Um novo gênero e espécie de Baetidae (Ephemeroptera) do Estado de Minas Gerais Sudeste do Brasil

Iguaira gen. nov., type species, I. poranga, sp. nov., based on one nymph from the State of Minas Gerais, Brazil, are proposed. The new taxon is distinguished by the labrum with multiple, unorganized setae dorsally; hypopharynx with three-lobed lingua; cleft mandibular incisors; labium with internally curved paraglossae; labial palps with second segment with strong, apically rounded distomedial process and third segment with truncate medial and apical margins; elongate tarsal claws with minute denticles; and absence of scales and scale bases.

Cytochemical study of Rhodnius neglectus and Rhodnius prolixus salivary gland cells (Hemiptera, Triatominae)

Triatomines are hematophagous bugs of medical interest in South and Central America, where they may act as invertebrate hosts of the hemoflagellate protozoa Trypanosoma cruzi (the causative of Chagas’ disease) and Trypanosoma rangeli (Tejera, 1920). Triatomines of Rhodnius genus have salivary gland formed by two close and independent units: the principal and the accessory. This gland secretes saliva that abounds in substances that facilitate and permit feeding. Despite this importance, there are few reports on its cytochemistry. In purpose of amplifying this understanding, in this work it was investigated the nuclear structures (chromatin and nucleolar corpuscles) of salivary gland cells of Rhodnius neglectus (Lent, 1954) and Rhodnius prolixus (Stål, 1859). The salivary glands were removed from adult insects, fixed and submitted to different cytochemical methods: lacto-acetic orcein, silver ion impregnation, Feulgen reaction, Toluidine Blue, Variant method of critical electrolyte concentration and C-banding. The results evidenced predominance of binucleated cells, with bulky and polyploid nucleus, decondensed chromatin and a large nucleolar area. In addition, cytoplasmic metachromasy and a clear association between nucleolar and heterochromatic corpuscles were observed. Such characteristics were associated with intense synthesis activity to produce saliva. Besides, the heterochromatic corpuscles observed with C Banding permitted the differentiation of sexes and species.

Biologia do saguirú (Characidae, Curimatinae)

In Brazil all the fishes belonging to the sub-family Curimatinae are called « saguirú ». The present work gives a biological study of the Curimatus elegans Steind., a small fish without any economical importance, which is to be found along the whole brazilian coast, down till Paraguay. The specimens utilized for the present study come from Fortaleza (Ceará, north-eastern Brazil). The C. elegans is « ilyophagus », that means, it feeds itself exclusively with those organic materials to be found in mud, specially with microscopical algae. The intestines are very extent, some of them measuring about 9 to 11 times body's length. Studies have been made about growth and age of the C. elegans; the biggest sizes found were of 153 mm. for females and 88 mm. for males. The C. elegans shows developed sexual glands during a long period (April to September). The movements of the spermatozoa, in contact with water is of 40 to 50 seconds of intense movements, ceasing after 70 to 100 seconds. In contact with 0.5% NaCl-solution spermatozoa show a big increase in movements-time, that can last till about 25 minutes. The eggs' diameter measures 0.70 to 0.73 mm., mature and hydrated it attains 0.93 to 1,00 mm. There is a certain correlation between the size of the body and the quantity of eggs. Big specimens can produce a total of 200.000 eggs. The average quantity contained in 1 gr. and 1 cc. is 6018 and 6229 eggs, respectively. Maturity and spawning in laboratory has been obtained due to injections of suspension of fish-hypophysis. Three or four hours after the injection, fishes show more movement and evident signs of excitation, proceeding spawning after 5 to 6 hours. Males, persecuting females, describe successive circles (merry-go-round) - carroussel), swimming side by side with females up to water's surface, where sexual products are start beating dry, for there is no blood yet. Circulation-scheme is to be found on fig. 4 and 5. The swim-bladder and the stomach are but delineated; the intestine is formed by a cylindric tube, all closed. At the place, where later on there will open the mouth, we find a group of ciliary hairs that produce a liquid current, very evident by the semi-circle formed by attached solid particles. After 36 hours, opening of the mouth and formation of the gill slits begin. At the age of 90 hours (4 mm.) the larvas swim well and start to feed themselves; the digestive tube is now all open and the swimbladder works already. During the first days of life, larvas have an adhesive organ situated at their frontal region (fig. 7) in form of a crescent, by means of which they hang to surrounding vegetation (fig. 6). When the larva begins to swim and to feed itself and its yolk are having been absorbed. the adhesive organ retracts and disappears. While larvas and alevins feed themselves with plancton, they have small eye-teeth, which disappear,. when fishes become « ilyophagus ». There exist too, during their life as larvas, pharyngeal-teeth. The lateral line appears in the larva after 16 to 18 days; more or less at the same time all fins are completely developed. Shortly after, first scales appear (20 to 23 days). Evolution of intestines twisting followed (fig. 9). Larvas show at different parts of their bodies small of organs excretory functions, that are constituted by bottons in serial disposition, every one with an excretory canal that opens towards the outside. These formations disappear suddenly when larvas attain their phase of alevin. The existence of a great number of said formations at the caudal fin (fig. 12) is of great interest. In our experiences of breeding we have employed several thousands of C. elegans larvas in different environs and we made conditions of surrounding change (illumination), depth of water, temperature, presence of sand at bottom of aquariums and without sand, food). In this way we could compare the results obtained, estimate the action of each factor for the realisation of a good bring-up of larvas.

