Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 48
Filter
1.
Occup Ther Health Care ; : 1-16, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38557162

ABSTRACT

Following a lecture on sexual health and function, occupational therapy students were surveyed regarding their past sex education and their comfort level with the topic of sex. Students indicated a lack of sexual education received from parents/guardians and a prevalence of fear-based education from formal or informal sources. Results reflected a significant increase in students' perceived comfort level with the topic following the lecture from a provider trained and certified in sexual health. As sexuality falls within the domain of occupational therapy, these results suggest a need for comprehensive sex education taught to students by qualified instructors.

2.
OTO Open ; 7(4): e97, 2023.
Article in English | MEDLINE | ID: mdl-38020046

ABSTRACT

Objective: We measured utilization of clinician-performed head and neck ultrasound among otolaryngologists, endocrinologists, and general surgeons, using Medicare Provider Utilization and Payment Data. Study Design: Retrospective analysis of Medicare billing database. Setting: University. Methods: For each year, the files were filtered to include 4 provider types: Diagnostic Radiology (DR), Endocrinology (ENDO), General Surgery (GS), and Otolaryngology (OTO). Billable procedures are listed by Healthcare Common Procedure Coding System code and a filter was applied to include 76536 Ultrasound, soft tissues of the head and neck. Results: In 2019, OTOs submitted charges for 2.1% of all head and neck diagnostic ultrasounds (76536) performed on Medicare beneficiaries. For each year 2012 to 2019, DRs submitted the most charges, followed by ENDOs, and then OTO and GS. Charges for all groups increased in a proportional manner across the 8-year period. 14.5% of OTOs submitted more than 100 charges apiece during 2019, that is, "super users." The percentage of super users within each specialty increased from 2012 to 2019. Overall, the data support an ever-increasing use of head and neck ultrasound (HNUS) among all provider types. Conclusion: Even with increased use among OTOs, this specialty only accounted for a small percentage of head & neck diagnostic ultrasounds performed on Medicare beneficiaries in 2019. Changes in volume of nonradiology point-of-care HNUS was not associated with changes in DR volume. A greater proportion of OTOs than DRs are "super users" among the ultrasound users within their specialty, performing more than 100 exams/year. Level of Evidence: V.

3.
Curr Biol ; 32(22): 4914-4924.e4, 2022 11 21.
Article in English | MEDLINE | ID: mdl-36261035

ABSTRACT

The role of the gustatory region of the insular cortex in mediating associative taste learning, such as conditioned taste aversion, has been well studied. However, while associative learning plays a role in some taste behaviors, such as avoiding toxins, animals often encounter taste stimuli in their natural environment without explicit consequences. This type of inconsequential experience with sensory stimuli has been studied in other sensory systems, generally with the finding that neuronal responses habituate with repeated sensory exposure. This study sought to determine the effect of taste familiarity on population taste coding in the mouse gustatory cortex (GC). Using microendoscope calcium imaging, we studied the taste responses of visually identifiable neurons over 5 days of taste experience, during which animals could freely choose to consume taste stimuli. We found that the number of active cells in the insular cortex, as well as the number of cells characterized as taste-responsive, significantly decreased as animals became familiar with taste stimuli. Moreover, the magnitude of taste-evoked excited responses increased while inhibited responses decreased with experience. By tracking individual neurons over time, we identified a subpopulation of stable neurons present on all days of the taste familiarity paradigm and further characterized their taste coding properties. The population-level response across these stable cells was distinct for each taste quality when taste stimuli were novel, but population responses for readily consumed stimuli became more correlated as the stimuli became familiar. Overall, these results highlight the effects of familiarity on both taste-specific and non-taste responses in the gustatory cortex.


Subject(s)
Cerebral Cortex , Taste , Mice , Animals , Cerebral Cortex/physiology , Taste/physiology , Taste Perception/physiology , Neurons/physiology , Recognition, Psychology
4.
Gland Surg ; 10(4): 1339-1346, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33968685

