The occurrence of acanthocephalans in teleost fish from the Bizerte lagoon, Tunisia.

Seven species of acanthocephalans were identified for the first time in teleost fish from the Bizerte lagoon, Tunisia, including Neoechinorhynchus (Hebesoma) agilis (Rudolphi, 1819) Van Cleave, 1916; N. (Neoechinorhynchus) rutili Müller, 1780 (Neoechinorhynchidae); Acanthocephaloide propinquus (Dujardin, 1845) Meyer, 1932; A. incrassatus (Molin, 1858) Meyer, 1932 (Arhythmacanthidae); Longicollum pagrosomi Yamaguti, 1935 (Pomphorhynchidae); Rhadinorhynchus cadenati (Golvan et Houin, 1964) Golvan, 1969 (Rhadinorhynchidae); and Telosentis exiguus (von Linstow, 1901) Van Cleave, 1923 (Illiosentidae). Acanthocephaloide propinquus, N. (N.) rutili, L. pagrosomi and R. cadenati were restricted to the rectum and the posterior intestine, whereas the other species (A. incrassatus, T. exiguus and N. (H.) agilis) colonized two or three parts of the intestine. The most diverse acanthocephalan fauna was recorded in Lithognathus mormyrus, with three species; two species were reported from Trachurus trachurus; and a single species was recorded in Liza aurata and in Atherina boyeri. Neoechinorhynchus (N.) rutili, L. pagrosomi and R. cadenati attained the lowest prevalences of less than 6% and were considered as to be rare species. Acanthocephaloide incrassatus, A. propinquus, T. exiguus and N. (H.) agilis were satellite species. The diversity of the acanthocephalan fauna in the fish from the Bizerte lagoon is compared with previous studies from other localities. The report of A. incrassatus, A. propinquus and N. (N.) rutili in L. mormyrus presents new host records in Mediterranean waters.

Digenean diversity in labrid fish from the Bay of Bizerte in Tunisia.

Six species of digeneans (Proctoeces maculatus (Looss, 1901), Helicometra fasciata (Odhner, 1902), Helicometra pulchella (Odhner, 1902), Macvicaria alacris (Looss, 1901), Peracreadium genu (Nicoll, 1909) and Zoogonus rubellus (Olson, 1868)) were found for the first time in labrid fish (Symphodus tinca (Linnaeus, 1758), Labrus merula (Linnaeus, 1758) and Labrus viridis (Linnaeus, 1758)) from the Bay of Bizerte. Except for P. maculatus and Z. rubellus, which are limited to the rectum, these helminths colonize the entire digestive tract. The study of the seasonal prevalence, abundance and mean intensity shows that three parasites, P. maculatus, H. fasciata and P. genu are present throughout the year while H. pulchella, M. alacris and Z. rubellus are less frequent and appear only in spring (H. pulchella and M. alacris) or in spring and summer (Z. rubellus). The levels of infection and digenean faunal diversity in labrid fish from the Tunisian coasts are generally lower than those from localities within the western Mediterranean.

The morphology and behaviour of Cercaria lata Lespés, 1857 (Digenea, Faustulidae) from the Mediterranean clam Tapes decussata (L.).

Cercaria lata (Digenea, Faustulidae), discovered by Lespés (1857) in Tapes decussata (L.) in the basin of Arcachon, was found for the first time, from the eastern Mediterranean, in the same lamellibranch from Tunisia (Bizerte and Tunis lagoons and Gulf of Gabes). These cercariae develop in daughter sporocysts, which develop in mother sporocysts in the gonads. Daughter sporocysts are observed in the gonads and sometimes in the digestive gland. A redescription and the behaviour of the naturally emerging cercariae and spatio-temporal distribution of the sporocysts are reported. A comparative study using multivariate analyses associated with morphology, biology and seasonality confirm the distinctness of Cercaria lata and the cercaria of Cercaria pectinata from Donax trunculus.

