Medial Constriction Research Articles

A New Species of Anacanthorus (Dactylogyridae, Anacanthorinae) Parasitizing Gills of Hoplias aff. malabaricus (Bloch, 1794) (Characiformes, Erythrinidae) from the Caatinga Domain.

Anacanthorus silvoi n. sp. (Dactylogyridae, Anacanthorinae) is described from the gills of Hoplias aff. malabaricus (Bloch, 1794) from the Salgado River, Ceará state, Brazil. The monogeneans were affixed onto slides using Gray and Wess's medium for examination of their sclerotized structures. For analysis of internal organs, a single specimen was preserved in 5% formalin, stained with Gomori's trichrome, and mounted in Gray and Wess's medium. Anacanthorus silvoi n. sp. is characterized by having a short broad tube MCO with a medial constriction (i.e., MCO with distal region wider than the proximal region, and flexed lateral flap in the distal region in A. cururutuiensis and a MCO with a small projection in the form of a hook in the distal region in A. siphonocommus). The present study corroborates previous studies that the absence of an accessory piece is a characteristic shared by all Anacanthorus members parasites of Erythrinidae.

Two new species of Baetodes Needham & Murphy, 1924 with an updated checklist of Baetidae (Ephemeroptera) of Rondônia state, Brazil.

Baetidae is one of the most taxon-rich families in the order Ephemeroptera, and the most studied mayfly in Brazil. Despite recent advances, the vast majority of the Brazilian territory has not yet had its diversity well documented. Some of these critical gaps are in the South-Western Amazon, with emphasis on the state of Rondônia due to the high level of environmental threat (especially deforestation). In the state, only one small survey was carried out 11 years ago. Given this scenario, the objective of this study is to describe two new species and provide access to primary biodiversity data of the family Baetidae in Rondônia. As a result, two new species, Baetodes vermelho sp. nov. and Baetodes cerejeiras sp. nov., are described. Baetodes vermelho sp. nov. can be differentiated from other species by the presence of robust and pointed setae on the dorsal margin of the femora and coxal gills with medial constriction; Baetodes cerejeiras sp. nov. can be differentiated from B. liviae Polegatto & Salles, 2008 (in Salles & Polegatto, 2008) and B. capixaba Souza, Salles & Nessimian, 2011 by the absence of a tubercle on the metanotum, the presence of small blunt setae on the dorsal arc of the labrum, and less prominent tubercles on the abdomen. We have documented 50 species across 54 sites in the Rondônia. Among these, 18 species are being reported for the first time in the state, three species are recorded for the first time in the north of Brazil, and two species are new records for Brazil. Rondônia is the most speciose state in Brazil regarding the family Baetidae.

Comparing morphology of Myzus persicae regarding the taxonomic clarification of a subspecies colonising tobacco

So far, multivariate analysis has been the go-to method for differentiation between the subspecies Myzus persicae persicae and M. persicae nicotianae. The present study used scanning electron microscopy (SEM) to analyse reared and field-collected individuals of both subspecies. Several characteristics led to subspecies differentiation at the morphometrical and micromorphological levels. The results are compared with earlier studies. Thus, previous differentiation by length was confirmed, which showed that M. persicae nicotianae has a relatively longer processus terminalis and siphunculus. In general, the apterae of M. p. nicotianae are larger, and both adult morphs exhibit longer hind legs than M. p. persicae.Comparing the alatae of M. p. persicae and M. p. nicotianae, only the latter possesses a scabrous cuticle covering the entire dorsal head. In contrast, alatae M. p. persicae exhibit a distal swelling of the siphunculi with a medial constriction. However, adult morphs of M. p. nicotianae bear siphunculi with constriction just beneath the flange. The SEM micromorphological analysis synergistically adds to the commonly used multivariate morphometry. Thus, closely related subspecies can be differentiated at a more detailed morphological level.

Two New Species of Backusella (Mucorales, Mucoromycota) from Soil in an Upland Forest in Northeastern Brazil with an Identification Key of Backusella from the Americas.

