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Biomedical subjects

J Bergström

Publications and source records attributed to J Bergström.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effects of methionine loading on plasma and erythrocyte sulphur amino acids and sulph-hydryls before and after co-factor supplementation in haemodialysis patients.

BACKGROUND: Hyperhomocysteinaemia, which is potentially atherogenic, is common in chronic haemodialysis (HD) patients but the reason for this is not yet known. The methionine (Met) loading test (MLT) is used to test the capacity of homocysteine (Hcy) disposal by the trans-sulphuration pathway and thus may provide information on the metabolism of sulphur amino acids. The availability of vitamin B(6) and folic acid, as co-factors for Hcy metabolism may affect the response to MLT. In the present study, we compared the effect of Met loading on plasma and erythrocyte (RBC) sulphur amino acids and sulph-hydryls before and after co-factor supplementation in healthy subjects and HD patients. METHODS: In 10 HD patients and 10 healthy subjects the effect of Met loading, 0.1 g/kg BW, on plasma and RBC methionine metabolites was studied over 7 h, before and after 4 weeks supplementation with high daily doses of vitamin B(6) (200 mg) and folic acid (15 mg). RESULTS: MLT before vitamin supplementation in HD patients, compared to the healthy subjects, caused significantly greater increases in plasma Hcy levels (43+/-12 vs 15+/-5 micromol/l), cysteinesulphinic acid (CSA) (1.34 vs 0.36 micromol/l) and gamma-glutamylcysteine (0.98+/-0.83 vs -01+/-0.42 micromol/l) and no decline in plasma cysteine (Cys) (0.5+/-33.9 vs -31+/-26 micromol/l), but no significant differences in plasma taurine, cysteinylglycine, and glutathione concentrations. In RBCs there was a small increase in Hcy levels and a more marked increase in Tau levels, with no difference between the healthy subjects and HD patients. Vitamin supplementation in pharmacological doses failed to correct the abnormal responses to MLT in the HD patients. CONCLUSIONS: Oral methionine loading in HD patients leads to higher accumulation of Hcy and other Met metabolites in plasma and RBCs than in healthy subjects, indicating impaired metabolism of sulphur amino acids via the trans-sulphuration pathway. Supplementation with high doses of vitamin B(6) and folic acid does not correct this impairment, suggesting that it most probably is not due to lack of these co-factors.

Adult↗
PubMed2001

Association between inflammation and changes in residual renal function and peritoneal transport rate during the first year of dialysis.

BACKGROUND: Peritoneal transport rate, a major determinant of peritoneal dialysis (PD) patient survival, increases in most patients starting on PD, while in other patients peritoneal transport rate may decline. Although several factors may contribute to changes in peritoneal transport rate, inflammation is known to be associated with a high peritoneal transport rate, and residual renal function (RRF), which often declines after start of PD, may also be related to inflammation. Therefore, we hypothesized that changes in peritoneal transport rate during patients' first year on PD and declining RRF may be linked with inflammation. METHODS: A total of 76 PD patients (40 males, mean age 56.8+/-14.1 years), who underwent two peritoneal equilibration tests at a mean of 0.4 months and 1 year after beginning PD, were included in the study. Based on the change in dialysate to plasma creatinine concentration ratio at 4-h dwell (D/P Cr) during first year on PD, the patients were divided into decreased or unchanged (group DUC; n=22) and increased (group I; n=54) groups. RESULTS: Initially, group I had a lower proportion of high transporters and more often high serum C-reactive protein (sCRP, > or =10 mg/l) and lower RRF compared with the DUC group. In group I, serum albumin and RRF decreased significantly and dialysate protein loss and glucose absorption increased significantly during the first year on PD. When patients were divided into two groups based on median change in RRF (1.9 ml/min), patients with a decrease in RRF >1.9 ml/min during first year on PD had a higher proportion of high sCRP, higher D/P Cr, and higher changes in D/P Cr compared to patients with a decrease in RRF < or =1.9 ml/min. Patients with elevated sCRP at one year included a higher proportion of patients who had high sCRP at the start of PD, higher increase in D/P Cr, lower serum albumin, lower RRF, and more decrease in RRF during first year on PD compared with patients having normal sCRP. RRF was inversely correlated with changes in D/P Cr during the first year on PD (r=-0.28, P=0.02). Multiple regression analysis revealed that the only factors affecting changes in D/P Cr were high sCRP and a low RRF. CONCLUSIONS: Our preliminary short-term study suggests that changes in peritoneal transport rate during patients' first year on PD may be linked with inflammation and declining residual renal function. Inflammation and residual renal function were identified as the only independent factors determining peritoneal transport rate during the first year on PD. It is possible that inflammation may cause both an increase in peritoneal transport rate and a decline in residual renal function, or that the decline in residual renal function and the increase in peritoneal transport rate may induce or aggravate inflammation. Further studies are needed to confirm these findings.

