Differential tumor and normal mucosa biomarker modulation by epidermal growth factor receptor (EGFR) inhibition using erlotinib in oral cavity squamous cell carcinoma (OCSCC)

6077

Background: Targeted therapy may improve the therapeutic index in locally advanced head neck cancer if differential EGFR inhibition in tumors compared to the normal mucosa is demonstrated. Based on prior published data, EGFR degradation is an important biomarker of cytotoxicity in a preclinical model. The aim of this pilot study was to determine if there are differences in biomarker modulation between tumor and the normal mucosa and confirm our initial preclinical findings regarding EGFR degradation. Methods: Patients with primary OCSCC requiring surgical resection had normal mucosa and tumor biopsies prior to a test course of erlotinib. Patients received one week of erlotinib 150 mg qd. Repeat tumor and normal mucosal biopsies were obtained at the time of surgical resection to evaluate the effect of the EGFR inhibitor on both tumor and the normal mucosa. Changes in known preclinical markers of EGFR activity (phospho, total EGFR, AKT, STAT3) were measured by immunoblotting assays. In addition, changes in distribution of these biomarkers were analyzed by immunohistochemical analysis. Results: 12 pts were enrolled; 7 pts with paired tumor and normal mucosa biopsies. Tumor specimens showed over-expression of EGFR compared to the normal mucosa (p = 0.005). Erlotinib treatment led to marked inhibition of both pEGFR and EGFR protein (p = 0.004 and p = 0.007, respectively) in tumor biopsies. In contrast, we found heterogeneity in EGFR inhibition in the normal mucosa following erlotinib. (p = 0.1 [pEGFR], and p = 0.07 [EGFR)]) We noted dramatic reduced levels of pSrc and pSTAT3 following erlotinib in tumors compared to untreated matched tumor samples. In addition, levels of p27 were enhanced. Conclusions: Differential EGFR inhibition in tumors compared to the normal mucosa, may suggest that the addition of EGFR inhibitors to chemo-RT or accelerated RT, whose dose limiting toxicity is acute mucositis, may select patients who will benefit from targeted therapy. Our results demonstrate that EGFR inhibition by erlotinib led to marked reduction in EGFR protein levels. EGFR degradation may be an important biomarker in selecting patients predicted to have a response to TKI. These results need further validation.

No significant financial relationships to disclose.

The polished tri-tapered stem for cement-in-cement revision hip arthroplasty, a reliable and reproducible technique?

The object of this study was to determine the short to medium term outcome of cementing a highly polished tapered implant into the old cement mantle once damaged cement is removed at the time of revision hip surgery. A consecutive series of 36 patients underwent c-stem cement-in-cement revision hip arthroplasty between June 2000 and April 2006. The primary outcome measure was the validated shortened Western Ontario and McMaster Universities (WOMAC) score, secondary outcomes were the Orthowave company patient satisfaction survey, radiological analysis, and general complications. The follow-up period was between 12 and 84 months (average 48.86 months). The mean post op WOMAC score at latest follow-up was 10.89 (0 to 29). Two patients died with their hip in situ. Two patients had radiological signs of prosthesis loosening on follow-up. Complications included: one sacral plexus palsy which had a partial recovery and one intra-operative periprosthetic fracture. One patient underwent cup revision for recurrent dislocation. Cement within cement revision hip arthroplasty using a highly polished tapered stem in the short to medium term provides satisfactory functional outcomes and is associated with a low complication rate and good survivorship.

Reactive synovitis following hip resurfacing: a case presentation

We report a case of metal-on-metal hip resurfacing complicated by a reactive synovitis and a large effusion resulting in dislocation, peripheral oedema and groin discomfort. Histological analysis of the retrieved specimens revealed an intense lymphocytosis. Conversion to a traditional hip replacement resulted in resolution of the symptoms.

Recurrent total hip arthroplasty dislocation in combination with massive osteolysis: an outline of management using a proximal femoral replacement

Recurrent dislocation of a total hip arthroplasty is a most distressing complication for both patient and surgeon. The situation is worsened when massive osteolysis occurs in combination with recurrent dislocation. Management options become more limited in this situation. We present such a case along with a discussion of the management options utilised.

