Long-Term Outcomes of Multidisciplinary Radiation Oncology Equity and Inclusion Committee Programming at an Academic Health System

PURPOSE/OBJECTIVE(S)

Academic radiation oncology departments are increasingly implementing educational programs to promote diversity, equity, and inclusion, but data on their impact remains sparse. This study aimed to assess learning outcomes and perceived impact of the programming of a multidisciplinary radiation oncology equity and inclusion committee (EIC).

MATERIALS/METHODS

Since August 2020, a committee of radiation therapists (RTTs), physicians (MDs), nurses (RNs), and administrators (ADs) has led an alternate-monthly online EIC meeting open to all radiation oncology employees at one health system. Learning goals of EIC programming are (1) to understand disparities in healthcare practice and outcomes for marginalized populations, (2) to discuss current events relevant to marginalized groups, and (3) to identify and address personal bias. EIC has featured expert guest speakers, open discussion, cultural events, and individual storytelling. In February 2023, we conducted a department-wide survey evaluating participation in one or more EIC meetings. EIC participants also completed an evaluation focused on learning goal achievement and program strengths/weaknesses. Multiple choice responses and 5-point Likert scale survey items were descriptively analyzed; open responses were qualitatively coded and categorized into themes.

RESULTS

There were 84 survey respondents, corresponding to a department response rate of 53%. Of these, 37 (44%) indicated participation in at least one EIC meeting. Participants were 35% RTTs, 16% MDs, 14% ADs, 3% physicists/dosimetrists, 3% RNs, and 19% undisclosed profession; 46% identified as a racial, ethnic, sexual, and/or gender minority. 41% of participants attended 5 or more sessions. Participants reported high overall value of the EIC meeting (mean value 3.7 / 5, SD 1.2) and 89% would recommend participation. There was strong agreement with achievement of EIC learning goals (mean agreement [MA] 3.9 / 5, SD 0.91), and most participants reported improved capability to understand (61%, MA 3.72 / 5, SD 0.99) and address (61%, MA 3.75 / 5, SD 0.83) the specific needs of their patients from marginalized groups. The three most common themes of EIC strengths were educational value, speaker quality, and improved work relationships. Commonly requested improvements included more practice scenarios, increasing participation, and giving more equitable attention to all minority groups. Among EIC non-participants, 75% reported non-participation due to scheduling, 71% felt that having an EIC was valuable, and 59% reported a desire to attend an EIC meeting in the future.

CONCLUSION

Nearly 3 years since implementation, EIC programming is highly valued. The majority of participants report achievement of learning goals and perceive self-improvement in care for marginalized groups as a result of participation. Further research is needed to externally validate the impact of this programming on learning and patient care domains.

Practice Patterns and Disparities of Fractionation Schemes for Post-Mastectomy Comprehensive Nodal Irradiation

PURPOSE/OBJECTIVE(S)

Hypofractionated (HF) radiotherapy is the established standard of care for whole breast irradiation and is being investigated for comprehensive nodal irradiation, but appropriate patient selection for the latter is currently undefined. This study aims to report national practice patterns and patient selection for HF comprehensive nodal irradiation compared to conventional fractionation (CF). The hypothesis is that the rate of HF for comprehensive nodal irradiation in breast cancer has been increasing over time and is more likely to be offered to disparate demographic populations.

MATERIALS/METHODS

We queried the National Cancer Database and identified 128,693 patients who received comprehensive nodal irradiation between 2008-2016 in the United States. No patient who underwent lumpectomy received HF nodal irradiation; therefore, only post-mastectomy patients were included in this study. After the exclusion, 29,053 post-mastectomy patients with adjuvant comprehensive nodal irradiation remained. A multivariable binomial regression analysis between HF and CF patients was performed.