Adult↗
PubMed2001

Effects of intraperitoneal heparin on peritoneal transport in a chronic animal model of peritoneal dialysis.

BACKGROUND: Heparin has anti-inflammatory effects and is often added to the peritoneal dialysis fluid to prevent fibrin formation. Conjugation of heparin to the surface of biomaterials has been shown to improve its biocompatibility. In this study, we describe for the first time an experimental chronic peritoneal dialysis model with repeated dwell studies in non-uraemic rats and evaluate the effect of addition of heparin to glucose-based peritoneal dialysis fluid on peritoneal fluid and solute transport. METHODS: Wistar male rats, weighing 340+/-15 g, with implanted peritoneal catheters were infused during 1 month, twice per day with 20 ml of Dianeal 1.36%+antibiotics (AB; n = 10) or Dianeal 1.36%+antibiotics+heparin 2500 U/l (HAB; n = 9). After 10 (DS 1) and 30 days (DS 2), a dwell study was performed in rats with free access to drinking water, by infusing 30 ml of Dianeal 3.86%. Dialysate samples were obtained at 0, 2, 30, 60, 120 and 240 min. Blood samples were drawn before and at the end of the dwell. Radiolabelled serum albumin was used as macromolecular volume marker. RESULTS: Peritoneal volumes during DS 1 were significantly greater for the HAB group as compared with the AB group. No differences in ultrafiltration were found during DS 2 for HAB vs AB. However, peritoneal volumes were significantly higher for DS 2 compared with DS 1 in the AB group. The amount of glucose absorbed over time did not differ between the solutions, while fluid absorption tended to be lower in the HAB group. CONCLUSIONS: Heparin may improve peritoneal fluid transport possibly due to better healing and reduced peritoneal inflammation as shown in this novel animal model of chronic peritoneal dialysis with repeated dwell studies.

Absorption↗
PubMed2001

Hyperhomocysteinemia in chronic renal failure patients: relation to nutritional status and cardiovascular disease.

A moderate increase in plasma total homocysteine (tHcy) is considered to be an independent risk factor for cardiovascular disease (CVD) in the general population. Almost all chronic renal failure (CRF) patients have plasma concentration of tHcy that is elevated 3 to 4 times above normal. The prevalence of CVD, diabetes mellitus, malnutrition and hypoalbuminemia is high in CRF patients. Previous investigations have focused on the role of vitamin status on plasma tHcy in CRF patients, but little information exists on the influence of nutritional status and hypoalbuminemia on plasma tHcy in CRF, although a substantial fraction of tHcy (>70%) is protein-bound, mainly to albumin. Our study in patients with end-stage renal disease showed that more than 90% of the patients had elevated plasma tHcy levels, which were higher in patients with normal nutritional status than in malnourished patients. Moreover, plasma tHcy was inversely correlated with subjective global nutritional assessment (high values denote malnutrition) and positively correlated with serum albumin and protein intake. Hence, it seems likely that serum-albumin is a strong determinant of plasma tHcy in CRF patients and this may contribute to the lower tHcy levels in malnourished patients. Patients with diabetes mellitus had lower serum-albumin and plasma tHcy than non-diabetic patients, irrespective whether they were malnourished or not. Patients with CVD had lower (although still elevated) plasma tHcy levels than those without CVD. An explanation may be that the prevalence of diabetes mellitus, malnutrition and hypoalbuminema, i.e. factors that decrease tHcy, was higher in patients with CVD, which may explain why they had less elevated values. Assuming that hyperhomocysteinemia carries an independent risk of CVD, this implies that almost all CRF patients are exposed to this risk. CRF patients with CVD had a higher prevalence of malnutrition, hypoalbuminemia and diabetes mellitus, which was associated with a lower plasma Hcy level. This may explain why plasma tHcy was lower (although still abnormally high) in patients with CVD than in patients without CVD. The lower tHcy levels in CVD patients do not contradict the assumption that hyperhomocysteinemia is a risk factor for CVD since almost all patients are exposed to this risk, and other factors might be present that confound the relationship between the absolute tHcy levels and CVD. Our findings imply that nutritional status and serum albumin, as well as the presence of diabetes mellitus, should be taken into consideration when evaluating tHcy as a risk factor for CVD in CRF patients.