IKKalpha in the regulation of inflammation and adaptive immunity

Inflammation is a beneficial response to insult or injury which plays an important role in orchestrating the adaptive immune response. The resolution of acute inflammation is an active process that involves the release of anti-inflammatory mediators and the termination of pro-inflammatory signalling pathways coincident with leucocyte apoptosis and phagocytic clearance and the migration of antigen-presenting cells from the site of inflammation to the local lymphatic tissue. The latter process is required for the development of adaptive immunity and immunological memory. The NF-kappaB (nuclear factor kappaB) pathway is an important regulator of inflammation and immunity; NF-kappaB activation is controlled by IKK [IkappaB (inhibitor of NF-kappaB) kinase] complex, which regulates NF-kappaB activation in response to pro-inflammatory stimuli. The IKK complex has two catalytic subunits, IKKalpha and IKKbeta; recent research shows that these highly homologous kinases have distinct roles in inflammation and adaptive immunity. Here, we discuss the emerging roles for IKKalpha in the tight regulation of inflammation and the development of adaptive immune responses.

Circulating molecular markers in predicting radiation-induced lung damage

7144

Background: We hypothesized that circulating molecular markers such as transforming growth factor-beta1 (TGF-β1), interleukin-6 (IL-6), and angiotensin-converting enzyme (ACE) change early during the course of radiotherapy (RT), and that such changes precede RILD after completion of the therapy. Methods and Materials: Patients with stage I-III NSCLC treated with RT (11) or chemoRT (15) (enrolled onto two prospective clinical trials) were included in this study. Serum and platelet poor plasma were obtained prior to (Pre-RT), at 40–50 Gy (during-RT), and at the end of RT (end-RT). The plasma TGF-β1 and IL-6 and serum ACE levels were measured using molecule specific enzyme-linked immunosorbent assays. The endpoints for RILD were ≥ grade 2 radiation pneumonitis (RP) and measures of pulmonary function tests such as forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV1), and diffusing capacity for carbon monoxide (DLCO). The minimal follow-up duration was 3 months. Data is presented as mean ± standard deviation; student t-test was used for significant analysis. Results: Plasma TGF-β1 and IL-6 levels changed remarkably after 40–50 Gy of RT. The mean relative TGF-β1 levels (during-RT over pre-RT) were 1.9 ± 0.9 and 0.9 ± 0.6 in patients with and without RP (p = 0.010), respectively. There were no significant associations between changes of plasma IL-6 and ACE levels and the occurrence of RP. Significant DLCO reduction was observed at 3 months after RT in almost every patient, and such reduction was significantly more remarkable in those who had radiation induced elevation in plasma IL-6 levels (34.8 ± 15.9% versus 15.6 ± 14.5%, p = 0.045). Interestingly, the pre-RT ACE level was significantly associated with changes of FEV1 (p = 0.037) and FVC (p = 0.014): improvement of 13.2 ± 12.0% and 11.0 ± 9.0% versus reduction of 7.6 ± 17.0% and 10.8 ± 17.7% for patients with high versus low levels, respectively. Conclusion: Radiation induced elevation in circulating TGF-β1 and IL-6 levels may be predictive of RILD, while serum ACE level may be associated with decreased risk of RILD.

No significant financial relationships to disclose.

Intracapsular hip fractures in end-stage renal failure

Patients with end-stage renal failure (ESRF) have metabolic bone disease. This increases the risk of femoral neck fracture and increases the risk of complications associated with fracture fixation such as non-union and avascular necrosis (AVN). We report the results of treatment in a consecutive series of 15 intracapsular fractures of the hip occurring in 13 patients with ESRF over a 5-year period. Six intracapsular hip fractures (of which five were undisplaced) were treated by internal fixation. Five out of these six (mean=83.3%) required conversion to total hip arthroplasty because of non-union or AVN. In all six of these patients, internal fixation was considered adequate post operatively. Of the remaining nine intracapsular hip fractures treated by hemiarthroplasty, only one required conversion to total hip arthroplasty because of stem subsidence (mean=11%). The difference in the revision rate for the two groups i.e. primary fixation versus primary hemiarthroplasty was statistically significant (p-value=0.01). The six patients with undisplaced intracapsular fractures treated by internal fixation required a total of 14 major operations, at an average rate (including initial fracture fixation and revision surgery) of 2.3 per patient. The 9 displaced fractures treated by hemiarthroplasty required just 10 operations in total, at an average rate of 1.1 per patient. (The difference was significant; p-value=0.006.) The 1-year mortality in the whole group (13 patients with 15 fractures) was 44.4%. We suggest that patients with ESRF with an intracapsular fracture of the neck of femur should be treated by replacement arthroplasty irrespective of femoral head displacement because of the high risk of revision surgery associated with internal fixation.

