The time-resolved atomic, molecular and optical science instrument at the Linac Coherent Light Source.

The newly constructed time-resolved atomic, molecular and optical science instrument (TMO) is configured to take full advantage of both linear accelerators at SLAC National Accelerator Laboratory, the copper accelerator operating at a repetition rate of 120 Hz providing high per-pulse energy as well as the superconducting accelerator operating at a repetition rate of about 1 MHz providing high average intensity. Both accelerators power a soft X-ray free-electron laser with the new variable-gap undulator section. With this flexible light source, TMO supports many experimental techniques not previously available at LCLS and will have two X-ray beam focus spots in line. Thereby, TMO supports atomic, molecular and optical, strong-field and nonlinear science and will also host a designated new dynamic reaction microscope with a sub-micrometer X-ray focus spot. The flexible instrument design is optimized for studying ultrafast electronic and molecular phenomena and can take full advantage of the sub-femtosecond soft X-ray pulse generation program.

Shortfalls in pediatric hydrocephalus clinical outcome analysis.

BACKGROUND: In this paper, we used search engine technology to study outcome analysis and cost awareness of child hydrocephalus in the literature. METHODS: The aggregate hospital charges of hydrocephalus treatment procedures for patients <18 years old was extracted from the Nationwide Inpatient Sample (NIS) data. Hydrocephalus literature was probed through the PubMed biomedical search engine. RESULTS: Aggregate hospital charges associated with ventriculo-peritoneal shunting as the principle procedure for patients <18 years old have increased 1.7-fold over a 13-year period to 235.6 million in 2009. Hospital discharges, however, decreased from 3,390 in 1997 to 2,525 in 2009 (25.5% decrease over 13 years). The number of papers in English language indexed by PubMed in relation to child hydrocephalus in humans increased from 81 papers in 1996 to 133 in 2010 (1.6-fold increase), totaling 1,694 over 15 years. Randomized controlled trials published in relation to child hydrocephalus totaled 16 over the same period (0.94% of child hydrocephalus papers). Papers related to child hydrocephalus with "costs and cost analysis" as medical subject heading totaled 13 papers (0.77%). CONCLUSIONS: Over the past 15 years, disappointingly the number of printed child hydrocephalus papers appeared to have only plateaued. Strikingly, only a very small number of these papers were directed toward randomized control studies, the sine qua non of high-grade clinical evidence. Moreover, very few papers make reference to cost analysis or economics in the treatment of hydrocephalus - an issue coming increasingly before the nation at this point.

Interleukin-lß induces migration of rat arterial smooth muscle cells through a mechanism involving increased matrix metalloproteinase-2 activity.

BACKGROUND: Interleukin-lß (IL-lß) is associated with vascular smooth muscle cell (VSMC) migration during neointimal formation following arterial injury, of which matrix metalloproteinase-2 (MMP-2) may have an important role. We investigated whether IL-lß stimulated migration and MMP-2 production in VSMC, and, if so, whether migration correlated with MMP-2 activity. MATERIALS AND METHODS: Modified Boyden chamber assay quantified cultured rat aorta VSMC migration. Methyl-thiazolyl-tetrazolium assay assessed cell growth. Gelatin zymography and Western blotting determined MMP-2 activity and protein levels, respectively. RESULTS: IL-lß (0.1 - 10 ng/mL) induced migration of VSMC in a concentration-dependent manner without cell proliferation. VSMC released increasing levels of active MMP-2 in a dose-response fashion at IL-1ß 1-10 ng/mL (P < 0.05) while significantly increased levels of latent MMP-2 (pro-MMP-2) were attained more gradually (10 ng/mL, P < 0.05). There was a dose-dependent increase in the ratio of active MMP-2 to pro-MMP-2 in response to IL-1ß (1-10 ng/mL, P < 0.05), suggesting extracellular activation of pro-MMP-2. Protein levels on Western blot paralleled enzyme activity, with the synthesis of more active MMP-2 than pro-MMP-2 in response to IL-1ß. IL-lß-stimulated VSMC migration was significantly attenuated by both the pan-selective MMP inhibitor GM6001 and cis-9-octadecenoyl-N-hydroxylamide, a MMP-2-selective inhibitor. CONCLUSIONS: IL-lß increases MMP-2 activity in VSMC through increased protein synthesis and activation of pro-MMP-2. VSMC migration induced by IL-lß requires active MMP-2. IL-lß may play a role in arterial remodeling following injury.

