Densidade, tamanho populacional e conservação de primatas em fragmento de Mata Atlântica no sul do Estado de Minas Gerais, Brasil

Este trabalho teve como objetivo estimar a densidade e o tamanho populacional de quatro espécies de primatas [Alouatta clamitans Cabrera, 1940; Callicebus nigrifrons (Spix, 1823); Callithrix aurita (É. Geoffroy, 1812); Cebus nigritus (Goldfuss, 1809)] que ocorrem em um fragmento de Mata Atlântica de aproximadamente 350 ha, localizado no município de Pouso Alegre, estado de Minas Gerais e reunir subsídios para a conservação dessas espécies na região. O levantamento populacional foi realizado através do método de amostragem de distâncias em transecções lineares (Distance Sampling). Os dados foram coletados entre os meses de abril e agosto de 2008 a partir de quatro transecções implantadas na área de estudo. Os cálculos de densidade e tamanho populacional foram realizados empregando-se o programa Distance 5.0. As densidades foram estimadas em 23,83 ± 9,78 ind./km² para Callicebus nigrifrons, 14,76 ± 5,92 ind./km² para Callithrix aurita e 7,71 ± 2,13 ind./km² para Cebus nigritus. O tamanho populacional foi estimado em 83,0 ± 34,0 indivíduos para C. nigrifrons, 52,0 ± 20,8 indivíduos para Callithrix aurita e 27,0 ± 7,4 indivíduos para Cebus nigritus. Com relação ao bugio (A. guariba clamitans), constatou-se que apenas um grupo com seis indivíduos sobrevive na área. Conclui-se que, no caso de continuarem isoladas, essas populações têm poucas chances de sobrevivência no futuro frente aos riscos de eventos estocásticos. A criação de corredores ecológicos conectando a área de estudo aos outros fragmentos em seu entorno e a translocação de indivíduos de outras áreas da Mata Atlântica para esta região poderão constituir alternativas para garantir a viabilidade dessas populações em longo prazo. Para tanto, é necessário que se consolide uma política pública no município de Pouso Alegre voltada à criação, ampliação e gestão de Unidades de Conservação, e ao incentivo para a adoção de práticas produtivas sob critérios de sustentabilidade no entorno dessas áreas de interesse ecológico.

Mitsuda's reactions: induced by BCG in the normal Rhesus ("Macacca mulatta")

