Development and internal validation of clinical prediction models for outcomes of complicated intra-abdominal infection.

BACKGROUND: Complicated intra-abdominal infections (cIAIs) are associated with significant morbidity and mortality. The aim of this study was to describe the clinical characteristics of patients with cIAI in a multicentre study and to develop clinical prediction models (CPMs) to help identify patients at risk of mortality or relapse. METHODS: A multicentre observational study was conducted from August 2016 to February 2017 in the UK. Adult patients diagnosed with cIAI were included. Multivariable logistic regression was performed to develop CPMs for mortality and cIAI relapse. The c-statistic was used to test model discrimination. Model calibration was tested using calibration slopes and calibration in the large (CITL). The CPMs were then presented as point scoring systems and validated further. RESULTS: Overall, 417 patients from 31 surgical centres were included in the analysis. At 90 days after diagnosis, 17.3 per cent had a cIAI relapse and the mortality rate was 11.3 per cent. Predictors in the mortality model were age, cIAI aetiology, presence of a perforated viscus and source control procedure. Predictors of cIAI relapse included the presence of collections, outcome of initial management, and duration of antibiotic treatment. The c-statistic adjusted for model optimism was 0.79 (95 per cent c.i. 0.75 to 0.87) and 0.74 (0.73 to 0.85) for mortality and cIAI relapse CPMs. Adjusted calibration slopes were 0.88 (95 per cent c.i. 0.76 to 0.90) for the mortality model and 0.91 (0.88 to 0.94) for the relapse model; CITL was -0.19 (95 per cent c.i. -0.39 to -0.12) and - 0.01 (- 0.17 to -0.03) respectively. CONCLUSION: Relapse of infection and death after complicated intra-abdominal infections are common. Clinical prediction models were developed to identify patients at increased risk of relapse or death after treatment, these now require external validation.

A phase I randomized trial to assess the effect on skin infiltrate thickness and tolerability of topical phosphodiesterase inhibitors in the treatment of psoriasis vulgaris using a modified psoriasis plaque test.

BACKGROUND: Oral phosphodiesterase (PDE)4 inhibitors have shown efficacy in chronic obstructive pulmonary disease and psoriasis. OBJECTIVES: To assess the effectiveness, local safety and tolerability, and systemic pharmacokinetics of two topical PDE4 inhibitors, roflumilast and TAK-084, in plaque psoriasis. METHODS: An intraindividual comparison of six topical products was made in 15 patients aged 18-65 years with stable chronic plaque psoriasis in an investigator-blinded, within-subject randomized study. The products evaluated were calcipotriol 0·005% cream; betamethasone valerate 0·1% (both in their marketed formulations); investigational cream formulations of roflumilast 0·5% and TAK-084 0·5% and 5%; and a vehicle cream formulation as a control. Each treatment was applied daily to different test sites located on psoriasis plaques for 3 weeks. RESULTS: The primary end point of (mean) change from baseline in skin infiltrate thickness after 3 weeks of treatment showed statistically significant improvements for all treatments: betamethasone valerate cream (-286·9 µm), the selective PDE4 inhibitors roflumilast 0·5% (-237·1 µm) and TAK-084 (0·5% cream, -153·6 µm; 5% cream, -216·7 µm) and calcipotriol 0·005% (-187·7 µm) when compared with vehicle cream control (all P < 0·001). Both the TAK-084 5% and roflumilast 0·5% formulations performed well overall compared with the potent corticosteroid, betamethasone, and were ranked better than the vitamin D analogue calcipotriol. All adverse events were mild or moderate and none was serious. CONCLUSIONS: Topical treatment with cream formulations of the PDE4 inhibitors roflumilast and TAK-084 reduced inflammation, measured as a change in skin infiltrate thickness, and reduced psoriasis severity. Corticosteroid treatments have known systemic and cutaneous side-effects; PDE4 inhibitors could offer an alternative to these and deserve further study.

Primary hip and knee arthroplasty in a temporary operating theatre is associated with a significant increase in deep periprosthetic infection.

