High-level bacterial expression and purification of apicomplexan micronemal proteins for structural studies

The cysteine-rich N-terminal domain of the micronemal adhesive protein MIC1 (MIC1-NT) from Toxoplasma gondii was cloned, expressed in Escherichia coli and purified. MIC1-NT is amenable to structural studies as shown by preliminary NMR and X-ray analysis. Positive results with two further micronemal proteins indicate that our strategy has wider application.

Application of recombinant BMP-7 on persistent upper and lower limb non-unions

The purpose of this study was to evaluate the efficacy and safety of recombinant bone morphogenetic protein 7 (rhBMP-7 or OP-1) as a bone-stimulating agent in the treatment of persistent fracture non-unions. Twenty-five consecutive patients [19 males, mean age 39.4 years (range: 18-79)] with 26 fracture non-unions were treated with rhBMP-7. There were 10 tibial non-unions, eight femoral, three humeral, three ulnar, one patellar, and one clavicular non-union. The mean follow-up was 15.3 months. The mean number of operations performed prior to rhBMP-7 application was 3.2, with autologous bone graft and bone marrow injection being used in 10 cases (38.5%). Both clinical and radiological union occurred in 24 (92.3%) cases, within a mean time of 4.2 months and 5.6 months, respectively. Of the remaining two cases, one patient ultimately underwent a below knee amputation, secondary to recurrence of deep sepsis. The other patient with recalcitrant ulnar non-union although the radiological union was incomplete, declined further intervention, as he was asymptomatic. No complications or adverse effects from the use of rhBMP-7 were encountered. This study supports the view that the application of rhBMP-7 as a bone-stimulating agent is safe and a power adjunct to be considered in the surgeon's armamentarium for the treatment of these challenging clinical conditions.

Radiation exposure to the hands of orthopaedic surgeons: are we underestimating the risk?

INTRODUCTION

Previous studies reported that the radiation exposure to the hands of orthopaedic surgeons was far below the acceptable limit. However, the risk could have been underestimated as some factors were overlooked, namely monitoring trainees during average workload, placing dosimeters over the most susceptible locations, measuring the cumulative dosage of radiation and considering the dose limit for non-classified workers.

MATERIALS AND METHODS

We performed a prospective study in two centres to estimate the radiation dose to the hands of two consultant trauma surgeons and two trainees (one assisting and one operating) while performing 47 fluoroscopy-assisted procedures. We used validated thermoluminescent dosimeters (TLDs) rings and fingerstalls for monitoring the cumulative dosage.

RESULTS

Trainees were at higher risk while performing intramedullary nailing and during assistance. Higher radiation doses were recorded from dominant index fingers and particularly fingertips.

CONCLUSION

The risk of radiation exposure appears to be higher than previously reported. Fingertips are more susceptible to radiation exposure and should therefore be monitored in forthcoming studies.

p97 and close encounters of every kind: a brief review

The AAA (ATPase associated with various cellular activities) ATPase, p97, is a hexameric protein of chaperone-like function, which has been reported to interact with a number of proteins of seemingly unrelated functions. For the first time, we report a classification of these proteins and aim to elucidate any common structural or functional features they may share. The interactors are grouped into those containing ubiquitin regulatory X domains, which presumably bind to p97 in the same way as the p47 adaptor, and into non-ubiquitin regulatory X domain proteins of different functional subgroups that may employ a different mode of interaction (assuming they also bind directly to p97 and are not experimental artifacts). Future studies will show whether interacting proteins direct p97 to different cellular pathways or a common one and structural elucidation of these interactions will be crucial in understanding these underlying functions.

The functional outcome of severe, open tibial fractures managed with early fixation and flap coverage

We studied the outcome and functional status of 33 patients with 34 severe open tibial fractures (Gustilo grade IIIb and IIIc). The treatment regime consisted of radical debridement, immediate bony stabilisation and early soft-tissue cover using a muscle flap (free or rotational). The review included standardised assessments of health-related quality of life (SF-36 and Euroqol) and measurement of the following parameters: gait, the use of walking aids, limb-length discrepancy, knee and ankle joint function, muscle wasting and the cosmetic appearance of the limb. Personal comments and overall patient satisfaction were also recorded. The mean follow-up was 46 months (15 to 80). There were 30 Gustilo grade IIIb fractures and and four grade IIIc fractures. Of the 33 patients, 29 had primary internal fixation and four, external fixation; 11 (34%) later required further surgery to achieve union and two needed bone transport procedures to reconstruct large segmental defects. The mean time to union was 41 weeks (12 to 104). Two patients (6.1%) developed deep infection; both resolved with treatment. The mean SF-36 physical and mental scores were 49 and 62 respectively. The mean state of health score for the Euroqol was 68. Patients with isolated tibial fractures had a better outcome than those with other associated injuries on both scoring systems. Knee stiffness was noted in seven patients (21%) and ankle stiffness in 19 (56%); 12 patients (41%) returned to work. Our results compare favourably with previous outcome measurements published for both limb salvage and amputation. All patients were pleased to have retained their limbs.

