bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relationship of insulin resistance and body fat in chronic kidney disease patients.
Authors: Satirapoj B. , Supasyndh O. , Boonyavarakul A. , Luesutthiviboon L. , Chuvicheer P. 
Published: January 2005

Background:
Insulin resistance has been associated with type 2 diabetes, hypertension, central obesity, and dyslipidemia, all of which are important risk factors for progression of chronic kidney disease (CKD). A greater degree of insulin resistance may predispose to renal injury by worsening renal hemodynamics through the elevation of glomerular filtration fraction. However, there are sparse data on the relationship between insulin resistance, glomerular filtration rate (GFR), and total body fat or phase angle in CKD without diabetes. Methods: We examined 84 non‐diabetes CKD patients according to the K/DOQI definitions; only 79 patients were enrolled into the study (GFR between 15 and 90 ml/min/1.73 m2). The value of insulin resistance was obtained by homeostasis model assessment (HOMA). Bioelectrical impedance analysis was performed to determine the percentage of total body fat or phase angle. GFR was calculated by the average of creatinine and urea clearances. Results: The correlation analysis showed that HOMA‐insulin resistance was positively correlated with phase angle (r = 0.35, P < 0.01), percentage of total body fat (r = 0.27, P < 0.01), body mass index (r = 0.48, P < 0.01) and serum triglyceride levels (r = 0.32, P < 0.01), but not significantly correlated with gender (r = −0.07, P > 0.05), age (r = 0.05, P > 0.05), GFR (r = −0.006, P > 0.05), and mean arterial blood pressure (r = 0.11, P > 0.05). Conclusion: In non‐diabetic chronic kidney disease patients, the major risk factor for insulin resistance is the amount of total body fat. The insulin level is not dependent on the GFR in these patients.
Long slow night hemodialysis and quality of life
Authors: Hakkarainen P. , Kapanen S. , Honkanen E. , Löflund E. 
Published: January 2005

Background:
Long slow hemodialysis (LS‐HD) improves many biochemical parameters compared with conventional HD. However, its influences on quality of life are less well known. Aims: The objective of this study was to examine the quality of life of patients on LS‐HD performed overnight compared to the patients on standard hemodialysis. This extends the previous study, conducted in 2001, which examined the LS‐HD patients, quality of life. Patients and methods: We sent questionnaires to 12 LS‐HD (overnight, treatment time 8 h × 3/wk) patients and 15 day HD (4.5 h × 3/wk) patients, all being treated using the limited care method. Data was collected using two different structured questionnaires. One was constructed for a previous study (2001) and the other one was a standardized set of questionnaires (RAND‐36). Research material was collected from patient documents, such as the essential biochemical parameters, blood pressure, weight gain, and weekly EPO doses were recorded. Ten of the LS‐HD patients (83%) and 13/15 (87%) of day HD patients returned the questionnaires. Three day hemodialysis patients returned empty questionnaires, which were disqualified. Results: Based on the medical facts, the results showed that the patients of LS‐HD felt better than the patients in another group. Patients on the LS‐HD had higher Kt/V (2.623 vs. 1.577) and Hb (118 vs. 111) and lower Pi (1.36 vs. 1.63) and EPO dose (epoietin‐beta 2667 ky/week vs. 5833 ky/week; darbepoetin 16 ky/week vs. 37 ky/week). However, their predialysis BP as well as the weight gain between treatments and salt and fluid balances caused problems furthermore. The experiences of the therapy of the LS‐HD patients were more positive than of the control group: they felt their medical condition was better than of the patients on day HD. However we didn’t observe significant differences in the replies showing physical or psychosocial conditions between the two groups. Conclusions: The study suggests that when patients can themselves make the choice between treatment modalities, it improves the quality of life of the patients. Control of anemia is improved in LS‐HD overnight patients with lower doses of EPO. The LS‐HD gives the patients more freedom of diet. However, more attention must be paid to salt and fluid restriction. The LS‐HD makes it possible for many patients to work normally.
Studies of phosphate dynamics during hemodialysis
Authors: Kjellstrand C.M. , Odar‐Cederlof I. , Ing T.S. , Blagg C.R. 
Published: January 2005

