Intramedullary nailing for pathological femoral fractures

PURPOSE

To evaluate whether the operating time correlates with the survival and outcome in patients who underwent intramedullary nailing for metastatic femoral fractures.

METHODS

Records of 10 men and 11 women aged 43 to 86 (mean, 66) years who underwent intramedullary nailing (4 bilaterally) for metastatic femoral fractures between 1999 and 2003 were reviewed. The patients were followed up for at least 2 years or until their death. The main outcome measure was the correlation between operating time and survival. Operating time was categorised into 5 groups from 60 to 210 minutes, with 30-minute increments.

RESULTS

Operating time does not correlate with survival and outcome. The mean survival period was 9.4 months. Pain relief was achieved in 90% of the patients. There was no implant failure, but one loss of reduction.

CONCLUSION

Intramedullary nailing appears safe and effective for treatment of metastatic bone disease, and confers good functional results, pain relief, and mobility.

Outcome of 17 pigmented villonodular synovitis (PVNS) of the knee at 6 years mean follow-up

Between January 1950 and December 2000, 16 patients were identified from Scottish Bone Tumour Registry with 17 histologically proven pigmented villonodular synovitis (PVNS) of the knee. The mean follow-up was 6 years (range, 1-14 years). A knee swelling of chronic duration with dull ache was the common presenting symptom. The mean duration of symptoms prior to presentation was 25 months (1-108 months), however it was much less (mean, 7 months) in four patients with a history of trauma. The mean age was 33 years (range, 16-58 years) with a slight male predominance. The lesion was predominantly anterior in nine patients, posterior in four, anterolateral in two, and medial and lateral in one each. Three patients (four knees) had localised disease and 13 diffuse. Anteroposterior and lateral radiographs of the knee revealed normal findings in 11 patients, features of gonarthrosis in four and a large suprapatellar loose body in one patient (both knees). Open (incisional-eight, excisional-eight) biopsy was carried out in all and all were histologically confirmed as PVNS. Removal of a localised synovial mass or loose body with surrounding partial synovectomy (four) was carried out for the localised variety, whilst open partial (three) or total (radical) synovectomy (10) was performed in all cases of diffuse PVNS. Three of seventeen knees had a recurrence, noted at 4, 6 and 8 years postoperatively (0% - localised, 23% - diffuse variety). A total (radical) synovectomy should be considered in diffuse PVNS in order to obtain optimal outcome.

Massive haemorrhage after a low-energy pubic ramus fracture in a 71-year-old woman

We describe a case of a patient receiving warfarin who presented with a superior pubic ramus fracture after a trivial fall at home. She developed a massive retroperitoneal haematoma as a result of vascular injury and subsequently died. This case emphasises the importance of admitting and observing patients with pubic rami fractures who are receiving antithrombotic treatment, and haemorrhage should be considered if they become haemodynamically compromised.

An unfavourable outcome after periprosthetic fracture following metal-on-metal surface hip arthroplasty

We report a case of a varus malunited periprosthetic femoral neck fracture following metal-on-metal hip resurfacing operation. Failure to closely observe and poor compliance in the young and active group of patients may contribute to such an unfavourable outcome.

Femoral neck fractures complicating metal-on-metal resurfaced hips: a report of 2 cases

Metal-on-metal hip resurfacing arthroplasty is increasingly popular for younger patients with advanced hip disease. Intra-operative or immediate postoperative femoral neck fracture after metal-on-metal hip resurfacing is a well-described technical complication, ranging from 0% to 1.5%. We report 2 cases of late femoral neck fracture occurring 8 and 15 months following the index operation, with a review of the literature. We recommend that patient selection should be of prime importance before embarking on metal-on-metal surface hip replacement to avoid such complications.

