A thorough understanding of nerve regeneration in Caenorhabditis elegans requires performing femtosecond laser nanoaxotomy while minimally affecting the worm. We present a microfluidic device that fulfills such criteria and can easily be automated to enable high-throughput genetic and pharmacological screenings. Using the 'nanoaxotomy' chip, we discovered that axonal regeneration occurs much faster than previously described, and notably, the distal fragment of the severed axon regrows in the absence of anesthetics.
View Article and Find Full Text PDFAcute inflammation is traditionally described as the influx of polymorphonuclear leukocytes (PMNs) followed by monocyte-derived macrophages, leading to resolution. This is a classic view, and despite subpopulations of lymphocytes possessing innate immune-regulatory properties, seldom is their role in acute inflammation and its resolution discussed. To redress this we show, using lymphocyte-deficient RAG1(-/-) mice, that peritoneal T/B lymphocytes control PMN trafficking by regulating cytokine synthesis.
View Article and Find Full Text PDFHematopoietic prostaglandin D(2) synthase (hPGD(2)S) metabolizes cyclooxygenase (COX)-derived PGH(2) to PGD(2) and 15-deoxyDelta(12-14) PGJ(2) (15d-PGJ(2)). Unlike COX, the role of hPGD(2)S in host defense is ambiguous. PGD(2) can be either pro- or antiinflammatory depending on disease etiology, whereas the existence of 15d-PGJ(2) and its relevance to pathophysiology remain controversial.
View Article and Find Full Text PDFConf Proc IEEE Eng Med Biol Soc
March 2008
Impaired lateral balance involving the frontal plane is particularly relevant to the problem of falls with aging. Protective stepping is critical to avoiding falling, and medio-lateral (M-L) stepping involves two quite complicated action choices -- lateral side step and crossover stepping. The aims of this study were to identify differences in movement patterns between young healthy subjects and elderly fallers and non-fallers (determined prospectively over a year), and to identify performance differences for the two types of stepping response.
View Article and Find Full Text PDFA report on the 16th International Meeting, Los Angeles, USA, 27 June-1 July 2007.
View Article and Find Full Text PDFThis case report examined the effectiveness of a home program using neuromuscular electrical stimulation (NMES) during voluntary task-oriented exercise to achieve functional and impairment improvements for an individual with primarily proximal arm paresis after a stroke. The subject initially achieved a Fugl-Meyer Assessment (FMA) score of 58/66, but she reported minimal functional use of her involved, dominant arm. The 6-wk intervention consisted of NMES-assisted task practice involving repetitive reaching for and manipulation of small objects for three daily 15-min sessions.
View Article and Find Full Text PDFSecreted proteins of the Wnt family affect axon guidance, asymmetric cell division, and cell fate. We show here that C. elegans Wnts acting through Frizzled receptors can shape axon and dendrite trajectories by reversing the anterior-posterior polarity of neurons.
View Article and Find Full Text PDFA set of conserved molecules guides axons along the metazoan dorsal-ventral axis. Recently, Wnt glycoproteins have been shown to guide axons along the anterior-posterior (A/P) axis of the mammalian spinal cord. Here, we show that, in the nematode Caenorhabditis elegans, multiple Wnts and Frizzled receptors regulate the anterior migrations of neurons and growth cones.
View Article and Find Full Text PDFThe alae, longitudinal ridges of the lateral cuticle, are the most visible specialization of the Caenorhabditis elegans surface. They are present only in L1 and dauer larvae and in adults. Little is known about the mechanisms through which at the appropriate stages secretion of cuticle components by the seam cells results in the formation of the alae.
View Article and Find Full Text PDFASH sensory neurons are required in Caenorhabditis elegans for a wide range of avoidance behaviors in response to chemical repellents, high osmotic solutions and nose touch. The ASH neurons are therefore hypothesized to be polymodal nociceptive neurons. To understand the nature of polymodal sensory response and adaptation at the cellular level, we expressed the calcium indicator protein cameleon in ASH and analyzed intracellular Ca(2+) responses following stimulation with chemical repellents, osmotic shock and nose touch.
