Visual pathways in the brain of the jumping spider Marpissa muscosa

Some animals have evolved task differentiation among their eyes. A particular example is spiders, where most species have eight eyes, of which two (the principal eyes) are used for object discrimination, whereas the other three pairs (secondary eyes) detect movement. In the ctenid spider Cupiennius salei, these two eye types correspond to two visual pathways in the brain. Each eye is associated with its own first- and second-order visual neuropil. The second-order neuropils of the principal eyes are connected to the arcuate body, whereas the second-order neuropils of the secondary eyes are linked to the mushroom body. We explored the principal- and secondary eye visual pathways of the jumping spider Marpissa muscosa, in which size and visual fields of the two eye types are considerably different. We found that the connectivity of the principal eye pathway is the same as in C. salei, while there are differences in the secondary eye pathways. In M. muscosa, all secondary eyes are connected to their own first-order visual neuropils. The first-order visual neuropils of the anterior lateral and posterior lateral eyes are connected with a second-order visual neuropil each and an additional shared one (L2). In the posterior median eyes, the axons of their first-order visual neuropils project directly to the arcuate body, suggesting that the posterior median eyes do not detect movement. The L2 might function as an upstream integration center enabling faster movement decisions.     

Risk factors and etiology of childhood hearing loss: a cohort review of 296 subjects

Abstract

Background: The association between the Joint Committee on Infant Hearing (JCIH) risk factors and etiology of hearing loss (HL) is not studied well in children.

Objectives: To clarify the etiologic causes and evaluate the JCIH risk characteristics of children with HL.

Methods: A retrospective study of 296 children with HL born between 2009.01 and 2013.12 in Stokholm. Demographic data, family and medical histories, audiologic results, imaging findings, and genetic results were ascertained and analyzed.

Results: In 221 with bilateral hearing loss (BHL), family history and neonatal risk indicators were the most common risks (59 each), followed by syndrome related risks. In 75 with unilateral hearing loss (UHL), craniofacial anomaly was the most common risk, followed by family history. Etiology was established in 93 with BHL, in which syndromic HL accounted for 37.2%, chromosomal aberrations for 21.3%, and environmental causes for 19.1%. Etiology was established in 35 with UHL, in which ear malformation accounted for the most (74.3%), followed by environmental causes (14.3%).

Conclusions and significance: Childhood HL can be attributed to a variety of causes with an etiology identifiable in 42.5% of BHL and 46.7% of UHL. BHL and UHL have different patterns of JCIH risk exposure and etiology.     

Impact of anthropogenic atmospheric nitrogen and sulfur deposition on ocean acidification and the inorganic carbon system

Fossil fuel combustion and agriculture result in atmospheric deposition of 0.8 Tmol/yr reactive sulfur and 2.7 Tmol/yr nitrogen to the coastal and open ocean near major source regions in North America, Europe, and South and East Asia. Atmospheric inputs of dissociation products of strong acids (HNO(3) and H2SO(4)) and bases (NH(3)) alter surface seawater alkalinity, pH, and inorganic carbon storage. We quantify the biogeochemical impacts by using atmosphere and ocean models. The direct acid/base flux to the ocean is predominately acidic (reducing total alkalinity) in the temperate Northern Hemisphere and alkaline in the tropics because of ammonia inputs. However, because most of the excess ammonia is nitrified to nitrate (NO(3)(-)) in the upper ocean, the effective net atmospheric input is acidic almost everywhere. The decrease in surface alkalinity drives a net air-sea efflux of CO(2), reducing surface dissolved inorganic carbon (DIC); the alkalinity and DIC changes mostly offset each other, and the decline in surface pH is small. Additional impacts arise from nitrogen fertilization, leading to elevated primary production and biological DIC drawdown that reverses in some places the sign of the surface pH and air-sea CO(2) flux perturbations. On a global scale, the alterations in surface water chemistry from anthropogenic nitrogen and sulfur deposition are a few percent of the acidification and DIC increases due to the oceanic uptake of anthropogenic CO(2). However, the impacts are more substantial in coastal waters, where the ecosystem responses to ocean acidification could have the most severe implications for mankind.     

Ligand autoradiographic receptor screening. II. Expression of receptor cDNA in transfected COS cells grown on polyester disks and its recovery.

A receptor autoradiographic method that can detect expressed receptor cDNA in 0.002% of plasmid clones and can allow cDNA recoveries and enrichments up to 300-fold in one cycle of screening is described.     

Impact of the microenvironment on the pathogenesis of mucosa-associated lymphoid tissue lymphomas

Approximately 8% of all non-Hodgkin lymphomas are extranodal marginal zone B cell lymphomas of mucosa-associated lymphoid tissue (MALT), also known as MALT lymphomas. These arise at a wide range of different extranodal sites, with most cases affecting the stomach, the lung, the ocular adnexa and the thyroid. The small intestine is involved in a lower percentage of cases. Lymphoma growth in the early stages is associated with long-lasting chronic inflammation provoked by bacterial infections (e.g., Helicobacter pylori or Chlamydia psittaci infections) or autoimmune conditions (e.g., Sjögren’s syndrome or Hashimoto thyroiditis). While these inflammatory processes trigger lymphoma cell proliferation and/or survival, they also shape the microenvironment. Thus, activated immune cells are actively recruited to the lymphoma, resulting in either direct lymphoma cell stimulation via surface receptor interactions and/or indirect lymphoma cell stimulation via secretion of soluble factors like cytokines. In addition, chronic inflammatory conditions cause the acquisition of genetic alterations resulting in autonomous lymphoma cell growth. Recently, novel agents targeting the microenvironment have been developed and clinically tested in MALT lymphomas as well as other lymphoid malignancies. In this review, we aim to describe the composition of the microenvironment of MALT lymphoma, the interaction of activated immune cells with lymphoma cells and novel therapeutic approaches in MALT lymphomas using immunomodulatory and/or microenvironment-targeting agents.     

