Pushing the Limits of Minimally Invasive Spine Surgery-From Preoperative to Intraoperative to Postoperative Management

The introduction of minimally invasive surgery ushered in a new era of spine surgery by minimizing the undue iatrogenic injury, recovery time, and blood loss, among other complications, of traditional open procedures. Over time, technological advancements have further refined the care of the operative minimally invasive spine patient. Moreover, pre-, and postoperative care have also undergone significant change by way of artificial intelligence risk stratification, advanced imaging for surgical planning and patient selection, postoperative recovery pathways, and digital health solutions. Despite these advancements, challenges persist necessitating ongoing research and collaboration to further optimize patient care in minimally invasive spine surgery.

Evolution of the Transforaminal Lumbar Interbody Fusion (TLIF): From Open to Percutaneous to Patient-Specific

The transforaminal lumbar interbody fusion (TLIF) has seen significant evolution since its early inception, reflecting advancements in surgical techniques, patient safety, and outcomes. Originally described as an improvement over the posterior lumbar interbody fusion (PLIF), the TLIF began as an open surgical procedure, that notably reduced the need for the extensive neural retractation that hindered the PLIF. In line with the broader practice of surgery, trending toward minimally invasive access, the TLIF was followed by the development of the minimally invasive TLIF (MIS-TLIF), a technique that further decreased tissue trauma and postoperative complications. Subsequent advancements, including Trans-Kambin's Triangle TLIF (percLIF) and transfacet LIF, have continued to refine surgical access, minimize surgical footprint, and reduce the risk of injury to the patient. The latest evolution, as we will describe it, the patient-specific TLIF, is a culmination of the aforementioned adaptations and incorporates advanced imaging and segmentation technologies into perioperative planning, allowing surgeons to tailor approaches based on individual patient anatomy and pathology. These developments signify a shift towards more precise methods in spine surgery. The ongoing evolution of the TLIF technique illustrates the dynamic nature of surgery and emphasizes the need for continued adaptation and refinement.

Observations and properties of the first laboratory fusion experiment to exceed a target gain of unity

An indirect-drive inertial fusion experiment on the National Ignition Facility was driven using 2.05 MJ of laser light at a wavelength of 351 nm and produced 3.1±0.16 MJ of total fusion yield, producing a target gain G=1.5±0.1 exceeding unity for the first time in a laboratory experiment [Phys. Rev. E 109, 025204 (2024)10.1103/PhysRevE.109.025204]. Herein we describe the experimental evidence for the increased drive on the capsule using additional laser energy and control over known degradation mechanisms, which are critical to achieving high performance. Improved fuel compression relative to previous megajoule-yield experiments is observed. Novel signatures of the ignition and burn propagation to high yield can now be studied in the laboratory for the first time.

Prophylactic Muscle Flaps Decrease Wound Complication Rates in Patients with Oncologic Spine Disease

BACKGROUND

Patients with oncologic spine disease face a high systemic illness burden and often require surgical intervention to alleviate pain and maintain spine stability. Wound healing complications are the most common reason for reoperation in this population and are known to impact quality of life and initiation of adjuvant therapy. Prophylactic muscle flap (MF) closure is known to reduce wound healing complications in high-risk patients; however, the efficacy in oncologic spine patients is not well established.

METHODS

A collaboration at our institution presented an opportunity to study the outcomes of prophylactic MF closure. The authors performed a retrospective cohort study of patients who underwent MF closure versus a cohort who underwent non-MF closure in the preceding time. Demographic and baseline health data were collected, as were postoperative wound complication data.

RESULTS

A total of 166 patients were enrolled, including 83 patients in the MF cohort and 83 control patients. Patients in the MF group were more likely to smoke ( P = 0.005) and had a higher incidence of prior spine irradiation ( P = 0.002). Postoperatively, five patients (6%) in the MF group developed wound complications, compared with 14 patients (17%) in the control group ( P = 0.028). The most common overall complication was wound dehiscence requiring conservative therapy, which occurred in six control patients (7%) and one MF patient (1%) ( P = 0.053).

CONCLUSIONS

Prophylactic MF closure during oncologic spine surgery significantly reduces the wound complication rate. Future studies should examine the precise patient population that stands to benefit most from this intervention.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Sociodemographic Trends in Telemedicine Visit Completion in Spine Patients During the COVID-19 Pandemic

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

This study identifies potential disparities in telemedicine utilization in the wake of the COVID-19 pandemic and its aftermath in patients receiving spine surgery.

