Estudos experimentais sôbre a origem do milho

1) It may seem rather strange that, in spite of the efforts of a considerable number of scientists, the problem of the origin of indian corn or maize still has remained an open question. There are no fossil remains or archaeological relics except those which are quite identical with types still existing. (Fig. 1). The main difficulty in finding the wild ancestor- which may still exist - results from the fact that it has been somewhat difficult to decide what it should be like and also where to look for it. 2) There is no need to discuss the literature since an excellent review has recently been published by MANGELSDORF and REEVES (1939). It may be sufficient to state that there are basically two hypotheses, that of ST. HILAIRE (1829) who considered Brazilian pod corn as the nearest relative of wild corn still existing, and that of ASCHERSON (1875) who considered Euchlaena from Central America as the wild ancestor of corn. Later hypotheses represent or variants of these two hypotheses or of other concepts, howewer generally with neither disproving their predecessors nor showing why the new hypotheses were better than the older ones. Since nearly all possible combinations of ideas have thus been put forward, it har- dly seems possible to find something theoretically new, while it is essential first to produce new facts. 3) The studies about the origin of maize received a new impulse from MANGELSDORF and REEVES'S experimental work on both Zea-Tripsacum and Zea-Euchlaena hybrids. Independently I started experiments in 1937 with the hope that new results might be obtained when using South American material. Having lost priority in some respects I decided to withold publication untill now, when I can put forward more concise ideas about the origin of maize, based on a new experimental reconstruction of the "wild type". 4) The two main aspects of MANGELSDORF and REEVES hypothesis are discussed. We agree with the authors that ST. HILAIRE's theory is probably correct in so far as the tunicata gene is a wild type relic gene, but cannot accept the reconstruction of wild corn as a homozygous pod corn with a hermaphroditic tassel. As shown experimentally (Fig. 2-3) these tassels have their central spike transformed into a terminal, many rowed ear with a flexible rachis, while possessing at the same time the lateral ear. Thus no explanation is given of the origin of the corn ear, which is the main feature of cultivated corn (BRIEGER, 1943). The second part of the hypothesis referring to the origin of Euchlaena from corn, inverting thus ASCHERSON's theory, cannot be accepted for several reasons, stated in some detail. The data at hand justify only the conclusion that both genera, Euchlaena and Zea, are related, and there is as little proof for considering the former as ancestor of the latter as there is for the new inverse theory. 5) The analysis of indigenous corn, which will be published in detail by BRIEGER and CUTLER, showed several very primitive characters, but no type was found which was in all characters sufficiently primitive. A genetical analysis of Paulista Pod Corn showed that it contains the same gene as other tunicates, in the IV chromosome, the segregation being complicated by a new gametophyte factor Ga3. The full results of this analysis shall be published elsewhere. (BRIEGER). Selection experiments with Paulista Pod Corn showed that no approximation to a wild ancestor may be obtained when limiting the studies to pure corn. Thus it seemed necessary to substitute "domesticated" by "wild type" modifiers, and the only means for achieving this substitution are hybridizations with Euchlaena. These hybrids have now been analysed init fourth generation, including backcrosses, and, again, the full data will be published elsewhere, by BRIEGER and ADDISON. In one present publication three forms obtained will be described only, which represent an approximation to wild type corn. 6) Before entering howewer into detail, some arguments against ST. HILAIRE's theory must be mentioned. The premendelian argument, referring to the instability of this character, is explained by the fact that all fertile pod corn plants are heterozygous for the dominant Tu factor. But the sterility of the homozygous TuTu, which phenotypically cannot be identified, is still unexplained. The most important argument against the acceptance of the Tunicata faetor as wild type relic gene was removed recently by CUTLER (not yet published) who showed that this type has been preserved for centuries by the Bolivian indians as a mystical "medicine". 7) The main botanical requirements for transforming the corn ear into a wild type structure are stated, and alternative solutions given. One series of these characters are found in Tripsacum and Euchlaena : 2 rows on opposite sides of the rachis, protection of the grains by scales, fragility of the rachis. There remains the other alternative : 4 rows, possibly forming double rows of female and male spikelets, protection of kernels by their glumes, separation of grains at their base from the cob which is thin and flexible. 