Empiric antibiotic choices for community-acquired biliary tract infections

SummaryBackgroundThe study was conducted to reveal the most appropriate empiric antibiotics for the treatment of community-acquired biliary tract infections (CA-BTI) at a regional hospital in Taiwan.MethodsThe study was performed between October 1, 2010 and October 31, 2012. All positive bile culture results of presumptive community-acquired origins were collected. The associated etiologic microorganisms and their antimicrobial susceptibilities were analyzed. The appropriateness of empiric therapy (defined as the effectiveness of the antibiotics against the etiologic agents) and the subsequent treatment response were examined through the review of medical records.ResultsA total of 115 patients (cholecystitis, 83 cases, 72.2%; cholangitis, 32 cases, 27.8%) and 189 isolates (136 Gram-negative bacilli, 37 Gram-positive cocci, and 16 anaerobes) were analyzed. The most frequent pathogens were Escherichia coli (n = 69, 36.5%), Klebsiella spp. (n = 37, 19.6%), enterococci (n = 29, 15.3%), and Bacteroides spp. (n = 11, 5.8%). Penicillin resistance (5.4%) was low in Gram-positive cocci, whereas higher resistance (>20%) to cefazolin, cefuroxime, and ampicillin–sulbactam was found in Gram-negative bacilli. Anaerobes also demonstrated high resistance to clindamycin (37.5%) but less to metronidazole (12.5%). Appropriate empiric therapy was found in 92 (80%) cases, and among them, 83 (90.2%) were treated successfully. The treatment success rate (69.6%) was significantly lower among the remaining 23 cases with inappropriate empiric therapy (16 of 23 vs. 83 of 92, p < 0.05). A high treatment success rate (97.2%) was observed among cases empirically treated with ceftriaxone plus metronidazole.ConclusionThe combination of ceftriaxone plus metronidazole appears to be the most appropriate empiric antibiotics for the treatment of CA-BTI at this hospital. Because different hospitals may encounter microorganisms of different antimicrobial susceptibilities, similar approaches may be followed by other hospitals where appropriate empiric therapy has not yet been established for the treatment of CA-BTI

Multiple metallic-shell nanocylinders for surface-enhanced spectroscopes

The optical properties of multiple dielectric-core-gold-shell nanocylinder pairs are investigated by two-dimensional finite difference time domain method. The core-shell cylinders are assumed to be of the same dimension and composition. For normal incidence, the diffraction spectra of multiple cylinder pairs contain the lightning-rod plasmon mode, and the electric field intensity is concentrated in the gap between the nanocylinder pairs in the infrared region. The resonance wavelength and local field enhancement of this plasmon mode can be tuned by varying the pair-distance between the pairs, the gap-distance between the pairs, and the optical constants of the dielectric-core and the surrounding medium. The results show that the multiple core-shell nanocylinder pair contains the plasmon mode same as that of the solid metallic cylinder pairs at the long wavelength part of the spectrum. The large electric field intensity in the infrared region at long wavelength makes multiple core-shell cylinders as ideal candidates for surface-enhanced spectroscopes

Nitroprusside modulates pulmonary vein arrhythmogenic activity

<p>Abstract</p> <p>Background</p> <p>Pulmonary veins (PVs) are the most important sources of ectopic beats with the initiation of paroxysmal atrial fibrillation, or the foci of ectopic atrial tachycardia and focal atrial fibrillation. Elimination of nitric oxide (NO) enhances cardiac triggered activity, and NO can decrease PV arrhythmogensis through mechano-electrical feedback. However, it is not clear whether NO may have direct electrophysiological effects on PV cardiomyocytes. This study is aimed to study the effects of nitroprusside (NO donor), on the ionic currents and arrhythmogenic activity of single cardiomyocytes from the PVs.</p> <p>Methods</p> <p>Single PV cardiomyocytes were isolated from the canine PVs. The action potential and ionic currents were investigated in isolated single canine PV cardiomyocytes before and after sodium nitroprusside (80 μM,) using the whole-cell patch clamp technique.</p> <p>Results</p> <p>Nitroprusside decreased PV cardiomyocytes spontaneous beating rates from 1.7 ± 0.3 Hz to 0.5 ± 0.4 Hz in 9 cells (P < 0.05); suppressed delayed afterdepolarization in 4 (80%) of 5 PV cardiomyocytes. Nitroprusside inhibited L-type calcium currents, transient outward currents and transient inward current, but increased delayed rectified potassium currents.</p> <p>Conclusion</p> <p>Nitroprusside regulates the electrical activity of PV cardiomyocytes, which suggests that NO may play a role in PV arrhythmogenesis.</p

The significance of seizures and other predictive factors during the acute illness for the long-term outcome after bacterial meningitis

