5,722 research outputs found
Clinical and biochemical response to neridronate treatment in a patient with osteoporosis-pseudoglioma syndrome (OPPG)
Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive syndrome characterized by juvenile-onset osteoporosis and ocular abnormalities due to a low-density lipoprotein receptor-related protein 5 (LRP5) gene mutation. Treatment with bisphosphonates, particularly with pamidronate and risedronate, has been reported to be of some efficacy in this condition. We report on a patient with OPPG due to an LRP5 gene mutation, who showed an encouraging response after a 36-month period of neridronate therapy. We report a case of a patient treated with bisphosphonates. Bisphosphonates should be administered in OPPG patients as a first-line therapy during early childhood
Serum creatine kinase isoenzymes in children with osteogenesis imperfecta
This study evaluates serum creatine kinase isoenzyme
activity in children with osteogenesis imperfecta to determine
its usefulness as a biochemical marker during treatment
with bisphosphonate. The changes of creatine kinase
(CK) isoenzyme activity during and after discontinuation therapy
were observed. These results could be useful in addressing
over-treatment risk prevention.
Introduction The brain isoenzyme of creatine kinase (CKbb)
is highly expressed in mature osteoclasts during osteoclastogenesis,
thus plays an important role in bone resorption. We
previously identified high serum CKbb levels in 18 children
with osteogenesis imperfect (OI) type 1 treated for 1 year with
bisphosphonate (neridronate). In the present study, serum CK
isoenzymes were evaluated in the same children with continuous
versus discontinued neridronate treatment over a further
2-year follow-up period.
Methods This study included 18 children with OI type 1, 12
with continued (group A) and 6 with ceased (group B)
neridronate treatment. Auxological data, serum biochemical
markers of bone metabolism, bone mineral density z-score,
and serum total CK and isoenzyme activities were determined
in both groups.
Results Serum CKbb was progressively and significantly increased
in group A (p < 0.004) but rapidly decreased to undetectable
levels in group B. In both groups, the cardiac muscle
creatine kinase isoenzyme (CKmb) showed a marked decrease,
while serum C-terminal telopeptide (CTx) levels were
almost unchanged.
Conclusions This study provides evidence of the cumulative
effect of neridronate administration in increasing serum CKbb
levels and the reversible effect after its discontinuation. This
approach could be employed for verifying the usefulness of
serum CKbb as a biochemical marker in patients receiving
prolonged bisphosphonate treatment. Moreover, the decreased
serum CKmb levels suggest a systemic effect of these drugs
Charge redistribution in the formation of one-dimensional lithium wires on Cu(001)
We describe the formation of one-dimensional lithium wires on a Cu(001) substrate, providing an atomic-scale description of the onset of metallization in this prototypical adsorption system. A combination of helium atom scattering and density-functional theory reveals pronounced changes in the electronic charge distribution on the formation of the c(5√2×√2)R45° Li/Cu(001) structure, as in-plane bonds are created. Charge donation from Li-substrate bonds is found to facilitate the formation of stable, bonded, and depolarized chains of Li adatoms that coexist with an interleaved phase of independent adatoms. The resultant overlayer has a commensurate charge distribution and lattice modulations but differs fundamentally from structurally similar charge-density wave systems
Buoyant MHD flows in a vertical channel: the levitation regime
Buoyant magnetohydrodynamic (MHD) flows with Joulean and viscous heating effects are considered in a vertical parallel plate channel. The applied magnetic field is uniform and perpendicular to the plates which are subject to adiabatic and isothermal boundary conditions, respectively. The main issue of the paper is the levitation regime, i.e., the fully developed flow regime for large values of the Hartmann number M, when the hydrodynamic pressure gradient evaluated at the temperature of the adiabatic wall is vanishing. The problem is solved analytically by Taylor series method and the solution is validated numerically. It is found that the fluid velocity points everywhere and for all values of M downward. For small M's, the velocity field extends nearly symmetrically (with respect to the mid-plane) over the whole section of the channel between the adiabatic and the isothermal walls. For large values of M, by contrast, the fluid levitates over a broad transversal range of the channel, while the motion becomes concentrated in a narrow boundary layer in the neighborhood of the isothermal wall. Accordingly, the fluid temperature is nearly uniform in the levitation range and decreases rapidly within the boundary layer in front of the isothermal wall. It also turns out that not only the volumetric heat generation by the Joule effect, but also that by viscous friction increases rapidly with increasing values of M, the latter effect being even larger than the former one for all
