Helminth community structure in two species of arctic-breeding waterfowl.

Climate change is occurring rapidly at high latitudes, and subsequent changes in parasite communities may have implications for hosts including wildlife and humans. Waterfowl, in particular, harbor numerous parasites and may facilitate parasite movement across broad geographic areas due to migratory movements. However, little is known about helminth community structure of waterfowl at northern latitudes. We investigated the helminth communities of two avian herbivores that breed at high latitudes, Pacific black brant (Branta bernicla nigricans), and greater white-fronted geese (Anser albifrons), to examine effects of species, geographic area, age, and sex on helminth species richness, aggregation, prevalence, and intensity. We collected 83 and 58 black brant and white-fronted geese, respectively, from Arctic and Subarctic Alaska July-August 2014. We identified 10 known helminth species (Amidostomum anseris, Amidostomum spatulatum, Drepanidotaenia lanceolata, Epomidiostomum crami, Heterakis dispar, Notocotylus attenuatus, Tetrameres striata, Trichostrongylus tenuis, Tschertkovilepis setigera, and Wardoides nyrocae) and 1 previously undescribed trematode. All geese sampled were infected with at least one helminth species. All helminth species identified were present in both age classes and species, providing evidence of transmission at high latitudes and suggesting broad host susceptibility. Also, all but one helminth species were present at both sites, suggesting conditions are suitable for transmission across a large latitudinal/environmental gradient. Our study provides important baseline information on avian parasites that can be used to evaluate the effects of a changing climate on host-parasite distributions.

Myosin heavy chain composition in normal and atrophic equine laryngeal muscle.

The myosin heavy chain (MHC) composition of a given muscle determines the contractile properties and, therefore, the fiber type distribution of the muscle. MHC isoform expression in the laryngeal muscle is modulated by neural input and function, and it represents the cellular level changes that occur with denervation and reinnervation of skeletal muscle. The objective of this study was to evaluate the pattern of MHC isoform expression in laryngeal muscle harvested from normal cadavers and cadavers with naturally occurring left laryngeal hemiplegia secondary to recurrent laryngeal neuropathy. Left and right thyroarytenoideus (TA) and cricoarytenoideus dorsalis (CAD) were obtained from 7 horses affected with left-sided intrinsic laryngeal muscle atrophy and from 2 normal horses. Frozen sections were evaluated histologically for degree of atrophy and fiber type composition. MHC isoform expression was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of muscle protein. Histologic atrophy was seen in all atrophic muscles and some right-sided muscles of 3 affected horses, as well as the left TA of 1 normal horse. Fiber type grouping or loss of type I muscle fibers was observed in the left-sided laryngeal muscles in all but 1 affected horse, as well as in the right muscles of 2 affected horses, and the left TA of 1 normal horse. SDS-PAGE showed 2 bands corresponding to the type I and type IIB myosin isoforms in the CAD and TA of the 2 normal horses. Affected horses demonstrated a trend toward increased expression of the type IIB isoform and decreased expression of the type I isoform in atrophic muscles. This study confirmed the presence of histologic abnormalities in grossly normal equine laryngeal muscle, and it demonstrated an increased expression of type IIB MHC with a concurrent decreased expression of type I MHC in affected muscles. Evaluation of muscle fiber changes at the cellular level under denervated and reinnervated conditions may aid in assessing future strategies for reinnervation or regeneration of atrophic laryngeal muscle.

Survivin expression in in situ and invasive breast cancer relates to COX-2 expression and DCIS recurrence.

