Organotypic endothelial adhesion molecules are key for Trypanosoma brucei tropism and virulence

Trypanosoma brucei is responsible for lethal diseases in humans and cattle in Sub-Saharan Africa. These extracellular parasites extravasate from the blood circulation into several tissues. The importance of the vasculature in tissue tropism is poorly understood. Using intravital imaging and bioluminescence, we observe that gonadal white adipose tissue and pancreas are the two main parasite reservoirs. We show that reservoir establishment happens before vascular permeability is compromised, suggesting that extravasation is an active mechanism. Blocking endothelial surface adhesion molecules (E-selectin, P-selectins, or ICAM2) significantly reduces extravascular parasite density in all organs and delays host lethality. Remarkably, blocking CD36 has a specific effect on adipose tissue tropism that is sufficient to delay lethality, suggesting that establishment of the adipose tissue reservoir is necessary for parasite virulence. This work demonstrates the importance of the vasculature in a T. brucei infection and identifies organ-specific adhesion molecules as key players for tissue tropism.

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Our study investigates the blood vasculature for T. brucei reservoir establishment

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We show the pancreas is a large extravascular reservoir

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We establish that T. brucei tropism is linked to organotypic adhesion molecules

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Interfering with adhesion molecules impacts parasite virulence and host survival

[Efficiency of etiologic correction of concomitant ascaridosis in the complex treatment of chronic pancreatitis]

The of antihelmintic preparation albendazole using in the complex treatment of patients with chronic pancreatitis with the concomitant ascaridosis was promote regression of clinical demonstration of basic and concomitant diseases (P < 0.05). Options of coprogram and the structural state of pancreas from data of ultrasonography in marks by Marseille-Cambridge classification of chronic pancreatitis, after the conducted treatment became the better (P < 0.05), that established expedience of the use of albendazole in complex treatment of patients with a chronic pancreatitis with a concomitant ascaridosis.

Clinical case of echinococcus of the pancreas

Hydatid disease is a major health problem worldwide. Its frequency is different worldwide depending to the climate and locoregional factors. Primary hydatid disease of the pancreas is very rare. We report the case of a 61-year-old man who presented with a cystic lesion in the body and tail region of the pancreas. A diagnosis of hydatid cyst in tail region of the pancreas, measuring 55/75 mm, was established by abdominal computed tomography before surgery. The treatment consisted of a distal pancreatectomy. The postoperative period was uneventful.

[Hydatid cysts of the pancreas, report of two cases]

BACKGROUND

Hydatid cyst of the pancreas is a rare affection with a frequency less than one percent of the various sites of hydatid disease.

AIM

We report two cases of hydatid cyst of the pancreas. CASE 1: A 49 year old woman with a history of laparotomy for liver and peritoneal hydatid cyst was admitted with recurrent liver and peritoneal hydatid disease associated with a head pancreatic cyst of 3 cm in size. Surgical treatment consisted in a resection of the protruding dome with uneventful postoperative course. CASE 2: A 45 year old man who underwent laparotomy four years ago for hepatic hydatid cyst was admitted with recurrent liver and peritoneal hydatid disease associated with a head pancreatic cyst of 4 cm in size. At laparotomy it was a head pancreatic hydatid cyst without duct pancreatic lesion. The treatment consisted in the resection of the protruding dome. The postoperative evolution was simple.

CONCLUSION

Hydatid cyst of the pancreas is rare. If associated with another hydatid localization, the diagnosis is generally easy. It can however be more difficult if the pancreatic localization is isolated. In most cases, resection of the protruding dome is sufficient.

[Helminthofauna of Steller's sea lion (Eumetopias jubatus) inhabiting the north-eastern coast of Asia]

Helminths collected from 55 Steller's sea lions in the western and central Bering Sea were examined. Helminth species, their localization in the host organism, invasion indices, categories, and host ranges are reported. Helminthofaunas of sea lions from various sea areas are compared. Forming of the recent Steller's sea lion helminthofauna and its links with other host are discussed. It was hypothesized that helminths do nor substantially affect the recent decline of the Steller's sea lion abundance.

Epigastric mass due to a hydatid cyst of the pancreas. A case report and review of the literature

CONTEXT

Primary hydatid disease of the pancreas is very rare.

CASE REPORT

We report the case of a 30-year-old man who presented with abdominal pain and an epigastric mass. A diagnosis of a pancreatic cyst was established by ultrasonography and CT scan before surgery. The treatment consisted of the resection of the protruding dome with a cystogastrostomy. The recovery was uneventful and the patient has remained symptom free so far.

CONCLUSIONS

Hydatid disease should be considered in the differential diagnosis of all cystic masses in the pancreas, especially in the geographical regions where the disease is endemic.

