Dynamic weakening of serpentinite gouges and bare surfaces at seismic slip rates.

To investigate differences in the frictional behavior between initially bare rock surfaces of serpentinite and powdered serpentinite ("gouge") at subseismic to seismic slip rates, we conducted single-velocity step and multiple-velocity step friction experiments on an antigorite-rich and lizardite-rich serpentinite at slip rates (V) from 0.003 m/s to 6.5 m/s, sliding displacements up to 1.6 m, and normal stresses (σn ) up to 22 MPa for gouge and 97 MPa for bare surfaces. Nominal steady state friction values (µnss) in gouge at V = 1 m/s are larger than in bare surfaces for all σn tested and demonstrate a strong σn dependence; µnss decreased from 0.51 at 4.0 MPa to 0.39 at 22.4 MPa. Conversely, µnss values for bare surfaces remained ∼0.1 with increasing σn and V. Additionally, the velocity at the onset of frictional weakening and the amount of slip prior to weakening were orders of magnitude larger in gouge than in bare surfaces. Extrapolation of the normal stress dependence for µnss suggests that the behavior of antigorite gouge approaches that of bare surfaces at σn ≥ 60 MPa. X-ray diffraction revealed dehydration reaction products in samples that frictionally weakened. Microstructural analysis revealed highly localized slip zones with melt-like textures in some cases gouge experiments and in all bare surfaces experiments for V ≥ 1 m/s. One-dimensional thermal modeling indicates that flash heating causes frictional weakening in both bare surfaces and gouge. Friction values for gouge decrease at higher velocities and after longer displacements than bare surfaces because strain is more distributed. KEY POINTS: Gouge friction approaches that of bare surfaces at high normal stressDehydration reactions and bulk melting in serpentinite in < 1 m of slipFlash heating causes dynamic frictional weakening in gouge and bare surfaces.

Sea lice, Lepeophtheirus salmonis, transfer between wild sympatric adult and juvenile salmon on the north coast of British Columbia, Canada.

We examine sea lice, Lepeophtheirus salmonis, on juvenile and adult salmon from the north coast of British Columbia between 2004 and 2006 in an area that does not at present contain salmon farms. There is a pronounced zonation in the abundance of L. salmonis on juvenile pink salmon, Oncorhynchus gorbuscha, in the Skeena and Nass estuaries. Abundances in the proximal and distal zones of these estuaries are 0.01 and 0.05 respectively. The outer zones serve as feeding and staging areas for the pink salmon smolts. Returning Chinook, Oncorhynchus tshawytscha, and coho salmon, Oncorhynchus kisutch, concentrate in these areas. We collected data in 2006 to examine whether L. salmonis on returning adult salmon are an important source of the sea lice that appear on juvenile pink salmon. Nearly all (99%) of the sea lice on returning Chinook and over 80% on coho salmon were L. salmonis. Most of the L. salmonis were motile stages including many ovigerous females. There was a sharp increase in the abundance of sea lice on juvenile pink salmon smolts between May and July 2006 near the sites of adult captures. As there are no salmon farms on the north coast, few sticklebacks, Gasterosteus aculeatus, and very few resident salmonids until later in the summer, it seems that the most important reservoir of L. salmonis under natural conditions is returning adult salmon. This natural source of sea lice results in levels of abundance that are one or two orders of magnitude lower than those observed on juvenile pink salmon in areas with salmon farms such as the Broughton Archipelago.

Ultrasound enhancement of cationic lipid-mediated gene transfer to primary tumors following systemic administration.