Early failure modalities in hip resurfacing?

Between 1996 and 2002, we treated 60 patients (65 hips) by hip resurfacing. The notes and radiographs of these cases were studied retrospectively and the modalities of failure identified. At a mean follow-up of 51 months, 14 of these cases (22%) required revision surgery. One patient had died from unrelated causes and one was lost to follow-up. At the time of primary surgery, the mean age of the patients in our series was 55 years. The commonest mechanism of failure in our series was fractured neck of femur (six cases). Four of these occurred in females over the age of 60. None of the fractured necks of femur were associated with trauma. There were four cases of loose acetabular components and one case of progressive AVN (avascular necrosis). Two patients required revision surgery for ongoing hip pain and one required a twostage revision for early deep infection. (Hip International 2005; 15: 155-8).

Evaluating changes in tumor volume using magnetic resonance imaging during the course of radiotherapy treatment of high-grade gliomas: Implications for conformal dose-escalation studies

OBJECTIVE

To determine whether changes in tumor volume occur during the course of conformal 3D radiotherapy of high-grade gliomas by use of magnetic resonance imaging (MRI) during treatment and whether these changes had an impact on tumor coverage.

METHODS AND MATERIALS

Between December 2000 and January 2004, 21 patients with WHO Grades 3 to 4 supratentorial malignant gliomas treated with 3D conformal radiotherapy (median dose, 70 Gy) were enrolled in a prospective clinical study. All patients underwent T1-weighted contrast-enhancing and T2-weighted and fluid-attenuated inversion recovery (FLAIR) imaging at approximately 1 to 2 weeks before radiotherapy, during radiotherapy (Weeks 1 and 3), and at routine intervals thereafter. All MRI scans were coregistered to the treatment-planning CT. Gross tumor volume (GTV Pre-Rx) was defined from a postoperative T1-weighted contrast-enhancing MRI performed 1 to 2 weeks before start of radiotherapy. A second GTV (GTV Week 3) was defined by use of an MRI performed during Week 3 of radiotherapy. A uniform 0.5 cm expansion of the respective GTV, PTV (Pre-Rx), and PTV (Week 3) was applied to the final boost plan. Dose-volume histograms (DVH) were used to analyze any potential adverse changes in tumor coverage based on Week 3 MRI.

RESULTS

All MRI scans were reviewed independently by a neuroradiologist (DGH). Two patients were noted to have multifocal disease at presentation and were excluded from analysis. In 19 cases, changes in the GTV based on MRI at Week 3 during radiotherapy were as follows: 2 cases had an objective decrease in GTV (> or =50%); 12 cases revealed a slight decrease in the rim enhancement or changes in cystic appearance of the GTV; 2 cases showed no change in GTV; and 3 cases demonstrated an increase in tumor volume. Both cases with objective decreases in GTV during treatment were Grade 3 tumors. No cases of tumor progression were noted in Grade 3 tumors during treatment. In comparison, three of 12 Grade 4 tumors had tumor progression, based on MRI obtained during Week 3 of radiotherapy. Median increase in GTV (Week 3) was 11.7 cc (range, 9.8-21.3). Retrospective DVH analysis of PTV (Pre-Rx) and PTV (Week 3) demonstrated a decrease in V(95%)(PTV volume receiving 95% of the prescribed dose) in those 3 cases.

CONCLUSIONS

Routine MR imaging during radiotherapy may be essential in ensuring tumor coverage if highly conformal radiotherapy techniques such as stereotactic boost and intensity-modulated radiotherapy are used in dose-escalation trials that utilize smaller treatment margins.

A cluster randomised controlled trial of smoking cessation in pregnant women comparing interventions based on the transtheoretical (stages of change) model to standard care

OBJECTIVES

To evaluate the effectiveness in helping pregnant women stop smoking of two interventions (Pro-Change for a healthy pregnancy) based on the transtheoretical model of behaviour change (TTM) compared to current standard care.

DESIGN

Cluster randomised trial.

SETTING

Antenatal clinics in West Midlands, UK general practices.

