[Evaluation of hearing results after tympanoplasty according to the classification of the development degree for pars flaccid cholesteatoma].

Our surgical treatment for middle ear cholesteatoma is based on the following 2 concepts: (1) Preservation of the physiological morphology and function of the middle ear, that is, maximal preservation of the posterior wall of the external auditory meatus and the middle ear mucosa and (2) Careful resection of the matrix membrane of the cholesteatoma through the continuity of the matrix membrane. In case the cholesteatoma matrix membrane is ruptured, a staged operation should be performed to prevent the development of residual cholesteatoma from the residual matrix. In this study, we classified a total of 238 cases of the pars flaccida cholesteatoma primary operated on Osaka Red Cross Hospital between January 2006 and March 2008 according to the Classification and Staging of Cholesteatoma proposed in 2010. The age of the patients ranged from 4 to 79 years (average: 49.8 years) and there were 123 males and 115 females. Follow up ranged from 1 year to 5 years with a mean follow-up period of 47.8 months. Regarding the stage, 38 (16.0%) ears had stage I cholesteatoma, 155 (65.1%) ears had stage II, and 45 (18.9%) ears had stage III. The successful outcome rate was 97.4% for stage I, 78.7% for stage II and 60.0% for stage III. The rate of the residue and the postoperative recurrence was 2.5% and 4.2%.

Clinical significance of Rho GDP dissociation inhibitor 2 in colorectal carcinoma.

BACKGROUND: Small GTPase proteins, including RhoA, RhoB, RhoC, Rac1, and cdc42, are important molecules for linking cell shape and cell-cycle progression because of their role in both cytoskeletal arrangements and mitogenic signaling. Over-expression of wild-type or constitutively active forms of RhoA has been shown to induce invasive behavior in non-invasive rat hepatoma cells in vitro. In addition, over-expression of RhoC has been found in melanoma cells with increasing metastatic activity as well as inflammatory breast cancer. These results indicate that overexpression of Rho proteins contributes to cancer cell invasion and metastasis. Rho GDP dissociation inhibitor 2 (RhoGDI2) was recently shown to act as a metastasis suppressor gene in bladder cancer. The purpose of this study was to clarify the clinical significance of this gene expression in patients with colorectal carcinoma. METHODS: Fifty pairs of normal mucosa and cancer specimens obtained at the time of surgery from patients with colorectal cancer (CRC) were subjected to reverse transcription-polymerase chain reaction for RhoGDI2. RESULTS: No patients with RhoGDI2-higher expression tumors had liver metastasis (0 in 8 cases); however, 33.3% (14 in 42 cases) of patients with RhoGDI2-lower expression tumors had liver metastasis. With regard to outcome in relation to RhoGDI2-positivity, RhoGDI2-higher expression tumors had a significant correlation with superior relapse-free survival (RFS) time as compared to RhoGDI2-lower expression tumors in stage III CRC (log-rank test, P < 0.05). Moreover, multivariate analysis indicated that RhoGDI2 was an independent prognostic factor for RFS. CONCLUSION: RhoGDI2 is a novel predictor of RFS in patients with colorectal carcinoma.

Effects of dehydration rate on physiological responses and survival after rehydration in larvae of the anhydrobiotic chironomid.

Strategies to combat desiccation are critical for organisms living in arid and semi-arid areas. Larvae of the Australian chironomid Paraborniella tonnoiri resist desiccation by reducing water loss. In contrast, larvae of the African species Polypedilum vanderplanki can withstand almost complete dehydration, referred to as anhydrobiosis. For successful anhydrobiosis, the dehydration rate of P. vanderplanki larvae has to be controlled. Here, we desiccated larvae by exposing them to different drying regimes, each progressing from high to low relative humidity, and examined survival after rehydration. In larvae of P. vanderplanki, reactions following desiccation can be categorized as follows: (I) no recovery at all (direct death), (II) dying by unrepairable damages after rehydration (delayed death), and (III) full recovery (successful anhydrobiosis). Initial conditions of desiccation severely affected survival following rehydration, i.e. P. vanderplanki preferred 100% relative humidity where body water content decreased slightly. In subsequent conditions, unfavorable dehydration rate, such as more than 0.7 mg water lost per day, resulted in markedly decreased survival rate of rehydrated larvae. Slow dehydration may be required for the synthesis and distribution of essential molecules for anhydrobiosis. Larvae desiccated at or above maximum tolerable rates sometimes showed temporary recovery but died soon after.

Physiological changes leading to anhydrobiosis improve radiation tolerance in Polypedilum vanderplanki larvae.

High tolerance against various extreme environments exhibited by some anhydrobionts might be due to being almost completely desiccated, a state where little or no chemical reactions occur. We have shown that anhydrobiotic larvae of Polypedilum vanderplanki have higher tolerance against both high- and low-linear energy transfer (LET) radiation than hydrated larvae. It is of great interest to know how the desiccating larvae gain radiation tolerance. We therefore examined effects of high-LET radiation on four kinds of larvae: (1) normal hydrated (intact) larva, (2) intermediates between the anhydrobiotic and normal hydrated state, (3) almost completely dehydrated (anhydrobiotic) larvae, and (4) immediately rehydrated larvae that are assumed to have a similar molecular profile to anhydrobiotic larvae. The intermediates and immediately rehydrated larvae survived longer after high-LET radiation than intact larvae, indicating that radiation tolerance could be enhanced even in hydrated larvae. Physiological changes toward anhydrobiosis, e.g. accumulation of protectants or increasing damage repair capacity, correlate with improved radiation tolerance in hydrated larvae. In addition, almost complete desiccation further enhanced radiation tolerance, possibly in a different way from the hydrated larvae.

