Attrition and temporal distribution of Schistosoma mansoni and S. haematobium schistosomula in laboratory mice

Parasitology ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 55-70 ◽  
Author(s):  
J. R. Georgi ◽  
S. E. Wade ◽  
D. A. Dean
Keyword(s):  
Body Weight ◽  
Schistosoma Mansoni ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Systemic Circulation ◽  
The Body ◽  
Portal System ◽  
Hepatic Portal System ◽  
Total Body ◽  
Hepatic Portal

SUMMARYThe total number and distribution of schistosomula of Schistosoma mansoni and S. haematobium in all tissues and organs of mice from infection to 14–27 days was determined by compressed tissue autoradiography. Attrition of schistosomula, manifested as a decrease in the number of autoradiographic foci, was observed in organs other than the liver. Attrition commenced about 2 days after cercariae entered the skin, and conformed to a single exponential function with a rate constant (± standard error) of 7·0±0·5%/day for S. mansoni and 3·2±0·7%/day for S. haematobium. The temporal distribution of schistosomula of S. mansoni and S. haematobium differed quantitatively. In the case of S. mansoni, concomittant with a decrease in skin counts, the lung curve rose rapidly to a peak centred on day 6 and thereafter decreased more or less parallel to the total body curve. Significant accumulation in the liver was not observed until day 7, whereupon liver counts rose steadily to a plateau that extended from about day 14 to the end of the experiment and approximated the number of adult worms recovered from the hepatic portal vessels on day 42. A maximum of 26% and mean of 12% of all foci in the body were counted on autoradiograms of tissues other than the skin, lung and liver. The pelt averaged 14% of the body weight yet schistosomula were detected only in the area initially exposed to cercariae. The eviscerated carcass averaged 54% of the body weight yet contained only 0·8% −3·4 % of the schistosomula during the period of accumulation in the liver. Between day 6 and day 14, the ratio of schistosomula in the pulmonary circulation to schistosomula in the systemic circulation did not remain constant, as would be the case if schistosomula circulated passively and randomly, but instead displayed a statistically significant decrease from 0·92 and 0·85. For these reasons, it was considered unlikely that schistosomula had circulated randomly and repeatedly through the pulmonary and systemic circulations and entered the hepatic portal system by chance, as hypothesized by Miller & Wilson (1980). Instead it was considered more probable that schistosomula migrating from lungs to liver had followed a directed path through intervening vessels (Kruger, Heitman, van Wyk & McCully, 1969) or tissues (Wilks, 1967). Schistosoma haematobium distribution patterns differed from those of S. mansoni in slower movement of schistosomula from skin, their peak accumulation in lungs at about day 8 followed by a low rate of decrease, and a very low liver plateau which approximated the number of adult worms recovered from the hepatic portal vessels on day 42.

Phenotypic plasticity of male Schistosoma mansoni from the peritoneal cavity and hepatic portal system of laboratory mice and hamsters

2014 ◽  
Vol 89 (3) ◽  
pp. 294-301 ◽  
Author(s):  
V.L.T Mati ◽  
R.M. Freitas ◽  
R.S. Bicalho ◽  
A.L. Melo
Keyword(s):  
Schistosoma Mansoni ◽  
Body Length ◽  
Peritoneal Cavity ◽  
Total Body Length ◽  
Portal System ◽  
Swiss Mice ◽  
Plastic Potential ◽  
Hepatic Portal System ◽  
Total Body ◽  
Hepatic Portal

AbstractMorphometric analysis of Schistosoma mansoni male worms obtained from AKR/J and Swiss mice was carried out. Rodents infected by the intraperitoneal route with 80 cercariae of the schistosome (LE strain) were killed by cervical dislocation at 45 and 60 days post-infection and both peritoneal lavage and perfusion of the portal system were performed for the recovery of adult worms. Characteristics including total body length, the distance between oral and ventral suckers, extension of testicular mass and the number of testes were considered in the morphological analysis. Changes that occurred in S. mansoni recovered from the peritoneal cavity or from the portal system of AKR/J and Swiss mice included total body length and reproductive characteristics. Significant morphometric alterations were also observed when worms recovered from the portal system of both strains of mice were compared with the schistosomes obtained from hamsters (Mesocricetus auratus), the vertebrate host in which the LE strain had been adapted and maintained by successive passages for more than four decades. The present results reinforce the idea that S. mansoni has high plastic potential and adaptive capacity.

