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1.
Allergy Asthma Proc ; 40(5): 329-337, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31514791

ABSTRACT

Background: This study was based on data from the Polish Mother and Child Cohort Study. Objective: The aim was to study associations between home environment factors and allergic diseases at 1 year of life and new onset and remission of children's allergy diagnosis at ages 7-9 years. Methods: Children's health status was assessed at ∼12 months of age and then at ages between 7-9 years by using a questionnaire administered to the mothers. Children were assessed by pediatrician/allergists. The patients, who were 7-9 years old, underwent skin-prick tests. Exposure to tobacco smoke was evaluated with a questionnaire addressed to parents and/or caregivers and cotinine measurements were taken of mother's saliva during pregnancy and in children's urine at ages 7-9 years. Incidence and remission were calculated by comparing symptoms in the first year of life with symptoms at 7-9 years. We studied the associations among demographic data, home environment, and new onset and remission of food allergy, atopic dermatitis, and asthma and allergic rhinitis in logistic regression analysis. All associations were adjusted for independent risk factors of dependent variables. Results: Data from 211 participants were included in the analysis. During the first year of life, food allergy was the most common symptom (39%), followed by atopic dermatitis (35%) and asthma (12%). When comparing diagnoses at ages 7-9 years with the first year of life, food allergy had decreased by as much as 18.6%, atopic dermatitis decreased by as much as 23.8%, and asthma decreased by as much as 8%, whereas asthma and allergic rhinitis had increased from 6% to 14.8%. More frequent house cleaning negatively correlated with the new onset of atopic dermatitis and of asthma and allergic rhinitis. Hypersensitivity to seasonal allergens and mites and to any other allergen positively correlated with new onset of food allergy, atopic dermatitis, and asthma and allergic rhinitis. Parental atopy positively correlated with the new onset of asthma and negatively correlated with asthma remission. Conclusion: Analysis of our findings indicated that new onset and/or remission of allergic diseases was linked with hypersensitivity to house-dust mites in children who were polysensitized and with parental atopy. In addition, children who had food allergy, allergic rhinitis, or atopic dermatitis at the age of 1 year had more of a chance developing other atopic disease (except asthma) at ages 7-9 years and less of a chance of having a remission of the disease.


Subject(s)
Environmental Exposure , Hypersensitivity/epidemiology , Hypersensitivity/etiology , Age Factors , Animals , Asthma/epidemiology , Child , Cohort Studies , Cotinine/analysis , Dermatitis, Atopic/epidemiology , Female , Food Hypersensitivity , Humans , Hypersensitivity/diagnosis , Infant , Male , Mothers , Poland/epidemiology , Pyroglyphidae/immunology , Recurrence , Skin Tests , Surveys and Questionnaires
2.
BJOG ; 126(8): 984-995, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30786138

ABSTRACT

OBJECTIVE: To assess the separate and combined associations of maternal pre-pregnancy body mass index (BMI) and gestational weight gain with the risks of pregnancy complications and their population impact. DESIGN: Individual participant data meta-analysis of 39 cohorts. SETTING: Europe, North America, and Oceania. POPULATION: 265 270 births. METHODS: Information on maternal pre-pregnancy BMI, gestational weight gain, and pregnancy complications was obtained. Multilevel binary logistic regression models were used. MAIN OUTCOME MEASURES: Gestational hypertension, pre-eclampsia, gestational diabetes, preterm birth, small and large for gestational age at birth. RESULTS: Higher maternal pre-pregnancy BMI and gestational weight gain were, across their full ranges, associated with higher risks of gestational hypertensive disorders, gestational diabetes, and large for gestational age at birth. Preterm birth risk was higher at lower and higher BMI and weight gain. Compared with normal weight mothers with medium gestational weight gain, obese mothers with high gestational weight gain had the highest risk of any pregnancy complication (odds ratio 2.51, 95% CI 2.31- 2.74). We estimated that 23.9% of any pregnancy complication was attributable to maternal overweight/obesity and 31.6% of large for gestational age infants was attributable to excessive gestational weight gain. CONCLUSIONS: Maternal pre-pregnancy BMI and gestational weight gain are, across their full ranges, associated with risks of pregnancy complications. Obese mothers with high gestational weight gain are at the highest risk of pregnancy complications. Promoting a healthy pre-pregnancy BMI and gestational weight gain may reduce the burden of pregnancy complications and ultimately the risk of maternal and neonatal morbidity. TWEETABLE ABSTRACT: Promoting a healthy body mass index and gestational weight gain might reduce the population burden of pregnancy complications.


