Involvement of cAMP-response element binding protein in corticotropin-releasing factor (CRF)-induced down-regulation of CRF receptor 1 gene expression in rat anterior pituitary cells

Corticotropin-releasing factor (CRF) is a major secretagogue of adrenocorticotopic hormone from the anterior pituitary and a key activator of the hypothalamic-pituitary-adrenal axis. We previously reported that CRF down-regulates expression of the CRF type-1 receptor (CRF-R1) mRNA in cultured rat anterior pituitary cells. The present study was conducted to clarify the signal transduction systems involved in CRF-induced down-regulation of CRF-R1 gene expression in the anterior pituitary. Northern blot analysis revealed that, under serum-free conditions, 10 nM CRF decreased CRF-R1 mRNA levels in cultured rat anterior pituitary cells as we reported previously. Treatment with 5 mM 8-Br-cAMP reduced CRF-R1 mRNA levels within 2 h. The mRNA level fell to 37+/-3% of the basal level at 2 h and remained low for 16 h after treatment. This CRF-induced reduction of CRF-R1 mRNA expression was inhibited completely by pretreatment with protein kinase A (PKA) inhibitor (1 microM H-89). Further examination revealed that after pretreatment with 10 microM of antisense oligodeoxynucleotide for cyclic AMP-response element binding protein (CREB), the CRF-induced inhibition of CRF-R1 mRNA was partially decreased to 79+/-4% of the control level 2 h after administration of CRF. These findings indicate that CRF may down-regulate CRF-R1 mRNA expression via a cAMP-PKA-mediated mechanism in rat anterior pituitary cells, and that CREB may mediate at least a portion of this inhibitory effect.

Momentum distribution of 15B fragments from the breakup of 17B

The two-neutron removal cross section (sigma(-2n)) and the longitudinal momentum distribution of 15B fragments from the breakup of 17B on 9Be were measured at 70A MeV. The distribution in the projectile rest frame is characterized by a FWHM of 80+/-10 MeV/c for 15B. The sigma(-2n) is found to be 0.22+/-0.05 b. A Glauber-type analysis of the data provides clear evidence of a two-neutron halo structure in 17B.

CD161+ T (NT) cells exist predominantly in human intestinal epithelium as well as in liver

It has been reported that human CD161 (NKR-P1A)+ T cells are counterparts of murine natural T (NT) cells and predominantly accumulate in the liver. However, NT cells in the human intestine have not been well analysed. The aim of this study was to assess the existence of NT cells in human intestinal epithelium and determine their phenotypical characterization. Intra-epithelial lymphocytes (IEL) were isolated from surgical specimens (jejunum, ileum and colon). The surface phenotype of IEL was analysed using a FACScan and compared with that of mononuclear cells (MNC) from other organs. CD161+ T cells were abundant in human intestinal epithelium as well as the liver. The majority of CD161+ T cells in IEL were CD8+ cells. About 50% of CD161+ T cells in hepatic lymphocytes (HL) expressed CD56, whereas only 14% of CD161+ T cells in IEL expressed CD56. The jejunum showed the greatest abundance of CD161+ T cells among the intestinal regions investigated. These results suggest that CD161+ T (NT) cells predominantly exist in human intestinal epithelium and may play an important role in local immunity.

The mature form of adrenomedullin correlates with brain natriuretic peptide in plasma of chronic hemodialysis patients

AIM

Adrenomedullin (AM), a hypotensive and natriuretic peptide, consists of an amidated mature form (mAM) and an intermediate form in human plasma, of which only mAM exerts biological activity. Like atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), plasma levels of mAM are reported to be significantly elevated in hemodialysis (HD) patients, suggesting that mAM may be stimulated partly by increased body fluid volume in a manner similar to the natriuretic peptides. Here, we examined the relationship between mAM levels and ANP or BNP levels and the effect of HD on plasma mAM in HD patients.

PATIENTS AND METHODS

We measured plasma levels of mAM, total AM (tAM), ANP and BNP before and after HD in patients on long-term HD (n = 22, mean age 56.3 +/- 3.2 years) using radioimmunoassay.

