Control of mRNA translation by dynamic ribosome modification.

Control of mRNA translation is a crucial regulatory mechanism used by bacteria to respond to their environment. In the soil bacterium Pseudomonas fluorescens, RimK modifies the C-terminus of ribosomal protein RpsF to influence important aspects of rhizosphere colonisation through proteome remodelling. In this study, we show that RimK activity is itself under complex, multifactorial control by the co-transcribed phosphodiesterase trigger enzyme (RimA) and a polyglutamate-specific protease (RimB). Furthermore, biochemical experimentation and mathematical modelling reveal a role for the nucleotide second messenger cyclic-di-GMP in coordinating these activities. Active ribosome regulation by RimK occurs by two main routes: indirectly, through changes in the abundance of the global translational regulator Hfq and directly, with translation of surface attachment factors, amino acid transporters and key secreted molecules linked specifically to RpsF modification. Our findings show that post-translational ribosomal modification functions as a rapid-response mechanism that tunes global gene translation in response to environmental signals.

Time and resources of peripherally inserted central catheter insertion procedures: a comparison between blind insertion/chest X-ray and a real time tip navigation and confirmation system.

BACKGROUND: The Sherlock 3CG™ Tip Confirmation System (TCS) provides real-time peripherally inserted central catheter (PICC) tip insertion information using passive magnetic navigation and patient cardiac electrical activity. It is an alternative tip confirmation method to fluoroscopy or chest X-ray for PICC tip insertion confirmation in adults. The purpose of this study was to evaluate time and cost of the Sherlock 3CG TCS and blind insertion with chest X-ray tip confirmation (BI/CXR) for PICC insertions. METHODS: A cross-sectional, observational Time and Motion study was conducted. Data were collected at four hospitals in the US. Two hospitals used Sherlock 3CG TCS and two hospitals used BI/CXR to place/confirm successful PICC tip location. Researchers observed PICC insertions, collecting data from the beginning (ie, PICC kit opening) to catheter tip confirmation (ie, released for intravenous [IV] therapy). An economic model was developed to project outcomes for a larger population. RESULTS: A total of 120 subjects were enrolled, with 60 subjects enrolled in each arm and 30 enrolled at each of the four US hospitals. The mean time from initiation of the PICC procedure to the time to release for IV therapy was 33.93 minutes in the Sherlock 3CG arm and 176.32 minutes in the BI/CXR arm (p < 0.001). No malpositions were observed for PICC insertions using the Sherlock 3CG TCS, while 20% of subjects in the BI/CXR arm had a malposition. BI/CXR subjects had significantly more total malpositions (mean 0.23 vs. 0, p < 0.001). For a hypothetical population of 1,000 annual patients, adoption of Sherlock 3CG TCS was predicted to be cost saving compared with BI/CXR in all three analysis years. CONCLUSION: The results from this study demonstrate that Sherlock 3CG TCS, when compared with BI/CXR, is a superior alternative with regard to time to release subject to therapy, malposition rates, and minimization of X-ray exposure.

Blunt splenic injury: use of a multidetector CT-based splenic injury grading system and clinical parameters for triage of patients at admission.

PURPOSE: To assess the use of a dual-phase multidetector computed tomography (CT)-based grading system alone and in combination with assessment of clinical parameters at triage of patients with blunt splenic injury for determination of appropriate treatment (observation, splenic artery embolization [SAE], or splenic surgery). MATERIALS AND METHODS: This HIPAA-compliant retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between January 2009 and July 2011, 171 hemodynamically stable patients with blunt splenic injury underwent multidetector CT at admission to the hospital. Images were reviewed by applying a multidetector CT-based grading system, and the amount of hemoperitoneum was quantified. Demographic data, vital signs, laboratory values, injury severity score, abbreviated injury severity, final treatment decision, and success of nonsurgical treatment were reviewed. Receiver operating characteristic curves and stepwise logistic regression analyses were performed to determine the optimal parameters for effective triage of patients. RESULTS: One hundred seventy one patients with splenic injury underwent multidetector CT. At triage, clinical treatment decisions were made, and patients received either observation (85 of 171 [50%]) or splenic intervention (surgery, 19 of 171 [11%] or splenic angiography, 67 of 171 [39%]). Four patients underwent SAE after unsuccessful observation. Six of 171 (3.5%) other patients received unsuccessful nonsurgical treatment with SAE. No patients who received observation required splenectomy. Areas under the receiver operating characteristic curve (AUCs) showed that the CT grading system was the best individual predictor of successful observation (AUC, 0.95), and stepwise logistic regression analysis results showed that multidetector CT grade and the abbreviated injury scale score (AUC, 0.97; P = .02) were the best combination of variables for selection of patients for observation versus splenic intervention. The combination of abbreviated injury scale score, systolic blood pressure reading, and serum glucose level was the best triage model for decision making between splenectomy and SAE (AUC, 0.84). CONCLUSION: The best individual predictor of successful observation in patients with blunt splenic injury was the CT-based grading system. Multidetector CT grade and abbreviated injury scale score were the best combination of variables for selection of patients for observation versus splenic intervention.

