3,053 research outputs found
Antimicrobial HPA3NT3 peptide analogs: Placement of aromatic rings and positive charges are key determinants for cell selectivity and mechanism of action
AbstractIn an earlier study, we determined that HP(2β20) (residues 2β20 of parental HP derived from the N-terminus of the Helicobacter pylori ribosomal protein L1) and its analog, HPA3NT3, had potent antimicrobial effects. However, HPA3NT3 also showed undesirable cytotoxicity against HaCaT cells. In the present study, we designed peptide analogs including HPA3NT3-F1A (βF1A), HPA3NT3-F8A (βF8A), HPA3NT3-F1AF8A (βF1AF8A), HPA3NT3-A1 (βA1) and HPA3NT3-A2 (βA2) in an effort to investigate the effects of amino acid substitutions in reducing their hydrophobicity or increasing their cationicity, and any resulting effects on their selectivity in their interactions with human cells and pathogens, as well as their mechanism of antimicrobial action. With the exception of HPA3NT3-A1, all of these peptides showed potent antimicrobial activity. Moreover, substitution of Ala for Phe at positions 1 and/or 8 of the HPA3NT3 peptides (βF1A, -F8A and -F1AF8A) dramatically reduced their cytotoxicity. Thus the cytotoxicity of HPA3NT3 appears to be related to its Phe residues (positions 1 and 8), which strongly interact with sphingomyelin in the mammalian cell membrane. HPA3NT3 exerted its bactericidal effects through membrane permeabilization mediated by pore formation. In contrast, fluorescent dye leakage and nucleic acid gel retardation assays showed that βA2 acted by penetrating into the cytoplasm, where it bound to nucleic acids and inhibited protein synthesis. Notably, Staphylococcus aureus did not develop resistance to -A2 as it did with rifampin. These results suggest that the -A2 peptide could potentially serve as an effective antibiotic agent against multidrug-resistant bacterial strains
The effects of pre-pregnancy body mass index and gestational weight gain on perinatal outcomes in Korean women: a retrospective cohort study
<p>Abstract</p> <p>Background</p> <p>The purpose of the study was to evaluate the effects of maternal pre-pregnancy body mass index (BMI) and gestational weight gain on perinatal outcomes in a population of Korean women.</p> <p>Methods</p> <p>We retrospectively reviewed the medical records of 2,454 women who had received antenatal care at Seoul St. Mary's Hospital from January 2007 to December 2009. We used World Health Organization definitions for Asian populations of underweight (BMI < 18.5), normal (BMI equal or higher 18.5 and < 23), overweight (BMI equal or higher 23 and < 25), and obese (BMI equal or higher 25). We analyzed perinatal outcomes according to the pre-pregnancy BMI and weight gain during pregnancy, and calculated the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from multiple logistic regression models by considering maternal age, parity, number of fetuses, length of gestation, and medical history.</p> <p>Results</p> <p>Among obese women, the adjusted ORs for gestational diabetes, hypertensive disorder, and incompetent internal os of cervix were 4.46, 2.53, and 3.70 (95% CI = 2.63-7.59, 1.26-5.07, and 1.50-9.12), respectively, and the adjusted ORs for neonatal complications such as macrosomia and low Apgar score were 2.08 and 1.98 (95% CI = 1.34-3.22 and 1.19-3.29), respectively, compared with normal weight women. However, there was no positive linear association between gestational weight gain and obstetric outcomes. In normal weight women, maternal and neonatal complications were significantly increased with inadequate weight gain during pregnancy (p < 0.0001 and = 0.0180, respectively), and we observed similar results in underweight women (p = 0.0136 and 0.0004, respectively).</p> <p>Conclusions</p> <p>This study shows that pre-pregnancy overweight and obesity are more closely related to the adverse obstetric outcomes than excess weight gain during pregnancy. In addition, inadequate weight gain during pregnancy can result in significant complications.</p
Hypertrophy of ligamentum flavum in lumbar spinal stenosis associated with increased proteinase inhibitor concentration
Li-Fi based on security cloud framework for future IT environment
This study was supported by the Research Program funded by the SeoulTech (Seoul National University of Science and Technology).Peer reviewedPublisher PD
HYPERTROPHY OF LIGAMENTUM FLAVUM IN LUMBAR SPINAL STENOSIS ASSOCIATED WITH INCREASED PROTEINASE INHIBITOR CONCENTRATION
Soybeans Ameliolate Diabetic Nephropathy in Rats