8) Three successive stages in the reconstruction of wild corn, obtained experimentally, are discussed and illustrated, all characterized by the presence of the Tu gene. a) The structure of the Fl hybrids has already been described in 1943. The main features of the Tunicata hybrids (Fig. -8), when compared with non-tunicate hybrids (Fig. 5-6), consist in the absence of scaly protections, the fragility of the rachis and finally the differentiation of the double rows into one male and one female spikelet. As has been pointed out, these characters represent new phenotypic effects of the tunicate factor which do not appear in the presence of pure maize modifiers. b) The next step was observed among the first backcross to teosinte (Fig. 9). As shown in the photography, Fig. 9D, the features are essencially those of the Fl plants, except that the rachis is more teosinte like, with longer internodes, irregular four-row-arrangement and a complete fragility on the nodes. c) In the next generation a completely new type appeared (Fig. 10) which resembles neither corn nor teosinte, mainly in consequence of one character: the rachis is thin and flexible and not fragile, while the grains have an abscission layer at the base, The medium sized, pointed, brownish and hard granis are protected by their well developed corneous glumes. This last form may not yet be the nearest approach to a wild grass, and I shall try in further experiments to introduce other changes such as an increase of fertile flowers per spikelet, the reduction of difference between terminal and lateral inflorescences, etc.. But the nature of the atavistic reversion is alveadwy such that it alters considerably our expectation when looking for a still existing wild ancestor of corn. 9) The next step in our deductions must now consist in an reversion of our question. We must now explain how we may obtain domesticated corn, starting from a hypothetical wild plant, similar to type c. Of the several changes which must have been necessary to attract the attention of the Indians, the following two seem to me the most important: the disappearance of all abscission layers and the reduction of the glumes. This may have been brought about by an accumulation of mutations. But it seems much more probable to assume that some crossing with a tripsacoid grass or even with Tripsacum australe may have been responsible. In such a cross, the two types of abscission layer would be counterbalanced as shown by the Flhybrids of corn, Tripsacum and Euchlaena. Furthermore in later generations a.tu-allele of Tripsacum may become homozygous and substitute the wild tunicate factor of corn. The hypothesis of a hybrid origin of cultivated corn is not completely new, but has been discussed already by HARSHBERGER and COLLINS. Our hypothesis differs from that of MANGELSDORF and REEVES who assume that crosses with Tripsacum are responsible only for some features of Central and North American corn. 10) The following arguments give indirects evidence in support of our hypothesis: a) Several characters have been observed in indigenous corn from the central region of South America, which may be interpreted as "tripsacoid". b) Equally "zeoid" characters seem to be present in Tripsacum australe of central South-America. c) A system of unbalanced factors, combined by the in-tergeneric cross, may be responsible for the sterility of the wild type tunicata factor when homozygous, a result of the action of modifiers, brought in from Tripsacum together with the tuallele. d) The hybrid theory may explain satisfactorily the presence of so many lethals and semilethals, responsible for the phenomenon of inbreeding in cultivated corn. It must be emphasized that corn does not possess any efficient mechanism to prevent crossing and which could explain the accumulation of these mutants during the evolutionary process. Teosinte which'has about the same mechanism of sexual reproduction has not accumulated such genes, nor self-sterile plants in spite of their pronounced preference for crossing. 11) The second most important step in domestication must have consisted in transforming a four rowed ear into an ear with many rows. The fusion theory, recently revived byLANGHAM is rejected. What happened evidently, just as in succulent pXants (Cactus) or in cones os Gymnosperms, is that there has been a change in phyllotaxy and a symmetry of longitudinal rows superimposed on the original spiral arrangement. 12) The geographical distribution of indigenous corn in South America has been discussed. So far, we may distinguish three zones. The most primitive corn appears in the central lowlands of what I call the Central Triangle of South America: east of the Andies, south of the Amazone-Basin, Northwest of a line formed by the rivers São Prancisco-Paraná and including the Paraguay-Basin. The uniformity of the types found in this extremely large zone is astonishing (BRIEGER and CUTLER). To the west, there is the well known Andian region, characterized by a large number of extremely diverse types from small pop corn to large Cuszco, from soft starch to modified sweet corn, from large cylindrical ears to small round ears, etc.. The third region extends along the atlantic coast in the east, from the Caribean Sea to the Argentine, and is characterized by Cateto, an orange hard flint corn. The Andean types must have been obtained very early, and undoubtedly are the result of the intense Inca agriculture. The Cateto type may be obtained easily by crosses, for instance, of "São Paulo Pointed Pop" to some orange soft corn of the central region. The relation of these three South American zones to Central and North America are not discussed, and it seems essential first to study the intermediate region of Ecuador, Colombia and Venezuela. The geograprical distribution of chromosome knobs is rapidly discussed; but it seems that no conclusions can be drawn before a large number of Tripsacum species has been analysed.