RESULTS

Baseline mAM (2.7 +/- 0.3 fmol/ml) and tAM (23.6 +/- 2.0 fmol/ml) were significantly higher in HD patients than in healthy subjects (1.1 +/- 0.2 fmol/ml, 9.0 +/- 2.1 fmol/ml, respectively). HD significantly reduced the levels to 1.2 +/- 0.2 fmol/ml and 13.8 +/- 1.4 fmol/ml, respectively, although tAM levels were still elevated compared to healthy subjects. Similar plasma ANP and BNP levels were obtained in HD patients. There were significant correlations between mAM and tAM levels before and after HD and between HD-induced changes in mAM and tAM levels. In the pre-HD state, levels of both mAM and tAM correlated significantly with BNP levels, but the correlation of BNP with mAM was closer than that with tAM. In contrast, no correlations were observed between the 2 forms of AM and ANP. Changes in mAM levels during HD also correlated significantly with BNP but not ANP levels, although the changes in tAM did not correlate with those of the 2 natriuretic peptides.

CONCLUSION

Our results suggest that the secretion/metabolism of mAM may be regulated in a manner similar to that of BNP in HD patients.

[Castleman lymphoma originated from the posterior mediastinum resected thoracoscopically: report of a case]

We report thoracoscopic resection of Castleman lymphoma originated from the posterior mediastinum. The patient was a 19-year-old woman, who was pointed out to show an abnormal shadow in the left upper lung in the chest X-ray photograph. It was diagnosed as a blood-rich posterior mediastinal tumor by dynamic MRI, and thoracoscopic surgery was performed. The tumor was adjacent to the vertebral body of the fourth thoracic vertebra. Although operation involved 2 hours and 40 minutes and 670 ml of bleeding due to a strong adhesion between the tumor and the intercostal muscle and considerable bleeding from the tumor itself, it was successfully removed under thoracoscopy. The tumor was elastic and hard, and 50 x 45 x 25 mm in size. The histopathological diagnosis was a Castleman lymphoma, hyaline vascular type. The postoperative course was satisfactory, and the patient was discharged from the hospital on the 7th postoperative day. Castleman lymphoma originated from the posterior mediastinum tends to bleed considerably during its resection. If a blood-rich posterior mediastinal tumor was found preoperatively, thoracoscopic operation must be advanced carefully keeping this disease in mind.

Plasma levels of soluble vascular adhesion molecule-1 and cholesterol oxidation product in type 2 diabetic patients with nephropathy

Functional impairment of the vascular endothelium is an early event in the development of atherosclerosis, and soluble adhesion molecules in plasma are regarded as an indicator of the endothelial damage in diabetes mellitus. We compared the soluble vascular adhesion molecule levels in the patients with diabetic nephropathy in concerning with plasma 7-ketocholesterol levels, which is major cholesterol auto-oxidation products. Average value of plasma VCAM-1 in 31 patients with type 2 diabetes mellitus was 297.6+/-10.2 ng/ml (mean+/-SE), and the value was significantly higher than that in 8 age-matched healthy controls (231.9+/-15.0 ng/ml). Among the 31 diabetic patients, the group with macroalbuminuria (n = 8) had the higher levels of plasma VCAM-1 (349.5+/-26.0 ng/ml) than the levels in the group with normoalbuminuria (n=15; 280.6+/-12.3 ng/ml). The levels of plasma 7-ketocholesterol in diabetes (26.9+/-1.5 ng/ml) or the patients with macroalbuminuria (31.4+/-3.3 ng/ml) were significantly higher than the control (22.5+/-1.8 ng/ml). The level of soluble VCAM-1 showed significant correlation between the values of 7-ketocholesterol (r=0.42, p=0.024), TC (r=0.42, p=0.014) and LDL-C (r=0.38, p=0.044). However no correlation was demonstrated with HbA1c nor creatinine level. We conclude that soluble VCAM-1 in plasma may be an indicator of oxidative stress and vascular injury in diabetic nephropathy.