Epidemiology of eurytrematosis (Eurytrema spp. Trematoda: Dicrocoeliidae) in slaughtered beef cattle from the central-west region of the State of Paraná, Brazil

Bovine eurytrematosis (BE) in Brazil is caused by Eurytrema coelomaticum; the disease results in the condemnation of the pancreas of infected animals. The objective of this study was to describe the epidemiology of eurytrematosis in cattle submitted for slaughter during June 2003 to May 2004 at the municipal abattoir of Campo Mourão, Paraná, Brazil, and compare gross observation of infection with histological findings. During the period studied, 1828 pancreases were collected randomly. The average prevalence was 47.8% (874/1828); prevalence varied from 26.9% (46/171) to 72.9% (105/144). It was discovered that the quantity of parasites within the interlobular pancreatic ducts was directly proportional to pancreatic destruction; females were more predominately infected relative to males; BE is endemic within the region of Campo Mourão; the average age of infection increases proportionally with prevalence; gross evaluation of bovine eurytrematosis is not efficient to characterize infection by E. coelomaticum in susceptible animals.

Clinical considerations of primary hydatid disease of the pancreas

BACKGROUND

The pancreas is a rare primary location of hydatid disease. The purpose of our study is to gain more insight into this entity and to focus on the management and the diagnostic approach to the disease.

METHODS

The medical records of 5 patients with hydatid cysts of the pancreas were reviewed.

RESULTS

Four of the cysts were primary, while in 1 case a coexisting cyst was found in the liver. The body and tail of the pancreas were the most common locations. Clinical presentation varied according to the anatomic location of the cyst. Abdominal pain, discomfort and vomiting were the main clinical symptoms. One patient presented with obstructive jaundice, while another patient manifested a mild episode of anaphylactic shock. The indirect hemagglutination test was positive in 3 of 4 cases. A computed tomography scan successfully imaged all cysts and calcification of the cystic wall was found in 3 of 4 cases. All patients underwent surgical therapy. Hydatid cysts in the tail of the pancreas were successfully treated with distal pancreatectomy, while cysts in the body and head of pancreas were treated with proper evacuation, pericystectomy and omentoplasty. The postoperative course was uneventful in all patients except 1 who presented a pancreatic fistula and was re-operated. The mean length of hospitalization after surgery was 11-12 (range 10-13) days, except for the patient who needed to be re-operated. No evidence of cyst recurrence was observed during the follow-up period.

CONCLUSIONS

Hydatid cystic masses of the upper abdomen might also originate from the pancreas especially in endemic countries. Surgical excision of the entire cystic lesion remains the optimal treatment, offering hope for a complete cure.

Macroparasites in stranded and bycaught harbour porpoises from German and Norwegian waters

Parasitological investigations were carried out on harbour porpoises Phocoena phocoena originating from 3 different areas: the German North Sea (28), the German Baltic (18) and Norwegian waters (22). The individuals were bycaught in gill-nets or found stranded during the period 1997 to 2000. A total of 7 species of parasites was identified from the investigated organs. These originated mainly from the respiratory tract and comprised 1 ascaridoid nematode (Anisakis simplex), 4 pseudaliid nematodes (Pseudalius inflexus, Torynurus convolutus, Halocercus invaginatus, Stenurus minor) and 2 trematodes (Campula oblonga, Pholeter gastrophilus). This is the first geographic record of H. invaginatus from German waters. Differences were found in the severity of the parasitic infection between stranded and bycaught animals as well as between porpoises from different areas. A correlation was shown between parasitic infection and observed lesions.

A case report of the unusual presence of hydatid disease in the pancreas and breast

CONTEXT

Hydatid cyst disease can occur in all viscera and soft tissues although the liver and the lungs are the most commonly involved organs. Pancreatic and breast involvement with the disease are extremely rare and the presence of this disease in these organs without any other organ involvement has not been previously reported.

CASE REPORT

We present herein a patient with isolated pancreatic cyst hydatid treated successfully with complete cyst excision. However, 18 months after the pancreatic surgery, hydatid disease was found in the breast and again the cyst was completely removed. No other organ involvement has been detected during a 2-year follow-up.

CONCLUSIONS

Hydatid disease should be considered in the differential diagnosis of all cystic masses in all anatomic locations, especially in regions where the disease is endemic. The ideal treatment is the complete excision of the cyst without any spillage.

Liver, spleen, pancreas and kidney involvement by human fascioliasis: imaging findings

Background

Fasciola hepatica primarily involves the liver, however in some exceptional situations other organs have been reported to be involved. The ectopic involvement is either a result of Parasite migration or perhaps eosinophilic reaction.

Case presentation

Here we report a known case of multiple myeloma who was under treatment with prednisolone and melphalan. He was infected by Fasciola hepatica, which involved many organs and the lesions were mistaken with metastatic ones.

Discussion

Presented here is a very unusual case of the disease, likely the first case involving the pancreas, spleen, and kidney, as well as the liver.

Human pentastomiasis discovered postmortem

The autopsy of an 18-year-old girl who had died suddenly at home revealed generalised pentastomiasis. The location of this disease in the intestines was responsible for death by hemorrhagic enterocolitis. This discovery constituted an atypical case in our daily practice of forensic medicine.