Regulation of phosphate (PO4) in hemodialysis patients is very difficult and ideal levels are rarely maintained. A high removal and a normal phosphate level is important, as high and low levels are both associated with morbidity and a very high mortality.We studied phosphate dynamics and its relation to other small “uremic” molecules in 48 patients by measuring pre‐ and postdialysis levels and all removed phosphate, urea and creatinine (creat) in all dialysate during 455 dialyses done at different frequencies (freq): 3.7 ± 1.2, range 3–6 treatments per week and durations of dialysis (t): mean: 196 ± 95, range 80–560 min and with high (HF) and low flux membranes.Kt/V‐PO4, Kt/V‐urea and Kt/V‐creat, volumes (Vr) for all solutes and their relationships to frequency and duration of dialysis, urea clearance and predialysis phosphate were calculated.

Factor/solute:
PO4
Urea‐N
Creatinine

Predialysis mg/dl
5.7 ± 1.9
73 ± 24
12 ± 3

Postdialysis mg/dl
3.0 ± 1.0
33 ± 15
6 ± 2

100 × Vr/BW
63 ± 78
58 ± 24
41 ± 15

Kt/V
1.01 ± 0.66
1.04 ± 0.32
0.97 ± 0.26

Weekly stdKt/V
1.75 ± 0.81
2.12 ± 0.68
1.96 ± 0.71

Removed gm/week
3.1 ± 1.3
56 ± 23
6.2 ± 2.5

Vr = removed solute ÷ (predialysis minus postdialysis concentration.); BW = body weight. Uf = ultrafiltration. Results: Vr as a percentage of BW for PO4 was dependent on predialysis PO4 and rose steeply as predialysis PO4 decreased: Vr% BW = 212 − 88 × ln (predialysis PO4), (r = 0.39, p < 0.0001). There was no such relationship for Vr for urea or creatinine and no relation between urea and PO4 Vr, (r = 0.07, p = 0.141).In stepwise multiple regression analysis: Mg PO4 removed per week = t × 6.5 + freq × 387 + Uf × 140 + pre‐PO4 × 273 + PO4 stdKt/V × 343 − HF × 375 − 1824, (r = 0.73, p < 0.0001). Blood flow(QB) and dialysate flow (QD), urea weekly stdKt/V were not significant variables in the model. Pre‐dialysis PO4 = 6.8 − Hrs/week × 0.07 − QB × 0.003 + Uf ×  0.26. QD, membrane type or dialyses/week did not enter the model. Only patients dialyzing>28 hrs/week could stop phosphate binders within 3 weeks. Conclusions: Phosphate shows a highly variable dynamic during dialysis. Apparently, the body maintains extracellular PO4 concentration by releasing PO4 from unknown compartments when the blood concentration of PO4 decreases. Vr for phosphate thus varies not only from patient to patient but also in a patient, depending on blood concentration of PO4. Kt/V for urea and creatinine are inaccurate in describing PO4 removal. To remove PO4 efficiently it is most important to use long and daily dialysis. QB, QD and membrane type are relatively unimportant in phosphate removal.
Single‐dose pharmacokinetics (PK) of ferric gluconate (FG) in iron‐deficient pediatric hemodialysis patients
Authors: Warady B.A 
Published: January 2005

Purpose:
Limited information exists on the use of any intravenous iron preparation in pediatric HD patients. This study was designed to describe the PK parameters of FG, now approved for use in children on HD. Methods:Iron‐deficient pediatric HD pts (≤15 yr) were randomized to 2 doses of FG. Blood samples taken during a 1 hr infusion and at intervals over 48 hrs were analyzed for total iron, transferrin‐bound iron (TBI), and FG‐bound iron (FGI). Results:49% of pts were male, 88% white, 57% age 6–12 yr, wt 16.3–63.2 Kg, ht 100–177.5 cm. Mean serum iron concentrations (total iron and FGI) rapidly increased in a dose‐dependent manner, approximately proportional to the FG dose administered. A rapid rise in total serum iron was followed by a slower, less prominent rise in TBI. Single‐dose PK of FGI was adequately described using non‐compartmental analytical methods. A standard 2‐compartment NONMEM model successfully fit the data and accurately described the time‐course of FGI concentrations.