ABSTRACT

BACKGROUND: Compressive symptoms are common in thyroid disease. Many studies have focused on the size of the gland and its effects on patients. However, few have taken into account the body mass of the patient. The aim of our study was to examine whether or not a patient's body mass index (BMI) influences symptomatic outcomes following thyroid surgery for benign disease. METHODS: We conducted a prospective analysis evaluating 60 patients that underwent thyroidectomy for benign goiter (single or multinodular) disease. Patients were classified as obese, overweight, or normal based on BMI. Pre- and post-operative surveys were administered including the MRC breathlessness scale, M.D. Anderson Dysphagia Inventory (MDADI), and the ThyPRO quality of life questionnaire to evaluate dysphagia, dyspnea, and quality of life respectively. RESULTS: Patients classified as obese (n=37) scored significantly worse pre-operatively on MRC, MDADI, and ThyPRO surveys when compared to overweight (n=13) or normal weight (n=10) counterparts. Subjects in the obese group, but not the other groups, showed post-surgical improvement on both the MRC and MDADI surveys (P<0.0001). Similarly, obese subjects showed significant improvement on all 11 domains of the ThyPRO survey following surgery (P<0.0001), and overall degree of improvement was highly correlated with BMI among all subjects (r=0.60; P=0.0005). CONCLUSIONS: Obesity, as determined by BMI, is a critical factor to consider in the alleviation of compressive symptoms before and after thyroidectomy for goiter. Our analysis of survey data indicates obese subjects have increased benefit of surgery compared to their lighter counterparts.

5.
Curr Opin Physiol ; 20: 52-56, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33681544

ABSTRACT

Over the years, many approaches towards studying the taste-responsive area of insular cortex have focused on how basic taste information is represented, and how lesions or silencing of this area impact taste-focused behaviors. Here, we review and highlight recent studies that imply that insular cortex does not contain a "primary" taste cortex in the traditional sense. Rather, taste is employed in concert with other internal and external sensory modalities by highly interconnected regions of insular cortex to guide ingestive decision-making, especially in context of estimating risk and reward. In rodent models, this may best be seen in context of foraging behaviors, which require flexibility and are dependent on learning and memory processes.

7.
Gland Surg ; 8(3): 212-217, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31328099

ABSTRACT

BACKGROUND: Several clinical conditions increase thyroid gland vascularity, impacting surgical blood loss. Bevacizumab has been observed to reduce thyroid function, possibly through its effect on gland angiogenesis. This study aimed to determine if bevacizumab has any effect on thyroid vascularity as measured by gland volume and superior thyroid artery (STA) flow velocity in the normal rat thyroid. METHODS: Sixteen adult female Sprague-Dawley rats were placed under general anesthesia to measure baseline thyroid gland characteristics. A Vevo 2100 high-frequency ultrasound with 40 mHz transducer was used to obtain STA flow measurements and thyroid gland dimensions. Four rats served as controls. Six rats received intrathyroidal (IT) injections and 6 received intraperitoneal (IP) injections of bevacizumab (4-5 mg/kg). After two weeks ultrasound measurements were repeated. RESULTS: Pretreatment animals displayed similar thyroid volume and vascularity. Thyroid volume decreased (62.583 vs. 42.161, P=0.004) after IP administration of bevacizumab, and blood flow measurements did not change [peak velocity 75.896 vs. 76.7, P=0.96, average velocity 45.748 vs. 43.867, P=0.88, or resistivity index (RI) 30.345 vs. 25.32, P=0.60]. IT bevacizumab did not change thyroid volume (55.229 vs. 58.16, P=0.64). The average peak (73.191 vs. 100.589 cm/s, P=0.03) and mean (45.047 vs. 62.843 m/s, P=0.03) velocities were increased, but did not differ in the RI (0.619 vs. 0.632, P=0.82). No differences were noted on VEGF or CD 31 immunohistochemical analysis. CONCLUSIONS: Single systemic administration of bevacizumab appears to decrease thyroid volume without an effect on STA flow, VEGF or CD31 staining. These preliminary findings support further study of pharmacologic intervention in thyroid conditions characterized by increased angiogenesis and vascularity, such as iodine deficiency, Graves disease, and hypothyroidism.

