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Adequate folate supplementation in the periconceptional phase is recommended to reduce the risk of neural tube defects. Oral contraceptives may provide a reasonable delivery vehicle for folate supplementation before conception in women of childbearing potential. This study aimed to demonstrate that a fixed-dose combination of an oral contraceptive and levomefolate calcium leads to sustainable improvements in folate status compared with an oral contraceptive + folic acid. This was a double-blind, randomized, parallel-group study in which 172 healthy women aged 18-40 years received ethinylestradiol (EE)-drospirenone-levomefolate calcium or EE-drospirenone + folic acid for 24 weeks (invasion phase), and EE-drospirenone for an additional 20 weeks (folate elimination phase). The main objective of the invasion phase was to examine the area under the folate concentration time-curve for plasma and red blood cell (RBC) folate, while the main objective of the elimination phase was to determine the duration of time for which RBC folate concentration remained ≥ 906 nmol/L after cessation of EE-drospirenone-levomefolate calcium. Mean concentration-time curves for plasma folate, RBC folate, and homocysteine were comparable between treatment groups during both study phases. During the invasion phase, plasma and RBC folate concentrations increased and approached steady-state after about 8 weeks (plasma) or 24 weeks (RBC). After cessation of treatment with levomefolate calcium, folate concentrations decreased slowly. The median time to RBC folate concentrations falling below 906 nmol/L was 10 weeks (95% confidence interval 8-12 weeks) after cessation of EE-drospirenone-levomefolate calcium treatment. Plasma and RBC folate levels remained above baseline values in 41.3% and 89.3% of women, respectively, at the end of the 20-week elimination phase. Improvements in folate status were comparable between EE-drospirenone-levomefolate calcium and EE-drospirenone + folic acid. Plasma and RBC folate levels remained elevated for several months following cessation of treatment with EE-drospirenone-levomefolate calcium.

A major component of the Entamoeba cyst wall is chitin, a homopolymer of β-(1,4)-linked N-acetyl-D-glucosamine. Polymerization of chitin requires the presence of active chitin synthases (CHS), a group of enzymes belonging to the family of β-glycosyl transferases. CHS have been described for fungi, insects, and nematodes; however, information is lacking about the structure and expression of this class of enzymes in protozoons such as Entamoeba. In this study, the primary structures of two putative E.histolytica CHS (EhCHS-1 and EhCHS-2) were determined by gene cloning and homologous proteins were identified in databases from E. dispar and the reptilian parasite E. invadens. The latter constitutes the widely used model organism for the study of Entamoeba cyst development. The two ameba enzymes revealed between 23% and 33% sequence similarity to CHS from other organisms with full conservation of all residues critically important for CHS activity. Interestingly, EhCHS-1 and EhCHS-2 differed substantially in their predicted molecular weights (73 kD vs. 114 kD) as well as in their isoelectric points (5.04 vs. 8.05), and homology was restricted to a central stretch of about 400amino acid residues containing the catalytic domain. Outside the catalytic domain, EhCHS-1 was predicted to have seven transmembrane helices (TMH) of which the majority is located within the C-terminal part, resembling the situation found in yeast; whereas, EhCHS-2 is structurally related to nematode or insect chitin synthases, as it contained 17 predicted TMHs of which the majority is located within the N-terminal part of the molecule. Northern blot analysis revealed that genes corresponding to CHS-1 and CHS-2 are not expressed in Entamoeba trophozoites, but substantial amounts of CHS-1 and CHS-2 RNA were present 4 to 8 hours after induction of cyst formation by glucose deprivation of E. invadens. The time-courses of expression differed slightly between the two ameba CHS genes, as in contrast to CHS-1 RNA, expression of CHS-2 RNA was more transient and no plateau was observed between 8 and 16 hours of encystation. However, both CHS RNAs were no longer detectable after 48hours when most of the cells had been transformed into mature cysts.

