Synergistic Effects of Clostridium perfringens Enterotoxin and Beta Toxin in Rabbit Small Intestinal Loops

The ability of Clostridium perfringens type C to cause human enteritis necroticans (EN) is attributed to beta toxin (CPB). However, many EN strains also express C. perfringens enterotoxin (CPE), suggesting that CPE could be another contributor to EN. Supporting this possibility, lysate supernatants from modified Duncan-Strong sporulation (MDS) medium cultures of three CPE-positive type C EN strains caused enteropathogenic effects in rabbit small intestinal loops, which is significant since CPE is produced only during sporulation and since C. perfringens can sporulate in the intestines. Consequently, CPE and CPB contributions to the enteropathogenic effects of MDS lysate supernatants of CPE-positive type C EN strain CN3758 were evaluated using isogenic cpb and cpe null mutants. While supernatants of wild-type CN3758 MDS lysates induced significant hemorrhagic lesions and luminal fluid accumulation, MDS lysate supernatants of the cpb and cpe mutants caused neither significant damage nor fluid accumulation. This attenuation was attributable to inactivating these toxin genes since complementing the cpe mutant or reversing the cpb mutation restored the enteropathogenic effects of MDS lysate supernatants. Confirming that both CPB and CPE are needed for the enteropathogenic effects of CN3758 MDS lysate supernatants, purified CPB and CPE at the same concentrations found in CN3758 MDS lysates also acted together synergistically in rabbit small intestinal loops; however, only higher doses of either purified toxin independently caused enteropathogenic effects. These findings provide the first evidence for potential synergistic toxin interactions during C. perfringens intestinal infections and support a possible role for CPE, as well as CPB, in some EN cases.     

Osteogenic Differentiation of Marrow Stromal Cells on Random and Aligned Electrospun Poly(l-lactide) Nanofibers

The fibrillar structure and sub-micron diameter of electrospun nanofibers can be used to reproduce the morphology and structure of the natural extracellular matrix (ECM). The objective of this work was to investigate the effect of fiber alignment on osteogenic differentiation of bone marrow stromal (BMS) cells. Random and aligned poly(l-lactide) (PLLA) nanofibers were produced by collecting the spun fibers on a stationary plate and a rotating wheel, respectively, as the ground electrode. Morphology and alignment of the BMS cells seeded on the fibers were characterized by SEM. The effect of fiber orientation on osteogenic differentiation of BMS cells was determined by measuring alkaline phosphatase (ALPase) activity, calcium content, and mRNA expression levels of osteogenic markers. There was a strong correlation between the fiber and cell distributions for the random (p = 0.16) and aligned (p = 0.81) fibers. Percent deviation from ideal randomness (PDIR) values indicated that cells seeded on the random fibers (PDIR = 6.5%) were likely to be distributed randomly in all directions while cells seeded on the aligned fibers (PDIR = 86%) were highly likely to be aligned with the direction of fibers. BMS cell seeded on random and aligned fibers had similar cell count and ALPase activity with incubation time, but the calcium content on aligned fibers was significantly higher after 21 days compared to that of random fibers (p = 0.003). Osteopontin (OP) and osteocalcin (OC) expression levels of BMS cells on fibers increased with incubation time. However, there was no difference between the expression levels of OP and OC on aligned vs. random fibers. The results indicate that BMS cells aligned in the direction of PLLA fibers to form long cell extensions, and fiber orientation affected the extent of mineralization, but it had no effect on cell proliferation or mRNA expression of osteogenic markers.     

中西医结合治疗急性脑梗死临床观察

目的:观察中西医结合治疗急性脑梗死的临床疗效。方法:100例随机分成对照组40例和治疗组60例,两组均用血塞通注射液、丹红注射液并常规对症治疗,治疗组加用中药汤剂治疗。结果:总有效率治疗组96.67%、对照组85.00%,两组比较有显著差异(P<0.05)。结论:中西医结合治疗脑梗死疗效明显。     

High-Resolution Melting Assay (HRMA) is a Simple and Sensitive Stool-Based DNA Test for the Detection of Mutations in Colorectal Neoplasms

BackgroundStool-based DNA testing for colorectal cancer is becoming a favored alternative to existing DNA screening tests. However, current methods of analysis often become more complicated and costly with increased sensitivity. The high-resolution melting assay (HRMA) is a simple and rapid mutation scanning method with low cost and superb accuracy. In this study, we verified the accuracy of HRMA for screening KRAS/TP53 mutations in stool-isolated DNA from patients with colorectal cancer.Materials and MethodsComparing to direct DNA sequencing, the accuracy of HRMA was verified by detecting KRAS/TP53 mutations in 2 independent stages. In study stage I, both tissue and stool samples from colorectal neoplasm patients were analyzed. In study stage II, stool samples from patients with colorectal neoplasms, and normal controls in clinical screening settings were examined.ResultsIn study stage I, the HRMA identified 14 of 17 target mutations (82.4%) in stools from cancer patients, and 4 of 5 (80.0%) target mutations in stools from advanced adenoma patients. The mutation detection rate in fecal samples (45.0%; 18/40) and referred tissue samples (55.0%; 22/40) was highly consistent (κ = 0.79). The HRMA detected 1% mutant DNA in a background of wild type DNA. In study stage II, the HRMA assay detected 58.8% (20/34) mutations in tumor samples, 41.5% (17/41) in advanced adenomas samples, and 3.33% (2/60) in age-matched normal control samples. The results from HRMA and DNA sequencing revealed 100% sensitivity and specificity in both tissue and stool samples.ConclusionHRMA is a simple, reliable, and sensitive method for detecting DNA mutations in the stool samples from patients with colorectal neoplasms.     