The impact of a localized application of ultrasound on gene transfer to primary tumors following systemic administration of cationic lipid based transfection complexes was investigated. We have previously shown that systemic administration of DOTMA (N-[(1-(2-3-dioleyloxy) propyl)]-N-N-N-trimethylammonium chloride):cholesterol-based transfection complexes to tumor-bearing mice resulted in expression in the tumor and other tissues, primarily the lungs. Application of ultrasound to the tumor before or after the injection resulted in a significant increase in gene transfer to the tumor with no increase observed in other tissues. The magnitude of increased expression ranged from three- to 270-fold depending upon the DNA dose. The following parameters were optimized for maximal increase: duration of ultrasound application, the time interval between plasmid injection and sonoporation, and plasmid dose. A combination of plasmid quantitation and fluorescence microscopy showed that ultrasound increased tumor uptake of the plasmid and that uptake was limited to the tumor vasculature. Using an IL- 12 expression plasmid, the combination of a single plasmid dose (10 microg) and ultrasound treatment produced significantly higher levels of IL-12 in tumor. This increased expression was sufficient to inhibit tumor growth compared with the control conditions. These data demonstrate the potential application of sonoporation as an effective method for enhancing the expression of systemically administered genes in tumor endothelium for cancer gene therapy.

Synthetic glycopeptide-based delivery systems for systemic gene targeting to hepatocytes.

PURPOSE: To design, synthesize, and test synthetic glycopeptide-based delivery systems for gene targeting to hepatocytes by systemic administration. METHODS: All peptides were synthesized by the solid phase method developed using Fmoc chemistry on a peptide synthesizer. The binding of galactosylated peptides to HepG2 cells and accessibility of the galactose residues on particle surface was demonstrated by a competition assay using 125I-labeled asialoorosomucoid and RCA lectin agglutination assay, respectively. DNA plasmid encoding chloramphenicol acetyl transferase (CAT) gene was complexed with a tri-galactosylated peptide (GM245.3) or tri-galactosylated lipopeptide (GM246.3) in the presence of an endosomolytic peptide (GM225.1) or endosomolytic lipopeptide (GM227.3) to obtain DNA particles of 100-150 nm in size. The plasmid/peptide complexes were added to HepG2 cell cultures or intravenously administered by tail vein injection into normal mice or rats. Plasmid uptake and expression was quantified by qPCR and ELISA, respectively. RESULTS: Multiple antennary glycopeptides that have the ability to condense and deliver DNA plasmid to hepatocytes were synthesized and complexed with DNA plasmid to obtain colloidally stable DNA/peptide complexes. Addition of DNA/GM245.3/GM225.1 peptide complexes (1:3:1 (-/+/-)) to HepG2 cell cultures yielded CAT expression in transfected cells. The transfection efficiency was significantly reduced in the absence of galactose ligand or removal of endosomolytic peptide. Intravenous administration of DNA/GM245.3 peptide complexes (1:0.5 (-/+)) into the tail vein of normal rats yielded DNA uptake in the liver. Substitution of GM245.3 by galactosylated lipopeptide GM246.3 resulted in more stable DNA particles, and a 10-fold enhancement in liver plasmid uptake. CAT expression was detectable in liver following intravenous administration of DNA/GM246.3 complexes. Addition of endosomolytic lipopeptide GM227.3 into the complexes (DNA/ GM246.3/GM227.3 (1:0.5:1 (-/+/-))) yielded a 5-fold increase in CAT expression. Liver expression was 8-fold and 40-fold higher than lung and spleen, respectively, and localized in the hepatocytes only. The transfection efficiency in liver was enhanced by increasing DNA dose and injection volume. The plasmid uptake and expression in liver using DNA/GM246.3/GM227.3 complexes was 100-200-fold higher than DNA formulated in glucose. Tissue examination and serum biochemistry did not show any adverse effect of the DNA/GM246.3/ GM227.3 (1:0.5:1 (-/+/-)) complexes after intravenous delivery. CONCLUSIONS: Gene targeting to hepatocytes was achieved by systemic administration of a well-tolerated synthetic glycopeptide-based delivery system. The transfection efficiency of this glycopeptide delivery system was dependent on peptide structure, endosomolytic activity, colloidal particle stability, and injection volume.

Optimization of cationic lipid/DNA complexes for systemic gene transfer to tumor lesions.

