Length-dependent axo-terminal degeneration at the neuromuscular synapses of type II muscle in SOD1 mice

In motor neuron diseases, there is a prolonged period of time before any clinical symptoms begin to appear. During this time, distal axonal degeneration, or "dying back" axonopathy, begins to occur before the onset of clinical symptoms and motor neuron death. This preclinical degeneration is a hallmark of motor neuron diseases in both animal models and human patients. Generally, in muscles with mixed fiber types, distal degeneration occurs in fast-fatigable α-motor axons innervating type IIb muscle fibers before axons innervating slow, type I muscle fibers. We investigated whether the "dying back" axonopathy in a pure fast-fatigable α-motor axon nerve is a length-dependent process. The lateral thoracic nerve (LTN) exclusively consists of motor nerves that innervate the very thin cutaneous maximus muscle (CMM) that solely contains type II neuromuscular synapses. We characterized the LTN and CMM synapses both morphologically and physiologically in the superoxide dismutase 1 (SOD1) mutant mouse model of amyotrophic lateral sclerosis (ALS). By 60days of age, there was a significant "dying back" phenomenon at the caudal region while the rostral region remained intact. The longer axons innervating the caudal region appear to be more susceptible to degeneration in the SOD1 mouse indicating that the axonal degeneration of motor neurons innervating type II fibers is a length-dependent process. Additionally, we identified how the simplicity of the LTN-CMM system offers a better method to investigate axon degeneration in an ALS mouse model and may be used to investigate possible therapeutic compounds for axon protection and regeneration.

Equine platelet lysate as an alternative to fetal bovine serum in equine mesenchymal stromal cell culture - too much of a good thing?

REASONS FOR PERFORMING STUDY

Multipotent mesenchymal stromal cells (MSC) are often culture-expanded in vitro. Presently, expansion medium (EM) for MSC is supplemented with fetal bovine serum (FBS). However, increasing cost, variable composition and potential risks associated with bovine antigens call for alternatives. Platelet lysate (PL) has shown promise as an alternative supplement.

OBJECTIVES

To determine how equine umbilical cord blood (CB) MSC proliferate in EM enriched with PL or FBS at various concentrations.

STUDY DESIGN

Randomised dose escalation study.

METHODS

Platelet concentrate was generated from 5 equine whole blood samples through a double centrifugation method and standardised to 1 × 10(12) platelets/l prior to a freeze/thaw cycle to produce PL. Pooled PL or pooled FBS was added to EM at concentrations of 5% to 60%. Proliferation of 4 equine CB-MSC cultures was determined after 4 days using a resazurin semiquantitative assay.

RESULTS

Cord blood-MSC proliferated with a dose-dependent response with no significant difference found between PL and FBS up to a 30% concentration. Beyond 30%, proliferation fell in the PL-cultured cells, while continued dose-dependent proliferation was noted in the FBS-cultured cells. Despite reduced cell numbers in high PL concentrations, live/dead staining revealed that adherent cells remained viable.

CONCLUSIONS

Expansion medium enriched with PL can support short-term equine CB-MSC proliferation at conventional culture concentrations. Based on the unexpected suppression of CB-MSC at higher PL concentrations, an in vivo dose study is indicated to investigate if combinational therapies of CB-MSC and platelet-rich plasma are associated with synergistic or antagonistic effect on CB-MSC function.

Correlation between facial morphology and esthetics in patients with repaired complete unilateral cleft lip and palate

OBJECTIVE

The purpose of this study was to determine if there were correlations between anthropometric nasolabial measurements and subjective assessments of nasal esthetics in individuals with repaired complete unilateral cleft lip and palate (CUCLP).

PARTICIPANTS

The sample consisted of 28 individuals with repaired CUCLP and 20 age- and gender-matched individuals without clefts.

OUTCOME MEASURES

Nasolabial morphology was assessed using 2D and 3D measurements made on frontal photographs, lateral cephalometric radiographs, and plaster nose casts. A panel of orthodontists rated nasal esthetics from frontal, lateral, three-quarter, and basal view photographs and plaster nose casts using visual analog scales, and they also order ranked the nose casts. Based on the nasal esthetics ratings and rankings, two groups that had the best and the worst esthetics representing the extremes of nasolabial esthetics were statistically identified. Measurements were compared between the cleft and noncleft and the best and worst groups using t tests and analysis of variance.