Abstract The incidence of femur fracture in noncemented hip arthroplasty has been reported to be between 4.1 % and 27.8%. To quantitate the hoop stress generated during insertion of a femoral broach in total hip arthroplasty and determine the effect of cerclage with both braided cable and wire, we harvested 14 pairs of embalmed cadaver femurs. These were reamed and broached to duplicate the surgical technique of inserting a straight non-cemented femoral component. Group one consisted of eight matched cadaver femurs which were tested using a single 2.0 mm chrome-cobalt cable placed around the calcar of one femur, with the other serving as a control. Group two consisted of five matched cadaver femurs which were tested using a single 18 gauge cerclage wire in the same manner. In group one, the femurs serving as controls were found to have a mean microstrain of (1425.00 ± 1 180.19). The eight femurs tested with a 2 mm cable were determined to have a mean microstrain of (4179 + 2853.89). In group two, the femurs serving as controls were found to have a mean microstrain of (962.60 ±956.78). The five femurs in group two tested with a cerclage wire were determined to have a mean microstrain of (1112.00 ±975.66). Using a paired t-test, statistical significance was achieved with a confidence level of P=s.01 in group one. Prophylactic wiring of the proximal femur with 2 mm cable increases the hoop stress resistance and, therefore, should decrease the incidence of intraoperative femur fractures in uncemented total hip arthroplasty.

The adherence of Entamoeba histolytica to colonic mucins and to host cells appears to be predominantly mediated by a 170-kDa surface lectin of the amoebae. By using an antiserum to the purified lectin, the corresponding cDNA was isolated from an expression library of the pathogenic E. histolytica isolate HM-1:IMSS. Northern blot analysis indicated a transcript of ≈4 kilobases, and Southern blot analyses suggested that multiple genes may encode the lectin or closely related proteins in HM-1:IMSS trophozoites. The cDNA-deduced amino acid sequence revealed an N-terminal signal peptide and a mature protein of 1270 amino acids corresponding to a molecular mass of 143 kDa, which comprises a short C-terminal cytoplasmic domain with potential phosphorylation sites, a transmembrane region, and a large extracellular portion with nine potential asparagine-linked glycosylation sites. The extracellular portion may be separated into a cysteine-poor domain and a cysteine-rich domain, the latter of which shows in part repetitive structural elements with a low degree of sequence homology to wheat germ agglutinin and to pDd63, a developmentally expressed protein of Dictyostelium discoideum.

There is greater potential for wound healing complication in rheumatoids, diabetics, and other patients with peripheral vascular disease. Local wound care in areas of avascularity and skin necrosis has poor results, especially if an ulcer is greater than 2 cm in diameter. Gastrocnemius muscle flap coverage of persistent wounds and areas of skin necrosis following total knee arthroplasty should be considered early in the course of such a complication.

ABSTRACT Thirty-five total joint arthroplasties (34 patients) were performed in patients who had protrusio acetabuli. Twenty-nine percent of the patients had acetabular protrusio of grade I, while 71% had grade II and grade III protrusio. The mean follow up was 4 years (range: 3 to 9). Cemented acetabular components were used in 11 hips; 24 hips received an uncemented porous coated acetabular component. The patient evaluations included preoperative and postoperative Harris Hip Ratings and standard radiographs. In all cases, the medial wall defect was reconstructed with the solid autogenous femoral head as described by Heywood. The mean preoperative Harris Hip Rating was 45 (range: 30 to 60 points), and the postoperative mean was 85 (range: 70 to 100 points). Radiographically, the preoperative protrusio measured a mean of 8.8 mm (range: 6 to 18 mm), and the mean postoperative placement of the femoral head was 10 mm lateral to Kohler's line (range: 6 to 13 mm). There were no acetabular component failures and no acetabular bone graft resorptions. All autogenous grafts were incorporated to the host radiographically by 1 year post-surgery. This study corroborates previous work which suggests that medial-placed bone grafting is not resorbed and consolidates with the host bone. We find this technique extremely useful in dealing with this technical problem.

A bstract Kinematic selection cuts and isolation requirements are a necessity in experimental measurements for identifying prompt leptons and photons that originate from the hard-interaction process of interest. We analyze how such cuts affect the application of the q T and N -jettiness subtraction methods for fixed-order calculations. We consider both fixed-cone and smooth-cone isolation methods. We find that kinematic selection and isolation cuts both induce parametrically enhanced power corrections with considerably slower convergence compared to the standard power corrections that are already present in inclusive cross sections without additional cuts. Using analytic arguments at next-to-leading order we derive their general scaling behavior as a function of the subtraction cutoff. We also study their numerical impact for the case of gluon-fusion Higgs production in the H → γγ decay mode and for pp → γγ direct diphoton production. We find that the relative enhancement of the additional cut-induced power corrections tends to be more severe for q T , where it can reach an order of magnitude or more, depending on the choice of parameters and subtraction cutoffs. We discuss how all such cuts can be incorporated without causing additional power corrections by implementing the subtractions differentially rather than through a global slicing method. We also highlight the close relation of this formulation of the subtractions to the projection-to-Born method.