A role for neuromedin U in stress response

Neuromedin U (NMU) is a hypothalamic peptide that has been recently found to reduce food intake, but few is known about its other functions in the central nervous system. We here studied behavioral activities induced by an intracerebroventricular (ICV) administration of NMU in rats and mice. NMU increased gross locomotor activity, face washing behavior, and grooming. NMU-induced stress response was significantly abolished by pretreatment with an antagonist of corticotropin-releasing hormone (CRH), alpha-helical CRH (9-41) (alpha-hCRH), or anti-CRH IgG. NMU did not induce locomotor activity in CRH knockout mice. NMU that interacts anatomically and/or functionally with the CRH system is a novel physiological regulator of stress response.

Possible role of organ-specific autoantigen for Fas ligand-mediated activation-induced cell death in murine Sjögren's syndrome

Activation-induced cell death (AICD) is a well-known mechanism of peripheral T cell tolerance that depends upon an interaction between Fas and Fas ligand (FasL). In this study, we demonstrate that the administration of a soluble form of anti-FasL Ab, FLIM58, results in severe destructive autoimmune exocrinopathy in the murine model of human Sjögren's syndrome (SS), and we found that an organ-specific autoantigen may play an important role on down-modulation of AICD. A high titer of serum autoantibodies against 120-kDa alpha-fodrin autoantigen was detected in the FLIM58-treated mice, and splenic T cell culture supernatants contained high levels of IFN-gamma. In vitro T cell apoptosis assay indicated that FasL-mediated AICD is down-regulated by autoantigen stimulation in spleen cells from the murine SS model, but not from Fas-deficient MRL/lpr mice and FasL-deficient MRL/gld mice. FasL undergo metalloproteinase-mediated proteolytic processing in their extracellular domains, resulting in the release of soluble trimeric ligands (soluble FasL). We showed that the processing of soluble FasL occurs in autoantigen-specific CD4(+) T cells, and that a significant increase in expressions of metalloproteinase-9 mRNA was observed in spleen cells from SS model mice. These findings indicate that the increased generation of soluble FasL inhibits the normal AICD process, leading to the proliferation of effector CD4(+) T cells in the murine SS model.

1α,25-Dihydroxyvitamin D3 directly induces fusion of alveolar macrophages by a mechanism involving RNA and protein synthesis, but not DNA synthesis

The results of our present study indicate that 1 alpha, 25-dihydroxyvitamin D3[1 alpha, 25(OH)2D3] directly induces fusion of mouse alveolar macrophages without any participation of T-lymphocytes by a mechanism involving RNA and protein synthesis but not DNA synthesis. We have reported that 1 alpha, 25(OH)2D3 induces fusion of alveolar macrophages by a direct mechanism and by a spleen cell-mediated indirect mechanism [(1983) Proc. Natl. Acad. Sci. USA 80, 5583-5587]. Alveolar macrophages pretreated with or without anti-Thy 1.2 antibody and complement fused similarly when they were incubated with 1 alpha, 25(OH)2D3. The vitamin suppressed DNA synthesis, but it significantly enhanced RNA and protein synthesis. The 1 alpha, 25(OH)2D3-induced fusion was blocked by adding actinomycin D or cycloheximide, but not by hydroxyurea.

[Epidemiologic study of diabetic retinopathy in nine hospitals in the Aomori area]

PURPOSE

To examine the prevalence of diabetic retinopathy and the relationship between diabetic retinopathy and systemic risk factors.

METHODS

A cross sectional study of diabetic retinopathy was conducted on 1,826 eyes of 913 randomly selected patients with type 2 diabetes in 9 central hospitals in Aomori Prefecture and the surrounding district. Retinopathy levels and maculopathy were assessed by binocular funduscopy, fundus photography and, if necessary, by fluorescein angiography. Multiple logistic regression analysis was performed to determine independent effects of systemic risk factors on diabetic retinopathy.