Alterações cutâneas do cão no Kala-Azar sul-americano

According to E. Chagas (1938), South-American Kala Azar is a widespread disease from the jungle, several cases being reported from North Brazil (Estado do Pará: Marajó Island, Tocantins and Gurupi river valleys; Estados do Piauí and Ceará: coast and hinterland). Other cases were found in Northeast Brazil (Estados de Pernambuco, Alagôas and Sergipe: coast and hinterland; Estado da Bahia: hinterland). A few cases were described from Estado de Mato-Grosso (Brazil), Provincia de Salta and Território do Chaco (Argentine), and Zona contestada do Chaco (Paraguai-Bolívia). A well defined secondary anemia associated with enlargement of the liver and spleen are the chief symptoms. Death usually occurs in cachexia and with symptoms of heart failure. Half the patients were children aged less than ten years (CHAGAS, CASTRO & FERREIRA, 1937). Quite exhaustive epidemiological researches performed by CHAGAS, FERREIRA, DEANE, DEANE & GUIMARÃES (1938) in Municipio de Abaeté (Estado do Pará, Brazil) gave the incidence of 1.48% for the natural infection in human, 4.49% in dogs, and 2.63% in cats. The infection was arcribed (CUNHA & CHAGAS, 1937) to a new species of Leishmania (L. chagasi). Latter CUNHA (1938) state, that it is identical to L. infantum. ADLER (1940) found that so far it has been impossible to distinguish L. chagasi from L. infantum by any laboratory test but a final judgment must be reserved until further experiments with different species of sandflies have been carried out. Skin changes in canine Kala Azar were signaled by many workers, and their importance as regards the transmission of the disease is recognized by some of them (ADLER & THEODOR, 1931, 2. CUNHA, 1933). Cutaneous ulcers in naturally infected dogs are referred by CRITIEN (1911) in Malta, by CHODUKIN & SCHEVTSCHENKO (1928) in Taschkent, by DONATIEN & LESTOCQUARD (1929) and by LESTOCQUARD & PARROT (1929) in Algeria, and by BLANC & CAMINOPETROS (1931) in Greece. Depilation is signaled by YAKIMOFF & KOHL-YAKIMOFF (1911) in Tunis, by YAKIMOFF (1915) in Turkestan. Eczematous areas or a condition described as "eczema furfurace" is sometimes noted in the areas of depilation (DONATIEN & LESTOCQUARD). The skin changes noticed by ADLER & THEODOR (1932) in dogs naturally infected with Mediterranean Kala Azar can be briefly summarized as a selective infiltration of macrophages around hair follicles including the sebaceous glands and the presence of infected macrophages in normal dermis. The latter phenomenon in the complete absence of secondary infiltration of round cells and plasma cells is the most striking characteristic of canine Kala Azar and differentiates it from L. tropica. In the more advanced stages the dermis is more cellular than that of normal dogs and may even contain a few small dense areas of infiltration with macrophages and some round cells and polymorphs. The external changes, i. e., seborrhea and depilation are roughly proportional to the number of affected hair follicles. In dogs experimentally infected with South-American Kala Azar the parasites were regularly found in blocks of skin removed from the living animal every fortnight (CUNHA, 1938). The changes noticed by CUNHA, besides the presence of Leishmania, were