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Biomedical subjects

K Molnár

Publications and source records attributed to K Molnár.

At least 37 records · Page 2Linked to original sources

Radiodiagnostic examination of the swimbladder of some fish species.

Radiodiagnostic methods have not been used previously for studying the anatomy and diseases of the swimbladder of freshwater fish species. In this study, the radiographic anatomy of the swimbladder and species-related differences in swimbladder structure were studied on plain radiographs taken of 12 Hungarian fish species of major economic importance. Changes observed by radiography were also studied by conventional parasitological methods. The radiodiagnostic method reported here appears to be a useful complement to diagnostic examinations that have been based merely on dissection so far. It enables evaluation of the pathological lesions in live condition, without causing damage to the fish.

Air Sacs↗

The immunoprotein scolexin and its synthesizing sites--the midgut epithelium and the epidermis.

Scolexin is one of the bacterial induced hemolymph proteins of tobacco homworm (Manduca sexta) larvae, that has hemocyte coagulation-provoking activity. The 72 kDa scolexin complex is composed of two 36 kDa subunits. To examine the protein secretory pathways in insect epithelia a polyclonal antibody was raised against the 36 kDa hemolymph protein. This MsH36 antibody recognised a 36 and a 72 kDa protein in tissue homogenates. On the basis of the characteristic labelling pattern observed on immunoblots and immunocytochemical sections we concluded that the 36 kDa protein in the hemolymph, in the midgut and in the epidermis was identical with the scolexin subunit. In present paper we report a labelling shift in the midgut epithelium between goblet and columnar cells that may be controlled by the hormonal system. A 72 kDa protein showed similar epitops and molecular weight to the scolexin complex and was detected in epidermis and in cuticle under both reducing and non-reducing conditions. Tissue localization of 36 kDa and 72 kDa MsH36 antibody labelling proteins indicated the possibility that the epidermal cells produce two kinds of scolexin-like proteins. The complex composed of 36 kDa subunits are transported basolaterally into the circulation and display hemocyte coagulation inducing activity while the 72 kDa form contains two subunits linked covalently secreted apically into the cuticle.

Animals↗

A potential dual apical pathway in polarized regenerative cells of the midgut of Manduca sexta.

Two novel proteins with apparent molecular weight of 38 (Manduca sexta midgut MsM38) and 46kDa (MsM46) were isolated from midgut homogenates in wandering stage Manduca sexta larvae and both of them were found to be present exclusively in this tissue on Western blots. Immunocytochemical studies revealed that both proteins are expressed in the regenerative cells however, their distribution pattern is clearly different. MsM38 is localized in the cytoplasm of resting regenerative cells during the feeding period, and is accumulated in the calcospherits at the beginning of the wandering period. Along with the delamination of the larval epithelium, this protein is released apically from these vesicles. The antiserum labels an additional 76 kDa protein in the wandering larval midgut homogenates. The appearance of this 76 kDa protein coincides with the accumulation of the immunopositive material in the calcospherits. MsM46 is similarly distributed during the feeding period in the cytoplasm of regenerative cells. At the beginning of the wandering period it accumulates around the newly forming large apical vacuoles, that are released at the time of complete delamination of the larval epithelium. In parallel with this process MsM46, and another 40 kDa protein, that becomes labeled from this period on Western blots appeares on the apical microvillar projections. Thus both isolated proteins are directed apically from different compartments, that raises the possibility of a dual apical routing pathway in regenerative cells.

Animals↗

Development of a system for detection of circulating antibodies against hemidesmosomal proteins in patients with bullous pemphigoid.

Specific antibodies directed against special hemidesmosomal proteins are involved in the pathogenesis of bullous pemphigoid (BP), and detection of these antibodies is crucial for a correct diagnosis. As the BP autoantigen primary structures are known, the question was addressed as to whether it is possible to demonstrate circulating antibodies against BP autoantigens (BPAG1 and BPAG2) by means of an ELISA system, using antigenic epitopes. With the help of the programs Peptidestructure and Plotstructure, antigenic epitopes of BP antigens were predicted, chemically synthesized and screened using serum from 43 proven BP patients. The coding sequences of the best antigenic epitopes were then chemically synthesized and inserted as monomer and homo- or hetero-oligomer forms into fusion-expression plasmids (PGEX-4T, Pharmacia) in-frame to the C-terminus of glutathione-S-transferase. Fusion products were expressed and purified from Escherichia coli cells by affinity chromatography. The recombinant proteins were used for the detection of antibodies in the serum of 43 BP patients and of 60 controls (including 30 healthy persons, 22 patients with pemphigus vulgaris and 8 patients with other bullous dermatoses). Use of the homo- and hetero-oligomers of the recombinant fusion peptides increased the sensitivity of the disease-specific antibody detection. When a mixture of the best recombinant fusion proteins was used, the sensitivity of the ELISA assays in the case of the BP patients' serum was 0.90. This system could form the basis of a rapid and simple system for the diagnosis of BP.

