The life cycle of myxosporidians in fish of the Kola Peninsula

Monthly studies on the seasonal parasite fauna dynamics of pike, minnow and perch were carried out from May, 1974 to September, 1977. It was found out that the myxosporidian Henneguya creplini has a one-year life cycle. The infection of perch with this parasite takes place at a water temperature not exceeding 13 degrees. In other species (Chloromyxum esocinum, Ch. mitenevi, Myxobolus cybinae) the life cycle is shorter, in consequence of which fishes can be infected with these parasites several times a year and in different seasons. The nature of seasonal changes in abundance of myxosporidians depends to a great extent on weather conditions of each concrete year.     

Light and ultrastructural data on Henneguya testicularis n. sp. (Myxozoa,Myxobolidae), a parasite from the testis of the Amazonian fish Moenkhausia oligolepis

Light and electron microscopical data on a myxosporidian found in the testis of Moenkhausia oligolepis Gunther (Teleostei, Characidae, Tetragonopterinae) from the lower Amazon River near Belém, Brazil, are described. Based on spore morphology, we conclude that this species belongs to the family Myxobolidae and genus Henneguya. Mature spores (total length 27.5 (27.0–28.5) µm) were observed at the periphery of the testis. The ellipsoidal spore body consists of two unequal shell valves adhering together along the suture lines. The spore body is ellipsoidal, 14.0 µm long and 6.5 µm wide. Each valve tapers to a single caudal projection, forming a 13.5 µm long tail (13.0–14.5 µm). The spore is surrounded by a homogenous dense sheath. The polar capsules, measuring 9.0 × 2.0 µm, contain 12–13 coils of the polar filaments. Morphological differences between this material and other species of the genus Henneguya indicated the erection of a new species, which was named H. testicularis. The taxonomic affinities of this parasite are discussed.     

Myxosporidian Parasites from the Fish of the River Lugg

SYNOPSIS. Six different species of Myxosporidia were recorded from fish of the River Lugg. Myxobolus muelleri, M. artus, M. macrocapsularis, Henneguya zschokkei, H. psorospermica and H. oviperda .
Leuciscus cephalus, L. leuciscus and Rutilus rutilus infected with M. muelleri were common; of these 3 hosts, L. cephalus had the highest intensity of infection and the greatest number of infected organs and tissues. M. muelleri was compared from all the different infection sites each month where possible, from the same host ( i.e., L. cephalus ) and from the same site on different hosts (i.e. from the gills of all 3 hosts). No seasonal variation in occurrence, spore shape or size was found for M. muelleri , but spore size varied depending on the host and site of infection.
Tailed and tailless forms of H. zschokkei were found on L. leucicus and H. oviperda on E. lucius . Only tailless H. psorospermica were found.
Variations in spore form and size are discussed in relation to their use as taxonomic characters.     

Expression of the proteinase specialized in bone resorption, cathepsin K, in granulomatous inflammation

BACKGROUND: The cysteine proteinase cathepsin K has aroused intense interest as the main effector in the digestion of extracellular matrix during bone resorption by osteoclasts. The enzyme is not a housekeeping lysosomal hydrolase, but is instead expressed with striking specificity in osteoclasts. In this work, we present evidence for the association of cathepsin K with the granulomatous reaction. Granulomas are inflammatory tissue reactions against persistent pathogens or foreign bodies. We came across cathepsin K while working on Echinococcus granulosus, a persistent tissue-dwelling, cyst-forming parasite that elicits a granulomatous response. MATERIALS AND METHODS: The walls of hydatid cysts from infected cattle were solubilized. Strong proteolytic activity was detected in the extracts. The proteinase responsible was purified by anion exchange and gel filtration. The purified protein was subjected to N-terminal sequencing, and its identity further confirmed by Western blotting, with a cathepsin K-specific antibody. The same antibody was used to localize the proteinase in paraffin-embedded sections of the parasite and the local host response. RESULTS: A proteinase was purified to near homogeneity from hydatid cyst extracts. The enzyme was unequivocally identified as host cathepsin K. Both the proenzyme and the mature enzyme forms were found. Cathepsin K was then immunolocalized both to the parasite cyst wall and to the epithelioid and giant multinucleated cells of the host granulomatous response. CONCLUSIONS: In the granulomatous response to the hydatid cyst, cathepsin K is expressed by epithelioid and giant multinucleated cells. We propose that, by analogy with bone resorption, cathepsin K is secreted by the host in an attempt to digest the persistent foreign body. Both processes, bone resorption and granulomatous reactions, therefore tackle persistent extracellular material (the bone matrix or the foreign body), and utilize specialized cells of the monocytic lineage (osteoclasts or epithelioid/giant cells) secreting cathepsin K as an effector.     

