Association of fine-particulate and acidic-gas air pollution with premenstrual syndrome risk.

OBJECTIVE: Air pollution had been reported to be associated with the reproductive health of women. However, the association of particulate matter (PM) and acid gases air pollution with premenstrual syndrome (PMS) warrants investigation. This study investigated the effects of air pollution on PMS risk. POPULATION: We combined data from the Taiwan Air Quality-Monitoring Database and the Longitudinal Health Insurance Database. In total, an observational cohort of 85 078 Taiwanese women not diagnosed as having PMS. METHODS: Air pollutant concentrations were grouped into four levels based on the concentration quartiles of several types of air pollutants. MAIN OUTCOME MEASURES: We then applied univariable and multivariable Cox proportional hazard regression models to assess PMS risk in association with each pollutant type. RESULTS: Women exposed to Q4-level SO2 exhibited a 7.77 times higher PMS risk compared with those to Q1-level SO2 (95% confidence interval [CI] = 6.22-9.71). Women exposed to Q4-level NOx exhibited a 2.86 times higher PMS risk compared with those exposed to Q1-level NOx (95% CI = 2.39-3.43). Women exposed to Q4-level NO exhibited a 3.17 times higher PMS risk compared with women exposed to Q1-level NO (95% CI = 2.68-3.75). Finally, women exposed to Q4-level PM with a ≤2.5-µm diameter (PM2.5) exhibited a 3.41 times higher PMS risk compared with those exposed to Q1-level PM2.5 (95% CI = 2.88-4.04). CONCLUSIONS: High incidences of PMS were noted in women who lived in areas with higher concentrations of SO2, NOx, NO, NO2 and PM2.5.

Gustatory changes in patients with chronic otitis media, before and after middle-ear surgery.

OBJECTIVE: We investigated gustatory changes in patients with chronic otitis media, before and after middle-ear surgery. METHODS: This prospective study included 38 patients with unilateral chronic otitis media. We used taste testing solutions to evaluate each patient's taste function. Intra-operative assessments of the chorda tympani nerve were also compared and analysed. RESULTS: Patients with chronic otitis media had significantly worse ipsilateral perception of sour, bitter and salty tastes. In patients with good intra-operative preservation of the chorda tympani nerve, there was significant improvement in gustatory function one month post-operatively, compared with the pre-operative baseline. In patients who sustained intra-operative chorda tympani nerve injury, one month post-operative gustatory function was the same as the pre-operative baseline. CONCLUSION: Middle-ear surgery for chronic otitis media not only treats the ear but also improves gustatory function in the majority of patients. In patients with intra-operative injury to the chorda tympani nerve, post-operative taste decline is only temporary.

Three-dimensional analysis of the root morphology of mandibular first molars with distolingual roots.

AIM: To determine the prevalence of distolingual roots in mandibular first molar teeth in Taiwanese Han Chinese, and its impact on root morphology. METHODOLOGY: The presence of distolingual roots in 375 subjects (521 molars) were assessed from 624 patients attending the dental clinics of medical centres around Taiwan island from August 2004 to April 2007 using computed tomography. The following observations were made: (i) numbers of roots and canals, (ii) mesial and distal root types and (iii) levels of furca in the molars presence or absence of distolingual root. RESULTS: The mean age of the subject was 45; 43% were women. Among all the examined molars, 56%, 27% and 18% were two-, three- and four-rooted, respectively. Two per cent, 72% and 26% of molars had two, three and four canals, respectively. All of the four-rooted molars had four canals, but all of the molars with four canals varied in the number of roots. All molars with distolingual roots had two mesial canals. Bilateral consistency in terms of distolingual root, root canal number, root number and root type was observed in subjects with bilateral molars. In molars with distolingual roots, a higher prevalence of two mesial roots and a shorter mesial root trunk were observed than in teeth without distolingual roots. CONCLUSIONS: A distolingual root was found in 22% of molars and in 24% of the subjects examined. Most subjects with a distolingual root had them bilaterally. The presence of a distolingual root was associated with variation in the root morphology, including the furcation level, the root type and the number of roots and canals.