Design, Development, and Evaluation of a Master-Slave Surgical System for Breast Biopsy under Continuous MRI.

Magnetic Resonance Imaging (MRI) provides superior soft-tissue contrast in cancer diagnosis compared to other imaging modalities. However, the strong magnetic field inside the MRI bore along with limited scanner bore size poses significant challenges. Since current approaches in breast biopsy using MR images is primarily a blind targeting approach, it is necessary to develop a MRI-compatible robot that can avoid multiple needle insertions into the breast tissue. This MRI-compatible robotic system could potentially lead to improvement in the targeting accuracy and reduce sampling errors. A master-slave surgical system has been developed comprising of a MRI-compatible slave robot which consists of one piezo motor and five pneumatic cylinders connected by long pneumatic transmission lines. The slave robot follows the configuration of the master robot, which provides an intuitive manipulation interface for the physician and operates inside the MRI bore to adjust the needle position and orientation and perform needle insertion task. Based on the MRI experiments using the slave robot, there was no significant distortion in the images and hence the slave robot can be safely operated inside the MRI with minimal loss in signal-to-noise ratio (SNR). Ex vivo and in vivo experiments have been conducted to evaluate the performance of the master-slave surgical system.

Real-time MR imaging guidance for percutaneous core biopsy of US- and CT-negative lesion.

Biopsies traditionally are performed under ultrasound (US), computed tomography (CT), or fluoroscopic guidance. In situations in which lesions are difficult to visualize with US or CT guidance, magnetic resonance (MR) imaging often can provide better imaging results. The authors describe a case in which a recurrent calf mass not well visualized under fluoroscopy, CT, or US was identified on MR imaging. In the absence of real-time needle visualization, percutaneous interventions under MR guidance have been limited by prohibitively long imaging times. A novel guidance system providing real-time MR guidance of needle position was used to procure a core biopsy specimen of the lesion.

Thinking outside the box: a metacognitive / theory of mind perspective on concrete thinking.

Concrete thinking, an extraordinarily difficult condition to treat, has been psychoanalytically theorized to result from failures of symbolization-problems forming, linking, or fathoming the meaning of symbols-and/or failures of differentiation, resulting in difficulties distinguishing symbols from the thing being symbolized, fantasy from reality, self from other. Though difficulties symbolizing and differentiating are clearly evident in patients whose thinking is concrete, these may be a manifestation of concrete thinking rather than a root cause. Childhood thinking is characteristically concrete, and a persistence of such thinking into adulthood can be adequately explained as a failure to develop a more sophisticated theory of mind. Given that patients who exhibit such thinking tend to respond poorly to classic psychoanalytic interpretations, alternative technical approaches have been proposed. One such approach, "metacognitive" in nature, draws on a mode of thought used by gifted individuals that helps them "think outside the box" by dispensing with a typical pattern-recognition search so that novel meanings might be discovered. Metacognition, thoughts about one's thoughts and thought processes, facilitates symbolic thinking by creating sufficient distance from one's thoughts to allow the consideration of alternative meanings.

Optimizing multidetector CT for visualization of splenic vascular injury. Validation by splenic arteriography in blunt abdominal trauma patients.

