Arterial Stiffness in Patients with Sarcoidosis and Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) and sarcoidosis have both been implied to be risk factors for increased arterial stiffness. However, it is unclear whether an elevated apnea–hypopnea index (AHI) in sarcoidosis patients increases arterial stiffness and thus the cardiovascular risk. Methods: We performed non-invasive applanation tonometry in 57 adults with sarcoidosis. The participants underwent SphygmoCor to assess arterial stiffness using an aortic augmentation index with a heart rate of 75/min (AIx) and level-3 respiratory polygraphy. An AHI of ≥5/h, ≥15/h, and ≥30/h defined mild, moderate, and severe OSA, respectively. Multivariate regression analysis was used to investigate the association between AIx and AHI, adjusted for prespecified risk factors for AIx. Results: 23 (40%) sarcoidosis patients had at least mild OSA (AHI ≥ 5), while 7 (12%) patients showed AHI ≥ 15/h. AHI was significantly associated with AIx (coef. (95%CI) of 0.31 (0.09/0.52), p = 0.006) even after adjustment for known risk factors of arterial stiffness. While severe OSA was positively associated with increased AIx, mild and moderate OSA were not associated with increased AIx after adjusting for known risk factors. Conclusions: Increased AHI is independently associated with increased arterial stiffness in sarcoidosis patients. Further investigations are needed to underline the association between OSA severity and the magnitude of arterial stiffness

The effect of longitudinal sleep monitoring on clinician agreement in obstructive sleep apnea diagnosis: The ELSA study

There is strong evidence for clinically relevant night‐to‐night variability of respiratory events in patients with suspected obstructive sleep apnea. Sleep experts retrospectively evaluated diagnostic data in 56 patients with suspected obstructive sleep apnea. Experts were blinded to the fact that they were diagnosing the same case twice, once based on a short report of a single in‐laboratory respiratory polygraphy and once with the additional information of 14 nights of pulse oximetry at home. All experts (n = 22) were highly qualified, 13 experts (59.1%) treated > 100 patients with suspected obstructive sleep apnea per year. In 12 patients, the apnea–hypopnea index in the respiratory polygraphy was  100 per year compared with 0–29 patients per year (Coef. [95% confidence interval] −0.63 [−1.22/−0.04] and −0.61 [−1.07/−0.15], respectively). Experts found already a high level of consensus regarding obstructive sleep apnea diagnosis, severity and continuous positive airway pressure recommendation after a single respiratory polygraphy. However, longitudinal sleep monitoring could help increase consensus in selected patients with diagnostic uncertainty

Are Predictors for Overall Mortality in COPD Patients Robust over Time?

(1) Background: Mortality is a major outcome in research on chronic obstructive pulmonary disease (COPD) with various predictors described. However, the dynamic courses of important predictors over time are disregarded. This study evaluates if longitudinal assessment of predictors provides additional information on the mortality risk in COPD when compared with a cross-sectional analysis.; (2) In a longitudinal, prospective, non-interventional cohort study including mild to very severe COPD patients, mortality and its various possible predictors were annually assessed up to seven years.; (3) Results: 297 patients were analysed. Mean (SD) age was 62.5 (7.6) years and 66% males. Mean (SD) FEV1 was 48.8 (21.4)%. A total of 105 events (35.4%) happened with a median (95% CI) survival time of 8.2 (7.2/NA) years. No evidence for a difference between the raw variable and the variable history on the predictive value for all tested variables over each visit was found. There was no evidence for changing effect estimates (coefficients) across the study visits due to the longitudinal assessment; (4) Conclusions: We found no evidence that predictors of mortality in COPD are time dependent. This implies that cross-sectional measured predictors show robust effect estimates over time and multiple assessments seem not to change the predictive value of the measure

Augmentation Index in Patients with Thoracic Aortic Aneurysm: A Matched Case-Control Study

Thoracic aortic aneurysms (TAA) may be associated with complications such as rupture and dissection, which can lead to a fatal outcome. Increased central arterial stiffness has been proposed to be present in patients with TAA compared to unmatched controls. We aimed to assess whether wall properties in patients with TAA are also altered when compared to a matched control group. Applanation tonometry was performed in 74 adults with TAA and 74 sex, age, weight, height, and left ventricular ejection fraction matched controls. Subsequently analysis of the pulse wave was done using the SphygmoCor System. For comparing the two groups, AIx was adjusted to a heart rate of 75/min (AIx@75). 148 1-to-1 matched participants were included in the final model. There was no significant difference in the Alx@75 between the TAA group and the matched control group [mean (SD) of 24.7 (11.2) % and 22.8 (11.2) %, p = 0.240]. Adjusted for known cardiovascular risk factors, there was no association between TAA and AIx@75. Patients with TAA showed comparable arterial wall properties to cardiovascular risk factor matched controls. Since higher arterial stiffness is associated with TAA progression, it remains to be investigated if increased central arterial stiffness is a relevant factor of TAA emergence. Keywords: thoracic aortic aneurysm; augmentation index; arterial stiffnes