The reversals of Mitsuda's reactions induced by BCG have been objected to based on the possiblem interference of other determination causes of the phenomenon: tuberculous primo-infections, communicants of unsuspected leprosy, revearsals due to other causes, such as anti-diphteric and anti-tetanic vaccination, etc. In order to study the problem, we have used Rhesus monkeys (Macaca mulatta), which were reared in isolation, in an attempt to avoid the referred to interferences. Prior to the experiments, all animals were tested and found negative to radiograph, tuberculin and lepromin tests and were then submitted to the application of BCG vaccine (from 1 to 3 days old), in different doses and by different via. At different times, after the application of BCG, they were again submitted to the radiographic, tuberculin and lepromin tests. In the tables I to IV the experiences were summarised. From the experiments, the following conclusions were reached: 1 - From 12 Rhesus that received BCG 11 showed reversals of the Mitsuda reaction (91.7%). 2 - These reverseals took place both in tests effected shortly after BCG (from 6 days to 2 months), and tests effected much later (from 7 to 12 months after BCG). 3 - Some differences were found in the results, according to the dosis and the application via of the BCG. a) - The testicular and peritonela via (0,02g) were the only that determined strong positive Mitsuda's reactions (+++). b) - By oral via, animals that received high dosis (0.6g and 1.2 g), there resulted uniform and regular reversals, even though of low intensity (+); but from those who got small doses (0.2 g.) one showed no reversals in all tests, and the other presented reversals in the 2nd and 3rd tests only, also with low positivity (+). 4) In the 2nd and 3rd Mitsuda's reactions in the same animals, positivity was always precocious (generally within 48 hours), one getting the impression that there occurs a sensibilization of the animal body by the antigen with the repetition of the tests, even though the intensity of the reaction always remains the same. This precocious reaction (Fernandez type) occurs both shortly and long time after the application of the BCG. Its precocity depends not of the antigen only because the first Mitsuda's reaction after the BCG application occurs after some time and seems not influenced by the control lepromin test effected on the Rhesus before the BCG. 5) On the control group, the animals which received a.a.f. bacilli suspensions (Mycobacterium sp.; M. avium, and M. smegmatis), did not show reverseals of the Mitsuda's reaction. Two Rhesus, however, which received dead BCG (120ºC autoclave 1 hour), one intradermically (0.006 g) and the other orally (1.2 g), did both present reversals of the Mitsuda's reaction, with weak positivity (+). In all animals of the control-group, the allergic reactions were found negative. 6) Strong local inflammatory reactions were observed in the Rhesus that had received living BCG by intradermal via, and in the one submitted to multipunctures, there occurred the formation of a large caseous abcess. 7) The allergic tuberculinic and infratuberculinic reactions appeared dissociated from the Mitsuda's reactions: sometimes they are more precocious, occurring before of the lepromin test; on other occasions they disappear, when the Mitsuda's reactions still persist; and finally, they may be absent, when the latter occur, especially after the oral application of the BCG. 8) In Rhesus which received BCG by testicular and peritonela via, in the infratuberculinic test (0.1 ml of total BCG extract), besides the classic answer, which occurs between 48 and 96 hours, one could observe a delayed answer (15 to 20 days), represented by a non-erythematous nodule, which persists for 11-14 days.

The specificity of TRIM5 alpha-mediated restriction is influenced by its coiled-coil domain.

Retroviruses are both powerful evolutionary forces and dangerous threats to genome integrity. As such, they have imposed strong selective pressure on their hosts, notably triggering the emergence of restriction factors, such as TRIM5 alpha, that act as potent barriers to their cross-species transmission. TRIM5 alpha orthologues from different primates have distinct retroviral restriction patterns, largely dictated by the sequence of their C-terminal PRYSPRY domain, which binds the capsid protein of incoming virions. Here, by combining genetic and functional analyses of human and squirrel monkey TRIM5 alpha, we demonstrate that the coiled-coil domain of this protein, thus far essentially known for mediating oligomerization, also conditions the spectrum of antiretroviral activity. Furthermore, we identify three coiled-coil residues responsible for this effect, one of which has been under positive selection during primate evolution, notably in New World monkeys. These results indicate that the PRYSPRY and coiled-coil domains cooperate to determine the specificity of TRIM5 alpha-mediated capture of retroviral capsids, shedding new light on this complex event.

Filariopsis barretoi (travassos, 1921) (Nematoda: metastrongyloidea) lung parasite of primates from South America - taxonomy, synonyms and pathology

Nematodes and fragments of lungs from Cebus ssp., Callithrix jacchus (l.) and Saimiri sciureus (L.) were studied. The worms from Cebus and Callithrix must be called Filariopsis barretoi (Travassos, 1921). The names Filariopsis arator Chandler, 1931 and Filaroides cebi Gebauer, 1933 are synonymized to F. barretoi. The status of Filariopsis gordius (Travassos, 1921) remains uncertain. The pathology is described. The parasites are located in the pulmonary paranchyma, near the pleural surface, constituting nodules.

