Femtosecond pulse laser cleaning of spray paint from heritage stone surfaces

We explore the use of femtosecond laser pulses to clean a variety of colors of spray paint from the Moruya granite, a stone with high heritage value that is widely used for monuments and sculptures in Sydney and New South Wales (Australia). The efficiency of the cleaning treatment and the effects on the stone substrate are evaluated using optical microscopy, optical profilometry, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and colorimetry. We demonstrate that femtosecond laser cleans granite without damaging it and without discoloration when the laser fluence is set below the damage threshold of the stone.

Direct Measurements of Collisional Dynamics in Cold Atom Triads

The introduction of optical tweezers for trapping atoms has opened remarkable opportunities for manipulating few-body systems. Here, we present the first bottom-up assembly of atom triads. We directly observe atom loss through inelastic collisions at the single event level, overcoming the substantial challenge in many-atom experiments of distinguishing one-, two-, and three-particle processes. We measure a strong suppression of three-body loss, which is not fully explained by the presently availably theory for three-body processes. The suppression of losses could indicate the presence of local anticorrelations due to the interplay of attractive short range interactions and low dimensional confinement. Our methodology opens a promising pathway in experimental few-body dynamics.

Effect of heat wave on N2 fixation and N remobilisation of lentil (Lens culinaris MEDIK) grown under free air CO2 enrichment in a mediterranean-type environment

The stimulatory effect of elevated [CO₂ ] (e[CO₂ ]) on crop production in future climates is likely to be cancelled out by predicted increases in average temperatures. This effect may become stronger through more frequent and severe heat waves, which are predicted to increase in most climate change scenarios. Whilst the growth and yield response of some legumes grown under the interactive effect of e[CO₂ ] and heat waves has been studied, little is known about how N₂ fixation and overall N metabolism is affected by this combination. To address these knowledge gaps, two lentil genotypes were grown under ambient [CO₂ ] (a[CO₂ ], ~400 µmol·mol^-1 ) and e[CO₂ ] (~550 µmol·mol^-1 ) in the Australian Grains Free Air CO₂ Enrichment facility and exposed to a simulated heat wave (3-day periods of high temperatures ~40 °C) at flat pod stage. Nodulation and concentrations of water-soluble carbohydrates (WSC), total free amino acids, N and N₂ fixation were assessed following the imposition of the heat wave until crop maturity. Elevated [CO₂ ] stimulated N₂ fixation so that total N₂ fixation in e[CO₂ ]-grown plants was always higher than in a[CO₂ ], non-stressed control plants. Heat wave triggered a significant decrease in active nodules and WSC concentrations, but e[CO₂ ] had the opposite effect. Leaf N remobilization and grain N improved under interaction of e[CO₂ ] and heat wave. These results suggested that larger WSC pools and nodulation under e[CO₂ ] can support post-heat wave recovery of N₂ fixation. Elevated [CO₂ ]-induced accelerated leaf N remobilisation might contribute to restore grain N concentration following a heat wave.

[Multihospital use of imaging techniques in decentralized trauma care]

BACKGROUND

Decentralized trauma care in the Wald and Weinviertel region in the north of lower Austria comprises five hospitals for primary care including one regional trauma center. Due to the geographical position and adverse weather conditions a web-based teleradiology system was established to ensure the best possible treatment and joint access to the results of radiological investigations.

OBJECTIVE

The article describes a new picture archiving and communication system (PACS), which provides an online teleradiological workflow between the central trauma care unit and peripheral departments in a local trauma network as well as the advantages and disadvantages.

MATERIAL AND METHODS

A corporately used PACS enables streaming-based full access to studies which are created within the system. Radiological studies can be obtained on request from all subscribers within the network.

RESULTS

Teleradiological networks can essentially contribute to a suitable treatment pathway in an association of hospitals and therefore lead to a rapid initiation of treatment.

CONCLUSION

Especially in rural areas with decentralized trauma care, the joint use of teleradiological resources can lead to a better treatment quality.

[Intracranial pressure monitoring in polytrauma patients with traumatic brain injury]

BACKGROUND

The monitoring of intracranial pressure (ICP) represents a cornerstone in the intensive care of patients with traumatic brain injury (TBI) and the industry provides various technical solutions to this end. Decompressive craniectomy can be an option if conservative measures fail to reduce excessive ICP.

