Permeation of Nanoparticles into Pulmonary Surfactant Monolayer: In Situ X-ray Standing Wave Studies.

High-resolution X-ray techniques were applied to examine the effects of gold nanoparticles (size <5 nm) on natural pulmonary surfactant and pure DPPC monolayers preliminarily formed on water subphase in a Langmuir trough. Hydrophobic and hydrophilic nanoparticles were delivered from nanoaerosol using electrodeposition method. Grazing incidence diffraction, X-ray reflectivity, and X-ray standing wave measurements allow to monitor the changes in molecular organization of lipid monolayer and to locate the position of gold nanoparticles. X-ray experiments were performed over a period of 9-14 h. The obtained results evidenced that, on a long time scale, the deposition of nanoparticles, even at low doses, can induce pronounced alterations in lipid monolayer. The presented data can help to elucidate the mechanism of pulmonary translocation of inhaled nanoparticles that is of special interest for biomedical investigations of potential risk of nanoaerosols for human health.

Effects of nanodispersed iron on the morphofunctional parameters of the blood system.

The effects of nanodispersed iron forms on the morphology and function of the blood system were studied. Maghemite and lepidocrocite caused a leukocytic shift towards segmented neutrophil forms, reduction of lymphocyte rigidity, and stimulated their compactization. In addition, the counts of small hyperchromatic erythrocytes with high rigidity increased in the blood flow. The results indicated that a single dose of nanodispersed iron-containing drugs improved the blood respiratory function and its microrheology.

[Reexamination of the life cycle of Isthmiophora melis (Trematoda: Echinostomatidae) on material from southeast Europe].

The life cycle of Isthmiophora melis (Schrank, 1788) on material from Southeast Europe was experimentally reexamined. Thirteen names or combinations can be accepted as true synonyms of I. melis: Distoma melis (Schrank, 1788) Zeder, 1800; Echinocirrus melis (Schrank, 1788) Mendhaim, 1943; Isthmiophora spiculator (Dujardin, 1845); Echinostoma trigonocephalum (Rud., 1802) Cobbold, 1861; E. melis (Schrank, 1788) Dietz, 1909; E. spiculator Dujardin, 1845; Euparyphium jassyense Leon and Ciurea, 1922; E. melis (Schrank, 1788) Railliet, 1919; E. suinum Ciurea, 1921; Fasciola armata Rud., 1802; F. melis Schrank, 1788; F. putorii Gmelin, 1791; F. trigonocephala Rud., 1802. The first intermediate hosts are the pulmonate freshwater snail Lymnaea stagnalis. The second intermediate hosts are many amphibians and freshwater fishes. The list of definitive hosts includes more than 30 species of vertebrates including humans. I. melis occurs in Europe, Asia and North America.

Life cycle and identification of an eyefluke from Israel transmitted by Melanoides tuberculata (Müller, 1774).

A philophthalmid species from Israel using the freshwater snail Melanoides tuberculata as intermediate host was studied. The biological and morphological characteristics of all developmental stages of the life cycle of this philophthalmid were described, and compared to those of Philophthalmus lucipetus Rudolphi, 1819 from Israel, Philophthalmus gralli Mathis and Leger, 1910 from Jordan, Philophthalmus palpebrarum Looss, 1899, Philophthalmus nocturnus Looss, 1907, Cercaria distomatosa Looss 1896 from Egypt, and Philophthalmus lucknowensis Baugh, 1962 from India. The possible identity with 1 of these species is discussed. On the basis of comparative analysis of the data for all parasite stages in the life cycle, geographical distribution, snail hosts, and snail host specificity, we propose to designate the Israeli Melanoides tuberculata-transmitted eye fluke to Philophthalmus distomatosa n. comb. (Looss, 1896), (Digenea: Philophthalmidae).

Argentophilic structures of miracidia and cercariae of Philophthalmus lucipetus (Philophthalmidae: Trematoda) from Israel.