A new species of Leiostracus from Bahia, Brazil (Gastropoda, Pulmonata, Orthalicidae)

A remarkable new species of pulmonate snail was recently collected in a small Atlantic Rainforest fragment near the city of Canavieiras, state of Bahia, Brazil, an area known for a high diversity of land snails. It is described herein as Leiostracus fetidus sp. nov. and can be easily identified by its color pattern of irregular brown to black axial stripes on a white to yellow background, a reddish axial band "separating" the white peristome from the rest of the shell and a broad brown spiral band surrounding the umbilical region. Other diagnostic features include a relatively small size, a proto columellar fold and two very weak folds delimiting the basal region of the aperture. This discovery is a reminder of how little this fauna is known and also an alarm for proper conservation of these forest fragments.

Ensaios de Mycologia

Morphologically the fungus reminds one of the Microsporum species of man. The microscopic elements are: the shape of the mycelia within the hairs, size and disposition of spores intercalar and terminal chlamydospores, simple clusters, hyphae, pectinate and denticulate elements. Of the 17 species of Microsporum described up to now, none can be identified with Microsporum circuluscentrum. The microsporum described is of the pure-by human type. (Culture fairly vivacious, almost total absence of spindles.) Microscopically at first sight the culture might be taken for Microsporum fulvum URIBURU 1917 or for M. felineum. These are however from animals. The bean shaped culture on potatoes leaves a place apart for it among Microsporum fungi. The anomalous elements seen in the cultures are also found in other species of Microsporum. Besides the pseudo-perithecia described and interpreted I must mention that the pseudo-nodular organs are not an exception among these fungi, for Microsporum fulvum also shows what writers have described as nodular organs. The spiral elements are also not exclusive features of the trichophytes. Microsporum tardum also shows quite characteristic spiral forms.

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.

Diagnosing pulmonary embolism in outpatients with clinical assessment, D-dimer measurement, venous ultrasound, and helical computed tomography: a multicenter management study.

PURPOSE: To evaluate a diagnostic strategy for pulmonary embolism that combined clinical assessment, plasma D-dimer measurement, lower limb venous ultrasonography, and helical computed tomography (CT). METHODS: A cohort of 965 consecutive patients presenting to the emergency departments of three general and teaching hospitals with clinically suspected pulmonary embolism underwent sequential noninvasive testing. Clinical probability was assessed by a prediction rule combined with implicit judgment. All patients were followed for 3 months. RESULTS: A normal D-dimer level (<500 microg/L by a rapid enzyme-linked immunosorbent assay) ruled out venous thromboembolism in 280 patients (29%), and finding a deep vein thrombosis by ultrasonography established the diagnosis in 92 patients (9.5%). Helical CT was required in only 593 patients (61%) and showed pulmonary embolism in 124 patients (12.8%). Pulmonary embolism was considered ruled out in the 450 patients (46.6%) with a negative ultrasound and CT scan and a low-to-intermediate clinical probability. The 8 patients with a negative ultrasound and CT scan despite a high clinical probability proceeded to pulmonary angiography (positive: 2; negative: 6). Helical CT was inconclusive in 11 patients (pulmonary embolism: 4; no pulmonary embolism: 7). The overall prevalence of pulmonary embolism was 23%. Patients classified as not having pulmonary embolism were not anticoagulated during follow-up and had a 3-month thromboembolic risk of 1.0% (95% confidence interval: 0.5% to 2.1%). CONCLUSION: A noninvasive diagnostic strategy combining clinical assessment, D-dimer measurement, ultrasonography, and helical CT yielded a diagnosis in 99% of outpatients suspected of pulmonary embolism, and appeared to be safe, provided that CT was combined with ultrasonography to rule out the disease.

