A combined physicochemical approach towards human tenocyte phenotype maintenance.

During in vitro culture, bereft of their optimal tissue context, tenocytes lose their phenotype and function. Considering that tenocytes in their native tissue milieu are exposed simultaneously to manifold signals, combination approaches (e.g. growth factor supplementation and mechanical stimulation) are continuously gaining pace to control cell fate during in vitro expansion, albeit with limited success due to the literally infinite number of possible permutations. In this work, we assessed the potential of scalable and potent physicochemical approaches that control cell fate (substrate stiffness, anisotropic surface topography, collagen type I coating) and enhance extracellular matrix deposition (macromolecular crowding) in maintaining human tenocyte phenotype in culture. Cell morphology was primarily responsive to surface topography. The tissue culture plastic induced the largest nuclei area, the lowest aspect ratio, and the highest focal adhesion kinase. Collagen type I coating increased cell number and metabolic activity. Cell viability was not affected by any of the variables assessed. Macromolecular crowding intensely enhanced and accelerated native extracellular matrix deposition, albeit not in an aligned fashion, even on the grooved substrates. Gene analysis at day 14 revealed that the 130 kPa grooved substrate without collagen type I coating and under macromolecular crowding conditions positively regulated human tenocyte phenotype. Collectively, this work illustrates the beneficial effects of combined physicochemical approaches in controlling cell fate during in vitro expansion.

Copper nanowire array as highly selective electrochemical sensor of nitrate ions in water.

Contamination of water with nitrate ions is a significant problem that affects many areas of the world. For this reason, European legislation has set the maximum permissible concentration of nitrates in drinking water at 44 mg/L. Thus, it is clear that a continuous monitoring of nitrate ions is of high technological interest but it must be rapid, easy to perform and directly performable in situ. In this work we have developed a nanostructured sensor based on array of copper nanowires obtained with the simple method of galvanic deposition. The nanostructured sensors have a very short response time with a detection limit less than 10 µM. Different interfering species were tested finding a negligible effect except for the chloride ions. However, this problem has been solved by removing chloride ions from the water through a simple precipitation of chloride compounds with low solubility. Nanostructured sensors were also used to analyze real water samples (rain, river and drinking water). In the case of drinking water, we have measured a concentration of nitrate ions very close to the that measured by conventional laboratory techniques.

Estimated Weight of Paediatric Patients versus Measured Weight ­ A Prospective Comparison

Introduction Weight measurement is fundamental in the management of paediatric patients. Many methods have been described for estimating a patient's weight. The aim of this study was to assess the accuracy of the APLS 2017 estimated weight guidelines. Methods 100 patient charts were analysed in University Hospital Limerick's Paediatric unit. Measured weights were recorded, and estimated weights were calculated using the APLS 2017 charts. Estimated and measured weight was compared using Bland Altman plots. Results Of 100 subjects, 53 (53%) were female and 47 (47%) male. Fifty subjects (50%) were Pre-School, 32 (32%) Primary School and 18 (18%) Secondary School. Estimated weight was a good predictor for measured weight, however weight was underestimated by between 2.34% and 16.39% of measured weight. Discussion The current APLS guidelines are reasonably accurate; but accuracy decreases with increasing age. Estimation cannot replace an accurate measurement, which is not always feasible in the acute setting.

Promotion of role clarification in the Health Care Team Challenge.

Interprofessional collaboration has consistently been associated with positive client-care outcomes. Role clarification is one facet of interprofessional collaboration that is thought to be crucial for effective interprofessional team functioning. Given the positive outcomes associated with interprofessional collaboration, educators have begun to integrate formal interprofessional education events into healthcare curricula. The Health Care Team Challenge (HCTC) is a collaborative competition designed to promote interprofessional competencies among students in healthcare fields. The current study empirically investigated whether this event promoted role clarification among participants. Sixteen participants in five healthcare professions (occupational therapy, physiotherapy, clinical psychology, nursing, and medicine) completed two questionnaires to assess role clarification before and after participating in this event. Results indicate that participants' understanding of their own and other professions' roles improved after participating in this team activity. These results suggest that the HCTC is effective in promoting role clarification and collaboration among healthcare students.

Pertussis in young infants: clinical presentation, course and prevention.