[An exceptional carotid tumor]. / Une tumeur rare du glomus carotidien.

Carotid paraganglioma (CP) is a relatively rare neoplasm, most commonly located in the head and neck. It is a slow-growing tumor and there has been some debate on the optimal techniques of excision. We report herein the case of a 35-year-old woman who presented with an asymptomatic mass in the right side of the neck. The diagnosis of CP was confirmed by computed tomography and carotid angiography. This tumor was successfully removed surgically without complication. Throughout the description of this case, we analyze the clinical, radiological, pathological and therapeutic particularities of this entity.

[Benign schwannoma of the breast: about two cases]. / Schwannome mammaire bénin: à propos de deux cas.

Schwannoma is a rare nervous tumor developed on schwan cells. Only 22 cases of breast schwannoma have been published since 2005. It usually appears as a breast lump having clinical and radiological characteristics suggestive of kindness. Its diagnosis is histological. Its treatment is surgical. Through two observations and a review of the literature we would try to remind the characteristics of this tumor.

[Fine aspects of the process of fertilization in Acanthobothrium filicolle Zschokke, 1888 (Cestoda: Tetraphyllidea, Onchobothriidae)]. / Particularités des processus de la fécondation chez Acanthobothrium filicolle Zschokke, 1888 (Cestoda: Tetraphyllidea, Onchobothriidae).

The electron microscopy study of fertilization points out that in the Cestode Acanthobothrium filicolle, fertilization occurs in the oviduct. After the coiling of the spermatozoon around the oocyte, the plasma membrane of the sperm fuses with that of the ovum. All the elements of the spermatozoon (the nucleus, the two axonemes, the microtubules and the crested body pass into the cytoplasm of the oocyte). For the first time it is shown that the oocyte eliminates a residue of fertilization that could be the result either from the rejection of all the sperm organites (axonemes, microtubules, crested body) or the polyspermy or both. This fertilization residue comprising a degenerated nucleuslike body has been observed only in Onchobothriidae, Tetraphyllidea Cestoda.

[Estimation of fertility and quality of oocytes emitted by the clam Ruditapes decussatus (Linnaeus 1758) during experimental inductions]. / Estimation de la fécondité et de la qualité des ovocytes émis par la palourde Ruditapes decussatus (Linné 1758) lors d'inductions expérimentales.

Experimental inductions were carried out on some genitors of clams Ruditapes decussatus to obtain sexual emissions and estimate the fecondity of this species. The genitors were collected from two sites of tunisian littoral. Higher percent of oocytes was found in summer with a maximum of 52 x 10(4) oocytes in Gargour (Golf of Gabès) against 45 x 10(4) in Menzel-Jemil (Lagoon of Bizerte). The observation under the electronic microscope of free oocytes allowed us to subdivised them in three groupes: immatures, matures and atretics. Only mature oocytes were susceptible to be feconded and underwent larval development with unknown proportion.

[Spermatogenesis of Bothriocephalus clavibothrium Ariola, 1899 (Cestoda: Pseudophyllidea)]. / Etude de la spermatogénèse de Bothriocephalus clavibothrium Ariola, 1899 (Cestoda: Pseudophyllidea).

The processes of spermatogenesis and spermiogenesis in the Pseudophyllidea Cestode Bothriocephalus clavibothrium were studied by light and electron microscopy. Spermatogenesis is for rosette type. The rosettes of secondary, tertiary and quaternary spermatogonia, primary and secondary spermatocytes and spermatid clusters are all resulting of a series of six incomplete, synchronous divisions (4 mitosis and 2 meiotic kinesis). The 64 nuclear syncytium of spermatids, during spermiogenesis process gives 64 mature spermatozoa, all originating from a single primary spermatogonium. The sperm differentiation is characterized by: 1. -- Formation of the differentiation zone containing an intercentriolar body and two basal bodies of the future axonemes; 2. -- Formation of a cytoplasmic expansion and induction of two flagella; 3. -- Migration of nucleus into medial cytoplasmic expansion inducing progressive longitudinal fusion of the later with two adjacent flagella into a single spermatozoon body. The filiforme spermatozoa of B. clavibothrium are about 300 micrometer long and their main components are . the nucleus, two axonemes, cortical microtubules and cytoplasm rich in beta-glycogen particles.

