Excessive daytime sleepiness in sleep apnea: any role of testosterone or vitamin D?

Recent studies reported association of sleep-disordered breathing (SDB) with testosterone and vitamin D deficiency. Low testosterone and vitamin D levels have been linked to fatigue and excessive daytime sleepiness (EDS). However, the impact of testosterone and vitamin D deficiency on EDS in subjects with SDB remains unknown. The aim of this study was to explore the predictors of EDS in habitual snorers. Role of testosterone, and vitamin D was studied in detail. We also looked for associations between testosterone, vitamin D, and sleep-related indices. We prospectively enrolled 291 consecutive male patients with habitual snoring. Baseline clinical characteristics were recorded on admission. Standard overnight polysomnography was performed to detect SDB, and Epworth Sleepiness Scale (ESS) was used to assess EDS. Blood samples were obtained in a fasting condition in the morning after polysomnography to determine levels of testosterone and vitamin D. Respiratory disturbance index (RDI) (95 % CI: 1.004-1.024, p=0.005) and the use of antihistamines (95 % CI: 1.083-11.901, p=0.037) were the only independent variables significantly associated with EDS in binary logistic regression analysis. In linear multiple regression analysis, body mass index (BMI) (Beta=-0.282, p<0.001) and oxygen desaturation index (Beta=-0.150, p=0.043) were the only independent variables significantly associated with testosterone levels, and BMI (Beta=-0.142, p=0.016) was the only independent variable significantly associated with vitamin D. We failed to find any independent association of testosterone and vitamin D with subjectively rated EDS among habitual snorers. Our results suggest an independent association between the magnitude of nocturnal desaturation and testosterone levels.

Effect of hydrocarbons and crude oil contamination on the sensitivity of French bean to alfalfa mosaic virus.

Determination of local necrotic lesions on primary leaves infected by alfalfa mosaic virus (AMV) revealed that hydrocarbons (HC) contamination of the substrate used for cultivation of French bean (Phaseolus vulgaris L., cv. Black Turtle Soup) caused a reduction of bean leaf area and an increase of plant sensitivity to AMV infection. On the other hand, superficial contamination of the leaves by crude oil caused an inhibition of lesion formation. Changes of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of extractable bean leaf proteins related to the cultivation substrate contamination by HC were also detected.

Susceptibility of some pea cultivars to pea seed-borne mosaic virus infection and virus transmission by seeds.

The susceptibility of 19 pea cultivars to pea seed-borne mosaic virus (PSbMV) by mechanical inoculation and the virus transmission by seeds were determined. All tested cultivars were highly susceptible to the virus infection. The virus transmission by seeds was found in 1.9% - 32.7%. A correlation between mechanical and vector-mediated infections of pea and virus transmission by seeds is discussed.

Resistance of green peas to legume viruses.

A total of 16 green pea cultivars (Pisum sativum L.) were screened for resistance to bean yellow mosaic virus (BYMV), pea enation mosaic virus (PEMV), and alfalfa mosaic virus (AMV). Cvs. Avola, Midget, Wawerplus, Wawerex, Bunny and Banff were found immune to BYMV infection. Cvs. Marx and Pion exhibited a high level (above 95%) of resistance to BYMV, but they were highly susceptible to PEMV and AMV. It is recommended to use BYMV-immune or highly BYMV-resistant cultivars for further breeding. There were no significant differences in AMV levels among the respective pea cultivars.

Tubular structures in cells of cucumovirus-infected Nicotiana glutinosa leaves.

Peculiar tubular structures about 250 nm in diameter were found in cells of Nicotiana glutinosa leaves infected with a cucumovirus strain isolated from field-grown tobacco in southwest Slovakia.

Intraspecies variability in transmission efficiency of stylet-borne viruses by the pea aphid (Acyrthosiphon pisum).

The efficiency of bean yellow mosaic virus (BYMV; Potyvirus group) tranasmission from pea to pea plants by 36 clones of the pea aphid (Acyrthosiphon pisum) was studied. The efficiency of the clones varied; it was not related to the aphid colour form (green, red or yellow) or the origin of the clone (host plant, geographic area). With alfalfa mosaic virus, the virus-vector relationships concerning transmission efficiency were, in general, similar to those found with BYMV. The behaviour of the clones to the circulative pea enation mosaic virus was, however, different.