RESULTS

Of the patients identified, 1,910 received HF (6.57%), and 27,143 received CF (93.43%) radiotherapy. All patients had locally advanced breast cancer treated with mastectomy, lymph node dissection, adjuvant radiation, and +/- chemotherapy. The median dose in the HF group was 4,256 cGy in 16 fractions, and in the CF group was 6,040 cGy in 33 fractions. HF rate grew from 3.56% in 2004-2007, 5.29% in 2008-2011, 7.42% in 2012-2013, and 12.05% in 2014-2016. HF was favored in older patients (median age 66 vs. 51, OR = 1.16, 95% Cl 1.11-1.22) and those who lived in suburban or rural regions compared to urban or metropolitan regions (OR = 9.48, 95% CI 1.17-76.9). However, there was no correlation when distance from treatment site was evaluated as a continuous variable. A "boost" dose was used in only 10.58% of HF patients compared to 54.6% of CF patients (OR = 0.17, 95% Cl 0.14-0.21). Chemotherapy was delivered in 36.91% of HF patients compared to 78.14% of CF patients (OR = 0.77, 95% Cl 0.59-0.99). There were no statistically significant correlates of either fractionation scheme for breast laterality, stage, grade, or receptor status. Notably, other than population density and age, demographic factors including race, Hispanic origin, insurance type, median income, and education level demonstrated no correlation with radiation fractionation scheme.

CONCLUSION

HF for comprehensive nodal irradiation in breast cancer is still uncommon but growing in popularity. Currently, HF is more likely to be used in elderly patients and lower population density centers and less likely to be used in those determined to benefit from receipt of a boost or chemotherapy.

A Dosimetric Assessment of Sexual Organ Sparing Proton Radiotherapy in Female Pelvic Cancer Patients

PURPOSE/OBJECTIVE(S)

Optimizing treatment techniques for female patients undergoing curative treatment for pelvic cancers requires incorporating the goals of maximizing cure while maintaining quality of life. Optimizing treatment to maintain sexual quality of life has received little attention in female patients despite the presence of and toxicity risks to functional anatomic organs and their associated neurovasculature, including the bulboclitoris, vagina, and ovaries. Recent dosimetric data without employing sexual organ sparing suggest that mean VMAT dose to the bulboclitoris in low rectal cancer is around 3300 cGy, and in anal cancer, mean dose is around 2000 cGy to the external genitalia and 4500-5000 cGy to the bulboclitoris, all of which would be expected to result in clinically significant toxicity. Therefore, investigation of the avoidance of these important organs is needed and we hypothesize that proton techniques may achieve greater sparing than photon techniques.

MATERIALS/METHODS

In this study, we dosimetrically compare proton- vs. photon-based techniques in sparing functional sexual organs. The cohort consisted of four consecutive female pelvic cancer cases that had received 5000 cGy or greater. All cases were re-planned with VMAT and protons while optimizing dose to functional sexual organs and maintaining target coverage. Sexual organ structures assessed include the genitalia, vagina, ovaries, bulboclitoris and internal pudendal arteries. Given the small number of patients included in this demonstration study, statistical tests were not performed.

RESULTS

MRI was required to appropriately delineate soft tissue. In all cases, dosimetric sparing of sexual organs was improved with proton therapy without compromising target coverage. Mean doses were marginally decreased for structures within the PTV, while structures such as the bulboclitoris were spared substantially. Mean dose to the external genitalia was low with sparing using both VMAT (Median [IQR] (cGy): 852 [811, 1090]) and Proton techniques (Median [IQR] (cGy): 39.4 [11.9, 78.5]). Similarly, mean dose with sparing to the external genitalia was lower than would be expected without sparing, using both VMAT and Proton techniques (Median (IQR) Dmean (cGy) VMAT 3100 [2890, 3580] vs. Proton 1530 [1100, 2090]), with protons demonstrating greater sparing. In one case of a sacral chordoma, ovaries were substantially spared to below ablative thresholds (Dmean (cGy) VMAT 3598.8 and 3548.0 vs Proton 34.1 and 103.3).

CONCLUSION

Magnetic resonance imaging at simulation combined with proton radiotherapy for female sexual organ sparing may provide a technically feasible route to more equitable sexual outcomes for female patients. These results will guide future studies to optimize proton treatment techniques for female sexual organ sparing for future trials.

