Serum leptin concentrations in pre- and postmenopausal women on sex hormone therapy.

AIM: The aim of the present study was to investigate the influence of endogenous estradiol and estrogen and estrogen-progestin therapies on concentration in pre- and postmenopausal women. MATERIALS AND METHODS: The study groups consisted of 26 women with surgical menopause (mean+/-standard deviation (SD): age 51.8+/-2.6 years, body mass index (BMI) 26.45+/-4.56 kg/m(2)), 54 with natural menopause (mean+/-SD: age 50.5+/-3.0 years, BMI 25.75+/-4.09 kg/m(2)) and 40 premenopausal controls (mean+/-SD: age 48.3+/-2.3 years, BMI 26.23+/-4.12 kg/m(2)). The group with surgical menopause received estradiol transdermally (50 microg/day) and those with natural menopause received additionally medroxyprogesterone acetate (5 mg/day) for the last 12 days of the cycle. Before and after 4 months of therapy, body weight, waist and hip circumferences and blood pressure were measured, and BMI and waist-to-hip ratio (WHR) were calculated. Serum leptin, follicle-stimulating hormone (FSH), estradiol (E(2)), testosterone, prolactin and dehydroepiandrosterone sulfate (DHEAS) were measured prior to and after treatment. RESULTS: Leptin concentrations did not differ statistically among the groups. No correlations between leptin and E(2), FSH, prolactin, testosterone and DHEAS concentrations were found in any of the groups before and after treatment. Leptin level correlated positively with body mass, BMI and hip and waist circumferences in all groups. There were no correlations between leptin and WHR in the pre- and postmenopausal groups. In the premenopausal group and in some postmenopausal groups, serum leptin level correlated with blood pressure. CONCLUSIONS: Endogenous E(2) and androgens in premenopausal women and estrogen and estrogen-progestin therapies in postmenopausal subjects do not influence serum leptin concentrations. Leptin level is related to body mass and BMI, but not to sex hormone status. The distribution of adipose tissue and the type of obesity (android or gynoid) have no influence on serum leptin concentration. The correlation between serum leptin level and blood pressure requires further investigation.     

Hydrophobic surfactant effects on aortic cholesterol accumulation and atherosclerosis in hypercholesterolemic rabbits

Studies were performed in hypercholesterolemic rabbits to determine whether the hydrophobic surfactant, Poloxalene 2930 (Pol), is of benefit under these conditions. Lipoprotein analyses plus chemical and morphologic studies of the aorta were performed to evaluate the results. In one study, rabbits were made hypercholesterolemic by dietary means and then divided into two groups and given a cholesterol-free diet with one group additionally given Pol with treatment continued for 10 weeks. Pol treatment resulted in less atherosclerosis but the mechanism for this effect was not apparent from lipoprotein analysis. In the other study 3 groups of rabbits were given a cholesterol-rich diet for 16 weeks. Two groups received Pol supplement with one of these groups receiving a dose that was too small to prevent hypercholesterolemia. In this group plus the group on diet alone comparable degrees of hypercholesterolemia were maintained throughout the study. Lipoprotein abnormalities were similar in these two groups except that those on Pol had a more normal cholesterol to apolipoprotein B ratio. The amount of atherosclerosis in both groups was mild but aortic cholesterol content was much less for the Pol group. It is concluded that Pol limits cholesterol accumulation in the aortic wall of hypercholesterolemic rabbits and can retard the development of atherosclerosis.     

Analysis of blood and hair to investigate the magnesium status of neonates and their mothers.

We examined 83 mothers from Szczecin (north-west part of Poland) and their 83 neonates. Concentrations of total and ionized magnesium in maternal and cord serum, as well as total magnesium in hair were determined. Higher levels of total magnesium were noted in neonates (cord serum, hair) than mothers. A positive correlation was ascertained between total magnesium in maternal and cord serum. Magnesium in maternal hair correlated negatively with ionized magnesium in cord serum. Male neonates demonstrated higher levels of magnesium in cord blood and hair than females. There was no effect of maternal age, education level, or number of past pregnancies on the concentration of magnesium in mothers or neonates.     

Habitual physical activity and estradiol levels in women of reproductive age.

Variation in the risk of breast cancer observed among women and among populations may be explained by variation in lifetime exposure to estrogens. The suppressive effect of exercise on estradiol levels in women is well documented, but it is unknown whether habitual (i.e. typical daily) physical activity has a similar effect. Epidemiological data suggest that physical activity is one of the few modifiable factors capable of reducing the risk of breast cancer in women. We investigated whether variation in the amount of habitual activity corresponds to variation in estradiol levels in women of reproductive age. One hundred and thirty-nine regularly menstruating women 24-37 years of age collected daily saliva samples for one complete menstrual cycle and kept a daily log of physical activity. Saliva samples were analyzed for concentration of estradiol. We observed a negative relationship between habitual physical activity and salivary levels of estradiol. Mean estradiol was 21.1 pmol/l in the low, 17.9 pmol/l in the moderate and 16.6 pmol/l in the high activity group (all pairwise differences were statistically significant at P<0.009). A strong association exists between physical activity and levels of estradiol among women of reproductive age. A modern lifestyle, characterized by reduced physical activity, may therefore contribute to a rise in the levels of estradiol produced during menstrual cycles and thus to higher cumulative lifetime exposure to estradiol, resulting in a higher risk of breast cancer.     

CADASIL or CADVaSIL?