RESULTS

The prevalence of background retinopathy was 31%, of preproliferative retinopathy 5%, and of proliferative retinopathy 5% in all patients. However, in 3 hospitals in which the patients were routinely examined by fluorescein angiography, background retinopathy was found to be present in 60%, preproliferative retinopathy in 5%, and prolifertive retinopathy in 7%. Maculopathy was found in 8% of diabetic patients and the prevalence was 11% in the eyes with background retinopathy, 40% with preproliferative retinopathy, and 50% with proliferative retinopathy. Multiple logistic regression analysis showed that retinopathy was significantly associated with duration of diabetes, methods of diabetic control, hypertension, nephropathy, and neuropathy.

CONCLUSION

The detection rate of background diabetic retinopathy by fluorescein angiography was twice as sensitive as that by binocular funduscopy and fundus photography. The prevalence of maculopathy increases with the progression of retinopathy. Several systemic risk factors have significant association with diabetic retinopathy and maculopathy.

Muramyl dipeptide-Lys stimulates the function of human dendritic cells

Muramyl dipeptide (MDP)-Lys (L18), a synthetic MDP analogue derived from bacterial cell walls, has been reported to be a potent immunoadjuvant that enhances protective immunity against pathogens and tumors by stimulating immune-competent cells, such as monocytes and macrophages. However, it is not known whether MDP-Lys modulates the function of dendritic cells (DCs), which are the most potent antigen-presenting cells and play a crucial role in initiating T cell-mediated immunity. Therefore, we examined the effects of MDP-Lys on the expression of surface molecules, cytokine production, and antigen-presenting function of human DCs generated from peripheral blood cells in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor. We found that MDP-Lys markedly up-regulated the expression of CD80, CD83, CD86, and CD40, but not human leukocyte antigen-DR, and stimulated the production of tumor necrosis factor-alpha, IL-6, IL-8, IL-10, and IL-12 (p40) by human DCs in a dose-dependent manner. Furthermore, MDP-Lys-treated DCs showed enhanced antigen-presenting function compared with untreated DCs, as assessed by an allogeneic mixed lymphocyte reaction. These results suggested that the immunoadjuvant activity of MDP-Lys in vivo is mediated, in part, by its stimulation of DC function.

N-Acetylglucosaminyltransferase V as a possible aid for the evaluation of tumor invasiveness in patients with hepatocellular carcinoma

BACKGROUND

A close relationship has been shown to exist between the metastatic potential and beta1-6 branched oligosaccharides in human and rodent cells. N-acetylglucosaminyltransferase V (GnT-V) catalyzes this process. Although this phenomenon has been reported, little is known about the clinical usefulness of the determination of GnT-V in the evaluations of tumor invasiveness in hepatocellular carcinoma (HCC). In this study, we measured the GnT-V activity in serum of patients with HCC, together with its activity and gene expression in HCC tissues, and elucidated the clinical usefulness of the GnT-V level in evaluating tumor invasiveness.

METHODS

Seventy-three serum samples from 38 patients with HCC, 11 with chronic hepatitis, eight with hepatic cirrhosis and 16 healthy controls were used. Twenty-one liver tissues were obtained by surgical resection from 17 patients with HCC, three with colorectal cancers and one with gallbladder cancer metastatic to the liver. The GnT-V activity was determined by using high performance liquid chromatography. The GnT-V mRNA was quantified by using competitive RT-PCR.

RESULTS

There were statistically significant correlations between GnT-V activity in sera of HCC, and GnT-V activity and GnT-V mRNA expression in tumor tissue. The mean GnT-V activity in the sera of patients with HCC increased in accordance with the degree of tumor invasion. The HCC group with intrahepatic and extrahepatic metastases showed the highest serum GnT-V-value.

CONCLUSIONS

The present study demonstrated that there was a close association between tumor invasiveness and GnT-V activity in sera, and that the measurement of GnT-V may improve prognostic estimates and therapeutic outcomes for patients with HCC.