Intravenous (i.v.) administration of cationic lipid N-[( 1-(2-3-dioleyloxy)propyl)]-N-N-N-trimethylammonium chloride (DOTMA)-based transfection complexes in mice with subcutaneous squamous cell tumors yielded plasmid delivery and expression in tumor lesions. The efficiency of gene transfer in tumors was significantly lower than in the lung. This was consistent with low plasmid levels associated with the tumor, suggesting that plasmid delivery to the tumor site was a limiting factor. Lowering the lipid/DNA charge ratio from 5:1 to 0.8:1 (+/-) did not change DNA levels in tumor but significantly reduced DNA levels in lung. However, expression levels were significantly reduced in both tissues at lower lipid/DNA charge ratios. Complexes prepared from small unilamellar liposomes gave significantly lower expression levels in the lungs but similar expression levels in tumors when compared to complexes prepared from larger unilamellar liposomes. The small liposome complexes were better tolerated than large liposome complexes. Varying the cationic lipid to colipid (cholesterol or DOPE) molar ratio from 4: 1 to 1: 1 significantly reduced expression levels in both tumor and lung. Cationic lipid substitution, using a cholesterol cationic lipid, diethyldiamino-carbamyl-cholesterol instead of DOTMA, produced reduced expression in all other tissues except tumor. Incorporation of PEG into preformed transfection complexes reduced DNA delivery to lung, increased circulation half-life, and enhanced DNA delivery to tumor. In a lung metastatic mouse tumor model, where the accessibility of the i.v. administered transfection complexes to tumor lesions should be less challenging, DOTMA: CHOL complexes (4: 1 lipid to colipid molar ratio, 3: 1 +/- lipid to plasmid charge ratio) were preferentially localized in tumor lesions. These data demonstrate that systemic gene transfer to distal tumor sites by lipid/ DNA complexes may be limited by low plasmid delivery. Modifying the chemical surface properties of transfection complexes enhanced both DNA delivery and expression in tumor and is one approach that may overcome limitations.

An initial investigation of validation of the Matrix Analogies Test-Expanded Form in Ecuador.

This is a first preliminary study of the validity and reliability of the Matrix Analogies Test--Expanded Form in South America. Participants were 104 Spanish-speaking children between the ages of 5 and 17 years living in Ecuador. Values of Cronbach alpha ranged from .87 to .92 for the 4 groups of items and was .95 for the total score. Raw scores on the MAT increased across ages. Scores of boys did not differ significantly from those of girls. Total test scores correlated significantly with scores on the Raven Standard Progressive Matrices (r = .62, p < .005; r = .82 before controlling for age). A principal factor analysis conducted to provide evidence of the test's construct validity indicated that all four sets of items loaded substantially on one unrotated factor, presumed to be g. In sum, these results suggest that the test is a valid and reliable nonverbal measure of general cognitive ability in this population.

Is short stature a handicap? A comparison of the psychosocial functioning of referred and nonreferred children with normal short stature and children with normal stature.

OBJECTIVES: Normal short stature (NSS), defined as height below the 5th percentile for age and sex norms that is not due to illness, hormonal deficiency, or part of a dysmorphic syndrome, has been thought to have a deleterious effect on psychosocial functioning based on observations of referred populations. Recent studies of nonreferred children with NSS, however, have demonstrated normal function. This study directly compared the psychosocial functioning of referred children with NSS, nonreferred children with NSS, and children with normal stature. STUDY DESIGN: Participants, 90 children (46 boys, 44 girls) between 6 and 12 years of age (mean, 9. 6 years), were administered intelligence and achievement tests. Parents and teachers assessed adaptive and problem behaviors. Family adaptability and cohesiveness were measured. RESULTS: Intelligence and achievement for referred and nonreferred children with NSS were average. Referred children with NSS were reported to have more externalizing behavior problems and poorer social skills than nonreferred children with NSS and children in the control group. Family adaptability and cohesiveness were comparable across groups. CONCLUSIONS: Children with NSS have normal psychosocial function, and results suggest that externalizing behavior problems, attention problems, and poor social skills in children referred to clinics for NSS are inappropriately attributed to short stature.