Cardiovascular Diseases↗
PubMed2001

Tobacco smoking and neutrophil activity in patients with periodontal disease.

BACKGROUND: Tobacco smoking has considerable negative effects on periodontal health. The mechanisms behind these effects are incompletely understood but may be related to the host response. The aim of the present study was to investigate the influence of tobacco smoking on the gingival crevicular fluid (GCF) levels of elastase, lactoferrin (LF), alpha-1-antitrypsin (alpha-1-AT), and alpha-2-macroglobulin (alpha-2-MG) under periodontally diseased conditions. METHODS: The study population included 15 smokers (5 women and 10 men) aged 34 to 69 years and 17 non-smokers (5 women and 12 men) aged 31 to 81 years. Clinical registration of gingival index (GI), plaque index (PI), probing depth, as well as sampling of GCF were made at 3 sites with severe lesions and 3 sites with moderate lesions in each individual. The elastase activity was measured with a chromogenic low molecular substrate and the LF, alpha-1-AT, and alpha-2-MG concentrations with ELISA. RESULTS: The results showed that, with regard to severe lesions, smokers had a significantly lower concentration of alpha-2-MG as well as significantly lower total amounts of alpha-2-MG and alpha-1-AT than non-smokers. With regard to moderate lesions, smokers tended to exhibit a lower concentration of alpha-2-MG, but the difference was not statistically significant. Comparing moderate and severe lesions, smokers exhibited no gradual increase with disease severity in contrast to non-smokers, who showed significantly or almost significantly increased levels of LF and alpha-2-MG in severe as compared to moderate lesions. CONCLUSIONS: The present results indicate that the levels of alpha-2-MG and alpha-1-AT are suppressed in smokers with periodontitis, suggesting that smoking interferes with these protease inhibitors. This may be one mechanism by which smoking affects the inflammatory response.

Adult↗
PubMed2001

Peritoneal dialysis solutions disturb the balance of apoptosis and proliferation of peritoneal cells in chronic dialysis model.

The present study investigated variation in apoptosis and proliferation, and the balance between apoptosis and proliferation, for peritoneal mesothelial cells (MCs) after exposure to peritoneal dialysis solution (PDS) in vivo. We implanted 32 male Sprague-Dawley rats (4 groups; n = 8 in each group) with catheters and intraperitoneally infused the animals with 20 mL Dianeal 1.36%, 2.27%, or 3.86% (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.) PDS twice daily for eight consecutive weeks, using saline as a control. At the end of the eighth week, samples of peritoneal membrane were fixed and sliced. Expression of apoptosis was checked with TUNEL kits (Boehringer Mannheim, Mannheim, Germany), and expression of proliferative cell nuclear antigen (PCNA) was checked by immunohistochemistry [streptoavidin-biotin-peroxidase complex (SABC) method]. The ratio of MC apoptosis to proliferation was measured from the same slices using the dual-stain combination of TUNEL and SABC. Cells positive for apoptosis and PCNA were counted for all samples by light microscopy in 50 consecutive grids (10 x by 40). Peritoneal dialysis solution was found to significantly induce MC apoptosis as compared with control at the end of the eighth week. The degree of apoptosis was proportional to the concentration of glucose in the PDS. The 1.36% PDS, but not the 2.27% or 3.86%, significantly stimulated the expression of PCNA. The degree of PCNA expression was negatively related to the glucose concentration of the PDS. The MC apoptosis: PCNA ratio was significantly higher for 3.86% and 2.27% PDS than for the control, but no significant difference was seen between 1.36% PDS and control. We conclude that glucose-based PDS may induce apoptosis and disturb the balance of MC apoptosis and proliferation, and that 1.36% PDS damages the balance less than does 2.27% or 3.86% PDS. These effects may be partly due to pH, calcium, hyperosmolality, and glucose degradation products (GDPs). Loss of balance between MC proliferation and apoptosis--induced by unphysiologic PDS--may be one of the major causes of peritoneal membrane failure during long-term continuous ambulatory peritoneal dialysis.

