bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction and enhancement of normal human megakaryocyte polyploidization are concomitant with perturbation in the actin metabolism
Authors: Baatout  , Chatelain  , Staquet  , Symann  , Chatelain
Published: March 2003

Background

Megakaryocyte polyploidization results from the lack of cytoplasmic separation while the nucleus keeps dividing.

Methods

To investigate the role of actin in the megakaryocyte polyploidization, three human cell lines with megakaryocytic properties (DAMI, HEL and K562) were incubated in the presence of cytochalasin B, an inhibitor of actin polymerization. These data were then compared with normal megakaryocytes.

Results

Compared with control conditions, cells cultured in the presence of cytochalasin B revealed an augmentation of cell size and ploidy and an arrest of cell proliferation. The expression of platelet membrane glycoproteins Ib, IIb/IIIa, IIIa and thrombospondin and transferrin receptors was augmented after treatment with cytochalasin B. Physiologically, the role of actin in inducing polyploidization could be related to an imbalance between G‐ and F‐actins. To test this hypothesis, we measured G‐, F‐ and total actin in cytochalasin B‐treated cells. Actin was found to be increased significantly in cytochalasin B‐treated DAMI and HEL cell lines. In contrast, the G/F‐actin ratio was not affected by cytochalasin B. To confirm these actin changes in physiological megakaryocytopoiesis, G‐ and F‐actin contents were then estimated in normal megakaryocytes. The G‐ and F‐actin contents of megakaryocytes from eight normal patients exponentially decreased from 2 to 128n, whereas the total actin content per cell kept increasing. The G/F ratio was unaffected.

Conclusion

Polyploidization of human megakaryocytes results from either a diminution of actin synthesis or an increased actin turnover, which in turn possibly abrogates the formation of the actin cleavage furrow in telophasis.
In vivo modifications of AcSDKP metabolism and haematopoiesis in mice treated with 5‐fluorouracil and Goralatide
Authors: Comte  , Lorgeot  , Bignon  , Volkov  , Dupuis  , Wdzieczak‐Bakala  , Praloran
Published: March 2003

Background

The tetrapeptide acetyl‐Ser‐Asp‐Lys‐Pro (AcSDKP), a physiological inhibitor of the proliferation of haematopoietic stem cells, is degraded by the angiotensin‐I‐converting enzyme (ACE). Whereas synthetic AcSDKP (Goralatide) protects normal mice from the haematological toxicity of chemotherapy, it has a lower beneficial effect in humans. This discrepancy could be dependent on Goralatide administration schedules, as well as on the endogenous concentrations of AcSDKP and ACE, which vary during chemotherapy.

Methods

We investigated the effect of one myelotoxic dose of 5‐fluorouracil (5‐FU, 200 mg kg−1) administered without or with Goralatide on blood, bone marrow (BM) and spleen AcSDKP concentrations, ACE activity, nucleated cell counts and survival of the primitive haematopoietic progenitors high proliferative potential colony‐forming cells (HPP‐CFCs).

Results

The 5‐FU treatment dramatically decreased the BM concentrations of AcSDKP by 73% and increased the ACE activity in plasma by 50% during the period of active BM regeneration. Repeated injections of Goralatide from 24 h before to 36 h after the i.p. injection of 5‐FU spared BM HPP‐CFCs. As an injection of 10 mg of Goralatide induced a short peak of plasma AcSDKP without modifying its BM concentrations, we suggest that its protective effect on HPP‐CFCs could be mediated by its interference with other plasma molecules targeting to the BM.

Conclusion

By improving our knowledge of the biology of AcSDKP in vivo during chemotherapy, our results could help to better define the therapeutic use of Goralatide.
The effects of iloprost infusion on microcirculation is independent of nitric oxide metabolites and endothelin‐1 in chronic peripheral ischaemia
Authors: Mazzone  , Cusa  , Bucci  , Vezzoli  , Ghio  , Buggia  , Regazzi  , Fossati  , Mazzucchelli  , Gritti
Published: March 2003

Background

Endothelial vascular tone modulators are thought to be involved in aetiopathogenesis of systemic sclerosis (SS) and of peripheral artery occlusive disease (PAOD). Iloprost, a prostacyclin (PGI2) analogue, induces clinical benefit in patients suffering from peripheral ischaemia. This study was performed to investigate the effect of this drug on endothelial function in vivo to elucidate the role of vascular tone modulators.

Methods

Fourteen PAOD and 15 SS patients were treated for 24 and 10 days respectively. On the first day, before and after therapy, nitric oxide metabolites (NO2−/NO3−) and endothelin‐1 (ET‐1) plasma concentrations were detected; moreover, the endothelium‐dependent vasodilatation in response to artificial ischaemia was evaluated by means of an echo‐Doppler device.

Results

The echo‐Doppler evaluation showed that the percentage of arterial reactive dilatation was not modified by placebo or by iloprost, and that the increase in blood velocity flow lasted for a significant longer time after drug infusion (226.79 ± 17.49 vs. 310.71 ± 36.32 s; P > 0.04). NO2−/NO3− and ET‐1 plasma concentration were higher in patients than in control subjects (P < 0.004). After 6 h of iloprost infusion, no significant modifications were detected.

