Search

The coronavirus disease 2019 (COVID-19) pandemic has revealed that even the best-resourced hospitals may lack sufficient ventilators to support patients under surge conditions. During a pandemic or mass trauma, an affordable, low-maintenance, off-the-shelf device that would allow health care teams to rapidly expand their ventilator capacity could prove lifesaving, but only if it can be safely integrated into a complex and rapidly changing clinical environment. Here, we define an approach to safe ventilator sharing that prioritizes predictable and independent care of patients sharing a ventilator. Subsequently, we detail the design and testing of a ventilator-splitting circuit that follows this approach and describe our clinical experience with this circuit during the COVID-19 pandemic. This circuit was able to provide individualized and titratable ventilatory support with individualized positive end-expiratory pressure (PEEP) to 2 critically ill patients at the same time, while insulating each patient from changes in the other's condition. We share insights from our experience using this technology in the intensive care unit and outline recommendations for future clinical applications.

Amenable actions of locally compact groups on von Neumann algebras are investigated by exploiting the natural module structure of the crossed product over the Fourier algebra of the acting group. The resulting characterisation of injectivity for crossed products generalises a result of Anantharaman-Delaroche on discrete groups. Amenable actions of locally compact groups on $C^*$-algebras are investigated in the same way, and amenability of the action is related to nuclearity of the corresponding crossed product. A survey is given to show that this notion of amenable action for $C^*$-algebras satisfies a number of expected properties. A notion of inner amenability for actions of locally compact groups is introduced, and a number of applications are given in the form of averaging arguments, relating approximation properties of crossed product von Neumann algebras to properties of the components of the underlying $w^*$-dynamical system. We use these results to answer a recent question of Buss-Echterhoff-Willett., Comment: Fixed a mistake in Section 6. Typo fixes

Using the recently developed notion of a Herz--Schur multiplier of a C*-dynamical system we introduce weak amenability of C*- and W*-dynamical systems. As a special case we recover Haagerup's characterisation of weak amenability of a discrete group. We also consider a generalisation of the Fourier algebra to crossed products and study its multipliers., 18 pages

This study looks into the current, and potential uses of Blockchain technology in business, specifically in Accounting and in cybersecurity. We relate Blockchain uses to current concerns within cyb...

Heterotopic ossification is a well-known complication after orthopaedic surgical procedures, with a pre-dilection of the hip and elbow. Heterotopic ossification is a rare complication after shoulder arthroscopy and is rarely clinically significant. We report a case of a 65-year old Caucasian man with a slow and painful recovery after arthroscopic shoulder surgery encompassing rotator cuff repair, biceps tenotomy and acromioplasty, with recurrence of impingement symptoms unresponsive to conservative therapy (physiotherapy and one sub- acromial injection). He developed a severe heterotopic ossification at the acromial insertion of the deltoid and in the coraco-acromial ligament. This was successfully treated by arthroscopic excision of the lesion and postoperative prophylactic therapy with nonsteroidal anti-inflammatory drugs.

We define operator-valued Schur and Herz–Schur multipliers in terms of module actions, and show that the standard properties of these multipliers follow from well-known facts about these module actions and duality theory for group actions. These results are applied to study the Herz–Schur multipliers of an abelian group acting on its Pontryagin dual: it is shown that a natural subset of these Herz–Schur multipliers can be identified with the classical Herz–Schur multipliers of the direct product of the group with its dual group.

Given a C ⁎ -dynamical system ( A , G , α ) , with G a discrete group, Schur A-multipliers and Herz–Schur ( A , G , α ) -multipliers are used to implement approximation properties, namely exactness and the strong operator approximation property (SOAP), of A ⋊ α , r G . The resulting characterisations of exactness and SOAP of A ⋊ α , r G generalise the corresponding statements for the reduced group C ⁎ -algebra.

We extend the notion of Herz-Schur multipliers to the setting of non-commutative dynamical systems: given a C*-algebra $A$, a locally compact group $G$, and an action $\alpha$ of $G$ on $A$, we define transformations on the (reduced) crossed product $A\rtimes_{r,\alpha} G$ of $A$ by $G$, which, in the case $A = \mathbb{C}$, reduce to the classical Herz-Schur multipliers. We also introduce a class of Schur $A$-multipliers, establish its characterisation which generalise the classical descriptions of Schur multipliers and present a transference theorem in the new setting, identifying isometrically the Herz-Schur multipliers of the dynamical system $(A,G,\alpha)$ with the invariant part of the Schur $A$-multipliers. We discuss special classes of Herz-Schur multipliers, in particular, those which are associated to a locally compact abelian group $G$ and its canonical action on the $C^*$-algebra $C^*(\Gamma)$ of the dual group $\Gamma$., Comment: 48 pages