Pathology of pentastomid infections (Sebekia mississippiensis) in fish

Differential pathogenesis was observed in two species of fish naturally infected with the pentastome Sebekia mississippiensis. Mosquitofish (Gambusia affinis) showed a mild inflammatory response to developing nymphs, whereas swordtails (Xiphophorus helleri) had an extensive granulomatous inflammatory reaction with accompanying hemorrhage, myositis, and myodegeneration. This suggested that certain species of tropical fish reared in the southeastern United States may be at risk to potentially harmful infections with this parasite.     

Five New Species of Henneguya (Protozoa: Myxosporida) from Ictalurid Fishes*

SYNOPSIS. Four new species of Henneguya (myxosporidan) are described from Ictalurus punctatus Rafinesque (channel catfish). They are as follows: Henneguya postexilis sp. n. and Henneguya longicauda sp. n. from the gills; Henneguya adiposa sp. n. from the adipose fin; and Henneguya diversis sp. n. from the liver, kidney, connective tissue of muscles and fins, and tumor-like external growths. Henneguya pellis sp. n. is described from the dermis of Ictalurus furcatus (LeSueur) (blue catfish). The development stages of all described species are discussed. Henneguya exilis Kudo was found on the gills of one I. punctatus; notes on its spore characteristics are presented.     

长江中游长吻鮠、蛇鮈寄生粘孢子虫感染率的季节动态

1.寄生长吻鮠上的粘孢子虫有3种:巨囊两极虫和四极虫一种,寄生在胆囊中,碘泡虫一种寄生在肾脏中;寄生蛇鮈上的粘孢子虫有2种:湖北碘泡虫,寄生在脑、鳃、肾、体腔、肠,主要寄生在脑,楚克拉虫一种,寄生在胆囊中。2.粘孢子虫对长吻鮠、蛇鮈的感染率存在明显的季节变化;对长吻鮠的感染率最高值出现在6月(95%),最低值出现在2月(43%),年平均值为65%;湖北碘泡虫对蛇鮈的总感染率最高值出现在12—2月(63—67%),其次在8月(58%),春秋两季感染率较低(36—44%),年平均值为51%。3.总感染率(IR)与鱼体全长(TL)的关系:长吻鮠IR=0.956-0.009TL;蛇鮈IR=-2.0678+0.3838(TL)-0.0136(TL)2,8厘米以下的蛇鮈未发现感染。4.粘孢子虫的感染率与长吻鮠、蛇鮈的性别无关。5.感染粘孢子虫的长吻鮠,肥满度下降不大(0.04),感染粘孢子虫的蛇鮈,肥满度下降0.12,体重平均下降12.4%。6.长吻鮠中寄生粘孢子虫的总感染率(IR)与长江中游水温(T℃)呈显著正相关,二者关系可用下式描述:IR=0.3129+0.0192(T℃)。蛇鮈寄生粘孢子虫的总感染率(IR)与水温(T℃)之间的关系呈一反抛物线型、两者关系可用下式描述 IR=1.1228-0.073777T+0.001795T2       

Difficulties in the fine needle aspiration (FNA) diagnosis of schwannoma

The results of nine FNAs of eight histologically proven schwannomas are presented. In only one of the aspirates was a diagnosis of schwannoma made; three additional cases were diagnosed as 'spindle cell neoplasm'. Two of the cases were considered to be non-diagnostic due to hypocellularity, while two cases containing cellular material raised the differential diagnosis of granulation tissue and granulomatous inflammation due to the presence of epithelioid cells and an inflammatory infiltrate, and are illustrated here. The remaining FNA was felt suggestive of branchial cleft cyst due to the presence of only cystic fluid in a neck mass. We observe that: (i) the acquisition of an adequate, representative specimen via FNA is often difficult in schwannoma, and (ii) diagnostic difficulties may be encountered in cases in which cellular material is obtained.     

