Profiled polyethylene terephthalate filaments that incorporate collagen and calcium phosphate enhance ligamentisation and bone formation.

Polyethylene terephthalate (PET) artificial ligaments offer an unlimited source of ligaments without donor-site-related morbidity and with good mechanical properties for a rapid return to sporting activities. Developing PET artificial ligaments with excellent ligamentisation and ligament-bone healing is still a considerable challenge. This study aimed to investigate the effects of the profiled PET/collagen/calcium phosphate (PET/C/CaP) ligament upon cell growth, ligamentisation and ligament-bone healing in vitro and in vivo. Profiled PET/C/CaP filaments were made by melt-spinning process with 2 % CaP hybrid spinning and collagen coating. Rat mesenchymal stem cells (MSCs) were cultured on the profiled PET/C filaments for cytotoxicity, viability, scanning electron microscopy (SEM) and ligament-related gene expression analysis. MSCs' osteogenic capacity on the profiled PET/CaP filaments was identified by detecting osteogenic gene expression and alizarin red S staining. For in vivo verification, an animal study was performed to evaluate the effect of the profiled PET/C/CaP ligament in a rabbit knee medial collateral ligament reinforcement reconstruction model. The graft ligamentisation and bone formation were investigated by SEM, histology, microcomputed tomography and mechanical tests. The profiled PET/C filaments enhanced MSC proliferation and ligament-related gene expression. Furthermore, they enhanced osteogenic gene expression, alkaline phosphatase activity and mineralisation of MSCs. The in vivo study indicated that the profiled PET/C/CaP ligament enhanced ligamentous matrix remodelling and bone formation. Therefore, their use is an effective strategy for promoting MSCs' ligamentous and osteogenic potential in vitro and enhancing ligamentous matrix remodelling and bone formation in vivo.

Histone deacetylase inhibitor treatment restores memory-related gene expression and learning ability in neonicotinoid-treated Apis mellifera.

Apis mellifera plays crucial roles in maintaining the balance of global ecosystems and stability of agricultural systems by helping pollination of flowering plants, including many crops. In recent years, this balance has been disrupted greatly by some pesticides, which results in great losses of honeybees worldwide. Previous studies have found that pesticide-caused memory loss might be one of the major reasons for colony loss. Histone deacetylase inhibitors (HDACis) are chemical compounds that inhibit the activity of histone deacetylases and are known to cause hyperacetylation of histone cores and influence gene expression. In our study, the HDACi sodium butyrate was applied to honeybees as a dietary supplement. The effect of sodium butyrate on the expression profiles of memory-related genes was analysed by quantitative reverse transcription PCR. The results revealed that this HDACi had up-regulation effects on most of the memory-related genes in bees, even in bees treated with imidacloprid. In addition, using the proboscis extension reflex to evaluate olfactory learning in bees, we found that this HDACi boosted the memory formation of bees after impairment owing to imidacloprid exposure. This study investigated the association between gene expression and memory formation from an epigenetic perspective. Additionally, we further demonstrate the possibility of enhancing bee learning using HDACis and provide initial data for future research.

Outpatient pre-operative assessment in joint replacement surgery.

An anaesthetist-led outpatient pre-operative assessment (OPA) clinic was introduced in our unit in an effort to improve patient care and cost-effectiveness. To assess the efficiency of the clinic, 112 patients who attended the OPA clinic (attendance rate 98%) during the first year were assessed prospectively and compared with 118 patients who did not undergo OPA the year before. There were fewer cancellations among those who attended the OPA clinic (13.6% compared to 3.6%), and the hospital stay was shortened from an average of 10.7 days to 7.0 days. This has resulted in more efficient utilization of operating theatre, reduced hospital costs and improved patient satisfaction. More extensive use of the pre-admission clinic is recommended and should be explored in other clinical settings.

Surgical wound mucormycosis necessitating hand amputation: a case report.