OBJECTIVE

To examine the pathophysiology of ICP in trauma, the management of polytrauma involving TBI, and the indications for decompressive craniectomy; and to compare the different monitoring systems and their complications.

MATERIAL AND METHODS

A retrospective analysis of TBI patients between 2010 and 2016 was performed. Relevant publications are discussed, particularly those relating to the indications for monitoring and its influence on polytrauma management.

RESULTS

Between 2010 and 2016, 106 patients with closed TBI and a mean age of 65.9 years received a total of 120 ICP monitors, most of which were parenchyma devices (111/120), followed by intraventricular catheters (8/120), and one combined system (1/120). Of these patients, 27.4% had sustained polytrauma, whilst 33% regularly used anticoagulants. ICP monitors were removed after 8.5 days on an average and the mean ICU stay was 20 days. Probe insertion was combined with craniectomy in 69.8% patients. Probe-related complications, most commonly involving malfunction, were seen in 6.6%. The duration of monitoring was significantly related to polytrauma (p ≤ 0.001) and age <60 (p = 0.03). ICU stay was also significantly related to polytrauma (p = 0.02) and monitoring complications (p ≤ 0.001). Mortality was related to anticoagulant medication (p = 0.01) and age <60 (p = 0.03).

CONCLUSIONS

ICP monitoring is one of the most important tools in TBI treatment. The course and outcome of these severe injuries is affected by polytrauma, age, and the use of anticoagulants.

Impact of Atomic-Scale Contact Geometry on Andreev Reflection

Charge transport has been examined in junctions comprising the normal-metal tip of a low-temperature scanning tunneling microscope, the surface of a conventional superconductor, and adsorbed C_{60} molecules. The Bardeen-Cooper-Schrieffer energy gap gradually evolves into a zero-bias peak with decreasing electrode separation. The peak is assigned to the spectroscopic signature of Andreev reflection. The conductance due to Andreev reflection is determined by the atomic termination of the tip apex and the molecular adsorption orientation. Transport calculations unveil the finite temperature and the strong molecule-electrode hybridization as the origin to the surprisingly good agreement between spectroscopic data and the Blonder-Tinkham-Klapwijk model that was conceived for macroscopic point contacts.

Investigation of isoniazid and ethionamide cross-resistance by whole genome sequencing and association with poor treatment outcomes of multidrug-resistant tuberculosis patients in South Africa

OBJECTIVE/BACKGROUND

Ethionamide (ETH) and isoniazid (INH) are part of the backbone regimen used for the treatment of multidrug-resistant tuberculosis (MDR-TB). Both ETH and INH are structurally similar and are activated by ethA and katG gene products. Resistance to INH among MDR-TB patients may cause ETH to be ineffective, as both target nicotinamide adenine dinucleotide-dependent enoyl-acyl carrier protein reductase inhA protein and mutations within inhA gene may lead to their cross-resistance. Furthermore, ETH resistance is caused by mutations within ethA and ethR genes forming part of the ETH drug activation pathway. Nicotinamide adenine dinucleotide is coded by the ndh gene, and its overexpresion may lead cross-resistance between INH and ETH drugs. Phenotypic drug susceptibility testing of ETH is difficult and often unreliable. We used whole genome sequencing to compare inhA, inhA promoter, ethA, ethR ndh, and katG genetic regions in serial isolates (baseline and follow-up) with treatment outcomes.

METHODS

MDR-TB strains were collected from 46 patients before and during second-line drug treatment in KwaZulu-Natal and Eastern Cape between 2005 and 2009. All patients had phenotypically determined MDR-TB at baseline and had treatment outcomes documented. Unfavorable treatment outcomes were defined as death, default, and failure, while favorable outcomes were cure and treatment completion. Each strain had baseline and at least one strain collected on follow-up. From each strain, DNA was extracted from colonies grown on Löwenstein-Jensen slants, and fragment and jumping paired-end Illumina DNA libraries were constructed and sequenced on the Illumina HiSeq 2000 (Broad Institute, Cambridge, MA, USA). Sequences were aligned to H37Rv genome and Pilon was run to generate a list of SNPs. In silico spoligotyping was performed to a database 43 unique spacer sequences. Cross-resistance was defined as the presence of both inhA and either ethA or ethR mutations in clinical isolates.

