A powerful and versatile new fixation protocol for immunostaining and in situ hybridization that preserves delicate tissues.

Background: Understanding how genes function to heal wounds and restore lost tissue is essential for studying regeneration. Whole-mount in situ hybridization (WISH) is a powerful and widely used technique to visualize the expression patterns of genes in different biological systems. Yet, existing methods to permeabilize samples for WISH can damage or destroy fragile regenerating tissues, thereby preventing such experiments.

A PAK family kinase and the Hippo/Yorkie pathway modulate WNT signaling to functionally integrate body axes during regeneration.

Successful regeneration of missing tissues requires seamless integration of positional information along the body axes. Planarians, which regenerate from almost any injury, use conserved, developmentally important signaling pathways to pattern the body axes. However, the molecular mechanisms which facilitate cross talk between these signaling pathways to integrate positional information remain poorly understood.

Hox genes regulate asexual reproductive behavior and tissue segmentation in adult animals.

Hox genes are highly conserved transcription factors renowned for their roles in the segmental patterning of the embryonic anterior-posterior (A/P) axis. We report functions for Hox genes in A/P tissue segmentation and transverse fission behavior underlying asexual reproduction in adult planarian flatworms, Schmidtea mediterranea. Silencing of each of the Hox family members identifies 5 Hox genes required for asexual reproduction.

Identification of rare, transient post-mitotic cell states that are induced by injury and required for whole-body regeneration in Schmidtea mediterranea.

Regeneration requires the coordination of stem cells, their progeny and distant differentiated tissues. Here, we present a comprehensive atlas of whole-body regeneration in Schmidtea mediterranea and identify wound-induced cell states. An analysis of 299,998 single-cell transcriptomes captured from regeneration-competent and regeneration-incompetent fragments identified transient regeneration-activated cell states (TRACS) in the muscle, epidermis and intestine.

Decellularization Enables Characterization and Functional Analysis of Extracellular Matrix in Planarian Regeneration.

The extracellular matrix (ECM) is a three-dimensional network of macromolecules that provides a microenvironment capable of supporting and regulating cell functions. However, only a few research organisms are available for the systematic dissection of the composition and functions of the ECM, particularly during regeneration. We utilized the free-living flatworm Schmidtea mediterranea to develop an integrative approach consisting of decellularization, proteomics, and RNAi to characterize and investigate ECM functions during tissue homeostasis and regeneration.

Deactivation of the GATA Transcription Factor ELT-2 Is a Major Driver of Normal Aging in C. elegans.

To understand the molecular processes underlying aging, we screened modENCODE ChIP-seq data to identify transcription factors that bind to age-regulated genes in C. elegans. The most significant hit was the GATA transcription factor encoded by elt-2, which is responsible for inducing expression of intestinal genes during embryogenesis.

The Perspectives of Six Latino Heritage Groups About Their Health Care.

The Latino population in the US is projected to grow substantially in the years ahead. Although often referred to as a single group, Latinos are not homogeneous. This article, based mainly on a national telephone survey of 1,478 Latino adults, examines the perspectives of six Latino heritage groups on the health care issues they face.

Detection and localization of peripheral vascular bleeding using Doppler ultrasound.

Background: Hemorrhage from wounds in the extremities is the leading cause of preventable death on the battlefield. To successfully treat these injuries, the exact source of bleeding must be localized.

Objective: The purpose of this study was to determine the feasibility of using Doppler ultrasound to precisely detect and localize peripheral vascular bleeding.

Systematic identification of balanced transposition polymorphisms in Saccharomyces cerevisiae.

High-throughput techniques for detecting DNA polymorphisms generally do not identify changes in which the genomic position of a sequence, but not its copy number, varies among individuals. To explore such balanced structural polymorphisms, we used array-based Comparative Genomic Hybridization (aCGH) to conduct a genome-wide screen for single-copy genomic segments that occupy different genomic positions in the standard laboratory strain of Saccharomyces cerevisiae (S90) and a polymorphic wild isolate (Y101) through analysis of six tetrads from a cross of these two strains. Paired-end high-throughput sequencing of Y101 validated four of the predicted rearrangements.

Color and pulsed Doppler sonography for arterial bleeding detection.

Objective: Hemorrhage resulting from penetrating injuries in the extremities is the leading cause of preventable death in the modern battlefield. Development of methods for detection and localization of vascular bleeding is needed that could be applied emergently without special training outside the hospital setting. Our objective was to assess whether Doppler sonography can provide quantitative parameters that characterize the bleeding site in the extremities.

Computed radiography dose data mining and surveillance as an ongoing quality assurance improvement process.

Objective: A data-mining program extracts computed radiography (CR) sensitivity-number (S-number) information from the PACS at our institution on a monthly basis as an ongoing quality assurance (QA) improvement project. These data are compared with the previous month's data and departmental S-number goals. The results are presented at monthly QA meetings.

Physician assistants in academic radiology: the Harborview experience.

