Different forms of DMP1 play distinct roles in mineralization.

Dentin matrix protein-1 (DMP1) is a major synthetic product of hypertrophic chondrocytes and osteocytes. Previous in vitro studies showed full-length DMP1 inhibits hydroxyapatite (HA) formation and growth, while its N-terminal fragment (37K) promotes HA formation. Since there are 3 fragments within the mineralized tissues [N-terminal, C-terminal (57K), and a chondroitin-sulfate-linked N-terminal fragment (DMP1-PG)], we predicted that each would have a distinct effect on mineralization related to its interaction with HA. In a gelatin-gel system, 37K and 57K fragments were both promoters of HA formation and growth; DMP1-PG was an inhibitor. The secondary structures of the 3 fragments and the full-length protein in the presence and absence of Ca2+ and HA determined by FTIR showed that the full-length protein undergoes slight conformational changes on binding to HA, while 37K, 57K, and DMP1-PG do not change conformation. These findings indicate that distinct forms of DMP1 may work collectively in controlling the mineralization process.

A comparison of the disposable Ambu AuraOnce Laryngeal Mask with the reusable LMA Classic laryngeal mask airway.

Single-use supraglottic airway devices are now available and are intended to be comparable with the reusable LMA Classic laryngeal mask airway. We performed a randomised cross-over study comparing the Ambu AuraOnce Laryngeal Mask with the LMA Classic. Fifty patients participated in the trial. Success rates for insertion at the first attempt were similar (92% with the Ambu and 84% with the LMA Classic; p = 0.22). The volumes of air required to inflate the cuff to produce a seal were similar, but the cuff pressure was lower for the Ambu Laryngeal Mask (median (IQR [range]) 18 (10-31 [0-100] cmH(2)O) than the LMA Classic 27 (17-50 [4-90] cmH(2)O; p = 0.007). Visual analogue scores for ease of insertion were 87 (73-93 [26-97]) mm for the Ambu and 84 (60-89 [18-96]) for the LMA Classic (p = 0.017). Complications were similar in both groups. We suggest that the disposable Ambu Laryngeal Mask is an acceptable alternative to the reusable LMA Classic.

Comparison of face masks in the bag-mask ventilation of a manikin.

BACKGROUND AND OBJECTIVE: We conducted a study investigating the effectiveness of four face mask designs in the bag-mask ventilation of a special manikin adapted to simulate a difficult airway. METHODS: Forty-eight anaesthetists volunteered to bag-mask ventilate the manikin for 3 min with four different face masks. The primary outcome of the study was to calculate mean percentage leak from the face masks over 3 min. Anaesthetists were also asked to rate the face masks using a visual analogue score. RESULTS: The single-use scented intersurgical face mask had the lowest mean leak (20%). This was significantly lower than the mean leak from the single-use, cushioned 7,000 series Air Safety Ltd. face mask (24%) and the reusable silicone Laerdal face mask (27%) but not significantly lower than the mean leak from the reusable anatomical intersurgical face mask (23%). CONCLUSIONS: There was a large variation in both performance and satisfaction between anaesthetists with each design. This highlights the importance of having a variety of face masks available for emergency use.

Balancing priorities in the management of hip fractures: guidelines versus resources.

BACKGROUND: About 60,000 patients are treated for hip fractures each year in the UK and the incidence is increasing. The majority of these patients are elderly and sick, and delay to operation may be fatal. The National Confidential Enquiry into Peri-Operative Deaths (NCEPOD) guidelines aim to improve quality of care for such patients. However, we present an audit highlighting the importance of balancing the implementation of such guidelines with available local resources to ensure that established priorities in the care of these patients remain paramount. METHODS: The 2001 NCEPOD report recommends that pre-operative transthoracic echocardiography be performed in patients who have evidence of aortic stenosis in order to identify those requiring invasive monitoring and high dependency unit care postoperatively. RESULTS: We have assessed the impact of the implementation of these guidelines on surgery for fractured neck of femur at our hospital, auditing both delay to surgery and the effect of the investigation on subsequent management. In the period studied prior to the introduction of the NCEPOD guidelines, no patients underwent pre-operative echocardiography. Subsequent to their introduction, 10% of patients underwent the investigation, which in the current study did not alter management but did delay surgery by 4-8 days in all cases. CONCLUSIONS: For such guidelines to be implemented, adequate resources should first be provided. In the absence of these resources, clinicians must balance the need for adequate pre-operative assessment with the need for urgent surgery.

Fractures of the distal tibia: minimally invasive plate osteosynthesis.