Incidence and causes of mortality following acute orthopaedic and trauma admissions

PURPOSE

To analyse the incidence and causes of mortality of orthopaedic and trauma patients.

METHODS

Between March 1995 and October 2000, there were 594 (404 females) in-patient deaths (2.8%) with a mean age of 82.14 years (range, 21-102 years) out of 21,122 acute admissions. The cause of death and details of the acute episode were collected from the hospital records, death certificates and postmortem examinations. Data collected were computerised and analysed using the Astute statistical package, University of Leeds.

RESULTS

The most common primary diagnosis on admission was fracture neck of femur 392 (69.1%; P = 0.001). In total, 443 (78.1%) patients underwent surgical intervention of their injuries prior to mortality with 21 patients (4.7%) dying on the same day of the operation. The mean number of days between the initial surgical intervention and death was 22.3 days (range, 0-154 days). Of the patients who were treated non-operatively, 124 died due to poor medical condition (4 [3.2%] died within 24 h, 66 [51.6%] died within the first week and the rest died thereafter). In the death certificate, the most common primary cause of death recorded in the group of patients of 64 years of age and below was cancer followed by multi-organ failure. In the age group of 65 years and above, the most common primary cause of mortality was pneumonia followed by heart failure and myocardial infarction.

CONCLUSIONS

In orthopaedic and trauma patients below the age of 65 years, the most common cause of death appears to be cancer followed by multiple system organ failure; in the elderly, pneumonia predominates followed by heart failure and myocardial infarction. Proximal femoral fractures accounted for 70% of the deaths.

Segmental tibial fractures: an assessment of procedures in 27 cases

Twenty-seven patients (two women) with segmental tibial fractures (19 open) were treated in our institution with a mean age of 38.9 years (range 22-67 years) and a mean Injury Severity Score of 11.5 (9-34). Sixteen fractures were stabilised initially with an interlocking nail, seven with an external fixator, one with a hybrid external fixator, two cases were plated and one was treated in plaster. The mean size of the segment was 11.5 cm (range 4-20 cm). Soft tissue coverage was required in 17 cases. There were three cases of compartment syndrome, six cases of superficial infection and four deep infection cases (two of which required amputation). In four cases, excision of the non-viable segment was necessary. Overall, 13 patients were subjected to a second operative procedure (OP) (four external fixators were replaced with the AO solid tibial nail, two Ilizarov bone transports following excision of the dead bone segment, 2 below knee amputations, 3 exchange reamed nailings, 1 LISS plate application for stability and 1 ring fixator for compression of a fracture). Five patients underwent third procedure (two Ilizarov for bone transport, two exchange nailing, and one bone grafting). The mean time to union of the proximal segment was 38.8 weeks (range 10-78 weeks) and 41.4 weeks (range 12-65 weeks) for the distal segment, respectively. The treatment of segmental tibial fractures poses many problems to the surgeon due to the precarious blood supply of the intermediate segment. The risk of non-union delayed union, infection and additional procedures is high as seen in this series of patients.

A phase II study of ZD0473 given as a short infusion every 3 weeks to patients with advanced or metastatic breast cancer: a National Cancer Institute of Canada Clinical Trials Group trial, IND 129

BACKGROUND

ZD0473 is a new generation platinum compound with activity against a wide range of human tumor cell lines and xenografts, including carboplatin- and cisplatin-resistant lines. A phase II study of ZD0473 in advanced breast cancer was initiated by the National Cancer Institute of Canada Clinical Trials Group.

PATIENTS AND METHODS

Women with metastatic breast cancer, measurable disease, an Eastern Cooperative Oncology Group performance status of up to two, and a maximum of one prior cytotoxic agent for recurrent disease were enrolled and treated at 120 mg/m(2) every 3 weeks. After 13 patients were enrolled, the dose was increased to 150 mg/m(2) on the basis of emergent data from studies ongoing at the time.

