The role of land use,nutrients, and other stressors in shaping benthic invertebrate assemblages in Slovenian rivers

Studying human impacts on riverine systems is challenging due to the natural diversity and multiple stressors that are co-occurring. The term stressor(s) refers to variable(s) of anthropogenic landscape changes and local abiotic stream conditions that reflect human activities. We compared the effects of different stressors and natural (typology) factors on benthic invertebrate assemblages in Slovenian rivers. A total of 270 river sites located in four European ecoregions were sampled, covering the gradient of human perturbation ranging from (near)natural to highly degraded/polluted. Stressors commonly affecting running waters were grouped into management-relevant stressor-groups: land use (percentage of urban, intensive and non-intensive agricultural, and natural land use in the catchment and sub-catchment), eutrophication (in-stream concentrations of phosphorus and nitrogen compounds) and other stressors (e.g., organic pollution, hydromorphological alteration). We compared the effects of the stressor-groups on invertebrate assemblages using partial Canonical Correspondence Analysis and tested the explanatory power of each stressor-group using typology variables as covariates. Stressors and typology variables showed high independent effects (40–65%) on invertebrate assemblages despite considerable joint effects from land use and typology. Stressors’ pure effects accounted for 70%, and interactions among the stressor-groups made up the remaining 30% of the total explained variability. Altogether, this study gives a good perspective on the ability to separate the effects of anthropogenic stressors from natural causes, as well as to separate effects among groups of stressors. Against this background, we advocate stressor-specific analyses to provide or improve guidelines for selecting appropriate measures to enhance the river status.     

The expression of interleukin-1 alpha, TNF and VEGF in corneal cells of patients with bullous keratopathy

Bullous keratopathy (BK) is a chronic corneal edema with or without subepithelial bullae as a result of a loss of the endothelial cells. 15 patients with BK after cataract surgery with intraocular lens implantation, due to Fuchs dystrophy (n = 3) or corneal endothelial trauma (n = 12) were included in the study. All patients were treated by amniotic membrane transplantation (AMT). Corneal epithelial cells in patients suffering from BK secreted 3.91 +/- 3.09 pg/mL of IL-1 alpha, 4446 +/- 16.8 pg/mL of TNF and 81.43 +/- 37.81 pg/mL of VEGF-I. Levels of all 3 investigated cytokines were significantly higher as compared to controls (p < 0.005). Amniotic membranes that were used to treat investigated patients contained 638.98 +/- 613.98 pg/mL of IL-1ra, 0.026 +/- 0.009 pg/mL of sTNF and 81.39 +/- 21.01 pg/mL of VEGF-R. Beneficial clinical effect of the AMT in treating BK could be explained by its natural production of pro-inflammatory cytokine antagonists such as IL-ra, sTNF antagonist and VEGF-R.     

Lymph node, spleen and peripheral blood lymphocytes as stimulators of alloreactivity

Before and after kidney transplantations, in vitro tests that measure the level of reactivity between donor and recipient lymphocytes are performed for better organ selection and as indicator of possible organ rejection. In these tests, donor's and recipient's lymphocytes are stimulated for proliferation, which intensity is measured and accordingly organ recipient reactivity towards graft is determined. Lymph node, spleen and peripheral blood lymphocytes are used for those purposes. For better interpretation of these in vitro tests it should be important to determine mitogenic ability of lymphocytes of different origin and to choose the most adequate cells. To compare mitogenic ability of deceased donor lymph node, spleen and peripheral blood lymphocytes one-way mixed lymphocyte culture (MLC) was used. As stimulators irradiated lymphocytes from spleen, lymph node and peripheral blood samples of 12 deceased donors were used while as responders lymphocytes from peripheral blood of healthy individuals, chosen according HLA-DRB1 alleles (stimulators and responders were HLA-DRB1 identical, semi-identical or different), were used. Spleen lymphocyte activity was the best with different cells and the weakest with identical cells. Impact of polyclonal mitogens (PHA - phytohemagglutinin, Con A - concanavalin A and PWM - pokeweed mitogen) on lymphocyte proliferation was tested on lymphocytes from spleen and lymph node of deceased donors. Results obtained in culture in vitro showed that spleen cells had exerted the best mitogenic potential and PHA had the greatest impact upon lymphocyte proliferation. This investigation is of importance for establishing the best model to reflect in vivo situation in transplanted patient.     

