67 research outputs found

    Cyclosporine-A-induced nephrotoxicity in children with minimal-change nephrotic syndrome: long-term treatment up to 10 years

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    The impact of cyclosporine A (CsA) therapy in patients with steroid-dependent nephrotic-syndrome (SDNS) on long-term renal function is controversial. Data beyond 5 years are rare. Long-term renal function was evaluated in children with SDNS with and without CsA therapy, especially beyond 5 years. Twenty children were treated with CsA (study group) for a mean of 5.4 ± 2.2 years (ten patients for 5–11 years). Glomerular filtration rate (GFR) was calculated before and after 3 and 12 months and at latest follow-up of therapy. Fifteen children with cyclophosphamide-treated SDNS without CsA served as controls. In the study group, GFR decreased within 12 months from 136 ± 19 to 120 ± 31, to 114 ± 14 ml/min per 1.73 m2 at latest follow-up (p < 0.0001). Patients with CsA > 5 years had a GFR of 111 ± 14 ml/min per 1.73 m2 at latest follow-up without a GFR below 90 ml/min per 1.73 m2. No CsA toxicity was found in biopsies. In the control group, GFR dropped within 3 months, from 137 ± 27 to 130 ± 24, to 126 ± 19 ml/min per 1.73 m2 at latest follow-up (p = 0.1). Patients with and without nephrotoxic CsA therapy showed a drop in GFR. In CsA-treated patients, GFR was about 12% lower at latest follow-up compared with patients without nephrotoxic therapy but always remained within normal range. CsA seems to be safe, even in long-term treatment for more than 5 years

    Responses of marine benthic microalgae to elevated CO<inf>2</inf>

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    Increasing anthropogenic CO2 emissions to the atmosphere are causing a rise in pCO2 concentrations in the ocean surface and lowering pH. To predict the effects of these changes, we need to improve our understanding of the responses of marine primary producers since these drive biogeochemical cycles and profoundly affect the structure and function of benthic habitats. The effects of increasing CO2 levels on the colonisation of artificial substrata by microalgal assemblages (periphyton) were examined across a CO2 gradient off the volcanic island of Vulcano (NE Sicily). We show that periphyton communities altered significantly as CO2 concentrations increased. CO2 enrichment caused significant increases in chlorophyll a concentrations and in diatom abundance although we did not detect any changes in cyanobacteria. SEM analysis revealed major shifts in diatom assemblage composition as CO2 levels increased. The responses of benthic microalgae to rising anthropogenic CO2 emissions are likely to have significant ecological ramifications for coastal systems. © 2011 Springer-Verlag

    Follow-up study on lead exposure in children living in a smelter community in northern Mexico

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    <p>Abstract</p> <p>Background</p> <p>To study the changes of children lead exposure in the city of Torreon during the last five years, after environmental and public health interventions, using the timeline of lead in blood concentration as the biomarker of exposure and its relation to lead in soil concentrations.</p> <p>Methods</p> <p>This follow-up study started in 2001 and consisted of 232 children living in nine neighborhoods in Torreon. Children were tested at 0, 6, 12 and 60 months. Lead in blood concentrations, Hemoglobin, Zinc-Protoporphyrin, anthropometric measures and socioeconomic status questionnaire was supplied to the parents.</p> <p>Results</p> <p>Median and range of lead in blood concentrations obtained at 0, 6, 12, 60 months were: 10.12 μg/dl (1.9 - 43.8), 8.75 μg/dl (1.85 - 41.45), 8.4 μg/dl (1.7 - 35.8) and 4.4 μg/dl (1.3 - 30.3), respectively. The decrease of lead in blood levels was significantly related to ages 0, 6, 12 and 60 months of the follow-up study. The timeline of B-Pb was associated with the timeline of lead in soil concentrations.</p> <p>Conclusions</p> <p>B-Pb levels have significantly decreased in the group of children studied. This could be explained by a) environmental interventions by authorities and the smelter companies, b) normal changes in hygienic habits as children age and c) lead redistribution from blood to hard tissues.</p

    Early Weight Bearing of Calcaneal Fractures Treated by Intraoperative 3D-Fluoroscopy and Locked-Screw Plate Fixation

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    Operative therapy of intraarticular fractures of the calcaneus is an established surgical standard. The aim is an accurate reduction of the fracture with reconstruction of Boehler’s angle, length, axis and subtalar joint surface. Intraoperative 3D-fluoroscopy with the Siremobil Iso-C 3D® mobile C-arm system is a valuable assistant for accurate reconstruction of these anatomical structures. Remaining incongruities can be recognized and corrected intraoperatively. The achieved reduction can be fixed by the advantages of an internal fixator (locked-screw plate interface). In the period of October 2002 until April 2007 we operated 136 patients with intraarticular fractures of the calcaneus by means of anatomical reduction, and internal plate fixator under intraoperative control of 3D-fluoroscopy. All patients were supplied with an orthesis after the operation which allowed weight bearing of 10 kg for 12 weeks for the patients operated between October 2002 and October 2004 (Group A). Transient local osteoporosis was observed in all X-Rays at follow-up after an average of 8,6 months. Therefore we changed our postoperative treatment plan for the patients operated between November 2004 and April 2007 (Group B). Weight bearing started with 20 KG after 6 weeks, was increased to 40 KG after 8 weeks and full weight bearing was allowed after 10 weeks for these patients. In no case a secondary dislocation of the fracture was seen. No bone graft was used. At follow up the average American Foot and Ankle Society Score (AOFAS) were 81 for Group_A, compared to 84 for Group B, treated with earlier weight bearing. Autologous bone graft was not necessary even if weight bearing was started after a period of six weeks postoperatively. The combination of 3D-fluoroscopy with locked internal fixation showed promising results. If the rate of patients developing subtalar arthrosis will decrease by this management will have to be shown in long term follow up

