Functional insights into the infective larval stage of Anisakis simplex s.s., Anisakis pegreffii and their hybrids based on gene expression patterns.

BACKGROUND: Anisakis simplex sensu stricto and Anisakis pegreffii are sibling species of nematodes parasitic on marine mammals. Zoonotic human infection with third stage infective larvae causes anisakiasis, a debilitating and potentially fatal disease. These 2 species show evidence of hybridisation in geographical areas where they are sympatric. How the species and their hybrids differ is still poorly understood. RESULTS: Third stage larvae of Anisakis simplex s.s., Anisakis pegreffii and hybrids were sampled from Merluccius merluccius (Teleosti) hosts captured in waters of the FAO 27 geographical area. Specimens of each species and hybrids were distinguished with a diagnostic genetic marker (ITS). RNA was extracted from pools of 10 individuals of each taxon. Transcriptomes were generated using Illumina RNA-Seq, and assembled de novo. A joint assembly (here called merged transcriptome) of all 3 samples was also generated. The inferred transcript sets were functionally annotated and compared globally and also on subsets of secreted proteins and putative allergen families. While intermediary metabolism appeared to be typical for nematodes in the 3 evaluated taxa, their transcriptomes present strong levels of differential expression and enrichment, mainly of transcripts related to metabolic pathways and gene ontologies associated to energy metabolism and other pathways, with significant presence of excreted/secreted proteins, most of them allergens. The allergome of the 2 species and their hybrids has also been thoroughly studied; at least 74 different allergen families were identified in the transcriptomes. CONCLUSIONS: A. simplex s.s., A. pegreffi and their hybrids differ in gene expression patterns in the L3 stage. Strong parent-of-origin effects were observed: A. pegreffi alleles dominate in the expression patterns of hybrids albeit the latter, and A. pegreffii also display significant differences indicating that hybrids are intermediate biological entities among their parental species, and thus of outstanding interest in the study of speciation in nematodes. Analyses of differential expression based on genes coding for secreted proteins suggests that co-infections presents different repertoires of released protein to the host environment. Both species and their hybrids, share more allergen genes than previously thought and are likely to induce overlapping disease responses.

The Gypsy Database (GyDB) of mobile genetic elements.

In this article, we introduce the Gypsy Database (GyDB) of mobile genetic elements, an in-progress database devoted to the non-redundant analysis and evolutionary-based classification of mobile genetic elements. In this first version, we contemplate eukaryotic Ty3/Gypsy and Retroviridae long terminal repeats (LTR) retroelements. Phylogenetic analyses based on the gag-pro-pol internal region commonly presented by these two groups strongly support a certain number of previously described Ty3/Gypsy lineages originally reported from reverse-transcriptase (RT) analyses. Vertebrate retroviruses (Retroviridae) are also constituted in several monophyletic groups consistent with genera proposed by the ICTV nomenclature, as well as with the current tendency to classify both endogenous and exogenous retroviruses by three major classes (I, II and III). Our inference indicates that all protein domains codified by the gag-pro-pol internal region of these two groups agree in a collective presentation of a particular evolutionary history, which may be used as a main criterion to differentiate their molecular diversity in a comprehensive collection of phylogenies and non-redundant molecular profiles useful in the identification of new Ty3/Gypsy and Retroviridae species. The GyDB project is available at http://gydb.uv.es.

Liver abscesses associated with stromal tumour of the stomach in a young woman.

A 23-year-old Japanese woman was admitted to hospital because of pyrexia and anaemia. She was found to have liver abscesses and a gastric submucosal mass by computed tomography and ultrasonography. Gastroscopy and a barium swallow revealed a round submucosal mass with a giant ulceration in the body of the stomach. The liver abscesses were successfully treated by percutaneous transhepatic drainage and intravenous administration of antibiotics. Cultures of the fluid from a liver abscess and gastric juice yielded alpha-haemolytic streptococci. Three weeks after the drainage, partial gastrectomy was performed. The tumour was diagnosed as a stromal tumour of the stomach (leiomyosarcoma) in the final histological report. The patient was discharged on postoperative day 17 without receiving adjuvant radio-chemotherapy. There have been no signs of recurrence two years after surgery. This is a rare case of a liver abscess associated with a stromal tumour of the stomach in a young patient. The bacteriological examinations suggested a possible association between these diseases.

Wide-spread distribution of sentinel lymph nodes in esophageal cancer.

Sentinel lymph nodes are the first draining nodes that contain tumor cells. Identification of sentinel nodes may help to determine the suitable extent of lymphadenectoy. To assess the location of sentinel lymph nodes, a series of 41 patients with single and two metastatic lymph nodes who underwent esophagectomy and 3-field lymphadenectomy between 1991 and 1999 were investigated retrospectively. Only 29 (47.5%) of 61 metastatic nodes showed correspondence between the tumor site and the regional metastatic lymph nodes by routine histologic examination. In the patients with tumors in the upper and middle thoracic esophagus, metastatic lymph nodes were distributed in the cervix, mediastinum and abdomen. Although sentinel nodes were limited to the regional and adjusting compartments in 82%, nodes were found beyond the adjusting compartments in 18%. The sentinel nodes were broadly distributed depending on the location of the tumor in esophageal cancer.

