Laboratory Study of Collisionless Magnetic Reconnection

A concise review is given on the past two decades' results from laboratory experiments on collisionless magnetic reconnection in direct relation with space measurements, especially by the Magnetospheric Multiscale (MMS) mission. Highlights include spatial structures of electromagnetic fields in ion and electron diffusion regions as a function of upstream symmetry and guide field strength, energy conversion and partitioning from magnetic field to ions and electrons including particle acceleration, electrostatic and electromagnetic kinetic plasma waves with various wavelengths, and plasmoid-mediated multiscale reconnection. Combined with the progress in theoretical, numerical, and observational studies, the physics foundation of fast reconnection in collisionless plasmas has been largely established, at least within the parameter ranges and spatial scales that were studied. Immediate and long-term future opportunities based on multiscale experiments and space missions supported by exascale computation are discussed, including dissipation by kinetic plasma waves, particle heating and acceleration, and multiscale physics across fluid and kinetic scales.

Finding equipoise: CEPI revises its equitable access policy

Launched at Davos in January 2017 with funding from sovereign investors and philanthropic institutions, the Coalition for Epidemic Preparedness Innovations (CEPI) is an innovative partnership between public, private, philanthropic, and civil organisations whose mission is to stimulate, finance and co-ordinate vaccine development against diseases with epidemic potential in cases where market incentives fail. As of December 2019, CEPI has committed to investing up to $706 million in vaccine development. This includes 19 vaccine candidates against its priority pathogens (Lassa fever virus, Middle East respiratory syndrome coronavirus, Nipah virus, Chikungunya, Rift Valley fever) and three vaccine platforms to develop vaccines against Disease X, a novel or unanticipated pathogen.

As an entity largely supported by public funds, ensuring equitable access to vaccines whose development it supports in low- and middle-income countries is CEPI’s primary focus. CEPI developed an initial equitable access policy shortly after its formation, with key stakeholders expressing strong views about its content and prescriptive nature. The CEPI board instructed that it be revisited after a year. This paper describes the process of revising the policy, and how key issues were resolved. CEPI will continue to take an iterative, rather than prescriptive, approach to its policy—one that reflects the needs of multiple stakeholders and ensures it can meet its equitable access goals.

Rectal dose to prostate cancer patients treated with proton therapy with or without rectal spacer

The purpose of this study was to evaluate whether a spacer inserted in the prerectal space could reduce modeled rectal dose and toxicity rates for patients with prostate cancer treated in silico with pencil beam scanning (PBS) proton therapy. A total of 20 patients were included in this study who received photon therapy (12 with rectal spacer (DuraSeal™ gel) and 8 without). Two PBS treatment plans were retrospectively created for each patient using the following beam arrangements: (1) lateral-opposed (LAT) fields and (2) left and right anterior oblique (LAO/RAO) fields. Dose volume histograms (DVH) were generated for the prostate, rectum, bladder, and right and left femoral heads. The normal tissue complication probability (NTCP) for ≥grade 2 rectal toxicity was calculated using the Lyman-Kutcher-Burman model and compared between patients with and without the rectal spacer. A significantly lower mean rectal DVH was achieved in patients with rectal spacer compared to those without. For LAT plans, the mean rectal V70 with and without rectal spacer was 4.19 and 13.5%, respectively. For LAO/RAO plans, the mean rectal V70 with and without rectal spacer was 5.07 and 13.5%, respectively. No significant differences were found in any rectal dosimetric parameters between the LAT and the LAO/RAO plans generated with the rectal spacers. We found that ≥ 9 mm space resulted in a significant decrease in NTCP modeled for ≥grade 2 rectal toxicity. Rectal spacers can significantly decrease modeled rectal dose and predicted ≥grade 2 rectal toxicity in prostate cancer patients treated in silico with PBS. A minimum of 9 mm separation between the prostate and anterior rectal wall yields the largest benefit.

