Differential hormonal profiles of adrenomedullin and proadrenomedullin N-terminal 20 peptide in patients with heart failure and effect of treatment on their plasma levels

BACKGROUND

Adrenomedullin (AM) is a potent vasodilatory peptide discovered in human pheochromocytoma tissue. Proadrenomedullin N-terminal 20 peptide (PAMP) processed from an AM precursor is also a novel hypotensive peptide which inhibits catecholamine secretion from sympathetic nerve endings.

HYPOTHESIS

The present study sought to examine the relationships between the two peptides and other clinical parameters by measuring the plasma AM and PAMP concentrations in 98 patients with heart failure.

METHODS

In all, 98 patients [65 men and 33 women, aged 58.2 +/- 11.0 years, mean +/- standard deviation (SD)] with heart failure and 26 healthy volunteers (12 men and 14 women, aged 54.1 +/- 8.6 years) were examined in this study. Heart failure was secondary to previous myocardial infarction in 58 patients, valvular disease in 28, cardiomyopathy in 9, and congenital heart disease in 3. All patients were classified into two groups of class I or II (Group 1) and class III or IV (Group 2) according to the New York Heart Association (NYHA) functional classification.

RESULTS

Both plasma AM and PAMP concentrations in the patients were significantly higher than those in healthy volunteers. In addition, plasma AM and PAMP concentrations in patients in class III or IV of New York Heart Association (NYHA) classification were significantly higher than those in NYHA class I or II. The elevated plasma concentrations of these peptides in patients in NYHA class III or IV significantly decreased in response to the treatment for 7 days. There was a significant correlation between plasma AM and PAMP, though the plasma concentration of PAMP was one-fifth to one-seventh of that of AM in patients and controls. The plasma AM concentration correlated significantly with the plasma concentrations of atrial and brain natriuretic peptides, epinephrine, and right atrial pressure, whereas such a relationship was not noted for the plasma PAMP concentration.

CONCLUSIONS

Judging from the difference in not only the biological actions but also the hormonal profiles between AM and PAMP, they may differentially modulate the cardiovascular system in patients with heart failure, although they are processed from the same precursor.

Bone morphogenetic protein signaling enhances invasion and bone metastasis of breast cancer cells through Smad pathway

Transforming growth factor (TGF)-beta is known to promote tumor invasion and metastasis. Although bone morphogenetic proteins (BMPs), members of the TGF-beta family, are expressed in a variety of human carcinoma cell lines, their roles in tumor progression have not been fully clarified. In this study, we sought to determine the roles of BMPs in the progression of breast cancer bone metastasis using human breast cancer samples and a mouse xenograft model. Immunohistochemical analysis of samples from breast cancer patients as well as a mouse xenograft model of MDA-231-D, highly metastatic human breast cancer cells, revealed phospho-Smad2 and phospho-Smad1/5/8 staining in the nuclei of cancer cells in primary tumor and/or bone metastasis. Using a functional in vivo bioluminescence imaging system, we showed that TGF-beta- and BMP-induced transcriptional pathways are active in bone metastatic lesions in vivo. In addition, both TGF-beta3 and BMP-2 promoted the motility and invasiveness of the MDA-231-D cells in vitro. Moreover, expression of dominant-negative receptors for TGF-beta and/or BMPs in the MDA-231-D cells inhibited invasiveness in vitro and bone metastasis in the xenograft model. These results suggest that BMPs as well as TGF-beta promote invasion and bone metastasis of breast cancer.

Frequent nocturnal vocalization in pure autonomic failure

Nocturnal vocalization is frequent in Parkinson's disease patients with rapid eye movement (REM) sleep behaviour disorder (RBD). We investigated the frequency of nocturnal vocalization and other sleep problems in patients with pure autonomic failure (PAF) and compared the results with idiopathic Parkinson's disease (IPD) and dementia with Lewy bodies (DLB). We interviewed consecutive patient-caregiver pairs with PAF (n = 13), IPD (n = 200) and DLB (n = 19), and ischaemic stroke patients (controls, n = 43). Nocturnal vocalization was similarly frequent in PAF, IPD and DLB. Other dream enactments and vivid dreams also were more frequent in PAF, IPD and DLB compared with controls. Excessive night-time awakenings and daytime sleepiness were frequent in IPD but rare in PAF and controls. Clinical manifestation of sleep disturbances, at least of RBD-like symptoms including nocturnal vocalization and other dream enactments, may occur in PAF, as in IPD and DLB.

Serotonin induces vasoconstriction of smooth muscle cell-rich neointima through 5-hydroxytryptamine2A receptor in rabbit femoral arteries

BACKGROUND

Smooth muscle cell (SMC)-rich intima is a morphological feature of atherosclerotic lesions that is observed in eroded plaque and spastic arteries. Arteries with SMC-rich intima are susceptible to vasoconstriction or vasospasm against some vasoactive agents.

OBJECTIVE

The present study evaluates the contribution of SMC-rich intima to thrombogenic vasoconstriction.

METHODS

We established SMC-rich neointima by damaging rabbit femoral arteries using balloons and then measured the isometric tension of the femoral strips against 5-hydroxytryptamine (5-HT), adenosine diphosphate, adenosine triphosphate and thrombin.

RESULTS

Among these agents, only 5-HT induced a hypercontractile response of the injured arteries with SMC-rich neointima, compared with non-injured arteries. Smooth muscle cells of both the neointima and media expressed 5-HT(2A) receptor, and sarpogrelate, a selective 5-HT(2A) receptor antagonist significantly inhibited the hypercontraction. Furthermore, 5-HT induced contraction of separated neointima and hypercontraction of separated media compared with non-injured media. Sarpogrelate and fasudil, a specific Rho-kinase inhibitor, significantly suppressed such contraction of both the neointima and media of injured arteries.