Prevalence and significance of vaginal group B streptococcus colonization in pregnant women from Osijek, Croatia

The aim of the study was to determine the prevalence of vaginal group B streptococcus (GBS) colonization in pregnant women from Osijek area, the possible effect of GBS colonization on pregnancy outcome and neonatal complications and the role of intrapartum prophylaxis in this context. This retrospective case-control study took place at the Department of Gynecology and Obstetrics, Osijek University Hospital Center from December 2003 to June 2006. A total of 118 pregnant women was enrolled in study and divided into two groups: 59 women in 35th-37th week of gestation, free from risk factors for infection (control group); and 59 women in 25th-41st week of gestation with risk factors for infection. Low vaginal swab for GBS isolation and identification on selective and enriched medium was obtained from each woman. GBS colonization was recorded in 29 (24.6%) women: 12 (20.3%) control and 17 (28.8%) women at risk of infection, yielding a statistically non-significant difference (Chi2 = 1.480489; p < 0.48). Early neonatal infection was observed in six (20.7%) neonates born to 29 mothers with GBS colonization, pointing to a correlation between vaginal GBS colonization and early neonatal infection (r(s) = 0.99). Early perinatal infection was found in 22 (18.6%) neonates, including 17 (28.8%) pregnancies with risk factors, pointing to a significant correlation between vaginal GBS colonization, risk factors and early perinatal infection (Chi2 = 88.68; p < 0.001); however, gestational age and pregnancy outcome were not influenced by GBS colonization. In eight (36.4%) newborns, early neonatal infection developed in spite of intrapartum administration of antibiotics; three of these children were born to GBS positive mothers, and perinatal GBS infection was demonstrated in one (0.84%) child. Study results revealed a relatively high rate of GBS colonization in the population of pregnant women in Croatia, occasionally leading to early neonatal infection. Large studies are needed to develop national strategy for the prevention of GBS infection in Croatia.     

Transplantation of amniotic membrane in corneal ulcers and persistant epithelial defects

Amniotic membrane transplantation (AMT) leads to reduction of inflammatory symptoms and causes faster epithelisation in corneal ulcers and persistant epithelial defect. 21 patients with corneal ulcer (n = 18) or non-healing epithelial defect (n = 3) unresponsive to conventional treatment were included in the study. All patients were treated by AMT. Corneal epithelial cells in patients suffering from corneal ulcer secreted 3.51 +/- 1.79 of IL-1alpha, 64.27 +/- 31.53 pg/mL of TNFalpha and 209.07 +/- 201.82 pg/mL of VEGF. Levels of all 3 investigated cytokines were significantly higher as compared to controls (p < 0.005). Amniotic membranes that were used contained 775.69 +/- 613.98 pg/mL of IL-1alpha, 0.036 +/- 0.033 pg/mL of sTNF and 175.01 +/- 166.63 pg/mL of VEGF-R. Supporting effect of the AMT could be explained by the fact that AM secretes its natural antinflammatory antagonists IL-1ra, sTNF and VEGF-R.     

Corneal thickness in congenital glaucoma

Central corneal thickness is very important measurement in glaucoma treatment because it influences the eye pressure measurements. A thinner cornea gives us artifactually lower intraocular pressure and a thicker cornea gives higher intraocular pressure reading, so it has to be corrected in both cases. The aim of this study is to compare central corneal thickness between congenital glaucoma patients and normal subjects. Prospective study included 27 patients with congenital glaucoma and 35 patients in control group. First group was subdivided in two subgroups: A--8 earlier operated patients, B--19 patients treated with topic therapy. Patients had no other corneal disorders, history of trauma, corneal surgery and they were not contact lens wearers. Measurements were performed by specular microscope Tomey EM 3000 on central corneas. This study showed that patients with congenital glaucoma have lower central corneal thickness than normal subjects. Also, the study showed that antiglaucomatous operation doesn't influence central corneal thickness. Central corneal thickness need to be a routine part of examination measurements because of need to correct intraocular pressure according to it, but also the thinner corneas values can suggest congenital glaucoma diagnosis beside the other parameters.     

