Predicting outcome of patients with high-grade gliomas after radiotherapy using quantitative analysis of T1-weighted magnetic resonance imaging

PURPOSE

The aim of this study was to test the hypothesis that measuring quantitative changes in signal intensity early after radiotherapy (RT) in the contrast-enhancing tumor rim and nonenhancing core may be a noninvasive marker of early treatment response in patients with high-grade gliomas.

METHODS AND MATERIALS

Twenty patients with high-grade gliomas had magnetic resonance imaging (MRI) performed 1 week before RT, during Weeks 1 and 3 of RT, and every 1 to 3 months after RT as part of a clinical prospective study. Regions of interest (ROI) including contrast-enhancing rim, and the nonenhancing core were defined automatically based on a calculated image of post- to precontrast T1-weighted MRI. Pretreatment T1-weighted MRI signal intensity changes were compared with Weeks 1 and 3 RT and 1 and 3 months post-RT MRI. Clinical and MRI parameters were then tested for prediction of overall survival.

RESULTS

Regional T1-weighted signal intensity changes in both the contrast-enhancing rim and the nonenhancing core were observed in all patients during Week 1 and Week 3 of RT. Imaging parameters including signal intensity change within the nonenhancing core after Weeks 1 to 2 RT (p = 0.004), Weeks 3 to 4 RT (p = 0.002) and 1 month after completion of RT (p = 0.002) were predictive of overall survival. Using multivariate analysis including RTOG recursive partitioning analysis (RPA) and signal intensity change, only the signal intensity change in the nonenhancing core at 1 month after RT (p = 0.01) retained significance.

CONCLUSION

Quantitative measurements of T1-weighted MRI signal intensity changes in the nonenhancing tumor core (using ratios of pre-post values) may provide valuable information regarding early response during treatment and improve our ability to predict posttreatment outcome.

Designing dose-escalation trials with late-onset toxicities using the time-to-event continual reassessment method

PURPOSE

The standard design for phase I trials of combined chemotherapy and radiation, which enters either three or six patients per dose level, has little statistical basis and is subject to opening and closing because of delayed toxicities that disrupt patient accrual. We compared the operating characteristics of this standard design and the time-to-event continual reassessment method (TITE-CRM) for dose-escalation trials of combination chemotherapy and radiation.

METHODS

The operating characteristics were determined by Monte Carlo simulation of 60,000 phase I trials.

RESULTS

Compared with the standard trial design, in studies with delayed toxicity (ie, where four or more patients are expected to enter onto the study during a single previously enrolled patient's observation for toxicity), TITE-CRM trials are significantly shorter when toxicity observation times are long, treat more patients at or above the maximum-tolerated dose, identify the maximum-tolerated dose (MTD) more accurately, and provide phase II information, but do not expose patients to significant additional risk. Estimation precision and overdose control of TITE-CRM increase as the design assumptions more closely resemble the true state of nature, but are reduced if, for instance, the toxicity of treatment has been grossly underestimated.

CONCLUSION

Compared with the standard design, if there is any prior knowledge concerning the toxicity profile of a treatment, TITE-CRM can leverage it to produce more accurate estimates of the MTD and does not expose patients to significant excess risk, but requires timely communication between clinical investigators, data managers, and study statisticians.

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.

(−)-Gossypol enhances response to radiation therapy and results in tumor regression of human prostate cancer

Radioresistance markedly impairs the efficacy of tumor radiotherapy and involves antiapoptotic signal transduction pathways that prevent radiation-induced cell death. The majority of human prostate cancers overexpress the important antiapoptotic proteins Bcl-2 and/or Bcl-xL, which render tumors resistant to radiation therapy. (−)-Gossypol, a natural polyphenol product from cottonseed, has recently been identified as a potent small molecule inhibitor of both Bcl-2 and Bcl-xL. In the current study, we investigated the antitumor activity of (−)-gossypol in prostate cancer and tested our hypothesis that (−)-gossypol may improve prostate cancer's response to radiation by potentiating radiation-induced apoptosis and thus making cancer cells more sensitive to ionizing radiation. Our data show that (−)-gossypol potently enhanced radiation-induced apoptosis and growth inhibition of human prostate cancer PC-3 cells, which have a high level of Bcl-2/Bcl-xL proteins. Our in vivo studies using PC-3 xenograft models in nude mice show that orally given (−)-gossypol significantly enhanced the antitumor activity of X-ray irradiation, leading to tumor regression in the combination therapy. In situ terminal deoxynucleotidyl transferase–mediated nick end labeling staining showed that significantly more apoptotic cells were induced in the tumors treated with (−)-gossypol plus radiation than either treatment alone. Anti-CD31 immunohistochemical staining indicates that (−)-gossypol plus radiation significantly inhibited tumor angiogenesis. Our results show that the natural polyphenol inhibitor of Bcl-2/Bcl-xL, (−)-gossypol, can radiosensitize prostate cancer in vitro and in vivo without augmenting toxicity. (−)-Gossypol may improve the outcome of current prostate cancer radiotherapy and represents a promising novel anticancer regime for molecular targeted therapy of hormone-refractory prostate cancer with Bcl-2/Bcl-xL overexpression.

