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shellsonly Group

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Samuel Thomas
Samuel Thomas

Leg Sex Tube

When the sperm is ejaculated inside the vagina at high speed, it ends up in your cervical mucus. The mucus holds sperm there for fertilization, and helps it travel through your reproductive system, regardless of gravity, she adds. In addition, some of the sperm can travel into the fallopian tubes in under two minutes, so raising your legs is unlikely to make any difference.

leg sex tube

The wide diameter of the common femoral artery makes it an ideal access point for endovascular procedures. A surgeon can insert a catheter (thin, flexible tube) into your femoral artery to access other blood vessels in your body, especially those near the heart.

This pill works in three different ways. First, it thickens the mucus between your uterus (where a baby grows) and your vagina, the tube leading to the uterus. Sperm have a hard time getting through the thick mucus to reach the egg.

To make investigation about risk of wound infection following cardiac surgery, we analyzed cases of primary aorto-coronary bypass surgery and/or primary valvular surgery. Cases required respirator for longer than 2 days, and those with drainage tube for longer than 5 days were excluded from this study, because these cases had antimicrobial agent postoperatively as therapeutic use rather than prophylactic use. Those received preoperative antimicrobial agent for infectious endocarditis and so on were also excluded for the same reason. 523 cases were entered this study. These cases received cefazolin (CEZ) postoperatively as prophylaxis. Sternal wound and leg/groin wound were separately analyzed. Risk factors (age, sex, diabetes mellitus, unstable angina, use of intraaortic balloon, internal thoracic artery harvest, re-exploration, previous myocardial infarction, NYHA classification, emergent operation, operation time, extracorporeal circulation time, blood product use, preoperative blood hemoglobin concentration, preoperative serum albumin, preoperative creatinine clearance (Ccr), duration of drainage tube insertion, body surface area, daily dose of CEZ, duration of prophylaxis) were examined using univariate (Chi square test was used for contingency table analysis, unpaired t test was used to compare averages) and multiple regression analysis. For sternal wound infection, only Ccr showed significant (P = 0.027) correlation. For leg/groin wound infection, 2 factors (smaller daily dose of CEZ: P = 0.009, more severe NYHA class: P = 0.03) showed significant correlation. To investigate appropriate duration of CEZ prophylaxis, cases were divided into 2 groups, those had CEZ within 48 hours postoperatively (group S) and those had CEZ for longer than 48 hours (group L).(ABSTRACT TRUNCATED AT 250 WORDS)