Army Urban Augmentation Medical Task Forces for COVID-19: Part 1-Development.

This article describes how the U.S. Army developed a new ad hoc medical formation, named Urban Augmentation Medical Task Force for the Department of Defense (DoD) in response to the Coronavirus Disease 2019 pandemic in the Continental United States during the spring of 2020. We review the role of the DoD support of the Federal Emergency Management Agency as a part of Defense Support of Civilian Authorities.

Army Urban Augmentation Medical Task Forces for COVID-19: Part 2-Initial Utilization.

This article describes the utilization of a new ad hoc medical formation, named Urban Augmentation Medical Task Force for the Department of Defense response to the coronavirus disease 2019 pandemic in the Continental United States during the spring of 2020. Military medical personnel from these units were used to staff a variety of different mission assignments. We review the benefits and limitation of this type of formation and recommend future force allocation models.

Thrombin stimulates mitogenesis in pig cerebrovascular smooth muscle cells involving activation of pro-matrix metalloproteinase-2.

Generation of thrombin is associated with vascular remodeling that involves proliferation of vascular smooth muscle cells (SMCs) and activation of pro-matrix metalloproteinases (pro-MMPs). The present study was to investigate whether thrombin would induce mitogenesis and activation of pro-MMPs in cerebrovascular SMCs (CSMCs), and if so, whether MMP activity would contribute to the CSMC mitogenesis. CSMCs were cultured from pig middle cerebral arteries and stimulated with thrombin. Thrombin (0.1-5U/ml), in a dose-dependent fashion, stimulated mitogenesis in CSMCs as detected by bromo-2'-deoxy-uridine (BrdU) incorporation. Additionally, zymographic analyses showed that thrombin stimulated the appearance of the active form of MMP-2 (MMP-2) in a concentration-dependent manner, but not the release of pro-MMP-2. Thrombin did not affect expression of cell-associated pro-MMP-2 protein as evaluated by Western blot analysis. Treatment with the synthetic MMP inhibitor GM6001 or antibodies to MMP-2 significantly reduced thrombin-induced BrdU incorporation in CSMCs. In conclusion, thrombin activates pro-MMP-2 in the absence of elevated pro-MMP-2 expression and secretion in CSMCs, and thrombin induces CSMC mitogenesis involving its action on MMP-2. These findings suggest that thrombin may have relevance in cerebrovascular remodeling associated with brain atherosclerosis and atherothrombotic ischemic stroke through a mechanism involving MMP-dependent CSMC mitogenesis.

Serum and cerebrospinal fluid C-reactive protein levels as predictors of vasospasm in aneurysmal subarachnoid hemorrhage. Clinical article.

OBJECT: Cerebral vasospasm is a common and potentially devastating complication of aneurysmal subarachnoid hemorrhage (aSAH). Inflammatory processes seem to play a major role in the pathogenesis of vasospasm. The C-reactive protein (CRP) constitutes a highly sensitive inflammatory marker. The association of elevated systemic CRP and coronary vasospasm has been well established. Additionally, elevation of the serum CRP levels has been demonstrated in patients with aSAH. The purpose of the current study was to evaluate the possible relationship between elevated CRP levels in the serum and CSF and the development of vasospasm in patients with aSAH. METHODS: A total of 41 adult patients in whom aSAH was diagnosed were included in the study. Their demographics, the admitting Glasgow Coma Scale (GCS) score, Hunt and Hess grade, Fisher grade, CT scans, digital subtraction angiography studies, and daily neurological examinations were recorded. Serial serum and CSF CRP measurements were obtained on Days 0, 1, 2, 3, 5, 7, and 9. All patients underwent either surgical or endovascular treatment within 48 hours of their admission. The outcome was evaluated using the Glasgow Outcome Scale and the modified Rankin Scale. RESULTS: The CRP levels in serum and CSF peaked on the 3rd postadmission day, and the CRP levels in CSF were always higher than the serum levels. Patients with lower admission GCS scores and higher Hunt and Hess and Fisher grades had statistically significantly higher levels of CRP in serum and CSF. Patients with angiographic vasospasm had higher CRP measurements in serum and CSF, in a statistically significant fashion (p < 0.0001). Additionally, patients with higher CRP levels in serum and CSF had less favorable outcome in this cohort. CONCLUSIONS: Patients with aSAH who had high Hunt and Hess and Fisher grades and low GCS scores showed elevated CRP levels in their CSF and serum. Furthermore, patients developing angiographically proven vasospasm demonstrated significantly elevated CRP levels in serum and CSF, and increased CRP measurements were strongly associated with poor clinical outcome in this cohort.

