135 resultados para Karyotype symmetry

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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PURPOSE: To investigate the facial symmetry of rats submitted to experimental mandibular condyle fracture and with protein undernutrition (8% of protein) by means of cephalometric measurements. METHODS: Forty-five adult Wistar rats were distributed in three groups: fracture group, submitted to condylar fracture with no changes in diet; undernourished fracture group, submitted to hypoproteic diet and condylar fracture; undernourished group, kept until the end of experiment, without condylar fracture. Displaced fractures of the right condyle were induced under general anesthesia. The specimens were submitted to axial radiographic incidence, and cephalometric mensurations were made using a computer system. The values obtained were subjected to statistical analyses among the groups and between the sides in each group. RESULTS: There was significative decrease of the values of serum proteins and albumin in the undernourished fracture group. There was deviation of the median line of the mandible relative to the median line of the maxilla, significative to undernutrition fracture group, as well as asymmetry of the maxilla and mandible, in special in the final period of experiment. CONCLUSION: The mandibular condyle fracture in rats with proteic undernutrition induced an asymmetry of the mandible, also leading to consequences in the maxilla.

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Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent.

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We investigate a recently proposed non-Markovian random walk model characterized by loss of memories of the recent past and amnestically induced persistence. We report numerical and analytical results showing the complete phase diagram, consisting of four phases, for this system: (i) classical nonpersistence, (ii) classical persistence, (iii) log-periodic nonpersistence, and (iv) log-periodic persistence driven by negative feedback. The first two phases possess continuous scale invariance symmetry, however, log-periodicity breaks this symmetry. Instead, log-periodic motion satisfies discrete scale invariance symmetry, with complex rather than real fractal dimensions. We find for log-periodic persistence evidence not only of statistical but also of geometric self-similarity.

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Background: The Trypanosoma cruzi genome was sequenced from a hybrid strain (CL Brener). However, high allelic variation and the repetitive nature of the genome have prevented the complete linear sequence of chromosomes being determined. Determining the full complement of chromosomes and establishing syntenic groups will be important in defining the structure of T. cruzi chromosomes. A large amount of information is now available for T. cruzi and Trypanosoma brucei, providing the opportunity to compare and describe the overall patterns of chromosomal evolution in these parasites. Methodology/Principal Findings: The genome sizes, repetitive DNA contents, and the numbers and sizes of chromosomes of nine strains of T. cruzi from four lineages (TcI, TcII, TcV and TcVI) were determined. The genome of the TcI group was statistically smaller than other lineages, with the exception of the TcI isolate Tc1161 (Jose-IMT). Satellite DNA content was correlated with genome size for all isolates, but this was not accompanied by simultaneous amplification of retrotransposons. Regardless of chromosomal polymorphism, large syntenic groups are conserved among T. cruzi lineages. Duplicated chromosome-sized regions were identified and could be retained as paralogous loci, increasing the dosage of several genes. By comparing T. cruzi and T. brucei chromosomes, homologous chromosomal regions in T. brucei were identified. Chromosomes Tb9 and Tb11 of T. brucei share regions of syntenic homology with three and six T. cruzi chromosomal bands, respectively. Conclusions: Despite genome size variation and karyotype polymorphism, T. cruzi lineages exhibit conservation of chromosome structure. Several syntenic groups are conserved among all isolates analyzed in this study. The syntenic regions are larger than expected if rearrangements occur randomly, suggesting that they are conserved owing to positive selection. Mapping of the syntenic regions on T. cruzi chromosomal bands provides evidence for the occurrence of fusion and split events involving T. brucei and T. cruzi chromosomes.

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We present precise tests of CP and CPT symmetry based on the full data set of K -> pi pi decays collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This data set contains 16 x 10(6) K -> pi(0)pi(0) and 69 x 10(6) K -> pi(+)pi(-) decays. We measure the direct CP violation parameter Re(epsilon'/epsilon) = (19.2 +/- 2.1) x 10(-4). We find the K(L) -> K(S) mass difference Delta m = (5270 +/- 12) x 10(6) (h) over tilde s(-1) and the K(S) lifetime tau(S) = (89.62 +/- 0.05) x 10(-12) s. We also measure several parameters that test CPT invariance. We find the difference between the phase of the indirect CP violation parameter epsilon and the superweak phase: phi(epsilon) - phi(SW) =(0.40 +/- 0.56)degrees. We measure the difference of the relative phases between the CP violating and CP conserving decay amplitudes for K -> pi(+)pi(-) (phi(+-)) and for K -> pi(0)pi(0) (phi(00)): Delta phi = (0.30 +/- 0.35)degrees. From these phase measurements, we place a limit on the mass difference between K(0) and (K) over bar (0): Delta M < 4.8 x 10(-19) GeV/c(2) at 95% C.L. These results are consistent with those of other experiments, our own earlier measurements, and CPT symmetry.