Argentophilic structures of Philophthalmus lucipetus miracidia and cercariae from Israel are described. Eighty-four of 87 miracidia examined displayed an epidermal plate arrangement of 6:8:4:2 = 20, similar to other Philophthalmus species. Twenty papilla-like structures are arranged on the terebratorium in 3 groups, along 1 axis. Sixteen body papillae are located at the bases of epidermal plates of row 1. Eyespots are mediodorsal, between rows 1 and 2. Excretory pores are lateral, between rows 2 and 3. Features common to Israeli and Bulgarian isolates, differentiating them from other species, include the presence of 16 body papillae as opposed to 10 in other species, and a maximum of 20 papillae on the terebratorium as opposed to 19 in the others. About 3% of the miracidia displayed different plate arrangements. Among the argentophilic structures of P. lucipetus cercariae, the Israeli and Bulgarian P. lucipetus show a common pattern of 2-4 excretory pores in the tail, but arrangement of cephalic CI3 and CI5 papillae in the 2 isolates is insufficiently unequivocal for species determination. The data presented show that miracidial characteristics, rather than those of cercariae, aid in determining the species of philophthalmids. They also support former evidence attesting to the identity of the Bulgarian and Israeli species.

Argentophilic structures of the miracidia and cercariae of Philophthalmus distomatosa n. comb. from Israel.

The morphology and patterns of distribution of the argentophilic structures of miracidia and cercariae of Philophthalmus distomatosa n. comb. are described. The epidermal plate arrangement of the vast majority (94.2%) of miracidia studied conformed to the formula 6:8:4:2 = 20. The rest (5.8%) displayed the following patterns of arrangement of epidermal plates: 6:7:4:2 = 19; 6:6:4:2 = 18; and 6:4:4:2 = 16. Twenty papillalike structures were observed on the terebratorium. They were arranged along 1 axis, in 3 groups. Most commonly, 16 papillae were present on the body, located between epidermal plates of the first and second rows. The eye spots were located dorsally, near interepidermal space S1. The numbers, arrangements, and locations of the excretory pores varied. Patterns of distribution of the tegumentary papillae of P. distomatosa n. comb. cercariae are given, including those of the cephalic regions, periacetabular region, and tail. Argentophilic structures of the mentioned larval stages and of other parameters clearly distinguishing between the presently described species and those of P. lucipetus from Israel are summarized. On the basis of comparison of the presently described larval stages and those of other Melanoides tuberculata-associated larval stages of Philophthalmus in Israel and Jordan, the possibility exists that a third species occurs in Israel.

Life history and identification of Philophthalmus lucipetus from Israel.

A Philophthalmus species whose larval stages have been isolated from Melanopsis praemorsa snails collected in Israel and formerly identified as probably belonging to Philophthalmus palpebrarum has now been reevaluated as belonging to Philophthalmus lucipetus. The present determination is based on a detailed study of all the stages of the parasite's life cycle--eggs, intramolluscan stages, cercariae, and adults. They were compared to the original species P. lucipetus, recently reexamined and redescribed from source material in Vienna, Austria. The identity of the eyefluke from Israel and P. lucipetus was further confirmed by successful cross-infections employing miracidia of the Israeli isolate in European (Bulgarian) Fagotia acicularis acicularis snails on the one hand and miracidia of P. lucipetus from Bulgaria in Israeli Melanopsis praemorsa on the other hand, but none infected Melanoïdes tuberculata snails from Israel.

Argentophilic structures of the miracidium of Echinochasmus perfoliatus (Trematoda: Echinostomatidae).