perivascular and diffuse infiltration of the cutis with mononuclears sometimes more marked near hair follicles, as well as depilation, seborrhea and ulceration. The parasites were first discovered and very numerous in the paws. Our material was obtained from dogs experimentally infected by Dr. A. MARQUES DA CUNHA< and they were the subject of a previous paper by CUNHA (1938). In this study, however, several animals were discarded as it was found that they did develop a superimposed infection by Demodex canis. This paper deals with the changes found in 88 blocks of skin removed from five dogs, two infected with two different canine strains, and three with two distinct human strains of South-American Kala Azar. CUNHA'S valuable material affords serial observations of the cutaneous changes in Kala Azar as most of the blocks of skin were taken every fortnight. The following conclusions were drawn after a careful microscopic study. (1) Skin changes directly induced in the dog by the parasites of South-American Kala Azar may b described as an infiltration of the corium (pars papillaris and upper portion of the reticular layer) by histocytes. Parasites are scanty, at first, latter becoming very numerous in the cytoplasm of such cells. Sometimes the histocytes either embedding or not leishman bodies appear as distinct nodes of infiltration or cell aggregations (histocytic granuloma, Figs. 8 and 22) having a perivascular distribution. The capillary loops in the papillae, the vessels of the sweat glands, the subpapillary plexus, the vertical twigs connecting the superficial and deep plexuses are the ordinary seats of the histocytic Kala Azar granulomata. (2) Some of the cutaneous changes are transient, and show spontaneous tendency to heal. A gradual transformation of the histocytes either containing or not leishman bodies into fixed connective tissue cells or fibroblasts occut and accounts for the natural regression just mentioned. Figs. 3, 5, 18, 19 and 20 are good illustrations of such fibroblastic transformation of the histocytic Kala Azar granulomata. (3) Skin changes induced by the causative organism of South-American Kala Azar are neither uniform nor simultaneous. The same stage may be found in the same dog in different periods of the disease, and not the same changes take place when pieces from several regions are examined in the same moment. The fibroblastic transformation of the histocytic granulomata marking the beginning of the process of repair, e. g., was recognised in dog C, in the 196th as well as in the 213rd (Fig. 18) and 231st (Fig. 19) days after the inoculation. (4) The connective tissue of the skin in dogs experimentally infected with South-American Kala Azar is overflowed by blood cells (monocytes and lymphocytes) besides the proliferation in situ of undifferentiated mesenchymal cells. A marked increase in the number of cells specially the "ruhende Wanderzellen" (Figs. 4 and 15) is noticed even during the first weeks after inoculation (prodomal stage) when no leishman bodies are yet found in the skin. Latter a massive infiltration by amoeboid wandering cells similar to typical blood monocytes (Fig. 21) associated to a small number of lymphocytes and plasma cells (Figs. 9, 17, 21, and 24) indicates that the emigration of blood cells...