Subject(s)
Body Mass Index , Gestational Weight Gain/physiology , Overweight/complications , Pregnancy Complications/etiology , Adult , Australia/epidemiology , Birth Weight , Cohort Studies , Europe/epidemiology , Female , Gestational Age , Humans , Infant, Newborn , North America/epidemiology , Odds Ratio , Pregnancy , Pregnancy Complications/epidemiology , Risk Factors
3.
BJOG ; 126(4): 459-470, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30230190

ABSTRACT

OBJECTIVE: Evidence on the impact of leisure time physical activity (LTPA) in pregnancy on birth size is inconsistent. We aimed to examine the association between LTPA during early and late pregnancy and newborn anthropometric outcomes. DESIGN: Individual level meta-analysis, which reduces heterogeneity across studies. SETTING: A consortium of eight population-based studies (seven European and one US) comprising 72 694 participants. METHODS: Generalised linear models with consistent inclusion of confounders (gestational age, sex, parity, maternal age, education, ethnicity, BMI, smoking, and alcohol intake) were used to test associations between self-reported LTPA at either early (8-18 weeks gestation) or late pregnancy (30+ weeks) and the outcomes. Results were pooled using random effects meta-analyses. MAIN OUTCOME MEASURES: Birth weight, large-for-gestational age (LGA), macrosomia, small-for-gestational age (SGA), % body fat, and ponderal index at birth. RESULTS: Late, but not early, gestation maternal moderate to vigorous physical activity (MVPA), vigorous activity, and LTPA energy expenditure were modestly inversely associated with BW, LGA, macrosomia, and ponderal index, without heterogeneity (all: I2  = 0%). For each extra hour/week of MVPA, RR for LGA and macrosomia were 0.97 (95% CI: 0.96, 0.98) and 0.96 (95% CI: 0.94, 0.98), respectively. Associations were only modestly reduced after additional adjustments for maternal BMI and gestational diabetes. No measure of LTPA was associated with risk for SGA. CONCLUSIONS: Physical activity in late, but not early, pregnancy is consistently associated with modestly lower risk of LGA and macrosomia, but not SGA. TWEETABLE ABSTRACT: In an individual participant meta-analysis, late pregnancy moderate to vigorous physical activity modestly reduced birth size outcomes.


Subject(s)
Birth Weight , Exercise , Fetal Macrosomia/epidemiology , Infant, Small for Gestational Age , Adipose Tissue , Adult , Cohort Studies , Diabetes, Gestational/epidemiology , Energy Metabolism , Female , Humans , Infant, Newborn , Linear Models , Obesity/epidemiology , Overweight/epidemiology , Pregnancy , Pregnancy Complications/epidemiology , Pregnancy Trimester, First , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Protective Factors , Risk Factors , Young Adult
4.
Science ; 357(6348): 287-290, 2017 07 21.
Article in English | MEDLINE | ID: mdl-28663438

ABSTRACT

Quantum spin Hall materials hold the promise of revolutionary devices with dissipationless spin currents but have required cryogenic temperatures owing to small energy gaps. Here we show theoretically that a room-temperature regime with a large energy gap may be achievable within a paradigm that exploits the atomic spin-orbit coupling. The concept is based on a substrate-supported monolayer of a high-atomic number element and is experimentally realized as a bismuth honeycomb lattice on top of the insulating silicon carbide substrate SiC(0001). Using scanning tunneling spectroscopy, we detect a gap of ~0.8 electron volt and conductive edge states consistent with theory. Our combined theoretical and experimental results demonstrate a concept for a quantum spin Hall wide-gap scenario, where the chemical potential resides in the global system gap, ensuring robust edge conductance.

