Observational evidence for interhemispheric hydroxyl-radical parity.

The hydroxyl radical (OH) is a key oxidant involved in the removal of air pollutants and greenhouse gases from the atmosphere. The ratio of Northern Hemispheric to Southern Hemispheric (NH/SH) OH concentration is important for our understanding of emission estimates of atmospheric species such as nitrogen oxides and methane. It remains poorly constrained, however, with a range of estimates from 0.85 to 1.4 (refs 4, 7-10). Here we determine the NH/SH ratio of OH with the help of methyl chloroform data (a proxy for OH concentrations) and an atmospheric transport model that accurately describes interhemispheric transport and modelled emissions. We find that for the years 2004-2011 the model predicts an annual mean NH-SH gradient of methyl chloroform that is a tight linear function of the modelled NH/SH ratio in annual mean OH. We estimate a NH/SH OH ratio of 0.97 ± 0.12 during this time period by optimizing global total emissions and mean OH abundance to fit methyl chloroform data from two surface-measurement networks and aircraft campaigns. Our findings suggest that top-down emission estimates of reactive species such as nitrogen oxides in key emitting countries in the NH that are based on a NH/SH OH ratio larger than 1 may be overestimated.

Comparison of iridial pigmentation between latanoprost and isopropyl unoprostone: a long term prospective comparative study.

AIM: To compare incidence of iridial pigmentation prospectively induced by long term treatment with latanoprost and isopropyl unoprostone (hereafter, unoprostone) in Japanese patients with glaucoma. METHODS: Patients with glaucoma treated with prostaglandin (PG) related ophthalmic solutions were sequentially enrolled. Patients treated for more than 30 months with PG related ophthalmic solutions were subjected to analysis. The entry criteria were no history of intraocular surgery, laser iridotomy, and/or laser trabeculoplasty within 12 months before and after the enrolment; and no history of uveitis; no changes in antiglaucoma drugs within 6 months before and after the enrolment. Photographs of the irides were taken under the same conditions and three glaucoma specialists evaluated the iridial pigmentation with masking of patient information. The correlation of iridial pigmentation with the background factors and the reduction of intraocular pressure (IOP) before and after the treatment were investigated. RESULTS: 48 eyes in 48 patients satisfied the enrolment criteria (25 eyes in the latanoprost group, 23 eyes in the unoprostone group). At the end of the follow up period, iridial pigmentation was present in 15 patients (60.0%) in the latanoprost group and seven patients (30.4%) in the unoprostone group. The correlation between development of iridial pigmentation and age, sex, concurrent use of other ophthalmic solutions, and IOP reduction was not significant. CONCLUSIONS: The incidence of iridial pigmentation induced by latanoprost or unoprostone is high in the case of long term treatment. Iridial pigmentation did not affect PG related ophthalmic solution induced IOP reduction.

Safety of ozonated solution as an antiseptic of the ocular surface prior to ophthalmic surgery.

PURPOSE: To evaluate the safety of an ozonated solution as an antiseptic of the ocular surface prior to ophthalmic surgery. METHODS: In experiment 1, a primary culture of rabbit corneal epithelium was established. Then, 0, 4 and 10 ppm ozonated solution and 1.25% povidone-iodine, respectively, were applied to confluent cells on collagen-coated filter inserts (Millicell-CM) for 10 min followed by replacement with fresh medium. The transepithelial electrical resistance (TER), which is a good indicator of cell barrier function, was sequentially measured for 30 min. In experiment 2, adult pigmented rabbit eyes were washed with 20 ml of 4 ppm ozonated solution, 1.25% povidone-iodine solution or saline. Slitlamp examinations were performed before and after washing. RESULTS: In experiment 1, 4 ppm ozonated solution did not change the TER as compared with the control. 10 ppm ozonated solution and 1.25% povidone-iodine similarly reduced the TER values significantly as compared with those of the control and 4 ppm ozonated solution. In experiment 2, 4 ppm ozonated solution and saline showed mild superficial punctate keratitis (SPK) in 8.3% of eyes. However, 1.25% povidone-iodine resulted in mild SPK in 17% of eyes and moderate SPK in 25% of eyes. The prevalence of SPK between two groups was significantly different (p = 0.03). CONCLUSION: Ozonated solution may be safe and a useful antiseptic of the ocular surface prior to ophthalmic surgery.

A sequence change (Arg158Gln) in the leucine zipper-like motif region of the MYOC/TIGR protein.

The myocilin/trabecular meshwork-inducible glucocorticoid response (MYOC/TIGR) gene was identified as a gene that caused open angle glaucoma (OAG). Single-strand conformation polymorphism analysis and subsequent sequence analysis were performed for the MYOC/TIGR gene in 120 unrelated Japanese OAG patients with increased intraocular pressure (IOP), 116 unrelated OAG patients without increased IOP, and 106 unrelated control subjects without glaucoma. An Arg158Gln sequence change in the leucine zipper-like motif (LZM) region in the myosin-homology domain was found in 2 OAG patients with or without increased IOP, and in a 56-year-old control subject without glaucoma. This is the first report of missense sequence change in the LZM region of the MYOC/TIGR protein in subjects showing various phenotypes, including a control subject. These findings suggest that Arg158Gln in the LZM region is probably a rare nondisease-causing polymorphism, despite its important role in this region, because it was found in a control subject, although Arg158Gln was previously reported as a probable disease-causing mutation.

Length of the eustachian tube and its postnatal development: computer-aided three-dimensional reconstruction and measurement study.

