Gender-specific change in leptin concentrations during long-term CPAP therapy

Purpose

Nasal continuous positive airway pressure (CPAP) alleviates sleepiness in patients with obstructive sleep apnoea syndrome (OSAS), but part of OSAS patients keep gaining weight. Leptin and insulin-like growth factor-1 (IGF-1) interact with energy balance, and CPAP therapy has been suggested to influence these endocrine factors. We hypothesised that leptin would decrease during long-term CPAP therapy, and weight gain would associate with OSAS severity, lower CPAP adherence, lower IGF-1, and leptin concentrations.

Methods

Consecutive patients (n?=?223) referred to sleep study with suspected OSAS were enrolled. Patients underwent cardiorespiratory polygraphy at baseline. Questionnaires were completed, and blood samples were drawn both at baseline and after 3 years. A total of 149 (67%; M 65, F 84) patients completed the follow-up. Plasma samples were available from 114 patients, 109 of which with CPAP adherence data (49 CPAP users, 60 non-users).

Results

At baseline, the CPAP users were more obese and had more severe OSAS than the non-users. Leptin concentrations did not differ. After follow-up, leptin concentrations were higher in CPAP users (30.2 ng/ml vs. 16.8 ng/ml; p?=?0.001). In regression analysis, increase in leptin concentrations was independent of age, baseline body mass index (BMI), or the change in BMI. Leptin concentrations increased among females (??8.9 vs. 12.7 ng/ml; p?<?0.001); whereas in men, CPAP did not have an effect, if not opposed the natural decrease in leptin observed in men not using CPAP. Change in IGF-1 levels did not differ.

Conclusions

Our results suggest increase in leptin concentrations during long-term CPAP therapy among females.

     

DNA Flow Cytometry in Surgically Treated Lung Cancer: Prognostic Significance

Although DNA aneuploidy and high proliferative activity (S-phase fraction, SPF) of tumour cells, measured by flow cytometry, have proved to be indicators of poor prognosis in most solid tumours, there have been conflicting results in lung cancer studies. During a four-year period we studied the prognostic significance of DNA ploidy and SPF in 99 surgically treated lung cancer patients. Flow cytometric analysis was done from archival, formalin-fixed, paraffin-embedded tumour specimens. DNA index and SPF were determined, using MultiCycle software with sliced nuclear correction to compensate for debris. There were 61 DNA diploid and 38 DNA aneuploid tumours. The median SPF was 10.2%. Neither ploidy nor SPF was associated with previously known prognostic factors. Survival was poorer in patients with aneuploid tumours than in the other patients, but the difference was not statistically significant. DNA ploidy and SPF thus do not seem to be useful prognostic indicators in surgically treated lung cancer.     

Spontaneous recovery of myocardial function after ligation of Ameroid-stenosed coronary artery

Objectives. We aimed to assess the spontaneous healing of myocardial function after occlusion of a chronically stenosed coronary vessel in a porcine model. Design. Ischemia and infarction was produced by Ameroid constrictor placement and a subsequent ligation of the left circumflex artery. Cardiac MRI and 18FDG-PET were performed one and five weeks later. Ki67 staining was used to identify proliferating cells. Results. Restoration of perfusion defect was detected by MRI (p=0.0065), reduced systolic function of the lateral segment spontaneously recovered (p=0.03). There was also a suggestive raise in impaired ejection fraction (p=0.06). Left ventricular early diastolic filling and peak filling rate were substantially improved (p=0.039 and p=0.0078). Scar size reduced (p=0.03). On the 18FDG-PET, deranged metabolism was alleviated (p=0.03). Cardiomyocytes with positive Ki-67 staining were located principally in the non-infarcted myocardium as compared to the infarction or border areas (p=0.037). Conclusions. We demonstrated spontaneous functional healing of ischemic and infarcted left ventricle, suggesting border zone perfusion recovery. Scar reduction was detected. Different pattern of myocyte proliferation between infarction and non-ischemic myocardium was seen.     

