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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Fine structure and cellular responses at the host-parasite interface in a range of fish-helminth systems
No full texttA series of ultrastructural-based studies were conducted on the interface region in differentfish–helminth systems: (a) an intestinal infection of the cestode Monobothrium wageneri intench, Tinca tinca; (b) an extensive intestinal submucosa and mucosal infection in tench bymetacercariae of an unidentified digenean trematode; (c) an intestinal infection in browntrout, Salmo trutta, by the acanthocephalan Dentitruncus truttae; (d) an extraintestinal infec-tion by larvae of the acanthocephalan, Pomphorhynchus laevis in three-spined sticklebacks,Gasterosteus aculeatus; and (e) an infection in the livers of Eurasian minnow, Phoxinus phoxi-nus, by larvae of the nematode Raphidascaris acus. Endoparasitic helminths frequently causeinflammation of the digestive tract and associated organs, inducing the recruitment of var-ious immune cells to the site of infection. In each of the fish–helminth systems that werestudied, a massive hyperplastic granulocyte response involving mast cells (MCs) and neu-trophils in close proximity to the helminths was documented. The current study presentsdata on the interface region in each fish–helminth system and documents the penetrationof mast cells granules within the tegument of P. laevis larvae. No extracellular vesicles con-taining tegumental secretions from any of the four different taxa of endoparasitic helminthsspecies at the host–parasite interface region were seen
Confirmation of the hosts involved in the life-cycle of an acanthocephalan parasite of Anguilla anguilla (L.) from Lake Piediluco and its effect on the reproductive potential of its amphipod intermediate host.
No full textA total of 37 European eels, Anguilla anguilla,
collected from Lake Piediluco, Central Italy, and measuring
35 to 75.5 cm in total length (mean±1 SD, 56.41±10.89 cm) were examined, and their acanthocephalan infections
assessed. Thirty-two (86.49%) eels were infected with
Acanthocephalus rhinensis (mean±1 SD, 67.38±65.16;
range, 1–350), a species that, purportedly, can be discriminated on the basis of a characteristic band of orange–brown
pigmentation encircling the anterior end of the t unk. This
feature, however, was not seen on any of the A. rhinensis
specimens that were removed, either attached to the gut wall or free within the gut lumen, from infected eels. Approximately 40% of the eels were coinfected with the dracunculid swimbladder nematode Anguillicoloides crassus, while a single eel was also coinfected with eight specimens of a second acanthocephalan, Dentitruncus truttae. From the stomachs of two eels, 109 intact and partially digested specimens of amphipod
Echinogammarus tibaldii (Pinkster & Stock 1970)
were recovered, 16 (14.6%) of these were infected with one to two cystacanths of A. rhinensis per host. From a sample of 850 E. tibaldii taken from the peripheral lakeside vegetation, 102 (12%; sex ratio, 1:1) gammarids were infected with one to two A. rhinensis cystacanths. Unparasitised ovigerous female E. tibaldii specimens had significantly higher numbers of eggs in their brood pouches compared with their infected counterparts
(t-test, P<0.01)
A comparative immunohitochemical study on a galanin-like peptide in the neuroendocrine system of the alimentary canal of three species of Siluriform catfishes.
No full textInnate immune defence mechanisms of tench, Tinca tinca (L.), naturally infected with the tapeworm Monobothrium wageneri
No full textA histochemical and ultrastructural investigation of the cellular inflammatory response within the intestines of tench Tinca tinca L. naturally infected with the caryophyllidean cestode Monobothrium wageneri was conducted and the data obtained compared to those in uninfected counterparts.
Cestode infections within the intestines were evident through the appearance of raised inflammatory swellings induced by the deep penetration of their scolices into the intestinal wall.
Cestodes typically attached in tight clusters, inducing a massive hyperplastic granulocyte response of mast cells and neutrophils, which were significantly more numerous (P < 0Æ01) in the intestines of infected (n = 14) than of uninfected (n = 9) tench. Neutrophils were more abundant than mast cells (P < 0Æ01) in host tissues in close proximity to the parasite tegument. In transmission electron microscopy sections, mast cells and neutrophils were frequently observed in contact with or inside capillaries, and in close proximity to the cestode. Degranulation of both cell types was seen in the
submucosa and lamina muscularis, notably in the immediate tissues surrounding the scolex of M. wageneri. No tegumental secretions were seen at the host–parasite interface. Occasional rodlet cells were encountered in the submucosa of infected fish
Selected pathological, immunohistochemical and ultrastructural changes associated with an infection by Diphyllobothrium dendriticum (Nitzsch, 1824) (Cestoda) plerocercoids in Coregonus lavaretus (L.) (Coregonidae).