Pancreatic lesions in acute experimental Chagas' disease

BACKGROUND

Chagas' disease is an endemic tropical affliction found from southern United States to Argentina. The acute phase of this disease is difficult to study in man because the symptoms are non-specific and most cases require no medical assistance. Experimental models have been developed for sequential studies, and intense parasitism in all organs and tissues, including the pancreas, have been detected in the acute phase.

PURPOSE

To evaluate the involvement of the pancreas in acute experimental Chagas' disease in a mouse model by histopathological characterization.

CASUISTIC AND METHODS

Ten BALBc mice, about 20 g, injected i.p. with 100 000 forms of the Y strain of Trypanosoma cruzi were used. The animals were sacrificed after 14 days of infection. Fragments of pancreas were processed by conventional paraffin embedding and hematoxylin-eosin staining.

RESULTS

Ruptured pseudocysts and release of parasites to the extracellular medium caused by necrosis of acinar and duct cells and foci of fat were the most striking histopathological features of acute Chagasic pancreatitis.

CONCLUSION

Parasitism is the main cause of acute pancreatitis in Chagas' disease.

Isolation of Neospora caninum from the brain of a pregnant sheep

Neospora caninum was isolated from the brain of a naturally infected pregnant sheep by inoculation of immunodeficient mice with a homogenate of the brain tissue. The ewe showed no clinical signs. Tachyzoites were observed in the tissues of the nu/nu mice injected with the brain tissue homogenate and the diagnosis was confirmed by immunohistochemical staining with anti-N. caninum antibodies and by detecting N. caninum-specific DNA by polymerase chain reaction.

Hepatobiliary and pancreatic complications of ascariasis in children: a study of seven cases

OBJECTIVES

This study presents seven cases of severe hepatobiliary and pancreatic complications of ascariasis in children. The authors describe the clinical, laboratory, and imaging findings, as well as the patients' clinical evolution.

METHODS

These cases were studied within a period of approximately 1 year and included children younger than 11 years (mean age, 4.4 years). The authors reviewed their medical history and evaluated the results of their main diagnostic examinations.

RESULTS

All of the patients had vomiting, abdominal pain, pallor, and abdominal distension at presentation. Passage of Ascaris lumbricoides in stool occurred in five cases, emesis with worms in three, fever in three, and hepatomegaly in two. Five patients had pancreatitis, of which two were necrohemorrhagic and one had pseudocyst of the pancreas. In three patients, A. lumbricoides was present in the pancreatic duct. Two patients had hepatic abscess (28.6%), and one of them also had cholangitis. One of the patients with pancreatitis also had signs of cholecystitis at presentation.

CONCLUSIONS

Ultrasonography was the imaging diagnostic method of choice and demonstrated the presence of A. lumbricoides in the biliary and the pancreatic ducts, as well as signs of pancreatitis, cholecystitis, and hepatic abscess. Endoscopic retrograde cholangiopancreatography, used to confirm the diagnosis, was a fundamental procedure in the treatment, allowing the removal of worms from the biliary duct in four of seven patients.

Mouse model for Chagas disease: immunohistochemical distribution of different stages of Trypanosoma cruzi in tissues throughout infection

Different stages of Trypanosoma cruzi are seen during mammalian infection. Histologic sections of infected hearts have shown amastigotes and, when using immunohistochemistry (IHC), parasite antigens; however, demonstration of trypomastigotes in these tissues has proven elusive. Using a mouse strain that develops chagasic cardiomyopathy (histologically similar to human infection) 70 days after injecting T. cruzi-Brazil strain, we studied the distribution of parasite stages and the extent of inflammation. All organs had varying amounts of mononuclear inflammation by day 10, which peaked between day 20 and day 30, and decreased by day 50. Amastigotes were detected in myocytes, histiocytes, acinar pancreatic cells, astrocytes and ependymal cells by day 10, and the number of amastigotes peaked on day 30. Immunohistochemistry demonstrated trypomastigotes in sinusoids, vessels and interstitial tissues of several organs between day 15 and 50. Abundant parasite antigens (granular staining) were detected in connective tissues throughout the infection. The burden of amastigotes and trypomastigotes during the acute phase seems to correlate with the degree of inflammation and granular staining in the chronic stage.

