Anatomo-radiographic description of the axial skeleton of the crab-eating fox (Cerdocyon thous)

The aim of this study was to describe the axial skeleton of a wild Brazilian carnivorous, the crab-eating fox (Cerdocyon thous). Five specimens of crab-eating fox were previously unfrozen for radiographic exams and their bones went through dissection and chemical maceration. This animal presents seven cervical vertebrae, and from the third on, they become shorter and wider than the other ones e the spinous process was makeable from the fifth cervical vertebrae on. There are thirteen thoracic vertebrae and the spinous process of the lumbar vertebrae, which are seven, decreases from the fifth on. The sacrum is formed by two vertebrae and there are twenty or twenty one caudal vertebrae. It can be concluded that the crab-eating fox axial skeleton is similar to that of the domestic dog.

Mode B ultrasonography and abdominal Doppler in crab-eating-foxes ( Cerdocyon thous )

Abstract: Annually hundreds of crab-eating foxes (Cerdocyon thous) are referred to rehabilitation centers and zoos in Brazil. The ultrasonographic study of wildlife species is an important tool for a non-invasive and accurate anatomical description and provides important information for wildlife veterinary care. The aim of the present study was to determine the characteristics of the main abdominal organs as well as the vascular indexes of the abdominal aorta and renal arteries of crab-eating foxes (Cerdocyon thous) using mode B ultrasonography and Doppler ultrasonography, respectively. Ultrasonographic features of the main abdominal organs were described and slight differences were noticed between ultrasound imaging of abdominal organs of crab-eating foxes and other species. The bladder presented wall thickness of 12±0.01mm, with three defined layers. Both, the right and left kidneys presented corticomedullary ratio of 1:1 and similarly to the adrenals and the liver, they were homogeneous and hypoechoic compared to the spleen. The spleen was homogeneous and hyperechoic compared to the kidneys. The stomach presented 3 to 5 peristaltic movements per minute, wall thickness of 39±0.05mm and lumen and mucosa with hyperechoic and hypoechoic features, respectively. Small and large intestines presented 2 to 3 peristaltic movements per minute, wall thickness of 34±0.03mm and three defined layers with hyperechogenic (submucosa and serosa) and hypoechogenic (muscular) features. Ovaries of the female crab-eating fox were hypoechoic compared to the spleen and with heterogeneous parenchyma due to the presence of 2x2mm ovarian follicles. Prostates of the six males were regular and with a well defined boundary, with a homogeneous and hyperechoic parenchyma compared to the spleen. Vascular indexes of the abdominal aorta (PSV: 25.60±0.32cm/s; EDV: 6.96±1.68cm/s; PI: 1.15±0.07 e RI: 0.73±0.07) and right (PSV: 23.08±3.34cm/s; EDV: 9.33±2.36cm/s; PI: 1.01±0.65 e RI: 0.65±0.16) and left renal arteries (PSV: 23.74±3.94cm/s; EDV: 9.07±3.02cm/s; PI: 1.04±0.31 e RI: 0.64±0.10) were determined. Thus, conventional and Doppler ultrasonographic imaging provides basic information that can be used as reference for the species as well for other wild canids and it is a precise and non-invasive method that can be safely used to evaluate and diagnose abdominal injuries in these patients.

Fecal cortisol metabolites as indicators of stress in crab-eating-fox (Cerdocyoun thous) in captivity

Abstract: Blood samples collection is a common method in biological research using domestic animals. However, most blood sampling techniques are complicated and highly invasive and may therefore not be appropriate for wildlife animals in research concerning stress. Thus, a non-invasive method to measure steroid hormones is critically needed. The first goal of this study was to determine how glucocorticoids concentrations are impacted by translocation and reproductive activity in crab-eating-fox (Cerdocyoun thous) in captivity. The physiological relevance of fecal glucocorticoid metabolites was further validated by demonstrating: (1) The translocation of a male to a females enclosure resulted in a 3.5-fold increase compared to baseline concentrations, (2) changes in adrenocortical activity, as reflected in concentrations of fecal cortisol metabolites during reproduction, gestation and lactation in females foxes, indicating that social interactions resulted in large increases of fecal glucocorticoids metabolites during the reproductive season. From these findings we conclude that fecal samples can be used for the non-invasive assessment of adrenocortical status in crab-eating-fox.

