Marked Negative Effect Research Articles

Diffusion of Au, Pd, Re, and P in FeNi alloys at High Pressure

Multi-anvil and piston cylinder experiments were performed to determine the effect of both pressure and temperature on the diffusivities of several siderophile elements in a Fe 90Ni 10 core-analog alloy. Activation energies were calculated to be between 244 and 257 kJ/mol for Re, Pd, and Au at 10 GPa, and 264 kJ/mol for P at 1 GPa. It was found that pressure has a marked negative effect on the diffusivities of Au, Re, and Pd, and activation volumes for these elements were calculated to be between 3 and 6 cm 3/mol at 10 GPa. The effect of both temperature and pressure on P diffusion is noticeably less, and the absolute diffusivity of phosphorus is consistently higher than that of the other elements. It is inferred that the reason for this difference is because P is diffusing via an interstitial mechanism as opposed to Re, Pd, and Au which occupy regular lattice sites in the crystal. The effect of pressure and temperature together with depth in the Earth suggests that these elements may continue to exhibit different behavior at more extreme conditions. The significance of these new results lies in the ability to place constraints on many time-dependent processes that pertain to the formation and evolution of planetary cores, as well as the formation and cooling histories of other metal-rich bodies in the solar system, such as meteorites.

Function of Jasmonate in Response and Tolerance of Arabidopsis to Thrip Feeding

We analyzed the interaction between Arabidopsis and western flower thrips (Frankliniella occidentalis), which are one of the most serious insect pests of cultivated plants. We focused on the function of the immunity-related plant hormones jasmonate (JA), ethylene (ET) and salicylic acid (SA) in the plant's response to thrip feeding. Expression of the marker genes for each hormone response was induced by thrip feeding in wild-type (WT) plants. Further analyses in the hormone-related mutants coi1-1 (JA insensitive), ein2-1 and ein3-1 (ET insensitive) and eds16-1 (SA deficient) suggested the importance of these hormones in the plant response to feeding. Comparative transcriptome analyses suggested a strong relationship between thrip feeding and JA treatment, but not ET or SA treatment. The JA content of WT plants was significantly increased after thrip feeding. Moreover, coi1-1, but not ein2-1, showed lower feeding tolerance against thrips than the WT. Application of JA to WT plants before thrip feeding enhanced the plants' feeding tolerance. JA modulates several defense responses in cooperation with ET, but application of the ET precursor 1-aminocyclopropane-carboxylic acid had a marked negative effect on feeding tolerance. Our results indicate that JA plays an important role in Arabidopsis in terms of response to, and tolerance against, thrip feeding.

Perceiving the speech of multiple concurrent talkers in a combined divided and selective attention task

Detection and identification of concurrently spoken key words was investigated using the Coordinate Response Measure corpus. On every trial, listeners first had to explicitly detect callsign keywords in a multi-talker stimulus (divided attention), and, if all callsigns were present, identify the color and number words produced by one of the talkers (selective attention). Increasing the number of concurrent talkers and the number of callsigns to be detected each had a marked negative effect on detection and identification performance. These findings indicate that, when memory involvement is limited, listeners cannot reliably detect more than two concurrently spoken words in diotic listening.

Insomnia and cerebral hypoperfusion

Insomnia is defined as difficulty with the initiation, maintenance, duration, or quality of sleep that results in the impairment of daytime functioning, despite adequate opportunity and circumstances for sleep. In most countries approximately every third inhabitant has insomnia. Insomnia can be classified as primary and secondary. The pathogenesis of primary insomnia is unknown, but available evidence suggests a state of hyperarousal. Insomnia secondary to other causes is more common than primary insomnia. Cerebral hypoperfusion can be the cause of insomnia in some cases. In such patients the cerebral blood flow should be improved using parenteral vascular therapy. If insomnia persists despite treatment, then therapy for primary insomnia should be instituted using benzodiazepine-receptor agonists such as Zolpidem, Zopiclone, or Zaleplon. In those cases Midazolam cannot be used for the treatment of insomnia due to its marked negative effect on cerebral blood flow. In Hungary there is a need to organize multidisciplinary Insomnia Clinics because insomnia is more than a disease, it is a public health problem in this century.

