Just keep swimming? Observations of resting behavior in gray reef sharks Carcharhinus amblyrhynchos (Bleeker, 1856).

Understanding the respiratory modes of sharks has important implications for studying the metabolism, energetics, and behavioral strategies of different species. Here we provide the first reported observations of resting behavior in the gray reef shark Carcharhinus amblyrhynchos, a species typically considered an obligate ram ventilator. Observations were made at several locations in the Republic of Seychelles, where sharks were found resting under reef ledges and were unresponsive to the presence of divers. These findings update our understanding of the respiratory mode of this species and have implications for future research.

Pseudo-Stener lesion due to proximal ulnar collateral ligament rupture: A case report.

INTRODUCTION AND IMPORTANCE: Ulnar collateral ligament (UCL) ruptures are a common injury of the thumb. The UCL will most commonly rupture at the distal insertion. It has been proposed that a partial or non-displaced tear can be managed non operatively. However, a complete rupture that occurs at the distal insertion will commonly not be able to heal non-operatively due to the interposition of the adductor aponeurosis. This clinical finding is known as a Stener lesion, first described by Bertil Stener in 1962. CASE PRESENTATION: We present the case of a 63-year-old-woman with instability of the thumb, pain, and a small mass at the ulnar side of the metacarpal phalangeal joint (MCPJ). CLINICAL DISCUSSION: A Stener lesion mass is commonly palpated on the ulnar MCPJ due to the ligament being trapped proximally to the overlying aponeurosis. Our patient mistakenly presented with a Stener lesion that was intraoperatively discovered to be a mass of granulation tissue. This patient underwent repair of the UCL and was able to return to unrestricted daily activities after six weeks. CONCLUSION: This case highlights an unusual rupture pattern and shows the proper surgical techniques for repairing such an injury. It is imperative to restore joint stability to prevent decreased grip strength and early onset of osteoarthritis of the MCPJ. LEVEL OF EVIDENCE: Therapeutic Level 3B.

Exhaled gases and the potential for cross-infection via noninvasive ventilation machines.

Guidelines suggest that exhaled gases do not reach the outlet of noninvasive ventilators in clinical use. In this study, when tidal volumes exceeded 800 mL, exhaled gases did reach the ventilator, leading to a risk of cross-infection between users. https://bit.ly/3EdvtY6.

Proinflammatory cytokine expression profile in degenerated and herniated human intervertebral disc tissues.

OBJECTIVE: Prior reports document macrophage and lymphocyte infiltration with proinflammatory cytokine expression in pathologic intervertebral disc (IVD) tissues. Nevertheless, the role of the Th17 lymphocyte lineage in mediating disc disease remains uninvestigated. We undertook this study to evaluate the immunophenotype of pathologic IVD specimens, including interleukin-17 (IL-17) expression, from surgically obtained IVD tissue and from nondegenerated autopsy control tissue. METHODS: Surgical IVD tissues were procured from patients with degenerative disc disease (n = 25) or herniated IVDs (n = 12); nondegenerated autopsy control tissue was also obtained (n = 8) from the anulus fibrosus and nucleus pulposus regions. Immunohistochemistry was performed for cell surface antigens (CD68 for macrophages, CD4 for lymphocytes) and various cytokines, with differences in cellularity and target immunoreactivity scores analyzed between surgical tissue groups and between autopsy control tissue regions. RESULTS: Immunoreactivity for IL-4, IL-6, IL-12, and interferon-gamma (IFNgamma) was modest in surgical IVD tissue, although expression was higher in herniated IVD samples and virtually nonexistent in control samples. The Th17 lymphocyte product IL-17 was present in >70% of surgical tissue fields, and among control samples was detected rarely in anulus fibrosus regions and modestly in nucleus pulposus regions. Macrophages were prevalent in surgical tissues, particularly herniated IVD samples, and lymphocytes were expectedly scarce. Control tissue revealed lesser infiltration by macrophages and a near absence of lymphocytes. CONCLUSION: Greater IFNgamma positivity, macrophage presence, and cellularity in herniated IVDs suggests a pattern of Th1 lymphocyte activation in this pathology. Remarkable pathologic IVD tissue expression of IL-17 is a novel finding that contrasts markedly with low levels of IL-17 in autopsy control tissue. These findings suggest involvement of Th17 lymphocytes in the pathomechanism of disc degeneration.

Managing Duchenne muscular dystrophy--the additive effect of spinal surgery and home nocturnal ventilation in improving survival.

OBJECTIVES: To determine the long term survival in patients with Duchenne muscular dystrophy (DMD) following spinal surgery and nocturnal ventilation. STUDY DESIGN: A retrospective review of 100 consecutive patients born between 1970 and 1990 was conducted. RESULTS: Forty-seven patients had surgical spinal fusion, 27 were subsequently ventilated. Fourteen patients received ventilation only. Thirty-nine patients received neither intervention. The age at which ventilation was required correlated with the age at which ambulation was lost. Those who walked for longer were less likely to require spinal surgery. Mean vital capacity dropped from 1.4 to 1.13 L 1 year post-operatively. Patients having both spinal surgery and ventilation had a median survival of 30 years whereas those who were only ventilated survived to 22.2 years. CONCLUSION: Nocturnal ventilation improves survival in DMD. Spinal surgery does not increase forced vital capacity but in combination with nocturnal ventilation further improves median survival to 30 years.

Effects of non-invasive ventilation on survival and quality of life in patients with amyotrophic lateral sclerosis: a randomised controlled trial.

