Cultural differences in web-based health information seeking of Finnish and Japanese students

Abstrakti

Immunocytochemistry of the mucilage cells of Araucaria angustifolia (Bertol.) Kuntze (Araucariaceae)

The use of monoclonal antibodies for specific pectic epitopes is an important tool in the study of the cell wall. Throughout the development of mucilage cells of Araucaria angustifolia (Bertol.) Kuntze, a gradient of distribution was observed in relation to the pectic de-esterification, as well as to the increase of galactan and arabinan epitope distribution, and to the reduction of arabinogalactans proteins (AGPs) epitope at maturity. AGP and methyl-esterified homogalacturonan (HGA) were present in the mucilage. Galactans and arabinans were also observed in the mucilage, though with weak labelling. Degradation of AGP in the maturity of mucilage cells, in cell wall, as well as in the secretion, could be involved in the programmed cell death (PCD). Different labellings found among parenchyma and mucilage cells suggested differences in the cell wall properties of the mucilage cells.

Autoradiography reveals regional metabolic differences in the endometrium of pregnant and nonpregnant mice

The rodent endometrium undergoes remarkable modifications during pregnancy, resulting from a redifferentiation of its fibroblasts. During this modification (decidualization), the fibroblasts transform into large, polyhedral cells that establish intercellular junctions. Decidualization proceeds from the subepithelial stroma towards the deep stroma situated next to the myometrium and creates regions composed of cells in different stages of differentiation. We studied by autoradiography whether cells of these different regions have different levels of macromolecular synthesis. Radioactive amino acids or radioactive sulfate were administered to mice during estrus or on different days of pregnancy. The animals were killed 30 min after injection of the precursors and the uteri were processed for light microscope autoradiography. Silver grains were counted over cells of different regions of the endometrium and are reported as the number of silver grains per area. Higher levels of incorporation of amino acids were found in pregnant animals as compared to animals in estrus. In pregnant animals, the region of decidual cells or the region of fibroblasts transforming into decidual cells showed the highest levels of synthesis. Radioactive sulfate incorporation, on the other hand, was generally higher in nonpregnant animals. Animals without decidual cell transformation (nonpregnant and 4th day of pregnancy) showed a differential incorporation by subepithelial and deep stroma fibroblasts. This study shows that regional differences in synthetic activity exist in cells that are in different stages of transformation into decidual cells as well as in different regions of the endometrium of nonpregnant mice

Differences between remaining ability and loss of capacity in maximum aerobic impairment

In the evaluation of exercise intolerance of patients with respiratory diseases the American Medical Association (AMA) and the American Thoracic Society (ATS) have proposed similar classifications for rating aerobic impairment using maximum oxygen uptake (VO2max) normalized for total body weight (ml min-1 kg-1). However, subjects with the same VO2max weight-corrected values may have considerably different losses of aerobic performance (VO2max expressed as % predicted). We have proposed a new, specific method for rating loss of aerobic capacity (VO2max, % predicted) and we have compared the two classifications in a prospective study involving 75 silicotic claimants. Logistic regression analysis showed that the disagreement between rating systems (higher dysfunction by the AMA/ATS classification) was associated with age >50 years (P<0.005) and overweight (P = 0.04). Interestingly, clinical (dyspnea score) and spirometric (FEV1) normality were only associated with the VO2max, % predicted, normal values (P<0.01); therefore, in older and obese subjects the AMA/ATS classification tended to overestimate the aerobic dysfunction. We conclude that in the evaluation of aerobic impairment in patients with respiratory diseases, the loss of aerobic capacity (VO2max, % predicted) should be used instead of the traditional method (remaining aerobic ability, VO2max, in ml min-1 kg-1).

Gender differences in the activities of aspirin-esterases in rat tissues

The activities of aspirin (acetylsalicylic acid)-esterases were measured in several tissues (liver, kidney, adrenal glands, brain and serum) from adult male and female Wistar rats. In males, both aspirin-esterase I (assayed at pH 5.5) and II (assayed at pH 7.4) activities were higher in liver homogenates when compared to females (aspirin-esterase I: males 48.9 ± 4.8 (N = 8) and females 29.3 ± 4.2 (N = 8) nmol of salicylic acid formed min-1 mg protein-1; aspirin-esterase II: males 41.4 ± 4.1 (N = 8) and females 26.1 ± 4.5 (N = 8) nmol of salicylic acid formed min-1 mg protein-1, P<0.001). In serum, enzyme activity was higher in females than in males (aspirin-esterase I: males 0.85 ± 0.06 (N = 6) and females 1.18 ± 0.11 (N = 6) nmol of salicylic acid formed min-1 mg protein-1; aspirin-esterase II: males 1.03 ± 0.13 (N = 6) and females 1.34 ± 0.11 (N = 6) nmol of salicylic acid formed min-1 mg protein-1, P<0.001). In the other tissues assayed, no statistically significant difference between males and females was found. There were no statistically significant differences when the enzymes were assayed in different phases of the estrous cycle in liver and serum. These results show that the differences in aspirin-esterase activity observed between males and females are not due to the estrous cycle. The gender difference obtained in our study may indicate an involvement of gonadal hormones in the control of the hydrolysis of aspirin. This possibility is currently under investigation.

