125 research outputs found
Dietary Restrictions in Dialysis Patients: Is There Anything Left to Eat?
A significant number of dietary restrictions are imposed traditionally and uniformly on maintenance dialysis patients, whereas there is very little data to support their benefits. Recent studies indicate that dietary restrictions of phosphorus may lead to worse survival and poorer nutritional status. Restricting dietary potassium may deprive dialysis patients of heart-healthy diets and lead to intake of more atherogenic diets. There is little data about the survival benefits of dietary sodium restriction, and limiting fluid intake may inherently lead to lower protein and calorie consumption, when in fact dialysis patients often need higher protein intake to prevent and correct protein-energy wasting. Restricting dietary carbohydrates in diabetic dialysis patients may not be beneficial in those with burnt-out diabetes. Dietary fat including omega-3 fatty acids may be important caloric sources and should not be restricted. Data to justify other dietary restrictions related to calcium, vitamins, and trace elements are scarce and often contradictory. The restriction of eating during hemodialysis treatment is likely another incorrect practice that may worsen hemodialysis induced hypoglycemia and nutritional derangements. We suggest careful relaxation of most dietary restrictions and adoption of a more balanced and individualized approach, thereby easing some of these overzealous restrictions that have not been proven to offer major advantages to patients and their outcomes and which may in fact worsen patients' quality of life and satisfaction. This manuscript critically reviews the current paradigms and practices of recommended dietary regimens in dialysis patients including those related to dietary protein, carbohydrate, fat, phosphorus, potassium, sodium, and calcium, and discusses the feasibility and implications of adherence to ardent dietary restrictions and future research
Generalized Boltzmann Equation for Lattice Gas Automata
In this paper, for the first time a theory is formulated that predicts
velocity and spatial correlations between occupation numbers that occur in
lattice gas automata violating semi-detailed balance. Starting from a coupled
BBGKY hierarchy for the -particle distribution functions, cluster expansion
techniques are used to derive approximate kinetic equations. In zeroth
approximation the standard nonlinear Boltzmann equation is obtained; the next
approximation yields the ring kinetic equation, similar to that for hard sphere
systems, describing the time evolution of pair correlations. As a quantitative
test we calculate equal time correlation functions in equilibrium for two
models that violate semi-detailed balance. One is a model of interacting random
walkers on a line, the other one is a two-dimensional fluid type model on a
triangular lattice. The numerical predictions agree very well with computer
simulations.Comment: 31 pages LaTeX, 12 uuencoded tar-compressed Encapsulated PostScript
figures (`psfig' macro), hardcopies available on request, 78kb + 52k
Multiple-Point and Multiple-Time Correlations Functions in a Hard-Sphere Fluid
A recent mode coupling theory of higher-order correlation functions is tested
on a simple hard-sphere fluid system at intermediate densities. Multi-point and
multi-time correlation functions of the densities of conserved variables are
calculated in the hydrodynamic limit and compared to results obtained from
event-based molecular dynamics simulations. It is demonstrated that the mode
coupling theory results are in excellent agreement with the simulation results
provided that dissipative couplings are included in the vertices appearing in
the theory. In contrast, simplified mode coupling theories in which the
densities obey Gaussian statistics neglect important contributions to both the
multi-point and multi-time correlation functions on all time scales.Comment: Second one in a sequence of two (in the first, the formalism was
developed). 12 pages REVTeX. 5 figures (eps). Submitted to Phys.Rev.
Mode-coupling theory for multiple-time correlation functions of tagged particle densities and dynamical filters designed for glassy systems
The theoretical framework for higher-order correlation functions involving
multiple times and multiple points in a classical, many-body system developed
by Van Zon and Schofield [Phys. Rev. E 65, 011106 (2002)] is extended here to
include tagged particle densities. Such densities have found an intriguing
application as proposed measures of dynamical heterogeneities in structural
glasses. The theoretical formalism is based upon projection operator techniques
which are used to isolate the slow time evolution of dynamical variables by
expanding the slowly-evolving component of arbitrary variables in an infinite
basis composed of the products of slow variables of the system. The resulting
formally exact mode-coupling expressions for multiple-point and multiple-time
correlation functions are made tractable by applying the so-called N-ordering
method. This theory is used to derive for moderate densities the leading mode
coupling expressions for indicators of relaxation type and domain relaxation,
which use dynamical filters that lead to multiple-time correlations of a tagged
particle density. The mode coupling expressions for higher order correlation
functions are also succesfully tested against simulations of a hard sphere
fluid at relatively low density.Comment: 15 pages, 2 figure
Bone mineral density in Iranian adolescents and young adults with β-thalassemia major