scholarly journals Genital Schistosomiasis: A Report on Two Cases of Ovarian Carcinomas Containing Viable Eggs ofSchistosoma mansoni

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Andressa Gonçalves Amorim ◽  
Fernanda Alves Barbosa Pagio ◽  
Rodrigo Neves Ferreira ◽  
Antônio Chambô Filho
Keyword(s):  
Schistosoma Mansoni ◽  
Benign Lesion ◽  
Parasitic Infection ◽  
Pelvic Mass ◽  
Abdominal Distension ◽  
Portal System ◽  
Serous Carcinoma ◽  
Ovarian Carcinomas ◽  
Hepatic Portal System ◽  
Hepatic Portal

Schistosomiasis is a parasitic infection that is highly prevalent worldwide, with a variety of species being responsible for causing the disease. In Brazil, however, the only identified species isSchistosoma mansoni. The adult parasites inhabit the blood vessels of the hepatic portal system of the main host. The disease may range from being asymptomatic to provoking liver damage or portal hypertension. Furthermore, ectopic schistosomiasis may develop, and several hypotheses have been raised to explain the occurrence of the disease. This paper describes two cases, one in a 39-year-old woman and the other in a 47-year-old woman. Both had similar symptoms of pain and abdominal distension caused by a large abdominal/pelvic mass. Histopathology of the ovary showed a mucinous cystadenocarcinoma of the intestinal type in the first patient and a papillary serous carcinoma in the second, with both tumors containing viable eggs ofSchistosoma mansoni. The neoplasms probably serve as a migratory route for the adult parasites and the embolization of eggs. Nevertheless, there is insufficient evidence to confirm the malignization of a benign lesion due to the presence ofSchistosoma mansoni. Few cases have been reported in the international literature on the association between ovarian schistosomiasis and neoplasms.

Bacterial, fungal, and parasitic infections of the liver

2011 ◽  
Author(s):  
R. Mark Beattie ◽  
Anil Dhawan ◽  
John W.L. Puntis
Keyword(s):  
Fungal Infections ◽  
Biliary Tree ◽  
Liver Parenchyma ◽  
Systemic Circulation ◽  
Portal System ◽  
Parasitic Infections ◽  
Direct Invasion ◽  
Rickettsial Infections ◽  
Hepatic Portal System ◽  
Hepatic Portal

Bacterial sepsis 428Spirochaetal infections 431Rickettsial infections 432Fungal infections 432Parasitic infections 434Granulomatous hepatitis 437Infectious agents can affect the liver either via direct invasion or by release of toxins. The liver's dual blood supply renders it uniquely susceptible to infection, receiving blood from the intestinal tract via the hepatic portal system, and from the systemic circulation via the hepatic artery. Because of this unique perfusion, the liver is frequently exposed to systemic or intestinal infections or the mediators of toxaemia. The biliary tree provides a further conduit for gut bacteria or parasites to access the liver parenchyma....

Memoirs: On the Occurrence of ‘Hepato-pancreatic’ Glands in the Indian Earthworms of the Genus Eutyphoeus Mich

1933 ◽  
Vol s2-76 (301) ◽  
pp. 107-127
Author(s):  
KARM NARAYAN BAUL ◽  
MAKUND BEHARI LAL
Keyword(s):  
Blood Supply ◽  
Dorsal Surface ◽  
The Body ◽  
Portal System ◽  
Dorsal Vessel ◽  
Gland Cells ◽  
Main Work ◽  
Hepatic Portal System ◽  
Glandular Cells ◽  
Hepatic Portal