Sex-dependent differences in the activities of acetylsalicylic acid-esterases in mouse kidneys

Acetylsalicylic acid (ASA), the most used drug worldwide, is hydrolyzed to salicylic acid and acetate by esterases present in tissues of several species including humans. Sex differences in drug metabolism by rodent liver are documented in the literature. In this paper we report a difference in the activities of the esterases (ASA-esterase I and II) in the kidneys of male and female mice. In this species there is no difference between males and females in liver ASA-esterases (ASA-esterase I: males 38.5 ± 7.9 (N = 5) and females 31.6 ± 7.6 (N = 5) nmol of salicylic acid formed min-1 mg protein-1, P>0.05; ASA-esterase II: males 77.3 ± 17.4 (N = 5) and females 61.4 ± 15.1 (N = 5) nmol of salicylic acid formed min-1 mg protein-1, P>0.05). However, in the kidneys males presented a much higher enzyme activity than females (ASA-esterase I: males 25.2 ± 6.3 (N = 5) and females 6.8 ± 0.6 (N = 5) nmol of salicylic acid formed min-1 mg protein-1, P<0.0002; ASA-esterase II: males 79.8 ± 10.1 (N = 5) and females 13.0 ± 1.1 (N = 5) nmol of salicylic acid formed min-1 mg protein-1, P<0.0001). The difference between sexes observed in mouse kidneys could serve as a model to study the molecular basis of this sex difference and also to determine the possible involvement of pituitary and gonadal hormones in this difference in ASA-esterase activities since these hormones control the sex differences in rodent liver enzyme activity.

Pharmacological differences between memory consolidation of habituation to an open field and inhibitory avoidance learning

Rats implanted bilaterally with cannulae in the CA1 region of the dorsal hippocampus or the entorhinal cortex were submitted to either a one-trial inhibitory avoidance task, or to 5 min of habituation to an open field. Immediately after training, they received intrahippocampal or intraentorhinal 0.5-µl infusions of saline, of a vehicle (2% dimethylsulfoxide in saline), of the glutamatergic N-methyl-D-aspartate (NMDA) receptor antagonist 2-amino-5-phosphono pentanoic acid (AP5), of the protein kinase A inhibitor Rp-cAMPs (0.5 µg/side), of the calcium-calmodulin protein kinase II inhibitor KN-62, of the dopaminergic D1 antagonist SCH23390, or of the mitogen-activated protein kinase kinase inhibitor PD098059. Animals were tested in each task 24 h after training. Intrahippocampal KN-62 was amnestic for habituation; none of the other treatments had any effect on the retention of this task. In contrast, all of them strongly affected memory of the avoidance task. Intrahippocampal Rp-cAMPs, KN-62 and AP5, and intraentorhinal Rp-cAMPs, KN-62, PD098059 and SCH23390 caused retrograde amnesia. In view of the known actions of the treatments used, the present findings point to important biochemical differences in memory consolidation processes of the two tasks.

Gender differences in vascular expression of endothelin and ET A/ET B receptors, but not in calcium handling mechanisms, in deoxycorticosterone acetate-salt hypertension