Alternative phenotypes of male mating behaviour in the two-spotted spider mite

Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male–male combat for available females. This may provide opportunity for weaker males to avoid fighting by adopting alternative mating behaviour such as sneaker or satellite tactics as observed in other animals. We investigated male precopulatory behaviour in the two-spotted spider mite by means of video-techniques and found three types of male mating behaviour: territorial, sneaker and opportunistic. Territorial and sneaker males associate with female teleiochrysales and spend much time guarding them. Territorial males are easily disturbed by rival males and engage themselves in fights with them. However, sneaker males are not at all disturbed by rival males, never engage in fights and, strikingly, never face attack by territorial males. Opportunistic males wander around in search of females that are in the teleiochrysalis stage but very close to or at emergence. To quickly classify any given mate-guarding male as territorial or sneaker we developed a method based on the instantaneous response of males to disturbance by a live male mounted on top of a brush. We tested this method against the response of the same males to natural disturbance by two or three other males. Because this method proved to be successful, we used it to collect territorial and sneaker males, and subjected them to morphological analysis to assess whether the various behavioural phenotypes are associated with different morphological characters. However, we found no statistical differences between territorial and sneaker males, concerning the length of the first legs, the stylets, the pedipalps or the body. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10493-013-9673-y) contains supplementary material, which is available to authorized users

Der spezifische Porenblocker AMBnTbeta-CD hemmt die Zellvergiftung durch Clostridium difficile Transferase und Diphtherie-Toxin

In der vorliegenden Arbeit wurde die Wirksamkeit des spezifischen Porenblockers AMBnTbeta-CD gegen die Intoxikation mit Clostridium difficile Transferase (CDT) von Clostridium difficile und Diphtherie-Toxin (DT) von Corynebacterium diphtheriae an verschiedenen Zelllinien untersucht. Bei CDT handelt es sich um ein binäres ADP ribosylierendes AB-Toxin, während das DT zur Familie der einkettigen ADP ribosylierenden AB-Toxine gehört. AMBnTbeta-CD ist ein symmetrisch 7-fach geladener Zuckerring, der ein Derivat der beta-Cyclodextrine darstellt. Es wird angenommen, dass dieser Inhibitor die Translokationspore bestimmter Toxine blockt und auf diese Weise die zytotoxische Wirkung der Toxine verhindert. In der vorliegenden Arbeit konnte gezeigt werden, dass AMBnTbetra-CD eine konzentrations- und zeitabhängige Inhibierung der Intoxikation von Vero-Zellen durch CDT aufweist. Die Messung des filamentären Aktingehalts (F-Aktin) der Vero-Zellen konnte die konzentrations- und zeitabhängige Hemmung der Depolymerisation des F-Aktins, die spezifisch für die CDT-Intoxikation ist, nachweisen. Durch Bindungsversuche und Enzymaktivitätsmessungen konnten eine reduzierte Rezeptorbindung und eine geminderte enzymatische Aktivität des Toxins als Wirkungsmechanismus des Inhibitors ausgeschlossen werden. Messungen der Proteinbiosynthese durch den H³-Leucin Aufnahmetest bei Vero- und CHO-K1 Zellen, die mit DT vergiftet wurden, zeigen, dass AMBnTbeta-CD auch die Intoxikation durch DT zeit- und konzentrationsabhängig inhibiert. Es konnte auch hier gezeigt werden, dass dieser Hemmeffekt nicht auf eine reduzierte Rezeptorbindung oder geminderte enzymatische Aktivität des DT zurückzuführen ist. Zusammenfassend unterstützen die Ergebnisse dieser Arbeit die Hypothese, dass es sich bei AMBnTbeta-CD nicht nur um einen universellen Inhibitor der binären ADP-ribosylierenden AB-Toxine handelt, sondern dass AMBnTbeta-CD auch einkettige AB-Toxine inhibiert