During a survey of Mucorales from a forest located in Pernambuco state, Brazil, two new Backusella species were discovered and described based on morphological and molecular data (internal transcribed spacer and large subunit ribosomal DNA sequences). Both species were characterized as unbranched sporangiophores and sporangia with columellae of varied shapes forming. Multispored sporangiola were frequent, whereas unispored sporangiola were rare. URM 8395 forms sporangiophores that may support hyaline, slightly curved or circinate pedicels with multispored sporangiola at their apical portion, and abundant giant cells and chlamydospores. Columellae of sporangia are hyaline, conical (majority), or ellipsoidal with a truncate base, globose to subglobose or subglobose to conical, and, rarely, with slight medial constriction. URM 8427 does not form sporangiola from pedicels, giant cells are not observed, and columellae of sporangia are globose to subglobose, cylindrical with a truncate base, some with a slight constriction, applanate, obovoid, ellipsoidal, or, rarely, conical. Some columellae may have one side more swollen than the other and some are arranged obliquely on the sporangiophores. Sterile sporangia may or may not be formed on short sporophores. The detailed description and illustration of both novel species as well as an identification key for Backusella from the Americas are provided.

Endosome-Mediated Epithelial Remodeling Downstream of Hedgehog-Gli Is Required for Tracheoesophageal Separation.

The trachea and esophagus arise from the separation of a common foregut tube during early fetal development. Mutations in key signaling pathways such as Hedgehog (HH)/Gli can disrupt tracheoesophageal (TE) morphogenesis and cause life-threatening birth defects (TEDs); however, the underlying cellular mechanisms are unknown. Here, we use mouse and Xenopus to define the HH/Gli-dependent processes orchestrating TE morphogenesis. We show that downstream of Gli the Foxf1+ splanchnic mesenchyme promotes medial constriction of the foregut at the boundary between the presumptive Sox2+ esophageal and Nkx2-1+ tracheal epithelium. We identify a unique boundary epithelium co-expressing Sox2 and Nkx2-1 that fuses to form a transient septum. Septum formation and resolution into distinct trachea and esophagus requires endosome-mediated epithelial remodeling involving the small GTPase Rab11 and localized extracellular matrix degradation. These are disrupted in Gli-deficient embryos. This work provides a new mechanistic framework for TE morphogenesis and informs the cellular basis of human TEDs.

Terapia breve e intensiva com finger kazoo em caso de disfonia orgânica pós-intubação orotraqueal

Objetivo: avaliar o efeito de um programa de Terapia Breve e Intensiva com a técnica finger kazoo em paciente adulta do sexo feminino com disfonia orgânica. Apresentação do caso clínico: realizadas medidas aerodinâmicas, acústicas, perceptivoauditivas, videolaringoestroboscópicas e autoavaliação vocal antes e após 15 sessões de terapia breve e intensiva com a técnica finger kazzo em uma mulher de 62 anos com disfonia orgânica por fibrose em prega vocal direita, fenda glótica do tipo irregular, com assimetria de fase e amplitude, além de edema da subglote e retração da porção anterior da prega vestibular direita decorrente de intubação orotraqueal. Após a terapia, houve melhora dos tempos máximos de fonação, de medidas acústicas de frequência, perturbação de frequência, ruído, segmentos sub-harmônicos, melhora do traçado espectrográfico e de todos os parâmetros perceptivoauditivos, além de melhora dos escores de qualidade de vida, de depressão e ansiedade. Na avaliação videolaringoestroboscópica, houve melhora da amplitude de vibração da mucosa das pregas vocais e redução da constrição medial do vestíbulo laríngeo. Conclusão: houve modificações vocais positivas em nível glótico, respiratório e ressonantal, bem como no exame videolaringoestroboscópico e na autoavaliação vocal, evidenciando que essa foi uma modalidade de tratamento efetiva para o caso.

Diplectanids (Monogenea) parasitic on sciaenid fish from Peru with the proposal of Pseudorhamnocercoides n. gen., the description of Rhamnocercus dominguesi n. sp. and the redescription of Rhamnocercoides menticirrhi Luque and Iannacone, 1991.