Epidemiologic characteristics of human campylobacteriosis in the County Primorsko-goranska (Croatia), 2003-2007

The aim of the study was to investigate campylobacteriosis incidence in the County Primorsko-goranska (Croatia) between 2003 and 2007 and to find out possible connection with environmental factors (the average monthly temperature and total monthly precipitation). The data (number of stool samples examined, age and sex distribution of patients, monthly distribution of isolates and distribution of isolates according to the species) from the Laboratory for Diagnostics of Enteric Infections of the Teaching Institute of Public Health of the County Primorsko-goranska (Croatia) were analyzed retrospectively. During the observed period 30,164 stool samples were examined for Campylobacter spp. Campylobacters were identified in 1,242 (4.12%) samples. The overall annual campylobacter incidence rate was 81.3 +/- 21.9/100,000 population. Campylobacter jejuni was found in 1,093 (88%) and C. coli in 149 (12%) patients. Our findings showed age distribution of patients typical for developed countries. The patients were mostly children under 5 years (484.4 +/- 129.1/ 100,000, p < 0.001) and between 5 and 9 years of age (226.5 +/- 60.5/100,000, p < 0.05). Male consistently experienced higher rates, but the difference between genders was significant in the age groups from birth till late twentieth (p < 0.001). Campylobacter rates were significantly associated with monthly average temperatures (p < 0.05), but not with precipitation. Further investigations into the incidence of campylobacteriosis on the national level are necessary. The causes of the noticed monthly distribution, sources of infection and connection with the routes of transmission in humans need to be elucidated as well.     

Factors affecting nest choice by Pekin ducks

To encourage nest use in breeder poultry flocks, it is important that nest boxes are attractive. Few studies have evaluated factors affecting nest attractiveness to ducks. We assessed the effects of nest box experience (Experiments 1 and 2) and features of nests, including degree of enclosure (Experiments 1 and 2) and the presence of an egg (Experiment 3), on nest site selection by sexually mature Pekin ducks. The hens were tested individually in pens containing different nest box choices. Nest preferences were determined based on the locations of 14 successively laid eggs. Ducks in Experiment 1 were provided with nest box access prior to the onset of lay (20 weeks of age, EXP group, N = 12) or at the time of preference testing (35 weeks of age, DELAYED-EXP group, N = 12). Delaying nest box access by 15 weeks did not significantly affect the proportion of eggs laid in nest boxes rather than on the floor (P = 0.40). Regardless of experience ducks laid more than 66% of their eggs in nest boxes offering a higher degree of enclosure. Ducks in Experiment 2 were reared with either open-top (OP, N = 12) or closed-top (CL, N = 12) boxes. Regardless of rearing condition, ducks preferred boxes with the highest level of enclosure offered. Ducks laid twice the expected proportion (25%) of eggs in CL boxes with curtains (P = 0.0004). CL boxes without curtains were used as predicted by chance, 25% (P = 0.746), while OP boxes with (P = 0.009) and without (P = 0.015) curtains each contained only half the expected number of eggs. Ducks in Experiment 3 were provided with two nest boxes, one of which contained the egg laid the previous day. Each day, the newly laid egg was marked and either placed back in the nest box where it was found (HANDLED, N = 12) or moved into the adjacent nest box (MOVED, N = 12). Ducks in HANDLED and MOVED laid 97.6% and 79.8%, respectively, of their eggs in boxes containing the previous day's egg. While ducks in HANDLED were consistent in their choice throughout the test, those in MOVED developed the preference over time (P = 0.039), suggesting that the preference for laying in a nest containing an egg may be influenced by experience. These results indicate that nest box enclosure and the presence of an egg are important in determining the nesting choices of Pekin ducks. Incorporating these features into nest boxes may be useful for increasing consistency of nest use in breeder duck flocks.     

An islet-specific pulse of TGF-β abrogates CTL function and promotes β cell survival independent of Foxp3+ T cells

Effective therapies that prevent chronic inflammation from developing into type 1 diabetes remain elusive. In this study, we show that expression of TGF-β for just 1 wk in inflamed islets of NOD mice significantly delays diabetes development. Time course studies demonstrated that the brief TGF-β pulse protects only if administered when extensive β cell destruction has occurred. Surprisingly, TGF-β-mediated protection is not linked to enhanced Foxp3(+) regulatory T cell activity or to decreased intrapancreatic presentation of islet Ags. Instead, TGF-β disables the transition of primed autoreactive CD8(+) T cells to cytotoxic effectors and decreases generation, or maintenance, of CD8(+) memory T cells within the pancreas, significantly impairing their diabetogenic capacity.