorized into 3 groups based on their age i.e., group I (1-5 yrs), group II (6-10 yrs) and group III (11 yrs and above) buffaloes. The eyeballs were isolated and fixed with Davidson’s fluid. The paraffin sections of cornea were subjected for routine histological study.Result: The mean total thickness (µm) of cornea was increased from group I to III animals and it was 747.22±13.57, 853.33±11.05 and 897.22±8.06. Hence, The mean thickness (µm) of all five layers of cornea increased with advancement of age. Superficial corneal epithelial layer was made up of non keratinized stratified squamous epithelium with 6 to 7 layers at early age and 12-14 layers of cells in adult animals. The mean thickness (µm) of corneal epithelium in group I to III animals was 117.04±3.37, 122.59±2.23 and 133.71±3.55 respectively. Bowman’s membrane of cornea was measured 12.97±0.86, 17.22±0.55 and 18.71±0.68 in group I, II and III animals respectively. The mean thickness (µm) of corneal stroma in group I to III animals was 600.75±10.33, 672.22±10.46 and 690.00±5.32 respectively. This was mainly due to progressive increase in number of collagenous lamellae. The keratocytes became thin in old animals. Thickness of posterior band zone (PBZ) of Descemet’s membrane was increased with advancement of age. The mean thickness (µm) of Descemet’s membrane and endothelium together was in group I, II and III animals was 16.48±0.91, 41.29±2.25 and 54.82±1.44 respectively. The corneal endothelial cells were enlarged and increased in size in old buffaloes. The age related pigmentation was also noticed in epithelium and stroma of cornea in animals of group III. Density of sub basal nerve plexuses between the stroma and the corneal epithelium was not altered with advancement of age.

Minimally invasive surgery rib fracture fixation based on location and anatomical landmarks.

Rib fracture is closely related to thoracic injury with high morbidity and mortality. This study aimed to investigate the clinical effect of Zhang ZhiFei (ZZF) zoning method on the selection of incision and approach in minimally invasive surgery for rib fracture. A total of 110 patients with rib fractures from July 2017 to July 2019 were enrolled in the study. Preoperative computed tomography and three-dimensional reconstruction of ribs was performed. Then, the rib fractures to be surgically fixed were divided into costal cartilage zone, chest zone, lateral costal zone, high posterior costal zone, low posterior costal subscapular zone, and low posterior costal paraspinal zone, which was called ZZF zoning method. Rib fractures in each zone had unique minimally invasive incision approach, and the open reduction and internal fixation of rib fracture was performed under minimally invasive surgery of corresponding small incision. The average incision length and number of incisions of the 110 patients were 6.2 cm and 1.3, respectively. The average number of internal fixation was 5.3 and the average operation time was 82 min. The postoperative fracture end was well aligned. After 3 months of follow-up, no internal fixation was displaced or detached. Based on the anatomical characteristics of different zones of the chest wall, ZZF zoning method provides a new idea and reference for the selection of incision and approach in minimally invasive internal fixation for rib fracture.

Research on environmental comfort and cognitive performance based on EEG+VR+LEC evaluation method in underground space

Significant research on space has been conducted to stimulate the potential of the environment to positively impact the human body and accurately optimize the quality of the living environment. In underground spaces, there is a reduced ability to connect with the outdoor natural environment; thus, it is very important to study methods of optimizing the quality of underground space by exploring people's feelings as they relate to the built environment. This study adopted an electroencephalogram (EEG) + virtual reality (VR) + laboratory environmental control (LEC) method to simulate the underground building environment, explore the mechanisms operating between building space information and human perception feedback, and reveal the laws of interaction between the two. The space prototype was a typical independent underground office space. Three experimental scenes were created using VR. An EEG test, blood oxygen rhythm evaluation, and subjective questionnaire were employed to identify the influence of the space on environmental comfort and cognitive performance. Through an analysis of the EEG energy distribution, CP6 was found to be the most significant active degree. Regarding regional distribution, the active areas of the scene elements were located in the posterior and central zones. Additionally, by analyzing the EEG rhythm, a correlational relationship between β H/β L and cognitive performance was identified. The results strongly indicate that in different scenes, subjects' cognitive performance was affected by changes in the environment. Therefore, this study provides accurate reference information for designers of architectural spaces, based on user satisfaction and physical and mental health.

Disentangling the family Blepharocorythidae (Ciliophora, Entodiniomorphida): a molecular assessment of morphological classification

The family Blepharocorythidae comprehends 26 species of ciliates that colonize the hindgut of many fermenting mammals, where they play a critical role in the process of food digestion. Recent molecular phylogenetic works indicate this family might be polyphyletic, possibly a consequence of the historical use of weak diagnostic character (long vestibulum, single contractile vacuole, and anterior and posterior ciliary zones) that do not reflect evolutionary divergences. Here, we revisited and reinterpreted data from old taxonomic studies aiming to resolve taxonomical inconsistencies and to shed some light into the systematics of this family of ciliates. Accordingly, we have identified clear morphological and morphogenetic features to propose a new organization scheme, which is in consonance with molecular phylogenetic data, highlighting the importance of revisiting old literature to improve the systematics within Ciliophora or in any other group of organisms.