MicroRNA-503 targets FGF2 and VEGFA and inhibits tumor angiogenesis and growth

FGF2 and VEGFA are the two most potent angiogenic factors. Here we report that miR-503 can simultaneously down-regulate FGF2 and VEGFA. The expression of miR-503 is repressed in HCC cells and primary tumors due to a potential epigenetic mechanism. Overexpression of miR-503 reduced tumor angiogenesis in vitro and in vivo. We also found that miR-503 expression was down-regulated by hypoxia through HIF1α. These results identify a miRNA that targets both FGF2 and VEGFA in cancers, demonstrate the anti-angiogenesis role of miR-503 in tumorigenesis, and provide a novel mechanism for hypoxia-induced FGF2 and VEGFA through HIF1α-mediated inhibition of miR-503.     

The role of tryptophan metabolism in postpartum depression

The Postpartum depression (PPD) is the most common postpartum psychiatric disorder, afflicting approximately 10%–20% of new mothers. Clinical symptoms of the PPD include depressive disorder, agitation, insomnia, anxiety and confusion, resulting in an increase in suicidal tendencies, thereby having significant impacts on the puerpera, newborn and their family. A growing body of data indicate a role for alterations in tryptophan metabolism in the PPD. The metabolism of tryptophan produces an array of crucial factors that can differentially regulate key physiological processes linked to the PPD. Importantly, an increase in stress hormones and immune-inflammatory activity drives tryptophan to the production of neuroregulatory kynurenine pathway products and away from the serotonin and melatonin pathways. This links the PPD to other disorders of depressed mood, which are classically associated with decreased serotonin and melatonin, coupled to increases in kynurenine pathway products. Several kynurenine pathway products, such as kynurenic acid and quinolinic acid, can have neuroregulatory effects, with consequences pathological underpinnings of the PPD. The current article reviews the role of alterations in tryptophan metabolism in the PPD.     

Influence Factors and Prediction Model of Bond Strength of Tunnel Fireproof Coating under Freeze–Thaw Cycles

The freeze–thaw resistant performance of a tunnel fireproof coating (TFC) has an important impact on bonding property and durability. The influence of redispersible emulsion powder, polypropylene fiber and air-entraining agent on TFCs was studied. Transverse fundamental frequency and ultrasonic sound velocity were used to evaluate the damage degree of TFC, and the mechanism was revealed by SEM and pore structure. The results show that the most beneficial effect on bond strength of TFC is redispersible emulsion powder, followed by air-entraining agent, and then polypropylene fiber. After freeze–thaw cycles, the cumulative pore volume of micropores in the TFC increases obviously, while the porosity of macropores does not change significantly. A prediction model was proposed, which can calculate the bond strength from the damage degree of TFC under freeze–thaw cycles. The achievement can promote the application of TFC in cold regions.     

Two new polyprenylated acylphloroglucinols from Hypericum scabrum

Two new polyprenylated acylphloroglucinols, (1S,32R,5S,6R,7R)-6-((R)-3,4-di-hydroxy-4-methylpentyl)-2-(2-hydroxypropan-2-yl)-7-isobutyryl-6-methyl-5,9-bis(3-methylbut-2-en-1-yl)-4,5,6,7-tetrahydro-2H-32,7-methanocycloocta[b]furan-8,10(3H)-dione (1) and (4R,5R,7R)-4-((R)-3,4-dihydroxy-4-methylpentyl)-2,2,4-trimethyl-5,7-bis(3-methyl-but-2-en-1-yl)-7-(5-methylhex-4-enoyl)-4,5,6,7-tetrahydrobenzofuran-3(2H)-one (2) were isolated from Hypericum scabrum. The structures were elucidated by means of spectroscopic methods, including MS, IR, NMR, OR, and CD.     

Lipid-rich Carcinoma of the Breast: a Case Report

Lipid-rich carcinoma is a rare variant and accounts for < 2% of all breast cancer diagnoses. We report a case occurring in a 53-year-old female. The patient presented with a painless, right breast mass. Clinical examination and mammography suggested malignancy. Subsequent modified radical mastectomy revealed the diagnosis of lipid-rich carcinoma. The morphological features, differential diagnosis and treatment along with a brief review of the literature are discussed in this article.

Lipid-rich carcinoma (L-RC) is a very rare variant of breast carcinomas with an aggressive clinical course and poor prognosis. It presents only 1% to 2% of all breast cases (1,2). It is classified as a specific variety of mammary carcinoma because the tumour cells possess abundant vacuolated cytoplasm which is strongly positive when stained for neutral fat. Aboumrad (2) first described it in 1963 as lipid-secreting carcinoma. However, Ramos and Taylor (1) renamed it as lipid-rich breast carcinoma. In China, the first case was reported in 1984 (3). Herein, we report a case of lipid-rich carcinoma occurring in a 53-year-old female patient, and the literature is reviewed.