RESULTS

Thirty-three women were evaluable for toxicity and 26 patients for response. Toxicity was mainly hematological with grade 3/4 thrombocytopenia in 12 of 20 patients (60%) treated at 150 mg/m(2) and grade 3 thrombocytopenia in three of 13 patients (23%) at 120 mg/m(2). Grade 3/4 neutropenia occurred in 15 patients (75%) at 150 mg/m(2) and two patients (10%) at 120 mg/m(2). Non-hematological toxicities were generally mild or moderate. There was one partial response seen for a response rate of 3.8% (95% confidence interval 0.1% to 19.5%) and stable disease in 15 patients.

CONCLUSION

ZD0473 has minor activity as a single agent in metastatic breast cancer. Combinations with other drugs including docetaxel are ongoing and may be of interest.

Injury patterns associated with mortality following motorcycle crashes

All patients involved in motorcycle crashes admitted to various hospitals in the Yorkshire region of UK between January 1993 and December 1999 were retrospectively reviewed to identify the factors that are likely to predict a reduced survival. Of the 1239 patients requiring hospital admission, 74 died. The probability of reduced survival was estimated by a logistic regression model using independent variables such as head injury, thoracic trauma, abdominal injury, spinal injury and pelvic fracture and a compound variable of pelvic fracture combined with a long bone fracture. The odds ratio for head injury was 0.349, chest injury 0.39, abdominal injury 0.42, and the compound variable (pelvis plus a long bone fracture) 0.576. The mean injury severity score (ISS) in the fatal group was 35.96 compared to 12.2 in the group that survived (P<0.01). There was a significant difference in the Glasgow coma scale (GCS) between patients wearing a helmet and those that did not wear any protective headgear (P=0.0007). Head injury followed by chest and abdominal trauma were found to predict a reduced survival rate. Use of helmets should continue to be compulsory. Chest and abdominal injuries should be diagnosed and treated early to reduce mortality.

The development of a new site-specific measure of quality of life for breast problems: the Cardiff breast scales

The management of women presenting to primary care with symptoms of breast disease is of increasing interest given recent organisational changes aimed at improving accuracy and speed of referrals. As part of a randomised controlled trial, 1063 women were recruited following a primary care consultation for a variety of breast-related problems. In the absence of a suitable outcome measure for such women, a site-specific instrument was developed to complement a generic quality of life scale (SF-36). Items were generated using key informant interviews with health professionals. Draft scale items were piloted using a postal questionnaire and subsequent patient debrief interviews. A sample of respondents were also sent the same questionnaire I month later to assess test-retest reliability. Across the whole sample (n = 848), three factors were identified: 'general well-being', 'concerns' and 'relationships'. These factors accounted for 60% of total variance. Evidence of scale validity, reliability and responsiveness are reported for this new outcome measure for use in women presenting with breast problems.

Friction burns within the tibia during reaming

We have carried out a prospective, randomised trial to measure the rise of temperature during reaming of the tibia before intramedullary nailing. We studied 34 patients with a mean age of 35.1 years (18 to 63) and mean injury severity score of 10 (9 to 13). The patients were randomised into two groups: group 1 included 18 patients whose procedure was undertaken without a tourniquet and group 2, 16 patients in whom a tourniquet was used. The temperature in the bone was measured directly by two thermocouples inserted into the cortical bone near the isthmus of the tibial diaphysis. Reaming was carried out to at least 1.5 mm above the required diameter of the nail. Blood loss was assessed by recording the preoperative and postoperative haemoglobin (Hb) level.

The minimum clinical follow-up was six months. In group 1 (no tourniquet), the mean Hb dropped 2.8 g/dl from 14.3 ± 1.02 g/dl to 11.5 ± 1.04 g/dl (p = 0.0001), whereas with the tourniquet, the mean decrease was 1.3 g/dl from 14 ± 1 g/dl to 12.7 ± 1.3 g/dl (p = 0.007). This difference was not statistically significant. The mean initial tibial temperature was 35.6°C (sd 0.6) and rose with reaming to levels between 36.3°C and 51.6°C. The highest temperatures were obtained with the largest reamers (11 and 12 mm, p = 0.0001) and the most rapid rise with the smallest diameters of medullary canal (8 or 9 mm). The rise of temperature was transient (20s).

We were unable to identify any effect of the use of a tourniquet on the temperature achieved. Reamed intramedullary tibial nailing induces a transient elevation of temperature which is directly related to the amount of reaming.