Canalicular adenoma of buccal mucosa.

Canalicular adenoma is a benign tumor which comprises 1% of salivary gland neoplasms and 4% of minor salivary gland tumors. It occurs in the upper lip mucosa in about 90% of cases. The next most common location is the buccal mucosa (9.5% of tumors). We present herein a new case of canalicular adenoma of buccal mucosa involving a 74-year-old man. He was suffering of a slowly growing and painless nodule of the right buccal mucosa. The treatment was surgery and histological findings were consistent with the diagnosis of canalicular adenoma. No recurrence was noted one year later.

Matrix-producing breast carcinoma: a case report of this rare entity.

Matrix-producing carcinoma of the breast is very rare with few cases reported in the literature. This entity is characterized by the association of malignant epithelial elements and a mesenchymal component. Therapeutic strategy is not well established and prognostic factors need further research. We report here a case of matrix-producing carcinoma in a 46-years-old woman who presented with a large lump in her left breast. A core biopsy concluded to an invasive carcinoma but neoadjuvant chemotherapy was not helpful. Diagnosis of matrix-producing carcinoma was done on the lumpectomy specimen after excision of the fast-growing mass. Immunophenotypic profile was very suggestive showing tumoral cells positivity for cytokeratins, epithelial membran antigen and S-100 protein. One year later, the patient developed lung metastases.

[Electron microscope study of spermatogenesis in two cestodes acanthobothrium filicolle benedenii Loennberg, 1889 and Onchobothrium uncinatum (Rud., 1819) (Tetraphyllidea, Onchobothriidae) (author's transl)]. / Etude en microscopie électronique de la spermatogénèse de deux cestodes Acanthobothrium filicolle benedenii Loennberg, 1889 et Onchobothrium uncinatum (Rud., 1819) (Tetraphyllidea, Onchobothriidae)

The spermatogenesis, spermatozoon differentiation and fine structure of Acanthobothrium filicolle benedenii Loennberg, 1889 and Onchobothrium uncinatum (Rud., 1819) were studied by means of light and electron microscopy. Spermatogenesis in both species is of the rosette type. During sperm differentiation, the five following stages have been distinguished: (1) formation of arching membranes and differentiation zone; (2) nuclear elongation; (3) formation of two flagella with a median cytoplasmic process; (4) flagellar rotation; (5) fusion of two flagella with the median cytoplasmic process induced by the migration of nucleus into the latter. The mature spermatozoa of both species are threadlike structures about 250 mum long. They consist of two axonemes of the platyhelminth type (9+1 pattern), elongated nucleus and cortical microtubules embedded in a cytoplasmic matrix containing numerus beta-glycogen particles. The body which appears on cross-sections as crest, lateral with respect to the axoneme, is present in both species. Such a body is reported for the first time in Cestode spermatozoa. There is no mitochondrion in the two Onchobothriidae sperms studied.

Cycle évolutif de Bucephalus anguillae Spakulová, Macko, Berrilli & Dezfuli, 2002 (Digenea, Bucephalidae) parasite de Anguilla anguilla (L.).

The species of Bucephalus from the eel Anguilla anguilla of the north-eastern Tunisian lagoons was identified as B. anguillae which was recently described by Spakulová et al. (2002) from the Adriatic coast of Italy. In order to confirm that this eel digenean is distinct from B. polymorphus von Baer, 1827 present in other freshwater fishes, we investigated the life-cycle of this species. Surveys in the wild and experimental studies have shown that the life-cycle of B. anguillae is completed in brackish environments, with the lamellibranch Abra tenuis as the first intermediate host and the cyprinodontid fish Aphanius fasciatus as the second intermediate host. This life-cycle differs from that of B. polymorphus and can be considered as an additional argument for the distinction of these two morphologically similar species.

