Induction of cysteine proteinase in the encapsulation of Hymenolepis diminuta eggs in the American cockroach, Periplaneta americana

Haemocytes play an essential role in defending invertebrates against pathogens and parasites that enter their haemocoel. In the present study, the cockroach, Periplaneta americana was able to encapsulate Hymenolepis diminuta eggs within 24 h after injection. Proteolytic activity of egg capsules was determined by gelatin zymography. A gelatinase-type proteolytic enzyme with molecular weight about 65 kDa was present at the time of capsule formation. Enzyme activity was obviously inhibited by leupeptin but not by ethylenediamine tetraacetic acid (EDTA) or 1,10-phenanthroline or phenylmethanesulfonyl fluoride (PMSF). Hence, we tentatively characterized this enzyme as a cysteine proteinase. The specificity of the cellular immune response in vivo and the increased cysteine proteinase activity coincided with the capsule size and encapsulation process. The possible function of this cysteine proteinase activity during encapsulation of the H. diminuta eggs by P. americana is discussed.     

Apoptosis in the fat body tissue of the beetle Tenebrio molitor parasitised by Hymenolepis diminuta

Many insects experience a decrease in reproductive output when parasitised. We are investigating mechanisms underlying this fecundity reduction using the rat tapeworm, Hymenolepis diminuta infection of Tenebrio molitor beetles. These include an increase in the resorption of developing ovarian follicles and a decrease in fat body synthesis of vitellogenin. The latter is the direct effect of a molecule produced by the parasite. Here we report a study to determine whether vitellogenin synthesis and follicle resorption are the result of parasite-induced apoptosis in the respective tissues and whether the parasite molecule acts directly on the fat body by inducing apoptosis. In vivo, the number of fat body cell nuclei with chromatin condensation are significantly elevated in parasitised females at all days examined and peaked at day 7 post-infection. A TUNEL assay to detect DNA fragmentation confirmed these observations of apoptosis. However, when fat body from uninfected females was co-cultured with live metacestodes they did not cause cells to die by apoptosis, showing that the induction signal does not come directly from the parasite. The follicle resorption observed in the ovaries of infected beetles was not associated with apoptosis of the epithelial cells. The possibility of several mechanisms underlying fecundity reduction is discussed.     

Ultrastructure of the tegumental microvilli (microtriches) of Hymenolepis diminuta

Summary The ultrastructure of microtriches of the rat tapeworm, Hymenolepis diminuta, was examined with a number of electron-microscopic techniques. Fixatives containing different buffers, non-ionic detergents, chelators, tannic acid and various concentrations of aldehydes were tested for ability to stabilize cytoskeletal components while extracting background material. These methods revealed features unique to these specialized microvilli, and permitted construction of a detailed model of microthrix architecture. The microtriches of H. diminuta are comprised of a microfilament-containing base, a dense cap and a complex junctional region between the base and cap. The microfilaments of the base are contiguous distally with a tubular structure (the junctional tubule) within the junctional region; proximally, the microfilaments end abruptly: a terminal web appears to be absent. A beveled bilayered cylinder of dense material (the core tunic) encircles the microfilamentous core. The core tunics and junctional tubules of the microtriches are specifically and uniformly aligned along the strobila. Microtriches therefore can be distinguished from other microvilli (e.g., those of enterocyte brush borders) by their complex ultrastructure and precise orientation upon the cytoplasmic surface.     

Hymenolepis diminuta: quantity of host amino acid dietary supplement and growth

Rats, each inoculated with 10 cysticercoids of Hymenolepis diminuta, were fed a synthetic protein-free, high-carbohydrate diet during the last 7 days of a 15-day experimental period. The diets were supplemented by isomolecular quantities of eight neutral amino acids, which differed in their molecular configuration and in their rate of absorption by the intestinal mucosa. The addition of an amino acid supplement to the host diet resulted in decreases in the dry weight, total nitrogen, total carbohydrate, and nonprotein dry weight components of the worms. Up to fourfold increases in the amount of the amino acid supplement did not result in corresponding decreases in worm dry weight, etc. The rate at which an amino acid is absorbed by the intestinal mucosa significantly affects worm growth: faster absorption, less decrease in worm size. Amino acids with the same type of molecular configuration have different effects on worm growth, indicating that this factor is not correlated with the decreases in worm dry weight, and associated parameters.     