Contaminação do solo com antraceno e creosoto e o crescimento vegetal e a colonização micorrízica pelo Glomus etunicatum

A contaminação do solo por compostos orgânicos, especialmente os hidrocarbonetos aromáticos policíclicos (HAPs) de petróleo, é um problema crescente e que traz graves conseqüências ambientais. Para avaliar os impactos causados por esses compostos, torna-se necessário conhecer seus efeitos sobre as plantas e a microbiota rizosférica associada. No presente estudo avaliaram-se os efeitos de antraceno e creosoto no crescimento e na colonização micorrízica de Brachiaria brizantha e Pueraria phaseoloides. Antraceno e creosoto foram aplicados a um solo infestado com o fungo micorrízico Glomus etunicatum, sendo: antraceno nas concentrações de 0; 0,25; 0,5; 0,75 e 1 g kg-1 solo; e creosoto nas concentrações de 0; 0,5; 1; 2 e 3 g kg-1 solo. O solo com os tratamentos foi colocado em tubetes (290 cm³) e semeado com as plantas-teste, as quais foram cultivadas por seis semanas. Verificou-se que o antraceno não afetou o crescimento da puerária e teve pequeno estímulo no crescimento da braquiária na dose mais baixa, enquanto o creosoto reduziu o crescimento da braquiária e não teve efeito na puerária. Entretanto, ambos os contaminantes inibiram a colonização micorrízica da puerária, atingindo redução de cerca de 90 % em relação ao controle. Em concentrações bem inferiores às encontradas em solos contaminados, a colonização micorrízica foi inibida em 50 %, ficando evidente o potencial de impacto desses poluentes na relação planta-fungo micorrízico. Na braquiária não foi encontrada colonização micorrízica. Fica evidenciada a resposta diferenciada das duas espécies estudadas aos contaminantes e o acentuado efeito negativo destes sobre a colonização micorrízica. A puerária, por ter se mostrado insensível aos HAPs, nas concentrações estudadas, apresenta potencial para aplicação na fitorremediação de áreas impactadas por esses contaminantes.

Resurrecting the In‐Stream Side of Riparian Forests

With all the trees you folks are planting around here,” the old farmer said as he watched staff members from the Stroud Water Research Center place yet another row of flags along a meadow creek on a clear fall morning, “pretty soon this whole area will be woods. You know,” he went on, “when our forefathers first set foot on this ground, there wasn’t a tree anywhere around here.” So began a conversation with a man who had no idea that the land his family had farmed for generations in “Penn’s Woods” had once been completely forested. This is less surprising than it may at first appear because within a century after the first Europeans had settled, virtually every tree in southeastern Pennsylvania (PA) had been felled. Some of the first to go were those in riparian forests, which were cut for firewood and building material, for agricultural land and access to fresh water. The streams and rivers became the flowing commons of the New World, providing drinking water and waste disposal, hydropower and irrigation, food, transportation, and hygiene – all free of charge. As settlers marched westward across the continent, chopping down riparian forests, planting crops up to the river’s edge, and letting their livestock contaminate creeks, they wrote a tragedy of those commons (Hardin 1968), for which the nation continues to pay. Even as the world increasingly acknowledges the vital things trees do for people and their environment, the destruction continues. During the 15-year period from 1985 to 2000, for example, the Delaware Valley region of southeastern Pennsylvania and southern New Jersey lost 12,655 ha or 1.5 percent of its heavy forest canopy, representing an annual loss of at least 1.5 million m3 of stormwater retention, 750,000 kg of air pollution abatement, and 643 million kg of stored carbon (American Forests 2003). Perhaps nowhere has the destruction of America’s forests been more devastating than along its streams – and particularly its small streams – which are the source of most of the nation’s fresh water. In fact, a recent study found 19 percent of the total length of small streams in the U.S. to be in poor condition due to “severely simplified riparian vegetation” (U.S. Environmental Protection Agency 2006). Note our use of the phrase “riparian forests” rather than “riparian buffers.” In the last two decades, many policy makers have come to recognize the need to create a physical space – or buffer – to protect their freshwater sources from the harmful effects of human activity. Such policies have been supported by a significant body of scientific research demonstrating that buffers act as barriers to keep sediment and other pollutants from running off the land and into the stream (see reviews by U.S. Environmental Protection Agency 1995, Lowrance et al. 1997, Bentrup et al. 2005, Mayer et al. 2005). As a result, riparian buffers have become best management practice in most U.S. landscapes. While the recognition of the importance of such buffers has been a valuable addition, both to the scientific literature and to public policy debates, it has also had a little-noted but marked negative effect. The emphasis on the role of the buffer as a barrier, shielding a stream from harmful human activities, caused people to overlook the substantial benefits that riparian forests provide to the health and integrity of the stream itself. In this essay, we explore the important role riparian forests play in protecting our streams and rivers in a number of ways:

Selective inhibition of the pacemaker channel If improves symptoms in severe dilated cardiomyopathy

Karl La Rosee Kardiologische Gemeinschaftspraxis Bonn, Germany Sirs: Systolic heart failure is a common health problem world wide. Due to sympathetic activation heart failure patients generally develop an elevated heart rate, which further deteriorates pathological changes and symptoms in a circulus vitiosus. Interruption of this circle is an important mechanism of beta-blocker therapy in heart failure. However, there may be several contraindications to beta-blockers like asthma bronchiale. For these patients so far no reasonable alternative medication is available, particularly because verapamil should not be given due to its marked negative inotropic effect. We present a patient with severe myasthenia gravis, dilated cardiomyopathy and sinus tachycardia, who was markedly improved by the selective If inhibitor ivabradine. Case report

The effect of EDDS chelate and inoculation with the arbuscular mycorrhizal fungus Glomus intraradices on the efficacy of lead phytoextraction by two tobacco clones

Two pot experiments were conducted to investigate the effect of inoculation with the arbuscular mycorrhizal (AM) fungus Glomus intraradices on Pb uptake by two clones of Nicotiana tabacum plants. Non-transgenic tobacco plants, variety Wisconsin 38, were compared in terms of Pb uptake with transgenic plants of the same variety with inserted gene coding for polyhistidine anchor in fusion with yeast metallothionein. Bioavailability of Pb in experimentally contaminated soil was enhanced by the application of a biodegradable chelate ethylenediaminedissuccinate (EDDS). EDDS addition (2.5 and 5.0 mmol kg −1 substrate) increased Pb uptake from the substrate and enhanced Pb translocation from the roots to the shoots, with shoot Pb concentrations reaching up to 800 mg kg −1 at the higher chelate dose. Application of a single dose of 5 mmol kg −1 proved to be more efficient at increasing shoot Pb concentrations than two successive doses of 2.5 mmol kg −1, in spite of a marked negative effect on plant growth and phytotoxicity symptoms. Pb amendment (1.4 g kg −1 substrate) connected with either dose of EDDS decreased significantly plant biomass as well as reduced the development of AM fungi. AM inoculation promoted the growth of tobacco plants and partly alleviated the negative effect of Pb contamination, mainly in the case of root biomass. No consistent difference in Pb uptake was found between transgenic and non-transgenic tobacco plants. The effect of AM inoculation on Pb concentrations in plant biomass varied between experiments, with no effect observed in the first experiment and significantly higher root Pb concentrations and increased root–shoot ratio of Pb concentrations in the biomass of inoculated plants in the second experiment. Due to probable retention of Pb in fungal mycelium, the potential of AM for phytoremediation resides rather in Pb stabilisation than in phytoextraction.

Determinants of health-related quality of life in women with vertebral fractures

Health-related quality of life (HRQL) is an important consideration in the management of patients with vertebral fractures. The purpose of this study was to examine patient-related factors that contribute to HRQL after vertebral fractures, including co-morbidities, medications, fracture history, family disease history, demographics, exercise, education and living environment. A total of 1,129 post-menopausal women (mean age 67.2, SD 11.9 years) was studied from the Canadian Database of Osteoporosis and Osteopenia (CANDOO). HRQL was measured using the mini-osteoporosis quality of life questionnaire (mini-OQLQ). Separate multivariable linear regression analyses [parameter estimates and corresponding 95% confidence intervals (CI)] were performed for each of the five mini-OQLQ domains: symptoms, physical functioning, emotional functioning, activities of daily living and leisure domains. A strong positive association was found between HRQL and post-secondary education, a family history of osteoporosis, working and thiazide therapy. Exercise improved HRQL; however, several hours a week were required to be meaningful. Living in long-term care had the most marked negative effect on HRQL. Smoking, past surgery of the hip or spine, sedatives, anticonvulsants, atherosclerotic disease and hypertension were also associated with a substantially decreased HRQL across several domains. Calcium channel-blockers, chemotherapy, corticosteroids, diabetes, migraines, the number of non-vertebral fractures and falls had a negative impact on selected domains. We demonstrated that several modifiable factors influence HRQL in patients with vertebral fractures, and physicians should be aware of these and other markers of reduced HRQL to enhance patient care.