SUMMARY OF BACKGROUND DATA

COVID-19 led to the rapid uptake of telemedicine in the spine surgery patient population. While previous studies in other medical subspecialties have identified sociodemographic disparities in telemedicine uptake, this is the first study to identify disparities in patients undergoing spine surgery.

MATERIALS AND METHODS

This study included patients who underwent spine surgery between June 12, 2018 and July 19, 2021. Patients were required to have at least one scheduled patient visit, either virtual (video or telephone visit) or in-person. Binary socioeconomic variables used for modeling included: urbanicity, age at the time of the procedure, sex, race, ethnicity, language, primary insurer, and patient portal utilization. Analyses were conducted for the entire cohort and separately for cohorts of patients who had visits scheduled within specific timeframes: Pre-COVID-19 surge, initial COVID-19 surge, and post-COVID-19 surge.

RESULTS

After adjusting for all variables in our multivariable analysis, patients who utilized the patient portal had higher odds of completing a video visit compared with those who did not (OR: 5.21; 95% CI: 1.28, 21.23). Hispanic patients (OR: 0.44; 95% CI: 0.2, 0.98) or those living in rural areas (OR: 0.58; 95% CI: 0.36, 0.93) had lower odds of completing a telephone visit. Patients with no insurance or on public insurance had higher odds of completing a virtual visit of either type (OR: 1.88; 95% CI: 1.10, 3.23).

CONCLUSION

This study demonstrates the disparity in telemedicine utilization across different populations within the surgical spine patient population. Surgeons may use this information to guide interventions aimed at reducing existing disparities and work with certain patient populations to find a solution.

Opportunities to Improve HPV Vaccination Among Pediatric, Adolescent, and Young Adult Cancer Survivors by Engaging both Oncology and Primary Care Teams

The incidence of second primary cancers is rising particularly among pediatric, adolescent, and young adult (PAYA) cancer survivors. While human papillomavirus (HPV)-associated cancers can be prevented by vaccination, their uptake is lower and delayed in this group. Because a recommendation from a health care provider is the strongest predictor of HPV vaccination, there are great opportunities for PAYA cancer care providers to positively impact HPV vaccination rates. Prioritizing PAYA cancer care provider education as well as improving the education of and coordination with primary care providers are viewed as opportunities to encourage HPV vaccine uptake and prevent future cancers. See related article by Garcia et al., p. 581.

The Association Between Sociodemographic Factors, Social Determinants of Health, and Spine Surgical Patient Portal Utilization

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To examine patient portal use among the surgical spine patient population across different sociodemographic groups and assess the impact of patient portal use on clinical outcomes.

SUMMARY OF BACKGROUND DATA

Patient portals (PP) have been shown to improve outcomes and quality of care. Engaging them requires internet access, technological literacy, and dexterity, which may serve as access barriers.

METHODS

After exclusion criteria were applied, the study included data for 9211 encounters from 7955 patients. PP utilization was defined as having activated and used the Duke University Medical Center patient portal system, MyChart, at least once. Sociodemographic characteristics included urbanicity, age, race, ethnicity, language, employment, and primary insurer. Clinical outcomes included the length of hospital stay during the procedure, 30-day return to the emergency department, 30-day readmission, and being discharged somewhere other than home.

RESULTS

Being older than 65, non-White, unemployed, non-English-speaking, male, not-partnered, uninsured or publicly insured (Medicaid, Medicare and under 65 years of age, or other government insurance), and living in a rural environment were all risk factors for decreased PP utilization among surgical spine patients. A one-risk factor decrease in the number of social risk factors was associated with a 78% increase in the odds of PP utilization [odds ratio (OR): 1.78; 95% Confidence interval (CI): 1.69-1.87; P <0.001]. Patients not utilizing the portal at the time of their procedure had higher odds of 30-day readmission (OR: 1.59; 95% CI: 1.26-2.00), discharge somewhere other than home (OR: 2.41, 95% CI: 1.95-2.99), and an increased length of hospital stay (geometric mean ratio: 1.21; 95% CI: 1.12-1.30) compared with those who utilized it.