RESULTS

A total of 92 sequences from 46 serial isolates of MDR-TB patients from KwaZulu-Natal (29 isolates) and Eastern Cape (17 isolates) were analyzed. Most patients (29/46; 63.0%) had unfavorable outcomes, 13 (28.3%) had favorable outcomes, while four (8.7%) had unknown outcomes. Phylogenetic reconstruction revealed that primary genotype differed by province. The Beijing genotype was predominant in Eastern Cape, while EuroAmerican lineage (S, T, LAM, X) was found in KwaZulu-Natal. Whole genome analysis revealed nonsynonymous insertions and deletions within katG, ethA, ethR, ndh, and inhA and its promoter region. Among patients with treatment outcome data, mutations were detected in 92.8% in katG, 50% in inhA, 53.6% in ethA, 2.4% in ethR, and 19% in ndh. The majority of mutations causing ETH (20/29; 68.9%) and INH (18/29; 62.1%) resistance occurred among patients with unfavorable outcomes. Both inhA and either ethA or ethR mutations were detected in 16/29 (55.2%) patients with unfavorable outcomes. Cross-resistance of both INH and ETH drugs was associated with unfavorable treatment outcomes (p=0.021) in 16/29 (55.2%) patients compared with favorable treatment outcomes in 2/13 (15.4%) patients.

CONCLUSION

Baseline ETH molecular resistance before second-line treatment is a concern. Unfavorable treatment outcomes of patients with ethA, ethR, and inhA mutations highlight the importance of genotypic testing before initiation of treatment containing ETH. The clinical significance of whole genome analysis for early detection of mutations predictive of treatment failure needs further investigation.

Chladni solitons and the onset of the snaking instability for dark solitons in confined superfluids

Complex solitary waves composed of intersecting vortex lines are predicted in a channeled superfluid. Their shapes in a cylindrical trap include a cross, spoke wheels, and Greek Φ, and trace the nodal lines of unstable vibration modes of a planar dark soliton in analogy to Chladni's figures of membrane vibrations. The stationary solitary waves extend a family of solutions that include the previously known solitonic vortex and vortex rings. Their bifurcation points from the dark soliton indicating the onset of new unstable modes of the snaking instability are predicted from scale separation for Bose-Einstein condensates (BECs) and superfluid Fermi gases across the BEC-BCS crossover, and confirmed by full numerical calculations. Chladni solitons could be observed in ultracold gas experiments by seeded decay of dark solitons.

Robust quantum enhanced phase estimation in a multimode interferometer [corrected]

By exploiting the correlation properties of ultracold atoms in a multimode interferometer, we show how quantum enhanced measurement precision can be achieved with strong robustness to particle loss. While the potential for enhanced measurement precision is limited for even moderate loss in two-mode schemes, multimode schemes can be more robust. A ring interferometer for sensing rotational motion with noninteracting fermionic atoms can realize an uncertainty scaling of 1/(N√η) for N particles with a fraction η remaining after loss, which undercuts the shot-noise limit of two-mode interferometers. A second scheme with strongly interacting bosons achieves a comparable measurement precision and improved readout.

Quantum tunneling of a vortex between two pinning potentials

A vortex can tunnel between two pinning potentials in an atomic Bose-Einstein condensate on a time scale of the order of 1s under typical experimental conditions. This makes it possible to detect the tunneling experimentally. We calculate the tunneling rate by phenomenologically treating vortices as charged particles moving in an inhomogeneous magnetic field. The obtained results are in close agreement with numerical simulations based on the stochastic c-field theory.

[Biodegradable screw versus a press-fit bone plug fixation for ACL reconstruction: a prospective randomized study]

BACKGROUND

Press-fit fixation of a tendon graft has been advocated in order to achieve tendon to bone healing.

HYPOTHESIS

Fixation of a tendon graft with a porous bone scaffold limits bone tunnel enlargement compared with a biodegradable interference screw fixation.

METHODS

Between 2005 and 2006, 20 patients (17 men, 3 women) were enrolled in this study for primary reconstruction of the ACL. Patients were randomized to either obtain graft fixation in the tibial tunnel by means of an interference screw (I) or a press-fit fixation with a porous bone cylinder (P). Three months after surgery, a CT scan of the knee was performed and tunnel enlargement was analysed in the coronal and sagittal planes for the proximal, middle and distal thirds of the tunnel. After 6 months, 1 and 2 years, International Knee Documentation Committee (IKDC), Tegner and Lysholm scores of both groups were compared.