Conclusion

This study provides evidence that iloprost enhances the microvascular functional capacity and clinical benefit for patients. The effects of the drug seem to be independently or not directly correlated with its interactions with vascular tone modulators such as NO2−/NO3− or ET‐1.
Post‐prandial chylomicron response may be predicted by a single measurement of plasma apolipoprotein B48 in the fasting state
Authors: Smith  , Watts  , Dane‐Stewart  , Mamo
Published: March 2003

Background

The clearance of chylomicron remnants was assessed in normolipaemic, dyslipidaemic and obese male subjects by monitoring the plasma kinetics of apolipoprotein (apo) B48, retinyl palmitate and triglyceride after a lipid meal. Regression analysis of fasting plasma apo B48 with the area under the post‐prandial curves of apo B48, retinyl ester and triglyceride was carried out in order to determine whether the post‐prandial response could be predicted by the fasting concentration of this exclusive chylomicron marker.

Materials and methods

Fasted subjects were given an oral fat load supplemented with retinyl palmitate, and blood samples were drawn over a 10‐h period. Apolipoprotein B48 was determined by Western blotting in the plasma density fraction less than 1.063 g mL−1. Plasma retinyl palmitate and triglyceride were determined by high‐performance liquid chromatography (HPLC) and colorimetric procedures respectively. The areas under the apo B48, retinyl ester and triglyceride curves were determined by integration. Relationships between the post‐prandial response and the fasting concentration of apolipoprotein B48 were assessed using least‐squares regression analysis.

Results

We found a strong positive relationship between the fasting plasma concentration of apo B48 and the post‐prandial kinetics of apo B48. Similarly, there was a positive relationship of fasting apo B48 with the retinyl ester area under the curve. Collectively, the data suggested that chylomicron remnant kinetics can be predicted based on the fasting level of apo B48. There was also a significant but weaker relationship of fasting apo B48 with post‐prandial triglyceride kinetics, consistent with removal of this lipid by hydrolytic mechanisms in addition to particle uptake.

Conclusion

The fasting plasma concentration of apo B48 appeared to be a good surrogate marker for the degree of post‐prandial lipidaemia and may circumvent the need for oral fat challenges. Moreover, in the fasting state apo B48 concentration is a marker of chylomicron remnants, which are considered to be the proatherogenic form of these intestinally derived lipoproteins.
Distribution of diacylglycerols among plasma lipoproteins in control subjects and in patients with non‐insulin‐dependent diabetes
Authors: Lalanne F. , Pruneta V. , Bernard S. , Ponsin G.
Published: March 2003

Background

Diacylglycerols (DAGs), which are well‐known components of insect lipophorins, have been recently recognized as a major glyceride of human high‐density lipoprotein (HDL). Moreover, DAGs are good substrates for hepatic lipase and for the phospholipid transfer protein (PLTP). The present work was undertaken to determine the lipoprotein concentrations of DAGs, in control subjects, in non‐insulin‐dependent diabetic (NIDD) patients and in patients with severe hypertriglyceridaemia.

Materials and methods

Lipoproteins were isolated from 11 control subjects, 17 diabetic patients and three hypertriglyceridaemic patients, using a combination of ultracentrifugation and precipitation. After lipid extraction, DAGs were separated by thin‐layer chromatography and quantified by a glyceride assay.

Results

DAGs were detectable in all lipoprotein fractions of the three groups of subjects. Total DAGs were correlated with total triglycerides (TGs) and even more strikingly with very low‐density lipoprotein triglycerides. Although the majority of DAG was recovered in apo B‐containing lipoproteins, the proportion of DAG with respect to TG was most elevated in HDL.

Conclusion

These findings indicate that DAGs are probably formed from TG during lipolysis and that they can be transported to HDL through the action of PLTP. This raises the question whether DAG might act as an inhibitor of phospholipid transfer by competition for binding to PLTP.
Glucocorticoid receptors are down‐regulated in inflamed colonic mucosa but not in peripheral blood mononuclear cells from patients with inflammatory bowel disease
Authors: Rogler  , Meinel  , Lingauer  , Michl  , Zietz  , Gross  , Lang  , Andus  , Schölmerich  , Palitzsch
Published: March 2003

Background

Growing evidence indicates that the immune system and the hypothalamic–pituitary–adrenal system are linked by several mechanisms, for example intracellular glucocorticoid receptors (hGR). Glucocorticoids are the standard treatment of acute attacks of inflammatory bowel disease (IBD). Binding of glucocorticoids to hGR down‐regulates the transcription of inflammatory genes that can propagate IBD.

Patients and methods

IBD patients were either treated with 5–60 mg of prednisolone for more than 1 week or were without glucocorticoid treatment for more than 4 weeks. hGR levels were determined from isolated cytosol of peripheral blood mononuclear cells (PBMCs) or mucosal biopsies using a radioassay with [3H]‐dexamethasone. Interleukin (IL) 6 levels were determined by enzyme‐linked immunosorbent assay (ELISA).

Results

The systemic (PBMC) hGR levels of corticosteroid‐treated IBD patients were significantly lower than those of control subjects (59.6 ± 57.1 dpm mg−1 cytosol protein vs. 227.0 ± 90.8 dpm mg−1 cytosol protein, P = 0.007) and IBD patients not receiving glucocorticoid treatment (179.7 ± 171.3 dpm mg−1 cytosol protein, P = 0.002). Systemic hGR levels in untreated IBD patients did not differ significantly from those in control subjects. In patients with connective tissue diseases, systemic hGR levels were also found to be decreased in the absence of glucocorticoid treatment. Systemic hGR levels in patients with Crohn's disease (CD) treated with steroids (66.6 ± 61.0 dpm mg−1 cytosol protein) were not different from those in patients with ulcerative colitis (UC) (56.1 ± 51.6 dpm mg−1 cytosol protein). In contrast to these findings, mucosal hGR levels were significantly decreased in both steroid‐treated (18.0 ± 15.5) and not steroid‐treated (37.8 ± 30.5) patients compared with control subjects (125.6 ± 97.1; P = 0.00009 and P = 0.0008 respectively). IL‐6 levels in all IBD groups with and without steroids were significantly different from those in control subjects.