We report an unusual case of cutaneous mucormycosis in a 17-year-old man who had no risk factors for fungal infection. The aggressive nature of cutaneous mucormycosis is illustrated. A high index of suspicion is crucial for identifying and preventing progression of this disease, which can lead to limb amputation, even death. Extra vigilance should be given to those who are immunocompromised, including those receiving short courses of steroids. Early recognition, prompt surgical intervention and initiation of an appropriate antifungal treatment are crucial in the management of this rare but potentially limb- and life-threatening infection.

Patient expectations for hallux valgus surgery.

PURPOSE: To determine preoperative patient expectations and their relative importance for hallux valgus surgery using a patient-derived questionnaire, and whether such expectations are influenced by age, gender, or occupation. METHODS: Two patient-derived questionnaires were developed using open-ended interviews. The 19 most commonly stated expectations were included in the Patient Expectation Questionnaire: 2 related to improvement in appearance, 2 to pain reduction, and 15 to functional improvements in performing daily and recreational activities. The top 9 expectations were included in the Patient Priority Questionnaire for prioritising. RESULTS: 153 eligible patients aged 16 to 79 (mean, 47) years completed the questionnaires; 29 (19%) aged less than 40 years, 84 (55%) aged 40 to 60 years, and 40 (26%) aged more than 60 years. 86% were women and 81% were Caucasian. 62% were housewives or retired pensioners. Overall, the most important expectation was improved walking, followed by reduced pain over the bunion and wearing daily shoes. These expectations varied according to age and gender but not occupation. CONCLUSION: Patient expectations differ from those of surgeons, and vary according to patient age and gender. Understanding preoperative patient expectations is crucial to achieve better clinical outcomes and satisfaction by selecting the most appropriate operation for each patient.

Noninvasive respiratory monitoring system based on the piezoceramic transducer's pyroelectric effect.

This paper presents a simple alternative method and system for noninvasive respiratory airflow monitoring. The proposed system uses a piezoceramic transducer to measure respiratory airflow. When a piezoceramic transducer is impacted by respiratory airflow, there is a piezoelectric and a pyroelectric response to pressure and thermal airflow fluctuations. In this study, the selected transducer's response output is dominated by the pyroelectricity factor. Therefore, the piezoelectric effect is not significant and can be ignored in this study. Using the transducer's pyroelectricity to measure thermal flow variations, a subject's respiratory rate and respiratory air volumetric flow rate can be monitored. The proposed system was evaluated for accuracy and response time using quiet and postphysical exertion breathing modes. Using the pneumotach system as a benchmark, the proposed system's respiratory rate measurement accuracy for the two breathing modes is approximately 98.78%. In addition, the proposed system's output voltage is highly correlated with the respiratory volumetric flow rate measured by the selected pneumotach (r2=0.9783). The average correlation coefficient between the pneumotach system's output waveform and the proposed system is approximately 0.9389. Moreover, the proposed system and the selected pneumotach have almost the same rapid response time to respiratory airflow. When compared to a temperature measurement thermistor system, the thermistor on average is approximately 25.3 ms slower than the proposed system. Furthermore, compared to the selected screen-type pneumotach system, the proposed system simplifies the respiration monitoring requirements. Instead of sensing the pressure drop across a mesh screen, like the screen-type pneumotach, it measures respiration at one point within the respiratory airflow. The proposed system benefits from simplified processing circuits and a mesh-free design. The advantages of this new respiratory airflow measurement method are fast response time, high accuracy, low cost, and ease of implementation.

Recurrent Chromobacterium violaceum infection in a patient with chronic granulomatous disease.

We report a rare case of recurrent infection of Chromobacterium violaceum in an immunocompromised patient. Despite the high mortality rate associated with this infection as reported in the literature, this patient survived three episodes of recurrent infection. We believe that with high clinical suspicion, prompt treatment and appropriate antimicrobial agents, it is possible for clinicians to treat this infection effectively and reduce the mortality rate.