Causes and risk factors for postoperative fever in spine surgery patients.

Postoperative fever is a common dilemma faced by neurosurgeons. To study this problem, we prospectively collected patients who developed fever after spine surgery during the academic year 2007-2008 for whom the internist's consultation was requested. Eighty-five (85) patients were identified, of which 17 had an identifiable infectious cause for their febrile reaction (20%) - fever was attributed to urinary tract infection in 8 cases, pneumonia in 5 cases, wound infection in 3 cases (all lumbar), and cholecystitis in 1 case. The remaining 68 patients (80%) had no definitive diagnosis and fever was attributed to a peripheral venous line which, in this case, was replaced or discontinued. In 32 (37.6%) of the patients, the fever developed on postoperative day (POD) 2 or later. There was no statistically significant relationship between day of fever appearance and whether the fever was due to definite infection (P = 0.737). Comparing the basic group with another group of 456 spine surgery patients from 2006-2007 who might or might not have developed fever postoperatively using ANOVA, we found a significant difference in age (P = 0.011) and a very significant difference in hemoglobin level (P = 0.000) and HbA1c level (P = 0.000), but not in body mass index (BMI) (P = 0.289). Thus, most of the postoperative fever cases after spine surgery have no identifiable infectious focus and develop mainly in older patients with anemia and inadequately controlled HbA1c. A meticulous investigation of the source of fever including laboratory and radiological studies remains essential. Early mobilization is recommended for individuals undergoing lower spine surgery in order to decrease bacterial contamination from the gluteal cleavage.

Quantitative estimation of the recurrent laryngeal nerve irritation by employing spontaneous intraoperative electromyographic monitoring during anterior cervical discectomy and fusion.

STUDY DESIGN: Prospective, clinical study. OBJECTIVE: The objective of our study was to evaluate the role of laryngeal intraoperative electromyography (IEMG) in predicting the development of postoperative recurrent laryngeal nerve (RLN) palsy in patients undergoing anterior cervical discectomy and fusion (ACDF). We also attempted to develop a method to quantify the total IEMG irritation of the RLN. SUMMARY OF BACKGROUND DATA: RLN injury has been recognized as the most common ACDF-associated neurologic injury. It has been postulated, that the employment of laryngeal IEMG may identify the operative events leading to RLN injury and subsequent postoperative palsy. METHODS: Laryngeal IEMG monitoring was performed in 298 patients undergoing ACDF. Preexistent baseline EMG activity, amplitude, and duration of IEMG activity were recorded. The total amount of RLN irritation was expressed as an Irritation Score (IS) applying a specially designed mathematical equation incorporating the amplitude, the duration, and the presence of any baseline EMG irritation. The relationship of IEMG activity with parameters such as the number of operative levels, the duration of the procedure, the presence of any previous neck surgeries, and the type of the used retractor was examined. RESULTS: IEMG activity was recorded in 14.4% of our patients. Postoperative RLN injury occurred in 2.3% of our patients. The sensitivity of IEMG was 100%, the specificity 87%, the positive predictive value 16%, and its negative predictive value 97%. The calculated IS ranged between 0.28 and 3.47 (mean IS: 2.09). Significantly increased IEMG activity was found in patients with previous surgical intervention, patients undergoing multilevel procedures, long-lasting procedures, and cases in which self-retained retractors were used. Likewise, significantly increased IS were observed in patients with previous surgeries and in cases where self-retained retractors were used. CONCLUSIONS: Our study indicates that laryngeal IEMG is a high-sensitivity modality that can provide real-time information and can potentially minimize the risk of operative RLN injury.

Interaction of age and opioid dependence on length of hospital stay for spine surgery patients.

