Specific induction of tumor neovasculature death by modified murine PPE-1 promoter armed with HSV-TK.

BACKGROUND: One strategy to increase tissue specificity of gene therapy is to use promoters or enhancers. OBJECTIVES: (1) To enhance the selectivity of a murine preproendothelin-1 (PPE-1) promoter in tumor angiogenesis by using a positive endothelial transcription-binding element. (2) To test the specificity and efficiency of the modified PPE-1 promoter [PPE-1(3X)] in vitro and in vivo by using reporter genes, and the therapeutic gene herpes simplex virus-thymidine kinase (HSV-TK) in a mouse model of Lewis lung carcinoma (LLC). RESULTS: The modified PPE-1 promoter specifically induced expression in the tumor angiogenic vascular bed with a 35-fold higher expression compared to the normal vasculare bed of the lung. Thus, when the HSV-TK gene controlled by the modified PPE-1 promoter was used systemically, it induced tumor-specific necrosis, apoptosis and mononuclear infiltrates, leading to massive destruction of the neovasculature of the pulmonary metastasis, which suppressed metastasis development. CONCLUSIONS: These results show that an adenoviral vector armed with HSV-TK controlled by the endothelial-selective murine PPE-1(3X) promoter is efficient and safe to target tumor neovasculature.

12/15-Lipoxygenase gene disruption attenuates atherogenesis in LDL receptor-deficient mice.

BACKGROUND: Human 15-lipoxygenase (LO) and its murine analogue 12/15-LO are capable of directly oxidizing esterified fatty acids in lipoproteins and phospholipids. Because these oxidized products possess atherogenic properties, it was suggested that LOs may be involved in enhancing atherogenesis. Previous in vivo tests of the role of LOs in atherogenesis animal models, however, have yielded conflicting results. METHODS AND RESULTS: Aiming to study the role of the 12/15-LO in murine atherogenesis, we crossed LDL-receptor-deficient mice (LDL-R(-/-)) with 12/15-LO-knockout mice and evaluated plaque formation 3 to 18 weeks after initiation of a high-fat diet. Atherosclerotic lesions were considerably reduced in the LDL-R/12/15-LO-double-knockout mice compared with LDL-R(-/-) mice at 3, 9, 12, and 18 weeks, at the aortic root as well as throughout the aorta. The cellular composition of plaques from mice deficient in 12/15-LO did not differ with respect to macrophage and T-lymphocyte content compared with plaques from 12/15-LO littermates. CONCLUSIONS: 12/15-LO plays a dominant role in promoting atherogenesis in LDL-R(-/-) mice.

Intracoronary injection of basic fibroblast growth factor enhances angiogenesis in infarcted swine myocardium.

OBJECTIVES: This study was performed to examine the effect of intracoronary exogenous basic fibroblast growth factor (bFGF) on angiogenesis in infarcted myocardial regions. BACKGROUND: Exogenous bFGF is a potent promoter of angiogenesis. Little information is available on its effect on myocardial angiogenesis. METHODS: Myocardial infarction was induced in 10 pigs by intracoronary injection of microscopic beads. Four pigs served as a control group; in six pigs slow-release bFGF was delivered by the beads. Cardiac performance was evaluated by repeated echocardiographic measurement and angiogenesis was evaluated by immunohistochemical studies 14 days later. RESULTS: As compared with control pigs, pigs treated with bFGF had higher microvessel counts (mean +/- SEM) in both viable tissue (141 +/- 27 per field vs. 39 +/- 4, p = 0.01) and nonviable tissue (329 +/- 26 per field vs. 95 +/- 7, p < 0.001) within the infarct area. No significant differences in total regional left ventricular wall motion were noted between the two groups throughout the 14-day study period. CONCLUSIONS: In the swine, direct intracoronary application of bFGF to infarcted myocardium enhances myocardial neovascularization within 2 weeks.

Histochemical analyses of steroid hormone receptors in breast and prostatic carcinoma.