Synergistic effect of formulated plasmid and needle-free injection for genetic vaccines.

PURPOSE: A plasmid-based gene expression system was complexed with protective, interactive, and non-condensing (PINC) polymer system and administered with Medi-Jector, a needle-free injection device (NFID), to achieve high and sustained levels of antigen-specific antibodies in blood circulation. METHODS: Human growth hormone (hGH) or bacterial beta-galactosidase gene expression plasmids driven by a cytomegalovirus (CMV) promoter were formulated in saline or complexed with a PINC polymer, polyvinylpyrrolidone (PVP), and intramuscularly or subcutaneously administered into dogs and pigs using a 22-gauge needle or a NFID. The hGH-specific IgG titers in serum were measured by an ELISA. Beta-galactosidase expression was measured in injected muscles by an enzymatic assay or immunohistochemistry. The effect of NFID on DNA stability and topology was assessed by gel electrophoresis. RESULTS: Intramuscular (i.m.) or subcutaneous (s.c.) injection of a hGH expression plasmid pCMV-hGH (0.05-0.5 mg/kg) in dogs and pigs elicited antigen-specific IgG antibody titers to expressed hGH. With both routes of injection, pDNA delivery by a NFID was superior to pDNA injection by needle. The magnitude of hGH-specific IgG titers with NFID was 15-20-fold higher than needle injection when pDNA was complexed with PVP, and only 3-4-fold higher with pDNA in saline. The transfection efficiency in the injected muscle, as measured by beta-galactosidase expression, following i.m. injection of pCMV-betagalactosidase/PVP, was not significantly different between needle and NFID-injected groups. CONCLUSIONS: These data demonstrate that the combination of pDNA/ PVP complexes and a NFID act synergistically to achieve high and sustained levels of antigen-specific IgG response to expressed antigen. This gene delivery approach may offer advantage over needle injection of naked DNA for the development of genetic vaccines.

An alternative training approach to clinical supervision: 2.

In this, the second of two articles focusing on the issue of training in clinical supervision, the alleged benefits of training students to be supervisees is highlighted. These are: a substantial reduction in training costs and time; a possible standardization of training; the creation of greater equality and intentionality in the working alliance; an increased student awareness and understanding that supervision is for their benefit; the sharing of values, ground rules, terms and aims between the supervisee/supervisor and the organization; a sense of comradeship between peers in a culture that is often described as having a sense of divide and rule; and a greater sense of team cohesion. The development of basic intrapersonal skills (e.g. reflecting on practice, choosing issues, asking for and using help appropriately) in a non-threatening forum is also of great benefit. The authors conclude that an educational model would include both theoretical and experimential components with the theory preceding the clinical supervision experience. Evaluation of this training could be carried out using a methodology similar to that used by Butterworth et al (1997) in evaluating the impact of receiving supervision.

An alternative training approach to clinical supervision: 1.

This article, the first of two-parts, introduces a new series on clinical supervision. It focuses on the issues of training in clinical supervision. The practice of clinical supervision is considered by the Chief Nursing Officer of the Department of Health to be fundamental to safeguarding standards, the development of expertise and the delivery of quality care. Clinical supervision allegedly brings significant benefits to clients and clinicians, and recent research has produced both quantitative and qualitative evidence to support this argument. Many trusts have already made attempts to introduce widespread implementation of clinical supervision and most developments are concerned with equipping clinicians to be supervisors not supervisees. This presents several logistical and financial problems, and currently neither the infrastructure nor the culture exist in nursing to facilitate its widespread and effective uptake. The authors argue that an alternative method of tackling this problem would be to train nurses to become supervisees not supervisors. Supervisee training could commence following the first year of the common foundation programme component of diploma and undergraduate nurse education.

Systemic effect of human growth hormone after intramuscular injection of a single dose of a muscle-specific gene medicine.

