139 resultados para Excretory organs


Relevância:

10.00% 10.00%

Publicador:

Resumo:

A new species of South American planorbid snail, Biomphalaria occidentalis, is described. It is indistinguishable from B. tenagophila (Orbigny, 1835), by the characteristics of the shell and of most organs of the genital system. In B. tenagophila there is a pouch on the ventral wall of the vagina (Fig. 4A, vp), absent in B. occidentalis (Fig. 3A), and on the ventral wall of the vagina (Fig. 4A, vp), absent in B. occidentalis (Fig. 3A), and the prepuce is much wider than the penial sheath, its width increasing distalward (Fig. 4, ps,pp), whereas in B. occidentalis the prepuce is wider than the penial sheath but keeps about the same width all along (Fig.3, ps, pp). The two species are biologically separate by absolute reproductive isolation. The geographical distribution of B. occidentalis is shown in Fig. 14. So far it has been found in the Brazilian states of Acre, Amazonas (?), Mato Grosso, Mato Grosso do Sul and Paraná, and in Paraguay. Its type-locality is Campo Grande, state of Mato Grosso do sul, where it was collected from several biotopes related to affluents of the Aquiduana river, chiefly Córrego Prosa and Córrego Ceroula. Specimens were deposited in the following malacological collections: Instituto Oswaldo Cruz, Rio de Janeiro; Academy of Natural Sciences, Philadelphia; Museum of Zoology, University of Michigan; and British Museum (Natural History).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A new species of South American lymnaeid snail, Lymnaea rupestris, is described. So far it has been found only in its type-locality, Nova TeuTõnia, a village in the municipality of Seara (27° 07' S, 52° 17' W), state of Santa Catarina, Brazil. It is distinguishable, by characteristics of the shell and internal organs, from the other two lymnaeid species known to occur in the area, Lymnaea columella and L. viatrix. Its shell has 4 markedly shouldered whorls, deep suture, ovoid or rounded aperture occupying about half the length of the shell, and reaches about 6 mm in length in adults; in columella and viatrix the shell has 4-5 rounded whorls, shallow suture, and reaches over 10 mm in adults; the aperture is ovoid, occupying about half the length of the shell in viatrix, about two thirds in columella. Anatomically it is readily separated from L. columella by the shape of the ureter, straight in rupestris, with a double flexure in columella. Comparison with L. viatrix shows the following main differences: distalmost portion of the oviduct with a low, caplike lateral swelling in rupestris, with a well-developed pouch in viatrix; uterus bent abruptly caudalward in rupestris, only slightly curved rightward in viatrix; basal half of the spermathecal duct hidden by the prostate in rupestris, wholly visible or nearly so in viatrix; spermiduct sinuous and uniformly wide in rupestris, straight and gradually narrowing in viatrix; prostate more than half as long and nearly as wide as the nidamental gland, and with a slit-like lumen in cross-section in rupestris, less than half as long as and much narrower than the nidamental gland, and with an inward fold in cross-section in viatrix; penial sheath about as long and as wide as the prepuce in rupesris, shorter and narrower than the prepuce in viatrix. An important ecological characteristic of L. rupestris is its habitat on wet rocks most often outside bodies of water, although in close proximity to them. Specimens were deposited in the following malacological collections: Instituto OswaldoCruz, Rio de Janeiro; Academy of Natural Sciences, Philadelphia; Museum of Zoology, University of Michigan; and British Museum (Natural History).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A new subspecies of planorbid snail, biomphalaria tenagophila guaibensis, is described. It has been found along the coastal belt of the Brazilian state of rio grande do Sul and the middle part of Uruguay, from Porto Alegre to Mercedes. It differs from the nominate subspecies, Biomphalaria tenagophila tenagophila, in the appearance of the penial complex (prepuce longer and proportionally slenderer in B. t. guaibensis, shorter and proportionally stouter in b. t. tenagophila), in the ratio between the lengths of the penial sheath and the prepuce, in the ratio between the lengths of the uterine complex and the penial complex, and in a coefficient of difference of 2.44 for the ratio between the penis sheath and prepuce and of 2.02 for the ratio between the uterine complex and penial complex. The shell and the other organs of the genital system are similar in both subspecies. B. t. guaibensis is very similar to Biomphalaria occidentalis Paraense, 1981, but is readily separated from it by the presence of a vaginal pouch, which is lacking in the latter, besides showing highly significant difference in the penis sheath: prepuce and uterine complex: penial complex ratios. Crossbreeding experiments which lend additional support to the recognition of B. t. guaibensis as a subspecies will be reported elsewhere.