Imaging Findings of Complications After Lateral Extra-Articular Tenodesis of the Knee: A Current Concepts Review

Background:

Despite successful anterior cruciate ligament (ACL) reconstruction, many patients continue to experience persistent anterolateral rotatory instability. Lateral extra-articular tenodesis (LET) is used to address this instability by harvesting a portion of the iliotibial band, passing it underneath the fibular collateral ligament, and attaching it just proximal and posterior to the lateral femoral epicondyle. Based on the most recent clinical evidence, the addition of LET to ACL reconstruction improves clinical outcomes, which has led to an increase in the use of this technique.

Purpose:

To provide an overview of the postoperative complications of the LET procedure and their associated imaging findings, with a focus on magnetic resonance imaging (MRI).

Study Design:

Narrative review.

Methods:

In this scoping review, the authors reviewed available radiographic, computed tomography, and MRI scans of patients who experienced postoperative complications after ACL reconstruction with LET, in which the complication was determined to be from the LET procedure. Images were reviewed and subsequently described by an on-staff musculoskeletal radiologist.

Results:

The authors found 9 different complications associated with LET: graft failure, hematoma, infection, chronic pain, tunnel convergence, fixation device migration, muscular hernia, peroneal nerve palsy, and knee stiffness. They supplemented these findings with radiographic evidence from 6 patients.

Conclusion:

As extra-articular reconstruction techniques including LET become more popular among orthopaedic surgeons, it is important that radiologists and surgeons be adept at recognizing the normal imaging findings of LET and associated complications.

Trends in mortality from aortic stenosis in Europe: 2000–2017

Background

Trends in mortality from aortic stenosis across Europe are not well understood, especially given the significant growth in transcatheter aortic valve replacement (TAVR) in the last 10 years.

Purpose

To describe trends in mortality from aortic stenosis in European countries from 2000 to 2017.

Methods

Age-standardised death rates were extracted from the World Health Organisation Mortality Database, using the International Classification of Diseases 10th edition code for non-rheumatic aortic stenosis for those aged >45 years between 2000 and 2017. The UK and countries from the European Union with at least 1,000,000 inhabitants and at least 50% available datapoints over the study period were included: a total of 23 countries. Trends were described using Joinpoint regression analysis.

Results

No reductions in mortality were demonstrated across all countries 2000–2017 (Figure 1). Large increases in mortality were found for Croatia, Poland and Slovakia for both sexes (>300% change). Mortality plateaued in Germany from 2008 in females and 2012 in males, whilst mortality in the Netherlands declined for both sexes from 2007. Mortality differences between the sexes were observed, with greater mortality for males than females across most countries.

Conclusions

Mortality from aortic stenosis has increased across Europe from 2000 to 2017. There are, however, sizable differences in mortality trends between Eastern and Western European countries. Significant plateauing or declining mortality was observed for recent years in countries with greater access to TAVR, whilst increasing trends were observed in countries with the least TAVR use. The need for health resource planning strategies to specifically target AS, particularly given the expected increase with aging populations, is highlighted.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Joinpoint regression analysis for trends in age-standardised death rates from non-rheumatic aortic stenosis for those aged >45 years in Europe from 2000 to 2017. Clear squares indicate males; filled circles indicate females. The lines (dotted for males, solid for females) represent modelled trends based on joinpoint data.

Pre-operative Two-Point Discrimination Predicts Response to Carpal Tunnel Release

BACKGROUND

Limited evidence informs whether pre-operative values of two-point discrimination (2PD) in patients with carpal tunnel syndrome predict response to surgery.

QUESTIONS/PURPOSES

The primary aim of this study was to determine the predictive value of pre-operative 2PD scores on outcomes following carpal tunnel release (CTR). In particular, we sought to evaluate whether a clinically relevant 2PD threshold exists that can predict symptomatic response after surgery.