In lung cancer cyclooxygenase-2 (COX-2) expression has been reported to stabilise survivin, an inhibitor of apoptosis (IAP) which prevents cell death by blocking activated caspases. COX-2 expression limits the ubiquitination of survivin, protecting it from degradation. To determine if COX-2 expression in breast cancer showed an association with survivin expression, we assessed the levels of each protein in ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC); relating expression patterns to recurrence of DCIS after surgery. Patterns of COX-2 and survivin expression were determined by intensity-graded immunohistochemistry of the primary tumours. Patients with DCIS (n=161) which had either recurred (n=47) or shown no evidence of recurrence (n=114) 5 years following primary surgery were studied. These were compared to 58 cases of IBC. Survivin was expressed in the cytoplasm of 59% of DCIS and 17% of IBC. High levels of both cytoplasmic survivin and COX-2 expression significantly correlated to DCIS recurrence. COX-2 expression was present in 72% of DCIS, and levels of expression positively correlated with cytoplasmic survivin expression in DCIS and invasive disease. The majority of DCIS that recurred expressed both proteins (69%) vs 39% nonrecurrent. Recurrence was not seen in DCIS lacking both proteins at 5 years (P=0.001). Expression of the IAP survivin is increased in DCIS and correlates closely with COX-2 expression. Increased expression of IAP, (leading to reduced apoptosis) may explain the effect of COX-2 in increasing recurrence of DCIS after surgical treatment.

Contaminants in molting long-tailed ducks and nesting common eiders in the Beaufort Sea.

In 2000, we collected blood from long-tailed ducks (Clangula hyemalis) and blood and eggs from common eiders (Somateria mollissima) at near-shore islands in the vicinity of Prudhoe Bay, Alaska, and at a reference area east of Prudhoe Bay. Blood was analyzed for trace elements and egg contents were analyzed for trace elements, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Except for Se (mean=36.1 microg/g dry weight (dw) in common eiders and 48.8 microg/g dw in long-tailed ducks), concentrations of trace elements in blood were low and, although several trace elements differed between areas, they were not consistently higher at one location. In long-tailed ducks, Se in blood was positively correlated with activities of two serum enzymes, suggestive of an adverse effect of increasing Se levels on the liver. Although common eiders had high Se concentrations in their blood, Se residues in eggs were low (mean=2.28 microg/g dw). Strontium and Ni were higher in eggs near Prudhoe Bay than at the reference area, but none of the other trace elements or organic contaminants in eggs differed between locations. Concentrations of Ca, Sr, Mg, and Ni differed among eggs having no visible development, early-stage embryos, or late-stage embryos. Residues of 4,4'-DDE, cis-nonachlor, dieldrin, hexachlorobenzene, oxychlordane, and trans-nonachlor were found in 100% of the common eider eggs, but at low concentrations (means of 2.35-7.45 microg/kg wet weight (ww)). The mean total PCB concentration in eggs was 15.12 microg/kg ww. Of PAHs tested for, residues of 1- and 2-methylnaphthalene and naphthalene were found in 100% of the eggs, at mean concentrations of 0.36-0.89 microg/kg ww.

c-Src and HSP72 interact in ATP-depleted renal epithelial cells.

Disruption of cell contact sites during ischemia contributes to the loss of organ function in acute renal failure. Because prior heat stress protects cell contact sites in ATP-depleted renal epithelial cells in vitro, we hypothesized that heat shock protein 72 (HSP72), the major inducible cytoprotectant in mammalian cells, interacts with protein kinases that regulate cell-cell and cell-matrix interactions. ATP depletion increased the content of Tyr(416) Src, the activated form of this kinase. c-Src activation was associated with an increase in the tyrosine phosphorylation state of beta-catenin, paxillin, and vinculin, three c-Src substrate proteins that localize to and regulate cell contact sites. Prior heat stress inhibited c-Src activation and decreased the degree of tyrosine phosphorylation of all three Src substrates during ATP depletion and/or early recovery. HSP72 coimmunoprecipitated with c-Src only in cells subjected to heat stress. ATP depletion markedly increased the interaction between HSP72 and c-Src, supporting the hypothesis that HSP72 regulates Src kinase activity. These results suggest that alterations in the tyrosine phosphorylation state of proteins located at the cell-cell and cell-matrix interface mediate, at least in part, the functional state of these structures during ATP depletion and may be modulated by interactions between HSP72 and c-Src.

Modulation of myosin heavy chains in rat laryngeal muscle.