Effects of speech-rate and pause duration on sentence intelligibility in younger and older normal-hearing listeners

Speech-rate conversion techniques aid speech comprehension by allowing more time for perceptual and cognitive processes. However, if only the speech-rate of a telecast is converted, auditory and visual information become asynchronous. One possible method to resolve the problem is to reduce the pause durations between phrases; unfortunately, this can evoke a marked negative effect. For that reason, the present study examines the effects of the speech-rate and pause duration on sentence intelligibility. We manipulated the lengths of phrases relative to the original length (0, +100, +200, +300, and +400 ms), and the pause durations between phrases in a sentence (0, 100, 200, 300, and 400 ms). Listeners were asked to write down sentences they discerned from the noise. The intelligibility score increased in younger and older listeners when the speech signal was expanded. Regarding the pause duration, intelligibility was best when the pause duration was 200 ms in younger listeners; in older listeners, the intelligibility score was highest when the pause durations were 200 ms and 400 ms. These results provide evidence that might benefit speech-rate conversion through better use of pause duration.

Impaired peroxisomal function in the central nervous system with inflammatory disease of experimental autoimmune encephalomyelitis animals and protection by lovastatin treatment

Peroxisomes are ubiquitous subcellular organelles and abnormality in their biogenesis and specific gene defects leads to fatal demyelinating disorders. We report that neuroinflammatory disease in brain of experimental autoimmune encephalomyelitis (EAE) rats decreased the peroxisomal functions. Degradation of very long chain fatty acids decreased by 47% and resulted in its accumulation (C26:0, 40%). Decreased activity (66% of control) of dihydroxyacetonephosphate acyltransferase (DHAP-AT), first enzyme in plasmalogens biosynthesis, resulted in decreased levels of plasmalogens (16–30%). Catalase activity, a peroxisomal enzyme, was also reduced (37%). Gene microarray analysis of EAE spinal cord showed significant decrease in transcripts encoding peroxisomal proteins including catalase (folds 3.2; p<0.001) and DHAP-AT (folds 2.6; p<0.001). These changes were confirmed by quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis, suggesting that decrease of peroxisomal functions in the central nervous system will have negative consequences for myelin integrity and repair because these lipids are major constituents of myelin. However, lovastatin (a cholesterol lowering and anti-inflammatory drug) administered during EAE induction provided protection against loss/down-regulation of peroxisomal functions. Attenuation of induction of neuroinflammatory mediators by statins in cultured brain cells [J. Clin. Invest. 100 (1997) 2671–2679], and in central nervous system of EAE animals and thus the EAE disease [J. Neurosci. Res. 66 (2001) 155–162] and the studies described here indicate that inflammatory mediators have a marked negative effect on peroxisomal functions and thus on myelin assembly and that these effects can be prevented by treatment with statins. These observations are of importance because statins are presently being tested as therapeutic agents against a number of neuroinflammatory demyelinating diseases.

Mechanism of vasoselective action of mebudipine, a new calcium channel blocker

In previous studies, mebudipine, a newly synthesized dihydropyridine calcium channel blocker, showed a considerable vasoselective action. To investigate the mechanism of this property, the pattern of inhibitory action on the KCl-induced contraction in isolated rat aortic rings and the effect of changing resting membrane potential on the potency of this compound were considered. In addition, its chronotropic and inotropic actions were also studied. Mebudipine inhibited KCl-induced contractions. Its inhibitory effect was progressive and needed time to reach maximum. Incubation of the aortic rings in depolarizing physiological solution (high potassium, zero calcium) resulted in the augmentation of mebudipine effect. The potency of mebudipine in inhibiting aortic contractions and its time- and voltage-dependent action were significantly greater than those of nifedipine. In comparison with nifedipine, mebudipine showed a greater negative chronotropic effect, but in the case of negative inotropism, the reverse relation was observed. It is concluded that mebudipine has a greater time- and voltage-dependent inhibitory effect, as compared to nifedipine and this property could explain its prominent vasoselective action. It has also marked negative chronotropic effect and minor negative inotropic action. With regard to the above findings, mebudipine might have a selective and protective calcium channel blocking effect in ischemic regions (ischemia-selectivity), and the potential to be used in cardiovascular diseases without causing harmful effects such as reflex tachycardia and heart failure which have sometimes been seen with the older agents.