Friction burns within the tibia during reaming. Are they affected by the use of a tourniquet?

We have carried out a prospective, randomised trial to measure the rise of temperature during reaming of the tibia before intramedullary nailing. We studied 34 patients with a mean age of 35.1 years (18 to 63) and mean injury severity score of 10 (9 to 13). The patients were randomised into two groups: group 1 included 18 patients whose procedure was undertaken without a tourniquet and group 2, 16 patients in whom a tourniquet was used. The temperature in the bone was measured directly by two thermocouples inserted into the cortical bone near the isthmus of the tibial diaphysis. Reaming was carried out to at least 1.5 mm above the required diameter of the nail. Blood loss was assessed by recording the preoperative and postoperative haemoglobin (Hb) level. The minimum clinical follow-up was six months. In group 1 (no tourniquet), the mean Hb dropped 2.8 g/dl from 14.3 +/- 1.02 g/dl to 11.5 +/- 1.04 g/dl (p = 0.0001), whereas with the tourniquet, the mean decrease was 1.3 g/dl from 14 +/- 1 g/dl to 12.7 +/- 1.3 g/dl (p = 0.007). This difference was not statistically significant. The mean initial tibial temperature was 35.6 degrees C (SD 0.6) and rose with reaming to levels between 36.3 degrees C and 51.6 degrees C. The highest temperatures were obtained with the largest reamers (11 and 12 mm, p = 0.0001) and the most rapid rise with the smallest diameters of medullary canal (8 or 9 mm). The rise of temperature was transient (20 s). We were unable to identify any effect of the use of a tourniquet on the temperature achieved. Reamed intramedullary tibial nailing induces a transient elevation of temperature which is directly related to the amount of reaming.

Temperature rise during reamed tibial nailing

The current study determined the temperature rise during reamed tibial intramedullary nailing in vivo. Eighteen adult patients were studied. The tibial medullary canal diameter ranged from 8 to 11 mm and was reamed to at least 1.5 mm above the required nail diameter with AO reamers. Reaming of the medullary cavity ranged from 9 to 12 mm before nail insertion. Intraoperative monitoring of the heat produced during reaming of the medullary cavity was done by inserting two platinum resistance thermometer probes into the cortical bone at the short isthmic segment of the tibial shaft. The probes were connected to a data logger, and temperature readings were taken every 5 seconds during each reaming procedure. The mean tibial temperature before initiation of reaming was 35.6 degrees C (standard deviation, +/- 0.5 degrees), and peak temperatures recorded were from 36.1 degrees C to 51.6 degrees C. A direct correlation was observed between temperature elevation and amount of reaming. With reaming above 10 mm, tibias with a canal diameter of 8 mm showed a statistically higher temperature rise compared with tibias with a canal diameter of 9, 10, or 11 mm. No patients had intraoperative or postoperative complications related to skin or bone thermal necrosis, and bony healing progressed uneventfully. The small amount of reaming required to insert a nail into a normal 9-, 10-, or 11- mm tibial canal does not seem to produce a clinical problem. Reaming smaller canals (8 mm) to a larger size may induce a significant heating effect.

Removal of the retained fragment of broken solid nails by the intra-medullary route

The development of solid nails has not eliminated the risk of occasional nail failure. It has been suggested that subsequent intra-medullary removal of solid nail fragment may be virtually impossible and thus major surgery is required for their revision. We report two cases of hardware failure of a solid intra-medullary nail (Synthes solid femoral and tibial nail) and describe their successful intra-medullary removal using the Synthes extraction kit.

The Bowman-Birk inhibitor reactive site loop sequence represents an independent structural beta-hairpin motif

We have determined the NMR structure in aqueous solution of a disulphide-cyclised 11-residue peptide that forms a stable beta-hairpin, incorporating a type VIb beta-turn. The structure is found to be extremely well ordered for a short peptide, with the 30 lowest energy simulated annealing structures having an average pairwise r.m.s. deviation of only 0.36 A over the backbone. All but three side-chains adopt distinct conformations, allowing a detailed analysis of their involvement in cross-strand interactions. The peptide sequence analysed originates from a previously reported study, which identified potent inhibitors of human leukocyte elastase from screening a combinatorial peptide library based on the short protein beta-sheet segment that forms the reactive site loop of Bowman-Birk inhibitors. A detailed comparison of the peptide's solution structure with the corresponding region in the whole protein structure reveals a very good correspondence not only for the backbone (r.m.s. deviation approximately 0.7 A) but also for the side-chains. This isolated beta-hairpin retains the biologically active "canonical conformation" typical of small serine proteinase inhibitor proteins, which explains why it retains inhibitory activity. Since the structural integrity is sequence-inherent and does not depend upon the presence of the remaining protein, this beta-hairpin represents an independent structural motif and so provides a useful model of this type of protein architecture and its relation to biological function. The relationship between the conformation of this beta-hairpin and its biological activity is discussed.

