The response of tenocytes to commercial scaffolds used for rotator cuff repair

Surgical repairs of rotator cuff tears have high re-tear rates and many scaffolds have been developed to augment the repair. Understanding the interaction between patients' cells and scaffolds is important for improving scaffold performance and tendon healing. In this in vitro study, we investigated the response of patient-derived tenocytes to eight different scaffolds. Tested scaffolds included X-Repair, Poly-Tape, LARS Ligament, BioFiber (synthetic scaffolds), BioFiber-CM (biosynthetic scaffold), GraftJacket, Permacol, and Conexa (biological scaffolds). Cell attachment, proliferation, gene expression, and morphology were assessed. After one day, more cells attached to synthetic scaffolds with dense, fine and aligned fibres (X-Repair and Poly-Tape). Despite low initial cell attachment, the human dermal scaffold (GraftJacket) promoted the greatest proliferation of cells over 13 days. Expression of collagen types I and III were upregulated in cells grown on non-cross-linked porcine dermis (Conexa). Interestingly, the ratio of collagen I to collagen III mRNA was lower on all dermal scaffolds compared to synthetic and biosynthetic scaffolds. These findings demonstrate significant differences in the response of patient-derived tendon cells to scaffolds that are routinely used for rotator cuff surgery. Synthetic scaffolds promoted increased cell adhesion and a tendon-like cellular phenotype, while biological scaffolds promoted cell proliferation and expression of collagen genes. However, no single scaffold was superior. Our results may help understand the way that patients' cells interact with scaffolds and guide the development of new scaffolds in the future.

An adaptable multiple power source for mass spectrometry and other scientific instruments

An Adaptable Multiple Power Source (AMPS) system has been designed and constructed. The AMPS system can provide up to 16 direct current (DC) (±400 V; 5 mA), 4 radio frequency (RF) (two 500 VPP sinusoidal signals each, 0.5-5 MHz) channels, 2 high voltage sources (±6 kV), and one ∼40 W, 250 °C temperature-regulated heater. The system is controlled by a microcontroller, capable of communicating with its front panel or a computer. It can assign not only pre-saved fixed DC and RF signals but also profiled DC voltages. The AMPS system is capable of driving many mass spectrometry components and ancillary devices and can be adapted to other instrumentation/engineering projects.

Spina bifida occulta and aperta: a review of current treatment paradigms

Spina bifida remains a challenging neurosurgical entity to manage despite both an increased awareness of the disease as well as a decreased incidence due to folic acid supplementation. We review the spectrum of neural tube defects, which are the second most common serious congenital defect and the most common of the central nervous system, and discuss the latest management paradigms. The challenges of timely diagnosis and treatment of spina bifida occulta and the latest advances in fetal repair of spina bifida aperta (myelomeningocele) will be discussed. The authors review the literature and share their experience with managing neural tube defects.

Proximal tubule epithelial cell specific ablation of the spermidine/spermine N1-acetyltransferase gene reduces the severity of renal ischemia/reperfusion injury

BACKGROUND

Expression and activity of spermidine/spermine N1-acetyltransferase (SSAT) increases in kidneys subjected to ischemia/reperfusion (I/R) injury, while its ablation reduces the severity of such injuries. These results suggest that increased SSAT levels contribute to organ injury; however, the role of SSAT specifically expressed in proximal tubule epithelial cells, which are the primary targets of I/R injury, in the mediation of renal damage remains unresolved.

METHODS

Severity of I/R injury in wt and renal proximal tubule specific SSAT-ko mice (PT-SSAT-Cko) subjected to bilateral renal I/R injury was assessed using cellular and molecular biological approaches.

RESULTS

Severity of the loss of kidney function and tubular damage are reduced in PT-SSAT-Cko- compared to wt-mice after I/R injury. In addition, animals treated with MDL72527, an inhibitor of polyamine oxidases, had less severe renal damage than their vehicle treated counter-parts. The renal expression of HMGB 1 and Toll like receptors (TLR) 2 and 4 were also reduced in PT-SSAT-Cko- compared to wt mice after I/R injury. Furthermore, infiltration of neutrophils, as well as expression of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) transcripts were lower in the kidneys of PT-SSAT-Cko compared to wt mice after I/R injury. Finally, the activation of caspase3 was more pronounced in the wt compared to PT-SSAT-Cko animals.

