- Vocal instabilities in a three-dimensional body-cover phonation model. [Journal Article]
- JAJ Acoust Soc Am 2018; 144(3):1216
- The goal of this study is to identify vocal fold conditions that produce irregular vocal fold vibration and the underlying physical mechanisms. Using a three-dimensional computational model of phonat...
The goal of this study is to identify vocal fold conditions that produce irregular vocal fold vibration and the underlying physical mechanisms. Using a three-dimensional computational model of phonation, parametric simulations are performed with co-variations in vocal fold geometry, stiffness, and vocal tract shape. For each simulation, the cycle-to-cycle variations in the amplitude and period of the glottal area function are calculated, based on which the voice is classified into three types corresponding to regular, quasi-steady or subharmonic, and chaotic phonation. The results show that vocal folds with a large medial surface vertical thickness and low transverse stiffness are more likely to exhibit irregular vocal fold vibration when tightly approximated and subject to high subglottal pressure. Transition from regular vocal fold vibration to vocal instabilities is often accompanied by energy redistribution among the first few vocal fold eigenmodes, presumably due to nonlinear interaction between eigenmodes during vocal fold contact. The presence of a vocal tract may suppress such contact-related vocal instabilities, but also induce new instabilities, particularly for less constricted vocal fold conditions, almost doubling the number of vocal fold conditions producing irregular vibration.
- Study of the Carrier-Aided Thin Film Electrode Array Design for Cochlear Insertion. [Journal Article]
- MMicromachines (Basel) 2018 Apr 27; 9(5)
- The micro-fabricated thin film electrode array (TFEA) has been a promising design for cochlear implants (CIs) because of its cost-effectiveness and fabrication precision. The latest polymer-based coc...
The micro-fabricated thin film electrode array (TFEA) has been a promising design for cochlear implants (CIs) because of its cost-effectiveness and fabrication precision. The latest polymer-based cochlear TFEAs have faced difficulties for cochlear insertion due to the lack of structural stiffness. To stiffen the TFEA, dissolvable stiffening materials, TFEAs with different structures, and TFEAs with commercial CIs as carriers have been invested. In this work, the concept of enhancing a Parylene TFEA with Kapton tape as a simpler carrier for cochlear insertion has been proved to be feasible. The bending stiffness of the Kapton-aided TFEA was characterized with an analytical model, a finite element model, and a cantilever bending experiment, respectively. While the Kapton tape increased the bending stiffness of the Parylene TFEA by 10³ times, the 6-μm-thick TFEA with a similar Young's modulus, as a polyimide, in turn significantly increased the bending stiffness of the 170-μm-thick Kapton carrier by 60%. This result indicated that even the TFEA is ultra-flexible and that its bending stiffness should not be neglected in the design or selection of its carrier.
- Quantification of injection force mechanics during injection laryngoplasty. [Journal Article]
- LLaryngoscope 2018 Nov 13
- CONCLUSIONS: Needle caliber, length, and bends impact steady-state forces and stiffness rates during vocal fold injection.
- Automated Indentation Mapping of Vocal Fold Structure and Cover Properties Across Species. [Journal Article]
- LLaryngoscope 2018 Nov 08
- CONCLUSIONS: Automated indentation mapping yielded reproducible biomechanical property measurement of the VF cover and intact VF. Divergent VF structural properties across canine, swine, and leporine species were observed.
- Microsurgical Clipping of a Ruptured Basilar Apex Aneurysm: 3-Dimensional Operative Video. [Journal Article]
- ONOper Neurosurg (Hagerstown) 2018 Nov 08
- A 59-yr-old woman presented with a sudden onset of headache with neck pain and stiffness, Hunt and Hess grade 2. Brain computed tomography (CT) showed subarachnoid hemorrhage, Fisher Grade 2. Intra-a...
A 59-yr-old woman presented with a sudden onset of headache with neck pain and stiffness, Hunt and Hess grade 2. Brain computed tomography (CT) showed subarachnoid hemorrhage, Fisher Grade 2. Intra-arterial digital subtraction angiography (IADSA) showed a basilar artery apex aneurysm, dome size 9 mm and neck 3 mm, leaning towards the right, and a dominant right artery of Percheron. Endovascular treatment and microsurgical clipping were both explained to the patient, but she decided to undergo microsurgery due to the durability of treatment.She underwent a right frontotemporal craniotomy and orbital osteotomy. We performed optic nerve decompression and intradural anterior clinoidectomy to enhance the exposure. Working through the carotid-oculomotor space, the posterior communicating artery was traced back to the posterior cerebral artery. The basilar artery was temporarily occluded for aneurysm dissection after burst suppression to protect the brain. The aneurysm was irregular, multilobulated, and projecting upward. The dominant thalamoperforate artery (artery of Percheron) was arising from the right P1, and densely adherent to the sac of the aneurysm. After dissection of the artery of Percheron away from the aneurysm, it was completely occluded by a side-curved titanium clip. The patient had right oculomotor nerve paresis and headache postoperatively, but at discharge 2 wk later the headache and paresis had completely resolved. The postoperative IADSA showed total occlusion of the aneurysm with patency of the artery of Percheron.This 3-dimensional video shows the technical nuances of microsurgical clipping of a ruptured basilar apex aneurysm and intraoperative dissection of the artery of Percheron.Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.