Simultaneous bilateral femoral fractures: systemic complications in 14 cases

We have retrospectively reviewed 14 patients with bilateral femoral shaft fractures who attended our institution between January 1993 and March 1999. The mean age of the patients was 38 years (19-75) and the median injury severity score (ISS) was 16 (interquartile range 10-20). Thirteen patients were treated with intramedullary nailing and 1 with plating and nailing within 24 h of admission to hospital. The mean resuscitation requirements were 10.6 (6-16) litres of colloid and crystalloid and 8.6 (4-30) units of blood. The mean intensive care unit/high dependency unit (ICU/HDU) stay was 4 days (1-14) and the mean hospital stay was 36.3 days (3-210). There were 6 cases of adult respiratory distress syndrome (ARDS), 1 compartment syndrome, 1 case of osteomyelitis, 1 above-knee amputation and 2 deaths (14.2%). The mean time to union was 24.5 weeks (12-37). Comparison to patients with unilateral injuries revealed a higher ISS, resuscitation requirements, ARDS, hospital stay and mortality.

Nonunion of the femoral diaphysis. The influence of reaming and non-steroidal anti-inflammatory drugs

We assessed factors which may affect union in 32 patients with nonunion of a fracture of the diaphysis of the femur and 67 comparable patients whose fracture had united. These included gender, age, smoking habit, the use of non-steroidal anti-inflammatory drugs (NSAIDs) the type of fracture (AO classification), soft-tissue injury (open or closed), the type of nail, the mode of locking, reaming nu non-reaming, infection, failure of the implant, distraction at the fracture site, and the time to full weight-bearing. Patients with severe head injuries were excluded. Both groups were comparable with regard to gender, Injury Severity Score and soft-tissue injury. There was no relationship between the rate of union and the type of implant, mode of locking, reaming, distraction or smoking. There were fewer cases of nonunion in more comminuted fractures (type C) and in patients who were able to bear weight early. There was a marked association between nonunion and the use of NSAIDs after injury (p = 0.000001) and delayed healing was noted in patients who took NSAIDs and whose fractures had united.

Compartment syndrome following isolated ankle fracture

We report two cases of compartment syndrome following isolated ankle fractures. Both required decompression of all the compartments following early clinical diagnosis and measurements of the intra-compartmental pressures.

Nonunion of the femoral diaphysis

We assessed factors which may affect union in 32 patients with nonunion of a fracture of the diaphysis of the femur and 67 comparable patients whose fracture had united. These included gender, age, smoking habit, the use of non-steroidal anti-inflammatory drugs (NSAIDs) the type of fracture (AO classification), soft-tissue injury (open or closed), the type of nail, the mode of locking, reaming v non-reaming, infection, failure of the implant, distraction at the fracture site, and the time to full weight-bearing. Patients with severe head injuries were excluded. Both groups were comparable with regard to gender, Injury Severity Score and soft-tissue injury.

There was no relationship between the rate of union and the type of implant, mode of locking, reaming, distraction or smoking. There were fewer cases of nonunion in more comminuted fractures (type C) and in patients who were able to bear weight early. There was a marked association between nonunion and the use of NSAIDs after injury (p = 0.000001) and delayed healing was noted in patients who took NSAIDs and whose fractures had united.

Stabilisation of acute femoral fractures in Paget's disease

Eleven cases of acute femoral fractures in patients with Paget's disease are presented following stabilisation with the solid AO femoral nail. In three cases with severe deformity of the femur, reaming was required to enable implant insertion. No corticotomies were required. The median operation time was 55 (35-65) min. There was no operative mortality and no patient developed signs of acute respiratory distress syndrome/fat embolism. Skeletal stability was achieved in all cases. The reconstruction proximal locking option (spiral blade) was utilised in ten of the eleven cases. In all cases a 9 mm nail was inserted. One patient (pagetic sarcoma) died 23 months after surgery. Ten of the eleven fractures healed uneventfully. The mean time to union was 32 (26-42) weeks.