Rodlet cells and other inflammatory cells of Phoxinus phoxinus infected with Raphidascaris acus (Nematoda)

Rodlet cells (RCs), and other inflammatory cells, namely eosinophile granule cells (EGCs), eosinophilic granulocytes and epithelioid cells in the liver, pancreas and peritoneal serosa of uninfected and naturally parasitized minnow Phoxinus phoxinus (Linnaeus, 1758), were studied by light and electron microscopy. Forty-eight minnows were examined and in 18 fishes encysted larvae of the nematode Raphidascaris acus (Bloch, 1779) were encountered, mainly in the pancreas. The number of larvae in the latter organ ranged from 2 to 46. Nematode larvae were encapsulated by epithelioid granulomata, and these cells displayed typical epithelial characteristics such as desmosomes and tonofilaments. EGCs and RCs characteristically surrounded the reactive foci and were suggestive of an integrated inflammatory network involving both cell types. In many instances RCs were noticed at the periphery of the pancreas, beneath the peritoneal serosa, partially or entirely surrounded by mesothelial cells. In the latter situation partially damaged RCs were present in the splancnic cavity entirely surrounded but not truly phagocytized (no phagolysosome occurred) by mesothelial cells, which shared the same ultrastructural features of epithelioid cells. This phenomenon has never been described and may represent a peculiar turnover of RCs in the pancreas likely related to the high sensitivity to damage. A significant difference (p < 0.01) in the number of RCs between uninfected and parasitized fish was noticed in the liver and pancreas. The data suggest that RCs represent an inflammatory cell type closely linked to other piscine inflammatory cells, such as EGCs, epithelioid cells and mesothelial cells.

Neospora caninum infected the alimentary tract of nude mice and was transmitted to other mice by intraperitoneal inoculation with the intestinal contents

Neospora caninum (BT-2 strain) that originated from the brain of a Holstein calf was serially passaged through 10 generations of BALB/c nude mice by intraperitoneal inoculation. Histological examination of the mice revealed that numerous clusters of tachyzoites appeared in the pancreas, stomach and small intestine as well as in the central nervous system (CNS) and skeletal muscles. Intestinal contents of the infected mice were inoculated intraperitoneally into uninfected nude mice and 3 of the 17 inoculated mice showed clinical signs at post inoculation days 3 to 10. The present experiments demonstrated a proliferation of N. caninum tachyzoites in the mucosa of the alimentary tract and pancreas of the nude mice and the intestinal contents of the mice were infective to other nude mice.

[The carbohydrate metabolic end products of trematodes parasitic in cattle]

The trematodes Eurytrema pancreaticum and Calicophoron ijimai during the incubation in vitro assimilated glucose from the incubation medium and utilized the endogenous glycogen. Final products of the carbohydrate metabolism in the calicophorones were lactic, acatic, propionic, isobutyric and alpha-methylbutyric acids; in the eurytremes they were lactic, acetic, propionic, isobutyric, alpha-methylbutyric, valerianic and capronic acids. The effect of anthelminthic preparations on the carbohydrate metabolism and its final products was investigated.

Pathological and immunological findings of athymic nude and congenic wild type BALB/c mice experimentally infected with Neospora caninum

Neospora is a cyst-forming coccidian parasite that causes abortions and neuromuscular disorders in a wide variety of mammals. Japanese bovine isolate JPA1 was inoculated intraperitoneally into BALB/c nu/ nu (athymic nude) and BALB/c (congenic wild type) female mice to examine the distribution of parasites and resistance mechanisms to Neospora infection. All the athymic nude mice died within 28 days after intraperitoneal injection of 2 x 10(5) JPA1 tachyzoites, whereas all the congenic wild type mice survived without exhibiting any clinical signs. Tachyzoites were identified in the uterus and pancreas and later spread to many other organs. Most tachyzoites identified in the necrotic foci were localized in the epithelium of the venules and capillaries. Nude mice developed high level of serum interferon-gamma and interleukin-6 as infection proceeded. Inflammatory response to Neospora infection might be mediated by Th1-type dependent cellular immunity.

An extensive ultrasound and serologic study to investigate the prevalence of human cystic echinococcosis in northern Libya