A number of important observables exhibit logarithms in their perturbative description that are induced by emissions at widely separated rapidities. These include transverse-momentum (qT) logarithms, logarithms involving heavy-quark or electroweak gauge boson masses, and small-x logarithms. In this paper, we initiate the study of rapidity logarithms, and the associated rapidity divergences, at subleading order in the power expansion. This is accomplished using the soft collinear effective theory (SCET). We discuss the structure of subleading-power rapidity divergences and how to consistently regulate them. We introduce a new pure rapidity regulator and a corresponding MS¯\\[ \\overline{\\mathrm{MS}} \\]-like scheme, which handles rapidity divergences while maintaining the homogeneity of the power expansion. We find that power-law rapidity divergences appear at subleading power, which give rise to derivatives of parton distribution functions. As a concrete example, we consider the qT spectrum for color-singlet production, for which we compute the complete qT2/Q2 suppressed power corrections at Oαs\\[ \\mathcal{O}\\left({\\alpha}_s\\right) \\], including both logarithmic and nonlogarithmic terms. Our results also represent an important first step towards carrying out a resummation of subleading-power rapidity logarithms.

A bstract We consider Drell-Yan production pp → V * X → LX at small q T ≪ Q , where q T and Q are the total transverse momentum and invariant mass of the leptonic final state L . Experimental measurements require fiducial cuts on L , which in general introduce enhanced, linear power corrections in q T /Q . We show that they can be unambiguously predicted from factorization, and resummed to the same order as the leading-power contribution. For the fiducial q T spectrum, they constitute the complete linear power corrections. We thus obtain predictions for the fiducial q T spectrum to N 3 LL and next-to-leading-power in q T /Q . Matching to full NNLO ( α s 2 ), we find that the linear power corrections are indeed the dominant ones, and once included by factorization, the remaining fixed-order corrections become almost negligible below q T ≲ 40 GeV. We also discuss the implications for more complicated observables, and provide predictions for the fiducial ϕ * spectrum at N 3 LL+NNLO. We find excellent agreement with ATLAS and CMS measurements of q T and ϕ * . We also consider the p T ℓ spectrum. We show that it develops leptonic power corrections in q T / ( Q − 2 p T ℓ ), which diverge near the Jacobian peak p T ℓ ∼ Q/ 2 and must be kept to all powers to obtain a meaningful result there. Doing so, we obtain for the first time an analytically resummed result for the p T ℓ spectrum around the Jacobian peak at N 3 LL+NNLO. Our method is based on performing a complete tensor decomposition for hadronic and leptonic tensors. We show that in practice this is equivalent to often-used recoil prescriptions, for which our results now provide rigorous, formal justification. Our tensor decomposition yields nine Lorentz-scalar hadronic structure functions, which for Z/γ * → ℓℓ or W → ℓν directly map onto the commonly used angular coefficients, but also holds for arbitrary leptonic final states. In particular, for suitably defined Born-projected leptons it still yields a LO-like angular decomposition even when including QED final-state radiation. Finally, we also discuss the application to q T subtractions. Including the unambiguously predicted fiducial power corrections significantly improves their performance, and in particular makes them applicable near kinematic edges where they otherwise break down due to large leptonic power corrections.

A bstract Differential spectra in observables that resolve additional soft or collinear QCD emissions exhibit Sudakov double logarithms in the form of logarithmic plus distributions. Important examples are the total transverse momentum q T in color-singlet production, N -jettiness (with thrust or beam thrust as special cases), but also jet mass and more complicated jet substructure observables. The all-order logarithmic structure of such distributions is often fully encoded in differential equations, so-called (renormalization group) evolution equations. We introduce a well-defined technique of distributional scale setting, which allows one to treat logarithmic plus distributions like ordinary logarithms when solving these differential equations. In particular, this allows one (through canonical scale choices) to minimize logarithmic contributions in the boundary terms of the solution, and to obtain the full distributional logarithmic structure from the solution’s evolution kernel directly in distribution space. We apply this technique to the q T distribution, where the two-dimensional nature of convolutions leads to additional difficulties (compared to one-dimensional cases like thrust), and for which the resummation in distribution (or momentum) space has been a long-standing open question. For the first time, we show how to perform the RG evolution fully in momentum space, thereby directly resumming the logarithms [ln n ( q T 2 / Q 2 )/ q T 2 ] + appearing in the physical q T distribution. The resummation accuracy is then solely determined by the perturbative expansion of the associated anomalous dimensions.