Urinary and bowel quality of life after image-guided, intensity modulated radiation therapy to the prostate bed

312

Background: Majority of patients with adverse pathological features on radical prostatectomy do not receive post-prostatectomy radiation due to concerns of negative impact on their quality of life (QOL). The purpose of this study is to evaluate QOL after post-prostatectomy intensity modulated radiation therapy (IMRT) in the “adjuvant”(ADJ) setting for positive surgical margins, extraprostatic extension, or seminal vesicle invasion with a PSA < 0.2 ng/mL and a “salvage”(SAL) setting for a PSA ≥ 0.2 ng/mL at the start of IMRT. Methods: Between 2004 and 2013, 130 patients underwent IMRT to the prostate bed. Sexual Health Inventory for Men (SHIM), International Prostate Symptom Score (IPSS), and Expanded Prostate cancer Index Composite-26 for bowel (EPIC-26-bowel) scores were recorded before radiation and at 3-month intervals after completion of treatment to assess sexual, urinary, and rectal QOL, respectively. A mixed model for repeated measurements was used to compare QOL scores over time among various subgroups. Results: ADJ and SAL radiation were delivered to 48 (37%), 82 (63%) respectively. Total radiotherapy doses were 64.8-68.4 Gy using 1.8-Gy daily in 56 (43%) patients and 70.2-72.0 Gy in 74 (57%) patients. Androgen deprivation therapy (ADT) was given to 4/48 (8%) ADJ patients and 9/82 (11%) SAL patients. Fiducials were placed in prostate bed for image guidance in 42 (32%) patients. Median follow up was 46 months. Total radiation dose did not significalntly affect QOL. SAL IMRT was associated with worse mean SHIM scores (3 points, p = 0.002) and ADJ IMRT was associated with lower mean IPSS scores (2 points, p = 0.03). Mean EPIC-26-bowel scores were lower without fiducial markers (16 points, p < 0.0001). Conclusions: SAL IMRT was associated with worse sexual QOL, possibly due to less frequent usage of phosphodiesterase-5 inhibitors. ADJ IMRT was associated with worse urinary QOL, possibly due to a shorter post-operative recovery period. Fiducial marker resulted in better rectal QOL due to greater rectal sparing. Urinary and rectal QOL with post-prostatectomy, image-guided IMRT compare favorably with previous QOL reports involving three-dimensional conformal radiation therapy.

Health-related quality of life changes due to high-dose rate brachytherapy, low-dose rate brachytherapy, or intensity-modulated radiation therapy for prostate cancer

72

Background: To compare urinary, bowel, and sexual health-related quality of life (HRQOL) changes due to high-dose rate (HDR) brachytherapy, low-dose rate (LDR) brachytherapy, or intensity modulated radiation therapy (IMRT) monotherapy for prostate cancer. Methods: Between January 2002 and September 2013, 413 low-risk or favorable intermediate-risk prostate cancer patients were treated with HDR brachytherapy monotherapy to 2,700-2,800 cGy in two fractions (n=85), iodine-125 LDR brachytherapy monotherapy to 14,500 cGy in one fraction (n=249), or IMRT monotherapy to 7,400-8,100 cGy in 37-45 fractions (n=79) without pelvic lymph node irradiation. No androgen deprivation therapy was given. Patients used an International Prostate Symptoms Score questionnaire, an Expanded Prostate cancer Index Composite-26 bowel questionnaire, and a Sexual Health Inventory for Men questionnaire to assess their urinary, bowel, and sexual HRQOL, respectively, pre-treatment and at 1, 3, 6, 9, 12, and 18 months post-treatment. Results: Median follow-up was 32 months. HDR brachytherapy and IMRT patients had significantly less deterioration in their urinary HRQOL than LDR brachytherapy patients at 1 and 3 months post-irradiation. The only significant decrease in bowel HRQOL between the groups was seen 18 months following treatment, at which point IMRT patients had a slight, but significant, deterioration in their bowel HRQOL compared with HDR and LDR brachytherapy patients. HDR brachytherapy patients had worse sexual HRQOL than both LDR brachytherapy and IMRT patients following treatment. Conclusions: IMRT and HDR brachytherapy cause less severe acute worsening of urinary HRQOL than LDR brachytherapy. However, IMRT causes a slight, but significant, worsening of bowel HRQOL compared with HDR and LDR brachytherapy.

A systematic review of barriers to data sharing in public health

Background

In the current information age, the use of data has become essential for decision making in public health at the local, national, and global level. Despite a global commitment to the use and sharing of public health data, this can be challenging in reality. No systematic framework or global operational guidelines have been created for data sharing in public health. Barriers at different levels have limited data sharing but have only been anecdotally discussed or in the context of specific case studies. Incomplete systematic evidence on the scope and variety of these barriers has limited opportunities to maximize the value and use of public health data for science and policy.

Methods

We conducted a systematic literature review of potential barriers to public health data sharing. Documents that described barriers to sharing of routinely collected public health data were eligible for inclusion and reviewed independently by a team of experts. We grouped identified barriers in a taxonomy for a focused international dialogue on solutions.