(-)-Gossypol enhances response to radiation therapy and results in tumor regression of human prostate cancer

Radioresistance markedly impairs the efficacy of tumor radiotherapy and involves antiapoptotic signal transduction pathways that prevent radiation-induced cell death. The majority of human prostate cancers overexpress the important antiapoptotic proteins Bcl-2 and/or Bcl-xL, which render tumors resistant to radiation therapy. (-)-Gossypol, a natural polyphenol product from cottonseed, has recently been identified as a potent small molecule inhibitor of both Bcl-2 and Bcl-xL. In the current study, we investigated the antitumor activity of (-)-gossypol in prostate cancer and tested our hypothesis that (-)-gossypol may improve prostate cancer's response to radiation by potentiating radiation-induced apoptosis and thus making cancer cells more sensitive to ionizing radiation. Our data show that (-)-gossypol potently enhanced radiation-induced apoptosis and growth inhibition of human prostate cancer PC-3 cells, which have a high level of Bcl-2/Bcl-xL proteins. Our in vivo studies using PC-3 xenograft models in nude mice show that orally given (-)-gossypol significantly enhanced the antitumor activity of X-ray irradiation, leading to tumor regression in the combination therapy. In situ terminal deoxynucleotidyl transferase-mediated nick end labeling staining showed that significantly more apoptotic cells were induced in the tumors treated with (-)-gossypol plus radiation than either treatment alone. Anti-CD31 immunohistochemical staining indicates that (-)-gossypol plus radiation significantly inhibited tumor angiogenesis. Our results show that the natural polyphenol inhibitor of Bcl-2/Bcl-xL, (-)-gossypol, can radiosensitize prostate cancer in vitro and in vivo without augmenting toxicity. (-)-Gossypol may improve the outcome of current prostate cancer radiotherapy and represents a promising novel anticancer regime for molecular targeted therapy of hormone-refractory prostate cancer with Bcl-2/Bcl-xL overexpression.

Vessel-sparing prostate radiotherapy: Dose limitation to critical erectile vascular structures (internal pudendal artery and corpus cavernosum) defined by MRI

PURPOSE

Most evidence suggests that impotence after prostate radiation therapy has a vascular etiology. The corpus cavernosum (CC) and the internal pudendal artery (IPA) are the critical vascular structures related to erectile function. This study suggests that it is feasible to markedly decrease radiation dose to the CC and the IPA and directly determine the impact of dose limitation on potency.

METHODS AND MATERIALS

Twenty-five patients (10 external beam, 15 brachytherapy) underwent MRI/CT-based treatment planning for prostate cancer. In addition, 10 patients entered on the vessel-sparing protocol underwent a time-of-flight MRI angiography sequence to define the IPA. The distance from the MRI-defined prostate apex to the penile bulb (PB), CC, and IPA was measured and compared to the distance from the CT-defined apex. Doses (D5 and D50) to the PB, CC, and IPA were determined for an 80 Gy external beam course. In 5 patients, CT plans were generated and compared to MRI-based plans.

RESULTS

The combination of coronal, sagittal, and axial MRI data sets allowed superior definition of the prostate apex and its relationship to critical vascular structures. The apex to PB distance averaged 1.45 cm (0.36 standard deviation) with a range of 0.7 cm to 2.1 cm. Peak dose (D5) to the proximal CC in the MRI-planned 80 Gy course was 26 (9) Gy (0.36 of CT-planned dose), and peak dose to the IPA was 39 (13) Gy (0.61 of CT-planned dose).

CONCLUSION

The distance between the prostate apex and critical vascular structures is highly variable. Current empiric rules for CT contouring (apex 1.5 cm above PB) overestimate or underestimate the distance between the prostate apex and critical vascular structures. When defined by MRI T2 and MRI angiogram with CT registration, limitation of dose to critical erectile structures is possible, with a more significant gain than has been previously reported using dose limitation by commonly applied intensity modulated radiation therapy studies based on CT imaging. These techniques make "vessel-sparing" prostate radiotherapy feasible.