Development of natural products as drugs acting on central nervous system

We have recenty studied several natural product constituents which have effects on the CNS. (1) Tetrahydropalmatine (THP) and its analogues were isolated from Corydalis ambigua and various species of Stephania. (+)-THP and (-)-THP posses not only analgesic activity, but also exert sedative-tranquillizing and hypnotic actions. Results of receptor binding assay and their pre-and post-synaptic effects on dopaminergic system indicate that (-)-THP and (-)-stepholidine are dopamine receptor antagonists while (+)-THP is a selective dopamine depletor. (2) 3-Acetylaconitine (AAC) is an alkaloid isolated from Aconitum flavum. The relative potency of analgesic action of AAC was 5.1-35.6 and 1250-3912 times that of morphine and aspirin, respectively. The analgesic effect of AAC was antagonized by naloxone, but was eliminated by reserpine. In monkeys, after AAC was injected for 92 days, no abstinence syndrome was seen after sudden AAC withdrawal or when challenged with nalorphine. (3) Huperzine A (Hup-A) is an alkaloid isolated from Huperzia serrata which was found to be a selective ChE inhibitor and could improve learning and retrieval process. Preliminary clinical studies showed that Hup-A improve short-and long-term memory in patients of cerebral arteriosclerosis with memory impairment. (4) Ranamargarin is a new tetradecapeptide isolated from the skin of the Chines frog Rana margaratae. This peptide may mainly act on NK-1 receptor.

Simian malaria in Brazil

In Brazil simian malaria is widely spread, being frequent in the Amazon region (10% of primates infected) and even more in the forested coastal mountains of the Southeastern and Southern regions (35% and 18% infected, respectively), but absent in the semi-arid Northeast. Only two species of plasmoidia have been found: the quartan-like Plasmodium brasilianum and the tertian-like P. simium, but the possible presence of other species is not excluded. P. brasilianum is found in all enzootic foci, but P. simium was detected only on the coast of the Southeastern and Southern regions, between parallels 20-S and 30-S. Nearly all hosts are monkeys (family Cebidae, 28 species harbouring plasmodia out of 46 examined) and very rarely marmosets or tamarins (family Callitrichidae, I especies out of 16). P. brasilianum was present in all infected species, P. simium in only two. The natural vector in the Southeastern and Southern regions was found to be Anopheles cruzi, but has not been conclusively identified in the Amazon. One natural, accidental human infection due to P. simium was observed. There is no evidence of the relation of the simian to human malaria in the Southeastern and Southern regions, where human malaria was eradicated in spite of the high rates of monkeys infected, but in the Amazon recent serological studies by other workers, revealing high positivity for P. brasilianum/P. malariae antibodies in local indians, would suggest that among them malaria might be regarded as a zoonosis.

Immunogenicity and antigenicity of the N-term repeat amino acid sequence of the Plasmodium falciparum P126 antigen

The P126 protein, a parasitosphorus vacuole antigen of Plasmodium falciparum has beenshoen to induce protective immunity in Saimiri and Aotus monkeys. In the present work we investigated its immunogenicity. Our results suggest that the N-term of P126 is poorly immunogenic and antibody response against the P126 could be under a MHC restricted control in C57BL/6(H-2b) mice, which could be problematic in ternms of a use of the P126 in a vaccine program. However, we observed that a synthetic peptide, copying the 6 octapeptide repeat corresponding to the N-term of the P126, induces an antibody response to the native molecule in C57BL/6 non-responder mice. Moreover, the vaccine-P126 recombinant induced anmtibodies against the N-term of the molecule in rabbits while the unprocessed P126 did not.

A recombinant hybrid protein as antigen for an anti-blood stage malaria vaccine: a study on the conservation of a protective component

Recently we have shown that two hybrid proteins expressed in Escherichia coli confer protective immunity to Aotus monkeys against an experimental Plasmodium falciparum infection (Knapp et al., 1992). Both hybrid proteins carry a sequence containing amino acids 631 to 764 of the serine stretch protein SERP (Knapp et al., 1989b). We have studied the diversity of this SERP region in field isolates of P. falciparum. Genomic DNA was extracted from the blood of six donors from different endemic areas of Brazil and West Africa. The SERP region encoding amino acids 630 to 781 was amplified by polymerase chain reaction (PCR) and sequenced. Only conserved amino acid substitutions in maximally two positions of the analyzed SERP fragment could be detected which supports the suitability of this SERP region as a component of anti-blood stage malaria vaccine.