Pertussis is a highly contagious disease caused by the Gram negative aerobic coccobacillus, Bordetella pertussis. It may present with severe symptoms and complications in infants and can pose a diagnostic challenge. This is a vaccine preventable illness covered by the Irish Childhood Immunisation Schedule. In 2011, a retrospective review was conducted of the records of infants, under six months, with a confirmed diagnosis of pertussis, presenting to Temple Street Children's University Hospital (TSCUH). A summery of notifications of pertussis nationally, from 2001 to 2012, was also examined as part of the study. This found that the rate of reported cases of pertussis has been increasing in Ireland. This national increase corresponds with a rising number of cases identified at TSCUH. Patients commonly presented severely ill with cyanosis and apnoea, on a background of prolonged cough. We found that pertussis was diagnosed rapidly in most cases however in all cases there was a delay to commencement of appropriate macrolide therapy.

Cytomegalovirus replication kinetics in solid organ transplant recipients managed by preemptive therapy.

After allotransplantation, cytomegalovirus (CMV) may be transmitted from the donor organ, giving rise to primary infection in a CMV negative recipient or reinfection in one who is CMV positive. In addition, latent CMV may reactivate in a CMV positive recipient. In this study, serial blood samples from 689 kidney or liver transplant recipients were tested for CMV DNA by quantitative PCR. CMV was managed using preemptive antiviral therapy and no patient received antiviral prophylaxis. Dynamic and quantitative measures of viremia and treatment were assessed. Median peak viral load, duration of viremia and duration of treatment were highest during primary infection, followed by reinfection then reactivation. In patients who experienced a second episode of viremia, the viral replication rate was significantly slower than in the first episode. Our data provide a clear demonstration of the immune control of CMV in immunosuppressed patients and emphasize the effectiveness of the preemptive approach for prevention of CMV syndrome and end organ disease. Overall, our findings provide quantitative biomarkers which can be used in pharmacodynamic assessments of the ability of novel CMV vaccines or antiviral drugs to reduce or even interrupt such transmission.

Dielectrophoretic self-assembly of polarized light emitting poly(9,9-dioctylfluorene) nanofibre arrays.

Conjugated polymer based 1D nanostructures are attractive building blocks for future opto-electronic nanoscale devices and systems. However, a critical challenge remains the lack of manipulation methods that enable controlled and reliable positioning and orientation of organic nanostructures in a fast, reliable and scalable manner. To address this challenge, we explore dielectrophoretic assembly of discrete poly(9,9-dioctylfluorene) nanofibres and demonstrate site selective assembly and orientation of these fibres. Nanofibre arrays were assembled preferentially at receptor electrode edges, being aligned parallel to the applied electric field with a high order parameter fit (∼ 0.9) and exhibiting an emission dichroic ratio of ∼ 4.0. As such, the dielectrophoretic method represents a fast, reliable and scalable self-assembly approach for manipulation of 1D organic nanostructures. The ability to fabricate nanofibre arrays in this manner could be potentially important for exploration and development of future nanoscale opto-electronic devices and systems.

Acute renal disease, as defined by the RIFLE criteria, post-liver transplantation.

Acute renal failure (ARF) can complicate up to 60% of orthotopic liver transplants (OLT). The RIFLE criteria were developed to provide a consensus definition for acute renal disease in critically ill patients. Using the RIFLE criteria, we aimed to determine the incidence and risk factors for ARF and acute renal injury (ARI), and to evaluate the link with the outcomes, patient survival and length of hospital stay. Three hundred patients, who received 359 OLTs, were retrospectively analyzed. ARI and ARF occurred post 11.1 and 25.7% of OLTs, respectively. By multivariate analysis, ARI was associated with pre-OLT hypertension and alcoholic liver disease and ARF with higher pre-OLT creatinine, inotrope and aminoglycoside use. ARF, but not ARI, had an impact on 30-day and 1-year patient survival and longer length of hospital stay. ARI and ARF, as defined by the RIFLE criteria, are common complications of OLT, with distinct risk factors and ARF has serious clinical consequences. The development of a consensus definition is a welcome advance, however these criteria do need to be validated in large studies in a wide variety of patient populations.

Role of interleukin (IL-10) in probiotic-mediated immune modulation: an assessment in wild-type and IL-10 knock-out mice.