Results

Twenty potential barriers were identified and classified in six categories: technical, motivational, economic, political, legal and ethical. The first three categories are deeply rooted in well-known challenges of health information systems for which structural solutions have yet to be found; the last three have solutions that lie in an international dialogue aimed at generating consensus on policies and instruments for data sharing.

Conclusions

The simultaneous effect of multiple interacting barriers ranging from technical to intangible issues has greatly complicated advances in public health data sharing. A systematic framework of barriers to data sharing in public health will be essential to accelerate the use of valuable information for the global good.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-1144) contains supplementary material, which is available to authorized users.

Intravesical ethiodized oil injection technique for image-guided radiation therapy for bladder cancer

337

Background: Bladder sparing trimodality therapy consisting of maximal TURBT, radiation, and chemotherapy offers a feasible and effective option to patients with muscle invasive bladder cancer that are unwilling to undergo cystectomy. The shape and position of the bladder change significantly during radiation therapy, and it is possible to miss the tumor bed when a radiation boost is delivered to only part of the bladder. This study describes the technique of injecting ethiodized oil in the submucosa of the urinary bladder wall as a novel modality to improve localization of muscle invasive bladder tumors prior to image-guided radiation therapy (IGRT). Methods: Eight patients underwent submucosal ethiodized oil injections at the time of transurethral bladder tumor re-resection. A rigid cystoscope with a working port was used to inject ethiodized oil into bladder submucosa circumferentially around the tumor bed (2-3 mm from margin of resection). Roughly 20-30 injections were used to demarcate the tumor bed for external beam radiation therapy, which was used as part of a bladder sparing approach. All patients were diagnosed with clinically localized, high-grade, muscle invasive carcinoma and were deemed nonsurgical candidates or were unwilling to undergo radical cystectomy. Results: 5 of the 8 patients underwent IGRT at our institution. 95% of ethiodized oil injections were visible on treatment planning CT scans and kV portal images throughout the 7-week course of IGRT. In 2 of 5 patients, the tumor bed based upon ethiodized oil extended outside a planning target volume that would have been treated with radiation therapy based upon cystoscopy reports and computed tomography scans without ethiodized oil. There were no adverse events or treatment-related toxicities secondary to ethiodized oil injection. Conclusions: Intravesical ethiodized oil injection is an easy-to-perform technique that is safe and effective. Ethiodized oil serves as a fiducial marker that improves tumor bed localization for radiation therapy, thereby reducing the likelihood of missing the tumor.

Quality of life after high-dose rate brachytherapy monotherapy for prostate cancer

278

Background: There is little information in the literature on health-related quality-of-life (HRQOL) changes due to high-dose-rate (HDR) brachytherapy monotherapy for prostate cancer. Methods: We conducted a prospective study of HRQOL changes due to HDR brachytherapy monotherapy for low risk or favorable intermediate risk prostate cancer. Forty-nine of 84 (58%) patients who were treated between February 2011 and April 2013 completed 50 questions comprising the Expanded Prostate Cancer Index Composite (EPIC) before treatment and 6 and/or 12 months after treatment. Results: Six months after treatment, there was a significant decrease (p<0.05) in EPIC urinary, bowel, and sexual scores, including urinary overall, urinary function, urinary bother, urinary irritative, bowel overall, bowel bother, sexual overall, and sexual bother scores. By one year after treatment, all EPIC scores had increased and were not significantly different from baseline values. Conclusions: HDR brachytherapy monotherapy is well-tolerated in patients with low and favorable intermediate risk prostate cancer. Urinary, bowel, and sexual domain scores returned to close to baseline 12 months after treatment.

Elevated serum levels of IL-10 are associated with inferior progression-free survival in patients with Hodgkin's disease treated with radiotherapy

Elevated pretreatment serum interleukin-10 (IL-10) is associated with inferior progression-free survival (PFS) in patients with Hodgkin's disease (HD) treated with ABVD or equivalent regimens. Therefore, we explored the association of serum IL-10 with presenting features and PFS in HD patients treated only by radiotherapy (RT) with curative intent. Eligible patients were previously untreated, had biopsy-proven HD, were older than 16 years, HIV-negative, and had unthawed pretreatment serum. Serum IL-10 levels were measured with ELISA and were considered high if > or = 10 pg/ml. We identified 69 patients with median age of 34 years (range 16 - 74), of who 52% were males, and 3% had B-symptoms. Ann Arbor Stage was I in 35%, II in 58%, and III in 7% of the patients. Histology was lymphocyte predominance in 26%, and classical HD in 74% of the patients. Serum IL-10 was elevated in 35% of the patients. After a median follow-up of 67 months for survivors, the 5-year PFS of patients with high vs. normal serum IL-10 was 50% vs. 81% (all patients, P = 0.006), and 43% vs. 77% for the subset with classical HD (P = 0.008). Multivariate analysis revealed that high serum IL-10 and beta2-microglobulin were independently associated with inferior PFS. Patients with none, 1, or 2 adverse features comprised 57%, 36%, and 7% of the population, and their 5-year PFS was 80%, 63%, and 0%, respectively (P < 0.0001). In conclusion, high serum IL-10 is independently associated with inferior PFS in patients with HD treated with RT.