CONCLUSIONS

In patients undergoing spine procedures, PPs are not equally utilized among different sociodemographic groups. PP utilization is also associated with better outcomes. Interventions aimed at increasing PP uptake may improve care for certain patients.

Associations between urbanicity and spinal cord astrocytoma management and outcomes

BACKGROUND

The management of spinal cord astrocytomas (SCAs) remains controversial and may include any combination of surgery, radiation, and chemotherapy. Factors such as urbanicity (metropolitan versus non-metropolitan residence) are shown to be associated with patterns of treatment and clinical outcomes in a variety of cancers, but the role urbanicity plays in SCA treatment remains unknown.

METHODS

The Central Brain Tumor Registry of the United States (CBTRUS) analytic dataset, which combines data from CDC's National Program of Cancer Registries (NPCR) and NCI's Surveillance, Epidemiology, and End Results Programs, was used to identify individuals with SCAs between 2004 and 2019. Individuals' county of residence was classified as metropolitan or non-metropolitan. Multivariable logistic regression models were used to evaluate associations between urbanicity and SCA. Cox proportional hazard models were constructed to assess the effect of urbanicity on survival using the NPCR survival dataset (2004-2018).

RESULTS

1697 metropolitan and 268 non-metropolitan SCA cases were identified. The cohorts did not differ in age or gender composition. The populations had different racial/ethnic compositions, with a higher White non-Hispanic population in the non-metropolitan cohort (86 % vs 66 %, p < 0.001) and a greater Black non-Hispanic population in the metropolitan cohort (14 % vs 9.9 %, p < 0.001). There were no significant differences in likelihood of receiving comprehensive treatment (OR=0.99, 95 % CI [0.56, 1.65], p = >0.9), or survival (hazard ratio [HR]=0.92, p = 0.4) when non-metropolitan and metropolitan cases were compared. In the metropolitan cohort, there were statistically significant differences in SCA treatment patterns when stratified by race/ethnicity (p = 0.002).

CONCLUSIONS

Urbanicity does not significantly impact SCA management or survival. Race/ethnicity may be associated with likelihood of receiving certain SCA treatments in metropolitan communities.

Regional anesthesia in spine surgery: A narrative review

Background: Regional anesthesia, which refers to the use of anesthetics to provide analgesia to a specific body part or nervous innervation territory, has become increasingly popular in the field of spine surgery. With the application of these techniques, it has been postulated that patients will require less systemic analgesia, intraoperatively and postoperatively. The authors of this narrative review discuss the common regional anesthetic modalities applied to spine surgery, in addition to patient selection criteria, success in patients with multiple comorbid illnesses, and its adoption by surgeons. Materials and Methods: An advanced search was performed in the PubMed database to obtain Englishlanguage articles discussing regional anesthesia, awake spine surgery, and postoperative complications. Articles were screened for relevance, and 47 articles were incorporated into this narrative review. Results: Classic neuraxial and paraspinal techniques have allowed surgeons to perform posterior decompression, fusion, and revision procedures. Transversus abdominus plane and quadratus lumborum blocks have enabled better pain control in patients undergoing surgeries requiring anterior or lateral approaches. Documented benefits of regional anesthesia include shorter operative time, improved pain control and hemodynamic stability, as well as decreased cost and length of stay. Several case series have demonstrated the success of these techniques in highly comorbid patients. Conclusion: Regional anesthesia provides an exciting opportunity to make surgical treatment possible for spine patients with significant comorbidities. Although additional randomized controlled trials are necessary to further refine patient selection criteria, current data demonstrates its safety and efficacy in the operating room.

QOL-18. CAN QUALITY OF LIFE FOR BRAIN TUMOR SURVIVORSHIP CARE

Cancer survivorship is an important area of medicine as it focuses on the quality of life of patients after experiencing cancer and cancer treatment. Thankfully, many patients survive cancers and other benign tumor diagnoses but must live with the side effects and subsequent consequences of their treatment. These, sometimes lifelong, effects can diminish quality of life and interfere with day-to-day activities. A number of therapy tools have been developed to aid in survivorship care, but how can we advance new digital therapy tools for cancer survivorship and brain-related diseases, specifically quality of life? The University of Cincinnati has curated an innovative team of faculty and students across disciplines to develop digital applications to emphasize cancer and brain tumor survivorship and create new methods for health and wellbeing at the hands of people. This includes the CAN Quality of Life applications which use novel technologies to administer digital pre-existing therapies. The first, ARMCan, is a digital music therapy instrument used by breast cancer patients with post-chemotherapy brain fog. The second, ARTCan, is a digital art therapy platform in which vestibular schwannoma and NF2 patients with mood issues can complete self-guided art activities. ARTCan is partnered with ARCCan, animal robotic-like companions. A narrative application for cancer survivors and caregivers is being developed. These CAN applications hope to improve the quality of life for the people they serve by improving executive function and mood, respectfully. ARMCan and ARTCan/ARCCan pilot feasibility studies are currently accruing subjects at our institution.

