181 research outputs found

    Perforated Appendiceal Mucinous Cystadenoma Mimicking Ruptured Appendicitis With Abscess Formation: CT Imaging Features

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    AbstractWe describe the imaging features of a perforated appendiceal mucinous cystadenoma in a 72-year-old woman presenting with right lower quadrant abdominal pain, mimicking ruptured appendicitis with abscess formation. Computed tomography revealed a rim-enhanced cystic lesion at the proximal appendiceal orifice, connecting with the swollen and dilated distal part of the appendix. Disruption of the appendiceal walls and peri-appendiceal fatty infiltrations were also noted. Under the impression of ruptured appendicitis with abscess formation, the patient underwent exploratory laparotomy and appendectomy. The pathologic diagnosis was perforated appendiceal mucinous cystadenoma associated with superinfection, complicated by secondary appendicitis. The patient was uneventfully discharged on the 7th hospital day. Although primary neoplasms of the appendix are uncommon, they should be considered as a predisposing factor in elderly patients manifesting with appendicitis

    Production of N-acetyl-D-neuraminic acid using two sequential enzymes overexpressed as double-tagged fusion proteins

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    <p>Abstract</p> <p>Background</p> <p>Two sequential enzymes in the production of sialic acids, N-acetyl-D-glucosamine 2-epimerase (GlcNAc 2-epimerase) and <it>N</it>-acetyl-D-neuraminic acid aldolase (Neu5Ac aldolase), were overexpressed as double-tagged gene fusions. Both were tagged with glutathione S-transferase (GST) at the N-terminus, but at the C-terminus, one was tagged with five contiguous aspartate residues (5D), and the other with five contiguous arginine residues (5R).</p> <p>Results</p> <p>Both fusion proteins were overexpressed in <it>Escherichia coli </it>and retained enzymatic activity. The fusions were designed so their surfaces were charged under enzyme reaction conditions, which allowed isolation and immobilization in a single step, through a simple capture with either an anionic or a cationic exchanger (Sepharose Q or Sepharose SP) that electrostatically bound the 5D or 5R tag. The introduction of double tags only marginally altered the affinity of the enzymes for their substrates, and the double-tagged proteins were enzymatically active in both soluble and immobilized forms. Combined use of the fusion proteins led to the production of <it>N</it>-acetyl-D-neuraminic acid (Neu5Ac) from <it>N</it>-acetyl-D-glucosamine (GlcNAc).</p> <p>Conclusion</p> <p>Double-tagged gene fusions were overexpressed to yield two enzymes that perform sequential steps in sialic acid synthesis. The proteins were easily immobilized via ionic tags onto ionic exchange resins and could thus be purified by direct capture from crude protein extracts. The immobilized, double-tagged proteins were effective for one-pot enzymatic production of sialic acid.</p

    Smart Grid as a Service: A Discussion on Design Issues

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    Smart grid allows the integration of distributed renewable energy resources into the conventional electricity distribution power grid such that the goals of reduction in power cost and in environment pollution can be met through an intelligent and efficient matching between power generators and power loads. Currently, this rapidly developing infrastructure is not as ā€œsmartā€ as it should be because of the lack of a flexible, scalable, and adaptive structure. As a solution, this work proposes smart grid as a service (SGaaS), which not only allows a smart grid to be composed out of basic services, but also allows power users to choose between different services based on their own requirements. The two important issues of service-level agreements and composition of services are also addressed in this work. Finally, we give the details of how SGaaS can be implemented using a FIPA-compliant JADE multiagent system

    Hedgehog overexpression leads to the formation of prostate cancer stem cells with metastatic property irrespective of androgen receptor expression in the mouse model