PARTICIPANTS

918 pregnant smokers

INTERVENTIONS

100 general practices were randomised into the three trial arms. Midwives in these practices delivered three interventions: A (standard care), B (TTM based self help manuals), and C (TTM based self help manuals plus sessions with an interactive computer program giving individualised smoking cessation advice).

MAIN OUTCOME MEASURES

Biochemically confirmed smoking cessation for 10 weeks previously, and point prevalence abstinence, both measured at 30 weeks of pregnancy and 10 days after delivery.

RESULTS

There were small differences between the TTM arms. Combining the two arms, the odds ratios at 30 weeks were 2.09 (95% confidence interval (CI) 0.90 to 4.85) for 10 week sustained abstinence and 2.92 (95% CI 1.42 to 6.03) for point prevalence abstinence relative to controls. At 10 days after delivery, the odds ratios were 2.81 (95% CI 1.11 to 7.13) and 1.85 (95% CI 1.00 to 3.41) for 10 week and point prevalence abstinence respectively.

CONCLUSIONS

While there is a small borderline significant increase in quitting in the combined intervention arms compared with the controls, the effect of the intervention is small. At 30 weeks gestation and at 10 days postnatal, only about 3% of the intervention groups achieved sustained cessation, with numbers needed to treat of 67 (30 weeks of gestation) and 53 (10 weeks postnatal) for one additional woman to achieve sustained confirmed cessation. Given also that the intervention was resource intensive, it is of doubtful benefit.

An unusual neurological complication following internal fixation of pertrochanteric fracture neck of the femur

Fracture of the femoral neck is a common injury in the elderly population and may be associated with significant morbidity. More than 25,000 patients per year in the UK receive treatment for femoral neck fractures. Neurological injury associated with pertrochanteric fracture of the neck of the femur is rare. Sciatic nerve injury following isolated pertrochanteric femoral neck fractures is very rare and has not previously been reported in the literature. We describe a case of foot drop secondary to sciatic nerve injury following fracture of neck of the femur, with recovery after surgical exploration and nerve release. (Hip International 2002; 4: 400-2).

Possible new role for NF-kappaB in the resolution of inflammation

Inflammation involves the sequential activation of signaling pathways leading to the production of both pro- and anti-inflammatory mediators. Although much attention has focused on pro-inflammatory pathways that initiate inflammation, relatively little is known about the mechanisms that switch off inflammation and resolve the inflammatory response. The transcription factor NF-kappaB is thought to have a central role in the induction of pro-inflammatory gene expression and has attracted interest as a new target for the treatment of inflammatory disease. We show here that NF-kappaB activation in leukocytes recruited during the onset of inflammation is associated with pro-inflammatory gene expression, whereas such activation during the resolution of inflammation is associated with the expression of anti-inflammatory genes and the induction of apoptosis. Inhibition of NF-kappaB during the resolution of inflammation protracts the inflammatory response and prevents apoptosis. This suggests that NF-kappaB has an anti-inflammatory role in vivo involving the regulation of inflammatory resolution.

Radiosensitization of p53 mutant cells by PD0166285, a novel G(2) checkpoint abrogator

The lack of functional p53 in many cancer cells offers a therapeutic target for treatment. Cells lacking p53 would not be anticipated to demonstrate a G(1) checkpoint and would depend on the G(2) checkpoint to permit DNA repair prior to undergoing mitosis. We hypothesized that the G(2) checkpoint abrogator could preferentially kill p53-inactive cancer cells by removing the only checkpoint that protects these cells from premature mitosis in response to DNA damage. Because Wee1 kinase is crucial in maintaining G(2) arrest through its inhibitory phosphorylation of Cdc2, we developed a high-throughput mass screening assay and used it to screen chemical library for Wee1 inhibitors. A pyridopyrimidine class of molecule, PD0166285 was identified that inhibited Wee1 at a nanomolar concentration. At the cellular level, 0.5 microM PD0166285 dramatically inhibits irradiation-induced Cdc2 phosphorylation at the Tyr-15 and Thr-14 in seven of seven cancer cell lines tested. PD0166285 abrogates irradiation-induced G(2) arrest as shown by both biochemical markers and fluorescence-activated cell sorter analysis and significantly increases mitotic cell populations. Biologically, PD0166285 acts as a radiosensitizer to sensitize cells to radiation-induced cell death with a sensitivity enhancement ratio of 1.23 as shown by standard clonogenic assay. This radiosensitizing activity is p53 dependent with a higher efficacy in p53-inactive cells. Thus, G(2) checkpoint abrogators represent a novel class of anticancer drugs that enhance cell killing of conventional cancer therapy through the induction of premature mitosis.