OBJECTIVES: To test the hypothesis that myosin heavy chain (MHC) composition is a biological marker indicative of appropriate and functional reinnervation. STUDY DESIGN: Age-matched adult rats were randomized for prospective study under three experimental conditions. METHODS: In adult rats, three experimental conditions were surgically created, including transient recurrent laryngeal nerve (RLN) crush injury, RLN transection and repair, and cricoarytenoid joint fixation with intact RLN. Animals were survived for 30, 90, and 180 days. At each interval, vocal fold mobility was assessed by rigid microlaryngoscopy. Laryngeal electromyography (EMG) was performed before euthanasia. The thyroarytenoid and posterior cricoarytenoid muscles were then excised, each muscle was processed for sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and MHC composition was determined. RESULTS: Thirty days after nerve crush injury, three of six animals regained vocal fold mobility and normal MHC composition. Impaired vocal fold motion in three of six animals was associated with MHC composition characteristic of denervation. At 90 and 180 days, normal vocal fold motion and normal MHC composition were observed in all animals. Following nerve transection and repair, impaired vocal fold motion and MHC composition characteristic of denervation were observed in all animals, despite evidence of reinnervation on EMG. Following joint fixation, alteration in MHC composition consistent with denervation was observed only at 30 days, as was evident in the nerve crush model. CONCLUSION: Temporary injury and vocal fold immobilization result in transient shifts in MHC composition. Nerve transection and repair result in persistent alteration of MHC composition and vocal fold dysfunction. The expression of normal MHC composition is dependent on the condition of appropriate neural contact and functional reinnervation.

A graded work site intervention program to improve sun protection and skin cancer awareness in outdoor workers in Israel.

OBJECTIVES: A graded worksite intervention program to improve sun protection and skin cancer awareness of outdoor workers was implemented and evaluated longitudinally over a period of 20 months. METHODS: Outdoor male workers (144/213 recruits) from geographically separated units of the Israel National Water Company were allocated to complete (n = 37), partial (n = 72) or minimal (n = 35) intervention groups. Subsequent to the assignment and training of local safety officers, an educational and medical screening package was provided to the corresponding groups either once, or repeatedly a year later. Personal sun protective gear was provided upon repeated intervention. Outcome measures were evaluated through self-response questionnaires administered prior to the first intervention pulse, and 8 months after the first and second interventions. RESULTS: A 15-61% improvement in sun-protection habits was noted in the entire study population 8 months after initialization, compared to no sunscreen use, 20% sun-exposed skin area and highest mean occupational exposure dose of 1.68 MED/day at pre-test. An even greater use of sunscreen was evident 1 year later in the complete and partial intervention groups, + 80% and + 52%, respectively. The baseline rate of self-examination of the skin in the same two groups (49%) increased significantly at post-test (+ 71% and + 53%, respectively). CONCLUSIONS: This integrated intervention program led to significantly improved sun protection and skin cancer awareness. Repeated intervention combined with the supply of sun-protective gear contributed to an even greater impact.

Evaluation and management of bilateral vocal cord immobility.

Bilateral vocal cord immobility can be life threatening for some patients. Others, who have an open glottic chink, may have a breathy dysphonia, intermittent dyspnea, and stridor. These signs and symptoms may also be found in a number of other conditions that cause weakness or paradoxical motion of the vocal cords that mimics paralysis. These other conditions include central nervous system diseases, neuromuscular disorders, laryngospasm, and psychogenic disorders. In addition, patients with cricoarytenoid joint immobility or interarytenoid scar can also have similar symptoms at presentation. It is critical to consider the differential diagnosis of an assumed bilateral vocal cord paralysis and understand the management of paradoxical movement, weakness, joint fixation, interarytenoid scar, laryngospasm, and psychogenic disorders. The treatment for bilateral immobility should proceed only after a thorough evaluation, which might include electromyography and/or examination during general anesthesia under dense anesthetic paralysis. Reconstructive procedures are the treatments of choice, and destructive procedures should be chosen only as a last resort.

Minimally invasive device to effect vocal fold lateralization.

Despite many operative procedures focused on vocal fold lateralization, none has achieved an acceptable level of dependability. Bilateral vocal fold abductor paralysis is treated by arytenoidectomy, cordotomy, suture lateralization, or partial cordectomy. Tracheotomy remains the gold standard for maximizing the airway and preserving phonatory function. We have developed a device that is minimally invasive, tunable, and reversible, with the potential for lateralization or medialization of the vocal process. The device consists of a polyethylene collar, a Vitallium cam, and a double-helix core for engaging soft tissue. It is introduced through a circular opening in the thyroid cartilage by a modified thyroplasty approach. Both the first and second iterations of this device have been evaluated for clinical effectiveness in 9 sheep by means of photographic and video documentation. Effectiveness in humans is currently being assessed. The results of the animal study permit us to have substantial optimism with respect to the clinical application of this device.