RESULTS

The bone tunnel enlargement was 106.9±10.9% for group P and 121.9±9.0% for group I (P<0.02) in the AP plane and 102.8±15.2% vs 121.5±10.1% in the coronal plane (P<0.01). IKDC, Tegner, and Lysholm scores improved in both groups from pre- to postoperative assessment without significant differences between the two groups. There was a trend to higher knee stability in group P after 3 months (0.6±1.4 mm vs 1.81±.5 mm, P=0.08).

CONCLUSIONS

Both interference screw and a press-fit fixation lead to a high number of good or very good outcomes after ACL reconstruction. Tibial press-fit fixation decreases the amount of proximal bone tunnel enlargement. Press-fit fixation decreases the amount of proximal bone tunnel enlargement and improves bone to tendon contact.

Comparison of three separate antiadhesive barriers for intraperitoneal onlay mesh hernia repair in an experimental model

Background

Adhesion formation is a common adverse effect in intraperitoneal onlay mesh (IPOM) surgery. Different methods of adhesion prevention have been developed, including coated meshes and separate antiadhesive barriers (SABs). In this study one type of mesh was tested with different SABs, which were fixed to the sutured mesh using fibrin sealant. The primary aim was to compare adhesion prevention between different SABs. Secondary aims were the assessment of tissue integration and evaluation of SAB fixation with fibrin sealant.

Methods

Thirty-two rats were randomized to one of three treatment groups (SurgiWrap®, Prevadh® and Seprafilm®) or a control group (no SAB). Animals were operated on with an open IPOM technique (8 per group). One macroporous polypropylene mesh per animal (2 × 2 cm) was fixed with four non-absorbable sutures. An antiadhesive barrier of 2·5 × 2·5 cm was fixed with fibrin sealant. After 30 days, adhesion formation, tissue integration, seroma formation, inflammation and vascularization were evaluated macroscopically and by histology.

Results

Prevadh® and Seprafilm® groups showed a significant reduction in adhesion formation compared with the control group. Tissue integration of the mesh was reduced in these groups. Fibrin sealant fixed the SAB to the mesh securely in all groups.

Conclusion

Prevadh® and Seprafilm® are potent materials for the reduction of adhesion formation. A potential relationship between effective adhesion prevention and impaired tissue integration of the implant was observed. Fibrin sealant proved an excellent agent for SAB fixation.

Accuracy of high tibial osteotomy: comparison between open- and closed-wedge technique

High tibial osteotomy is an established technique for the treatment of varus malaligned knees. This study analyses the difference between the amount of correction in the preoperative planning and the postoperative result. Furthermore, it compares the difference of the accuracy between open-wedge osteotomy and closed-wedge osteotomy. About 61 patients were either treated with open-wedge or closed-wedge high tibial osteotomy. Preoperative planning and postoperative analysis were performed with a special planning software. The influence of operative technique, aetiology, age, number of previous surgeries, amount of correction and accuracy of the correction compared to the preoperative planning were analysed. The overall postoperative mechanical axis differed form preoperative planning by 2.1° ± 1.7°. The accuracy in the open-wedge group (1.7° ± 1.6°) was significantly higher than in the closed-wedge group (2.6° ± 1.8°; P = 0.038). In patients with congenital varus deformity, the accuracy of the correction was significantly higher than in patients with post-traumatic deformity. The authors recommend open-wedge technique in combination with fixed-angle plates for high tibial osteotomy.

[Multiple trauma in pediatric patients]

Important prerequisites to adequately treat pediatric patients with multiple trauma are a profound knowledge of the underlying mechanisms of injury, common injury patterns and the associated mortality. The younger the child the more injury patterns as well as organ-specific injury severity differ in comparison to adult trauma patients. Traumatic brain and thorax injuries are the key to the prognosis of the injured child. Abdominal injuries rarely require surgery in contrast to adults. Spine and pelvic injuries as well as injuries of the extremities make age-adapted surgical procedures mandatory. The present article describes the established primary diagnostic evaluation after admittance to the emergency room as well as specific treatment options for particular organ systems with respect to age-specific anatomical characteristics and pitfalls in children.