Compartment syndrome--current trends in Scottish practice

The results are reported of a postal survey into current trends in the management of compartment syndrome and the use of compartment pressure monitoring (CPM) within Scottish trauma units. The majority of consultants in the study felt that all patients, especially the obtunded, with suspected compartment syndrome should be diagnosed using a combination of clinical review and CPM. 73% had CPM devices available representing an increase of 27% compared with previously published UK data. 43% improvised a device using a standard CVP/Arterial-line, transducer and monitor. Marked variation in threshold pressure was noted with the majority recommending perfusion pressure (PP) of diastolic blood pressure (DBP)--intracompartmental pressure (ICP) < 30 mmHg for intervention. We have found no published evidence to suggest that CPM in itself is harmful. Although a marked variation in intervention threshold exists in the literature, we would support a perfusion pressure of < 30 mmHg as being a safe, familiar and conservative intervention threshold, particularly when used in conjunction with clinical assessment.

Linezolid penetration into osteo-articular tissues

Penetration of linezolid into osteo-articular tissue and fluid was studied in 10 patients undergoing primary total knee replacement. Linezolid 600 mg 12 hourly was given orally over the 48 h before operation and intravenously 1 h before induction of anaesthesia. Mean concentrations of linezolid at 90 min after the final dose, in serum, synovial fluid, synovium, muscle and cancellous bone, assayed by HPLC, were at least twice the MIC(90) for staphylococci and streptococci. The concentrations obtained indicate good penetration of this antibiotic and support its use in the management of multidrug-resistant Gram-positive bone, joint and deep-seated soft-tissue infections.

COX-2 selective inhibition reverses the trophic properties of gastrin in colorectal cancer

Gastrin is a gastrointestinal peptide that possesses potent trophic properties on both normal and neoplastic cells of gastrointestinal origin. Previous studies have indicated that chronic hypergastrinaemia increases the risk of colorectal cancer and cancer growth and that interruption of the effects of gastrin could be a potential target in the treatment of colorectal cancer. Here we demonstrate that gastrin leads to a dose-dependent increase in colon cancer cell proliferation and tumour growth in vitro and in vivo, and that this increment is progressively reversed by pretreatment with the cyclo-oxygenase-2 inhibitor NS-398. Gastrin was able to induce cyclo-oxygenase-2 protein expression, as well as the synthesis of prostaglandin E2, the major product of cyclo-oxygenase. Moreover, gastrin leads to approximately a two-fold induction of cyclo-oxygenase-2 promoter activity in transiently transfected cells. The results of these studies demonstrate that cyclo-oxygenase-2 appears to represent one of the downstream targets of gastrin and that selective cyclo-oxygenase-2 inhibition is capable of reversing the trophic properties of gastrin and presumably might prevent the growth of colorectal cancer induced by hypergastrinaemia.

RXR beta isoforms in neuroblastoma cells and evidence for a novel 3'-end transcript

RXR beta is predominantly involved in retinoid responses in neuroblastoma cells, in particular the N-type SH SY 5Y cells and the S-type SH S EP cells, both derivatives of a mixed phenotype neuroblastoma cell line. The aim of this study was to identify RXR beta isoforms expressed in neuroblastoma cells and to characterise a putative novel RXR beta transcript. RXR beta 1 and RXR beta 2 were expressed in these neuroblastoma cells. An isoform with an insertion into the ligand binding domain, RXR beta(SLSR) (referred to in previous studies as RXR beta 3), was expressed at a similar level to RXR beta. A novel RXR beta transcript was identified by RNase protection assays and was at least as abundant as the expected RXR beta transcript and expressed in other cell types. Evidence suggests that this novel transcript was transcribed from an internal promoter between exons 5 and 6, contained a retained intron (intron 6) and was alternatively spliced with and without the SLSR insertion. These data show that the pattern of RXR beta expression is complex. The relative abundance of the novel RXR beta transcript suggests that it may be an important aspect of RXR beta function or regulation in a range of cell types.

Sarcoma arising adjacent to a total hip arthroplasty

We present the case of a 79-year-old woman who developed a high grade spindle cell sarcoma adjacent to total hip arthroplasty 13 years after the index operation. MRI scan appeared to show a direct communication between the tumour and intra medullary canal through a breach in the femoral cortex.

