Open tibia fractures in HIV positive patients

Open tibia fractures are common injuries, particularly in developing countries.Pedestrian or bicycle to motor car contact is the most common mechanism.These injuries result in high morbidity and often long-term disability. HIV infection complicates open fractures by raising theincidence of infectionin the open wound (5 of 7 patients in our series). This risk may be compounded if internal fixation techniques are used (5 of 12 HIV patients with internal fixation of any open fracture). There is also asuggestion that HIV may delay bone union (4 of 7 patients united at 6 months). External fixation offers an alternative method of fracture stabilisation. It avoids the risks associated with putting metal-ware in the wound, but creates a new issue of pin track sepsis. We found thatpin track infection was more common in patients with HIV, but the rate at which pins required removal was 7%. We consider external fixation to be a lower-risk strategy than internal fixation in such patients but open fracture wound sepsis remains a problem. We have not yet demonstrateda difference in severity or frequency of complications in patients of low CD4 count, but logically one expects septic complications to increase as CD4 count falls. Antiretroviral medication decreases viral load and elevates the CD4 count. Research is underway regarding potential effectivenessof such drugs in reducing wound and fracture healing complications. Above all, meticulous and timely all-round care is required to achieve satisfactory results in immunecompromised patients. This includes, debridement, bonystability, and soft-tissue reconstruction

Establishing a children’s orthopaedic hospital for Malawi: An assessment after 5 years

Beit Cure International Hospital (BCIH) is a specialist orthopaedic hospital providing surgical services to the children of Malawi. The hospital started treating patients in late 2002, and this analysis represents an attempt to assess the impact of the hospital, and develop strategies for future partnerships and development. Analysis was made of all the 563 case files of new patients treated operatively in the fifth year of hospital services. Data recorded included district and region of origin of patient, diagnosis, age and sex. Patients were treated from all 3 regions, with almost 50% coming from Southern region. Club foot, burn contracture, and genu varus were the most common diagnoses. Half the children were infants up to 5 years of age, while 60% were male. The underlying reasons behind these findings are analysed and their implications in terms of future hospital strategy are discussed

Monocular and Binocular Contributions to Oculomotor Plasticity

Most eye movements in the real-world redirect the foveae to objects at a new depth and thus require the co-ordination of monocular saccade amplitudes and binocular vergence eye movements. Additionally to maintain the accuracy of these oculomotor control processes across the lifespan, ongoing calibration is required to compensate for errors in foveal landing positions. Such oculomotor plasticity has generally been studied under conditions in which both eyes receive a common error signal, which cannot resolve the long-standing debate regarding whether both eyes are innervated by a common cortical signal or by a separate signal for each eye. Here we examine oculomotor plasticity when error signals are independently manipulated in each eye, which can occur naturally owing to aging changes in each eye’s orbit and extra-ocular muscles, or in oculomotor dysfunctions. We find that both rapid saccades and slow vergence eye movements are continuously recalibrated independently of one another and corrections can occur in opposite directions in each eye. Whereas existing models assume a single cortical representation of space employed for the control of both eyes, our findings provide evidence for independent monoculomotor and binoculomotor plasticities and dissociable spatial mapping for each eye

Hip and Knee Replacement in the HIV positive patient

Arthroplasty is used to relieve pain associated with degenerative or inflammatory joint disease, some post-traumatic joint problems, and avascular necrosis. Avascular necrosis, inflammatory and post-traumatic problems are seen on a regular basis in areas of high HIV seroprevalence. Degenerative arthritis is rare in younger HIV patients, however. Historically the only group of HIV patients in which arthroplasty has been common is that which received contaminated factor VIII transfusions in the 1980’s. Haemophiliacs get a haemophilic arthropathy from repeated bleeds into joints and so is an additional complication.Much of the previous literature on this topic has focused on haemophiliac patients. This review examines the success of arthroplasty in HIV positive patients, with an emphasis on non-haemophiliac patients. We conclude that arthroplasty can be a safe procedure for HIV positive individuals if the surgery is carried out in good conditions, and early results are encouraging

Performance queries on Semi-Markov Stochastic Petri nets with an extended continuous Stochastic logic

Semi-Markov Stochastic Petri Nets (SM-SPNs) are a highlevel formalism for defining semi-Markov processes. We present an extended Continuous Stochastic Logic (eCSL) which provides an expressive way to articulate performance queries at the SM-SPN model level. eCSL supports queries involving steady-state, transient and passage time measures. We demonstrate this by formulating and answering eCSL queries on an SM-SPN model of a distributed voting system with up to ¢¤£¦ ¥ states.