We determined if the increased vascular responsiveness to endothelin-1 (ET-1) observed in male, but not in female, DOCA-salt rats is associated with differential vascular mRNA expression of ET-1 and/or ET A/ET B receptors or with functional differences in Ca2+ handling mechanisms by vascular myocytes. Uninephrectomized male and female Wistar rats received DOCA and drinking water containing NaCl/KCl. Control rats received vehicle and tap water. Blood pressure and contractile responses of endothelium-denuded aortic rings to agents which induce Ca2+ influx and/or its release from internal stores were measured using standard procedures. Expression of mRNA for ET-1 and ET A/ET B receptors was evaluated by RT-PCR after isolation of total cell RNA from both aorta and mesenteric arteries. Systolic blood pressure was higher in male than in female DOCA rats. Contractions induced by Bay K8644 (which activates Ca2+ influx through voltage-operated L-type channels), and by caffeine, serotonin or ET-1 in Ca2+-free buffer (which reflect Ca2+ release from internal stores) were significantly increased in aortas from male and female DOCA-salt compared to control aortas. DOCA-salt treatment of male, but not female, rats statistically increased vascular mRNA expression of ET-1 and ET B receptors, but decreased the expression of ET A receptors. Molecular up-regulation of vascular ET B receptors, rather than differential changes in smooth muscle Ca2+ handling mechanisms, seems to account for the increased vascular reactivity to ET-1/ET B receptor agonists and higher blood pressure levels observed in male DOCA-salt rats.

Gender-related differences in the effects of nitric oxide donors on neuroleptic-induced catalepsy in mice

It has been suggested that nigrostriatal dopaminergic transmission is modulated by nitric oxide (NO). Since there is evidence that gonadal hormones can affect extrapyramidal motor behavior in mammals, we investigated the effects of isosorbide dinitrate (ISD), linsidomine (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP), three pharmacologically different NO donors, on neuroleptic-induced catalepsy in 60- to 80-day-old male and female albino mice. Catalepsy was induced with haloperidol (1 mg/kg, ip) and measured at 30-min intervals by means of a bar test. Drugs (or appropriate vehicle) were injected ip 30 min before haloperidol, with each animal being used only once. ISD (5, 20 and 50 mg/kg) caused a dose-dependent inhibition of catalepsy in male mice (maximal effect 120 min after haloperidol: 64% inhibition). In the females only at the highest dose of ISD was an attenuation of catalepsy observed, which was mild and short lasting. SIN-1 (10 and 50 mg/kg) did not significantly affect catalepsy in female mice, while a significant attenuation was observed in males at the dose of 50 mg/kg (maximal inhibition: 60%). SNAP (20 mg/kg) significantly attenuated catalepsy in males 120 min after haloperidol (44% inhibition), but had no significant effect on females. These results basically agree with literature data showing that NO facilitates central dopaminergic transmission, although the mechanisms are not fully understood. They also reveal the existence of gender-related differences in this nitrergic modulation in mice, with females being less affected than males.

Differences in pressure and temperature transitions of proteins and polymer gels

Pressure-driven and temperature-driven transitions of two thermoresponsive polymers, poly(N-isopropylacrylamide) (pNIPAM) and poly(N-vinylisobutyramide) (pNVIBA)), in both a soluble linear polymer form and a cross-linked hydro-gel form, were examined by a dynamic light-scattering method and direct microscopic observation, respectively. Their behavior was compared with that of protein systems. Changes in some characteristic parameters in the time-intensity correlation functions of dynamic light-scattering measurement of aqueous solutions of pNIPAM at various pressures and temperatures showed no essential differences during temperature and pressure scanning and, as a whole, the motions of polymers in aqueous solutions were similar in two types of transitions until chain shrinkage occurred. The gels (cross-linked polymer gels) prepared from the thermoresponsive polymers also showed similar volume transitions responding to the pressure and temperature increase. In temperature transitions, however, gels showed drastic volume shrinkage with loss of transparency, while pressure-induced transition showed a slow recovery of transparency while keeping the size, after first transient drastic volume shrinkage with loss of transparency. At a temperature slightly higher than the transition under atmospheric temperature, so-called reentry of the volume change and recovery of the transparency were observed during the pressure-increasing process, which implies much smaller aggregation or non-aggregated collapsed polymer chains in the gel at higher pressures, indicating a certain mechanistic difference of the dehydration processes induced by temperature and pressure.

An Update on Inter-Country Differences in Recovery and Utilization of Recycled Paper

The use of recovered paper as raw material in the paper and board industry has increased heavily during recent decades. At the same time, growing environmental awareness has raised the interest in recycling and a more sustainable way of living, at least in high-income countries. This paper combines these topics and explores how economic, demographic and environmental factors have affected the recovery and utilization of recycled paper between 1992 and 2010 in a sample of 70 countries. This study updates and extends the previous research on the topic using panel data and panel data estimation methods. The results confirm the roles of economic determinants but also indicate that concern for the environment impacts the recovery of recycled paper particularly in high-income countries. Moreover, the motives for recycling appear to depend on the income level of a country, which is something that future policies should consider.