CONCLUSIONS

These results suggest that 5-HT plays a crucial role in thrombogenic vasoconstriction, and that SMC-rich intima as well as media directly contributes to the hypercontractile response of atherosclerotic vessels through the 5-HT(2A) receptor and the Rho-kinase pathway.

A survey of patients with self-reported severe food allergies in Japan

Food allergies have increased in recent years in Japan. Details of causative foods, places where anaphylaxis developed, and other allergic factors remain unknown, and we investigated them. A'questionnaire survey for the prevention of food allergies' was conducted using a nationwide group of patients with food allergies. A total of 1383 patients from 878 families (including 319 patients who experienced anaphylaxis) provided valid answers to the questionnaire. The average age of the first anaphylactic attack was 3.20 +/- 6.327 yr. The most common allergens causing anaphylaxis were in order milk, eggs, wheat, peanuts, and soybeans, followed by sesame and buckwheat. The most common place where anaphylaxis developed was the patient's own home, followed by fast food restaurants, places visited, restaurants, and schools. In patients' own homes, fast food restaurants (buffet), places visited and schools, the most common allergens were milk, eggs, and wheat. In restaurants and accommodation facilities, eggs were the most common allergen followed by milk. As possible food allergies can cause anaphylaxis, it is necessary to provide precise information for consumers regarding packaged and processed foods.

Gingipains from Porphyromonas gingivalis synergistically induce the production of proinflammatory cytokines through protease-activated receptors with Toll-like receptor and NOD1/2 ligands in human monocytic cells

Gingipains (HRgpA, RgpB and Kgp) are cysteine proteinases and virulence factors of Porphyromonas gingivalis, the major causative bacterium of periodontal disease. To study synergistic effects of gingipains and signalling via Toll-like receptors (TLRs) and NOD1/2, we investigated effects of a gingipain on the secretion of proinflammatory cytokines from monocytic THP-1 cells in the presence of pathogen-associated molecular patterns (PAMPs). Gingipains stimulated interleukin (IL)-8's secretion from THP-1 cells, which was completely inhibited by proteinase inhibitors of gingipain and increased in the presence of PAMPs. Synergistic effects of gingipains and PAMPs were also seen in the secretion of IL-6 and MCP-1 and reduced to about 50% the secretion of IL-8 from THP-1 cells treated with siRNA targeting either protease-activated receptor (PAR)-1, -2 or -3. PAR agonist peptides mimicked the synergistic effects of gingipains with PAMPs. These results indicate that gingipains stimulate the secretion of cytokines from monocytic cells through the activation of PARs with synergistic effects by PAMPs. This is the first report of synergism of signalling via PARs, and TLRs or NOD1/2. The host defence system against P. gingivalis may be triggered through the activation of PARs by gingipains and augmented by PAMPs from this pathogen via TLRs or NOD1/2.

Low expression of FGF1 (fibroblast growth factor-1) in rat parasympathetic preganglionic neurons

Fibroblast growth factor-1 (FGF1), a member of the FGF family of growth factors, is localized in cholinergic neurons where it has trophic activity. We recently reported that cholinergic neurons in the dorsal motor nucleus of the vagus (DMNV) contain little FGF1, raising the possibility that FGF1 is not localized to parasympathetic preganglionic cholinergic neurons. To clarify this issue, we investigated the co-localization of FGF1 with cholinergic neuron markers in the Edinger-Westphal nucleus (EWN), salivatory nucleus, DMNV, and sacral parasympathetic nucleus by double immunofluorescence using antibodies to FGF1 and choline acetyltransferase (ChAT). The neurons in the EWN were devoid of FGF1. In the salivatory nucleus, 13% of ChAT-positive neurons were also positive for FGF1. In the DMNV, only 8% of ChAT-positive neurons contained FGF1, and in the sacral parasympathetic nucleus, 18% of ChAT-positive neurons were FGF1-positive. We also confirmed that a large number of ChAT-positive motor neurons in the oculomotor nucleus, facial nucleus, hypoglossal nucleus, and spinal motor neurons contained FGF1. The results confirmed that parasympathetic preganglionic neurons are largely devoid of FGF1, which is a unique feature among cholinergic neurons.

Modulation of the functional binding sites for TGF-β on the type II receptor leads to suppression of TGF-β signaling

Transforming growth factor-beta (TGF-beta) binds to two different types of serine/threonine kinase receptors termed type II (TbetaR-II) and type I (TbetaR-I). TGF-beta is unable to bind to TbetaR-I in the absence of TbetaR-II, and initiates receptor assembly by binding with high affinity to TbetaR-II. Previous structural analysis of the TGF-beta3-TbetaR-II complex has suggested that two charged amino acid residues, D55 and E142 of TbetaR-II, are binding sites of TGF-beta. In the present study, we have shown that mutations of the amino-acid residues, D55 and E142 of TbetaR-II, resulted in loss of TGF-beta binding and downstream signaling activity. Moreover, we found that 3,5,7,2',4'-pentahydroxyflavone (Morin) inhibits TGF-beta binding to TbetaR-II, and suppresses phosphorylation of Smad2 and expression of a TGF-beta target gene Smad7 induced by TGF-beta. Our findings may thus provide useful information for designing therapeutic agents for various diseases induced by TGF-beta, including advanced cancers.