Unstable fractures of the distal tibia that are not suitable for intramedullary nailing are commonly treated by open reduction and internal fixation and/or external fixation, or treated non-operatively. Treatment of these injuries using minimally invasive plate osteosynthesis (MIPO) techniques may minimise soft tissue injury and damage to the vascular integrity of the fracture fragments. We report the results of 20 patients treated by MIPO for closed fractures of the distal tibia. Their mean age was 38.3 years (range: 17-71 years). Fractures were classified according to the AO system, and intra-articular extensions according to Rüedi and Allgöwer. The mean time to full weight-bearing was 12 weeks (range: 8-20 weeks) and to union was 23 weeks (range: 18-29 weeks), without need for further surgery. There was one malunion, no deep infections and no failures of fixation. MIPO is an effective treatment for closed, unstable fractures of the distal tibia, avoiding the complications associated with more traditional methods of internal fixation and/or external fixation.

Comment on "Mobility spectrum computational analysis using a maximum entropy approach".

We point out that the comparison in Fig. 1 of the recent publication by S. Kiatgamolchai et al. [Phys. Rev. E 66, 036705 (2002)] of the proposed maximum entropy-mobility spectrum analysis (ME-MSA) with our quantitative mobility spectrum analysis (QMSA) is misleading. Rather than comparing with the more recent "improved" version of QMSA [Vurgaftman et al., J. Appl. Phys. 84, 4966 (1998)], a preliminary version that was three years older and demonstrably inferior was employed. We show that ME-MSA and the improved QMSA give quite similar results.

AIDS-related ankle arthropathy: Mycobacterium avium-intracellulare infection.

We present a case of Mycobacterium avium-intracellulare (MAI) infection of the ankle joint in a patient with HIV infection. The patient presented with a painful, destructive arthropathy of the ankle. Initial microbiological studies were negative but infection with MAI was later identified from biopsies taken during hindfoot fusion. Antibiotic triple therapy was given and the patient remains pain-free without evidence of active infection. To our knowledge, this is the first case of MAI infection of the ankle reported in the literature. A high index of suspicion of (atypical) Mycobacterial infection should be maintained in patients with HIV infection presenting with an indolent but destructive arthropathy of the ankle joint.

Seasonal differences in the onset of the EBV-positive and -negative forms of paediatric Hodgkin's lymphoma.

In this study, we have shown that there are seasonal differences in the onset of the (Epstein-Barr virus) EBV-positive and -negative forms of paediatric Hodgkin's lymphoma (HL). This suggests aetiological differences between the two forms of this disease. EBV-positive HL might be a rare consequence of primary EBV infection.

Outcome following a second hip fracture.

Hip fracture has a significant impact on medical resources and patient morbidity and mortality. Few patients admitted with a hip fracture are considered for prophylactic measures aimed at the reduction of further fracture risk. Currently, 10-13% of patients will later sustain a second hip fracture. In considering the possible role of prophylactic measures in the prevention of second hip fracture, we investigated whether second hip fracture has a significant further impact on patients' mobility and social independence. We also sought to identify a pattern to second hip fracture that may allow targeting of those patients who are most likely to benefit from currently available prophylactic measures. We undertook a retrospective review of 49 consecutive patients admitted with a second hip fracture between August 1999 and September 2000. Fewer patients maintained their ability to walk independently after the second fracture than did so after the first (53 and 91% respectively, P<0.0005). Following second hip fracture, patients' level of mobility determined their future social independence. Older patients and those with a history of multiple falls had a shorter time interval between fractures. Second hip fracture has a significant further impact on patients' mobility and social independence. Younger patients and those without a history of multiple falls are most likely to benefit from medical prophylaxis.

Accuracy of intra-articular injections for osteoarthritis of the trapeziometacarpal joint.

A study was conducted to determine the accuracy of intra-articular injections for osteoarthritis (OA) of the trapeziometacarpal joint (TMCJ). Over a period of 12 months intra-articular injections on 60 TMCJs (12 males and 48 females) were carried out. All the injections were performed in the operating theatre. The operator inserted the needle into the position clinically assessed to be the TMCJ and the position was assessed using biplanar fluoroscopy. In 42% of cases, the needle was incorrectly placed and its position had to be adjusted, using fluoroscopy, to ensure correct intra-articular placement. Entry into an osteoarthritic TMCJ with a blind passage of the needle is not straightforward. A proper injection technique must be employed to enter the correct joint. Using an image intensifier greatly facilitates accurate needle placement.

Radial nerve palsy in an elite bodybuilder.

A case is reported of high radial nerve palsy in an elite bodybuilder caused by an extrinsic mass effect of muscular hypertrophy. Surgical decompression resulted in complete clinical resolution.