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    <p>Abstract</p> <p>Background</p> <p>Hedgehog signalling has been implicated in prostate tumorigenesis in human subjects and mouse models, but its effects on transforming normal basal/stem cells toward malignant cancer stem cells remain poorly understood.</p> <p>Methods</p> <p>We produced pCX-shh-IG mice that overexpress Hedgehog protein persistently in adult prostates, allowing for elucidation of the mechanism during prostate cancer initiation and progression. Various markers were used to characterize and confirm the transformation of normal prostate basal/stem cells into malignant cancer stem cells under the influence of Hedgehog overexpression.</p> <p>Results</p> <p>The pCX-shh-IG mice developed prostatic intraepithelial neoplasia (PIN) that led to invasive and metastatic prostate cancers within 90 days. The prostate cancer was initiated through activation of P63<sup>+ </sup>basal/stem cells along with simultaneous activation of Hedgehog signalling members, suggesting that P63<sup>+</sup>/Patch1<sup>+ </sup>and P63<sup>+</sup>/Smo<sup>+ </sup>cells may serve as cancer-initiating cells and progress into malignant prostate cancer stem cells (PCSCs). In the hyperplastic lesions and tumors, the progeny of PCSCs differentiated into cells of basal-intermediate and intermediate-luminal characteristics, whereas rare ChgA<sup>+ </sup>neuroendocrine differentiation was seen. Furthermore, in the metastatic loci within lymph nodes, kidneys, and lungs, the P63<sup>+ </sup>PCSCs formed prostate-like glandular structures, characteristic of the primitive structures during early prostate development. Besides, androgen receptor (AR) expression was detected heterogeneously during tumor progression. The existence of P63<sup>+</sup>/AR<sup>-</sup>, CK14<sup>+</sup>/AR<sup>- </sup>and CD44<sup>+</sup>/AR<sup>- </sup>progeny indicates direct procurement of AR<sup>- </sup>malignant cancer trait.</p> <p>Conclusions</p> <p>These data support a cancer stem cell scenario in which Hedgehog signalling plays important roles in transforming normal prostate basal/stem cells into PCSCs and in the progression of PCSCs into metastatic tumor cells.</p

    Antinociceptive effects of morphine and naloxone in mu-opioid receptor knockout mice transfected with the MORS196A gene

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    <p>Abstract</p> <p>Background</p> <p>Opioid analgesics such as morphine and meperidine have been used to control moderate to severe pain for many years. However, these opioids have many side effects, including the development of tolerance and dependence after long-term use, which has limited their clinical use. We previously reported that mutations in the mu-opioid receptors (MOR) S196L and S196A rendered them responsive to the opioid antagonist naloxone without altering the agonist phenotype. In MORS196A knock-in mice, naloxone and naltrexone were antinociceptive but did not cause tolerance or physical dependence. In this study we delivery this mutated MOR gene into pain related pathway to confirm the possibility of <it>in vivo </it>transfecting MORS196A gene and using naloxone as a new analgesic agent.</p> <p>Methods</p> <p>The MOR-knockout (MOR-KO) mice were used to investigate whether morphine and naloxone could show antinociceptive effects when MORS196A gene was transfected into the spinal cords of MOR-KO mice. Double-stranded adeno-associated virus type 2 (dsAAV2) was used to deliver the MORS196A-enhanced green fluorescence protein (EGFP) gene by microinjected the virus into the spinal cord (S2/S3) dorsal horn region. Tail-flick test was used to measure the antinociceptive effect of drugs.</p> <p>Results</p> <p>Morphine (10 mg/kg, s.c.) and naloxone (10 mg/kg, s.c.) had no antinociceptive effects in MOR-KO mice before gene transfection. However, two or three weeks after the MOR-S196A gene had been injected locally into the spinal cord of MOR-KO mice, significant antinociceptive effects could be induced by naloxone or morphine. On the other hand, only morphine but not naloxone induced significant tolerance after sub-chronic treatment.</p> <p>Conclusion</p> <p>Transfecting the MORS196A gene into the spinal cord and systemically administering naloxone in MOR-KO mice activated the exogenously delivered mutant MOR and provided antinociceptive effect without causing tolerance. Since naloxone will not activate natural MOR in normal animals or humans, it is expected to produce fewer side effects and less tolerance and dependence than traditional opioid agonists do.</p

    Adiponectin gene (ADIPOQ) polymorphisms correlate with the progression of nephropathy in Taiwanese male patients with type 2 diabetes

