Prevalence of human papillomavirus types in women with pre-neoplastic and neoplastic cervical lesions in the Federal District of Brazil

As a contribution to the public health authorities in planning prophylactic and therapeutic vaccine strategies, we describe the prevalence of human papillomavirus (HPV) types in women presenting abnormal cytological results in Pap smear screening tests in the Federal District, Central Brazil. We studied 129 cervical scraping samples from women whose cytological tests showed either pre-neoplastic or neoplastic lesions. Amplification of HPV DNA was performed by polymerase chain reaction using consensus primers MY09 and MY11 followed by identification of isolates by restriction fragment length polymorphism. We detected HPV DNA in 62% of the samples, including HPV-16 in 43.8%, HPV-58 in 12.5%, HPV-31 in 10%, HPV-53 in 6.3%, each of HPV-18 and HPV-33 in 3.8% of the isolates. Other types (HPV-35, -52, -66, -CP8304, -6, -11, and -CP8061) were less frequent (= or < 2.5% each). The prevalence of HPV-58 was relatively higher in this population than in data in South America, but similar to results obtained in other studies in Latin America, Europe, and Eastern Asia. Case-control studies need to be carried out to establish the association between the prevalence of HPV types specially the less frequent high-risk types and cervical cancer.

Foco de doença de Chagas em Arcádia, estado do Rio de Janeiro, Brasil

Following the report of triatomine nymphs in a house in Arcadia, Miguel Pereira, state of Rio de Janeiro, Brazil, the infested dwelling was checked. Several eggs and 46 specimens of Triatoma vitticeps (Stal, 1859) were collected. Among them, adults and nymphal instars accounted for 43.5% and 56.5%, respectively. Analysis of blood meals showed the ecletism of this species; 24 (52.2%) were single feeds, 18 insects (39.1%) fed on two hosts and 4 (8.7%) on three hosts. Trypanosoma cruzi infection rate of examined specimens was 13%. Finally one of the residents of the house was positive for anti-T. cruzi antibodies using indirect immunofluorescence.

First report of Lymnaea columella Say, 1817 (Pulmonata: Lymnaeidae) naturally infected with Fasciola hepatica (Linnaeus,1758) (Trematoda: Digenea) in Argentina

We report the first evidence of natural infection of Lymnaea columella with Fasciola hepatica in Argentina. A sample of 601 snails was collected in May 2003 in northeastern Corrientes, a province bounded on the north by Paraguay, on the east by Brazil and on the southeast by Uruguay. Among 500 examined snails, 44 (8.8%) were exclusively infected with F. hepatica. Parasite identification was based on morphological features of cercariae from snails, and of eggs and adult flukes from Wistar rats. We discuss the events suggesting that an enzootic transmission cycle of F. hepatica has been recently established in northeastern Corrientes.

Angiostrongylus costaricensis and experimental infection of Sarasinula marginata II: elimination routes

Angiostrongylus costaricensis intermediate hosts are terrestrial mollusks mostly belonging to the Veronicellidae family. In the present investigation we focused on the mechanisms of larval expulsion from Sarasinula marginata infected with A. costaricensis. Twenty-five mollusks were individually infected with 5000 L1 and sacrificed at 30 min and 1, 2, 4, 6, and 8 h post-infection and at days 1, 2, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 20, 21, 22, 25, 26, 28, and 30 post-infection; the mollusks were then fixed and stained. Diverse organs involved throughout the course of the migratory routes of larvae from oral penetration on were specified and the mechanisms of larval access to the fibromuscular layer through the kidney, rectum, and vascular system were defined. The elimination of L3, derived from oral and/or cutaneous infections, appears to depend on granulomas located close to the excretory ducts of mucous cells.