A prevalence study of abdominal cystic echinococcosis (CE) was undertaken in the northwest, north-central, and northeast regions of Libya. A total of 36 villages along the coast were included, in which 20,220 people were screened by portable ultrasound. Three hundred thirty-nine (1.7%) were diagnosed with CE. There was no significant difference between CE prevalence rates in the three regions of Libya (mean = 1.6%); however, intervillage rates were variable, ranging from 0% to 4.5%. The prevalence of CE increased significantly with age (P < 0.0001) and females were significantly more affected (2%) than males (1.3%) (P < 0.0001). Cases of CE were distributed among 3.2% of housewives, 2.6% of farmers, 2.3% of male civil servants, 1.3% of female students, and 1.1% of male students. Housewives (P < 0.0001) and students (P < 0.0001) were significantly more at risk for CE. A statistically significant proportion (62% [210 of 339]) of CE cases kept dogs (P < 0.0001). Of the ultrasound-positive CE cases 69% (233 of 339) were antibody seropositive by ELISA using Echinococcus granulosus hydatid cyst fluid antigen B. Blood samples (n = 10,096) collected onto filter papers were taken randomly from ultrasound-negative people who entered the study, of which 11.2% were found to be seropositive. Seropositivity increased with age (P < 0.0001), with females exhibiting higher seroprevalence than males for all age groups (P < 0.0001). Seroprevalence was distributed occupationally among 17.3% of female students, 11.2% of male students, 8.3% of housewives, 7.3% of farmers, and 6.4% of male civil servants. Housewives and students were more likely to be seropositive (P < 0.0001). Forty-seven percent (526) of the seroreactors kept dogs. All liver hydatid cysts detected by ultrasound during community screening were classified according to morphology and size into six types. Type I (17.5% of all cases) were small univesicular cysts less than 50 mm in diameter with no laminations or daughter cysts. Type II (34%) were univesicular cysts with only laminations. Type IIIa (8.5%) were univesicular cysts with the appearance of laminations and daughter cysts. Type IIIb (13%) were univesicular with laminations and less prominent daughter cysts. Type IV (5.6%) presented as a solid mass. Type V were degenerated calcified or partially calcified cysts (13.2%). Type VI presented as multiple cysts (8% of all cases). The CE cases that exhibited Types II, IIIa, IIIb, IV or VI cysts showed the highest seropositivity (86%, 96%, 95%, 100%, and 96%, respectively), while Types I and V were the least seroreactive (38% and 22%, respectively). Cases of CE occurred in 311 families, with 93% having only one member as a CE case while 7% of the families had two or more cases. However, 25% of the ultrasound-negative persons belonging to families with an index CE case were seropositive for antibodies to Echinococcus. These results confirm the importance of human CE in Libya. They also confirm the usefulness of ultrasound combined with serology as a mass screening approach for CE in north African communities.

MR cholangiography: techniques and clinical applications

Magnetic resonance cholangiography (MRCP) is a new non-invasive imaging technique for the evaluation of bilio-pancreatic disorders. Different sequences, using both breathhold and non-breathhold techniques, have been employed in order to obtain MRCP images. The authors discuss the technical aspects, particularly focusing their attention on a non-breathhold, three-dimensional, fat-suppressed turbo-spin-echo sequence, optimized on a 0.5-T magnet with 15 mT/m gradients. Clinical applications of MRCP are evaluated, presenting data from both the literature and personal experience. The main indication for MRCP study is represented by the evaluation of common bile duct obstruction, with the aim of assessing the presence of the obstruction (accuracy 85-100 %) and, subsequently, its level (accuracy 91-100 %) and its cause. The utility of associating conventional MR images to MRCP in malignant strictures in order to characterize and stage the malignant lesions is also discussed. Finally, data are presented regarding the indications and utility of MR pancreatography in the evaluation of patients with chronic pancreatitis.

Neospora caninum: role for immune cytokines in host immunity

Neospora caninum is a coccidial protozoan parasite that infects a large range of mammals including dogs, cats, mice, and cattle. Morphologically, N. caninum appears indistinguishable from Toxoplasma gondii, although they are genetically distinct. To date there have been no reported cases of this infection in humans, although nonhuman primates may be susceptible to infection. Inbred A/J mice develop no clinical and little histologic evidence of infection in spite of a high-dose inoculum of N. caninum. Splenocytes obtained from infected mice proliferate in vitro in response to both N. caninum and T. gondii-soluble antigen. A transient state of T cell hyporesponsiveness to parasite antigen and mitogen was observed at Day 7 p.i. This downregulatory response could be partially reversed by the addition of the nitric oxide antagonist LNMMA, but not antibody to IL-10. Mice infected with N. caninum produce significant quantities of IL-12 and IFN gamma, most evident shortly after infection. In vivo, antibody to IL-12 is able to neutralize immune resistance to the parasite. Moreover, in vivo depletion of IFN gamma with antibody renders the mice susceptible to infection. These observations suggest that N. caninum induces a T cell immune response in the infected host that is at least partially mediated by IL-12 and IFN gamma.

Trypanosoma cruzi: paninfectivity of CL strain during murine acute infection

A systematic study of the distribution of intracellular parasites in the organs and tissues of mice acutely infected (15 days) with the CL strain of Trypanosoma cruzi was performed. Almost all tissues and organs were parasitized with different intensities, including several epithelial cell types. In addition to striated, cardiac, and smooth muscles a very high parasitism of fat cells, pancreas, and genital adnexa was observed. A smaller number of parasites was found in all other structures studied except in highly vascularized structures such as in the penile corpora cavernosa, pulmonary and renal parenchyma, islets of Langerhans, hepatic sinusoids, and in atrial endothelium. This paper also shows, for the first time in the literature, the parasitism of milky spots, cornea epithelium, cornea stroma, retroorbital fibroblasts, seminal vesicles, and coagulative, Cowper's, urethral, preputial, sebaceous anal, and clitoris glands. The results indicated that CL strain is highly invasive, being able to infect cells derived from the three embryonic layers (ectoderm, mesoderm, and endoderm), suggesting that the paninfectivity may influence the outcome of immunological and pathological events.