Diabetic nephropathy is one of the most frequent and serious complications of diabetes mellitus. Soybeans have been shown to reduce urinary albumin excretion and total cholesterol in non-diabetic patients with nephrotic syndrome. However, reports focusing specifically on diabetic nephropathy are scarce and the available results are inconsistent. It was reported that soybean consumption reduced urinary protein excretion in type 1 diabetic patients with diabetic nephropathy, whereas it was found to elicit an increase in urinary protein excretion when soybeans were consumed by type 2 diabetic patients. This study aims to investigate the effects of soybean in diabetic nephropathy, particularly the effects of consuming soybeans on the histopathology of diabetic nephropathy, using aquaporin (AQP) and osteopontin (OPN) expression as diagnostic markers. Male Sprague-Dawley rats were assigned to one of three groups: control, diabetic with red chow diet and diabetic with soybean diet. For histological examination, the expression of OPN and AQP, renal function and hemoglobin A1c were evaluated at the end of the study. Improvements in glomerular and tubulointerstitial lesions were demonstrated in the diabetic rat group given a soybean diet. OPN and AQP expression were suppressed in the kidney specimens of diabetic rats with the soybean diet. In conclusion, soybeans may prevent the weight loss and morphological disruption of the kidney associated with diabetes mellitus. Soybeans also may improve glycemic control. It seems likely that long-term control of blood glucose levels using a soybean diet could prevent the progression of diabetes mellitus, and therefore, nephropathy could be prevented
Regulation of endothelial nitric oxide synthase by agmatine after transient global cerebral ischemia in rat brain
Nitric oxide (NO) production by endothelial nitric oxide synthase (eNOS) plays a protective role in cerebral ischemia by maintaining vascular permeability, whereas NO derived from neuronal and inducible NOS is neurotoxic and can participate in neuronal damage occurring in ischemia. Matrix metalloproteinases (MMPs) are up-regulated by ischemic injury and degrade the basement membrane if brain vessels to promote cell death and tissue injury. We previously reported that agmatine, synthesized from L-arginine by arginine decarboxylase (ADC) which is expressed in endothelial cells, has shown a direct increased eNOS expression and decreased MMPs expression in bEnd3 cells. But, there are few reports about the regulation of eNOS by agmatine in ischemic animal model. In the present study, we examined the expression of eNOS and MMPs by agmatine treatment after transient global ischemia in vivo. Global ischemia was induced with four vessel occlusion (4-VO) and agmatine (100 mg/kg) was administered intraperitoneally at the onset of reperfusion. The animals were euthanized at 6 and 24 hours after global ischemia and prepared for other analysis. Global ischemia led severe neuronal damage in the rat hippocampus and cerebral cortex, but agmatine treatment protected neurons from ischemic injury. Moreover, the level and expression of eNOS was increased by agmatine treatment, whereas inducible NOS (iNOS) and MMP-9 protein expressions were decreased in the brain. These results suggest that agmatine protects microvessels in the brain by activation eNOS as well as reduces extracellular matrix degradation during the early phase of ischemic insult
Comparison between a reanalyzed product by 3-dimensional variational assimilation technique and observations in the Ulleung Basin of the East/Japan Sea
Author Posting. Β© Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Marine Systems 78 (2009): 249-264, doi:10.1016/j.jmarsys.2009.02.017.Reanalyzed products from a MOM3-based East Sea Regional Ocean Model with a 3-
dimentional variational data assimilation module (DA-ESROM), have been compared
with the observed hydrographic and current datasets in the Ulleung Basin (UB) of the
East/Japan Sea (EJS). Satellite-borne sea surface temperature and sea surface height
data, and in-situ temperature profiles have been assimilated into the DA-ESROM. The
performance of the DA-ESROM appears to be efficient enough to be used in an
operational ocean forecast system.
Comparing with the results from Mitchell et al. (2005a), the DA-ESROM fairly well
simulates the high variability of the Ulleung Warm Eddy and Dok Cold Eddy as well as
the branching of the Tsushima Warm Current in the UB. The overall root-mean-square
error between 100m temperature field reproduced by the DA-ESROM and the observed
100-dbar temperature field is 2.1Β°C, and the spatially averaged grid-to-grid correlation
between the two temperature fields is high with a mean value of 0.79 for the intercomparison
period.
The DA-ESROM reproduces the development of strong southward North Korean
Cold Current (NKCC) in summer consistent with the observational results, which is
thought to be an improvement of the previous numerical models in the EJS. The
reanalyzed products show that the NKCC is about 35 km wide, and flows southward
along the Korean coast from spring to summer with maximum monthly mean volume
transport of about 0.8 Sv in August-September.The major part of this works was conducted with financial support by Agency for Defense Development under the contract UD031003AD. The first and seventh authors were supported at the final stage of this work by KORDIβs research projects (PE9830Q and PG47100). The second author was supported by EAST-I Program of the Ministry of Maritime Affairs and Fisheries
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