Hip fracture patients admitted to hospital on weekends are not at increased risk of 30-day mortality as compared with weekdays.

BACKGROUND: Hip fractures remain a major health concern owing to the increasing elderly population and their association with significant morbidity and mortality. The effects of weekend admission on mortality have been studied since the late 1970s. Despite most studies showing that mortality rates are higher for patients admitted on a weekend, the characteristics of the admitted patients have remained unclear. We aim to investigate this 'weekend effect' at our hospital in patients presenting with a hip fracture. METHODS: Patients undergoing acute hip fracture surgery were identified from the local National Hip Fracture Database. Patient demographics, fracture type, co-morbidities and admission blood parameters were examined. The outcome analysed was 30-day mortality. The data were analysed with regard to day of admission, i.e. weekday (Monday to Friday) or weekend (Saturday and Sunday). RESULTS: A total of 894 patients were included. Results demonstrated that 30-day mortality was similar on the weekend compared with the weekday (6.96% versus 10.39%, OR 0.65, 95% CI 0.36-1.14, p = 0.128) for patients who sustained an acute hip fracture. The total number of deaths within 30 days was 85 (69 weekday versus 16 weekend). This remained non-significant after adjusting for several variables: age and sex only (OR = 0.65, 95% CI 0.37-1.16, p = 0.146), age, sex, and care variables (OR = 0.59, 95% CI 0.33-1.06, p = 0.080), age, sex, and blood test results (OR = 0.62, 95% CI 0.35-1.12, p = 0.111), and all covariates (OR = 0.69, 95% CI 0.29-1.62, p = 0.392). In the fully adjusted model, the following variables were independent predictors of mortality: sex (male) (OR = 1.93, 95% CI 1.11-3.35, p = 0.019) and ASA > 2 (OR = 2.6, 95% CI 1.11-6.11, p = 0.028) and age (1.08, 95% CI 1.04-1.13, p < 0.001). CONCLUSION: The evidence for a 'weekend effect' in patients with a hip fracture is absent in this study. However, we have shown other factors that are associated with increased mortality such as increased age, male sex and higher ASA grade. LEVEL OF EVIDENCE: Level 3.

P.F.C Sigma® cruciate retaining fixed-bearing versus mobile-bearing knee arthroplasty: a prospective comparative study with minimum 10-year follow-up.

AIMS: To prospectively compare long-term clinical and radiological outcomes following a cruciate retaining fixed-bearing (FB) and a mobile-bearing (MB) primary total knee replacement (TKR). METHODS: We prospectively reviewed 113 TKRs in 99 patients (14 bilateral) with a PFC sigma cruciate retaining rotating platform system, at an average follow-up of 11.1 years (range 10-12). Results were contrasted with those from 89 TKRs in 72 patients (17 bilateral) with a PFC sigma cruciate fixed-bearing prosthesis, at an average follow-up of 12.1 years (range 10-14.1). Outcomes collected included pre- and post-operative range of motion, Oxford Knee Scores, complications encountered, as well as radiographical assessments of polyethylene wear. RESULTS: In the MB group, mean Oxford Knee Scores improved from 16 pre-operatively to 42 at final follow-up. The mean range of motion was 115° (75-130). In the FB group, mean Oxford Knee Scores improved from 16.2 pre-operatively to 42.5 at final follow-up. The mean range of motion was 111.2 (80-135) degrees at final follow-up. CONCLUSION: We failed to elicit an objectively demonstrable clinical difference between the MB- and FB-implanted knees. Similarly, radiological benefits of the MB implants with regard to polyethylene wear were not evident at a minimum 10-year follow-up.

Dual stimuli-responsive coating designed through layer-by-layer assembly of PAA-b-PNIPAM block copolymers for the control of protein adsorption.

In this paper, we describe the successful construction, characteristics and interaction with proteins of stimuli-responsive thin nanostructured films prepared by layer-by-layer (LbL) sequential assembly of PNIPAM-containing polyelectrolytes and PAH. PAA-b-PNIPAM block copolymers were synthesized in order to benefit from (i) the ionizable properties of PAA, to be involved in the LbL assembly, and (ii) the sensitivity of PNIPAM to temperature stimulus. The impact of parameters related to the structure and size of the macromolecules (their molecular weight and the relative degree of polymerization of PAA and PNIPAM), and the interaction with proteins under physico-chemical stimuli, such as pH and temperature, are carefully investigated. The incorporation of PAA-b-PNIPAM into multilayered films is shown to be successful whatever the block copolymer used, resulting in slightly thicker films than the corresponding (PAA/PAH)n film. Importantly, the protein adsorption studies demonstrate that it is possible to alter the adsorption behavior of proteins on (PAA-b-PNIPAM/PAH)n surfaces by varying the temperature and/or the pH of the medium, which seems to be intimately related to two key factors: (i) the ability of PNIPAM units to undergo conformational changes and (ii) the structural changes of the film made of weak polyelectrolytes. The simplicity of construction of these PNIPAM block copolymer-based LbL coatings on a large range of substrates, combined with their highly tunable features, make them ideal candidates to be employed for various biomedical applications requiring the control of protein adsorption.