Nonoperative management of blunt splenic injury is the treatment of choice in hemodynamically stable patients. Detection of vascular injury by multidetector CT (MDCT) is the most significant factor predicting the need for endovascular treatment. This study evaluated the timing of the appearance of vascular lesions during angiography. Images from 20 patients embolized for pseudoaneurysms (PSA) were evaluated. Angiograms were reviewed for phase and timing of PSA. Admission MDCT was reviewed for injury grade and PSA. Initial MDCT evaluation indicated grade III and IV splenic injuries in 9 and 11 patients, respectively. PSA was seen on MDCT in 14/20 (70%) patients. Time from opacification of the aorta to vascular injury was 1.32 s for arterial phase injuries compared with 2.05 s for postcapillary injuries (P=0.097). Angiography demonstrated 15 vascular injuries during the arterial and 5 in the venous phase. Of injuries seen during arterial phase angiography, 10/15 (66%) were identified on MDCT. Of the five injuries that exhibited postcapillary-phase findings, 4/5 (80%) demonstrated PSA (P=0.5). Vascular lesions are a better indicator of subsequent clinical deterioration than splenic injury grade. PSAs are more frequently seen in postcapillary vascular injuries than arterial phase lesions with the current timing of MDCT. In a subset of patients in whom splenic injury grades III and IV warrant angiography, PSAs are not initially demonstrated on MDCT. Therefore, alteration of MDCT timing parameters to better correlate with arterial phase angiography may improve initial diagnosis of vascular injury.

Cryoablation of renal fossa recurrence after radical nephrectomy.

BACKGROUND AND PURPOSE: Renal fossa recurrence of renal-cell carcinoma (RCC) after radical nephrectomy historically necessitates open surgical resection. Cryoablation provides a minimally invasive alternative to open resection for local recurrence. We describe our experience with percutaneous cryoablation in three patients who were experiencing fossa recurrence. PATIENTS AND METHODS: We retrospectively reviewed medical records of three patients with renal fossa recurrence of RCC who were treated with percutaneous cryoablation. RESULTS: Percutaneous cryoablation was well tolerated; no complications were noted, and patients were discharged within 23 hours. One patient needed an additional cryoablation procedure, and one patient underwent subsequent open extirpation. Metastatic disease developed in one patient, while the other two patients remain negative for disease by axial imaging and percutaneous biopsy. All patients are alive at 43 months (range 22-54 months). CONCLUSIONS: Percutaneous cryoablation, a minimally invasive intervention, has low morbidity and may be offered as an alternative to extirpation, although long-term oncologic data are lacking.

Towards a teleoperated needle driver robot with haptic feedback for RFA of breast tumors under continuous MRI.

OBJECTIVE: The purpose of this paper is to explore the feasibility of developing a MRI-compatible needle driver system for radiofrequency ablation (RFA) of breast tumors under continuous MRI imaging while being teleoperated by a haptic feedback device from outside the scanning room. The developed needle driver prototype was designed and tested for both tumor targeting capability as well as RFA. METHODS: The single degree-of-freedom (DOF) prototype was interfaced with a PHANToM haptic device controlled from outside the scanning room. Experiments were performed to demonstrate MRI-compatibility and position control accuracy with hydraulic actuation, along with an experiment to determine the PHANToM's ability to guide the RFA tool to a tumor nodule within a phantom breast tissue model while continuously imaging within the MRI and receiving force feedback from the RFA tool. RESULTS: Hydraulic actuation is shown to be a feasible actuation technique for operation in an MRI environment. The design is MRI-compatible in all aspects except for force sensing in the directions perpendicular to the direction of motion. Experiments confirm that the user is able to detect healthy vs. cancerous tissue in a phantom model when provided with both visual (imaging) feedback and haptic feedback. CONCLUSION: The teleoperated 1-DOF needle driver system presented in this paper demonstrates the feasibility of implementing a MRI-compatible robot for RFA of breast tumors with haptic feedback capability.

Percutaneous fluoroscopically guided jejunostomy placement.