8.
Chem Senses ; 44(4): 237-247, 2019 04 15.
Article in English | MEDLINE | ID: mdl-30788507

ABSTRACT

The gustatory system encodes information about chemical identity, nutritional value, and concentration of sensory stimuli before transmitting the signal from taste buds to central neurons that process and transform the signal. Deciphering the coding logic for taste quality requires examining responses at each level along the neural axis-from peripheral sensory organs to gustatory cortex. From the earliest single-fiber recordings, it was clear that some afferent neurons respond uniquely and others to stimuli of multiple qualities. There is frequently a "best stimulus" for a given neuron, leading to the suggestion that taste exhibits "labeled line coding." In the extreme, a strict "labeled line" requires neurons and pathways dedicated to single qualities (e.g., sweet, bitter, etc.). At the other end of the spectrum, "across-fiber," "combinatorial," or "ensemble" coding requires minimal specific information to be imparted by a single neuron. Instead, taste quality information is encoded by simultaneous activity in ensembles of afferent fibers. Further, "temporal coding" models have proposed that certain features of taste quality may be embedded in the cadence of impulse activity. Taste receptor proteins are often expressed in nonoverlapping sets of cells in taste buds apparently supporting "labeled lines." Yet, taste buds include both narrowly and broadly tuned cells. As gustatory signals proceed to the hindbrain and on to higher centers, coding becomes more distributed and temporal patterns of activity become important. Here, we present the conundrum of taste coding in the light of current electrophysiological and imaging techniques at several levels of the gustatory processing pathway.


Subject(s)
Neurons/physiology , Recognition, Psychology/physiology , Taste Buds/physiology , Taste/physiology , Animals , Humans , Stimulation, Chemical
9.
Brain Res ; 1714: 99-110, 2019 07 01.
Article in English | MEDLINE | ID: mdl-30807736

ABSTRACT

This study investigated neural projections from the parabrachial nucleus (PBN), a gustatory and visceral processing area in the brainstem, to the ventral tegmental area (VTA) in the midbrain. The VTA contains a large population of dopaminergic neurons that have been shown to play a role in reward processing. Anterograde neural tracing methods were first used to confirm that a robust projection from the caudal PBN terminates in the dorsal VTA; this projection was larger on the contralateral side. In the next experiment, we combined dual retrograde tracing from the VTA and the gustatory ventral posteromedial thalamus (VPMpc) with taste-evoked Fos protein expression, which labels activated neurons. Mice were stimulated through an intraoral cannula with sucrose, quinine, or water, and PBN sections were processed for immunofluorescent detection of Fos and retrograde tracers. The distribution of tracer-labeled PBN neurons demonstrated that the populations of cells projecting to the VTA or VPMpc are largely independent. Quantification of cells double labeled for Fos and either tracer demonstrated that sucrose and quinine were effective in activating both pathways. These results indicate that information about both appetitive and aversive tastes is delivered to a key midbrain reward interface via direct projections from the PBN.


Subject(s)
Parabrachial Nucleus/metabolism , Taste/physiology , Ventral Tegmental Area/metabolism , Animals , Dopaminergic Neurons/metabolism , Female , Male , Mice , Mice, Inbred C57BL , Neural Pathways/physiology , Neurites/metabolism , Neurons/metabolism , Parabrachial Nucleus/physiology , Quinine/metabolism , Reward , Sugars/metabolism , Ventral Thalamic Nuclei/metabolism
10.
Gland Surg ; 7(5): 433-439, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30505764

ABSTRACT

BACKGROUND: Post-thyroidectomy dysphonia can result from recurrent laryngeal nerve (RLN) injury. Confirmation of postoperative recurrent nerve function has prompted many surgeons to advocate laryngoscopic examination. Indirect and flexible laryngoscopy permit visualization of vocal cord motion, but not all thyroid surgeons are skilled in these techniques. Indirect laryngoscopy has a significant failure rate due to gag reflexes or anatomical obstruction. Flexible fiberoptic laryngoscopy, the current gold standard, allows reliable visualization of the cords, but perioperative examination is not always feasible for lack of equipment or training. Recent studies suggest vocal fold ultrasound as an alternative to flexible laryngoscopy. It offers the advantages of being non-invasive and painless without radiation exposure or sedation. Whereas ultrasound has been compared to laryngoscopy in the clinical setting, there remains a need for correlation of laryngeal ultrasound results with known neurophysiology in the normal and injured state. An animal model was proposed that reproduces neck surgery-associated recurrent nerve injury. The model allowed simultaneous recording of laryngeal endoscopy and transcutaneous high-resolution ultrasound during stimulation of intact and injured RLNs. METHODS: One RLN was injured in each of 4 rats. Rats were kept anesthetized during the fiberoptic examination and laryngeal ultrasound procedures. Following surgery and subsequent imaging the rats were given a lethal anesthetic dose. Results of both imaging modalities were compared to the presence or absence of neuromuscular action potential following stimulation of the recurrent nerve. RESULTS: The investigators observed a 100% correlation between endoscopic and ultrasonographic assessments. CONCLUSIONS: This study validated the clinical use of diagnostic ultrasound in vocal cord dysfunction in a rodent model.