SummaryBackgroundSeizures are important neurological complications of bacterial meningitis, but no information about its epidemiology and the outcomes of seizures after community-acquired bacterial meningitis (CABM) in an adult population have been reported.AimsTo determine the frequency, clinical relevance, subtypes of seizures during the acute phase of bacterial meningitis, and the long-term outcomes of seizure complicating adult CABM.MethodsIn this 12-year retrospective study, 117 adult patients were identified with culture-proven CABM. A comparison was made between the clinical data of the patients with and without seizures during hospitalization.ResultsThirty-one patients had seizures during CABM, accounting for 27% (31/117) of the episodes. The time interval between the onset of bacterial meningitis and the seizures was 1–21 days (mean, 4 days). Furthermore, 80% (25/31) of the episodes occurred within 24h of presentation. Ten patients who had seizures progressed to status epilepticus. At follow-up after completing treatment, 10 patients completely recovered and were seizure-free, 19 died of meningitis during the acute stage and the other two progressed to chronic epilepsy.ConclusionA log-rank test demonstrated that the long-term outcome of adult CABM with acute seizures produced worse outcomes than for those who had no seizures, though no difference was noted between focal and generalized seizures. None of our patients without seizures in the acute phase of bacterial meningitis developed late seizures during the follow-up periods. Poor outcome in this study may attribute to neurological complications such as seizure, hydrocephalus, infection itself, or a combination of complications

Arctigenin from Arctium lappa inhibits interleukin-2 and interferon gene expression in primary human T lymphocytes

<p>Abstract</p> <p>Background</p> <p><it>Arctium lappa </it>(<it>Niubang</it>), a Chinese herbal medicine, is used to treat tissue inflammation. This study investigates the effects of arctigenin (AC), isolated from <it>A. lappa</it>, on anti-CD3/CD28 Ab-stimulated cell proliferation and cytokine gene expression in primary human T lymphocytes.</p> <p>Methods</p> <p>Cell proliferation was determined with enzyme immunoassays and the tritiated thymidine uptake method. Cytokine production and gene expression were analyzed with reverse transcription-polymerase chain reaction.</p> <p>Results</p> <p>AC inhibited primary human T lymphocytes proliferation activated by anti-CD3/CD28 Ab. Cell viability test indicated that the inhibitory effects of AC on primary human T lymphocyte proliferation were not due to direct cytotoxicity. AC suppressed interleukin-2 (IL-2) and interferon-γ (IFN-γ) production in a concentration-dependent manner. Furthermore, AC decreased the IL-2 and IFN-γ gene expression in primary human T lymphocytes induced by anti-CD3/CD28 Ab. Reporter gene analyses revealed that AC decreased NF-AT-mediated reporter gene expression.</p> <p>Conclusion</p> <p>AC inhibited T lymphocyte proliferation and decreased the gene expression of IL-2, IFN-γ and NF-AT.</p

Efficient Prodrug Activator Gene Therapy by Retroviral Replicating Vectors Prolongs Survival in an Immune-Competent Intracerebral Glioma Model.

Prodrug activator gene therapy mediated by murine leukemia virus (MLV)-based retroviral replicating vectors (RRV) was previously shown to be highly effective in killing glioma cells both in culture and in vivo. To avoid receptor interference and enable dual vector co-infection with MLV-RRV, we have developed another RRV based on gibbon ape leukemia virus (GALV) that also shows robust replicative spread in a wide variety of tumor cells. We evaluated the potential of GALV-based RRV as a cancer therapeutic agent by incorporating yeast cytosine deaminase (CD) and E. coli nitroreductase (NTR) prodrug activator genes into the vector. The expression of CD and NTR genes from GALV-RRV achieved highly efficient delivery of these prodrug activator genes to RG-2 glioma cells, resulting in enhanced cytotoxicity after administering their respective prodrugs 5-fluorocytosine and CB1954 in vitro. In an immune-competent intracerebral RG-2 glioma model, GALV-mediated CD and NTR gene therapy both significantly suppressed tumor growth with CB1954 administration after a single injection of vector supernatant. However, NTR showed greater potency than CD, with control animals receiving GALV-NTR vector alone (i.e., without CB1954 prodrug) showing extensive tumor growth with a median survival time of 17.5 days, while animals receiving GALV-NTR and CB1954 showed significantly prolonged survival with a median survival time of 30 days. In conclusion, GALV-RRV enabled high-efficiency gene transfer and persistent expression of NTR, resulting in efficient cell killing, suppression of tumor growth, and prolonged survival upon CB1954 administration. This validates the use of therapeutic strategies employing this prodrug activator gene to arm GALV-RRV, and opens the door to the possibility of future combination gene therapy with CD-armed MLV-RRV, as the latter vector is currently being evaluated in clinical trials