Third-generation alumina-on-alumina ceramic bearings in cementless total hip arthroplasty.

BACKGROUND: Wear debris has been implicated in the pathogenesis of osteolysis. Alumina-on-alumina ceramic bearings have a low wear rate, which may reduce the prevalence of osteolysis. The purpose of this study was to determine the rates of wear and osteolysis associated with modern cementless hip arthroplasty with alumina-on-alumina bearings at five years. METHODS: We analyzed a series of 301 third-generation alumina-on-alumina cementless primary total hip replacements in 283 patients. The average age of the patients at the time of the arthroplasty was fifty-eight years. All procedures were performed with use of the same surgical technique and the same implant at a single center. At a minimum of five years postoperatively, ten patients had died and twenty-two patients were lost to follow-up. We assessed patients clinically and radiographically, and all retrieved bearings were analyzed for wear. RESULTS: At the time of the latest follow-up, the mean Harris hip score was 95 points. All surviving implants had radiographic evidence of stable bone ingrowth. There were nine revisions of one or both components. Four stems were revised following periprosthetic fracture, one stem was revised because of aseptic loosening at two months, and one stem was revised to facilitate a femoral shortening osteotomy. Two cups were revised because of psoas tendinitis, and both components of one arthroplasty were revised because of impingement and osteolysis. The rate of survival of both components, with revision because of aseptic loosening or osteolysis as the end point, was 99% at seven years. The retrieved femoral heads showed an early median wear rate of 0.2 mm(3) per year. CONCLUSIONS: Cementless primary total hip prostheses with a third-generation alumina-on-alumina bearing showed very low wear and were associated with minimal osteolysis at the time of follow-up, at a minimum of five years.

Five- to 12-year follow-up of a hydroxyapatite-coated, cementless total knee replacement in young, active patients.

We carried out a prospective study of 118 hydroxyapatite-coated, cementless total knee replacements in patients who were

Management of suspected scaphoid fractures in accident and emergency departments--time for new guidelines.

INTRODUCTION: The objectives of this work were to assess the clinical knowledge of clinicians in the accident and emergency (A&E) departments in England & Wales and evaluate the current trend for the acute management of radiologically normal, but clinically suspected, fractures of the scaphoid. SUBJECTS AND METHODS: We conducted a telephone survey on 146 A&E senior house officers (SHOs) in 50 different hospitals. This survey assessed the clinicians' experience, their clinical and radiological diagnostic methods, and their initial treatment of suspected scaphoid fractures. RESULTS: The majority (55.8%) of SHOs performed only one clinical test to diagnose suspected scaphoid fractures. Overall, 41% were unable to cite the number of the radiographic views taken and only 10% of departments have direct access to further radiological investigation. There is wide variation in the early treatment of this injury, with the scaphoid cast used most commonly (46%). The majority of SHOs (89%) were unable to describe the features of immobilisation. The mean follow-up period was 10 days, and 53% of cases were followed-up by the senior staff in A&E. Of SHOs, 54% were not aware of any local guidelines for the management of suspected scaphoid fractures in their departments, and 92% were not aware of the existence of the 1992 British Association for Accident and Emergency Medicine (BAEM) guidelines. CONCLUSIONS: The clinical knowledge and the management of suspected scaphoid fractures in A&E are unsatisfactory. We, therefore, suggest that the dissemination of up-to-date guidelines could help to educate clinicians to provide better care to the patients.

Intra-operative assessment of excision margins using breast imprint and scrape cytology.

Local recurrence in breast cancer surgery is related to the completeness of excision. Histological analysis of excision margins is time consuming and impractical for use intra-operatively. Our group evaluated breast imprint and scrape cytology (ISC) for the assessment of excision margins in a feasibility study in 1993-4, with 10 year clinical follow-up. Twenty-six consecutive women undergoing 27 wide local excisions for breast cancer had excision margins prospectively assessed with intra-operative ISC blinded to histology. All ISC results were ready (range 22-30 min) before surgery was completed. ISC agreed with histology in 21/27 (=78%) and disagreed in 6/27 (=22%) of the cases. In two cases with local recurrence, histology was positive in one case, whereas ISC margins were positive in both. Intra-operative ISC is reliable and could help the surgeon to excise more tissue to prevent a second (re-excision) operation. ISC margins may predict clinical outcome, although a larger interventional follow-up study is required.