11.
J Neurol Surg Rep ; 79(2): e31-e35, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29761066

ABSTRACT

Objectives This article aims (1) to determine whether there is any difference in cerebrospinal fluid (CSF) leak rate after anterior skull base autologous fat reconstruction based on how the fat is prepared, and (2) to measure impact on surgical times by reconstruction type. Design Translational animal model surgical technique 3-arm trial, comparing two different methods of autologous fat skull base reconstruction versus a nonreconstructed control group. Setting Animal study. Subjects Adult Sprague-Dawley rats. Main Outcome Measures Resolution of CSF rhinorrhea after repair of a surgically created anterior skull base defect. Results Both wet (uncompressed) and dry (compressed) fat reconstruction of an anterior skull base defect demonstrated lower CSF leak rates than nonreconstructed defects. Dry fat reconstruction achieved significance in superiority of controlling CSF leak over no reconstruction (64% success vs. 31%); while wet fat reconstruction trended toward significance (50% vs. 31%). Reconstruction procedure time was longer than nonreconstructed controls, but there was no significant difference between type of fat preparation in surgical time. Conclusions This study demonstrates that drying and compressing the fat graft improves autologous fat reconstruction success for anterior skull base defects, and does not add significantly to surgical time over nonprepared fat.

12.
J Neurosci ; 37(32): 7595-7605, 2017 08 09.
Article in English | MEDLINE | ID: mdl-28674169

ABSTRACT

Both physiological and imaging approaches have led to often-disparate conclusions about the organization of taste information in gustatory cortex (GC). In this study, we used neuroanatomical and imaging approaches to delineate the likely area of insular cortex given to gustatory function and to characterize taste responses within this delineated area in female and male C57BL/6J mice. Anterograde tracers were injected into the taste thalamus (the medial parvicellular portion of the ventral posterior medial division, VPMpc) of mice and the thalamic terminal field was investigated across the cortex. Working within the delineated area, we used two-photon imaging to measure basic taste responses in >780 neurons in layer 2/3 located just posterior to the middle cerebral artery. A nonbiased, hierarchical cluster analysis revealed multiple clusters of cells responding best to either individual or combinations of taste stimuli. Taste quality was represented in the activity of taste-responsive cells; however, there was no apparent spatial organization of primary taste qualities in this region.SIGNIFICANCE STATEMENT Recent studies investigating taste coding within the gustatory cortex have reported highly segregated, taste-specific regions containing only narrowly tuned cells responding to a single taste separated by large non-taste-coding areas. However, focusing on the center of this area, we found a large number of taste responsive cells ranging from narrowly to broadly responsive with no apparent local spatial organization. Further, population analysis reveals that activity in the neuronal population in this area appears to be related to measures of taste quality or hedonics.


Subject(s)
Cerebral Cortex/physiology , Taste Perception/physiology , Taste/physiology , Animals , Cerebral Cortex/drug effects , Cluster Analysis , Female , Male , Mice, Inbred C57BL , Mouth Mucosa/drug effects , Mouth Mucosa/physiology , Principal Component Analysis , Random Allocation , Sucrose/administration & dosage , Taste/drug effects , Taste Perception/drug effects , Ventral Thalamic Nuclei/physiology
13.
Otolaryngol Head Neck Surg ; 157(1): 36-41, 2017 07.
Article in English | MEDLINE | ID: mdl-28669310

ABSTRACT

Objective The iliac crest is the gold standard for cancellous bone grafting. This site is distant from head and neck reconstruction and may lead to significant postoperative morbidity. We propose an alternative harvest site within the head and neck with potentially less mobility deficits, the manubrium. Study Design Fresh-frozen cadaveric study. Setting Gross anatomy laboratory. Subjects and Methods Access to 18 cadavers was granted from the Medical Education and Research Institute in Memphis, Tennessee. The anterior iliac crests were exposed and H-type osteotomies performed. The manubrium was accessed through a substernal notch incision and a cortical window created through the anterior manubrium. Cancellous bone was harvested from these sites. Cadaveric demographics and noncompressed and compressed volumes were recorded with statistical comparisons. Results The population was predominantly male (12/18) with a mean age of 69.6 (95% confidence interval [CI], 64.0-75.3) years. The mean body mass index was 22.9 (95% CI, 18.8-27.1) kg/m2 with no sex propensity. Uncompressed volumes did not vary, ranging from 6.4 to 7.5 mL. Compressed volumes (mL) for the right iliac crest (4.3; 95% CI, 3.0-5.6), left iliac crest (3.5; 95% CI, 2.7-4.2), and manubrium (2.4; 95% CI, 1.8-3.0) varied (1-way analysis of variance: F(2, 51) = 4.63; P < .02). Furthermore, there was correlation between compressed volumes taken from either area ( r = 0.58; P < .02). Conclusions The manubrium can be used for cancellous bone grafting. This site affords a proximity to the head and neck rather than the distant iliac crest but with slightly lower yields. Potential applications include reconstructing small mandibular defects, mandible nonunion, or alveolar bone grafting.