Differences in functional and structural properties of segments of the rat tail artery

The investigation of resistance vessels is generally costly and difficult to execute. The present study investigated the diameters and the vascular reactivity of different segments of the rat tail artery (base, middle, and tail end) of 30 male Wister rats (EPM strain) to characterize a conductance or resistance vessel, using a low-cost simple technique. The diameters (mean ± SEM) of the base and middle segments were 471 ± 4.97 and 540 ± 8.39 µm, respectively, the tail end was 253 ± 2.58 µm. To test reactivity, the whole tail arteries or segments were perfused under constant flow and the reactivity to phenylephrine (PHE; 0.01-300 µg) was evaluated before and after removal of the endothelium or drug administration. The maximal response (Emax) and sensitivity (pED50) to PHE of the whole tail and the base segment increased after endothelium removal or treatment with 100 µM L-NAME, which suggests modulation by nitric oxide. Indomethacin (10 µM) and tetraethylammonium (5 mM) did not change the Emax or pED50 of these segments. PHE and L-NAME increased the pED50 of the middle and the tail end only and indomethacin did not change pED50 or Emax. Tetraethylammonium increased the sensitivity only at the tail end, which suggests a blockade of vasodilator release. Results indicate that the proximal segment of the tail artery possesses a diameter compatible with a conductance vessel, while the tail end has the diameter of a resistance vessel. In addition, the vascular reactivity to PHE in the proximal segment is nitric oxide-dependent, while the tail end is dependent on endothelium-derived hyperpolarizing factor.

Gender and age differences in polysomnography findings and sleep complaints of patients referred to a sleep laboratory

Our objective was to examine the effet of gender on the sleep pattern of patients referred to a sleep laboratory. The data (questionnaires and polysomnographic recordings) were collected from a total of 2365 patients (1550 men and 815 women). The polysomnography permits an objective assessment of the sleep pattern. We included only polysomnography exams obtained with no more than one recording system in order to permit normalization of the data. Men had a significantly higher body mass index than women (28.5 ± 4.8 vs 27.7 ± 6.35 kg/m²) and had a significantly higher score on the Epworth Sleepiness Scale (10.8 ± 5.3 vs 9.5 ± 6.0), suggesting daytime sleepiness. Women had a significantly higher sleep latency than men, as well as a higher rapid eye movement (REM) latency. Men spent more time in stages 1 (4.6 ± 4.1 vs 3.9 ± 3.8) and 2 (57.0 ± 10.5 vs 55.2 ± 10.1) of non-REM sleep than women, whereas women spent significantly more time in deep sleep stages (3 and 4) than men (22.6 ± 9.0 vs 19.9 ± 9.0). The apnea/hypopnea and arousal indexes were significantly higher and more frequent in men than in women (31.0 ± 31.5 vs 17.3 ± 19.7). Also, periodic leg movement index did not differ significantly between genders, but rather differed among age groups. We did not find significant differences between genders in the percentage of REM sleep and sleep efficiency. The results of the current study suggest that there are specific gender differences in sleep pattern.

Promoter region sequence differences in the A and G gamma globin genes of Brazilian sickle cell anemia patients

Fetal hemoglobin (HbF), encoded by the HBG2 and HBG1 genes, is the best-known genetic modulator of sickle cell anemia, varying dramatically in concentration in the blood of these patients. This variation is partially associated with polymorphisms located in the promoter region of the HBG2 and HBG1 genes. In order to explore known and unknown polymorphisms in these genes, the sequences of their promoter regions were screened in sickle cell anemia patients and correlated with both their HbF levels and their βS-globin haplotypes. Additionally, the sequences were compared with genes from 2 healthy groups, a reference one (N = 104) and an Afro-descendant one (N = 98), to identify polymorphisms linked to the ethnic background.The reference group was composed by healthy individuals from the general population. Four polymorphisms were identified in the promoter region of HBG2 and 8 in the promoter region of HBG1 among the studied groups. Four novel single nucleotide polymorphisms (SNP) located at positions -324, -317, -309 and -307 were identified in the reference group. A deletion located between -396 and -391 in the HBG2 promoter region and the SNP -271 C→T in the HBG1 promoter region were associated with the Central African Republic βS-globin haplotype. In contrast, the -369 C→G and 309 A→G SNPs in the HBG2 promoter region were correlated to the Benin haplotype. The polymorphisms -396_-391 del HBG2, -369 SNP HBG2 and -271 SNP HBG1 correlated with HbF levels. Hence, we suggest an important role of HBG2 and HBG1 gene polymorphisms on the HbF synthesis.