RESULTS

Differences in anthropometric measurements between the groups were identified. The columellar width and nose base and nasolabial angles significantly differed between the best and worst groups (p < .05). Differences in panel ratings of nasolabial esthetics between the best and worst groups were statistically detected using lateral and three-quarter view photographs (p < .05).

CONCLUSIONS

Although morphologic differences between the cleft and noncleft and between the best and worst groups were identified, the slight morphologic differences noted were not sufficient to explain the subjective esthetic evaluation by the panel.

Are antineutrophil cytoplasmic antibodies pathogenic? Experimental approaches to understand the antineutrophil cytoplasmic antibody phenomenon

Antineutrophil cytoplasmic antibodies (ANCA) directed against the neutrophil enzymes PR3 and MPO are tightly associated with the development of small vessel vasculitis. This article reviews the large body of data derived from in vitro experiments documenting many different proinflammatory effects of these ANCA on neutrophils, monocytes, and endothelial cells. Taken in conjunction with clinical observations and data from animal models, a concept of the pathogenicity of ANCA emerges.

Orthodontic treatment for patients with Turner syndrome

The purpose of this study was to review the distinctive characteristics of Turner syndrome and to illustrate how they influenced the orthodontic treatment of a 17-year-old patient with Turner syndrome. The rate and the timing of growth, the development of the craniofacial structures, and the somatic and dental morphology unique to Turner syndrome significantly influence orthodontic treatment. Modifications that might be required to orthodontic treatment plans include (1) antibiotic prophylaxis, (2) occlusal adjustments to account for altered dental morphology, (3) altered treatment timing because of major differences in growth and differences between chronological and skeletal ages, and (4) growth hormone therapy. Orthodontists must understand the characteristics of Turner syndrome and modify the patient's treatment plan accordingly.

Nasal morphology and shape parameters as predictors of nasal esthetics in individuals with complete unilateral cleft lip and palate

OBJECTIVE

The purpose of this study was to assess the ability of shape parameters of nasal morphology to predict esthetics in individuals with complete unilateral cleft lip and palate (CUCLP).

METHODS

This retrospective study involved 28 patients with repaired CUCLP. Nostril morphology was analyzed using nose casts and a video-imaging technique. Calculated shape parameters included area, perimeter, centroid, angle of the principal axis, major and minor moments of area, anisometry, bulkiness, lateral offset, and three-dimensional internostril angles. Esthetics was assessed using a panel of six orthodontists who rated nasal esthetics from frontal, lateral, basal, and three-quarters view slides and from nose casts. Correlations between esthetics and the shape parameters were completed using the entire group as well as using two statistically determined subsets: those with the best and those with the worst esthetics.

RESULTS

Nasal esthetics was related to only the perimeter and bulkiness parameter ratios. Symmetry of the perimeters between the right and left nostrils positively correlated with better esthetics using the entire sample group while symmetry of bulkiness between the right and left nostrils positively correlated with better esthetics using both the entire sample group and the best and worst subsets.

CONCLUSIONS

Only perimeter and bulkiness showed positive correlations with nasal esthetics. The group of parameters used to assess nostril morphology had neither significant correlation with-nor predictive power for-esthetics. Thus, an assessment of the entire nasal surface topography in three dimensions needs to be completed and assessed with respect to predictability of nasal esthetics.

In vitro assessment of the mechanical properties of latex and non-latex orthodontic elastics

The increased incidence of latex allergies has led to the development of non-latex orthodontic products. The purpose of this study was to compare the mechanical properties of latex and non-latex orthodontic elastics. The elastics tested were from 2 manufacturers (GAC and Masel) and made of 2 materials (latex and non-latex). The properties tested included cross-sectional area, breaking force, peak load, peak stress, stiffness, modulus, hysteresis, and 24-hour load relaxation. The data were analyzed with 1-sample t tests, an analysis of variance, and the Fisher PLSD test. Between GAC and Masel, the GAC non-latex elastics had greater breaking forces than did the Masel non-latex elastics. The Masel latex elastics had greater breaking forces than did the Masel non-latex elastics. The GAC non-latex elastics showed more viscoelastic properties than both the GAC latex elastics and the Masel non-latex elastics; however, the Masel elastics were more viscoelastic than the GAC elastics. Forces generated by the elastics decreased over 24 hours to an average load approximating 75% of the manufacturers' values (GAC latex, Masel latex, and Masel non-latex elastics) and to 60% for the GAC non-latex elastics. The mechanical properties of the non-latex elastics were not comparable to those of the latex elastics. Therefore, the clinical choice of elastics should be based on the patient's medical history and the specific mechanical properties of the type of elastic.