- Vertigo caused by longus colli tendonitis: A case report and literature review. [Journal Article]
- MMedicine (Baltimore) 2018; 97(45):e13130
- CONCLUSIONS: Longus colli tendinitis with vertigo is an under-reported condition in the literature and physicians should be aware of its existence. A lack of familiarity with the anatomy of the prevertebral space and its variable radiographic appearance makes the diagnosis of longus colli tendinitis clinically difficult. Misdiagnosis of this condition may lead to unnecessary interventions in vertigo.
- D-optimal mixture design: Formulation development, mechanical characterization, and optimization of curcumin chewing gums using oppanol® B 12 elastomer as a gum-base. [Journal Article]
- IJInt J Pharm 2018 Oct 19; 553(1-2):210-219
- Curcumin (CUR) chewing gums have potential therapeutic benefits to head and neck cancer patients. The objective of this work was to develop medicated chewing gums (MCGs) with high CUR loading and des...
Curcumin (CUR) chewing gums have potential therapeutic benefits to head and neck cancer patients. The objective of this work was to develop medicated chewing gums (MCGs) with high CUR loading and desirable mastication properties. This was accomplished by evaluating the effect of five gum ingredients: (X1) polyisobutene, (X2) polyvinyl acetate, (X3) wood rosin, (X4) wax, and (X5) CUR on the mechanical properties of the MCGs using a 25-run, five-factor, two-level D-Optimal mixture design. CUR MCGs were prepared by the conventional fusion method for making chewing gums. They were characterized by a two-bites texture and uniaxial tension tests to generate force-displacement curves from which the cohesiveness (Y1), springiness (Y2), chewiness (Y3), compressibility (Y4), resistance to extension (Y5), and extensibility (Y6) were measured. Observed responses were used to generate polynomial models correlating the independent with the dependent variables. Elasticity and stiffness of the gums were found to be readily impacted by PIB and CUR levels. Fitted models were then used to predict a gum composition that has comparable mechanical properties to commercially procured chewing gums. The optimized MCG was loaded with 50% of either CUR or CUR/SBE-β-CD inclusion complex and tested in vitro for drug release. Although no differences in mechanical properties were observed, substituting CUR with the inclusion complex was found to significantly enhance drug release. This study highlighted the impact of each gum ingredient on the quality of the MCGs and demonstrated the feasibility of preparing chewing gums with up to 50% drug loading.
- Effect of nerve root block guided by ultrasound on cervicogenic pain and its influence on immune function. [Letter]
- JBJ Biol Regul Homeost Agents 2018 Sep-Oct; 32(5):1177-1183
- Cervicogenic pain is a common chronic disease that needs individualized treatment according to the place of pain. This study aimed to observe the effect of ultrasound-guided nerve root block in the t...
Cervicogenic pain is a common chronic disease that needs individualized treatment according to the place of pain. This study aimed to observe the effect of ultrasound-guided nerve root block in the treatment of cervicogenic pain and its influence on immune function. A total of 30 patients (group A) with cervical discogenic pain (CDP) were treated by selective cervical nerve root block and 30 patients (group B) with CDP were treated with cervical spinal block under the X-ray C-arm guidance. The two groups of patients were examined with regard to the analgesic effect by Numerical Rating Scale (NRS), and the changes in the preoperative and postoperative range of motion in the neck (ROM). In addition, weekly pain attacks and the duration of each attack were recorded. The content of CD3+, CD4+ and CD8+ in the peripheral blood T lymphocyte subsets in the two groups was evaluated by flow cytometry. The levels of these subsets were compared 24 h before treatment, 24 h after treatment, 3 days (d) after treatment and 7 d after treatment. At the time periods of 24 h, 3 d, and 7 d after treatment, the NRS of the two groups decreased significantly compared with before treatment (P less than 0.01). The changes of the ROM, the number of weekly pain attacks, the duration of each pain attack, and the stiffness of the head and neck were significantly lower in the two groups compared with those prior to the treatment (P less than 0.05). In group A and group B, the number of CD3+, CD4+ and CD8+ T cells 24 h and 3 d after treatment increased significantly compared with that noted before treatment (P less than 0.05). Seven days after treatment, the levels of CD3+, CD4+ and CD8+ T cells in the peripheral blood T lymphocytes of group A were significantly higher than those of group B (P less than 0.05). Selective cervical nerve root block under ultrasound is an effective method for the treatment of cervical discogenic pain. The effect is better than that of the X-ray C-arm-guided cervical block method. The mechanism of selective cervical nerve root block under ultrasound may be related to the regulation of the content of CD3+, CD4+, CD8+ T cells in the peripheral blood T lymphocyte subsets and the enhancement of cellular immunity.