AIMS: Infection following total hip or knee arthroplasty is a serious complication. We noted an increase in post-operative infection in cases carried out in temporary operating theatres. We therefore compared those cases performed in standard and temporary operating theatres and examined the deep periprosthetic infection rates. PATIENTS AND METHODS: A total of 1223 primary hip and knee arthroplasties were performed between August 2012 and June 2013. A total of 539 (44%) were performed in temporary theatres. The two groups were matched for age, gender, body mass index and American Society of Anesthesiologists grade. RESULTS: The deep infection rate for standard operating theatres was 0 of 684 (0%); for temporary theatres it was eight of 539 (1.5%) (p = 0.001). CONCLUSION: Use of a temporary operating theatre for primary hip and knee arthroplasty was associated with an unacceptable increase in deep infection. We do not advocate the use of these theatres for primary joint arthroplasty. Cite this article: Bone Joint J 2017;99-B:917-20.

Antibiotic prophylaxis in orthopaedic surgery: difficult decisions in an era of evolving antibiotic resistance.

Prophylactic antibiotics can decrease the risk of wound infection and have been routinely employed in orthopaedic surgery for decades. Despite their widespread use, questions still surround the selection of antibiotics for prophylaxis, timing and duration of administration. The health economic costs associated with wound infections are significant, and the judicious but appropriate use of antibiotics can reduce this risk. This review examines the evidence behind commonly debated topics in antibiotic prophylaxis and highlights the uses and advantages of some commonly used antibiotics. Cite this article: Bone Joint J 2016;98-B:1014-19.

Iron binding to, and release from, the basolateral membrane of mouse duodenal enterocytes.

The basolateral membrane of mouse duodenal enterocytes can be selectively labelled in vitro with 59Fe by incubating intact enterocytes with 59Fe(III)-nitrilotriacetate at 0-4 degrees C. It has been proposed that this labelling represents binding to a site important in the transfer of intracellular Fe to the portal plasma (Snape, S., Simpson, R.J. and Peters, T.J. (1990) Cell Biochem. Funct. 8, 107-115). Studies presented here show binding to intact enterocytes in vitro was complete within 1 h and was proportional to enterocyte protein concentration. Binding to enterocytes isolated from both normal and chronically hypoxic mice showed a hyperbolic dependence on medium Fe(III) concentration, consistent with a single class of binding sites. Neither apparent binding constant nor maximal binding were increased by hypoxic exposure of mice, suggesting that the increased in vivo labelling of this site in hypoxia is not due to an increase in affinity or capacity of this site for iron. Release of iron from intact enterocytes, labelled at 0-4 degrees C, was measured at 37 degrees C and 0-4 degrees C. Release of 59Fe was extensive and more rapid at 37 degrees C with highest release to mouse serum. Iron released to serum was found to be bound to transferrin. Prior dialysis of serum against buffer led to complete failure of enterocytes to release iron. Reconstituting serum by adding back the dialysate restores release to levels seen in fresh serum, suggesting that low molecular weight serum components, notably bicarbonate, mediate iron transfer from the basolateral membrane to serum transferrin. The properties of the basolateral membrane iron binding site described here are consistent with a role in the iron transfer process.

Subcellular distribution of recently absorbed iron and of transferrin in the mouse duodenal mucosa.

A successful method for the analytical subcellular fractionation of mouse duodenal mucosa organelles was established. 59Fe(III)-nitrilotriacetate (pH 7.2) was injected into tied-off duodenal segments in vivo and, after 2-20 min, mucosal homogenates were subjected to subcellular fractionation. Radioactivity was recovered in the cytosolic fractions and in the gradient at a density of 1.18-1.20 g/ml. Enhanced iron absorption was achieved by placing the animals in a hypobaric chamber for 3 days. These animals had a higher proportion of particulate 59Fe compared to controls. Homogenisation in sucrose medium containing the selective plasma membrane perturbant digitonin shifted the particulate iron fraction to a higher density region of the gradient indicating a localisation of the iron binding site to the plasma membrane region of the mucosal cells. No significant radioactive iron was observed in the brush-border region of the gradient. Transferrin immunoreactivity was found only in the cytosolic region of the gradient and was not associated with any organelle.

Studies on the role of transferrin and endocytosis in the uptake of Fe3+ from Fe-nitrilotriacetate by mouse duodenum.

