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1.
J Laryngol Otol ; : 1-8, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38644734

ABSTRACT

OBJECTIVE: Evidence for necrotising otitis externa (NOE) diagnosis and management is limited, and outcome reporting is heterogeneous. International best practice guidelines were used to develop consensus diagnostic criteria and a core outcome set (COS). METHODS: The study was pre-registered on the Core Outcome Measures in Effectiveness Trials (COMET) database. Systematic literature review identified candidate items. Patient-centred items were identified via a qualitative study. Items and their definitions were refined by multidisciplinary stakeholders in a two-round Delphi exercise and subsequent consensus meeting. RESULTS: The final COS incorporates 36 items within 12 themes: Signs and symptoms; Pain; Advanced Disease Indicators; Complications; Survival; Antibiotic regimes and side effects; Patient comorbidities; Non-antibiotic treatments; Patient compliance; Duration and cessation of treatment; Relapse and readmission; Multidisciplinary team management.Consensus diagnostic criteria include 12 items within 6 themes: Signs and symptoms (oedema, otorrhoea, granulation); Pain (otalgia, nocturnal otalgia); Investigations (microbiology [does not have to be positive], histology [malignancy excluded], positive CT and MRI); Persistent symptoms despite local and/or systemic treatment for at least two weeks; At least one risk factor for impaired immune response; Indicators of advanced disease (not obligatory but mut be reported when present at diagnosis). Stakeholders were unanimous that there is no role for secondary, graded, or optional diagnostic items. The consensus meeting identified themes for future research. CONCLUSION: The adoption of consensus-defined diagnostic criteria and COS facilitates standardised research reporting and robust data synthesis. Inclusion of patient and professional perspectives ensures best practice stakeholder engagement.

2.
J Biol Educ ; 58(1): 202-208, 2024.
Article in English | MEDLINE | ID: mdl-38426212

ABSTRACT

Live cell imaging is a standard technique in experimental biology that enables the observation of isolated cells and tissue slices in real time; and the testing of cellular responses to changes in buffer composition. However, most live cell imaging devices require the use of dedicated microscopes and/or specialized stage adaptors, and come at a reasonably high cost. We employed 3D printing technology to create a low-cost imaging chamber with side ports to exchange fluids, to be used on upright microscopes. The chamber increased the functionality of a standard upright epifluorescent microscope to allow dynamic, real-time calcium imaging of cultured hypothalamic astrocytes from mice, and to test the effects of ATP stimulation upon calcium signaling. It was also used on slices obtained from mouse brain using a brain matrix slicer. The advantages of this chamber include a very simple design that can be used with upright epifluorescence microscopes, does not require any special stage adaptor, and includes ports to permit fluid exchange during imaging. This chamber is ideal for educational settings with undergraduate laboratories that do not have access to dedicated inverted fluorescent microscopes for tissue culture experiments.

3.
Proc Natl Acad Sci U S A ; 120(4): e2209472120, 2023 01 24.
Article in English | MEDLINE | ID: mdl-36649426

ABSTRACT

Climate change is an indisputable threat to human health, especially for societies already confronted with rising social inequality, political and economic uncertainty, and a cascade of concurrent environmental challenges. Archaeological data about past climate and environment provide an important source of evidence about the potential challenges humans face and the long-term outcomes of alternative short-term adaptive strategies. Evidence from well-dated archaeological human skeletons and mummified remains speaks directly to patterns of human health over time through changing circumstances. Here, we describe variation in human epidemiological patterns in the context of past rapid climate change (RCC) events and other periods of past environmental change. Case studies confirm that human communities responded to environmental changes in diverse ways depending on historical, sociocultural, and biological contingencies. Certain factors, such as social inequality and disproportionate access to resources in large, complex societies may influence the probability of major sociopolitical disruptions and reorganizations-commonly known as "collapse." This survey of Holocene human-environmental relations demonstrates how flexibility, variation, and maintenance of Indigenous knowledge can be mitigating factors in the face of environmental challenges. Although contemporary climate change is more rapid and of greater magnitude than the RCC events and other environmental changes we discuss here, these lessons from the past provide clarity about potential priorities for equitable, sustainable development and the constraints of modernity we must address.