Adelmidrol, a palmitoylethanolamide analogue, reduces chronic inflammation in a carrageenin-granuloma model in rats

Palmitoylethanolamide (PEA) and some of its analogues have shown great efficacy in the treatment of pain and inflammation. Adelmidrol – the International Nonproprietary Name (INN) of the di-amide derivative of azelaic acid – is one of these analogues. The anti-inflammatory and analgesic effects of PEA and adelmidrol are hypothesized to be mediated, at least in part, by mast cell down-modulation. Mast cell mediators released at early stage of the inflammatory process drive the inflammatory reaction to chronicity as it happens in X-carrageenin-induced granulomatous tissue formation. In the present study, the choice of testing adelmidrol depends upon the physicochemical properties of the compound, i.e. the amphipatic feature, that make it more easily soluble than PEA. In this study, we investigated the effect of adelmidrol on granuloma formation induced by λ-carrageenin-soaked sponge implant in rats. Our results show that the local administration of the compound under study significantly decreases weight and neo-angiogenesis in granulomatous tissue. The anti-inflammatory effect was due to the modulation of mast cells degranulation, as shown by histological analysis and by the inhibition of the release of several pro-inflammatory and pro-angiogenic enzymes ( e.g. iNOS, chymase and metalloproteinase MMP-9), and mediators ( e.g. nitric oxide and TNF-α). The results indicate that adelmidrol, given locally, may represent a potential therapeutic tool in controlling chronic inflammation.     

Damage due to parasites in Mediterranean teleosts

Evaluation of damages by parasites in teleosts, even if underextimated in the past, is today one of the most used methods to understand the effective impact of a parasite on a certain ichtyc species. The damage caused by a parasite on the host could be classified into direct, with tissue changes, or indirect, with a decrease of the productive performances. Based on this, a preliminary difference could be traced distinguishing parasites that show a coevolution with their host species, characterized by a low damage, and those parasites that can occasionally infect new host species, showing a high degree of damage. In consideration of the damage, parasites can have different actions on the host: subtractive, irritative, mechanical, traumatic, toxic, dismetabolic, antigenic and foretic. Those parasites able to cause tissue changes must be furtherly classified considering the type of inflammation they evoke on tissues: ulcerous, catarral, haemorrhagic, necrotic and granulomatous. Some parasites are encysted in tissues without any host reaction. The fish response against parasite can be inflammatory, the most frequent, but also hyperplastic, metaplastic, neoplastic and immunitary. The paper goes through different tissue changes due to the main parasites of Mediterranean teleosts.     

Intravesical BCG administration in the guinea pig. A histomorphological study

Intravesical BCG administration is used as an adjuvant therapy after transurethral resection for superficial bladder cancer in man. The mechanisms of its antitumor activity are not known. The aim of this study was to characterize the histomorphological changes in various organs of the guinea pig after intravesical BCG administration. The BCG preparation used was BCG-RIVM, a Dutch BCG preparation. Instillations were performed in previously undamaged bladders weekly for 6 consecutive weeks and lasted 30 min or 1 h. Different doses were used ranging from 10(3) culturable particles (c.p.) to 5 x 10(7) c.p. of BCG. After 6 weeks, the animals were killed and postmortem examination was performed. The bladder wall, retroperitoneal lymph nodes, spleen, liver, lungs and distant lymph nodes were examined histologically. The BCG therapy, with a dose of 10(6) culturable particles and higher, induced an inflammatory reaction consisting of mononuclear infiltrates in the subepithelial tissue of the bladder wall. In approximately 50% of the animals investigated, the infiltrates were accompanied by non-caseating granulomatous lesions indicated by the presence of epithelioid cells. In general, the epithelial layer of the bladder showed no visible alterations. Similarly, a granulomatous inflammatory reaction was observed in the first retroperitoneal (iliac) lymph nodes draining the bladder. Granulomatous lesions were occasionally also present in liver and lung. In three of the 29 animals investigated, lesions were present both in liver and lungs, and in two of these three animals a granulomatous reaction was observed in the spleen and distant lymph nodes indicating a generalized inflammatory response induced by BCG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Histological evaluation of immunologically mediated tumor regression of the line 10 guinea pig hepatocarcinoma