Conclusion

In IBD there is no difference in systemic hGR levels between not steroid‐treated patients and control subjects, in spite of inflammatory activity (IL‐6). Mucosal hGR levels were decreased independently of treatment, probably leading to a decreased protection against NF‐κB action in the intestinal mucosa.
Chlamydia pneumoniae reactive T lymphocytes in the walls of abdominal aortic aneurysms
Authors: Halme S. , Juvonen T. , Laurila A. , Juvonen J. , Mosorin M. , Saikku P. , Surcel H.‐M.
Published: March 2003

Background

The presence of Chlamydia pneumoniae in the walls of abdominal aortic aneurysms (AAAs) has been demonstrated recently, but its role in the cause and/or maintenance of aortic wall inflammation is not known. In the present study, we have investigated the possible relationship between C. pneumoniae and the antigen specificity of T lymphocytes mediating inflammation in AAA tissue.

Materials and methods

Tissue specimens were obtained from 22 consecutive AAA patients undergoing elective surgery (mean age 67 ± 1 year). Immunohistochemical analysis of the formalin‐fixed tissue was performed using the streptavidin–biotin–peroxidase method. In vivo activated T lymphocytes were propagated from the specimens with interleukin (IL) 2, and antigen specificity of the established T‐cell lines was analysed in the presence of autologous antigen‐presenting cells using radioactive thymidine labelling.

Results

Immunohistological staining of AAA tissue showed the presence of C. pneumoniae antigen in 55% (6/11) of the samples studied. The inflammatory cell infiltrate of the AAA tissue contained 60–90% T (CD45RO) and 0–10% B (CD20) cells. When the tissue specimens were cultured without antigen in the presence of IL‐2, lymphocyte propagation was achieved in 17 out of the 22 samples. Chlamydia pneumoniae antigen was found to induce a positive proliferative response in 8 of the 17 lines.

Conclusions

The presence of C. pneumoniae specific T lymphocytes among in vivo activated cells from the AAA tissue specimens suggests that C. pneumoniae participates in the maintenance of the inflammatory response in the tissue and may thus be involved in the progression of the disease.
Muscle creatine phosphate in gyrate atrophy of the choroid and retina with hyperornithinaemia–clues to pathogenesis
Authors: Heinänen  , Näntö‐Salonen  , Komu  , Erkintalo  , Heinonen  , Pulkki  , Valtonen  , Nikoskelainen  , Alanen  , Simell
Published: March 2003

Background

In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), inherited deficiency of ornithine‐δ‐aminotransferase leads to progressive fundus destruction and atrophy of type II skeletal muscle fibres. Because high ornithine concentrations inhibit creatine biosynthesis, the ensuing deficiency of high‐energy creatine phosphate may mediate the pathogenesis.

Materials and methods

Relative concentrations of inorganic phosphate (Pi), creatine phosphate (PCr) and ATP in resting calf muscle were recorded in 23 GA patients and 33 control subjects using 31P‐magnetic resonance spectroscopy (MRS). Eight patients with autosomal recessive retinitis pigmentosa with matched control subjects constituted an additional reference group.

Results

The PCr/Pi and PCr/ATP ratios (means ± SD) were lower for the GA patients than for healthy control subjects [4.66 ± 0.37 vs. 9.75 ± 2.17 (P < 0.0001) and 2.85 ± 0.37 vs. 3.70 ± 0.50 (P < 0.05) respectively]. In retinitis pigmentosa the respective values were 9.12 ± 2.57 and 4.25 ± 0.45. Age and stage of the disease had no effect.

Conclusion

Muscle 31P‐MRS spectra were markedly abnormal in all GA patients.
Lack of association between changes in plasma leptin concentration and in food intake during the menstrual cycle
Authors: Paolisso G. , Rizzo M. R. , Mazziotti G. , Rotondi M. , Tagliamonte M. R. , Varricchio G. , Carella C. , Varricchio M.
Published: March 2003

Background

Changes in plasma leptin concentration and food intake occur during the menstrual cycle; because leptin regulates food intake, one could hypothesize that changes in plasma leptin concentration and in food intake are associated throughout the menstrual cycle. However, no data have ever been provided to support such a relationship. The aim of our study was to investigate, during the different phases of the menstrual cycle, (a) the changes in plasma leptin concentration and, if such changes were demonstrated, (b) the potential relationship between the changes in plasma leptin concentration and food intake.

Design

The study was designed as an observational study. The plasma leptin concentration was determined in 16 healthy, young women during different phases of the menstrual cycle. At the same time, the basal metabolic rate (BMR), respiratory quotient (RQ) and food intake (FI) were also determined.

Results

The plasma leptin concentration increased throughout the menstrual cycle (P < 0.01 for trend) and was significantly correlated with plasma progesterone concentration (r = 0.55, P < 0.007, for follicular phase, r = 0.58, P < 0.02, for the periovulatory period and r = 0.57, P < 0.02, for the luteal phase). No significant differences in BMR and fasting RQ throughout the different phases of the menstrual cycle were found. In contrast, FI significantly declined in the periovulatory phase. No significant correlations between BMR, RQ and FI values and fasting plasma leptin concentration at all menstrual phases were found.