Rhamnocercoides menticirrhi Luque and Iannacone, 1991 is redescribed from newly collected material of snakehead kingcroaker Menticirrhus ophicephalus (Jenyns, 1840) from Peru, and as a result of this redescription, the diagnosis of Rhamnocercoides is emended. Rhamnocercus dominguesi n. sp. is described from the Peruvian banded croaker Paralonchurus peruanus (Steindachner, 1875). It differs from congeneric species mainly in the morphology of the male copulatory organ (with distal and proximal portion of the external tube expanded and distal portion of the internal tube uncovered by external tube) and the number of peduncular spines (18-22, arranged in 2 longitudinal rows). Pseudorhamnocercoides n. gen. is proposed for species with two longitudinal rows of peduncular spines with anterior and posterior roots, two longitudinal rows of acicular spines associated with peduncular spines, a medial constriction in the ventral bar and more than six haptoral accessory spines at level of the ventral bar with fan-like distal extremity. Rhamnocercoides stichospinus (Seamster and Monaco, 1956) is transferred to Pseudorhamnocercoides n. gen as Pseudorhamnocercoides stichospinus (Seamster and Monaco, 1956) n. comb (assigned as type species).

The properties, functions, and pathophysiology of maxi-anion channels.

The maxi-anion channels (MACs) with a unitary conductance of 200-500 pS are detected in virtually every part of the whole body and found in cells from mammals to amphibia. The channels are normally silent but can be activated by physiologically/pathophysiologically relevant stimuli, such as osmotic, salt, metabolic, oxidative, and mechanical stresses, receptor activation, serum, heat, and intracellular Ca(2+) rise. In some MACs, protein dephosphorylation is associated with channel activation. Among MACs so far studied, around 60 % (designated here as Maxi-Cl) possess, in common, the following phenotypical biophysical properties: (1) unitary conductance of 300-400 pS, (2) a linear current-voltage relationship, (3) high anion-to-cation selectivity with PCl/Pcation of >8, and (4) inactivation at positive and negative potentials over a certain level (usually ±20 mV). The pore configuration of the Maxi-Cl is asymmetrical with extracellular and intracellular radii of ∼1.42 and ∼1.16 nm, respectively, and a medial constriction down to ∼0.55-0.75 nm. The classical function of MACs is control of membrane potential and fluid movement. Permeability to ATP and glutamate turns MACs to signaling channels in purinergic and glutamatergic signal transduction defining them as a perspective target for drug discovery. The molecular identification is an urgent task that would greatly promote the developments in this field. A possible relationship between these channels and some transporters is discussed.

New species of Proterometra (Digenea: Azygiidae) and its life cycle in the Chickasawhay River, Mississippi, USA, with supplemental observations of Proterometra autraini

We describe Proterometra ariasae n. sp. based upon cercariae shed from a freshwater snail, Pleurocera sp., and adults infecting the buccal cavity of longear sunfish, Lepomis megalotis, captured from the Chickasawhay River, Mississippi, USA. We also provide supplemental observations of cercarial and adult paratypes of Proterometra autraini from the Au Train River, Michigan, USA. Sequence data for the ribosomal internal transcribed spacer 2 (ITS2) from adults and cercariae of the new species were identical. Adults of the new species differ from congeners by having (i) a markedly large body, (ii) a proportionally large oral sucker, (iii) ovoid testes, (iv) a strongly muscular and laterally expanded pars prostatica, (v) a uterus that is extensively convoluted between the ovary and ventral sucker (vi) and a vitellarium as long as the caeca and extending posteriad beyond the anterior margin of the testes. Cercariae of the new species differ from those of its congeners by having (i) a tail stem that is shorter than 10mm and that lacks a medial constriction, (ii) obcordate furcae that are wider than long, (iii) mamillae distributed throughout the anterior tail stem only, and (v) a proportionally small distome that has relatively few uterine eggs and remains withdrawn in the anterior tail stem region in actively swimming cercariae. This is the first report of Proterometra from Mississippi, the second description to employ morphology and sequence data to elucidate a life cycle for Proterometra, and the third species of Proterometra from an intermediate host not assigned to Elimia.