5.
Allergol. immunopatol ; 45(1): 18-24, ene.-feb. 2017. tab, graf
Article in English | IBECS | ID: ibc-158970

ABSTRACT

BACKGROUND: Studies indicate that exposure to polycyclic aromatic hydrocarbons (PAH) is associated with adverse respiratory and allergy outcomes. Exposure to PAH may impair the immune function of the foetus and, subsequently, be responsible for an increased susceptibility of children to allergic diseases. OBJECTIVES: The aim of the present study was to assess the association between mother's exposure to PAH during pregnancy and allergy diseases in their infants. We also assessed the above associations using measured PAH exposure in children's urine during the first two years of life. METHODS: The current analysis was restricted to 455 mothers and their children from Lodz district. The women were interviewed three times during the pregnancy in order to collect demographic, socio-economic and medical history data. Children's health status was assessed at the age of 10-18 months and repeated at two years of age. The associations between dependent dichotomous variables and urine concentrations of 1-hydroxypyrene (1-HP) were analysed using logistic regression. RESULTS: We showed that higher urine concentrations of 1-HP in mothers at 20-24 weeks of pregnancy increased the risk of more frequent respiratory infections (p = 0.02) in children during their first year of life. Higher 1-HP concentrations in children's urine increased the risk of food allergy (p = 0.002) in children during their first two years of life. CONCLUSIONS: This study suggests awareness of environmental factors, which may affect children's health since PAH showed to be a risk factor for airway infections and food allergy in children after adjustment for other risk factors


No disponible


Subject(s)
Humans , Polycyclic Aromatic Hydrocarbons/adverse effects , Respiratory Hypersensitivity/epidemiology , Food Hypersensitivity/epidemiology , Respiratory Tract Infections/epidemiology , Maternal Exposure , Risk Factors , Environmental Pollutants/analysis , Polycyclic Aromatic Hydrocarbons/urine , Poland/epidemiology , Maternal Exposure/adverse effects
6.
Allergol Immunopathol (Madr) ; 45(1): 18-24, 2017.
Article in English | MEDLINE | ID: mdl-27789067

ABSTRACT

BACKGROUND: Studies indicate that exposure to polycyclic aromatic hydrocarbons (PAH) is associated with adverse respiratory and allergy outcomes. Exposure to PAH may impair the immune function of the foetus and, subsequently, be responsible for an increased susceptibility of children to allergic diseases. OBJECTIVES: The aim of the present study was to assess the association between mother's exposure to PAH during pregnancy and allergy diseases in their infants. We also assessed the above associations using measured PAH exposure in children's urine during the first two years of life. METHODS: The current analysis was restricted to 455 mothers and their children from Lodz district. The women were interviewed three times during the pregnancy in order to collect demographic, socio-economic and medical history data. Children's health status was assessed at the age of 10-18 months and repeated at two years of age. The associations between dependent dichotomous variables and urine concentrations of 1-hydroxypyrene (1-HP) were analysed using logistic regression. RESULTS: We showed that higher urine concentrations of 1-HP in mothers at 20-24 weeks of pregnancy increased the risk of more frequent respiratory infections (p=0.02) in children during their first year of life. Higher 1-HP concentrations in children's urine increased the risk of food allergy (p=0.002) in children during their first two years of life. CONCLUSIONS: This study suggests awareness of environmental factors, which may affect children's health since PAH showed to be a risk factor for airway infections and food allergy in children after adjustment for other risk factors.