Argentophilic structures of the miracidium of Echinochasmus perfoliatus were described from material collected in the vicinity of Vladivostok, Far East of Russia. Impregnated with 0.5% solution of AgNO3 miracidium showed 21 epidermal plates arranged in four rows: 6 + 9 + 4 + 2. Up to 23 papilla-like structures on the terebratorium were arranged along three axes and in four groups. A single papilla was located at the base of each of ventral and dorsal epidermal plates of the first row. Two papillae were located at the base of each of lateral epidermal plates of the first row. The eyespots were located posterior to the first row of plates. Two excretory pores were located anterior to the last row of plates. The results obtained were compared with the argentophilic structures of closely related species of the genus Echinochasmus.

Comparative observations on cercariae and metacercariae of Echinostoma trivolvis and Echinoparyphium sp.

Comparative observations were made on cercariae of Echinoparyphium sp. from Physa gyrina in Charlie's pond, Stokes County, North Carolina and cercariae of Echinostoma trivolvis from Helisoma trivolvis in Northampton County, Pennsylvania. The cercaria of Echinoparyphium sp. has 43 collar spines, lacks penetration and paraesophageal glands, and has a conical tail without fin folds. The cercaria of E. trivolvis has 37 collar spines, penetration and paraesophageal glands, a finger-like process at the tip of the tail and fin folds. The length of the cercarial body and tail of E. trivolvis was significantly greater than that of Echinoparyphium sp. Cercariae of both species encysted in Biomphalaria glabrata snails in single and concurrent infections. In concurrent infections with a single cercaria of each species, 2 encysted metacercariae were adjacent to each other in the saccular kidney of the snail at 24 hr postinfection. The diameter of encysted metacercariae of E. trivolvis was significantly greater than that of Echinoparyphium sp. Echinoparyphium sp. metacercariae excysted at 39 C in an alkaline trypsin-bile salts medium used previously to excyst E. trivolvis. The length of excysted metacercariae of E. trivolvis was significantly greater than that of Echinoparyphium sp.

The occurrence and identification of Echinostoma revolutum from North American Lymnaea elodes snails.

Lymnaea elodes snails collected in northern Indiana, U.S.A., were infected with larval stages of an echinostome bearing 37 collar spines and resembling members of the Echinostoma group. The taxonomic status of this digenean was determined through experimental infections of various definitive and first-intermediate hosts. In addition, characteristics of the penetration and paraesophageal glands in cercariae from this echinostomatid were compared with those from E. revolutum and E. trivolvis. Results indicate that this recently discovered 37-collar-spined echinostome parasitizing lymnaeid snails is E. revolutum, making this the first clear report of this trematode in North America.

Cytological study of Rubenstrema exasperatum (Trematoda:Omphalometridae).

Cytological studies on Rubenstrema exasperatum were carried out. The number of chromosomes in diploid cells (2n = 16), and the morphological characteristics of the karyotype were determined. All the chromosomes (from Nos 2 to 8) had a well-defined short arm and, in accordance with the Ic values, were determined to be meta-submetacentric. Polymorphism was established in the length of the 2 homologues of the 1st chromosome. This pair is probably linked with sex determination.

Argentophilic structures of the miracidium of Echinostoma trivolvis (Cort, 1914) (Trematoda: Echinostomatidae).

Argentophilic structures of the miracidium of Echinostoma trivolvis were described from 80 specimens reared from material originally collected in eastern Pennsylvania, U.S.A. Miracidia were impregnated with 0.5% aqueous silver nitrate solution. The miracidium has 18 epidermal plates arranged in 4 rows of 6 + 6 + 4 + 2 = 18. Up to 20 papillalike structures on the terebratorium were arranged along 3 axes and in 5 groups. A single papilla was located at the base of each of the 6 epidermal plates of the first row. The eyespots were located posterior to the first row of plates and 2 excretory pores were located anterior to the last row of plates.

Lymnaea truncatula, intermediate host of some Plagiorchiidae and Notocotylidae species in León, nw Spain.