AP-2 REGULATION Notch signaling relieves the joint-suppressive activity of Defective proventriculus in the Drosophila leg: The joint-suppressive activity of Dve is required to repress dAP-2 expression Segmentation plays crucial roles during morphogenesis. Drosophila legs are divided into segments along the proximal-distal axis by flexible structures called joints. Notch signaling is necessary and sufficient to promote leg growth and joint formation, and is activated in distal cells of each segment in everting prepupal leg discs. The homeobox gene defective proventriculus (dve) is expressed in regions both proximal and distal to the intersegmental folds at 4 h after puparium formation (APF). Dve-expressing region partly overlaps with the Notch-activated region, and they become a complementary pattern at 6 h APF. Interestingly, dve mutant legs resulted in extra joint formation at the center of each tarsal segment, and the forced expression of dve caused a jointless phenotype. Evidence that Dve suppresses the potential joint-forming activity, and that Notch signaling represses Dve expression to form joints (Shirai, 2007).To achieve specific developmental programs, antagonism between Notch and EGFR signaling has been widely observed. A graded activity of EGFR signaling from the distal tip of a leg disc is crucial for patterning the distal structure, and it should be converted into the segmental activation, which is critical for suppression of inappropriate joint formation. One possible explanation is that P-D patterning genes define the segment boundary, and thereby refine the Notch signaling pathway in the distal region of each segment, where EGFR signaling should be repressed. The expanded expression of argos-lacZ in Nts mutants strongly suggests that the Notch signaling pathway antagonizes EGFR signaling. Interestingly, a similar type of regulation has been reported for Caenorhabditis elegans vulval development. Thus, the antagonistic interaction between EGFR and Notch signaling establishes the complementary activation of these pathways in neighboring cells, and is crucial for both vulval cell fate determination and leg joint formation (Shirai, 2007).In vertebrates, the early process of body segmentation, i.e., somitogenesis, takes place sequentially from head to tail. Somites are generated from the presomitic mesoderm (PSM), the unsegmented paraxial mesoderm at the tail end of the embryo. A 'clock and wavefront' model has been proposed to explain the mechanism of sequential somite formation. Oscillated gene expression, i.e., the clock, driven by Wnt and Notch signaling in the posterior PSM is translated into the segmental units in the wavefront, which is generated in the anterior PSM in response to the decreased activities of graded Wnt and FGF signaling from the tail end. As an embryo grows caudally, the wavefront moves backwards at a constant rate. Thus, the segment boundary is set at the interface between the Notch-activated and -repressed domains in the anterior PSM (Shirai, 2007).During vertebrate somitogenesis, it has been shown that the interface between the Notch-activated and Notch-repressed domains is generated on suppression of Notch activity through induction of the lunatic-fringe (Lfng) gene in the segment boundary. This refinement is under the control of the basic helix-loop-helix type transcription factor Mesp2, which is expressed in the rostral half of the anterior PSM, indicating that rostral-caudal polarity within a somite is important for restricted Notch activation. The results indicate that the restricted Notch activation during Drosophila leg segmentation also occurs at the segment boundary rather than the center of each segment, suggesting that a conserved mechanism in both Drosophila legs and vertebrate somites underlies the activation of Notch signaling adjacent to the segment boundary (Shirai, 2007).A Dve-expressing region straddles the fold of the segment boundary, and the following observations indicate that Dve has joint-suppressive activity: (1) dve mutant legs resulted in extra joint formation and (2) forced expression of dve in the presumptive joint region suppressed joint formation. Thus, the mechanism of joint development can be explained as follows; Notch-mediated Dve repression on the proximal side to the intersegmental fold relieves the above joint-suppressive activity, leading to normal leg joint formation. This is reminiscent of the abdomen-suppressive activity of Hunchback, which is relieved by Nanos to induce the abdominal structure. In contrast, Dve expression on the distal side to the fold should be maintained to suppress inappropriate joint formation, because dve mutation leads to extra joint formation with reverse polarity. It appears that Dve activity is only induced to suppress joint formation and that temporally regulated Dve repression is crucial for normal leg joint formation, because dve mutations did not affect normal joint formation (Shirai, 2007).Extra joints with reverse polarity (reverse joints) are derived from mutants deficient in the PCP or EGFR signaling pathway. Previous reports have suggested a model in which the Notch signal activation proximal to the Notch ligand-expressing domains is blocked by these signals, only allowing the Notch signal activation in a distally adjacent region, i.e., the distal region of each segment. Based on the expression pattern of the Notch ligand Ser, it is assumed that the center of a segment is highly potent for receiving Notch signaling. This idea can explain the reverse polarity of extra joints, because Ser activates the Notch