Bilateral anterior shoulder fracture-dislocation. A case report and a review of the literature

We report an unusual case of bilateral anterior shoulder dislocation following trauma. Previously reported cases were either of bilateral dislocations or bilateral fracture dislocations. In our case the patient suffered bilateral anterior dislocation with a three part fracture dislocation on the right. A review of the literature is presented.

Exchange nailing for femoral shaft aseptic non-union

Although rare, non-union of femoral shaft fractures is a cause of significant morbidity. In aseptic non-union, excellent union rates have historically been reported following reamed exchange femoral nailing. However, recently, a high incidence of failure requiring additional procedures has been reported. In light of these concerns and a recent change in our practice to the use of thin solid nails we undertook a retrospective study to determine the efficacy of exchange nailing with these modern nails in our hands. We reviewed records and radiographs of 25 patients who had a reamed exchange femoral nailing for established aseptic non-union. 24 patients (96%) united after exchange without the need for an additional procedure. The mean time to union was 29.75 weeks. Patients who had open bone grafting performed at the same procedure tended to unite quicker, but this did not achieve statistical significance (p = 0.14). Union times were not affected by smoking habits or nail type. This study demonstrates that reamed exchange nailing for aseptic femoral non-union remains an effective treatment. We believe that the nail type is less important than the biological effects of reaming, bone grafting and dynamization.

Long-term reduction of renal interstitial hydrostatic pressure after neonatal renin-angiotensin system inhibition in the rat

BACKGROUND

Neonatal inhibition of the renin angiotensin system (RAS) causes a decreased urinary concentrating ability, papillary atrophy, and tubulointerstitial inflammation long term. As a consequence of these morphological changes, we surmised that renal blood flow and renal interstitial hydrostatic pressure (RIHP) may be altered during and shortly after cessation of neonatal angiotensin-converting enzyme (ACE) inhibition, and that tentative changes of these variables would persist long after treatment withdrawal.

METHODS

Rats were given daily intraperitoneal injections of the ACE inhibitor, enalapril (10 mg/kg) or saline from days 3 to 23 postpartum, and the relationship between renal perfusion pressure (PP) and RIHP was investigated in 6- and 13-week-old anaesthetized rats.

RESULTS

Neonatal ACE inhibition did not affect baseline RIHP short term, whereas RIHP was reduced at 13 weeks of age versus controls (11.6+/-1.6 vs 18.5+/-1.0 mmHg, P<0.05). Changes in RIHP correlated positively to changes in renal PP, independent of treatment and age (slope averaged 0.11+/-0.03). Ongoing ACE inhibition until 6 weeks of age neither affected baseline RIHP nor altered the reactivity to changes in perfusion pressure. Mild renal histopathological abnormalities were present already 3 weeks after cessation of treatment and were aggravated significantly in the 13-week-old rats, showing a complete loss of the papillary parenchyma.

CONCLUSION

The reduced baseline RIHP in adult rats seemed to constitute a functional correlate to the major papillary atrophy. However, RIHP responses to changes in renal perfusion pressure was maintained, possibly indicating a compensatory effect of the remaining vasa recta and/or peritubular capillary network. Taken together, lack of neonatal angiotensin II type-1 (AT1) receptor stimulation induces not only irreversible abnormalities of the renal architecture, but causes alteration of intrarenal haemodynamics, such as a reduced RIHP, which may have implications for the regulation of pressure-natriuresis.

Some NMR experiments and a structure determination employing a [15N,2H] enriched protein

We present the results of studies of an aqueous sample of a highly [15N,2H] enriched protein, the SH3 domain from Fyn. Measurements of 1H relaxation and interactions between H2O solvent and exchangeable protons are given, as well as a method for increasing the effective longitudinal relaxation of solvent exchangeable proton resonances. The long-range isotope shifts are measured, for 1H and 15N, which arise due to perdeuteration. Simulations, which employed a 7 or 8 spin relaxation matrix analysis, were compared to the experimental data from a time series of 2D NOESY datasets for some resonances. The agreement between experiment and simulation suggest that, with this 1H dilute sample, relatively long mixing times (up to 1.2 s) can be used to detect specific dipolar interactions between amide protons up to about 7A apart. A set of 155 inter-amide NOEs and 7 side chain NOEs were thus identified in a series of 3D HSQC-NOESY-HSQC experiments. These data, alone and in combination with previously collected restraints, were used to calculate sets of structures using X-PLOR. These results are compared to the available X-ray and NMR structures of the Fyn SH3 domain.