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Extirpation of endocrine organs - a classic maneuver in hormonal research - has been difficult or impossible in the case of the prothoracic glands (PG) of insects. In larval and pupal Lepidoptera the glands are virtually inaccessible unless one sacrifices the insect. Even then, the PG are not easy to remove in their entirety. Consequently, in order to obtain viable preparations lacking PG, one costomarily makes use of abdomens isolated by litigation or surgery.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The fates of purified 32P-vitellin and 32P-lipophorin were followed in vitellogenic females of Rhodnius prolixus. While the radioactivity from 32P-vitellin 6 hours after injection was found almost exclusively in the ovary, the radioactivity from injected 32P-lipophorin was found distributed among several organs. In the ovary, the radioactivity from 32P-vitellin was associated with the contents of the yolk granules. 32P-lipophorin delivered a great amount of radioactive phospholipids to the ovary with no accumulation of its protein moiety, as observed after its iodination with 131I. The delivery of phospholipids was inhibited at 0ºC and by the metabolic inhibitors, sodium azide and sodium fluoride. Comparison of the radioactivity incorporation from 32P-lipophorin with that of 14C-inulin suggests that the 32P-phospholipids from lipophorin are not taken up by fluid phase endocytosis. The data presented here are compatible with the concept of lipophorin as a carrier of lipids in insects and provide evidence that lipophorin transports phospholipids as shown previously for other classes of lipids. The utilization by the oocytes of the phospholipids transported by lipophorin is discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper the authors briefly describe a human Schistosoma mansoni strain from Pará State, Brazil. The CIRENE'S strain was capable of infecting 71.4% of the snail vector Biomphalaria glabrata (Telegrafo's strain) provided by the "Evando Chagas" Institute, Belém. The cycle was completed by the infection of six mice. The thoracic and abdominal organs were examined microscopically which demonstrated the passage of the worm into the liver and lungs. The authors discuss the importance of these results in the epidemiology of schistosomiasis in Pará.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dinosoma clupeola sp. n. is described from Harengula clupeola, and resembles D. hawaiiense Yamaguti, 1970, from which it differs in the entire, elongate-saccular seminal vesicle, tegument weakly plicated, smaller size of body and internal organs, and slightly larger and narrower eggs. Pseudoacanthostomum floridensis Nahhas & Short, 1965 is referred to Netuma barba, which represents a new host record.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We studied by sanning electron microscopy the number, types, structure and distribution of the antennal sensilla of the medical important ceratopogonid Culicoides paraensis (Goeldi). There are about 174 sense organs on the antenmal flagellum which are classified as sensilla chaetica; sharp-tipped and blunt-tipped (type I and II) sensilla trichodea; sensilla basiconica; sensilla coeloconica; sensilla ampullacea and styloconic-type sensilla. The role of antennal sensory organs are discussed regarding the host preference of the biting midges.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tissue parasitism, inflammatory process (histologic methods) and sympathetic denervation (glyoxylic acid-induced histofluorescence for demonstration of catecholamines) were studied in the heart (atrium and verntricle) and the submandibular gland of rats infected with the Y strain of Trypanosoma cruzi. In the heart paralleling intense parasitism and inflammatory process, the sympathetic denervation started at day 6 of infection and at the end of the acute phase (day 20) practically no varicose nerve terminals were found in both myocardium and vessels. In the submandibular gland, in spite of the rarity of anastigote pseudocysts and the scarcity of inflammatory foci, slight to moderate (days 13-15 of infection) or moderate to severe denervation (day 20) was found. At day 120 of infection both organs exhibited normal pattern of sympathetic innervation and only the heart showed some inflammatory foci and rare psudocysts (ventricle). Our data suggest the involvement of circulating factors in the sympathetic denervation phenomena but indicate that local inflammatory process is, at least, an aggravating factor.