Subject(s)
Food Hypersensitivity/epidemiology , Polycyclic Aromatic Hydrocarbons , Prenatal Exposure Delayed Effects/epidemiology , Respiratory Tract Infections/epidemiology , Urban Population , Adult , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Male , Maternal Exposure/adverse effects , Poland/epidemiology , Pregnancy , Pyrenes/urine
7.
Int J Impot Res ; 28(4): 148-54, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27076112

ABSTRACT

The clinical significance of sperm DNA damage lies in its association with natural conception rates and also might have a serious consequence on developmental outcome of the newborn. The aim of the present study is to determine whether stress and everyday life factors are associated with sperm DNA damage in adult men. The study population consisted of 286 men who attended the infertility clinic for diagnostic purposes and who had normal semen concentration of 20-300 m ml(-1) or with slight oligozoospermia (semen concentration of 15-20 m ml(-1)) (WHO, 1999). Participants were interviewed and provided a semen sample. The sperm chromatin structure assay was assessed using flow cytometry. In the present study, we found evidence for a relationship between sperm DNA damage parameters and everyday life factors. High and medium level of occupational stress and age increase DNA fragmentation index (P=0.03, P=0.004 and P=0.03, respectively). Other lifestyle factors that were positively associated with percentage of immature sperms (high DNA stainability index) included: obesity and cell phone use for more than 10 years (P=0.02 and P=0.04, respectively). Our findings indicate that stress and lifestyle factor may affect sperm DNA damage. Data from the present study showed a significant effect of age, obesity, mobile phone radiation and occupational stress on sperm DNA damage. As DNA fragmentation represents an extremely important parameter indicative of infertility and potential outcome of assisted reproduction treatment, and most of the lifestyle factors are easily modifiable, the information about factors that may affect DNA damage are important.


Subject(s)
DNA Damage , Infertility, Male/etiology , Life Style , Spermatozoa , Stress, Psychological/genetics , Adult , Humans , Infertility, Male/genetics , Male , Semen Analysis , Young Adult
8.
Phys Rev Lett ; 114(24): 247602, 2015 Jun 19.
Article in English | MEDLINE | ID: mdl-26197013

ABSTRACT

Two-dimensional (2D) atom lattices provide model setups with Coulomb correlations that induce competing ground states. Here, SiC emerges as a wide-gap substrate with reduced screening. We report the first artificial high-Z atom lattice on SiC(0001) by Sn adatoms, based on experimental realization and theoretical modeling. Density-functional theory of our triangular structure model closely reproduces the scanning tunneling microscopy. Photoemission data show a deeply gapped state (∼2 eV gap), and, based on our calculations including dynamic mean-field theory, we argue that this reflects a pronounced Mott-insulating scenario. We also find indications that the system is susceptible to antiferromagnetic superstructures. Such artificial lattices on SiC(0001) thus offer a novel platform for coexisting Coulomb correlations and spin-orbit coupling, with bearing for unusual magnetic phases and proposed topological quantum states of matter.

9.
Ned Tijdschr Geneeskd ; 159: A8273, 2015.
Article in Dutch | MEDLINE | ID: mdl-25650030

ABSTRACT

Although unusual in the Netherlands, acute kidney injury is sometimes caused by infection with Hantavirus, a zoonosis transmitted by rodents. Hantavirus infections can cause a syndrome known as 'haemorrhagic fever with renal syndrome', characterized by fever, acute kidney injury and thrombocytopenia. Recovery is spontaneous and treatment is mostly supportive. We describe two cases of otherwise healthy men presenting with fever and acute kidney injury. Laboratory tests revealed raised inflammatory parameters and thrombocytopenia. Urine analysis revealed proteinuria, microscopic haematuria and cell casts. Despite treatment with fluids, renal function declined and oliguria and fluid retention developed in one patient. Dialysis could be avoided, with spontaneous recovery of renal function in both cases. Serological testing revealed acute Hantavirus infection. Acute kidney injury caused by Hantavirus infections is rare in the Netherlands, but should be suspected in any patient presenting with renal failure and a history of viral infection.


