This study reinforces the importance and benefits of psychiatric services for SARS team members in reducing their secondary traumatization. It is hoped that the results will enhance our knowledge on the needs of frontline health care workers and support the planning of better psychiatric services in future epidemics.

Acorn worms, also known as enteropneust (literally, ‘gut-breathing’) hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal ‘gill’ slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor.

Expression of the nodal gene initiates the gene regulatory network which establishes the transcriptional specification of the oral ectoderm in the sea urchin embryo. This gene encodes a TGFbeta ligand, and in Strongylocentrotus purpuratus its transcription is activated in the presumptive oral ectoderm at about the 30-cell stage. Thereafter Nodal signaling occurs among all cells of the oral ectoderm territory, and nodal expression is required for expression of oral ectoderm regulatory genes. The cis-regulatory system of the nodal gene transduces anisotropically distributed cytoplasmic cues that distinguish the future oral and aboral domains of the early embryo. Here we establish the genomic basis for the initiation and maintenance of nodal gene expression in the oral ectoderm. Functional cis-regulatory control modules of the nodal gene were identified by interspecific sequence conservation. A 5' cis-regulatory module functions both to initiate expression of the nodal gene and to maintain its expression by means of feedback input from the Nodal signal transduction system. These functions are mediated respectively by target sites for bZIP transcription factors, and by SMAD target sites. At least one SMAD site is also needed for the initiation of expression. An intron module also contains SMAD sites which respond to Nodal feedback, and in addition acts to repress vegetal expression. These observations explain the main features of nodal expression in the oral ectoderm: since the activity of bZIP factors is redox sensitive, and the initial polarization of oral vs. aboral fate is manifested in a redox differential, the bZIP sites account for the activation of nodal on the oral side; and since the immediate early signal transduction response factors for Nodal are SMAD factors, the SMAD sites account for the feedback maintenance of nodal gene expression.

Etk (also calledBmxEtk (also called Bmx) is a member of the Btk nonreceptor tyrosine kinase family (48,51,57). This family of kinases is characterized by a modular structure, including an N-terminal pleckstrin homology (PH) domain, a Tec homology domain, Src homology 2 (SH2) and SH3 domains, and a C-terminal kinase domain. Many members of the Btk family are predominantly expressed in cells of hematopoietic origin. Btk is expressed in B cells and myeloid cell lineages and is essential for B-cell development and signaling. Loss-of-function mutations in Btk result in human X-linked agammaglobulinemia and murine X-linked B-cell immunodeficiency (50,53

The origin of germline cells was a crucial step in animal evolution. Therefore, in both developmental biology and evolutionary biology, the mechanisms of germline specification have been extensively studied over the past two centuries. However, in many animals, the process of germline specification remains unclear. Here, we show that in the cephalochordate amphioxus Branchiostoma floridae, the germ cell-specific molecular markers Vasa and Nanos become localized to the vegetal pole cytoplasm during oogenesis and are inherited asymmetrically by a single blastomere during cleavage. After gastrulation, this founder cell gives rise to a cluster of progeny that display typical characters of primordial germ cells (PGCs). Blastomeres separated at the two-cell stage grow into twin embryos, but one of the twins fails to develop this Vasa-positive cell population, suggesting that the vegetal pole cytoplasm is required for the formation of putative PGCs in amphioxus embryos. Contrary to the hypothesis that cephalochordates may form their PGCs by epigenesis, our data strongly support a preformation mode of germ cell specification in amphioxus. In addition to the early localization of their maternal transcripts in the putative PGCs, amphioxus Vasa and Nanos are also expressed zygotically in the tail bud, which is the posterior growth zone of amphioxus. Thus, in addition to PGC specification, amphioxus Vasa and Nanos may also function in highly proliferating somatic stem cells.