Subject(s)
Carcinoma, Renal Cell , Kidney Neoplasms , Humans , Climate Change , Sustainable Development , Probability
7.
Article in English | MEDLINE | ID: mdl-31866537

ABSTRACT

Immersing anemones in calcium-free seawater disorganizes hair bundle mechanoreceptors on tentacles of sea anemones while causing a loss of vibration sensitivity. Remarkably, anemone hair bundles recover after being returned to calcium-containing seawater. Reorganization of actin in stereocilia likely follows during the recovery of normal morphology of hair bundles after such immersion. Previous studies have reported that Rho G-proteins are located in the stereocilia of hair bundles in sea anemones where they participate in polymerizing actin in stereocilia upon activation of specific chemoreceptors. We here find that immersing anemones in calcium-free seawater significantly reduces the abundance of hair bundles. A partial recovery of abundance of hair bundles occurs within 3 h post-immersion, but a full recovery of abundance does not occur even 6 h after specimens are returned to calcium-containing seawater. Anemones recovering from immersion in calcium-free seawater feature hair bundles that are significantly wider at their tips than in controls. The hair bundles subsequently narrow at their tips, becoming comparable to those of untreated controls within 6 h. Stereocilia of hair bundles are significantly longer in experimental animals than in controls at 2 h of recovery before shortening to lengths comparable to untreated controls at 6 h. In the presence of Rho inhibitors, the recovery in abundance of hair bundles through 6 h is delayed or inhibited. Likewise, in the presence of Rho inhibitors, stereocilia fail to significantly elongate within 2 h of recovery. These data suggest that Rho G-proteins participate in the normal recovery of abundance and recovery of normal morphology of experimentally damaged hair bundle mechanoreceptors.


Subject(s)
Actins/metabolism , Calcium/metabolism , Chemoreceptor Cells/metabolism , Hair/physiology , Mechanoreceptors/metabolism , Sea Anemones/physiology , rho GTP-Binding Proteins/metabolism , Animals , Cilia/physiology , Hair/chemistry , rho GTP-Binding Proteins/genetics
8.
Biol Bull ; 235(2): 83-90, 2018 10.
Article in English | MEDLINE | ID: mdl-30358448

ABSTRACT

Certain species of sea anemone live in tightly packed communities, among clonemates and non-clonemates. Competition for space leads to intraspecific and interspecific aggressive interactions among anemones. The initial aggressive interactions appear to involve reciprocal discharge of cnidae triggered by contact with non-self feeding tentacles. We asked whether molecules contained in anemone-derived mucus constituted an important cue alone or in combination with cell surface molecules in stimulating aggressive or avoidance behaviors. In this study, we found that self and non-self stimuli differentially influenced two effector systems: cnida discharge and tentacle contraction. Interspecific mucus enhanced nematocyst discharge by 44% and spirocyst discharge by 90%, as compared to baseline discharge obtained in seawater alone. Conspecific stimuli accompanying touch inhibited specific tentacle contractions occurring on the far side of anemones relative to the site of contact. The greatest tentacle contractions occurred with exposure to interspecific mucus and tissue. Thus, several receptor systems are involved that integrate chemical and mechanical cues in order to initiate appropriate and graded effector responses during competition for space.


Subject(s)
Nematocyst/physiology , Sea Anemones/physiology , Aggression/physiology , Animals , Mucus/chemistry , Nematocyst/drug effects , Touch/physiology
9.
Article in English | MEDLINE | ID: mdl-28315771