Physa Marmorata Guilding, 1828 (Pulmonata: Physidae)

A description of Physa marmorata Guilding, 1828, based on material collected at its type-locality, the Caribbean island of Saint Vincent, is presented. The shell is thin, horn-colored, surface very glossy, diaphanous. Spire acute, elevated; protoconch distinct, rounded-conical, reddish-brown; five not shouldered, broadly convex whorls with subobsolete spiral lines and thin growth lines. Aperture elongated, 1.4-2.0 times as long as the remaining shell length, narrow obovate-lunate; upper half acute-angled,lower half oval,narrowly rounded at the base, outer lip sharp, inner lip completely closing the umbilical region; a very distinct callus on the parietal wall; columellar lip with a low ridge gradually merging into the callus. ratios: shell width/shell length = 0.44 - 0.52 (mean 0.47); spire length /shell lenght = 0.33-0.41 (mean 0.39); aperture length/shell lenght = 0.59-0.67 (mean 0.62). Oral lappets laterally mucronate, foot spatulate with deeply pigmented acuminate tail. Mantle reflection with 6-10 short triangular dentations covering nearly half the right surface of the body whorl, and 4-6 covering a part of the ventral wall. Body surface with tiny dots of greenish-yellow pigment besides melanin. Renal tube tightly folded in toa zigzag course. Ovotestis diverticula acinous, laterally pressed against each other around a collecting canal. Ovispermiduct with well-developed seminal vesicle. oviduct highly convoluted, merging into a less convoluted nidamental gland which narrows to a funnel-shaped uterus and a short vagina. Spermathecal body oblong, more or less constricted in the middle and somewhat curved; spermathecal duct uniformly narrow, a little longer than be body. About 20 prostatic diverticula, simple, bifurcate or divided into a few short branches, distalmost ones assembled into a cluster. Penis long, nearly uniformly narrow; penial canal with lateral opening about the junction of its middle and lower thirds. Penial sheath with a bulbous terminal expasion the tip of which isinserted into the caudal end of the prepuce. Prepuce shouldered, much wider than the narrow portion of the penial sheath. Penial sheath/prepuce ratio about 2.08 (1.45-2.75). The main extrinsic muscles of the penial complex are a retractor, with a branch attached to the bulb, and another to the caudal end of the penial sheath; and a protractor, with a branch attached to the shoulder of the prepuce and adjoining area of the penial sheath, and another to the caudal end of the penial sheath. Egg capsule C-shaped, with 10-30 elliptical eggs (snails 10mm long) measuring about 1.10 mm (0.90-1.32) through the long axis and surrounded by an inner and an outer lamellate membranes. Jaw a simple obtusely V-shaped plate. radula will be described separately.

Physa cubensis Pfeiffer, 1839 (Pulmonata: Physidae)

A description of Physa cubensis Pfeiffer, 1839, based on 15 speciments collected in Havana, Cuba, is presented. The shell, measuring 9.0 x 4,8mm to 12.3 x 6.4mm, is ovate-oblong, thin, diaphanous, horncolored, shining. Spire elevated, broadly conical; protoconch distinct, roundish, reddish-brown. About five moderately shouldered, roundly convex whorls, penultimate whorl expanded; spiral striation subobsolete; growth line faint on the intermediate whorls, clearly visible on the body whorl, crowded here and there. Suture well impressed. Aperture elongated 2.05 - 2.67 (mean 2.27) times as long as the remaining length of the shell, narrow obovulate-lunate; upper half acute-angled, lower half oval, narrowly rounded at the base; outer lip sharp, inner lip completely closing the umbilical region; a thick callus on the parietal wall; columellar plait well marked. Ratios: shell width/shell length - 0.52-0.61 (mean 0.55); spire length/shell length = 0.27 - 0.33 (mean 0.31); aperture length/shell length = 0.67 - 0.73 (mean 0.69). Oral lappets laterally mucronate; foot spatulate with acuminate tail. Mantle relection with 6 - 8 short triangular dentations in the right lobe (columellar side) and 4 - 6 in the left lobe (near the pneumostome). Renal tube tightly folded into a zigzag course. Ovotestis, ovispermiduct, seminal vesicle, oviduct, nidamental gland, uterus and vagina as in Physa marmorata (see Paraense, 1986, Mem. Inst. Oswaldo Cruz, 81: 459-469). Spermathecal body egg-shaped or pear-shaped; spermathecal ducta uniformly narrow with expanded base, a little longer than the body. Spermiduct, prostate and vas deferens as in P. marmorata (Paraense, loc. cit.). Penis wide proximally, narrowing gradually apicad; penial canal with subterminal outlet. Penial sheath following the width of the penis and ending up by a bulbous expansion somewhat narrower than the proximal portion. Penaial sheath/prepuce ration = 1,25 - 1,83 (mean 1.49). Prepuce much wider than the bulb of the penial shealth, moderately shouldered owing to the intromission of the bulb, and with a large gland in one side of its proximal half occupating about a third of its length. Extrinsic muscles of the penial complex as in P. marmorata. Jaw a simple obtusely V-shaped plate. Radula to be described separetely.