Aspectos parasitários observados no local inoculado com esporozoitos de Plasmodium Gallinaceum

The following is a summary of the studies made on the development of Plasmodium gallinaceum sporozoites inoculated into normal chicks. Initially large numbers of laboratory reared Aëdes aegypti were fed on pullets heavily infected with gametocytes. Following the infectious meal the mosquitoes were kept on a diet of sugar and water syrup until the appearance of the sporozoites in the salivary glands. Normal chicks kept in hematophagous arthropod proof cages were then inoculated either by bite of the infected mosquitoes or by subcutaneous inoculations of salivary gland suspensions. By the first method ten mosquitoes fed to engorgement on each normal chick and were then sacrificed immediately afterwards to determine the sporozoite count. By the second method five pairs of salivary glands were dissected out at room temperature, triturated in physiological saline and inoculated subcutaneously. The epidermis and dermis at the site of inoculation were excised from six hours after inoculation to forty eight hours after appearance of the parasites in the blood stream and stretched out on filter paper with the epithelial surface downward. The dermis was then curretted. Slides were made of the scrapings consisting of connective tissue and epithelial cells of the basal layers which were fixed by metyl alcohol and stained with Giemsa for examination under the oil immersion lens. Skin fragments removed from normal chicks and from regions other than the site of inoculation in the infected chicks were used as controls. In these, only the normal histological aspect was ever encountered. In the biopsy made at the earliest period following inoculation clearly defined elongated forms with eight or more chromatin granules arranged in rosary formation were found. The author believes these to be products of the sporozoite evolution. Search for transition stages between these forms and sporozoites is planned in biopsies to be taken immediately following inoculation and at given intervals up to the six hour period. 1.) 6 and 12 hour periods. The bodies referred to above found in the first period in great abundance, apparently in proportion to the large numbers of sporozoites inoculated, were perceptibly reduced in numbers in the second period. 2.) 18 hour period. Only one biopsy was examined. This presented a binuclear body shown in Fig. 1, having a more or less hyaline protoplasm staining an intense blue and a narrow vacuole delimiting the cell boundaries. The two chromatin grains were quite large presenting a clearly defined nuclear texture. 3.) 24 hour period. A similar body to that above (Fig. 2) was seen in the only preparation examined. 4.) 60 hour period. The exoerythrocytic schizonts were found more frequently from this period onward. Several such were found no longer to contain the previously described vacuoles (Fig. 3). 5.) 84 hour period. Cells bearing eight or more schizonts were frequently encountered here. That these are apparently not bodies in process of division may be seen in Fig. 4. From this time onward small violet granules similar to volutine grains appeared constantly in the schizont nucleus and protoplasm. These are definitely not hemozoin. The above observations fell within the incubation period as repeated examinations of the peripheral and visceral blood were negative. Exoery-throcytic parasites also were never encountered in the viscera at this time. Exoerythrocytic schizonts searched for at site of inoculation 1, 24 and 48 hours after the incubation period were present in large number at all three times with apparent tendency to diminish as the number within the blood stream increased. Many of them presented the violet granules mentioned above. The appearance of the chromatin and the intensity of staining of the protoplasm varied from body to body which doubtless corresponds to the evolutionary stage of each. This diversity of aspect may frequently be seen in the parasites of the same host cell (Fig. 5.). These findings lend substance to the theory that the exoerythrocytic forms are the link between the sporozoites and the pigmented parasites of the red blood corpuscles. The explanation of their continued presence in the organism after infection of the blood stream takes place and their presence in cases infected by the inoculation blood does not come within the scope of this work. Large scale observations shortly to be undertaken will be reported in more detail particularly observations on the first evolutionary phases of the sporozoite within the organism of the vertebrate host.

Alterações patológicas do apêndice vermiforme contendo Proglottis de Taenia sp

Pathological changes in the vermiform appendix harbouring tapeworm's proglottides are reported. Marked local (tissue) eosinophilia in the stroma of the mucous coat and to a less degree in the sub-mucosa and around the vessels in the inner circular layer of the muscular coat is the essential change observed. Peculiar changes such as an striking increase in the volume of the mucus-producing goblet-cells either in the epithelium covering the free surface or in the glands of Lieberkühn, as well as new epithelium atypical in form and arrangement were noticed in direct connection and likely induced by the tapeworn as a foreign body (mechanical injury). The local (tissue) eosinophilia probably represents an anaphylactoid response to foreign proteins originating in the tapeworm. Acute appendicitis in its recognized varieties such as appendicitis superficalis catarrhalis, a. s. exulcerans, a. s. haemorrhagica, a. phlegmonosa, and a. phlegmonosa-ulcerosa could be microscopically excluded. It seems, however, that local (tissue) eosinophilia when particularly widespread is able to give clinical symtoms suggestive of acute appendicitis.