- Cell-Specific Transcriptome Analysis Shows That Adult Pillar and Deiters' Cells Express Genes Encoding Machinery for Specializations of Cochlear Hair Cells. [Journal Article]
- FMFront Mol Neurosci 2018; 11:356
- The mammalian auditory sensory epithelium, the organ of Corti, is composed of hair cells and supporting cells. Hair cells contain specializations in the apical, basolateral and synaptic membranes. Th...
The mammalian auditory sensory epithelium, the organ of Corti, is composed of hair cells and supporting cells. Hair cells contain specializations in the apical, basolateral and synaptic membranes. These specializations mediate mechanotransduction, electrical and mechanical activities and synaptic transmission. Supporting cells maintain homeostasis of the ionic and chemical environment of the cochlea and contribute to the stiffness of the cochlear partition. While spontaneous proliferation and transdifferentiation of supporting cells are the source of the regenerative response to replace lost hair cells in lower vertebrates, supporting cells in adult mammals no longer retain that capability. An important first step to revealing the basic biological properties of supporting cells is to characterize their cell-type specific transcriptomes. Using RNA-seq, we examined the transcriptomes of 1,000 pillar and 1,000 Deiters' cells, as well as the two types of hair cells, individually collected from adult CBA/J mouse cochleae using a suction pipette technique. Our goal was to determine whether pillar and Deiters' cells, the commonly targeted cells for hair cell replacement, express the genes known for encoding machinery for hair cell specializations in the apical, basolateral, and synaptic membranes. We showed that both pillar and Deiters' cells express these genes, with pillar cells being more similar to hair cells than Deiters' cells. The fact that adult pillar and Deiters' cells express the genes cognate to hair cell specializations provides a strong molecular basis for targeting these cells for mammalian hair cell replacement after hair cells are lost due to damage.
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- Inflammatory Arthritis Induced by Pembrolizumab in a Patient With Head and Neck Squamous Cell Carcinoma. [Journal Article]
- FOFront Oncol 2018; 8:409
- Introduction: T cell checkpoint inhibitors targeting Programmed cell Death protein-1 (PD-1) have emerged as novel immunotherapy agents showing remarkable efficacy in head and neck squamous cell carci...
Introduction: T cell checkpoint inhibitors targeting Programmed cell Death protein-1 (PD-1) have emerged as novel immunotherapy agents showing remarkable efficacy in head and neck squamous cell carcinoma (HNSCC). Despite important clinical benefits, they are associated with side effects that occur as a consequence of general immunological stimulation due to loss of T cell inhibition. Herein, we report the unusual case of inflammatory arthritis induced by anti-PD-1 agent pembrolizumab. Case report: A 55-years old male was treated with pembrolizumab at a dose of 200 mg every 3 weeks for a metastatic hypopharyngeal carcinoma. Following two cycles of immunotherapy, and while complete response of lung metastases was achieved, the patient presented with stiffness, swelling and pain of the right knee. Clinical examination and synovial fluid analysis revealed a seronegative inflammatory arthritis. Pembrolizumab therapy was interrupted and low-dose prednisone was administered with remarkable clinical improvement. Pembrolizumab was reintroduced, but after the fifth cycle, the patient developed inflammatory polyarthritis involving both knees and interphalangeal joints of both hands resulting in severe clinical deterioration. At that time, treatment with pembrolizumab was permanently discontinued. High-dose prednisone and methotrexate treatment led to remission of clinical symptoms. Conclusion: Pembrolizumab-induced inflammatory arthritis is an unusual rheumatic immune-related adverse event that physicians are likely to encounter as ICI use expands. Multidisciplinary management and rheumatology consultation are necessary to provide immediate treatment and avoid permanent joint damage.