Investigating Giant (Gt) Repression in the Formation of Partially Overlapping Pair-Rule Stripes

Drosophila pair-rule genes are expressed in striped patterns with a precise order of overlap between stripes of different genes. We investigated the role of Giant (Gt) in the regulation of even-skipped, hairy, runt, and fushi tarazu stripes formed in the vicinity of Gt expression domains. In gt null embryos, specific stripes of eve, h, run, and ftz are disrupted. With an ectopic expression system, we verified that stripes affected in the mutant are also repressed. Simultaneously hybridizing gt misxpressing embryos with two pair-rule gene probes, we were able to distinguish differences in the repression of pairs of stripes that overlap extensively. Together, our results showed Gt repression roles in the regulation of two groups of partially overlapping stripes and that Gt morphogen activity is part of the mechanism responsible for the differential positioning of these stripes borders. We discuss the possibility that other factors regulate Gt stripe targets as well. Developmental Dynamics 239:2989-2999, 2010. (C) 2010 Wiley-Liss, Inc.

Identification by computer-simulated RFLP of phytoplasmas associated with eggplant giant calyx representative of two subgroups, a lineage of 16SrIII-J and the new subgroup 16SrIII-U

Symptoms resembling giant calyx, a graft-transmissible disease, were observed on 1-5% of eggplant (aubergine; Solanum melongena L.) plants in production fields in Sao Paulo state, Brazil. Phytoplasmas were detected in 1 2 of 1 2 samples from symptomatic plants that were analysed by a nested PCR assay employing 16S rRNA gene primers R16mF2/R16mR1 followed by R16F2n/R16R2. RFLP analysis of the resulting rRNA gene products (1.2 kb) indicated that all plants contained similar phytoplasmas, each closely resembling strains previously classified as members of RFLP group 16SrIII (X-disease group). Virtual RFLP and phylogenetic analyses of sequences derived from PCR products identified phytoplasmas infecting eggplant crops grown in Piracicaba as a lineage of the subgroup 16SrIII-J, whereas phytoplasmas detected in plants grown in Braganca Paulista were tentatively classified as members of a novel subgroup 16SrIII-U. These findings confirm eggplant as a new host of group 16SrIII-J phytoplasmas and extend the known diversity of strains belonging to this group in Brazil.

Presynaptic long-term depression at a central glutamatergic synapse: a role for CaMKII

CaMKII is a calcium-activated kinase that is abundant in neurons and has been strongly implicated in memory and learning. Here we show that low-frequency stimulation of glutamatergic afferents in hippocampal slices from juvenile domestic chicks results in long-term depression of synaptic transmission. This reduction does not require activation of NMDA or metabotropic glutamate receptors and does not require a rise in postsynaptic calcium. However, buffering presynaptic calcium prevents the reduction of the excitatory postsynaptic potential or current that is induced by low-frequency stimulation. in addition, application of the calmodulin antagonist calmidazolium, or the specific CaMKII antagonist KN-93, completely blocks long-term depression. These findings demonstrate a newsy discovered form of long-term synaptic depression in the avian hippocampus.

Net uptake of dissolved free amino acids by the giant clam, Tridacna maxima: alternative sources of energy and nitrogen?

The role of dissolved free amino acids (DFAA) in nitrogen and energy budgets was investigated for the giant clam, Tridacna maxima, growing under field conditions at One Tree Island, at the southern end of the Great Barrier Reef, Australia. Giant clams (121.5-143.7 mm in shell length) took up neutral, acidic and basic amino acids. The rates of net uptake of DFAA did not differ between light and dark, nor for clams growing under normal or slightly enriched ammonium concentrations. Calculations based on the net uptake concentrations typical of the maximum concentrations of DFAA found in coral reef waters (similar to 0.1 mu M)revealed that DFAA could only contribute 0.1% and 1% of the energy and nitrogen demands of giant clams, respectively. These results suggest that DFAA does not supply significant amounts of energy or nitrogen for giant clams or their symbionts.

Influence of field-based nutrient enrichment on the photobiology of the giant clam Tridacna maxima

Nutrients were added to 12 microatolls in One Tree Island lagoon every low tide for 13 mo to an initial concentration of 10 mu M (ammonium, N) and 2 mu M (phosphate, P). These concentrations remained above background for 2 to 3 h after addition. The addition of ammonium (N and NI-P but not P alone) significantly increased P, (gross photosynthesis) P,, (net photosynthesis) and R (respiration) per unit wet-tissue weight and cc (photosynthetic efficiency) in Tridacna maxima after 3 mo nutrient enrichment. These responses to small and transient changes in ammonium concentrations suggest that symbiotic clams are not nutrient-replete, and that even subtle changes in nutrients can have a measurable effect on photosynthesis. The same clams did not show significant differences in photosynthetic parameters 6 mo after the beginning of nutrient enrichment, suggesting that their previous responses had either been seasonal or that symbiotic clams such as T. maxima are able to adjust their photophysiology following external changes in nutrient concentrations.

