Santiago Sánchez

Parasite fauna of rodents (Murinae) from El Hierro (Canary Islands, Spain): a multidisciplinary approach.

The parasite fauna (protozoa, helminths and insects) of the two most widespread Murinae rodents in El Hierro (Canary Islands, Spain), the black rat (Rattus rattus) and the house mouse (Mus musculus domesticus) was studied. Faunistic, ecological, ecotoxicological data, as well as information on the biology of some nematode parasites of R. rattus are provided. The present work is unprecedented in the Canary Islands, and provides the first data on the parasite biodiversity in Murinae from the archipelago. Concerning to parasitofaunas stands out: a) impoverishment of biodiversity of helminths respect of which have the same hosts in other islands; b) increasing the number of species of Siphonaptera, even compared with flea species that parasitize the same hosts from continental biotopes.

Positive co-occurrence of flea infestation at a low biological cost in two rodent hosts in the Canary archipelago.

Non-random assemblages have been described as a common pattern of flea co-occurrence across mainland host species. However, to date, patterns of flea co-occurrence on islands are unknown. The present work investigates, on one hand, whether the decrease in the number of species on islands affects the pattern of flea co-occurrence, and on the other hand, how the cost of higher flea burdens affects host body mass. The study was carried out in the Canary Islands (Spain) using null models to analyse flea co-occurrence on Rattus rattus and Mus musculus. Results supported aggregation of flea species in Mus but not in Rattus, probably due to the relationship between abundance and both prevalence and intensity of infection of the main flea species parasitizing Mus. In addition, heavy individuals of both rodent species showed the highest flea burdens as well as higher species richness, probably due to the continued accumulation of fleas throughout life and/or immunological resistance mechanisms. Whatever the mechanisms involved, it is clear that co-occurrence and high parasite intensities do not imply a detrimental biological cost for the rodents of the Canary Islands.

On the biology of Spiruroidea parasites of murine rodents on El Hierro (Canary Islands, Spain) with molecular characterization of Streptopharagus greenbergi Wertheim, 1993.

This paper reports the role of darkling beetles Pimelia laevigata costipennis and Hegeter amaroides (Tenebrionidae) as intermediate hosts of spiruroid nematodes parasites of the black rat and house mouse of El Hierro (Canary Islands). Larvae of spiruroid species were found in the two tenebrionids (18.1% in P. l. costipennis, 7.8% in H. amaroides), Streptopharagus greenbergi being predominant in both (16.1% and 7.1%, respectively), ahead of Mastophorus muris and Gongylonema type larva. The larval stages of S. greenbergi are described for the first time, and adult worms were obtained experimentally from an infected laboratory rat, allowing the identification of the species. Morphometric measurements of experimental adults match those of adults detected in naturally infected rats on the island. Molecular data for S. greenbergi, and the ITS nucleotide sequence of the genus Streptopharagus are also provided for the first time. After the isolation of S. greenbergi DNA and amplification of the ITS region, the ITS1 of this spirocercid was sequenced and deposited in the GenBank database.

Controversias en la obtención del injerto hepático procedente de donante vivo

Adult liver transplants from a living donor are a valid and effective alternative as a treatment in terminal liver disease. However, in the context of a donation from a brain dead donor, as in western countries (Spain), it is very high, and there are still controversial aspects that should be continuously assessed in order to ensure good results. Live donations are currently stable and represent about 5% of the total liver transplants performed in Europe. Morbidity and mortality is around 35% and 0.1%, respectively, probably reasonable figures given the characteristics of the intervention. The 1 and 5 year survival rates of the recipients of a living donor are currently 95% and 75%, which are similar to those coming from brain dead donors. However the level of biliary complications in this patient group is higher, with an incidence of around 35-40%. However, this incidence has not had any effect on the long-term results up until now.

Controversies in living donor liver transplants

Adult liver transplants from a living donor are a valid and effective alternative as a treatment in terminal liver disease. However, in the context of a donation from a brain dead donor, as in western countries (Spain), it is very high, and there are still controversial aspects that should be continuously assessed in order to ensure good results. Live donations are currently stable and represent about 5% of the total liver transplants performed in Europe. Morbidity and mortality is around 35% and 0.1%, respectively, probably reasonable figures given the characteristics of the intervention. The 1 and 5 year survival rates of the recipients of a living donor are currently 95% and 75%, which are similar to those coming from brain dead donors. However the level of biliary complications in this patient group is higher, with an incidence of around 35%–40%. However, this incidence has not had any effect on the long-term results up until now.

