362 research outputs found
Androgens correlate with increased erythropoiesis in women with congenital adrenal hyperplasia.
OBJECTIVE: Hyperandrogenism in congenital adrenal hyperplasia (CAH) provides an in vivo model for exploring the effect of androgens on erythropoiesis in women. We investigated the association of androgens with haemoglobin (Hb) and haematocrit (Hct) in women with CAH. DESIGN: Cross-validation study PATIENTS: Women with CAH from Sheffield Teaching Hospitals, UK (cohort 1, the training set: n=23) and National Institutes of Health, USA (cohort 2, the validation set: n=53). MEASUREMENTS: Androgens, full blood count and basic biochemistry, all measured on the same day. Demographic and anthropometric data. RESULTS: Significant age-adjusted correlations (P<0.001) were observed for Ln testosterone with Hb and Hct in cohorts 1 and 2 (Hb r=0.712 & 0.524 and Hct r=0.705 & 0.466), which remained significant after adjustments for CAH status, glucocorticoid treatment dose and serum creatinine. In the combined cohorts Hb correlated with androstenedione (P=0.002) and 17-hydroxyprogesterone (P=0.008). Hb and Hct were significantly higher in cohort 1 than those in cohort 2, while there were no group differences in androgen levels, glucocorticoid treatment dose or body mass index. In both cohorts, women with Hb and Hct in the highest tertile had significantly higher testosterone levels than women with Hb and Hct in the lowest tertile. CONCLUSIONS: In women with CAH, erythropoiesis may be driven by androgens and could be considered a biomarker for disease control
EFFECTS OF CHANGE IN BODY POSTURE ON PLASMA AND SERUM ELECTROLYTES IN NORMAL SUBJECTS AND IN PRIMARY ALDOSTERONISM
We observed that change in body posture from the supine to the erect position in normal volunteers was associated with a rise in circulating potassium and a fall in sodium concentrations, irrespective of whether the electrolytes were measured in serum or plasma, or whether head-up tilt or ambulation was used. In patients with primary aldosteronism, the fall in serum sodium and rise in serum potassium with ambulation tended to obscure the characteristic electrolyte abnormalities of that syndrome. These changes in potassium and sodium could contribute to the rise in aldosterone secretion on orthostasis. The body posture of patients should be considered in the interpretation of plasma and serum electrolyte levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75439/1/j.1365-2265.1981.tb02972.x.pd
Broken-Symmetry States in Quantum Hall Superlattices
We argue that broken-symmetry states with either spatially diagonal or
spatially off-diagonal order are likely in the quantum Hall regime, for clean
multiple quantum well (MQW) systems with small layer separations. We find that
for MQW systems, unlike bilayers, charge order tends to be favored over
spontaneous interlayer coherence. We estimate the size of the interlayer
tunneling amplitude needed to stabilize superlattice Bloch minibands by
comparing the variational energies of interlayer-coherent superlattice miniband
states with those of states with charge order and states with no broken
symmetries. We predict that when coherent miniband ground states are stable,
strong interlayer electronic correlations will strongly enhance the
growth-direction tunneling conductance and promote the possibility of Bloch
oscillations.Comment: 9 pages LaTeX, 4 figures EPS, to be published in PR
Equine leukoencephalomalacia associated with ingestion of corn contaminated with fumonisin B1
Lepton Flavor Non-Conservation
In the present work we review the most prominent lepton flavor violating
processes (\mu \ra e\gamma, \mu \ra 3e, conversion,
oscillations etc), in the context of unified gauge theories. Many currently
fashionable extensions of the standard model are considered, such as: {\it i)}
extensions of the fermion sector (right-handed neutrino); {\it ii)} minimal
extensions involving additional Higgs scalars (more than one isodoublets,
singly and doubly charged isosinglets, isotriplets with doubly charged members
etc.); {\it iii)} supersymmetric or superstring inspired unified models
emphasizing the implications of the renormalization group equations in the
leptonic sector. Special attention is given to the experimentaly most
interesting conversion in the presence of nuclei. The relevant
nuclear aspects of the amplitudes are discussed in a number of fashionable
nuclear models. The main features of the relevant experiments are also
discussed, and detailed predictions of the above models are compared to the
present experimental limits.Comment: (IOA-300/93, review article, 83p, 6 epsf figures , available upon
request from [email protected])
Lepton Flavour Violating Leptonic/Semileptonic Decays of Charged Leptons in the Minimal Supersymmetric Standard Model
We consider the leptonic and semileptonic (SL) lepton flavour violating (LFV)
decays of the charged leptons in the minimal supersymmetric standard model
(MSSM). The formalism for evaluation of branching fractions for the SL LFV
charged-lepton decays with one or two pseudoscalar mesons, or one vector meson
in the final state, is given. Previous amplitudes for the SL LFV charged-lepton
decays in MSSM are improved, for instance the -penguin amplitude is
corrected to assure the gauge invariance. The decays are studied not only in
the model-independent formulation of the theory in the frame of MSSM, but also
within the frame of the minimal supersymmetric SO(10) model within which the
parameters of the MSSM are determined. The latter model gives predictions for
the neutrino-Dirac Yukawa coupling matrix, once free parameters in the model
are appropriately fixed to accommodate the recent neutrino oscillation data.
Using this unambiguous neutrino-Dirac Yukawa couplings, we calculate the LFV
leptonic and SL decay processes assuming the minimal supergravity scenario. A
very detailed numerical analysis is done to constrain the MSSM parameters.
Numerical results for SL LFV processes are given, for instance for tau -> e
(mu) pi0, tau -> e (mu) eta, tau -> e (mu) eta', tau -> e (mu) rho0, tau -> e
(mu) phi, tau -> e (mu) omega, etc.Comment: 36 pages, 3 tables, 5 .eps figure
Single Spin Asymmetry in Polarized Proton-Proton Elastic Scattering at GeV
We report a high precision measurement of the transverse single spin
asymmetry at the center of mass energy GeV in elastic
proton-proton scattering by the STAR experiment at RHIC. The was measured
in the four-momentum transfer squared range \GeVcSq, the region of a significant interference between the
electromagnetic and hadronic scattering amplitudes. The measured values of
and its -dependence are consistent with a vanishing hadronic spin-flip
amplitude, thus providing strong constraints on the ratio of the single
spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated
by the Pomeron amplitude at this , we conclude that this measurement
addresses the question about the presence of a hadronic spin flip due to the
Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure
Radiative Decay Modes of the Meson
Using data recorded by the CLEO-II detector at CESR we have searched for four
radiative decay modes of the meson: ,
, , and . We
obtain 90% CL upper limits on the branching ratios of these modes of , , and
respectively.Comment: 15 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Fechamento das placas epifisárias do metacarpiano principal, do rádio e da tíbia em potros Crioulos
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