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21.
The rapid advances made by ultrasound in recent years have increasingly taken 3-D ultrasound (3DUS) and 4-D ultrasound (4DUS) from the research setting to the patient's bedside. There are still unexplored areas like renal percutaneous intervention, where 4DUS has yet to be proven an effective tool. Ultrasound-only guidance in renal percutaneous access is used in selected well-dilated pelvi-calyceal systems (PCS), and fluoroscopy is often utilized as an adjunct. Our aim was to compare 2-D and 4-D guidance for punctures, with fluoroscopy as control, using an in vitro ultrasound phantom. Agar and latex were the tissue-mimicking materials used for the construction of the phantom. The latex targets were designed to simulate multidirection-facing minimally dilated renal calyces. Two interventional fellows punctured the "calyces" using first 2DUS and then 4DUS guidance, making use of a different set of targets each time. The time to puncture, time to introduction of wire, quality of puncture (judged on fluoroscopy) and global rating of both modalities were documented. There was no significant difference between the times to puncture using 2DUS (1.8 min) and 4DUS (2 min). Nor was there a significant difference in the quality of puncture. 4DUS had a higher median difficulty rating. The multiplanar reformatted (MPR) longitudinal and transverse images were found to be the most useful for needle guidance. Cross hairs in all MPR images were not just useful in aligning the images on target but also as surrogate targets. The phantom was found to be robust, with only one instance of air introduction after 30 punctures. We have found that 4DUS is at least as good as 2DUS in terms of quality of punctures in vitro. The technology still has some way to go as frame rates, transducer size and resolution improve.  相似文献   
22.
Quality in healthcare is increasingly graded through a patient-centric lens, using reports of satisfaction and self-perceived outcome. Preestablished expectations have been recognized to influence these measures. With this review, we aim to examine the impact of expectations on satisfaction and patient-reported outcomes (PRO) for individuals undergoing elective spine surgery. We systematically searched MEDLINE, EMBASE, CINAHL, and Cochrane Library electronic databases from inception to July 2015 for studies examining the relationship between expectations and satisfaction/PROs in the context of elective spinal surgery. Qualitative synthesis centered around three key questions: (1) Does the magnitude of preoperative expectations impact patient satisfaction and/or PRO after surgery? (2) Does the underlying spinal pathology influence this relationship? (3) What is the impact of unmet expectations on satisfaction? A total of 1489 citations were retrieved. Nineteen met our inclusion criteria. These comprised 3383 patients; 3200 had lumbar and only 183 had cervical spine surgery. Three findings prevailed: (1) high preoperative expectations appear to be associated with higher satisfaction and PROs after surgery for focal lumbar disc herniation, but not for lumbar spinal stenosis; (2) patient expectations frequently exceed actual outcome, creating an “expectation-actuality discrepancy” (E-AD); and (3) high-quality studies suggest a larger E-AD portends lower satisfaction. Limitations to the data include heterogeneous study populations and surgical indications, along with the use of non-validated assessment tools, particularly for satisfaction. Our findings highlight the potential importance of establishing realistic expectations prior to surgery and may serve to direct future research efforts.  相似文献   
23.
We have previously reported that 2,5,6-trichloro-1-(beta-D-ribofuranosyl)benzimidazole (TCRB) and its 2-bromo analog (2-bromo-5,6-dichloro-1-(beta-D-ribofuranosy)benzimidazole [BDCRB]) are potent and selective inhibitors of human cytomegalovirus (HCMV) replication that block viral DNA maturation via HCMV gene products UL89 and UL56. To determine if phosphorylation is required for antiviral activity, the in vitro metabolism of BDCRB was examined and the antiviral activities of nonphosphorylatable 5'-deoxy analogs were determined. Reverse-phase high-performance liquid chromatography (HPLC) analysis of extracts from uninfected and HCMV-infected cells incubated with [(3)H]BDCRB revealed two major metabolites. Both were less polar than naturally occurring nucleoside monophosphates, but one peak coeluted with a BDCRB-5'-monophosphate (BDCRB-5'-MP) standard. Further analysis revealed, however, that neither metabolite partitioned with BDCRB-5'-MP on anion-exchange HPLC. Their retention patterns were not affected by incubation with alkaline phosphatase, thereby establishing that the compounds were not nucleoside 5'-monophosphates. Both compounds were detected in uninfected and HCMV-infected cells and in mouse live extracts, but neither has been identified. Like TCRB and BDCRB, the nonphosphorylatable 5'-deoxy analogs were potent and selective inhibitors of HCMV replication. The 5'-deoxy analogs maintained inhibition of HCMV replication upon removal of BDCRB, whereas an inhibitor of DNA synthesis did not. Similar to TCRB, its 5'-deoxy analog (5'-dTCRB) did not affect viral DNA synthesis, but 5'-dTCRB did inhibit viral DNA maturation to genome-length units. Additionally, virus isolates resistant to TCRB were also resistant to 5'-dTCRB and the 5'-deoxy analog of BDCRB. Taken together, these results confirm that TCRB, BDCRB, and their 5'-deoxy analogs have common mechanisms of action and establish that these benzimidazole ribonucleosides, unlike other antiviral nucleosides, do not require phosphorylation at the 5' position for antiviral activity.  相似文献   
24.