No full textFine structure and cellular responses at the host-parasite interface in a range of fish-helminth systems
No full textA series of ultrastructural-based studies were conducted on the interface region in different fish-helminth systems: (a) an intestinal infection of the cestode Monobothrium wageneri in tench, Tinca tinca; (b) an extensive intestinal submucosa and mucosal infection in tench by metacercariae of an unidentified digenean trematode; (c) an intestinal infection in brown trout, Salmo trutta, by the acanthocephalan Dentitruncus truttae; (d) an extraintestinal infection by larvae of the acanthocephalan, Pomphorhynchus laevis in three-spined sticklebacks, Gasterosteus aculeatus; and (e) an infection in the livers of Eurasian minnow, Phoxinus phoxinus, by larvae of the nematode Raphidascaris acus. Endoparasitic helminths frequently cause inflammation of the digestive tract and associated organs, inducing the recruitment of various immune cells to the site of infection. In each of the fish-helminth systems that were studied, a massive hyperplastic granulocyte response involving mast cells (MCs) and neutrophils in close proximity to the helminths was documented. The current study presents data on the interface region in each fish-helminth system and documents the penetration of mast cells granules within the tegument of P. laevis larvae. No extracellular vesicles containing tegumental secretions from any of the four different taxa of endoparasitic helminths species at the host-parasite interface region were seen
The presence of a galanin-like peptide in the gut neuroendocrine system of Lampetra fluviatilis and Acipenser transmontanus: An immunohistochemical study
No full textGalanin is a brain-gut neuropeptide present in the central and peripheral nervous systems of vertebrates. In the present survey, the galaninergic and the diffuse endocrine systems of the alimentary canal of the river lamprey, Lampetra fluviatilis, and the white sturgeon, Acipenser transmontanus, were studied by immunohistochemistry. The results show the presence of galanin-like immunoreactive endocrine cells in the gut of L. fluviatilis. In addition, a galanin-like immunoreactivity was detected in enteric intramural neurons of both species. It is conceivable that the galaninergic system plays in both species a role in the regulation of the gut muscle contractility and in the modulation of mucosal secretive/absorptive processes. In A. transmontanus, the presence of galanin-like immunoreactive nerve fibres associated with components of the gut associated-lymphoid tissue is possibly correlated with a control of the defensive events at this site. The presence of
galanin-!ike immunoreactivity in the neuroendocrine system of these two ancient fishes confirms the hypothesis on the early occurrence of this regu!ative molecule in the gastro-enteric system of vertebrates
Histological damage and inflammatory response elicited by Monobothrium wageneri (Cestoda) in the intestine of Tinca tinca (Cyprinidae)
No full textBackground: Among the European cyprinids, tench, Tinca tinca (L.), and the pathological effects their cestodes
may effect, have received very little or no attention. Most literature relating to Monobothrium wageneri Nybelin,
1922, a common intestinal cestode of tench, for example, has focused on aspects of its morphology rather than on
aspects of the host-parasite interaction.
Results: Immunopathological and ultrastructural studies were conducted on the intestines of 28 tench, collected
from Lake Piediluco, of which 16 specimens harboured tight clusters of numerous M. wageneri attached to the
intestinal wall. The infection was associated with the degeneration of the mucosal layer and the formation of
raised inflammatory swelling surrounding the worms. At the site of infection, the number of granulocytes in the
intestine of T. tinca was significantly higher than the number determined 1 cm away from the site of infection or
the number found in uninfected fish. Using transmission electron microscopy, mast cells and neutrophils were
frequently observed in close proximity to, and inside, the intestinal capillaries; often these cells were in contact
with the cestode tegument. At the host-parasite interface, no secretion from the parasite’s tegument was observed.
Intense degranulation of the mast cells was seen within the submucosa and lamina muscularis, most noticeably at
sites close to the tegument of the scolex. In some instances, rodlet cells were encountered in the submucosa. In
histological sections, hyperplasia of the mucous cells, notably those giving an alcian blue positive reaction, were
evident in the intestinal tissues close to the swelling surrounding the worms. Enhanced mucus secretion was
recorded in the intestines of infected tench.
Conclusions: The pathological changes and the inflammatory cellular response induced by the caryophyllidean
monozoic tapeworm M. wageneri within the intestinal tract of an Italian population of wild tench is reported for
the first time
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