Aged↗

A survey on coccidian infection of Lake Biwa fishes in Japan, with the description of four new species of Goussia labbe, 1896 (Apicomplexa).

Thirty-two specimens of 11 freshwater fish species from Lake Biwa, Japan were surveyed for coccidian infections. Four fish species proved to be infected with apicomplexans belonging to the genus Goussia. Altogether, seven Goussia species were found. Oöcysts of four species inhabiting the intestinal epithelium were shed at the sporulated stage. Two other intestinal species left the fish unsporulated. A few relatively large and aged oöcysts of a further species were found in the renal tubules. The sporulated intestinal species were described as Goussia biwaensis n. sp., G. grygieri n. sp., G. nipponica n. sp. and G. wakabayashii n. sp.

Animals↗

Survey on Myxobolus infection of the bleak (Alburnus alburnus L.) in the river Danube and in Lake Balaton.

In a three-year survey of myxosporean infections of the bleak (Alburnus alburnus), involving the examination of 205 fish specimens from the River Danube and 50 from Lake Balaton, four Myxobolus species (two gill parasites, one fin parasite and a species parasitising the skeletal muscles) were detected. Two of the species could be identified as M. alburni and M. obesus. Of the other two species, the gill parasite proved to be a hitherto undescribed species which is described here as a new species by the name of M. margitae. One of the two gill-parasitic species, M. obesus, formed plasmodia in the respiratory lamellae of the gill filaments, while the plasmodia of M. margitae n. sp. were formed in the afferent artery of the primary gill filaments. The plasmodia containing spores morphologically identifiable with the species M. alburni were located in the connective tissue between the fin rays. The less frequently found muscle-parasitic Myxobolus species has not been identified precisely. The plasmodia of M. obesus were found in the fish in May and June, while those of M. alburni and M. margitae n. sp. in July and August. The prevalence of infection in fish examined in these periods was 15.5% for M. obesus, 11.5% for M. margitae and 14.0% for M. alburni.

Animals↗

Myxobolus intrachondrealis sp. n. (Myxosporea: Myxobolidae), a parasite of the gill cartilage of the common carp, Cyprinus carpio.

A species not identifiable with any of the about 23 Myxobolus species recorded from the common carp so far, was detected in the gills of one- and two-summer-old specimens of the common carp ((Cyprinus carpio L.) cultured in pond farms in Hungary. The strictly tissue-specific plasmodia of the parasite were located, surrounded by hyaline cartilage cells, in the chondrous substance of the terminal parts of the gill arches and in the cartilage structure ventrally connecting the gill arches. The spores of the parasite described as Myxobolus intrachondrealis sp. n. developed in globular or ellipsoidal plasmodia measuring 300-600 microm. By their elongated ellipsoidal shape and similarly elongated polar capsules the spores were well distinguishable from the hitherto described Myxobolus species parasitic in the common carp and also from the cartilage-parasitic Myxobolus species of other fishes.

Animals↗

Experimental detection of the actinospores of Myxobolus pseudodispar (Myxosporea: Myxobolidae) in oligochaete alternate hosts.

The development of Myxobolus pseudodispar Gorbunova, 1936, an intracellular myxosporean muscle parasite of the roach Rutilus rutilus L., was studied in experimentally infected oligochaetes. In one experiment, uninfected Tubifex tubifex Müller and Limnodrilus hoffmeisteri (Claparéde) were exposed to mature spores of M. pseudodispar. Triactinomyxon spores developed both in T. tubifex and L. hoffmeisteri specimens. Triactinospores were first released from the oligochaetes 76 d after initial exposure. At that time, pansporocysts containing 8 triactinospores were located in the gut epithelium of experimentally infected oligochaetes, but free actinosporean stages were also found in their gut lumen. Each triactinospore had 3 pyriform polar capsules and an elongated cylindrical sporoplasm with 8 secondary cells. The spore body joined the 3 caudal projections with a relatively long style. One of the 3 caudal projections was shorter than the other two. The total length of the triactinospore was on average 206.5 microns.