PURPOSE: To describe our experience with fluoroscopically guided direct jejunostomy placement in patients with enterocutaneous fistula, or neoplastic or postsurgical changes of the stomach or duodenum that preclude traditional gastrostomy placement. MATERIALS: Nineteen patients underwent percutaneous direct jejunostomy tube placement with fluoroscopic guidance from August 2004 through March 2006. There were 15 men and four women whose ages ranged from 28 to 82 years (mean, 54 years). Seven patients had surgical changes to the stomach that precluded traditional gastrostomy access, one patient had a duodenal tumor, two had unresectable gastric tumors, and nine had small bowel pathology that required distal access. RESULTS: Jejunal access was initially successful in 18 of 19 (95%) procedures. Follow-up ranged from 10 days to 509 days. Two catheters were removed as they were no longer needed. Seven patients' initial tubes were still functioning at the end of their follow-up. One tube was removed secondary to pain and irritation at the insertion site. Three tubes were occluded. One patients' tube was inadvertently pulled out. In two patients, feeding was not tolerated secondary to fistula distal to the jejunostomy. Two patients died with their initial tubes. Primary patency was 285 days (95% CI 162-407). One death occurred 10 days postprocedure for a 30-day mortality of 1 of 19 (5%). CONCLUSIONS: Percutaneous direct jejunostomy placement is a relatively safe and effective means of gaining enteral access in patients who have enterocutaneous fistula or who have either postsurgical or neoplastic changes of the stomach that preclude traditional gastrostomy placement.

Correlation of multidetector CT findings with splenic arteriography and surgery: prospective study in 392 patients.

BACKGROUND: To determine the accuracy of contrast-enhanced multidetector CT (MDCT) in demonstrating splenic vascular injury based on results of splenic angiography and operation. STUDY DESIGN: This institutional review board-approved study included 392 hemodynamically stable blunt trauma patients whose admission MDCTs demonstrated splenic injury. Images were assessed for parenchymal injury grade, hemoperitoneum volume, and evidence of bleeding and nonbleeding splenic vascular injury. Splenic arteriography was performed for high splenic injury grade and splenic vascular injury. Medical records were reviewed to determine arteriographic interpretation, surgery indications and findings, outcomes, and demographics. Sensitivity, specificity, predictive values, and accuracy of MDCT in detecting vascular injury were calculated based on results of arteriography and operation. RESULTS: Splenic vascular injury was seen in 22% of patients (86 of 392) on MDCT. Presence of a vascular injury correlated with the CT-based parenchymal splenic injury grade (p < 0.0001). Active splenic bleeding was associated with subsequent clinical deterioration (p < 0.0001). Overall, MDCT had a sensitivity of 76% (76 of 100); specificity of 90% (95 of 106); negative and positive predictive values of 80% (95 of 119) and 87% (76 of 87), respectively; and accuracy of 83% (171 of 206) in detecting vascular injury compared with reference standards. The success rate of nonoperative management was 96%. CONCLUSIONS: MDCT provides valuable information to direct initial clinical management of patients with blunt splenic trauma by demonstrating both active bleeding and nonbleeding vascular injuries. Not all vascular injuries are detected on MDCT, and splenic angiography is still indicated for high-grade parenchymal injury.

Evaluation of the Amplatzer vascular plug for proximal splenic artery embolization.

PURPOSE: Proximal splenic artery embolization is performed for splenic salvage in the setting of trauma or before splenectomy in patients with splenomegaly. Typically, this has been done with the use of metallic coils, but precise placement of the first deposited coil may be limited. The Amplatzer vascular plug (AVP) may be used to accomplish precise proximal splenic artery embolization. MATERIALS AND METHODS: Fourteen patients had proximal splenic artery embolization performed with the AVP. Thirteen were performed to allow splenic salvage after blunt trauma and one was performed before splenectomy for massive splenomegaly. Devices ranging in diameter from 8 to 12 mm were placed through 5-F or 6-F guiding catheters. Desired AVP location was distal to the dorsal pancreatic artery and proximal to the most peripheral pancreatica magna branch. Test injections of contrast agent were performed after approximately 5 minutes and then at 3-5-minute intervals until occlusion was seen. If this was not noted by 15 minutes, an adjunctive closure method was chosen. Computed tomography (CT) follow-up was performed in all patients. RESULTS: Device placement in the desired location was successful in all cases, with device repositioning required in two. Occlusion took an average of approximately 10 minutes. Additional coils placed in three patients could all be packed into a tight configuration. A second AVP was placed in one patient. There were no complications of the procedures. Follow-up CT images showed no evidence of migration or recanalization of any of the devices. Minimal artifact was noted from the AVP on CT. CONCLUSION: In this preliminary series, use of the AVP allowed for precise proximal splenic artery embolization.