Students of the Oligochaeta are well aware of the fact that there is a great difference of opinion amongst various observers even with regard to the function of the calciferous glands. Michaelsen (6, 1895) holds strongly that the function of the calciferous glands is the absorption of nutriment, and he always designates them as ‘chyle-sacs’. The excretion of lime, according to him, is a secondary function. The main objection urged against his view is the situation of the calciferous glands, since they lie far forward, and the main digestive region, i.e. the intestine, lies behind them. But this objection does not hold in the case of the intestinal glands, since they lie just at the right place, a little behind the middle of the body where the typhlosole ends, and the gut still extends behind for another 107 to 127 segments. They lie, therefore, just in the region where the main work of digestion and absorption takes place. That the glands open into the gut by as many as eighteen openings in five segments strongly indicates that their secretions are poured into the gut through these openings. The nature of the secretions seems to be tryptic, since ammo-acids were formed as products of digestion in the experiments made. Further, the greater part of the blood of the last portion of the intestine (107 to 127 segments) is collected and taken to these glands, where it permeates the substance of the gland through a sinusoid capillary network. The blood from the glands is collected again by the intestino-dorsals and taken to the dorsal vessel, the entire blood-supply of the glands resembling a hepatic portal system. These facts taken together with the demonstration of glycogen granules within the glandular cells strongly suggest that the intestinal glands are of the nature of a hepato-pancreas. The structure of the gland-cells themselves and the development of the glands further corroborate these conclusions. The observations and conclusions arrived at may now be summarized: 1. The intestinal glands of Butyphoeus waltoni lie on the dorsal surface of the gut and extend as paired glands from segments 79 to 83. As the two glands of a pair are fused in the middle dorsal line and the glands of successive segments are connected, we should speak of it as one large gland ex-tending over five segments. 2. The gland forms the posterior boundary of the typhlosole of the gut, there being no typhlosole behind the region of the gland. 3. The gland is more or less solid and consists of lobules of glandular epithelium and interlacing lamellae. The lobules are separated from one another by sinusoid capillaries, while the two epithelial folds of a lamella enclose a blood-sinus between them. 4. The gland-cells are rhomboidal to polyhedral in outline, and their shape and structure strongly resemble those of livercells. They do not bear cilia or rodlets. 5. The whole gland opens into the gut through as many as eighteen apertures over five segments. These apertures are lined with the ciliated gut-epithelium. 6. The blood-supply of the gland resembles a hepatic portal system. The blood is collected from the gut of the last 107 to 127 segments into a ventral i n t e s t i n a l sinus which empties all its blood into the sinusoid capillaries of the gland. The capillaries of the gland join together to form five pairs of i n t e s t i n o - d o r s a l vessels which carry all the blood of the glands into the dorsal vessel. 7. The glands develop as dorsal outgrowths of the endodermal lining of the embryonic gut. 8. The glands secrete no calcium whatever. Calcified milk was curdled by the gland-extract in fourteen minutes. A tryptic enzyme has been demonstrated by the formation of amino-acids in digestion experiments. 9. Thickly set glycogen granules have been demonstrated by staining the gland-cells with Best's carmine. 10. The glands are, therefore, of the nature of a hepatopancreas.

Pathologically induced alterations in the dimensions of the hepatic portal vasculature of mice infected with Schistosoma mansoni

Parasitology ◽  
1987 ◽  
Vol 94 (1) ◽  
pp. 69-80 ◽  
Author(s):  
S. M. McHugh ◽  
Patricia S. Coulson ◽  
R. A. Wilson
Keyword(s):  
Portal Hypertension ◽  
Schistosoma Mansoni ◽  
Rank Order ◽  
Progressive Increase ◽  
The Body ◽  
Portal System ◽  
Injection Technique ◽  
Pathological State ◽  
Hepatic Portal ◽  
Collateral Vessels

SUMMARYAlterations in the hepatic portal vasculature of NMRI mice infected with Schistosoma mansoni were assessed using a microsphere injection technique. The accumulation of eggs in the livers of infected mice and the development of portal hypertension were closely related to the worm pair burden during the first 15 weeks of infection. Individual variation between mice harbouring identical patent worm pair burdens was partially explained by the reduced fecundity of females from sexually biased infections. As eggs accumulated in the liver and portal hypertension increased, the number of injected microspheres escaping from the hepatic portal system rose in rank order of diameter from 9 μm through 15 μm and 25 μm to 50 μm. There was a strong correlation between the numbers of parasite eggs in the lungs and injected microspheres recovered from the lungs. The pattern of detection of microspheres in the lungs indicated a progressive increase in diameter of intra-hepatic porta-systemic connexions, followed by development of large-bore extra-hepatic collateral vessels. An accurate temporal profile of the pathological state of the host and the extent of collateral vessel formation was obtained. Injection of 141Ce-labelled microspheres demonstrated that the arterial supply to all organs of the body was affected by alterations in the micro-vasculature of the liver and lungs.

