ABSTRACT
OBJECTIVE: To evaluate the frequency of restless legs syndrome (RLS) in patients with chronic renal failure (CRF) in Petr polis, Brazil, and investigate associations between the syndrome and: demographic characteristics, biochemical variables and comorbidities. METHOD: A cross-sectional study in which we interviewed 176 patients on dialytic therapy based on criteria elaborated by the International Restless Legs Syndrome Study Group, and compared data of patients with and without RLS. RESULTS: The frequency was 14.8 %. There were no significant differences between the two groups in demographic and biochemical variables investigated (iron, creatinine, intact parathyroid hormone, hemoglobin, calcium, phosphate). We found no association between RLS and the most common comorbidities, except for chronic glomerulonephritis (CGN) (OR = 3.84, p < 0.01). CONCLUSION: In the studied population RLS is a common disorder, and is not associated with the investigated biochemical abnormalities. A higher frequency of RLS in subjects with CGN is a finding that needs further investigation.
Subject(s)
Kidney Failure, Chronic/epidemiology , Restless Legs Syndrome/epidemiology , Brazil/epidemiology , Cross-Sectional Studies , Female , Humans , Kidney Failure, Chronic/metabolism , Male , Middle Aged , Prevalence , Renal Dialysis , Restless Legs Syndrome/etiologyABSTRACT
OBJECTIVE: To evaluate the frequency of restless legs syndrome (RLS) in patients with chronic renal failure (CRF) in Petrópolis, Brazil, and investigate associations between the syndrome and: demographic characteristics, biochemical variables and comorbidities. METHOD: A cross-sectional study in which we interviewed 176 patients on dialytic therapy based on criteria elaborated by the International Restless Legs Syndrome Study Group, and compared data of patients with and without RLS. RESULTS: The frequency was 14.8 percent. There were no significant differences between the two groups in demographic and biochemical variables investigated (iron, creatinine, intact parathyroid hormone, hemoglobin, calcium, phosphate). We found no association between RLS and the most common comorbidities, except for chronic glomerulonephritis (CGN) (OR = 3.84, p < 0.01). CONCLUSION: In the studied population RLS is a common disorder, and is not associated with the investigated biochemical abnormalities. A higher frequency of RLS in subjects with CGN is a finding that needs further investigation
Subject(s)
Humans , Male , Female , Middle Aged , Kidney Failure, Chronic , Restless Legs Syndrome/epidemiology , Brazil , Cross-Sectional Studies , Kidney Failure, Chronic , Prevalence , Renal Dialysis , Restless Legs Syndrome/etiologyABSTRACT
Oxy- as well as deoxymyoglobin exhibit a pronounced temperature dependence of the quadrupole splitting of the heme iron as detected by conventional Mössbauer spectroscopy. With nuclear resonant forward scattering (NFS) of synchrotron radiation, which can be viewed as Mössbauer spectroscopy in the time domain, it is shown that this spectroscopic behavior, although it is phenomenologically similar in the two cases, is based on completely different physical mechanisms. It is demonstrated that stochastic fluctuations of the iron electric field gradient in MbO(2), which are due to the dynamic structural disorder of the FeO(2) moiety, are the reason for the temperature-dependent alterations of the coherent quantum beat pattern in the NFS spectra of MbO(2), in contrast to deoxyMb where transitions between orbital states of iron take place. This subtle spectroscopic difference cannot be inferred from conventional Mössbauer spectroscopy.
Subject(s)
Hemoglobins/chemistry , Iron/chemistry , Myoglobin/chemistry , Oxygen/chemistry , Spectroscopy, Mossbauer/methods , Electrochemistry/methods , Molecular Conformation , Scattering, Radiation , Spectrum Analysis/methods , Stochastic Processes , TemperatureABSTRACT
Nuclear inelastic scattering (NIS) spectra were recorded for a monocrystal of the spin-crossover complex [Fe(tptMetame)] (ClO (4))(2) (tptMetame = 1,1,1-tris([N-(2-pyridylmethyl)-N-methylamino]-methyl)ethane) at T = 30 K (low-spin state) and at room temperature (high-spin state) for different crystal orientations. The high energy resolution (0.65 meV) allowed us to resolve individual molecular vibrations which were unambiguously identified by density functional calculations. From the NIS spectra for the first time the angular-resolved iron-partial density of phonon states (PDOS) was extracted. The PDOS corroborates a vibrational entropy difference as driving force of the spin transition.
