Potentiation of catechin gallate-mediated sensitization of Staphylococcus aureus to oxacillin by nongalloylated catechins

(-)-Epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg) reduce oxacillin resistance in mecA-containing strains of Staphylococcus aureus. Their binding to staphylococcal cells is enhanced by the nongalloyl analogues (-)-epicatechin (EC) and (-)-epigallocatechin (EGC). EC and EGC significantly increased the capacity of ECg and EGCg to reduce levels of staphylococcal oxacillin resistance.     

Agmatine suppresses mesangial cell proliferation by modulating polyamine metabolism

Polyamines play an essential role in the growth and differentiation of mammalian cells. The depletion of intracellular polyamines results in the suppression of growth. Proliferation of glomerular mesangial cells (MC) is the most common pathologic change in many forms of glomerulonephritis. Agmatine is a metabolite of arginine via arginine decarboxylase (ADC), highly expressed in the kidney, and unique in its capacity to suppress intracellular polyamine levels required for proliferation. As agmatine enters mammalian cells via the polyamine transport system, its antiproliferative effects may preferentially target cells with increased proliferative kinetics. In the present study, we evaluated the antiproliferative effects of agmatine on human MC in vitro. MC proliferation was stimulated with 20% fetal bovine serum (FBS) or platelet-derived growth factor (PDGF-BB, 20 ng/ml). Cell proliferation was measured using the (4.3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) (MTT) proliferation assay. Intracellular polyamine levels were assayed by high performance liquid chromatography, and cell death was assessed by cellular DNA fragmentation enzyme-linked immunosorbent assay. The MTT proliferation assay showed that agmatine significantly suppressed proliferation of human MC treated with 20% FBS or 5% FBS + PDGF as compared to human MC treated with 5% FBS. Polyamine levels were markedly lower in cells treated with agmatine, and proliferation was rescued by administration of putrescine. The fragmented DNA was hardly detected in agmatine-treated human MC. In summary, human MC stimulated to increase their proliferative kinetics are significantly more sensitive to the antiproliferative effects of agmatine than normally cultured cells. Suppressed proliferation of the agmatine-treated human MC is not due to increased cell death. These results suggest that agmatine is a promising drug candidate for the treatment of human mesangial proliferative glomerulonephritis.     

Preparation and characterization of laminin-derived peptide AG73-coated liposomes as a selective gene delivery tool

Targeted gene delivery to cancer cells is considered as a promising strategy for cancer therapy. Since, several targeting ligands have been studied for cancer gene therapy, such as transferrin, folate, anisamide, RGD-peptide, and antibodies. We have focused on AG73 peptide, which is derived from the globular domain of the laminin α1 chain. AG73 peptide is known as a ligand for syndecans, one of the major heparin sulfate-containing transmembrane proteoglycans. Syndecan-2 is highly expressed in various cancer cells and plays a role in angiogenesis. In this study, we prepared AG73-labeled polyethyleneglycol-modified liposomes (AG73-PEG liposomes) for gene delivery tool to syndecan-2 overexpressing cancer cells, and assessed the characterization of AG73-PEG liposomes. We confirmed the conjugation of AG73 peptide to PEG liposomes by reverse-phase high-performance liquid chromatography analysis. Electron microscopy analysis showed that monodiseperse AG73-labeled lipsomes were prepared. We also assessed the gene transfection efficiency of AG73-PEG liposomes in syndecan-2 overexpressing cancer cells or syndecan-2 less expressing cancer cells. As a result, AG73-mediated liposomal gene transfection efficiency was increased by 100-fold in syndecan-2 overexpressing cancer cells compared to syndecan-2 less expressing cancer cells. These results suggested that AG73-PEG liposomes were successfully prepared from a point of view of the modification of AG73 peptide to PEG-liposomes and the particle size of liposomes, which presented nano size. Furthermore, our results suggest that AG73-PEG liposomes can be a useful targeted gene delivery vehicle for syndecan-2 overexpressing cancer cells.     

Estimation of cardiac left ventricular ejection fraction in transfusional cardiac iron overload by R2* magnetic resonance

Cardiac dysfunction due to transfusional iron overload is one of the most critical complications for patients with transfusion-dependent hematological disorders. Clinical parameters such as total red blood cell (RBC) transfusion units and serum ferritin level are usually considered as indicators for initiation of iron chelation therapy. We used MRI-T2*, MRI-R2* values, and left ventricular ejection fraction in 19 adult patients with blood transfusion-dependent hematological disorders without consecutive oral iron chelation therapy, and propose possible formulae of cardiac function using known parameters, such as total RBC transfusion units and serum ferritin levels. We found a positive correlation in all patients between both R2* values (reciprocal values of T2*) and serum ferritin levels (r = 0.81) and also total RBC transfusion volume (r = 0.90), but not when we analyzed subgroups of patients whose T2* values were over 30 ms (0.52). From the formulae of the R2*, we concluded that approximately 50 Japanese units or 2,900 pmol/L ferritin might be the cutoff value indicating possible future cardiac dysfunction.     