Pressure-induced expression of monocyte chemoattractant protein-1 through activation of MAP kinase

BACKGROUND

In glomerular hypertension, mesangial cells (MC) are subjected to at least two physical forces: a high pressure and mechanical stretch. In 5/6 nephrectomized rat, a model of progressive glomerular sclerosis associated with glomerular hypertension, monocyte chemoattractant protein-1 (MCP-1) is expressed in glomeruli, suggesting the possible role of MCP-1 in the pathogenesis of glomerular sclerosis; however, whether pressure directly affects MCP-1 expression remains undetermined. Here we examined the effects of pressure on MCP-1 expression in cultured rat MC and the signal transduction pathways that lead to MCP-1 expression.

METHODS

Pressure was applied to MC by instilling compressed helium gas into sealed plates. MCP-1 mRNA and protein levels in MC were detected by reverse transcription-polymerase chain reaction (RT-PCR) or Northern blotting and ELISA or Western blotting, respectively. Mitogen-activated protein (MAP) kinase activity was measured with the catalytic activity of p42/p44 MAP kinase and anti-phospho p42/p44 MAP kinase antibody. A transient transfection assay that specifically modulates MAP kinase kinase (MEK) activity was carried out.

RESULTS

MCs subjected to external pressure expressed MCP-1 mRNA rapidly and transiently with the peak level noted at 10 minutes and 80 mm Hg pressure. MCP-1 protein levels in cell lysates and culture medium also significantly increased after pressure loading. Pressure rapidly increased the phosphorylation level and activity of p42/p44 MAP kinase. Treatment of MC with a MAP kinase kinase (MEK) inhibitor, PD98059, suppressed levels of both pressure-induced MAP kinase activities and MCP-1 mRNA expression. The constitutively activated type of MEK1 induced MCP-1 expression (13.7-fold) even in non-pressurized MC.

CONCLUSIONS

Our results indicate that pressure per se can induce MCP-1 via activation of MAP kinase pathway, suggesting that glomerular hypertension might be involved in the progression of renal diseases through the expression of MCP-1 in MC.

Relativistic effects and two-body currents in (H)((-->)e(')p)n using out-of-plane detection

Measurements of the (2)H((-->)e,e(')p)n reaction were performed with the out-of-plane magnetic spectrometers (OOPS) at the MIT-Bates Linear Accelerator. The longitudinal-transverse, f(LT) and f(')(LT), and the transverse-transverse, f(TT), interference responses at a missing momentum of 210 MeV/c were simultaneously extracted in the dip region at Q2 = 0.15 (GeV/c)(2). In comparison to models of deuteron electrodisintegration, the data clearly reveal strong effects of relativity and final-state interactions and the importance of two-body meson-exchange currents and isobar configurations. We demonstrate that such effects can be disentangled by extracting these responses using the novel out-of-plane technique.

Bifurcation of osteoclasts and dendritic cells from common progenitors

Osteoclasts and dendritic cells are derived from monocyte/macrophage precursor cells; however, how their lineage commitment is regulated is unknown. This study investigated the differentiation pathways of osteoclasts and dendritic cells from common precursor cells at the single-cell level. Osteoclastogenesis induced by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kappaB ligand (RANKL) or tumor necrosis factor-alpha (TNF-alpha) is completely inhibited by addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 at early stages of differentiation. GM-CSF-treated cells express both c-Fms and RANK and also low levels of CD11c and DEC205, which are detected on dendritic cells. Addition of GM-CSF also reduces expression of both c-Fos and Fra-1, which is an important event for inhibition of osteoclastogenesis. Overexpression of c-Fos by retroviral infection or induction in transgenic mice can rescue a failure in osteoclast differentiation even in the presence of GM-CSF. By contrast, differentiation into dendritic cells is inhibited by M-CSF, indicating that M-CSF and GM-CSF reciprocally regulate the differentiation of both lineages. Dendritic cell maturation is also inhibited when c-Fos is expressed at an early stage of differentiation. Taken together, these findings suggest that c-Fos is a key mediator of the lineage commitment between osteoclasts and dendritic cells. The lineage determination of osteoclast progenitors seen following GM-CSF treatment functions through the regulation of c-Fos expression.