Animals↗

Isolation and characterization of an apically sorted 41-kDa protein from the midgut of tobacco hornworm (Manduca sexta).

Immunocytochemical localization and sorting properties of a newly purified 41-kDa protein (MsM41) were investigated in an insect, the tobacco hornworm Manduca sexta. The protein purified from midgut homogenates of feeding fifth-stadium larvae was found exclusively in this tissue on Western blots. Presence of MsM41 protein was indicated in both anterior and posterior regions of the midgut during the whole fifth stadium. However, in the posterior region an additional 39-kDa protein was also detected during the feeding period of the last larval stage. Upon light-microscopic examination immunoreactivity was localized in the columnar cells, while the goblet, endocrine and regenerative cells remained unlabeled. Distribution of the label during the feeding period was different in the anterior and posterior regions. In the anterior region immunoreactivity was localized only to the brush border membrane of columnar cells, while in the posterior region some cytoplasmic structures identified as large trans-Golgi vesicles, endoplasmic reticulum and small secretory vesicles were also labeled. Large, apical extrusions remained immunonegative. In vitro translation confirmed that our protein was expressed only in the posterior region of the midgut. The primary translation product was a 39-kDa protein. Putative post-translational modifications yielded the 41-kDa form, which was then secreted apically. Its presence in the region of the anterior part microvilli was probably due to the countercurrent flux of the ectoperitrophic fluid.

Animals↗

Antineutrophil cytoplasmic antibodies and other immunologic abnormalities in patients with habitual abortion.

PROBLEM: The immunologic mechanisms of pregnancy loss in habitual aborters with antiphospholipid and antinuclear antibodies have not been fully clarified. The possible association of antineutrophil cytoplasmic antibodies (ANCAs) with recurrent miscarriage was examined. METHOD OF STUDY: In a prospective, controlled trial of 59 women with recurrent abortion, the prevalence of pANCA (antimyeloperoxidase), cANCA (antiproteinase-3), and immunoserologic abnormalities of systemic lupus erythematosus (SLE) anti double-stranded DNA, anti-SSA, anti-SSB, anti-U1RNP, anti-Sm, anticardiolipin and antinuclear antibodies, LE-cell, lupus anticoagulant, and complement-3 were investigated. RESULTS: pANCA occurred in 2, and cANCA in 6 of 59 case patients, but neither was observed in the controls (P = 0.09 for cANCA). cANCA levels were significantly higher in patients than in controls (P = 0.028). Six recurrent aborters were identified as having a group of immunoserologic abnormalities characteristic of SLE. CONCLUSIONS: Immunologic mechanisms detectable in SLE may operate in a subgroup of habitual aborters with suspected immunologic cause. ANCAs occur more frequently in patients with recurrent miscarriage than in controls.

Abortion, Habitual↗

Insect cuticle, an in vivo model of protein trafficking.

In the course of this study more than 20 proteins have been isolated from the larval cuticle of Manduca sexta. Synthesis, secretion, transport and accumulation of four particular proteins, representative members of four characteristic groups, were followed during metamorphosis by immunoblot and immuncytochemical methods and are described in detail in this paper. We established that only some of the proteins of the soft cuticle of Lepidopteran larvae are synthesized in epidermal cells at the beginning of the larval stages and are digested during the moulting period (MsCP29). Other proteins (MsCP30/11) are secreted into the cuticle by the epidermal cells in different forms during various developmental stages. Some proteins are secreted apically during the feeding period, but before ecdysis they are then taken up by epidermal cells and transported in a basolateral direction back into the hemolymph and saved in an immunologically intact form by the fat body cells (MsCP12.3). Some cuticle proteins have a non-epidermal origin. They are transported from the hemolymph into the cuticle. Before and during ecdysis these molecules reappear in the hemolymph and are detectable again in the pupal cuticle (MsCP78). Our data prove that the cuticle is not a non-living part of the insect body: it is not only an inert, protective armor, but maintains a continuous and dynamic metabolic connection with the other organs of the organism.

Animals↗

Redescription of Myxobolus hungaricus Jaczó, 1940 (Myxosporea: Myxobolidae), a parasite of bream (Abramis brama L.).