On the determination of reducing corticosteroids

1. The authors preconize the use of Folin-Ciocalteu's reagent in the colorimetric determination of reducing cortcosteroids. 2. The reaction follows Beer's law in the range 0-50 μg of 11-desoxycorticosterone. 3. Determinations made in human urine and adrenal glands of rats and guinea pigs are comparable with results obtained by other methods.

Hiperglicemia na intoxicação escorpiônica experimental em cão

The production of hyperglycemia during the acute phase of scorpion poisoning produced by T. bahiensis in dogs is confirmed now. The highest degree on average, was reached 10 minutes after the injection of venom. In our hands, the previous bilateral adrenalectomy did not avoid the hyperglycemia. The average of the blood sugar level has been similar to that observed in dogs with adrenal glands, the highest blood sugar level was also registered after 10 minutes. The hyperglycemia obtained in adrenolectomized dogs is, probably, due to the liberation of Sympatin (Nor-adrenalin and adrenalin) as a consequence of the central excitation by the poison on the hepatic nerves and other ganglionar terminations of the Sympathetic Nervous System. Our present researches suggest that the venom has adrenergic action besides the central action.

Estudo do mecanismo da hiperglicemia e da hipertensão arterial, produzidas pelo veneno de escorpião, no cão

In the present paper we studied the mechanism of the hyperglycemia and hypertension evoked by the intravenous injection of scorpion venom (Tityus bahiensis) in the dog. We used 34 dogs, of both sex, weighing between 4.3 to 22 kg. These animals were divided in 3 groups and the following experiments were performed: in the first group (8 dogs) the animals were adrenalectomized after the intravenous injection of chlorpromazine; in the second group (16 dogs) the animals were injected with ganglionic blocking drugs (9.295 Ciba and hexamethonium); in the third group (10 dogs) the naimals were injected with dibenamine, and in 3 of them the adrenal glands were removed. The dogs of each group were injected intravenously with aqueous extract of 2 telsons of scorpion/kg; the average weight of each telson was 6,5 mg. The following results were obtained: 1) The hyperglycemia evoked by scorpion venom, in adrenalectomized dogs, was inhibited by chlorpromazine; 2) Ganglionic blocking drugs (9.295 Ciba and hexamthonium) were inefective as far as the hyperglycemic and pressor effects of venom are concerned; 3) In the animals treated with dibenamine, the venom produced a fall in blood pressure, both in the controle and in the adrenalectomized. The present experiments suggest that the scorpion venom has, besides the central action already described by other investigators, an adrenergic action, very similar to the adrenaline. On basis of our experiments we think that the adrenergic action is responsible, in part, by the productrion of hyperglycemia and hypertension.

A study of the endocervical columnar cells I - morphology and frequency

After the observation of many thousands of histological sections of the endocervical mucosa it became evident that its columnar cells present a great variety of aspects not only those of the surface of the canal but also those of the glands. A classification of these cells was made taking into account the staining affinity, the intensity staining of the cytoplasm, the presence or absence of cilia, the shape and location of the nucleus. The various combinations of these different data made possible the characterization of 26 types of cells which we labelled by the alphabetical letters. Two hundred and fifty cervices obtained by cervical amputation and by hysterectomy were studied. The uteri presented lesions in the course of routine laboratory examination. In each of the 250 histological sections there were specifically counted 2,000 columnar cells which cover the cervical canal and 2,000columnar cells which form the glands. A graphic representation of the frequency of both the superficial and glandular columnar cells was presented; this was given the name EPITHELIOGRAM. The variation of the cellular "composition" of each epithelium is discussed and the frequency of the various cellular types after the count of one million of cells is presented.