A muscle-specific gene medicine is described that provides for long-term secretion of biologically active human growth hormone (hGH) from skeletal muscle into the systemic circulation. The hGH gene medicine is composed of a muscle-specific hGH plasmid expression system complexed with a protective, interactive, non-condensing (PINC) delivery system. The muscle-specific gene expression system, pSK-hGH-GH, was constructed by linking the promoter/enhancer regions of chicken skeletal alpha-actin to hGH gene. C2C12 myoblast transfection with pSK-hGH-GH resulted in the synthesis of hGH in a muscle-specific manner. Direct injection into rat tibialis cranialis muscle of pSK-hGH-GH complexed with a polymeric PINC delivery system, polyvinylpyrrolidone (PVP), produced hGH levels in muscle that were 10- to 15-fold higher compared with plasmid formulated in saline at 14 days post-injection. Intratracheal instillation in rat lung of pSK-hGH-GH did not produce significantly detectable levels of hGH. In hypophysectomized rats, a single intramuscular dose of the pSK-hGH-GH/PVP complex resulted in hGH expression and a subsequent increase in serum levels of rat IGF-I and growth. hGH expression and effects on rat serum IGF-I levels were detectable up to 28 days after injection of formulated plasmid and effects on growth were detectable unto 21 days. Anti-hGH antibodies were detectable in serum at 14 days post-injection, reached a plateau at 21 days, and remained elevated through the study period. Cyclosporin treatment of the pSK-hGH-GH/PVP-injected animals completely inhibited the antibody response and resulted in increased hGH expression.

Etiology and treatment of fluid retention (hydrops) in Ménière's syndrome.

For years low sodium diets have been recommended in the treatment of Ménière's syndrome. Elevated levels of insulin play an important role in sodium retention in renal tubules. Insulin production is stimulated by high carbohydrate diets. Adrenaline, cortisone, and glucagon levels may be increased by stress or food or inhalant allergies, further elevating insulin levels. The end result of prolonged hyperinsulinemia includes vasoconstriction and eventually arterial smooth muscle hypertrophy. Individual susceptibility to Ménière's syndrome may occur as a result of inflammatory changes in the endolymphatic sac or cochlear aqueduct secondary to primary or latent viral infections, thus predisposing to fluid retention. Long term medical treatment of Ménière's should be directed towards preventing sodium retention through sodium restriction and carbohydrate management. Other factors including stress and allergy should also be considered.

Quartz prism sequence for reduction of cubic phase in a mode-locked Ti:Al(2)O(3) laser.

A sequence of four quartz prisms can be used to obtain large negative group-velocity dispersion with reasonable prism spacings and a small residual cubic phase. For a given value of the second-order dispersion and assuming minimal prism insertion, the third-order dispersion is 20% less than that of prism pairs that have been used in Ti:Al(2)O(3) lasers. A mode-locked Ti:Al(2)O(3) laser that includes the prism sequence generates pulses with intensity autocorrelations as short as 33 fs. Spectral bandwidths as large as 80 nm can also be obtained. A measurement of the dispersion of the laser shows that the cubic phase is approximately that of the prism sequence and the laser rod.

The anatomy of the facial nerve.

The course of the facial nerve from its origin in the human brain-stem to the termination of its end fibers in the muscles of facial expression is reviewed in detail. The relation of the facial nerve to important adjacent structures is emphasized so that the aural surgeon is better prepared to explore in this intricate area.

Anatomic variations and anomalies involving the facial canal.

Congenital bony dehiscences in the facial canal result from incomplete closure during development and are observed in approximately 55% of temporal bones. Anomalies involving the facial canal frequently are encountered in malformations of the temporal bone. These anomalies include aberrations of the course of one or all of the segments of the canal; abnormal relation to the oval and round window; bifurcations and trifurcations of the nerve; and associations with dysplasia of the stapes, oval window, external ear canal, and auricle. Rarely, the facial nerve may be hypoplastic or totally absent. Two abnormal vessels occasionally may accompany the facial nerve in the Fallopian canal: a persistent stapedial artery and a persistent lateral capital vein.