Long-term habituation (LTH) in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory

A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (³15 trials, intertrial interval (ITI) of 171 s) invariably yielded LTH, while a weak training protocol (WTP) (£10 trials, ITI = 171 s) invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA) activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining). The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

Electron microscopy of glial cells of the central nervous system in the crab Ucides cordatus

Invertebrate glial cells show a variety of morphologies depending on species and location. They have been classified according to relatively general morphological or functional criteria and also to their location. The present study was carried out to characterize the organization of glial cells and their processes in the zona fasciculata and in the protocerebral tract of the crab Ucides cordatus. We performed routine and cytochemical procedures for electron microscopy analysis. Semithin sections were observed at the light microscope. The Thiéry procedure indicated the presence of carbohydrates, particularly glycogen, in tissue and in cells. To better visualize the axonal ensheathment at the ultrastructural level, we employed a method to enhance the unsaturated fatty acids present in membranes. Our results showed that there are at least two types of glial cells in these nervous structures, a light one and a dark one. Most of the dark cell processes have been mentioned in the literature as extracellular matrix, but since they presented an enveloping membrane, glycogen and mitochondria - intact and with different degrees of disruption - they were considered to be glial cells in the present study. We assume that they correspond to the perineurial cells on the basis of their location. The light cells must correspond to the periaxonal cells. Some characteristics of the axons such as their organization, ensheathment and subcellular structures are also described.

Acute and chronic effects of cadmium on blood homeostasis of an estuarine crab, Chasmagnathus granulata, and the modifying effect of salinity

Whole body oxygen consumption and some hemolymph parameters such as pH, partial pressure of gases, level of ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both acute (96 h) and chronic (2 weeks) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all instances, the crabs developed hemolymph acidosis, but no respiratory (increased PCO2) or lactate increases were evident. Hemolymph levels of sodium and calcium were always increased by cadmium exposure. The chronic toxicity of cadmium was enhanced at 12‰ salinity, even causing a significantly higher mortality in comparison with the higher salinity (30‰) used. A general metabolic arrest took place at 12‰ salinity in the crabs chronically exposed to cadmium, as indicated by decreases of oxygen consumption and PCO2, an increase of PO2, along with no changes in lactate levels. These imbalances were associated with severe necrosis and telangiectasia in the respiratory gills, probably leading to respiratory impairment and finally histotoxic hypoxia and death of the animals.

Pediculus capitis infestation according to sex and social factors in Argentina

OBJECTIVE: To determine the intensity of Pediculus capitis infestation (abundance) among Argentinean schoolchildren. Children's sex and social stratum were analyzed as modifiers of the general prevalence and degree of parasitism. METHODS: The study included 1,370 schoolchildren (692 girls, 678 boys) from 26 schools of the province of La Rioja (21 public schools, five private schools). Classic prevalence was obtained as the percentage of children with nits and/or lice. Moreover, five degrees of parasitism were classified: 0) children with no signs of pediculosis; 0+) children with evidence of past infestation; 1) children with a recent infestation and low probability of active parasitism; 2) children with a recent infestation and high probability of active parasitism; 3) children with mobile lice (active pediculosis). RESULTS: The general prevalence was 61.4% (girls: 79%; boys: 44%, p<0.001). Private schools showed lower prevalence than public schools (p=0.02), especially due to the low prevalence in boys. Fifty percent of children were classified in classes 0 and 0+, 22% in class 1; and 28% in grades 2 and 3. The proportion of children in grade 3 was higher in public schools than in private schools. There were significant sexual differences in the intensity of parasitism for grades 2 and 3, where girls' rates exceeded twice those of boys'. CONCLUSIONS: Sex and social stratum are important modifiers of P. capitis general prevalence and degree of infestation. The classification of children by intensity of infestation allowed a more precise delimitation of this condition, which is especially important for disease surveillance and application of control measures.