To study the distribution of Lymnaea truncatula in the Porma river basin (León, NW Spain) and its helminth fauna, malacological samplings were carried out at 66 points in the basin and the presence of these molluscs was detected in 31. To trace the dynamics of this mollusc population and the prevalence and intensity of its infection by trematodes, malacological samplings were made at fortnightly intervals over two years at five locations, situated in the upper and middle regions of the river Porma basin. To confirm the identity of the larval stages found in the molluscs, second intermediate and/or definitive hosts, depending on the trematode species, were experimentally infected to complete the life cycles. Two different species of Plagiorchiidae and one of Notocotylidae were identified. The infection prevalence of Plagiorchis elegans for the 6291 specimens of L. truncatula examined was 2.8% and infection was observed in snails collected in 7 of the 31 sample localities. This parasite was found in all months of the year, with the highest prevalence observed in July and October. When the corrected frequency values were considered, a slightly positive relationship was observed between the infection prevalence and the latter months. The highest percentages of snails harbouring immature sporocysts were detected in March and June-July, while the highest percentages with sporocysts containing mature cercariae were observed in spring and at the end of summer-autumn, and cercarial shedding in the latter. Of the 6291 L. truncatula examined 0.3% were infected by sporocysts of Opisthioglyphe ranae.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental observations on the specificity of Strigea falconispalumbi (Trematoda: Strigeidae) toward planorbid first intermediate hosts.

Planorbis planorbis, Planorbarius corneus and Biomphalaria alexandrina (Egyptian strain) were ascertained as new experimental first intermediate hosts, thus bringing the total number of planorbid experimental first intermediate hosts to eight. The highest degree of compatibility was exhibited with P. planorbis (infection prevalence 80%) followed by P. corneus (46.6%), whereas B. alexandrina (as snail species not occurring in the geographical range of S. falconispalumbi) showed the lowest degree of compatibility (23.3%).

Strigea falconispalumbi (Trematoda: Strigeidae): argentophilic structures of the miracidium.

A study of the argentophilic structures of the miracidium of the strigeid digenean Strigea falconispalumbi VIBORG, 1795 was carried out. Miracidia were hatched under laboratory conditions from eggs obtained from adult S. falconispalumbi from the intestine of a naturally infected Buzzard (Buteo buteo). Miracidia were stained with 0.5%. Silver Nitrate solution using standard techniques. The epidermal plates of the miracidium are arranged in four tiers according to the formula (6 + 8 + 4 + 3) = 21. The terabratorium bears 20 papillare. Papillae are also present at the bases of the epidermal plates of the first tier, and also at the margins of the terabratorium between the epidermal plates. The two pores of the excretory ducts are positioned laterally between the third and fourth tiers of epidermal plates.

Trematodes nervous system.

Three main themes are discussed: 1. Development of the nervous system in the ontogeny of digenetic trematodes; 2. Central and integumentary nervous elements in Cercaria echinata (Echinostomatidae), their evolution in metacercaria and adult; 3. Chaetotaxy and systematics. The structure of the nervous system in digenetic trematodes is based on the occurrence of various neurotransmitters in the nerve tissue. Two major trends in the evolution of the nervous system from cercaria to adult are discerned, one leading to definitive, small number of commissures, established early in the development of the cercaria, the other one leading to formation of great number of commissures completed in the adult. Structure of the nervous system in sporocystic and/or redial generations in various groups of trematodes is compared. Its primitiveness in relation to that of other generations is noted. The central nervous system of Cercaria echinata is pointed out by fixation in glioxylic acid and examination in green light fluorescence. The integumentary sensory elements observed in light microscope, SEM and transmission electron microscope reveal a large variety in structures; propositions are made about their functions. In the corresponding metacercaria, the anterior part of the central nervous system remains unchanged; meanwhile the posterior part increases; several integumentary sensory elements disappear and poorly developed structures, improve; in the adult, transformations are completed. In about 200 various species of cercariae, the sensory receptors are arranged in a conspicuous relation with the nervous system. The study of their number and position; the chaetotaxy is used in systematics and allows very accurate conclusions in specific or infraspecific identifications and in all high taxonomical levels: family, sub-order, super-order. In the same way, miracidial and redial chaetotaxy are used n taxonomy.

