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.

     

Reactions and Attitudes to Postpartal Mental Symptoms in a Rural Community

We examined the reactions of population, social and health care professionals and local politicians in the context of a narrative case of a newborn and her mother evincing postpartal mental symptoms. The results of this postal questionnaire study indicated that in assessing the urgent need for support, a significant positive association prevailed in the resident cohort with female gender, age over 50 years or being a parent. Professionals and politicians estimated that appropriate care and access to care would be obtained in the maternity and child health clinic in the local health centre. Residents would contact relatives rather than social and health care professionals. A future challenge is to promote the knowledge and sensitivity of the general population in recognizing mental symptoms in mothers with small children. Adequate information is also called for regarding local services and means of access to care.     

Increased activation of blood coagulation in pregnant women with the Factor V Leiden mutation

Background

The risk of venous thromboembolism is enhanced in pregnant carriers of the Factor V Leiden mutation. The primary aim of the study was to compare prothrombin fragments 1 + 2, soluble fibrin and D-dimer levels in pregnant Factor V Leiden mutation carriers with those in non-carriers. Secondary aims were to evaluate whether these biomarkers could predict placenta-mediated complications or venous thromboembolism, and to study blood coagulation after caesarean section with thromboprophylaxis and after vaginal delivery without thromboprophylaxis.

Material/Methods

Prothrombin fragments 1 + 2, soluble fibrin and D-dimer levels were studied longitudinally in 476 carriers with singleton pregnancies from gestational weeks 23–25 until 8–10 weeks postpartum.

Results

Prothrombin fragments 1 + 2 and D-dimer levels gradually increased during pregnancy. D-dimer levels were higher in carriers, both during pregnancy and puerperium, compared to non-carriers. D-dimer levels above 0.5 mg/l were found in about 30% and 20% of the heterozygous carriers at 4–5 and 8–10 weeks postpartum, respectively. Soluble fibrin levels were mainly unchanged during pregnancy, with no difference between carriers and non-carriers. Biomarker levels were similar in carriers with uncomplicated and complicated pregnancies.

Conclusion

Higher D-dimer levels indicate increased blood coagulation and fibrinolysis activity in carriers. The high proportion of carriers with D-dimer levels exceeding 0.5 mg/l postpartum must be considered when assessing the probability of venous thromboembolism. Large overlaps in biomarker levels in normal and complicated pregnancies suggest that these biomarkers cannot be used as predictors. Thromboprophylaxis following caesarean section may prevent increased activation of blood coagulation.     

Cyanobacteria produce a high variety of hepatotoxic peptides in lichen symbiosis

Lichens are symbiotic associations between fungi and photosynthetic algae or cyanobacteria. Microcystins are potent toxins that are responsible for the poisoning of both humans and animals. These toxins are mainly associated with aquatic cyanobacterial blooms, but here we show that the cyanobacterial symbionts of terrestrial lichens from all over the world commonly produce microcystins. We screened 803 lichen specimens from five different continents for cyanobacterial toxins by amplifying a part of the gene cluster encoding the enzyme complex responsible for microcystin production and detecting toxins directly from lichen thalli. We found either the biosynthetic genes for making microcystins or the toxin itself in 12% of all analyzed lichen specimens. A plethora of different microcystins was found with over 50 chemical variants, and many of the variants detected have only rarely been reported from free-living cyanobacteria. In addition, high amounts of nodularin, up to 60 μg g(-1), were detected from some lichen thalli. This microcystin analog and potent hepatotoxin has previously been known only from the aquatic bloom-forming genus Nodularia. Our results demonstrate that the production of cyanobacterial hepatotoxins in lichen symbiosis is a global phenomenon and occurs in many different lichen lineages. The very high genetic diversity of the mcyE gene and the chemical diversity of microcystins suggest that lichen symbioses may have been an important environment for diversification of these cyanobacteria.     