In the present study, morphological examination of patients from two unrelated Polish families with CADASIL was performed. Using light microscopy, there were evident changes characteristic to the disease. On electron microscopy, deposits of granular osmiophillic material (GOM) were found not only in cerebral arteries and veins but also in cerebral capillaries and vessels of the internal organs. These findings indicate that pathological process in CADASIL is generalized and involves also small vessels devoid of smooth muscle cells. Therefore, we propose to consider a replacement for the name CADASIL that better reflects the morphological picture of the disease like, for example, cerebral autosomal dominant vasculopathy with subcortical infarcts and leukoencephalopathy (CADVaSIL) or, to preserve the commonly known acronym, cerebral autosomal dominant angiopathy with subcortical infarcts and leukoencephalopathy.     

The reaction of antibodies with the native and deglycosylated thyrotropin receptor obtained from transfected insect cells

The role of glycan moieties in thyrotropin receptor molecule in binding of antibodies is a subject of intense debate. To approach the function of sugars in recognition by antibody of the extracellular part of the receptor (ETSHR) we studied the reaction of the HPLC purified ETSHR from insect cells in the reaction with autoantibodies and antibodies of animal origin. None of the autoantibodies from Graves' patients sera bound to ETSHR. In contrast, each of the animal antibodies: three monoclonal, five polyclonal antireceptor and two polyclonal anti peptide corresponding to the amino acid sequence present in the receptor, became bound to the native receptor from insect cells as well as to its deglycosylated form. The shape of the dilution curves of particular antibodies in the reaction with either form of the receptor was almost the same. The coefficients of correlation was about 0.9. It seems that the correct receptor glycosylation is not crucial for binding of animal origin antibodies.     

Anionic block polymerization initiated by potassium solutions, 2. Synthesis of poly(2-oxetanone)-block-polystyrene-block-poly(2-oxetanone)

The block polymerization of styrene with 2-oxetanone (β-propiolactone) proceeds fast with a yield of more than 90%, in the presence of potassium solutions in THF containing 18-crown-6. Poly(2-oxetanone)-block-polystyrene-block-poly(2-oxetanone) ABA triblock polymers having the expected molecular mass and composition are formed. Their glass transition and melting temperatures as well as their melting enthalpies determined by DSC show a strict correlation with block polymer composition. The mechanism of this block polymerization involving acyloxygen and alkyl-oxygen bond scission in 2-oxetanone is in good agreement with previous results of the homopolymerization of β-lactones by alkali metal solutions abounding in potassium anions.     

Temperature can prime human peripheral blood neutrophils in a p38MAPKalpha-dependent manner

INTRODUCTION: Previous ex vivo experiments by others suggest that elevated body temperature can prime the respiratory burst of human neutrophils. The mechanism of the priming phenomenon induced by temperature has not been addressed so far. Furthermore, the priming temperature range was not defined. MATERIAL/METHODS: In the present study we explored ,under in vitro conditions, the influence of febrile-range temperatures on reactive oxygen species (ROS)generation by human peripheral blood neutrophils. ROS production was measured using whole.blood luminol-dependent chemiluminescence. Two elements of signal transduction pathways, calcium and p38 mitogen.activated protein kinase alpha (p38MAPKalpha) ,frequently underlying neutrophil priming were also examined.Calcium levels in the cytosol of resting and fMLP. stimulated isolated neutrophils were measured with the Fura-2AM spectrofluorimetric method. The activity of p38MAPKalpha was assessed indirectly with a specific inhibitor of the kinase, SB 203580. RESULTS: The study revealed a priming effect at 38 degrees C toward human peripheral blood neutrophil ROS production. Any concomitant effect on calcium response was not observed. Instead, experiments with SB 203580,a specific inhibitor of p38MAPKalpha, pointed to an increased activity of the kinase as a molecular background of temperature-induced priming. However, the priming effect of temperature was confined to 38 degrees C, while higher temperatures proved to exert no effect (39 and 40 degrees C)or even inhibited ROS generation by neutrophils (43 degrees C). CONCLUSIONS: Our study suggests a heterogeneous influence of temperature on human neutrophil functioning, including the priming of the cells by a low-febrile-range temperature. It also suggests a p38MAPKalpha-dependent molecular background of the priming phenomenon.     

Effects of social rearing conditions on conditioned suppression in rats

Twenty-two rats were reared in standard conditions during the first two months of their life. Then the animals were divided into two groups exposed to different rearing conditions. Twelve animals (Group SO) were housed socially, six animals per cage, and for three weeks they were subjected to sensory stimulation in an enriched environment. The other ten subjects were kept individually (Group IN); one rat per mesh cage, in conditions of relatively impoverished sensory stimulation. In both groups the training of the conditioned emotional response (CER) was performed when animals were three months old. In contrast to IN subjects, the rats subjected to permanent social contacts and reared in the enriched environment (Group SO) revealed almost equally low instrumental response rates in trials with the conditioned stimulus (CS) paired with nociceptive foot-shock (US), and in periods when no CS and/or US were applied. The results suggested that early exposure to an enriched environment caused a later decrease of the animals' capability to differentiate between the aversive CS and cues of the experimental context. This cognitive impairment was probably a secondary effect of fear generalized to the entire experimental situation.     

Coordination polymerization of lactides, 3. Copolymerization of L,L-lactide and ε-caprolactone in the presence of initiators containing Zn and Al

High-molecular-weight copolymers of L ,L -lactide with ε-caprolactone were synthesized using initiators containing aluminium and zinc, i.e., AlEt₂OEt, ZnEtOiPr, Al(acac)₃ and AlEt₃ + ZnEt₂ + H₂O. The chain microstructure was revealed to vary from random to diblock arrangement, depending on temperature and the kind of initiator used. In case of Al(acac)₃ as initiator, the reactivity ratios of L ,L -lactide and ε-caprolactone were determined to be r_L = 44 and r_C = 0,28, respectively.