Molecular cytogenetic characterization of two non-MYCN amplified neuroblastoma cell lines with complex t(11;17).

The pediatric tumor neuroblastoma is characterized by a very variable, and at times unpredictable, pattern of clinical behavior, ranging from a benign localized tumor to an aggressive malignancy with poor prognosis. Standard clinical and pathological assessments do not always differentiate reliably between tumor subtypes and, therefore, genetic markers are now playing an increasingly important role in treatment decisions. MYCN oncogene amplification, for example, provides a useful marker of poor prognosis. However, less than one-half of all patients who present with, or who later develop, metastatic disease show MYCN amplification. Consequently, the identification of characteristic patterns of genetic alteration in the remaining tumors is of importance. In this report, we describe two new cell lines that we have established from metastatic, non-MYCN amplified, advanced stage neuroblastomas. These cell lines show a number of features in common, including unbalanced translocation between 11q and 17q, loss of 3p, 4p and 11q and gain of 17q. Therefore, they provide a valuable resource for the characterization of genetic pathways leading to aggressive tumor growth in non-MYCN amplified neuroblastomas.

Arthroscopic removal of a shotgun pellet from the elbow joint.

A case of arthroscopic identification and removal of a shotgun pellet from the elbow joint is presented. The pellet had entered the soft tissues over the dorsum of the joint and had migrated to an intra-articular position, causing interference with movement of the elbow. Arthroscopy of the joint was performed using standard portals. The pellet was discovered anterior to the coronoid process of the ulna in the anterior recess of the joint and was removed using forceps. At follow-up, the patient reported a symptom-free elbow with full range of movement.

South Asian ethnicity and material deprivation increase the risk of Epstein-Barr virus infection in childhood Hodgkin's disease.

In order to further define the factors associated with the observed variations in the Epstein-Barr virus-positive rate in childhood Hodgkin's disease, we have studied the effect of material deprivation (measured by the Townsend score) and ethnic origin on the frequency of Epstein-Barr virus-positivity in 55 cases of childhood Hodgkin's disease, diagnosed between 1981 and 1999, from a multi-ethnic region of the United Kingdom. Epstein-Barr virus status was determined by immunohistochemistry for the Epstein-Barr virus-encoded latent membrane protein-1. 62% of cases were Epstein-Barr virus-positive. Ethnic group was the strongest predictor of Epstein-Barr virus-positivity, with South Asians having a more than 20-fold risk of being Epstein-Barr virus-positive compared with non-South Asians. An increased risk was still present after adjusting for deprivation. Townsend scores were significantly higher (indicating more deprivation) in the Epstein-Barr virus-positive group, particularly in males. The relative risk of Epstein-Barr virus-positivity showed a gradient with increasing Townsend score; the risk being 7-times higher in the most deprived quartile compared with the least deprived group. Although the association between Townsend score and Epstein-Barr virus-positivity was reduced after adjusting for ethnic group, the risk of Epstein-Barr virus-positivity was still 3-times higher in the most deprived compared with the least deprived quartile. In addition, cases having 2 or more siblings were 5-times as likely to be Epstein-Barr virus-positive as those from smaller families. These results provide the first evidence of a strong association between Epstein-Barr virus-positive Hodgkin's disease and South Asian children from the United Kingdom. In addition, deprivation may increase the likelihood of Epstein-Barr virus-positive disease independently of ethnicity.

Revision total elbow replacement using the Souter-Strathclyde prosthesis.

The Souter-Strathclyde prosthesis was used in 52 evisions of total elbow replacements (TERs) between August 1986 and May 1997. Of these, 50, carried out in 45 patients, were prospectively followed for a mean of 53 months (14 to 139). The procedure produced reliable relief of pain, and the range of movement was preserved. There was a considerable incidence of adverse events associated with revision (30%), and 12 further procedures have been required. Nonetheless, a revision is the preferred salvage procedure for failed primary arthroplasty in the absence of sepsis.

Patterns of articular wear in the cadaveric elbow joint.

Thirty-two fixed cadaveric elbow specimens from an elderly population were examined photographically after staining of the articular cartilage. The photographic images of the articular wear areas observed were calibrated and superimposed to determine the overall pattern of articular wear in the elbow. In this group, the radiohumeral compartment showed the most frequent degenerative changes. A pattern of involvement could have been identified, proceeding from the posteromedial region of the radial head and the apex of the capitellum. Eventually, the entire lateral compartment is involved, but in most specimens examined the ulnohumeral and radioulnar articulations are preserved.