Longitudinal pancreaticogastrostomy in patients with chronic pancreatitis

The Partington–Rochelle (P–R) or Puestow procedure1 is one of the most commonly performed drainage procedures for chronic pancreatitis and can be achieved with low rates of morbidity and mortality to obtain good relief of chronic abdominal pain.2 Frey and Smith3 combined this with duodenal-preserving limited pancreatic head resection (LHR) and drainage of the resection cavity (in patients in whom pancreatic head enlargement predominated) with similar outcomes.4 The current article presents a new modification of the classical P–R and LHR procedures in which the Roux-en-Y pancreaticojejunostomy has been eliminated, and the dilated pancreatic duct or the locally excised head of the pancreas is covered with a longitudinally opened segment of the stomach. The laparoscopic technique for the modified P–R procedure and the side-to-side procedure to obtain gastric drainage of the pancreatic remnant after pancreaticoduodenectomy are both described.

Liver Regeneration Rate Analysis in Living Donor Liver Transplantation

Introduction and Aim Liver surgery has had an exponential development making possible the use of partial liver grafts for living donor liver transplantation (LDLT). Nonetheless, LDLT indication still depends on the graft size used for the recipient, due to the development of “small for size syndrome” (SFSS) which can be better understood through the study of hepatocellular regeneration. The aim of this study is to analyze the liver regeneration rate (LRR, grams/day) of a healthy human liver after a major liver resection such as donation of the right hepatic lobe (RHL). We have also evaluated the LRR in the recipients of this RHL and the different factors that can affect it. Materials and Methods In between January 2005 to December 2015 fifty LDLT were performed in our institution, 46 donors with their respective recipients were included being the ones de RHL was used (92%). A MRI was performed during follow up at the first, third and twelve months to all donors and recipients. With this MRI, the LRR was calculated within 3 periods of time (1 month, 1-3m and 12m after donation). Results and Discusion The median age of the donors and recipients was 35 (r=20-46) and 57 years old (r=49-66) respectively. Fifty two percent of the donors and 84.8% of the recipients were male. Intraoperative baseline biopsy of the donor was normal in almost all cases except 7 (15%) in which we found mild steatosis (<10%). Liver transplant indication was due to end stage liver disease in 20 patients (9 alcohol related, 28 with HCV infection and 9 of other causes) and the other 26 recipients the indication was due to HCC. The liver remnant volume in the donors was approximately 36.5% (r=30.5-45.2) of the total liver volume (1588g, r=1065-2079). The body to graft weigh ratio in the recipient had a median of 1.2 (r= 0.7-2.0). The median of the LRR in donors was of 14.5 g/d the first month, 0.47 g/d between 1-3m and of 0.49 g/d between 3-12m. The liver volume at the end of follow up (1 year) was 1196 g (r=864-2229). In the recipients, the LRR for the same periods of time was 13.42 g/d, 2.74 g/d and-0.26 g/d respectively and the graft volume at the end was 1503 g (r=931-2042). Interestingly the LRR in patients with HCV infection was diminished with statistical difference in the first month and in the 3-12m period after transplantation (22,19 vs 13,4 y 1,23 vs 0,14, p=0.044 y p=0.035 respectively). Conclusions We have confirmed how liver regeneration is an acute process that mainly develops in the first month after liver resection in a healthy liver when leaving and adequate liver remnant. This LR is similar in the context of LDLT when the graft has a correct volume, even though this regeneration can be affected by HCV re-infection.

The Flea (Xenopsylla guancha (Siphonaptera, Pulicidae) Beaucournu, Alcover & Launay, 1990) Endemic to the Canary Islands, on an Unusual Host

Xenopsylla guancha is the only flea species endemic to the Canary Islands (Beaucournu and Launay, 1990). According to Sánchez and Gómez (2012), its distribution is limited to the easternmost i slands (Fuerteventura, Lanzarote and La Graciosa) where the geographic and climatic conditi ons are suitable for the completion of its life cycle. The principal host of X. guancha is Mus musculus but it also parasitizes Rattus rattus (Beaucournu and Launay, 1990). This note reports the discovery of X. guancha on Crocidura canariensis (Soricomorpha: Soricidae), and it represents the first account of this flea species on a non-rodent host.