Analysis of P-gp genes relative expression associated to ivermectin resistance in Haemonchus contortus larval stages from in vitro cultures (L3 and xL3) and from gerbils (Meriones unguiculatus) (L4) as models of study.

The aim of the study was to compare the relative gene expression of Haemonchus contortus P-glycoprotein genes (Hco-pgp) between fourth (L4), infective (L3), and transitory infective (xL3) larval stages as laboratory models to study ivermectin (IVM) resistance. The H. contortus resistant to IVM (IVMr) and susceptible to IVM (IVMs) strains were used to develop xL3in vitro culture and to infect Meriones unguiculatus (gerbils) to collect L4 stages. Morphometric differences were evaluated from 25 individuals of H. contortus from each strain. Relative gene expression from xL3 and L4 was determined between comparison of IVMr stages and from IVMr vs IVMs stages. Seven Hco-pgp genes (1, 2, 3, 4, 9, 10, and 16) were analysed by RT-qPCR using L3 stage as control group, per strain, and GAPDH and ß-tubulin as constitutive genes. Morphological changes were confirmed between xL3 and L4 developing oral shape, oesophagus, and intestinal tube. In addition, the body length and width showed statistical differences (p < 0.05). The Hco-pgp1, 2, 3, and 4 genes (p < 0.05) were upregulated from 7.1- to 463.82-fold changes between IVMr stages, and Hco-pgp9 (13.12-fold) and Hco-pgp10 (13.56-fold) genes showed differences between L4 and xL3, respectively. The comparative study between IVMr vs IVMs strains associated to xL3 and L4 displayed significant upregulation for most of the Hco-pgp genes among 4.89-188.71 fold-change. In conclusion, these results suggest the use of H. contortus xL3 and L4 as suitable laboratory models to study IVMr associated with Hco-pgp genes to contribute to the understanding of anthelmintic resistance.

Neutral processes forming large clones during colonization of new areas.

In species reproducing both sexually and asexually clones are often more common in recently established populations. Earlier studies have suggested that this pattern arises due to natural selection favouring generally or locally successful genotypes in new environments. Alternatively, as we show here, this pattern may result from neutral processes during species' range expansions. We model a dioecious species expanding into a new area in which all individuals are capable of both sexual and asexual reproduction, and all individuals have equal survival rates and dispersal distances. Even under conditions that favour sexual recruitment in the long run, colonization starts with an asexual wave. After colonization is completed, a sexual wave erodes clonal dominance. If individuals reproduce more than one season, and with only local dispersal, a few large clones typically dominate for thousands of reproductive seasons. Adding occasional long-distance dispersal, more dominant clones emerge, but they persist for a shorter period of time. The general mechanism involved is simple: edge effects at the expansion front favour asexual (uniparental) recruitment where potential mates are rare. Specifically, our model shows that neutral processes (with respect to genotype fitness) during the population expansion, such as random dispersal and demographic stochasticity, produce genotype patterns that differ from the patterns arising in a selection model. The comparison with empirical data from a post-glacially established seaweed species (Fucus radicans) shows that in this case, a neutral mechanism is strongly supported.

Parallel speciation or long-distance dispersal? Lessons from seaweeds (Fucus) in the Baltic Sea.

Parallel evolution has been invoked as a forceful mechanism of ecotype and species formation in many animal taxa. However, parallelism may be difficult to separate from recently monophyletically diverged species that are likely to show complex genetic relationships as a result of considerable shared ancestral variation and secondary hybridization in local areas. Thus, species' degrees of reproductive isolation, barriers to dispersal and, in particular, limited capacities for long-distance dispersal will affect demographical structures underlying mechanisms of divergent evolution. Here, we used nine microsatellite DNA markers to study intra- and interspecific genetic diversity of two recently diverged species of brown macroalgae, Fucus radicans (L. Bergström & L. Kautsky) and F. vesiculosus (Linnaeus), in the Baltic Sea. We further performed biophysical modelling to identify likely connectivity patterns influencing the species' genetic structures. For each species, we found intraspecific contrasting patterns of clonality incidence and population structure. In addition, strong genetic differentiation between the two species within each locality supported the existence of two distinct evolutionary lineages (FST  = 0.15-0.41). However, overall genetic clustering analyses across both species' populations revealed that all populations from one region (Estonia) were more genetically similar to each other than to their own taxon from the other two regions (Sweden and Finland). Our data support a hypothesis of parallel speciation. Alternatively, Estonia may be the ancestral source of both species, but is presently isolated by oceanographic barriers to dispersal. Thus, a limited gene flow in combination with genetic drift could have shaped the seemingly parallel structure.

