Determinants of the current and future distribution of the West Nile virus mosquito vector Culex pipiens in Spain

Changes in environmental conditions, whether related or not to human activities, are continuously modifying the geographic distribution of vectors, which in turn affects the dynamics and distribution of vector-borne infectious diseases. Determining the main ecological drivers of vector distribution and how predicted changes in these drivers may alter their future distributions is therefore of major importance. However, the drivers of vector populations are largely specific to each vector species and region. Here, we identify the most important human-activity-related and bioclimatic predictors affecting the current distribution and habitat suitability of the mosquito Culex pipiens and potential future changes in its distribution in Spain. We determined the niche of occurrence (NOO) of the species, which considers only those areas lying within the range of suitable environmental conditions using presence data. Although almost ubiquitous, the distribution of Cx. pipiens is mostly explained by elevation and the degree of urbanization but also, to a lesser extent, by mean temperatures during the wettest season and temperature seasonality. The combination of these predictors highlights the existence of a heterogeneous pattern of habitat suitability, with most suitable areas located in the southern and northeastern coastal areas of Spain, and unsuitable areas located at higher altitude and in colder regions. Future climatic predictions indicate a net decrease in distribution of up to 29.55%, probably due to warming and greater temperature oscillations. Despite these predicted changes in vector distribution, their effects on the incidence of infectious diseases are, however, difficult to forecast since different processes such as local adaptation to temperature, vector-pathogen interactions, and human-derived changes in landscape may play important roles in shaping the future dynamics of pathogen transmission.

Our Nine-Year Experience with the Self-Locating Catheter: Comparison of Malfunction Rate with Other Tenckhoff Catheter Variants

Objective

To evaluate catheter-related complications among self-locating and other variants of Tenckhoff catheters.

Patients and Methods

We studied all self-locating catheters implanted in our hospitals from May/97 to Dec/05. We extended the follow-up to Jun/05. We collected demographic data, causes of catheter withdrawal and dropping of PD. We studied data about technique and catheter related complications.

Results

We included 328 catheters in 285 patients. There were 258 self-locating, 55 straight and 15 curled. There was a higher rate of catheter withdrawal due to malfunction in patients with straight or pig-tail catheters than in self-locating ones (log-rank, p<0.001).

Conclusion

In our patients, self-locating catheters have a lower malfunction rate than other variants of Tenckhoff catheters.

Context-dependent effects of yolk androgens on nestling growth and immune function in a multibrooded passerine

Female birds may adjust their offspring phenotype to the specific requirements of the environment by differential allocation of physiologically active substances into yolks, such as androgens. Yolk androgens have been shown to accelerate embryonic development, growth rate and competitive ability of nestlings, but they can also entail immunological costs. The balance between costs and benefits of androgen allocation is expected to depend on nestling environment. We tested this hypothesis in a multibrooded passerine, the spotless starling, Sturnus unicolor. We experimentally manipulated yolk androgen levels using a between-brood design and evaluated its effects on nestling development, survival and immune function. Both in first and replacement broods, the embryonic development period was shorter for androgen-treated chicks than controls, but there were no differences in second broods. In replacement broods, androgen-treated chicks were heavier and larger than those hatched from control eggs, but this effect was not observed in the other breeding attempts. Androgen exposure reduced survival with respect to controls only in second broods. Regarding immune function, we detected nonsignificant trends for androgen treatment to activate two important components of innate and adaptive immunity (IL-6 and Ig-A levels, respectively). Similarly, androgen-treated chicks showed greater lymphocyte proliferation than controls in the first brood and an opposite trend in the second brood. Our results indicate that yolk androgen effects on nestling development and immunity depend on the environmental conditions of each breeding attempt. Variation in maternal androgen allocation to eggs could be explained as the result of context-dependent optimal strategies to maximize offspring fitness.

The European contribution to "Sugarbaker's protocol" for the treatment of colorectal peritoneal carcinomatosis

INTRODUCTION

In 1981, Dr. PH Sugarbaker, challenging oncological orthodoxy, considered carcinomatosis to be a locoregional stage of the disease that was still susceptible to treatment with curative intent. To this end he developed a new therapeutic alternative based on the combined treatment. The macroscopic disease treated by maximum radical oncological cytoreductive surgery (through the peritonectomies described by him), followed by treatment of the residual microscopic disease with the direct intra-abdominal application of intraoperative chemotherapy with locoregional intensification, modulated by hyperthermia and early normothermic postoperative intra-abdominal chemotherapy. Using this new therapeutic regimen, known as "Sugarbaker s Protocol", his group has reported 45% survival rates in carcinomatosis of colorectal origin at 5 years, and, in selected groups of patients, 50% survival rates at 5 years. The scientific community, however, has criticized these results considering that: it is a personal experience, with a not homogenous treatment protocol with developmental modifications over time, that it is a retrospective non-randomized study, and finally that the cytostatics used in his protocol are obsolete. Various European groups have replied to these main criticisms confirming the good results that this new therapeutic alternative offers for patients with carcinomatosis of colorectal origin. The purpose of this article is to present these contributions.

MATERIAL AND METHODS

All the articles published in the English language by European groups in the world s medical literature have been reviewed using the Pubmed-MEDLINE database to identify the relevant articles related to the treatment of carcinomatosis of colorectal origin using cytoreduction and intraperitoneal chemotherapy from January 1980 to January 2008.

RESULTS

The European contribution during these 25 years in favour of the "Sugarbaker s Protocol" has consisted fundamentally in: a) one multicenter retrospective study; b) two randomized prospective phase III studies; and c) the use of oxaliplatin and irinotecan as new cytostatic agents in the protocols for intraperitoneal chemotherapy. At the same time, two new transcendental European contributions have been made in which the possibility has been considered of combined simultaneous treatment for patients with hepatic metastases and carcinomatosis, and the introduction, as a selection factor, of patients responsive to intravenous induction chemotherapy within the regimen of sandwich treatment (with systemic neoadjuvant and adjuvant chemotherapy) complementary to intraperitoneal chemotherapy.

CONCLUSIONS

The results obtained by European groups using "Sugarbaker s protocol" and "Elias protocol" with oxaliplatin compel us to request that these treatments be considered by all professionals involved in the treatment of patients with colorectal carcinomatosis as the best treatment currently available for this condition. Furthermore a randomized, prospective, multicenter study should be carried out to clarify its value and the degree of scientific evidence. A validation of this treatment will change, in the future, the dogmatic consideration of carcinomatosis as an incurable disease stage.