Subject(s)
Bone Transplantation/methods , Cancellous Bone/transplantation , Ilium/transplantation , Manubrium/transplantation , Cadaver , Female , Head and Neck Neoplasms/surgery , Humans , Male , Osteotomy , Tissue and Organ Harvesting , Transplantation, Autologous
14.
Physiol Behav ; 177: 34-43, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28411104

ABSTRACT

In order to examine genetic influences on fluid ingestion, 20-min intake of either water or 0.1M sucrose was measured in a lickometer in 18 isogenic strains of mice, including 15 inbred strains and 3 F1 hybrid crosses. Intake and licking data were examined at a number of levels, including lick rate as defined by mean or median interlick interval, as well as several microstructural parameters (i.e. burst-pause structure). In general, strain variation for ingestive phenotypes were correlated across water and sucrose in all strains, indicating fundamental, rather than stimulus-specific, mechanisms of intake. Strain variation was substantial and robust, with heritabilities for phenotypes ranging from 0.22 to 0.73. For mean interlick interval (MPI; a measure of lick rate) strains varied continuously from 94.3 to 127.0ms, a range consistent with previous studies. Furthermore, variation among strains for microstructural traits such as burst size and number suggested that strains possess different overall ingestive strategies, with some favoring more short bursts, and others favoring fewer, long bursts. Strains also varied in cumulative intake functions, exhibiting both linear and decelerated rates of intake across the session.


Subject(s)
Feeding Behavior , Motor Activity/genetics , Mouth , Animals , Central Pattern Generators , Dietary Sucrose , Feeding Behavior/physiology , Female , Male , Mice , Motor Activity/physiology , Phenotype , Species Specificity , Water
15.
Surg Radiol Anat ; 39(9): 975-979, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28243697

ABSTRACT

INTRODUCTION: Lateral pharyngotomy (LP) is a surgical procedure that allows exposure to tumors of the pharynx and supraglottic larynx. This study was undertaken to: (1) propose a classification system of LP used in exposing various sites of the oropharynx, supraglottis, and hypopharynx. (2) Describe the structures visible with each category of LP. MATERIALS AND METHODS: Five tissue-fixed human cadavers from our gross anatomy laboratory were dissected in a manner similar to surgical lateral pharyngotomy. After exposure of the neurovascular structures of the anterior compartment of the neck and laryngeal framework, traditional pharyngotomy was performed with entry between the hypoglossal nerve cephalically and the superior laryngeal nerve caudally (traditional LP). Progressively increased exposure was created by division of adjacent structures. The ability to visualize certain structures (epiglottis, ipsilateral and contralateral base of tongue, postcricoid area, arytenoids, uvula, soft palate, and vallecula) through the pharyngotomy was recorded. RESULTS: The epiglottis and ipsilateral tongue base were visible via the traditional or Type I LP. Type II, III, and IV LP provided exposure to increasingly remote sites of the pharynx and supraglottic larynx. The additional exposure provided by each type of LP was consistent across all five cadaver specimens. CONCLUSION: Our system catalogs the additional exposure of both cephalic and caudal tumor sites associated with division of adjacent structures. This anatomic study illustrates and systematizes the structures requiring division to provide access to a given tumor location.