Histochemical analyses estrogen (ER) and progesterone (PgR) receptors in breast cancer were statistically correlated with results of dextran-coated charcoal (DDC) and sucrose gradient assays. Correlated for ER was 91% of 363 cases, and for PgR 88% of 255 specimens. Breast cancer ER/PgR positivity by histochemistry correlated with a favorable clinical response to endocrine therapies in 72% of 25 cases, while ER/PgR negativity correlated with a lack of response in 96% of 22 cases with Stage IV disease. Nuclear ER/PgR correlated with a poor response to therapy in 8 of 12 patients. An in vitro technique to detect nuclear translocation of ER revealed two groups of ER positive cases, with 11 of 17 exhibiting translocation and 6 not displaying translocation. In prostatic carcinoma, 72% of 65 men were positive for ER and/or androgen receptor. Comparison of specimens obtained without and with electrocautery revealed a preponderance of nuclear binding in the latter, suggesting heat-induced nuclear translocation of receptor. coumestrol, a naturally fluorescent, entirely unaltered estrogen was also used for histochemical detection of ER. Results correlated with ER by DCC in 87% of 61 breast cancers. Coumestrol was additionally used to visually observe receptor and nuclear translocation of ER in intact whole cells in culture.

Noninvasive evaluation of microcirculatory hemodynamic changes during hemorrhage followed by saline or blood transfusion.

The purpose of the study was to examine the ability of a system combining laser Doppler flowmetry (LDF), photoplethysmograph (PPG), and transcutaneous oxygen tension (tc-PO2) to follow changes in the microcirculation during hemorrhage and following blood or saline return, and to test the hypothesis that such changes precede and might predict changes in the systemic blood pressure. Measurements were performed on the skin of anesthetized rabbits (n = 10) during mild (0-8%), moderate (9-24%), and severe (25-30% of blood volume) hemorrhage, and following complete volume restitution by blood or saline. We found the following: 1) hemorrhage caused typical changes in the LDF, PPG, and tc-PO2 signals that could be formulated by mathematical models, 2) these signals identified blood as being more efficient than saline for volume restitution following hemorrhage, and 3) microcirculatory changes precede and might predict systemic hemodynamic events.

Evidence that epinephrine acutely redistributes blood flow to experimental intrahepatic tumors.

Tumor microcirculation was studied in Sprague-Dawley rats with solitary intrahepatic implants of Walker carcinosarcoma tumors. Thioflavine S (TS), a fluorescent dye that stains capillary endothelium acutely, was injected intraportally or intra-arterially in order to demonstrate patterns of blood flow through normal liver tissue and through tumor. The dye was given immediately after intraportal injection of 10 micrograms of epinephrine in some animals and 3 minutes after the epinephrine in others. Control animals received TS alone. Additional animals were given TS immediately after intra-arterial epinephrine. The degree of resulting fluorescence in tumor and liver was graded subjectively from 0 to 3+. In the controls and in animals receiving TS 3 minutes after epinephrine, fluorescence in the centers of tumors was absent or, at most, faintly present. In contrast, all animals given epinephrine either intraportally or intra-arterially immediately before the dye showed intense fluorescent staining within the centers of the tumors. Subjective grading averaged 0.6 +/- 0.1 in the controls, 2.2 +/- 0.1 in those receiving intraportal epinephrine immediately before TS, and 1.0 +/- 0.3 in those receiving TS 3 minutes after epinephrine. Results were significantly higher in the latter group (p less than 0.01). Subjective grading in animals receiving intra-arterial epinephrine immediately before TS averaged 2.5 +/- 0.3. These experiments confirm previous studies in this laboratory that demonstrated an acute short-lived redistribution of blood flow into the centers of intrahepatic tumors after administration of epinephrine.

Enhancement of tumor blood flow and tumoricidal effect of doxorubicin by intraportal epinephrine in experimental liver metastasis.

Laser Doppler capillary perfusion monitoring was performed in 25 Sprague-Dawley rats with solitary intrahepatic implants of Walker carcinosarcomas. Doses of intraportal epinephrine from 1 to 10 micrograms produced an immediate rise in capillary blood flow, reaching peak levels by 16 s. The increased flow lasted an average of 57 s. Because epinephrine selectively increased tumor blood flow, studies were performed to determine if enhancement of the chemotherapeutic effect of doxorubicin could be achieved. Forty-two rats with seven-day hepatic implants were treated sequentially with intraportal epinephrine (10 micrograms) and doxorubicin hydrochloride (10 mg/kg) or doxorubicin alone. After only two courses of chemotherapy, a significant difference in necrosis and cell viability was obtained in those animals treated with epinephrine intraportally prior to doxorubicin infusion. Enhancement of the tumoricidal effect of chemotherapy can be achieved by manipulating the blood flow to developing tumors pharmacologically.