Portal shunting and resistance to Schistosoma mansoni in 129 strain mice

Parasitology ◽  
1989 ◽  
Vol 99 (3) ◽  
pp. 383-389 ◽  
Author(s):  
P. S. Coulson ◽  
R. A. Wilson
Keyword(s):  
Schistosoma Mansoni ◽  
Post Infection ◽  
Superior Mesenteric Vein ◽  
Negative Association ◽  
Portal System ◽  
Hepatic Veins ◽  
Mesenteric Vein ◽  
Hepatic Portal System ◽  
Hepatic Portal

SummaryThe integrity of the hepatic portal vasculature was examined, relative to the resistance to Schistosoma mansoni observed in 68°0 of 129/Ola mice. The passage of microspheres to the lungs, following their injection via the superior mesenteric vein, indicated the presence of shunts in the majority of both naive and infected mice. There was a negative association between shunting of microspheres to the lungs and paucity of liver worms at 28/35 days post-infection. Schistosomula accumulated in the livers of resistant mice at a slower rate than in susceptible animals, and after day 21 relocated to the lungs. Many lung schistosomula injected via the superior mesenteric passed immediately to the lungs; the shunts thus greatly reduce the probability of trapping in the liver. Some parasites migrated back from the lungs, successfully lodged in the liver and began to feed on blood. Latex infusion demonstrated the location of large intrahepatic connections between the portal and hepatic veins. We suggest that as these liver worms grow, migrating upstream into progressively larger vessels, they reach the connections, pass out of the hepatic portal system, and relocate to the lungs. The presence of the natural shunts thus accounts for the resistant status of the mice.

Schistosoma mansoni: a scanning electron microscope study of the developing schistosomulum

Parasitology ◽  
1980 ◽  
Vol 81 (3) ◽  
pp. 553-564 ◽  
Author(s):  
Jean E. Crabtree ◽  
R. A. Wilson
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Mouth Opening ◽  
The Body ◽  
Portal System ◽  
Anterior Surface ◽  
Scanning Electron Microscope Study ◽  
Hepatic Portal System ◽  
Hepatic Portal ◽  
Scanning Electron

SUMMARYThe surface morphology of schistosomula extracted from the skin, lungs and hepatic portal system (hps) of mice was investigated from Days 0 to 18 post-infection. Skin schistosomula and newly arrived schistosomula from the hps were of similar dimensions but were morphologically distinct. Lung schistosomula were considerably elongated with an estimated 53% increase in surface area compared to skin schistosomula. The pitted tegument of lung schistosomula was formed into ridges and troughs. These were compressed together in contracted individuals recovered from the hps on Day 10. The annular ridges were cross-linked by longitudinal septae which possibly prevent further elongation of the body. A regression of the spines between the mouth and the ventral sucker was observed in Day 2 skin schistosomula. In lung schistosomula only the spines at the anterior and posterior of the body remained. New spines were formed after the schistosomula reached the hps. It is suggested that the spines in the mid-region of the body are selectively disassembled and that their loss facilitates migration along the lumina of capillaries with the residual spines acting as anterior and posterior anchors. The mouth opening was enlarged in schistosomula from the hps recovered from Day 10 onwards. Skin schistosomula lost the cercarial apical tegumentary ridges between 24 and 48 h after penetration but a spineless protrusible area remained. After arrival in the hps this area became integrated into the anterior surface as the oral sucker developed around the sub-terminal mouth. The cercarial ciliated papillae were lost on penetration. The migrating schistosomulum had few visible sensory papillae but following arrival in the hps new papillae were observed.

Recovery of Schistosoma mansoni from the skin, lungs and hepatic portal system of naive mice and mice previously exposed to S. mansoni: evidence for two phases of parasite attrition in immune mice

Parasitology ◽  
1980 ◽  
Vol 80 (2) ◽  
pp. 289-300 ◽  
Author(s):  
S. R. Smithers ◽  
K. Gammage
Keyword(s):  
Schistosoma Mansoni ◽  
Early Phase ◽  
Late Phase ◽  
Significant Loss ◽  
Challenge Infection ◽  
Egg Laying ◽  
Portal System ◽  
Hepatic Portal System ◽  
Two Phases ◽  
Hepatic Portal