Clinical information suggests that opioid dependence is a major contributor to poor outcomes involving health status and to increased length of stay in hospital settings. Before spine surgery, 150 patients who were using an opioid medication for pain relief were interviewed using the six World Health Organization (WHO) guidelines for the diagnosis of opioid dependence. Three groups were defined: opioid-dependent, nonopioid-dependent, and a subclinical group. Results revealed an average of 20% of patients (N = 30) who met the WHO criteria for the diagnosis of opioid dependence. There were significant positive correlations between age and number of positive WHO criteria, length of stay, and time under surgery. Length of stay was significantly higher for the older age group (> 55 yr.). ANCOVA analysis using two opioid dependence groups (+ and -) and age group as independent variables affecting length of stay, after controlling for type of surgery, pain intensity, and number of previous spine surgeries, revealed that effects of opioid dependence status and age were significant but their interaction was not. Age did add length of stay independently of opioid dependence status; older adults remain in the hospital longer for various reasons probably associated with comorbidities.

Terson hemorrhage in patients suffering aneurysmal subarachnoid hemorrhage: predisposing factors and prognostic significance.

OBJECT: The association of vitreous and/or subhyaloid hemorrhage with aneurysmal subarachnoid hemorrhage (SAH) has been frequently identified since the original description by Terson in 1900. In this prospective clinical study the authors examined the actual incidence of Terson hemorrhage in patients suffering aneurysmal SAH, they attempted to identify those parameters that could predispose its development, and they evaluated its prognostic significance in the overall patients' outcome. METHODS: A total of 174 patients suffering aneurysmal SAH were included in this study. The admitting Glasgow Coma Scale scores (GCS), World Federation of Neurological Societies (WFNS) scale scores, Hunt and Hess grades, and Fisher grades were recorded. A careful ophthalmological evaluation was performed in all participants. The exact anatomical locations and the largest diameter of the dome of the ruptured aneurysms were also recorded. Surgical clipping or endovascular coiling was used in 165 patients. Clinical outcome was evaluated at discharge from the hospital by using the Glasgow Outcome Scale and the modified Rankin Scale. Periodic ophthalmological evaluations were performed for 2 years. RESULTS: In this series, the observed incidence of Terson hemorrhage was 12.1%. Statistical analysis of our data demonstrated that patients with low GCS scores and high WFNS scores, Hunt and Hess grades, and Fisher grades had an increased incidence of Terson hemorrhage. The mortality rate for patients with Terson hemorrhage was 28.6%, whereas that for patients without Terson hemorrhage was 2.0%. Moreover, patients with Terson hemorrhage who survived had significantly worse outcomes than those in patients without Terson hemorrhage. CONCLUSIONS: Terson hemorrhage constitutes a common SAH-associated complication. Its incidence is increased in patients with low GCS and high WFNS scores, and high Hunt and Hess and Fisher grades. Its presence is associated with increased mortality and morbidity rates.

Brain metastasis from thymic carcinoma in association with SIADH and pituitary enlargement: a case report.

A 49-year-old white female presented to the emergency room complaining of severe headaches. A brain computed tomography (CT) showed a large right temporal mass that measured 2.9 x 5 cm. Sodium was low at admission, which indicated syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Her pituitary gland was enlarged. Thorax CT revealed a large anterior mediastinal mass measuring 6.3 x 3.6 cm. Pathology revealed a poorly differentiated carcinoma arising from the thymus. This case is unique because thymic cancer rarely results in brain metastases and very rarely causes SIADH with changes in pituitary volume and signal quality.

The fifth vital sign--what does it mean?

Acute pain is reported as a presenting symptom in over 80% of physician visits. Chronic pain affects an estimated 76.2 million Americans--more than diabetes, heart disease, and cancer combined. It has been estimated to be undertreated in up to 80% of patients in some settings. Pain costs the American public more than $100 billion each year in health care, compensation, and litigation. That's why pain was officially declared "The Fifth Vital Sign." Henceforth the evaluation of pain became a requirement of proper patient care as important and basic as the assessment and management of temperature, blood pressure, respiratory rate, and heart rate. The numeric pain scale certainly has a place in care and in pain management; however, it is important to assess the patient's communication and self-management style and to recognize that patients, like pain, are on a continuum with varied styles of communication and adaptation. It is easy to get lost in the process, even when the process is initiated with the best of intentions. In the quest for individualized medicine, it might be best to keep pain assessment in the individualization arena.