Feeding, defecation, and development times of Meccus longipennis Usinger, 1939 (Hemiptera: Reduviidae: Triatominae) under laboratory conditions

Aspects related to hatching, time-lapse between presenting the blood-meal and beginning of feeding, feeding time, postfeed defecation delay, mortality, and fecundity for each stage of Meccus longipennis life-cycle were evaluated. The bugs were maintained in a dark incubator at 27 ± 1ºC and 80 ± 5% rh, were fed weekly and checked daily for ecdysis or death. The hatching rate observed for 300 eggs was 76.7% and the average time of hatching was 19.8 days. Mean time-lapse between presentation of the blood meal and the beginning of feeding was under 5 min in nymphal stages and postfeed defecation delay was under 10 min in most stages, except in fourth and fifth stages. Mean feeding time was longer than 10 min in most stages, except in fourth stage. One hundred thirty-one nymphs (N) (65.5%) completed the cycle and the average time from NI to adult was 192.6 ± 34.8 days. The average span in days for each stage was 18.1 for NI, 21.4 for NII, 29.5 for NIII, 45.5 for NIV and 55.9 for NV. The number of bloodmeals at each nymphal stage varied from 1 to 5. The mortality rate was 3.29 for NI, 6.8 for NII, 2.92 for NIII 3.76 for NIV, and 10.16 for NV nymphs. The average number of eggs laid per female in a 9-month period was 615.6. Based on our results, we conclude that M. longipennis has some biological and behavioral characteristics which influence its capacity of becoming infected and transmitting Trypanosoma cruzi to human populations in those areas of Mexico where it is currently present.

Ultrastructural study of the in vitro interaction between Biomphalaria glabrata hemocytes and Schistosoma mansoni miracidia

Biomphalaria glabrata and Schistosoma mansoni relationship was studied by light microscopy (LM) and freeze-fracture replica technique (FFR). We observed very thin cytoplasmic extensions of hemocytes in the LM, which then surround immobilize the miracidia. FFR images showed that the contact site between hemocytes cytoplasmic extensions and the external tegumentary coat involved only superficial layers of miracidia. Numerous vacuoles and filopodia were observed in the hemocyte cytoplasm, the latter binding with those from neighboring cells. In spite of the close interfilopodia contact, no cellular junctions were seen at these sites nor between filopodia-miracidia contact areas. The observed migration of hemocytes and their disposition in layers surrounding the miracidia in vitro correspond to previous studies.

Flight metabolism in Panstrongylus megistus (Hemiptera: Reduviidae): the role of carbohydrates and lipids

The metabolism of lipids and carbohydrates related to flight activity in Panstrongylus megistus was investigated. Insects were subjected to different times of flight under laboratory conditions and changes in total lipids, lipophorin density and carbohydrates were followed in the hemolymph. Lipids and glycogen were also assayed in fat body and flight muscle. In resting insects, hemolymph lipids averaged 3.4 mg/ml and significantly increased after 45 min of flight (8.8 mg/ml, P < 0.001). High-density lipophorin was the sole lipoprotein observed in resting animals. A second fraction with lower density corresponding to low-density lipophorin appeared in insects subjected to flight. Particles from both fractions showed significant differences in diacylglycerol content and size. In resting insects, carbohydrate levels averaged 0.52 mg/ml. They sharply declined more than twofold after 15 min of flight, being undetectable in hemolymph of insects flown for 45 min. Lipid and glycogen from fat body and flight muscle decreased significantly after 45 min of flight. Taken together, the results indicate that P. megistus uses carbohydrates during the initiation of the flight after which, switching fuel for flight from carbohydrates to lipids.

An alternative technique to reveal polysaccharides in Toxoplasma gondii tissue cysts

Ultrathin sections of tissue cysts isolated from the brain of Toxoplasma gondii infected mice were submitted to two different methodologies derived from the periodic acid - Schiff's reagent (PAS) technique. The use of osmium tetroxide vapor as a developing agent of the aldehyde oxidation to reveal polysaccharides with periodic acid resulted in positive reaction in amylopectin granules in bradyzoites, as well as in the wall and matrix of the cysts, with excellent increment of the ultrastructural morphology. This technique can be used for study of T. gondii-host cell intracellular cycle, the differentiation tachyzoite-bradyzoite, and also for the formation of cysts into the host cells.