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The stomachs of most vertebrates operate at an acidic pH of 2 generated by the gastric H + / K + -ATPase located in parietal cells. The acidic pH in stomachs of vertebrates is believed to aid digestion and to protect against environmental pathogens. Little attention has been placed on whether acidic gastric pH regulation is a vertebrate character or a deuterostome ancestral trait. Here, we report alkaline conditions up to pH 10.5 in the larval digestive systems of ambulacraria (echinoderm + hemichordate), the closest relative of the chordate. Microelectrode measurements in combination with specific inhibitors for acid-base transporters and ion pumps demonstrated that the gastric alkalization machinery in sea urchin larvae is mainly based on direct H + secretion from the stomach lumen and involves a conserved set of ion pumps and transporters. Hemichordate larvae additionally utilized HCO 3 − transport pathways to generate even more alkaline digestive conditions. Molecular analyses in combination with acidification experiments supported these findings and identified genes coding for ion pumps energizing gastric alkalization. Given that insect larval guts were also reported to be alkaline, our discovery raises the hypothesis that the bilaterian ancestor utilized alkaline digestive system while the vertebrate lineage has evolved a strategy to strongly acidify their stomachs.The highly acidic pH of most vertebrate stomachs is believed to protect against environmental pathogens and the mechanisms of gastric acidification are well described [1][2][3] . The H + /K + -ATPase (HKA) in luminal membranes of parietal cells drives H + ions into the stomach lumen leading to an accumulation of hydrochloric acid 4 . This enables vertebrates to generate highly acidic conditions in their digestive systems. In contrast, midgut alkalization in lepidopteran and dipteran insect larvae, is energized by an V-H + -ATPase (VHA) coupled to processes that result in net export of H + from the luminal space [5][6][7] . These observations demonstrate that different gastric pH regulatory mechanisms have evolved in the animal kingdom. An interest is thus raised in regard to whether the highly acidic or alkaline digestive system is an ancestral character of the bilaterian.Although marine invertebrates were described to have slightly acidic to neutral pH in their digestive systems 8,9 virtually nothing is known regarding gastric pH regulation of their larval stages. In a previous study we demonstrated that larvae of the green sea urchin, Strongylocentrotus droebachiensis, have alkaline conditions in their digestive systems 10 . This study also demonstrated that their digestive enzymes are adapted to alkaline conditions and the digestive efficiency is reduced when gastric pH is decreased.

The authors' preliminary study selected 22 items for Depression and Somatic Symptoms Scale (DSSS), including depression subscale (DS) and somatic subscale (SS). The aim of the study was to test reliability and validity of the DSSS. The study enrolled 135 consecutive outpatients (34 male and 101 female) experiencing a major depressive episode (the MDE group), 95 of whom (25 male and 70 female) accepted 1 month of treatment (the treatment group). Diagnosis was confirmed by using the Structured Clinical Interview for 4 th edition with text revision Diagnostic and Statistical Manual Axis I Disorders. The DSSS and Hamilton Depression Rating Scale (HAMD) were given and evaluated. Cronbach's alpha was used to assess internal consistency. The correlation between the improvement percentage (IP) for the HAMD and the IP for the DSSS was calculated for the treatment group. Factor analysis was performed by using the principal-axis factoring method with promax rotation. Cronbach's alpha values of the DSSS and its subscales ranged from 0.73 to 0.94. Pearson correlation coefficients for the relationship between the DSSS and HAMD ranged from 0.63 to 0.86. In the treatment group, DSSS and HAMD scores were significantly decreased after treatment and the IP for the HAMD and the DSSS were similar and correlated (correlation coefficient = 0.78). The results of the factor analysis demonstrated that most of the items in DS and SS appropriately loaded in Depression and Somatic factors, respectively. The discriminative ability of the DSSS for anxiety comorbidities was not inferior to that of the HAMD. Therefore, the DSSS is reliable and sensitive to the treatment and has acceptable convergent, factorial, and distinctgroups validities. Because it assesses both depression and somatic symptoms, DSSS may overcome the deficiency of other depression scales with few somatic items.