Xenopus Tadpole Melanophores Are Controlled by Dark and Light and Melatonin Without Influence of Time of Day

Melanophores were studied in tadpoles of the South African clawed toad, Xenopus laevis , during the first week after hatching (stages 46–49) at 25°C. The tadpoles had melanophores with dispersed melanosomes in the light and punctate melanophores in the dark in LD12:12. The melanophores remained punctate in constant dark and the melanosomes remained dispersed in constant light. Lights-out (in the light-time of LD12:12) caused the melanophores to become punctate, which occurred more quickly than the dispersion of melanosomes, which commenced when the lights were turned on (in the dark-time of LD12:12). Melanophores with dispersed melanosomes in tadpoles (in constant light) became punctate in response to a series of melatonin concentrations (0.2–5 ng/ml) in their bathing water irrespective of the time of day melatonin was administered. An image-analysis technique for assessing melanophore responses was tested.     

Tau immunoreactivity and SDS solubility of two populations of paired helical filaments that differ in morphology

To further understand the processes that lead to the formation of neurofibrillary tangles from paired helical filaments (PHF) in Alzheimer brains, we studied two morphologically distinct fractions of PHF separated on sucrose density gradient. In a fraction with mostly short and non-aggregated PHF, the majority of filaments could be solubilized in SDS. In a fraction containing primarily PHF aggregated into clusters or bundles, sometimes resembling neurofibrillary tangles, filaments were less soluble in SDS. Immunogold labelling with a panel of tau-immunoreactive antibodies demonstrated that N-terminal epitopes of tau were preserved in the short filaments, but were reduced or absent in aggregated filaments. In contrast, C-terminal epitopes were present in both fractions. Furthermore, the accessibility of the microtubule-binding domain to immunolabelling was markedly impaired in short and non-aggregated filaments compared to aggregated filaments. These results are consistent with proteolytic degradation of the N-terminal epitopes and preservation of the C-terminal epitopes and the microtubule-binding domain of tau in the aggregated filaments. Partial proteolysis may be involved in the generation of aggregated PHF in neurofibrillary tangles.     

Erythropoietin levels in amniotic fluid and extraembryonic coelomic fluid in the first trimester of pregnancy.

OBJECTIVE: The aim was to measure erythropoietin levels in amniotic fluid and extraembryonic coelomic fluid from 7-12 weeks' gestation. SUBJECTS: Twenty healthy women with ultrasonographically normal first trimester pregnancies prior to surgical termination. METHODS: Paired samples of amniotic fluid and extraembryonic coelomic fluid were collected by transvaginal ultrasound guided needling. Erythropoietin was measured in both pregnancy fluids using a radioimmunoassay. RESULTS: There was a highly significant difference between erythropoietin levels in extraembryonic coelomic fluid (median level 15.45 mU/ml; range 6.8-32.1 mU/ml) and those in amniotic fluid (median 5.0 mU/ml; range < 5.0-5.8 mU/ml) (P < 0.0001; Mann-Whitney U-test). The levels of erythropoietin in maternal serum (median 15.4 mU/ml; range 5.6-29.4 mU/ml) were similar to those in the extra-embryonic coelom (P = 0.81; Mann-Whitney U-test). No relation was demonstrated between erythropoietin levels in amniotic fluid or coelomic fluid and stage of gestation. CONCLUSION: High levels of erythropoietin in coelomic fluid suggests that the hormone is involved in the process of human extraembryonic erythropoiesis. The exact regulatory role remains unknown.     

Psoas abscess following ingestion of psoas.

A case of right psoas abscess that was caused by duodenal perforation following the ingestion of a wooden skewer from a filet mignon is presented. Surgical repair of the perforation, drainage of the abscess and 5 days of intravenous antibiotics resulted in prompt recovery.     

Chest hair micrografts display extended growth in scalp tissue: a case report.

Conventional follicle harvesting techniques for hair transplantation are limited by the available scalp donor hair. The development of an innovative technique of microsurgical single follicular unit extraction has made it possible to exploit body hair grafts for scalp transplantation. This case study reports on 18 months of follow-up on a patient with extensive scalp scarring who underwent a transplantation procedure using donor chest hair. The photographically documented results show a change in the length of the chest hair measuring an average of 4 cm at transplant to 15 cm by 18 months post-transplant. The transplanted chest grafts provided an excellent cosmetic result for hair replacement.     

The clinical nurse leader: a response from practice.

In October 2003, over 200 nurse leaders from education and practice met at the invitation of the American Association of Colleges of Nursing. A newly released white paper, describing the role of the clinical nurse leader, was discussed at the conference. This article outlines a response to that white paper from one practice setting. The article shares information about another role, that of team coordinator, that is similar to clinical nurse leader and has been implemented at an integrated not-for-profit health care system in 5 hospitals. The comparison of the team coordinator role to the clinical nurse leader role might assist in visualizing such a role in practice. Although the roles are not identical, many of the driving forces for change were similar; these included the need to meet the changing demands for improved patient outcomes and nurse retention. The team coordinator role has 4 domains of practice that are crosswalked against the clinical nurse leader 15 core competencies. An evaluation of the team coordinator role showed changes that need to be made, such as placing more emphasis on clinical progression of patients. Lessons learned are shared, including keeping the scope of the role manageable, providing documentation standards for new roles, and the leadership required of the nursing executive to implement change.     