Juvenile hormone titre and egg production in Tenebrio molitor infected by Hymenolepis diminuta: effect of male and/or female infection,male age and mating

Infection of Tenebrio molitor with Hymenolepis diminuta induces curtailment of female fertility. We examined ovulation and oviposition, and associated titres of juvenile hormone (JH), in relation to parasitism and mating. Oviposition was significantly increased in infected mated and virgin beetles by days 6 and 9 post-emergence. Ovulation was not changed by infection; by the end of the 18-day experiment, the total number of laid eggs was not significantly altered. On day 6, JH levels were significantly higher in virgin infected insects, compared to non-infected controls (236+/-37.7 and 107+/-9.62 pg/g wet weight). Oviposition increased after mating, but total eggs ovulated remained the same. JH levels were higher in mated females on days 12 and 18 post-emergence, for infected and control insects. Previous studies suggested that male reproductive potential might rise following infection, because uninfected females lay more eggs when mated to infected males. We tested whether this caused an increase in female JH. Males were mated on days 5 or 12, when significant changes in their reproductive physiology begin to be observed, and are maximal, respectively. However, male age was of greater significance in promoting JH levels in females (p=0.001), than infection status of either partner (p=0.33).     

Heavy Hymenolepis nana Infection Possibly Through Organic Foods: Report of a Case

We encountered a patient with heavy Hymenolepis nana infection. The patient was a 44-year-old Korean man who had suffered from chronic hepatitis (type B) for 15 years. A large number of H. nana adult worms were found during colonoscopy that was performed as a part of routine health screening. The parasites were scattered throughout the colon, as well as in the terminal ileum, although the patient was immunocompetent. Based on this study, colonoscopy may be helpful for diagnosis of asymptomatic H. nana infections.     

Hymenolepis diminuta: experimental studies on the antioxidant system with short and long term infection periods in the rats

Many helminths cause long-lasting infections, living for several years in mammalian hosts reflecting a well balanced coexistence between host and parasite. There are many possible explanations as to how they can survive for lengthy periods. One possibility is their antioxidant systems, which can serve as defence mechanisms against host-generated oxygen radicals. Therefore, the aim of this experimental study was to examine the antioxidant system in Hymenolepisdiminuta during short (1.5 months young tapeworms) and long (1.5 years old tapeworms) term infection in the rat small intestine.The strobilae of H. diminuta tapeworms (14 young and three old) were divided into three pieces: the anterior part, containing the genital primordiae in the immature segments; the medial part, containing the early uterus in the mature, hermaphroditic proglottids and the terminal part with the mature gravid uterus in the gravid segments. Supernatants of these fragments were used for determination of markers of oxidative stress: concentration of thiobarbiturate reactive substances (TBARS) and of reduced glutathione (GSH), and the activity of antioxidant enzymes: superoxide dismutase (SOD1 and SOD2), catalase (CAT), glutathione peroxidases (GSHPxs), glutathione transferase (GST) and glutathione reductase (GSHR).The results indicated changes in levels of oxidative stress markers and antioxidant enzyme activity in both the young and old forms of H. diminuta. Relatively high activity of SOD (particularly in the anterior part of young tapeworms) was observed, as was increased activity of total GSHPx and a relatively high concentration of GSH in all parts of the tapeworms. These are caused by exposure to increased amount of ROS, which are produced during the inflammatory state. Due to the high activity of antioxidant enzymes, the anterior section of young and old tapeworms is equipped with a very effective antioxidant system. Old organisms also effectively resist oxidative stress due to reduced levels of lipid peroxidation and the high activity of GST, all of which suggest good adaptation to the hostile environment in the host’s intestine.     

Hymenolepis diminuta: Analysis of the expression of Toll-like receptor genes (TLR2 and TLR4) in the small and large intestines of rats. Part II

Toll-like receptors in the gastrointestinal tract can influence intestinal homeostasis and play a role in the repair and restitution of intestinal epithelium following tissue damage. In our previous study a statistically significant increase in the level of TLR4 and TLR2 gene expression was observed in rats in early stages of hymenolepidosis. Moreover, the immunopositive cell number and the intensity of immunohistochemical staining (indicating the presence of TLRs within intestinal epithelial cells) increased over the infection period.     