[Ultrastructural study of spermiogenesis in Acanthobothrium filicolle var. filicolle Zschokke, 1988 (Cestoda, Tetraphyllidea, Onchobothriidae)]. / Etude ultrastructurale de la spermiogenése de Acanthobothrium filicolle var. filicolle Zschokke, 1888 (Cestoda, Tetraphyllidea, Onchobothriidae).

The spermiogenesis of the Onchobothriidae Tetraphyllidea A. filicolle filicolle is similar to that of the other Onchobothriidae. In this study, it is proved that: --the longitudinal displacement of the axonemes seen in the spermatozoon results from the sliding of one of the two axonemes during spermiogenesis. --the basal bodies and their attached rootlets which appear in the early spermiogenesis are enclosed within the spermatozoon body. --the crested like body indicates the extremity from which the spermatozoon detaches from residual cytoplasm. The origin of cortical microtubules and the gutter-like arranged ones near the axoneme, is discussed.

[Embryonic development of three Cestoda from the genus Acanthobothrium (Tetraphyllidea, Onchobothriidae) (author's transl)]. / Développement embryonnaire de trois cestodes du genre Acanthobothrium (Tetraphyllidea, Onchobothriidae)

The embryonic development from the egg to the oncosphere is examined in three Cestoda: Acanthobothrium coronatum (Rud., 1819), Acanthobothrium filicolle, Zschokke, 1888 and Acanthobothrium zschokkei Baer, 1948 (Tetraphyllidea, Onchobothriidae). The three ontogeneses have in common the following data: -- Two vitelline cells pass with the zygote into the ootype where a thin shell is formed out of a material which comes from the vitelline cells. -- At first the cleavage is equal, then it becomes unequal resulting in the formation of four types of blastomeres: macromere, secondary macromere, mesomere and micromere. -- The preoncospheral phase is characterized first by the blastomere multiplication and later by their decreasing number and differentiation. -- The embryonic envelopes are formed within the shell. The vitelline layer includes the cytoplasm, a vitelline nucleus and possibly the secondary macromere, the nucleus of which always lies against the outer membrane of this envelope. The syncytial embryophore develops from mesomeres coming from the embryo. -- The oncosphere is limited by its owm membrane whose posterior region seems to double in order to form a kind of cap bending over the six hook tips. The final number of embryonic hexacantha cells is relatively low.

[Vitellogenesis in Echeneibothrium beauchampi Euzet, 1959 (Cestoda: Tetraphyllidea, Phyllobothriidae) (author's transl)]. / Vitellogénèse chez Echeneibothrium beauchampi Euzet, 1959 (Cestoda: Tetraphyllidea, Phyllobothriidae

The vitellogenesis in Echeneibothrium beauchampi is studied by means of electron microscopy. In the follicles, the vitelline cells undergo three progressive changes characterized by cellular size, membrane system development and nature of stored inclusions. 1. Immature cells have a gonial morphology. 2. Maturing cells display a very well developed membrane system. Their cytoplasm is gradually filled with abundant lipid droplets. At the same time, a small number of homogeneous vesicles occur which contain protein material moderately electron dense. Glycogen (alpha and beta) appears at the end of the vitellogenesis. 3. Mature cells show a conspicuous regression of the membrane system. Cellular organelles, nucleus and protein vesicles are found in the peripheral cytoplasmic layer which still contains numerous free ribosomes. The amorphous remaining cytoplasm is filled with large amounts of aggregated lipid droplets which often surround glycogen areas. 4. The presence of numerous lipid droplets and glycogen in the vitelline cells of E. beauchampi shows evidence that this Tetraphyllidea is close to Pseudophyllidea, but the aspect of protein vesicles (shell-protein material) brings it near the Cyclophyllidea.