Myosin heavy chain composition in human laryngeal muscles.

OBJECTIVES: Myosin heavy chain (MHC) composition of human thyroarytenoid (TA), lateral cricoarytenoid (LCA), interarytenoid (IA), vocalis, posterior cricoarytenoid (PCA), and cricothyroid muscles were examined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western bolt techniques. The presence of superfast MHC was also assessed using antibodies directed against the extraocular MHC. STUDY DESIGN: MHC protein was analyzed using fresh human laryngeal muscles. METHODS: Laryngeal muscles excised from cadavers were processed for SDS-PAGE. The composition of MHC isoforms was determined by densitometry. Western blot was carried out to identify specific bands. RESULTS: MHC types IIA and IIB are the predominant MHC components in human laryngeal muscles. The adductor muscles--TA, LCA, and IA--have a higher percentage of type IIB MHC and a lower percentage of type I when compared with the abductor--PCA. The rank file order for type IIB MHC composition (TA > LCA > or = IA > PCA) is the same in all specimens. A band migrating between type IIA and type I was observed in several specimens. Although similar to type IIL in rats, this atypical band did not react with anti-extraocular MHC antibody on Western blot. CONCLUSION: Characterization of laryngeal muscles determined by the composition of MHC is correlated with function and neural input. Human laryngeal muscle is characterized by a predominance of fast-type MHCs in laryngeal closing muscle and mixed fast-slow type MHCs in respiratory and phonatory muscle groups. Although an atypical myosin band similar to type IIL (superfast) MHC in rat was identified, it did not react with anti-extraocular MHC antibody.

Human insulinlike growth factor 1 gene transfer into paralyzed rat larynx: single vs multiple injection.

OBJECTIVE: To compare the biological effects of single vs multiple treatment of rat denervated laryngeal muscle with human insulinlike growth factor 1 (hIGF1) gene therapy. EXPERIMENTAL METHODS OR DESIGN: A muscle-specific nonviral vector containing the alpha-actin promoter and hIGF1 gene formulated with polyvinyl polymers was injected into denervated adult rat thyroarytenoid muscle. The effects on animals given a single injection (n = 16) vs those given multiple injections (n = 14) vs control groups (n = 18) were evaluated. Twenty-eight days after the first injection, gene expression, muscle fiber size, motor endplate length, and nerve-to-motor endplate contact were evaluated. RESULTS: Gene expression, detected by reverse transcriptase polymerase chain reaction for hIGF1 messenger RNA, occurred in 13 (81%) of 16 animals receiving single injections and 14 (100%) of 14 animals receiving multiple injections. Compared with controls, hIGF1-transfected animals in both single- and multiple-injection groups had a significant increase in the lesser diameter of muscle fiber, a significant decrease in motor endplate length, and a significant increase in the percentage of endplates with nerve contact (P <.05 for all). There was no statistical difference between single- and multiple-injection groups. CONCLUSIONS: Applied to laryngeal paralysis, hIGF1 gene therapy provides an opportunity to augment surgical treatment modalities by the prevention or reversal of muscle atrophy, and enhancement of nerve sprouting and muscle reinnervation. Although the percentage of denervated muscles demonstrating hIGF1 expression was increased following multiple injections, no difference was observed in the biological response compared with that in the single-injection treatment groups. Further investigation will be conducted to assess long-term benefits and physiological responses and to define the limitations of this potentially valuable therapeutic strategy.

Postnatal development of myosin heavy chain isoforms in rat laryngeal muscles.