METHODS

Patients who underwent CTR between 2014 and 2018 were retrospectively reviewed. Static 2PD scores in each digit, as well as Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and Levine-Katz scores, were collected from pre- and post-operative records. Pearson correlation coefficients assessed the relationship between pre-operative 2PD, early post-operative 2PD, and patient-reported outcome scores. Poor 2PD was defined as 2PD greater than 10 mm.

RESULTS

Eighty-nine hands in 73 patients with a mean follow-up of 1.8 years were analyzed. Mean pre- and post-operative 2PD was 7.2 mm and 6.4 mm, respectively, in the most affected digit when measurable. Twenty patients had poor 2PD scores pre-operatively and 14 post-operatively. There was a positive correlation between pre- and early post-operative 2PD scores but no correlation between pre-operative 2PD score and final post-operative functional scores. Only 30% of patients with poor pre-operative 2PD scores demonstrated improvement, compared with 69% of patients with measurable 2PD.

CONCLUSION

We found that greater pre-operative 2PD scores predicted greater early post-operative 2PD scores but did not lead to worse functional outcome scores post-operatively. Patients with poor pre-operative 2PD scores were likely to demonstrate improvement in functional outcomes scores, while having less reliable improvement in 2PD after CTR. Patients with poor 2PD should be counseled that improvement of tactile perception is less predictable.

Impact of multidisciplinary engagement in a quality improvement blood conservation protocol for craniosynostosis

OBJECTIVE

Patients undergoing open cranial vault remodeling for craniosynostosis frequently experience substantial blood loss requiring blood transfusion. Multiple reports in the literature have evaluated the impact of individual blood conservation techniques on blood transfusion rates during craniosynostosis surgery. The authors engaged a multidisciplinary team and assessed the impact of input from multiple stakeholders on the evolution of a comprehensive quality improvement protocol aimed at reducing or eliminating blood transfusion in patients undergoing open surgery for craniosynostosis.

METHODS

Over a 4-year period from 2012 to 2016, 39 nonsyndromic patients were operated on by a single craniofacial plastic surgeon. Initially, no clear blood conservation protocol existed, and specific interventions were individually driven. In 2014, a new pediatric neurosurgeon joined the craniofacial team, and additional stakeholders in anesthesiology, transfusion medicine, critical care, and hematology were brought together to evaluate opportunities for developing a comprehensive blood conservation protocol. The initial version of the protocol involved the standardized administration of intraoperative aminocaproic acid (ACA) and the use of a cell saver. In the second version of the protocol, the team implemented the preoperative use of erythropoietin (EPO). In addition, intraoperative and postoperative resuscitation and transfusion guidelines were more clearly defined. The primary outcomes of estimated blood loss (EBL), transfusion rate, and intraoperative transfusion volume were analyzed. The secondary impact of multidisciplinary stakeholder input was inferred by trends in the data obtained with the implementation of the partial and full protocols.

RESULTS

Implementing the full quality improvement protocol resulted in a 66% transfusion-free rate at the time of discharge compared to 0% without any conservation protocol and 27% with the intermediate protocol. The administration of EPO significantly increased starting hemoglobin/hematocrit (11.1 g/dl/31.8% to 14.7 g/dl/45.6%, p < 0.05). The group of patients receiving ACA had lower intraoperative EBL than those not receiving ACA, and trends in the final-protocol cohort, which had received both preoperative EPO and intraoperative ACA, demonstrated decreasing transfusion volumes, though the decrease did not reach statistical significance.

CONCLUSIONS

Patients undergoing open calvarial vault remodeling procedures benefit from the input of a multidisciplinary stakeholder group in blood conservation protocols. Further research into comprehensive protocols for blood conservation may benefit from input from the full surgical team (plastic surgery, neurosurgery, anesthesiology) as well as additional pediatric subspecialty stakeholders including transfusion medicine, critical care, and hematology.

Mortality from abdominal aortic aneurysm: trends in European Union 15+ countries from 1990 to 2017

BACKGROUND

This observational study assessed trends in abdominal aortic aneurysm (AAA) death rates in European Union (EU) 15+ countries for the years 1990 to 2017.