Animals↗
PubMed2001

Effect in a rat model of heparinized peritoneal dialysis catheters on bacterial colonization and the healing of the exit site.

We performed a prospective, double-blind, randomized study to evaluate whether stable surface heparinization of silicone peritoneal dialysis (PD) catheters prevents bacterial colonization or biofilm formation and improves healing of the exit site. Heparinized catheters were implanted in 20 Sprague-Dawley rats (group H) and non heparinized catheters in another 20 (group C). The PD catheters, constructed of silicon tubing with two polyester cuffs, were patterned after the standard Tenckhoff catheter. A covalent multipoint method of attachment onto polymeric surfaces was used for stable, permanent chemical immobilization of heparin on the PD catheter. Dialysis exchanges (25-mL instillation volume) were performed twice daily for 4 weeks through the permanent catheter. Prophylactic antibiotics were not used. The exit sites were evaluated at 2-week intervals. The extent of biofilm coverage on the intraperitoneal portion of the catheter (obtained at the end of the experiment) was assessed, and sonicated fluid from the catheter tip was cultured for evaluating bacterial colonization of the catheter. Exit-site scores in group H were lower than in group C (p = 0.052) at the end of week 4. Bacterial colonization tended to be less common in group H [2 of 12 catheters (17%)] than in group C [8 of 15 catheters (53%); p = 0.058], but the extent of biofilm, the peritonitis rate, and the inflammation score of tissue adjacent to the cuff were not different between the groups. Those data suggest that heparinized PD catheters can be a practical approach to the prevention of bacterial colonization and can improve healing of the exit site.

Animals↗
PubMed2001

The effect of icodextrin-based solutions on peritoneal transport in rats undergoing chronic peritoneal dialysis.

BACKGROUND: We evaluated the effect of icodextrin on peritoneal permeability and inflammation in an experimental chronic peritoneal dialysis (PD) model with repeated dwell studies (DSs) in non uremic rats. METHODS: Male Wistar rats with implanted peritoneal catheters were infused twice daily for 3 weeks with 20 mL Dianeal 3.86% (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.) (n = 11) or icodextrin 7.5% (n = 12). After 10 days (DS1) and 21 days (DS2), a 4-hour DS using 30 mL icodextrin solution was performed in conscious animals. Radioiodinated serum albumin (RISA) was used as a macromolecular volume marker. Blood samples were drawn before the start of the dwell and at its end. RESULTS: We observed a steady increase in intraperitoneal volume (IPV) versus dwell time (0-240 minutes) during DS1 and DS2 in both groups. No significant differences in peritoneal permeability to solutes were observed between the groups. However, in both groups, IPV volume was significantly higher during DS2 after the 4-hour dwell time [IPV icodextrin: 34.4 +/- 1.4 mL (DS1), 35.4 +/- 1.1 mL (DS2), p < 0.002; IPV Dianeal: 34.2 +/- 0.9 mL (DS1), 35.2 +/- 0.7 mL (DS2), p < 0.01]. CONCLUSION: Changes of peritoneal permeability seen during in vivo experimental models of chronic peritoneal dialysis in rats with repeated dwell studies are comparable to results obtained in humans on continuous ambulatory peritoneal dialysis (CAPD).

Animals↗
PubMed2000

Use of an affinity proteomics approach for the identification of low-abundant bacterial adhesins as applied on the Lewis(b)-binding adhesin of Helicobacter pylori.