Pharmacokinetic Parameter
1.5 mg/kg FG (n = 22)
3.0 mg/kg FG (n = 26)

Cmax(mean ± SD, mcg/dL)
1287 ± 285
2283 ± 637

AUC0–48(mean ± SD, mcg·hr/dL)
9327 ± 4038
16,830 ± 6526

AUC0–∞(mean ± SD, mcg·hr/dL)
9499 ± 4089
17,087 ± 6776

Tmax(mean ± SD, hrs)
1.1 ± 0.23
1.1 ± 0.19

t1/2(mean ± SD, hrs)
2.0 ± 0.7
2.5 ± 1.8

Kel(mean ± SD, hr−1)
0.43 ± 0.30
0.39 ± 0.27

Cl (mean ± SD, L/hr)
0.69 ± 0.50
0.66 ± 0.52

Vd(mean ± SD, L)
1.6 ± 0.6
1.9 ± 1.1

Conclusions:
Cmax values in pediatric HD population were similar to Cmax values previously reported with similar FG doses in healthy iron‐deficient adults (Ferrlecit® prescribing information). In contrast, mean AUC0−∞ values were approximately 2 times greater, and mean Cl rates were 5.4 times slower in pediatric pts.
Intima‐media thickness of radial artery is associated with early access failure in hemodialysis patients
Authors: Kim Y.O. , Choi Y.J. , Kim J.I. , Shin M.J. , Kim B.S. , Song H.C. , Yoon S.A. , Kim Y.S. , Kim S.Y. , Choi E.J. , Chang Y.S. , Bang B.K. 
Published: January 2005

Objective:
We have reported that intimal hyperplasia, which is the pathologic change of the radial artery, is associated with early failure of arteriovenous fistula (AVF) in hemodialysis (HD) patients (Am J Kidney Dis, 41:422–428, 2003). Intima‐media thickness (IMT), which represents the whole thickness of arterial wall, can be easily measured by ultrasonography, unlike intima thickness. This study was performed to investigate the impact of IMT of radial artery on early failure of AVF in HD patients. Methods: Ninety HD patients undergoing radiocephalic AVF operation were included in this study. The AVF was constructed in an end vein–to–side artery fashion at the wrist by one vascular surgeon. During the operation, 10‐mm long partial arterial walls were removed with elliptical form for microscopic analysis. Specimens were stained with trichrome and examined by a pathologist blinded to the clinical data. AVF patency was prospectively followed up for 1 year after the operation. Results: Mean age of the patients was 56 ± 13 years and the number of females was 44 (48.9%). Mean IMT was 430 ± 132 μm (133–760 μm). Of the total 90 patients, 31 patients (34.4%) had AVF failure within 1 year after the operation. Mean IMT was higher in the failed group (n = 31) than in patent group (n = 59)(486 ± 130 μm vs. 330 ± 178 μm, p = 0.004). Using a threshold of 500 μm of IMT, AVF patency rate was compared between these two groups using Kaplan‐Meier method with log rank test. The AVF patency rate within 1 year after the operation was higher in patients with IMT ≥ 500 μm (n = 26) than in patients with IMT < 500 μm (n = 64)(p < 0.001). The patients with IMT ≥ 500 μm were older and had higher incidence of diabetes mellitus, compared to the patients with IMT < 500 μm. There was no difference in sex, smoking, hypertension, total cholesterol and albumin levels between the two groups. Conclusion: Our data suggest that increased intima‐media thickness of radial artery is associated with early failure of radiocephalic arteriovenous fistula in hemodialysis patients.
Tandem dialyzers with dual monitors to meet Kt/V targets
Authors: Sridhar N. , Hurst C. , Hayes P. 
Published: January 2005