Conclusion

Changes in plasma leptin concentration and in food intake were found at different phases of the menstrual cycle. Nevertheless, no correlation among those parameters at any phase of the menstrual cycle was observed.
Integrin mediated adhesion of mononuclear cells from patients with familial hypercholesterolemia
Authors: De Bont  , Geijtenbeek  , Netea  , Smilde  , Demacker  , Figdor  , Van Der Meer  , Stalenhoef
Published: March 2003

Background

Low‐density lipoproteins (LDL) can induce the adhesion of monocytes to endothelial cells. Monocytes of patients with familial hypercholesterolemia (FH) are exposed to high concentrations of LDL, and it has been reported that adhesiveness of these cells in hypercholesterolemic patients is enhanced. We investigated whether LFA‐1 or VLA‐4 mediated adhesion is altered in FH patients and whether HMG‐CoA reductase inhibitors influence this adhesion.

Patients and methods

LFA‐1 and VLA‐4 mediated adhesion to ICAM‐1 and VCAM‐1 coated beads was investigated using freshly isolated monocytes and T‐lymphocytes from patients with homozygous FH, heterozygous FH (before and after cholesterol lowering treatment), and from controls. In addition, the expression of β1‐ and β2‐integrins on these cells was determined.

Results

Both LFA‐1 and VLA‐4 mediated adhesion and integrin expression of monocytes and CD3+ cells from patients with homozygous FH and heterozygous FH was similar to that of monocytes from a control population. Treatment with HMG‐CoA reductase inhibitors did not affect the adherence to ICAM‐1 or VCAM‐1, and did not influence the expression of integrins.

Conclusions

In contrast to studies by others, we demonstrated in the present study that the actual LFA‐1 and VLA‐4 mediated adhesion of T‐lymphocytes and monocytes is not altered in patients with FH.
Hypoleptinemia in female and male elite gymnasts
Authors: Weimann  , Blum  , Witzel  , Schwidergall  , Böhles
Published: March 2003

Background

Elite gymnasts favour low body fat mass as the current aesthetic ideal required for complex movements in this sports discipline. Pubertal development and growth are retarded in juvenile gymnasts. Leptin, the protein product of the ob‐gene, is secreted by fat cells. Besides its role in regulation of body weight, leptin also stimulates the reproductive axis. We investigated various serum hormones including leptin, body composition and nutrition in cohorts of female and male elite gymnasts to elucidate if there is a relationship between leptin levels and delayed puberty in elite gymnasts.

Materials and methods

Twenty‐two female and 18 male elite gymnasts were enrolled in this study. Pubertal stage, various hormonal levels and body composition were determined and nutritional intake was assessed. Leptin was analysed using a specific RIA.

Results

Pubertal development and growth were delayed in the study group, especially in girls. The percentage of body fat was reduced as compared to a normal age‐matched population: 14.4% versus 21.9% in girls and 10.4% versus 15.1% in boys. Serum leptin levels were decreased, especially in pubertal girls, and did not show the normal developmental pattern with a steady increase in girls and a peak in boys of pubertal stage 2. In all gymnasts leptin levels correlated with the amount of fat mass (r = 0.6, P = 0.005 in girls; r = 0.44, P = 0.038 in boys). When leptin levels were transformed into standard deviation scores (SDS) it became obvious that the gymnasts, especially pubertal females, had significantly lower values than normal controls of the same sex, pubertal stage and body mass index (BMI): leptin SDS (BMI) = –1.21 and −3.99 in prepubertal and pubertal girls, − 0.94 and −0.91 in prepubertal and pubertal boys, respectively. When leptin SDS were based on % body fat instead of BMI, mean values were still significantly decreased compared to normal controls: −1.05 in girls (P < 0.001) and −0.60 in boys (P = 0.025).

Conclusions

Adjustment of serum leptin levels in elite gymnasts for gender, pubertal stage and BMI or % body fat reveals inappropriately low values. The reason for this hypoleptinemia is most probably insufficient caloric intake. The data suggest that hypoleptinemia in turn causes delayed puberty and growth in this particular group of athletes.
Changes of plasma total homocysteine levels during the menstrual cycle
Authors: Tallova  , Tomandl  , Bicikova  , Hill
Published: March 2003

Background

It is known that plasma total homocysteine (tHcy) levels are lower in premenopausal and pregnant women compared with postmenopausal women. To confirm the suggestion that sex steroid hormones are nongenetic factors affecting homocysteine metabolism, we investigated the effect of natural steroid hormone levels on the fasting plasma tHcy in healthy women during the menstrual cycle.

Materials and methods

Fifteen premenopausal women were enrolled in this study. Plasma tHcy, estradiol, progesterone and cortisol concentrations were measured in the luteal and follicular phase. The plasma tHcy concentration was determined by high performance liquid chromatography with fluorescence detection, and the steroid hormones by RIA methods.

Results

Mean homocysteine values increased from 7.8 μmol L−1 in the luteal phase to 8.9 μmol L−1 in the follicular phase (P < 0.000005, Student's paired t‐test). We also found slight negative but insignificant correlations of homocysteine levels with estradiol in both phases of the menstrual cycle. In the case of cortisol and progesterone, no significant correlations with plasma homocysteine were found.

Conclusion

The study provides the first evidence of significant differences in plasma homocysteine concentration during the menstrual cycle. From our observed findings it is necessary to account for the phase of the menstrual cycle when determining homocysteine in premenopausal women.
Does jejunal feeding activate exocrine pancreatic secretion?
Authors: Vu  , Van Der Veek  , Frölich  , Souverijn  , Biemond  , Lamers  , Masclee
Published: March 2003

Background

The upper small bowel is of pivotal importance for the stimulation of exocrine pancreatic secretion in response to a meal. We hypothesize that more distal delivery of nutrients into the small intestine will result in less activation of pancreatic secretion.