The histology of immunologically mediated tumor regression was studied in the syngenic strain 2 guinea pig/line 10 hepatocellular carcinoma tumor system. Tumor regression was induced non-specifically by the intralesional injection of living Bacillus Calmette-Guérin (BCG) in 7-day-old established tumors (diameter 8-10 mm). In untreated line 10 tumors at day 7 a mild to moderate inflammatory reaction was present, which consisted mainly of small mononuclear cells; in addition large mononuclear cells and basophils were present. Intratumoral BCG-treatment induced a prominent increase in the inflammatory reaction due to an influx of small and large mononuclear cells and neutrophils. Small mononuclear cells were identified mainly as lymphocytes whereas large mononuclear cells belonged mainly to the macrophage line. Intratumoral administration of BCG resulted in a granulomatous reaction. A time-related decrease in the number of tumor cells and an increase in inflammation, associated with purulent lysis of the granulomatous tissue, was observed. Specific immune-mediated tumor rejection occurred in animals both after active immunization and after adoptive transfer of immune spleen cells. In actively immunized animals the tumor cells were rapidly rejected and from day 4 onwards no tumor cells could be detected at the injection site. Lymphocytes were the major component of the inflammatory reaction; large mononuclear cells were present to a lesser extent and basophilic granulocytes were regularly observed. After adoptive transfer of immunity with immune spleen cells given simultaneously with an intradermal innoculation of tumor cells, an essentially similar rejection reaction was found, although tumor cell rejection was delayed. Lymphocytes and large mononuclear cells were found in equal proportions, whereas basophilic granulocytes were always present in smaller numbers. After BCG-induced regression and in adoptively transferred immune rejection, a fibroblast component was more prominent than in untreated control tumors. This reaction tended to isolate smaller tumor cell areas into islets of decreasing sizes. In contrast with the fibroblast component of growing tumors, the proliferative pre-existing fibrous tissue in tumors undergoing regression or rejection showed a loosely arranged architecture and contained a marked cellular infiltrate. From the results of the present study it was concluded that the morphological expression of line 10 tumor rejection varies. Without immune cells, BCG is needed for the induction of a local inflammatory reaction, which was granulomatous in type and eventually led to complete tumor cell eradication.(ABSTRACT TRUNCATED AT 400 WORDS)     

Fine Structure of the Cyst and Some Sporulation Stages of Ichthyosporidium (Microsporida)*

SYNOPSIS. Ichthyosporidium sp. Schwartz, 1963, apparently identical with the type species, I. giganteum (Thélohan, 1895) Swarczewsky, 1914, was studied with the electron microscope. Only late stages, a mature cyst containing sporulation stages and a cyst in the terminal (necrotic) stage were observed. The cyst, originating from host tissue, is a highly organized structure that is integrated with the surrounding connective tissue by means of numerous conspicuous processes. It is interpreted as essentially a manifestation of a defensive reaction of the host that is elicited by the parasite and then used to its advantage. Eventually the cyst dies and disintegrates. This type of cyst, peculiar among those associated with microsporidia, may be regarded as a distinctive character of the poorly defined genus Ichthyosporidium. Other observations let to an hypothesis which reconciles several different views regarding the identity of the Golgi complex. According to this new interpretation, these different views concern different aspects af the total complex. When all such views are integrated, a “classical Golgi” can be recognized in the presporoblastic stages and the “primitive Golgi” concept disappears. This “classical Golgi” then becomes highly modified during spore morphogenesis, giving rise to many of the internal organelles that are peculiar to the spore.     