Host nutritional status as a contributory factor to the remodeling of schistosomal hepatic fibrosis

Weaning Swiss mice were percutaneously infected with 30 cercariae of Schistosoma mansoni and submitted to a shifting either from a deficient to a balanced diet or vice-versa, for 24 weeks. The nutritional status was weekly evaluated by measurements of growth curves and food intake. Hepatic fibrosis and periovular granulomas were studied by histological, morphometric and biochemical methods. All mice fed on a deficient diet failed to develop periportal "pipestem" fibrosis after chronic infection. An unexpected finding was the absence of pipestem fibrosis in mice on normal diet, probably related to the sample size. The lower values for nutritional parameters were mainly due to the deficient diet, rather than to infection. Liver/body weight ratio was higher in "early undernutrition" group, after shifting to the balanced diet. Volume density and numerical density of egg granulomas reached lowest values in undernourished animals. The amount of collagen was reduced in undernourished mice, attaining higher concentrations in well-fed controls and in "late undernutrition" (balanced diet shifted to a deficient one), where collagen deposition appeared increased in granulomas. That finding suggested interference with collagen degradation and resorption in "late" undernourished animals. Thus, host nutritional status plays a role in connective tissue changes of hepatic schistosomiasis in mice.

Some coccidial parasites of the lizard Amphisbaena alba (Reptilia: Amphisbaenia: Amphisbaenidae)

Five parasites are described in the lizard Amphisbaena alba (Amphisbaenidae) from the state of Pará, North Brazil. Mature oocysts of Choleoeimeria amphisbaenae n. sp., are passed already mature in the faeces. They are ellipsoidal-cylindrical, average 33.7 x 22.8 µm and are devoid of micropyle, oocyst residuum or polar body. The colourless wall is smooth and of 2 layers. The 4 dizoic sporocysts have no Stieda body and average 13 x 9.3 µm. Endogenous stages develop in the epithelial cells of the gall-bladder in the manner described for the genus and may cause extensive tissue damage. Sporulation of Isospora capanemaensis n. sp., is completed 3 days after the oocysts are voided in the faeces. They average 14.8 x 14.5 µm and have no micropyle, oocyst residuum or polar body. The 2 tetrazoic sporocysts are pear-shaped, average 8.6 x 6.6 and have an inconspicuous Stieda body. Endogenous development is in the epithelial cells of the ileum, and heavy infections cause considerable tissue destruction. Multisporocystic oocysts passed in the faeces of one A. alba possibly originated from an invertebrate host ingested by the lizard. A globidium-like cyst in the digestive tract of A. alba measured 105 x 85 µm and contained many hundreds of merozoites. A stained kidney smear of the same lizard revealed the presence of an unidentified parasite producing multinucleate cyst-like stages.

Hemilucilia segmentaria (Fabricius, 1805) (Diptera: Calliphoridae) as new biological vector of eggs of Dermatobia hominis (Linnaeus Jr., 1781) (Diptera: Oestridae) in Reserva Biológica do Tinguá, Rio de Janeiro, Brazil

The aim of this note was to record for the first time the finding of Hemilucilia segmentaria acting as biological vector of Dermatobia hominis, during a study of the diversity of Calliphoridae at Reserva Biológica do Tinguá, Rio de Janeiro, Brazil. The insects were captured using traps baited with chicken vicera, for a period of 28-30 h twice per month. In the period of one year, 1987 insects were collected, 7.5% of which belonged to the H. segmentaria; of these a female was captured in May 2001, carrying a mass of 20 eggs on the left side of its abdomen.