ABSTRACT

Cytochalasin D (CD) was employed to disrupt F-actin within stereocilia of anemone hair bundles. CD treatment decreases the abundance of hair bundles (by 85%) while significantly impairing predation. The remaining hair bundles are 'CD-resistant.' Surprisingly, the morphology and F-actin content of resistant hair bundles are comparable to those of untreated controls. However, the resistant hair bundles fail to respond normally to the N-acetylated sugar, NANA, by elongating. Instead, they remain at resting length. Immediately after CD treatment, when only CD-resistant hair bundles are present, nematocyst discharge is normal into targets touched to tentacles in the absence of vibrations (i.e., baseline) but fails to increase normally in the presence of nearby vibrations at 56Hz, a key frequency. After CD treatment, the abundance of hair bundles recovers to control levels within three hours. At 2h after CD treatment, when CD-resistant and CD-sensitive hair bundles are both present, but a full-recovery is not yet complete, somewhat enhanced discharge of nematocysts occurs into targets touched to tentacles in the presence of nearby vibrations at 56Hz (at least as compared to the response of CD-treated animals to contact with test probes in the absence of vibrations). Additionally, at 2h after CD-treatment, prey capture recovers to normal. Thus, two populations of hair bundles may be present on tentacles of sea anemones: those that are CD-resistant and those that are CD-sensitive. The functions of these hair bundles may be distinct.


Subject(s)
Actins/drug effects , Hair/physiology , Predatory Behavior/drug effects , Sea Anemones/physiology , Actins/metabolism , Animals , Carbohydrate Metabolism/drug effects , Cytochalasin D/pharmacology , Hair/drug effects , N-Acetylneuraminic Acid/metabolism , Sea Anemones/metabolism , Vibration
10.
J Exp Biol ; 219(Pt 15): 2265-70, 2016 08 01.
Article in English | MEDLINE | ID: mdl-27489215

ABSTRACT

Mammalian hair cells possess only a limited ability to repair damage after trauma. In contrast, sea anemones show a marked capability to repair damaged hair bundles by means of secreted repair proteins (RPs). Previously, it was found that recovery of traumatized hair cells in blind cavefish was enhanced by anemone-derived RPs; therefore, the ability of anemone RPs to assist recovery of damaged hair cells in mammals was tested here. After a 1 h incubation in RP-enriched culture media, uptake of FM1-43 by experimentally traumatized murine cochlear hair cells was restored to levels comparable to those exhibited by healthy controls. In addition, RP-treated explants had significantly more normally structured hair bundles than time-matched traumatized control explants. Collectively, these results indicate that anemone-derived RPs assist in restoring normal function and structure of experimentally traumatized hair cells of the mouse cochlea.


Subject(s)
Hair Cells, Auditory, Outer/pathology , Proteins/pharmacology , Sea Anemones/chemistry , Animals , Culture Media/pharmacology , Hair Cells, Auditory, Outer/drug effects , Mice , Proteome/metabolism , Pyridinium Compounds/metabolism , Quaternary Ammonium Compounds/metabolism , Sequence Homology, Amino Acid
11.
Ear Nose Throat J ; 95(6): E12-6, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27304446

ABSTRACT

Vascular tumors arising in the temporal bone represent 0.7% of all lesions in this area. Hemangiomas confined to the tympanic membrane are exceptionally rare. We report a new case of tympanic membrane hemangioma that arose in 59-year-old man who presented with a 2-month history of constant right-sided pulsatile tinnitus and associated neck discomfort. The lesion and a cuff of healthy tympanic membrane were excised, and the resulting defect was repaired with a temporalis fascia graft. At 3 months, the neotympanum was well healed and the patient's symptoms had resolved. We also review the limited number of previously published cases of tympanic membrane hemangioma, and we discuss the presentation and management of these lesions. Some tympanic hemangiomas are asymptomatic and others present as hearing loss, tinnitus, otalgia, and/or otorrhea. Pure-tone audiometry and high-resolution computed tomography of the temporal bones are essential to determine the extent of the lesion. An excisional biopsy is recommended because it is curative and it provides histologic confirmation of the diagnosis. Excision requires elevation of a tympanomeatal flap, en bloc resection, and reconstruction of the tympanic membrane defect. Small lesions can be excised via a permeatal or endaural approach, while larger lesions require a postauricular approach.