Disseminated microsporidiosis especially infecting the brain, heart, and kidneys. Report of a newly recognized pansporoblastic species in two symptomatic AIDS patients

Microsporidia have emerged as important opportunistic AIDS pathogens of the alimentary, respiratory, and urinary tracts. Although nonhuman mammalian microsporidia infections typically include encephalitis, CNS microsporidiosis has not been reported in patients with AIDS. A 33-year-old white male and an 8-year-old black girl presented with seizures and declining mental status. Central nervous system (CNS) imaging studies revealed small peripherally and diffusely enhancing lesions present for at least 2 and 4 months before death, respectively. Both patients expired despite empirical anti-toxoplasma therapy. Their brains contained innumerable soft gray matter lesions that consisted of central areas of necrosis, filled with free spores and spore-laden macrophages, surrounded by microsporidia-infected astrocytes. The complete autopsy of the child also revealed necrotizing and sclerosing cardiac and renal microsporidiosis and infection of the pancreas, thyroid, parathyroids, liver, spleen, lymph nodes, and bone marrow. Infected cells included astrocytes, cardiac myocytes, epithelium, endothelium, vascular smooth muscle cells, hepatocytes, adipocytes, Schwann cells, and macrophages. Light and electron microscopic studies revealed pansporoblastic development within thick-walled sporophorous vacuoles of parasite origin. Although most similar to Pleistophora sp and Thelohania sp, this microsporidian is different from any known species. Microsporidiosis should be considered as the possible cause of a wide range of diseases in AIDS patients, including CNS, cardiac, and renal.

Light and electron microscopic studies of Isospora chalchidis (Amoudi, 1989) infecting Chalcides ocellatus in Egypt

Oocysts of Isospora chalchidis (Amoudi, 1989) were described from the faeces of the skink Chalcides ocellatus in Egypt. Non-sporulated oocysts were spheroidal, measuring 20 (18.5-21) microns in diameter and contained granulated zygotes. Sporulated oocysts had the same dimensions of the nonsporulated ones and each contained two sporocysts. Sporocysts were ovoid with stieda and sporocyst residual bodies. Sporulation time was 50 hours at room temperature. Merogony and gamogony occurred in the intestinal mucosa. Electron microscopic investigations showed that meronts, merozoites, gamonts and gametes developed in a narrow parasitophorous vacuole within the host-cell nucleus. Nuclei of meronts were surrounded by rough endoplasmic reticulum. Merozoites showed the main characteristics of motile stages of Apicomplexa. Macrogametes contained a large nucleus, two types of wall-forming bodies and a large amount of lipid inclusions. Nuclei of microgamonts were peripherally arranged and lacked nucleoli. Microgametes were flagellated.

Frequency of schistosomiasis mansoni, of its clinicopathological forms and of the ectopic locations of the parasite in autopsies in Belo Horizonte, Brazil

The frequency of schistosomiasis mansoni, of its clinicopathological forms, and of the distribution of Schistosoma mansoni eggs in ectopic locations in each clinicopathological form were studied in 1863 complete consecutive autopsies performed in Belo Horizonte, Brazil, in the period from 1971 to 1990. Three hundred and thirteen cases of S. mansoni infection (16.8%) were found. The intestinal form was the most frequent (67.4%), followed by the hepatosplenic form without pulmonary hypertension (24.9%). The intestinal form showed a smaller number of ectopic sites and a lower percentage of involvement of these sites compared to the more severe forms, particularly the hepatosplenic form with pulmonary hypertension. The distribution of the frequency of schistosomiasis mansoni cases, of the clinicopathological forms of the disease, and of the ectopic sites of S. mansoni eggs over the decades considered showed a marked reduction in all of these parameters, particularly in the more severe forms. These findings can be explained only by earlier diagnosis of the disease and the greater efficacy of the specific chemotherapy used today, preventing progression to the more severe forms of the parasitosis.

Histopathology of cultured sea bass (Lates calcarifer) (Centropomidae) infected with Cruoricola lates (Trematoda: Sanguinicolidae) from Pulau Ketam, Malaysia

Cruoricola lates are found throughout sea bass (Lates calcarifer), most commonly in the mesenteric blood vessels, kidney, pericardial vessels, and eye. Eggs of C. lates were predominantly found in the gills, ventricle, hepatopancreas, and kidneys, but only develop to miracidia regularly in the gills and heart. Single miracidia escaping appear to cause little damage, but groups induce an inflammatory response and haemorrhage. Endocardial macrophages encapsulate eggs trapped between trabeculae in the heart. The reaction to eggs in the kidneys, hepatopancreas and spleen consists of fibrocytic encapsulation. Infection at the levels observed in this study were insufficient to cause lethal pathological changes, but could result in reduced food conversion ratios or impaired immunological capacity.