Subject(s)
Acute Kidney Injury/diagnosis , Acute Kidney Injury/virology , Hantavirus Infections/complications , Hantavirus Infections/diagnosis , Acute Disease , Adult , Fever/diagnosis , Fever/virology , Humans , Male , Middle Aged , Netherlands , Renal Insufficiency/diagnosis , Renal Insufficiency/virology
10.
Respir Med ; 109(1): 38-43, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25468413

ABSTRACT

BACKGROUND: There are investigations concluding that reduced vitamin D status in pregnancy, may be a risk factor for the development of allergic outcomes in offspring. However, studies on the relationship between cord levels of 25-hydroxyvitamin D (25[OH]D) and risk of early childhood wheezing and early-onset atopic dermatitis/food allergy are very limited. OBJECTIVE: To assess the associations between cord blood concentration of 25[OH]D and occurrence of the incidence of wheezing, atopic dermatitis, food allergy, during the first two years of life. METHODS: We evaluated 240 children by the age of 2 years from the Polish Mother and Child Cohort Study. Women were interviewed during pregnancy to collect demographic and socioeconomic data, the medical and reproductive history. At delivery, umbilical cord blood plasma was sampled. The child's health status were examined at approximately 2 years. In the analyses multivariable model was used. RESULTS: Data from 190 participants were included into the analysis. The median value and quartile range of 25[OH]D in cord blood [ng/ml] were as follows: 6.33, 4.16-8.53. 25[OH]D in cord blood below lower quartile increases the risk of multi-triggered wheezing (MTW) in children during first 2 years of life (OR: 2.81; 95% CI: 1.13-7.00). Higher cord serum level of 25[OH]D reduces the risk of viral induced wheezing (VIW). The cord serum level of 25[OH]D below median value (OR: 6.06; 95% CI: 1.3-28.3) or below lower quartile (OR: 5.43; 95% CI: 1.66-17.7) increases the risk of VIW. All above effects of vitamin D level in cord blood were corrected for the effects other independent risk factors of wheezing and VIW in this cohort. CONCLUSIONS: Cord serum 25[OH]D levels were inversely associated with the risk of multi-triggered wheezing, and especially viral-induced wheezing by the age of 2 years, but no association was found with food allergy, atopic dermatitis and frequencies of infections.


Subject(s)
Fetal Blood/metabolism , Prenatal Exposure Delayed Effects/immunology , Respiratory Sounds/etiology , Virus Diseases/immunology , Vitamin D/analogs & derivatives , Adult , Child, Preschool , Cohort Studies , Dermatitis, Atopic/immunology , Female , Food Hypersensitivity/immunology , Humans , Infant , Pregnancy , Pregnancy Complications/blood , Respiratory Sounds/immunology , Risk Factors , Vitamin D/blood , Vitamin D Deficiency/blood
11.
Ann Hum Biol ; 41(3): 220-8, 2014.
Article in English | MEDLINE | ID: mdl-24180268

ABSTRACT

BACKGROUND AND AIMS: Although psychological stress has been implicated as a cause of idiopathic infertility in both men and women, it has received little scientific attention among males as compared to females. The aim of the study was to examine the association between occupational, life stress, family functioning and semen quality. METHODS AND RESULTS: The study population consisted of 327 men who were attending an infertility clinic for diagnostic purposes. Psychological stress was assessed based on two questionnaires: The Subjective Work Characteristics Questionnaire and the Perceived Stress Scale. The level of satisfaction with family functioning and support was evaluated by means of the APGAR Family Scale. The findings suggest that, on the one hand, exposure to occupational stressors can be negatively associated with semen quality (there was a positive association between stress and the percentage of sperm with DNA damage (p = 0.03) and atypical sperm (p = 0.05)); on the other hand, there was no correlation between the level of life stress and semen quality indicators. Negative associations were found between satisfaction with family functioning and the percentage of motile sperm cells (p = 0.02), VAP (p = 0.05), VSL (p = 0.05) and VCL (p = 0.04). CONCLUSION: The study indicates that occupational stress can affect male semen quality; however, due to limited data on this issue, the obtained results should be confirmed in longitudinal studies.