Phosphorus sorption and availability in soils amended with animal manures and sewage sludge.

Soils that receive large applications of animal wastes and sewage sludge are vulnerable to releasing environmentally significant concentrations of dissolved P available to subsurface flow owing to the gradual saturation of the soil's P sorption capacity. This study evaluated P sorption (calculated from Langmuir isotherms) and availability of P (as CaCl2-P and resin P) in soils incubated for 20 d with poultry litter, poultry manure, cattle slurry, municipal sewage sludge, or KH2PO4, added on a P-equivalent basis (100 mg P kg(-1)). All the P sources had a marked negative effect on P sorption and a positive effect on P availability in all soils. In the cattle slurry- and KH2PO4-treated soils, the decreases in P sorption maximum (19-66%) and binding energy (25-89%) were consistently larger than the corresponding decreases (7-41% and 11-30%) in poultry litter-, poultry manure-, and sewage sludge-treated soils. The effects of cattle slurry and KH2PO4 on P availability were, in most cases, larger than those of the other P sources. In the poultry litter, poultry manure, and sewage sludge treatments, the increase in soil solution P was inversely related (R2 = 0.75) to the input of Ca from these relatively high Ca (13.5-42 g kg(-1)) sources. Correlation analyses implied that the magnitude of the changes in P sorption and availability was not related to the water-extractable P content of the P sources. Future research on the sustainable application of organic wastes to agricultural soils needs to consider the non-P- as well as P-containing components of the waste.

The effects of slash management on nutrient cycling and tree growth in Eucalyptus plantations in the Congo

Since 1978, 42,000 ha of clonal Eucalyptus plantations have been established around Pointe-Noire. These plantations are growing on sandy and acidic soils with small reserves of available nutrients; therefore, risks of nutrient deficiencies exist in the medium or long-term. The effects of slash and litter management practices on soil properties, tree nutrition and growth were quantified to evaluate harvesting methods with respect to sustainable management of the replanted sites. The experimental design was a randomized complete block with four replications and six treatments: R, all aboveground organic residues removed; WTH, whole-trees harvested and removed; SBH, stemwood and bark removed; SH, stemwood-only removed; DS, double slash retained; B, stemwood-only removed and all organic residues burned. After 12 months removal of all slash material (R) had a marked negative effect on total biomass (5.9 t ha −1 vs a mean of 7.2 t ha −1 for the other treatments). During the first 18 months of the study no significant differences among treatments were detected ( P<0.05), but at 24 months, tree growth was significantly reduced where all organic residues were removed (R), compared to DS (12.9 m 3 ha −1 per year vs 22.2 m 3 ha −1 per year). The best growth was measured in plots with the highest organic residues (treatments DS and SH). Nutrient content in the aboveground biomass of the 1-year-old stand was strongly dependent on the type of slash and litter management. Differences in tree nutrient concentrations in various treatments demonstrated the ability of trees to store available nutrients in aboveground biomass. The rate of decomposition of organic residues during the first 8 months after harvesting ranged from 36% (WTH) to 56% (SH). Between 7 and 24 months, the annual production of inorganic nitrogen in the top soil (0–13 cm layer) was 71.6, 66.7, and 85.7 kg ha −1 per year for R, SH, and DS, respectively. The rate of soil nitrification was high, and therefore nitrogen leaching may have occurred in the early development stage when trees are not able to take up all the available nitrogen.

Long-term effects of Graves' ophthalmopathy on health-related quality of life.