The authors investigated the prevalence of low bone mass in patients from Tehran, Iran, with β-thalassemia major (n = 203), aged 10-20 years, and the potential risk factors for osteoporosis in this patient population. Prevalence of osteoporosis was 50.7 in lumbar spine, 10.8 in femur, and 7.9 in both regions with no significant difference between the two genders. The following factors were associated with low BMD: height for age and weight for age below 3rd percentile, delayed puberty or hypogonadism, age when Desferal (for iron chelation) was started, duration of Desferal therapy, and serum zinc. Low serum copper and 25(OH)D were not associated with low BMD. Copyright © Informa Healthcare USA, Inc
The comprehensive study of possibility ecological control Mnemiopsis leidyi in Caspian Sea activity: The study and recognization parasitic fauna and Bacterial flore in ctenophore (Mnemiopsis leidyi and Bereo ovata)
Bacterial flora and parasitic fauna of M. leidyi an exotic invader jelly fish to Caspian Sea ecosystem and B. ovata to Black sea an alternative biological control agent was studied. During summer 1382 to spring 1383, using routine Bacteriological work. 72 sample of sea water Caspian Sea obtained from depth 20 and 50 meters, 36 sample of M. leidyi from depth 20 meters, 10 sample of B. ovata and 3 sample of sea water (Black sea) were collected and according to Bacteriological was studied. 216 sample of M. leidyi from depth 10 to 50 meters of Caspian Sea and 47 sample of B. ovata from Black and Marmarreh Sea (Turkey) were collected and was studied. In this study no parasite from was identified in M. leidyi (Caspian sea) but 64 percentage and 73 percentage of B. ovata (Marmarreh and Black sea respectively) contaminated to Trichodina ctenophore at varians concentration B. ovata of Black sea (130 min 1050 max) and B. ovata Marmarre sea (420 min 2100 max). While B. ovata kept at high salinity of 21 ppt was more contaminated with this pretrichial protozoan (Trichodina) than in low salinity (12/5 ppt). in comparision of bacterial flore in two cetenophore (M. leidyi and B. ovata) was observed that some of bacteria such as micrococcus sp, Aeromonas sp. Bacillus coagulans in both ctenophore and some other bacteria such as Agromobacterium and chromobacterium only observed in B. ovata but other researcher have reported fram Caspin sea and some of bacteria to specific Shewanella , Vibrio harveiy and bacillus linens was observed in B. ovata . Of course specific bacteria cannot transfer to Caspian Sea (different of salinity black sea (2/1%) to Caspian Sea (1/25 %)). Therefore if B. ovata to introduce to south Caspian Sea for biological control population M. leidyi. it is necessary at first some of viral pathogen in aquatic animal (fish) such as VNN, IPN,IHN,VHS,SVC was studied and then with confidence 95% non-infestation B. ovata to viruses and pass from bath anti parasite and anti-bacterial must be introduce to south Caspian sea
Low levels of vitamin C in dialysis patients is associated with decreased prealbumin and increased C-reactive protein
<p>Abstract</p> <p>Background</p> <p>Subclinical inflammation is a common phenomenon in patients on either continuous ambulatory peritoneal dialysis (CAPD) or maintenance hemodialysis (MHD). We hypothesized that vitamin C had anti-inflammation effect because of its electron offering ability. The current study was designed to test the relationship of plasma vitamin C level and some inflammatory markers.</p> <p>Methods</p> <p>In this cross-sectional study, 284 dialysis patients were recruited, including 117 MHD and 167 CAPD patients. The demographics were recorded. Plasma vitamin C was measured by high-performance liquid chromatography. And we also measured body mass index (BMI, calculated as weight/height<sup>2</sup>), Kt/V, serum albumin, serum prealbumin, high-sensitivity C-reactive protein (hsCRP), ferritin, hemoglobin. The relationships between vitamin C and albumin, pre-albumin and hsCRP levels were tested by Spearman correlation analysis and multiple regression analysis.</p> <p>Patients were classified into three subgroups by vitamin C level according to previous recommendation <abbrgrp><abbr bid="B1">1</abbr><abbr bid="B2">2</abbr></abbrgrp> in MHD and CAPD patients respectively: group A: < 2 ug/ml (< 11.4 umol/l, deficiency), group B: 2-4 ug/ml (11.4-22.8 umol/l, insufficiency) and group C: > 4 ug/ml (> 22.8 umol/l, normal and above).</p> <p>Results</p> <p>Patients showed a widely distribution of plasma vitamin C levels in the total 284 dialysis patients. Vitamin C deficiency (< 2 ug/ml) was present in 95(33.45%) and insufficiency (2-4 ug/ml) in 88(30.99%). 73(25.70%) patients had plasma vitamin C levels within normal range (4-14 ug/ml) and 28(9.86%) at higher than normal levels (> 14 ug/ml). The similar proportion of different vitamin C levels was found in both MHD and CAPD groups.</p> <p>Plasma vitamin C level was inversely associated with hsCRP concentration (Spearman r = -0.201, P = 0.001) and positively associated with prealbumin (Spearman r = 0.268, P < 0.001), albumin levels (Spearman r = 0.161, P = 0.007). In multiple linear regression analysis, plasma vitamin C level was inversely associated with log<sub>10</sub>hsCRP (P = 0.048) and positively with prealbumin levels (P = 0.002) adjusted for gender, age, diabetes, modality of dialysis and some other confounding effects.</p> <p>Conclusions</p> <p>The investigation indicates that vitamin C deficiency is common in both MHD patients and CAPD patients. Plasma vitamin C level is positively associated with serum prealbumin level and negatively associated with hsCRP level in both groups. Vitamin C deficiency may play an important role in the increased inflammatory status in dialysis patients. Further studies are needed to determine whether inflammatory status in dialysis patients can be improved by using vitamin C supplements.</p
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