Taxonomy of 37-collar spined Echinostoma (Trematoda: Echinostomatidae) in studies on the population regulation in experimental rodent hosts.

With reference to a recent taxonomic revision the species of the echinostomes used in key studies on the population regulation in infections with 37-collar-spined Echinostoma species in experimental rodent hosts were reconsidered. This was considered essential to prevent taxonomic problems blocking further fruitful progress within this field of experimental parasitology.

Pseudechinoparyphium echinatum (Digenea: Echinostomatidae): experimental observations on cercarial specificity toward second intermediate hosts.

Infectivity of Pseudechinoparyphium echinatum cercariae to 11 species of gastropod was examined experimentally. Broad specificity and differential host-parasite compatibility were exhibited. Nine gastropod species functioned as second intermediate hosts. Planorbarius corneus, Physa fontinalis, Lymnaea peregra and Biomphalaria alexandrina showed high levels of compatibility with the parasite. In single-species exposures over 90% of cercariae encysted in each of these hosts. Low compatibility with the first intermediate host species Lymnaea stagnalis may be a mechanism preventing super-infection of emitting snails. Cercariae did not infect the prosobranchs Bithynia tentaculata and Viviparus viviparus. Experimental infection of a host community comprised of 8 European gastropod species revealed an order of host utilization similar to that shown in single-species exposures. However, cercarial transmission success in P. fontinalis and L. peregra (compared to that in P. corneus) was significantly reduced. This may have been due to the marked preference of cercariae for P. corneus compared to the other two highly suitable hosts for whom cercariae showed equal preference.

Chaetotaxy of cercariae of Opisthioglyphe ranae (Frölich, 1791) (Trematoda: Plagiorchidae).

A detailed observation of the sensory apparatus of Opisthioglyphe ranae (Frölich, 1791) cercariae was carried out. The species was determined on the basis of an experimental study of the life cycle and morphology of sporocysts, cercariae, metacercariae, and adults. In contrast to other species of the family Plagiorchidae, no papillae were present in the positions CId1, CId2, CII0, CII3 and CII4. Papillae with markedly ventral situation on the postacetabular zone were found very rarely. Some of the cercariae possessed ventral papillae variously distributed in the preacetabular zone. A comparative analysis of the chaetotaxy revealed that the cercaria studied by us was very similar to Cercaria 4 of Richard, 1971, with the exception of the number of acetabular papillae and some groups of ventral papillae. Compared to the cercaria of O. ranae studied by Dobrovolskiy (1965). AID papillae and a part of ventral papillae were distributed differently. The chaetotaxy was identical with that of experimentally obtained cercariae of O. ranae from L. stagnalis and of cercariae of the same species obtained from Bulgaria.

[Cercarial chaetotaxy of Echinostoma revolutum (Froelich, 1802) and E. echinatum (Zeder, 1803) (Trematoda, Echinostomatidae)]. / Chétotaxie cercarienne d'Echinostoma revolutum (Froelich, 1802) et E. echinatum (Zeder, 1803) (Trematoda, Echinostomatidae).

The life-cycles of Echinostoma revolutum and E. echinatum were carried out by using cercariae emitted by naturally infected Molluscs. E. revolutum strain was issued from Lymnaea auricularia, E. echinatum from Lymnaea truncatula and Planorbis planorbis, Planorbarius corneus produced an Echinostome which may possibly be E. echinatum or another species E. sp. Metacercarial stages and adults were obtained from laboratory experimental hosts. None of these adult Echinostomes displayed well-defined morphological differences: nevertheless their respective larval stages exhibited discrepancies used for species diagnosis. Cercarial chaetotaxy is given for every batch and compared with that of other species described as E. audyi, E. lindoense and E. caproni; discriminating features are discussed.