Mechanisms of protective immunity against asexual blood stages of Plasmodium falciparum in the experimental host Saimiri

In the Saimiri monkey, an experimental host for human malaria, acquired protection against Plasmodium falciparum blood stages depends on the IgG antibody populations developed. In vivo protective anti-falciparum activity of IgG antibodies is correlated with the in vivo opsonizing activity promoting phagocytosis of parasited red bloood cells. In contrast, non protective antibodies inhibit this mechanism by competing at the target level. A similar phenomenon can be and human infection. Anti-cytoadherent and anti-rosette antibodies developed by Saimiri and humans prevent the development of physiopathological events like cerebral malaria which can also occur in this experimental host. Furthermore, transfer to protective human anti-falciparum IgG antibodies into infected Saimiri monkeys exerts an anti parasite activity as efficient as that observed when it is transfered into acute falciparum malaria patients, making the Saimiri an even more attractive host. Studies on the role of immunocompetent cells in the protective immune reponse are still in their infancy, however the existance of a restricted polymorphism of MHC II class molecules in the Saimiri confers additional theoretical and practical importance to this model.

Lentiviral gene transfer to the nonhuman primate brain.

Lentiviral vectors infect quiescent cells and allow for the delivery of genes to discrete brain regions. The present study assessed whether stable lentiviral gene transduction can be achieved in the monkey nigrostriatal system. Three young adult Rhesus monkeys received injections of a lentiviral vector encoding for the marker gene beta galatosidase (beta Gal). On one side of the brain, each monkey received multiple lentivirus injections into the caudate and putamen. On the opposite side, each animal received a single injection aimed at the substantia nigra. The first two monkeys were sacrificed 1 month postinjection, while the third monkey was sacrificed 3 months postinjection. Robust incorporation of the beta Gal gene was seen in the striatum of all three monkeys. Stereological counts revealed that 930,218; 1,192,359; and 1,501,217 cells in the striatum were beta Gal positive in monkeys 1 (n = 2) and 3 (n = 1) months later, respectively. Only the third monkey had an injection placed directly into the substantia nigra and 187,308 beta Gal-positive cells were identified in this animal. The injections induced only minor perivascular cuffing and there was no apparent inflammatory response resulting from the lentivirus injections. Double label experiments revealed that between 80 and 87% of the beta Gal-positive cells were neurons. These data indicate that robust transduction of striatal and nigral cells can occur in the nonhuman primate brain for up to 3 months. Studies are now ongoing testing the ability of lentivirus encoding for dopaminergic trophic factors to augment the nigrostriatal system in nonhuman primate models of Parkinson's disease.

Aspects of immunity for the AMA-1 family of molecules in humans and non-human primates malarias

The apical membrane antigen (AMA-1) family of malaria merozoite proteins is characterised by a high degree of inter-species conservation. Evidence that the protein (PK66/AMA-1) from the simian parasite Plasmodium knowlesi was protective in rhesus monkeys suggested that the 83kDa P. falciparum equivalent (PF83/AMA-1) should be investigated for protective effects in humans. Here we briefly review pertinent comparative data, and describe the use of an eukaryotic full length recombinant PF83/AMA-1 molecule to develop a sensitive ELISA for the determination of serological responses in endemic populations. The assay has revealed surprisingly high levels of humoral response to this quantitatively minor antigen. We also show that PK66/AMA-1 inhibitory mAb's are active against merozoites subsequent to release from schizont-infected red cells, further implicating AMA-1 molecules in red cell invasion.