Lactoferrin sequestration and its contribution to iron-deficiency anemia in Helicobacter pylori-infected gastric mucosa

BACKGROUND AND AIM: It is known that lactoferrin serves as a source of iron for Helicobacter pylori in gastric mucosa. The present study was undertaken to investigate the relationship between lactoferrin and H. pylori infection coexistent with iron-deficiency anemia by determining the lactoferrin levels in gastric biopsy specimens, and by locating the major sites of lactoferrin expression, according to the presence or absence of iron-deficiency anemia. METHODS: One hundred and one adolescents who underwent gastroduodenoscopy were divided into four groups: controls without H. pylori infection (NL; n =43); patients with H. pylori infection (HP; n = 26); patients with iron-deficiency anemia (IDA; n = 6); and patients with H. pylori gastritis and coexisting iron-deficiency anemia (HPIDA; n = 26). The gastric mucosal levels of lactoferrin were measured by immunoassay. Immunohistochemical technique was used to allow identification of the location and quantification of the lactoferrin expression. RESULTS: The mucosal level of lactoferrin was highest (3.93 +/- 2.73 ng/microg protein) in HPIDA, followed by 2.67 +/- 1.79 ng/microg protein in HP, 0.59 +/- 0.57 ng/microg protein in NL and 0.14 +/- 0.10 ng/microg protein in IDA. Their multiple comparisons were statistically significant at the 0.05 level. After the eradication of H. pylori in 12 HPIDA patients who underwent follow-up endoscopy, the mean mucosal level of lactoferrin decreased significantly, while the blood hemoglobin level correspondingly increased. The major sites of lactoferrin expression by immunohistochemistry were in glands and neutrophils within epithelium. Lactoferrin was stained weakly in NL and IDA, and strongly in HP and HPIDA. CONCLUSION: The lactoferrin sequestration in the gastric mucosa of HPIDA was remarkable, and this finding seems to give a clue that leads to the clarification of the mechanism by which H. pylori infection contributes to iron-deficiency anemia.     

Methylprednisolone pulse plus mizoribine in children with Henoch–Schoenlein purpura nephritis

We evaluated whether methylprednisolone and urokinase pulse therapy combined with mizoribine (MUPM) was effective in children with severe Henoch–Schoenlein purpura nephritis (HSPN). We studied 12 patients who had been diagnosed with HSPN of at least ISKDC type III. All patients were treated with MUPM. Clinical features, pathological findings, and prognosis were prospectively investigated. Ten patients (responders; nine with ISKDC grade IIIb and one with grade IVb) were treated with MUPM, whereas MUPM was discontinued due to the lack of response in two patients (non-responders; two with grade IVb). Among responders, urinary protein excretion had decreased significantly from 99.7 ± 37.8 to 25.9 ± 33.4 mg/m² per hour after 3 months of therapy. The acute index and tubulointerstitial scores decreased significantly from 5.8 ± 1.5 and 3.8 ± 0.6 at the first biopsy to 2.3 ± 1.3 and 1.0 ± 0.8 at the second biopsy, respectively. At the most recent follow-up, eight of the responders had normal urine, and two had minor urinary abnormalities. Non-responders demonstrated continued high levels of urinary protein excretion after 3 months of therapy, and MUPM was discontinued. Our study suggests that MUPM is effective in ameliorating the proteinuria and the histological severity of HSPN in patients with <50% crescents but is not so effective for HSPN in patients with >50% crescents.     

Postnatal blocking of interferon-gamma function prevented atherosclerotic plaque formation in apolipoprotein E-knockout mice.