Fulminant disseminated toxoplasmosis in an HIV patient

Disseminated toxoplasmosis in AIDS is a rare condition. We present an unusual case of a fulminant form of disseminated toxoplasmosis in a young male homosexual. He was a 30-year-old HIV-positive (diagnosed 4 months earlier), admitted with a 5-day history of diarrhea, vomiting, fever, and cough. He had been generally healthy except for an 8-week history of weight loss and malaise. On admission, except for a temperature of 37.6 degrees C, the physical examination was normal. He was treated symptomatically. Four days after admission he suddenly became short of breath. Despite intensive management, he continued to deteriorate and expired 6 h later. Postmortem examination revealed disseminated toxoplasmosis involving the heart, lungs, brain, stomach, small intestine, and colon. This is an unusual presentation of disseminated toxoplasmosis because of its rapid course with no prior indication of infection. To our knowledge, such an atypical and rapid downhill course of toxoplasmosis (with minimal clinical and laboratory features) has not been reported previously. Increased awareness of this infection in all HIV patients and its possibly rapid course is needed.

Cryptosporidiosis of liver and pancreas in rhesus monkeys with experimental SIV infection

Following an experimental SIV infection, 11 rhesus monkeys were evaluated to determine the presence of opportunistic infections. Five animals had severe alterations of the hepatobiliary tree, three of which were associated with the presence of numerous Cryptosporidium spp. Subacute to chronic inflammatory changes were observed in the pancreatic ducts of four animals, one without histologic evidence of parasites. In one animal, the inflamed ducts were associated with a chronic interstitial pancreatitis. The rate of Cryptosporidium infection together with hepatic and pancreatic involvement (36%) supports the hypothesis that systemic cryptosporidiosis is the result of a loss of protective mucosal immunity.

[The adenosinetriphosphatases of trematodes parasitizing cattle and the effect on them of anthelmintic preparations]

Activities and properties of adenosine triphosphatases in mitochondrial and microsomal fractions of trematodes Eurytrema pancreaticum and Calicophoron ijimai were studied. The highest ATPase activity was observed in mitochondrial fractions. The effect of anthelmintic preparations on activity of enzyme was investigated. Trichlorophene, bitionol, oxinide, G-937 and G-1028 turned out to be the most effective preparations.

Extracerebral toxoplasmosis in the acquired immunodeficiency syndrome (AIDS)

Although Toxoplasma gondii frequently causes lesions of the central nervous system in AIDS, the exact incidence of extracerebral toxoplasmosis in these immunodepressed patients remains difficult to determine. Isolation of the parasite outside the central nervous system is rarely performed ante mortem, and most diagnoses of extracerebral toxoplasmosis are made post mortem. This article describes 23 cases of extracerebral toxoplasmosis diagnosed between 1987 and 1991 in an autopsy series of 170 patients infected with the human immunodeficiency virus (HIV). Ante mortem diagnosis of extracerebral involvement was affirmed in 4 of these 23 patients by identification of trophozoites in bronchoalveolar lavage fluid (2 cases), a surgical pulmonary biopsy specimen, and a bladder biopsy. Clinical and paraclinical findings suggested cardiac involvement in 4 other patients. Post mortem examination demonstrated disseminated toxoplasmosis in 18 cases and extracerebral monovisceral involvement in 5 cases. Extracerebral toxoplasmosis was directly responsible for the death of 6 patients. The most frequent extracerebral sites of Toxoplasma gondii involvement were the heart (21/23 cases; 91%), the lungs (14/23 cases; 61%) and the pancreas (6/23 cases; 26%). The tissular consequences of toxoplasmic involvement varied considerably, from formation of pseudocysts or cysts without any surrounding inflammatory reaction to necrotic lesions rich in neutrophilic polynuclear cells containing numerous free parasites. Immunoperoxidase study using antitoxoplasmic antibodies contributed to the diagnosis of 8 extracerebral localizations. Electron microscopy examination of a surgical lung biopsy and myocardial specimens (2 cases) demonstrated the ultrastructural characteristics of Toxoplasma gondii trophozoites.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of the number of Eurytrema sp. eggs per gram of feces in naturally infected cattle

Eurytrema sp. egg counts (epg) in the feces of naturally infected cattle were performed and the technique employed showed 94.2% probability of detecting positive cases of the infection with a single examination independently of the host parasite burden. It was also demonstrated that the epg of Eurytrema sp. follows a negative binomial distribution model and is characterized by its small magnitude.

Necrotizing pancreatitis and multisystem organ failure associated with toxoplasmosis in a patient with AIDS

Extraneural manifestations of toxoplasmosis often are not recognized antemortem in patients with AIDS. We describe a patient who was seropositive for human immunodeficiency virus and presented with lethargy, abdominal tenderness, rapidly progressive ventilatory failure, rhabdomyolysis, myoglobinuria, and disseminated intravascular coagulation. Although the diagnosis of pancreatitis was not considered while the patient was alive, an autopsy demonstrated pancreatic necrosis associated with toxoplasmal cysts. No other infection was evident. This case suggests that Toxoplasma gondii can cause severe pancreatitis in patients with AIDS.