Antineutrophil cytoplasmic antibodies reacting with the pro form of proteinase 3 and disease activity in patients with Wegener's granulomatosis and microscopic polyangiitis

OBJECTIVE

Antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) are diagnostic markers for the small vessel vasculitides Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA). Correlation of disease activity with PR3 ANCA levels, as determined by standard methods, is not apparent in every patient. PR3 ANCA react with yet to be identified conformational epitopes. We have identified PR3 ANCA subsets that react differentially with mature recombinant PR3 (rPR3; lacking the N-terminal activation dipeptide) and the pro form of this enzyme (pro-rPR3). The present study was performed to determine the association of these PR3 ANCA subsets with disease activity.

METHODS

Sera from 61 PR3 ANCA-positive patients with WG or MPA were assayed by capture enzyme-linked immunosorbent assay using pro-rPR3 and rPR3 as target antigens, and were correlated with disease activity as determined by the Birmingham Vasculitis Activity Score (BVAS).

RESULTS

Median levels of PR3 ANCA reacting with pro-rPR3 were higher during active (n = 32) than during inactive (n = 29) disease (P = 0.016). Reactivity with mature rPR3 was not significantly different (P = 0.71). Serial followup in individual patients also indicated better correlation of PR3 ANCA reactivity with pro-rPR3 than with mature rPR3.

CONCLUSION

PR3 ANCA subsets reactive with epitopes accessible on pro-PR3 correlate better with disease activity than do subsets reactive with epitopes accessible only on mature PR3. This observation may explain why ANCA levels determined with current standard methods are suboptimal for monitoring disease activity. It raises new questions about the primary target of the PR3 ANCA immune response in patients with small vessel vasculitis.

Congenitally missing maxillary lateral incisors and orthodontic treatment considerations for the single-tooth implant

Implant restorations have become a primary treatment option for the replacement of congenitally missing lateral incisors. The central incisor and canine often erupt in less than optimal positions adjacent to the edentulous lateral incisor space, and therefore preprosthetic orthodontic treatment is frequently required. Derotation of the central incisor and canine, space closure and correction of root proximities may be required to create appropriate space in which to place the implant and achieve an esthetic restoration. This paper discusses aspects of preprosthetic orthodontic diagnosis and treatment that need to be considered with implant restorations.

Video-imaging assessment of nasal morphology in individuals with complete unilateral cleft lip and palate

OBJECTIVE

The purpose of this study was to develop a video-imaging mathematical method to assess nostril morphology.

DESIGN

This retrospective study involved two age-matched groups: 28 subjects with complete unilateral cleft lip and palate (CUCLP) and 19 noncleft controls. Nose casts were reproducibly oriented in a jig such that the casts could be rotated about the coronal axis. Video images of the nostrils were captured and then analyzed for area, perimeter, centroid, principal axis, moments about the major and minor axes (I11, I22), anisometry, bulkiness, lateral offset, internostril angle, and rotational angle.

RESULTS

All parameters identified nostril asymmetry in both groups. The results of the analyses using anisometry, I11, and I22 showed that, in both groups, one nostril was rounder and one was more elliptical. This asymmetry, however, differed between the two groups, and the difference was primarily based on the degree of ellipticity of the nostrils. Maximum dimension, perimeter, lateral offset, I11, and I22 were more asymmetric in the cleft group. In the control group, the right nostril was more elliptical and had a greater perimeter, and the left-side nostril had a greater bulkiness (enfolding).

CONCLUSIONS

The method developed was validated for assessment of nasal morphology in cleft and noncleft samples. Nostril morphology was asymmetric in both groups but more asymmetric in the cleft group than the control group. The dominant influence of the cleft resulted in more elliptical noncleft nostrils and greater nostril shape asymmetry in the cleft group. The validated video-imaging method can now be used to assess the efficacy of treatment on nasal morphology.

A review of impacted permanent maxillary cuspids--diagnosis and prevention

As impacted permanent maxillary cuspids occur in 1-2% of the population, the general dentist should know the signs and symptoms of this condition and the interceptive treatment. Features of buccal or palatal cuspid impaction include lack of canine bulges in the buccal sulcus indicating a lingual eruption path and possible impaction; lack of symmetry between the exfoliation and eruption of cuspids that may indicate palatal or lingual impaction; and abnormal mesiodistal location and angulation of the developing maxillary permanent cuspids on radiographs. Diagnosis of impacted cuspid teeth at age 8-10 years can significantly reduce serious ramifications, including surgical exposure and orthodontic alignment as well as root resorption of the lateral incisors. In specific cases, extraction of the primary maxillary cuspids can prevent impaction of the permanent maxillary cuspids and additional sequelae.