Trade-off to low-grade toxicity with conformal radiation therapy for prostate cancer on Radiation Therapy Oncology Group 9406

The aim of this study was to evaluate and compare the rates of grade 2 or worse late effects in patients treated for prostate cancer on Radiation Therapy Oncology Group (RTOG) 9406. The authors previously have reported the results of patients treated on the first 2 dose levels of this study with respect to grade 3 or greater late toxicity. This analysis examines the incidence of grade 2 toxicity in this study. From August 1994 to September 1999, 424 patients were entered on this dose escalation trial of 3-dimensional conformal radiation therapy (3D CRT) for localized adenocarcinoma of the prostate at doses of 68.4 Gy (level I) and 73.8 Gy (level II). All radiation prescriptions were a minimum dose to a planning target volume. Patients were stratified according to clinical stage and risk of seminal vesicle invasion based on Gleason score and presenting prostate-specific antigen. Average time at risk after completion of therapy ranged from 33.1 to 40.1 months for patients treated at dose level I and 15.6 to 34.2 months for patients at dose level II. The frequency of late effects > or = grade 2 was compared with a similar group of patients treated on RTOG studies 7506 and 7706 with adjustments made for the interval from completion of therapy. The RTOG toxicity scoring scales for late effects were used. The rate of grade 3 or greater late toxicity continues to be low compared with RTOG historical controls. No grade 4 or 5 late complications were reported in any of the 406 evaluable patients during the period of observation. Interestingly, the incidence of grade 2 late toxicity was increased relative to historical controls in all groups and dose levels. In group 1, level I and group 3, level II, the increase in grade 2 complications was statistically significant; 16 complications were observed in group 1, level I when 9.2 were expected (P =.026) and 22 were observed in group 3, level II when 7.6 were expected (P <.0001). When examining all late effects > or = grade 2, there were no significant differences in the rate of late effects in both groups and both dose levels with the exception of group 1, level II. This, in combination with the statistically significant decrease in late effects > or = grade 3, suggests that in most circumstances there has been a shift of grade 3 complications to grade 2. In group 1, dose level II there was a statistically significant reduction in > or = grade 2 late effects, suggesting there was no shift from grade 3 to grade 2 in these patients. In this circumstance there may have been a global reduction in all complications or a shift to late effects less severe than grade 2. In group 2, dose level II there is a trend (P =.085) toward this same result. It is important to continue to examine late effects closely in patients treated on RTOG 9406. The primary objective of dose escalation without an increase rate of > or = grade 3 complications has been achieved. However, the reduction in grade 3 complications may have resulted in a higher incidence of grade 2 late effects. Because grade 2 late effects may have a significant impact on a patient's quality of life, it is important to reduce these complications as much as possible. Improved conformal treatment delivery with intensity-modulated radiation therapy or the use of radioprotective agents could be considered. Clinical trials should use quality-of-life measures to determine that trade-offs between severity and rates of toxicity are acceptable to patients.

Twice-weekly paclitaxel and weekly carboplatin with concurrent thoracic radiation followed by carboplatin/paclitaxel consolidation for stage III non-small-cell lung cancer: a California Cancer Consortium phase II trial

PURPOSE

Recent studies have suggested the superiority of concurrent chemoradiotherapy and the efficacy of paclitaxel/carboplatin in advanced non-small-cell lung cancer (NSCLC). In view of those results, we sought to examine the safety and efficacy of administration of radiosensitizing paclitaxel twice weekly and carboplatin weekly with concurrent thoracic radiation therapy (XRT) followed by consolidation paclitaxel and carboplatin for stage III NSCLC in a multi-institutional phase II trial.

PATIENTS AND METHODS

Induction chemoradiotherapy consisted of paclitaxel 30 mg/m2 delivered intravenously (IV) for 1 hour twice weekly for 6 weeks, carboplatin at a dose based on an area under the concentration-time curve (AUC) of 1.5 mg/mL x min, given IV once weekly for 6 weeks, and concomitant XRT of 1.8 to 2.0 Gy daily for a total of 61 Gy. Patients who achieved a complete response, partial response, or stable disease received two 21-day cycles of consolidation chemotherapy consisting of paclitaxel 200 mg/m2 IV for 3 hours and carboplatin at a dose based on an AUC of 6 mg/mL x min.