Unusual cause of deep vein thrombosis following dynamic hip screw fixation.

We report a case of profunda femoris false aneurysm following internal fixation of an intertrochanteric neck of femur fracture, caused by proximal migration of a fracture fragment. The case is unique in that the mode of presentation was that of deep venous thrombosis, due to extrinsic compression of the venous system by the false aneurysm. (Hip International 2004; 14: 262-4).

Methicillin-resistant Staphylococcus aureus in orthopaedic surgery.

We prospectively studied the incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation and infection, the patterns and types of operation associated with MRSA acquisition in an orthopaedic and trauma unit in London, UK. Over the 12-month study period from January to December 2000, we found that 1.6% of the total admission was diagnosed to be either MRSA infected or colonised, with an average of three new MRSA cases detected per month. A significant proportion of patients (23%) were diagnosed within the first 48h of admission. Both hip joint surgery, especially emergency procedures for femoral neck fractures, and the presence of a wound presented higher risk of infection. The Intensive Care Unit (ICU) did not appear to be a significant source for intra-hospital dissemination among the orthopaedic patients. MRSA infection or colonisation contributed to an increased length of hospital stay; 88 days compared to 11 days on average for non-MRSA patients; 41% of the positive patients still carried MRSA on discharge. Our data show the importance of diagnosing MRSA in orthopaedic surgery and emphasises that understanding its epidemiology will be crucial to secure a decrease in the incidence of MRSA. Hand hygiene, patient screening, careful surveillance of infections and the prompt implementation of isolation policies, are essential components of control.

Acetabular labrum and its tears.

Groin pain is a major cause of morbidity in athletes. Only in the last decade have acetabular labrum tears been recognised as a possible diagnosis. Awareness of this condition is important for appropriate management. The basic science and pathological and clinical features of acetabular labrum tears are reviewed, and diagnostic and treatment options are presented.

Antibiotic prophylaxis in surgery of the intervertebral disc. A comparison between gentamicin and cefuroxime.

Antibiotics are often administrated prophylactically in spinal procedures to reduce the risk of infection of the disc space. It is still not known which antibiotics are able to penetrate the intervertebral disc effectively. In a prospective, randomised, double-blind clinical study, we examined the penetration of the intervertebral discs of two commonly used antibiotics, cefuroxime and gentamicin. The patients, randomised into two groups, received either 1.5 g of cefuroxime or 5 mg/kg of gentamicin prophylactically two hours before their intervertebral discs were removed. A specimen of blood, from which serum antibiotic levels were determined, was obtained at the time of discectomy. Therapeutic levels of antibiotic were detectable in the intervertebral discs of the ten patients who received gentamicin. Only two of the ten patients (20%) who received cefuroxime had a quantifiable level of antibiotic in their discs although therapeutic serum levels of cefuroxime were found in all ten patients. Our results show that cefuroxime does not diffuse into human intervertebral discs as readily as gentamicin. It is possible that the charge due to ionisable groups on the antibiotics can influence the penetration of the antibiotics. We therefore recommend the use of gentamicin in a single prophylactic dose for all spinal procedures in order to reduce the risk of discitis.

Effects of long-term octreotide treatment on the response of portal-systemic collaterals to vasopressin in portal hypertensive rats.