Arginine-specific gingipains from Porphyromonas gingivalis deprive protective functions of secretory leucocyte protease inhibitor in periodontal tissue

Chronic periodontitis is correlated with Porphyromonas gingivalis infection. In this study, we found that the expression of secretory leucocyte protease inhibitor (SLPI), an endogenous inhibitor for neutrophil-derived proteases, was reduced in gingival tissues with chronic periodontitis associated with P. gingivalis infection. The addition of vesicles of P. gingivalis decreased the amount of SLPI in the media of primary human gingival keratinocytes compared to untreated cultures. We therefore investigated how arginine-specific gingipains (Rgps) affect the functions of SLPI, because Rgps are the major virulence factors in the vesicles and cleave a wide range of in-host proteins. We found that Rgps digest SLPI in vitro, suppressing the release of SLPI. Rgps proteolysis of SLPI disrupted SLPI functions, which normally suppresses neutrophil elastase and neutralizes pro-inflammatory effects of bacterial cell wall compounds in cultured human gingival fibroblasts. The protease inhibitory action of SLPI was not exerted towards Rgps. These results suggest that Rgps reduce the protective effects of SLPI on neutrophil proteases and bacterial proinflammatory compounds, by which disease in gingival tissue may be accelerated at the sites with P. gingivalis infection.

Accuracy of economic studies on surgical site infection

Estimating the cost of hospital infection has become a matter of increasing interest in terms of health economics. This study aimed to assess the accuracy of economic studies on hospital infections, using surgical site infection (SSI) as an example. A search was performed for original articles reporting the cost of SSI, published in the English language between 1996 and 2005. For the critical review, the period of cost tracking, classification of costs and cost counting methods were noted. Fifteen articles met the inclusion criteria. The costs of SSI vary according to surgical procedures, country, publication year, study design and accounting method. Only two studies estimated the additional cost of SSI after discharge. All 15 studies included healthcare costs and none measured patient/family resources. In 10 studies, the costs were calculated based on accounting. Three studies used estimated costs from the ratio of costs to charges and two studies used charge data in place of cost data. It will become increasingly important for future studies to perform multi-centre prospective surveys, establish a standard method for cost accounting, include the cost of healthcare services following hospitalization and consider the morbidity cost to patients themselves from a societal perspective.

Factor XI contributes to thrombus propagation on injured neointima of the rabbit iliac artery

BACKGROUND

Thrombus formation through the activation of tissue factor (TF) and factor (F) XI is a critical event in the onset of cardiovascular disease. TF expressed in atherosclerotic plaques and circulating blood is an important determinant of thrombogenicity that contributes to fibrin-rich thrombus formation after plaque disruption. However, the contribution of FXI to thrombus formation on disrupted plaques remains unclear.

METHODS

A mouse monoclonal antibody against FXI and activated FXI (FXIa) (XI-5108) was generated by immunization with activated human FXI. Prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time, and ex vivo platelet aggregation in rabbits were measured before and after an intravenous bolus injection of XI-5108. We investigated the role of FXI upon arterial thrombus growth in the rabbit iliac artery in the presence of repeated balloon injury.

RESULTS

The XI-5108 antibody reacted to the light chain of human and rabbit FXI/FXIa, and inhibited FXIa-initiated FXa and FXIa generation. Fibrin-rich thrombi developed on the injured neointima that was obviously immunopositive for glycoprotein IIb-IIIa, fibrin, TF, and FXI. Intravenous administration of XI-5108 (3.0 mg kg(-1)) remarkably reduced thrombus growth, and the APTT was significantly prolonged. However, PT, bleeding time and platelet aggregation were not affected.

CONCLUSIONS

These results indicate that plasma FXI plays a potent role in thrombus growth on the injured neointima. Inhibition of plasma FXI activity might help to reduce thrombus growth on ruptured plaques without prolonging bleeding time.

Allogeneic stem cell transplantation in children with acute lymphoblastic leukemia after isolated central nervous system relapse: our experiences and review of the literature

The prognosis of patients with acute lymphoblastic leukemia (ALL) and central nervous system (CNS) relapse has historically been very poor. Although chemo-radiotherapy has improved outcomes, some patients still have a poor prognosis after CNS relapse. Therefore, allogeneic hematopoietic stem cell transplantation (allo-SCT) has recently become an option for treatment of CNS leukemia; however, information, particularly on the long-term outcome of transplant recipients, is limited. We performed allo-SCT in eight pediatric patients with ALL (n=7) or T-cell type non-Hodgkin's lymphoma (n=1), who had isolated CNS relapse. All patients survived for a median of 70.5 (range, 13-153) months after SCT. Sequelae developed late in some patients: mental retardation (IQ=47) in one patient, severe alopecia in two patients, limited chronic graft-versus-host-disease in three patients, and amenorrhea and/or hypothyroidism in three patients. Except for a pre-school child with post transplant CNS relapse, six out of seven patients show normal school/social performance. Our results clearly indicate a high cure rate of isolated CNS relapse by allo-SCT in pediatric lymphoid malignancies; however, there needs to be further studies to determine which are the appropriate candidates for transplantation and what is the best transplant regimen to achieve high cure rate and maintain good quality of life.

Inhibition of 5-hydroxytryptamine receptor prevents occlusive thrombus formation on neointima of the rabbit femoral artery

BACKGROUND

Thrombus propagation on disrupted plaque is a major cause of acute coronary events and serious complication after coronary intervention. 5-Hydroxytryptamine (5-HT) is a potent vasoactive and platelet-aggregating substance that is predominantly mediated by 5-HT2A receptor. However, the roles of 5-HT2A receptor in occlusive thrombus formation on disrupted plaque remain obscure.