Subject(s)
Ear Neoplasms/diagnostic imaging , Hemangioma/diagnostic imaging , Tympanic Membrane/diagnostic imaging , Ear Neoplasms/pathology , Ear Neoplasms/surgery , Hemangioma/pathology , Hemangioma/surgery , Humans , Male , Middle Aged , Otoscopy , Tomography, X-Ray Computed , Tympanic Membrane/pathology , Tympanic Membrane/surgery
12.
Otol Neurotol ; 36(10): 1601-3, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26496671

ABSTRACT

OBJECTIVE: The aim of this study is to determine if the cumulative summation test for the learning curve (LC-CUSUM) and the cumulative summation graph (CUSUM) can be used to demonstrate landmark points of competence and maintenance of proficiency in stapes surgery over a continuous time period. STUDY DESIGN: Retrospective review from January 1999 until August 2014. SETTING: Tertiary referral hospital. PATIENTS: All adult patients with confirmed otosclerosis. INTERVENTION(S): Two-hundred and four primary and revision stapedotomy. MAIN OUTCOME MEASURE(S): Learning curves were constructed using the CUSUM and LC-CUSUM. Failure was defined as closure of the ABG >10 dB in less than 10% of patients to demonstrate the landmark point of competency and to highlight any fluctuations over a prolonged period. RESULTS: When the failure rate was defined as closure of the ABG >10 dB, it was not possible to create useful LC-CUSUM and CUSUM graphs, but by redefining the failure rate as > 15 dB, competency was reached at case 43 and maintained with natural fluctuations occurring between cases 137 and 149 and again at case 196. CONCLUSIONS: LC-CUSUM and CUSUM are a more robust analytical method of illustrating the learning curve and suggest that the traditional benchmark of closure of the ABG ≤10 dB in more than 90% of patients may need reconsideration. It can also be used as standardized audit tools when monitoring results and used to plan future training programs as they clearly define a point when novice trainees become competent.


Subject(s)
Clinical Competence/statistics & numerical data , Learning Curve , Otosclerosis/surgery , Stapes Surgery/methods , Adult , Clinical Competence/standards , Female , Humans , Male , Middle Aged , Reoperation , Retrospective Studies , Stapes Surgery/standards
13.
Hear Res ; 327: 245-56, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26183436

ABSTRACT

Sea anemones have an extraordinary capability to repair damaged hair bundles, even after severe trauma. A group of secreted proteins, named repair proteins (RPs), found in mucus covering sea anemones significantly assists the repair of damaged hair bundle mechanoreceptors both in the sea anemone Haliplanella luciae and the blind cavefish Astyanax hubbsi. The polypeptide constituents of RPs must be identified in order to gain insight into the molecular mechanisms by which repair of hair bundles is accomplished. In this study, several polypeptides of RPs were isolated from mucus using blue native PAGE and then sequenced using LC-MS/MS. Thirty-seven known polypeptides were identified, including Hsp70s, as well as many polypeptide subunits of the 20S proteasome. Other identified polypeptides included those involved in cellular stress responses, protein folding, and protein degradation. Specific inhibitors of Hsp70s and the 20S proteasome were employed in experiments to test their involvement in hair bundle repair. The results of those experiments suggested that repair requires biologically active Hsp70s and 20S proteasomes. A model is proposed that considers the function of extracellular Hsp70s and 20S proteasomes in the repair of damaged hair cells.


Subject(s)
Hair Cells, Auditory/metabolism , Proteins/metabolism , Proteomics , Sea Anemones/metabolism , Animals , Chromatography, Liquid , HSP70 Heat-Shock Proteins/metabolism , Hair Cells, Auditory/pathology , Proteasome Endopeptidase Complex/metabolism , Proteomics/methods , Tandem Mass Spectrometry
14.
Ecol Appl ; 25(8): 2240-54, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26910952