BACKGROUND: Chronic portal hypertension is associated with the development of portal-systemic collaterals. Long-term octreotide treatment has been shown to enhance the constrictive response to vasopressin in the mesenteric arteries of portal hypertensive rats. This study investigated the effects of long-term octreotide treatment on the response of portal-systemic collaterals to vasopressin in portal hypertensive rats. METHODS: Partially portal vein-ligated rats were divided into two groups to receive subcutaneous injection of either placebo (5% dextrose in water) or octreotide (30 microg kg(-1)) twice daily for 7 days. Two series of experiments were performed to measure: (a) the systemic and portal hemodynamics and cumulative concentration-response curves of collateral vessels to vasopressin (10(-10) to 10(-7 )M) and (b) the slopes of the flow-pressure curves of collaterals (an index of portal-systemic shunting). The cumulative concentration-response curves and flow pressure curves were determined by the in situ collateral perfusion. RESULTS: Long-term octreotide treatment significantly lowered the portal pressure without changes in the mean arterial pressure. Vasopressin significantly and similarly increased the perfusion pressure of collateral vessels in both the placebo- and octreotide-treated groups. In addition, long-term octreotide treatment exerted no effect on the EC(50) of vasopressin (-8.25 +/- 0.19 vs. -8.20 +/- 0.10, P > 0.05) and the slopes of flow-pressure curves (0.97 +/- 0.02 vs. 0.94 +/- 0.04, P > 0.05) in the collaterals. CONCLUSION: Despite lowering the portal pressure, long-term octreotide treatment did not enhance the vasoconstrictive effect of vasopressin in the collateral vessels of portal hypertensive rats and ameliorate the degree of portal-systemic shunting.

Prospective analysis of secondary alveolar bone grafting using computed tomography.

PURPOSE: This study radiographically evaluated the quantity and quality of secondary alveolar bone grafts from the anterior iliac crest to maxillary alveolar clefts in cleft lip and palate patients with the use of computed tomography. PATIENTS AND METHODS: A 1-year prospective study was conducted by using 14 unilateral and bilateral cleft lip and palate patients. Axial and coronal computed tomography (CT) scans were obtained during the immediate postoperative phase and at 1-year follow-up. RESULTS: This study showed that the average alveolar cleft requires a bone graft volume ranging from 0.9 to 3.6 cm3, with a mean volume of 2.10 cm3. The percentage of bone loss derived from the linear dimensional changes to the alveolar bone graft between the immediate postoperative and follow-up CT scans were as follows: 17.9% in maximal bone height, 29.9% in maximal anteroposterior bone width, and 13.7% in maximal transverse width. As compared with the linear measurements, the volumetric analysis showed a disproportional amount of volume loss equaling 43.7% and 42.5% in the coronal and axial studies, respectively. This showed a total average volume loss of 43.1% at approximately 1 year after the secondary alveolar cleft repair. However, as the canine tooth erupts through the bone graft, it can account for up to 53.4% of the total average volume loss. All 14 patients (17 clefts) showed bone bridging between the alveolar cleft radiographically, with good incorporation and maturation of the bone graft, and no recurrence of the oronasal fistula. CONCLUSION: The CT scan is a valuable radiographic imaging modality to assess and follow the clinical outcome of secondary alveolar bone grafting.

Neocortical neurons lacking the protein-tyrosine kinase B receptor display abnormal differentiation and process elongation in vitro and in vivo.