Microbial attachment to host cell surfaces is considered to be the first essential step for colonization and infection. In most known cases, attachment is mediated by a specific protein-carbohydrate interaction. We have used a carbohydrate-containing crosslinking probe to select bacterial surface adhesins for trypsin digestion, MALDI-TOF mass spectrometry and identification against genome sequence. The present paper describes this functional proteomics approach for identification of the recently cloned low-abundant Lewis(b)-binding adhesin of Helicobacter pylori. Protein identification was obtained through the enrichment of approximately 300 fmol of adhesin from solubilized cells.

Adhesins, Bacterial↗
PubMed2000

Purification and characterization of RNA polymerase II holoenzyme from Schizosaccharomyces pombe.

We have purified the RNA polymerase II holoenzyme from Schizosaccharomyces pombe to near homogeneity. The Mediator complex is considerably smaller than its counterpart in Saccharomyces cerevisiae, containing only nine polypeptides larger than 19 kDa. Five of these Mediator subunits have been identified as the S. pombe homologs to Rgr1, Srb4, Med7, and Nut2 found in S. cerevisiae and the gene product of a previously uncharacterized open reading frame, PMC2, with no clear homologies to any described protein. The presence of Mediator in a S. pombe RNA polymerase II holoenzyme stimulated phosphorylation of the C-terminal domain by TFIIH purified from S. pombe. This stimulation was species-specific, because S. pombe Mediator could not stimulate TFIIH purified from S. cerevisiae. We suggest that the overall structure and mechanism of the Mediator is evolutionary conserved. The subunit composition, however, has evolved to respond properly to physiological signals.

Amino Acid Sequence↗
PubMed2000

Exposure to tobacco smoking and periodontal health.

BACKGROUND: The influence of smoking behavior on the periodontal health condition was clinically and radiographically studied in 257 dentally aware adults in the age range 20-69 years, including 50 current smokers, 61 former smokers and 133 non-smokers. AIMS: The clinical variables to be investigated were frequency of diseased sites > or =4 mm, frequency of gingival bleeding sites and plaque index. In addition, the periodontal bone height was radiographically assessed as a % of the dental root length. METHODS: All variables were based on full-mouth examinations including all teeth and periodontia. RESULTS: The observations indicated an inferior periodontal health condition associated with smoking. This was evidenced by a significantly greater frequency of diseased sites and a significantly greater reduction of periodontal bone height in current smokers as compared to non-smokers. The condition of former smokers was intermediate between current smokers and non-smokers, suggesting that former smokers who have quit smoking have a better periodontal health condition than current smokers, although worse than that of non-smokers. The finding that former smokers exhibited less disease than current smokers suggests that smoking cessation may be beneficial and mitigate the untoward effects inflicted by smoking, allowing a normalization towards non-smoker conditions. Heavy exposure was consistently associated with more severe a condition than light exposure, suggesting that the relationship between smoking exposure and periodontal morbidity is dose-dependent. CONCLUSIONS: Altogether, the present observations identify a negative impact from smoking on periodontal health and provide further evidence that tobacco smoking is an avoidable risk for periodontal disease.

Adult↗
PubMed2000

Smoking and GCF levels of IL-1beta and IL-1ra in periodontal disease.

AIMS: GCF levels of the cytokine IL-1beta and its receptor antagonist IL-1ra were analyzed with respect to smoking in patients with moderate to severe periodontal disease. The study population included 22 smokers and 18 non-smokers in the age range 32-86 years. Concomitantly, the GCF levels of IgA, IgG, albumin and total protein were analyzed. METHOD: Samples of GCF were obtained from 2 diseased sites in each patient by means of an aspiration method. IL-1beta, IL-1ra, IgA and IgG were determined with immunoelectrophoresis. Total protein was determined by the BCA method. RESULTS: The clinical characteristics in terms of probing depth and frequency of diseased sites and supragingival plaque did not differ between smokers and non-smokers. Gingival bleeding, however, was significantly depressed in smokers. IL-1beta was detected in GCF of 95% of both smokers and non-smokers and IL-1ra in all patients. The GCF level of IL-1ra was approximately 1,000-fold that of IL-1beta. The GCF levels of IL-1beta and IL-1ra were high in comparison with those of TNF-alpha and IL-6 determined by the same method in our earlier studies. CONCLUSION: Our observations did not reveal any influence of smoking on the levels of IL-1beta and IL-1ra in GCF.