Portal vein embolization before right hepatectomy: prospective clinical trial.

OBJECTIVE: To assess the impact of liver hypertrophy of the future liver remnant volume (FLR) induced by preoperative portal vein embolization (PVE) on the immediate postoperative complications after a standardized major liver resection. SUMMARY BACKGROUND DATA: PVE is usually indicated when FLR is estimated to be too small for major liver resection. However, few data exist regarding the exact quantification of sufficient minimal functional hepatic volume required to avoid postoperative complications in both patients with or without chronic liver disease. METHODS: All consecutive patients in whom an elective right hepatectomy was feasible and who fulfilled the inclusion and exclusion criteria between 1998 and 2000 were assigned to have alternatively either immediate surgery or surgery after PVE. Among 55 patients (25 liver metastases, 2 cholangiocarcinoma, and 28 hepatocellular carcinoma), 28 underwent right hepatectomy after PVE and 27 underwent immediate surgery. Twenty-eight patients had chronic liver disease. FLR and estimated rate of functional future liver remnant (%FFLR) volumes were assessed by computed tomography. RESULTS: The mean increase of FLR and %FFLR 4 to 8 weeks after PVE were respectively 44 +/- 19% and 16 +/- 7% for patients with normal liver and 35 +/- 28% and 9 +/- 3% for those with chronic liver disease. All patients with normal liver and 86% with chronic liver disease experienced hypertrophy after PVE. The postoperative course of patients with normal liver who underwent PVE before right hepatectomy was similar to those with immediate surgery. In contrast, PVE in patients with chronic liver disease significantly decreased the incidence of postoperative complications as well as the intensive care unit stay and total hospital stay after right hepatectomy. CONCLUSIONS: Before elective right hepatectomy, the hypertrophy of FLR induced by PVE had no beneficial effect on the postoperative course in patients with normal liver. In contrast, in patients with chronic liver disease, the hypertrophy of the FLR induced by PVE decreased significantly the rate of postoperative complications.

Observations on the morphology of Pomacea lineata (Spix, 1827) (Mollusca, Ampullariidae)

This paper deals with the morpholgy of Pomacea lineata (Spix, 1827) collected at its type locality. The shell is globose, moderately heavy, horn-colored with brown spiral bands; apex subelevated; 4 - 5 rounded whorls increasing in diameter rather rapidly, separated by deep suture. Aperture large and ovoid; outer lip sharp; umbilicus narrow and deep; operculum concentric, corneous. Ratios: shell width/shell length = 0.74 - 0.83 (mean 0.78); spire length/shell length = 0.10 - 0.18 (mean 0.13); aperture length/shell length = 0.70 - 0.77 (mean 0.73). The animal is longisiphonate. Renal organ brownish with marked invagination at its right edge. Ureter elongated with its long axis transverse to the main axis of the kidney. The radula is taenioglossate (2.1.1.1.2) and has on average 35 transverse rows of teeth. The form and arrangement of the radula teeth are nearly the same as in other Ampullariidae. The testis is cream-colored and lies in the first three whorls of the spire. Spermiduct uniformly narrow, running to the base of the spire. Seminal vesicle whitish, slightly pressed dorsoventrally. Prostate cylindric and thick, similar in color to the testis. Penis whiplike, with a closed circular spermiduct. Penis pouch ovoid completely envelping the penis. Penis sheath elongated, broad prosimally, tapering distally. Its inner surface shows a longitudinal channel along its proximal half and two glands, one on the middle and the other apical. Ovary composed of branched whitish tubules situated on the surface of the digestive gland. Oviduct slender running along the columellar axis toward the base of the spire. Seminal receptalble tubiform, thick-walled and rounded proximally. Albumen gland large, pink, enclosing the receptacle and the spiral capsule gland. Vestigial male copulatory apparatus (penis and its sheath) present in all females examined.