The change-in-stage and updated smoking status results from a cluster-randomized trial of smoking prevention and cessation using the transtheoretical model among British adolescents

BACKGROUND

The transtheoretical model (TTM) and computer technology are promising technologies for changing health behavior, but there is little evidence of their effectiveness among adolescents.

METHOD

Four thousand two hundred twenty-seven Year 9 (ages 13-14) pupils in 26 schools were randomly allocated to control and 4,125 in 26 schools were allocated to TTM intervention. TTM pupils received three whole class lessons and three sessions with an interactive computer program. Control pupils received no special intervention. Positive change in stage and smoking status was assessed from a questionnaire completed at baseline, 1 year, and 2 years. Random effects logistic regression was used to compare the change in stage and smoking status between the arms.

RESULTS

Eighty-nine percent of the TTM group and 89.3% of the control group were present at 1-year and 86.0 and 83.1%, respectively, were present at 2-year follow-up. The adjusted odds ratio (95% confidence interval) for positive stage movement in the TTM relative to control was 1.13 (0.91-1.41) at 1 year and 1.25 (0.95-1.64) at 2 years and for regular smoking was 1.14 (0.93-1.39) at 1 year and 1.06 (0.86-1.31) at 2 years. Subgroup analysis by initial smoking status revealed no benefit for prevention or cessation.

CONCLUSIONS

The intervention was ineffective.

Determination of ventilatory liver movement via radiographic evaluation of diaphragm position

PURPOSE

To determine the accuracy of estimation of liver movement inferred by observing diaphragm excursion on radiographic images.

METHODS AND MATERIALS

Eight patients with focal liver cancer had platinum embolization microcoils implanted in their livers during catheterization of the hepatic artery for delivery of regional chemotherapy. These patients underwent fluoroscopy, during which normal breathing movement was recorded on videotape. Movies of breathing movement were digitized, and the relative projected positions of the diaphragm and coils were recorded. For 6 patients, daily radiographs were also acquired during treatment. Retrospective measurements of coil position were taken after the diaphragm was aligned with the superior portion of the liver on digitally reconstructed radiographs.

RESULTS

Coil movement of 4.9 to 30.4 mm was observed during normal breathing. Diaphragm position tracked inferior-superior coil displacement accurately (population sigma 1.04 mm) throughout the breathing cycle. The range of coil movement was predicted by the range of diaphragm movement with an accuracy of 2.09 mm (sigma). The maximum error observed measuring coil movement using diaphragm position was 3.8 mm for a coil 9.8 cm inferior to the diaphragm. However, the distance of the coil from the top of the diaphragm did not correlate significantly with the error in predicting liver excursion. Analysis of daily radiographs showed that the error in predicting coil position using the diaphragm as an alignment landmark was 1.8 mm (sigma) in the inferior-superior direction and 2.2 mm in the left-right direction, similar in magnitude to the inherent uncertainty in alignment.

CONCLUSIONS

This study demonstrated that the range of ventilatory movement of different locations within the liver is predicted by diaphragm position to an accuracy that matches or exceeds existing systems for ventilatory tracking. This suggests that the diaphragm is an acceptable anatomic landmark for radiographic estimation of liver movement in anterior-posterior projections for most patients.

Altered entrainment and feedback loop function effected by a mutant period protein

The period (per) and timeless (tim) genes encode interacting components of the circadian clock. Levels and phosphorylation states of both proteins cycle with a circadian rhythm, and the proteins drive cyclic expression of their RNAs through a feedback mechanism that is, at least in part, negative. We report here that a hypophosphorylated mutant PER protein, produced by creating a small internal deletion, displays increased stability and low-amplitude oscillations, consistent with previous reports that phosphorylation is required for protein turnover. In addition, this protein appears to be defective in feedback repression because it is associated with relatively high levels of RNA and high levels of TIM. Transgenic flies carrying the mutant PER protein display a temperature-dependent shortening of circadian period and are impaired in their response to light, particularly to pulses of light in the late night that normally advance the phase of the rhythm. Interestingly, per RNA is induced by light in these flies, most likely because of the removal of the light-sensitive TIM protein, thus implicating a more direct role for TIM in transcriptional inhibition. These data have relevance for mechanisms of feedback repression, and they also address existing models for the differential behavioral response to light at different times of the night.