Objective:
A large body mass and/or a poorly functioning vascular access predispose to inadequate Kt/V. Double dialyzers in parallel and tandem have been shown to enhance Kt/V to levels recommended by K/DOQI. We experienced difficulties with unintended excessive ultrafitration (UF), positive transmembrane pressure (TMP)‐triggered pump stoppage, need for large volume saline infusion (inflating Kt/V), and a high incidence of clotting of the second dialyzer in tandem. Since blood and dialysate flow rates are higher in the tandem configuration, Kt/V should be theoretically higher. We developed a technique of using the tandem configuration with two monitors in which all the UF could be limited to the second dialyzer, the TMP of the two dialyzers independently controlled, TMP reversal eliminated, and saline infusion and unintended UF minimized. Methods: 3 large male patients with AV grafts (AVG) and 2 with tunneled catheters (TC) had 7 treatments (with Kt/V and URR calculated using the stop‐flow technique in the last 5) sessions of each of single, double parallel, and tandem configurations. Blood (Qb) and dialysate‐flow (Qd) were halved with Y‐connectors in the parallel configuration. Qb through both dialyzers and Qd through the second were controlled with the first monitor and Qd (TMP set to near zero) through the first dialyzer controlled with the second monitor using recirculating saline through its blood pump (with the “venous” pressure adjusted using an air‐filled syringe) in the tandem configuration. The patient's blood did not circulate through the blood‐pump of the first machine. Qd was 500 ml/min through each dialyzer in the single and tandem and 250 ml/min in the parallel configurations. Processed blood volume (dialysis time) was exactly 85 L with AVG and 60 L with TC. Heparin dosage was constant. ANOVA, 2 × k tables, and Neuman‐Keuls test were used in analyzing data. Results: Mean Kt/V (%URR) increased from 1.15 (62) with single to 1.35 (68) with parallel (p < 0.02) and 1.48 (71) with tandem (p < 0.001) dialyzers in patients with AVG but not TC [1.05 (58), 1.02 (55), and 1.25 (64) with single, parallel, and tandem, respectively]. Tandem dialyzers met targets for URR (p < 0.001) and Kt/V ( p < 0.05) more frequently than parallel with AVG but not TC. Conclusions: Tandem dialyzers with 2 monitors are more successful than parallel dialyzers in delivering target Kt/V and URR when Qb is not compromised.
CTLA4 polymorphisms are associated with vitiligo, in patients with concomitant autoimmune diseases
Authors: Blomhoff Anne , Helen Kemp E. , Gawkrodger David J. , Weetman Anthony P. , Husebye Eystein S. , Akselsen Hanne E. , Lie Benedicte A. , Undlien Dag E. 
Published: January 2005

SummaryThe cytotoxic T lymphocyte antigen4 (CTLA4) gene plays a critical role in the control of T cell activation. The gene encodes a surface molecule with inhibitory effects on activated T cells. Several studies have disclosed an association between the previously known variants of the CTLA4 gene and autoimmune disorders, but no study has as yet found any definite association between vitiligo and the CTLA4 polymorphisms. A recent study identified new candidate susceptibility polymorphisms in this region, associated with differential gene splicing and thereby the relative abundance of soluble CTLA4. To assess these new polymorphisms in patients with vitiligo, we genotyped 100 vitiligo patients and 140 healthy controls from the UK, for these novel polymorphisms. No association was found in patients with isolated vitiligo, but a significant association was seen in patients with vitiligo and other autoimmune diseases. The results indicate that the polymorphisms in the CTLA4 gene region confer susceptibility to vitiligo when occurring together with other autoimmune diseases, but not in patients with isolated vitiligo. This raises the possibility that there are two distinct forms of vitiligo where only a subgroup of patients may have a disease caused by the autoimmune destruction of melanocytes.
Metal–ion interactions and the structural organization of Sepia eumelanin
Authors: Liu Yan , Simon John D. 
Published: January 2005

