Diagnosis on pitting failure in gear equipment using time - frequency domain analysis

In order to discuss the health monitoring method using time-frequency analysis on the vibration of gear sets, the fatigue test employed for a steel gear pair was carried out using a power circulating gear testing machine. Furthermore, the dynamic characteristics of both steel and sintered gears were measured using a power circulating gear testing machine and were analyzed in a time-frequency domain by the continuous and discrete wavelet transforms. In the case of the failure at the dedendum surface of driven gear, not only the vibration of the gear sets but also the condition of tooth meshing would have to be taken into consideration to diagnose the failed teeth

Factors Affecting Postoperative Hearing Results in Type IV Tympanoplasty: Preliminary Study of the Influence of External Auditory Canal Packing Material

[Background] Postoperative hearing results of type IV tympanoplasty have been shown to have poorer results than other reconstruction techniques. There are numerous reports evaluating the factors for hearing improvement. This preliminary study aimed to analyze and determine the factors that affect hearing results. [Methods] A total of 80 patients who underwent type IV tympanoplasty were evaluated to participate in this study. The medical records of the candidate patients were collected retrospectively. Fifty out of the 80 recruited patients were excluded due to the following reasons: they could not be followed-up for more than a year after the final operation, their initial surgery was not performed in our department, or they needed a revision surgery. The pre-, intra-, and postoperative factors were evaluated and analyzed using EZR software. Cases were divided into two groups according to postoperative hearing results, and each factor was analyzed univariately. The explanatory variables included in the multivariate analysis were the variables that satisfied P < 0.1 in the univariate analysis. Furthermore, all cases were divided into two groups according to the qualitative variables that showed significant difference in the multivariate analysis, and the background factors were evaluated. [Results] The results of univariate analysis showed P < 0.1 for ‘Age’ and ‘Material of external auditory canal (EAC) packing’. Multivariate analysis showed P < 0.05 for both. The comparison between the two packing material groups showed that the gauze group was more likely to have improved hearing than Spongel? group, and the ossicular chain condition of the gauze group was maintained better. [Conclusion] ‘Age’ and ‘Material of EAC packing’ were considered to be significant factors affecting the postoperative hearing results. The selection and use of packing materials that provide stability should be considered to obtain better postoperative hearing results in type IV tympanoplasty

A Case of Cochlear Implantation in a Patient with Superficial Siderosis

Superficial siderosis is a disease in which iron from hemoglobin is deposited in the central nervous system, resulting in conditions such as progressive sensorineural hearing loss, cerebellar ataxia, dementia, and pyramidal signs. A 30-year-old man with superficial siderosis received a cochlear implant in the left ear, which had shown complete hearing loss. Good auditory responses were obtained at 14 days after implantation. The postoperative average hearing level with the cochlear implant was 56.7 dB at 3 months and 55.0 dB at 6 months. However, the patient showed gradual hearing loss, and the dynamic range changed each time the electrode parameters were adjusted. To assess residual hearing ability, single-photon emission computed tomography was performed together with an assessment of electrical auditory brainstem response, which showed a good response and increased blood flow in both the temporal lobes. Based on this result, we asked the patient to continue using the cochlear implant to see whether a perception of speech response would be obtained. However, the patient discontinued using the cochlear implant because he could not hear satisfactorily. Hearing outcomes after cochlear implant surgery for patients with superficial siderosis are not necessarily good. Therefore, the possibility of unsatisfactory Results should be fully explained before recommending this surgery to patients

A Case of Gorham-Stout Disease Treated with Fistula Closure by Transmeatal Approach

Gorham-Stout disease, a rare and intractable disease of unknown etiology, causes systemic bone lysis and replacement with lymphoid tissue. Here, we report a case of Gorham-Stout disease with cerebrospinal fluid leakage in a 16-year-old boy. The patient complained of nasal discharge, right ear obstruction, fever, and headache. A computed tomography scan of the head showed osteolysis around the right internal carotid artery, vestibule, and cochlea and osteolytic changes in the left parietal bone. It was suggested that the patient had bacterial meningitis owing to the leakage of cerebrospinal fluid from the fistula caused by the temporal bone osteolysis. He was treated with meropenem, and a transmeatal fistula closure and a bone biopsy of the left parietal bone were performed. Intraoperatively, osteolysis was observed on the promontory and around the internal carotid artery. The fistula was closed by dense filling and compression around the fistula, in the middle ear cavity, and in the external auditory canal. The symptoms disappeared after the surgery. Bone biopsy showed the presence of a lymphangioma, and Gorham-Stout disease was diagnosed. Prophylactic bisphosphonate therapy was initiated. A 4-year follow-up revealed no progression of the disease

Hemostatic Control with Gelatin Sponge and Quantum Molecular Resonance Coagulation in a Case of Glomus Tympanicum