METHODS

Age-standardized death rates (ASDRs) were extracted from the Global Burden of Disease Study Global Health Data Exchange. Trends were analysed using joinpoint regression analysis.

RESULTS

Between 1990 and 2017, ASDRs from AAA decreased in all 19 EU15+ countries for women, and in 18 of 19 countries for men. Increasing AAA mortality was observed only for men in Greece (+5·3 per cent). The largest relative decreases in ASDR between 1990 and 2017 were observed in Australia (men -65·6 per cent, women -50·4 per cent) and Canada (men -60·8 per cent, women -48·6 per cent). Over the 28-year interval, the smallest decreases in ASDR for women were noted in Greece (-2·3 per cent) and in Italy (-2·5 per cent). In 2017, the highest mortality rates were observed in the UK for both men and women (7·5 per 100 000 and 3·7 per 100 000 respectively). The lowest ASDR was observed in Portugal for men (2·8 per 100 000) and in Spain for women (1·0 per 100 000). ASDRs for AAA in 2017 were higher for men than women in all 19 EU15+ countries. The most recent trends demonstrated increasing AAA ASDRs in 14 of 19 countries for both sexes; the increases were relatively small compared with the improvements in the preceding years.

CONCLUSION

This observational study identified decreasing mortality from AAA across EU15+ countries since 1990. The most recent trends demonstrated relatively small increases in AAA mortality across the majority of EU15+ countries since 2012.

Trends in malignant melanoma mortality in 31 countries from 1985 to 2015

BACKGROUND

Malignant melanoma (MM) causes the highest absolute number of deaths among skin cancers. An up-to-date analysis of international MM mortality trends is required for assessing the burden of disease, and may support the assessment of the effectiveness of new diagnostic, therapeutic and preventative strategies.

OBJECTIVES

To report MM mortality trends between 1985 and 2015 using the World Health Organization (WHO) Mortality Database.

MATERIALS AND METHODS

We used country-level MM mortality data from the WHO Mortality Database for all countries with high usability death registration data. Mortality trends were described using Joinpoint regression modelling.

RESULTS

Thirty-one countries met the inclusion criteria. All countries, except the Czech Republic, demonstrated increased age-standardized death rates (ASDRs) in males over the observation period. More countries exhibited decreased or stable MM mortality in females. The median mortality rate for 2013-2015 was 2·57 deaths per 100 000 for males and 1·55 per 100 000 for females. Australia and Norway had the highest ASDRs for males (5·72 per 100 000 and 4·55 per 100 000, respectively). Norway and Slovenia had the highest ASDRs for females (3·02 per 100 000 and 2·58 per 100 000, respectively). MM mortality was greater for males than females in all countries, with sex disparity increasing across the period. Disparity in mortality between older and younger cohorts in several countries was also found.

CONCLUSIONS

An overall increase in MM mortality over the past 30 years was observed. However, there was notable variation in mortality trends between countries, as well as between males and females, and between different age groups.

Cadaveric Evaluation of Myelinated Nerve Fiber Count in the Nerve to the Gracilis Muscle in Relation to Use as a Free Functional Muscle Transfer for Elbow Flexion

BACKGROUND

 Optimizing axon count is essential for successful nerve transfer surgery, and a donor-to-recipient axon count ratio greater than 0.7:1 has been associated with improved outcomes. A gracilis free functioning muscle transfer (FFMT) is an option to restore elbow flexion, but its axon count has not been evaluated. Our aim was to quantify the axon count of the nerve to the gracilis muscle.

METHODS

 The nerve to the gracilis was dissected in 10 fresh frozen adult cadaveric hindquarter specimens (four females and six males). The length of the nerve to the gracilis was measured and a biopsy taken. A validated histologic preparation technique was utilized, and axons were counted. The mean length and axon counts were calculated.

RESULTS

 The average axon count in the nerve to the gracilis was 818 (range = 684-1,000, standard deviation [SD] = 116). The average length was 98 mm (range = 81-115 mm, SD = 13 mm).