The recruitment of mast cells, exclusively of the mucosal phenotype, into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali: recruitment is irrespective of site

Adults of the porocephalid pentastomid Porocephalus crotali infect the lung of rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early stage in infections, granulomas become increasingly infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype. Mucosal mast cells are concentrated along the dorsal region of the parasite and in a plug of tissue containing degenerating cuticles within independent granulomas, which is located between its head and tail. ELISAs against the rat mast cell proteases I and II (RMCP I and II), extracted from abdominal fat, lung, spleen, liver and kidney granulomas at various intervals post-infection, reveal a substantially elevated concentration of RMCP II in all lesions. In fat, concentrations increase up to about 100 days post-infection, at which time moulting ceases and inflammatory responses subside. RMCP II was scarcely detectable in matched control tissues. Unlike infections with certain nematode parasites, where enteric mucosal mast cells secrete RMCP II systemically, concentrations of RMCP II in the serum of infected rats were significantly reduced when compared with age-matched uninfected controls. These results confirm that P. crotali can selectively recruit mucosal mast cells to a variety of tissue sites, most of which are non-mucosal. Possible mechanisms are discussed.

Pathologic effects of Sphaerospora dicentrarchi Sitjà-Bobadilla and Alvarez-Pellitero, 1992 and S. testicularis Sitjà-Bobadilla and Alvarez-Pellitero, 1990 (Myxosporea: Bivalvulida) parasitic in the Mediterranean sea bass Dicentrarchus labrax L. (Teleostei: Serranidae) and the cell-mediated immune reaction: a light and electron microscopy study

In the present study, the pathogenic effects of Sphaerospora dicentrarchi and S. testicularis, histozoic and coelozoic myxosporean parasites of the Mediterranean sea bass Dicentrarchus labrax L., respectively, are described. The infection caused by the latter, which usually invades the testes and neighboring tissues, is considered to represent parasitic castration. S. dicentrarchi seems to be harmless except in massive infections, which probably result in organic disfunctions. The cellular host reaction generated by S. testicularis depends on the location of the parasite and is more intense than that produced by S. dicentrarchi. In both sphaerosporoses, macrophages, granulocytes, lymphocytes, plasmacytes, and fibroblast-like cells are involved. The role of the different immune cells is discussed.

Population structure of Lankatrematoides gardneri (Digenea: Opisthotrematidae) in the pancreas of the dugong (Dugong dugon) (Mammalia: Sirenia)

The distribution among size and reproductive classes of the digenean Lankatrematoides gardneri was recorded from the pancreatic ducts of 41 dugongs from the Gulf of Papua, Papua New Guinea. Infrapopulation sizes ranged from 5 to 921 worms and showed no correlation with host age, sex, or month of capture. Immature worms tended to be concentrated in intermediate size classes, the largest immatures being no more numerous than matures. The mean proportion of mature worms in the 29 infrapopulations containing them was small (9.8%). Mature worms were significantly greater in mass than the largest immatures. There is evidence of an interaction between the presence or absence of mature worms and the distribution of immatures among classes.

[Histopathology of Kingiella chilenica (bivalvia, cyamiidae) parasitized by rediae and cercariae of the Gymnophallidae family]

Gonadal and digestive gland tissues of Kingiella chilenica specimens, which were infected with trematode larvae, were examined to determine the organs that are normally invaded by these parasites. Rediae containing cercariae of this digenetic trematod, appeared exclusively restricted to the tissues of the digestive gland. Consequently, no damage or alterations were observed in the gonad or other related tissues of the infected specimens. This, linked to the fact that parasitized females may also appear with brooded embryos, supports the conclusion that the reproductive activities of the bivalve mollusc are not affected by the presence of these infecting larvae.

Studies on the developmental cycle of Trichospirura leptostoma (Nematoda: Thelaziidae). Experimental infection of the intermediate hosts Blatella germanica and Supella longipalpa and the definitive host Callithrix jacchus and development in the intermediate hosts

The cockroaches Blatella germanica and Supella longipalpa can act as intermediate hosts of Trichospirura leptostoma as demonstrated by experimental infestation. The parasite developed from the embryonated egg into the infective larval stage (L3) in cockroaches within 5-6 weeks. After experimental infection of marmosets (Callithrix jacchus), eggs were first found in faecal samples (prepatency) at 8-9 weeks post-infection. Patency lasts about 2 years. Despite the presence of living adult worms in the marmosets' pancreas, no additional eggs were observed in their faeces after the patent period.

Effect of praziquantel on pancreatic histopathological changes in experimental schistosomiasis mansoni

The pancreatic tissue showed deposition of S. mansoni eggs on the 8th week of infection, multiple granulomata, interstitial oedema, inflammatory infiltrate, acinar atrophy and decrease in the size of islets of Langerhans. It was found that the most effective dose of praziquantel in such changes was 300 mg/kg/mouse, irrespective of being administered once or in three divided doses every four hours in the same day.