The role of preoperative MRI in knee arthroscopy: a retrospective analysis of 2,000 patients

The aim of this study was to investigate, to what extent routine preoperative MRI scans could set the indications for knee arthroscopies and reduce the number of diagnostic arthroscopies. For this retrospective cohort study, 1,000 patients who had knee arthroscopies documented in 1994/1995 were compared with 1,000 patients that were treated in 2004/2005. The preoperative diagnoses that gave indications for knee arthroscopy were compared with the intraoperative findings. The congruence of preoperative diagnosis with the intraoperative findings was evaluated comparing both study populations. The number of patients who were referred to orthopaedic trauma surgeons with MRI increased from 24% to 56%. A high congruence of preoperative diagnosis and intraoperative findings was found in 49% in 1994/1995 and 55% in 2004/2005. However, regarding the most important outcome parameter, the number of diagnostic arthroscopies, no improvement was found (3% in both periods). The presented data suggests that MRI scans are not routinely necessary as an indication for knee arthroscopy, as clinical examination and plain radiograph are sufficient. However, MRI scans do allow a more detailed characterization of the expected findings and can therefore be helpful in therapy planning.

[Total knee replacement in a below-knee amputee. Technical reference points and possible solutions]

We present the case of a 62-year-old man with posttraumatic osteoarthritis after a tibial head fracture. A below-knee amputation of the same limb had been performed years ago because of a chronic diabetic foot ulcus. The patient underwent total knee replacement, and the 2-year postoperative clinical outcome was very good. The problem of how to address missing anatomic reference points for the implantation of the tibial component in below-knee amputees and the question whether navigation offers a potential benefit in this situation are discussed.

A cyclic testing comparison of FasT-Fix and RapidLoc devices in human cadaveric meniscus

INTRODUCTION

Cyclic testing may provide a more valid depiction of how arthroscopic meniscal repairs will withstand the forces of activities of daily living (ADLs) and therapeutic exercises early post-surgery than single cycle load to failure testing. This study compared the meniscal fixation provided by vertically or horizontally placed FasT-Fix devices to horizontally placed RapidLoc devices under submaximal cyclic test conditions.

MATERIALS AND METHODS

Eighteen human cadaveric menisci were divided into three groups of six specimens. A scalpel was used to create a 2 cm lesion at 3 mm from the outer edge of the posterior third of each specimen. Merselene tape loops were placed around each side of the lesion and the tears were repaired using two vertical FasT-Fix, two horizontal FasT-Fix, or two RapidLoc devices. Cyclic testing (5-50 N at 1 Hz for 500 cycles) was performed on a servo hydraulic device. One-way ANOVA and Scheffe post-hoc tests were used to evaluate group differences (P < 0.05).

RESULTS

The vertical FasT-Fix group had less displacement over the initial ten loading cycles compared to the RapidLoc group (P = 0.004), but did not differ from the horizontal FasT-Fix group (P = 0.07). At 50, 100, 200, 300, 400, and 500 cycles, the vertical FasT-Fix group had less displacement than the horizontal FasT-Fix or RapidLoc groups (P < or = 0.004). At each interval the vertical FasT-Fix group had greater relative stiffness than the other groups (P < or = 0.009).

CONCLUSIONS

The vertical FasT-Fix group had comparatively less displacement (primarily repair site gapping) and greater relative stiffness.

[Recurrence of solitary enchondroma at the hand after operative treatment]

PURPOSE

Solitary enchondroma is the most common bone tumour at the hand. Nevertheless there are only a few studies referring to a recurrence of this lesion after operative treatment.

PATIENTS AND METHOD

21 patients (17 women/4 men) were examined retrospectively 2 to 18 (mean: 9) years after operative treatment. Clinical and radiological examinations were performed. 3 to 4 years later 9 of these patients were re-examined. 1 patient was first seen at the time of the second examination. Recurrence was the endpoint of the study.

RESULTS

At the first examination 11 patients had normal cancellous bone structure 4 to 18 (mean: 8) years after operative treatment. 7 patients had remaining bone defects and their follow-up was 2 to 15 (mean: 8) years. Recurrence was found in 3 patients 11 to 17 years postoperatively. Through the re-examination of 9 patients 2 further recurrences were found 4 to 6 or, respectively, 11 to 14 years postoperatively arising from remaining defects. Another remaining defect became normal cancellous bone structure 2 to 5 years postoperatively. Over all 6 recurrences were found in 22 patients. All patients were free of clinical symptoms.

CONCLUSION

Recurrence may occur even more than 10 years postoperatively. Therefore we recommend periodical radiological re-examination for recurrence before weakness of bone can lead to a pathological fracture. Re-examination intervals of 2 to 5 years would probably be adequate.