Validating an uncoupled laser-aiming device for serial implant radiography

Precision of bone level measurements adjacent to implants in longitudinal studies is, in part, dependent on the accurate reproduction of the relationships of the central x-ray beam, object, and film. The purpose of this study was to test the precision of a prototype aiming device consisting of three laser pointers symmetrically mounted on an x-ray cone, a ring supporting three mirrors aligned to reflect the laser light onto a grid on the x-ray head, and a custom film holder to align the film with the implant and the mirrors. Multiple regression analysis revealed a very high correlation between the angular change of the central ray and the position of the reflected light beam (R2 = 0.999, sig. < 0.001). Precision of the aiming device was determined from measurements made on digitized serial radiographs, exposed by two operators, of three dental implants in dried mandibles. The interthread distances and thread widths on each radiograph were measured using the NIH Image program. Chi-square tests demonstrated that the clinical use of the aiming device was independent of the operators and clinically applicable in all areas of the jaw. These tests also revealed that the significant errors found were directly related to the measurement of the thread width. This indicates a measurement technique problem rather than a deficiency with the aiming device. Additionally, none of the errors was greater than 0.032 mm, which is less than the accepted standard of 0.2 mm annual bone loss, and therefore should not be clinically significant. These results support the feasibility of using a three-beam reflected-light aiming device for precision of x-ray geometry in serial studies.

Gorlin-Goltz: what's in a name?

This paper describes the clinical features of two very distinct syndromes with similar names: Gorlin-Goltz and Goltz-Gorlin Syndromes. A case report is presented that highlights the differences between these syndromes. To avoid errors in diagnosis because of the similarity in names, the authors caution that, based on additional information now available, the preferred names should be Focal Dermal Hypoplasia syndrome for Goltz-Gorlin syndrome and Nevoid Basal Cell Carcinoma syndrome for Gorlin-Goltz syndrome.

Peroxisomal targeting, import, and assembly of alcohol oxidase in Pichia pastoris

Alcohol oxidase (AOX), the first enzyme in the yeast methanol utilization pathway is a homooctameric peroxisomal matrix protein. In peroxisome biogenesis-defective (pex) mutants of the yeast Pichia pastoris, AOX fails to assemble into active octamers and instead forms inactive cytoplasmic aggregates. The apparent inability of AOX to assemble in the cytoplasm contrasts with other peroxisomal proteins that are able to oligomerize before import. To further investigate the import of AOX, we first identified its peroxisomal targeting signal (PTS). We found that sequences essential for targeting AOX are primarily located within the four COOH-terminal amino acids of the protein leucine-alanine-arginine-phenylalanine COOH (LARF). To examine whether AOX can oligomerize before import, we coexpressed AOX without its PTS along with wild-type AOX and determined whether the mutant AOX could be coimported into peroxisomes. To identify the mutant form of AOX, the COOH-terminal LARF sequence of the protein was replaced with a hemagglutinin epitope tag (AOX-HA). Coexpression of AOX-HA with wild-type AOX (AOX-WT) did not result in an increase in the proportion of AOX-HA present in octameric active AOX, suggesting that newly synthesized AOX-HA cannot oligomerize with AOX-WT in the cytoplasm. Thus, AOX cannot initiate oligomerization in the cytoplasm, but must first be targeted to the organelle before assembly begins.

Characterization of the molecular defect in a null allele of the opaque-2 locus of maize

The molecular defect in an opaque-2 (o2) mutant, previously characterized as a null allele, has been identified as containing an insertion of the transposable element of the Bergamo (Bg) family. Restriction mapping and partial sequence analysis of the Bg in the o2 null allele indicates that this element is distinct from the previously described Bg as well as the defective Bg (rbg) of the o2m(r) allele. It is, however, inserted at the same site in O2 as the rbg of o2m(r) and can transpose when Bg is present. This study shows that, depending on genetic background, this allele may not behave as a stable null which could dramatically influence the conclusions drawn from experiments based on this particular mutant.