Phase I Trial Using a Time-to-Event Continual Reassessment Strategy for Dose Escalation of Cisplatin Combined With Gemcitabine and Radiation Therapy in Pancreatic Cancer

Purpose

The primary objective of this study was to determine the maximum-tolerated dose of cisplatin that could be added to full-dose gemcitabine and radiation therapy (RT) in patients with pancreatic cancer.

Patients and Methods

Nineteen patients were treated. Gemcitabine 1,000 mg/m2 was administered over 30 minutes on days 1, 8, and 15 of a 28-day cycle. Cisplatin followed gemcitabine on days 1 and 15. The initial dose level of cisplatin was 30 mg/m2, escalated to a targeted dose of 50 mg/m2 using Time-to-Event Continual Reassessment Method. RT was initiated on cycle 1, day 1, in 2.4 Gy fractions to a total dose of 36 Gy. A second cycle of chemotherapy was planned following a 1-week rest.

Results

Four of eight patients experienced acute dose limiting toxicity at the 50 mg/m2 cisplatin dose level. Patients treated at 30 and 40 mg/m2 cisplatin dose level tolerated therapy without dose-limiting toxicity. Median survival was 10.7 months (95% CI, 5.4 to 18.2) for all patients, and 12.9 months (95% CI, 7.4 to 21.2) for those without metastasis.

Conclusion

Cisplatin at doses up to 40 mg/m2 may be safely added to full-dose gemcitabine and conformal RT. The Time-to-Event Continual Reassessment Method trial design allowed rapid completion of the study and confidence in the conclusion about the maximum tolerated dose, but accrued more patients to a dose level above the maximum tolerated dose than the typical phase I design. Local and systemic disease control and survival in this study cohort supports further investigation of gemcitabine-based RT and combination chemotherapy in this disease.

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.

The growth hormone response to clonidine in acute and remitted depressed male patients

The growth hormone (GH) response to clonidine was evaluated in 28 acutely depressed male patients, 17 remitted depressed patients, and 26 normal control subjects. The GH response to clonidine was blunted (delta less than 4 ng/ml) in a significantly increased proportion of both acute and remitted patients compared to control subjects. Covarying for age effects, the GH response to clonidine (as area-under-the-curve) was not significantly different between any of the three groups, but was significantly diminished in both the acute and remitted depressed patients who were ever hospitalized for an episode of depression, compared to control subjects. Six patients studied in both the acute and remitted states were blunted in both states. These findings could not be accounted for by other clinical and demographic variables including weight, time off antidepressants, severity of current depressive symptoms, and subtype of depression. These results raise the possibility that the blunted GH response to clonidine may represent a state-independent correlate of some forms of severe depression. Issues regarding the specificity and interpretation of this finding require further clarification.

Detection of bacteriuria and pyuria by URISCREEN a rapid enzymatic screening test

A multicenter study was performed to evaluate the ability of the URISCREEN (Analytab Products, Plainview, N.Y.), a 2-min catalase tube test, to detect bacteriuria and pyuria. This test was compared with the Chemstrip LN (BioDynamics, Division of Boehringer Mannheim Diagnostics, Indianapolis, Ind.), a 2-min enzyme dipstick test; a semiquantitative plate culture method was used as the reference test for bacteriuria, and the Gram stain or a quantitative chamber count method was used as the reference test for pyuria. Each test was evaluated for its ability to detect probable pathogens at greater than or equal to 10(2) CFU/ml and/or greater than or equal to 1 leukocyte per oil immersion field, as determined by the Gram stain method, or greater than 10 leukocytes per microliter, as determined by the quantitative count method. A total of 1,500 urine specimens were included in this evaluation. There were 298 specimens with greater than or equal 10(2) CFU/ml and 451 specimens with pyuria. Of the 298 specimens with probable pathogens isolated at various colony counts, 219 specimens had colony counts of greater than or equal to 10(5) CFU/ml, 51 specimens had between 10(4) and 10(5) CFU/ml, and 28 specimens had between 10(2) and less than 10(4) CFU/ml. Both the URISCREEN and the Chemstrip LN detected 93% (204 of 219) of the specimens with probable pathogens at greater than or equal to 10(5) CFU/ml. For the specimens with probable pathogens at greater than or equal to 10(2) CFU/ml, the sensitivities of the URISCREEN and the Chemstrip LN were 86% (256 of 298) and 81% (241 of 298), respectively. Of the 451 specimens with pyuria, the URISCREEN detected 88% (398 of 451) and Chemstrip LN detected 78% (350 if 451). There were 204 specimens with both greater than or equal to 10(2) CFU/ml and pyuria; the sensitivities of both methods were 95% (193 of 204) for these specimens. Overall, there were 545 specimens with probable pathogens at greater than or equal to 10(2) CFU/ml and/or pyuria. The URISCREEN detected 85% (461 of 545), and the Chemstrip LN detected 73% (398 of 545). A majority (76%) of the false-negative results obtained with either method were for specimens without leukocytes in the urine. There were 955 specimens with no probable pathogens or leukocytes. Of these, 28% (270 of 955) were found positive by the URISCREEN and 13% (122 of 955) were found positive by the Chemstrip LN. A majority of the false-positive results were probably due, in part, to the detection of enzymes present in both bacterial and somatic cells by each of the test systems. Overall, the URISCREEN is rapid, manual, easy-to-perform enzymatic test that yields findings similar to those yielded by the Chemstrip LN for specimens with both greater than or equal to 10(2) CFU/ml and pyuria or for specimens with greater than or equal to 10(5) CFU/ml and with or without pyuria. However, when the data were analyzed for either probable pathogens at less 10(5) CFU/ml or pyuria, the sensitivity of the URISCREEN was higher (P less than 0.05).