Impact of Sarcopenia on Outcomes Following Intra-arterial Therapy of Hepatic Malignancies

Background

Assessment of patient performance status is often subjective. Sarcopenia—measurement of muscle wasting—may be a more objective means to assess performance status and therefore mortality risk following intra-arterial therapy (IAT).

Methods

Total psoas area (TPA) was measured on cross-sectional imaging in 216 patients undergoing IAT of hepatic malignancies between 2002 and 2012. Sarcopenia was defined as TPA in the lowest sex-specific quartile. Impact of sarcopenia was assessed relative to other clinicopathological factors.

Results

Indications for IAT included hepatocellular carcinoma (51 %), intrahepatic cholangiocarcinoma (13 %), colorectal liver metastasis (7 %), or other metastatic disease (30 %). Median TPA among men (568 mm²/m²) was greater than women (413 mm²/m²). IAT involved conventional chemoembolization (54 %), drug-eluting beads (40 %), or yttrium-90 (6 %). Median tumor size was 5.8 cm; most patients had multiple lesions (74 %). Ninety-day mortality was 9.3 %; 3-year survival was 39 %. Factors associated with risk of death were tumor size (HR?=?1.84) and Child's score (HR?=?2.15) (all P?<?0.05). On multivariate analysis, sarcopenia remained independently associated with increased risk of death (lowest vs. highest TPA quartile, HR?=?1.84; P?=?0.04). Sarcopenic patients had a 3-year survival of 28 vs. 44 % for non-sarcopenic patients.

Conclusions

Sarcopenia was an independent predictor of mortality following IAT with sarcopenic patients having a twofold increased risk of death. Sarcopenia is an objective measure of frailty that can help clinical decision-making regarding IAT for hepatic malignancies.     

Inspiratory stridor and dysphagia in two newborn infants caused by ectopic thymus tissue

We report two cases of ectopic cervical thymus, a solid thymic lesion, and a thymus cyst causing inspiratory stridor and mild dysphagia in the neonatal period. Because of the rarity of thymic dystopia, the two masses were initially misdiagnosed as more common entities, namely, lymph node enlargement and lymphangioma, respectively. The correct diagnosis was made only after surgical excision and histopathological examination. This case report is completed by a short review of embryogenic development, diagnostic procedures with differential diagnoses, and therapeutic outcome of ectopic thymus.     

Auditory neuropathy-a rare condition where CI provides improved hearing and speech development

Auditory neuropathy (AN) was reported 30 years ago in 1979 when Davis and Hirsh presented the first case with normal or near normal hearing threshold but absent auditory brainstem responses. Many names have been given since then including paradoxical hearing loss, brainstem auditory processing syndrome, central auditory dysfunction, neural synchrony disorder or neural dyssynchrony. The term auditory neuropathy was first given by Sininger and colleagues in 1995. More and more AN articles have been published in recent years. The present short review and case report focus on the most important characteristics from a clinical point of view in order to let young physicians know AN, and consequently make correct diagnosis.     

Justify Your Answer: The Role of Written Think Aloud in Script Concordance Testing

Construct: Clinical reasoning assessment is a growing area of interest in the medical education literature. Script concordance testing (SCT) evaluates clinical reasoning in conditions of uncertainty and has emerged as an innovative tool in the domain of clinical reasoning assessment. SCT quantifies the degree of concordance between a learner and an experienced clinician and attempts to capture the breadth of responses of expert clinicians, acknowledging the significant yet acceptable variation in practice under situations of uncertainty. Background: SCT has been shown to be a valid and reliable clinical reasoning assessment tool. However, as SCT provides only quantitative information, it may not provide a complete assessment of clinical reasoning. Approach: Think aloud (TA) is a qualitative research tool used in clinical reasoning assessment in which learners verbalize their thought process around an assigned task. This study explores the use of TA, in the form of written reflection, in SCT to assess resident clinical reasoning, hypothesizing that the information obtained from the written TA would enrich the quantitative data obtained through SCT. Ninety-one pediatric postgraduate trainees and 21 pediatricians from 4 Canadian training centers completed an online test consisting of 24 SCT cases immediately followed by retrospective written TA. Six of 24 cases were selected to gather TA data. These cases were chosen to allow all phases of clinical decision making (diagnosis, investigation, and treatment) to be represented in the TA data. Inductive thematic analysis was employed when systematically reviewing TA responses. Results: Three main benefits of adding written TA to SCT were identified: (a) uncovering instances of incorrect clinical reasoning despite a correct SCT response, (b) revealing sound clinical reasoning in the context of a suboptimal SCT response, and (c) detecting question misinterpretation. Conclusions: Written TA can optimize SCT by demonstrating when correct examinee responses are based on guessing or uncertainty rather than robust clinical rationale. TA can also enhance SCT by allowing examinees to provide justification for responses that otherwise would have been considered incorrect and by identifying questions that are frequently misinterpreted to avoid including them in future examinations. TA also has significant value in differentiating between acceptable variations in expert clinician responses and deviance associated with faulty rationale or question misinterpretation; this could improve SCT reliability. A written TA protocol appears to be a valuable tool to assess trainees' clinical reasoning and can strengthen the quantitative assessment provided by SCT.