Insurance status as a mediator of clinical presentation, type of intervention, and short-term outcomes for patients with metastatic spine disease

BACKGROUND

It is well established that insurance status is a mediator of disease management, treatment course, and clinical outcomes in cancer patients. Our study assessed differences in clinical presentation, treatment course, mortality rates, and in-hospital complications for patients admitted to the hospital with late-stage cancer - specifically, metastatic spine disease (MSD), by insurance status.

METHODS

The United States National Inpatient Sample (NIS) database (2012-2014) was queried to identify patients with visceral metastases, metastatic spinal cord compression (MSCC) or pathological fracture of the spine in the setting of cancer. Clinical presentation, type of intervention, mortality rates, and in-hospital complications were compared amongst patients by insurance coverage (Medicare, Medicaid, commercial or unknown). Multivariable logistical regression and age sensitivity analyses were performed.

RESULTS

A total of 48,560 MSD patients were identified. Patients with Medicaid coverage presented with significantly higher rates of MSCC (p < 0.001), paralysis (0.008), and visceral metastases (p < 0.001). Patients with commercial insurance were more likely to receive surgical intervention (OR 1.43; p < 0.001). Patients with Medicaid < 65 had higher rates of prolonged length of stay (PLOS) (OR 1.26; 95% CI, 1.01-1.55; p = 0.040) while both Medicare and Medicaid patients < 65 were more likely to have non-routine discharges. In-hospital mortality rates were significantly higher for patients with Medicaid (OR 2.66; 95% CI 1.20-5.89; p = 0.016) and commercial insurance (OR 1.58; 95% CI 1.09-2.27;p = 0.013) older than 65.

CONCLUSION

Given the differing severity in MSD presentation, mortality rates, and rates of PLOS by insurance status, our results identify disparities based on insurance coverage.

Objective Test Scores Throughout Orthopedic Surgery Residency Suggest Disparities in Training Experience

Diversifying clinical residencies, particularly in fields that are historically dominated by majority male (M/M) cohorts, is critical to improve both the training experiences of residents and the overall physician workforce. Orthopedic surgery in particular has low numbers of females and under-represented minorities (F/URM) at all levels of training and practice. Despite efforts to increase its diversity, this field has become more homogeneous in recent years. To highlight potential barriers and disparate training environments that may contribute to this dynamic, we present 25 years' worth of institutional data on standardized exam performance throughout residency. We report that despite starting residency with standardized exam scores that were comparable to their M/M peers, F/URM orthopedic surgery residents performed progressively worse on Orthopaedic In-service Training Exams throughout residency and had lower first pass rates on the American Board of Orthopedic Surgery Part 1. Given these findings, we propose that disparate performance on standardized test scores throughout residency could identify trainees that may have different experiences that negatively impact their exam performance. Shedding light on these underlying disparities provides opportunities to find meaningful and sustained ways to develop a culture of diversity and inclusion. It may also allow for other programs to identify similar patterns within their training programs. Overall, we propose monitoring test performance on standardized exams throughout orthopedic surgery residency to identify potential disparities in training experience; further, we acknowledge that interventions to mitigate these disparities require a broad, systems wide approach and a firm institutional commitment to reducing bias and working toward sustainable change.