CONCLUSIONS

Enhanced SSAT expression by proximal tubule epithelial cells leads to tubular damage, and its deficiency reduces the severity of renal I/R injury through reduction of cellular damage and modulation of the innate immune response.

One-stage resection of giant invasive thoracic schwannoma: case report and review of literature

BACKGROUND

Schwannomas comprise approximately 25% of all spinal tumors, being the third most frequent soft-tissue tumor after hemangiomas and lipomas. Grade 5 invasive giant schwannomas erode the vertebral bodies, involve 2 or more levels, and invade the myofascial planes. Because 3 compartments are involved, these tumors represent a surgical challenge and frequently require staged surgeries with a multidisciplinary surgical team.

CASE REPORT

We report the case of a 62-year-old female who presented with intermittent upper back pain for 3 years. A magnetic resonance imaging scan of the thoracic spine showed a mass invading the vertebral body, pedicle, and lamina of T4 and part of T3 and T5. Needle biopsy confirmed the diagnosis of schwannoma. The patient underwent surgery using a parascapular extracavitary costotransversectomy approach.

CONCLUSION

Giant invasive spinal schwannomas are rare in the thoracic spine, and surgical approaches usually have entailed multiple-stage surgeries with the assistance of other surgical specialties. Our 1-stage complete surgical resection of a giant invasive spinal schwannoma used a parascapular costotransversectomy approach that maintained spinal stability and thus avoided the need for instrumentation.

Large Molecule Characterization Based upon Individual Ion Detection with Electrospray Ionization-FTICR Mass Spectrometry

We report a new method for mass spectrometric measurements of high-molecular-weight species based on the summation of sequential Fourier transform ion cyclotron resonance (FTICR) spectra of individual multiply charged ions. This approach produces statistically useful mass spectra for large multiply charged molecular species formed by electrospray ionization and circumvents conventional limitations upon achievable resolving power and precision for high-molecular-weight species which arise due to Coulombic constraints. For very large molecules with tens to thousands of charges each, the total number of charges required to define the charge-state distribution, and thus provide accurate mass information, greatly exceeds the useful charge capacity of the FTICR cell. As trapped ion populations approach or exceed this capacity, FTICR performance degrades due to large frequency shifts, peak coalescence phenomena, and rapid loss of ion packet coherence, which effectively precludes high-resolution and precision measurements for molecules above ∼80-kDa size for a 7-T magnetic field strength. The present approach is based on the summation of many spectra having moderate populations of individual ions and relies on sensitivity sufficient for individual ion detection. While the number of trapped ions contributing to each mass spectrum may generally be insufficient to define the isotopic or charge-state distributions (and thus produce accurate information on the molecular weight distribution in a conventional fashion), the present data processing and summation approach suppresses the noise component (as well as smaller signals) that would otherwise be problematic. Importantly, this approach circumvents natural limitations for very high molecular weight species due to Coulombic interactions and thus provides a basis for much greater resolution and mass measurement accuracy than otherwise possible. This paper presents the details of this approach and its demonstration for the 66-kDa protein bovine serum albumin (where the conventional approach is also feasible) and discusses important aspects of the data manipulation.

Economics of fall prevention programs: evidence and research priorities

Injurious falls, particularly among the elderly, are a leading cause of morbidity, mortality and health and social care expenditure. Non injurious falls may result in significant quality of life losses through generating a fear of subsequent falls. Falls may be due to intrinsic (age-related physiological changes, diseases or polypharmacy) or extrinsic (environmental hazards and behavior) factors. Although interventions target both of these, much of the focus is upon extrinsic factors, through changes to behavior and the environment. This paper reviews the cost-effectiveness of such interventions in reducing the risk of new falls, or modifying the harm caused in the event of a fall, for the general unselected population of the elderly living independently in the community.

Developmental changes in the germinability, desiccation tolerance, hardseededness, and longevity of individual seeds of Trifolium ambiguum

BACKGROUND AND AIMS

Using two parental clones of outcrossing Trifolium ambiguum as a potential model system, we examined how during seed development the maternal parent, number of seeds per pod, seed position within the pod, and pod position within the inflorescence influenced individual seed fresh weight, dry weight, water content, germinability, desiccation tolerance, hardseededness, and subsequent longevity of individual seeds.

METHODS

Near simultaneous, manual reciprocal crosses were carried out between clonal lines for two experiments. Infructescences were harvested at intervals during seed development. Each individual seed was weighed and then used to determine dry weight or one of the physiological behaviour traits.