OBJECTIVE

We investigated the role of 5-HT2A receptor in thrombus formation using a rabbit model of repeated balloon-injury.

METHODS

Three weeks after a first balloon-injury of the femoral arteries, luminal diameter, neointimal growth, and vasoconstriction by 5-HT in vitro were examined. Thrombus propagation and the role of 5-HT2A receptor after a second balloon-injury were evaluated using sarpogrelate, a selective 5-HT2A receptor antagonist.

RESULTS

Three weeks after the first balloon-injury, luminal stenosis was evident in the femoral arteries, where the neointima expressed tissue factor and 5-HT2A receptor. The hypercontractile response of the stenotic arteries to 5-HT was significantly reduced by sarpogrelate. Balloon-injury of the neointima with substantially reduced blood flow promoted the formation of occlusive thrombus that was immunoreactive against glycoprotein IIb-IIIa, 5-HT2A receptor and fibrin. Intravenous injection of sarpogrelate significantly inhibited ex vivo platelet aggregation induced by adenosine 5'-diphosphate, thrombin and collagen alone as well as with 5-HT, and significantly prevented occlusive thrombus formation in vivo.

CONCLUSIONS

The 5-HT2A receptor appears to play a crucial role in occlusive thrombus formation in diseased arteries via platelet aggregation and vasoconstriction. Inhibition of 5-HT2A receptor might help reduce the onset of acute coronary events and of acute coronary occlusion after the intervention.

Population pharmacokinetics of theophylline in very premature Japanese infants with apnoea

OBJECTIVE

To estimate the population pharmacokinetics of theophylline in very premature infants using the non-linear mixed effects modelling.

METHOD

A total of 167 serum concentration measurements obtained from routine theophylline monitoring of 107 very premature Japanese infants were collected.

RESULTS

The final pharmacokinetic parameters were CL (mL/h) = [6.98 . body weight (BW) (kg)(2.17) + 0.244 . post-conceptional age (weeks)] . 1.24(oxygen support), Vd (L) = 0.492 . BW (kg) and F = 0.660, respectively. Clearance was increased by 24% for patients receiving oxygen support. The inter-individual variabilities in clearance and apparent volume of distribution were 15.6% and 80.4%, respectively, and the residual variability was 34.2% as a coefficient of variation.

CONCLUSION

Application of the findings in this study to patient care may permit selection of an appropriate initial maintenance dosage to achieve target theophylline concentrations, thus enabling the clinician to achieve the desired therapeutic effect in very premature Japanese infants.

Tolerance mechanism of the ethanol-tolerant mutant of sake yeast

Several ethanol-tolerant mutants have been bred from industrial sake yeasts, but the mechanism of ethanol tolerance in these mutants has not been elucidated. After the determination of the entire genome sequence of Saccharomyces cerevisiae, various methods to monitor the whole-gene expression of the yeast have been developed. In this study, we used a commercially available nylon membrane on which virtually every gene of S. cerevisiae was spotted to compare expression profiles between the ethanol-tolerant mutant and its parent sake yeast to investigate the mechanism of ethanol tolerance in this mutant. As a result, we found that several genes were highly expressed only in the ethanol-tolerant mutant but not in the parent strain. These genes were known to be induced in cells that were exposed to various stresses, such as ethanol, heat, and high osmolarity, or at the stationary-phase but not at the log-phase. In the ethanol-tolerant mutant, the expression level of these stress-responsive genes was further increased after exposure to ethanol. We also found that substances such as catalase, glycerol and trehalose that may have protective roles under stressful conditions were accumulated in high amounts in the ethanol-tolerant mutant. The ethanol-tolerant mutant also exhibited resistance to other stresses including heat, high osmolarity and oxidative stress in addition to ethanol tolerance. These results indicate that the mutant exhibits multiple stress tolerance because of elevated expression of stress-responsive genes, resulting in accumulation of stress protective substances.

Angiotensin II stimulates cardiac adrenomedullin production and causes accumulation of mature adrenomedullin independently of hemodynamic stress in vivo

Adrenomedullin is a potent hypotensive peptide that may act on myocytes to inhibit hypertrophy and on fibroblasts to inhibit growth in vitro induced by mechanical stretching and angiotensin II. Adrenomedullin is processed from the inactive intermediate adrenomedullin precursor with a glycine extension, which is subsequently converted to biologically active mature adrenomedullin by enzymatic amidation. Total adrenomedullin is the sum of intermediate and mature adrenomedullin. We examined the effect of a subpressor dose of angiotensin II on the production of left ventricular adrenomedullin and on protein levels of mature adrenomedullin in the left ventricle in vivo. We also investigated whether the effect is mediated by the angiotensin II type 1 receptor. Concentrations of total and mature adrenomedullin in the left ventricle and mature adrenomedullin-to-intermediate adrenomedullin ratio were significantly increased by angiotensin II infusion, regardless of pressure overload. Total and mature adrenomedullin concentrations significantly correlated with the weight of the left ventricle. Furthermore, increased adrenomedullin gene expression and protein levels were completely suppressed by a subdepressor dose of angiotensin II type 1 receptor blocker. In conclusion, angiotensin II stimulates the production of cardiac adrenomedullin and accumulates mature adrenomedullin in the left ventricle independently of hemodynamic stress. These processes are partially regulated through the angiotensin II type 1 receptor in vivo.