Subject(s)
Job Satisfaction , Semen/physiology , Stress, Psychological , Adult , Humans , Male , Middle Aged , Poland , Semen Analysis , Surveys and Questionnaires , Young Adult
12.
Curr Med Chem ; 21(12): 1458-66, 2014.
Article in English | MEDLINE | ID: mdl-24059238

ABSTRACT

UNLABELLED: Cationic peptides (polylysines and polyarginines) are being developed as drug delivery systems to nuclei. Therefore, a detailed description of tissue response changes upon the application of cationic peptides over intact basement membranes of excitable tissue is of interest in pharmacology. In this paper we examine the effects of two naturally occurring cationic peptides protamine (polyarginine) and crotamine (polylysine) on the optical profiles of retinal spreading depression waves (RSDs). This intrinsic optical signal (IOS), recorded non-invasively, provides information about dissipation of electrochemical gradients within the tissue and its metabolic consequences. Protamine at nanomolar range brought the tissue excitability to collapse without any signs of acute toxicity whereas crotamine, a known myotoxin from rattlesnake, decreased the tissue transparency and changed markedly the optical profiles of RSDs. Also, fluorescent crotamine was incorporated to Müller cells in a few minutes, suggesting a close membrane interaction. The optical changes brought about by crotamine were easily washed off. By contrast, the excitability collapse in presence of protamine lasted for at least two hours. CONCLUSIONS: we concluded that crotamine has fusogenic properties that alters ion transport in excitable tissue. Protamine effect seems to be similar to its effect on basement membrane of epithelium due to its property of making heteropolymers with heparan sulfate. The clinical syndrome expressed in mice after crotamine injection suggested excitotoxic CNS effects confirmed by the isolated retina experiments.


Subject(s)
Basement Membrane/metabolism , Peptides/metabolism , Retina/metabolism , Animals , Behavior, Animal , Chickens , Male , Mice
13.
Phys Rev Lett ; 111(15): 157205, 2013 Oct 11.
Article in English | MEDLINE | ID: mdl-24160626

ABSTRACT

We report on the epitaxial fabrication and electronic properties of a topological phase in strained α-Sn on InSb. The topological surface state forms in the presence of an unusual band order not based on direct spin-orbit coupling, as shown in density functional and GW slab-layer calculations. Angle-resolved photoemission including spin detection probes experimentally how the topological spin-polarized state emerges from the second bulk valence band. Moreover, we demonstrate the precise control of the Fermi level by dopants.

14.
Phys Rev Lett ; 108(18): 186801, 2012 May 04.
Article in English | MEDLINE | ID: mdl-22681100

ABSTRACT

The spin texture of the metallic two-dimensional electron system (sqrt[3]×sqrt[3])-Au/Ge(111) is revealed by fully three-dimensional spin-resolved photoemission, as well as by density functional calculations. The large hexagonal Fermi surface, generated by the Au atoms, shows a significant splitting due to spin-orbit interactions. The planar components of the spin exhibit a helical character, accompanied by a strong out-of-plane spin component with alternating signs along the six Fermi surface sections. Moreover, in-plane spin rotations toward a radial direction are observed close to the hexagon corners. Such a threefold-symmetric spin pattern is not described by the conventional Rashba model. Instead, it reveals an interplay with Dresselhaus-like spin-orbit effects as a result of the crystalline anisotropies.

15.
Philos Trans R Soc Lond B Biol Sci ; 366(1581): 3077-84, 2011 Nov 12.
Article in English | MEDLINE | ID: mdl-21969689

ABSTRACT

Beside their haptic function, vibrissae of harbour seals (Phocidae) and California sea lions (Otariidae) both represent highly sensitive hydrodynamic receptor systems, although their vibrissal hair shafts differ considerably in structure. To quantify the sensory performance of both hair types, isolated single whiskers were used to measure vortex shedding frequencies produced in the wake of a cylinder immersed in a rotational flow tank. These measurements revealed that both whisker types were able to detect the vortex shedding frequency but differed considerably with respect to the signal-to-noise ratio (SNR). While the signal detected by sea lion whiskers was substantially corrupted by noise, harbour seal whiskers showed a higher SNR with largely reduced noise. However, further analysis revealed that in sea lion whiskers, each noise signal contained a dominant frequency suggested to function as a characteristic carrier signal. While in harbour seal whiskers the unique surface structure explains its high sensitivity, this more or less steady fundamental frequency might represent the mechanism underlying hydrodynamic reception in the fast swimming sea lion by being modulated in response to hydrodynamic stimuli impinging on the hair.