The developmental transitions of myosin heavy chain (MHC) isoforms of rat posterior cricoarytenoid (PCA), thyroarytenoid (TA), cricothyroid (CT), and lateral cricoarytenoid (LCA) muscles were examined by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot techniques. The muscles were microscopically dissected from animals on postnatal days 0, 3, 7, 10, 14, 21, 28, 35, 45, and 55 and from adult animals. Silver-stained SDS-PAGE gels of each muscle were analyzed densitometrically to measure the composition of MHC isoforms, and Western blot was carried out to identify specific bands. Characterizations of the internal laryngeal muscles determined by the composition of MHCs were correlated with their function in the adult. Temporally, differentiation reflects onset of function. Differentiation of isoforms and transition to adult forms occur first in the TA muscle, followed by the PCA, LCA, and CT muscles. Expression of type IIL was observed only in muscles innervated by the recurrent laryngeal nerve. Postnatally observed developmental differences of myosin phenotypes suggest that regulation of MHC expression is influenced by neural activity or other environmental factors.

IGF-1 gene transfer into denervated rat laryngeal muscle.

OBJECTIVES: To demonstrate gene transfer in rat laryngeal muscle using a reporter gene, beta-galactosidase, and a muscle-specific expression system containing the human IGF-1 (hIGF-1) gene sequence and to investigate the myotrophic and neurotrophic effects of hIGF-1 gene transfer in denervated rat laryngeal muscle. METHODS: In 8 adult rats, a polyvinyl-based formulation containing beta-galactosidase DNA was injected into denervated thyroarytenoid muscle. Twelve animals were similarly administered a polyvinyl-based formulation containing a muscle-specific expression system and hIGF-1 DNA. Twelve animals were injected with isotonic sodium chloride solution, and all animals survived for 1 month. The production of beta-galactosidase and hIGF-1 was detected using immunohistochemical techniques. The effects of hIGF-1 on motor endplates and nerve sprouting were assessed using cholinesterase or silver staining and immunostaining for growth-associated protein (GAP-43). mals by immunostaining, X-gal histochemical staining, or both. In frozen section specimens, hIGF-1 immunoreactivity was positive in 3 of 8 animals. In sequential sections, GAP-43 was localized to areas of hIGF-1 expression in 2 of the 3 hIGF-1-positive specimens. Increased nerve sprouting and motor endplate contact occurred in 2 of 4 animals treated with hIGF-1. CONCLUSIONS: Gene transfer into laryngeal muscle was demonstrated using a polyvinyl-based formulation containing a muscle-specific gene expression system. Preliminary findings indicate a positive effect on motor endplates, nerve sprouting, and the expression of GAP-43 in animals treated with the hIGF-1 vector. This study establishes a foundation for investigating hIGF-1 gene transfer as a novel treatment of laryngeal paralysis. Further studies are necessary to quantify myotrophic and neurotrophic effects and to establish therapeutic benefit.

Cell adhesion molecules in normal laryngeal development.

Larynges taken from normally developing rats ranging from embryos starting at embryonic day 10 to adults were harvested. Sections of the larynges were prepared with the use of immunohistochemical techniques with primary antibodies directed to the neural cell adhesion molecule; selected sections were exposed to antibodies directed against the embryonic polysialated form of the neural cell adhesion molecule and against L1. Cell adhesion molecules were present throughout embryonic development associated with the recurrent laryngeal nerve. Downregulation of expression was observed after postnatal day 14. We conclude that cell adhesion molecules may play a role in the normal neural development of the larynx in rats.

Expression of extraocular-superfast-myosin heavy chain in rat laryngeal muscles.

Superfast myosin heavy chain (MHC), which is found in jaw-closing muscle and extraocular muscle (EOM), may also be found in rat laryngeal muscles. Immunostaining and Western blot using anti-EOM antibody were performed to identify and localize EOM MHC in laryngeal muscles. Specific reactivity of laryngeal IIL MHC was confirmed by Western blot and on immunostaining, all fibers in the lateral part of thyroarytenoid muscle reacted with EOM antibody. A scattered pattern of positive fibers was observed in the medial part of the thyroarytenoid, the posterior cricoarytenoid and the lateral cricoarytenoid muscles. EOM MHC was not detected in the cricothyroid muscle. The expression of EOM MHC in rat laryngeal muscle is consistent with the functional demands of the airway protection reflex.