View Article and Find Full Text PDFAn animal's ability to detect and avoid toxic compounds in the environment is crucial for survival. We show that the nematode Caenorhabditis elegans avoids many water-soluble substances that are toxic and that taste bitter to humans. We have used laser ablation and a genetic cell rescue strategy to identify sensory neurons involved in the avoidance of the bitter substance quinine, and found that ASH, a polymodal nociceptive neuron that senses many aversive stimuli, is the principal player in this response.
View Article and Find Full Text PDFThe disorder Amish microcephaly (MCPHA) is characterized by severe congenital microcephaly, elevated levels of alpha-ketoglutarate in the urine and premature death. The disorder is inherited in an autosomal recessive pattern and has been observed only in Old Order Amish families whose ancestors lived in Lancaster County, Pennsylvania. Here we show, by using a genealogy database and automated pedigree software, that 23 nuclear families affected with MCPHA are connected to a single ancestral couple.
View Article and Find Full Text PDFThe phasmids are bilateral sensory organs located in the tail of Caenorhabditis elegans and other nematodes. The similar structures of the phasmids and the amphid chemosensory organs in the head have long suggested a chemosensory function for the phasmids. However, the PHA and PHB phasmid neurons are not required for chemotaxis or for dauer formation, and no direct proof of a chemosensory function of the phasmids has been obtained.
View Article and Find Full Text PDFKallmann syndrome is an inherited disorder defined by the association of anosmia and hypogonadism, owing to impaired targeting and migration of olfactory axons and gonadotropin-releasing hormone secreting neurons. The gene responsible for the X-linked form of Kallmann syndrome, KAL-1, encodes a secreted protein of still elusive function. It has been proposed that KAL-1 might be involved in some aspects of olfactory axon guidance.
View Article and Find Full Text PDFWe have investigated the role of Caenorhabditis elegans RAD-51 during meiotic prophase and embryogenesis, making use of the silencing effect of RNA interference (RNAi). rad-51 RNAi leads to severe defects in chromosome morphology in diakinesis oocytes. We have explored the effect of rad-51 RNAi in mutants lacking fundamental components of the recombination machinery.
View Article and Find Full Text PDFEps15 represents the prototype of a family of evolutionarily conserved proteins that are characterized by the presence of the EH domain, a protein-protein interaction module, and that are involved in many aspects of intracellular vesicular sorting. Although biochemical and functional studies have implicated Eps15 in endocytosis, its function in the endocytic machinery remains unclear. Here we show that the Caenorhabditis elegans gene, zk1248.
View Article and Find Full Text PDFEmerg Med Clin North Am
November 1999
This article focuses on disorders of the hand most commonly presented to the practitioner in an emergency setting. An initial review of functional anatomy is followed by discussions of the clinical findings and treatment of fractures, tendon injuries, infections, nailbed injuries, high-pressure injection injuries, and nerve injuries. The information presented in this article provides a basis for proper evaluation, diagnosis, and treatment of hand injuries.
View Article and Find Full Text PDFBackground: In 1995, a program was begun at the University of South Alabama (USA) to improve the reporting of medical risk factors on birth certificates.
Methods: Data on medical risk factors for USA Hospital and the remainder of the state for 1994 and 1996 were examined to observe the effects of the USA Medical Center program.
Results: The number of medical risk factors reported changed markedly between 1994 and 1996 for most items and changed hardly at all for the remainder of the state.
Proc Natl Acad Sci U S A
August 1999
With cDNA microarrays, it is now possible to compare the expression of many genes simultaneously. To maximize the likelihood of finding genes whose expression is altered under the experimental conditions, it would be advantageous to be able to select clones for tissue-appropriate cDNA sets. We have taken advantage of the extensive sequence information in the dbEST expressed sequence tag (EST) database to identify a neural crest-derived melanocyte cDNA set for microarray analysis.
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