Polynuclear growth model with external source and random matrix model with deterministic source

We present a random matrix interpretation of the distribution functions which have appeared in the study of the one-dimensional polynuclear growth (PNG) model with external sources. It is shown that the distribution, GOE2 , which is defined as the square of the Gaussian orthogonal ensemble (GOE) Tracy-Widom distribution, can be obtained as the scaled largest eigenvalue distribution of a special case of a random matrix model with a deterministic source, which have been studied in a different context previously. Compared to the original interpretation of the GOE2 as "the square of GOE," ours has an advantage in that it can also describe the transition from the Gaussian unitary ensemble (GUE) Tracy-Widom distribution to the GOE2 . We further demonstrate that our random matrix interpretation can be obtained naturally by noting the similarity of the topology between a certain noncolliding Brownian motion model and the multilayer PNG model with an external source. This provides us with a multimatrix model interpretation of the multipoint height distributions of the PNG model with an external source.

Increased adrenomedullin immunoreactivity and mRNA expression in coronary plaques obtained from patients with unstable angina

OBJECTIVE

To examine the expression and localisation of adrenomedullin in human coronary atherosclerotic lesions from patients with unstable angina (UAP) and stable angina (SAP), and to study the relation between adrenomedullin expression and plaque instability.

DESIGN

A retrospective observational study.

PATIENTS

Directional coronary atherectomy samples were obtained from 15 patients with UAP and 12 with SAP.

METHODS

The localisation of adrenomedullin was examined by immunohistochemistry, and adreno-medullin mRNA expression was measured by quantitative polymerase chain reaction.

RESULTS

Adrenomedullin immunoreactivity was preferentially localised in macrophages, intimal smooth muscle cells, and proliferated microvessels. The mean number of adrenomedullin positive cells in five high power fields (x 400) per specimen was higher in patients with UAP than in those with SAP (mean (SEM), 110 (13) v 76 (7); p < 0.05); and the ratio of adrenomedullin positive to total cells was higher in patients with UAP (43.0 (2.2)% v 34.2 (2.0)%; p < 0.01). More adrenomedullin mRNA was expressed in the plaque of patients with UAP than in those with SAP (60.4 (16.9)% v 9.7 (3.3)%; p < 0.01).

CONCLUSIONS

The findings suggest that adrenomedullin is involved in the development of atherosclerosis and plaque instability in human coronary arteries, in an autocrine or paracrine manner.

Hepatitis B virus X protein (HBx)-induced apoptosis in HuH-7 cells: influence of HBV genotype and basal core promoter mutations

BACKGROUND

Hepatitis B virus (HBV) infection is a serious, world-wide problem. HBV genotype and basal core promoter (BCP) mutations affect the clinical course of HBV-infected patients. BCP mutations also lead to mutations at HBV X protein (HBx) codons 130/131. The functional significance of naturally occurring variants of human HBx remains largely unknown. The purpose of the study was to investigate whether HBV genotypes or double mutations affect HBx-induced apoptosis.

METHODS

We constructed genotype A, B, C, and D HBx expression vectors and HBx expression vectors with double mutations at HBx codons 130K and 131V or positions 130M and 131I using site-directed mutagenesis. A transient expression system in HuH-7 cells was established and this model was utilized to address the effect of HBx on cell viability.

RESULTS

HBx-transfected cells showed a dose-dependent decrease in cell viability by MTS assay. A subset of cells expressing HBx underwent apoptosis according to terminal transferase enzyme-mediated end labeling of DNA and caspase-3 activity. This study demonstrated that HBx can induce cell death by apoptosis in a dose-dependent manner and that HBV genotypes and double mutations did not affect HBx-induced apoptosis.

CONCLUSIONS

HBV genotypes and mutation of two amino acids directly adjacent to the conserved Kunitz domain essential for transcription activating activity of HBx did not change the pro-apoptotic activity of HBx. Further study is needed to determine whether HBV genotypes and double mutations have any effect on the function of HBx.

133SUBOPTIMAL OOCYTE ACTIVATION CAUSES METHYLATION CHANGE IN TWO IMPRINTED GENES IN THE MOUSE

In mammals, the dynamic of Ca2+ oscillations induced by fertilization causes the remodeling of the parental chromosomes and activates the developmental processes. The objective of the present study was to evaluate whether the modulation of the regime of Ca2+ oscillations during the process of egg activation is capable of inducing specific chromatin modification. The sensitivity of chromatin modification during oocyte activation was evaluated by comparison of the methylation profile of Igf2r, the maternal allele of which is methylated, and H19, the maternal allele of which is unmethylated. Freshly ovulated mouse oocytes were parthenogenetically activated by a series of repetitive Ca2+ ion influxes induced by electropermeabilization of the plasma membrane in a microfluidic processor. The first treatment (T1) consisted of 24 electrical pulses (1.45kVcm−1) given every 8min for 3h in the presence of 100μM of Ca2+. The treated oocytes were almost all activated, 98% (328/338), and formed pronuclei 3 or 4h after the first pulse. The second treatment (T2) was made up of 16 electrical pulses of lower amplitude (1.12kVcm−1), given every 8 min for 2h under the same conditions. The rate of egg activation dropped to 29%, (86/298), and the time course of pronucleus formation was completed 7h after the first pulse. The remaining oocytes, 71% (212/298), extruded the second polar body, but their chromatin did not undergo full decondensation and then did not proceed further to pronucleus formation. The methylation profiles of the two imprinted genes were analyzed by using the bisulfite sequencing method. Oocytes that formed pronuclei after being subjected to either the T1 or the T2 treatment displayed methylation profiles of the two alleles similar to those of the non-treated oocytes. The Igf2r-DMR was found fully methylated on all 13 copies examined, and the H19 DMR was found mostly unmethylated (13 out of 19 copies; 6 were partially methylated). Thus, when parthenogenetic activation results in formation of a pronucleus the methylation profile of these two genes is maintained. In contrast, those from oocytes that responded by PB extrusion showed the following: fully unmethylated Igf2r-DMR copies (9/9) and partially methylated H19-DMR copies (4/11). These results reveal that rapid de novo methylating and demethylating activity are present when cells are subjected to partial activation. Thus, when the biological response of the oocyte is incomplete, that is to say, when the chromatin remains partially decondensed after suboptimal activation, both active demethylation and de novo methylation can be remarkably dynamic. While the molecular mechanism needs to be clarified, these results reveal that modulation of the process of egg activation might give new opportunities to better understand the epigenetic chromatin changes caused by fertilization.