Cluster randomised controlled trial of expert system based on the transtheoretical ("stages of change") model for smoking prevention and cessation in schools

OBJECTIVES

To examine whether a year long programme based on the transtheoretical model of behaviour change, incorporating three sessions using an expert system computer program and three class lessons, could reduce the prevalence of teenage smoking.

DESIGN

Cluster randomised trial comparing the intervention to a control group exposed only to health education as part of the English national curriculum.

SETTING

52 schools in the West Midlands region.

PARTICIPANTS

8352 students in year 9 (age 13-14 years) at those schools.

MAIN OUTCOME MEASURES

Prevalence of teenage smoking 12 months after the start of the intervention.

RESULTS

Of the 8352 students recruited, 7444 (89.1%) were followed up at 12 months. The intention to treat odds ratio for smoking in the intervention group relative to control was 1.08 (95% confidence interval 0.89 to 1.33). Sensitivity analysis for loss to follow up and adjustment for potential confounders did not alter these findings.

CONCLUSIONS

The smoking prevention and cessation intervention based on the transtheoretical model, as delivered in this trial, is ineffective in schoolchildren aged 13-14.

Analysis of routine histological evaluation of tissues removed during primary hip and knee arthroplasty

BACKGROUND

It has often been hospital policy to send all resected specimens obtained during a total hip or knee arthroplasty for histological evaluation. This practice is expensive and may be unnecessary. We sought to determine the ability of surgeons to diagnose primary joint conditions correctly, and we attempted to identify any possible risks to the patient resulting from the omission of routine histological evaluation of specimens at the surgeon's discretion. Our objective was to ascertain whether routine histological evaluation could be safely omitted from the protocol for primary hip and knee arthroplasty without compromising the care of the patient.

METHODS

A total of 1388 consecutive arthroplasties in 1136 patients were identified from a database of primary total hip and knee arthroplasties that was prospectively maintained by the senior one of us. Follow-up data obtained at a mean of 5.5 years (range, two to ten years) were available after 92 percent (1273) of the 1388 arthroplasties. The preoperative diagnosis was determined from the history, findings on clinical examination, and radiographs. The intraoperative diagnosis was determined by gross inspection of joint fluid, articular cartilage, synovial tissue, and the cut surfaces of resected specimens. The combination of the preoperative and intraoperative diagnoses was considered to be the surgeon's clinical diagnosis. All resected specimens were sent for routine histological evaluation, and a pathological diagnosis was made. Attention was given to whether a discrepancy between the surgeon's clinical diagnosis and the pathological diagnosis altered the management of the patient. The original diagnoses were updated with use of annual radiographs and clinical assessments. The cost of histological examination of specimens obtained at arthroplasty was determined by consultation with hospital administration, accounting, and pathology department personnel.

RESULTS

A pathological fracture or an impending fracture was diagnosed preoperatively and confirmed intraoperatively during twelve of the 1388 arthroplasties. Histological analysis demonstrated malignancy in specimens obtained during eleven of these arthroplasties and evidence of a benign rheumatoid geode in the specimen obtained during the twelfth arthroplasty. The preoperative and intraoperative diagnoses made before and during the remaining 1376 arthroplasties were benign conditions, which were confirmed histologically in all patients. No diagnosis changed during the follow-up period. As demonstrated by a comparison with the histological diagnosis, the surgeon's clinical diagnosis of malignancy had a sensitivity of 100 percent (95 percent confidence interval, 74.0 to 100 percent), a specificity of 99.9 percent (95 percent confidence interval, 99.6 to 100 percent), a positive predictive value of 91.7 percent (95 percent confidence interval, 64.6 to 98.5 percent), and a negative predictive value of 100 percent (95 percent confidence interval, 99.7 to 100 percent). There was a discrepancy between the preoperative and intraoperative diagnoses associated with eleven arthroplasties. All eleven intraoperative diagnoses were correct, as confirmed histologically. Excluding the patients who had a pathological or impending fracture, the accuracy of the surgeon's preoperative diagnosis was 99.2 percent (95 percent confidence interval, 98.6 to 99.5 percent). When the intraoperative and preoperative diagnoses were combined, the accuracy was 100 percent (95 percent confidence interval, 99.7 to 100 percent). Histological evaluation at our hospital resulted in total charges, including hospital costs and professional fees, of $196.27 and a mean total reimbursement of $102.59 per evaluation. In our series of 1136 patients with 1388 arthroplasties, these costs could have been eliminated for all but the twelve patients who had a suspected malignant lesion and the one patient in whom pigmented villonodular synovitis was found. (ABSTRACT