Vesicle-associated proteins and transmitter release from sympathetic ganglionic boutons

A method is reported for introducing peptides derived from SNARE proteins that control exocytosis of vesicles at boutons formed by sympathetic ganglion cells in tissue culture. These peptides were coupled to the DNA binding domain of the Drosophila transcription factor antennapedia, called penetratin, This facilitated the passage of peptides across the bouton membrane. FMI-43 was used to monitor the exocytosis of transmitter from depolarized boutons after their exposure to the penetratin-peptide sequences IETRHNEIIKLETSIRELHD of syntaxin and KGFLSSLFGGSSK of alpha -SNAP. both of which blocked secretion, whereas the peptide sequences SELDDRA-DALQAGASQFETSAAKLKRK of synaptobrevin did not. This report introduces a readily applicable method for determining the effect of different peptide sequences of vesicle-associated proteins on secretion at vertebrate boutons and presents an account of the effects of a selection of such peptides on exocytosis. NeuroReport 12:607-610 (C) 2001 Lippincott Williams & Wilkins.

Successful outcome of a surgically treated giant retroperitoneal liposarcoma during pregnancy

Background Retroperitoneal liposarcomas occur more frequently between the fifth and seventh decades. Fortunately, these tumors are exceedingly rare in pregnancy, but when they occur, their management becomes even more challenging. Case A pregnant patient with a retroperitoneal liposarcoma was treated by complete surgical resection at 13 weeks of gestation. The patient gave birth at 37 weeks of gestation to a normal newborn and remains free of disease after a year. Conclusions Individualized approach should be taken according to gestational phase, tumor kinetics and overall patient`s condition. Any disturbance to materno-fetal equilibrium, should be an indication for urgent therapeutic approach.

Giant protein kinases: Domain interactions and structural basis of autoregulation

The myosin-associated giant protein kinases twitchin and titin are composed predominantly of fibronectin- and immunoglobulin-like modules, We report the crystal structures of two autoinhibited twitchin kinase fragments, one from Aplysia and a larger fragment from Caenorhabditis elegans containing an additional C-terminal immunoglobulin-like domain, The structure of the longer fragment shoes that the immunoglobulin domain contacts the protein kinase domain on the opposite side from the catalytic cleft, laterally exposing potential myosin binding residues, Together, the structures reveal the cooperative interactions between the autoregulatory region and the residues from the catalytic domain involved in protein substrate binding, ATP binding, catalysis and the activation loop, and explain the differences between the observed autoinhibitory mechanism and the one found in the structure of calmodulin-dependent kinase I.

Isolation and molecular identification of planctomycete bacteria from postlarvae of the giant tiger prawn, Penaeus monodon

Bacteria phenotypically resembling members of the phylogenetically distinct planctomycete group of the domain Bacteria were isolated from postlarvae of the giant tiger prawn, Penaeus monodon. A selective medium designed in the light of planctomycete antibiotic resistance characteristics was used for this isolation. Planctomycetes were isolated from both healthy and monodon baculovirus-infected prawn postlarvae, The predominant colony type recovered from postlarvae regardless of viral infection status was nonpigmented. Other, less commonly observed types were pink or orange pigmented, A planctomycete-specific 16S rRNA-directed probe was designed and used to screen the isolates for their identity as planctomycetes prior to molecular phylogenetic characterization. 16S rRNA genes from nine prawn isolates together with two planctomycete reference strains (Planctomyces brasiliensis and Gemmata obscuriglobus) were sequenced and compared with reference sequences from the planctomycetes and other members of the domain Bacteria, Phylogenetic analyses and sequence signatures of the 16S rRNA genes demonstrated that the prawn isolates were members of the planctomycete group, Five representatives of the predominant nonpigmented colony type were members of the Pirellula group within the planctomycetes, as were three pink-pigmented colony type representatives. Homology values and tree topology indicated that representatives of the nonpigmented and pink-pigmented colony types formed two discrete clusters within the Pirellula group, not identical to any known Pirellula species, A sole representative of the orange colony type was a member of the Planctomyces group, virtually identical in 16S rDNA sequence to P. brasiliensis, and exhibited distinctive morphology.

Magnetic characterization by SQUID and FMR of a biocompatible ferrofluid based on Fe(3)O(4)

Biocompatible superparamagnetic iron oxide nanoparticles of magnetite coated with dextran were magnetically characterized using the techniques of SQUID (superconducting quantum interference device) magnetometry and ferromagnetic resonance (FMR). The SQUID magnetometry characterization was performed by isothermal measurements under applied magnetic field using the methods of zero-field-cooling (ZFC) and field-cooling (FC). The magnetic behavior of the nanoparticles indicated their superparamagnetic nature and it was assumed that they consisted exclusively of monodomains. The transition to a blocked state was observed at the temperature T(B) = (43 +/- 1) K for frozen ferrofluid and at (52 +/- 1) K for the lyophilized ferrofluid samples. The FMR analysis showed that the derivative peak-to-peak linewidth (Delta H(PP)), gyromagnetic factor (g), number of spins (N(S)), and spin-spin relaxation time (T(2)) were strongly dependent on both temperature and super-exchange interaction. This information is important for possible nanotechnological applications, mainly those which are strongly dependent on the magnetic parameters.