[(Over-)flowing bone: the rare disease of melorheostosis: clinical presentation and therapeutic concepts demonstrated by three cases]

Melorheostosis is a rare, benign, and sporadically occurring osteosclerosis of unknown cause. The onset of the disease is usually in early adulthood. Melorheostosis affects both genders, develops progressively, and is usually limited to one side of the human body. The sclerosis originates predominantly from the cortices of the long bones of the lower limbs and rarely the upper limbs. Frequently, the sclerosis involves the soft tissue surrounding the affected bones which may cause limitations in the range of motion, contractures, deformities, and pain. Melorheostosis is usually diagnosed by radiograms. Pain relief and restoration of the full range of motion are the primary goals of the therapeutic approach. A good outcome cannot always be achieved and a recurrence of the disease happens very often.

[Suspension arthroplasty of the thumb carpometacarpal joint in different views--a questionnaire]

PURPOSE

Obviously there are different judgements of the results of suspension arthroplasties of the thumb carpometacarpal joint. Consequently, the three main groups involved in therapy were asked about this topic.

PATIENTS AND METHODS

51 patients who had had a suspension arthroplasty on the thumb carpometacarpal joint in the period 1998 - 2006 were questioned. 12 of these patients were operated on both hands (63 operations). A questionnaire sent to 250 family doctors was compared with the results from the 51 patients. Furthermore there was an interview by telephone which included 25 practising specialists (orthopaedicians and surgeons).

RESULTS

The results contrasted widely. Concerning the operation, 50 from 51 patients had a high subjective satisfaction. The family doctors had a different view. Nearly 80 % disregarded the success of the operation or they could not judge the chances. Only 50 % of all family doctors arranged for an X-ray or a consultation at a specialist when the patient had continuing problems. The results of the 25 specialists were also not uniform. 50 % of them, especially the hand surgeons, believe in the success of the primary osteoarthritis operation. The high barrier to operations for rhizarthrosis is based on a lack of information.

Die Suspensionsarthroplastik am Daumensattelgelenk

PURPOSE

A modified surgical technique using suspension arthroplasty against primary osteoarthritis of the thumb carpometacarpal joint was analysed.

MATERIAL AND METHODS

This retrospective analysis focused on 41 patients who underwent suspension arthroplasties with a modified technique between 1997-2005. With the help of this technique, a long-range preparation of the flexor carpi radialis tendon can be avoided. Only the ca. 3 cm of tendon which is visible in the site was split in half and cut off proximally. This half tendon was provided with a suture in baseball-stitch technique. It was then press-fit fixed with a suture in a sloping drill hole of the MC 1 basis. The patients required a cast for only 3 weeks postoperatively. Afterwards, they received an orthesis for 2-3 weeks with increasing mobilisation. The postoperative course was clinically and radiologically analysed. The results were analysed at 3 months and 1-7 years after surgery. All patients were operated as outpatients.

RESULTS

Of the 41 patients, 40 had a high subjective satisfaction. A total of 45 operations showed excellent results. There were no poor results. Only one patient would not undergo the surgery again. The radiological distance between metacarpal 1 and the distal scaphoid lay between 4 mm and 9 mm after 3 months and 1-7 years.

CONCLUSION

The described modification of suspension arthroplasty with a short-range mobilisation of the flexor carpi radialis tendon reduced the morbidity of preparation and led to stable suspension. Thus, immobilisation over 3 weeks was not necessary. Patients obtained good, early functional results.

The treatment of inflammatory arthritis with methotrexate in clinical practice: treatment duration and incidence of adverse drug reactions

OBJECTIVE

To identify the proportion of patients with inflammatory arthritis who remain on methotrexate in the medium to long term and the incidence of side-effects in clinical practice.

METHOD

The study population comprised all patients with inflammatory arthritis treated with methotrexate and monitored in clinics under the auspices of Staffordshire Rheumatology Centre. Two clinical auditors collected data retrospectively from the computer database used to support monitoring of patients on disease-modifying anti-rheumatic drugs. Information was collected on duration of treatments and reasons for stopping treatment. For patients identified as having potentially serious side-effects or who died whilst taking methotrexate, further information on their outcome was collected from patients' medical notes and where applicable post mortem reports and death registers.