Subject(s)
Larynx/anatomy & histology , Pharyngectomy/methods , Pharynx/anatomy & histology , Cadaver , Humans , Laryngeal Diseases/surgery , Neck Dissection , Pharyngeal Diseases/surgery
16.
Physiol Behav ; 153: 97-108, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26524511

ABSTRACT

Self-administration of LiCl solution has been shown to result in the formation of a conditioned taste aversion (CTA) that generalizes to NaCl in rats. This paradigm may have considerable ecological validity as it models CTA learning in natural settings, and also allows for the investigation of drinking microstructure as an assay of potential shifts in stimulus palatability. We used this paradigm to examine possible mouse strain differences in CTA acquisition, generalization, and extinction. In the first experiment, C57BL/6J (B6) and DBA/2J (D2) mice self-administered LiCl (or control NaCl) over a 20-minute free access acquisition period and were tested on the following day with a panel of taste solutions available in brief (5-s) trials delivered in random order. In the second experiment, mice again self-administered LiCl or NaCl (at low, 0.12 M, or high, 0.24 M concentrations) in a 20-minute session, and on the following day received a 20-minute free access period to equimolar NaCl. Strain differences were found for aspects of ingestive behavior, with B6 mice showing greater consumption of all stimuli, including water, while D2 mice lick faster, in less frequent but longer bursts. We did not, however, find evidence of a robust strain difference in taste aversion learning. Both strains demonstrated profound alterations in licking microstructure in the generalization session relative to controls. We suggest that a decrease in "lick efficiency" (the percentage of inter-lick intervals within a burst of short duration vs. longer duration) reflects avoidance behavior, and signals a shift in palatability of a stimulus following CTA.


Subject(s)
Avoidance Learning/drug effects , Conditioning, Psychological/drug effects , Drinking Behavior/drug effects , Lithium Chloride/administration & dosage , Lithium Chloride/pharmacology , Taste/drug effects , Animals , Avoidance Learning/physiology , Conditioning, Psychological/physiology , Dose-Response Relationship, Drug , Drinking Behavior/physiology , Extinction, Psychological , Female , Generalization, Psychological , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Self Administration , Sodium Chloride/pharmacology , Taste/physiology , Time Factors
17.
Chem Senses ; 40(5): 295-303, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25820205

ABSTRACT

Previous electrophysiological investigation shows that combinations of compounds classified by humans as umami-tasting, such as glutamate salts and 5'-ribonucleotides, elicit synergistic responses in neurons throughout the rodent taste system and produce a pattern that resembles responses to sweet compounds. The current study tested the hypothesis that a synergistic mixture of monopotassium glutamate (MPG) and inositol monophosphate (IMP) possesses perceptual similarity to sucrose in mice. We estimated behavioral similarity among these tastants and the individual umami compounds using a series of conditioned taste aversion (CTA) tests, a procedure that measures whether a CTA formed to one stimulus generalizes to another. Our primary finding was that a CTA to a synergistic mixture of MPG + IMP generalizes to sucrose, and vice-versa. This indicates umami synergistic mixtures are perceived as having a sweet, or at least sucrose-like, taste to mice. Considering other recent studies, our data argue strongly in favor of multiple receptor mechanisms for umami detection, and complexity in taste perception models for rodents.


Subject(s)
Glutamic Acid , Inositol Phosphates , Taste/physiology , Animals , Female , Glutamic Acid/administration & dosage , Inositol Phosphates/administration & dosage , Male , Mice , Mice, Inbred C57BL , Sucrose/administration & dosage
18.
Article in English | MEDLINE | ID: mdl-25120438

ABSTRACT

The present study investigated a subpopulation of neurons in the mouse parabrachial nucleus (PbN), a gustatory and visceral relay area in the brainstem, that project to the lateral hypothalamus (LH). We made injections of the retrograde tracer Fluorogold (FG) into LH, resulting in fluorescent labeling of neurons located in different regions of the PbN. Mice were stimulated through an intraoral cannula with one of seven different taste stimuli, and PbN sections were processed for immunohistochemical detection of the immediate early gene c-Fos, which labels activated neurons. LH projection neurons were found in all PbN subnuclei, but in greater concentration in lateral subnuclei, including the dorsal lateral subnucleus (dl). Fos-like immunoreactivity (FLI) was observed in the PbN in a stimulus-dependent pattern, with the greatest differentiation between intraoral stimulation with sweet (0.5 M sucrose) and bitter (0.003 M quinine) compounds. In particular, sweet and umami-tasting stimuli evoked robust FLI in cells in the dl, whereas quinine evoked almost no FLI in cells in this subnucleus. Double-labeled cells were also found in the greatest quantity in the dl. Overall, these results support the hypothesis that the dl contains direct a projection to the LH that is activated preferentially by appetitive compounds; this projection may be mediated by taste and/or postingestive mechanisms.