Decreased thickening of normal myocardium with transient increased wall thickness during stress echocardiography with atrial pacing.

Stress echocardiography is used increasingly in the evaluation of coronary artery disease. The echocardiographic evaluation of ischemia is based on stress-induced changes in wall motion and wall thickening of the ischemic segments. Studies have demonstrated that left ventricular volumetric changes may induce changes in wall thickness. The aim of the study was to evaluate whether significant changes in ventricular volume, wall thickness, and wall thickening occur during stress echocardiography with atrial pacing. Seven German Landrace female pigs were studied 4 weeks after the induction of a small myocardial infarction. Echocardiographic measurements were conducted in noninfarcted segments on the short-axis view at baseline and during atrial pacing at 120, 150, and 180 beats/min. End-diastolic circumferential area decreased from 12.3 +/- 2.0 cm2 at baseline to 8.9 +/- 1.9 cm2 at 180 beats/min of atrial pacing (p < 0.01). Mean wall thickness (interventricular septal plus posterior wall thickness divided by 2) increased markedly and progressively from 6.7 +/- 0.6 mm at baseline to 9.8 +/- 1.0 mm at 180 beats/min (p < 0.01). The increase in wall thickness correlated inversely with end-diastolic area (r = -0.57; p < 0.01). Percent systolic thickening decreased from 38.9 +/- 12.0 at baseline to 14.9 +/- 7.4 at 180 beats/min of atrial pacing (p < 0.01). The decrease in percent wall thickening correlated with the increase in wall thickness (r = -0.71; p < 0.01). In conclusion, this study shows that a marked increase in wall thickness (pseudohypertrophy) and decrease in percent systolic thickening are observed during rapid atrial pacing in normal myocardium and do not indicate stress-induced left ventricular dysfunction.

Carcinoma of the cheek mucosa. A retrospective analysis.

A 16 year experience with 121 patients treated for squamous cell carcinoma arising in the cheek mucosa is described. Treatment was almost exclusively surgical, and 5 year determinate cure rates ranged from 77 and 65 percent in stage I and II lesions to 27 and 18 percent in those with stage III and IV lesions, respectively. Twenty-four percent of previously treated patients remained alive and well at 5 years. The 42 percent overall salvage rate was low, reflecting the high proportion of patients who developed cervical metastasis during the course of the disease. In an attempt to improve local control, we now advocate irradiation of the primary tumor and neck after aggressive resection with radical neck dissection in any patient who has clinical evidence of nodal involvement or other unfavorable findings.

Thrombotic occlusion of the left common iliac artery after an anterior retroperitoneal approach to the lumbar spine.

Thrombotic occlusion of the left common iliac artery occurred in a 59-year-old man after an anterior and posterior spinal fusion. Preoperatively, the patient was known to have peripheral vascular disease. Symptoms of an L4-5 radiculopathy were noted postoperatively. After an iliac-iliac bypass, the symptoms completely resolved. Retraction of the vessels during the anterior retroperitoneal approach was the presumed cause. To the authors' knowledge, this is the first report of a thrombotic occlusion developing in a patient after an anterior retroperitoneal approach to the lumbar spine. It is their hope that through an increased awareness similar complication will be prevented.

The perioperative course of combined anterior and posterior spinal fusion.

A retrospective study was undertaken to characterize and compare the perioperative course of 91 cases of one- and two-stage combined anterior and posterior spinal fusions over a 7-year period. The two patient populations were similar regarding preoperative characteristics and the number of levels fused. Significantly decreased operative and anesthesia time, operative blood loss, and postoperative hospital days were seen in the one-stage population compared to the two-stage cases (P < 0.05). For the spinal deformity subgroup, a longer chest-tube duration, decreased anesthesia time, and decreased postoperative hospital stay in the one-stage group were the only significant differences. Surgical treatment delays were noted in 8% of one-stage cases and in 23% of two-stage cases. Complications occurred in 53% of all cases, with a significantly higher major complication rate in patients with preoperative medical comorbidities who underwent two-stage combined fusion versus one-stage reconstruction. Higher complication rates were also associated with an age greater than 40 years, the presence of medical comorbidities, and cases treated with a thoracoabdominal anterior approach.