Little is known about the long-term effects of Graves' ophthalmopathy (GO) on health-related quality of life (HRQL) after the eye treatment is considered to be finished. The aim of this study was to quantify these effects using validated HRQL questionnaires. A cross-sectional follow-up study was carried out in GO patients who had started radiotherapy and/or prednisone treatment between 1982 and 1992. Between 1998 and 2000 these patients received an HRQL questionnaire containing the SF-36, EuroQol and GO-QOL questionnaires. All patients were invited for a follow-up ophthalmological examination. HRQL scores of the respondents were compared with those of two reference populations of 'healthy' persons and to scores of several other GO populations. One hundred and sixty-eight patients were included; 163 completed the HRQL questionnaire and 154 visited the outpatient clinic. The median follow-up was 11.7 years. A considerable number of symptoms related to GO were found. More than half of the patients had diplopia and 28% had a low visual acuity. Sixty per cent had a proptosis of at least 20 mm. The HRQL scores were considerably better than those of newly diagnosed GO patients (untreated) and GO patients who completed the questionnaire during treatment, but worse than those of 'healthy' persons. Although we did not perform a longitudinal study, we included a selected group of patients who had been treated with radiotherapy and/or prednisone in the Academic Medical Centre of the University of Amsterdam, and though we could not assess HRQL at comparable times after receiving treatment, this is the first study that presents any data on the long-term effects of GO on HRQL. GO has a marked negative effect on HRQL, even many years after treatment. These findings suggest that GO should be considered a chronic disease. Aftercare is needed for these patients after their immunosuppressive and surgical treatments.

The effect of load length, width and mass on transport rate in the grass-cutting ant Atta vollenweideri.

In the present study we investigated the economics of load transport in the grass-cutting ant Atta vollenweideri by focusing on the effects of load mass, width and length on individual transport rates. Both running speed of foragers and the amount of material transported a given distance per unit time, i.e. gross material transport rate, were evaluated in both field and laboratory colonies. In order to separate the effects of load mass, load length and width on transport rate, workers were presented with paper fragments which differed twofold either in length, width or mass, but not in the other parameters. When controlling for fragment mass, both running speed of foragers and gross material transport rate were observed to be higher when they carried short fragments: A twofold increase in fragment length had a marked negative effect on manoeuvrability during transport and, as a consequence, on material transport rate. In contrast, if fragment mass was doubled and length maintained, running speed differed according to the mass of the loads, with heavier fragments being transported at the slower pace. For the sizes tested, heavy fragments yielded a higher transport rate in spite of the slower speed of transport, as they did not slow down foragers so much that it counterbalanced the positive effects of fragment mass on material transport rate. Doubling the width of the fragments without changing their mass had no influence on running speed and transport rate. When presented with a choice of dropped fragments differing in the size variables mentioned above, workers discriminated among fragments of different size and preferred shorter fragments, thus rejecting loads that are associated with higher travel times and lower material transport rates. It is argued that, based on the energetics of cutting, workers might maximize their individual harvesting rate by cutting long grass fragments, since the longer a grass fragment, the larger the amount of material harvested per unit cutting effort. Our results indicate, however, that larger loads negatively affect transport rates. The sizes of the fragments cut by grass-cutting ants under natural conditions may represent the outcome of an evolutionary trade-off between maximizing harvesting rate at the cutting site and minimizing the effects of fragment size on material transport rates.

Review: Effect of Some Components of Milk- and Soy-Based Infant Formulas on Mineral Bioavailability

Infants’ high nutritional needs are fulfilled by mother’s milk or infant formulas to provide all the necessary nutrients, among them minerals. Minerals uptake depends not only on mineral content but also on their bioavailability which, in turn, is affected by the different components of the infant formulas. An understanding of these effects would help to improve mineral bioavailability. This work reviews the influence of endogenous (proteins and phytates) and added (ascorbic and citric acid) components in infant formulas on the bioavailability of nutritionally important mineral elements (calcium, zinc, iron and copper) and their interactions. Special attention is given to the influence of protein, which is positive for calcium and negative for iron absorption. The marked negative effect of phytates on iron and zinc absorption can be counteracted by a dephytinization process. Of the added compounds, ascorbic acid has a positive effect on iron absorption that depends on the molar ratio between ascorbic acid and iron. In fact, adding ascorbic acid can counteract the negative effect of phytic acid on iron absorption but does not alter the effect of phytic acid on zinc absorption. The null effect of an increase in citric acid content can be ascribed to the fact that the citrate contents of infant formulas are already high. One of the most important element interactions is the negative effect of calcium on zinc and iron intestinal absorption and also the interaction between zinc and iron. These interactions deserve our attention because these minerals are essential to infants’ growth and development.