We describe a model of how physician assistants can be used in an academic medical center to expand radiologist productivity, and to enhance the departmental academic and educational missions. At Harborview Medical Center, following a training program and graduated responsibility under supervision, physician assistants provide initial interpretation of radiology studies, consultation to referring physicians, and perform less complicated interventional procedures. Acceptance of physician assistants by the radiologists, radiology residents, and referring physicians has been high.

Diagnosis and treatment of craniocervical dislocation in a series of 17 consecutive survivors during an 8-year period.

Object: Craniocervical dissociation (CCD) is a highly unstable and usually fatal injury resulting from osseoligamentous disruption between the occiput and C-2. The purpose of this study was to elucidate systematic factors associated with delays in diagnosing and treating this life-threatening condition and to introduce an injury-severity classification with therapeutic implications.

Methods: In a retrospective evaluation of institutional databases, the authors reviewed medical records and original images obtained in 17 consecutive surviving patients with CCD treated between 1994 and 2002.

Diagnostic errors in polytrauma: a structured review of the recent literature.

Clinically important diagnostic errors are relatively common among polytrauma patients (2-40%). Errors are not random; they are more frequent in the spine and periarticular appendicular skeleton, especially in hemodynamically unstable patients who require resuscitation or operative intervention before completion of secondary or tertiary clinical survey. Misleading history, distracting findings, and misjudgments all contribute to risks of diagnostic errors.

Severe posttraumatic craniocervical instability in the very young patient. Report of three cases.

Children younger than 3 years of age represent a distinct subpopulation of patients at particular risk for high cervical and craniovertebral injuries. There are few descriptions of survivors of severe craniocervical trauma among the very young, and scarce data exist regarding management after initial emergency stabilization. The authors describe three children, age 1 to 32 months, who presented with craniocervical junction injuries.

Cervical spine fractures in patients 65 years and older: a clinical prediction rule for blunt trauma.

Purpose: To determine clinical predictors of cervical spine fracture in the elderly and to develop a clinical prediction rule to guide appropriate imaging in high-risk patients.

Materials And Methods: Institutional review board approval was received with waiver of informed consent. A retrospective case-control study was performed on blunt trauma patients 65 years and older with cervical spine fractures and on randomly selected control subjects without fracture.

Can we rely on mediastinal widening on chest radiography to identify subjects with aortic injury?

Widening of the mediastinum on chest radiography is widely promoted as a useful criterion for detecting aortic injury. We sought to determine the reliability, sensitivity, and specificity of this sign. The initial chest radiographs from 30 subjects with aortic injury and 47 controls were independently reviewed by six radiologists, who were blinded to diagnosis.

Four-channel multidetector CT in facial fractures: do we need 2 x 0.5 mm collimation?

Objective: Our aim was to optimize acquisition protocols and multiplanar reformation algorithms for the evaluation of facial fractures using multidetector CT (MDCT) and to determine whether 2 x 0.5 mm collimation is necessary.

Materials And Methods: A cadaveric head with artificial blunt facial trauma was examined using a four-channel MDCT scanner.

Cerebral infarct in head injury: relationship to child abuse.

Background: To determine whether CT-detected cerebral infarct in young children is associated more often with abuse or unintentional head injury.

Methods: Retrospective case-control study of injured children under age 6 who had abnormal initial head CT scans and who were admitted to the only Level I pediatric trauma center in Washington State for closed head injury (CHI) from January 1, 1992 to December 31, 1998.

Results: Fifteen children developed cerebral infarct after CHI during the 7 year period.

Atypical focal nodular hyperplasia of the liver: imaging features of nonspecific and liver-specific MR contrast agents.

Objective: The objective of our study was to describe the functional and differential uptake features of atypical focal nodular hyperplasia using different MR contrast agents and to evaluate their potential role in the diagnosis and characterization of focal nodular hyperplasia.

Materials And Methods: Contrast-enhanced MR images of 45 patients with 85 focal nodular hyperplasia lesions were retrospectively reviewed. In these patients, sonographic findings were nonspecific (n = 37), or CT features were inconclusive (n = 8).

Trans-Atlantic hospital agreement in reading first day radiographs of clinically suspected scaphoid fractures.

The purpose of this study was to describe the agreement between two hospitals on either side of the Atlantic Ocean in reading first day plain radiographs of suspected scaphoid fractures. Two groups of observers, one North American and one European, consisting of observers at various levels of training were compared. Kappa statistics were used to determine inter- and intra-observer agreement.

Anatomic and radiographic considerations for placement of transiliac screws in lumbopelvic fixations.

Lumbopelvic fixation in spinal and pelvic surgery relies on rods or screws as an iliac anchor. Secure placement of screws with maximum diameter and length for the greatest pullout strength requires knowledge of the iliac structure and of intraoperative fluoroscopic landmarks for secure placement. Therefore, the authors evaluated the intrailiac length, inner width, and cortical thickness of three different transiliac screw anchor paths aimed toward the anterior inferior iliac spine and initiated at the iliac tubercle, posterior superior iliac spine, or posterior inferior iliac spine.