An improved speciation method for mercury by GC/CVAFS after aqueous phase ethylation and room temperature precollection.

An improvement has been made in previous mercury speciation methods, which omits the use of liquid nitrogen by modifying the GC conditions. In addition, the sometimes observed thermal decomposition of ethylation derivatives in the process of desorbing the compounds to the GC column has been investigated and overcome. The resulting improvements have allowed simultaneous determination of methylmercury (MMHg) and inorganic mercury (Hg(II)). They have also increased the precision of the ethylation reaction and refined the MMHg determination. Optimal conditions for MMHg were confirmed and supplemented, while the parameters for dimethyl mercury (DMHg) and Hg(II) were thoroughly investigated for the first time. The absolute detection limits (DL) for 2sigma of the reagent blanks as Hg and about 0.6, 0.6 and 1.3 pg for DMHg, MMHg and Hg(II), respectively. The improved method is five-fold faster than the original method, allowing up to 80 samples to be analyzed within 8 hr.

Potential effects of forest fire and storm flow on total mercury and methylmercury in sediments of an arid-lands reservoir.

A study was conducted from July 1995 to June 1996 to examine the spatial and temporal changes of mercury concentrations in sediments of an arid-lands reservoir. Prior to the first sample collection in July, a forest fire burned 2930 ha of mixed conifer and ponderosa pine in the watershed of Caballo Reservoir in south-central New Mexico. The fire was eventually extinguished by summer rains and storm runoff resulting in the mobilization and transport of charred vegetative material into an intermittent tributary (Palomas Creek) that drains the watershed into Caballo Reservoir. Concentrations of total mercury (THg), monomethlymercury (MMHg), and total organic carbon (TOC) in surficial sediments revealed fire, followed by storm runoff, enhanced the transport of mercury and organic matter to the reservoir. Concentrations of THg in sediments increased from 7.5 etag/g in July to 46.1 etag/g by November 1995 at one site (Palomas) nearest the outflow of Palomas Creek. No other spatial or temporal trends were observed for THg at other sites throughout the remainder of the study. Concentrations of MMHg in sediments at the Palomas site increased from 0.428 etag/g in July to 12.46 etag/g by October 1995 compared to concentrations in sediments at the remaining sites which ranged from 0.11 to 1.50 etag/g throughout the study. The ratio of MMHg to THg (a gross index of methylation activity) was greatest in sediments from the Palomas site (5.4-33.8%) compared to the remaining sites (0.01-3.60%). The ratio was mirrored by elevated TOC in sediments at the Palomas site (2.5-11.8%) that remained elevated throughout the study. Fire and subsequent late-summer rains may have had a twofold effect on mercury concentrations in Caballo Reservoir. The storm-driven runoff following the forest fire carried mercury complexed to organic matter which resulted in elevated levels of mercury as well as providing a carbon source for microbial methylation processes in sediment.

Discharge of methylmercury-enriched hypolimnetic water from a stratified reservoir.

A study conducted from July 1995 to June 1996 examining spatial and temporal distribution of mercury (Hg) at the Caballo Reservoir, New Mexico, revealed that the highest levels of methylmercury (MMHg) occurred in both the inlet and the Rio Grande upstream of the reservoir. As a result, a second study was designed to identify possible sources of the elevated levels of MMHg, and to determine if water discharged from the Elephant Butte Reservoir upstream could be a primary source. In July 1996, as anoxia began to develop in the hypolimnion of the Elephant Butte Reservoir, surface water MMHg concentrations were below the MDL of 0.018 ng/l while water discharged into the tailrace was 0.149 ng/l MMHg. By September 1996, when the anoxic hypolimnion spanned 60% of the total reservoir depth, surface water MMHg was still below the MDL, while discharge water had increased to 1.144 ng/l MMHg. Following reservoir turnover in November 1996, surface water increased to 0.264 ng/l MMHg while discharge water decreased to 0.420 ng/l MMHg. By January 1997, MMHg in the tailrace decreased to pre-stratification levels, and both surface water and discharge water reached similar MMHg levels until the onset of summer stratification in July 1997. This trend was repeated the following year when MMHg concentrations in the tailrace increased from 0.190 ng/l in August 1997 to 1.240 ng/l in September 1997. In addition, vertical profile sampling of the reservoir from August 1997 to September 1997 showed a buildup of MMHg in the anoxic hypolimnion which coincided with increasing levels of MMHg discharged into the tailrace. During the course of this study the single largest contribution of MMHg to the river below the reservoir was from water released through the dam during the fall months of the year.