A new species of Chironius Fitzinger, 1826 from the state of Bahia, Northeastern Brazil (Serpentes: Colubridae).

We describe a new species of Chironius Fitzinger, 1826 from the highlands of Chapada Diamantina, state of Bahia, Brazil. The new species is distinguished from all currently recognized congeners by a unique combination of states of characters on coloration, scale counts, scale ornamentation, and hemipenis. The new species closely resembles Chironius flavolineatus (Jan, 1863) in color pattern, but differs from the later taxon by the presence of two to four posterior temporal scales; cloacal shield entire; six to ten rows of keeled dorsal scales at midbody; ventral scales with posterior dark edges forming conspicuous transverse bars along almost the entire venter; conspicuous dark longitudinal stripes (in "zigzag") in the midventral portion of subcaudals; region of medial constriction of hemipenis slightly covered with spinules separating calyces of apex from spines below region of constriction; and sulcus spermaticus situated on convex face of hemipenis in lateral view. The new species is apparently restricted to Chapada Diamantina, corroborating the biological importance of this region from a conservational perspective.

First description of imago and redescription of nymph for Cloeodes irvingi Waltz & McCafferty, 1987 (Ephemeroptera: Baetidae).

The male imago of Cloeodes irvingi Waltz & McCafferty, 1987 is described for the first time based on reared nymphs collected from the state of Pernambuco, northeastern Brazil. It is differentiated from Neotropical congeners, among other characteristics, by the marginal intercalary veins being paired, except between veins ICu1-ICu2 and ICu2-CuP where they are single and between Sc-R1 and CuP-A where they are absent; segment II of forceps with a medial constriction; and the posterior margin of the subgenital plate being rounded. The nymph of this species is redescribed based on new and original specimens. It is differentiated from Neotropical congeners, among others characteristics, by having a labrum with a dorsal arc composed of 2 + 0 + 2 long, spine-like setae, a labial palp segment III that is subquadrangular, and the fore femur with an apex that is not projected, with 2 blunt setae.

Visual Targeting of Motor Actions in Climbing Drosophila

Drosophila melanogaster flies cross surmountable gaps in their walkway of widths exceeding their body length with an astounding maneuver but avoid attempts at insurmountable gaps by visual width estimation. Different mutant lines affect specific aspects of this maneuver, indicating a high complexity and modularity of the underlying motor control. Here we report on two mutants, ocelliless(1) and tay bridge(1), that, although making a correct decision to climb, fail dramatically in aiming at the right direction. Both mutants show structural defects in the protocerebral bridge, a central complex neuropil formed like a handlebar spanning the brain hemispheres. The bridge has been implicated in step-length control in walking flies and celestial E-vector orientation in locusts. In rescue experiments using tay bridge(1) flies, the integrity of the bridge was reestablished, concomitantly leading to a significant improvement of their orientation at the gap. Although producing directional scatter, their attempts were clearly aimed at the landing site. However, this partial rescue was lost in these flies at a reduced-visibility landing site. We therefore conclude that the protocerebral bridge is an essential part of a visual targeting network that transmits directional clues to the motor output via a known projection system.

Magnetic Resonance Imaging Assessment of Velopharyngeal Motion in Chinese Children After Primary Palatal Repair