ABSTRACT

Emissions from smelting not only contaminate water and soil with metals, but also induce extensive forest dieback and changes in resource availability and microclimate. The relative effects of such co-occurring stressors are often unknown, but this information is imperative in developing targeted restoration strategies. We assessed the role and relative effects of structural alterations of terrestrial habitat and metal pollution caused by century-long smelting operations on amphibian and reptile communities by collecting environmental and time- and area-standardized multivariate abundance data along three spatially replicated impact gradients. Overall, species richness, diversity, and abundance declined progressively with increasing levels of metals (As, Cu, and Ni) and soil temperature (T(s)) and decreasing canopy cover, amount of coarse woody debris (CWD), and relative humidity (RH). The composite habitat variable (which included canopy cover, CWD, T(s), and RH) was more strongly associated with most response metrics than the composite metal variable (As, Cu, and Ni), and canopy cover alone explained 19-74% of the variance. Moreover, species that use terrestrial habitat for specific behaviors (e.g., hibernation, dispersal), especially forest-dependent species, were more severely affected than largely aquatic species. These results suggest that structural alterations of terrestrial habitat and concomitant changes in the resource availability and microclimate have stronger effects than metal pollution per se. Furthermore, much of the variation in response metrics was explained by the joint action of several environmental variables, implying synergistic effects (e.g., exacerbation of metal toxicity by elevated temperatures in sites with reduced canopy cover). We thus argue that the restoration of terrestrial habitat conditions is a key to successful recovery of herpetofauna communities in smelting-altered landscapes.


Subject(s)
Amphibians/physiology , Ecosystem , Environmental Pollutants/toxicity , Metals/toxicity , Mining , Reptiles/physiology , Animals , Environmental Monitoring , Environmental Restoration and Remediation , Ontario , Population Dynamics
15.
PLoS One ; 9(1): e86084, 2014.
Article in English | MEDLINE | ID: mdl-24465885

ABSTRACT

Cadherin 23 (CDH23), a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1) the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2) the interaction is crucial for normal mechanotransduction and morphology of hair bundles.


Subject(s)
Cadherins/metabolism , Hair Cells, Auditory, Inner/metabolism , Sea Anemones/metabolism , Actins/metabolism , Animals , Cadherins/chemistry , Hair Cells, Auditory, Inner/pathology , Hair Cells, Auditory, Inner/physiology , Immunohistochemistry , Mechanotransduction, Cellular , Nematocyst , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Protein Binding , Sea Anemones/physiology , Stereocilia/metabolism
16.
Ear Nose Throat J ; 92(12): E20-2, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24366710

ABSTRACT

We present the case of a 33-year-old man who was admitted with intermittent ataxia, vertigo, and sensorineural hearing loss as a result of a vertebral artery dissection following minor neck trauma. Our aim is to highlight the importance of obtaining magnetic resonance imaging, magnetic resonance angiography, and/or duplex color-flow imaging when presented with a case of fluctuating vertigo and sensorineural hearing loss with side-specific ataxia. Likewise, it is important to obtain the input of neurologists to optimize a patient's prognosis and minimize long-term sequelae.


Subject(s)
Vertebral Artery Dissection/complications , Vertebral Artery Dissection/diagnosis , Adult , Cerebellar Ataxia/etiology , Hearing Loss, Sensorineural/etiology , Humans , Magnetic Resonance Angiography , Male , Ultrasonography, Doppler, Color , Vertebral Artery Dissection/drug therapy , Vertigo/etiology
17.
Article in English | MEDLINE | ID: mdl-23474255

ABSTRACT

Adjustable hair bundle mechanoreceptors located on anemone tentacles detect movements of nearby, swimming prey. The hair bundles are formed by numerous actin-based stereocilia that converge onto a single, central kinocilium. Interestingly, morphological and functional changes to the hair bundles are induced by activating chemoreceptors that bind prey-derived N-acetylated sugars and proline, respectively. Morphological changes to the hair bundles involve alterations to the actin cytoskeleton of stereocilia. A pharmacological activation of Rho induces hair bundles to elongate to lengths comparable to those normally induced by exposure to N-acetylneuraminic acid (NANA) and prevents shortening of hair bundles normally induced by proline. Rho inhibition prevents NANA-induced elongation, but does not prevent proline-induced shortening of hair bundles. Western blots feature a band similar in mass to that predicted for a Rho homolog in the genome of Nematostella. Immunocytochemistry localizes Rho in stereocilia of the hair bundle. Anemone hair bundles arise from multicellular complexes. Data from experiments using heptanol, a gap junction uncoupler, indicate that cell-cell communication is required in order for activated chemoreceptors to induce morphological changes to the hair bundles.


