Obstructive sleep apnea and heart rate asymmetry microstructure during sleep

Purpose

Heart rate decelerations and accelerations have unequal input to heart rate variability (HRV) and patterns created by consecutive cardiac cycles—this phenomenon is known as heart rate asymmetry (HRA). The analysis of monotonic runs of heart rate decelerations and accelerations provides a detailed insight into the HRA microstructure and thus of HRV.

Aim

To evaluate the relation between the severity of obstructive sleep apnea (OSA) and the HRA microstructure during sleep.

Methods

Seventy-eight patients with suspected OSA underwent overnight polysomnography. The 300-min ECGs from the polysomnography were selected and analyzed. The HRA microstructure was quantified by measuring (1) the contribution of monotonic runs of decelerations or accelerations of different lengths to the number of all sinus beats, and (2) the length of the longest deceleration and acceleration runs.

Results

There were 19 patients with no/mild OSA (Apnea/Hypopnea Index (AHI) 5.1 ± 2.5/h), 18 with moderate OSA (AHI 21.8 ± 4.0/h) and 41 with severe OSA (AHI 42.8 ± 17.4/h). Patients with severe OSA had significantly reduced deceleration and acceleration runs of length 1 compared to the moderate OSA group, and compared to patients with no/mild OSA they had an increased number of longer runs (from 5 to 10 for accelerations and from 5 to 8 for decelerations; p < 0.05 for all comparisons). The longest acceleration runs were significantly longer in severe OSA group (p < 0.05) than in subjects with no/mild OSA.

Conclusions

HRA microstructure is related with OSA severity. An increased number of longer deceleration and acceleration runs is more common in severe OSA patients.     

Pain among the oldest old in community and institutional settings

The relationship between pain and increasing age was investigated using data from two different care settings collected on a province-wide basis in Ontario. Home care clients (HC) and complex continuing care patients (CCC) are assessed using the Resident Assessment Instrument-Home Care and Resident Assessment Instrument 2.0 instruments, respectively, as part of normal clinical practice. For this study, the sample was restricted to those aged 65 years and older and totaled 193,158 individuals. Centenarians (those 100 years of age or older) made up 0.41% (n=788) of the sample. Pain was assessed according to a previously validated pain scale embedded in both assessments that uses items on frequency and intensity. Based on 5-year age groups beginning at 65, the mean reported pain score was lower with each increment in age for men and women. Multiple logistic regression models were constructed and the odds ratios for pain in both HC and CCC groups decreased consistently in higher age groups after adjusting for disease diagnoses, cognition, functional status and health indicators. A model that included categories of analgesic medications coded based on the WHO pain ladder showed the relationship persisted after controlling for analgesia. In clinical settings, the oldest old appear to have lower levels of pain compared with the young old after adjusting for a variety of potential confounding variables.     

The complement system in primary Sjögren’s syndrome: the expression of certain cascade and regulatory proteins in labial salivary glands – observational study

IntroductionThe complement cascade and regulatory proteins are involved in the pathogenesis of the Sjögren’s syndrome and other autoimmune diseases. The complement activation via the alternative pathway was recognized as a major pathogenic mechanism in autoimmune conditions. The aim of this study was to assess expression of complement cascade components and regulatory proteins in minor salivary glands in patients with primary Sjögren’s syndrome (pSS).Materials and methodsThe expression of C1q and C5b-9 – membrane attack complex and regulatory proteins such as: membrane cofactor protein (MCP), decay-accelerating factor (DAF) and protectin were examined using immunochemistry method in specimens from biopsy of minor salivary glands in pSS patients. The biopsy material was obtained from 20 pSS patients, 5 patients with non-specific sialadenitis and from 5 patients with suspicion of dryness syndrome without sialadenitis confirmation.ResultsNone of the examined samples showed the expression of C1q or the effector C5b-9. Membrane cofactor protein expression was lower in pSS group than in both non-specific sialadenitis and noninflamed salivary glands. The inflammatory cells in pSS samples partially expressed MCP. There were differences in the sites and intensity of membrane protectin expression exclusively on the luminal surfaces in pSS; on the luminal and, partially, antiluminal surface in non-specific inflammation, and on the entire cell surface in unaffected salivary glands. There were no DAF expression in salivary gland tissue in biopsy specimens in all studied subjects.ConclusionsThe study demonstrated the absence of complement-cascade proteins (C1q, MAC) in the salivary glands of pSS patients, which may indicated a lack of local complement activation via the classical pathway and the observed gland tissue damage being due to a mechanism other than MAC-induced cytolysis. The differences in the expression of complement regulatory proteins between pSS, non-specific sialadenitis, and normal salivary glands may indicate that alternative functions of these regulatory proteins may be of greater significance in pSS. Low MCP expression in pSS in comparison with non-specific sialadenitis and normal salivary glands, may suggest altered modulation of cell-mediated immunity in pSS. The differences in the location and intensity of protectin (CD59) expression indicates a possibility of reducing the proinflammatory effect of protectin in pSS.     