Short communication: Effect of glucose infusion dose and stage of lactation on glucose tolerance test kinetics in lactating dairy cows

The objective for this study was to determine the effect of glucose dose and days following peak milk yield on plasma glucose, serum insulin, and plasma nonesterified fatty acids (NEFA) kinetics during an intravenous glucose tolerance test (IVGTT) in lactating dairy cattle. Six lactating Holstein dairy cows (3 primiparous and 3 multiparous) were assigned to 2 squares and received 0.092, 0.15, or 0.3 g of glucose/kg of body weight (BW) during an IVGTT at 74 and 221 d in milk (DIM), representing early (post-peak) lactation and mid lactation, respectively. Treatments were applied in a replicated Latin square design using contiguous 7-d periods within each stage of lactation. Milk production and dry matter intake were determined daily during the first 6 d of each period. The IVGTT was performed on d 7. For the IVGTT, cows were prepared with indwelling catheters in each jugular vein, and blood samples were collected at -15, -10, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min relative to the glucose infusion. Samples were analyzed for plasma glucose, serum insulin, and plasma NEFA concentrations. Increasing the glucose dose during the IVGTT increased plasma glucose area under the curve (AUC), decreased glucose half-life, and increased maximal plasma glucose concentrations in plasma during the IVGTT. Greater glucose dose during the IVGTT elevated serum insulin AUC and increased nadir NEFA concentrations. Maximal plasma glucose concentration during the IVGTT was lower, whereas maximum NEFA concentration, NEFA AUC, and NEFA clearance rate were greater at 74 than at 221 DIM. Only glucose half-life was responsive to stage of lactation × glucose dose effects during the IVGTT, and the decrease in glucose half-life with increasing glucose dose was greater at 74 than at 221 DIM. Glucose AUC was greater and NEFA AUC lower for cows at 74 than at 221 DIM. For the doses tested, a glucose dose greater than 0.092 g/kg of BW resulted in peak blood glucose concentration that exceeded the previously reported renal glucose excretion threshold of 8.3 mM. There is a need for accompanying data to determine if this is the case for the glucose doses evaluated in this experiment. Based on maximal peak glucose concentrations and effects on glucose half-life, we identify 0.092 g of glucose/kg of BW (0.46 g/kg of metabolic body weight) as the preferred dose for the IVGTT for cows at 74 and 221 DIM in this study.

Predicting Patient-Centered Outcomes from Spine Surgery Using Risk Assessment Tools: a Systematic Review

PURPOSE OF REVIEW

The purpose of this systematic review is to evaluate the current literature in patients undergoing spine surgery in the cervical, thoracic, and lumbar spine to determine the available risk assessment tools to predict the patient-centered outcomes of pain, disability, physical function, quality of life, psychological disposition, and return to work after surgery.

RECENT FINDINGS

Risk assessment tools can assist surgeons and other healthcare providers in identifying the benefit-risk ratio of surgical candidates. These tools gather demographic, medical history, and other pertinent patient-reported measures to calculate a probability utilizing regression or machine learning statistical foundations. Currently, much is still unknown about the use of these tools to predict quality of life, disability, and other factors following spine surgery. A systematic review was conducted using PRISMA guidelines that identified risk assessment tools that utilized patient-reported outcome measures as part of the calculation. From 8128 identified studies, 13 articles met inclusion criteria and were accepted into this review. The range of c-index values reported in the studies was between 0.63 and 0.84, indicating fair to excellent model performance. Post-surgical patient-reported outcomes were identified in the following categories (n = total number of predictive models): return to work (n = 3), pain (n = 9), physical functioning and disability (n = 5), quality of life (QOL) (n = 6), and psychosocial disposition (n = 2). Our review has synthesized the available evidence on risk assessment tools for predicting patient-centered outcomes in patients undergoing spine surgery and described their findings and clinical utility.

Total en bloc resection of primary and metastatic spine tumors

Primary and metastatic tumors of the spine represent a significant cause of patient morbidity, and present a management challenge to treating providers. From a neurosurgical standpoint, resection surgery may be warranted in cases of spinal instability, progressive disease, neurological compromise, or intractable symptoms. Removal of a tumor "en bloc" offers a more aggressive modality over more conservative resection techniques. En bloc resection entails the removal of the entirety of a tumor without violation of its capsule, and may offer improved rates of local control and overall survival in appropriately selected patients. Conversely, this technique carries a higher complication rate, and requires a unique set of technical skills as compared to more traditional resection. Here, we describe the technical aspects of en bloc resection, as well as specific indications and considerations when employing this operative technique.