The role of microvascular surgery in limb-sparing procedures for malignant tumors of the knee.

Limb-sparing surgery has proven to be a feasible alternative to amputation for treatment of malignant tumors about the knee. Microvascular surgery and the possibility of providing healthy, stable soft-tissue coverage to the affected limb have expanded the possible role of limb-sparing techniques. Microvascular free flaps were utilized in 26 patients undergoing resection for large malignant tumors of the knee or adjacent to the knee. Patients were then followed for a minimum of 3 years to a maximum of 7 years and evaluated for tumor recurrence and limb function. Survival and disease-free interval were 68 and 77 percent, respectively, in stage II patients and only 50 and 0 percent, respectively, in stage III patients. Function, as determined by the MSTS functional evaluation system, was found to be fair to good in all patients. Microvascular free-tissue transfer has proven to be a valuable adjunct in limb-sparing surgery.

Hormone relationships in breast cancer: the role of receptor-binding proteins.

The introduction of receptor protein studies as markers for hormone dependence of breast carcinomas has had a profound effect on the management of advanced disease. All breast carcinomas, regardless of stage, should have receptor binding protein studies for estrogen and progesterone by the sucrose gradient method or by the dextran-coated charcoal method as a good alternative. A simpler test is needed. In cases of primary advanced disease or in recurrent disease, receptor binding protein studies effectively identify the subgroup of hormone-dependent tumors that should be managed by surgical hormone ablation or endocrine manipulation. These tests are even more effective in identifying patients that should not receive hormone therapy and respond better to chemotherapy. In primary, potentially surgically curable disease, receptor studies may serve as a therapeutic guide to adjuvant hormone or chemotherapy. In all breast cancers, ER and PgR receptor studies should be performed and the information should be stored for possible future use. If possible, tisssue should be stored in a freezer in anticipation of future tests and for confirmation of hormone dependence in the event of recurrence.

Electrical injury in the femoral artery of rabbits as a model for arterial thrombosis: a pilot study.

Electrical stimulation was delivered to the femoral artery of 20 rabbits to examine whether endothelial injury results in a consistent formation of arterial thrombosis. The arterial patency was monitored throughout the experiment by flowmeter and was visualized by femoral angiography in 5/20 cases. The arterial segments remained totally occluded in 7/20 (35%), partially occluded in 9/20 (45%), and patent in 4/20 (20%) rabbits following stimulation with 200 microA anodal current for 180 minutes. The average time of electrical stimulation needed to achieve total occlusion (n = 7) was 110 +/- 49 minutes. Alternating occlusion and recanalization of the artery (cyclic flow variation) was observed in 12 rabbits, with total occlusion ensuing in 6/12 cases. Intravenous administration of recombinant tissue-type plasminogen activator (20 micrograms/kg/min for sixty minutes) resulted in femoral reflow and subsequent reocclusion in 2/5 cases. Histopathologic examination disclosed arterial thrombi composed of platelets, fibrin, and red blood cells. Thus, according to these data this technique was found to induce arterial thrombosis following electrical stimulation of the rabbit femoral artery but was inconsistent regarding the arterial patency.

Failure of captopril to attenuate myocardial damage, neutrophil accumulation, and mortality following coronary artery occlusion and reperfusion in rat.

Captopril, a sulfhydryl-containing angiotensin-converting enzyme inhibitor, has been suggested as possessing antiischemic and antiinflammatory properties. To test the hypothesis that captopril may prevent neutrophil-induced myocardial injury during acute myocardial infarction (AMI), the authors subjected rats to coronary occlusion for thirty minutes and reperfusion for twenty-four hours (MI) or to sham operation (sham MI). Oral captopril (100 mg/kg) or vehicle was administered thirty minutes before coronary occlusion. The effect of captopril on mean arterial blood pressure was assessed in separate group of animals (n = 8). Infarct size and neutrophil accumulation in myocardium were determined by measuring creatine phosphokinase depletion and myeloperoxidase (MPO) activity, respectively, in the left ventricular free wall (LVFW). Animals treated with 100 mg/kg of captopril exhibited significant reduction in mean arterial blood pressure compared with vehicle-treated animals (P < 0.01). Compared with vehicle-treated animals, administration of 100 mg/kg of captopril to MI animals attenuated neither twenty-four-hour mortality (56% vs 52%, respectively), nor infarct size (36 +/- 7% vs 34% +/- 7% respectively), nor MPO activity (1.0 +/- 0.17 vs 1.26 +/- 0.19). Thus, in the present experiment captopril did not reduce neutrophil-induced myocardial damage following coronary occlusion and reperfusion. These findings may be partly explained by the negative effect of captopril on arterial blood pressure during AMI.