The possible impact of cervical stenosis on cephalad neuronal dysfunction.

Earlier observers have speculated on the causal relationships between abnormal CSF circulation and a variety of neurological dysfunctions. Such speculations have been at least partially validated by recent evidence and inquiries contravening the traditional static viewpoint of CSF circulation. More contemporary inquiries establish a number of factors which influence both CSF production and absorption (sleep disturbance, neck position, cerebral metabolism, brain atrophy, medications, etc.). Thus, transient periods of abnormality are possibly mingled with periods of normality. Such episodic alterations suggest that the physiological arrangements which underpin CSF circulation may be in some ways likened to blood pressure alterations, in that long-standing CSF abnormalities may be both unappreciated and gradual, though virulent enough to cause substantial neurological injury. We suggest that cervical stenosis (blocking an important CSF decompressive pathway into the vertebral canal) is among the largely unappreciated causes of abnormal CSF circulation and may play a role in cephalad neuronal dysfunction. Such a blockage is correlated with age and easily assessed by cine MRI study. Indeed, episodic disturbances can diminish CSF cerebral flow circulation increasing deposition in cerebral parenchyma of contrary metabolic products (e.g. beta Amyloid), possibly having a causal influence on senile dementia. Additionally, cervical stenosis, by increasing posterior fossa cerebral pressure, could play a causal role in a number of afflictions, among them sleep apnea, concomitant respiratory and circulatory dysfunction, hypertension, chronic occipital headaches, tinnitus, etc. We further suggest that among those patients with substantial cervical stenosis (extensive enough to block CSF circulation in the cervical area as identified by cine MRI) appropriate comparative clinical studies could be undertaken to demarcate associations with presenile dementia, sleep disturbance and posterior fossa dysfunction. Additionally, we suggest that an intracranial monitoring implant be perfected to chronically monitor both intracranial pressure and CSF flow - a monitoring device comparable to the rather less invasive sphygmometric evaluation of blood pressure. If such speculations prove correct, different therapeutic regimens which might improve outcome could be imagined. Among them better sleep hygiene (to by position maximize CSF flow) and possibly more aggressive operative decompressive intervention to diminish cervical obstruction.

Accurate placement of the distal end of a ventriculoatrial shunt with the aid of real-time transesophageal echocardiography. Technical note.

OBJECTIVE: Ventriculoatrial (VA) shunts remain a valid option for the treatment of hydrocephalus, especially in patients in whom ventriculoperitoneal (VP) shunts fail. Correct positioning of the distal end of the catheter in the right atrium is of paramount importance for maintaining shunt patency and reducing the incidence of VA shunt-associated morbidity. The authors present their experience with real-time transesophageal echocardiography (TEE) monitoring for the accurate placement of the distal catheter of a VA shunt. METHODS: Four patients underwent conversion of a VP shunt to a VA shunt under the guidance of intraoperative fluoroscopy and TEE between May 2003 and December 2004. After induction of general anesthesia, the TEE transducer was advanced into the esophagus. A cervical incision was made and the external jugular vein was visualized. An introducer was passed through an opening in the jugular vein and a guidewire was placed through the introducer. Under continuous TEE guidance, the guidewire was carefully advanced into the superior vena cava. A distal shunt catheter overlying a J-wire was then passed to the superior vena cava, again under TEE guidance. The catheter was advanced to the right atrium after removing the guidewire. Final visualization with TEE and fluoroscopy revealed a good position of the catheter in the right atrium in all four cases. The mean duration of the operation was 91 minutes (range 65-120 minutes) and the mean operative blood loss was 23 ml (range 10-50 ml). No procedure-related complication was noted. CONCLUSIONS: Real-time TEE is a safe and simple technique for the accurate placement of the distal catheter of a VA shunt.

Cervical epidural hematoma in children: a rare clinical entity. Case report and review of the literature.

Pediatric spinal epidural hematoma is a very rare clinicopathological entity. In the vast majority of cases, spinal epidural hematomas have a nonspecific clinical presentation; this, along with their rapid progression, makes their early diagnosis and prompt surgical evacuation critical. Magnetic resonance imaging is the neuroimaging modality of choice, whereas hemilaminectomy or laminectomy is the indicated surgical intervention. The outcome is good when hematoma evacuation is performed before the onset of complete sensorimotor paralysis. In this communication, the authors describe a 12-year-old girl with a traumatic acute cervical epidural hematoma. This lesion was successfully evacuated through a hemilaminectomy, and the patient had an excellent outcome. The pertinent literature is reviewed in terms of the incidence, origin, management, and prognosis of this rare and potentially disastrous clinical entity.