Adult↗
PubMed2000

Effect of peritonitis on peritoneal transport characteristics: glucose solution versus polyglucose solution.

BACKGROUND: Peritonitis is a common clinical problem and contributes to the high rate of technique failure in continuous ambulatory peritoneal dialysis treatment. The present study investigated the effect of peritonitis on peritoneal fluid and solute transport characteristics using glucose and polyglucose (icodextrin) solutions. METHODS: A four-hour dwell was performed in 32 Sprague-Dawley rats (8 rats in each group), with 131I albumin as an intraperitoneal volume marker. Peritonitis was induced by an intraperitoneal injection of 2 mL lipopolysaccharide (100 microg/mL phosphate-buffered saline) four hours before the dwell. Each rat was intraperitoneally infused with 25 mL of 3.86% glucose [glucose solution control group (Gcon) and glucose solution peritonitis group (Gpts)] or 7.5% icodextrin solution [icodextrin solution control group (Pgcon) and icodextrin peritonitis group (PGpts)]. RESULTS: Net ultrafiltration was significantly lower (by 44%) in the Gpts as compared with the Gcon group, but was significantly higher (by 138%) in the PGpts as compared with the PGcon group. The peritoneal fluid absorption rate, including the direct lymphatic absorption rate, was significantly increased (by 78%) in the Gpts group as compared with the Gcon group. However, the total fluid absorption did not differ between the PGpts and the PGcon groups. The dialysate osmolality decreased much faster in the Gpts group as compared with the Gcon group, resulting in significantly lower (by 9%) transcapillary ultrafiltration in the Gpts group. In contrast, the dialysate osmolality increased faster in the PGpts group as compared with the PGcon group, resulting in higher (by 40%) transcapillary ultrafiltration in the PGpts group. The in vitro increase in dialysate osmolality was also higher in the PGpts group as compared with the PGcon group. The solute diffusive transport rates were, in general, increased in the two peritonitis groups as compared with their respective control groups. CONCLUSIONS: Our results suggest the following: (1) Peritonitis results in decreased net ultrafiltration using glucose solution caused by (a) decreased transcapillary ultrafiltration and (b) increased peritoneal fluid absorption. (2) Ultrafiltration induced by the icodextrin solution appears to be related to the increase in dialysate osmolality (mainly because of the degradation of icodextrin). (3) Peritonitis results in increased degradation of icodextrin and a faster increase in dialysate osmolality and therefore better ultrafiltration, whereas the fluid absorption rate does not change. (4) Peritonitis results in increased peritoneal diffusive permeability.

Animals↗
PubMed2000

Hyperhomocysteinemia, nutritional status, and cardiovascular disease in hemodialysis patients.

BACKGROUND: Hyperhomocysteinemia, cardiovascular disease (CVD), and malnutrition are common in patients with end-stage renal disease (ESRD). This study was designed to assess possible relationships between total plasma homocysteine (tHcy), nutritional status, and ischemic CVD. METHODS: We performed a cross-sectional study in 117 unselected patients on maintenance hemodialysis (HD) treatment, among whom there was a high prevalence of malnutrition (56%), as assessed by the subjective global nutritional assessment (SGNA), and a high prevalence of CVD (60%), and prospectively, we followed-up the overall mortality for four years. RESULTS: The level of tHcy was elevated in 95% of the HD patients, and that of total plasma cysteine (tCys) was also significantly elevated, while the plasma concentrations of methionine (Met), serine (Ser), and taurine (Tau) were significantly lower than those in healthy controls. The 65 patients who were malnourished according to the SGNA score had significantly lower levels of serum albumin (SAlb), plasma IFG-1 (p-IGF-1), tHcy, tCys, and Met than the 52 patients with normal nutritional status, whereas the levels of Ser, Tau, plasma folate, and vitamin B12 were similar in the two groups. The prevalence of malnutrition was 30% in the 47 patients without CVD and was significantly higher (70%, P < 0.001) in the 70 patients with CVD, who also had lower tHcy, SAlb, plasma IGF-1, serum creatinine (SCr), and blood hemoglobin. The tHcy levels were positively correlated with SAlb, Met, tCys, and SCr. Stepwise, multiple-regression analysis showed that tCys, SAlb, and normalized protein equivalent of nitrogen appearance (nPNA), an indicator of protein intake, were independent predictors of tHcy. The patients with tHcy <24 micromol/L (median value) had a significantly worse four-year survival than those with a higher tHcy (> or =24 micromol/L). CONCLUSIONS: Our results demonstrate that most of HD patients have grossly elevated tHcy levels, but that the absolute level appears to be dependent on nutritional status, protein intake, and SAlb. The results also suggest that the lower tHcy levels in patients with CVD than in those without CVD may be related to the higher prevalence of malnutrition and hypoalbuminemia in the CVD patients. This is also in accordance with our observation that the patients with lower tHcy had a worse survival rate than those with higher tHcy, considering that malnutrition is a strong risk factor for mortality and that CVD is the most common cause of death in ESRD patients.