A study of the endocervical columnar cells II - effects of physiological changes and of oathological lesions of the uterus on the specific numerical composition of the endocervical epithelium

In the second part of this paper we nalysed the correlation between the clinical pathological alterations and the sum of the types of columnar cells of 300 histological sections of cervix. Fifty histological sections of normal cervix of sexually mature women were selected and considered as normal in pattern. The specific counts of the columnar cells which line the endocervical mucosa and those of the glands of 50 normal cervices were compared with other similar counts made in 50 histological sections of cervices of old women and emphasized the differences. Comparisons were made also between 50 normal cervices and 50 sections of cervices with chronic inflammation, 50 cervices with epidermoid metaplasia and 50 cervices with myoma of the corpus. Counts were made from 50 cervices of patients who on the occasion of the surgical operation were in the proliferative phase of the menstrual cycle; these were compared with the counts of 50 cervices of uteri in the luteal phase. Finally, the numerical frequency of the following data encountered in the 300 cervices was recorded: 1. aspects of the ectocervical epithelium; 2. number of Nabothian cysts; 3. number of cervical glands; 5. number of deliveries and 6. aspect of the material within the cervical canal.

Anatomy and histology of Embolyntha batesi MacLahlan, 1877 (Embiidina)

The Embioptera are rather generalized insects whose internal anatomy is simple and not subject to great modifications. For this reason these insects form an ideal group for elementary anatomical and histological studies (fig. 2). The digestive tract is a long, simple tube without convolutions or diverticulae from the buccal cavity to the rectum. The buccal structures are of the chewing type. The oesophagus and ingluvia are differentiated only by slight dilation of their walls. In nymphs and females the proventriculus is very distinct due to folds which flatten as the structure becomes packed with food. The enteron is the largest in such forms and in both sexes limited caudally by the Malpighian tubules. The proctodeus has six large rectal papillae. The nervous system is complete with only the fifth abdominal segment lacking a ganglion in the metathorax includes the ganglion of the first abdominal segment. The brain exhibits very clear structure in histological sections. The tracheal system includes two pairs of thoracic spiracles and eight abdominal pairs. Only th metathoracic spiracle has an air expiration function; all others serve for inspiration. Various structures in the spiracles protect the atrium. The circulatory system includes a long, simple dorsal vessel which extends forward from the ninth abdominal segment into the cranium. It opens anteriorly near the circumoesophageal connectives. The dorsal vessel has a pair of ostia and valves corresponding to each abdominal and thoracic segment. It lacks the diverticulae or folds commonly found in more highly evolved insects. The excretory system is represented by Malphighian tubules, pericardial cells, and fat-body. The number and disposition of Malpighian tubules is variable within the order. The pericardial cells are localized around the entire dorsal vessel up to the opening of the aorta in the head. The fat-bodies form compact layers in the dorsal and ventral regions of the body. In males they are more developed in the abdominal region. The mandibles, maxillae, and salivary glands are of a simple type with very few cytological modifications. Only the salivary glands which extend into the mesothoracic region show appreciable specialization. The reproductive system is bi-sixual and shows considerable sexual dimorphism. Males have five pair of testes with a metameric disposition, two distinct ducts, two epidymis, and the ejaculatory organs. The accessory glands vary in number and size and open in the anterior portion of the ejaculatory duct. The female reproductive organs are of the panoistic type. The system includes five pairs of ovarioles, two long paired oviducts a small, unpaired oviduct and the spermatheca which opens in the vagina. Reproduction usually involves a union of male and female gametes, and eggs are usually laid in clusters attached to a substrate.