Preparation and characterizations of EGDE crosslinked chitosan electrospun membranes.

Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethylene oxide was successfully prepared with bead free morphology via electrospinning technique followed by heat mediated chemical crosslinking. Architectural stability of nanofiber mat in aqueous medium was achieved by chemical crosslinking of only 1% EGDE, and tensile strength tests revealed that increasing EGDE content has considerably enhance the elastic modulus of nanofibers. The structure, morphology and mechanical properties of nanofibers were characterized by Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and Instron machine, respectively. Skin fibroblasts and endothelial cells showed good attachment, proliferation and viability on crosslinked electrospun membranes. The results indicate a good biocompatibility and non-toxic nature of the resulted membrane.

Changes in heat shock protein 70, blood parameters, and fear-related behavior in broiler chickens as affected by pleasant and unpleasant human contact.

An experiment was conducted to determine the effects of combining both pleasant and unpleasant contacts with human beings on physiology and behavior of broiler chickens. Birds were subjected to the following treatments: (i) received no physical or visual contact with humans (control); (ii) from d 1 to 28, chicks were individually stroked gently for 30 s once daily (PL); (iii) from d 1 to 28, chicks were picked up individually, suspended by both legs, exposed to recorded noise, and swung gently for 15 s once daily (UNPL); (iv) from d 1 to 14 and from d 15 to 28, chicks were subjected to PL and UNPL, respectively (PL-UNPL); and (v) from d 1 to 14 and from d 15 to 28, chicks were subjected to UNPL and PL, respectively (UNPL-PL). On d 42, birds from each treatment group were road-transported for 3 h. Heat shock protein (hsp) 70 expression, plasma levels of corticosterone, serum creatine kinase concentration, heterophil/lymphocyte ratios (HLR), and tonic immobility duration were determined pre- and posttransit. There were significant (P < 0.05) duration of transportation × human contact treatment interactions for HLR and hsp 70 density. Following transit, the PL chicks had significantly (P < 0.05) lower HLR and greater hsp 70 density than the other groups. The corticosterone of PL and UNPL chicks were lower than their control, PL-UNPL, and UNPL-PL counterparts. The PL and PL-UNPL treatments were effective in shortening tonic immobility duration significantly (P < 0.05). Except for UNPL-PL, the serum creatine kinase activity of PL was significantly lower than the other groups. In conclusion, subjecting birds to pleasant human contact reduced stress and fear reactions to transportation by enhancing the ability to express hsp 70 in the brain. Unpleasant human contact had adverse effect on the birds' response to transportation. Early age pleasant experience with humans failed to negate the adverse effects of subsequent unpleasant contact.

Physicochemical properties of pH-controlled polyion complex (PIC) micelles of poly(acrylic acid)-based double hydrophilic block copolymers and various polyamines.

The physicochemical properties of polyion complex (PIC) micelles were investigated in order to characterize the cores constituted of electrostatic complexes of two oppositely charged polyelectrolytes. The pH-sensitive micelles were obtained with double hydrophilic block copolymers containing a poly(acrylic acid) block linked to a modified poly(ethylene oxide) block and various polyamines (polylysine, linear and branched polyethyleneimine, polyvinylpyridine, and polyallylamine). The pH range of micellization in which both components are ionized was determined for each polyamine. The resulting PIC micelles were characterized using dynamic light scattering and small-angle X-ray scattering experiments (SAXS). The PIC micelles presented a core-corona nanostructure with variable polymer density contrasts between the core and the corona, as revealed by the analysis of the SAXS curves. It was shown that PIC micelle cores constituted by polyacrylate chains and polyamines were more or less dense depending on the nature of the polyamine. It was also determined that the density of the cores of the PIC micelles depended strongly on the nature of the polyamine. These homogeneous cores were surrounded by a large hairy corona of hydrated polyethylene oxide block chains. Auramine O (AO) was successfully entrapped in the PIC micelles, and its fluorescence properties were used to get more insight on the core properties. Fluorescence data confirmed that the cores of such micelles are quite compact and that their microviscosity depended on the nature of the polyamine. The results obtained on these core-shell micelles allow contemplating a wide range of applications in which the AO probe would be replaced by various cationic drugs or other similarly charged species to form drug nanocarriers or new functional nanodevices.