A carbon fiber-reinforced polyetheretherketone intramedullary nail improves fracture site visibility on postoperative radiographic images

IntroductionTo evaluate the advantages of a carbon fiber-reinforced polyetheretherketone (CFR/PEEK) intramedullary nail on the diagnosis of fracture healing because of its radiolucency, we retrospectively reviewed radiographs and computed tomography (CT) images of trochanteric femoral fractures that underwent internal fixation with the CFR/PEEK intramedullary nail or a traditional metallic intramedullary nail. MethodsRadiographs and CT images from 20 patients with intertrochanteric femoral fractures treated with a CFR/PEEK intramedullary nail and 20 similar patients treated with a metallic intramedullary nail were reviewed. After division of the intertrochanteric region into three zones on anteroposterior and lateral views of the radiographs, the visibilities of the fracture site, fracture line, and bone formation were evaluated in each zone. A three-grade assessment for existence of scattering and effect of scattering on diagnosis of the surrounding bone was performed on three axial slices of the CT images. ResultsIn the CFR/PEEK group, the fracture site was visible in all zones for all cases except for the posterior zone on the lateral view in one case. In the cranial and middle zones on anteroposterior views and the middle zone on lateral views of the radiographs, the visible fracture site rates in the CFR/PEEK group were significantly higher than those in the metal group. The grades for existence of scattering and effect of scattering on diagnosis of surrounding bone on the CT images were significantly lower in the CFR/PEEK group compared with the metal group. ConclusionSuperior fracture site visibility on radiographs was demonstrated in cases treated with the CFR/PEEK intramedullary nail compared with cases treated with the traditional metallic intramedullary nail, thereby confirming the advantages of the CFR/PEEK intramedullary nail for evaluation of fracture reduction and bone formation. The CFR/PEEK nail evoked little scattering on CT images, leading to higher diagnostic values for the peri-prosthetic cancellous and cortical bone compared with the metallic nail.

Comparison of clinical outcomes of conbercept versus ranibizumab treatment for retinopathy of prematurity: a multicentral prospective randomised controlled trial

PurposeTo compare the recurrence rate and surgical complications of retinopathy of prematurity (ROP) between patients treated with intravitreal injection of conbercept (IVC) and intravitreal injection of ranibizumab (IVR) within 6...

A conserved role for arrow in posterior axis patterning across Arthropoda

Segmentation is a key characteristic of Arthropoda that is linked to the evolutionary success of this lineage. It has previously been shown in both vertebrates and short germ insects that posterior segmentation requires canonical Wnt (cWnt) signaling, which maintains the expression of Caudal and the posterior growth zone; disruption of cWnt signaling incurs posterior truncations in these lineages due to the loss of the tail bud. However, comparable datasets for Wnt signaling are limited outside of holometabolous insects, due to incomparable phenotypic spectra and inefficacy of gene misexpression methods in certain model species. We applied RNA interference (RNAi) against the Wnt co-receptor arrow (arr), a key member of the cWnt signaling pathway in holometabolous insects and vertebrates, to examine posterior axis elongation of the cobweb spider Parasteatoda tepidariorum (short germ embryogenesis; one Wnt8 homolog), the cricket Gryllus bimaculatus (intermediate germ; one Wnt8 homolog), and the milkweed bug Oncopeltus fasciatus (short germ; two Wnt8 homologs). Knockdown of arr in insects resulted in posterior truncations affecting the gnathos through the abdomen in O. fasciatus, whereas posterior truncations only affected the T3 segment through the abdomen in G. bimaculatus. Spider embryos with disrupted arr expression exhibited defects along the entire axis, including segmentation defects throughout the germband. RNA-Seq-based differential gene expression analysis of severe Ptep-arr loss-of-function phenotypes at two developmental stages was used to confirm that knockdown of Ptep-arr results in systemic disruption of the Wnt pathway. Intriguingly, we found that knockdown of arr did not abrogate Wnt8 expression in any of the three species, with cad expression additionally retained in severe loss-of-function phenotypes in the cricket and the spider. Together with data from a holometabolous insect, our results suggest that cWnt signaling is not required for maintenance of Wnt8 expression across Arthropoda. These outcomes underscore the diagnostic power of differential gene expression analyses in characterizing catastrophic phenotypes in emerging model species.

Effects of ketamine on brain function during metacognition of episodic memory.