Cloning of a new aquaporin (AQP10) abundantly expressed in duodenum and jejunum

A new aquaporin (AQP10) was identified in human small intestine. This gene encoded a 264-amino-acid protein with high sequence identity with AQP3 (53%), 9 (52%), and 7 (43%). These AQPs constitute one subfamily of AQP family that is differentiated from the other subfamily of AQP (AQP0, 1, 2, 4, 5, 6, and 8) by sequence homology. Ribonuclease protection assay and Northern blotting demonstrated almost exclusive expression of AQP10 mRNA in the duodenum and jejunum. In situ hybridization localized it in absorptive jejunal epithelial cells. Xenopus oocytes expressing AQP10 exhibited an increased osmotic water permeability in a mercury-sensitive manner. Although AQP10 belongs to the AQP subfamily, which has been characterized by permeability to water and neutral solutes such as urea and glycerol, it was not permeable to urea nor glycerol. The specific expression of AQP10 suggests its contribution to the water transport in the upper portion of small intestine.

ALCAM (CD166): its role in hematopoietic and endothelial development

A critical role for the endothelium of yolk sac and dorsal aorta has been shown in embryonic hematopoiesis. A stromal cell line derived from yolk sac, YSCL-72, has been chosen to search for a novel molecule associated with embryonic hematopoiesis. Analysis between YSCL-72 and an adult aorta-derived endothelial cell line, EOMA, demonstrated that activated leukocyte cell adhesion molecule (ALCAM, or CD166) was specifically expressed in YSCL-72 but not in EOMA. Immunohistochemical study showed that ALCAM was expressed in the endothelium of yolk sac and dorsal aorta but not in adult aorta. ALCAM-transfected EOMA cells supported development of hematopoietic progenitor cells compared with vector-transfected EOMA cells, suggesting that ALCAM appeared to be crucial for hematopoiesis. In addition, ALCAM was found to be involved in capillary tube formation and hemangioblast differentiation. Taken together with these findings, ALCAM is highly associated not only with embryonic hematopoiesis but also vasculoangiogenesis.

Transforming growth factor beta affects osteoclast differentiation via direct and indirect actions

Transforming growth factor beta (TGF-beta) is abundant in bone and has complex effects on osteolysis, with both positive and negative effects on osteoclast differentiation, suggesting that it acts via more than one mechanism. Osteoclastogenesis is determined primarily by osteoblast (OB) expression of the tumor necrosis factor (TNF)-related molecule receptor activator of NF-kappaB ligand (RANKL) and its decoy receptor osteoprotegerin (OPG), which are increased and decreased, respectively, by osteolytic factors. A RANKL-independent osteoclastogenic mechanism mediated by TNF-alpha has also been shown. Therefore, we investigated TGF-beta effects on osteoclast formation in culture systems in which osteoclastogenic stimulus is dependent on OBs and culture systems where it was provided by exogenously added RANKL or TNF-alpha. Both OPG and TGF-beta inhibited osteoclast formation in hemopoietic cell/OB cocultures, but the kinetics of their action differed. TGF-beta also inhibited osteoclastogenesis in cocultures of cells derived from OPG null (opg-/-) mice. TGF-beta strongly decreased RANKL messenger RNA (mRNA) expression in cultured osteoblasts, and addition of exogenous RANKL to TGFbeta-inhibited cocultures of opg-/- cells partially restored osteoclastogenesis. Combined, these data indicate that the inhibitory actions of TGF-beta were mediated mainly by decreased OB production of RANKL. In contrast, in the absence of OBs, TGF-beta greatly increased osteoclast formation in recombinant RANKL- or TNF-alpha-stimulated cultures of hemopoietic cells or RAW 264.7 macrophage-like cells to levels several-fold greater than attainable by maximal stimulation by RANKL or TNF-alpha. These data suggest that TGF-beta may increase osteoclast formation via action on osteoclast precursors. Therefore, although RANKL (or TNF-alpha) is essential for osteoclast formation, factors such as TGF-beta may powerfully modify these osteoclastogenic stimuli. Such actions may be critical to the control of physiological and pathophysiological osteolysis.