Materials and methods

Eight healthy subjects (3 male, 5 female; age 23 ± 1 years) participated in two experiments, performed in random order. Subjects were intubated with a 4‐lumen tube. Duodenal outputs of pancreatic enzymes and bilirubin were measured by aspiration using a recovery marker. The distal opening was used for continuous administration of a mixed liquid meal and located at either the ligament of Treitz or 60 cm further distally. Gallbladder volume was measured and blood samples were drawn for determination of gastrointestinal hormones. The duration of each experiment was 4 h; with 1 h fasting and 3 h continuous administration of nutrients.

Results

During proximal jejunal feeding, pancreatic enzyme output increased significantly over basal levels. No significant increase over basal levels was observed during distal jejunal feeding. Bilirubin output and gallbladder contraction were significantly (P < 0.05) reduced during distal compared to proximal jejunal feeding. No significant differences were found in plasma levels of CCK, PYY and neurotensin between proximal and distal jejunal feeding.

Conclusion

Continuous feeding in the distal jejunum does not stimulate exocrine pancreatic secretion but maintains gallbladder contraction, although to a lesser extent. These effects are not related to hormonal changes but probably reduced activation of the enteropancreatic reflexes.
Exhaled nitric oxide during incremental and constant workload exercise in chronic cardiac failure
Authors: Lovell  , Stevenson  , Young  , McDowell  , McEneaney  , Riley  , Nicholls
Published: March 2003

Background

Nitric oxide (NO) is present in exhaled breath and produced by the pulmonary vascular endothelium as a potent vasodilator. Exercise is normally associated with pulmonary vasodilatation and a decrease in pulmonary vascular resistance to accommodate the increase in cardiac output. If production of NO is impaired in patients with chronic congestive cardiac failure (CCF), this might contribute to their exercise intolerance.

Patients and methods

We quantified NO production (V˙ NO) in 12 patients with chronic stable CCF and 12 controls, at rest and during incremental cardiopulmonary exercise on a treadmill, and at a later date during constant workload exercise.

Results

Patients had reduced V˙ NO compared with controls during incremental exercise [381 (180) vs. 777 (275) nL min−1; mean (SD); P < 0.0001] but at constant workload V˙ NO was similar between the two groups [353 (124) vs. 389 (189) nL min−1; P = 0.25]. Plasma levels of nitrate, the stable end‐product of NO production, were significantly higher in patients [resting value 46.1 (21.6) vs. 23.0 (10.0) μM; P = 0.004] and were not influenced by exercise.

Conclusion

Impaired NO‐mediated pulmonary vasodilatation does not appear to contribute to exercise limitation in CCF. Alternatively, the lower NO production observed during maximal exercise in the patient group compared with controls may reflect a reduced incremental response of a system that is already abnormally activated in heart failure.
Effects of exogenous zinc supplementation on intestinal epithelial repair in vitro
Authors: Cario  , Jung  , Harder d'Heureuse  , Schulte  , Sturm  , Wiedenmann  , Goebell  , Dignass
Published: March 2003

Background

Substitution of zinc modulates antioxidant capabilities within the intestinal mucosa and improves intestinal wound healing in zinc‐deficient patients with inflammatory bowel diseases. The aim of this study was to characterize the modulating effects of zinc on intestinal epithelial cell function in vitro.

Materials and methods

The effects of zinc on intestinal epithelial cell morphology were assessed by phase contrast and transmission electron microscopy using the non‐transformed small intestinal epithelial cell line IEC‐6. Zinc‐induced apoptosis was assessed by DNA fragmentation analysis, lactate dehydrogluase (LDH) release and flow cytometry with propidium iodine staining. Furthermore, the effects of zinc on IEC‐6 cell proliferation were assessed using a colorimetric thiazolyl blue (MTT) assay and on IEC‐6 cell restitution using an in vitro wounding model.

Results

Physiological concentrations of zinc (25 μm) did not significantly alter the morphological appearance of IEC‐6 cells. However, a 10‐fold higher dose of zinc (250 μm) induced epithelial cell rounding, loss of adherence and apoptotic characteristics. While physiological zinc concentrations (< 100 μm) did not induce apoptosis, supraphysiological zinc concentrations (> 100 μm) caused apoptosis. Physiological concentrations of zinc (6.25–50 μm) had no significant effect on intestinal epithelial cell proliferation. In contrast, physiological concentrations of zinc (12.5–50 μm) significantly enhanced epithelial cell restitution through a transforming growth factor‐β (TGFβ)‐independent mechanism. Simultaneous addition of TGFβ and zinc resulted in an additive stimulation of IEC‐6 cell restitution.

Conclusion

Zinc may promote intestinal epithelial wound healing by enhancement of epithelial cell restitution, the initial step of epithelial wound healing. Zinc supplementation may improve epithelial repair; however, excessive amounts of zinc may cause tissue injury and impair epithelial wound healing.
Detrimental effects of nitric oxide inhibition on hepatic encephalopathy in rats with thioacetamide‐induced fulminant hepatic failure
Authors: Chu C.‐J. , Wang S.‐S. , Lee F.‐Y. , Chang F.‐Y. , Lin H.‐C. , Hou M.‐C. , Chan C.‐C. , Wu S.‐L. , Chen C.‐T. , Huang H.‐C. , Lee S.‐D.
Published: March 2003

Hepatic encephalopathy is a complex neuropsychiatric syndrome seen secondary to acute liver failure, chronic parenchymal liver disease, or portal‐systemic anastomosis. Vasodilatation induced by nitric oxide (NO) may be involved in the development of hepatic coma. However, there are no comprehensive data concerning the effects of NO inhibition on the severity of hepatic encephalopathy.