signaling pathway in two different directions: from proximal to distal for normal joints, and distal to proximal for extra joints. However, it seems unlikely that ectopic activation of Notch signaling is restricted at the center of a segment. A Notch-target gene, dAP-2, is autonomously activated in response to ectopic Notch signaling, and, in pk mutants, ectopic dAP-2 expression has expanded on the distal side to the intersegmental fold, the most proximal but not the central region in a segment. Furthermore, the joint-suppressive activity of Dve is also required to repress dAP-2 expression on the distal side to the intersegmental fold. These results suggest that reverse joints are derived from the distally adjacent region to the intersegmental fold (Shirai, 2007).Based on the results, a model is proposed in which joint-forming activity is generated from the intersegmental fold in a bidirectional manner, and that an inappropriate signal having reverse polarity is blocked by Dve activity, and the PCP and EGFR signaling pathways. In this model, Dve activity is required to suppress Notch target genes, such as dAP-2, involved in joint formation. This is very similar to the situation observed in wing discs, where the Notch target gene wg is repressed by Dve in regions adjacent to the Notch-activated D-V boundary. It is an intriguing possibility that the vertebrate somite boundary generates similar bidirectional signals, and that the inhibition of either one is closely linked to the rostral-caudal polarity within a somite. Further characterization of Drosophila leg segmentation is needed to determine whether this model is applicable to vertebrate somitogenesis or other segmentation processes (Shirai, 2007). dAP-2 and defective proventriculus regulate Serrate and Delta expression in the tarsus of Drosophila melanogasterThe segmentation of the proximal-distal axis of the Drosophila leg depends on the localized activation of the Notch receptor. The expression of the Notch ligand genes Serrate and Delta in concentric, segmental rings results in the localized activation of Notch, which induces joint formation and is required for the growth of leg segments. This study reports that the expression of Serrate and Delta in the leg is regulated by the transcription factor genes dAP-2 and defective proventriculus. Previous studies have shown that Notch activation induces dAP-2 in cells distal and adjacent to the Serrate/Delta domain of expression. Serrate and Delta are ectopically expressed in dAP-2 mutant legs, and Serrate and Delta are repressed by ectopic expression of dAP-2. Furthermore, Serrate is induced cell-autonomously in dAP-2 mutant clones in many regions of the leg. It was also found that the expression of a defective proventriculus reporter overlaps with dAP-2 expression and is complementary to Serrate expression in the tarsal segments. Ectopic expression of defective proventriculus is sufficient to block joint formation and Serrate and Delta expression. Loss of defective proventriculus results in localized, ectopic Serrate expression and the formation of ectopic joints with reversed polarity. Thus, in tarsal segments, dAP-2 and defective proventriculus are necessary for the correct proximal and distal boundaries of Serrate expression and repression of Serrate by defective proventriculus contributes to tarsal segment asymmetry. The repression of the Notch ligand genes Serrate and Delta by the Notch target gene dAP-2 may be a pattern-refining mechanism similar to those acting in embryonic segmentation and compartment boundary formation (Ciechanska, 2007).The female-specific doublesex isoform regulates pleiotropic transcription factors to pattern genital development in Drosophila.Regulatory networks driving morphogenesis of animal genitalia must integrate sexual identity and positional information. Although the genetic hierarchy that controls somatic sexual identity in Drosophila is well understood, there are very few cases in which the mechanism by which it controls tissue-specific gene activity is known. In flies, the sex-determination hierarchy terminates in the doublesex (dsx) gene, which produces sex-specific transcription factors via alternative splicing of its transcripts. To identify sex-specifically expressed genes downstream of dsx that drive the sexually dimorphic development of the genitalia, genome-wide transcriptional profiling was performed of dissected genital imaginal discs of each sex at three time points during early morphogenesis. Using a stringent statistical threshold, 23 genes that have sex-differential transcript levels at all three time points were identified, of which 13 encode transcription factors, a significant enrichment. This study focused on three sex-specifically expressed transcription factors encoded by lozenge (lz), Drop (Dr) and AP-2. In female genital discs, Dsx activates lz and represses Dr and AP-2. It was further shown that the regulation of Dr by Dsx mediates the previously identified expression of the fibroblast growth factor Branchless in male genital discs. The phenotypes observed upon loss of lz or Dr function in genital discs explain the presence or absence of particular structures in dsx mutant flies and thereby clarify previously puzzling observations. This time course of expression data also lays the foundation for elucidating the regulatory networks downstream of the sex-specifically deployed transcription factors (Chatterjee, 2011).A common theme in the evolution of development is that a limited 'toolkit' of regulatory factors is deployed for different purposes during morphogenesis. It