Echocardiographic evaluation and N-terminal pro-brain natriuretic peptide measurement of patients hospitalized for heart failure during weaning from mechanical ventilation

BACKGROUND

Weaning patients with heart failure who have required mechanical ventilation remains challenging. We evaluated echocardiographic indexes and N-terminal pro-brain natriuretic peptide (NT-proBNP) as markers of acute cardiac dysfunction before and after spontaneous breathing trials (SBT) in such patients to assess their ability to predict subsequent successful extubation.

METHODS

Forty-four patients who underwent their first SBT were prospectively included. Plasma levels of NT-proBNP and transthoracic echocardiography indices including cardiac index, E/A ratio and E/Ea ratio were recorded immediately before commencing and just before the end of SBT.

RESULTS

Ten patients (22.7%) failed their SBT. No significant difference was observed concerning baseline echocardiographic data and NT-proBNP level between the patients who succeeded the SBT or those that failed. Cardiac index increased significantly at end-SBT in patients who passed (3.3 [3.06-3.77] vs. 3 [2.68-3.3] L/min/m(2), P<0.001), whereas it remained unchanged in those that failed. E/Ea ratio (16.8 [8.5-27.3] vs. 10.7 [6.7-20.5], P=0.006) and NT-proBNP level (8199 [3106-10949] vs. 4200 [1855-7125] pg/mL, P=0.004) increased significantly in those who failed the SBT, in contrast to the weaning success group where they remained unchanged.

CONCLUSION

Neither NT-proBNP level nor the studied echocardiographic indices before SBT were able to predict SBT outcome in patients presenting with severe heart failure. Failure to increase the cardiac index and increases in both E/Ea ratio and NT-proBNP levels were seen at end-SBT in patients who failed the SBT, and may reflect failure of myocardial reserve to cope with the stress of SBT.

Lisfranc injuries in sport

Injuries to the Lisfranc ligament complex have traditionally been associated with high energy trauma such as motor vehicle collisions and industrial accidents. Recently, there has been a greater appreciation of mid-foot sprains that represent a spectrum of injury to the Lisfranc ligament complex. As a result, there has been an increased incidence of such injury resulting from low-energy trauma in activities ranging from recreational activity to elite athletic activity. This article discusses issues related to anatomy, clinical presentation, mechanism of injury, and diagnosis that are necessary to provide appropriate treatment for these injuries. There should be a high index of suspicion of this injury, and prompt diagnosis is important to allow athletes to return to sport with the best possible outcome.

Mass spectrometric detection of attomole amounts of the prion protein by nanoLC/MS/MS

Sensitive quantitation of prions in biological samples is an extremely important and challenging analytical problem. Prions are the cause of several fatal neurodegenerative diseases known as transmissible spongiform encephalopathies (TSEs). At this time, there are no methods to diagnose TSEs in live animals or to assure a prion-free blood supply for humans. Prions have been shown to be present in blood by transfusion experiments, but based on the amount of infectivity found in these types of experiments, the amount of misfolded prion protein in blood is estimated to be only 30 to 625 amol/mL. More sensitive detection of prions in brain would allow earlier detection of disease and assure a safer food supply. We studied quantitation of the prion protein by use of nanoscale liquid chromatography coupled to a tandem mass spectrometer using the multiple reaction monitoring mode of operation. We developed a method based on the detection of VVEQMCTTQYQK obtained by reduction, alkylation, and digestion with trypsin of the prion protein. Detection of VVEQMCTTQYQK was more sensitive than for the derivative with phenylisothiocyanate (PITC) because of decreased ionization efficiency of the PITC-derivatized peptides. The VVEQMCTTQYQK method has a LOD of 20 to 30 amol for pure standards. Proof of principle is demonstrated by quantitation of the amount of PrP 27-30 in the brains of terminally ill Syrian hamsters.

Anaplasma phagocytophilum in central and western Wisconsin: a molecular survey

Anaplasma phagocytophilum is an obligate intracellular bacterium that is transmitted to humans through the bite of Ixodes spp. ticks, and causes a febrile disease known as human granulocytic anaplasmosis. The presence of A. phagocytophilum in Wisconsin white-tailed deer blood and in deer ticks was assessed using PCR and DNA sequencing. Sampling sites in the western part of the state (Buffalo County) and central region (Waushara, Waupaca, and Green Lake counties) were used. In Buffalo County, 5.6% of deer and 8.9% of ticks were infected. At Hartman Creek State Park (Waupaca County), 11.5% of ticks were infected, while the observed prevalence in deer from counties to the south of the park (Waushara and Green Lake) reached 19-26%. Based on 16S rRNA sequences, A. phagocytophilum strains associated and not associated with human infections were identified. Furthermore, two novel A. phagocytophilum variants were found in deer blood samples. Transmission of Lyme disease has been documented in both the Western and Central regions we sampled, and the presence of A. phagocytophilum in naturally occurring tick populations could present an additional risk of disease to humans that enter tick habitats.