RESULTS

Between 1986 and 1999, 673 patients were treated with methotrexate, of whom 551 had a diagnosis of rheumatoid arthritis. From the Kaplan-Meier analysis, the probability of patients remaining on treatment 5 yr after starting methotrexate was 0.74. Three hundred and sixteen patients stopped methotrexate between 1986 and 1999. In 117 patients, the methotrexate was restarted. Seventy-two patients (10.7% of all patients) stopped because of inefficacy or patient choice or situation. Thirty-seven patients (5.5%) stopped methotrexate due to abnormal haematology (usually low neutrophils). Thirty-seven patients (5.5%) stopped methotrexate due to abnormalities in liver function tests. Life-threatening side-effects were identified in 12 patients (1.8%). These included six pneumonitis, five cytopenias and one disseminated varicella zoster. Two of these patients (0.3%) died, one from pneumonitis and one from disseminated varicella zoster. A total of 25 patients (3.7%) died while taking methotrexate and four died (0.6%) within 3 months of stopping methotrexate. One death (0.15%) was directly attributable to methotrexate (methotrexate pneumonitis).

CONCLUSION

This study has shown that methotrexate is well tolerated in clinical practice in the medium to long term. It has produced accurate data on the incidence of adverse effects of methotrexate in a local population in a non-research setting. It has identified the incidence of life-threatening side-effects to be 1.7% with one death (0.15%) directly due to methotrexate. This information should prove useful when recommending such treatment to patients with inflammatory arthritis.

Investigation of proton conductance in liver mitochondria of broilers with pulmonary hypertension syndrome

We previously reported an impaired ability to regulate hepatic mitochondrial state 4 respiration rate in response to sequential additions of adenosine diphosphate in pulmonary hypertension syndrome (PHS). As proton conductance is a major contributor to State 4 respiration, the major goal of this study was to investigate the nature of proton conductance in hepatic mitochondria isolated from broilers with and without PHS. Broilers were placed on floor litter in environmental chambers and exposed to cold temperatures (15 degrees C) from 3 to 7 wk of age to induce PHS. Liver mitochondria were isolated from birds that exhibited PHS (cyanosis, right ventricular weight ratio > 0.30) or from birds that appeared healthy (no cyanosis, right ventricular weight ratio < 0.27). Isolated mitochondria were placed in a chamber equipped with the ability to measure oxygen content and mitochondrial membrane potential. The mitochondrial membrane potential was assessed by an ion sensitive electrode to measure the distribution of methyltriphenylphosphonium across the inner mitochondrial membrane. Proton conductance was assessed by simultaneously measuring State 4 oxygen consumption rate as respiration was progressively inhibited with increasing concentrations of malonate. The addition of cardiolipin, a lipid found in high concentrations in mitochondrial membranes that can alter proton conductance, had no affect on respiration or mitochondrial membrane potential in either group. The relationship of curves depicting State 4 respiration and mitochondrial membrane potential indicates that PHS mitochondria exhibit impaired substrate oxidation and reduced proton conductance relative to controls. These findings provide further characterization of the altered cellular oxygen utilization in broilers with PHS.

Phylogeography and divergence in the chloroplast genome of Western Australian Sandalwood (Santalum spicatum)

Western Australian sandalwood (Santalum spicatum) is widespread throughout Western Australia across the semiarid and arid regions. The diversity and phylogeographic patterns within the chloroplast genome of S. spicatum were investigated using restriction fragment length polymorphism analysis of 23 populations. The chloroplast diversity was structured into two main clades that were geographically separated, one centred in the southern (semiarid region) and the other in the northern (arid) region. Fragmentation due to climatic instability was identified as the most likely influence on the differentiation of the lineages. The lineage in the arid region showed a greater level of differentiation than that in the southern region, suggesting a higher level of gene flow or a more recent range expansion of sandalwood in the southern region. The phylogeographic pattern in the chloroplast genome is congruent with that detected in the nuclear genome, which identified different genetic influences between the regions and also suggested a more recent expansion of sandalwood in the southern region.

Spontaneous soliton formation and modulational instability in Bose-Einstein condensates

The dynamics of an elongated attractive Bose-Einstein condensate in an axisymmetric harmonic trap is studied. It is shown that density fringes caused by self-interference of the condensate order parameter seed modulational instability. The latter has novel features in contradistinction to the usual homogeneous case known from nonlinear fiber optics. Several open questions in the interpretation of the recent creation of the first matter-wave bright soliton train [Nature (London) 417, 150 (2002)]] are addressed. It is shown that primary transverse collapse, followed by secondary collapse induced by soliton-soliton interactions, produces bursts of hot atoms at different time scales.