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Forty-tree (31.4%) out of 137 serum samples obtained from two Indian communities living in the Amazon region were found to be positive for HTLV-I antibody, as tested by enzyme-linked immunosorbent assay (Elisa). Eighty-two sera were collected from Mekranoiti Indians, yielding 39% of positivity, whereas 11 (20.0%) or the 55 Tiriyo serum samples had antibody to HTLV-I. In addition, positive results occurred in 10 (23.2%) out of 43 sera obtained from patients living in the Belem area, who were suffering from cancer affecting different organs. Five (16.7%) out of 30 Elisa positive specimens were also shown to be positive by either Western blot analysis (WB) or indirect immunogold electron microscopy (IIG-EM).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus) or organized tissues or organs put in culture, under controlled sterile conditions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Specimens of Fissurella crassa (Archaeogastropoda) from Ilo, southern Perú, are infected with the adult stage of the digenetic trematode Proctoeces lintoni (Fellodistomidae). The histopatological analysis of the male and female gonads show a strong effect of the parasite on the structure and function of these organs. P. lintoni live unencysted in the gonads, and the main mechanical damage is originated by the action of a well developed acetabulum. Chemical actions of parasitic secretions may also be involved. The infected gonads show altered structure and the gametogenic processes is aborted. There is no evidence of hemocytic response, but leucocite infiltration is evident at least in male infected gonads. An increased content of polysaccarides is evident in infected gonads.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Two lots of 20 young male guinea pigs were inoculated subcutaneously in the tarsi with 10 (elevated to fourth potency) amastigotes of Leishmania braziliensis or L. b. guyanensis to study the susceptibility of this Neotropical hystricomorph rodent the autochthonous parasites. Almost 50% of the animals showed lesions in the inoculation site and had parazitations that were infective to hamsters, as shown by inoculating homogenates of the dermal lesion, of the spleen, of the liver, and of the nasal mucosa into hamsters at 20, 40, 60 and 120 days after inoculation of the guinea pig. Smears of the above organs showed the presence of amastigotes. Parasites inoculated into the tarsi were detected early in the skin, spleen, and liver of the guinea pig host. Blood cultures made by cardiopuncture on sacrifice of the guinea pigs were uniformly negative. The nasal mucosa of nearly all animals positive in the skin or viscera was invaded early by the parasites, although with grater frequency between 60 and 120 days post-inoculation. The use of this model for the study of mucocutaneous parasitism by L. brasiliensis is discussed, together with the phenomena of parasitism at a distance from the inoculation site, the temperature of the body regions affected, and the possible genetic influence on susceptibility of the guinea pig to L. brasiliensis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nomimoscolex touzeti n. sp. is described from one Ceratophrys cornuta (L.) caught in Amazonian Ecuador. Its taxonomic relationships to the others species are discussed. This new species is characterized by a cortical position of vitellaria; by the presence in the uteroduct of conglomerates of 20-40 eggs; by a weak ovary width/proglottis width ratio; by ventral excretory canals anastomosed; by a powerful vaginal sphincter and by a long cirrus. N. touzeti is the first record of Monticellidae in an amphibian host.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The morphology of the male and female of Bunostomum phlebotomum are described based on scanning electron microscope (SEM) observations. The attachment of the worms to the small intestinal mucosa and during the copula were observed. Structures of the bucal capsule and genital organs were also studied.