Addition of iron-binding proteins (human serum transferrin, mouse serum transferrin, human lactoferrin) to the luminal fluid in tied-off segments of mouse intestine in vivo led to reduced 59Fe3+ absorption from 59Fe3+-nitrilotriacetate when compared to 59Fe3+-nitrilotriacetate alone. Assay of transferrin in luminal fluid from tied segments revealed only trace amounts of immunoreactivity. The levels of luminal transferrin are unaltered in chronic hypoxia where iron absorption is significantly enhanced. Studies in vitro revealed that NH4Cl, dansylcadavarine, para-chloromercuribenzoate and trinitrobenzenesulphonate have no effect on initial 59Fe3+ uptake rates from 59Fe3+-nitrilotriacetate, while N-ethylmaleimide (1 mM) caused a 40% inhibition. In vivo 59Fe3+ uptake was unaffected by preincubation of tied-off segments with colchicine (5 mM) for up to 2 h. These results suggest that receptor-mediated endocytosis of transferrin is not a significant mechanism in the uptake of luminal Fe3+ by mouse duodenum.

Investigating the impact of clinical anaesthetic practice on bacterial contamination of intravenous fluids and drugs.

Syringes (N = 426), ventilator machine swabs (N = 202) and intravenous (IV) fluid administration sets (N = 47) from 101 surgical cases were evaluated for bacterial contamination. Cultures from the external surface of syringe tips and syringe contents were positive in 46% and 15% of cases, respectively. The same bacterial species was cultured from both ventilator and syringe in 13% of cases, and was also detected in the IV fluid administration set in two cases. A significant association was found between emergency cases and contaminated syringes (odds ratio 4.5, 95% confidence interval 1.37-14.8; P = 0.01). Other risk factors included not using gloves and failure to cap syringes.

Safety and tolerability of zalcitabine (ddC) in patients with AIDS or advanced AIDS-related complex in the European expanded access programme.

This international expanded access programme was initiated to provide zalcitabine (o 75 mg three times daily) to patients with AIDS or advanced ARC who had failed, were no longer able to tolerate or were ineligible to receive zidovudine (ZDV). Data are available from 517 patients. No unexpected adverse events occurred during the study with 13.2% of patients discontinuing treatment due to drug-related adverse events. Peripheral neuropathy (PN) was the most common adverse event reported. This was considered to be at least possibly related to zalcitabine in 12.2% of patients, with only 2.3% of patients withdrawing from the study due to zalcitabine-associated PN. Patients with a baseline diagnosis of AIDS and a CD4 count

Galactosyltransferase activity is not localized to the brush border membrane of human small intestine.

A recent report [Roth et al. (1985) J. Cell Biol. 100: 118-125], using immunocytochemical techniques, claimed that human duodenal galactosyltransferase is located predominantly on the external aspect of enterocyte brush border membranes. Analytical subcellular fractionation by sucrose density gradient centrifugation of human jejunum biopsy homogenates demonstrated that galactosyltransferase activity is localized to the Golgi fraction (equilibrium density of 1.14 g cm-3) and is not found in significant amounts in the brush border membrane (equilibrium density of 1.22 g cm-3).

Baroness Coxand Section 28.

In reply to an article in Nursing Standard (February28 - March 6), 'Facts, please' by Baroness Cox, I feel I must reply. While welcoming the fact that Baroness Cox has with drawn from the chair of the forth coming RCN/BMA conference on HIV and AIDS, I would question her view that she has been the victim of 'unfounded', 'misguided' and 'possiblymalicious' attacks. Her accusation that some nurses who disagree with her are prejudiced, bigoted and even unprofessional cannot go unchallenged in the absence of evidence.

A randomized controlled trial of botulinum toxin on lower limb spasticity following acute acquired severe brain injury.

OBJECTIVE: To determine whether serial casting combined with botulinum toxin reduces the development of calf contracture after severe head injury. DESIGN: A double-blind placebo-controlled trial of three parallel treatments for lower limb spasticity. SETTING: Acute general hospital in the UK. SUBJECTS: Adults aged 17-70 years admitted to hospital following a severe brain INTERVENTIONS: Current physical treatment (group I), lower leg casting plus injections with either saline (group II), or with botulinum toxin (group III) into gastrocnemius and soleus muscles. MEASURES: Limit of ankle dorsiflexion at entry and exit after up to 12 weeks, the Glasgow Outcome Scale (GOS) and Modified Ashworth Scale (MAS). RESULTS: Two hundred and fifty-three patients were screened and 35 were entered into the trial. Three patients died and four failed to complete the trial. Eighty-eight per cent of those entering the randomized part of the study developed spasticity within 14 days of their injury and the mean range of improvement in the angle of passive ankle dorsiflexion was 4.59 degrees in controls, 11.69 degrees in cast and saline and 13.59 degrees in cast and botulinum toxin. There were significant improvements in the MAS scores in actively treated groups, but not in controls. Cast and botulinum toxin patients also demonstrated a significant improvement in the GOS. CONCLUSIONS: Active intervention with casting prevents talipes equinovarus deformities in patients losing ankle movement following severe brain injury. Casting alone in these patients is sufficient; the role of additional botulinum toxin needs further investigation, but is safe in these patients.