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We analyze the breaking of Lorentz invariance in a 3D model of fermion fields self-coupled through four-fermion interactions. The low-energy limit of the theory contains various submodels which are similar to those used in the study of graphene or in the description of irrational charge fractionalization.

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In a 4D chiral Thirring model we analyze the possibility that radiative corrections may produce spontaneous breaking of Lorentz and CPT symmetry. By studying the effective potential, we verified that the chiral current (psi) over bar gamma(mu)gamma(5)psi may assume a nonzero vacuum expectation value which triggers Lorentz and CPT violations. Furthermore, by making fluctuations on the minimum of the potential we dynamically induce a bumblebee-like model containing a Chem-Simons term.

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The local site symmetry of Ce(3+) ions in the diluted magnetic semiconductors Pb(1-x)Ce(x)A (A=S, Se, and Te) has been investigated by electron-paramagnetic resonance (EPR). The experiments were carried out on single crystals with cerium concentration x ranging from 0.001 to 0.035. The isotropic line due to Ce(3+) ions located at the substitutional Pb cation site with octahedral symmetry was observed for all the studied samples. We determined the effective Lande factors to be g=1.333, 1.364, and 1.402 for A=S, Se, and Te, respectively. The small difference with the predicted Lande factor g of 10/7 for the Gamma(7) (J=5/2) ground state was attributed to crystal-field admixture. In addition, EPR lines from Ce(3+) ions located at sites with small distortion from the original octahedral symmetry were also observed. Two distinct sites with axial distortion along the < 001 > crystallographic direction were identified and a third signal in the spectrum was attributed to sites with the cubic symmetry distorted along the < 110 > direction. The distortion at these distinct Ce sites is attributed to Pb lattice vacancies near the cerium ions that compensate for its donor activity.

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We determined the absolute branch of the T=2 superallowed decay of (32)Ar by detecting the beta(+)-delayed protons and gamma decays of the daughter state. We obtain b(SA)(beta)=(22.71 +/- 0.16)%, which represents the first determination of a proton branch to better than 1%. Using this branch along with the previously determined (32)Ar half-life and energy release, we determined ft=(1552 +/- 12) s for the superallowed decay. This ft value, together with the corrected Ft value extracted from previously known T=1 superallowed decays, yields a measurement of the isospin symmetry breaking correction in (32)Ar decay delta(exp)(C)=(2.1 +/- 0.8)%. This can be compared to a theoretical calculation delta(C)=(2.0 +/- 0.4)%. As by-products of this work, we determined the gamma and proton branches for the decay of the lowest T=2 state of (32)Cl, made a precise determination of the total proton branch and relative intensities of proton groups that leave (31)S in its first excited state and deduced an improved value for the (32)Cl mass.

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The dynamical breaking of gauge symmetry in the supersymmetric quantum electrodynamics in three-dimensional spacetime is studied at two-loop approximation. At this level, the effective superpotential is evaluated in a supersymmetric phase. At one-loop order, we observe a generation of the Chern-Simons term due to a parity violating term present in the classical action. At two-loop order, the scalar background superfield acquires a nonvanishing vacuum expectation value, generating a mass term A(alpha)A(alpha) through the Coleman-Weinberg mechanism. It is observed that the mass of gauge superfield is predominantly an effect of the topological Chern-Simons term.

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Ticlopidine hydrochloride (TICLID (R)) is a platelet antiaggregating agent whose use as a potent antithrombotic pharmaceutical ingredient is widespread, even though this drug has not been well characterized in the solid state. Only the crystal phase used for drug product manufacturing is known. Here, a new polymorph of ticlopidine hydrochloride was discovered and its structure was determined. While the antecedent polymorph crystallizes in the triclinic space group P (1) over bar, the new crystal phase was solved in the monoclinic space group P2(1)/c. Both polymorphs crystallize as racemic mixtures of enantiomeric (ticlopidine)(+) cations. Detailed geometrical and packing comparisons between the crystal structures of the two polymorphs have allowed us to understand how different supramolecular architectures are assembled. It was feasible to conclude that the main difference between the two polymorphs is a rotation of about 120 degrees on the bridging bond between the thienopyridine and o-chlorobenzyl moieties. The differential o-chlorobenzyl conformation is related to changeable patterns of weak intermolecular contacts involving this moiety, such as edge-to-face Cl center dot center dot center dot pi and C-H center dot center dot center dot pi interactions in the new polymorph and face-to-face pi center dot center dot center dot pi contacts in the triclinic crystal phase, leading to a symmetry increase in the ticlopidine hydrochloride solid state form described for the first time in this study. Other conformational features are slightly different between the two polymorphs, such as the thienopyridine puckerings and the o-chlorophenyl orientations. These conformational characteristics were also correlated to the crystal packing patterns.

