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A sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.
Environmental parameters influencing the distribution of parasite species in three neighbourhoods of differing socioeconomic conditions in La Plata, Argentina were analysed. Coproparasitological screenings were performed in children up to 14 years old from a marginal zone (100), a suburban neighbourhood (101), and an urban area (91) in 1999--2000. The presence of parasite species in environmental samples (water and soil) and the degree of association among parasite communities was documented and evaluated. The prevalence of infection in each population was 73.0%, 54.4% and 35.2%, respectively. The frequencies of helminths and pathogenic protozoa were both higher in the marginal zone, where sanitary and environmental conditions were significantly inferior compared with the other zones. The high prevalence of intestinal parasites in this infantile population was related to parasitic contamination of the soil and water sources in addition to deficient sanitary and sociocultural conditions. Calculation of an equitability index revealed that the specific richness was less equitable once socioeconomic conditions and hygienic practices were improved. This study demonstrates the need to implement management practices for the control of intestinal parasitoses in accordance with the environmental and sociocultural characteristics of a given ecosystem.
To estimate prevalence of amphistomiasis and its association with bovine Fasciola gigantica infections in Zambia, 709 faeces of cattle presented for slaughter from three major cattle rearing areas of Central, Southern and Western provinces were analysed. The prevalence rate of amphistomes was 51.6%. Egg counts per gram (EPG) of faeces ranged from 0 to 385 with a mean (± SEM) of 11.96±1.07. The origin of the cattle had a significant influence (P<0.001) on the prevalence rate. Fasciola gigantica infections accounted for 46.7% of the cattle examined. The mean EPG count (± SEM) was 6.3±0.66 with a range of 0 to 223. A total of 34.6% were mixed infections while single Fasciola and amphistome infections represented 12.1% and 17.1%, respectively. Significantly more cattle (63.8%) were infected with either single or both trematode infections (P<0.0001) than not. Mixed trematode infections were highest in the Southern province (80.0%) while the lowest were recorded in Central province (16.3%). A positive correlation (r2=0.0428) was present in mixed infections. In order to minimize losses, epidemiology and cross-resistance of amphistomiasis and fascioliasis should be studied in different ecological regions of Zambia to formulate efficient control programmes.
The helminth fauna of the barbary partridge (Alectoris barbara) in Tenerife Island (Canary Archipelago) was studied from 2001 to 2002, as there were no records of helminths from this host in the Canary Islands. Seven helminth species were identified: two cestodes Choanotaenia infundibulum and Lyruterina nigropunctata, and five nematodes Aonchotheca caudinflata, Baruscapillaria obsignata, Eucoleus annulatus, Ascaridia galli and Heterakis gallinarum. Lyruterina nigropunctata, A. galli and E. annulatus are recorded for first time in A. barbara. An analysis of available data on Alectoris spp. reveals the importance of intermediate hosts such as arthropods and earthworms in the diet of partridges. Terrestrial helminths are dominant species, with monoxenous and heteroxenous species being present in similar numbers in different Alectoris species along their geographical distribution. Helminth species found in Tenerife from A. barbara are poor indicators of the host colonization from North Africa because these helminths are species that are commonly found in fowl with a cosmopolitan distribution.