TaqMan DNA technology confirms likely overestimation of cod (Gadus morhua L.) egg abundance in the Irish Sea: implications for the assessment of the cod stock and mapping of spawning areas using egg-based methods.

Recent substantial declines in northeastern Atlantic cod stocks necessitate improved biological knowledge and the development of techniques to complement standard stock assessment methods (which largely depend on accurate commercial catch data). In 2003, an ichthyoplankton survey was undertaken in the Irish Sea and subsamples of 'cod-like' eggs were analysed using a TaqMan multiplex, PCR (polymerase chain reaction) assay (with specific probes for cod, haddock and whiting). The TaqMan method was readily applied to the large number of samples (n = 2770) generated during the survey and when combined with a manual DNA extraction protocol had a low failure rate of 6%. Of the early stage 'cod-like' eggs (1.2-1.75 mm diameter) positively identified: 34% were cod, 8% haddock and 58% whiting. As previous stock estimates based on egg surveys for Irish Sea cod assumed that the majority of 'cod-like' eggs were from cod, the TaqMan results confirm that there was probably substantial contamination by eggs of whiting and haddock that would have inflated estimates of the stock biomass.

[Asymptomatic carriers of hydatidosis: epidemiology, diagnosis, and treatment]. / Portadores asintomáticos de hidatidosis: epidemiología, diagnóstico y tratamiento.

Until a short time ago, hydatidosis was considered a pathology that could only be resolved surgically. However, in recent years progress has been made with the epidemiology, diagnosis, and treatment of the disease, and new information on the natural history of hydatidosis has helped define new criteria for its treatment. It is now known that as many as 67% of the carriers of liver cysts who are asymptomatic remain so throughout their lives. This situation produces special results in immunologic testing. Enzyme-linked immunosorbent assay (ELISA) has a sensitivity of 63% and a specificity of 97% with asymptomatic carriers, while the double diffusion arc 5 test (DD5) achieves a sensitivity of only 31% with the same population. On the other hand, imaging studies based on ultrasonography have become the method of choice to detect asymptomatic carriers. Ultrasonography studies are 49% to 73% more sensitive than serological tests, and they can even be used as a part of epidemiological surveillance systems and to monitor control programs. Treatment schemes have also been modernized. Treating asymptomatic carriers chemotherapeutically with albendazole produces favorable results in as many as 69% of cases, while such minimally invasive surgical treatments as puncture-aspiration-injection-reaspiration (PAIR) reduce average cyst volume by as much as 66%. These factors have made it possible for hospital services in the province of Río Negro, Argentina, to establish a treatment scheme for asymptomatic carriers. It is based on the monitoring of small cysts (type Ia on the modified Gharbi scale); initial treatment with albendazole, followed by PAIR if there is no response, in larger or more complex cysts (types Ib, II, and III); and follow-up of inviable or dead cysts (types IV and V).

Quiste hidatídico hepático complicado: ruptura a la cavidad peritoneal / Complicated hepatic hydatid cyst: rupture into abdominal cavity

Antecedentes:La ruptura traumática de un quiste hidatídico hepático en la cavidad abdominal es infrecuente. Objetivo: Comunicar una observación, mostrando la sintomatología, metodología diagnóstica, conducta terapéutica y la evolución postquirúrgica. Lugar de realización: Servicio de Cirúgia General de Hospital Público. Diseño: Análisis de un caso clínico.Población: Paciente sexo femenino, 8 años, atendida por dolor abdominal, secundario a un traumatismo. Diagnóstico: quiste hidatídico hepático roto en la cavidad peritineal. Cirugía: Tratamiento del quiste(Mabit-Lagrot)y lavado de cavidad. Resultados: Buena evolución postquirúrgica. Tratamiento médico con albendazol. Actualmente asintomática