Oral oseltamivir in human experimental influenza B infection

Oseltamivir is the prodrug of Ro64-0802 (GS4071), a potent and selective inhibitor of influenza A and B virus neuraminidases. Three randomized, double-blind, placebo-controlled, parallel-group studies evaluated oral oseltamivir for early treatment (75 or 150 mg twice daily for 5 days) or prevention (75 mg once or twice daily for 7 days) of experimental influenza B virus infection in healthy susceptible adults. Treatment study A (n=60) demonstrated similar trends to treatment study B (n=117), in which 75 mg doses of oseltamivir introduced 24 h after inoculation reduced median area under curve (AUC) virus titre (oseltamivir, 22.7; placebo, 131.1 log10 TCID50 x h/ml; P=0.002) and duration of viral shedding (oseltamivir, 23.9 h; placebo, 95.8 h; P=0.0005). In prevention study C (n=58), oseltamivir did not reduce infection rates (85 versus 84%) but significantly reduced median AUC virus titre (10.0 versus 66.9 log10 TCID50 x h/ml; P=0.03) and duration of viral shedding (36 versus 84 h; P=0.03) compared with placebo. Oseltamivir was well tolerated. No emergence of drug-resistant variants was detected by testing last-day isolates (n=112) in neuraminidase inhibition assays. These results indicate that oseltamivir has significant antiviral activity in experimental human influenza B virus infection when used for prophylaxis or early treatment.

The DNA binding activity of C/EBP transcription factor is regulated in the G1 phase of the hepatocyte cell cycle

We have isolated the promoter of the rat C/EBP alpha gene and find a high degree of homology with the mouse gene, particularly in putative regulatory domains. Transactivation of this promoter by ectopic expression of rat C/EBP beta occurs through a C/EBP regulatory domain at position -170 to -195. An oligonucleotide corresponding to this domain binds to complexes expressed in rat liver that comprise C/EBP alpha-C/EBP beta heterodimers (alpha beta) as well as C/EBP beta complexed with itself and/or other unidentified nuclear factors (beta 1, beta 2, and beta 3). The DNA binding activity of these complexes changes both qualitatively and quantitatively following partial hepatectomy. Within 2-5 h postsurgery, the binding activity of the alpha beta complexes drops severalfold, reaching a nadir by 20 h. During the ensuing 3-8 days, as regeneration nears completion, this activity slowly returns to normal quiescent liver levels. Western blot analysis shows 3 major C/EBP alpha polypeptide species (42, 40, and 30 kDa), whose abundance in general parallels the decrease and recovery in DNA binding activity. In contrast to C/EBP alpha behavior, the DNA binding activity of the beta complexes is transiently induced severalfold during the early G1 period between 2 and 6 h posthepatectomy. The major C/EBP beta polypeptide is the 32-kDa LAP protein, whereas the LIP protein (21 kDa) is weakly expressed. Both remain essentially constant throughout the course of regeneration, suggesting that changes in DNA binding activity may reflect changes in the complexed proteins rather than the C/EBP beta polypeptides themselves. In primary hepatocyte cultures, under growth supporting conditions, in the absence of growth factors proliferation is negligible; C/EBP alpha is abundantly expressed at the outset, but is then extensively down-regulated. Epidermal growth factor causes further decay of C/EBP alpha polypeptides and DNA binding activity, and down-regulates C/EBP beta DNA binding activity as well. Addition of transforming growth factor beta completely antagonizes the effects of epidermal growth factor on C/EBP beta activity, and partially overcomes the effect on C/EBP alpha. These results demonstrate that the DNA binding activity of C/EBP alpha and C/EBP beta complexes is regulated in the regenerating liver, and in hepatocyte cultures responding to growth factors that regulate their proliferation.