Serum p53 antibody as a predictor of early recurrence in patients with postoperative esophageal squamous cell carcinoma.

It is reported that surveillance of serum p53 antibody (Ab) is a useful marker in detecting esophageal squamous cell carcinoma (ESCC). But there is little reported about prognostic significance of serum p53-Ab in postoperative patients with ESCC. The aim of this study is to evaluate the significance of preoperative serum p53-Ab as a marker of early recurrence after curative resection for ESCC. Enzyme-linked immunosorvent assay (ELISA) was used to analyze serum p53-Ab before treatment in 44 patients with ESCC. Carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC-Ag) were examined by immunoradiometric assay. The patients who were strongly positive and positive in serum p53-Ab were more likely to have early recurrence after curative resection than seronegative patients. There were no significant correlations between CEA, SCC-Ag positivity and early recurrence. We found that serum p53-Ab was useful to predict a risk of early recurrence after curative surgical resection for ESCC.

An approach to a muscle model with a stimulus frequency-force relationship for FES applications.

A simplified model of electrically stimulated muscle for use in applications of functional electrical stimulation (FES) is discussed in this paper. The muscle model was required to have both stimulus frequency and stimulus intensity (amplitude/width) inputs. The stimulus frequency versus force relationship of rabbit muscle was modeled first with a small number of model parameters that could be identified by simple experiments in a short time. The model identified was found to be applicable to human muscles. The frequency-force relationships of electrically stimulated fast and slow type muscles were also predicted by the model. The frequency-force model and a simplified model of muscle activation dynamics were used to construct a muscle model that described the summation of muscle contraction. The use of this model decreased the time burden on patients during parameter identification at the clinical site. The clinical applicability of these new model descriptions was suggested through computer simulations.

A muscle activation model of variable stimulation frequency response and stimulation history, based on positive feedback in calcium dynamics.

Muscle fiber response to a train of variable-frequency pulses includes the potentiation and catch-like effect. For better understanding of these phenomena, we built an activation model with emphasis on the calcium liberation from and re-sequestration into the sarcoplasmic reticulum, including calcium-induced calcium release. The model had two stable equilibrium points in the calcium concentration. Changes from the low to the high equilibrium point could be produced by high-frequency trains of pulses and would account for the potentiation. The model also showed a catch-like effect, as a long-lasting increment of muscle force after the application of a single extra pulse. The increase in force appeared in resting muscle, disappeared when the muscle was potentiated, and reappeared briefly if the stimulation was continued for long periods.

Computer-aided generation of stimulation data and model identification for functional electrical stimulation (FES) control of lower extremities.

Standard stimulation data for unassisted standing up of paraplegic patients was generated by dynamic optimization linked with model simulation, to overcome the difficulties in the present electromyogram (EMG)-based method. The generated stimulation data were roughly in agreement with the normal subjects' EMG. From these, it is suggested that the 'model-based' method is useful as an alternative of the 'EMG-based method'. The same technique can be applied to generation of patient-specific stimulation data once the musculoskeletal system of a patient is properly identified. The musculoskeletal system must be identified from data taken from simple and noninvasive experiments for the identification method to be practically acceptable. We developed a musculoskeletal model and systematic identification protocols for this purpose. They were validated for the vastus lateralis muscle at the knee joint. The identification was successful and the predicted joint angle trajectories closely matched the experimental data. This implies that the model-based generation of patient-specific stimulation data is possible.

Response to preoperative chemotherapy affects prognosis in esophageal cancer.

The effect of preoperative chemotherapy on prognosis is still controversial. We have investigated the relationship between responses to preoperative chemotherapy and prognosis after curative operations in patients with esophageal squamous cell carcinoma. Thirty-nine patients received preoperative chemotherapy with continuous infusion of 500 mg/m2 of 5-fluorouracil (5-FU) and intravenous injection of 20 mg/m2 of leucovorin every 12 hours for 5 days. On the 5th day alone, 70 mg/m2 of cisplatin was also infused. The effect was evaluated approximately 14 days after the end of one course of chemotherapy. The rates of responders and non-responders were 64.1% and 35.9%, respectively. After an interval of 21-28 days, transthoracic esophagectomy was performed. Significant histological effect by chemotherapy was found in responders compared to non-responders (P < 0.05). Responders had a significantly better prognosis than non-responders by Log-rank test (P < 0.01). This suggests that preoperative chemotherapy may contribute to better prognosis when the tumor is sensitive to chemotherapy.