Male Sprague‐Dawley rats weighing 300–350 g were used. Fulminant hepatic failure was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg kg−1day−1) for 3 days. Rats were divided into two groups to receive eitherNG‐nitro‐l‐arginine methyl ester (l‐NAME, 20 mg kg−1 day−1via intragastric gavage) or normal saline (N/S) from 2 days prior to TAA administration for 5 days. Severity of encephalopathy was assessed by counts of motor activity and neurobehaviour test scores. Plasma levels of endotoxin, tumour necrosis factor‐α and nitrate/nitrite were determined by the chromogenicLimulusassay, enzyme‐linked immunosorbent assay and colorimetric assay, respectively.

Compared with N/S‐treated rats, the mortality rate was significantly higher in rats receivingl‐NAME (59% vs. 18%,P < 0·01). Inhibition of NO had detrimental effects on the counts of motor activities (P < 0·05) and neurobehaviour score (P < 0·01). Rats treated withl‐NAME had significantly higher plasma levels of endotoxin (26·7 ± 3·8 pg mL−1) and tumour necrosis factor‐α (29·4 ± 6·5 pg mL−1) compared with rats treated with N/S (13·2 ± 2·7 pg mL−1and 11·2 ± 2·6 pg mL−1, respectively,P < 0·01). Plasma levels of endotoxin and tumour necrosis factor‐α, but not of nitrate/nitrite, were significantly correlated with the severity of hepatic encephalopathy (P < 0·05).

Chronicl‐NAME administration had detrimental effects on the severity of encephalopathy in TAA‐treated rats, suggesting a protective role of NO in the development of fulminant hepatic failure.
Increased expression of VEGF following exercise training in patients with heart failure
Authors: Gustafsson T. , Bodin K. , Sylvén C. , Gordon A. , Tyni‐Lenné R. , Jansson E.
Published: March 2003

Background and aims During the last decades several angiogenic factors have been characterized but so far it is unknown whether local muscle exercise training increases the expression of these factors in patients with moderate heart failure. Expression of the major putative angiogenic factor vascular endothelial growth factor (VEGF) at the level of messneger RNA (mRNA) and/or protein was therefore studied before and after 8 weeks of training in patient with chronic heart failure.

Methods VEGF mRNA and protein concentrations were determined in skeletal muscle biopsies before and after 8 weeks of one‐legged knee extension training in patients with chronic heart failure (New York Heart Association II–III).

Results Exercise training increased the citrate synthase activity and peripheral exercise capacity by 46% and 36%, respectively, in parallel with a two‐fold increase in VEGF at both the mRNA (P = 0·03) and protein (P = 0·02) levels

Conclusion The increase in VEGF gene expression in response to exercise training indicates VEGF to be one possible mediator in exercise‐induced angiogenesis and may therefore regulate an important and early step in adaptation to increased muscle activity in patient with chronic heart failure.
Sodium–lithium countertransport is increased in normoalbuminuric type 1 diabetes but is not related to other risk factors for microangiopathy
Authors: Vervoort G. , Elving L. D. , Wetzels J. F. M. , Lutterman J. A. , Smits P. , De Pont J. J. H. H. M. , Berden J. H. M.
Published: March 2003

Background It has been reported that sodium–lithium countertransport (Na/Li CT) activity is increased in patients with diabetes mellitus and that this increased Na/Li CT activity is associated with the development of diabetic nephropathy. It is unclear however, whether Na/Li CT is related to other pathophysiological factors in diabetic patients. We studied kinetic parameters of Na/Li CT activity together with other putative risk factors for microangiopathy in normoalbuminuric type 1 diabetic patients and matched control subjects.

Subjects and methods We measured maximum velocity (Vmax) and sodium affinity (Km) of Na/Li CT in 53 diabetic patients and 45 healthy controls. Endothelial function was assessed by monitoring forearm vascular response to intrabrachial infusion of acetylcholine. Blood samples were collected for measurement of HbA1c, glucose, insulin and lipids. Blood pressure was measured intra‐arterially. Renal haemodynamics were measured by inulin/p‐aminohippurate clearance. Urinary albumin was measured by enzyme‐linked immunosorbent assay. Transcapillary escape of albumin (TERalb) was calculated by the disappearance curve of 125I‐labelled albumin.

Results V
max was increased in diabetic patients (779 ± 36 µmol Li+ h−1 L−1 erythrocytes vs. 623 ± 35 in controls, P < 0·01), whereas Km was decreased (64 ± 16 mmol L−1 vs. 76 ± 27 in controls, P = 0·03). The ratio of Vmax : Km was 12·4 ± 0·6 in diabetic patients and 8·9 ± 0·9 in controls (P < 0·001). When comparing diabetic patients in the lowest and highest quartile of Vmax or Km there were no differences in blood pressure, renal haemodynamics, urinary albumin excretion, TERalb, endothelial function, HbA1c, glucose, insulin, or lipid profile.

Conclusion Na/Li CT is increased in uncomplicated type 1 diabetes and characterized by an increase in Vmax and a decrease in Km. The increase in Na/Li CT is not associated with changes in endothelial function, degree of metabolic control, blood pressure or renal haemodynamics.
Serum paraoxonase activity in patients with type 1 diabetes compared to healthy controls
Authors: Mackness B. , Durrington P. N. , Boulton A. J. M. , Hine D. , Mackness M. I.
Published: March 2003

Background The oxidation of low‐density lipoprotein (LDL) is central to current theories on the initiation and progression of atherosclerosis. Type 1 diabetes is associated with an increase in oxidative stress, which may be responsible for the increased susceptibility to coronary heart disease seen in type 1 diabetes. High‐density lipoprotein (HDL) associated paraoxonase (PON1) can retard the oxidation of LDL.