Chagas' disease in the Brazilian Amazon: II. A serological survey

A serological survey, involving indirect immunofluorescence testing of blood sera samples, was carried out on the residents of one in every five dwellings in the town of Barcelos (in the northern part of the State of Amazonas, on the right bank of the Rio Negro, 490 Km from Manaus by river) and on the rural populations of the villages of Piloto and Marará (also on the right bank of the Rio Negro, 30 minutes by boat from Barcelos). A total of 710 sera samples were tested, 628 from the resident population in the town of Barcelos, 35 from Piloto and 47 from Marará. The tests were carried out using human anti-gammaglobulin type IgG (Biolab) and antigen from formolized culture of T.cruzi Y strain. The sera were serially diluted from 1:40 to 1:320 in PBS 7.2. Of the 710 samples examined 89(12.5%) were positive for anti-T.cruzi antibodies: 2 of these (2.2%) at a dilution of 1:320; 12(13.4%) at 1:160; 38 (42.6%) at 1:80; and the remainder at 1:40, giving a median serological dilution of 1:80. The following questions are discussed: the high serological prevalence for Chagas'infection found in our survey; the possibility of serological cross-reactions; the need for confirmatory tests for the positives reactions; and the strong correlation between our results and preliminary epidemiological data (such as the level of human contact with wild triatominae, know locally as "Piacava's lice". We draw attention to the isolation by xenodiagnosis of one strain of T.cruzi from a patient with positive serology for Chagas' infection.

Chagas' disease in the Brazilian Amazon: III. a cross-sectional sutdy

Two serological surveys for Chagas' infection were carried out, in 1991 and 1993, respectively, using a conglomerate family samples from the residents in the town of Barcelos (in the northern part of the State of Amazonas, on the right bank of the Rio Negro, 490 Km up-river from Manaus), using indirect immunofluorescent tests for anti-T. cruzi antibodies. In the first survey (1991), 628 blood samples from the residents of 142 dwellings were tested, showing positive in 12.7% for anti-T. cruzi antibodies and in 1993 an other 658 samples from residents of 171 dwellings showed positive in 13.7% of the tests, thus confirming the previous results. From 170 individuals with positive serology for T. cruzi antibodies, 112 (66%) were interviewed and submitted to electrocardiographic and clinical examinations; 82 (73.2%) of them gave consent for xenodiagnosis. From the 112 interviewed 52 (46.4%) recognized the triatomines as "piaçavas' lice", 48 (42.8%) knew the bugs from their work places being gatherers of piaçava fibers in rural areas and 19 (16.9%) said that have been bitten by bugs in their huts. Only 2 (2.4%) of 82 xenodiagnosis applied were positive for T. cruzi and 9 (8%) of the ECG had alterations compatible with Chagas' disease.

Paragonimosis in the Cajabamba and Condebamba districts, Cajamarca, Peru

Stool samples from 409 pre-school and school students, living in six villages of the Cajabamba and Condebamba districts, Cajamarca, Perú, were examined using wet preparations and Lumbreras' method, looking for Paragonimus eggs. Fecal and sputum samples from two children (0.5%) of 6 and 8 year-old showed eggs of Paragonimus. One hundred and twenty freshwater crabs, Hypolobocera chilensis eigenmanni, were collected from the Condebamba valley and 21 (17.5%) of them were infected with P. mexicanus (syn. P. peruvianus) metacercariae. Our results show the persistence of Paragonimus in human beings and in the main source of infection, the crabs.