SummaryThe structural organization of melanin granules isolated from ink sacs of Sepia officinalis was examined as a function of metal ion content by scanning electron microscopy and atomic force microscopy. Exposing Sepia melanin granules to ethelenediaminetetraacetic acid (EDTA) solution or to metal salt solutions changed the metal content in the melanin, but did not alter granular morphology. Thus ionic forces between the organic components and metal ions in melanin are not required to sustain the natural morphology once the granule is assembled. However, when aqueous suspensions of Sepia melanin granules of varying metal content are ultra‐sonicated, EDTA‐washed and Fe‐saturated melanin samples lose material to the solution more readily than the corresponding Ca(II) and Mg(II)‐loaded samples. The solubilized components are found to be 5,6‐dihydroxyindole‐2‐carboxylic acid (DHICA)‐rich constituents. Associated with different metal ions, Na(I), Ca(II) and Mg(II) or Fe(III), these DHICA‐rich entities form distinct two‐dimensional aggregation structures when dried on the flat surface of mica. The data suggest multiply‐charged ions play an important role in assisting or templating the assembly of the metal‐free organic components to form the three‐dimensional substructure distributed along the protein scaffold within the granule.
Role of keratinocyte‐derived factors involved in regulating the proliferation and differentiation of mammalian epidermal melanocytes
Authors: Hirobe Tomohisa 
Published: January 2005

SummaryMelanocytes characterized by the activities of tyrosinase, tyrosinase‐related protein (TRP)‐1 and TRP‐2 as well as by melanosomes and dendrites are located mainly in the epidermis, dermis and hair bulb of the mammalian skin. Melanocytes differentiate from melanoblasts, undifferentiated precursors, derived from embryonic neural crest cells. Because hair bulb melanocytes are derived from epidermal melanoblasts and melanocytes, the mechanism of the regulation of the proliferation and differentiation of epidermal melanocytes should be clarified. The regulation by the tissue environment, especially by keratinocytes is indispensable in addition to the regulation by genetic factors in melanocytes. Recent advances in the techniques of tissue culture and biochemistry have enabled us to clarify factors derived from keratinocytes. Alpha‐melanocyte‐stimulating hormone, adrenocorticotrophic hormone, basic fibroblast growth factor, nerve growth factor, endothelins, granulocyte‐macrophage colony‐stimulating factor, steel factor, leukemia inhibitory factor and hepatocyte growth factor have been suggested to be the keratinocyte‐derived factors and to regulate the proliferation and/or differentiation of mammalian epidermal melanocytes. Numerous factors may be produced in and released from keratinocytes and be involved in regulating the proliferation and differentiation of mammalian epidermal melanocytes through receptor‐mediated signaling pathways.
Pigment cell‐related manifestations in neurofibromatosis type 1: an overview
Authors: Schepper Sofie De , Boucneau Joachim , Lambert Jo , Messiaen Ludwine , Naeyaert Jean‐Marie 
Published: January 2005

SummaryNeurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous disorder, affecting approximately 1 in 3500 individuals. The most commonly seen tumors in NF1 patients are the (sub)cutaneous neurofibromas. However, individuals with NF1 typically present in childhood with well‐defined pigmentary defects, including café‐au‐lait macules (CALMs), intertriginous freckling and iris Lisch nodules. NF1 is considered a neurocristopathy, primarily affecting tissues derived from the neural crest. Since the pigment producing melanocyte originates in the neural crest, the presence of (hyper)pigmentary lesions in the NF1 phenotype because of changes in melanocyte cell growth and differentiation is to be expected. We want to discuss the pigmentary cutaneous manifestations of NF1 represented by CALMs and intertriginous freckles and the pigmentary non‐cutaneous manifestations represented by iris Lisch nodules. Several hypotheses have been suggested in explaining the poorly understood etiopathogenesis of CALMs. Whether other pigmentary manifestations might share similar etiopathogenic mechanisms remains obscure. Additional attention will be drawn to a readily seen phenomenon in NF1: hyperpigmentation overlying (plexiform) neurofibromas, which could suggest common etiopathogenetic‐environmental cues or mechanisms underlying CALMs and neurofibromas. Finally, we want to address the relationship between malignant melanoma and NF1.
Physicochemical characterization of carboxymethyl lipid A derivatives in relation to biological activity
Authors: Seydel Ulrich , Schromm Andra B. , Brade Lore , Gronow Sabine , Andrä Jörg , Müller Mareike , Koch Michel H. J. , Fukase Koichi , Kataoka Mikayo , Hashimoto Masaya , Kusumoto Shoichi , Brandenburg Klaus 
Published: January 2005

Lipopolysaccharide (LPS) from the outer membrane of Gram‐negative bacteria belongs to the most potent activators of the mammalian immune system. Its lipid moiety, lipid A, the ‘endotoxic principle’ of LPS, carries two negatively charged phosphate groups and six acyl chain residues in a defined asymmetric distribution (corresponding to synthetic compound 506). Tetraacyl lipid A (precursor IVa or synthetic 406), which lacks the two hydroxylated acyl chains, is agonistically completely inactive, but is a strong antagonist to bioactive LPS when administered to the cells before LPS addition.The two negative charges of lipid A, represented by the two phosphate groups, are essential for agonistic as well as for antagonistic activity and no highly active lipid A are known with negative charges other than phosphate groups. We hypothesized that the phosphate groups could be substituted by other negatively charged groups without changing the endotoxic properties of lipid A. To test this hypothesis, we synthesized carboxymethyl (CM) derivatives of hexaacyl lipid A (CM‐506 and Bis‐CM‐506) and of tetraacyl lipid A (Bis‐CM‐406) and correlated their physicochemical with their endotoxic properties. We found that, similarly to compounds 506 and 406, also for their carboxymethyl derivatives a particular molecular (‘endotoxic’) conformation and with that, a particular aggregate structure is a prerequisite for high cytokine‐inducing capacity and antagonistic activity, respectively.In other parameters such as acyl chain melting behaviour, antibody binding, activity in the Limulus lysate assay, and partially the binding of 3‐deoxy‐d‐manno‐oct‐2‐ulosonic acid transferase, strong deviations from the properties of the phosphorylated compounds were observed. These data allow a better understanding of endotoxic activity and its structural prerequisites.
K-Ras is essential for normal fetal liver erythropoiesis
Authors: Khalaf Waleed F. , White Hilary , Wenning Mary Jo , Orazi Attilio , Kapur Reuben , Ingram David A. 
Published: January 2005

AbstractIn vitro studies suggest that Ras activation is necessary for erythroid cell development. However, genetic inactivation of the Ras isoforms H-Ras, N-Ras, and K-Ras in mice reportedly did not affect adult or fetal erythropoiesis, though K-Ras-/- embryos were anemic. Given these discrepancies, we performed a more detailed analysis of fetal erythropoiesis in K-Ras-/- embryos. Day-13.5 K-Ras-/- embryos were pale with a marked reduction of mature erythrocytes in their fetal livers. The frequency and number of both early (erythroid burst-forming unit [BFU-E]) and late erythroid progenitors (erythroid colony-forming unit [CFU-E]) were reduced in K-Ras-/- fetal livers compared with wild-type controls and displayed a delay in terminal erythroid cell maturation. Further, K-Ras-/- hematopoietic progenitors had reduced proliferation in response to erythropoietin and Kit ligand compared with control cells. Thus, these studies identify K-Ras as a unique Ras isoform that is essential for regulating fetal erythropoiesis in vivo.