Reinnervation of motor endplates and increased muscle fiber size after human insulin-like growth factor I gene transfer into the paralyzed larynx.

Current surgical strategies for the treatment of laryngeal paralysis are limited by the muscle atrophy associated with denervation. Moreover, attempts at reinnervation have not effected significant change in surgical outcome. To address this clinical problem, we have developed a rat laryngeal paralysis model to study novel gene transfer strategies. Using this model, the human insulin-like growth factor I (hIGF-I) gene was introduced into paralyzed rat laryngeal muscle to assess the benefit of sustained local hIGF-I production. A muscle-specific nonviral vector containing the alpha-actin promoter and hIGF-I gene was used in formulation with a polyvinyl-based delivery system and injected into paralyzed adult rat laryngeal muscle. Twenty-eight days after a single injection, gene transfer efficiency, muscle fiber size, motor endplate length, and nerve-to-motor endplate contact were evaluated. Gene transfer was detected in 100% of injected animals by PCR. Gene transfer with expression, as measured by RT-PCR for hIGF-I mRNA, occurred in 81.3 % of injected animals. When compared with controls, hIGF-I-transfected animals presented a significant increase in muscle fiber diameter [17.56 (+/-0.97 SD) microm versus 14.70 (+/-1.43 SD) microm; p = 0.0002], a significant decrease in motor endplate length [20.88 (+/-1.42 SD) microm versus 25.41 (+/-3.19 SD) microm; p = 0.0025], and a significant increase in percentage of endplates with nerve contact (20.3% (+/-13.9 SD) versus 4.4% (+/-4.2 SD); p = 0.0079). In the context of laryngeal paralysis, gene therapy represents a tremendous opportunity to augment current surgical treatment modalities by preventing or reversing muscle atrophy, and by enhancing nerve sprouting and reinnervation.

Myosin heavy chain composition in rat laryngeal muscles after denervation.

OBJECTIVES: The effects of denervation on myosin heavy chain (MHC) expression in specific laryngeal muscles are characterized using gel electrophoresis. Observed temporal changes in MHC composition will then be used as a biologic marker in studies designed to develop strategies for laryngeal reinnervation and gene therapy. STUDY DESIGN: Animal study using an adult rat model for laryngeal paralysis. METHODS: In anesthetized rats the left recurrent and superior laryngeal nerve were divided. Animals were survived for 7, 14, 28, 90, and 180 days. Animals were euthanized and the thyroarytenoid (TA), vocalis (VOC), posterior cricoarytenoid (PCA), lateral cricoarytenoid (LCA), and cricothyroid (CT) muscle excised. Each muscle was processed for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and densitometric measurements were obtained to determine composition of MHC fiber types. RESULTS: The changes in relative MHC composition are described for each specific laryngeal muscle. In general, a decrease in type IIB and an increase in IIA and IIX are seen after denervation. Expression of IIL in the denervated condition is variable and the relative change in type I is minimal. CONCLUSION: This study supports previous work using rat soleus muscle in which IIA/IIX expression is favored in conditions with decreased neuromuscular activity, and conversely, IIB expression is activity dependent. Expression of type I appears to be independent of neural activity. Further study will be undertaken to quantify expression of MHC components and to study factors modulating expression.

Squamous cell carcinoma of the tongue associated with cinnamon gum use: a case report.

BACKGROUND: Cinnamon aldehydes found in cinnamon-flavored gums can incite mucosal alterations at points of contact with the oral mucosa. These alterations may include inflammation and epithelial proliferation, but as a rule, the changes are reversible and promptly resolve when gum-chewing activity is discontinued. METHODS: The authors report a case of a 24-year-old woman who developed a squamous cell carcinoma of the tongue following persistent and prolonged exposure to cinnamon-flavored gum. RESULTS: Several social, clinical, and histopathologic features point to the cinnamon-flavored chewing gum as a possible causal factor in the development of the patient's oral carcinoma. CONCLUSIONS: Prompt withdrawal of cinnamon products is encouraged in heavy gum chewers who develop cinnamon-related oral lesions. For those lesions which do not promptly resolve upon cinnamon withdrawal, diagnostic biopsy should be considered to exclude the possibility of a squamous cell carcinoma.