Subject(s)
Caniformia/physiology , Touch/physiology , Vibrissae/physiology , Animals , Caniformia/anatomy & histology , Hydrodynamics , Signal-To-Noise Ratio , Vibrissae/anatomy & histology
16.
Am J Physiol Renal Physiol ; 301(3): F476-85, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21367923

ABSTRACT

There is increasing evidence that proteins in tubular fluid are "nephrotoxic." In vivo it is difficult to study protein loading of tubular epithelial cells in isolation, i.e., without concomitant glomerular damage or changes of renal hemodynamics, etc. Recently, a unique amphibian model has been described which takes advantage of the special anatomy of the amphibian kidney in which a subset of nephrons drains the peritoneal cavity (open nephrons) so that intraperitoneal injection of protein selectively causes protein storage in and peritubular fibrosis around open but not around closed tubules. There is an ongoing debate as to what degree albumin per se is nephrotoxic and whether modification of albumin alters its nephrotoxicity. We tested the hypothesis that carbamylation and glycation render albumin more nephrotoxic compared with native albumin and alternative albumin modifications, e.g., lipid oxidation and lipid depletion. Preparations of native and modified albumin were injected into the axolotl peritoneum. The kidneys were retrieved after 10 days and studied by light microscopy as well as by immunohistochemistry [transforming growth factor (TGF)-ß, PDGF, NF-κB, collagen I and IV, RAGE], nonradioactive in situ hybridization, and Western blotting. Two investigators unaware of the animal groups evaluated and scored renal histology. Compared with unmodified albumin, glycated and carbamylated albumin caused more pronounced protein storage. After no more than 10 days, selective peritubular fibrosis was seen around nephrons draining the peritoneal cavity (open nephrons), but not around closed nephrons. Additionally, more intense expression of RAGE, NF-κB, as well as PDGF, TGF-ß, EGF, ET-1, and others was noted by histochemistry and confirmed by RT-PCR for fibronectin and TGF-ß as well as nonradioactive in situ hybridization for TGF-ß and fibronectin. The data indicate that carbamylation and glycation increase the capacity of albumin to cause tubular cell damage and peritubular fibrosis.


Subject(s)
Albumins/metabolism , Albumins/pharmacology , Ambystoma mexicanum/physiology , Carbamates/metabolism , Kidney/drug effects , Serum Albumin/pharmacology , Albumins/administration & dosage , Animals , Fibrosis , Glycation End Products, Advanced , Injections, Intraperitoneal , Kidney/metabolism , Kidney/pathology , Models, Animal , NF-kappa B/metabolism , Nephrons/drug effects , Nephrons/metabolism , Nephrons/pathology , Receptor for Advanced Glycation End Products , Receptors, Immunologic/metabolism , Serum Albumin/administration & dosage , Transforming Growth Factor beta/metabolism , Glycated Serum Albumin
17.
J Exp Biol ; 213(Pt 21): 3734-40, 2010 Nov 01.
Article in English | MEDLINE | ID: mdl-20952623