Psychosocial work environment and cross‐cultural competence among native and foreign‐born registered nurses

Cross‐cultural competence is an essential component of the nursing profession, but little is known about the specific psychosocial work characteristics that potentially promote or hinder such competence. In the present study, psychosocial work characteristics were based on Karasek's Job Demand—Control Model. The researchers examined whether Karasek's psychosocial work characteristics, such as high‐strain jobs, high‐strain isolated jobs, active jobs, and active collective jobs, are associated with cross‐cultural competence (empathy, skills, positive attitudes, and motivation), and whether there are differences between native and foreign‐born registered nurses (RN) in these potential associations. A random sample of 744 native RNs (91.0% women) and a total sample (n = 212) of foreign‐born RNs (94.3% women) working in Finland were used. Data were collected using a questionnaire and analyzed with a series of multiple linear regression analyses. High‐strain and high‐strain isolated jobs were negatively associated with all four dimensions of cross‐cultural competence. Active collective jobs, but not active jobs, were positively associated with cross‐cultural skills. There were no differences between native and migrant nurses in these associations. The psychosocial work environment is associated with cross‐cultural competence in both native and migrant nurses. Improvements in psychosocial working conditions, especially minimizing negative factors in the work environment, such as high‐strain and high‐strain isolated jobs, may need to be considered as a part of the efforts aimed to enhance cross‐cultural competence among nursing personnel.     

Periodic properties of the histaminergic system of the mouse brain

Brain histamine is involved in the regulation of the sleep–wake cycle and alertness. Despite the widespread use of the mouse as an experimental model, the periodic properties of major markers of the mouse histaminergic system have not been comprehensively characterized. We analysed the daily levels of histamine and its first metabolite, 1‐methylhistamine, in different brain structures of C57BL/6J and CBA/J mouse strains, and the mRNA level and activity of histidine decarboxylase and histamine‐N‐methyltransferase in C57BL/6J mice. In the C57BL/6J strain, histamine release, assessed by in vivo microdialysis, underwent prominent periodic changes. The main period was 24 h peaking during the activity period. Additional 8 h periods were also observed. The release was highly positively correlated with active wakefulness, as shown by electroencephalography. In both mouse strains, tissue histamine levels remained steady for 24 h in all structures except for the hypothalamus of CBA/J mice, where 24‐h periodicity was observed. Brain tissue 1‐methylhistamine levels in both strains reached their maxima in the periods of activity. The mRNA level of histidine decarboxylase in the tuberomamillary nucleus and the activities of histidine decarboxylase and histamine‐N‐methyltransferase in the striatum and cortex did not show a 24‐h rhythm, whereas in the hypothalamus the activities of both enzymes had a 12‐h periodicity. These results show that the activities of histamine‐metabolizing enzymes are not under simple direct circadian regulation. The complex and non‐uniform temporal patterns of the histaminergic system of the mouse brain suggest that histamine is strongly involved in the maintenance of active wakefulness.     

Pressure injury prevalence and incidence in acute inpatient care and related risk factors: A cross‐sectional national study

The aim of this national cross‐sectional study was to explore the prevalence of pressure injuries and incidence of hospital‐acquired pressure injuries, and the relating factors in somatic‐specialised inpatient care in Finland. The study was conducted in 16 (out of 21) Finnish health care organisations offering specialised health care services. Data were collected in 2018 and 2019 from adult patients (N = 5902) in inpatient, emergency follow‐up, and rehabilitation units. Pressure injury prevalence (all stages/categories) was 12.7%, and the incidence of hospital‐acquired pressure injuries was 10%. Of the participants, 2.6% had at least one pressure injury at admission. The risk of hospital‐acquired pressure injuries was increased for medical patients with a higher age, the inability to move independently, mode of arrival, being underweight, and the absence of a skin assessment or pressure injury risk assessment at admission. For surgical patients, the risk was associated with the inability to move independently, mode of arrival, and lack of skin assessment at admission, while being overweight protected the patients. Overall, medical patients were in greater risk of hospital‐acquired pressure injuries than the surgical patients. An assessment of the pressure injury risk and skin status should be carried out more systematically in Finnish acute care hospitals.