RESULTS

Thirty-four patients were eligible. Their median age was 62 years (range, 39 to 73 years), 59% were female, 41% were male, 94% had a performance status of 0 or 1, 38% had stage IIIA NSCLC, and 62% had stage IIIB NSCLC. Common grade III and IV toxicities during the induction chemoradiation phase included esophagitis (38%) and neutropenia (12%). The most common adverse reaction during consolidation chemotherapy was grade III neutropenia in five patients (15%). The overall response rate was 71%, which was achieved in the induction phase. The median follow-up was 20 months, the median survival was 17 months, and 2-year actuarial survival rate was 40% (95% confidence interval, 20% to 65%).

CONCLUSION

This regimen is tolerable and results are promising. We recommend further evaluation of this regimen in a phase III trial.

Pharmacodynamic effects of ketoprofen on crevicular fluid prostanoids in adult periodontitis

The reported therapeutic benefits of nonsteroidal anti-inflammatory drugs (NSAIDs) in slowing periodontal disease progression appear intimately linked to the effective inhibition of local prostaglandin synthesis. This randomized, partially double-blind, controlled trial was conducted to evaluate the pharmacodynamic effects of the NSAID, ketoprofen (KTP), on gingival crevicular fluid (GCF) prostanoids. 42 subjects, ages 35-57 years, with moderate to advanced adult periodontitis were recruited and monitored for 22 days. On day 1, subjects were randomized for 1 of 5 treatments: i) 0.5% KTP gel; ii) 1.0% KTP gel; iii) 1.0% KTP alternate gel; iv) 2.0% KTP gel; v) 25 mg KTP capsule (positive control). Subjects applied 1 ml of gel topically to their gingiva or administered one capsule p.o., b.i.d. for 14.5 days. GCF samples were collected from posterior, interproximal sites on days 1 (pre-dosing; 1, 2, 3, 6 h), 8 (pre-dosing; 2 h), 15 (pre-dosing; 2 h) and 22 (post-treatment). GCF levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were determined using RIA, and expressed in ng/ml and % reduction from baseline (%Effect). Neither a significant difference among groups nor a dose response in % effect for either prostanoid was evident, both overall and among cohorts with elevated baseline mediator levels ([PGE2]>34 ng/ml; [LTB4]>300 ng/ml). When data were combined from all groups, significant (p<0.01) % reductions in GCF PGE2 were noted at 1 and 2 h post-dosing (29% and 24% respectively). In comparing topical versus systemic formulations, all topical formulations were as equipotent as systemic dosing in altering local prostaglandin levels despite lower KTP exposures with gel treatments. These data indicate that both topical and systemic KTP therapies pharmacodynamically reduce GCF PGE2 levels in adult periodontitis subjects, allowing for potential inhibition of disease progression.

Concurrent twice-weekly paclitaxel and thoracic irradiation for stage III non-small cell lung cancer

Concurrent twice-weekly paclitaxel and thoracic radiation (XRT) for stage III non-small cell lung cancer were studied in a phase I trial. Radiation was delivered in fractions of 1.8 to 2.0 Gy/d to a total dose of 61 Gy. Paclitaxel, at a starting dose of 25 mg/m2/d, was administered intravenously over 1 hour before daily XRT on Mondays and Thursdays for 6 weeks for a total of 12 doses. The paclitaxel dose was escalated by 5 mg/m2/d for each cohort of patients to determine the maximum tolerated dose. The highest dose of paclitaxel reached was 40 mg/m2, which resulted in dose-limiting toxicities of esophagitis and local skin desquamation. For each dose group, the median total number of paclitaxel doses administered was 12 and the median total XRT dose delivered was 61 Gy. The overall response rate was 80%. The overall median survival was 20 months and the 3-year survival rate was 20%. We conclude that the maximum tolerated dose of paclitaxel is 35 mg/m2 given twice weekly for 6 weeks concurrently with XRT. This study provides the basis for using paclitaxel, given twice weekly at 30 mg/m2, with weekly carboplatin and concurrent XRT for stage III non-small cell lung cancer in an ongoing phase II trial.