Pathology of experimental Sarcocystis falcatula infections of canaries (Serinus canarius) and pigeons (Columba livia)

Sarcocystis falcatula is an apicomplexan parasite with a broad range of avian intermediate hosts. The pathology and pathogenesis of infection with this parasite has been studied experimentally in the budgerigar (Melopsittacus undulatus). The present study quantitatively examines the pathology of this parasite in canaries (Serinus canarius) and pigeons (Columba livia) and compares it with that found in budgerigars. The general progression of merogony and cyst formation is similar qualitatively to that seen in budgerigars, but it differs quantitatively. The principal site of precystic merogony is in pulmonary endothelial cells. The magnitude of pulmonary meront burdens (at similar inoculated dosages) varies in different intermediate host species. Merogony is less persistent than in budgerigars. Among the various species of birds, the magnitude of precystic merogony correlates differently with the magnitude of skeletal muscle cyst burdens. The distribution of cyst burdens among various muscles also differs. The composition of inflammatory cells differs among various avian species' response to S. falcatula. Pathologic changes quantitatively parallel tissue meront burdens (except possibly in the liver of canaries), resulting in an interstitial pneumonitis, hepatitis, and mild inflammatory lesions of other organs.     

Variability of myxospores in the myxosporidian genus Henneguya depending on host and geography in the transect "Khubsugul Lake (Mongolia)--Baikal Lake--Laptev Sea (Russia)"

Analysis of variability and estimation of significance of the differences in morphometric parameters of spores have been carried out for three species of the genus Henneguya (Myxosporidia). Representatives of these species collected both in the same water body (but from different host species) and in geographically distant localities were compared. Thus, we compared samples of Henneguya zschokkei from different host species in Chivyrkui Bay of Baical Lake and in Laptev Sea, and also we compared samples of this species from Baikal Lake with those from Laptev Sea. Materials on Henneguya cerebralis from Baikal Lake were compared with those from Khubsugul Lake; samples of H. cutanea from one host species (Siberian dace) but from water bodies of different type (lake or river) were compared.     

Pathology of pulmonary parasitic migration: morphological and bronchoalveolar cellular responses following Nippostrongylus brasiliensis infection in rats

Nippostrongylus brasiliensis has an obligatory migratory phase through the lungs during its development in rats. This migration is associated with marked tissue damage and pronounced cellular reaction. Given that cells from the lower respiratory tract, especially alveolar macrophages, can adhere to and kill larvae of N. brasiliensis in vitro, we studied the time course of morphological changes associated with parasitic migration. Compared to a primary infection, a secondary infection resulted in significant changes in the pulmonary tissue characterized by an early acute inflammation leading to granulomatous reaction in the parenchyma and a leucocytosis in the bronchoalveolar lavage fluids with an anamnestic increase in absolute numbers of neutrophils, alveolar macrophages, eosinophils, and lymphocytes. Scanning electron microscopy showed that inflammatory cells, especially alveolar macrophages, granulocytes, lymphocytes, erythrocytes, and platelets, adhered to the larvae following secondary infection and this adhesion was associated with disruption of cuticular surface in some larvae. Secondary infection also resulted in retention of larvae in granulomatous lesions in the lungs even up to 21 days postinfection. There was mast cell and type II pneumocyte hyperplasia and these cells appeared to be activated. Thus, the histopathological changes in lungs correlated with the bronchoalveolar cellular responses and further document the inflammatory and immunological reactions during the migration of N. brasiliensis larvae.     