Surgical removal of tumor is the primary treatment of choice for glomus tympanicum (GT). However, because the tumor has abundant blood flow, bleeding control is crucial, and preoperative embolization may be performed. Here, we report the case of a 46-year-old female who visited our hospital with a complaint of right pulsatile tinnitus. A red pulsatile mass was found in the right tympanic cavity, and she was diagnosed with class B1 GT and subsequently underwent surgical treatment. We judged that bleeding could be controlled by intratympanic cavity manipulation alone and decided to perform transmeatal tumor resection without preoperative arterial embolization. After creating a tympanomeatal flap and performing an atticotomy, some pieces of Spongel® were inserted between the tumor and the tympanic wall. The Spongel® absorbed the blood and created a space between the tumor and tympanic wall, which allowed for the insertion of the tip of the Vesalius® handpiece to coagulate the tumor. The coagulation caused the tumor to shrink, thereby widening the space and allowing for further resection. Although the surgical manipulation caused bleeding, complete resection was achieved by the application of Spongel® and coagulation with Vesalius®. Since the tip of the Vesalius® was not burned, hemostasis was successfully achieved, and the operation proceeded while maintaining a clear field of view. There was little bleeding and no postoperative complications. The patient was discharged on the sixth postoperative day. One year after surgery, pure tone audiometry showed no change in the level of bone conduction. Spongel® and Vesalius® are useful tools that allow to safely perform surgeries even in narrow spaces such as the tympanic cavity

Unexpected Role of α-Fetoprotein in Spermatogenesis

BACKGROUND: Heat shock severely affects sperm production (spermatogenesis) and results in a rapid loss of haploid germ cells, or in other words, sperm formation (spermiogenesis) is inhibited. However, the mechanisms behind the effects of heat shock on spermatogenesis are obscure. METHODOLOGY/PRINCIPAL FINDINGS: To identify the inhibitory factor of spermiogenesis, experimental cryptorchid (EC) mice were used in this study. Here we show that α-fetoprotein (AFP) is specifically expressed in the testes of EC mice by proteome analysis. AFP was also specifically localized spermatocytes by immunohistochemical analysis and was secreted into the circulation system of EC mice by immunoblot analysis. Since spermatogenesis of an advanced mammal cannot be reproduced with in vitro, we performed the microinjection of AFP into the seminiferous tubules of normal mice to determine whether AFP inhibits spermiogenesis in vivo. AFP was directly responsible for the block in spermiogenesis of normal mice. To investigate whether AFP inhibits cell differentiation in other models, using EC mice we performed a partial hepatectomy (PH) that triggers a rapid regenerative response in the remnant liver tissue. We also found that liver regeneration is inhibited in EC mice with PH. The result suggests that AFP released into the blood of EC mice regulates liver regeneration by inhibiting the cell division of hepatocytes. CONCLUSIONS/SIGNIFICANCE: AFP is a well-known cancer-specific marker, but AFP has no known function in healthy human beings. Our findings indicate that AFP expressed under EC conditions plays a role as a regulatory factor in spermatogenesis and in hepatic generation

A Case of Skull Base Chondrosarcoma with Intraoperative Trigemino-Cardiac Reflex

A 75-year-old female patient presented with a suspected recurrence of a clival chordoma. The tumor was resected using the infratemporal fossa type B and anterior petrosal approach with the help of a neurosurgeon. During cauterization of the trigeminal nerve, the patient developed cardiac arrest for approximately 10 seconds because of the trigemino-cardiac reflex (TCR). After several sternal compressions, there was return of spontaneous circulation. The operation was resumed after the circulatory dynamics stabilized. Subsequently, the surgery was completed with partial resection of the tumor without the recurrence of cardiac arrest. The pathological diagnosis was chondrosarcoma, and postoperative treatment with radiotherapy was started. Stimulation of the sensory branches of the trigeminal nerve induces TCR. There are reports of TCR developing in approximately 10% of skull base surgery cases in the absence of atropine administration. We report a rare case of TCR during the surgical procedure for the treatment of a skull base chondrosarcoma

Effects of ethyl-esterization, chain-lengths, unsaturation degrees, and hyperthermia on carcinostatic effect of omega-hydroxylated fatty acids