Cell-extracellular matrix interactions can regulate the switch between growth and differentiation in rat hepatocytes: reciprocal expression of C/EBP alpha and immediate-early growth response transcription factors

Previous investigations have shown that culture of freshly isolated hepatocytes under conventional conditions, i.e., on dried rat tail collagen in the presence of growth factors, facilitates cell growth but also causes an extensive down-regulation of most liver-specific functions. This dedifferentiation process can be prevented if the cells are cultured on a reconstituted basement membrane gel matrix derived from the Englebreth-Holm-Swarm mouse sarcoma tumor (EHS gel). To gain insight into the mechanisms regulating this response to extracellular matrix, we are analyzing the activities of two families of transcription factors, C/EBP and AP-1, which control the transcription of hepatic and growth-responsive genes, respectively. We demonstrate that isolation of hepatocytes from the normal quiescent rat liver by collagenase perfusion activates the immediate-early growth response program, as indicated by increased expression of c-jun, junB, c-fos, and c-myc mRNAs. Adhesion of these activated cells to dried rat tail collagen augments the elevated levels of these mRNAs for the initial 1 to 2 h postplating; junB and c-myc mRNA levels then drop steeply, with junB returning to normal quiescence and the c-myc level remaining slightly elevated during the 3-day culture period. Levels of c-jun mRNA and AP-1 DNA binding activity, however, remain elevated from the outset, while C/EBP alpha mRNA expression is down-regulated, resulting in a decrease in the steady-state levels of the 42- and 30-kDa C/EBP alpha polypeptides and C/EBP alpha DNA binding activity. In contrast, C/EBP beta mRNA production remains at near-normal hepatic levels for 5 to 8 days of culture, although its DNA binding activity decreases severalfold during this time. Adhesion of hepatocytes to the EHS gel for the same period of time dramatically alters this program: it arrests growth and inhibits AP-1 DNA binding activity and the expression of c-jun, junB, and c-myc mRNAs, but, in addition, it restores C/EBP alpha mRNA and protein as well as C/EBP alpha and C/EBP beta DNA binding activities to the abundant levels present in freshly isolated hepatocytes. These changes are not due merely to growth inhibition, because suppression of hepatocyte proliferation on collagen by epidermal growth factor starvation or addition of transforming growth factor beta does not inhibit AP-1 activity or restore C/EBP alpha DNA binding activity to normal hepatic levels. These data suggest that expression of the normal hepatic phenotype requires that hepatocytes exist in a G0 state of growth arrest, facilitated here by adhesion of cells to the EHS gel, in order to express high levels of hepatic transcription factors such as C/EBP alpha.

Inhibition of neuronal nicotinic acetylcholine receptors by imipramine and desipramine

The actions of two structurally related tricyclic antidepressants on neuronal nicotinic acetylcholine receptors were investigated in human neuroblastoma (SY-SY5Y) cells, using whole-cell patch-clamp recordings. Both desipramine and imipramine reversibly inhibited inward currents evoked by application of the nicotinic receptor agonist dimethylphenylpiperazinium iodide (30-300 microM) with IC50 values of 0.17 microM and 1.0 microM respectively (holding potential -70 mV). The degree of current inhibition caused by either tricyclic compound was unaffected by agonist concentration (30-300 microM). The effects of desipramine were voltage-independent over the range -40 mV to -100 mV, and inhibition caused by imipramine only increased very slightly with membrane hyperpolarization over the same range. These results indicate that tricyclic antidepressants can inhibit neuronal nicotinic acetylcholine receptors by mechanisms which are distinct from their actions at non-neuronal nicotinic acetylcholine receptors.

Differential regulation of glucose transporter 1 and 2 mRNA expression by epidermal growth factor and transforming growth factor-beta in rat hepatocytes