A performance curve for assessing change in Percentage of Consonants Correct Revised (PCC-R).

PURPOSE: Interpreting the rapidly changing speech skills of young children recovering from neurological injury is difficult because developmental expectations are generally available only at relatively lengthy intervals (e.g., 6 or 12 months). In this research note, the authors describe the process of generating a Percentage of Consonants Correct-Revised (PCC-R; L. D. Shriberg, D. Austin, B. A. Lewis, J. L. McSweeny, & D. L. Wilson, 1997a) performance curve and illustrate some of its applications for assessing change in performance over time. METHOD: The authors compiled mean PCC-R scores from 16 samples of typically developing children (18-172 months) and used curve fitting to test more than 11,000 statistical models of monthly growth in PCC-R. They selected a parsimonious and developmentally plausible model with R(2) = .9839 (p < .0005) and used it to generate the PCC-R, standard deviation, and standard error expected at each monthly age. RESULTS: The PCC-R performance curve distinguished among 65 children (37-57 months of age) diagnosed independently with normal or disordered speech with a high degree of success. More important, the PCC-R performance curve can be used to identify the points at which children (18-172 months) recovering from neurological injury achieve normal-range consonant production. CONCLUSION: The curve-fitting approach holds promise as a means of interpreting temporal variations in speech production at a finer grain than existing normative data currently allow.     

Decrement of the skin conductance response to repeated volitional inspiration.

OBJECTIVE: To examine response decrement of the recently reported inspiratory skin conductance response (SCR) [Lim CL, Seto-Poon M, Clouston PD, Morris JG. Sudomotor nerve conduction velocity and central processing time of the skin conductance response. Clin Neurophysiol 2003;114:2172-80]. METHODS: Twelve healthy adult volunteers performed 3 tasks (A) a control task of maintaining tidal breathing and then two randomized tasks, (B) a deep inspiration to a target oral pressure and (C) tapping with a finger. Each task was performed 30 times on cue every 20s in 3 runs with 5 min of rest between runs. The SCR, oral pressure, airflow, inspired volume and cue signal were recorded continuously and analysed offline. SCR amplitude was logarithmically transformed and then statistically analysed, using a linear mixed effects model, as a function of run number, trial number and absolute error between target and actual oral pressures. RESULTS: Inspiratory efforts elicited exponentially decreasing SCR amplitude with increasing trial number during each run (P < 0.0001). After adjusting for trial number, the mean SCR amplitude of the second and the third run were, respectively, 24.2 (95% CI (0.175, 0.336), P < 0.001) and 14.4% (95% CI (0.104, 0.200), P < 0.001) of the first run amplitude. CONCLUSIONS: Volitional deep inspiration reliably activates an SCR that exhibits response decrement with repetition, which may be habituation. SIGNIFICANCE: The volitional inspiratory SCR may assist in the assessment of sympathetic autonomic status in patients with peripheral afferent neuropathy.     

Construction and validation of a Parkinson's disease mutation genotyping array for the Parkin gene.

Parkin mutations account for the majority of familial and sporadic early onset Parkinson's disease (EOPD) cases with a known genetic association. More than 100 mutations have been described in the Parkin gene that includes homozygous, compound heterozygous, and single heterozygous mutations. We have designed a Parkin mutation genotyping array (gene chip) that includes published Parkin sequence variants and allows their simultaneous detection. The chip was validated by screening 85 PD cases and 47 controls previously tested for Parkin mutations. Similar genotyping microarrays have been developed for other genetically heterogeneous diseases including age-related macular degeneration. Here, we show the utility of a genotyping array for Parkinson's disease by analysis of 60 subjects from the Genetic Epidemiology of Parkinson Disease (GEPD) study that includes 15 early-onset PD case probands and 45 relatives.     

Plasma pharmacokinetics of high-dose oral busulfan in children and adults undergoing bone marrow transplantation

Abstract: We have analyzed the plasma pharmacokinetics of busulfan in 272 patients receiving high-dose oral busulfan and intravenous cyclophosphamide in conjunction with allogeneic or autologous bone marrow transplantation. The patients ranged in age from 2 months to 59 yr (mean 10, median 12 yr) and had the following diagnoses: thalassemia or sickle cell anemia (n = 74); leukemia or myelodysplasia (n = 112); inborn errors of metabolism (n = 41) or immunodeficiency (n = 45). Plasma specimens were collected following the first dose for each patient which ranged from 1 to 4 mg/kg (mean ± SD, 1.21 ± 0.41, median 1.15). Busulfan was quantitated using ultraviolet absorbance detection after derivatization and HPLC separation. Pharmacokinetic parameters were derived by modeling the raw data to fit first-order single compartment kinetics. The kinetic parameters showed wide interpatient variability independent of age and diagnosis. There was a statistically significant correlation of age with the following parameters: area under the curve (AUC); maximal concentration; minimum concentration; clearance; volume of distribution and absorption half-time. The coefficients of determination (i.e. correlation coefficient squared) were low ranging from 0.04 to 0.12 implying only a small part (i.e. 4–12%) of the variance was explained by age. Although busulfan pharmacokinetics are age-related most of the variability is not explained by age or diagnosis.