BACKGROUND: Few patients with amyotrophic lateral sclerosis currently receive non-invasive ventilation (NIV), reflecting clinical uncertainty about the role of this intervention. We aimed to assess the effect of NIV on quality of life and survival in amyotrophic lateral sclerosis in a randomised controlled trial. METHODS: 92 of 102 eligible patients participated. They were assessed every 2 months and randomly assigned to NIV (n=22) or standard care (n=19) when they developed either orthopnoea with maximum inspiratory pressure less than 60% of that predicted or symptomatic hypercapnia. Primary validated quality-of-life outcome measures were the short form 36 mental component summary (MCS) and the sleep apnoea quality-of-life index symptoms domain (sym). Both time maintained above 75% of baseline (T(i)MCS and T(i)sym) and mean improvement (microMCS and microsym) were measured. FINDINGS: NIV improved T(i)MCS, T(i)sym, microMCS, microsym, and survival in all patients and in the subgroup with better bulbar function (n=20). This subgroup showed improvement in several measures of quality of life and a median survival benefit of 205 days (p=0.006) with maintained quality of life for most of this period. NIV improved some quality-of-life indices in those with poor bulbar function, including microsym (p=0.018), but conferred no survival benefit. INTERPRETATION: In patients with amyotrophic lateral sclerosis without severe bulbar dysfunction, NIV improves survival with maintenance of, and improvement in, quality of life. The survival benefit from NIV in this group is much greater than that from currently available neuroprotective therapy. In patients with severe bulbar impairment, NIV improves sleep-related symptoms, but is unlikely to confer a large survival advantage.

Survival in Duchenne muscular dystrophy: improvements in life expectancy since 1967 and the impact of home nocturnal ventilation.

We reviewed the notes of 197 patients with Duchenne muscular dystrophy whose treatment was managed at the Newcastle muscle centre from 1967 to 2002, to determine whether survival has improved over the decades and whether the impact of nocturnal ventilation altered the pattern of survival. Patients were grouped according to the decade of death and whether or not they were ventilated. Kaplan Meier survival analyses showed significant decade on decade improvement in survival. Mean age of death in the 1960s was 14.4 years, whereas for those ventilated since 1990 it was 25.3 years. Cardiomyopathy significantly shortened life expectancy from 19 years to a mean age of 16.9 years. Better coordinated care probably improved the chances of survival to 25 years from 0% in the 1960s to 4% in the 1970s and 12% in the 1980s, but the impact of nocturnal ventilation has further improved this chance to 53% for those ventilated since 1990.

Predicting clinical ischaemia during awake carotid endarterectomy: use of the SJVO2 probe as a guide to selective shunting.

Stroke is a major cause of disability within the western world. About 20% of strokes are a consequence of atheromatous narrowing of the origin of the internal carotid artery. Carotid endarterectomy has been shown to be an effective treatment for those with symptomatic and severe stenosis, provided the risk of death and peri-operative stroke is less than 7%. The aim of this study was to investigate the clinical value of jugular venous oxygen saturation (SJVO2) monitoring in identifying patients who develop cerebral ischaemia whilst undergoing an awake carotid endarterectomy by comparison with a simple neurological assessment. Each patient underwent a standard awake carotid endarterectomy. Peri-operatively a SJVO2 catheter was inserted, and the jugular oxygen saturation was correlated with the presence or absence of cerebral ischaemia. Data from 34 patients were analysed using time-series plots and by calculating a receiver operator characteristic (ROC) curve. The optimal sensitivity and specificity for this technique were found to be 1.0 and 0.8, respectively, when a 25% change in SJVO2 was used as a threshold. Although a small observational study, we have shown that percentage change in SJVO2 correlates well with the development of clinically apparent cerebral ischaemia. This technique may improve the safety of carotid endarterectomy under general anaesthesia when used with other more established monitoring methods.

Release and activity of anti-TNFalpha therapeutics from injectable chitosan preparations for local drug delivery.

BACKGROUND: Tumor necrosis factor alpha (TNFalpha) is a cytokine that regulates immune and inflammatory overactivation in various pathological states. Protein therapeutics may antagonize this cytokine, but may also have systemic toxicities. Small molecule natural products are also efficacious, but can suffer from poor oral bioavailability. A drug delivery vehicle is needed to sustain release of active therapeutics and address localized inflammation. MATERIALS: Chitosan is a biocompatible aminopolysaccharide that undergoes thermally-initiated gelation in cosolutions with glycerophosphate (GP), and may entrap and sustain release of additive therapeutics. Gelation time and temperature of chitosan/GP were evaluated by turbidity (OD(350)), as was the kinetic effect of bovine serum albumin (BSA) entrapment. We investigated in vitro release of BSA and various anti-TNF agents (curcumin, sTNFRII, anti-TNF antibody) and confirmed in vitro activity of the released drugs using an established bioassay. RESULTS: Turbidity results show that chitosan/GP thermogel achieves gelation at 37 degrees C within 10 min, even with significant protein loading. Sustained BSA release occurred with 50% retained at 7 days. All anti-TNF therapeutics exhibited sustained release, with 10% of sTNFRII and anti-TNF antibody remaining after 7 days and 10% of curcumin remaining after 20 days. After release, each compound antagonized TNFalpha-cytotoxicity in murine fibrosarcoma cells. CONCLUSIONS: This study demonstrates that thermogelling chitosan/GP entraps and sustains release of a broad range of anti-TNF agents. Such delivery of disease-modifying therapy could establish a drug depot to treat local inflammation. The breadth of molecular sizes demonstrates significant versatility, and slow release could protect against toxicities of systemic delivery.