For a $C^*$-algebra $A$ and a set $X$ we give a Stinespring-type characterisation of the completely positive Schur $A$-multipliers on $K(\ell^2(X))\otimes A$. We then relate them to completely positive Herz-Schur multipliers on $C^*$-algebraic crossed products of the form $A\rtimes_{\alpha,r} G$, with $G$ a discrete group, whose various versions were considered earlier by Anantharaman-Delaroche, B\'edos and Conti, and Dong and Ruan. The latter maps are shown to implement approximation properties, such as nuclearity or the Haagerup property, for $A\rtimes_{\alpha,r} G$., Comment: 21 pages, v2 corrects a few minor typos. The paper will appear in the Mathematical Proceedings of the Cambridge Philosophical Society

We present results of four-corner carpal arthrodesis with the Acumed® HubcapTM circular plate performed at our unit. Eight patients underwent eight procedures over five years, for scapholunate advanced collapse (five wrists) and scaphoid non-union advanced collapse (three wrists). Outcomes included range of motion, quickDASH scores, and visual analogue scores for satisfaction. At final follow-up, mean flexion-extension arc was 56°, mean radial-ulnar deviation 29° and mean quickDASH score was 23/100. Mean score for satisfaction was 7.7/10 (77%). Seven out of eight (87.5%) patients said they would have it done again, and would also recommend it to others. Radiological union was achieved in all cases. One screw broke in one arthrodesis without causing symptoms. The functional outcomes with our use of the HubcapTM are comparable to those reported in literature to date with other circular plates (e.g. Spider plate). There were no non-unions, which is the main reported complication with these plates.

A series of pantolactone and pantothenic acid derivatives (1–10) were synthesized to be tested for their potential as lipid regulating agents that act as Coenzyme‐A mimics. The syntheses were performed with moderate to high yields.

Tissue engineering has made considerable progress in the past decade, but advances have stopped short of clinical application for most tissues. We postulated that an obstacle in engineering human tissues is the limited replicative capacity of adult somatic cells. To test this hypothesis, the effectiveness of telomerase expression to extend cellular lifespan was assessed in a model of human vascular tissue engineering. Telomerase expression in vascular cells isolated from elderly patients enabled the successful culture of engineered autologous blood vessels. Engineered vessels may one day provide a source of bypass conduit for patients with atherosclerotic disease.

Traumatic hip dislocation is uncommon in the paediatric population. Post reduction radiographs often show an incongruent hip because of tissue interposition. We report the case of a 12-year-old boy who was transferred to our hospital with an incongruent hip after a skiing accident, without a history of hip dislocation.

A series of long (11-15) hydrocarbon chain diols and diacids with various central functional groups and terminal gem-dimethyl or -methyl/aryl substituents was synthesized and evaluated in both in vivo and in vitro assays for its potential to favorably alter lipid disorders including metabolic syndrome. Compounds were assessed for their effects on the de novo incorporation of radiolabeled acetate into lipids in primary cultures of rat hepatocytes, as well as for their effects on lipid and glycemic variables in obese female Zucker fatty rats, Crl:(ZUC)-faBR. The most active compounds were hydroxyl-substituted symmetrical diacids and diols with a 13-atom chain and terminal gem-dimethyl substituents. Furthermore, biological activity was enhanced by central substitution with O, C=O, S, S=O compared to the methylene analogues and was diminished for compounds with central functional groups such as carbamate, ester, urea, acetylmethylene, and hydroxymethylene.

Until recently, reversible acetylation was thought to occur exclusively in the nucleus. Now it is known that several cytoplasmic processes require reversible acetylation. The first identified cytoplasmic deacetylase was HDAC6, a member of the histone deacetylase (HDAC) family. HDAC6 modulates a-tubulin acetylation and thus can regulate cytoskeletal dynamics and cell motility. HDAC6 has also been shown recently to play an essential role in the cell’s response to misfolded proteins. Using the characterization of HDAC6 as a starting point, in this chapter we review the role of HDACs in the cellular response to misfolded proteins. Specifically, we address how HDACs regulate the formation of aggresomes. We also discuss the relevance of these findings to neurodegenerative disease.