Unravelling the riddle of exhibitionism: a lesson in the power tactics of perverse interpersonal relationships.

Through an examination of the varied paradoxes embedded within the phenomenon of genital exhibitionism, the author establishes exhibitionism as a paradigm for interpersonal relations whereby one individual entices another to lose himself, to a benign or dangerous degree, in a presented portrayal/enactment. Efforts to entice that cause an extreme loss of the subject's sense of self--making it exceedingly hard to break free of--are designed to render the subject powerless and take psychic possession of him. The perpetrator accomplishes this feat by interacting with his victim in ways capable of producing a sudden and profound regression with sufficient loss of autonomous ego functioning that the subject finds it hard, if not impossible, to act on his own behalf. The essential feature of the perpetrator's efforts is his violation of the unspoken but understood rules of interpersonal engagement that, when violated, cause extreme disorientation and a loss of trust in one's most basic assumptions about how humans treat one another. When this happens, we would describe the interaction as having been perverted to serve the exclusive needs of the predator--to gain as complete control over the other as possible.

Thinking with, and about, patients too scared to think: can non-interpretive maneuvers stimulate reflective thought?

Patients incapable of higher-order (symbolic) thinking can often not tolerate evidence of the analyst's separate existence, particularly when that "otherness" becomes evident in the process of the analyst's reflecting upon and interpreting how the patient experiences or represents the analyst. The patient's intolerance of the analyst's efforts to think (reflect upon and interpret) renders the usual psychoanalytic maneuvers employed to stimulate reflective thought ineffective with such patients. Such patients have to learn to tolerate multiple perspectives before they can allow the analyst, or themselves, to think in the other's presence. The author presents two clinical vignettes that illustrate how the analyst's efforts to think about the patient were experienced by the patient as both intolerably distancing and as rejecting of an aspect of the patient's subjective reality. Working psychoanalytically with such patients requires the analyst to forego the use of narrow interpretations that elucidate unconscious meanings and motives in favor of alternate technical maneuvers capable of facilitating the development of symbolic thinking and reflective thought (insightfulness). These maneuvers include a demonstration of the analyst's willingness and ability to withstand (rather than "interpret away") how he is being psychically represented by the patient, without becoming destroyed by, or lost within, the patient's characterization of him. Beside modeling a tolerance of alternate perspectives of one's self, other non-interpretive maneuvers that help facilitate the development of self-reflective thought include: stimulating the patient's curiosity about the workings of his own mind by identifying incompletely understood behaviors or reactions worthy of greater psychological understanding, and insinuating doubt about the adequacy of the patient's explanations of such phenomena.

Thoracic angiography and intervention in trauma.

Interventional radiologists are involved less often in the initial diagnostic evaluation of patients who have acute chest trauma today than in the past. Patients are cleared of significant injury by CT, or, when a significant injury is present, they are triaged appropriately to open surgery or endovascular intervention. Significant advances in catheter-based technology, such as stent grafts and embolization coils, allow definitive repair of thoracic aortic and branch vessel injury. The opportunity to treat these types of injury with minimally invasive techniques has reinforced a continuing need for the maintenance and continued development of skills in the performance and interpretation of thoracic angiography. This article reviews these techniques and examines the status and the future of endovascular interventions in thoracic trauma.

Endovascular technique for revision of excess catheter length in subcutaneous implanted venous access devices.

To describe the implementation of a technique to trim the excess length of a central venous catheter via a process of endovascular snaring without exposing or changing the device. We report on the outcome of this technique in 3 patients. The technique was successful in two cases and successful with a modification in the remaining case. The technique is useful to salvage an implanted venous access device. It appears to be less invasive with reduced procedure time and less patient discomfort than other techniques.