Orthodontic treatment in the mixed dentition

In the mixed dentition, the goal of orthodontic treatment is to maintain or improve arch integrity for the eruption of the permanent teeth, and to prevent the development of a more complicated malocclusion. The importance of correct diagnosis prior to the treatment of mixed-dentition patients cannot be over emphasized. An understanding of the mixed dentition's normal development allows clinicians to determine if the occlusion is developing outside of the normal range. Appropriate treatment can only be planned after this determination has been made. Once it is concluded that orthodontic treatment is required, decisions must be made regarding the timing of treatment, the specific type of treatment needed, and the provider of treatment. By employing a systematic approach to examination and treatment planning, the general dental practitioner can provide an important service to patients with a mixed dentition.

PER3, a gene required for peroxisome biogenesis in Pichia pastoris, encodes a peroxisomal membrane protein involved in protein import

PER genes are essential for the biogenesis of peroxisomes in the yeast Pichia pastoris. Here we describe the cloning of PER3 and functional characterization of its product Per3p. The PER3 sequence predicts that Per3p is a 713-amino acid (81-kDa) hydrophobic protein with at least three potential membrane-spanning domains. We show that Per3p is a membrane protein of the peroxisome. Methanol- or oleate-induced cells of per3-1, a mutant strain generated by chemical mutagenesis, lack normal peroxisomes but contain numerous abnormal vesicular structures. The vesicles contain thiolase, a PTS2 protein, but only a small portion of several other peroxisomal enzymes, including heterologously expressed luciferase, a PTS1 protein. These results suggest that the vesicles in per3-1 cells are peroxisomal remnants similar to those observed in cells of patients with the peroxisomal disorder Zellweger syndrome, and that the mutant is deficient in PTS1 but not PTS2 import. In a strain in which most of PER3 was deleted, peroxisomes as well as peroxisomal remnants appeared to be completely absent, and both PTS1- and PTS2-containing enzymes were located in the cytosol. We propose that Per3p is an essential component of the machinery required for import of all peroxisomal matrix proteins and is composed of independent domains involved in the import of specific PTS groups.

Satisfaction of recent University of British Columbia dietetics graduates with undergraduate education and current job

This study was designed to investigate the career status of recent University of British Columbia (UBC) dietetics graduates and their satisfaction with undergraduate education and current job. All graduates from the UBC Dietetics Program between 1978-1987, inclusive (n = 238), were mailed questionnaires. Information was sought regarding success in obtaining a dietetic internship, current employment status, job satisfaction, and satisfaction with undergraduate education. Questionnaires were returned by 67% (n = 130) of those who received them. Approximately 83% were eventually successful in obtaining an internship. Most respondents (68.5%) were employed as dietitian/nutritionists, and 69% of those who were employed worked full-time. Those who interned had significantly higher salaries than those who did not. A measure of overall job satisfaction revealed that 89.6% were satisfied to very satisfied with their present job, and scores on the Brayfield-Rothe Index of Job Satisfaction revealed no differences between those who did and did not intern. With regard to undergraduate education, respondents were most satisfied with library resources, class size and quality of teaching, and least satisfied with internship opportunities. Those who had interned were significantly more satisfied with their undergraduate education than were those who had not. We conclude that success in obtaining a dietetic internship affects salary and satisfaction with undergraduate education, but does not affect job satisfaction.

Pericentric inversion of chromosome 16 in a large kindred: spectrum of morbidity and mortality in offspring

Constitutional pericentric inversions of chromosome 16 are rare in the general population. We report here a large kindred who carry an inv(16)(p13q22) rearrangement. In general, individuals with the inv(16) are in good health but prone to reproductive loss. Two different types of recombinant offspring were identified in this family and analyzed at the molecular level using probes from the alpha-globin and polycystic kidney disease loci. Both were associated with serious major malformations.

The effects of tricaine methanesulfonate (MS-222) on plasma nonesterified fatty acids in rainbow trout, Oncorhynchus mykiss

The effects of tricaine methanesulfonate (MS-222), a commonly used fish anesthetic, on plasma nonesterified fatty acid levels (NEFA) were examined in rainbow trout, Oncorhynchus mykiss. Total NEFA levels declined with increasing duration of exposure to MS-222. Most of the decline in total NEFA was due to decreases in saturated fatty acids (14:0, 16:0 and 18:0). The fatty acid displaying the most rapid response to exposure to MS-222 was 20:5n-3. The lower plasma NEFA levels in anesthetized fish may be explained by depressed lipolysis in the presence of the anesthetic.