RENAL TRANSPLANTATION IN PATIENTS WITH LUPUS NEPHRITIS

Zahvaćanje bubrega teška je komplikacija sistemskog eritemskog lupusa, praćena visokim pobolijevanjem i smrtnošću. Do razvoja lupusnog nefritisa dolazi u do 60% oboljelih, a unatoč primjeni novih i potentnijih terapijskih protokola u 5 do 22% ove specifične populacije razvije se završni stadij kronične bubrežne bolesti unutar 15 godina od postavljanja dijagnoze. Kako je SLE ponajprije vezan uz mlađu životnu dob, izuzetno je važno odabrati optimalan modalitet nadomještanja bubrežne funkcije. Brojne su studije provedene ne bi li se odgovorilo na kontroverzna pitanja vezana uz ovu specifičnu populaciju. Veća sklonost infekcijama, rizik od povratka osnovne bolesti u presadak, nedefinirani kriteriji praćenja aktivnosti bolesti nakon transplantacije te veća učestalost epizoda odbacivanja i trombotskih događaja rizični su čimbenici zbog kojih se ovoj skupini dugo vremena onemogućavalo liječenje transplantacijom. Rezultati studija nedvojbeno pokazuju da je dugoročno preživljenje podjednako u liječenih hemodijalizom i peritonealnom dijalizom, no transplantacija bubrega nametnula se kao mnogo bolja metoda koja omogućava dulje preživljenje i veću kvalitetu života, umanjujući istodobno aktivnost samog SLE-a. Iako postoje brojna neistražena i neodgovorena pitanja vezana uz zbrinjavanje ove imunosno vrlo osjetljive i zahtjevne skupine bolesnika, pažljiva skrb prije i nakon transplantacije te uska suradnja nefrologa i imunologa omogućavaju dobar ishod uz znatno povećanje kvalitete života.Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE), associated with high morbidity and mortality. Up to 60% of SLE patients develop LN, and despite novel and potent therapeutic regimens, 5 to 22% develop end-stage renal disease within 15 years of diagnosis. While LN primarily affects younger individuals, it is important to choose optimal method of renal replacement therapy for those who develop end-stage renal disease. Numerous studies were carried out trying to solve problems of treatment of patients with LN. Increased risk of infections, disease recurrence in renal allograft, undefined criteria for follow-up of disease activity after transplantation, as well as higher incidence of rejection episodes and thrombotic events are well known risks which have postponed and restricted access to transplantation for patients with LN for long-time. However, numerous studies have demonstrated similar long-term survival in patients treated with haemodialysis or peritoneal dialysis, with clear superiority of renal transplantation regarding the prolonged survival and better quality of life for SLE patients. Many questions are still waiting for answers. Close cooperation between nephrologists and immunologists provides the best treatment for SLE patients with end-stage renal disease

Crop Pests and Predators Exhibit Inconsistent Responses to Surrounding Landscape Composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

The effect of fragmentation (scale) on the number of surviving species out of 21 under the reference conditions at five competitive settings (A-E).

<p>Different lines indicate the amount of surviving species out of 21 at different time intervals (<i>t</i> in years) since the start of the simulation. Bold lines indicate the diversity in the whole landscape and thin lines indicate the average patch diversity. Every point represents the average of 30 simulations. The landscape configuration consists of 100 patches that vary in size and are distributed at random, the average patch carrying capacity is 20 breeding pairs. The figure illustrates that the metapopulation diversity is highest at high fragmentation scales in all competitive settings whereas patch diversity is highest at intermediate fragmentation levels.</p

Description of the parameters, their units and their default values as used in the model.

<p>*Range for random species competition setting</p><p>Description of the parameters, their units and their default values as used in the model.</p

Single representative simulations of the meta-community dynamics of 21 bird species in contrasting competitive settings and inter-patch connectivity (scale).

<p>Each graph depicts a single representative simulation. Different lines and colors represent the population level of different competing species. Left column (A, C, E, G) have low inter-patch distances and high connectivity, scale = 1. Right column (B, D, F, H) have 10 times as large inter-patch distances and low connectivity, scale = 10. Competitive setting: (A, B) coexisting competition, (C, D) neutral competition, (E, F) hierarchical competition, (G, H) random species competition. The figure illustrates that at high connectivity we get faster extinction of species in these competitive settings.</p

Fraction of occupied patched in a metapopulation based on the Levins model dependents on colonization rate.

<p>The dotted red line represents the unstable equilibrium, and the drawn blue line the stable equilibrium. The figure illustrates that there is a connectivity threshold (<i>c</i>/<i>e</i> = 1) below which long term survival of a metapopulation is impossible.</p