CONCLUSION

 Our study found the average axon count in the nerve to the gracilis was 818. Prior literature suggests axon count ratio greater than 0.7:1 is associated with better clinical outcomes. Using data from prior studies, the spinal accessory, three intercostal, and two intercostal nerves are all sufficient for the transfer to the nerve to the gracilis with donor to recipient ratios of 1.7:1, 1.3:1, and 0.9:1, respectively.

The Effect of Plate Design on the Flexor Pollicis Longus Tendon After Volar Locked Plating of Distal Radial Fractures

BACKGROUND

Injury to and rupture of the flexor pollicis longus (FPL) tendon are known complications after volar locking plate fixation for distal radial fractures. Recent investigations have demonstrated that plate positioning contributes to the risk of tendon rupture; however, the impact of plate design has yet to be established. The purpose of this study was to compare FPL tendon-to-plate distance, FPL tendon-plate contact, and sonographic changes in the FPL tendon for 2 volar locking plate designs (ADAPTIVE compared with FPL) using ultrasound examination.

METHODS

We identified patients who underwent distal radial fracture fixation by 2 fellowship-trained hand surgeons with either standard (ADAPTIVE) or FPL plates. Patients were matched by age, sex, and Soong grade. Enrolled patients returned for a research-related office visit for a clinical examination and bilateral wrist ultrasound. We measured plate-tendon distance, plate-tendon contact, sonographic changes in the FPL tendon, and postoperative radiographic parameters in the operatively treated wrist and the uninjured wrist.

RESULTS

Forty patients with Soong grade-1 or 2 plate prominence underwent bilateral wrist ultrasound examination; all of the patients had distal radial fracture fixation, 20 with the standard volar locking plate and 20 with the FPL volar locking plate. Similar proportions of patients with the FPL plate (65%) and those with the standard plate (79%) had plate-tendon contact (p = 0.48); however, the FPL volar locking plate group had significantly less of the FPL tendon in contact with the volar plate than the standard volar locking plate group at wrist extension at both 0° (p < 0.001) and 45° (p < 0.001). There was no difference (p = 0.5) in the proportion of patients with sonographic changes in the FPL tendon between the FPL volar locking plate group (25%) and the standard volar locking plate group (21%). The postoperative volar tilt was significantly lower in patients with FPL plate-tendon contact (p = 0.01) and correlated moderately with the percentage of FPL tendon-plate contact at 0° (r = -0.51; p < 0.001) and 45° (r = -0.53; p < 0.001). There were no cases of tendon rupture in the cohort.

CONCLUSIONS

We found that the FPL volar locking plate and increased volar tilt significantly reduced the plate-tendon contact area compared with the standard volar locking plate. In our asymptomatic cohort, we were unable to find a difference in sonographic changes in the FPL tendon. Further studies are needed to determine the clinical importance of decreased tendon-plate contact area seen in modified volar locking plate designs.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of Levels of Evidence.

Innovative Surgical Treatment of Severe Cherubism

Background:

Cherubism is an autosomal dominant syndrome characterized by excessive bilateral maxillomandibular bony degeneration and fibrous tissue hyperplasia. Conservative management is the preferred treatment as cherubism has a self-limiting course. Functional or emotional disturbances may, however, demand surgical intervention. We report a patient who underwent surgical intervention.

Method/Description:

He had significant enlargement of lower cheeks and bilateral lower lid scleral show. On computed tomography of the face, the patient had significant fibrous tissue involving bilateral maxilla and mandible. The mandibular tumor was excised. Given normal inferior border, bilateral sagittal split osteotomy was performed to infracture and inset the outer cortex. During the procedure, patient required blood transfusion intraoperatively, so the maxillary portion of the procedure was delayed until 6 months later. For the maxilla, bilateral transconjunctival approach was used to resect parts of the orbital floors that were concave, resulting in 1 × 2 cm defects bilaterally which were reconstructed using resorbable plates. Then the anterior maxillary tumor was excised.