Velopharyngeal inadequacy (VPI), which has a significant negative impact on speech intelligibility and resonance quality, may be caused by physiological inadequacy. The current study aimed to investigate the maximal velar and pharyngeal motions and levator muscle shortening in the children with repaired cleft palate and different speech outcomes as well as children without cleft palate by using magnetic resonance imaging techniques without general anesthesia. Three groups of sex- and age-matched children were recruited: children with repaired cleft palate and adequate velopharyngeal function condition (VPC), children with repaired cleft palate and VPI, and the normal controls (noncleft). The children were trained to perform sustained /a:/, /i:/, /ts:/, and /m:/, while keeping the head still during magnetic resonance imaging scan. The maximal velar elevation and stretch, pharyngeal medial constriction, velopharyngeal ratio (VP ratio), and levator muscle shortening ratio were measured and compared across the 3 groups. The VPI group showed the least maximal velar stretch, lowest maximal velar height, smallest maximal pharyngeal constriction, and lowest maximal VP ratio among the 3 groups. The VPI and VPC groups differed significantly in velar and pharyngeal mobility. The effective VP ratio at rest has a strong correlation with that during sustained phonation across the 3 groups. The maximal velar stretch ratio correlates to the maximal pharyngeal constriction ratio strongly in the VPI group only. The VPI group had significantly reduced velar and pharyngeal mobility during speech compared with the VPC and noncleft groups. The possible physiological causes of VPI after primary palatal repair were discussed.

Structures Constituting the Sound Source After the Treatment of Early Glottic Cancer

We indicate the exclusive radiation therapy as initial approach for T1a glottic tumors, and the frontolateral laryngectomy for the tumors staged as T1b and selected T2 glottic tumors. The videolaryngostroboscopy is a useful tool to analyze the laryngeal structural changes and compensatory motion after the therapeutic approach. To evaluate the endolaryngeal structures of patients who participate in the vibratory sound source after the early glottic cancer treatment through the videolaryngostroboscopy. It was a retrospective transversal study in which 20 patients who underwent exclusive radiation therapy and 25 patients who underwent frontolateral laryngectomy were analyzed by means of videolaryngostroboscopy. The radiation doses ranged from 5000 to 7020 cGy in the radiation therapy group. The mucosal wave and the vibratory source components were evaluated. All of the irradiated patients presented vibratory behavior, and hyperfunction was occasionally observed in four cases. The mucosal wave source was glottic in 18 cases and mixed in two cases. In the laryngectomy group, 10 supraglottic sources, 10 glottic sources, and five mixed sources were identified. Among the 10 cases of supraglottic source, eight patients presented global constriction and two patients presented medial constriction. Among the five cases of mixed source, two patients presented global constriction, one patient presented medial constriction, and one patient presented anteroposterior constriction. Regarding the number of anatomical structures presenting vibratory pattern, five patients had two structures, four patients had three structures, and one patient had four structures. Patients who underwent radiation therapy recruit less supraglottic structures as vibratory source than the patients undergoing vertical laryngectomy.

Liriomyza spp.

<i>Liriomyza</i> spp.

Brasilochondria riograndensis gen. nov., sp. nov. (Copepoda, Chondracanthidae) a parasite of flounders of Rio Grande do Sul State, Brazil

Brasilochondria riograndensis gen. nov., sp. nov. (Copepoda, Chondracanthidae) a parasite of the flounder, Paralichthys orbignyanus (Valenciennes, 1839), is described. The new genus has a spherical head a post-mandibular "neck" and two pairs of modified biramous legs. In these respects, it resembles Argentinochondria patagonensis Etchegoin, Timi &amp; Sardella, 2003. In the Argentine genus, however, the bulbous head has a medial constriction and the posterior of the female lacks the lateral extensions that are present in the new genus. Pseudolernentoma brasiliensis Luque &amp; Alves, 2003, also resembles the new genus but it lacks the lateral extensions of the trunk and the latter is cylindrical rather than flat. The second leg of the new genus is small and the endopod is shorter than the exopod. The other two genera have large second legs with subequal rami.

Gyrodactylus gemini n. sp. (Monogenea: Gyrodactylidae), a parasite of Semaprochilodus taeniurus (Steindachner) from the Venezuelan Amazon

Gyrodactylus gemini n. sp. (Monogenea, Gyrodactylidae) is described from the surface of the body and fins of the fish Semaprochilodus taeniurus (Steindachner) imported into Britain from the Venezuelan Amazon. The new species differs from other species of the genus, including those described from South and Central America, by having: (i) stout hamuli with straight shafts and diverging roots; (ii) marginal hooks with the sickle length larger than the width; (iii) a dorsal bar without a medial constriction; (iv) a rectangular ventral bar with short processes; (v) a triangular ventral bar membrane; and, most obviously, (vi) at least two generations which can develop two embryos simultaneously. This is the first known species of the genus Gyrodactylus from the Venezuelan Amazon and the first record of the subgenus Gyrodactylus (Gyrodactylus) from South America.