Design Paraoxonase activity, concentration and genotype were therefore investigated in 152 people with type 1 diabetes and 282 healthy controls. These parameters were also investigated in the group with type 1 diabetes in relation to the presence of diabetic complications.

Results Both PON1 activity and concentration were significantly lower by 16·7% and 19·2% (both P < 0·05) in the type 1 diabetes group. These differences were independent of the PON1 coding region polymorphisms. The distribution of PON1 activity and mass were the same in both populations, i.e. for the PON1‐192 polymorphism RR > RQ > QQ and for the PON1‐55 polymorphism LL > LM > MM. There were no differences in either the PON1 polymorphisms, PON1 activity and concentration in people with type 1 diabetes in the presence or absence of micro and macro vascular complications of diabetes.

Conclusions Low PON1 activity may contribute to the increased atherosclerosis found in type 1 diabetes by reducing the ability of HDL to retard LDL oxidation despite the frequently‐found increased HDL in type 1 diabetes when good glycaemic control is established.
Glucocorticoids and 11β‐hydroxysteroid dehydrogenase type 2 gene expression in the aging kidney
Authors: Audigé A. , Dick B. , Frey B. M. , Frey F. J. , Corman B. , Vogt B.
Published: March 2003

Background Aging is associated with increased concentrations of circulating glucocorticoids, a situation expected to induce a glucocorticoid‐mediated mineralocorticoid effect, resulting in sodium retention and hypertension unless counteracting mechanisms are operative. Conversion of glucocorticoids to inert 11β‐keto compounds by the enzyme 11β‐hydroxysteroid dehydrogenase type 2 (11β‐HSD2) is one of these mechanisms. We hypothesized therefore that 11β‐HSD2 gene expression and/or activity increase with age in male WAG/Rij rats, a strain without increased blood pressure with age or senescence‐related obesity or kidney disease.

Materials and methods Corticosterone (B) concentrations in plasma and urinary excretion of corticosterone and dehydrocorticosterone (A) tetrahydro metabolites, THB + 5α‐THB + THA, were assessed by gas chromatography‐mass spectrometry (GC‐MS) in 10‐month‐old‐rats (n = 6) and in 30‐month‐old rats (n = 6). Renal 11β‐HSD2 messenger ribonucleic acid (mRNA) abundance was measured by real‐time quantitative TaqMan polymerase chain reaction and microarray assays.

Results Thirty‐month‐old rats had significantly higher corticosterone concentrations in plasma and increased urinary excretion of corticosterone and dehydrocorticosterone tetrahydro metabolites. Conversion of B to A in kidney microsomes from 30‐month‐old rats was moderately but not significantly increased compared with 10‐month‐old rats. The urinary ratios of (THB + 5α‐THB)/THA and free B/A and renal 11β‐HSD2 mRNA abundance were equal in 10‐ and 30‐month‐old rats.

Conclusions There is no evidence for an enhanced gene expression or activity of renal 11β‐HSD2 in these aging rats, suggesting either that endogenous 11β‐HSD2 is able to cope with the increased corticosterone concentrations characteristic of the aging process or that alternative mechanisms contribute to the maintenance of a normal sodium excretion in these animals.
Intestinal absorption and biliary secretion of ursodeoxycholic acid and its taurine conjugate
Authors: Rudolph G. , Kloeters‐Plachky P. , Sauer P. , Stiehl A.
Published: March 2003

Background  Ursodeoxycholic acid (UDCA) and its taurine conjugate (TUDCA) exert a protective effect in cholestatic liver diseases. A greater hepatoprotective effect of TUDCA has been suggested. Absorption appears to be a limiting factor and up to now has not been studied in man.

Methods  We studied absorption and biliary bile acid secretion and composition after administration of UDCA and TUDCA in patients who had complete extrahepatic biliary obstruction caused by pancreatic carcinoma but had no intestinal or liver disease. After 5 days of intact enterohepatic circulation eight patients with a percutaneous biliary–duodenal drainage received, during two study periods, 1000 mg (1916·9 µmol; mean 29·6 µmol kg−1) TUDCA and 750 mg (1910·4 µmol; mean 29·5 µmol kg−1) UDCA in random order. Each patient served as his own control.

Results  After UDCA and TUDCA administration the biliary UDCA content increased to 55·2% and 54·6% of total bile acids, respectively (not significant). Biliary secretion of cholic and chenodeoxycholic acids remained unchanged whereas that of lithocholic acid increased slightly. A total of 64·6% of the orally administered TUDCA and 55·1% of the UDCA was absorbed (not significant). After TUDCA administration, biliary UDCA was preferentially (95·4%) taurine‐conjugated whereas after UDCA administration biliary UDCA was mainly (79·8%) glycine‐conjugated.

Conclusions  After oral administration of TUDCA and UDCA, no significant differences in their absorption and in biliary bile acid secretion exist. Whether biliary enrichment with taurine conjugates of UDCA instead of glycine conjugates offers advantages in the treatment of cholestatic liver disease is unclear at present.
Factor XIII a‐positive dermal dendrocytes and shear wave propagation in human skin
Authors: Hermanns‐Lê T. , Uhoda I. , Piérard‐Franchimont C. , Piérard G. E.
Published: March 2003

Background The in vivo interdependence between the phenotypic characteristics of dermal cells and the strain imposed on the tissue has not been studied thoroughly in humans. In particular the mechanical force modulation of Factor XIII a expression in dermal dendrocytes (DD) remains unknown.

Materials and methods The present study compares the numerical density of Factor XIII a‐positive DD and the in vivo shear wave velocity in the skin. The investigation was performed in 20 men of normal weight and 20 obese men before and after entering a slimming process.