Humoral and cellular immunopathology of hepatic and cardiac hamster-into-rat xenograft rejection: Marked stimulation of IgM<sup>++bright</sup>/IgD<sup>+dull</sup> splenic B cells
Normal Lewis rat serum contains antibodies (IgM > IgG) that bind to hamster leukocytes and endothelial cells. Transplantation of either the heart or liver from hamster rat results in release of hamster hematolymphoid cells from the graft, which lodge in the recipient spleen (cell migration), where recipient T- and B-cell populations initiate DNA synthesis within one day. There is marked stimulation of splenic IgM++(bright)/IgD+(dull) B cells in the marginal zone and red pulp, which account for 48% of the total splenic blast cell population by 4 days after liver transplantation. CD4+ predominant T-cell proliferation in the splenic periarterial lymphatic sheath and paracortex of peripheral lymph nodes occurs almost simultaneously. The effector phase of rejection in cardiac recipients is dominated by complement-fixing IgM antibodies, which increase daily and result in graft destruction in 3 to 4 days, even in animals treated with FK506. In liver recipients, combined antibody and cellular rejection, associated with graft infiltration by OX8+ natural killer, and fewer W3/25+ (CD4) lymphocytes, are responsible for graft failure in untreated recipients at 6 to 7 days. FK506 inhibits the T-cell response in liver recipients and significantly prolongs graft survival, but does not prevent the rise or deposition of IgM antibodies in the graft. However, a single injection of cyclophosphamide 10 days before transplantation effectively depletes the splenic IgM++(bright)/IgD+(dull) cells and in combination with FK506, results in 100% survival of both cardiac and hepatic xenografts for more than 60 days. Although extrapolation of morphological findings to functional significance is fraught with potential problems, we propose the following mechanisms of xenograft rejection. The reaction initially appears to involve primitive host defense mechanisms, including an IgM-producing subpopulation of splenic B cells and natural killer cells. Based on the reaction and distribution of OX8+ and W3/25+ cells, antibody dependent cell cytotoxicity and delayed-type hypersensitivity responses seem worthy of further investigation as possible effector mechanisms. Effective control of xenograft rejection is likely to require a dual pharmaceutical approach, one to contain T-cell immunity and another to blunt the primitive B-cell response
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Comparison of arterial and venous blood biomarker levels in chronic obstructive pulmonary disease
Purpose: The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD). Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9), vascular endothelial growth factor A (VEGF-A) and interleukin 6 (IL-6) in arterial compared with venous blood. Methods: Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. Results were compared using a Student’s paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples. Results: In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6. Conclusions: In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose
A new application of reduced Rayleigh equations to electromagnetic wave scattering by two-dimensional randomly rough surfaces
The small perturbations method has been extensively used for waves scattering
by rough surfaces. The standard method developped by Rice is difficult to apply
when we consider second and third order of scattered fields as a function of
the surface height. Calculations can be greatly simplified with the use of
reduced Rayleigh equations, because one of the unknown fields can be
eliminated. We derive a new set of four reduced equations for the scattering
amplitudes, which are applied to the cases of a rough conducting surface, and
to a slab where one of the boundary is a rough surface. As in the
one-dimensional case, numerical simulations show the appearance of enhanced
backscattering for these structures.Comment: RevTeX 4 style, 38 pages, 16 figures, added references and comments
on the satellites peak
Metals in high magnetic field: a new universality class of Fermi liquids
Parquet equations, describing the competition between superconducting and
density-wave instabilities, are solved for a three-dimensional isotropic metal
in a high magnetic field when only the lowest Landau level is filled. In the
case of a repulsive interaction between electrons, a phase transition to the
density-wave state is found at finite temperature. In the opposite case of
attractive interaction, no phase transition is found. With decreasing
temperature , the effective vertex of interaction between electrons
renormalizes toward a one-dimensional limit in a self-similar way with the
characteristic length (transverse to the magnetic field) decreasing as
( is a cutoff). Correlation functions have
new forms, previously unknown for conventional one-dimensional or
three-dimensional Fermi-liquids.Comment: 13 pages + 4 figures (included
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