Based on preclinical investigations, magnesium sulfate (MgSO4) has gained interest as a neuroprotective agent. However, the ability of peripherally administered MgSO4 to penetrate the blood-brain barrier is limited in normal brain. The current study measured the passage of intravenously administered Mg into cerebrospinal fluid in patients with brain injury requiring ventricular drainage.A prospective evaluation of the cerebrospinal fluid total and ionized magnesium concentration, [Mg], during sustained hypermagnesemia was performed.Neurosciences intensive care unit at a major teaching institution.Thirty patients with acute brain injury secondary to subarachnoid hemorrhage, traumatic brain injury, primary intracerebral hemorrhage, subdural hematoma, brain tumor, central nervous system infection, or ischemic stroke were studied.Patients underwent 24 hrs of induced hypermagnesemia during which total and ionized cerebrospinal fluid [Mg] was measured. Serum [Mg] was adjusted to 2.1-2.5 mmol/L. Cerebrospinal fluid [Mg] was measured at baseline, at 12 and 24 hrs after onset of infusion, and at 12 hrs following infusion termination.At baseline, total (1.25 +/- 0.14 mmol/L) and ionized (0.80 +/- 0.10 mmol/L) cerebrospinal fluid [Mg] was greater than serum total (0.92 +/- 0.18 mmol/L) and ionized (0.63 +/- 0.07 mmol/L) [Mg] (p.05). Total (1.43 +/- 0.13 mmol/L) and ionized (0.89 +/- 0.12 mmol/L) cerebrospinal fluid [Mg] was maximally increased by 15% and 11% relative to baseline, respectively, during induced hypermagnesemia (p.05).Hypermagnesemia produced only marginal increases in total and ionized cerebrospinal fluid [Mg]. Regulation of cerebrospinal fluid [Mg] is largely maintained following acute brain injury and limits the brain bioavailability of MgSO4.

There is a pressing need to develop methods to engineer small-calibre arteries for bypass surgery. We hypothesized that the rate-limiting step that has thwarted previous attempts to engineer such vessels from non-neonatal tissues is the limited proliferative capacity of smooth muscle cells (SMCs), which are the main cellular component of these vessels. Ectopic expression of the human telomerase reverse transcriptase subunit (hTERT) has been shown recently to extend the lifespan of certain human cells. We therefore introduced hTERT into human SMCs and found that the resulting cells proliferated far beyond their normal lifespan but retained characteristics of normal control SMCs. Importantly, using these non-neonatal SMCs, we were able to engineer mechanically robust human vessels, a crucial step towards creating arteries of clinical value for bypass surgery.

Background Closed suction drainage systems are frequently used to drain fluids, particularly blood, from surgical wounds. The aim of these systems is to reduce the occurrence of wound haematomas and infection. Objectives To evaluate the effectiveness of closed suction drainage systems for orthopaedic surgery. Search methods We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2006), and contacted the Cochrane Wounds Group. We also searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 1), and MEDLINE (1966 to March 2006). Articles of all languages were considered. Selection criteria All randomised or quasi-randomised trials comparing the use of closed suction drainage systems with no drainage systems for all types of elective and emergency orthopaedic surgery. Data collection and analysis Two authors independently assessed trial quality, using a nine item scale, and extracted data. Where appropriate, results of comparable studies were pooled. Main results Thirty-six studies involving 5464 participants with 5697 surgical wounds were identified. The types of surgery involved were hip and knee replacement, shoulder surgery, hip fracture surgery, spinal surgery, cruciate ligament reconstruction, open meniscectomy and fracture fixation surgery. Pooling of results indicated no statistically significant difference in the incidence of wound infection, haematoma, dehiscence or re-operations between those allocated to drains and the un-drained wounds. Blood transfusion was required more frequently in those who received drains. The need for reinforcement of wound dressings and the occurrence of bruising were more common in the group without drains. Authors' conclusions There is insufficient evidence from randomised trials to support the routine use of closed suction drainage in orthopaedic surgery. Further randomised trials with larger patient numbers are required for different operations before definite conclusions can be made for all types of orthopaedic operations.

Previous studies have established that the vasopres- sin-regulated water channel of the collecting duct, aquaporin-2, is excreted in the urine, providing a means for assessment of regulation and dysregulation of aquaporin-2 in humans. This article addresses the hypothesis that membrane transporters from upstream nephron segments are normally detectable in urine. The experiments employed rabbit polyclonal antibodies against the major Na transporters of the proximal tubule (the type 3 Na-H exchanger (NHE3)), the thick ascending limb of Henle's loop (the bumetanide-sensitive Na-K-2Cl cotrans- porter (NKCC2)), and the distal convoluted tubule (the thia- zide-sensitive Na-Cl cotransporter (NCC)) in immunoblotting experiments. All three of these transporters were readily de- tectable as high molecular weight complexes present in low- density membrane fractions from urine of normal rats. Cross linking studies of NHE3, NKCC2, and NCC revealed that high molecular weight complexes are normally present in renal tissue. The molecular weights of the complexes in urine matched those of the cross-linked complexes in native kidney tissue. The presence in urine of integral membrane proteins representative of each nephron segment raises the possibility that limited or comprehensive proteomic analysis of urine samples may be useful in clinical settings.