Erythema elevatum diutinum presenting with a giant annular pattern

A 45-year-old woman presented with a 3-year history of cutaneous lesions. Clinical examination revealed red-yellow to brownish infiltrated papules coalescing into annular-shaped plaques of several sizes with a hyperpigmented center affecting the abdomen and lower limbs, as well as multiple firm nodules on the right palm, elbows, and knees (Fig. 1a-c). The patient also reported sporadic arthralgia and low fever. She had been treated for leprosy for 2 years with multidrug therapy (clofazimine, dapsone, and rifampicin), with complete remission of the lesions during treatment, but recurrence after discontinuation. Histologic examination of a biopsy specimen taken from the cutaneous lesions showed an interstitial inflammatory infiltrate with the presence of many neutrophils and occasional foamy histiocytes (Fig. 2a). A pattern of perivascular eosinophilic fibrosis was observed in a biopsy specimen from a nodule (Fig. 2b). Special stains for acid-fast bacilli and fungi were negative. Laboratory findings included elevated immunoglobulin A (IgA) serum levels (1016 mg/dL; normal range, 69-382 mg/dL), elevated beta-globulin, and strong tuberculin reactivity. Normal or negative tests included direct immunofluorescence, serum immunofixation, anti-streptolysin O, and chest radiography. Autoimmune disorders and inflammatory intestinal diseases were excluded. The patient was treated with dapsone, 100 mg/day, with great improvement of the clinical picture. Hyperpigmented residual macules and some fibrotic nodules remained after 3 months.

Giant multilocular thymic cyst in an HIV-infected adolescent

A girl with vertically acquired HIV infection presented with a 6-month history of dyspnea and chest pain. Computed tomography of the thorax showed a heterogenous mass measuring 13 x 9 x 17 cm located in the anterior mediastinum. Complete surgical resection was accomplished with no complications. The final diagnosis was multilocular thymic cyst, a distinct pathologic entity that is morphologically distinguishable and unrelated to congenital thymic cyst. (C) 2011 Elsevier Inc. All rights reserved.

GIANT FUSIFORM ANEURYSM ARISING FROM FENESTRATED POSTERIOR CEREBRAL ARTERY AND BASILAR TIP VARIATION: CASE REPORT

OBJECTIVE: A giant fusiform aneurysm in the posterior cerebral artery (PCA) is rare, as is fenestration of the PCA and basilar apex variation. We describe the angiographic and surgical findings of a giant fusiform aneurysm in the P1-P2 PCA segment associated with PCA bilateral fenestration and superior cerebellar artery double origin. CLINICAL PRESENTATION: A 26-year-old woman presented with a 2-month history of visual blurring. Digital subtraction angiography showed a giant (2.5 cm) fusiform PCA aneurysm in the right P1-P2 segment. The 3-dimensional view showed a caudal fusion pattern from the upper portion of the basilar artery associated with a bilateral long fenestration of the P1 and P2 segments and superior cerebellar artery double origin. INTERVENTION: Surgical trapping of the right P1 -P2 segment, including the posterior communicating artery, was performed by a pretemporal approach. Angiograms performed 3 and 13 months after surgery showed complete aneurysm exclusion, and the PCA was permeated and filled the PCA territory. Clinical follow-up at 14 months showed the patient with no deficits and a return to normal life. CONCLUSION: To our knowledge, this is the first report of a giant fusiform aneurysm of the PCA associated with P1-P2 segment fenestration and other variations of the basilar apex (bilateral superior cerebellar artery duplication and caudal fusion). Comprehension of the embryology and anatomy of the PCA and its related vessels and branches is fundamental to the decision-making process for a PCA aneurysm, especially when parent vessel occlusion is planned.

Placental transmogrification of the lung presenting as giant bullae with soft-fatty components

A 44-year-old man presented with progressive dyspnea and a previous pneumothorax. Chest CT scan showed a mediastinal shift due to giant bullae containing soft tissue and fatty components in the left lower lung Lobe, and a right upper lung lobe partially collapsed. The pulmonary function tests revealed forced vital capacity (FVC) 53% (of the predicted) and forced vital capacity in 1 s (FEV1) 52%. Then, resection of the lower lobe was performed with intention to prevent other pneumothoraxes and to revert the upper lobe collapse. The pathological examination showed a placental. transmogrification of the lung (PTL). One month after the surgery, the patient was asymptomatic, the pulmonary function tests normalized and the upper lobe was well expanded. In conclusion, we described the first CT finding of soft tissue and fatty components within the PTL-related bullae, and the PTL should be considered in the differential diagnosis of pulmonary lesions with soft-fatty and air components. (c) 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.