A New Species of Thaumaleus (Copepoda, Monstrilloida) From the Eastern Coast of the Yucatan Peninsula, Mexico

From plankton samples taken at the Bahia de Ascension, in the central portion of the eastern coast of the Yucatan Peninsula, an undcscribed species of a monstrilloid copepod belonging to the genus Thaumaleus was collected. The new species is best distinguished by the absence of a medial constriction in the genital segment, by the armature and structure of the fifth legs, and by the armature of the antennulae. This is the second record of the genus Thaumaleus in the region.

Meiotic association and segregation of the achiasmatic giant sex chromosomes in the male field vole (Microtus agrestis)

Controversy exists regarding the meiotic behaviour of the giant sex chromosomes during spermatogenesis in the field vole, Microtus agrestis. Both univalents and bivalents have been observed between diakinesis and metaphase I. These differences seem to be dependent on the technique used. The present study employs electron microscopy of serially sectioned testes tubules and light microscopy of microspread preparations to re-examine the behaviour of sex chromosomes during meiosis. In microspreads, about one-third of the early pachytene nuclei examined showed end joining of the X and Y axes. The longitudinal heterogeneity of the chromosomes in the form of axial thickenings allowed the detection of two different end-joining patterns. In the remaining early pachytene cells as well as in all mid to late pachytene cells seen, the X and Y axes had, though near to each other, no contact in the form of a synaptonemal complex. If a synaptonemal complex is a prerequisite for genetic exchange, the sex chromosomes in M. agrestis males must be achiasmatic. The analysis of serial sections through an early pachytene and a late prophase I nucleus with the electron microscope revealed that the sex chromosomes occupied a common area. By metaphase I, the centromeres of the X and Y were oriented towards opposite spindle poles while the chromosomes remained attached to one another by their distal segments at the level of the metaphase I plate. As a consequence of the large size of the sex chromosomes their centromeres lay close to the spindle poles. In anaphase I the sex chromosomes maintained their metaphase position until the autosomes approached the spindle poles. During autosomal migration a medial constriction developed where the sex chromosomes were mutually associated, the X and Y became separated, and joined the autosomes. In metaphase II the chromatids of the sex chromosomes lay side by side and exhibited a delayed separation in the subsequent anaphase. It is suggested that heterochromatin, which represents a major part of both sex chromosomes, plays a role in the association of the two achiasmatic sex chromosomes in metaphase I and in the delayed separation of the chromatids of the sex chromosomes in anaphase II.

Mitosis and the phylogeny of the genus Neocallimastix

Ultrastructural details of mitosis in species of the anaerobic chytridiomycete rumen fungal genus Neocallimastix are described in an attempt to clarify the phylogeny of the genus. Mitosis and spindle formation are entirely intranuclear and start with a group of kinetochores subtending a differentiated region of the nuclear envelope adjacent to extranuclear nucleus-associated organelles. Following duplication of the nucleus-associated organelles, a bipolar spindle develops among the kinetochores and elongates as the nucleus-associated organelles separate. At metaphase the kinetochores are spread along the spindle; heterochromatin is associated with them and also lies throughout the nucleoplasm remote from the spindle. During anaphase the kinetochore microtubules shorten and the two interdigitating arrays of nonkinetochore microtubules slide apart. Karyokinesis involves medial constriction of the nucleus and the persistent nucleolus. Mitotic nuclei in young thalli bear discoidal nucleus-associated organelles which are replaced by a variable number of centrioles in older thalli. These features are dissimilar from other described chytridiomycete mitoses and indicate either a distant relationship between the Neocallimasticaceae and other chytridiomycetes or substantial changes induced in the mitotic apparatus by the specialized environment of the organisms.