The effect of heparin on motility parameters and protein phosphorylation during bovine sperm capacitation

It is generally accepted that incubation with heparin is required to induce capacitation of ejaculated bovine spermatozoa in vitro. The capacitation process implicates many biochemical events, and is correlated with modified sperm motility and the phosphorylation of specific proteins on tyrosine residues. To better understand the molecular basis of heparin-induced capacitation, bovine spermatozoa were incorporated with a radioactive substrate of protein kinases [γ 32P]-ATP, to observe protein phosphorylation dynamics over time. Sperm motion parameters including the percentage of motile spermatozoa, amplitude of lateral head displacement (ALH) and flagellar beat cross frequency (BCF) were assessed to determine whether the protein phosphorylation patterns induced by heparin also promote changes in motility. Capacitation was confirmed using the chlortetracycline fluorescence assay and the appearance of ‘pattern B’ stained spermatozoa. Evaluation of the different motility parameters during capacitation reveal that heparin has a marked negative effect, over time, on the percentage of motile spermatozoa, consistent with hyperactivation. Indeed, the presence of heparin greatly increases the BCF of bull spermatozoa and induces a significant increase in the ALH compared to spermatozoa incubated without heparin. We detected several sperm proteins that are phosphorylated over time. A 45 kDa protein is the most intensely phosphorylated of the sperm proteins. However, it is visible regardless of the presence of heparin. Interestingly, a second phosphorylated protein of approximately 50 kDa undergoes more intense phosphorylation with heparin than without. In summary, the present study demonstrated that heparin induces physiological changes in several sperm motility parameters including ALH, BCF and the percentage of motile spermatozoa. Heparin also increases the intensity of phosphorylation of a 50 kDa sperm protein. These results suggest that capacitation of bovine spermatozoa and capacitation-associated motility changes may be regulated by a mechanism that includes protein phosphorylation, and that a presently unknown protein kinase is involved.

Long-term outcome of early childhood hearing impairments in northern Finland.

Early childhood hearing impairment (HI) may have a marked negative effect on educational outcome and employment status in adulthood. The late outcome of 51 Finnish mildly to profoundly HId children born in the period 1965-1979 was studied using a questionnaire posted to the subjects. Subjects included in the study had an early childhood sensorineural, non-syndromal hearing impairment with no known associated handicaps. The response rate to the inquiry was as high as 88% (45/51). The subjects had qualified educationally at a somewhat lower level than their age peers according to nationwide statistics; 48% of the respondents belonging to the labour force were currently unemployed (versus 15% of all the 25-to 29-year-olds in Finland in 1997), but their employment status was not associated with the HI grade. In particular, the severely and profoundly HId often had needed special support from the employment authorities to find work.

Inhibition by SR 59119A of Isoprenaline-, Forskolin- and VIP-induced Relaxation of Human Isolated Bronchi

In the human isolated bronchus (HIB) it has been shown that β3-adrenoceptor stimulation fails to induce relaxation of airway smooth muscle. It has however been reported in human ventricular endomyocardial biopsies that β3-adrenoceptor stimulation induced a marked negative inotropic effect which could be linked to Gi protein activation. The aims of this study were: (1) to determine in HIB (internal diameter 1–2 mm) whether the selective β3-adrenoceptor agonist SR 59119A (N[7-methoxy-1,2,3,4-tetrahydronaphthalen-(2R)methyl]-(2R)-2-hydroxy-2-(3-chlorophenyl)ethanamine hydrochloride) was able to inhibit adenylate–cyclase-mediated airway smooth muscle relaxation induced by isoprenaline, forskolin or vasoactive intestinal peptide (VIP) and (2) to investigate the role of the Gi protein in this interaction. SR 59119A (0.1 μM and 1 μM) induced a shift to the right of concentration response curve for isoprenaline (−0.15±0.06 and −0.54±0.21 log unit, P<0.05 and P<0.01 respectively), forskolin (−0.12±0.02 and −0.30±0.05 log unit, P<0.001), and VIP (−0.42±0.12 log unit, P<0.01 with SR59119A 10−6M). The inhibitory effect of SR 59119A was (1) abolished by an incubation of HIB with pertussis toxin (1 μg/ml, during 15 h in Krebs–Henseleit solution, at 21°C), which is known to inactivate the Gi protein and (2) increased after an incubation of HIB with the pro-inflammatory cytokine IL-1β (10 ng/ml, during 15 h in Krebs–Henseleit solution, at 21°C), which is known to up-regulate Gi protein expression. Our results suggest that the selective β3-adrenoceptor agonist SR59119A might inhibit the cAMP-dependent relaxation of human isolated bronchus through Gi protein-mediated inhibition of adenylate cyclase.