KEY RESULTS

Whilst population mass maturity was reached at 33-36 days after pollination (DAP), seed-to-seed variation in maximum seed dry weight, when it was achieved, and when maturation drying commenced, was considerable. Individual seeds acquired germinability between 14 and 44 DAP, desiccation tolerance between 30 and 40 DAP, and the capability to become hardseeded between 30 and 47 DAP. The time for viability to fall to 50 % (p(50)) at 60 % relative humidity and 45 degrees C increased between 36 and 56 DAP, when the seed coats of most individuals had become dark orange, but declined thereafter. Individual seed f. wt at harvest did not correlate with air-dry storage survival period. Analysing survival data for cohorts of seeds reduced the standard deviation of the normal distribution of seed deaths in time, but no sub-population showed complete uniformity of survival period.

CONCLUSIONS

Variation in individual seed behaviours within a developing population is inherent and inevitable. In this outbreeder, there is significant variation in seed longevity which appears dependent on embryo genotype with little effect of maternal genotype or architectural factors.

National health system reform

The Louisiana State Medical Society (LSMS) believes reform of the nation's health care system is long overdue and we are extremely pleased the debate on reform is now underway in the Congress. We share your concerns about the availability of quality health care coverage for all Americans, multiple choices of health care financing mechanisms in a open market setting, affordable and portable coverage options, and the elimination of fraud and abuse that siphons precious resources needed to assure the continued viability of the delivery systems. We have examined the current proposals in light of the above concerns and with the compendium of LSMS health care reform policies. Although some of the concepts are compatible with those policies the majority of proposed changes differ significantly from our vision of needed system reform. The conscious injection of a progressive pattern of more government control of the health care system, even the actual delivery of the care itself, is the most alarming and objectionable aspect of the proposals. Therefore, the Louisiana State Medical Society's key points of concern regarding the current proposals are detailed in this letter.

The Alpha Project: a model system for systems biology research

One goal of systems biology is to understand how genome-encoded parts interact to produce quantitative phenotypes. The Alpha Project is a medium-scale, interdisciplinary systems biology effort that aims to achieve this goal by understanding fundamental quantitative behaviours of a prototypic signal transduction pathway, the yeast pheromone response system from Saccharomyces cerevisiae. The Alpha Project distinguishes itself from many other systems biology projects by studying a tightly bounded and well-characterised system that is easily modified by genetic means, and by focusing on deep understanding of a discrete number of important and accessible quantitative behaviours. During the project, the authors have developed tools to measure the appropriate data and develop models at appropriate levels of detail to study a number of these quantitative behaviours. The authors have also developed transportable experimental tools and conceptual frameworks for understanding other signalling systems. In particular, the authors have begun to interpret system behaviours and their underlying molecular mechanisms through the lens of information transmission, a principal function of signalling systems. The Alpha Project demonstrates that interdisciplinary studies that identify key quantitative behaviours and measure important quantities, in the context of well-articulated abstractions of system function and appropriate analytical frameworks, can lead to deeper biological understanding. The authors' experience may provide a productive template for systems biology investigations of other cellular systems.

Partially wrong? Partial equilibrium and the economic analysis of public health emergencies of international concern

We argue that traditional health economic analysis is ill-equipped to estimate the cost effectiveness and cost benefit of interventions that aim at controlling and/or preventing public health emergencies of international concern (such as pandemic influenza or severe acute respiratory syndrome). The implicit assumption of partial equilibrium within both the health sector itself and--if a wider perspective is adopted--the economy as a whole would be violated by such emergencies. We propose an alternative, with the specific aim of accounting for the behavioural changes and capacity problems that are expected to occur when such an outbreak strikes.

Dry versus wet aging of beef: Retail cutting yields and consumer sensory attribute evaluations of steaks from ribeyes, strip loins, and top sirloins from two quality grade groups

Top Choice (n=48) and Select (n=48) paired bone-in ribeye rolls, bone-in strip loins, and boneless top sirloin butts were assigned randomly to one of two aging treatments, dry or wet, and were aged for 14, 21, 28 or 35d. Cutting tests, performed to determine retail yields and processing times, showed dry-aged subprimals had lower total saleable yield percentages and increased processing times compared to wet-aged subprimals. Sensory and Warner-Bratzler shear evaluation was conducted to determine palatability characteristics. For the most part, aging treatment and aging period did not affect consumer sensory attributes. However, ribeye and top loin steaks from the Top Choice quality grade group received higher sensory ratings than their Select counterparts. For top sirloin steaks, no consumer sensory attributes were affected by aging treatment, aging period, or quality grade group.