The effect of low molecular weight heparin (fragmin) on myocardial neutrophil accumulation and infarct size in a rat model of myocardial infarction.

BACKGROUND: Heparin molecules possess immunomodulating properties, which are thought to complement their established antithrombotic activity. The purpose of this study was to evaluate whether the antiinflammatory properties of low molecular weight heparin (LMWH) can attenuate polymorphonuclear neutrophil accumulation and infarct size in a rat model of myocardial infarction. METHODS: Myocardial infarction was induced by ligating the left main coronary artery. LMWH (fragmin 500 anti-FXa u/kg) or vehicle (saline) were administered subcutaneously thirty minutes prior to coronary artery occlusion. Significant anticoagulant activity was attained with LMWH for more than eight hours. Twenty-four hours later, neutrophil accumulation and infarct size were determined by measuring left ventricular free wall myeloperoxidase and residual creatine kinase activity, respectively. RESULTS: As compared with rats administered vehicle, myeloperoxidase activity was insignificantly decreased in rats treated with LMWH (1.24 +/- 0.28 u/g vs 1.66 +/- 0.15 u/g, P = 0.16. Infarct size was also not significantly different between the groups (62.48 +/- 3.5% and 50.67 +/- 7.2% of left ventricular free wall with vehicle and LMWH, respectively, P = 0.1). CONCLUSION: The authors conclude that LMWH does not significantly reduce myocardial neutrophil accumulation and infarct size twenty-four hours after myocardial infarction in the rat.

Effect of active limb movements on symptoms in patients with low back pain.

STUDY DESIGN: A descriptive, correlational study of patients with mechanical low back pain (LBP). OBJECTIVES: To assess the effect of active limb movements on symptoms in patients with LBP and to examine the relationship between symptoms with limb movements and select patient characteristics. BACKGROUND: Limb movements result in forces applied to the spine and, thus, may be important in the examination and treatment of patients with LBP. METHODS AND MEASURES: A total of 188 people with LBP, 84 men and 104 women, participated in a standardized examination. Six of the items required patients to move their limbs and note LBP symptoms as increased, remained the same, or decreased. The prevalence of various symptom responses with each limb movement test was calculated. Relationships between patient characteristics and reports of increased symptoms were examined with Cochran's linear trend statistic and the Spearman and Pearson correlation coefficients. Differences in characteristics of patients with and without increased symptoms were examined with chi2 test, Mann-Whitney U test, or Student's t test for independent groups. RESULTS: An increase in symptoms was reported by 149 patients with at least 1 of the limb movement tests, and 3 of the patients reported a decrease in symptoms. Across the patient sample, the mean number of limb movement tests for which symptoms were reported as increased was 2.30 +/- 1.64. Patients with an increase in symptoms reported higher average pain intensity the week prior to the examination (median = 2; range: 1-5) and higher functional disability (mean = 0.25; SD = 0.15) than those without a change in symptoms (pain intensity: median = 1; range: 0-2 and functional disability: mean = 0.16; SD = 0.12). The correlation between the number of increased symptoms and the person's average pain intensity was r = 0.23; the correlation with the functional disability score was r = 0.36. Patients with a history of LBP tended to report an increase in symptoms with more of the limb movement tests (mean = 3.5; SD = 1.40) than those without a previous history of LBP (mean = 2.0; SD = 1.11). CONCLUSIONS: Active limb movements performed during the examination primarily resulted in increased LBP symptoms. The presence and number of increased symptoms with the active limb movements was related to the patient's report of average pain intensity and functional disability. Tests of symptoms with active limb movements may provide insight into factors contributing to a LBP problem, as well as information to guide the treatment of patients with LBP.