Aim: To evaluate promotive effect of hyperthermia on the carcinostatic activity of synthesized omega-hydroxy fatty acids (wHFAs) and their ethylesters agaist Ehrlich ascites tumor (EAT) cells. Methods: EAT cells were cultured with either wHFAs or their ethylester derivatives in a water bath at either 37 °C or 42 °C for 30 min, followed by incubation in a CO2 incubator for 20 or 72 h. Mitochondrial dehydrogenase-based WST-1 assay and trypan blue dye exclusion assay were then conducted after incubation. Morphological changes were observed by scanning electron microscopy (SEM). Results: Omega-HFA having a saturated 16-carbon straight-chain (wH16:0) was the most carcinostatic (at 37 °C – viability level: 60.0%; at 42 °C – 49.6% (WST-1)) among saturated and unsaturated wHFAs with 12, 15 or 16 carbon atoms, when administrated to EAT cells at 100 µM for 20 h. Carcinostatic activity was markedly enhanced by ethyl-esterization of saturated fatty acids, such as wH16:0 (at 37 °C – 42.3%; at 42 °C – 11.2% , ibid) and wH15:0 (at 37 °C – 74.6%; at 42 °C – 25.3% , ibid), and their unsaturated counterparts were extremely effective only in combination with hyperthermia. Prolongation of the incubation period to 72 h at the same concentration increased appreciably their carcinostatic effect (wH16:0 ethylesther: 1.3%; wH15:0 ethylesther: 8.0%). These values were also supported by dye exclusion assay. The carcinostatic activity enhanced more markedly by hyperthermia (1.2%; 2.1%, ibid). SEM shows that wH16:0 ethylester-exposed EAT cells underwent extensive injury, such as deformation of cell structure or disappearance of microvilli. Conclusions: wH16:0 ethylester possesses high carcinostatic activity in vitro in combination with hyperthermia and may be utilized as potent anticancer therapeutic agent.Цель: проанализировать усиливающий эффект гипертермии на канцеростатическую активность синтезированных омегагидроксилированных жирных кислот (HFAs) и их этиловых эфиров по отноению к клеткам асцитной опухоли рлиха (EAT). Методы: клетки EAT инкубировали с HFAs или их этилэфирными производными на водной ане при 37 ° или 42 ° в течение 30 мин с дальнейим культивированием в 2 инкубаторе на протяжении 20 или 72 ч, после чего анализировали жизнеспособность клеток методами анализа WST-1, основанного на активности митохондриальных дегидрогеназ, и по включению трипанового синего. Морфологические изменения клеток определяли с использованием сканирующей электронной микроскопии. Результаты: при культивации клеток EAT в присутствии 100 M соединений в течение 20 ч омега-HFA с насыщенной 16-углеродной прямой цепью (H16:0) проявляли наиболее выраженный канцеростатический эффект (при 37 ° уровень жизнеспосоности составил 60,0%; при 42 ° 49,6% (WST-1)) по сравнению с таковым насыщенных и ненасыщенных HFAs, содержащих 12, 15 или 16 атомов углерода. анцеростатическая активность значительно возрастала при этилэтерификации насыщенных жирных кислот, таких как H16:0 (при 37 ° 42,3%; при 42 ° 11,2%, ibid) и H15:0 (при 37 ° 74,6%; при 42 ° 25,3% , ibid), в то время как производные ненасыщенных кислот были высокоэффективны только в комбинации с гипертермией. Увеличение периода инкубации клеток до 72 ч при той же концентрации веществ приводило к значительному увеличению их канцеростатического действия (этиловый эфир H16:0 1,3%; этиловый эфир H15:0 ethylesther 8,0%), подтвержденного данными окраски трипановым синим. рименение гипертермии также усиливало канцеростатическое действие соединений (1,2%; 2,1%, ibid). Результаты исследования методом SEM показали, что клетки EAT, инкубированные с этиловым эфиром H16:0, разруаются с нарушением клеточной структуры и исчезновением микроволокон. Выводы: в комбинации с гипертермией этиловый эфир H16:0 про ет высокую канцеростатическую активность in vitro, что говорит о возможности применения соединения в терапии опухолевых заболеваний

Three Dimensional Motion Analysis of Hand Tremors During Endoscopic Ear Surgery

[Background] Endoscopic surgery is developing in various clinical specialties. During ear endoscopic surgery, a surgeon has to hold an endoscope with one hand and operate the surgical instruments with another hand. Therefore, the stability of the surgeon’s hand affects the field of surgical view and quality of the surgery considerably. There are few techniques which are used during surgery to stabilize the endoscope. However, no study has evaluated the efficacy of such techniques in detail. This study examined the three dimensional movement of an endoscope to compare and evaluate the effect of various stabilization techniques to reduce the hand tremor while using the endoscope. [Methods] A non-randomized controlled trial involving 15 medical students was conducted in Tottori University, Japan. Subjects held an endoscope with their non-dominant hand and manipulated it using three different stabilization techniques i.e. with resting the elbow on the table, resting the endoscope on the ear canal, both with the elbow on the table and endoscope on the ear canal. For the control, subjects were made to use the endoscope without any stabilization technique. The endoscopic movement was measured with and without using the stabilization techniques. [Results] The results obtained in this study indicated that manipulating the endoscope with resting the elbow on the table restrains both vertical (Y-axis) and optical axis (Z-axis) direction of tremor, and manipulating the endoscope by resting it on the ear canal restrains both vertical (Y-axis) and horizontal axis (X-axis) direction while the combined use of both the techniques reduces the endoscope movement in all the three X, Y and Z axes. [Conclusion] In conclusion, concomitant use of both techniques appears to be clinically beneficial in endoscopic ear surgery