Subcellular localization of recently-absorbed iron in mouse duodenal enterocytes: identification of a basolateral membrane iron-binding site.

The subcellular distribution of newly absorbed iron in isolated mouse duodenal enterocytes was investigated by analytical subcellular fractionation using sucrose density gradient centifugation. Two major peaks of mucosal 59Fe activity were observed: one soluble and one particulate (density 1.18-1.20 g ml-1). The latter was increased following prior exposure of animals to chronic hypoxia. The particulate 59Fe was localized to the basolateral membranes using the marker enzyme Na+, K+ activated, Mg2+ dependent, ATPase and by washing intact enterocytes with the selective plasma membrane perturbant digitonin. The basolateral membrane can be selectively labelled by in vitro incubation of intact enterocytes at 0 degrees C with 59Fe(III)-nitrilotriacetate complex, confirming the presence of a 59Fe binding site on this membrane. No significant difference in in vitro iron binding to this site was observed between normal and chronically hypoxic animals. Iron binding to the basolateral membrane was significantly higher in disrupted, compared to intact enterocytes, indicating that this site is present on both sides of the basolateral membrane. It is therefore suggested that the increased labelling of this site in hypoxia, in vivo, is a consequence of an increase in a mucosal Fe pool which is available for binding to a membrane receptor.

An early marker of hyperoxic lung injury in the rat and its pharmacological modulation.

Of three possible early biochemical changes which were investigated in rats after hyperoxia, one was shown to be a useful marker of damage in this species. Mitochondrial oxygen uptake measured in lung homogenates has already been reported to be impaired after 24 h. With a purified mitochondrial fraction, we found significant impairment after only 3 h exposure to 100% oxygen. To our knowledge, this is the earliest significant change reported in this species. The antioxidants N-acetyl cysteine, dimethyl sulphoxide and allopurinol were found to ameliorate the injury. This suggests a possible link with the pulmonary damage and survival of rats in hyperoxia, which may be modulated also by antioxidant therapy.

Endogenous interleukin-10 modulates proinflammatory response in Plasmodium falciparum malaria.

Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6 are implicated in the pathogenesis of severe Plasmodium falciparum malaria. In this study, the effect of IL-10 on their production by peripheral blood mononuclear cells (PBMC) from acutely infected patients was examined. Exogenous IL-10 inhibited malarial antigen-induced cytokine production by reducing mRNA accumulation. Maximal inhibition occurred when IL-10 was added in the first 2 h of stimulation. Conversely, the addition of anti-IL-10 markedly enhanced TNF-alpha, IL-1beta, and IL-6 production. The effect was significantly greater on PBMC from patients with uncomplicated infection than PBMC from patients with severe disease. Kinetics studies showed that TNF-alpha, IL-6, and IL-1beta were produced within 2-4 h of stimulation, while IL-10 was first detectable after 8 h. These findings suggest that IL-10 counter-regulates the proinflammatory response to P. falciparum. Severe falciparum malaria may be associated with an inadequate negative feedback response by IL-10.

Intestinal iron absorption and mucosal transferrin in rats subjected to hypoxia.

Three days hypoxia (0.5 atm) increased the haemoglobin and haematocrit values in rats paralleled by enhanced intestinal iron absorption. The destination of recently-absorbed iron was primarily the erythropoietic system, viz. bone marrow, spleen and red cells. Total plasma transferrin, was increased by 30%, but no significant changes in mucosal transferrin were found. No increase in labelling of mucosal transferrin by absorbed iron was observed. These results suggest that mucosal transferrin does not play a major role in the regulation of intestinal iron absorption in hypoxia.