Comparisons were made of the immune and inflammatory responses of four strains of inbred mice to infection with the intestinal nematodes Trichinella spiralis and Nippostrongylus brasiliensis to determine whether genetically determined ‘high responsiveness’ to infection, seen most clearly in intestinal responses, is independent of the parasite concerned and necessarily correlated with protection. The time course of infection was followed by counting adult worms at intervals after infection. Mucosal mast cells and Paneth cell numbers were determined as indices of the intestinal inflammatory response. Levels of IgG2a and IgG1 antibodies and of the cytokines IFN-γ and IL-5 released from in vitro-stimulated mesenteric node lymphocytes were measured to assess type 1 and type 2 responses. NIH and CBA mice were the most resistant to T. spiralis and N. brasiliensis respectively, resistance in each case being correlated with the most intense intestinal inflammatory responses. C57BL/10 (B10) and B10.BR were the least resistant to T. spiralis, but were as resistant as CBA to N. brasiliensis, despite their intestinal inflammatory responses to both parasites being much lower than the other two strains. Mice infected with T. spiralis made the expected switch from a type 1 (IFN-γ) to a type 2 (IL-5) response between days 2 and 8, and there were no significant differences in levels of these cytokines between the strains. In contrast, when infected with N. brasiliensis, CBA showed an IFN-γ response at day 4, all strains switching to IL-5 by day 8 and NIH mice releasing the greatest amount of IL-5. The results indicate that the ‘high responder’ phenotype to intestinal nematode infection is in part determined by host characteristics, but is also determined by the parasite concerned – seen most clearly by the differences between NIH and CBA when infected with T. spiralis and N. brasiliensis. The fact that ‘low responder’ B10 background mice were more resistant to N. brasiliensis than ‘high responder’ NIH implies that each parasite elicits a particular pattern of protective host responses, rather than parasites being differentially susceptible to the same response profile.
The Galician definite article and direct object clitics exhibit allomorphy-like alternations which raise a number of questions for the morphology-phonology interface. This squib highlights inadequacies of allomorphic approaches to these alternations, outlining a novel way forward in which segmental changes apply to a stem in a fashion reminiscent of Celtic mutation. Differences between the article and the object clitic can then be ascribed to their prosodic weights, evident elsewhere in the language. Taken together, these findings expand our view of potential triggers for morphophonological alternations.
Outbred LACA mice were administered low (100 ova), medium (1000 ova), high (3000 ova) and trickle (4×250 ova) doses of Toxocara canis ova and the effect of infection was examined with respect to the number of larvae recovered from the brain and their behaviour. Recovery of larvae from the brain was generally low with the % recovery expressed in terms of the total dose administered being highest for the 3000 dose (6.1%) and 1000 dose (6%), followed by the 100 (4.4%) and trickle (3.5%) doses. The variation in larval recoveries was large between individual mice receiving similar doses. The level of infection in the brain was lower in mice receiving a multiple as opposed to an equivalent single dose of ova. Mice were then divided into three larval intensity groupings based upon the number of larvae recovered from their brain. The ranges for the groups were as follows: low intensity group, 0–15 larvae; moderate intensity group, 27–55 larvae; high intensity group, 66–557 larvae. Three behavioural tests were carried out on control and infected mice. Exploration and response to novelty was examined using a ‘T’ maze and learning was investigated by means of a water-finding task. Anxiety was measured using an elevated plus maze apparatus. Infected mice were less explorative and less responsive to novelty in the ‘T’ maze and this was particularly pronounced for the heavily infected mice. In the elevated plus maze, infected mice displayed reduced levels of anxiety to aversive and exposed areas of the maze, particularly in the case of the moderate and high intensity mice. There was evidence for impaired learning ability in the water task apparatus for moderate and high intensity mice. In general, the effects of infection on behaviour were more pronounced in the moderate and high intensity groups compared to the low intensity group.
Brachylaima cribbi is a recently described species of terrestrial trematode that infects mammals and birds with helicid land snails as its first and second intermediate hosts. The adult worm is 2.5–6.0 mm long by 0.5–0.8 mm wide being a long slender cylindrical worm with oral and ventral suckers in the anterior quarter and genital pore in the posterior quarter. Scanning electron microscopy shows that there is a dense covering of tegumental spines at the anterior end which diminishes towards the posterior extremities of the worm. Development of spines was observed in juvenile and mature adult worms. In young worms 1–3 weeks post infection (wpi) spines appear as buds with a serrated edge each having 1–4 spikes per spine. As the worm ages the spines broaden and by 5 wpi the number of spikes per spine increases to an average of 8.1. The serial development of oral sucker papillae in the cercaria, metacercaria and adult worm was observed with the finding of an elongated papilla with a bifurcated tip on the cercaria becoming a shorter and thicker elongated papilla with a large central stoma on the metacercaria. In the adult worm, this papilla becomes dome-shaped with a small central stoma. For some of these papillae a cilium could be seen extended from the central stoma. Other life-cycle stages illustrated were the hatched egg with an extruded egg membrane minus an operculum and a portion of the branched sporocyst dissected from the digestive gland of the land snail Theba pisana showing a terminal birth pore. Scanning electron microscopy morphological features of the adult worm observed for the first time in a Brachylaima were the unarmed cirrus extended from the genital pore with released sperm present and the Laurer's canal opening visible in tegumental folds on the dorsal surface approximately 300 μm posterior to the genital pore.