Familial intracranial ependymomas. Report of three cases in a family and review of the literature.

Familial cases of intracranial ependymomas have been well documented in the literature. The authors present two cases from a family in which three members harbored intracranial ependymomas. A 54-year-old man with fourth ventricular ependymoma underwent resection of the tumor followed by radiation therapy. His son presented at age 36 years with a fourth ventricular tanycytic ependymoma and underwent total resection of the ependymoma with postoperative radiation therapy. The father's sister had been treated at another institution for a posterior fossa ependymoma.The association of ependymomas with molecular genetic alterations in chromosome 22 has been previously described. Further investigation of the genetic influences may lead to better therapeutic approaches for this relatively rare clinicopathological entity.

History of acoustic neurinoma surgery.

The purpose of this article is to provide insight into the development of surgery for acoustic neurinomas throughout the years. The significant contribution of surgical authorities such as Cushing, Dandy, and House are discussed. The advances in surgical techniques from the very first operations for acoustic tumors at the end of the 19th century until today are described, with special emphasis on the technological and diagnostic milestones that preceded each step of this development.

Postoperative cauda equina syndrome in patients undergoing single-level lumbar microdiscectomy. Report of two cases.

Cauda equina syndrome is a well-documented complication of uneventful lumbar microdiscectomy. In the vast majority of cases, no radiological explanation can be obtained. In this paper, the authors report two cases of postoperative cauda equina syndrome in patients undergoing single-level de novo lumbar microdiscectomy in which intraoperative electrophysiological monitoring was used. In both patients, the amplitudes of cortical and subcortical intraoperative somatosensory evoked potentials (SSEPs) abruptly decreased during discectomy and foraminotomy. In the first patient, a slow, partial improvement of SSEPs was observed before the end of the operation, whereas no improvement was observed in the second patient. In the first case, clinical findings consistent with cauda equina syndrome were seen immediately postoperatively, whereas in the second one the symptoms developed within 1.5 hours after the procedure. Postoperative magnetic resonance images obtained in both patients, and a lumbar myelogram obtained in the second one revealed no signs of conus medullaris or nerve root compression. Both patients showed marked improvement after an intense course of rehabilitation. The authors' findings support the proposition that intraoperative SSEP monitoring may be useful in predicting the development of cauda equina syndrome in patients undergoing lumbar microdiscectomy. Nevertheless, further prospective clinical studies are necessary for validation of these findings.

Immediate and early postoperative pain relief after kyphoplasty without significant restoration of vertebral body height in acute osteoporotic vertebral fractures.

OBJECT: Painful osteoporotic vertebral compression fractures (VCFs) are a significant cause of disability in the elderly population. Kyphoplasty, a recently developed minimally invasive procedure, has been advocated for the successful management of these fractures in terms of immediate pain relief, and also for restoration of the premorbid level of daily activities. In this retrospective study the authors report on their experience with the early management of VCFs with kyphoplasty. METHODS: A retrospective analysis was conducted in 13 patients (seven women and six men) whose ages ranged from 48 to 87 years (mean age 71.5 +/- 11 years [mean +/- standard deviation]). The interval between onset of symptoms and surgical intervention ranged from 4 to 9 weeks. Twenty levels (12 thoracic, eight lumbar) were treated in this cohort. Immediate and early postoperative (1-month follow-up visit) visual analog scale (VAS) pain scores, activity levels, and restoration of vertebral body (VB) height were assessed. The mean preoperative VAS score was 8 +/- 1, whereas the immediate and early postoperative scores were 1 +/- 1. These findings reflected a resolution of 90 to 100% of preoperative pain. All patients resumed routine activities within hours of the procedure, although improvement in VB height was not accomplished in this cohort. No major complications were encountered in this clinical series. CONCLUSIONS: Kyphoplasty is a safe and effective method for the treatment of osteoporotic VCFs. Failure to restore VB height does not seem to interfere with the excellent pain management and good functional outcome provided by this procedure.