Challenges in evaluating primary health care for teenagers. Research Sub-Committee of the Adolescent Working Party of the Royal College of General Practitioners, London, UK

This paper concerns the evaluation of health care for teenagers and examines the role of primary care and its interaction with the teenage users of this service. It recognizes that the majority of health care for teenagers takes place within general practice. The challenge posed is to identify and put in place suitable evaluation tools. There are government targets to improve the health of teenagers by reducing teenage pregnancy, drug use, smoking rates and suicides. It is an assumption of this paper that improvements in experiences of primary care will lead to improvements in more population-based outcomes of care, although this link needs investigation. The paper shows that there are few measures of generic outcome which are available for use in experiments to assess teenage health care as a baseline now. This has implications for conducting future research projects. Such measures are important and it is a necessary feature of research into teenage health that these measures are devised, tested and validated as a priority.

Saved by a hernia: an unusual presentation of ovarian cancer

A lump in the groin of a 75-year-old woman co-existed with a single ovarian cyst. It was eventually diagnosed as a solitary necrotic omental metastasis from a cystadenocarcinoma of the ovary which had herniated through the femoral canal.

Nutritional regulation of insulin-like growth factor-I mRNA expression in barramundi, Lates calcarifer

The effect of nutritional status on IGF-I mRNA expression in the liver and brain of juvenile barramundi (Lates calcarifer) was investigated. Fish were either fed a satiety ration (SAT) or starved (STV) for 6 weeks. Starved fish demonstrated significantly lower condition factor and hepatic IGF-I mRNA expression at 3 and 6 weeks, when compared with the SAT group. IGF-I mRNA expression in the brain was 10 fold lower than the liver and was not affected by ration size. These results suggest the liver is the major site of IGF-I mRNA synthesis and hepatic but not brain IGF-I mRNA expression is regulated by food availability in juvenile barramundi.

The acetabular notch in hip dysplasia

In the first few months of life, a notch may be seen on radiographs of the superolateral margin of the infant hip. It may be associated with a steeply inclined acetabular roof and may be an indicator of persistent neonatal instability or displacement of the femoral head.

The acetabular notch in hip dysplasia

In the first few months of life, a notch may be seen on radiographs of the superolateral margin of the infant hip. It may be associated with a steeply inclined acetabular roof and may be an indicator of persistent neonatal instability or displacement of the femoral head.

13C NMR study of the effects of mutation on the tryptophan dynamics in chymotrypsin inhibitor 2: correlations with structure and stability

Recombinant chymotrypsin inhibitor 2 (CI-2) and the three mutants Ile39-->Val, Ile39-->Leu, and Arg67-->Ala were successfully enriched with [2-13C]tryptophan at position 24 within the hydrophobic core of the protein. Carbon-13 NMR relaxation measurements were then used to investigate the effect of these mutations on the dynamics of the tryptophan residue. In addition, the stability of wild-type and mutant CI-2s was measured by their susceptibility to unfolding by guanidine hydrochloride. The mutant proteins were all found to be less stable, giving delta delta GU values relative to wild-type of 1.17, 1.96, and 1.21 kcal mol-1, respectively. The indole moiety of the tryptophan residue was found to be more mobile in all the mutants studied than in wild-type CI-2. Order parameters of 0.69, 0.60, 0.56, and 0.44 were derived for wild-type, Ile39-->Val, Ile39-->Leu, and Arg67-->Ala CI-2, respectively. It is concluded that there is a correlation between the protein stability and the picosecond dynamics within the hydrophobic core and that mutations can influence the dynamic behavior of the residues that are relatively distant in the three-dimensional structure.

A role for tumour necrosis factor-alpha in the human mixed lymphocyte culture reaction

The possible role and influence of tumour necrosis factor-alpha (TNF-alpha) in the human mixed lymphocyte culture (MLC) reaction was investigated. Polyclonal rabbit sera to recombinant human-TNF-alpha (rhTNF-alpha) consistently inhibited the MLC, and this could be reversed by simultaneous addition of rhTNF-alpha to the culture medium. Under optimal cell culture conditions, the exogenous addition of 1000 U/mL of rh TNF-alpha had a variable but generally small enhancing effect on the MLC reaction. Additional studies have clearly highlighted the importance of MLC assay conditions in influencing the effect of exogenous rhTNF-alpha. Enhancement of the MLC reaction was only consistently observed under suboptimal cell culture conditions. While the present study clearly supports an important role for TNF in controlling the proliferative response in the human MLC reaction it also highlights the influence of in vitro tissue culture conditions in determining the effect of exogenous TNF-alpha in this assay.

