The inhibition of autoreactive T cell functions by a peptide based on the CDR1 of an anti-DNA autoantibody is via TGF-beta-mediated suppression of LFA-1 and CD44 expression and function

Systemic lupus erythematosus (SLE), which is characterized by the increased production of autoantibodies and defective T cell responses, can be induced in mice by immunization with a human anti-DNA mAb that expresses a major Id, designated 16/6Id. A peptide based on the sequence of the CDR1 of the 16/6Id (human CDR1 (hCDR1)) ameliorated the clinical manifestations of SLE and down-regulated, ex vivo, the 16/6Id-induced T cell proliferation. In this study, we examined the mechanism responsible for the hCDR1-induced modulation of T cell functions related to the pathogenesis of SLE. We found that injection of hCDR1 into BALB/c mice concomitant with their immunization with 16/6Id resulted in a marked elevation of TGF-beta secretion 10 days later. Addition of TGF-beta suppressed the 16/6Id-stimulated T cell proliferation similarly to hCDR1. In addition, we provide evidence that one possible mechanism underlying the hCDR1- and TGFbeta-induced inhibition of T cell proliferation is by down-regulating the expression, and therefore the functions, of a pair of key cell adhesion receptors, LFA-1 (alphaLbeta2) and CD44, which operate as accessory molecules in mediating APC-T cell interactions. Indeed, T cells of mice treated with hCDR1 showed a TGF-beta-induced suppression of adhesion to the LFA-1 and CD44 ligands, hyaluronic acid and ICAM-1, respectively, induced by stromal cell-derived factor-1alpha and PMA. The latter suppression is through the inhibition of ERK phosphorylation. Thus, the down-regulation of SLE-associated responses by hCDR1 treatment may be due to the effect of the up-regulated TGF-beta on the expression and function of T cell adhesion receptors and, consequently, on T cell stimulation, adhesion, and proliferation.     

Thyroxine attenuates hippocampal neuronal damage caused by ischemia in the rat.

We investigated the effect of thyroxine against neuronal damage caused by ischemia in the rat. Neuronal damage was evaluated in the hippocampal CA1 subfield 7 days after a 10 min forebrain ischemia. Thyroxine was administered to animals divided in three groups: 15 min prior to ischemia (group 1), immediately after ischemia (group 2), and both before and after ischemia (group 3). The treatment of rats with a single dose of thyroxine given pre- or postischemia failed to prevent the loss of CA1 pyramidal cells. In contrast, repetitive administration of thyroxine before and after ischemia reduced the damage of the CA1 pyramidal cells. The mechanisms possibly underlying this neuroprotective effect are discussed.     

Genetics of autosomal recessive intellectual disability

In the last few years, next-generation sequencing has led to enormous progress in deciphering monogenic forms of intellectual disability. Autosomal dominant intellectual disability (ADID) and X chromosomal intellectual disability (XLID) have been the focus of research. Apart from metabolic disorders, autosomal recessive intellectual disability (ARID) is still behind, probably because it is more heterogeneous and less prevalent in industrial populations. The prevalence of ARID in a cohort of affected children of an outbred population is estimated to be about 10%, with an upward tendency in still unclarified cases. The risk for ARID in children of first cousins or closer is a magnitude higher than for children of unrelated parents. Taken together, it seems that children of related parents are at a 2 to 3 times higher risk for ID. There are no prevalent ARID genes, pathways, or protein complexes and the functions of the affected proteins are very diverse and limited not only to neurological aspects. Thus, in a regular case, there is no reasoning for picking a few genes for a first diagnostic step, and a genetic diagnosis of ID in general, and ARID specifically, is better made using large panels or exome sequencing. In addition, in the last few months, evidence has been growing that many ARID genes are pleiotropic and that the resulting phenotypes may have a broad spectrum. For an exhaustive deciphering of the genetics of ARID, we suggest research at the level of single genes rather than large meta-analyses.     