Chagas disease in the Brazilian Amazon: IV. a new cross-sectional study

A new conglomerate family sample of 194 dwellings with 996 resident persons were studied in the town of Barcelos, State of Amazonas, in order to re-evaluate the risk of Chagas disease. During the survey the persons were interviewed and in this occasion we showed to them a collection of Panstrongylus, Rhodnius and Triatoma, asking if they recognized and eventually have been bitten by this kind of bugs. At this time we collected 500 ul of blood in microtainer® tubes from 886 interviewed persons who gave permission after informed consent. A screening test for T. cruzi antibodies based on agglutination of colored polymer particles, sensitized with three different synthetic peptides of T. cruzi (ID-PaGIA Chagas Test)®, showed 13.2% of sera positivity, but only 6.8% were confirmed by indirect immunofluorescence, and ELISA with purified T. cruzi antigens. Two hundred and six interviewed persons (20.7%) recognized the triatomines, as "piaçavas' lice" and 62 (30%) confirmed that have been bitten by the bugs, 25.8% of them had a positive serology for T. cruzi infection. Electrocardiographic alterations were shown in 9.3% of the seropositives and in 11.9% of the seronegative cases. This was considered not statistically significant.

Vibrio spp. and Salmonella spp., presence and susceptibility in crabs Ucides cordatus

The presence of Vibrio spp. and Salmonella spp. in crabs marketed at the Bezerra de Menezes Ave., Fortaleza, State of Ceará, Brazil, was assessed between February and May, 2003. The number of individuals sampled in each one of the fifteen weekly samplings ranged between four and eight. Seven strains of Salmonella, from four different samplings, were identified, being five of them identified as serotype S. Senftenberg and two as S. Poona. All strains of Salmonella were sensitive to the tested anti-microbial drugs, with the exception of tetracycline and nalidixic acid, for which an intermediary sensibility was found. The MPN's for Vibrio ranged between 110/g and 110,000/g. Of the forty five Vibrio strains isolated from the crab samples, only 10 were identified up to the species level: two V. alginolyticus and eight V. parahaemolyticus. Bacteria belonging to the Enterobacteriaceae and Pseudomonaceae families were also identified, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pantoea agglomerans and Pseudomonas aeruginosa. The proper cooking of the animals is recommended in order to avoid problems for the consumers of this crustacean.

Prevalence of pediculosis capitis in children from a rural school in Yucatan, Mexico

We conducted an analytical cross-sectional survey to estimate the prevalence of and factors associated with active head lice infestation. In total 140 children, aged 6 to 16-years, from a public school in rural Yucatan, Mexico, were examined by wet-combing. A structured questionnaire was used to collect information on individuals and the conditions in the surrounding environment. Head lice infestation was found in 19 out of the 140 children tested (13.6%) and this was associated with both lower income (OR 9.9, 95% CI 2.15-45.79, p = 0.003) and a higher frequency of hair washing (OR 8, 95% CI 1.58-50, p = 0.012). Intersectoral control programs that take into account the socioeconomic differences of children should be implemented.

PREHISTORICAL Pediculus humanus capitis INFESTATION: QUANTITATIVE DATA AND LOW VACUUM SCANNING MICROSCOPY

A pre-Columbian Peruvian scalp was examined decades ago by a researcher from the Oswaldo Cruz Foundation. Professor Olympio da Fonseca Filho described nits and adult lice attached to hair shafts and commented about the origin of head lice infestations on mankind. This same scalp was sent to our laboratory and is the subject of the present paper. Analysis showed a massive infestation with nine eggs/cm2 and an impressive number of very well preserved adult lice. The infestation age was roughly estimated as nine months before death based on the distance of nits from the hair root and the medium rate of hair growth. A small traditional textile was associated with the scalp, possibly part of the funerary belongings. Other morphological aspects visualized by low-vacuum scanning electron microscopy are also presented here for adults and nits.

Uma nova Sterculia L. (Sterculiaceae) para a Amazônia

Descoberta na Reserva A. Ducke, Manaus, Amazonas, Sterculia duckei Taylor ex J. A. C. Silva et Μ. F. Silva, nov. sp., mostra afinidade com S. pruriens, diferindo dela, principalmente, por apresentar em suas flores pêlos estrelados e glândulas distribuídos desde o ápice até a base do cálice, pêlos glandulares ausentes. É registrada para os Estados do Amazonas e Pará.