Sensitive, preclinical detection of prions in brain by nanospray liquid chromatography/tandem mass spectrometry

More sensitive detection of prions in brain is important because it would allow early detection of disease in young animals and assure a safer food supply. We have quantitated the amount of proteinase K-resistant prion protein (PrP 27-30) by use of nano-scale liquid chromatography coupled to tandem mass spectrometry using the multiple reaction monitoring mode of operation. We used a method based on the detection of VVEQMCTTQYQK (residues 209-220) obtained by reduction, alkylation and digestion with trypsin. Quantitation of the amount of PrP 27-30 in the brains of Syrian hamsters was possible as early as 24 h after inoculation. Our results show sensitive detection of 180 fmol of PrP 27-30 per g brain (wet weight) as early as 24 h after inoculation. Clinical symptoms are not observed until 9 weeks after inoculation.

Non-particulate (continuous bed or monolithic) acrylate-based capillary columns for reversed-phase liquid chromatography and electrochromatography

Three approaches are described to synthesize acrylic non-particulate beds (also called continuous beds or monoliths) in aqueous polymerization media for reversed-phase capillary liquid chromatography/electrochromatography. In the first, hexyl acrylate comonomer was dissolved together with water soluble polar comonomers using a non-ionic detergent. In the second, a new alkyl ammonium salt comonomer, (3-allylamino-2-hydroxypropyl)dodecyldimethylammonium chloride was used, which is water soluble and has detergent properties itself. The alkyl group of this comonomer provides hydrophobicity while the ionic groups generate electroosmosis in the non-particulate bed. In the third approach, the alkyl comonomer was used as a detergent to dissolve another hydrophobic comonomer in an aqueous polymerization medium. All three approaches were evaluated with respect to hydrophobicity, efficiency and electroosmotic properties of the beds. Hydrophobicity expressed as methylene group selectivity for the three types of the beds in 50% methanol mobile phase was 1.86, 1.16 and 1.78, electroosmotic mobility -5.14 x 10(-5), 6.89 x 10(-5) and 6.37 x 10(-5) cm2 V(-1) s(-1) and efficiency for the retained compound (methylparabene) 67,000, 93,000 and 110,000 plates m(-1) correspondingly. The columns were tested using pressure driven capillary chromatography and capillary electrochromatography. The influence of polymerization temperature on hydrodynamic permeability, separation impedance and inverse size exclusion porosimetry characteristics were used to evaluate the separation columns. The increase of the polymerization temperature resulted higher permeability of the bed, separation impedance and lower polymeric skeleton porosity. Further characterisation was provided by examining the separation efficiency observed for a series of benzoic acid esters and alkyl parabens.

Botulinum toxin A and chronic low back pain: A randomized, double-blind study

OBJECTIVES

To investigate the efficacy of botulinum toxin A in chronic low back pain and associated disabilities.

METHODS

Thirty-one consecutive patients with chronic low back pain who met the inclusion criteria were studied: 15 received 200 units of botulinum toxin type A, 40 units/site at five lumbar paravertebral levels on the side of maximum discomfort, and 16 received normal saline. Each patient's baseline level of pain and degree of disability was documented using the visual analogue scale (VAS) and the Oswestry Low Back Pain Questionnaire (OLBPQ). The authors reevaluated the patients at 3 and 8 weeks (visual analogue scale) and at 8 weeks (OLBPQ).

RESULTS

At 3 weeks, 11 of 15 patients who received botulinum toxin (73.3%) had >50% pain relief vs four of 16 (25%) in the saline group (p = 0.012). At 8 weeks, nine of 15 (60%) in the botulinum toxin group and two of 16 (12.5%) in the saline group had relief (p = 0.009). Repeat OLBPQ at 8 weeks showed improvement in 10 of 15 (66.7%) in the botulinum toxin group vs three of 16 (18.8%) in the saline group (p = 0.011). No patient experienced side effects.