The spatial and temporal expression of the protein-tyrosine kinase B (TrkB) receptor and its ligands has been correlated with the development of the neocortex. Activation of the receptor has been associated with neocortical neuronal survival, differentiation, connectivity and neurotransmitter release. Although such findings suggest an important role for TrkB signaling in corticogenesis, conclusive evidence from targeted gene deletion ("knockout"; TrkB -/-) mice has been limited, due in part to the neonatal lethality of most of these mutant mice and the confounding variables associated with the poor health of those few surviving slightly longer postnatally. In the present study, the effects of TrkB signaling on the survival, differentiation and integration of neocortical neurons was directly investigated in vitro and in vivo. First, we conducted a neuron-specific immunocytochemical analysis of TrkB -/- mice to determine whether early cortical structure and patterns of histogenesis were normal or perturbed. We then employed in vitro and in vivo approaches to extend the life of TrkB -/- neocortical neurons beyond the period possible in TrkB -/- mutant mice themselves: (i) dissociated cell culture to directly compare the developmental potential of TrkB -/-, +/- and +/+ neurons; and (ii) neural transplantation into homochronic wild-type recipients to investigate the cell-autonomous effects of the receptor knockout on the differentiation, growth and integration of neocortical neurons. These latter experiments allowed, for the first time, study of the survival and differentiation potential of TrkB -/- neocortical neurons beyond the initial stages of corticogenesis. Direct comparison of brains of TrkB -/-, +/- and +/+ littermates immunocytochemically labeled with antibodies to microtubule-associated protein-2, neurofilament and beta-tubulin III revealed subtle anatomical anomalies in the mutant mice. These anomalies include abnormally diffuse microtubule-associated protein-2 positive neurons just dorsal to the corpus callosum, and heterotopic aggregations of postmitotic neurons in the subventricular zones of the ganglionic eminences, both suggesting delayed neuronal migration and differentiation. Cell culture experiments revealed substantially reduced survival by TrkB -/- neocortical neurons, and a significant reduction in neurite outgrowth by surviving TrkB -/- neurons. In experiments where prelabeled embryonic or neonatal TrkB -/- neocortical neurons were transplanted into the cerebral cortices of neonatal wild-type recipients, a similar quantitatively significant defect in the formation of dendrites, as well as reduced integration of TrkB -/- neocortical neurons, was also evident. These findings demonstrate cell-autonomous abnormalities in the development of neocortical neurons from TrkB -/- mice, and the subtle, but potentially critical, role of protein-tyrosine kinase B signaling in neocortical neuronal survival, differentiation and connectivity.

Tuning metal-to-metal charge transfer of mixed-valence complexes containing ferrocenylpyridine and rutheniumammines via solvent donicity and substituent effects.

A homogeneous series of heterobimetallic complexes of [R-Fc(4-py)Ru(NH3)5](PF6)2 (R = H, Et, Br, acetyl; Fc(4-py) = 4-ferrocenylpyridine) have been prepared and characterized. The mixed-valence species generated in situ using ferrocenium hexafluorophosphate as the oxidant show class II behavior, and the oxidized sites are ruthenium centered. deltaE(1/2), E(1/2)(Fe(III)/Fe(II)) - E(1/2)(Ru(III)/Ru(II)), an upper limit for deltaGo that is an energetic difference between the donor and acceptor sites, changes sharply and linearly with Gutmann solvent donor number (DN) and Hammett substituent constants (sigma). The solvent-dependent and substituent-dependent intervalence transfer bands were found to vary almost exclusively with deltaE(1/2). The activation energy for the optical electron transfer versus deltaE(1/2) plot yields a common nuclear reorganization energy (lambda) of 0.74 +/- 0.04 eV for this series. The equation that allows one to incorporate the effect of both solvent donicity and substituents on optical electron transfer is Eop = lambda + deltaGo, where deltaGo = (deltaGo)intrinsic + (deltaGo)solvent donicity + (deltaGo)substituent effect (deltaGo )intinnsic with a numerical value of 0.083 +/- 0.045 eV was obtained from the intercept of the deltaE(1/2) of [H-Fc(4-py)Ru(NH3)5]2+,3+,4+ versus DN plot. (deltaGo)solvent donicity was obtained from the average slopes of the deltaE(1/2) of [R-Fc-(4-py)Ru(NH3)5]2+,3+,4+ versus DN plot, and (deltaGo)substituent effect was obtained from the average slopes of the corresponding deltaE(1/2) versus sigma plot. The empirical equation allows one to finely tune Eop of this series to Eop = 0.82 + 0.019(DN) + 0.44sigma eV at 298 K, and the discrepancy between the calculated and experimental data is less than 6%.