DUE of ciprofloxacin in the treatment of urinary tract infections in hospitalized patients

In this retrospective study of 30 patients with urinary tract infections, a drug usage evaluation indicated that 60% of the patient population sampled were appropriately switched to ciprofloxacin from IV antimicrobial agents; inappropriate use was identified in 40%. The drug's safety profile indicates that patients can be safely removed from IV antimicrobial therapy and continue treatment on ciprofloxacin, a measure which reduces treatment costs. These costs also can be lowered when inappropriate ciprofloxacin use is ruled out in patients with organisms sensitive to less costly oral antimicrobials. Identifying which patients should be removed from parenteral therapy maximizes the economic benefit of ciprofloxacin therapy and optimizes the impact of pharmacy intervention on patient care.

Anterior cruciate ligament reconstruction using the Gore-tex ligament

Twenty two Army patients with synthetic (Gore-tex) anterior cruciate ligament (ACL) reconstructions were reviewed (mean follow up 18 months). Reconstruction appeared to abolish the pivot shift sign in all cases, but some subjective instability persisted in all but 6 patients. Outcome was also assessed by medical (PULHHEEMS) grading: 6 patients were fully fit (graded L2), 7 returned to moderate activity but not full fitness (L3), and 9 remained severely incapacitated (L7 or L8) with 4 of this group being medically discharged. Specific operative complications included: prosthesis breakage (3 partial, 1 complete), infected prosthesis(1), and problems with the tibial screw(3). The range and frequency of complications was similar in other series. Physical fitness is an integral part of a soldier's job, placing particular demands on the knee and on surgical repair of knee injuries. Reports on the Gore-tex ACL prosthesis in other groups have been more encouraging, but there are difficulties in comparing this study with others. ACL insufficiency remains a serious problem, with implications for a soldier's fitness and career. The Gore-tex prosthesis improves stability but does not always allow a soldier to return to full fitness.

Acute cerebellar syndrome, conjunctivitis, and hearing loss associated with low-dose cytarabine administration

An unusual reaction associated with chronic low-dose cytarabine is described. A 77-year-old man complained of three to four weeks of hearing loss and progressive inability to walk without assistance. He had received two courses of cytarabine 100 mg sc/wk for the management of myelofibrosis myeloid metaplasia over 21 months. He received a total of 3 g over seven months during his first course followed ten months later with a 1.2 g over four months. Conjunctivitis was also identified on physical examination at the time of his admission. He was admitted to the neurology service where a complete neurological work-up with consultations from the ophthalmology, audiology, hematology, and ear, nose, and throat services failed to identify a cause of his symptoms. Cytarabine was discontinued on the suspicion that his symptoms were drug induced. The conjunctivitis resolved completely with ophthalmic antibiotics and corticosteroids. His hearing slowly improved over three to four weeks, and he was able to ambulate with a walker. He continued to improve at home although some hearing loss remained three months after his initial presentation. Although conjunctivitis and neurotoxicity are well-known complications of high-dose cytarabine, there are no prior reports of these reactions after low-dose therapy. Hearing loss, which has not been previously reported with cytarabine alone, appears to be a new complication of cytarabine administration.

Hepatotoxicity associated with choline magnesium trisalicylate: case report and review of salicylate-induced hepatotoxicity

A case of a 21-year-old woman who had developed mild hepatotoxicity while receiving choline magnesium trisalicylate therapy is described. She presented with fever and mild hepatic enzyme elevations before salicylate therapy was instituted. Liver function tests (LFT) returned to normal within five days of hospitalization but she continued to develop daily fevers. Blood, urine, and throat cultures were negative. An acute viral illness or reactivation of systemic lupus erythematosus were the suspected diagnoses. Choline magnesium trisalicylate was then administered in an effort to control her fever, and was successful. After three days of salicylate therapy her LFT values began to rise. They continued to rise for five more days before salicylate hepatotoxicity was suspected. Choline magnesium trisalicylate was discontinued after eight days and the patient's LFT quickly returned to normal. The source of fever was never identified, although infection with cytomegalovirus was considered the most likely cause. Salicylate-induced hepatotoxicity is reviewed.