Development of sporogonic cycle of Plasmodium vivax in experimentally infected Anopheles albimanus mosquitoes

The sporogonic cycle of Plasmodium vivax was established and maintained under laboratory conditions in two different strains of Anopheles albimanus mosquitoes using as a parasite source blood from human patients or from Aotus monkeys infected with the VCC-2 P.vivax colombian isolate. Both the Tecojate strain isolate from Guatemala and the Cartagena strain from the colombian Pacific coast were susceptible to infections with P.vivax. A higher percentage of Cartagena mosquitoes was infected per trial, however the Tecojate strain developed higher sporozoite loads. Intravenous inoculation of Aotus monkeys with sporozoites obtained from both anopheline strains resulted in successful blood infections. Animals infected with sporozoites from the Tecojate strain presented a patent period of 21-32 days whereas parasitemia appeared between days 19-53 in monkeys infected with sporozites from Cartagena strain.

Simian malaria at two sites in the Brazilian Amazon - II: Vertical distribution and frequency of anopheline species inside and outside the forest

An anopheline survey was carried out in two simian malaria areas in the Brazilian Amazon, Balbina and Samuel, to determine the potential vectors of Plasmodium brasilianum. The most abundant and/or acrodendrophilic anophelines in the forest and the most likely vector were Anopheles mediopunctatus, An. nuneztovari, An. oswaldoi, An. triannulatus and An. shannoni. An. darlingi and An. marajoara were captured essentially in anthropic habitats outside the forest and are unlikely to be involved in the transmission of P. brasilianum among monkeys within the forests and from monkeys to man in their surroundings in the Amazon.

Antibodies anti Bloodstream and Circumsporozoite Antigens (Plasmodium vivax and Plasmodium malariae/P. brasilianum) in Areas of Very Low Malaria Endemicity in Brazil

During 1992-1994, 33 malaria cases were reported in two regions in Brazil where few sporadic atypical cases occur, most of them in home owners, who are weekenders, while home caretakers live there permanently. Indirect Fluorescent Antibody Test (IFAT), with Plasmodium vivax, and Enzime Linked Immunosorbent Assay (ELISA) with repeat peptides of the circumsporozoite (CS) proteins of the 3 known P. vivax variants and P. malarie/P. brasilianum, were performed on 277 sera, obtained within a 5 to 10 km range of malaria cases. Very rarely did any of these donors recall typical malaria episodes. Blood smears of all but 5 were negative. One of the 5 malaria cases included in our serology was of a home owner, 1 of a permanent resident, 3 from Superintendência de Controle de Endemias employees who went there to capture mosquitoes. In Region 1 the prevalence of IFAT positive sera was 73% and 28% among caretakers, 18% and 9.6% among home owners. In Region 2 (3 localities) no distinction was possible between caretakers and home owners, IFAT positivity being 38%, 28% and 7%. The relative percentage of positive anti-CS repeats ELISA, differed for each of the peptides among localities. Dwellings are in the vicinity of woods, where monkeys are frequently seen. The origin of these malaria cases, geographical differences and high seropositivity is discussed

Pulmonary biology of anti-interleukin 5 antibodies

Interleukin 5 (IL-5) is a critical cytokine for the maturation of eosinophil precursors to eosinophils in the bone marrow and those eosinophils then accumulate in the lungs during asthma. We have studied anti IL-5 antibodies on allergic responses in mice, guinea pigs and monkeys and are extending this experiment into humans with a humanized antibody. In a monkey model of pulmonary inflammation and airway hyperreactivity, we found that the TRFK-5 antibody blocked both responses for three months following a single dose of 0.3 mg/kg, i.v. This antibody also blocked lung eosinophilia in mice by inhibiting release from the bone marrow. To facilitate multiple dosing and to reduce immunogenicity in humans, we prepared Sch 55700, a humanized antibody against IL-5. Sch 55700 was also active against lung eosinophilia in allergic monkeys and mice and against pulmonary eosinophilia and airway hyperresponsiveness in guinea pigs. Furthermore, as opposed to steroids, Sch 55700 did not cause immunosuppression in guinea pigs. Studies with this antibody in humans will be critical to establishing the therapeutic potential of IL-5 inhibition.