Proteolysis of ICAM-1 on human oral epithelial cells by gingipains

Cysteine proteinases (gingipains) from Porphyromonas gingivalis are considered key virulence factors of severe periodontitis and host immune evasion. Since expression of intercellular adhesion molecule-1 (ICAM-1) on gingival epithelium is indispensable in polymorphonuclear leukocyte (PMN) migration at the site of periodontitis, we examined the effects of gingipains on the expression of ICAM-1 on human oral epithelial cell lines (KB and HSC-2) by flow cytometry and Western blotting. We found that three purified forms of gingipains efficiently reduced ICAM-1 expression on the cells in a time- and dose-dependent manner. Gingipains reduced the expression on fixed cells and degraded the ICAM-1 in the cell membranes, indicating that the reduction resulted from direct proteolysis. They then disturbed the ICAM-1-dependent adhesion of PMNs to the cells. These results indicate that gingipains cleave ICAM-1 on oral epithelial cells, consequently disrupting PMN-oral epithelial cell interaction, and are involved in immune evasion by the bacterium in periodontal tissues.

Distribution of hepatitis B viral genotypes and mutations in the core promoter and precore regions in acute forms of liver disease in patients from Chiba, Japan

BACKGROUND

Although it has been reported that different hepatitis B virus (HBV) genotypes induce different clinical characteristics in patients with chronic liver diseases (CLD), there have been few reports that have detailed the distribution of HBV genotypes in acute forms of liver disease.

METHODS

HBV genotypes were determined in 61 patients who had acute forms of liver disease (45 had acute self limited hepatitis (AH) and 16 had fulminant hepatitis (FH)) and in 531 patients with CLD, including 19 patients with severe acute exacerbation of CLD. We also analysed the enhancer II, core promoter, and precore region sequences for the presence of mutations.

RESULTS

Expression of genotype B in patients with acute forms of liver disease was significantly greater than in those with CLD (39.3% v 11.7%, respectively; p<0.001). Furthermore, expression of genotype B was significantly greater in patients with FH than in those with AH (62.5% v 31.1%, respectively; p=0.027). The precore mutation A1896 and the core promoter mutation at nt 1753 and 1754 were found more frequently in FH than in AH, and genotype B was predominant in FH regardless of the presence of these mutations.

CONCLUSIONS

HBV genotype B was found more frequently in patients with acute forms of liver disease than in patients with CLD, and more frequently in patients with FH than in those with AH. These results suggest that this HBV genotype may induce more severe liver damage than other viral genotypes, at least in patients from Chiba, Japan.

Long-term hypoxia changes myometrial responsiveness and oxytocin receptors in the pregnant ewe: differential effects on longitudinal versus circular smooth muscle

Previous studies from our laboratory demonstrated that long-term hypoxia (LTH) altered in vitro contractile responses to oxytocin in full-thickness myometrial strips from pregnant sheep. The present study was designed to determine, first, if the reduced contractile response to oxytocin following LTH is the result of combined effects on longitudinal and circular smooth muscle or if the effect is specific to a single muscle layer and, second, if the reduced contractile response to oxytocin following LTH is caused by changes in oxytocin-receptor protein. Pregnant ewes were maintained at high altitude (3820 m) from Day 30 to Days 137-142 of gestation, when the ewes were killed for collection of myometrial tissue. Tissue was also collected from age-matched, normoxic controls. Longitudinal and circular layers were separated, length-tension curves generated to determine optimal resting tension, and all strips exposed to increasing half-log doses of oxytocin ranging from 10-12 to 10-6.5 M. The expression of oxytocin-receptor protein was measured using Western blot analysis. We found that LTH did not affect KCl-induced contraction of either smooth muscle layer, whereas the sensitivity of both myometrial layers to oxytocin was altered. A decreased maximum contractile response of the circular layer to oxytocin was also observed. Additionally, LTH decreased expression of oxytocin-receptor protein in the circular layer and increased levels in the longitudinal layer. Results from the present study indicate that LTH alters contractile responses and oxytocin-receptor protein expression in a layer-specific manner in the pregnant sheep myometrium.