Quiste hidatídico hepático complicado: ruptura a la cavidad peritoneal / Complicated hepatic hydatid cyst: rupture into abdominal cavity

Antecedentes:La ruptura traumática de un quiste hidatídico hepático en la cavidad abdominal es infrecuente. Objetivo: Comunicar una observación, mostrando la sintomatología, metodología diagnóstica, conducta terapéutica y la evolución postquirúrgica. Lugar de realización: Servicio de Cirúgia General de Hospital Público. Diseño: Análisis de un caso clínico.Población: Paciente sexo femenino, 8 años, atendida por dolor abdominal, secundario a un traumatismo. Diagnóstico: quiste hidatídico hepático roto en la cavidad peritineal. Cirugía: Tratamiento del quiste(Mabit-Lagrot)y lavado de cavidad. Resultados: Buena evolución postquirúrgica. Tratamiento médico con albendazol. Actualmente asintomática

Combined femorotibial bypass and distal intraoperative transluminal angioplasty.

Distal intraoperative transluminal angioplasty (IOTLA) combined with femorotibial bypass was performed in three patients. All three patients were elderly diabetic men with multilevel occlusive disease associated with rest pain and ischemic lesions of the feet. IOTLA allowed recanalization of segmentally occluded distal vessels or dilatation of multiple distal severe stenoses. These lesions would have been inaccessible to usual percutaneous angioplasty techniques because of intervening occlusions in the thigh. The technique and instrumentation of IOTLA are described. All patients had intraoperative prereconstruction and completion arteriography. In femorotibial bypass grafting, the adjunctive use of IOTLA improved runoff and graft patency to target vessels that would otherwise have been unsuitable. Although the experience is limited and the follow-up period short, the early results are encouraging; the technique deserves further investigation.

Management of massive hepatic hemangiomas in infants and children: a review of 13 cases.

From 1958 through 1978, 13 patients with diffused hepatic hemangioma were seen at Childrens Hospital of Los Angeles. Based on this experience and review of the literature, liver biopsy in these patients was found to be unnecessary and hazardous. Diagnosis can be made by dynamic and static hepatic scintigraphy and selective hepatic arteriography. Nonsurgical measures including treatment of congestive heart failure, corticosteroids, and radiotherapy are recommended for treatment of these patients. Surgery should be reserved only for emergencies, such as rupture of the tumor and hemorrhage, or for patients with severe congestive heart failure unresponsive to medical treatment. For the latter group of patients hepatic artery ligation is recommended. Hepatic artery embolization has recently been used, but experience with this new mode of therapy is limited.

Littre's hernia in infancy presenting as undescended testicle.

Littre's hernia is defined as any hernial sac which contains a Meckel's diverticulum. It has been reported in association with inguinal, umbilical, femoral, sciatic, ventral, and lumbar hernias. This hernia is rare, particularly in children, in whom the umbilical variety is reported by some to be most common. Littre's hernia is difficult to diagnose, but should be suspected in patients with gastrointestinal bleeding, incompletely reducible hernias, and fecal hernial fistulas. It may be confused with cryptorchidism when Meckel's diverticulum adheres to and envelops the testicle making palpation of the gonad difficult. Recommended treatment is resection of the Meckel's diverticulum from within the opened hernial sac followed by herniorrhaphy.

Central venous cannulation in neonates.

A modified technique for central venous cannulation for parenteral nutrition in neonates has been developed. The internal or external jugular veins are cannulated and the catheter is tunneled out onto the anterior part of the chest wall through a long subcutaneous tunnel. Fixation of the catheter is accomplished by gluing two small pieces of Silastic sheeting to the catheter and then suturing this sandwich to the skin. Over 150 central venous catheters for total parenteral nutrition have been placed using this method. The reduced rate of catheter-related complications and improved ease of nursing care have provided excellent results.