A First Case of Human Trichuriasis from a Roman Lead Coffin in France

A paleoparasitological study was carried out on 2 lead coffins recovered from the Roman site of Jaunay-Clan (near Poitiers, France). For the first time, this particular type of burial gave positive parasitological results, and eggs of the whipworm Trichuris trichiura were identified in 1 individual. In the present case, thanatomorphose associated with funerary practices may explain the scarcity of the recovered eggs. However, human whipworm has now been observed in 9 individuals dated to the Roman period. The very high frequency of Trichuris sp. eggs in Roman archaeological sites (up to 80%) suggests that fecal peril, hygiene, and waste management were problematic during this period. Finally, due to the fact that very few analyses have been conducted on human bodies dated to the Roman period, more analyses must be performed in the future to provide further information about diseases in the Roman world.     

Periocular Dirofilariasis in a Young Woman: A Case Report

A case of periocular dirofilariasis has been diagnosed in Iran. A 27-yr old female referred with a history of edema and redness in the left eye since 2 wk ago. On slit lamp examination, a moving thread-like worm was seen in the subconjunctival area. Two days later, a 126 mm long, live filaria worm was extracted from the lower lid subcutaneous tissue. The worm was diagnosed as, likelihood, Dirofilaria immitis on microscopic examinations. The present case suggests that D. immitis can cause periocular infections.     

Hymenolepis diminuta: mitochondrial transhydrogenase as an additional site for anaerobic phosphorylation

Employing adult Hymenolepis diminuta SMP and exogenous pyridine nucleotide-generating systems, reduced pyridine nucleotide-dependent net 32P incorporation into ATP was examined. NADH supported rotenone-sensitive 32P incorporation and this rate increased markedly with fumarate addition, in keeping with an active fumarate reductase. Interestingly, corresponding evaluations with NADPH did not result in detectable phosphorylation in the absence or presence of fumarate. However, with NAD addition, but without NAD generation, active NADPH-dependent phosphorylation occurred, thereby demonstrating mitochondrial transhydrogenase involvement, and 32P incorporation increased significantly with fumarate addition. More importantly, in the presence of rotenone and both NADPH and NAD generation, significant net 32P incorporation was noted, but was undetectable in the presence of DCCD or protonophores (e.g., niclosamide). Without NAD generation, minimal phosphorylation occurred. These data demonstrate that with ongoing NADPH and NAD generation, the H. diminuta, proton-translocating, mitochondrial transhydrogenase can serve as an additional anaerobic phosphorylation site. A model is presented.     

A Case of Human Pulmonary Dirofilariasis in a 48-Year-Old Korean Man

Dirofilariasis is a rare disease in humans. We report here a case of a 48-year-old male who was diagnosed with pulmonary dirofilariasis in Korea. On chest radiographs, a coin lesion of 1 cm in diameter was shown. Although it looked like a benign inflammatory nodule, malignancy could not be excluded. So, the nodule was resected by video-assisted thoracic surgery. Pathologically, chronic granulomatous inflammation composed of coagulation necrosis with rim of fibrous tissues and granulations was seen. In the center of the necrotic nodules, a degenerating parasitic organism was found. The parasite had prominent internal cuticular ridges and thick cuticle, a well-developed muscle layer, an intestinal tube, and uterine tubules. The parasite was diagnosed as an immature female worm of Dirofilaria immitis. This is the second reported case of human pulmonary dirofilariasis in Korea.     

Four Human Cases of Acanthotrema felis (Digenea: Heterophyidae) Infection in Korea

Acanthotrema felis is an intestinal trematode of cats originally reported from the Republic of Korea. Only 1 human case infected with a single adult worm has been previously recorded. In the present study, we report 4 human cases infected with a total of 10 worms recovered after anthelmintic treatment and purging. All 4 patients reside in coastal areas of Jeollanam-do, Korea, and have consumed brackish water fish including the gobies, Acanthogobius flavimanus. The worms averaged 0.47 mm in length and 0.27 mm in width, and had 3 sclerites on the ventrogenital sac; 1 was short and thumb-like, another was long and blunt-ended, and the 3rd was long and broad-tipped. They were identified as A. felis Sohn, Han, & Chai, 2003. Surveys on coastal areas to detect further human cases infected with A. felis are required.     