Estimation of radiation tolerance to high LET heavy ions in an anhydrobiotic insect, Polypedilum vanderplanki.

PURPOSE: Anhydrobiotic larvae of Polypedilum vanderplanki are known to show an extremely high tolerance against a range of stresses. We have recently reported that this insect withstands exposure to high doses of gamma-rays (linear energy transfer [LET] 0.2 keV/microm). However, its tolerance against high LET radiation remains unknown. The aim of this study is to characterize the tolerance to high-LET radiations of P. vanderplanki. MATERIALS AND METHODS: Larval survival and subsequent metamorphoses were compared between anhydrobiotic (dry) and non-anhydrobiotic (wet) samples after exposure to 1 - 7000 Gy of three types of heavy ions delivered from the azimuthally varying field (AVF) cyclotron with LET values ranging from 16.2 - 321 keV/microm. The tolerance against 4He ions was also compared among three chironomid species. RESULTS: At all LET values measured, dry larvae consistently showed greater radiation tolerance than hydrated larvae, perhaps due to the presence of high concentrations of the disaccharide trehalose in anhydrobiotic animals, and the radiation-induced damage became evident at lower doses as development progressed. Relative biological effectiveness (RBE) values based on the median inhibitory doses reached a maximum at 116 keV/microm (12C), and the maximum RBE clearly increased as development progressed. Lower D0 (dose to reduce survival from relative value 1.00 - 0.37 on the exponential part of the survival curve), and higher Dq (quasi-threshold dose) were found in individuals exposed to 4He ions, compared to gamma-rays, and in P. vanderplanki larvae compared to non-anhydrobiotic chironomids. CONCLUSION: Anhydrobiosis potentiates radiation tolerance in terms of larval survival, pupation and adult emergence of P. vanderplanki exposed to high-LET radiations as well as to low-LET radiation. P. vanderplanki larvae might have more efficient DNA damage repair after radiation than other chironomid species.

Biological effects of anhydrobiosis in an African chironomid, Polypedilum vanderplanki on radiation tolerance.

PURPOSE: Anhydrobiotic organisms are known to have an extremely high tolerance against a range of stresses. However, the functional role of anhydrobiosis in radiation tolerance is poorly understood, especially in development following irradiation. The present study aims to evaluate effects of anhydrobiosis on radiation tolerance in an anhydrobiotic insect, Polypedilum vanderplanki. MATERIALS AND METHODS: Larval survival (48 h), anhydrobiotic ability, metamorphosis and reproduction after exposure to 1-9000 Gy of gamma-rays at the larval stage were compared between anhydrobiotic (dry) and normal (wet) phases. RESULTS: Wet larvae were killed in a dose-dependent manner at doses higher than 2000 Gy, and all died within 8 h after 4000 Gy exposure. In contrast, dry larvae survived even 5000 Gy, and some of them still tolerated 7000 Gy and were alive at 48 h after rehydration. Moreover, greater radiotolerance of dry larva, compared to wet ones, was demonstrated in terms of metamorphoses. However, anhydrobiosis did not protect against radiation damage in terms of producing viable offspring. CONCLUSION: These results indicate that anhydrobiosis enhances radiotolerance, resulting in increases of successful metamorphoses.

Induction of anhydrobiosis in fat body tissue from an insect.

The larva of the African chironomid Polypedilum vanderplanki can withstand complete desiccation. Our previous reports revealed that even when the larva is dehydrated without a brain, it accumulated a great amount of trehalose and successfully went into anhydrobiosis. In this paper we determined the viability after rehydration in tissues from the larvae followed by complete dehydration. Only fat-body tissues that were the main producer of trehalose could be preserved in a dry state at room temperature for an extended period of more than 18 months in a viable form. Thus we have confirmed that the central nervous system is not involved in the induction of anhydrobiosis, even in this complex multicellular organism.

[The efficacy of video intubating laryngoscope for novice residents].

BACKGROUND: The visibility and quality of the tracheal intubation may be improved by the video intubating laryngoscope (VIL). However, the efficacy using VIL among novice residents has not been reported. METHODS: Total of 154 cases of tracheal intubation experienced by 5 novice residents in 8 weeks were divided into VIL (X-Lite: Rüsch, Germany) group (n = 59) and ordinary laryngoscope group (OL: n = 95), retrospectively. Number of attempts, success and failure were recorded in both groups. In VIL group, video image of the entire procedure was recorded. Success rates were compared between OL and VIL. In VIL group, elapsed time for intubation and findings during laryngoscopic procedure were examined retrospectively. RESULTS: In the first attempt, the success rate was significantly higher in VIL (83%) than OL (68%). Including secondary attempt, the rate increased to 85% in OL and 97% in VIL, and the difference was also significant. In VIL group, elapsed time for entire intubation was 42 +/- 18 seconds (mean +/- SD). It was significantly decreased in 4, 6 and 7th week compared in the first week. Residents showed different pattern of findings during their laryngoscopic procedure. CONCLUSIONS: The use of VIL improved success rate of tracheal intubation compared with OL. Retrospective analysis of video image revealed their progress and characteristics features in their laryngoscopic procedure. VIL was efficient in the education of the novice residents.