SummaryNew or improved techniques for recovering Schistosoma mansoni from the skin, lungs and liver have enabled us to trace the attrition of a challenge infection in naive (i.e. previously uninfected) and chronically infected mice. Within each experiment, the numbers of schistosomes recovered from the skin of naive mice on day 2 after challenge or from the skin and lungs on days 3, 4 or 5, did not differ significantly from the numbers recovered from the liver on days 14, 21, 28 or 35. Approximately 65% of cercariae which penetrated the skin failed to be recovered from naive mice by any of the assays and it appeared that these schistosomes had already died in the skin in the first 24 h. No further significant loss of the infection was detected in naive mice. In chronically infected mice a further attrition of the challenge infection was demonstrated in two distinct phases. An ‘early phase’ occurred within the first 3 days of exposure and accounted for the death of 30% of the remaining parasites. A ‘late phase’ occurred between days 6 and 14 and accounted for an additional 43% of deaths. Thus, the two phases of attrition accounted for a loss of approximately 73% of the infection that would have survived in naive mice. The late phase of attrition could be demonstrated before the primary infection had matured, in contrast to the early phase of attrition which was seen only after egg laying had commenced. We believe that the early phase of attrition takes place in the skin and the late phase occurs after the schistosomes have left the lungs, either en route for the liver or as soon as they arrive in that organ. The results suggest that there are two distinct mechanisms of immunity against re-infection with S. mansoni in mice.

Migration of the schistosomula of Schistosoma mansoni from the lungs to the hepatic portal system

Parasitology ◽  
1980 ◽  
Vol 80 (2) ◽  
pp. 267-288 ◽  
Author(s):  
Patricia Miller ◽  
R. A. Wilson
Keyword(s):  
Computer Simulation ◽  
Cardiac Output ◽  
Pleural Cavity ◽  
Systemic Circulation ◽  
Portal System ◽  
Abdominal Skin ◽  
Post Exposure ◽  
Hepatic Portal System ◽  
Hepatic Portal ◽  
Complete Circuit

SummaryThe pattern of recovery of schistosomula from the lungs of mice, hamsters and rats is described following normal percutaneous infection via the abdominal skin. Peak numbers were found in hamsters and rats on day 5 and in mice on day 6 post-exposure. Schistosomula were recovered from the lungs up to approximately day 20 post-exposure in all 3 species. None were found in pleural washings and only 2 were recovered following mincing and incubation of host diaphragms. The pattern of recovery of schistosomula from the lungs of mice was also described following the injection of a pulse of parasites into the tail vein. Approximately 54% of these injected schistosomula eventually reached maturity in the hepatic portal system. The ability of schistosomula to migrate and mature following their injection into unusual locations was tested. Small numbers reached maturity in the hepatic portal system following injection into the pleural cavity or subcutaneously, more when injected intra-peritoneally and largest numbers following intravenous injection. Small numbers of schistosomula were recovered by mincing and incubation of systemic organs such as the kidney and spleen. Schistosomula injected into the left ventricle of hamsters were able to migrate via the systemic organs to the lungs and 47% eventually matured in the hepatic portal system. The pattern of schistosomulum accumulation in the hepatic portal system of mice, hamsters and rats is described. Following normal percutaneous infection, schistosomula were first detected in this site from day 6 to day 9 depending on the host species. In mice, migration was complete around day 20 but continued in hamsters up to day 40 post-exposure. Following injection of schistosomula into the tail veins of mice, the first arrivals in the hepatic portal system were detected 12 h later and were found to lose their ability to migrate shortly after arrival. However, a proportion of lung schistosomula injected directly into the hepatic portal system were able to traverse hepatic sinusoids and reach the lungs. It was concluded that the route of migration of schistosomula from lungs to liver was entirely intravascular, with potentially several passages round the pulmonary-systemic circulation, before chance entry into arteries leading to the hepatic portal system. The proportion of schistosomula exiting from the pulmonary-systemic circuit was estimated as 0·14/day. A computer simulation produced values of 11 h and 5 h for the duration of migration through pulmonary and systemic capillary beds. The time for 1 complete circuit would thus be 16 h and the proportion of schistosomula exiting per circuit would be 0·095. This approximates to the proportion of cardiac output going to splanchnic organs in the resting rat (0·128). The narrowness of hepatic sinusoids may be one factor contributing to the sequestration of schistosomula in the hepatic portal system.

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