Nuclear receptor Rev-erb alpha (Nr1d1) functions in concert with Nr2e3 to regulate transcriptional networks in the retina.

The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated by genes such as nuclear hormone receptors. The nuclear hormone receptor gene Rev-erb alpha/Nr1d1 has been widely studied for its role in the circadian cycle and cell metabolism, however its role in the retina is unknown. In order to understand the role of Rev-erb alpha/Nr1d1 in the retina, we evaluated the effects of loss of Nr1d1 to the developing retina and its co-regulation with the photoreceptor-specific nuclear receptor gene Nr2e3 in the developing and mature retina. Knock-down of Nr1d1 expression in the developing retina results in pan-retinal spotting and reduced retinal function by electroretinogram. Our studies show that NR1D1 protein is co-expressed with NR2E3 in the outer neuroblastic layer of the developing mouse retina. In the adult retina, NR1D1 is expressed in the ganglion cell layer and is co-expressed with NR2E3 in the outer nuclear layer, within rods and cones. Several genes co-targeted by NR2E3 and NR1D1 were identified that include: Nr2c1, Recoverin, Rgr, Rarres2, Pde8a, and Nupr1. We examined the cyclic expression of Nr1d1 and Nr2e3 over a twenty-four hour period and observed that both nuclear receptors cycle in a similar manner. Taken together, these studies reveal a novel role for Nr1d1, in conjunction with its cofactor Nr2e3, in regulating transcriptional networks critical for photoreceptor development and function.

Helminth parasites of fishes from the hydroeletric power station of eletrosul (Brazil). I: Procamallanus petterae n. sp. and Spirocamallanus pintoi n. sp. (Nematoda, Camallanidae) from the reservoir of Salto Osório

Procamallanus petterae n. sp. from Plecostomus albopunctarus and Spirocamallanus pintoi n. sp. from Corydoras paleatus are described. procamallanus petterae n. sp. differs from all other species of the genus by having a buccal capsule without spiral bands, with five teeth-like structures on its base and four plate-like structures near the anterior margin; length ratio of oesophagus muscular/glandular 1:1.4; spicules short, 21µ m and 16µ m long and tails ending abruptly in a sharp point, in both sexes. Spirocamallanus pintoi n. sp. is characterized by having 6 to 8 spiral thickenings in the buccal capsule of male and 9 to 10 in female, occupying 2/3 of the length of the capsule; length of glandular oesophagus more than twice the muscular; spicules short, the right 94µ m and the left 82µ m long.

Miniaturización de componentes planares de microondas mediante técnicas basadas en metamateriales: aplicación a un desfasador de cuadratura

En este trabajo se describe la miniaturización del diseño de un desfasador de cuadratura mediante líneas de transmisión metamaterial en tecnología microstrip. Para conseguir la miniaturización del diseño se utiliza la topología Spiral Resonator (SR). Los desfasadores de cuadratura han sido diseñados, fabricados y medidos. Mediante este proceso se ha consiguido un dispositivo metamaterial que presenta una reducción de un 77% del tamaño respecto a las líneas convencionales.

Endogenous opioid peptides in parasympathetic, sympathetic and sensory nerves in the guinea-pig heart.