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    Aims: Polymorphisms of the ADIPOQ gene were associated with diabetic nephropathy (DN) in case-control studies predominantly among European populations. Gender may modify the ADIPOQ associated risk for DN. We investigated the association of 18 ADIPOQ polymorphisms with DN in a prospective Taiwanese cohort of type 2 diabetes (T2D) and explored whether gender plays a role in this genetic association. Methods: Selected single nucleotide polymorphisms (SNPs) of ADIPOQ were genotyped in 566 T2D patients with normoalbuminuria at baseline. DN was defined based on urinary albumin-to-creatinine ratio (ACR). The Cox proportional hazard model was used to explore the association of individual SNP to DN events under different genetic models over a 6-year follow-up period. Analyses were further stratified by gender. Results: In male patients, the adjusted hazard ratios under the recessive models were 1.81 for rs2241766 TT (vs. GT+GG, 95% CI=1.10-2.96, p=0.019) and 1.89 for rs1063537 CC (vs. CT+TT, 95% CI=1.15-3.11, p=0.013). In the Kaplan-Meier survival curve, males carrying rs2241766 TT (vs. GT+GG, p=0.050) and rs1063537 CC (vs. CT+TT, p=0.037) recessive homozygotes also had a reduced nephropathy-free survival rate. SNPs rs2241767 and rs2082940, both in strong correlation with tag SNP rs1063537 (rā‰„0.96), were also associated with DN progression in males. In females, ADIPOQ polymorphisms were not associated with the progression of DN. Conclusions: ADIPOQ genetic polymorphisms rs2241766 (+45T>G), rs1063537, rs2241767 and rs2082940 were correlated with the progression of DN in Taiwanese male patients with T2D. The role of gender in this ADIPOQ genetic association needs to be further investigated in other populations

    Pretreatment with a Heat-Killed Probiotic Modulates the NLRP3 Inflammasome and Attenuates Colitis-Associated Colorectal Cancer in Mice.

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    Colorectal cancer (CRC) is one of the most common malignancies worldwide. Inflammation contributes to cancer development and inflammatory bowel disease is an important risk factor for CRC. The aim of this study is to assess whether a widely used probiotic Enterococcus faecalis can modulate the NLRP3 inflammasome and protect against colitis and colitis-associated CRC. We studied the effect of heat-killed cells of E. faecalis on NLRP3 inflammasome activation in THP-1-derived macrophages. Pretreatment of E. faecalis or NLRP3 siRNA can inhibit NLRP3 inflammasome activation in macrophages in response to fecal content or commensal microbes, P. mirabilis or E. coli, according to the reduction of caspase-1 activation and IL-1Ī² maturation. Mechanistically, E. faecalis attenuates the phagocytosis that is required for the full activation of the NLRP3 inflammasome. In in vivo mouse experiments, E. faecalis can ameliorate the severity of intestinal inflammation and thereby protect mice from dextran sodium sulfate (DSS)-induced colitis and the formation of CRC in wild type mice. On the other hand, E. faecalis cannot prevent DSS-induced colitis in NLRP3 knockout mice. Our findings indicate that application of the inactivated probiotic, E. faecalis, may be a useful and safe strategy for attenuation of NLRP3-mediated colitis and inflammation-associated colon carcinogenesis

    A colliding maxillary sinus cancer of adenosquamous carcinoma and small cell neuroendocrine carcinoma - a case report with EGFR copy number analysis

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    <p>Abstract</p> <p>Background</p> <p>Small cell neuroendocrine carcinoma (SNEC) of maxillary sinus is a rare and aggressive malignancy. A tumor with squamous cell carcinoma, adenocarcinoma and SNEC co-existence is extremely rare.</p> <p>Case presentation</p> <p>We present a colliding tumor of squamous cell, adenocarcinoma and SNEC in maxillary sinus. The clinical features, diagnosis and EGFR flourescence in situ hybridization (FISH) study are presented. A 52-year-old female had a 1-month history of progressing left cheek swelling and purulent rhinorrhea. Magnetic resonance imaging showed a tumor involving left maxilla and orbital floor. Excision of tumor was done and the defect was reconstructed with free flap. The pathology revealed a malignant tumor composed of squamous cell carcinoma, adenocarcinoma and SNEC components. EGFR FISH study showed no gene amplification in 3 components of this tumor. The tumor progressed rapidly and the patient expired at 8 months after surgery.</p> <p>Conclusion</p> <p>A colliding tumor of squamous cell, adenocarcinoma and neuroendocrine carcinoma in maxillary sinus was aggressive in behavior and the treatment response was poor due to the complexity of tumor.</p
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