The in-vitro activity of temafloxacin, against gram-positive bacteria

Temafloxacin, a new fluoroquinolone with enhanced activity against Gram-positive bacteria, was compared with other antibiotics. A review of the literature on the in-vitro activity of temafloxacin was also done. The susceptibility of Gram-positive cocci isolated from blood cultures was determined using a broth microdilution method. Temafloxacin MIC90s for Staphylococcus aureus (oxacillin-sensitive and -resistant) and Streptococcus pneumoniae were less than 0.12, less than 0.12 and 0.76 mg/L respectively. Temafloxacin was more active than either ciprofloxacin or ofloxacin against these organisms. A review of the literature supported these findings. Temafloxacin was the most active of the quinolones tested against a small number of S. pneumoniae with decreased sensitivity to penicillin. Temafloxacin activity was not appreciably affected by changes in pH or the presence of serum, but activity was slightly reduced in urine at pH 6.5-7.2, and at high magnesium ion concentrations. With the exception of S. pneumoniae at high concentration, no significant inoculum effect was observed.

Growth hormone responses to intravenous clonidine challenge correlate with behavioral irritability in psychiatric patients and healthy volunteers

To explore the relationship between central noradrenergic receptor responsivity and indices of impulsive aggression, growth hormone responses to infusions with the alpha 2-adrenergic receptor agonist clonidine (GH[CLON]) and responses on the Buss-Durkee Hostility Inventory (BDHI) were examined in healthy male volunteers and male patients with major affective or personality disorder. GH[CLON] values were found to correlate significantly with the BDHI "Irritability" subscale in all subjects, but especially in healthy volunteer and personality disorder patients. GH[CLON] values did not correlate with the BDHI "Assault" subscale. These results suggest a role for central alpha 2-adrenergic receptor responsivity in the personality trait characterized by behavioral irritability, but not overt assaultiveness, in humans.

Effect of nitrogen fertilizer on beef production and forage quality of Russian wildrye

A grazing study was conducted for 12 yr on a Brown loam in a semi-arid climate at Swift Current, Saskatchewan to determine the effect of nitrogen (N) fertilizer on beef production, forage quality, and economic returns of Russian wildrye (Psathyrostachys juncea (Fisch) Nevski) (RWR). Treatments were: annual broadcast of N fertilizer such that available soil N (0–60 cm depth) plus applied N totalled 55 kg ha−1; an application in which available plus applied N totalled 110 kg ha−1; a one-time application of 390 kg N ha−1 (April 1977); and a control treatment with no fertilizer. Treatments were compared by regression analysis using soil available plus fertilizer N and age of stand as the independent variables. Pastures were grazed each year with yearling steers from early May until 5 cm grass height remained or when steers did not gain weight in a 2-wk period (resulting in an average grazing period of 120 d). Total grazing days averaged 166, 179, 165 and 132 days ha−1, respectively, for the four treatments. For the 55 N treatment, in which 32 kg N ha−1 was applied annually, an average of 1 kg of beef gain was obtained for each kilogram of N applied. Daily gain of steers averaged 0.84 kg d−1 for all years and treatments. Stocking rate (grazing days/ha) was positively correlated to spring soil moisture plus grazing season precipitation (r = 0.67) and negatively related to pan evaporation (r = 0.87). Fertilizer treatments marginally increased forage N and OMD early in the season. Forage N, phosphorus, and organic matter digestibility (OMD) declined in a linear relationship with time from 1 May. The rate of decline was not affected by the treatments. On the basis of liveweight gain, all fertilizer treatments were profitable. Profitability varied with the ratio of the cost of fertilizer N to steer price; annual fertilizer applications were more profitable than the one-time application. Key words: Psathyrostachys juncea, yearling steer performance, forage digestibility, forage quality