It is unknown whether interferon-gamma has a positive or negative impact on atherosclerotic plaque formation. Thus, we examined the effects of postnatal interferon-gamma function blocking on plaque formation in apolipoprotein E-knockout (apoEKO) mice by overexpressing a soluble mutant of interferon-gamma receptor (sIFNgammaR), an interferon-gamma inhibitory protein. Mice were fed a Western-type diet from 8 weeks of age. sIFNgammaR or mock plasmid (control) was injected into the thigh muscle at 8 and 10 weeks' age, because serum sIFNgammaR protein was transiently increased with a peak at 2 days after a single sIFNgammaR gene transfer and remained elevated for 2 weeks. At 12 weeks' age, control apoEKO mice showed marked atherosclerotic plaques from the ascending aorta to the aortic arch. The plaques in the aortic root had massive lipid cores and macrophage infiltration with thin fibrous cap and few smooth muscle cells, demonstrating low plaque stability. In contrast, the luminal plaque area was remarkably reduced in sIFNgammaR-treated apoEKO mice. sIFNgammaR treatment not only reduced lipid core areas and macrophage infiltration but also increased smooth muscle cell count and fibrotic area, suggesting improved plaque stability. In controls, interleukin-1beta, monocyte chemoattractant protein-1, and vascular cell adhesion molecules-1 were remarkably upregulated in the aortic wall. These changes were significantly reversed by sIFNgammaR. sIFNgammaR treatment had no effects on serum cholesterol levels. In conclusion, sIFNgammaR treatment prevented plaque formation in apoEKO mice by inhibiting inflammatory changes in the arterial wall. The present study provides insight into a new strategy for preventing atherosclerosis.     

Quinapril with High Affinity to Tissue Angiotensin-Converting Enzyme Reduces Restenosis after Percutaneous Transcatheter Coronary Intervention

Experimental studies have demonstrated that vascular injury resulted in an induction of vascular angiotensin-converting enzyme (ACE), and have suggested that inhibition of vascular ACE might be important in the prevention of restenosis. The present study aimed to determine the effect of quinapril, an ACE inhibitor with high affinity to tissue ACE, on restenosis following coronary intervention. The design of this study was a prospective, randomized, open, and non-placebo controlled trial. Patients with ischemic heart disease were enrolled after successful percutaneous transluminal coronary angioplasty or stent implantation at 7 participating institutions. Two hundred and fifty-three patients with 294 lesions were randomly assigned to the quinapril (10–20 mg per day) group or control group. Administration of quinapril was continued for 3–6 months of the follow-up. Quantitative coronary angiography was performed before and after angioplasty and at follow-up. Core laboratory measurements were performed independently and blinded. Follow-up angiography was performed in 108 patients with 124 lesions in the quinapril group and in 107 patients with 130 lesions in the control group. The baseline characteristics and findings of angioplasty showed no significant differences between the two groups. However, in the quinapril group, restenosis per patient and per lesion was significantly lower (34.3% vs. 47.7%, p < 0.05 and 30.6% vs. 43.8%, p < 0.05). Multivariable analysis revealed that administration of quinapril independently contributed to reducing the restenosis per patient and per lesion (odds ratio, 0.73; 95% confidence interval, 0.54–0.99 and odds ratio, 0.75; 95% confidence interval, 0.57–0.99). In conclusion, quinapril significantly reduces restenosis following coronary intervention.     

Improvement of alanine aminotransferase by administration of suplatast tosilate plus ursodeoxycholic acid in patients with resistance to ursodeoxycholic acid monotherapy on hepatitis C virus-related chronic liver disease

OBJECTIVE: Inflammatory liver damage and viral persistence after hepatitis C virus (HCV) infection are known to be related in host immunity. Suplatast tosilate is an immunomodulator that selectively inhibits type 2 cytokine production by helper T cells. We investigated the efficacy and safety of the administration of suplatast tosilate for patients with HCV infection by examining the level of serum alanine aminotransferase (ALT) and viremia. PATIENTS AND METHODS: Thirty-eight patients who had shown resistance to ursodeoxycholic acid (UDCA) therapy (600 mg/day tid) over 6 months for HCV-related chronic liver disease were randomized into two groups and received UDCA alone (600 mg/day tid) or UDCA (600 mg/day tid) plus suplatast tosilate (300 mg/day tid) by means of sealed envelopes. RESULTS: After 24 weeks, serum ALT was decreased in the patients receiving UDCA plus suplatast tosilate, with the mean reduction being 40.2% (from 132 to 79 IU/l; p=0.001). In the patients receiving UDCA alone, ALT decreased by 8.3% (from 133 to 122 IU/l; ns). Multiple comparison of individual ALT changes showed that the UDCA plus suplatast tosilate achieved significantly greater improvement (p = 0.001). However, serum HCV RNA was unchanged in both groups. Two patients developed adverse reactions to suplatast tosilate, which resolved promptly after the discontinuation of the therapy. CONCLUSION: These findings suggest that suplatast tosilate promotes biochemical improvement in the patients with chronic hepatitis C.