Only little research has been conducted on the pharmacological underpinnings of metacognition. Here, we tested the modulatory effects of a single intravenous dose (100 ng/ml) of the N-methyl-D-aspartate-glutamate-receptor antagonist ketamine, a compound known to induce altered states of consciousness, on metacognition and its neural correlates. Fifty-three young, healthy adults completed two study phases of an episodic memory task involving both encoding and retrieval in a double-blind, placebo-controlled fMRI study. Trial-by-trial confidence ratings were collected during retrieval. Effects on the subjective state of consciousness were assessed using the 5D-ASC questionnaire. Confirming that the drug elicited a psychedelic state, there were effects of ketamine on all 5D-ASC scales. Acute ketamine administration during retrieval had deleterious effects on metacognitive sensitivity (meta-d′) and led to larger metacognitive bias, with retrieval performance (d′) and reaction times remaining unaffected. However, there was no ketamine effect on metacognitive efficiency (meta-d′/d′). Measures of the BOLD signal revealed that ketamine compared to placebo elicited higher activation of posterior cortical brain areas, including superior and inferior parietal lobe, calcarine gyrus, and lingual gyrus, albeit not specific to metacognitive confidence ratings. Ketamine administered during encoding did not significantly affect performance or brain activation. Overall, our findings suggest that ketamine impacts metacognition, leading to significantly larger metacognitive bias and deterioration of metacognitive sensitivity as well as unspecific activation increases in posterior hot zone areas of the neural correlates of consciousness.

How hot is the hot zone? Computational modelling clarifies the role of parietal and frontoparietal connectivity during anaesthetic-induced loss of consciousness

In recent years, specific cortical networks have been proposed to be crucial for sustaining consciousness, including the posterior hot zone and frontoparietal resting state networks (RSN). Here, we computationally evaluate the relative contributions of three RSNs – the default mode network (DMN), the salience network (SAL), and the central executive network (CEN) – to consciousness and its loss during propofol anaesthesia. Specifically, we use dynamic causal modelling (DCM) of 10 min of high-density EEG recordings (N = 10, 4 males) obtained during behavioural responsiveness, unconsciousness and post-anaesthetic recovery to characterise differences in effective connectivity within frontal areas, the posterior ‘hot zone’, frontoparietal connections, and between-RSN connections. We estimate – for the first time – a large DCM model (LAR) of resting EEG, combining the three RSNs into a rich club of interconnectivity. Consistent with the hot zone theory, our findings demonstrate reductions in inter-RSN connectivity in the parietal cortex. Within the DMN itself, the strongest reductions are in feed-forward frontoparietal and parietal connections at the precuneus node. Within the SAL and CEN, loss of consciousness generates small increases in bidirectional connectivity. Using novel DCM leave-one-out cross-validation, we show that the most consistent out-of-sample predictions of the state of consciousness come from a key set of frontoparietal connections. This finding also generalises to unseen data collected during post-anaesthetic recovery. Our findings provide new, computational evidence for the importance of the posterior hot zone in explaining the loss of consciousness, highlighting also the distinct role of frontoparietal connectivity in underpinning conscious responsiveness, and consequently, suggest a dissociation between the mechanisms most prominently associated with explaining the contrast between conscious awareness and unconsciousness, and those maintaining consciousness.

Factors affecting final functional outcomes in open\u2010globe injuries and use of ocular trauma score as a predictive tool in Nepalese population

BackgroundOpen globe injury (OGI) is one of the most devastating form of ocular trauma. The aim of the study is to identify the epidemiology and predict visual outcomes in traumatic open globe injuries using ocular trauma score (OTS) and correlate with final visual acuity (VA) at 3 months.MethodsPatients older than 5 years, presenting to B.P. Koirala Lions Centre for Ophthalmic Studies (BPKLCOS) from March 2016- March 2017 with OGI that met inclusion criteria were evaluated. Patient profile, nature and cause of injury, and time to presentation were recorded. Patients were managed accordingly and followed up to 3 months. An OTS score for each patient was calculated and raw scores were categorized accordingly. The VA after 3 months were compared to the predicted OTS values.ResultsSeventy-three eyes of 72 patients were examined. 76 % were male, and the mean age was 26.17 years (median, 23.5 years). The mean time from injury to presentation was < 6 hours (30 patients, 41 %). Thirty-seven eyes (51 %) had zone I trauma, followed by twenty eyes (27 %) with zone II, and sixteen eyes (22 %) with zone III trauma. Sixty-five patients (90 %) were managed surgically, and fifty (68 %) received intravitreal antibiotics with steroid. When compared, the projected VA as per OTS were able to predict actual final visual outcomes in 60 % of the eyes with OGI of various zones.ConclusionsOTS can be an accurate predictive tool for final visual acuity even with a short follow up period of 3 months; with poor presenting visual acuity, delayed presentation, posterior zones of injury, need for intravitreal injections, endophthalmitis, and globe rupture associated with poorer prognosis.