Myxobolus hungaricus Jaczó, 1940 forms relatively large plasmodia on the gills of bream (Abramis brama). The authors give a redescription of this deficiently described parasite on the basis of spores collected from the original habitat, which spores are indicated as a neotype. The plasmodia of the parasite can be found on the gills typically in the spring months, and are located in the central part of the gill filaments. They start to develop in the lumen of capillaries of the secondary lamellae and remain in intralamellar location also after they have reached the mature stage. The spores have a very characteristic shape, as on the surface of the spore valves a distinctly emerging ridge runs parallel to the sutural line. In addition to breams from the typical habitat, Lake Balaton, the plasmodia of M. hungaricus could be detected also on breams originating from the river Danube.

Animals↗

Myxobolus infection of the gills of common bream (Abramis brama L.) in Lake Balaton and in the Kis-Balaton reservoir, Hungary.

During a five-year survey including studies on the parasite fauna of bream (Abramis brama), four gill-parasitic Myxobolus species (M. bramae, M. hungaricus, M. impressus and M. macrocapsularis) were recorded in a total of 313 breams from Lake Balaton. The commonest species, M. bramae showed a prevalence of 33%, while the other species occurred sporadically. Myxobolus bramae and M. macrocapsularis infected the tips of the gill filaments and caused both intralamellar and interlamellar infection. Intralamellar plasmodia of small size developed in the capillary network of the gill lamellae whereas the much larger interlamellar plasmodia were formed in the arteria afferens. The intralamellar plasmodia of M. hungaricus always infected the basal or central part of the gill filaments. In contrast to the above species developing in the blood vessels, M. impressus proved to be an epithelial parasite, as its plasmodia always developed in the adjacent gill filaments of two opposite haemibranchia, in the stratified epithelium between the respiratory plates, causing changes of the haemibranchium which were well visible even by the naked eye.

Animals↗

Relationships among members of the genus Myxobolus (Myxozoa: Bilvalvidae) based on small subunit ribosomal DNA sequences.

Sequences representing approximately 1,700 base pairs of the 18S rRNA gene from 10 different species in the genus Myxobolus were found to group them into 3 clusters that showed little correlation with spore morphology and size or host specificity, criteria currently used for both higher and lower taxonomic placements in the Myxozoa. Of the phenotypic criteria examined, tissue tropism was most correlated with the rRNA groupings observed. Spores of similar size and shape (Myxobolus cerebralis vs. Myxobolus squamalis) were distantly related in some instances, whereas spores with divergent morphology and size were sometimes found to be closely related (M. cerebralis and Myxobolus insidiosus). These initial investigations into the phylogenetic relationships of putative members of the genus Myxobolus clearly indicate the potential limitations of groupings based on size and morphological properties of the spores and host species infected. We propose that 18S rRNA gene sequences, combined with information on tissue tropism, host species infected, and developmental cycles in the fish and alternate host (when and if known) be given greater consideration in taxonomic placements of myxosporeans.

Animals↗

Radiodiagnostic method for studying swimbladder inflammation caused by Anguillicola crassus (Nematoda: Dracunculoidea).

The nematode Anguillicola crassus appeared in Europe about 15 yr ago, and has subsequently become recognised as a cause of major pathological lesions in the swimbladder of the European eel Anguilla anguilla. The radiographic method reported in this paper showed be a useful complement to diagnostic methods that have so far been based exclusively on fish dissection. Using this method, the infection of the swimbladder and the severity of its pathological changes can be assessed in a reliable manner without causing damage to the fish. By analysing radiographs of 45 eels from Lake Balaton, 5 stages of swimbladder lesions were distinguished. The method enables the examiner to draw conclusions on the air, worm and exudate content of the swimbladder; however, data on thickening of the swimbladder wall can be obtained only indirectly. The radiograph also provides information on the air and worm content of the pneumatic duct. Results obtained by radiography showed good agreement with dissection findings. Radiographic results are compared with pathological findings obtained from fish dissections separately for each severity grade of infection.

Air Sacs↗

Juvenile pemphigus foliaceus.

A 7-year-old girl with generalized erythematous, scaling plaques and vesiculobullous lesions on the extremities was diagnosed as having pemphigus foliaceus. Lesional direct immunofluorescence revealed intercellular IgG, IgA and C3 deposition. The patient's serum gave positive reactions against one epitope of desmoglein 3 and the epitope of desmoglein 1 in enzyme-linked immunosorbent assays, but the blood sample for indirect immunofluorescence did not display any circulating antibodies. The patient was successfully treated systemically with prednisolone and dapsone. Currently, she is taking dapsone, 12.5 mg daily. She has been free of lesions for the last 3 years.

Anti-Inflammatory Agents, Non-Steroidal↗