The roots and rhizomes of various species of the perennial herb licorice (Glycyrrhiza) are used in traditional medicine for the treatment of several diseases. In experimental and clinical studies, licorice has been shown to have several pharmacological properties including antiinflammatory, antiviral, antimicrobial, antioxidative, antidiabetic, antiasthma, and anticancer activities as well as immunomodulatory, gastroprotective, hepatoprotective, neuroprotective, and cardioprotective effects. In recent years, several of the biochemical, molecular, and cellular mechanisms of licorice and its active components have also been demonstrated in experimental studies. In this review, we summarized the new phytochemical, pharmacological, and toxicological data from recent experimental and clinical studies of licorice and its bioactive constituents after our previous published review. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
25.
26.
The marine diatom Skeletonema costatum was used to study mechanisms of detoxification when submitted to cadmium and copper contamination. After 96 h of growth, concentration corresponding to 50% growth inhibition (IC50, 96 h) was 0.224 mg/L for cadmium and 0.045 mg/L for copper, indicating that copper is more toxic for S. costatum than cadmium. Heavy cellular damages were observed for cadmium and copper concentrations close to the IC50. Exposure to these concentrations induced a migration of inclusions from the peripheral cytoplasm to the vacuole. Electron energy loss spectroscopy (EELS) investigations demonstrated that Cd and Cu were specifically trapped in these inclusions. However, Cu was less sequestered than cadmium in the vacuole. EELS determination of oxidation states evidenced that trace metals were sequestered as Cd2+ and Cu2+. Nitrogen and sulfur are involved in metallic storage, especially in the case of cadmium contamination. Received: 6 August 1996/Revised: 18 February 1997  相似文献   
27.
The sodium salts of 4-chloro- and several 4-chloro-5-substituted-7H-pyrrolo[2,3-d]pyrimidines were treated with [1,3-bis(benzyloxy)-2-propoxy]methyl chloride (6) to provide the corresponding 4-chloro- and 4-chloro-5-substituted-7-[[1,3-bis(benzyloxy)-2-propoxy]methyl]pyrrolo [2,3-d]pyrimidines (7-11). Debenzylation with boron trichloride at -78 degrees C furnished 4-chloro- and several 4-chloro-5-substituted-7-[(1,3-dihydroxy-2-propoxy)methyl]pyrrolo[2,3- d]pyrimidines (12.16). Subsequent amination of 12-16 yielded the 4-amino-5-substituted-7-[(1,3-dihydroxy-2-propoxy)methyl]pyrrolo[2,3- d]pyrimidines (17-21). Treatment of 14 with methylamine and 13 and 14 with ethylamine yielded the 4-(alkylamino)-5-halo-7-[(1,3-dihydroxy-2- propoxy)methyl]pyrrolo[2,3-d]pyrimidines (22-24). Treatment of 12-15 with hydroxylamine in refluxing 2-propanol yielded the 5-substituted-4-(hydroxyamino)-7-[(1,3-dihydroxy-2-propoxy)methyl]pyrrol o [2,3-d]pyrimidines (25-28). Treatment of compound 12 with Pd/C under a hydrogen atmosphere has furnished the nebularine analogue 31. The antiproliferative activity of compounds 17-28 and 31 was studied using L1210 cells in vitro. The 4-amino- and 4-(hydroxyamino)-5-halogenated derivatives (compounds 18-20, 26-28) inhibited cell growth. Although the effect of compounds 18-20 and 27 on final growth rate was pronounced (IC50 = 2.3, 0.7, 2.8, and 3.7 microM, respectively), cells underwent at least one doubling before cell division stopped. The remaining compounds were less cytotoxic, with IC50's greater than 30 microM for 21, 23, 26, and 28, whereas no inhibition of L1210 cell growth was observed with compounds 17, 22, 24, 25, and 31 at 100 microM. The antiviral activity of these compounds also was tested. Compounds 18-20 and 26-28 were active against human cytomegalovirus and herpes simplex type 1. The 4-amino derivatives (18-20) were more active than the 4-hydroxyamino derivatives (26-28), the 4-amino-5-bromo and 4-amino-5-iodo derivatives produced more than five log reductions in virus titer at concentrations of 10-100 microM. Although some cytotoxicity was observed at these concentrations, compound 19 was active against murine cytomegalovirus in vivo. At 5.6 mg/kg, 14/15 animals survived compared to 10/15 treated with 5.6 mg/kg of ganciclovir or 1/15 treated with placebo.  相似文献   
28.