Intravesical BCG administration in the guinea pig

Intravesical BCG administration is used as an adjuvant therapy after transurethral resection for superficial bladder cancer in man. The mechanisms of its antitumor activity are not known. The aim of this study was to characterize the histomorphological changes in various organs of the guinea pig after intravesical BCG administration. The BCG preparation used was BCG-RIVM, a Dutch BCG preparation. Instillations were performed in previously undamaged bladders weekly for 6 consecutive weeks and lasted 30 min or 1 h. Different doses were used ranging from 10³ culturable particles (c.p.) to 5 × 10⁷ c.p. of BCG. After 6 weeks, the animals were killed and postmortem examination was performed. The bladder wall, retroperitoneal lymph nodes, spleen, liver, lungs and distant lymph nodes were examined histologically. The BCG therapy, with a dose of 10₆ culturable particles and higher, induced an inflammatory reaction consisting of mononuclear infiltrates in the subepithelial tissue of the bladder wall. In approximately 50% of the animals investigated, the infiltrates were accompanied by noncaseating granulomatous lesions indicated by the presence of epithelioid cells. In general, the epithelial layer of the bladder showed no visible alterations. Similarly, a granulomatous inflammatory reaction was observed in the first retroperitoneal (iliac) lymph nodes draining the bladder. Granulomatous lesions were occasionally also present in liver and lung. In three of the 29 animals investigated, lesions were present both in liver and lungs, and in two of these three animals a granulomatous reaction was observed in the spleen and distant lymph nodes indicating a generalized inflammatory response induced by BCG. No microorganisms were detected by Ziehl-Neelsen (ZN) staining or culture in L?wenstein-Jensen medium in the first draining (iliac) lymph nodes of the bladder or in the spleen. In this study we found that BCG could induce inflammatory reactions in the bladder wall after its introduction into the previously undamaged bladder. Ulceration of the epithelium covering the mononuclear infiltrates was not observed. Occasionally a generalized inflammatory response to BCG was present in the animals investigated.     

Characterization of the tuberculous granuloma in murine and human lungs: cellular composition and relative tissue oxygen tension

The granulomatous reaction is the hallmark of the host response to infection with Mycobacterium tuberculosis. Despite its apparent importance to host defence against the tubercle bacillus, the granulomatous response remains to be completely defined. The present study used histological, immunohistochemical and flow-cytometric analyses to characterize pulmonic granulomatous tissues of tuberculous mice and humans. The kinetics of recruitment of neutrophils, macrophages, dendritic cells, and T and B lymphocytes into the lungs of mice infected aerogenically with the virulent Erdman strain of M. tuberculosis was evaluated in detail in both the acute and persistent phase of infection. A hypoxia-sensing compound based on the 2-nitroimidazole structure (EF5), together with immunohistochemical studies targeting endothelial cells were used to examine the relative oxygen tension in tuberculous granulomatous tissues in mice. The results have provided evidence that: (i) the granulomatous tissues are a highly organized structure whose formation is regulated by orderly recruitment of specific immune cells exhibiting distinct spatial relationship with one another; (ii) the granulomatous reaction, at least in the mouse, may represent an exaggerated response to the tubercle bacillus that can play a role in the development of immunopathology; (iii) B lymphoid aggregates are a prominent feature in both murine and human granulomatous tissues, although the immune cells that are most prominently associated with these clusters vary among the two species; (iv) murine tuberculous granulomatous tissues are relatively aerobic, suggesting that mouse models of persistent tuberculosis may not be suitable for the study of any hypoxic response of M. tuberculosis.     

Evidence for thyroglobulin-reactive T cells in good responder mice.

Trehalose dimycolates and monomycolates isolated from a variety of Mycobacteria species as well as synthetic trehalose mycolates and trehalose behenylbehenate produced granulomatous responses in the lungs of mice. Trehalose alone or mycolic acids or their methyl esters, however, did not. These data suggest that the sugar moiety of these defined fatty acid esters is required for the production of this cellular inflammatory reaction. When mice were challenged with virulent Mycobactorium tuberculosis they showed increased resistance against infection during the time when the granulomatous response was greatest.     

Chloromyxum schurovi sp.n.--new myxosporidian species (Myxosporea: Sphaerosporidae) from salmonid fishes (Salmonidae)

New species of the myxosporidian genus Chloromyxum is described from salmonid fishes collected in Karelia, Norway and Finland in 1992-1998.