Endoscopic soft palate augmentation using injectable materials in dogs to ameliorate velopharyngeal insufficiency

Background Velopharyngeal structure augmentation methods are used as alternatives to pharyngeal flap operations. Recently, we investigated the sites of velopharyngeal structure augmentation in dogs and reported that the most effective injection location is the soft palate. However, there have been no reports regarding the optimal materials for implantation or injection. In this study, we aimed to investigate the injectable materials used in soft palate augmentation in dogs to ameliorate velopharyngeal insufficiency (VPI). Methods Endoscopic soft palate augmentation (ESPA) was performed in dogs using purified sodium hyaluronate, atelocollagen, or autogenic fat tissue. ESPA is an original technique developed by our group, and this is the first report of its performance. Moreover, we assessed the amount of nasal air leakage during inspiration at rest and during expiration under the rebreathing system at 1, 2, 3, 4, 5, and 6 months after injection of these materials. Results The amount of nasal air leakage during expiration under the rebreathing system was significantly decreased in all dogs injected with the ESPA materials, but neither apnea nor hypopnea was observed. Conclusions We investigated the optimal materials for use in ESPA, such as purified sodium hyaluronate, atelocollagen, or autogenic fat tissue. We found that all of them reduced nasal air leakage and only autogenic fat tissue showed significant histologic differences in dogs at 6 months. This technique may also be useful for the treatment of patients with VPI.Endoscopic soft palate augmentation using injectable materials in dogs to ameliorate velopharyngeal insufficiency. Isomura ET, Matsukawa M, Nakagawa K, Mitsui R, Kogo M. PLOS ONE. 2020. 15(9) e0238646. doi:10.1371/journal.pone.023864

Evaluation of sites of velopharyngeal structure augmentation in dogs for improvement of velopharyngeal insufficiency

Background Velopharyngeal structure augmentation methods are used as alternatives to velopharyngeal plasty. Anatomic sites of implantation/injection vary widely due to a lack of standardized criteria. Here, we experimentally investigated optimal sites of velopharyngeal structure augmentation via saline injection in dogs as they naturally exhibit velopharyngeal insufficiency (VPI). Methods Velopharyngeal structure augmentation was performed on 10 beagles (age range: 20–24 months; weight range: 9–12 kg). Saline containing 1/80,000 epinephrine was injected intraorally in 1-mL increments into the nasal mucosa of the soft palate (n = 4), posterior pharyngeal wall (n = 3), or bilateral pharyngeal walls (n = 3) of each dog. Nasal air leakage was measured under rebreathing until velopharyngeal closure was achieved; the measurement was performed using flow meter sensors on both nasal apertures, and the oral cavity was filled with alginate impression material to prevent oral air leakage. Results Pre-injection, the dogs exhibited an average of 0.455 L/s air leakage from the nasal cavity. The dogs with saline injected into the nasal mucosa of the soft palate achieved steady augmentation, and nasal air leakage disappeared under rebreathing following 6-mL saline injection. Conversely, nasal air leakage remained in the dogs with saline injected in the posterior pharyngeal wall or bilateral pharyngeal walls. Conclusions During VPI treatment in dogs, augmentation was most effective at the nasal mucosa of the soft palate. Improvement in nasal air leakage was highly dependent on the saline injection volume. Although velopharyngeal structures vary between dogs and humans, velopharyngeal closure style is similar. Thus, our results may aid in the treatment of VPI patients.Evaluation of sites of velopharyngeal structure augmentation in dogs for improvement of velopharyngeal insufficiency. Isomura ET, Nakagawa K, Matsukawa M, Mitsui R, Kogo M. PLOS ONE. 2019. 14(2) e0212752. doi:10.1371/journal.pone.021275

General Factors and Dental-Related Risk Factors for Postoperative Pneumonia or Infectious Complications: A Retrospective Study

Numerous studies report that perioperative oral care decreases the frequency of postoperative pneumonia or infection. However, no studies have analyzed the specific impact of oral infection sources on the postoperative course, and the criteria for preoperative dental care differ among institutions. This study aimed to analyze the factors and dental conditions present in patients with postoperative pneumonia and infection. Our results suggest that general factors related to postoperative pneumonia, including thoracic surgery, sex (male > female), the presence or absence of perioperative oral management, smoking history, and operation time, were identified, but there were no dental-related risk factors associated with it. However, the only general factor related to postoperative infectious complications was operation time, and the only dental-related risk factor was periodontal pocket (4 mm or higher). These results suggest that oral management immediately before surgery is sufficient to prevent postoperative pneumonia, but that moderate periodontal disease must be eliminated to prevent postoperative infectious complication, which requires periodontal treatment not only immediately before surgery, but also on a daily basis.Isomura E.T., Fujimoto Y., Matsukawa M., et al. General Factors and Dental-Related Risk Factors for Postoperative Pneumonia or Infectious Complications: A Retrospective Study. Journal of Clinical Medicine 12, 3529 (2023); https://doi.org/10.3390/jcm12103529

Magnetization and transport properties in the superconducting Pr2_{2}Ba4_{4}Cu7_{7}O15−δ_{15-\delta} with metallic double-chain

We have reported the effect of pressure on the magnetization, and transport properties in the nominal composition Pr$_{2}$Ba$_{4}$Cu$_{7}$O$_{15-\delta}$ synthesized by a sol-gel technique. A reduction treatment of the as-sintered sample in vacuum causes higher superconductivity achieving $T_{c,on}=\sim 30$ K for $\delta =0.94$. Application of hydrostatic pressure on the oxygen depleted sample enhances its onset temperature up to 36 K at 1.2 GPa, indicating the nearly optimum doping level of the charge carrier in comparison to the pressure dependence of lower $T_{c}$ samples with $\delta =0.45$. Seebeck coefficient of the superconducting sample shows a metallic conduction, followed by a clear drop below $T_{c,on}$ and is in its temperature dependence below 100 K quite different from that of the non-superconducting one. This finding strongly suggests a dramatic change of the electronic state along the CuO double chain due to the reduction treatment for the appearance of superconductivity .Comment: 5 pages,4 figure

Measurements of Cosmic-ray Low-energy Antiproton and Proton Spectra in a Transient Period of the Solar Field Reversal

The energy spectra of cosmic-ray low-energy antiprotons and protons have been measured by BESS in 1999 and 2000, during a period covering the solar magnetic field reversal. Based on these measurements, a sudden increase of the antiproton to proton flux ratio following the solar magnetic field reversal was observed, and it generally agrees with a drift model of the solar modulation.Comment: 4 pages, 4 figures, revised version accepted for publication in Phys. Rev. Let