Renal anaemia treatment in haemodialysis patients in the Central and Eastern European countries in everyday clinical practice follow-up

Background

Chronic kidney disease is almost always accompanied by anaemia. Erythropoietin-stimulating agents (ESA) can increase haemoglobin concentration and thus reduce the frequency of anaemia-related complications including the cardiovascular events.

Aim

The aim of the study was to collect prospective data on 12-month standard ESA therapy used in haemodialyzed patients in selected CEE countries as well as on cardiovascular complications, iron status and anaemia treatment.

Patients and methods

Fifty centres in 3 countries participated in the study. A group of 398 haemodialysed stable patients (M-231, F-167) aged 19–90 years (57.5 ± 14.7) on standard ESA therapy for chronic renal anaemia were recruited. Twelve-month prospective data on iron parameters, ESA therapy and cardiovascular events were collected. The use of iron, folic acid and blood transfusions were also assessed. Patient were divided into three groups according to ESA therapy start: group A—patients who received ESA after start of haemodialysis, group B—patients who received ESA within 3 months from the day of first haemodialysis and group C—patients who had received ESA more than 3 months before haemodialysis. Chi² test for qualitative data and Kruskall–Wallis test for quantitative data with p < 0.05 were used in statistical analysis.

Results

At prestudy period, the mean weekly dose of ESA in group C was statistically lower than in the remaining two groups (3,823 ± 3,169 vs. 5,276 ± 2,915 and 6,427 ± 3,441 units/week, p < 0.001), but during prospective phase of the study the doses did not differ among groups A, B and C. No major fluctuation of ESA administration schedule was observed during the study in the groups; however, at majority of visits, the mean frequency of ESA administration in group C was statistically higher than in groups A and B. At baseline visit, the haemoglobin concentration in group A patients (10.86 ± 1.34 g/dL) was slightly lower than in group B (11.26 ± 1.43 g/dL) and group C (10.98 ± 1.35 g/dL) (p = 0.025), but at subsequent visits these differences disappeared and mean haemoglobin concentration was stable around 11 g/dL. Ferritin concentration increased from 280 ± 241 at baseline to 506 ± 405 at month 12, and no important differences in the groups were observed. The other haematological parameters (haematocrit, iron concentration) remained stable during the entire study. The frequency of blood transfusion and total volume of blood in group C were lower than in groups A and B. During the prospective 12-month follow-up, 23 (5.8 %) of the patients died and 35 (8.8 %) were transplanted. No differences in death or transplantation rate were observed among groups A, B and C. The number of patients with adverse events, serious adverse events or drug-related adverse events in all groups was similar. In conclusion, ESA therapy increased haemoglobin concentration and no major differences in haematological parameters among the groups were observed during the entire study irrespective of early versus late start. Mortality, cardiovascular events or other adverse events were similar among the groups during the observation period; however, the limitation of the study is the sample size.     

The Effect of the Reaction pH on Properties of Lead(II) Azide

Lead(II) azide is an initiating explosive; even a small amount can trigger an explosion caused by simple external stimuli, such as sparks, flames, friction or pinpricks, and is able to initiate the explosive reaction of rock-crushing explosives. Due to the fact that this initiating explosive triggers further reactions, the effect of priming detonators depends on the properties of its material. Its sensitivity is associated with the size of its crystals. For instance, it is used for mining detonators in the form of fine crystals. The quality of the crystals is also correlated to the safety of the production process, i.e., the crystals should be round-shaped rather than needle-like since breaking it would inevitably trigger an explosion. The process of lead(II) azide production on an industrial scale is based on the reaction of lead(II) nitrate with sodium azide with the presence of dextrin, which determines the desired shape of the crystals. The reaction pH affects the number of sediment particles formed in a periodical reactor. Changing the pH from 6.5 to 7.5 leads to the rapid growth of crystal particles.