The brightly echogenic appearance of the diaphragm on routine clinical scans is not easily reconciled with the well-documented echo-poor appearance of muscle elsewhere in the body. A series of specimens of normal human diaphragm freshly excised at autopsy were suspended in a water bath. Articulated arm scans were done varying the angle of the incident beam to the specimen by 5-degree increments and recording the maximum attenuation which allowed visualization (ie, an extinction point). This was accomplished for intact diaphragm, peritoneal membrane alone, and diaphragmatic muscle alone with both membranes stripped. The bright specular echoes seen are due almost exclusively to the membranes (parietal pleura and peritoneum) and the diaphragmatic muscle itself produces only low-level scattered echoes as elsewhere. However, these scattered echoes account for persistent visualization of the diaphragm at steep angles of the incident beam. A considerable portion of the in vivo thickness of the diaphragmatic echo complex is, therefore, produced by diaphragm-lung interface.  相似文献   
29.
In vitro evaluation of a series of previously prepared tubercidin analogues revealed that certain 5-halogen-substituted analogues were active against human cytomegalovirus (HCMV) at concentrations lower than those that produced comparable cytotoxicity in uninfected cells. In contrast, tubercidin was cytotoxic at all antiviral concentrations. Even though the antiviral selectivity of the 5-substituted compounds was slight, this observation led us to prepare a series of acyclic analogues. Treatment of the sodium salt of 4-chloropyrrolo[2,3-d]pyrimidine (2) with (2-acetoxyethoxy)methyl bromide (2a) provided the acyclic nucleoside 4-chloro-7-[(2-acetoxyethoxy)methyl]pyrrolo[2,3-d]pyrimidine (3). A nucleophilic displacement of the 4-chloro group with methoxide, methylamine, and dimethylamine yielded the corresponding 4-substituted compounds 4, 5, and 6, respectively, in good yield. Electrophilic substitution (chlorination, bromination, and iodination) was effected at the C-5 position of compound 3 with N-chlorosuccinimide, N-bromosuccinimide, and iodine monochloride, respectively, in methylene chloride. Removal of the acetyl group from these intermediates (7a-9a) with methanolic ammonia at room temperature afforded the 5-chloro (7b), 5-bromo (8b), and 5-iodo (9b) derivatives of 4-chloro-7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidine. Treatment of compounds 7b-9b with methanolic ammonia at an elevated temperature produced the corresponding 5-halotubercidin analogues 10, 11, and 12, respectively. An alternate procedure for the preparation of these 4,5-disubstituted 7-[(2-hydroxyethoxy)methyl]pyrrolo[2,3-d]pyrimidines involved an electrophilic substitution prior to the condensation of the heterocycle with 2a. Treatment of 2 with N-chlorosuccinimide and N-bromosuccinimide gave compounds 13a and 13b, respectively. The condensation of 13a and 13b with 2a and subsequent treatment with methylamine and ethylamine furnished the corresponding 5-halo-4-substituted-pyrrolo[2,3-d]pyrimidines 14a, 14b, 14c, and 14d, respectively. Evaluation of the target compounds (4-6, 7b-9b, 10-12, and 14a-14d) for cytotoxicity and activity against HCMV and herpes simplex virus type 1 (HSV-1) revealed that all compounds except the 5-halogen-substituted compounds 10, 11, and 12 were inactive. Compounds 10, 11, and 12 were active against both viruses at noncytotoxic concentrations. The activity of compound 11 was particularly noteworthy, being at least 10-fold more potent than acyclovir.  相似文献   
30.
One of the promises of modern biotechnology is to improve medical care by providing accurate diagnosis and targeted treatment to patients who will derive the maximum benefit. Delivery of this promise in the 21st century is the result of major advances in biotechnology over the past 20 years. Sequencing of the human genome and other high-volume data discovery has become possible, owing to relatively inexpensive computation power and automation. The same forces that drove the human genome project are now being focused on cataloging various disease processes at the DNA, RNA and protein levels. As these high-throughput technologies are entering the clinical care environment, the major task at hand is to integrate the complex data and derive clinically useful information. In spite of major breakthroughs in molecular approaches to the diagnosis and prognostication of cancer, there remain significant obstacles in applying these technologies to clinical samples. The time-honored conventional histopathology, for example, is still the backbone of tumor diagnosis and prognostication. The traditional fixation and processing methods are, however, rapidly losing ground, as they do not protect important tissue macromolecules. Formalin, the common universal fixative, is losing its place in histopathology. In addition to its toxicity, it alters macromolecules and renders the tissue unfit for most advanced molecular studies. This has prompted the use of fresh or fresh-frozen biopsy material for most biomolecular discoveries and clinical assays. This of course is impractical, or even impossible, in most clinical settings, particularly since tumors are being detected earlier and smaller. Also, many preneoplastic conditions are impossible to triage for freezing since their accurate diagnosis requires the use of the entire sample for detailed microscopic examination. The focus in this report is on breast cancer, where the value of the innovative approaches of the tissue detection of biomolecular predictors is examined. To this end, novel tissue handling platforms are introduced that are not only suitable for histological diagnosis, but allow the detection of tumor proteome and expression profiles on the same biopsy sample.  相似文献   
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