CONCLUSION

Paravertebral administration of botulinum toxin A in patients with chronic low back pain relieved pain and improved function at 3 and 8 weeks after treatment.

Bilateral painful hand-moving fingers: electrophysiological assessment of the central nervous system oscillator

We describe a 35-year-old woman who presented with the syndrome of painful hand-moving fingers on the right side. Eight months later, she developed similar finger movements and hand discomfort on the left side. She had a history of hand trauma and recurrent shoulder dislocation on the right side. Kinesiologic electromyography suggested a common central oscillator for finger movements in both hands. Electrophysiological assessment of spinal alpha motor neuron excitability, reciprocal inhibition, and Renshaw cell inhibition failed to show any abnormalities. Somatosensory evoked potential test showed marked attenuation of N20 potential recorded from the left somatosensory cortex; paired transcortical magnetic stimulation of the left motor cortex suggested failure of cortical facilitation. The data suggest that the central oscillator responsible for finger movements is located above the spinal cord level in this patient.

Ultraviolet spectrophotometric characterization and bactericidal properties of electrolyzed oxidizing water as influenced by amperage and pH

To identify the primary component responsible in electrolyzed oxidizing (EO) water for inactivation, this study determined the concentrations of hypochlorous acid (HOCl) and hypochlorite ions (OCl-) and related those concentrations to the microbicidal activity of the water. The ultraviolet absorption spectra were used to determine the concentrations of HOCl and OCl- in EO water and the chemical equilibrium of these species with change in pH and amperage. EO water generated at higher amperage contained a higher chlorine concentration. The maximum concentration of HOCl was observed around pH 4 where the maximum log reduction (2.3 log10 CFU/ml) of Bacillus cereus F4431/73 vegetative cells also occurred. The high correlation (r = 0.95) between HOCl concentrations and bactericidal effectiveness of EO water supports HOCl's role as the primary inactivation agent. Caution should be taken with standard titrimetric methods for measurement of chlorine as they cannot differentiate the levels of HOCl present in EO water of varying pHs.

Respiratory changes in vasovagal syncope

INTRODUCTION

Respiratory changes accompany the cardiovascular changes during head-up, tilt test-induced vasovagal syncope.

METHODS AND RESULTS

Using the 45-minute 60 degrees head-up Westminster protocol, 29 patients were studied (mean age 53.9+/-20.0 years; 19 females). Two groups resulted: tilt-induced vasovagal syncope positive and negative. The cardiorespiratory parameters blood pressure (BP), heart rate (HR), tidal volume, and minute volume were measured. Comparisons of the cardiorespiratory parameters were made within the positive group and negative group, and then between the two groups. There were 14 in the positive group and 15 in the negative group. Baseline measurements were normalized to 1.0. Comparing the late tilt periods between the positive and negative groups, there were differences in BP (P < 0.002), HR (P < 0.002), tidal volume (P < 0.05), and minute volume (P < 0.002). In the positive group comparing early with late intervals: BP 1.11+/-0.09 versus 0.49+/-0.17, P < 0.0001; HR 1.18+/-0.12 versus 0.85+/-0.35, P < 0.009; tidal volume 1.39+/-0.34 versus 2.17+/-1.00, P < 0.015; and minute volume 1.24+/-0.26 versus 3.3+/-2.03, P < 0.0025. There were no comparable cardiorespiratory changes in the negative group.

CONCLUSION

There were significant differences in the respiratory and cardiovascular parameters measured between those who were positive and those who were negative for tilt-induced vasovagal syncope. Within the positive group, in addition to the falls in HR and BP, there were significant increases in minute volume and tidal volume during late tilt. This suggests that there may be a role for respiratory sensors in vasovagal syncope that may permit earlier and hence possibly more effective therapy for selected patients.

Sensitive method for detection of human herpesviruses 6 and 7 in saliva collected in field studies

To facilitate studies of the epidemiology and natural history of human herpesviruses 6 and 7 in infants, a practical method for collecting and quantifying the DNA of these viruses was developed. Saliva was collected using small strips of filter paper, and virus was detected using a real-time quantitative fluorescent-probe PCR assay. The sensitivity and specificity of this method even after prolonged drying of the specimens compared favorably to those of our traditional method of collecting and assaying saliva.