Three-dimensional image analysis of the temporal bone in patients with unilateral attic cholesteatoma.

We determined temporal bone anatomy in patients with unilateral attic cholesteatoma. We compared the affected and normal ears of ten patients with unilateral attic cholesteatoma using three-dimensionally reconstructed high-resolution computed tomography images of the temporal bone. We determined the eustachian tube angle, eustachian tube length, sizes of the tympanic orifice of the eustachian tube, the pars flaccida, and the mastoid cavity, and distances of the pars flaccida and the tympanic orifice of the eustachian tube from the epitympanic roof. No significant differences were found between the normal and affected ears with regard to the size of the eustachian tube orifice, eustachian tube length or distances of the pars flaccida and the tympanic orifice of the eustachian tube from the epitympanic roof. By contrast, the mastoid cavity and the eustachian tube angle were significantly larger in the normal ears than in the affected ears [mean, 6.99 cm(3) (S.D.,4.9 cm(3)) vs. 1.28 cm(3) (0.81 cm(3)) and 16.7° (4.12°) vs. 13.89° (5.30°), respectively]. The pars flaccida was significantly smaller in the normal ears [1.07 cm (0.31 cm)] than in the affected ears [2.19 cm (0.77 cm)]. The inherent anatomy of the eustachian tube may be particularly important in the formation of attic cholesteatomas.

Oxidative stress in nonallergic nasal polyps associated with bronchial hyperresponsiveness.

BACKGROUND: Nasal polyposis (NP) is a chronic inflammatory disease of upper airway with unknown etiology. NP is frequently associated with asthma; the interaction between these comorbidities remains interesting. Oxidative stress has been implicated in the pathophysiology of NP and asthma. The aim of this study is to investigate the significance of oxidative stress in sinonasal microenvironments by evaluating its association with clinopathological parameters and its impacts on the pathogenesis of bronchial hyperresponsiveness (BHR) in NP. METHODS: Polyp biopsy specimens were obtained from 20 nonallergic patients; control mucosas were obtained from 20 volunteers. The levels of free radicals in the tissues and in blood were determined by a sensitive chemiluminescence (CL) method. NP patients were substratified into three subgroups, NP without BHR, NP with asymptomatic BHR, and NP with BHR and asthma by the results of provocative testing. Four histological characteristics of NP, inflammatory cells, eosinophil infiltration, edema and fibrosis were estimated and applied to correlate with the tissue-CL. RESULTS: The mean CL level in polyp-tissues, but not in blood, was higher than in the control specimens. In NP patients, tissue-CL was associated with endoscopy score; high tissue-CL levels were positively correlated with the abundance of inflammatory cells and eosinophils. Tissue-CL and endoscopy score were associated with BHR/asthma phenotype. CONCLUSION: These results suggest an important role for oxidative stress in the pathophysiology of NP and a causal relation between oxidative stress and inflammatory cells, especially the eosinophils. Free radical levels in polyp-tissues associated with NP severity and with BHR/asthma phenotype in nonallergic NP patients.

Electrons ejected with half the projectile velocity and the saddle point mechanism in ion-atom collisions

Full three-dimensional ejected electron momentum distributions for proton impact ionization of atomic hydrogen are calculated for impact energies 10 through 50 keV. The distributions show a peak in the longitudinal momentum at half the projectile impact velocity: the v/2 peak. A quantitative assessment of saddle point ionization, based on quantum and classical analysis, reveals that the v/2 peak is a false indicator for this mechanism. The influence of the potential saddle on ionization is seen to decrease rapidly from 10 to 50 keV.

Efficient method for calculating the resonance energy expression of benzenoid hydrocarbons based on the eunumeration of conjugated circuits

To reduce the calculating time for the summations over linearly independent and minimal conjugated circuits of benzenoid hydrocarbons (BHs), an approximate method is proposed that counts only the numbers of the first four classes of conjugated circuits R1, R2, R3, and R4, respectively. By representation of BHs as custom-made "ring-block chains" and use of the techniques of Database and visual computing, an application software is realized that is much faster and more powerful than the old one based on an enumeration technique.