Research has suggested that exogenous opioid substances can have direct effects on cardiac muscle or influence neurotransmitter release via presynaptic modulation of neuronal inputs to the heart. In the present study, multiple-labelling immunohistochemistry was employed to determine the distribution of endogenous opioid peptides within the guinea-pig heart. Approximately 40% of cardiac ganglion cells contained immunoreactivity for dynorphin A (1-8), dynorphin A (1-17) and dynorphin B whilst 20% displayed leu-enkephalin immunoreactivity. Different populations of opioid-containing ganglion cells were identified according to the co-existence of opioid immunoreactivity with immunoreactivity for somatostatin and neuropeptide Y. Immunoreactivity for prodynorphin-derived peptides was observed in many sympathetic axons in the heart and was also observed, though to a lesser extent, in sensory axons. Leu-enkephalin immunoreactivity was observed in occasional sympathetic and sensory axons. No immunoreactivity was observed for met-enkephalin-arg-gly-leu or for beta-endorphin. These results demonstrate that prodynorphin-derived peptides are present in parasympathetic, sympathetic and sensory nerves within the heart, but suggest that only the prodynorphin gene is expressed in guinea-pig cardiac nerves. This study has shown that endogenous opioid peptides are well placed to regulate cardiac function via both autonomic and sensory pathways.

Characterization of pip5k3 fleck corneal dystrophy-linked gene in zebrafish.

PIKfyve is a kinase encoded by pip5k3 involved in phosphatidylinositols (PdtIns) pathways. These lipids building cell membranes have structural functions and are involved in complex intracellular regulations. Mutations in human PIP5K3 are associated with François-Neetens mouchetée fleck corneal dystrophy [Li, S., Tiab, L., Jiao, X., Munier, F.L., Zografos, L., Frueh, B.E., Sergeev, Y., Smith, J., Rubin, B., Meallet, M.A., Forster, R.K., Hejtmancik, J.F., Schorderet, D.F., 2005. Mutations in PIP5K3 are associated with François-Neetens mouchetee fleck corneal dystrophy. Am. J. Hum. Genet. 77, 54-63]. We cloned the zebrafish pip5k3 and report its molecular characterization and expression pattern in adult fish as well as during development. The zebrafish PIKfyve was 70% similar to the human homologue. The gene encompassed 42 exons and presented four alternatively spliced variants. It had a widespread expression in the adult organs and was localized in specific cell types in the eye as the cornea, lens, ganglion cell layer, inner nuclear layer and outer limiting membrane. Pip5k3 transcripts were detected in early cleavage stage embryos. Then it was uniformly expressed at 10 somites, 18 somites and 24 hpf. Its expression was then restricted to the head region at 48 hpf, 72 hpf and 5 dpf and partial expression was found in somites at 72 hpf and 5 dpf. In situ on eye sections at 3 dpf showed a staining mainly in lens, outer limiting membrane, inner nuclear layer and ganglion cell layer. A similar expression pattern was found in the eye at 5 dpf. A temporal regulation of the spliced variants was observed at 1, 3 and 5 dpf and they were also found in the adult eye.

On Pomacea canaliculata (Lamarck, 1822) (Mollusca; Pilidae: Ampullariidae)

This paper deals with the morphology of Pomacea caniculata (Lamarck, 1822) collected at Corrientes, Argentina. Comparison is made with Pomacea lineata (Spix, 1827) and Pomacea sordida (Swainson, 1823). The shell is globose, heavy, with greenish or horn-colored periostracum and dark spiral bands; apex subelevated, 5-6 whorls increasing rather rapidly and separated by very deep suture. Aperture large, rounded to subelongated; lip sometimes reddish; umbilicus large and deep; operculum corneous, entirely closing the aperture. Ratios: shell width/shell length = 0.78-0.96 (mean 0.86); aperture length/shell length = 0.68-0.77 (mean 0.72). Radula similar to other congeneric species. Testis and spermiduct as in P. lineata and P. sordida; prostate cylindric and short, cream in color as the testis. Penial sheath straight bearing a central outer gland deeply embedded in the tissue of its basal portion and a large wrinkled gland occupying 2/3 of the distal tip of its inner surface; the rigth margin of the sheath overlaps the left one until 2/3 of its proximal end. Female reproductive apparatus similar to that P. lineata; vestigial male copulatory apparatus (penis and its sheath) present in all females examined.