Advanced optical imaging in living embryos

Developmental biology investigations have evolved from static studies of embryo anatomy and into dynamic studies of the genetic and cellular mechanisms responsible for shaping the embryo anatomy. With the advancement of fluorescent protein fusions, the ability to visualize and comprehend how thousands to millions of cells interact with one another to form tissues and organs in three dimensions (xyz) over time (t) is just beginning to be realized and exploited. In this review, we explore recent advances utilizing confocal and multi-photon time-lapse microscopy to capture gene expression, cell behavior, and embryo development. From choosing the appropriate fluorophore, to labeling strategy, to experimental set-up, and data pipeline handling, this review covers the various aspects related to acquiring and analyzing multi-dimensional data sets. These innovative techniques in multi-dimensional imaging and analysis can be applied across a number of fields in time and space including protein dynamics to cell biology to morphogenesis

Widespread divergence of the CEACAM/PSG genes in vertebrates and humans suggests sensitivity to selection

In mammals, carcinoembryonic antigen cell adhesion molecules (CEACAMs) and pregnancy-specific glycoproteins (PSGs) play important roles in the regulation of pathogen transmission, tumorigenesis, insulin signaling turnover, and fetal–maternal interactions. However, how these genes evolved and to what extent they diverged in humans remain to be investigated specifically. Based on syntenic mapping of chordate genomes, we reveal that diverging homologs with a prototypic CEACAM architecture–including an extracellular domain with immunoglobulin variable and constant domain-like regions, and an intracellular domain containing ITAM motif–are present from cartilaginous fish to humans, but are absent in sea lamprey, cephalochordate or urochordate. Interestingly, the CEACAM/PSG gene inventory underwent radical divergence in various vertebrate lineages: from zero in avian species to dozens in therian mammals. In addition, analyses of genetic variations in human populations showed the presence of various types of copy number variations (CNVs) at the CEACAM/PSG locus. These copy number polymorphisms have 3–80% frequency in select populations, and encompass single to more than six PSG genes. Furthermore, we found that CEACAM/PSG genes contain a significantly higher density of nonsynonymous single nucleotide polymorphism (SNP) compared to the chromosome average, and many CEACAM/PSG SNPs exhibit high population differentiation. Taken together, our study suggested that CEACAM/PSG genes have had a more dynamic evolutionary history in vertebrates than previously thought. Given that CEACAM/PSGs play important roles in maternal–fetal interaction and pathogen recognition, these data have laid the groundwork for future analysis of adaptive CEACAM/PSG genotype-phenotypic relationships in normal and complicated pregnancies as well as other etiologies.Chia Lin Chang, Jenia Semyonov, Po Jen Cheng, Shang Yu Huang, Jae Il Park, Huai-Jen Tsai, Cheng-Yung Lin, Frank Grützner, Yung Kuei Soong, James J. Cai, Sheau Yu Teddy Hs

Cord compression secondary to intradural ossification.

The authors describe two patients presenting with a previous history of spinal trauma and a several-year history of sensory changes secondary to spinal cord compression. Both patients underwent laminectomy and spinal decompression operations. In both cases intradural bone causing neural compression was removed at operation. Potential mechanisms to explain intradural ossification and the relevant literature are reviewed

Amyloid in neurosurgical and neurological practice.

The amyloidoses are a diverse group of diseases characterized by the deposition of specific proteins with distinct affinity to the dye Congo red, collectively called amyloid. The amyloidogenic proteins have acquired an abnormal, highly ordered, beta-pleated sheet configuration with a propensity to self-aggregate. The amyloid may be distributed in different organs with a remarkable diversity. Two broad categories of amyloidoses are recognised: The systemic (consisting of the primary or light chain form, the secondary or reactive form and the familial or hereditary form) and the localised that target specific organs. A tropism of amyloid proteins to the neural tissue produces certain patterns of central nervous system diseases: cerebral amyloid angiopathy, a substrate of spontaneous intracerebral haemorrhage; mature neuritic plaques found in Alzheimer disease and a subset of prion diseases; a topographically restricted accumulation of extracellular proteins giving rise to tumour-mimicking masses, the amyloidomas; and finally, spinal extradural amyloid collections that occasionally are found in the context of rheumatoid arthritis. In this review article we present original illustrative cases of amyloid diseases of the central nervous system that may be encountered in neurosurgical and neurological practice. Molecular aspects and clinical management problems are discussed

Internal fixation for osteomyelitis of cervical spine: the issue of persistence of culture positive infection around the implants.

BACKGROUND: We describe the management of osteomyelitis of the cervical spine, utilizing internal fixation with subsequent removal and culture of the implants. Four out of five patients had evidence of bacterial colonisation in close proximity to the internal fixation device. METHODS: Five consecutive patients (all female, ranging in age from 50 to 74 yrs) presenting with unstable cervical osteomyelitis were treated by surgical decompression, primary internal fixation followed by three months of intravenous antibiotics. The internal fixation was removed in 4 out of 5 cases within a year of stopping the intravenous regime. The remaining patient was deemed medically unfit for further operation. Multiple specimens from the screw sites were taken at the time of metal removal. A final course of oral antibiotics was prescribed based on the results of these specimens. FINDINGS: Four patients, who had removal of the implants, had positive cultures growing different bacteria from the primary infection, at the time of removal of the implant. None of the patients developed instability after removal of the implant. INTERPRETATION: Asymptomatic bacterial colonisation of a metallic implant has profound management implications. We recommend long-term oral antibiotic regimes after insertion of internal fixation devices in the face of infection and eventual removal of these implants and microbiological re-sampling

Cervical dural arteriovenous fistulae manifesting as subarachnoid hemorrhage: report of two cases and literature review.

Dural arteriovenous fistulas (DAVFs) in the craniocervical junction are rare but clinically important. DAVFs can be associated with subarachnoid hemorrhage (SAH), a feature distinguishing them from DAVFs in the thoracolumbar region. These lesions are often overlooked at cerebral angiography performed to assess SAH and account for a small proportion of angiographically negative SAHs. After managing two cases of cervical spinal DAVF manifesting as SAH, we analyzed all cases in the literature to identify features associated with bleeding at presentation