While the impact of Bifidobacterium infantis 35624 and other probiotics on cytokines has been shown in established colitis, the effects of B. infantis consumption in pre-inflammation of interleukin (IL)-10 knock-out (KO) mice and on the wild-type (WT) C57Bl/6 mice have not been well demonstrated. The objective of this study was to examine cytokine responses in mucosal and systemic lymphoid compartments of IL-10 KO mice early in disease and to compare with control WT mice. Mice were fed B. infantis or placebo for 5 weeks and culled prior to the onset of chronic intestinal inflammation (12-14 weeks). The spleen, Peyer's patches and intestinal mucosa were removed and stimulated with various bacterial stimuli. Cytokine levels were measured by enzyme-linked immunosorbent assay. While basal intestinal and systemic cytokine profiles of WT and IL-10 KO mice were similar, transforming growth factor (TGF)-beta was reduced in the spleen of IL-10 KO mice. Following probiotic consumption, interferon (IFN)-gamma was reduced in the Peyer's patch of both WT and IL-10 KO mice. Alterations in IFN-gamma in the Peyer's patches of WT mice (enhancement) versus IL-10 KO (reduction) were observed following in vitro stimulation with salmonella. Differential IL-12p40, CCL2 and CCL5 responses were also observed in IL-10 KO mice and WT mice. The cytokine profile of IL-10 KO mice in early disease was similar to that of WT mice. The most pronounced changes occurred in the Peyer's patch of IL-10 KO mice, suggesting a probiotic mechanism of action independent of IL-10. This study provides a rationale for the use of B. infantis 35624 for the treatment of gastrointestinal inflammation.

Vancomycin-resistant peritonitis associated with peritoneal dialysis: a cause for concern.

BACKGROUND: Peritonitis resulting from peritoneal dialysis (PD) remains a serious cause of morbidity and even mortality among dialysis patients. AIM: To highlight the danger of antibiotic resistance in patients on dialysis who have received multiple courses of antibiotics. METHODS: Two cases are reported in which the patients developed peritonitis resistant to vancomycin. CONCLUSIONS: Multi-drug resistance is a growing danger. It is imperative to use the most appropriate antibiotics in the proper dosage. If infections persist, early removal of the catheters is essential. The use of antibiotics in PD patients needs to be limited. Sensitivity patterns of the cultured organisms must be monitored regularly as the lack of vigilance may help accelerate the development of the so-called 'super bug' resistant to all antibiotics.

Role of prostaglandin E(2) and Ca(2+) in bradykinin induced contractions of guinea-pig gallbladder in vitro.

In this study, we investigated the contribution of prostaglandin E(2) to bradykinin induced contractions of guinea-pig gallbladder in vitro and characterized the sources of activator Ca(2+) for the bradykinin mediated contractions. Contractions induced by bradykinin in guinea-pig gallbladder smooth muscle strips were significantly attenuated by the cyclooxygenase inhibitor piroxicam (10 microM). In the presence of piroxicam, a threshold concentration of prostaglandin E(2) (1 nM) significantly enhanced the contractile response to subsequent challenge with bradykinin. Contractile responses to bradykinin were abolished in a Ca(2+)-free medium plus EDTA. The inhibitor of receptor mediated Ca(2+) entry, SK&F 96365 (1-[beta-[3-(4-methoxyphenyl)-propoxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride, 10-50 microM) dose dependently abolished the response to bradykinin, while this response was only partially attenuated by nifedipine (10-50 microM; a voltage-operated Ca(2+) channel antagonist). Thapsigargin (an inhibitor of the sarcoplasmic reticulum calcium ATP-ase pump, 1 microM) produced sustained contractions of guinea-pig gallbladder strips that were dependent on extracellular Ca(2+). After incubation of strips in a Ca(2+)-free medium with thapsigargin, replacement of Ca(2+) caused a large sustained contraction. We conclude that the contractile response of guinea-pig gallbladder to bradykinin is modulated by prostaglandin E(2). Bradykinin induced contractions of guinea-pig gallbladder are highly dependent on extracellular Ca(2+) which enters through store-operated Ca(2+) channels and partially through voltage-operated Ca(2+) channels.

Sources of calcium in neurokinin A-induced contractions of human colonic smooth muscle in vitro.

OBJECTIVES: Tachykinins have been implicated in the pathogenesis of colonic dysmotility. The sources of activator calcium for neurokinin A (NKA)-induced contraction of human colonic smooth muscle have not been assessed. We evaluated the contribution of extracellular and intracellular Ca2+ to NKA-induced contractions. METHODS: Circular smooth muscle strips of human colon were suspended under 1 g of tension in organ baths containing Krebs solution at 37 degrees C gased with 95% O2/5% CO2. Contractile activity was recorded isometrically. RESULTS: Cumulatively applied NKA (0.1 nmol/L-0.3 micromol/L), produced concentration-dependent contractions of human colonic smooth muscle strips that were not affected by tetrodotoxin (1 micromol/L). The contractile response to NKA was abolished in a Ca2+-free medium containing ethylenediaminetetraacetate (EDTA) (1 mmol/L). Pretreatment of muscle strips with nifedipine (1 micromol/L), an L-type voltage-operated Ca2+ channel antagonist, abolished the contractile responses to NKA. Pretreatment with SK&F 96365 (10 micromol/L and 30 micromol/L), a putative receptor-activated and voltage-operated Ca2+ channel antagonist, attenuated the contractile responses. Depletion of intracellular Ca2+ stores with thapsigargin (1 micromol/L), an inhibitor of the sarcoplasmic reticulum Ca2+ ATP-ase, had no effect on NKA-induced contractions. CONCLUSIONS: NKA-mediated contraction of human colonic smooth muscle is dependent on an influx of extracellular Ca2+ through L-type voltage-operated Ca2+ channels. Intracellular Ca2+ release seems to have little role to play in NKA-mediated contractions.