Dictyocaulus capreolus n. sp. recovered from roe deer, Capreolus capreolus and moose, Alces alces in Sweden is described and figured. Morphological studies revealed the new species to be closest to D. eckerti and D. africanus on the basis of mouth shape, all three species having an elongate mouth opening. The other species of the genus, including D. viviparus, all have a circular to oval mouth opening. Dictyocaulus capreolus n. sp. can be distinguished from D. eckerti and D. africanus on the basis of the morphology of the buccal capsule and the bursa. These morphological studies support earlier evidence of the presence of a new species of Dictyocaulus in roe deer and moose that could be distinguished from D. eckerti and D. viviparus using either a PCR-linked hybridization assay or image analysis software to study the dimensions of the buccal capsule.
The effect of praziquantel (PZQ) on the strobilar development of the cyclophyllidean cestode Mesocestoides corti was explored. Mesocestoides corti larvae were cultivated under conditions reported to favour their differentiation to the adult stage. Parasites were exposed to 0.1 μg ml-1 PZQ for 16 h and subsequently transferred to drug-free medium. The ocurrence of segmentation — an early event of the larval somatic differentiation to the adult worm — was considered as quantitative data. This phenomenon was evidenced earlier in worms transiently exposed to PZQ with respect to control cultures. Moreover, the rate of segmentation of drug-treated worms at the end of the experiment almost doubled that of control worms. To date, no similar effect on any cestode developmental process has been reported for an anthelmintic drug. In the light of the existing knowledge and understanding of PZQ mechanisms of action, the proposed experimental approach could contribute to the elucidation of pathways and mechanisms involved in cestode strobilar development.
Release of Echinostoma caproni cercariae and Schistosoma mansoni from experimentally infected Biomphalaria glabrata snails maintained under different laboratory conditions was studied. Infected snails were isolated individually for 1 h in Stender dishes containing 5 ml of artificial spring water and the number of cercariae released during this time was recorded. Of numerous conditions tested, the addition of lettuce, the use of water conditioned by B. glabrata snails and a temperature of 35°C significantly increased the release of E. caproni cercariae. A significant increase in cercarial release of S. mansoni was seen only in cultures fed lettuce. A temperature of 12°C caused a significant decrease in cercarial release of both E. caproni and S. mansoni. Increased snail activity associated with feeding behaviour was probably responsible for the enhanced cercarial sheds observed in this study.
Transformative justice is a vision, a framework, and a theory of change which pushes for radical abolition and reimagining of entire systems. It is a community-led strategy which centers on and seeks to uproot structural determinants of oppression. In this article, I outline how applied linguistics can and should draw on transformative justice principles as a methodology for doing applied linguistics and as an underpinning theory of change for the discipline itself. I explore how transformative justice in applied linguistics involves addressing the colonial roots of the discipline and its complicity in perpetuating raciolinguistic ideologies and co-constituted discourses of linguistic deficiency. I argue for new conceptualizations of impact which prioritize community solidarity. I argue for applied linguists to end collaborations with the police, the military, and the prison industrial complex, showing how these collaborations rely on systems of punitive accountability and modest reforms. I argue that transformative justice is a life-affirming theory of change for the discipline of applied linguistics and for the marginalized communities we work with.