ABSTRACT

The mystacial vibrissae of harbour seals (Phoca vitulina) constitute a highly sensitive hydrodynamic receptor system enabling the seals to detect and follow hydrodynamic trails. In the wild, hydrodynamic trails, as generated by swimming fish, consist of cyclic burst-and-glide phases, associated with various differences in the physical parameters of the trail. Here, we investigated the impact of glide phases on the trackability of differently aged hydrodynamic trails in a harbour seal. As fish are not easily trained to swim certain paths with predetermined burst-and-glide phases, the respective hydrodynamic trails were generated using a remote-controlled miniature submarine. Gliding phases in hydrodynamic trails had a negative impact on the trackability when trails were 15 s old. The seal lost the generated trails more often within the transition zones, when the submarine switched from a burst to a glide moving pattern. Hydrodynamic parameter analysis (particle image velocimetry) revealed that the smaller dimensions and faster decay of hydrodynamic trails generated by the gliding submarine are responsible for the impaired success of the seal tracking the gliding phase. Furthermore, the change of gross water flow generated by the submarine from a rearwards-directed stream in the burst phase to a water flow passively dragged behind the submarine during gliding might influence the ability of the seal to follow the trail as this might cause a weaker deflection of the vibrissae. The possible ecological implications of intermittent swimming behaviour in fish for piscivorous predators are discussed.


Subject(s)
Hydrodynamics , Phoca/physiology , Swimming/physiology , Water Movements , Animals , Color , Male , Physical Stimulation , Remote Sensing Technology
18.
J Exp Biol ; 213(Pt 13): 2194-200, 2010 Jul 01.
Article in English | MEDLINE | ID: mdl-20543117

ABSTRACT

Harbour seals can use their vibrissal system to detect and follow hydrodynamic trails left by moving objects. In this study we determined the maximum time after which a harbour seal could indicate the moving direction of an artificial fish tail and analysed the hydrodynamic parameters allowing the discrimination. Hydrodynamic trails were generated using a fin-like paddle moving from left to right or from right to left in the calm water of an experimental box. The blindfolded seal was able to recognise the direction of the paddle movement when the hydrodynamic trail was up to 35 s old. Particle Image Velocimetry (PIV) revealed that the seal might have perceived and used two different hydrodynamic parameters to determine the moving direction of the fin-like paddle. The structure and spatial arrangement of the vortices in the hydrodynamic trail and high water velocities between two counter-rotating vortices are characteristic of the movement direction and are within the sensory range of the seal.


Subject(s)
Phoca/physiology , Swimming , Animals , Discrimination Learning , Male , Perception , Rheology
19.
J Exp Biol ; 210(Pt 5): 781-7, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17297138

ABSTRACT

For seals hunting in dark and murky waters one source of sensory information for locating prey consists of fish-generated water movements, which they can detect using their highly sensitive mystacial vibrissae. As water movements in the wake of fishes can persist for several minutes, hydrodynamic trails of considerable length are generated. It has been demonstrated that seals can use their vibrissae to detect and track hydrodynamic trails generated artificially by miniature submarines. In the present study, we trained a harbour seal to swim predefined courses, thus generating biogenic hydrodynamic trails. The structure of these trails was measured using Particle Image Velocimetry. A second seal was trained to search for and track the trail after the trail-generating seal had left the water. Our trail-following seal was able to detect and accurately track the hydrodynamic trail, showing search patterns either mostly congruent with the trail or crossing the trail repeatedly in an undulatory way. The undulatory trail-following search pattern might allow a seal to relocate a lost trail or successfully track a fleeing, zigzagging prey fish.


Subject(s)
Perception/physiology , Phoca/physiology , Psychomotor Performance/physiology , Swimming/physiology , Water Movements , Animals , Male , Orientation/physiology , Video Recording
20.
Phys Rev Lett ; 99(25): 257002, 2007 Dec 21.
Article in English | MEDLINE | ID: mdl-18233549

ABSTRACT

Recent experiments (angle-resolved photoemission spectroscopy and Raman) suggest the presence of two distinct energy gaps in high-temperature superconductors (HTSC), exhibiting different doping dependences. The results of a variational cluster approach to the superconducting state of the two-dimensional Hubbard model are presented which show that this model qualitatively describes this gap dichotomy. The antinodal gap increases with less doping, a behavior long considered as reflecting the general gap behavior of the HTSC. On the other hand, the near-nodal gap does even slightly decrease with underdoping. An explanation of this unexpected behavior is given which emphasizes the crucial role of spin fluctuations in the pairing mechanism.

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