Changes in heat shock protein 70 expression and blood characteristics in transported broiler chickens as affected by housing and early age feed restriction.

An experiment was conducted to determine the effects of 2 types of housing systems and early age feed restriction on heat shock protein (hsp) 70 expression and blood parameters in broiler chickens subjected to road transportation. On d 1, female chicks were housed either in windowless environmentally controlled chambers (temperature was set at 32 degrees C on d 1 and gradually reduced to 23 degrees C by d 21; CH) or in conventional open-sided houses (OH) with cyclic temperatures (minimum, 24 degrees C; maximum, 34 degrees C). Equal number of chicks from each housing system were subjected to either ad libitum feeding or 60% feed restriction on d 4, 5, and 6 (FR). On d 42, all of the birds were crated and transported for 6 h. Birds raised in OH had smaller increases in heterophil:lymphocyte ratios and plasma corticosterone concentrations than those of CH. Subjecting birds to FR dampened heterophil:lymphocyte ratios and corticosterone reactions to transportation. After 4 h of transportation, the OH birds had greater hsp 70 expression than their CH counterparts. Within the CH, the FR chicks showed higher hsp 70 density than those of the ad libitum-fed group. Except for glucose, housing system had a negligible effect on serum levels of cholesterol, potassium, and chloride. Collectively, the results suggest that the improved tolerance to transport stress in OH and FR chicks could be associated with better hsp 70 expression.

Crating and heat stress influence blood parameters and heat shock protein 70 expression in broiler chickens showing short or long tonic immobility reactions.

Two hundred thirty-five 1-d-old broiler chickens showing short or long tonic immobility responses were classified as low fear (LF) or high fear (HF) responders, respectively. On d 41, they were subjected to either crating or heat challenge (34 +/- 1 degrees C) for 3 h and its effect on plasma corticosterone concentration, heterophil/lymphocyte ratios, and heat shock protein (HSP) 70 expression in brain tissue were determined. Crating and heat exposure elevated heterophil/lymphocyte ratios in both LF and HF birds. Circulating corticosterone, however, was greater in HF than LF birds after crating and heat challenge. Although differences between fear responder group for HSP 70 were negligible before heat challenge, after 3 h of heat exposure, the response was greater for the HF than the LF group. Both LF and HF showed similar increases in HSP 70 after crating.

Preparation of stable suspensions of gold nanoparticles in water by sonoelectrochemistry.

Stable suspensions of gold nanoparticles in water were prepared with high yield by a novel one-step ultrasound assisted electrochemical process. Various strategies based on the addition of either tailor-made polymers or mixtures of commercially available polymers, in the electrochemical bath have been found successful to avoid nanoparticles aggregation commonly observed by sonoelectrochemistry. alpha-Methoxy-omega-mercapto-poly(ethylene oxide) or poly(vinyl pyrrolidone)/polyethylene oxide mixtures were able to build up a coalescence barrier around the gold nanoparticles. The results showed that the size of the gold nanoparticles could be easily tuned between 5 nm and 35 nm by simple control of the electrochemical parameters, i.e. the deposition time (T(ON)) from 10 ms to 20 ms. The properties of as-prepared gold nanoparticles were compared to the ones of gold colloids prepared by the more conventional wet nanoprecipitation method using chemical reductive agents.

Cardiac monitoring after phenytoin overdose.

OBJECTIVE: To evaluate whether patients admitted to the hospital with oral phenytoin overdose should receive cardiac telemetry monitoring. DESIGN: Retrospective chart review over a 4-year period. SETTING: Eastern United States community teaching hospital. PATIENTS: Forty-four patients admitted with a diagnosis of oral phenytoin overdose, with a toxic serum concentration defined as a peak level higher than 20 micrograms/ml, who had electrocardiography performed both at the time of admission and after the phenytoin level had decreased below the toxic threshold. INTERVENTIONS: None. RESULTS: Chi-square, t test, and Fisher's exact tests were used for analysis. Mean peak phenytoin concentration was 36.7 +/- 12.1 micrograms/ml, with a maximum concentration of 75 micrograms/ml. Electrocardiograms recorded at the time of hospital admission in all 44 cases revealed no clinically significant abnormalities attributable to phenytoin when toxic and posttoxic states were compared. There were no circulatory complications or deaths. CONCLUSION: Patients admitted with oral phenytoin overdose with serum concentrations as high as 75 micrograms/ml did not experience any significant cardiovascular arrhythmias or complications. Patients with oral phenytoin overdose do not warrant routine admission to a telemetry bed for management of their condition.