    A Novel Mouse Synaptonemal Complex Protein Is Essential for Loading of Central Element Proteins, Recombination, and Fertility

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    The synaptonemal complex (SC) is a proteinaceous, meiosis-specific structure that is highly conserved in evolution. During meiosis, the SC mediates synapsis of homologous chromosomes. It is essential for proper recombination and segregation of homologous chromosomes, and therefore for genome haploidization. Mutations in human SC genes can cause infertility. In order to gain a better understanding of the process of SC assembly in a model system that would be relevant for humans, we are investigating meiosis in mice. Here, we report on a newly identified component of the murine SC, which we named SYCE3. SYCE3 is strongly conserved among mammals and localizes to the central element (CE) of the SC. By generating a Syce3 knockout mouse, we found that SYCE3 is required for fertility in both sexes. Loss of SYCE3 blocks synapsis initiation and results in meiotic arrest. In the absence of SYCE3, initiation of meiotic recombination appears to be normal, but its progression is severely impaired resulting in complete absence of MLH1 foci, which are presumed markers of crossovers in wild-type meiocytes. In the process of SC assembly, SYCE3 is required downstream of transverse filament protein SYCP1, but upstream of the other previously described CE–specific proteins. We conclude that SYCE3 enables chromosome loading of the other CE–specific proteins, which in turn would promote synapsis between homologous chromosomes

    Serotonin synthesis, release and reuptake in terminals: a mathematical model

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    <p>Abstract</p> <p>Background</p> <p>Serotonin is a neurotransmitter that has been linked to a wide variety of behaviors including feeding and body-weight regulation, social hierarchies, aggression and suicidality, obsessive compulsive disorder, alcoholism, anxiety, and affective disorders. Full understanding of serotonergic systems in the central nervous system involves genomics, neurochemistry, electrophysiology, and behavior. Though associations have been found between functions at these different levels, in most cases the causal mechanisms are unknown. The scientific issues are daunting but important for human health because of the use of selective serotonin reuptake inhibitors and other pharmacological agents to treat disorders in the serotonergic signaling system.</p> <p>Methods</p> <p>We construct a mathematical model of serotonin synthesis, release, and reuptake in a single serotonergic neuron terminal. The model includes the effects of autoreceptors, the transport of tryptophan into the terminal, and the metabolism of serotonin, as well as the dependence of release on the firing rate. The model is based on real physiology determined experimentally and is compared to experimental data.</p> <p>Results</p> <p>We compare the variations in serotonin and dopamine synthesis due to meals and find that dopamine synthesis is insensitive to the availability of tyrosine but serotonin synthesis is sensitive to the availability of tryptophan. We conduct <it>in silico </it>experiments on the clearance of extracellular serotonin, normally and in the presence of fluoxetine, and compare to experimental data. We study the effects of various polymorphisms in the genes for the serotonin transporter and for tryptophan hydroxylase on synthesis, release, and reuptake. We find that, because of the homeostatic feedback mechanisms of the autoreceptors, the polymorphisms have smaller effects than one expects. We compute the expected steady concentrations of serotonin transporter knockout mice and compare to experimental data. Finally, we study how the properties of the the serotonin transporter and the autoreceptors give rise to the time courses of extracellular serotonin in various projection regions after a dose of fluoxetine.</p> <p>Conclusions</p> <p>Serotonergic systems must respond robustly to important biological signals, while at the same time maintaining homeostasis in the face of normal biological fluctuations in inputs, expression levels, and firing rates. This is accomplished through the cooperative effect of many different homeostatic mechanisms including special properties of the serotonin transporters and the serotonin autoreceptors. Many difficult questions remain in order to fully understand how serotonin biochemistry affects serotonin electrophysiology and vice versa, and how both are changed in the presence of selective serotonin reuptake inhibitors. Mathematical models are useful tools for investigating some of these questions.</p

    Natural history and description of Oncothrips kinchega, a new species of gall-inducing thrips with soldiers (Thysanoptera : Phlaeothripidae)

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    A new species of gall-inducing thrips, Oncothrips kinchega sp. n., is described and its biology on the host plant Acacia carneorum was investigated. Our study showed that a single foundress initiates a gall. Her first-laid eggs develop into soldiers (mean number of soldiers ± SE = 28 ± 15, 40% males, with no evidence for protogyny or protandry). The soldiers, along with the foundress, produce the (subsequent) dispersing generation (mean number of dispersers ± SE = 187 ± 10, 37% males with no evidence for protogyny or protandry). The brood development-pattern of O. kinchega is similar to that found in the complex of forms currently referred to as Oncothrips habrus Mound and Oncothrips waterhousei Mound & Crespi and is different from that of Oncothrips morrisi Mound, Crespi & Kranz, a species with soldiers but a non-social development pattern. However, O. kinchega shares several life history characteristics with O. morrisi, and appears intermediate in brood size between O. morrisi and the remainder of the gall-inducers. The possible evolutionary significance of these observations is discussed.Taryn E Wills, Thomas W Chapman, Laurence A Mound, Brenda D Kranz and Michael P Schwar
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