Estudos anatômicos e histológicos sobre a subfamilia Triatominae (Heteroptera, reduviidae): cérebro e seus nervos de Triatoma infestans

A fim de apresentar um conhecimento detalhado da estrutura e função dos diferentes sistemas nervosos dos Triatominae, começamos neste estudo com a descrição do sistema senso-motor. Como primeira parte escolhemos o cérebro e os nervos deste. A forma externa do cérebro é predeterminada pela anatomia da cápsula craniana. O cérebro localiza-se na parte posterior da cabeça, embaixo e por trás dos dois ocelos. É caracterizado por um encurtamento em sentido longitudinal, de modo que as conectivas entre sincérebro e Gnatocérebro são extremamente curtas, porém largas, além disto, a terceira comissura é incluída na massa do segmento mandibular do Gnatocérebro. As três massas ópticas são de formação típica, bem como a comissura óptica. O corpo central é grande e está em ligação direta com a maioria dos centros do Protocérebro e do Deutocérebro. O corpo pedunculado possui apenas um único glomérulo em forma de cogumelo pedunculado sem sinal de formação de um cálice como em formigas e outros insetos mais evoluídos. As extremidades do pedúnculo desfazem-se embaixo do Corpo central em um grande complexo de anexos claviformes como encontrado nos Machilidae. O Deutocérebro é caracterizado por um grande centro antenal, composto de numerosos pequenos glomérulos em situação periférica. O Tritocérebro é pequeno, mostrando na sua parte anterior duas conectivas frontais muito curtas, de modo que o gãnglio frontal se situa perto do Tritocérebro. A massa compacta do Gnatocérebro mostra sua composição por três pares de gânglios apenas em séries de cortes. Além dos Lobos ópticos, saem do cérebro 8 pares de nervos e 3 nervos ímpares: Do Protocérebro: Os nervos dos ocelos e o nervo do Corpus allatum; Do Deutocérebro: Os nervos das antenas e os da faringe; Do tritocérebro: Os nervos labrais e, através do gânglio frontal, o nervo recurrente e o nervo dos músculos da faringe; Do gnatocérebro: Os nervos das mandíbulas, maxilas, do lábio e das glândulas salivares.

Factors influencing the development of Plasmodium gallinaceum in Aedes fluviatilis

Aedes fluviatilis is susceptible to infection by Plasmodium gallinaceum and is a convenient insect host for the malaria parasite in countries where Aedees aegypti cannot be maintained in laboratories. In South America, for instance, the rearing of A. aegypti the main vector of urban yellow fever, is not advaisable because of the potential health hazard it represents. Our results of the comparative studies carried out between the sporogonic cycle produced with two lines of P. gallinaceum parasites into A. fuviatilis were as follows. As proved for A. aegypti, mosquito infection rates were variable when A. fluviatilis blood-fed on chicks infected with and old syringe-passaged strain of P. gallinaceum. Oocysts developed in 41% of those mosquitos and the mean peak of oocyst production was 56 per stomach. Salivary gland infections developed in about 6% of the mosquitos. The course of sporogony was unrelated to the size of the inoculum administered to chicks or to the route by which the birds were infected. The development of infected salivary glands was unrelated to oocyst production. Sporogony of P. gallinaceum was more uniform when mosquitos blood-fed on chicks infected with a sporozoite-passaged strain. Oocysts developed in about 50% of those mosquitoes and the mean peak of oocyst production was 138 per stomach, with some individuals having as many as 600-800 oocysts. Infected salivary glands developed in a mean of 27% of the mosquitos but, in some batches, was a high as 50%. Patterns of salivary gland parasitism were similar to those of oocyst production. The course of sporogony of P. gallinaceum in A. fluviatilis is analized in relation to degree of parasitemia and gametocytemia in the vertebrate host.

Effects of juvenile hormone analogue on ecdysis prevention induced by precocene in Rhodnius prolixus (Hemiptera: Reduviidae)

Precocene II, added to the meal of fourth-instar larvae of Rhodnius prolixus (25 mug/ml of blood), induced an in crease in the duration of the molting cycle. This effect was related to the decrease of both the nuclear area of the prothoracic gland cells and the mitotic activity in epidermal cellS. juvenile hormone analogue applied topically (60 mug/insect) together with Precocene II treatment avoided atrophy of the prothoracic glands and induced a higher number of epidermal mitosis accelerating the time of subsequent ecdysis. A possible relationship between juvenile hormone and production of ecdysone is discussed.