Search

Assessing variation in breeding performance in relation to habitat characteristics may provide insights into predicting the consequences of land-use change on species ecology and population dynamics. We compared four Marsh Harrier Circus aeruginosus populations subject to similar environmental conditions, but which differed in habitat composition, ranging from natural habitats to intensively cultivated areas. Using a 6-year dataset, we characterized breeding habitat and diet in these four study sites, and analysed breeding performance in relation to this gradient of land-use intensification. There was minimal variation in breeding performance between study years but consistent variation between study sites. Unexpectedly, Marsh Harriers breeding in intensively cultivated habitats had higher reproductive success than those breeding in more natural habitats, which, however, hosted higher breeding densities, so overall net population productivity (fledglings per unit area) was similar across sites. This resulted from combined effects of density-dependence and different predation rates between study sites. The colonization of intensive farmland habitats may not necessarily impact negatively on population sustainability when breeding success and population density are traded against each other. However, our findings should not mask longer-term conservation issues for populations breeding in these intensively managed areas, and further studies should assess potential long-term negative effects of occupancy of human-altered habitat.

Objective To report on the long-term followup of a cohort of patients with hepatitis C virus (HCV)–related vasculitis treated with rituximab with or without PEGylated interferon alfa-2b (PEG–IFN alfa-2b) plus ribavirin. Methods The study group comprised 32 HCV RNA–positive patients with HCV-related vasculitis: 20 patients were treated with rituximab and PEG–IFN alfa-2b (9 of whom had not previously received antiviral treatment and 11 of whom had experienced disease resistance to or relapse with antiviral treatment), and 12 antiviral-intolerant patients were treated with rituximab alone. Results Treatment with rituximab and PEG–IFN alfa-2b plus ribavirin induced a complete clinical response and a partial clinical response in 80% and 15% of patients, respectively, a complete immunologic response and a partial immunologic response in 67% and 33% of patients, respectively, and a sustained virologic response in 55% of patients. Treatment with rituximab alone induced a complete clinical response and a partial clinical response in 58% and 9% of patients, respectively, and a complete immunologic response and a partial immunologic response in 46% and 36% of patients, respectively. B cell depletion was achieved in 96% of patients, and B cell recovery began after a median delay of 12 months. After a mean ± SD followup period of 23 ± 12 months, 22% of patients experienced a clinical relapse, and 34% of patients experienced an immunologic relapse. All relapses were associated with the absence of virologic control, and 78% of relapses were associated with B cell recovery. Six patients were re-treated with rituximab. All 6 of these patients had a complete clinical response, 50% had a complete immunologic response, and 50% had a partial immunologic response. Rituximab was well tolerated overall. Conclusion Rituximab is an effective treatment of severe and/or refractory HCV-related vasculitis. Relapses were consistently associated with the absence of virologic control. The clinical and immunologic efficacy of rituximab after repeated infusion appeared to be the same as that observed after induction therapy.

Background: The association between chronic alcohol consumption and an increasing risk of infectious and neoplastic disease is related to an impairment of cellular immunity. However, studies of the number and activity of lymphocyte subsets show highly variable results. The aim of this study was to assess the expression of perforin, one of the main molecular agents of T and natural killer (NK) cell–mediated cytotoxicity, in alcoholic patients without cirrhosis. Methods: Eighteen patients with chronic alcoholism were prospectively included and compared with 18 age- and sex-matched healthy volunteers. Signs of hepatic insufficiency or portal hypertension, viral co-infection, other serious medical illness, and immune-related medications were exclusion criteria. Lymphocyte phenotype was assessed, and perforin expression was analyzed by flow cytometry in CD3+CD56+ T cells and NK cells. Granzyme synthesis was also evaluated in 11 of the 18 patients and compared with that of 11 age- and sex-matched controls. Results: The mean number of white blood cells and lymphocytes was not different between the controls and alcoholic patients, whereas the mean number of NK cells was significantly decreased in alcoholic patients (110 ± 79/mm3 versus 271 ± 192/mm3; p < 0.03). Perforin expression in T CD3+/CD56+ and in NK cells was significantly decreased in alcoholic patients compared with controls: 16 ± 3% vs. 36 ± 4% (p < 0.03) and 65 ± 15% vs. 78 ± 9% (p= 0.04), respectively. The percentage of cells expressing granzyme was similar in both groups. Conclusions: A decrease in perforin expression by cytotoxic cells could be a major factor in explaining the physiopathologic mechanisms of several alcohol-associated diseases.

Purpose We assessed the resistance index (RI) in the superior mesenteric artery under fasting and postprandial conditions in healthy subjects and in patients with cirrhosis to determine whether the amount of change in the RI reflects the presence or severity of liver dysfunction. Methods Fifteen subjects with normal livers and 27 patients with cirrhosis underwent Doppler sonography of the superior mesenteric artery before and after ingesting a standard meal. The RI at baseline (fasting state) and the postprandial RI were compared between the 2 groups. The fasting RIs and post postprandial RIs changes in cirrhotic patients were correlated with the severity of disease. Results No difference was found between the baseline RIs in healthy (RI = 0.85) and cirrhotic subjects (RI = 0.84), nor was there a difference in baseline RIs between subgroups of cirrhotic patients according to the severity of liver disease. The RI decreased significantly (p < 0.05) after the meal in both the healthy (13%) and cirrhotic (8%) subjects, but the postprandial decrease was significantly less pronounced (p < 0.05) in cirrhotic patients than in healthy subjects. Among cirrhotic patients, there was no correlation between the postprandial decrease of the RI and severity of liver disease. Conclusions The marked decrease in the postprandial RI in the SMA in healthy subjects is generally not seen in patients with cirrhosis, and changes in the postprandial RI do not reliably predict the severity of liver dysfunction. © 1998 John Wiley & Sons, Inc. J Clin Ultrasound 26:131–136, 1998.

In the areas studied, an unusual structure and dynamic behavior was exhibited by the plankton ecosystems, due for the most part to industrial and natural effluents from the Rhǒne and Durance. The ecosystem was kept at a low state of maturity, which is characterized by frequent periods of intense multiplication by small species with high metabolic rates, such as the diatom, Skeletonema costatum, and the dinoflagellates, Exuviaella and Prorocentrum. Brackish water seems congenial to that type of proliferation. The turnover rate of these populations decreases as they become older and cell size increases. A lack of competition by species of the same genus is a characteristic of the photo-autotrophic organisms in these environments. Secondary production follows the same cycle as the primary production by the dinoflagellate population. Zooplankton species of the genus Acartia have periods of intensive development in these areas.

Influences of unsalted waters penetration, in the Gulf of Fos, are marked as much on the primary step structuration level as on the component cellular physiology one. At their outlet, the weak structuration and the considerable biomasses resulting from an intense eutrophication go with a strong mortality clearly shown as well as by ATP/chlorophyll ratio than these of ATP, ADP and AMP inside the adenylic nucleotides pool. The primary step acquires a larger maturity in the salt share of the south eastern area. Spectrum variations of the population specific cellular volumes in terms of population importance can in a certain measure explain the intracellular rate variations into biochemical components.