We have examined by Northern blot analysis the expression of two members of the glucose transporter family of genes (GLUT-1 and GLUT-2) in regenerating liver and in hepatocytes cultured under various conditions. GLUT-1, although thought to be a growth-associated gene, is not expressed in normal or regenerating liver, whereas GLUT-2, a liver-specific gene, is abundant in normal liver and gradually up-regulated during liver regeneration. Conversely, in hepatocytes cultured conventionally on dried rat tail collagen (RTC) in the presence of EGF and insulin, which potentiate proliferation, GLUT-1 mRNA is rapidly and abundantly expressed, whereas GLUT-2 is depressed. To investigate the causes of this "switch" in glucose transporter expression seen when hepatocytes are removed from the liver and cultured under the conventional proliferative conditions, we examined the effects of specific growth factors and extracellular matrices on cultured hepatocytes. EGF, a potent liver mitogen, although causing a threefold induction of GLUT-1, was found to have no effect on GLUT-2 expression, suggesting that the increase in GLUT-2 seen in regenerating liver is not due to EGF. Inhibition of protein synthesis by cycloheximide in cultured hepatocytes does not prevent the induction of GLUT-1 mRNA. In addition, treatment of cells with cycloheximide appears to stabilize the GLUT-2 mRNA, preventing the usual down-regulation of this gene in cultured hepatocytes. The expression of the two glucose transporter mRNAs also differed when the hepatocytes were adherent to particular cell matrices. Culture of hepatocytes on a reconstituted basement membrane gel matrix (EHS) is known to restrain their growth and mediate high levels of differentiated hepatocytic functions that are lost under conventional culture conditions. Unlike cells on RTC, hepatocytes on EHS expressed low levels of GLUT-1 mRNA, and decreased GLUT-2 mRNA. TGF-beta, an attenuator of DNA synthesis, when added to cultures on RTC, substantially down-regulated GLUT-2 but had no effect on GLUT-1. We propose that the effectors, EGF, TGF-beta and basement membrane components, play a significant role in the regulation of expression of GLUT-1 and GLUT-2 in hepatocytes.

Growth-dependent inhibition of CCAAT enhancer-binding protein (C/EBP alpha) gene expression during hepatocyte proliferation in the regenerating liver and in culture

As an approach to understanding physiological mechanisms that control the proliferation of highly differentiated cells, we are addressing whether certain hepatic transcription factors participate in mechanisms that control the growth of hepatocytes. We have focused on CCAAT enhancer-binding protein (C/EBP alpha), a transcription factor which is highly abundant in normal liver and is considered to regulate expression of many genes, including some involved in energy metabolism (S. L. McKnight, M. D. Lane, and S. Gluecksohn-Walsh. Genes Dev. 3:2021-2024, 1989). Using Northern (RNA) blot analysis, we have examined the expression of C/EBP alpha mRNA during liver regeneration and in primary cultures of hepatocytes. C/EBP alpha mRNA levels decrease 60 to 80% within 1 to 3 h after partial hepatectomy as the cells move from G0 to G1 and decrease further when cells progress into S phase. Run-on transcription analysis is in agreement with the Northern blot data, thus suggesting that C/EBP alpha is transcriptionally regulated in regenerating liver. C/EBP alpha mRNA expression also decreases dramatically during the growth of freshly isolated normal hepatocytes cultured under conventional conditions (on dried rat tail collagen; stimulated to proliferate by epidermal growth factor [EGF] and insulin). Cultures of hepatocytes on rat tail collagen in the presence or absence of EGF clearly show that within 3 h, EGF depresses C/EBP alpha mRNA expression and that this effect is substantially greater by 4 h. Inhibition of protein synthesis in the liver by cycloheximide or in cultured hepatocytes by puromycin or cycloheximide effectively blocks the down-regulation of C/EBP alpha gene expression, apparently by stabilizing the normal rapid turnover of the C/EBP alpha mRNA (half-life of <2 h). This drop in C/EBP alpha gene expression in response to activation of hepatocyte growth is consistent with the proposal that C/EBP alpha has an antiproliferative role to play in highly differentiated cells (R. M. Umek, A. D. Friedman, and S. L. McKnight, Science 251: 288-292, 1991).

A national outbreak of Salmonella typhimurium DT 124 caused by contaminated salami sticks

An outbreak of Salmonella typhimurium DT 124 infection which affected 101 people in England in December 1987 and January 1988 was detected through surveillance of laboratory reports from medical microbiology laboratories of the NHS and PHLS. Within 1 week of noting the increase in reports, epidemiological and microbiological investigations identified a small German salami stick as the vehicle of infection and the product was withdrawn from sale. The epidemiological investigation highlighted the occurrence of a long incubation period, bloody diarrhoea. Prompt recognition and investigation of the outbreak prevented further cases of severe infection.