is therefore not surprising that the key regulators of genital morphogenesis that this study identified are pleiotropic factors with roles in other developmental processes (Chatterjee, 2011).Two genes that are expressed sex-differentially in the genital disc, branchless (bnl) and dachshund (dac), provide the best picture of how dsx controls genital morphogenesis. Bnl, which is the fly fibroblast growth factor (FGF), is expressed in two bowl-like sets of cells in the A9 primordium in male discs; there is no expression in female discs because DsxF cell-autonomously represses bnl. Bnl recruits mesodermal cells expressing the FGF receptor Breathless (Btl) to fill the bowls; these Btl-expressing cells develop into the vas deferens and accessory glands (Chatterjee, 2011 and references therein).Dac, a transcription factor, is expressed in male discs in lateral domains of the A9 primordium and in female discs in a medial domain of the A8 primordium. These lateral and medial domains correspond to regions exposed to high levels of the morphogens Decapentaplegic (Dpp) and Wingless (Wg), respectively. Dsx determines whether these signals activate or repress dac. Male dac mutants have small claspers with fewer bristles and lack the single, long mechanosensory bristle. Female dac mutants have fused spermathecal ducts (Chatterjee, 2011 and references therein).As with bnl and dac, it remains to be determined whether these downstream genes are direct Dsx targets. Each contains at least one match within an intron to the consensus Dsx binding sequence ACAATGT. Future work will determine whether these matches are indeed contained within Dsx-regulated genital disc enhancers. Moreover, efforts are underway to define Dsx binding locations genome-wide through experiments rather than bioinformatics (B. Baker and D. Luo, personal communication to Chatterjee, 2011); combined with the current expression data, these binding data could speed the discovery of a large number of sex-regulated genital disc enhancers (Chatterjee, 2011). An important future direction will be to determine how spatial and temporal cues are integrated with dsx to regulate downstream genes. Because lz is expressed in the anterior medial region of the female disc, it is hypothesized that, like dac, it is activated by Wg and repressed by Dpp. Such combinatorial regulation could explain the spatially restricted competence of cells in the male disc to activate lz in response to DsxF. Although Dr, AP-2 and lz are expressed at L3, P6 and P20, many other genes are differentially expressed at only one or two of these time points. How these timing differences are regulated is an important unanswered question, especially for genes such as ac, which shifts from highly female biased at P6 to highly male biased at P20. The finding that Dsx binding sites are most enriched in genes with sex-biased expression at L3 suggests that indirect regulation through a cascade of interactions might contribute to expression timing differences (Chatterjee, 2011).It has already been shown that DsxF indirectly represses bnl by repressing Dr. To date, Dr has been shown to repress, but not activate, transcription. Therefore, activation of bnl by Dr might itself be indirect, via repression of a repressor. The regulation of bnl by Dr is sufficient to explain the sex-specific expression of bnl. However, upstream of bnl are two sequence clusters that match the consensus binding motif of Dsx. Thus, bnl might be repressed both directly and indirectly by Dsx, in a coherent feed-forward loop (FFL). FFLs attenuate noisy input signals. An FFL emanating from Dsx could provide a mechanism of robustly preventing bnl activation in female discs, despite potential fluctuations in DsxF levels (Chatterjee, 2011).Understanding how Dr controls the morphogenesis of external structures is also important. The posterior lobe will be of particular interest because it is the most rapidly evolving morphological feature between D. melanogaster and its sibling species. Mutations in Poxn and sal also impair posterior lobe development. Understanding how these two regulators work with Dr to specify and pattern the developing posterior lobe could substantially advance efforts to understand its morphological divergence. Likewise, understanding how lz governs spermathecal development could advance evolutionary studies, as this organ also shows rapid evolution (Chatterjee, 2011).The extent to which the regulators that were identified play deeply conserved roles in genital development remains to be determined. Although sex-determination mechanisms evolve rapidly, some features are shared by divergent animal lineages. The observation that FGF signaling is crucial to male differentiation in mammals, or that mutations in a human sal homolog cause anogenital defects, could reflect ancient roles in genital development or convergent draws from the toolkit (Chatterjee, 2011). Whether AP-2, Dr and lz play conserved roles in vertebrate sexual development is similarly uncertain. In mice, an AP-2 homolog is expressed in the urogenital epithelium (albeit in both sexes) and at least one AP-2 homolog shows sexually dimorphic expression (albeit in the brain). The mouse Dr homolog Msx1 is expressed in the genital ridge and Msx2 functions in female reproductive tract development. In chick embryos, Msx1 and Msx2 are expressed male specifically in the Müllerian ducts. The mouse lz homolog Aml1 (Runx1) is expressed in the Müllerian ducts and genital tubercle. As more data accumulate on the genetic mech


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