Orexin-A (hypocretin-1) impairs Morris water maze performance and CA1-Schaffer collateral long-term potentiation in rats

Glucose-sensitive neurons in the lateral hypothalamic area produce orexin-A (hypocretin-1) and orexin-B (hypocretin-2) and send their axons to the hippocampus, which predominantly expresses orexin receptor 1 showing a higher sensitivity to orexin-A. The purpose of the present study was to assess the effects of orexin-A on the performance of Wistar rats during the Morris water maze test and then to determine the effects of orexin-A on both the long-term potentiation and long-term depression in Schaffer collateral/commissural-CA1 synapses in hippocampal slices. The results of the Morris water maze test show that 1.0 and 10 nmol of orexin-A, when administered intracerebroventricularly, retarded spatial learning. A probe test examined after training of water maze task also showed an impairment in spatial memory. The results of an electrophysiological study using hippocampal slices demonstrated that 1.0 to 30 nM of orexin-A applied to the perfusate produces a dose-dependent and time dependent suppression of the long-term potentiation. In addition, the long-term depression was not affected by orexin-A. The results of a paired-pulse facilitation experiment indicated that the effects of orexin-A were post-synaptic and not due to presynaptic transmitter release. These results show that orexin-A impairs spatial performance and these impairments can be attributed to a suppression of long-term potentiation in the Schaffer collateral-CA1 hippocampal synapses.

Successful bone marrow transplantation from an unrelated donor in a patient with adult T cell leukemia

We report a 51-year-old male with adult T cell leukemia (ATL) who received a BMT from an HLA-identical unrelated donor. The ATL proved refractory to chemotherapy, and he underwent BMT conditioned with CY/TBI. Complications of encephalitis of unknown origin were successfully treated with steroid therapy and the patient has been in CR for 16 months after BMT. Human T cell leukemia virus type 1 proviral DNA loads were reduced to undetectable levels in PBMC sampled 12 months after BMT. This encouraging result suggests that BMT from an unrelated donor should be considered for ATL even if the disease is refractory to chemotherapy.

A novel infant acute lymphoblastic leukemia cell line with MLL-AF5q31 fusion transcript

Infant acute lymphoblastic leukemia (ALL) is characterized by the presence of the proB phenotype (CD10(-)/CD19(+)), poor prognosis and frequent rearrangement of the mixed lineage leukemia (MLL) gene. The most frequent rearrangement is t(4;11)(q21;q23), the role of whose product, the MLL-AF4 fusion transcript, has been extensively studied in leukemogenesis. In a cell line of infant leukemia with MLL rearrangement denoted KP-L-RY, panhandle PCR amplification of cDNA revealed the presence of a fusion transcript, MLL-AF5q31, indicating that AF5q31 is also a partner gene of MLL. In this fusion transcript the MLL exon 6 is fused in frame to the 5' side of the putative transactivation domain of AF5q31. The AF5q31 protein is a member of the AF4/LAF4/FMR2-related family of proteins, which have been suggested to play a role in hematopoietic cell growth and differentiation. The MLL-AF5q31 fusion transcript, although probably rare, appears to be associated with the pathogenesis of infant ALL like MLL-AF4. Co-expression of HoxA9 and Meis1 genes in the KP-L-RY cell line indicated possible functional similarity between MLL-AF4 and MLL-AF5q31. Further understanding of the function of AF5q31 as well as the specific leukemogenic mechanism of MLL-AF5q31 awaits future studies.

Epstein-Barr virus-associated T-lymphoproliferative disease with hemophagocytic syndrome, followed by fatal intestinal B lymphoma in a young adult female with WHIM syndrome. Warts, hypogammaglobulinemia, infections, and myelokathexis

A rare association of Epstein-Barr virus-associated T- and B-lymphoproliferative disease (EBV(+) T- and EBV(+) B-LPD) in a patient with WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome is reported. A 26-year-old Japanese female, who had been treated for WHIM syndrome since early childhood, developed hemophagocytic syndrome associated with EBV(+) T-LPD at the lymph nodes and spleen. The disease rapidly resolved in response to prednisolone therapy. However, 6 weeks later, fatal EBV(+) B lymphoma unresponsive to chemotherapy occurred in the intestine and other organs. Caution must be exercised that the patient with WHIM syndrome may be at risk for EBV-LPD.

Transient global amnesia: increased signal intensity in the right hippocampus on diffusion-weighted magnetic resonance imaging

We report on a patient with pure transient global amnesia (TGA) whose magnetic resonance imaging (MRI) demonstrated a small region of increased signal intensity in the right hippocampus on diffusion-weighted imaging (DWI). DWI was sensitive and useful for evaluating the early stage of TGA and might help to explain the pathophysiology of TGA.

The N domain of Smad7 is essential for specific inhibition of transforming growth factor-beta signaling

Inhibitory Smads (I-Smads) repress signaling by cytokines of the transforming growth factor-beta (TGF-beta) superfamily. I-Smads have conserved carboxy-terminal Mad homology 2 (MH2) domains, whereas the amino acid sequences of their amino-terminal regions (N domains) are highly divergent from those of other Smads. Of the two different I-Smads in mammals, Smad7 inhibited signaling by both TGF-beta and bone morphogenetic proteins (BMPs), whereas Smad6 was less effective in inhibiting TGF-beta signaling. Analyses using deletion mutants and chimeras of Smad6 and Smad7 revealed that the MH2 domains were responsible for the inhibition of both TGF-beta and BMP signaling by I-Smads, but the isolated MH2 domains of Smad6 and Smad7 were less potent than the full-length Smad7 in inhibiting TGF-beta signaling. The N domains of I-Smads determined the subcellular localization of these molecules. Chimeras containing the N domain of Smad7 interacted with the TGF-beta type I receptor (TbetaR-I) more efficiently, and were more potent in repressing TGF-beta signaling, than those containing the N domain of Smad6. The isolated N domain of Smad7 physically interacted with the MH2 domain of Smad7, and enhanced the inhibitory activity of the latter through facilitating interaction with TGF-beta receptors. The N domain of Smad7 thus plays an important role in the specific inhibition of TGF-beta signaling.