Effects of TNF-alpha on [Ca2+]i and contractility in isolated adult rabbit ventricular myocytes

The mechanism of the acute negative inotropic effect of tumor necrosis factor-alpha (TNF-alpha) was studied in enzymatically isolated adult rabbit ventricular myocytes. In cells loaded with fura 2 acetoxymethyl ester (AM) and paced intermittently at 0.2 Hz, TNF-alpha at doses < or = 10,000 U/ml caused a significant reduction in active cell shortening at 20 min, without reducing the amplitude of the accompanying intracellular Ca2+ concentration ([Ca2+]i) transient. Similar results were obtained in cells loaded with indo 1-AM and paced continuously at 0.2 Hz during exposure to TNF-alpha (10,000 U/ml). The effect of TNF-alpha on cell shortening could be prevented by the nitric oxide (NO) synthase blocker NG-nitro-L-arginine methyl ester (L-NAME) but not its inactive enantiomer NG-nitro-D-arginine methyl ester (D-NAME). The NO scavenger hemoglobin also attenuated the effects of TNF-alpha. TNF-alpha also caused a significant increase in diastolic cell length without any change in diastolic [Ca2+]i. The effect on cell length was prevented by L-NAME but not D-NAME. In cells loaded with the pH indicator seminaphthorhodafluor-AM, TNF-alpha did not alter pH sufficiently to account for the negative inotropic effect. These data suggest that high doses of TNF-alpha can acutely induce NO synthesis in isolated myocytes and reduce contractility by decreasing myofilament [Ca2+]i responsiveness. The mechanism of this altered myofilament [Ca2+]i response is unknown but does not appear to be pH mediated.

A three-dimensional approach for re-irradiation of recurrent colorectal adenocarcinoma

A large number of patients with resected rectal cancer will develop a symptomatic pelvic recurrence despite previous adjuvant radiation therapy. Re-irradiation after previous high dose radiation therapy carries an increased risk of complications in the normal tissues of the pelvis. However, other treatment modalities are not likely to provide a palliative benefit. Previous studies have shown that re-irradiation may be feasible and may palliate the patient. As minimal data is available on the toxicity of additional radiation therapy, this approach would be considered only when there is no other alternative for effective therapy and in the face of progressive and severe symptoms. With the use of three dimensional (3-D) treatment planning, portals can be designed to limit dose to previously irradiated critical structures while minimizing the risk of treatment related complications.

Radial tunnel syndrome. A retrospective review of 30 decompressions of the radial nerve

Radial tunnel syndrome results from compression of the radial nerve by the free edge of the supinator muscle or closely related structures in the vicinity of the elbow joint. Despite numerous reports on the surgical management of this disorder, it remains largely unrecognized and often neglected. The symptoms of radial tunnel syndrome can resemble those of tennis elbow, chronic wrist pain or tenosynovitis. Reliable objective criteria are not available to differentiate between these pathologies. These difficulties are discussed in relation to 29 patients who underwent 30 primary explorations and proximal decompressions of the radial nerve. Excellent or good results were obtained in 70%, fair results in 13% and poor results in 17% of patients. The results can be satisfactory despite the prolonged duration of symptoms. We believe that a diagnosis of radial tunnel syndrome should always be born in mind when dealing with patients with forearm and wrist pain that has not responded to more conventional treatment. Patients with occupations requiring repetitive manual tasks seem to be particularly at risk of developing radial tunnel syndrome and it is also interesting to note that 66% of patients with on-going medico-legal claims had successful outcomes following surgery.