A prospective study of complications associated with cuffed, tunnelled haemodialysis catheters.

BACKGROUND: Despite the US Dialysis Outcome Quality Initiative )DOQI( guidelines, for various reasons, increasing numbers of end-stage renal disease patients are becoming dependent on cuffed haemodialysis catheters (HCs) for chronic haemodialysis access. Their use is complicated by frequent failure due to thrombosis and catheter-related sepsis. In our unit, all HCs are put in place by the radiology department. METHODS: In a prospective study we looked at the outcome of all HCs over a three-year period, during which time 573 consecutive HCs were placed in 336 patients. Each line was followed individually until it was removed or until the end of the study. RESULTS: In a survival analysis of those HCs removed following HC failure, HC half-life was 312 days and one-year HC survival was 47.5%. The most frequent indications for HC removal were non-function (36.6%), clinical suspicion of line sepsis (16.4%) and patient death (14.4%). Using a Cox proportional hazards model, catheter number in a given patient and the presence of diabetes mellitus were found to be independent predictors of HC failure. The total incidence of HC-related sepsis was 1.3 episodes/1000 catheter days. The probability of developing bacteraemic HC-related sepsis was 27.5% at one year. CONCLUSIONS: Less than half of the HCs were removed electively because of availability of a more permanent mode of renal replacement, thereby illustrating the level of dependence that has developed on them as permanent access. Consequently, their limitations (infection and malfunction) are placing an ever increasing burden on the healthcare services.

Familial occurrence of discrete subaortic membrane.

The first case of multiple family members with discrete subaortic membrane and no other congenital defects is presented. One family member presents with findings suggesting a forme fruste of this disease. Increased surveillance of family members of individuals with discrete subaortic membrane is warranted, as the clinical findings of mild subaortic obstruction may be indistinguishable from those of an innocent flow murmur.

Pacemaker contact sensitivity: clinical recognition and management.

We report a patient in whom vesicular lesions of the skin developed overlying the pacemaker at intervals of 3 to 8 months after each of three consecutive insertions. Patch skin tests were positive for titanium and polyurethane sensitization. Although pacemaker contact sensitivity is rare, its recognition is of vital importance to the pacemaker-dependent patient.

Recurrent obstruction after subclavian flap repair of coarctation of the aorta in infants. Can it be predicted or prevented?

Recoarctation is a problem in some patients after subclavian flap aortoplasty. To investigate the reason for recoarctation, we reviewed the records of 26 infants who underwent subclavian flap repair for symptomatic coarctation of the aorta at less than 3 months of age between June, 1979, and December, 1983. Age at repair ranged from 2 to 65 days (median 16 days) and weight from 2.1 to 4.9 kg (median 3.4 kg). In 14 patients the coarctation was associated with significant intracardiac defects (complex in six). There were two intraoperative deaths and one early death (surgical mortality 12%). The survivors were followed from 6 weeks to 66 months (median 12 months). Five survivors (22%), all operated on at less than 14 days of age, developed severe recoarctation 6 weeks to 6 months (median 5 months) after repair. The obstruction appeared to be due to lumen obliteration by shelf-life posterior wall tissue. Morphometric analysis of preoperative angiograms showed no correlation between recoarctation and distance between the left subclavian artery and the site of coarctation, length of the isthmus, diameter of the isthmus, combined cross-sectional area of the left subclavian artery and isthmus, or the ratio of the combined cross-sectional area of the left subclavian artery and isthmus to the cross-sectional area of the descending thoracic aorta. Recoarctation did not correlate with weight at operation, but it correlated significantly with age at aortoplasty (p = 0.02). The results suggest that intrinsic abnormalities of the periductal aortic wall are responsible for recoarctation after subclavian flap aortoplasty. Particular attention to this abnormal tissue at repair may prevent early recurrence in young infants.