Subject(s)
Chemoreceptor Cells/physiology , Mechanoreceptors/physiology , Sea Anemones/physiology , rho GTP-Binding Proteins/metabolism , Actin Cytoskeleton/metabolism , Amino Acid Sequence , Animals , Blotting, Western , Calcimycin/pharmacology , Calcium Ionophores/pharmacology , Cell Communication/drug effects , Cell Communication/physiology , Chemoreceptor Cells/drug effects , Chemoreceptor Cells/metabolism , Epidermal Cells , Epidermis/metabolism , Gap Junctions/drug effects , Gap Junctions/metabolism , Gap Junctions/physiology , Heptanol/pharmacology , Immunohistochemistry , Mechanoreceptors/cytology , Mechanoreceptors/metabolism , Models, Biological , Molecular Sequence Data , N-Acetylneuraminic Acid/pharmacology , Sea Anemones/cytology , Sea Anemones/metabolism , Signal Transduction/drug effects , rho GTP-Binding Proteins/genetics
18.
Biol Open ; 1(6): 582-7, 2012 Jun 15.
Article in English | MEDLINE | ID: mdl-23213451

ABSTRACT

Sea anemones discharge cnidae ('stinging capsules' including nematocysts) to capture prey and to defend themselves. In the present study, we tested the relationship between the force of test probes striking feeding tentacles and discharge of microbasic p-mastigophore nematocysts into the test probes. In seawater alone, the response curve is bimodal with maximal discharge observed at 0.33 and 1.10 millinewtons (mN) and with minimal discharge at 1.50 mN. Upon activating chemoreceptors for N-acetylated sugars, maximal discharge is observed across a broad range of smaller forces from 0.16 to 0.9 mN before decreasing to a minimum at 1.50 mN. Likewise, in the presence of nearby vibrations at key frequencies, maximal discharge is observed over a broad range of smaller forces before decreasing to a minimum at 1.50 mN. It appears that sensory input indicating proximity of potential prey expands the range of small forces of impact that stimulate maximal discharge (i.e. to less than 1.10 mN) but not at larger forces of impact (i.e. at approximately 1.50 mN). Thus, contact by small prey would stimulate maximal discharge, and all the more so if such contact is accompanied by specific odorants or by vibrations at specific frequencies. Nevertheless, anemones would not maximally discharge nematocysts into large animals that blunder into contact with their tentacles.

19.
PLoS One ; 7(2): e29727, 2012.
Article in English | MEDLINE | ID: mdl-22359538

ABSTRACT

The lateral line sensory system, found in fish and amphibians, is used in prey detection, predator avoidance and schooling behavior. This system includes cell clusters, called superficial neuromasts, located on the surface of head and trunk of developing larvae. Mechanosensory hair cells in the center of each neuromast respond to disturbances in the water and convey information to the brain via the lateral line ganglia. The convenient location of mechanosensory hair cells on the body surface has made the lateral line a valuable system in which to study hair cell damage and regeneration. One way to measure hair cell survival and recovery is to assay behaviors that depend on their function. We built a system in which orientation against constant water flow, positive rheotaxis, can be quantitatively assessed. We found that zebrafish larvae perform positive rheotaxis and that, similar to adult fish, larvae use both visual and lateral line input to perform this behavior. Disruption or damage of hair cells in the absence of vision leads to a marked decrease in rheotaxis that recovers upon hair cell repair or regeneration.


Subject(s)
Locomotion/physiology , Mechanotransduction, Cellular , Animals , Behavior, Animal , Cell Movement , Larva , Lateral Line System , Rheology , Zebrafish
20.
Popul Trends ; (143): 6-9, 2011.
Article in English | MEDLINE | ID: mdl-21464827
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