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Host Interface (host + interface)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

RNA interference in ticks: a study using histamine binding protein dsRNA in the female tick Amblyomma americanum

INSECT MOLECULAR BIOLOGY, Issue 3 2003
M. N. Aljamali
Abstract RNA interference (RNAi), a gene silencing process, has been recently exploited to determine gene function by degrading specific mRNAs in several eukaryotic organisms. We constructed a double stranded RNA (dsRNA) from a previously cloned putative Amblyomma americanum histamine binding protein (HBP) to test the significance of using this methodology in the assessment of the function and importance of gene products in ectoparasitic ticks. The female salivary glands incubated in vitro with HBP dsRNA had a significantly lower histamine binding ability. In addition, the injection of HBP dsRNA into the unfed females led both to a reduced histamine binding ability in the isolated salivary glands and to an aberrant tick feeding pattern or host response. Molecular data demonstrated less expression of the HBP mRNA in the RNAi group. Taken together, these results suggest that RNAi might be an important tool for assessing the significance of tick salivary gland secreted proteins modulating responses at the tick,host interface. [source]

Evaluation of blood vessel ingrowth in fibrin gel subject to type and concentration of growth factors

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9a 2009
A. Arkudas
Abstract Our aim was to quantitatively assess the angiogenetic effects of VEGF and bFGF immobilized in a fibrin-based drug delivery system in a suitable subcutaneous rat model. After evaluation of a suitable implantation technique (6 rats), four teflon isolation chambers containing fibrin gel matrices were implanted subcutaneously in an upside-down fashion on the back of 30 Lewis rats. The matrices consisted of 500 ,l fibrin gel with two different fibrinogen concentrations (10 mg/ml or 40 mg/ml fibrinogen) and 2 I.U./ml thrombin and contained VEGF and bFGF in five different concentrations (0 to 250 ng/ml each). At 3, 7 and 14 days after implantation, matrices were explanted and subjected to histological and morphometrical analysis. At 1 week, the volume of the fibrin clots was significantly smaller in the 100 and 250 ng/ml VEGF and bFGF groups in comparison to lower concentrated growth factors. At 1 and 2 weeks, the use of growth factors in low concentrations (25 ng/ml VEGF and bFGF) significantly increased the amount of fibrovascular tissue, average fraction of blood vessels and number of blood vessels at the matrix,host interface in comparison to growth factor-free controls. Higher concentrations were neither associated with further increase of tissue formation nor with increased sprouting of blood vessels in this model. This study demonstrates that fibrin gel-immobilized angioinductive growth factors efficiently stimulate generation of fibrovascular tissue and sprouting of blood vessels in a newly developed subcutaneous upside-down isolation chamber model with an optimum between 25 and 100 ng/ml. [source]

Mature teratoma of the uterine cervix with lymphoid hyperplasia

PATHOLOGY INTERNATIONAL, Issue 5 2003
Sung-chul Lim
A rare case of an extragonadal teratoma, which occurred primarily in the uterus, is described. The tumor developed in the uterine cervix as a conventional cervical polyp, 3 months after an elective abortion in a 27-year-old woman. Microscopically, the solid 2.2 × 1.8 × 1.5 cm mass was a mature teratoma with exuberant lymphoid elements. It consisted of ectodermal, mesodermal and endodermal derivatives. The lymphoid elements may have been a lymphoid hyperplasia, a chronic inflammatory reaction or a component of the teratoma. However, as the lymphoid tissues had no spatial relation to the teratomatous components, the possibility of a teratomatous element was excluded. This could be regarded as a result of an immunological reaction to the tissues composing the tumor, rather than just a chronic inflammatory response because the lymphoid reaction was present in the tumor, the tumor,host interface and the perivascular areas. Because of the patient's history of an abortion and a lymphoid reaction, the possibility of fetal remnants implantation was raised, so DNA typing to compare the teratoma portion with a normal portion of the host was performed. We found the teratoma portions to be in accordance with that of the host, and hence ruled out fetal remnants implantation. This case showed that a mature teratoma of the uterine cervix may manifest as a feature of implanted fetal tissue. In addition, a real teratoma should be included in the differential diagnosis of uterine teratomatous lesion, even when detected in patients with a recent history of pregnancy and lymphoid hyperplasia. [source]

The secreted and surface proteomes of the adult stage of the carcinogenic human liver fluke Opisthorchis viverrini

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 5 2010
Jason Mulvenna
Abstract Infection with the human liver fluke, Opisthorchis viverrini, is a serious public health problem in Thailand, Laos and nearby locations in Southeast Asia. Both experimental and epidemiological evidence strongly implicate liver fluke infection in the etiology of one of the liver cancer subtypes, cholangiocarcinoma (CCA). To identify parasite proteins critical for liver fluke survival and the etiology of CCA, OFFGEL electrophoresis and multiple reaction monitoring were employed to characterize 300 parasite proteins from the O. viverrini excretory/secretory products and, utilizing selective labeling and sequential solubilization, from the host-exposed tegument. The excretory/secretory included a complex mixture of proteins that have been associated with cancers, including proteases of different mechanistic classes and orthologues of mammalian growth factors and anti-apoptotic proteins. Also identified was a cysteine protease inhibitor which, in other helminth pathogens, induces nitric oxide production by macrophages, and, hence may contribute to malignant transformation of inflamed cells. More than 160 tegumental proteins were identified using sequential solubilization of isolated teguments, and a subset of these was localized to the surface membrane of the tegument by labeling living flukes with biotin and confirming surface localization with fluorescence microscopy. These included annexins, which are potential immuno-modulators, and orthologues of the schistosomiasis vaccine antigens Sm29 and tetraspanin-2. Novel roles in pathogenesis were suggested for the tegument,host interface since more than ten surface proteins had no homologues in the public databases. The O. viverrini proteins identified here provide an extensive catalogue of novel leads for research on the pathogenesis of opisthorchiasis and the development of novel interventions for this disease and CCA, as well as providing a scaffold for sequencing the genome of this fluke. [source]