[Embryonic development of 2 Phyllobothriidae (Cestoda: Tetraphyllidea)]. / Développement embryonnaire de deux Phyllobothriidae (Cestoda: Tetraphyllidea)

Caulobothrium longicolle (Linton, 1890) and Phyllobothrium gracile (Weld, 1855) (Cestoda: Tetraphyllidea, Phyllobothriidae) have the same embryonic development with the following characteristic data: --a small number of vitelline cells (2 or 3) pass with the zygote in the ootype;--a non operculate thin egg-shell;--the entire and equal zyhote cleavage following by unequal divisions leading to the formation of four blastomere types (Macromeres, secondary Macromere, Mesomeres and Micromeres);--the differentiation of two syncytial embryonic envelopes during the preoncospheral phase. The outer envelope encloses the vitelline material remnant and three Macromeres among which the secondary Macromere. The inner envelope or embryophore, originates from five or six Mesomeres;--the presence of the oncospheral membrane;--the Phyllobothriidae ontogenesis is similar to that of the Onchobothriidae. By their embryonic features, the Tetraphyllidea are close to the Cyclophyllidea. This similarity suggests a phylogenic relationship between those two Cestoda orders.

[A new castode Phyllobothrium pastinacae sp. n. described from the spiral valve of Dasyatis pastinaca taken from Tunis gulf (author's transl)]. / Phyllobothrium pastinacae n. sp. (Cestoda, Tetraphyllidea, Phyllobothriidae parasite de Dasyatis pastinaca (Linnaeus, 1758)

Distinguishing characteristics include: - scolece divided into four distincty curled bilobed bothridia with marginal loculi, -anatomy without post vaginal tests, - lateral genital atrium always in posterior 1/4 of segments, - about 100 testes.

[Viral infection in a platyhelminth parasite]. / Infection virale chez un Plathelminthe parasite

In parenchyme cells of the parasitic Plathelminthe Diplectanum aequans virus-like cytoplasmic particles were observed. Their formation is noted in virogenic areas and they are often gathered in regular geometric arrangements. The infected cells show important lesions.

[Comparative fine structure of the cestode spermatozoon. Relationship to phylogenesis]. / Ultrastructure comparée du spermatozoide des Cestodes. Relations avec la phylogénèse.

The comparison of the ultrastructure of spermatozoa in Cestodes from seven different orders shows that they have the same general pattern of organization. The main common features are following: (a) a long thread-like body; (b) an elongated nucleus; (c) cortical microtubules underlying plasma membrane; (d) the absence of mitochondria and of a typical acrosome. The mode of spermatozoon differentiation indicates an inversion of the polarity. The number of axonemes of the 9 + "1" pattern, characteristic of the platyhelminthes, allow us to distinguish two types of spermatozoa among cestodes: --The "two-axonemes"-type is considered as primitive as it has also been found in the free-living platyhelminths. This type has been observed in the Pseudophyllidea, Proteocephalidea, Tetrarhynchidea and Tetraphyllidea (Onchobothriidae). --The "one-axoneme"-type has been found in the Cyclophyllidea, Caryophyllaeidea, Diphyllidea and Tetraphyllidea (Phyllobothriidae). It has been proved that the one axoneme type of the spermatozoon, observed in Tetraphyllidea, Phyllobothriidae arises from the two axoneme type by early abortion of the second axoneme. In all the tetraphyllidean species studied so far, we found an helicoidal body forming so-called "crested body" or "spiral crest" at the proximal end of the spermatozoon, which is opposite to the nuclear part. This division of the cestodes into two groups, according to the number of axonemes in the spermatozoon is compared with the phylogenetic diagrammes of Cestoda proposed by Freeman (1973) and Euzet (1974). As result, two hypothesis can be forwarded to explain the relationships between the Tetraphyllidea, Proteocephalidea and Cyclophyllidea. The importance of data on the cestode spermatozoa as a criterion in analysis of cestode phylogenesis is drawn and discussed.