Late rupture of extensor pollicis longus after wrist arthroscopy

The first cases of impending rupture of the extensor pollicis longus after wrist arthroscopy are reported and the etiology is compared with extensor pollicis longus ruptures after nondisplaced or minimally displaced Colles fractures. Both cases were treated with extensor indices proprius to extensor pollicis longus transfer with good clinical results.

Treatment of polydipsia and hyponatremia in psychiatric patients. Can clozapine be a new option?

Polydipsia occurs frequently in chronic schizophrenic patients, some of whom develop intermittent hyponatremia. Most therapeutic efforts have tried to control the hyponatremia. Four schizophrenic patients, followed for more than one year, showed improvement on clozapine. Case 1 was an outpatient without history of hyponatremia who improved from polydipsia and psychosis. The last three were inpatients with polydipsia, intermittent hyponatremia, and psychosis who showed minimal improvement of psychosis but significant decrease in polydipsia and water intoxication. Case 2 relapsed to polydipsia when clozapine was discontinued on two occasions. Case 3 demonstrated polyuria during 39% of days before clozapine and in 0% of days after two weeks of clozapine. In case 4, most baseline sodium levels were abnormal, but all became normal after clozapine. A time-series analysis for intervention effects showed a significant effect of clozapine (p = .017). The limited information provided by these case reports suggest the need for controlled studies of the clozapine effect on polydipsic patients.

Traction radiographs in the diagnosis of chronic wrist pain

A sensitive non-invasive diagnostic test for intrinsic ligament rupture in patients with chronic wrist pain has still to be found. Differential displacement of the scaphoid, lunate and triquetrum can in some instances be seen during arthroscopy of acute wrist injuries and also on overdistraction of distal radial fractures with an external fixator. We performed a prospective study on 20 patients with chronic wrist pain using 2 kg and 5 kg traction radiographs without and with the addition of an ischaemic block, to assess differential displacement as a diagnostic criterion for intrinsic ligament rupture. Arthroscopy was used as arbiter of diagnosis. The sensitivity ranged from 14% to 57% and the specificity ranged from 53.7% to 100% according to the amount of traction and ischaemic block. In view of these poor results we conclude the stretch test has no additional value in the preoperative assessment of chronic wrist pain.

The stability of plasma growth hormone and MHPG responses to repeated clonidine challenge in normal males

Clonidine is a centrally acting alpha 2-adrenergic agonist used in many psychiatric studies to assess adrenergic functioning. The short- and long-term stability of plasma growth hormone (GH) and plasma 3-methoxy-4-hydroxy phenylglycol (MHPG) responses to clonidine (2 micrograms/kg IV) over a 60-min period were assessed in subsets of 13 male normal controls on 2 consecutive days (Study A; n = 11) and on 2 days separated by several months (Study B; n = 11). In Study A, no significant differences between consecutive days were found in either baseline plasma GH or MHPG or their responses to clonidine. The 60 minute plasma GH responses between consecutive days were highly correlated (r = 0.75, n = II, p < .001), while the 60 min plasma MHPG responses were not. In Study B, no significant differences in baseline plasma GH or MHPG, or their responses to clonidine challenge, were found between the 2 test days. However, neither the plasma GH responses nor the plasma MHPG responses to clonidine at 60 min correlated significantly between the 2 study days separated by several months. Both in Study-A and in Study B, 8 of 11 subjects had a stable GH response to clonidine across both study days when defined dichotomously (blunted < 4 ng/ml; otherwise, not blunted). These results suggest that the plasma GH response and plasma MHPG response to clonidine are unaffected by repeat clonidine challenge separated by 24 h, and that the plasma GH response to clonidine may be more stable over time than the plasma MHPG response to clonidine.

In vitro activities of ramoplanin, selected glycopeptides, fluoroquinolones, and other antibiotics against clinical bloodstream isolates of gram-positive cocci

The susceptibilities of 316 gram-positive bacteremic isolates to ramoplanin, vancomycin, and teicoplanin and seven other antibiotics were tested. Ramoplanin demonstrated MICs of < or = 0.25 microgram/ml for at least 99% of Staphylococcus aureus isolates and 100% of coagulase-negative staphylococci tested. For both oxacillin-susceptible and oxacillin-resistant S. aureus and coagulase-negative staphylococci, the activity of ramoplanin surpassed those of both vancomycin and teicoplanin. Ramoplanin and teicoplanin had comparable activities against enterococci and Streptococcus pneumoniae and were superior to vancomycin.