Sympatric occurrence of three leaf beetle species of Macroplea Samouelle, 1819 (Coleoptera,Chrysomelidae, Donaciinae) in Finland with a key to species in Northern Europe

Macroplea Samouelle, 1819 is the only known fully aquatic leaf beetle genus with three European species that have earlier been classified by their assumed water salinity preferences. We studied the inter- and intraspecific variation of the specimens living in Northern Europe using both molecular (cytochrome c oxidase subunit I, COI) and morphological evidence. The variation in the COI sequences between M. mutica (Fabricius, 1792) and M. pubipennis (Reuter, 1875) was 8.4%–9%, M. mutica and M. appendiculata (Panzer, 1794) – 3.9%–4.9%, and M. appendiculata and M. pubipennis – 8.8%–9.2%. All three species were sampled together in the Bothnian Sea on the same water plants, showing that neither salinity nor plant species bear a decisive importance in their occurrence in the region. Phylogenetic results suggest the existence of two currently unknown Macroplea species that are evolutionarily close to M. appendiculata. A key to the Nordic species is provided.     

How do chronic nutrient loading and the duration of nutrient pulses affect nutrient uptake in headwater streams?

Our study aimed to analyze the effects of chronic nutrient loading on the capacity of headwater streams to retain phosphorus and ammonium pulses of different duration. For this purpose, we selected nine headwater streams located across a gradient of increasing agricultural land use and eutrophication. In each stream, we performed sequential plateau additions with increasing nutrient concentrations in summer 2015 and instantaneous slug additions in summer 2016 under similar hydrological conditions. We modelled kinetic uptake curves from the slug additions via the Tracer Additions for Spiraling Curve Characterization method and calculated ambient uptake parameters. Ambient uptake rates generally increased (1.4–20.8 µg m^?2 s^?1 for NH₄–N and 0.3–10.3 µg m^?2 s^?1 for SRP, respectively), while ambient uptake velocities decreased from oligotrophic to polytrophic streams (1.8–14.0 mm min^?1 for NH₄–N and 1.6–9.9 mm min^?1 for SRP, respectively). However, correlations between ambient uptake parameters and background concentrations were weak. Concentration-dependent uptake rates followed either a linear or a Michaelis–Menten saturation model, regardless of the degree of nutrient loading. Uptake rate curves showed counter-clockwise hysteresis in oligotrophic streams and clockwise hysteresis in streams of higher trophic states, indicating a reduced significance of hyporheic uptake with increasing nutrient loading. Comparisons of slug and plateau additions revealed that oligotrophic streams were most efficient in uptake during short nutrient pulses, while eutrophic streams profited from longer pulse duration. The results indicate that nutrient uptake is increasingly transport-controlled in polluted streams where increased biofilm thickness and clogging of sediments restrict nutrient transport to reactive sites.     

Hibernation by the lepidopteran stalk borers, Busseola fusca and Chilo partellus on grain sorghum

The lepidopteran stalk borers, the indigenous Busseola fusca (Fuller) (Noctuidae), and the exotic Chilo partellus (Swinhoe) (Pyralidae), were studied in grain sorghum fields, Sorghum bicolor (L.) Moench (cultivar SSK-52), in the dry season of 1986 (April–October) at Delmas and Brits, Transvaal, South Africa. More than 90% of plants at both sites were infested, but as winter progressed, the proportion of plants infested and the level of infestation dropped gradually. The borer larvae hibernated inside the dry stalks, but the location differed: 65% of B. fusca were in the lower third and 30% in the middle third, whereas for C. partellus it was 45 and 50% respectively. Both borers overwintered as larvae in either of the last three instars, but the proportions of larval instars were different. About 82% of B. fusca hibernated as 6th and 16% as 5th larval instars whereas with C. partellus it was 40 and 45% respectively. C. partellus started to emerge from diapause in the second part of August and it lasted until the first week of November, a period of 12 weeks, but with B. fusca on the other hand pupation lasted only 3 weeks during October–November. Parasitism was low on both species, but higher on B. fusca. Three parasites, Chelonus curvinaculatus Cameron, Chelonus sp. and Pristomerus sp. hibernated in the borers, one parasite Iphiaulax sp., hibernated in its cocoon inside the stalks, and two parasites Apanteles sesamiae Cameron and Bracon sp. were active in winter. Two ants, Pheidole megacephala Febricius, and Dorylus helvolus (L.), preyed on the borer larvae in winter.