Pharmacokinetic and safety evaluations of ketoprofen gels in subjects with adult periodontitis

This clinical trial used a randomized, partially double-blind, controlled parallel design to evaluate the pharmacokinetics and safety of the NSAID, ketoprofen (KTP), in gel formulations. Forty-two subjects, ages 35 to 57 years, with generalized, moderate to advanced adult periodontitis were recruited and randomized to one of 5 treatments over a 14 1/2-day treatment period: (1) 0.5% KTP gel; (2) 1.0% KTP gel; (3) 1.0% KTP alternate gel; (4) 2.0% KTP gel; and (5) 25 mg KTP capsule (positive control). Plasma samples were obtained on days 1 (pre-dosing, 0.5, 1, 2, 3, 6 hr), 8 (pre-dosing, 2 hr), 15 (pre-dosing, 2 hr), and 22 (7 days post-treatment). Plasma KTP concentrations were determined by means of high-performance liquid chromatography. Significant differences in mean area under the plasma concentration vs. time curve (AUC(0-infinity)) among the groups were detected (p < 0.001), with the 25 mg p.o. capsule exhibiting the largest value (5054 ng-hr/mL), the 2.0% gel exhibiting an intermediate value (2244 ng-hr/mL), the 1.0% gels exhibiting lower but comparable values (1516 for the alternate formulation vs. 1461 ng-hr/mL), and the 0.5% gel showing the lowest value (736 ng-hr/mL). Significant differences in dose- and weight-adjusted maximum plasma concentration (Cmax/dose/kg) were detected overall such that the 25 mg p.o. capsule demonstrated higher values as compared with the 4 gel formulations (p = 0.001). The 5 treatments exhibited similar mean times of maximum plasma concentration (tmax) values ranging from 0.6 to 1 hr. Systemic exposures relative to dose and body weight were lower for the gel formulations than for the capsule. The relative systemic bioavailability of the gels compared with peroral administration ranged from 54% to 69%.

High dose versus low dose fludarabine in the treatment of patients with severe refractory rheumatoid arthritis

OBJECTIVE

Fludarabine, a nucleoside analog that targets both resting and proliferating lymphocytes, is a promising drug for the treatment of autoimmune diseases. We conducted a 2 dose, open label clinical trial to evaluate the toxicity/safety of the fludarabine treatment and its clinical and immunological effects.

METHODS

Twenty-six patients with severe rheumatoid arthritis (RA) refractory to treatment with at least one slow acting antirheumatic drug were treated with intravenous fludarabine [20 mg/m2 body surface area (n=12) or 30 mg/m2 body surface area (n=14) per day for 3 consecutive days] given monthly for 6 months. Second line agents with the exception of glucocorticoids were discontinued at least 4 weeks before study entry. Measurements included toxicity and tolerability monitored at monthly intervals: efficacy, by both a 50% reduction in tender or swollen joint count and American College of Rheumatology (ACR) criteria for 20% response; and phenotypic analysis of peripheral blood mononuclear cells and T cell functional assays.

RESULTS

Using intention-to-treat analysis, 2 of 12 (17%) patients in the low dose and 7 of 14 (50%) in the high dose groups had 50% or greater reduction in tender and/or swollen joint count after 6 months of therapy compared to baseline (p=0.09). Two of 12 (17%) in the low dose group and 5 of 14 (36%) in the high dose group met ACR criteria for 20% improvement (p=0.28). No immediate toxicity was observed. Several infections occurred, including 4 episodes of limited Herpes zoster, which responded to standard therapy. Significant lymphopenia involving T and B cells was observed in all patients. Both naive (CD4+CD45RA+) and memory CD4+ T cells (CD4+CD45RO+) were reduced (naive > memory). No significant regeneration of naive T cells was observed, which may suggest limited thymic regenerative capacity. Fludarabine decreased the proliferative response of peripheral blood lymphocytes to mitogens, as well as the production of T cell (interleukin 2 and interferon-gamma) and monocyte derived (tumor necrosis factor-alpha and IL-10) cytokines.

CONCLUSION

Fludarabine treatment of patients with severe, refractory RA resulted in significant lymphopenia, suppression of lymphocyte function, and clinical improvement in the high dose group. There was no immediate toxicity; however, several infections occurred. Controlled trials are needed to substantiate the clinical improvement observed in this open label trial.