Dry versus wet aging of beef: Retail cutting yields and consumer palatability evaluations of steaks from US Choice and US Select short loins

Paired beef short loins from US Choice (n=48) and US Select (n=48) carcasses were assigned to be dry or wet aged for 14, 21, 28 or 35d. After aging, short loins were processed to determine retail yields and processing times. Upon completion of cutting tests, steaks were served to consumers to assess palatability characteristics. Retail cutting tests showed that dry-aged short loins had reduced yields and increased cutting times when compared to wet-aged short loins. Consumers were unable to determine differences between dry- and wet-aged steaks and for aging periods; however, USDA quality grade had a significant impact on consumer perception of palatability attributes.

Systemic distribution of West Nile virus infection: postmortem immunohistochemical study of six cases

Rare cases of West Nile virus (WNV)-associated inflammation outside the central nervous system (CNS) have been reported. We evaluated the systemic distribution of WNV in postmortem tissues during encephalitis in six patients using immunohistochemistry. WNV antigens were detected in neurons of CNS (all 6 cases), kidney (4 cases), lungs (2 cases), pancreas (2 cases), thyroid (2 cases), intestine (2 cases), stomach (1 case), esophagus (1 case), bile duct (1 case), skin (1 case), prostate (1 case) and testis (1 case). In systemic organs epithelial cells were infected. In none of the six cases were viral antigens identified in hepatocytes, heart, adrenal gland, nerves, skeletal muscles, bone, vessels and fat. All cases in which viral antigens were identified in systemic organs in addition to CNS were severely immunocompromised transplant recipients. With the exception of testis and brain, most foci of infection were not associated with inflammation. While the absence of inflammation may in part be due to patient immunosuppression or to possible transient nature of any host response, compartmentalization of viral antigen to the luminal region of epithelial cells may sequester WNV from immune recognition. Comparison of our findings with previous reports suggests that patients with WNV encephalitis can have widespread systemic infection.

Integrated molecular signature of disease: analysis of influenza virus-infected macaques through functional genomics and proteomics

Recent outbreaks of avian influenza in humans have stressed the need for an improved nonhuman primate model of influenza pathogenesis. In order to further develop a macaque model, we expanded our previous in vivo genomics experiments with influenza virus-infected macaques by focusing on the innate immune response at day 2 postinoculation and on gene expression in affected lung tissue with viral genetic material present. Finally, we sought to identify signature genes for early infection in whole blood. For these purposes, we infected six pigtailed macaques (Macaca nemestrina) with reconstructed influenza A/Texas/36/91 virus and three control animals with a sham inoculate. We sacrificed one control and two experimental animals at days 2, 4, and 7 postinfection. Lung tissue was harvested for pathology, gene expression profiling, and proteomics. Blood was collected for genomics every other day from each animal until the experimental endpoint. Gross and microscopic pathology, immunohistochemistry, viral gene expression by arrays, and/or quantitative real-time reverse transcription-PCR confirmed successful yet mild infections in all experimental animals. Genomic experiments were performed using macaque-specific oligonucleotide arrays, and high-throughput proteomics revealed the host response to infection at the mRNA and protein levels. Our data showed dramatic differences in gene expression within regions in influenza virus-induced lesions based on the presence or absence of viral mRNA. We also identified genes tightly coregulated in peripheral white blood cells and in lung tissue at day 2 postinoculation. This latter finding opens the possibility of using gene expression arrays on whole blood to detect infection after exposure but prior to onset of symptoms or shedding.

Thrombogenesis in experimental microvascular anastomosis

A large number of microvascular anastomoses, involving both arteriovenous and artery-artery end-to-side and end-to-end anastomoses, were carried out in the rat to develop a temporal and morphologic profile of thrombogenesis. While excellent patency rates were obtained in purely arterial preparations, significant thrombus formation occurred in the arteriovenous preparations, both at the suture line and more distally in the vein. Factors contributing to thrombogenesis in these microvascular anastomoses are discussed.

An analysis of urinary tract trauma in Scotland: imnpact on management and resource needs

OBJECTIVE

We report the incidence, distribution, aetiology and outcome of urological trauma in a unique national database to provide an insight into its contemporary management.