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Despite modern reanimation surgical techniques, facial paralysis presents with functional and aesthetic deficits. We evaluated facial symmetry after treating with botulinum toxin the healthy side of the face of 25 patients with long-standing facial paralysis who had previously been treated by surgical methods, with 6 months follow-up. Evaluation consisted of a clinical score, the two subscales of the Facial Disability Index, and surface electromyography. The mean botulinum toxin dose was 38 +/- A 5 U (range = 15-69 U). The clinical score showed significant reduction of asymmetry of 48.4% at 1 month and 16.8% after 6 months. The initial result was a consequence of reduced motion on the treated side combined with better motion on the paralyzed side. At 6 months, the treated side returned to basal scores. The residual effect seen in symmetry was due to an increase (18%) of motion in the paralyzed side. There was a significant decrease in the action potential of muscles on the nonparalyzed side 1 month post injection but completely reverted after 6 months. The Physical Function Index increased, but not significantly. The Social/Well-Being Function Index showed a significant increase at 6 months compared to pretreatment. The proposed treatment improved facial symmetry for up to 6 months. Even after the end of the clinical effect of the drug, the paralyzed side`s clinical score was 18% higher than pretreatment, with an increased quality of life.

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Objectives: To evaluate the anatomic variations of neurovascular structures adjacent to the sphenoid sinus and their agreement between right and left sides as well as differences between sexes. Methods: Forty-five cadavers were dissected (24 men, and differences between sexes and agreement of anatomic variations of the sphenoid sinus between sides were analyzed. Results: The mean distance from the sphenoid sinus ostium to the anterior nasal spine was greater in males than in females by an average of 3.0 mm (p = 0.001) while the mean difference of distances between the right and left side was -1.1 +/- 3.1 mm. Female cadavers had a greater frequency of optic-carotid recess (p = 0.04) and dehiscence over the maxillary nerve (p = 0.02), as well as greater relative risk of optic nerve protrusion (p < 0.001), and dehiscence over the internal carotid artery (ICA) (p = 0.002). In male cadavers the intersinus septum was inserted on the course of the ICA 3.5 times more often than in female (p = 0.02). Agreement of anatomic variations between sides ranged from moderate to almost perfect depending on the structures evaluated. Conclusions: There are anatomic differences of the sphenoid sinus between sexes and between right and left sides, and these differences should be taken into consideration during surgery.

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In the present study, the molecular karyotypes of 12 KP1(+) and KP1(-) Trypanosoma rangeli strains were determined and 10 different molecular markers were hybridized to the chromosomes of the parasite, including seven obtained from T. rangeli [ubiquitin hydrolase (UH), a predicted serine/threonine protein kinase (STK), hexose transporter, hypothetical protein, three anonymous sequences] and three from Trypanosoma cruzi [ubiquitin-conjugating enzyme E2 (UBE2), ribosomal RNA methyltransferase (rRNAmtr), proteasome non-ATPase regulatory subunit 6 (PSMD6)]. Despite intraspecific variation, analysis of the karyotype profiles permitted the division of the T rangeli strains into two groups coinciding with the KP1(+) and KP1(-) genotypes. Southern blot hybridization showed that, except for the hexose transporter probe, all other probes produced distinct patterns able to differentiate the KP1(+) and KP1(-) genotypes. The UH, STK and An-1A04 probes exclusively hybridized to the chromosomes of KP1(+) strains and can be used as markers of this group. In addition, the UBE2, rRNAmtr and PSMD6 markers, which are present in a conserved region in all trypanosomatid species sequenced so far, co-hybridized to the same T. rangeli chromosomal bands, suggesting the occurrence of gene synteny in these species. The finding of distinct molecular karyotypes in KP1(+) and KP1 (-) strains of T rangeli is noteworthy and might be used as a new approach to the study of genetic variability in this parasite. Together with the Southern blot hybridization results, these findings demonstrate that differences at the kDNA level might be associated with variations in nuclear DNA. (c) 2009 Elsevier BY. All rights reserved.