No abstract

Polymer vesicles formed by a pair of oppositely charged poly(ethylene glycol) (PEG)-based block aniomer and homocatiomer, termed "PICsomes", have tunable size, and are characterized by unique semipermeable property due to the flexible and tunable hydrophilicity of polyion complex (PIC) membranes. The PICsomes can encapsulate a variety of molecules in an inner aqueous phase just by a simple vortex mixing of solution, expecting their utility as nanocontainers of substances with biomedical interests. Here, we report on a new functionality of the PICsomes: photoinduced release of photoactive agents for intracellular drug delivery. A potent photosensitizer, Al(III) phthalocyanine chloride disulfonic acid (AlPcS2a), was efficiently incorporated into the PICsomes (11%(w/w)), and its quick release was induced by photoirradiation possibly due to the photochemical damage of the PIC membranes. The combination of a high-resolution fluorescent confocal microscopy and a lysosome membrane-specific staining method revealed that such photoinduced release of AlPcS2a occurred even in the lysosomes of living cells after endocytic internalization. Simultaneously, the released AlPcS2a photochemically affected the integrity of the lysosomal membranes, leading to the translocation of AlPcS2a and PICsomes themselves to the cytoplasm. Consequently, the AlPcS2a-encapsulated PICsomes (AlPcS2a-PICsomes) exhibited appreciably stronger photocytotoxicity compared with free AlPcS2a alone. Thus, the AlPcS2a-PICsomes have promising feasibility for the photodynamic therapy or the photoinduced cytoplasmic delivery of therapeutic molecules.

Objective: To evaluate the function of the superior and inferior vestibular nerve systems in children with profound sensorineural hearing loss, and to assess the influence of dysfunction of each vestibular nerve system on the development of gross motor function. Study Design: Retrospective study. Setting: A tertiary referral center. Methods: Eighty-nine children (age range: 20–97 months) with profound sensorineural hearing loss who were due to undergo cochlear implant surgery were recruited. Function of the superior vestibular nerve system was evaluated by the damped rotation test and the caloric test, whereas functions of the inferior vestibular nerve systems were evaluated by the vestibular evoked myogenic potential (VEMP) test. Gross motor development was assessed using the age of acquisition of head control and independent walking. Results: Among the children able to complete the vestibular function tests, abnormalities were found in 20% (16 of 84 children) in the damped rotation test, 41% (31 of 75 children) in the caloric test and 42% (26 of 62 children) in the VEMP test. Children who showed abnormal responses in the vestibular function tests showed significantly delayed acquisition of head control (p < 0.05) and independent walking (p < 0.05) in comparison with children with normal responses. The children who showed abnormal responses in all 3 vestibular tests showed the greatest delay in acquisition of gross motor function in comparison with the other groups. Conclusions: Children with profound hearing loss tend to have dysfunction in the superior as well as the inferior vestibular nerve systems. Both the superior and inferior vestibular nerve systems are important for the development of gross motor function in children.

To clarify if migraine-associated vertigo (MAV) and Meniere's disease (MD) share a common pathophysiology, vestibular-evoked myogenic potentials (VEMP) were measured in 11 patients with MAV, 11 with unilateral MD and eight healthy subjects. As acoustic stimuli, tone bursts (TB; 250, 500, 1000 and 2000 Hz) were presented. In healthy subjects, 500-Hz TB evoked the largest amplitude. To quantify this tendency, 500-1000 VEMP slope was calculated, and 500-1000 VEMP slope was the smallest on the affected side of MD patients. Among the 11 MD patients, five had significantly decreased 500-1000 VEMP asymmetry (shift of the tuning to 1000 Hz). Three of the 11 MAV patients also showed a significantly decreased 500-1000 VEMP slope. This finding suggests that MAV might share a common pathophysiology with MD. In addition to this finding, four of the other eight MAV patients showed prolonged p13 latencies. This suggests that MAV could consist of patients with different lesion sites.

No abstract

Multifrequency tympanometry (MFT) is the measurement of the impedance of the middle ear transmission system at a wide range of frequencies from 200 Hz to 2 kHz. A potential use of MFT as a new diagnostic tool for detecting endolymphatic hydrops has recently been reported. However, its clinical usefulness for diagnosing Ménière’s disease (MD) remains unclear. To evaluate the clinical usefulness of MFT as a new qualitative and diagnostic test for MD, we performed MFT in 70 patients with unilateral or bilateral MD and in 29 normal control subjects. The width of double peaks in the admittance tympanograms (Y width) at 2 kHz and the resonance frequency (RF) were analyzed, and receiver operating characteristic (ROC) curves were constructed. The Y width in MD-affected ears was significantly greater than that in control ears (p < 0.001). The RF in MD-affected ears was significantly lower than that in control ears (p < 0.01). Neither the Y width nor RF had a significant relationship with hearing levels or the results of caloric and vestibular myogenic potential testings. The area under the ROC curve was 0.71 for the Y width and 0.66 for the RF. At the optimal cutoff points, the sensitivity and specificity of the Y width were 47.3 and 86.8%, respectively, and those of the RF were 41.3 and 84.2%, respectively. These results indicated that MFT is significantly associated with the presence of MD, but its diagnostic accuracy is only modest. MFT is a simple, noninvasive test, which should be considered as a complementary test in the diagnosis of MD.

The bimolecular annihilation of singlet excitons in pyrene, perylene, and anthracene crystals was studied by the aid of a nitrogen gas laser. The rate constant, γ, for bimolecular annihilation was estimated at 293°K to be 9×10−15 and 8×10−14 cm3 sec−1 for pyrene and perylene, respectively. The temperature dependence of γ was measured with the result that it increases with the increasing temperature for the pyrene and perylene crystals, while it is almost independent of temperature for anthracene between 77°K and 293°K. The difference in the temperature dependence of γ was attributed to the difference in the mechanism of the exciton migration of the crystals. The method developed by the present authors for studying the exciton migration based on the exciton bimolecular annihilation was compared with that obtained previously by the use of mixed crystals.

In our study, we found a recognizable pattern of the midface in three retinoblastoma patients with interstitial deletion of chromosome 13 in lymphocytes. Further photographs of patients reported by other authors confirmed our conclusion that the midface in children with interstitial deletion of 13q from q12 to q22, always involving q14, is characterized by prominent eyebrows, broad nasal bridge, bulbous tip of the nose, a large mouth with a thin upper lip, and a long philtrum. This midface pattern could not be recognized in patients with normal karyotypes, suggesting that the critical segment for the midface phenotype as well as for retinoblastoma may exist in band 13q14.