PATIENTS AND METHODS

The Scottish Trauma Audit Group prospectively collected data from severe trauma presenting to all major Scottish hospitals. We examined data from 24,666 trauma admissions from 1999 to 2002. Patients who sustained urological injuries were identified and studied in detail.

RESULTS

362 patients had urological injuries, comprising 1.5% of the trauma population, and an incidence of 1 per 45,000 head of adult population per year. Blunt injury (n = 285, 79%) was the main cause of urological trauma. Road traffic accidents were most frequent (197 patients, 54%), followed by assaults (76, 21%) and high falls (45, 12%). Renal injuries were the most common (n = 241, 67%), followed by injuries to the external genitalia (71, 20%), bladder (65, 18%), urethra (16, 4%) and ureter (3, 1%). Only 52 patients (14%) had isolated urological trauma. One hundred and fifty nine out of 310 (51%) urological patients with associated injuries were physiologically compromised on arrival in A&E, compared with only 4/52 (8%) patients with isolated urological trauma. All patients with isolated urological trauma survived, whereas 110/310 (35%) of those with associated injuries died.

CONCLUSION

Urological injuries in Scotland mostly result from blunt trauma due to high-energy impacts. Isolated urological injuries are uncommon and all such patients survived. The majority of patients with urological trauma have multiple injuries and require a multi-disciplinary approach. Current urological services appear adequately distributed to cope with contemporary demands of urological trauma.

Increased cholesterol decreases uterine activity: functional effects of cholesterol alteration in pregnant rat myometrium

Uterine quiescence is essential for successful pregnancy. Cholesterol and triglycerides are markedly increased in pregnancy. Cholesterol is enriched in microdomains of the plasma membrane known as rafts and caveolae. Both lipid rafts and caveolae have been implicated in cellular signaling cascades. The purpose of this work was to investigate whether manipulation of cholesterol content alters uterine contractility. Late pregnancy (19–21 days) rats were humanely euthanized and strips of longitudinal myometrium were then dissected. Force and Ca2+ measurements were simultaneously recorded and cholesterol increased by the addition of 5 mg/ml cholesterol or 0.25 mg/ml low-density lipoproteins (LDLs) or reduced by 2% methyl-β-cyclodextrin (MCD) or 2 U/ml cholesterol oxidase addition to the perfusate. Both LDLs and cholesterol profoundly inhibited spontaneous uterine force production and associated Ca2+ transients; frequency, amplitude, and duration of contraction were all significantly reduced compared with preceding control contractions. Force and Ca2+ were also reduced by cholesterol when 1 nM oxytocin was used to stimulate the myometrium. Uterine activity was significantly increased by cholesterol extraction with MCD or cholesterol oxidase treatment. Electron microscopy confirmed the lipid raft disrupting effect of MCD, as formerly electron microscopy-visible caveolae in the myometrial cell membrane all but disappeared after MCD treatment. These data show that uterine smooth muscle cell cholesterol content is critically important for functional activity. A novel finding of our study is that cholesterol is inhibitory for force generation. It may be one of the mechanisms operating to maintain uterine quiescence throughout gestation and may also contribute to difficulties in labor suffered by obese women.

Pineal ganglioglioma in a young girl: a case report and review of the literature

Gangliogliomas are exceedingly rare in the pineal region. We present the case of a 16-year-old girl diagnosed with a pineal-region mass, initially diagnosed as a germ-cell tumor on the frozen section examination. The tumor was resected completely despite the frozen section results. The final pathological diagnosis was that of a ganglioglioma. This diagnosis obviated the need for postoperative adjuvant therapy. Gangliogliomas, although rare, should be considered in the differential diagnosis of the pineal region tumors. Frozen section results can be misleading since the large neuronal cells can mimic germ cells. Gangliogliomas are not sensitive to adjuvant therapy. Initial gross total resection should be attempted if the anatomy is favorable.

Mechanisms of action of pH-induced effects on vascular smooth muscle

It is clear that pH has many effects on vascular smooth muscle and the overall action of pH on force will depend on the type of vascular smooth muscle in question and the combined effects on all the potential modulatory mechanisms. The major effects of pH on force appear to be mediated via modulation of [Ca]i rather than changes in the sensitivity of the contractile machinery to Ca2+. There are still numerous gaps in our understanding of the actions of pH and as more data become available, we will be able to better understand the major mechanisms involved.