Avascular necrosis of the femoral head in HIV positive patients-an assessment of risk factors and early response to surgical treatment

26 consecutive patients (37 hips) with avascular necrosis (AVN) of the femoral head treated surgically at our institution from 1999 to 2008 were reviewed . The aims of the study were to evaluate the risk factors associated with AVN in HIV positive and HIV negative individuals, and assess early response to total hip replacement (THR) surgery in HIV positive and negative patients. There were 15 male and 11 female  patients in total. The mean age for all patients was 47.1± 8.0 years  (range, 33 to 66 years). 12 patients were HIV positive, 11 patients were HIV negative and 3 patients had unknown HIV status. Excessive alcohol intake was the most common risk factor for developing AVN .15 patients (58%) had more than one risk factor for AVN and only 2/12 (17%) HIV positive patients had no other risk factor apart from HIV infection. There were no early postoperative complications in 34 arthroplasties in both HIV positive and negative patients. The aetiology of AVN seems often to be multifactorial, even in the presence of HIV infection. Early response to arthroplasty surgery in AVN of the femoral head is equally good irrespective of the HIV serostatus of the patients

Establishing a children’s orthopaedic hospital for Malawi: A review after 10 years

BackgroundBEIT CURE International Hospital (BCIH) opened in 2002 providingorthopaedic surgical services to children in Malawi. This study reviews thehospital’s progress 10 years after establishment of operational services. Inaddition we assess the impact of the hospital’s Malawi national clubfootprogramme (MNCP) and influence on orthopaedic training.MethodsAll operative paediatric procedures performed by BCIH services in the10th operative year were included. Data on clubfoot clinic locations andnumber of patients treated were obtained from the MNCP. BCIH recordswere reviewed to identify the number of healthcare professionals whohave received training at the BCIH.Results609 new patients were operated on in the 10th year of hospital service.Patients were treated from all regions; however 60% came fromSouthern regions compared with the 48% in the 5th year. Clubfoot,burn contracture and angular lower limb deformities were the three mostcommon pathologies treated surgically. In total BCIH managed 9,842patients surgically over a 10-year period. BCIH helped to establish andco-ordinate the MNCP since 2007. At present the program has a totalof 29 clinics, which have treated 5748 patients. Furthermore, BCIH hasoverseen the full or partial training of 5 orthopaedic surgeons and 82orthopaedic clinical officers in Malawi.ConclusionThe BCIH has improved the care of paediatric patients in a country thatprior to its establishment had no dedicated paediatric orthopaedic service,treating almost 10,000 patients surgically and 6,000 patients in the MNCP.This service has remained consistent over a 10-year period despite times of global austerity. Whilst the type of training placement offered at BCIH has changed in the last 10 years, the priority placed on training has remained paramount. The strategic impact of long-term training  commitments are now being realised, in particular by the addition of Orthopaedic surgeons serving the nation

Ionotropic and metabotropic signalling in neuronal development and differentiation

This thesis investigates ionotropic and metabotropic signalling mechanisms in developing neurons from human embryonic stem cell and primary sources. Focus is placed on the measurement of functional activity using primarily whole-cell patchclamp and Ca2+ imaging techniques These signalling mechanisms were investigated in undifferentiated human embryonic stem cells, hESC-derived neurons, fetal primary human neurons and neonatal primary mouse neurons. The results of this research are separated into three chapters. Preliminary work carried out on iPSC-derived neurons is also included as an indication of future direction Chapter 3: P2 Receptors in hESCs Purinergic signalling was shown to be active in undifferentiated hESC populations. Specifically, the activity of P2Y1 receptors was confirmed pharmacologically. This is a novel observation and indicates a mechanism for physiologically relevant signalling molecules to modify [Ca2+]i Chapter 4: Functional Characterisation of hESC-Derived and Primary Neurons Functional characteristics associated with neuronal development were measured in human embryonic stem cells during terminal neuronal differentiation in a chemically-defined medium. The presence and activity of voltage-gated Na+, K+ and Ca2+ channels were recorded, alongside data on neuronal excitability (Vm, iAP induction and threshold and spontaneous electrical activity). These data were also recorded in fetal hWGE- and neonatal mWGE-derived neurons for comparison. hESC-derived neurons were shown to be functionally more similar to fetal hWGEneurons suggesting an immature neuronal phenotype Chapter 5: GABAergic Signalling in hESC-Derived and Primary Neurons GABAergic signalling in hESC-, mWGE- and hWGE-derived neuronal populations was investigated. Focus was placed on hWGE-derived neurons and the developmental state of GABAergic responses. In fetal hWGE-derived neurons, a percentage of cells displayed an ‘inhibitory’ response to GABAAR activation. This is a novel observation with implications in human neuronal development. In vitro modulation of GABAergic signalling was also shown, providing potential tools for future research into this phenomenon Chapter 6: Future Developments and General Discussion iPSC-derived neuronal populations were shown to display basic neuronal functional properties. This work will form the basis of future studies on these cell