Subject(s)
Gastrointestinal Tract/innervation , Hypothalamic Area, Lateral/physiology , Mouth/innervation , Neural Pathways/physiology , Neurons/physiology , Parabrachial Nucleus/cytology , Animals , Cell Count , Female , Functional Laterality , Male , Mice , Mice, Inbred C57BL , Proto-Oncogene Proteins c-fos/metabolism , Quinine/pharmacology , Stilbamidines/metabolism , Stimulation, Chemical
19.
J Invest Surg ; 27(5): 294-303, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24833437

ABSTRACT

PURPOSE/AIM: To design, synthesize, and test in vivo an aerogel-based top-open peripheral nerve scaffold to simultaneously support and guide multiple completely severed peripheral nerves in a rat model. Also, to explore options for immobilizing severed nerves on the aerogel material without the use of sutures resulting in reduced surgical time. MATERIALS AND METHOD: A novel material and approach was developed for the reattachment of severed peripheral nerves. Nerve confinement and alignment in this case relies on the surface properties of a lightweight, highly porous, polyurea crosslinked silica aerogel scaffold. The distal and proximal ends of completely transected nerve terminals were positioned inside prefabricated "top-open" corrugated channels that cradled approximately two thirds of the circumference of the nerve trunk and connectivity of the severed nerves was evaluated using sciatic function index (SFI) technique for five months post-surgery on 10 female Sprague-Dawley rats then compared with the gold standard for peripheral nerve repair. The interaction of nerves with the surface of the scaffold was investigated also. RESULTS AND CONCLUSION: Multichannel aerogel-based nerve support scaffold showed similar SFI recovery trend as the case suture repair technique. Usage of an adhesion-promoting coating reduced the friction between the nerve and the scaffold leading to slippage and lack of attachment between nerve and surface. The aerogel scaffold used in this study did not collapse under pressure during the incubation period and allowed for a rapid and non-invasive peripheral nerve repair approach without the demands of microsurgery on both time and surgical expertise. This technique may allow for simultaneous repair and reconnection of multiple severed nerves particularly relevant to nerve branching sites.


Subject(s)
Guided Tissue Regeneration/methods , Peripheral Nerve Injuries/surgery , Tissue Scaffolds/chemistry , Animals , Cross-Linking Reagents , Female , Gait , Guided Tissue Regeneration/instrumentation , Nerve Regeneration , Peripheral Nerve Injuries/physiopathology , Pilot Projects , Polymers , Rats , Rats, Sprague-Dawley , Sciatic Nerve/injuries , Sciatic Nerve/physiopathology , Sciatic Nerve/surgery , Silica Gel , Tensile Strength
20.
PLoS One ; 8(6): e66348, 2013.
Article in English | MEDLINE | ID: mdl-23799093

ABSTRACT

BACKGROUND: Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. The highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken advantage of for non-invasive external imaging techniques. Sound-based detection of implants is a low cost, non-invasive, portable, and rapid technique that is routinely used and readily available in major clinics and hospitals. METHODOLOGY: In this study the first in vivo ultrasound response of polyurea crosslinked silica aerogel implants was investigated by means of a GE Medical Systems LogiQe diagnostic ultrasound machine with a linear array probe. Aerogel samples were inserted subcutaneously and sub-muscularly in a) fresh animal model and b) cadaveric human model for analysis. For comparison, samples of polydimethylsiloxane (PDMS) were also imaged under similar conditions as the aerogel samples. CONCLUSION/SIGNIFICANCE: Polyurea crosslinked silica aerogel (X-Si aerogel) implants were easily identified when inserted in either of the regions in both fresh animal model and cadaveric model. The implant dimensions inferred from the images matched the actual size of the implants and no apparent damage was sustained by the X-Si aerogel implants as a result of the ultrasonic imaging process. The aerogel implants demonstrated hyperechoic behavior and significant posterior shadowing. Results obtained were compared with images acquired from the PDMS implants inserted at the same location.


Subject(s)
Polymers/chemistry , Prostheses and Implants , Silicon Dioxide/chemistry , Abdominal Muscles/diagnostic imaging , Animals , Female , Gels , Humans , Materials Testing , Rats , Rats, Sprague-Dawley , Subcutaneous Tissue/diagnostic imaging , Ultrasonography
SELECTION OF CITATIONS
SEARCH DETAIL
...