Hymenolepis diminuta: Activity of anti-oxidant enzymes in different parts of rat gastrointestinal tract

The aim of this study was to assess the intensity of oxidative stress by measuring levels of lipid peroxidation products in the duodenum, jejunum and colon of rats infected with Hymenolepis diminuta and evaluate the effectiveness of protection against oxidative stress by measuring the glutathione levels and activity of anti-oxidant enzymes: superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase.In exposed rats we observed a significant increase of lipid peroxidation products in the duodenum and jejunum. A significant decrease in superoxide dismutase activity in all the examined parts of the digestive tract was observed. Additionally, rats from 16 to 40 days post H. diminuta infection (dpi) had a decreased catalase activity in the colon, while at 60 dpi it increased. The glutathione peroxidase activity increased significantly in the colon at 60 dpi. The increase in glutathione reductase activity was observed in the colon in rats 60 dpi. There was a lack of changes in the levels of glutathione in the duodenum and a significant increase in its concentration in the jejunum and colon from 40 to 60 dpi and from 16 to 40 dpi, respectively. In this study we observed altered activity of anti-oxidant enzymes and glutathione level in experimental hymenolepidosis, as a consequence of oxidative stress. It may indicate a decrease in the efficiency of intestinal protection against oxidative stress induced by the presence of the parasite. The imbalance between oxidant and anti-oxidant processes may play a major role in pathology associated with hymenolepidosis.     

A Human Case of Clinostomum complanatum Infection in Korea

A 33-year-old Korean man visited a medical clinic with complaints of throat discomfort and pain for one week. The symptoms occurred one day after eating raw brackish water fish, perch. Endoscopy revealed a fluke, about 5 mm in length, attaching to and peristaltically moving on the surface of the mucosa at the arytenoid region of the larynx. Microscopically, the testes were triangular, tandem, and separated by the uterus. The ovary and cirrus pouch were placed apart from median line between testes. Numerous blood cells were observed in the ceca. The worm was identified to be Clinostomum complanatum. This is the second human case of clinostomiasis in Korea.     

Fatal Balamuthia Amebic Encephalitis in a Healthy Child: A Case Report with Review of Survival Cases

Balamuthia mandrillaris is one of the 4 amebas in fresh water and soil that cause diseases in humans. Granulomatous amebic encephalitis (GAE), caused by B. mandrillaris, is a rare but life-threatening condition. A 4-year-old, previously healthy, Thai girl presented with progressive headache and ataxia for over a month. Neuroimaging studies showed an infiltrative mass at the right cerebellar hemisphere mimicking a malignant cerebellar tumor. The pathological finding after total mass removal revealed severe necrotizing inflammation, with presence of scattered amebic trophozoites. Cerebrospinal fluid (CSF) obtained from lumbar puncture showed evidence of non-specific inflammation without identifiable organisms. A combination of pentamidine, sulfasalazine, fluconazole, and clarithromycin had been initiated promptly before PCR confirmed the diagnosis of Balamuthia amebic encephalitis (BAE). The patient showed initial improvement after the surgery and combined medical treatment, but gradually deteriorated and died of multiple organ failure within 46 days upon admission despite early diagnosis and treatment. In addition to the case, 10 survivors of BAE reported in the PubMed database were briefly reviewed in an attempt to identify the possible factors leading to survival of the patients diagnosed with this rare disease.     

Complete resistance to challenges with Hymenolepis nana cysticercoids derived from mouse, rat and beetle in mice

and 1986. Complete resistance to challenges with Hymenolepis nana cysticercoids derived from mouse, rat and beetle in mice. International Journal for Parasitology 16: 623–628. When BALB/c and dd strains of mice were given eggs of Hymenolepis nana, they all became completely resistant not only to challenge with mouse-derived cysticercoids but also to challenges with rat-derived and beetle-derived cysticercoids. Serum IgG antibodies at 47–60 days post egg inoculation reacted strongly with these three different host-derived cysticercoids when examined by IFA test, but IgA and IgM isotypes reacted very weakly. Antibodies of infected mouse sera (IgG, IgM and IgA were examined) reacted not only with the protoscolex (scolex of the excysted juvenile) but also with the outer cyst wall. By contrast, uninfected mouse sera and immune sera prepared seven days post cysticercoid inoculation did not react at all. Antigens of both cyst wall and protoscolex appeared to be of parasite origin and not of host origin, and appeared similar in parasites from the different host species.