Adult↗
PubMed2000

Isolectins from Solanum tuberosum with different detailed carbohydrate binding specificities: unexpected recognition of lactosylceramide by N-acetyllactosamine-binding lectins.

Glycosphingolipid recognition by two isolectins from Solanum tuberosum was compared by the chromatogram binding assay. One lectin (PL-I) was isolated from potato tubers by affinity chromatography, and identified by MALDI-TOF mass spectrometry as a homodimer with a subunit molecular mass of 63,000. The other (PL-II) was a commercial lectin, characterized as two homodimeric isolectins with subunit molecular masses of 52,000 and 55,000, respectively. Both lectins recognized N-acetyllactosamine-containing glycosphingolipids, but the fine details of their carbohydrate binding specificities differed. PL-II preferentially bound to glycosphingolipids with N-acetyllactosamine branches, as Galbeta4GlcNAcbeta6(Galbeta4GlcNAcbeta3)Galbeta4Glcbeta1C er. PL-I also recognized this glycosphingolipid, but bound equally well to the linear glycosphingolipid Galbeta4GlcNAcbeta3Galbeta4GlcNAcbeta3Galbeta4Glcbeta1Cer. Neolactotetraosylceramide and the B5 pentaglycosylceramide were also bound by PL-I, while other glycosphingolipids with only one N-acetyllactosamine unit were non-binding. Surprisingly, both lectins also bound to lactosylceramide, with an absolute requirement for sphingosine and non-hydroxy fatty acids. The inhibition of binding to both lactosylceramide and N-acetyllactosamine-containing glycosphingolipids by N-acetylchitotetraose suggests that lactosylceramide is also accomodated within the N-acetylchitotetraose/N-acetyllactosamine-binding sites of the lectins. Through docking of glycosphingolipids onto a three-dimensional model of the PL-I hevein binding domain, a Galbeta4GlcNAcbeta3Galbeta4 binding epitope was defined. Furthermore, direct involvement of the ceramide in the binding of lactosylceramide was suggested.

Amino Sugars↗
PubMed2000

Electrolytes, water, RNA, total creatine and calculated resting membrane potential in muscle tissue from pregnant women.

BACKGROUND: The nutritional situation of the fetus and pregnant woman is important for human health, but knowledge of how nutrition affects maternal metabolism and physiology during pregnancy is limited. Such knowledge is important, for example in body composition studies, when information about lean tissue composition is needed. Muscle, a main part of lean tissue, changes its composition in response to age and sex, but the effect of pregnancy on this composition is unknown. METHODS: Muscle samples from 11 pregnant and 16 nonpregnant women were analyzed for water, electrolytes, total creatine, alkali-soluble protein (ASP), DNA and RNA. Plasma was analyzed for electrolytes. The amount of extracellular and intracellular water as well as the resting membrane potential (RMP) in muscle were calculated. RESULTS: Pregnant women had lower plasma concentrations of potassium and sodium but higher muscle concentrations of sodium and water (total and extracellular) than nonpregnant women. RMP was more negative in pregnant than in nonpregnant women. Total creatine in muscle (per kilogram ASP) was increased during pregnancy. The muscle content of RNA (per kilogram DNA) was lower in gestational week 18 than in nonpregnant controls. CONCLUSION: Pregnancy influences muscle composition in several ways that are relevant for an increased understanding of interactions between nutrition and reproduction.

Adult↗