The tegument of adult Saccocoelioides godoyi Kohn & Froes, 1986 (Digenea: Haploporidae), specimens of which were collected from the intestine of the freshwater fish, Leporinus friderici (Bloch, 1794) (Anostomidae) from the reservoir of Itaipu Hydroelectric Power Station, Parana State, Brazil, was studied by transmission electron microscopy. The tegument comprises an external anucleate layer, covered by a surface plasma membrane and associated glycocalyx. The surface layer is bound by the basal plasma membrane and contains spines, two types of inclusion bodies and mitochondria. Tegumental cell bodies are located beneath the surface musculature and contain a single nucleus, cytoplasm with rough endoplasmic reticulum, mitochondria, ribosomes, and inclusion bodies similar to those found in the external layer. Cytoplasmic strands connect the cell bodies to the external surface layer, suggesting that the inclusion bodies are produced in these cells and pass up into the syncytium, as is known for other digeneans from experimental evidence.
Investigations were conducted on the host response in rainbow trout and the associated changes in mucous cell density during infection with the skin monogenean Gyrodactylus derjavini. Parasite populations increased on all naive hosts and peaked 4–5 weeks p.i. after which infection levels decreased. Introduction of naive fish into responding host populations resulted in heavy infections of the naive fish, whereas parasite expulsion continued in the responding host groups showing an acquired, non-sterile immunity. This non-sterile immunity lasted at least a month as these hosts were refractory to reinfection despite being exposed to a high infection pressure. Mucous cell hyperplasia was seen in some groups during the intermediary phase of infection, but at the termination of the study a significant depletion was evident. Passive immunization of naive host (with sera from immune hosts) did not confer protection. This indicates differences between host responses to G. derjavini compared to responses against other pathogens where such a passive immunity has been described.
T helper cell (Th1 and Th2) associated responses were examined following a primary infection with the gastrointestinal nematode Heligmosomoides polygyrus in five inbred strains of mice with different resistance phenotypes. Levels of (i) mast cell protease, (ii) specific IgE, (iii) nitric oxide and (iv) specific IgG2a, as markers of Th2 and Th1 associated responses, respectively, were determined in sera and intestinal fluids and correlated with worm burdens. The ‘fast’ responder (resistant) strains SWR and SJL produced strong Th2 and Th1 associated responses respectively in a mutually exclusive fashion. The F1 hybrid (SWR×SJL) F1, showed rapid expulsion of the parasite and expressed both intense Th1 and Th2 responses, suggesting synergism between Th1 and Th2 activity in these mice. The results indicate that both Th2 and Th1 responses operate in mice following a primary infection with H. polygyrus and that each Th response may be involved to a greater or lesser degree within certain strains. Resistance to H. polygyrus was found to correlate only to the intensity of either the gut-associated mastocytosis or nitric oxide production in these strains but not to either specific IgE or IgG2a titres. Chronic infections in the ‘slow’ response phenotype mouse strains CBA and C57BL/10, were associated with both poor Th2 and poor Th1-associated responses attributed to a general parasite-mediated immunosuppression of the host immune response to infection.
Waterfowl from Lake Wanaka and the Waitaki Lakes watershed of New Zealand's South Island were surveyed to find natural hosts with adult echinostomes and schistosomes to provide sufficient numbers of eggs for laboratory studies. The Canada goose (Branta canadensis) was found to host an echinostome determined to be a New Zealand strain of Echinostoma revolutum. The New Zealand scaup (Aythya novaeseelandia) concurrently hosts three species of echinostomes (E. revolutum, Echinoparyphium cinctum and E. recurvatum) plus two species of avian schistosomes (Trichobilharzia sp. and Dendritobilharzia pulverulenta). In the Canada goose and the New Zealand scaup, adult gravid echinostomes predominated over juveniles. In other waterfowl surveyed, very few echinostomes were found, with juveniles predominating.