Role of hematopoietic stem cells in angiogenesis

Angiogenesis is an important event for embryonic organogenesis as well as for tissue repair in the adult. Here we show that hematopoietic stem cells (HSCs) are essential for angiogenesis during embryogenesis. To investigate the role of HSCs in endothelial cell (EC) development, we analyzed AML1-deficient embryos, which lack definitive hematopoiesis. These embryos showed defective angiogenesis in the head, pericardium, and fetal liver. Para-aortic splanchnopleural (P-Sp) explant cultures on stromal cells (P-Sp cultures) did not generate definitive hematopoietic cells and showed defective angiogenesis in the AML1-null embryo. Disrupted angiogenesis in P-Sp cultures from AML1-null embryos was rescued by addition of HSCs. HSCsspecifically produce angiopoietin-1 (Ang1). Thus HSCs,which expressAng1, directly promoted migration of ECs. These findings suggest that HSCs alone prepare the hematopoietic microenvironment.

Endomucin is expressed in embryonic dorsal aorta and is able to inhibit cell adhesion

Recent studies have suggested the existence of progenitors common to hematopoietic and endothelial cells, called hemangioblasts, in, for instance, embryonic dorsal aorta. To identify a membrane-bound or secretory molecule regulating early hematopoiesis, we screened a cDNA library from dorsal aortas of embryonic day (E) 10.5 mice by a signal sequence trap method and obtained a clone encoding a sialoprotein, endomucin-1. Immunohistochemistry revealed that the endomucin-1 transcript was specifically expressed in the endothelial cells of dorsal aorta of E10.5 mouse embryo. Overexpression of endomucin-1 strongly inhibited adhesion and aggregation of cells, including cultured endothelial cells from E10.5 dorsal aorta. These data suggest that endomucin-1 may play a role in detachment of hematopoietic cells from endothelium during early hematopoiesis.

Oral supplementation of branched-chain amino acid improves nutritional status in elderly patients on chronic haemodialysis

BACKGROUND

Anorexia may be associated with decreased plasma levels of branched-chain amino acids (BCAA). In malnourished elderly haemodialysis (HD) patients, oral BCAA supplementation may improve anorexia, resulting in improved nutritional status.

METHODS

Among 44 elderly (age >70 years) patients on chronic HD, 28 patients with low plasma albumin concentration (<3.5 g/dl) were classified as the malnourished group; they also suffered from anorexia. The other 16 patients did not complain of anorexia and were classified as the well-nourished group. We performed a 12-month, placebo-controlled, double-blind study on the malnourished group. Fourteen patients each received daily oral BCAA supplementation (12 g/day) or a placebo in random order in a crossover trial for 6 months. Body fat percentage, lean body mass, plasma albumin concentration, dietary protein and caloric intakes, and plasma amino acid profiles were monitored.

RESULTS

Lower plasma levels of BCAA and lower protein and caloric intakes were found in the malnourished group as compared to the well-nourished group. In BCAA-treated malnourished patients, anorexia and poor oral protein and caloric intakes improved within a month concomitant with the improvement in plasma BCAA levels over the values in well-nourished patients. After 6 months of BCAA supplementation, anthropometric indices showed a statistically significant increase and mean plasma albumin concentration increased from 3.31 g/dl to 3.93 g/dl. After exchanging BCAA for a placebo, spontaneous oral food intake decreased, but the favourable nutritional status persisted for the next 6 months. In 14 patients initially treated with a placebo, no significant changes in nutritional parameters were observed during the first 6 months. However, positive results were obtained by BCAA supplementation during the subsequent 6 months, and mean plasma albumin concentration increased from 3.27 g/dl to 3.81 g/dl.

CONCLUSIONS

Normalization of low plasma levels of BCAA by oral supplementation can reduce anorexia and significantly improve overall nutritional status in elderly malnourished HD patients.