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Hibernation des chenilles de deux espèces de mineuses, Busseola fusca et Chilo partellu dans les tiges de Sorghum bicolor

Résumé Deux chenilles mineuses de tiges, B. fusca, Noctuidae indigène, et C. partellus, Pyralidae exotique, ont été étudiées dans des champs de S. bicolor (cultivar SSK-52), pendant la saison sèche de 1986 (Avril–Octobre) à Delmas et Brits, au Transvaal en Afrique du Sud. Plus de 90% des pieds des deux stations étaient infestés, mais plus l'hiver avançait, plus la proportion de plantes in festées et le taux d'infestation diminuaient. Les chenilles ont hiverné dans les tiges sèches, mais leurs positions étaient différentes: 65% des B. fusca étaient dans le tiers inférieur et 30% dans le tiers médian, tandis que pour C. partellus, il s'agissait respectivement de 45 et 50%. Les duex chenilles hivernaient à l'un des 3 derniers stades larvaires, mais les proportions étaient différentes. Pour B. fusca environ 82% hivernaient au 6ème stade et 16% au 5ème stade, tandis que pour C. partellus c'étaient 40 et 45% respectivement. C. partellus a commencé à sortir de diapause pendant la seconde moitié d'Août et a continué jusqu'à la première semaine de Novembre, soit durant une période de 12 semaines, mais avec B. fusca la nymphose a duré seulement 3 semaines en Octobre–Novembre. Le parasitisme des deux espèces a été faible, mais plus important chez B. fusca. Trois parasites, Chelonus curvimaculatus Cameron, Chelonus sp. et Pristomerus sp. ont hiverné dans leurs cocons à l'intérieur des tiges, et deux parasites, Apanteles sesamiae Cameron et Bracon sp. étaient actifs en hiver. Deux fourmis, Pheidole megacephala Fabricius et Dorylus helvolus L. capturaient des chenilles de ces mineuses pendant l'hiver.

     

Modeling of interstitial fluid movement in soft tissue under negative pressure – relevance to treatment of tissue swelling

Exact physiological mechanisms behind the potential positive treatment effects of pathological tissue swelling (edema), such as increased interstitial fluid flow, are poorly understood. Finite-element model was created and the model response was matched with the deformation data from the negative pressure (suction) measurements in human (N = 11) forearm. Two experimental suction protocols were simulated to evaluate their impact on interstitial fluid flow in soft tissues. Simulated continuous suction was up to 27 times more efficient in fluid transportation compared to the cyclic suction. The continuous suction that transports the interstitial fluid effectively may help to decrease soft tissue edema.     

Effect of irrigation frequency and nitrogen on groundnut yield and nutrient uptake

Summary Field experiments were conducted during 1979 and 1980 summer seasons on sandy loam soils of low moisture retentive capacity to study the effect of high frequency irrigation at different levels of N on groundnut yield and nutrient uptake (NPK). Four irrigation frequencies (irrigation at 2, 4, 6 and 8 cm cumulative can evaporation, corresponding to irrigation once in 3, 5, 7 and 10 days respectively) and four levels of nitrogen (0, 20, 40 and 60 kg N/ha) were tested in a factorial randomized block design with three replications. Pod yield of groundnut was maximum (3,293 kg/ha) when irrigations were scheduled at 4 cm cumulative can evaporation (once in 5 days). Addition of N did not increase the pod yield. N and P uptake by the crop was maximum (180 kg N and 18 kg P/ha) with high frequency irrigation of scheduling irrigation at 4 cm cumulative can evaporation. Highest uptake of N (183 kg/ha) and P (19 kg/ha) was with a combination of 20 kg N/ha and high frequency irrigation (4 cm CCE). K uptake was low with low irrigation frequency, while it was highest (67 kg K/ha) at 20 kg N/ha.     

The expression patterns of integrin subunits on human breast tissues obtained during pregnancy

Integrins have been shown to exert regulatory influences on mammary differentiation and morphogenesis in rodent experimental systems. We have, therefore, examined the expression patterns of integrin subunits on human breast tissues obtained at the 12th, 15th and 18th weeks of pregnancy. Myoepithelial cells were positive for all the integrin subunits examined. alpha2, alpha6 and beta4 showed increased and more defined labelling during pregnancy, indicating that myoepithelial cells and extracellular matrix strengthen their support for the expanding alveoli during pregnancy. Sub-populations of stromal cells were positive for alpha1, alpha3, alpha6, beta1 and beta4. On luminal epithelial cells, alpha1, alpha2, alpha3, alpha6 and beta1 were detectable. alpha2 showed a focal decrease, but the expression patterns of other integrins in luminal cells did not change during pregnancy. Therefore, the expression patterns of most integrins existing prior to pregnancy seem sufficient in this cell type to support the morphological and functional development during early pregnancy.