Carbon-13 nuclear magnetic resonance (NMR) spectroscopy was employed to investigate alterations in hepatic carbohydrate metabolism in Meriones unguiculatus infected with Echinococcus multilocularis. Following portal vein injections of an equimolar mixture of ]#x005B;1,2-13C2]acetate and [3-13C]lactate, perchloric acid extracts of the livers were prepared and NMR spectra obtained. Isotopomer analysis using glutamate resonances in these spectra showed that the relative contributions of endogenous and exogenous substrates to the acetyl-CoA entering the tricarboxylic acid cycle differed significantly between infected and control groups. The mole fraction of acetyl-CoA that was derived from endogenous, unlabelled sources (FU) was 0.50±0.10 in controls compared to 0.34±0.04 in infected animals. However, the fraction of acetyl-CoA derived from [3-13C]lactate (FLL) was larger in livers of infected animals than those from controls with values of 0.27±0.04 and 0.18±0.04, respectively. Similarly, the fraction of acetyl-CoA derived from [1,2-13C2]acetate (FLA) was larger in livers of infected animals compared to those in controls; the fractions were 0.38±0.01 and 0.32±0.07, respectively. The ratio of FLA:FLL was significantly smaller in the infected group with a value of 1.42±0.18 compared to 1.74±0.09 for the controls. These results indicate that alveolar hydatid disease has a pronounced effect on the partitioning of substrates within the pathways of carbohydrate metabolism in the host liver.
We report the midterm results of our strategy utilizing transatrial-transpulmonary repair for tetralogy of Fallot at a single institution in a low-middle income country.
Methods:
Medical records were retrospectively reviewed for 532 consecutive patients who underwent definitive repair of tetralogy of Fallot at our institution from 2010 to 2020.
Results:
The median age and weight of patients in the study patients were 11.6 months (interquartile range, 8.6–17.2 months) and 7.5 kg (interquartile range, 6.8-8.8 kg). The pulmonary valve annulus was preserved (no transannular patch) in 398 patients (75%) and a mini-transannular patch was utilized for 134 patients (25%). The overall survival was 98% at 1 year, and 97% at 10-years follow-up, respectively. Longer postoperative ventilation time was the only risk factor correlated to early death (p = 0.004; Odds Risk, 1.04; 95% confidence intervals, 1.01–1.07). Fourteen patients required pulmonary valve replacement (2.6%, 14/532), four required surgical resection to relieve right ventricular outflow tract obstruction (0.8%, 4/532), and freedom from reoperation of the right ventricular outflow tract was 87% at 10 years. The only risk factor for right ventricular outflow tract reoperation was a postoperative systolic pressure gradient through the right ventricular outflow tract of greater than 50 mmHg (p < 0.001; HR, 47; 95% confidence intervals, 9.1–244). In total, 94.6% (471/489) of the patients were asymptomatic at the latest follow-up without significant arrhythmia.
Conclusion:
At our institution in an low-middle income country, the transatrial-transpulmonary repair for tetralogy of Fallot has excellent midterm results with few reoperations required. Close long-term follow-up is essential for patients who undergo repair with a mini-transannular patch and may eventually require pulmonary valve replacement.
In this study, the excretory–secretory products (ESP) of the daughter sporocysts of Vesicocoelium solenophagum (Trematoda) and plasma proteins of its host, Sinonovacula constricta were characterized by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) and gelatin-substrate gel analyses, and the relationships between them were analysed using immunoblotting. Proteinase activity was detected in the ESP from daughter sporocysts of V. solenophagum. Some polypeptides of the ESP were found to be recognized by antiserum, raised against plasma from non-infected S. constricta, suggesting that the ESP may mimic host molecules (molecular mimicry). In contrast, neither the obvious proteinase activity nor the binding to the antisera was observed for the soluble proteins of daughter sporocyst, indicating that the ESP may play a important role in the parasite–host relationship. Although the plasma of infected S. constricta contained polypeptides that were similar to the plasma of non-infected bivalves, increased quantities of proteins at >170 kDa, 15 kDa and decreased quantities at 60 kDa were observed in the plasma of infected bivalves. Immunoblotting analysis revealed that the plasma of infected bivalves had a faint reaction with both anti-non-infected plasma antisera and anti-sporocyst antisera. These results indicated that the structure and quantity of some polypeptides from the plasma of infected bivalves had changed because of the infection with V. solenophagum. The polypeptides between the plasma of bivalves from a non-epidemic area and that from an epidemic area were similar, but the former had more polypeptides of 170–220 kDa and much greater proteinase activity than the latter, suggesting that the increased polypeptides of 170–220 kDa and the high proteinase activity in plasma may be favourable for protecting the host from being invaded by the parasites.