Estudo morfométrico do gênero Panstrongylus Berg, 1879 (Hemiptera, Reduviidae, Triatominae)

The subfamily Triatominae is actually represented by 137 species distributed among 6 tribes and 19 genera. Within this subfamily, the genus Panstrongylus, Berg 1879, is composed by 13 species widespread in sylvatic, peridomestic, and domestic habitats of Neotropical regions. These species are vectors of Chagas disease and consequently are found associated with its main hosts, such as birds and mammals. Interest in species of this genus has been increasing in the last few years. Reports of several authors indicate these Triatominae to invade and colonize houses, increasing their epidemiological significance. Morphometry was used in this study to investigate correlations among possible closely related species. We measured 224 specimens among 13 species through a set of metric variables of the head. The results indicated that the genus Panstrongylus seems to be homogeneous since 10 of the 14 species were shown to be closely related.

Differential expression of adhesion moleculesshaping the T-cell subset prevalence during the early phase of autoimmune and Trypanosoma cruzi-elicited myocarditis

The participation of cell adhesion molecules (CAMs) in the establishment of autoimmune and infectious myocarditis is an important matter of investigation and may have therapeutic implication. Trypanosoma cruzi infection induces a CD8-mediated myocarditis in patients with severe cardiomyopathy and experimental animals. Previously, we have proposed that this predominance of CD8+ T-cells is, at least in part, consequence of the differential expression of CAMs on circulating CD8+ lymphocytes. In the present study we investigated the participation of CAMs in shaping the phenotypic nature of the autoimmune CD4-mediated myosin-induced and the CD8-mediated T. cruzi-elicited myocarditis. We provide evidence that the prevalence of a certain T-cell subset inside the inflamed heart reflects the differential profile of the adhesion molecules VLA-4, LFA-1, and ICAM-1 displayed on a large proportion of this particular T-cell population in peripheral blood during the early phase of inflammation. Further, the expression of VCAM-1, ligand for VLA-4, and ICAM-1, counter-receptor for LFA-1, was up-regulated on vascular endothelium and paralleled the entrance of inflammatory cells into the cardiac tissue. Thus, this up-regulated expression of receptors-counter-receptors that regulate T-cell transmigration through the vascular endothelium may have an important role in the pathogenesis of the early phase of both autoimmune and infectious myocarditis.

Parameters affecting cellular invasion and escape from the parasitophorous vacuole by different infective forms of Trypanosoma cruzi

In this study we have examined certain aspects of the process of cell invasion and parasitophorous vacuole escape by metacyclic trypomastigotes and extracellular amastigote forms of Trypanosoma cruzi (G strain). Using Vero (and HeLa) cells as targets, we detected differences in the kinetics of vacuole escape by the two forms. Alcalinization of intercellular pH influenced both invasion as well as the escape from the parasitophorous vacuole by metacyclic trypomastigotes, but not the escape kinetics of extracellular amastigotes. We used sialic acid mutants as target cells and observed that the deficiency of this molecule facilitated the escape of both infective forms. Hemolysin activity was only detected in extracellular amastigotes and neither form presented detectable transialidase activity. Invasion of extracellular amastigotes and trypomastigotes in Vero cells was affected in different ways by drugs that interfere with host cell Ca2+ mobilization. These results are in line with previous results that indicate that metacyclic trypomastigotes and extracellular amastigote forms utilize mechanisms with particular features to invade host cells and to escape from their parasitophorous vacuoles.

Antimicrobial activity in vitro of plumbagin isolated from Plumbago species

Plumbagin is a naturally occurring naphthoquinone isolated from roots of Plumbago scandens. The plant was collected at the Campus of Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. P. scandens is used as a traditional medicine for the treatment of several diseases. The antimicrobial activity of plumbagin was evaluated using the macrodilution method. The compound exhibited relatively specific activity against bacteria and yeast. The minimum inhibitory concentration test showed the growth inhibiton of Staphylococcus aureus at a concentration of 1.56 µg/ml and of Candida albicans at a concentration of 0.78 µg/ml. These results suggest the naphthoquinone plumbagin as a promising antimicrobial agent.