Eleven normal human temporal bone-eustachian tube (ET) specimens obtained from 11 individuals whose ages were 3 months to 88 years were studied to investigate the path length along the ET lumen and its postnatal development by means of a computer-aided 3-dimensional reconstruction and measurement method. The path length of the ET lumen of the 3-month-old infant was 21.2 mm, and its growth was in correlation with age to attain its adult length (average, 37.00 +/- 4.16 mm). The ratio of the length of the cartilaginous portion together with the junctional portion to the length of the bony portion was 8:1 in an infant at the age of 3 months and 4:1 in adults. That the bony portion of the ET develops relatively more than the cartilaginous and junctional portions may cause this finding. In addition, there is a developmental shift in the orientation of the cartilaginous portion with respect to the bony portion of the ET. In children, the cartilaginous and bony portions are both aligned with the line that connects the pharyngeal orifice and the tympanic orifice. In adults, however, the cartilaginous portion is angled inferiorly and laterally from the bony portion. This change may reflect the relative growth of the face.

Postnatal development of eustachian tube cartilage. A study of normal and cleft palate cases.

Infants with cleft palate (CP) display eustachian tube (ET) dysfunction. This study compared the postnatal development of the volume of ET cartilage in 34 normal cases and 10 CP cases using a personal computer. In cases with age under 1 month old, the total volume of ET cartilage was 61.94+/-20.89 mm(3) (mean+/-S.D.) in 16 normal control cases and 50.07+/-24.69 mm(3) in nine CP cases (t-test, not significantly different from normal). The ratio of lateral lamina (LL) to medial lamina (ML) volume (LL/ML) was reduced significantly (t-test, P<0.001) from 0.23+/-0.07 in 16 normal control cases to 0.09+/-0.05 in nine CP cases under 1 month old. In 34 normal ET cases whose ages were under 20 years, statistically significant positive correlations were found between the total volume of ET cartilage (y1) and age (x), volume of LL (y2) and age, and volume of ML (y3) and age (P<0.01, r=0.731, 0.614, 0.719). The regression lines were y1=20.37x+95.57, y2=2.02x+15.60, and y3=18. 35x+79.97. With the result obtained from this study, it is assumed that immaturity of the ET cartilage in infants, especially that of LL of the ET cartilage in CP infants, may be a significant risk factor for developing otitis media with effusion.

Multiple temporal bone anomalies in isotretinoin syndrome: a temporal bone histopathologic case report.

Vitamin A and its derivatives are known teratogens. To our knowledge, this is the second temporal bone histopathologic report on anomalies related to these substances. A white boy (aged 4 years 5 months at death) was born with a complex central nervous system dysgenesis related to his mother's use of isotretinoin (Accutane) early in pregnancy. Histopathologic examination revealed multiple anomalies in the temporal bones: a narrow external auditory canal, protrusion of bone marrow into the middle ear cavity, anomalies of the ossicles, hypoplasia of the facial nerve, absence of the chorda tympani nerve and the stapedius muscle, anomalies of the membranous labyrinth in the vestibule, a hypoplastic lateral semicircular canal, and a large vestibular aqueduct and endolymphatic sac.

Histopathological changes of the eustachian tube cartilage and the tensor veli palatini muscle with aging.

OBJECTIVES: The eustachian tube (ET) and the tensor veli palatini muscle (TVPM) are thought to play an important role in ventilatory function. Calcification of the ET cartilage and the replacement of TVPM by fat tissue are often observed histologically in elderly patients. To our knowledge, however, there are no quantitative studies of these pathological findings in relation to age. STUDY DESIGN: The calcification of the ET cartilage and the atrophy of the TVPM in 36 normal human temporal bones obtained from 36 individuals with ages ranging from 2 days to 88 years were investigated. METHODS: The number of calcified chondrocytes in the midportion of the ET cartilage was quantified as the average number of cells per square millimeter. Atrophy of the TVPM was evaluated at the midportion of the site where the TVPM is attached to the tip of lateral lamina of ET cartilage. A grade of 0, 1, 2, 3, or 4 was assessed for each section, which indicated approximately 0% to 5%, 5% to 30%, 30% to 70%, 70% to 95%, or 95% to 100% of the TVPM replacement by fat tissue, respectively. RESULTS: A statistically significant correlation was found between the number of the calcified cells and aging (P < .001). A statistically significant correlation was also found between the degree of the atrophy of TVPM and aging (P < .001). CONCLUSIONS: The calcification of the ET cartilage and the atrophy of the TVPM are closely associated with aging. Therefore, it is suggested that these two findings may be a predisposing factor for ET dysfunction in elderly adults.

Pathophysiological and therapeutic considerations of otitis media with effusion from viewpoint of middle ear ventilation.

Using nitrous oxide, we examined the gas exchange function through the middle ear mucosa in ears with otitis media with effusion (OME) in children, and found the function to be impaired in 50% of them. The size of the mastoid was significantly smaller in ears with negative gas exchange function than those with positive function, and the presence or absence of the function was even more significantly correlated with the presence or absence of aeration in the middle ear. Furthermore, the presence or absence of aeration in ears with OME was found to be significantly correlated with their prognosis (response of OME to antibiotics treatment) and also with the presence or absence of eardrum mobility examined by a pneumatic otoscope. Finally, after myringotomy and removal of effusion, the gas exchange function recovered in most of the ears with impaired function. These results indicate that the eardrum mobility test may serve as an appropriate indicator for the surgical treatment for OME.