Complex Regional Pain Syndromes: guidelines for therapy

This report aims to present an orderly approach to the treatment of Chronic Regional Pain Syndrome (CRPS) types I and II through an algorithm. The central theme is functional restoration: a coordinated but progressive approach that introduces each of the treatment modalities needed to achieve both remission and rehabilitation. Reaching objective and measurable rehabilitation goals is an essential element. Specific exercise therapy to reestablish function after musculoskeletal injury is central to this functional restoration. Its application to CRPS is more contingent on varying rates of progress that characterize the restoration of function in patients with CRPS. Also, the various modalities that may be used, including analgesia by pharmacologic means or regional anesthesia or the use of neuromodulation, behavioral management, and the qualitatively different approaches that are unique to the management of children with CRPS, are provided only to facilitate functional improvement in a stepwise but methodical manner. Patients with CRPS need an individual approach that requires extreme flexibility. This distinguishes the management of these conditions from other well-described medical conditions having a known pathophysiology. In particular, the special biopsychosocial factors that are critical to achieving a successful outcome are emphasized. This algorithm is a departure from the contemporary heterogeneous approach to treatment of patients with CRPS. The underlying principles are motivation, mobilization, and desensitization facilitated by the relief of pain and the use of pharmacologic and interventional procedures to treat specific signs and symptoms. Self-management techniques are emphasized, and functional rehabilitation is the key to the success of this algorithm.

Twice-weekly paclitaxel and radiation for stage III non-small cell lung cancer

A phase I study was conducted to investigate the safety and efficacy of twice-weekly paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and concurrent thoracic irradiation in patients with stage III non-small cell lung cancer. Radiation therapy beginning on day 1 was delivered in 1.8- to 2.0-Gy daily fractions, to a total dose of 61 Gy. Paclitaxel at a starting dose of 25 mg/m2/d was administered intravenously over 1 hour before daily radiation on days 1, 4, 8, 11, 15, 18, 22, 25, 29, 32, 36, and 39, for a total of 12 doses over 6 weeks. The paclitaxel dose was escalated by 5 mg/m2/d in each cohort of patients to determine the maximum tolerated dose. The highest paclitaxel dose reached was 40 mg/m2/d, as defined by dose-limiting toxicities of esophagitis and desquamation within the radiation fields. For each dose group, the median total number of paclitaxel doses administered was 12 and the median total radiation dose was 61 Gy. Response rates ranging from 50% to 100% were observed (three of six patients at paclitaxel 25 mg/m2, four of six at 30 mg/m2, seven of seven at 35 mg/m2, six of six at 40 mg/m2), for an overall response rate of 80%. We conclude that the maximum tolerated dose of paclitaxel is 35 mg/m2 given twice weekly in a 1-hour infusion for 6 weeks concurrently with thoracic irradiation. This study provides the basis for an ongoing trial combining twice-weekly paclitaxel and carboplatin with concurrent thoracic irradiation for patients with stage III non-small cell lung cancer.

Glucocorticoids prolong rat sciatic nerve blockade in vivo from bupivacaine microspheres

BACKGROUND

Previous work showed that incorporation of dexamethasone (0.05 weight/weight percentage) into bupivacaine microspheres prolonged blockade by eight to 13 times compared with that produced by bupivacaine microspheres alone. The determinants of dexamethasone's block-prolonging effect were examined and reported here.

METHODS

Polylactic-co-glycolic acid polymer microspheres (65/35) with 75 weight/weight percentage bupivacaine were prepared. Microspheres were injected adjacent to the rat sciatic nerve, and sensory and motor blockade were assessed. A procedure was developed to test drugs for block-prolonging ability in vivo by placing test drugs in the injection fluid along with a suspension of bupivacaine microspheres.

RESULTS

Dexamethasone alone in suspension did not produce blockade, nor did it prolong blockade induced by aqueous bupivacaine. Bupivacaine microspheres (150 mg drug/kg rat weight) produced blockade for 6 to 10 h. Dexamethasone in the suspending solution of microspheres prolonged block by up to five times. Glucocorticoids prolonged block in proportion to glucocorticoid/antiinflammatory potency. The corticosteroid antagonist cortexolone inhibited dexamethasone's blockade-prolonging action. Durations of blockade with or without dexamethasone were unaltered by hydroxyurea-induced neutrophil depletion. Microspheres were extracted from rats at time points ranging from 7 h to 7 days, and residual microsphere dry weight and bupivacaine content were similar in groups of rats injected with either bupivacaine microspheres or bupivacaine microspheres containing dexamethasone, respectively.

CONCLUSIONS

Glucocorticoids prolong blockade from bupivacaine microspheres. The mechanism appears unrelated to the kinetics of bupivacaine release in vivo.