Direct biosynthesis of poly(3-hydroxyalkanoates) bearing epoxide groups

The biosynthesis of poly(3-hydroxyalkanoates) (PHAs) by Pseudomonas cichorii YN2 cultured with C6-C12 1-alkenes was studied. PHAs containing repeating units with terminal epoxide groups were obtained when C7-C12 1-alkenes were fed separately as the only carbon source, but no epoxidized unit was detected when 1-hexene was fed. The content of epoxidized units in the polymers was in the range of 4-20 mol%, which was not dependent on the C atom length of the 1-alkene used as a substrate. The polymers produced undergo a glass transition at around -40 degrees C, and number average molecular weights were in the range of 150000-200000 as determined by GPC relative to polystyrene, with M(w)/M(n) ratios of 1.9-2.5. As an intermediate, the corresponding 1,2-epoxyalkane was found in the culture medium. According to this result, the epoxidation of the 1-alkene is the initial step in the synthetic pathway of the epoxy unit in the polymer.

beta -Arrestin-mediated recruitment of the Src family kinase Yes mediates endothelin-1-stimulated glucose transport

The insulin and the endothelin type A (ETA) receptor both can couple into the heterotrimeric G protein alpha(q/11) (Galpha(q/11)), leading to Galpha(q/11) tyrosine phosphorylation, phosphatidylinositol 3-kinase activation, and subsequent stimulation of glucose transport. In this study, we assessed the potential role of Src kinase in ET-1 signaling to glucose transport in 3T3-L1 adipocytes. Src kinase inhibitor PP2 blocked ET-1-induced Src kinase activity, Galpha(q/11) tyrosine phosphorylation, and glucose transport stimulation. To determine which Src family kinase member was involved, we microinjected anti-c-Src, -c-Fyn, or -c-Yes antibody into these cells and found that only anti-c-Yes antibody blocked GLUT4 translocation (70% decreased). Overexpression or microinjection of a dominant negative mutant (K298M) of Src kinase also inhibited ET-1-induced Galpha(q/11) tyrosine phosphorylation and GLUT4 translocation. In co-immunoprecipitation experiments, we found that beta-arrestin 1 associated with the ETA receptor in an agonist-dependent manner and that beta-arrestin 1 recruited Src kinase to a molecular complex that included the ETA receptor. Microinjection of beta-arrestin 1 antibody inhibited ET-1- but not insulin-stimulated GLUT4 translocation. In conclusion, 1) the Src kinase Yes can induce tyrosine phosphorylation of Galpha(q/11) in response to ET-1 stimulation, and 2) beta-arrestin 1 and Src kinase form a molecular complex with the ETA receptor to mediate ET-1 signaling to Galpha(q/11) with subsequent glucose transport stimulation.

Insulin can regulate GLUT4 internalization by signaling to Rab5 and the motor protein dynein

Insulin stimulates glucose transport by promoting translocation of the insulin-sensitive glucose transporter isoform 4 (GLUT4) from an intracellular compartment to the cell surface. This movement is accomplished by stimulation of GLUT4 exocytosis as well as inhibition of endocytosis. However, the molecular mechanisms for these effects remain unclear. In this study, we found that the GTP-binding protein Rab5 physically associated with the motor protein dynein in immunoprecipitants from both untransfected cells and cells transfected with GFP-Rab5 constructs. Microinjection of anti-Rab5 or anti-dynein antibody into 3T3-L1 adipocytes increased the basal level of surface GLUT4, did not change the insulin-stimulated surface GLUT4 level, and inhibited GLUT4 internalization after the removal of insulin. Photoaffinity labeling of Rab5 with [gamma-(32)P]GTP-azidoanilide showed that insulin inhibited Rab5-GTP loading. By using microtubule-capture assays, we found that insulin also caused a significant decrease in the binding of dynein to microtubules. Furthermore, pretreatment of cells with the PI3-kinase inhibitor LY294002 inhibited the effects of insulin on both Rab5-GTP loading and dynein binding to microtubules. In conclusion, these data indicate that insulin signaling inhibits Rab5 activity and the interaction of dynein with microtubules in a PI3-kinase-dependent manner, and that these effects may inhibit the rate of GLUT4 internalization. As such, our results present a previously uncharacterized insulin-signaling pathway involving Rab5, the motor protein dynein, and the cytoskeleton to regulate directional GLUT4 movement, facilitating GLUT4 distribution to the cell surface.

[A case of acute disseminated encephalomyelitis after renal transplantation]

We report a patient of acute disseminated encephalomyelitis (ADEM) in a recipient of renal transplantation. A 43-year-old man suffered from generalized convulsion and consciousness disturbance followed by coma on day 53 of after the transplantation. He was receiving several immunosuppressants, and an increase of serum antigen for cytomegalovirus was observed one day before the ictus. T2 and diffusion-weighted image of MRI showed high intensity lesions in the bilateral cerebral white matter, basal ganglia, thalamus, midbrain, pons and cerebellum. Examination of cerebrospinal fluid revealed elevated myelin basic protein level. The patient was diagnosed as having ADEM and was treated with methylpredonisolone pulse therapy in combination with intravenous immune globulin. He gradually recovered and became capable to eat and sit on a wheel chair. White matter lesions on MRI were also diminished. ADEM may occur in recipients of organ transplantation even if they have immunosuppressive treatment.