Results Excess cutaneous fat places the skin under increased intrinsic tension. The resonance running time measurement (RRTM) and the DD density were significantly reduced in overweight individuals. After a short‐term but intense slimming process, the same individuals showed a trend to normalization of these two parameters without, however, reaching significance. Pooling all data yielded a significant logarithmic correlation between RRTM values and densities in Factor XIII a‐positive DD.

Conclusion Factor XIII a expression in human DD may be partially regulated by the intrinsic resting tensions in the skin.
Starvation reduces allergen‐induced skin wheal responses and plasma substance P and vasoactive intestinal peptide in patients with atopic eczema/dermatitis syndrome
Authors: Kimata H.
Published: March 2003

The effect of starvation on allergen‐induced skin wheal responses and plasma neuropeptide levels was not previously reported. Starvation for 24 h reduces allergen‐induced skin wheal responses and plasma levels of substance P and vasoactive intestinal peptide in patients with atopic eczema/dermatitis syndrome, but not in control subjects. These results may have implications for the pathophysiology of the atopic eczema/dermatitis syndrome.
Soluble leptin receptors and serum leptin in end‐stage renal disease: relationship with inflammation and body composition
Authors: Pecoits‐Filho R. , Nordfors L. , Heimbürger O. , Lindholm B. , Anderstam B. , Marchlewska A. , Stenvinkel P.
Published: March 2003

Background Elevated serum leptin (S‐leptin) levels have been reported in patients with end‐stage renal disease (ESRD). Apart from the decreased glomerular filtration rate (GFR), body composition and inflammation may affect leptin levels in ESRD. Leptin circulates both free of and bound to soluble leptin receptors (sOB‐R), which are the main determinants of leptin activity and have not been described in ESRD until now.

Design To analyze the association between S‐leptin, sOB‐R, and inflammation and body composition, we studied 149 (62% males) normal weight (BMI 24·7 ± 0·4 kg m−2) ESRD patients (51 ± 1 years old) shortly before the start of dialysis (GFR 7·0 ± 0·2 mL min−1). sOB‐R and plasma interleukin‐6 (IL‐6; n= 113) levels were evaluated using ELISA, S‐leptin using RIA, and body composition was assessed by X‐ray absorptiometry (n = 139). Forty‐one healthy subjects age (51 ± 1 years), BMI (23·6 ± 0·5 kg m−2) and gender‐matched (59% males) were used as controls.

Results Median S‐leptin was higher in the ESRD patients (10·0 ng mL−1) compared with the controls (3·9 ng mL−1) (P < 0·001). The median sOB‐R did not differ significantly between the ESRD patients (44 U mL−1) and the controls (37 U mL−1). Thus, the sOB‐R/S‐leptin ratio was lower in the ESRD patients (9·5 ± 1·2 vs. 12·3 ± 1·8; P < 0·01) than the controls. A negative correlation was observed between S‐leptin and sOB‐R (Rho = −0·42; P < 0·0001) in the ESRD patients, a positive correlation was observed between lean body mass and the sOB‐R/S‐leptin ratio (Rho = 0·33, P = 0·0001) whereas fat mass was negatively correlated to both sOB‐R (Rho = −0·26, P = 0·002), and the sOB‐R/S‐leptin ratio (Rho = −0·62, P < 0·0001). Positive correlations were observed between IL‐6 and S‐leptin (Rho = 0·19; P < 0·05) and weak but significant body fat mass (Rho = 0·20; P < 0·05), respectively.

Conclusions This study demonstrates that despite markedly elevated S‐leptin levels in the ESRD patients, sOB‐R did not differ from the controls. In view of the anorexigenic and pro‐atherogenic effects of leptin, further elucidation of the consequences of free bioactive leptin in the development of complications such as malnutrition and cardiovascular disease in ESRD patients is required.
p53 codon 72 polymorphism and susceptibility to development of human papilloma virus‐associated cervical cancer in Indian women
Authors: Nagpal J. K. , Sahni S. , Das B. R.
Published: March 2003

Background Infection with human papilloma virus (HPV) is an important etiological factor in the development of cervical cancer and it has been proposed that individuals homozygous for Arg/Arg at codon‐72 of p53 are seven times more susceptible to HPV‐mediated cancer. In this study, we have analyzed the genetic predisposition of the India population to HPV infection and cervical carcinogenesis.

Methods We investigated 71 cases of squamous cell carcinoma of the cervix, 14 cases of low‐grade squamous intraepithelial lesions, 25 cases of high‐grade squamous intraepithelial lesions and 29 noncancer controls for presence of HPV16/18 infections by L‐1‐specific PCR assay and Southern hybridization, and its association with polymorphism at p53 codon 72.

Results We observed that 69·1% (76/110) of the cervical cancer patients were HPV positive, among which the presence of HPV16, 18 and 16/18 coinfection was 40·9%, 8·2% and 13·6%, respectively. The allele frequencies of the three p53 genotypes Arg/Arg, Arg/Pro and Pro/Pro in the HPV‐positive tumour samples were 0·34, 0·57 and 0·09 in comparison with frequencies of 0·18, 0·44 and 0·38 for HPV‐negative tumours. Hence, there is a significant difference in the allelic frequency of p53 Arg/Arg in high‐risk HPV‐infected cervical carcinoma cases (0·34) and HPV‐negative carcinomas (0·18).

Conclusion Our results indicate a striking over‐representation of homozygous arginine at codon 72 of p53 in HPV‐associated cervical carcinogenesis. We conclude that women with Arg/Arg homozygous allele are more prone to infection by HPV16/18, which leads to cervical carcinomas having poor prognosis.