Exercise stimulates interleukin-6 secretion: inhibition by glucocorticoids and correlation with catecholamines

In experimental animals, stress and catecholamines stimulate endogenous interleukin-6 (IL-6) secretion, whereas glucocorticoids inhibit it. To examine whether physical stress alters the secretion of IL-6 in humans, and to what extent this is correlated with catecholamines and modified by glucocorticoids, we performed high-intensity treadmill exercise test runs on 15 male volunteers, in a double-blind crossover design, after pretreatment with placebo, hydrocortisone, or dexamethasone. Plasma epinephrine and norepinephrine concentrations peaked 15 min after the start of exercise, whereas plasma IL-6 concentrations peaked twice, 15 min and 45 min after the onset of the test run. There was no difference in either the epinephrine or norepinephrine peaks among the three treatments, but the net area under the curve for IL-6 was smaller after hydrocortisone or dexamethasone than after placebo and smaller after dexamethasone than after hydrocortisone. A positive correlation was observed between peak plasma epinephrine or norepinephrine and IL-6 levels at 15 min. These findings suggest that IL-6 secretion is stimulated during exercise, possibly by catecholamines, whereas exogenous glucocorticoids attenuate this effect without affecting the catecholamine levels.

Reduction of plasma prolactin by acute administration of CB-154 in ovariectomized F344 and Holtzman rats treated with diethylstilbestrol: a comparison of RIA and Nb2 lymphoma bioassay

Fischer 344 (F344) and Holtzman Sprague-Dawley female rats were ovariectomized and implanted with a s.c. Silastic capsule of diethylstilbestrol (DES). At 1, 4 and 8 weeks of DES exposure, blood samples were obtained by infraorbital sinus puncture under light ether anesthesia before and 2 hours after s.c. administration of CB-154 (2.5 mg/rat). The plasma obtained was assayed for prolactin by radioimmunoassay (RIA) and Nb2 lymphoma cell bioassay (BA). At 1 week of DES treatment plasma prolactin in F344 rats measured by RIA was decreased by CB-154 (approximately 60%) whereas the level measured by BA was not changed and the BA:RIA ratio was increased from 2.4 +/- 0.2 to 4.8 +/- 0.9. CB-154 decreased plasma prolactin levels at 4 weeks but the effect seen by RIA (approximately 80%) was greater than that seen by BA (approximately 60%) and the BA:RIA ratio was increased (2.2 +/- 0.2 vs 3.4 +/- 0.5). By 8 weeks of DES exposure, CB-154 was as effective in reducing the levels measured by BA (approximately 89%) as those measured by RIA (approximately 85%) and the BA: RIA was not affected by the dopamine agonist. In Holtzman rats CB-154 decreased prolactin levels measured by RIA and BA to the same extent at both 1 and 4 weeks resulting in no change in the BA:RIA ratio, but at 8 weeks the BA:RIA was decreased by CB-154 (2.1 +/- 0.1 to 1.7 +/- 0.1). As was observed in F344 rats, the reduction in plasma prolactin induced by CB-154 increased as the duration of DES treatment increased (1 week approximately 45%; 4 weeks approximately 55-60%; 8 weeks approximately 80-85% inhibition) regardless of assay method. It is concluded that DES increases the BA:RIA ratio of plasma prolactin and that acute CB-154 treatment increases, decreases or does not change the BA:RIA ratio depending on the strain of rat used and the duration of DES treatment.

Systemic bioavailability and pharmacokinetics of methylprednisolone in patients with rheumatoid arthritis following 'high-dose' pulse administration

The absolute and relative bioavailability of two methylprednisolone formulations (capsules and suspension) was determined along with its pharmacokinetics in four arthritic female patients, following an unconventional high-dose pulse of 1 g. Plasma concentrations of the drug were measured by a sensitive and specific high-performance liquid chromatographic (HPLC) procedure. The disposition of methylprednisolone from plasma following intravenous (i.v.) infusion of its succinate ester appeared monoexponential with a mean half-life of 2.4 h and an apparent volume of distribution (Vd) of 50 l (0.87 l/kg). The total body clearance (Cl) averaged 15.12 l/h. Absolute bioavailability was assessed by comparing the areas under the plasma concentration time curves (normalized to dose) following oral administration of capsule or suspension with those of intravenous administration. No significant difference (p greater than 0.2) was observed when systemic availability (f, expressed in per cent) following administration of drug in capsule (f = 49.35 per cent) was compared with that obtained following the administration of drug in a suspension (f = 58.26 per cent). The difference in the observed and predicted f may be due to incomplete absorption, hepatic and/or extrahepatic metabolism of methylprednisolone. Subjective evaluation showed no side effects of this high-dose pulse therapy in any of the patients.