Extreme sarcoplasmic reticulum volume loss and compensatory T-tubule remodeling after Serca2 knockout

Cardiomyocyte contraction and relaxation are controlled by Ca(2+) handling, which can be regulated to meet demand. Indeed, major reduction in sarcoplasmic reticulum (SR) function in mice with Serca2 knockout (KO) is compensated by enhanced plasmalemmal Ca(2+) fluxes. Here we investigate whether altered Ca(2+) fluxes are facilitated by reorganization of cardiomyocyte ultrastructure. Hearts were fixed for electron microscopy and enzymatically dissociated for confocal microscopy and electrophysiology. SR relative surface area and volume densities were reduced by 63% and 76%, indicating marked loss and collapse of the free SR in KO. Although overall cardiomyocyte dimensions were unaltered, total surface area was increased. This resulted from increased T-tubule density, as revealed by confocal images. Fourier analysis indicated a maintained organization of transverse T-tubules but an increased presence of longitudinal T-tubules. This demonstrates a remarkable plasticity of the tubular system in the adult myocardium. Immunocytochemical data showed that the newly grown longitudinal T-tubules contained Na(+)/Ca(2+)-exchanger proximal to ryanodine receptors in the SR but did not contain Ca(2+)-channels. Ca(2+) measurements demonstrated a switch from SR-driven to Ca(2+) influx-driven Ca(2+) transients in KO. Still, SR Ca(2+) release constituted 20% of the Ca(2+) transient in KO. Mathematical modeling suggested that Ca(2+) influx via Na(+)/Ca(2+)-exchange in longitudinal T-tubules triggers release from apposing ryanodine receptors in KO, partially compensating for reduced SERCA by allowing for local Ca(2+) release near the myofilaments. T-tubule proliferation occurs without loss of the original ordered transverse orientation and thus constitutes the basis for compensation of the declining SR function without structural disarrangement.     

Colonic methanogenesis in vivo and in vitro and fecal pH after resection of colorectal cancer and in healthy intact colon

Purpose  

We compared colonic methanogenesis in vivo and in vitro as well as fecal pH in healthy subjects and in patients with resected colorectal cancer thus without the possible confounding effects of the tumor.     

Thyroid effects of endocrine disrupting chemicals

In recent years, many studies of thyroid-disrupting effects of environmental chemicals have been published. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing organism may have deleterious effects on neurological outcome. Chemicals may exert thyroid effects through a variety of mechanisms of action, and some animal experiments and in vitro studies have focused on elucidating the mode of action of specific chemical compounds. Long-term human studies on effects of environmental chemicals on thyroid related outcomes such as growth and development are still lacking. The human exposure scenario with life long exposure to a vast mixture of chemicals in low doses and the large physiological variation in thyroid hormone levels between individuals render human studies very difficult. However, there is now reasonably firm evidence that PCBs have thyroid-disrupting effects, and there is emerging evidence that also phthalates, bisphenol A, brominated flame retardants and perfluorinated chemicals may have thyroid disrupting properties.     

The diagnostic accuracy of an incidental memory modification of the Boston Naming Test (memo-BNT) in differentiating between normal aging and mild Alzheimer's disease

Early Alzheimer's disease (AD) is associated with deficits in episodic memory. Semantic memory and naming have also been found to be affected, although to a lesser degree than episodic memory. Most episodic memory tests used in clinical settings assess intentional memory. The aim of the present paper was to present an incidental memory modification of the Boston Naming Test (memo-BNT) and to study the diagnostic accuracy of the BNT and the memo-BNT in differentiating between healthy old controls and AD patients. There were three groups in the study: 22 young controls (mean age 21.7), 23 normally aged old controls (mean age 70.6), and 23 patients with mild AD (mean age 74.0). There were no differences in the memo-BNT test scores between the old and young control participants. There were, however, significant differences between the AD patients and both control groups in several of the memo-BNT measures. Incidental free recall was the best measure in discriminating between the healthy aged controls and the AD patients (AUC?=?.939) and it had a better diagnostic accuracy than naming (AUC?=?880). The results indicate that the memo-BNT could be used in clinical settings especially to differentiate between normal aging and mild AD.