Results:

The patient and his parents were satisfied with his appearance after surgery. The patient was noted to have improvement in contour and decreased scleral show. He has most recently followed up 15 months after the initial surgery. There were no long-term complications.

Conclusions:

Severity of cherubism influences the type of surgical intervention. The present case is innovative because this is the first reported case of recontouring orbital floors with resorbable plates and infracturing of the mandible using sagittal split osteotomies for surgical treatment of cherubism.

Phase I trial of plerixafor combined with decitabine in newly diagnosed older patients with acute myeloid leukemia

Acute myeloid leukemia carries a dismal prognosis in older patients. The objective of this study was to investigate the safety and efficacy of decitabine combined with the CXCR4 antagonist plerixafor in newly diagnosed older patients with acute myeloid leukemia and to evaluate the effects of plerixafor on leukemia stem cells. Patients were treated with monthly cycles of decitabine 20 mg/m² days 1–10 and escalating doses of plerixafor (320–810 mcg/kg) days 1–5. Sixty-nine patients were treated, with an overall response rate of 43%. Adverse karyotype did not predict response (P=0.31). Prior hypomethylating agent treatment was the strongest independent predictor of adverse overall survival (hazard ratio 3.1; 95%CI: 1.3–7.3; P=0.008) and response (14% in previously treated patients, 46% in treatment naïve; P=0.002). As expected, the most common toxicities were myelosuppression and infection. Plerixafor induced mobilization of leukemia stem and progenitor cells, but did not cause clinically significant hyperleukocytosis. Reduction in leukemia stem cells appeared to correlate with duration of response. Plerixafor can be safely added to decitabine in poor-prognosis, elderly acute myeloid leukemia patients. The maximum tolerated dose of the combination was 810 mcg/kg. While mobilization of leukemia stem cells was observed in some patients, the clinical benefit of adding plerixafor was uncertain. This trial was registered at clinicaltrials.gov identifier: 01352650.

Subcutaneously administered Repronex in oligoovulatory female patients undergoing ovulation induction is as effective and well tolerated as intramuscular human menopausal gonadotropin treatment

OBJECTIVE

To determine the efficacy and safety of Repronex SC as compared with Repronex IM and Pergonal IM in patients undergoing ovulation induction.

DESIGN

Randomized, open-label, multicenter, parallel group study.

SETTING

Ten academic and private fertility clinics with expertise in ovualtion induction.

PATIENT(S)

Premenopausal anovulatory and oligoovulatory females (n = 115) undergoing ovulation induction.

INTERVENTION(S)

Down-regulation with leuprolide acetate followed by up to 12 days of treatment with gonadotropins and hCG administration and luteal phase progesterone support.

MAIN OUTCOME MEASURE(S)

Percentage of patients ovulating; percentage of cycles with follicular development meeting criteria for hCG administration; number of follicles recruited per cycle meeting hCG criteria; peak serum E(2) levels; rates of chemical, clinical and ongoing pregnancies; adverse events; injection-site pain scores.

RESULT(S)

There was no statistically significant difference in the percentage of women who ovulated among the treatment groups. However, Repronex SC was significantly more effective than Pergonal IM in producing follicular development in patients who met hCG criteria. There were no significant differences in clinical, ongoing, or continuing pregnancy rates or in multiple pregnancies among the treatment groups. No differences were found in the safety assessments, proportions or seriousness of adverse events or treatment discontinuations. Also, there were no differences between the three treatment groups in patient-recorded scores of injection-site pain or injection-site reactions.

CONCLUSION(S)

Repronex SC is as efficacious and well tolerated as Repronex IM or Pergonal IM in ovulation induction. Self-administration of Repronex SC provides a convenient treatment alternative to daily IM injections.

Allochronic speciation, secondary contact, and reproductive character displacement in periodical cicadas (Hemiptera: Magicicada spp.): genetic, morphological, and behavioural evidence

Periodical cicadas have proven useful in testing a variety of ecological and evolutionary hypotheses because of their unusual life history, extraordinary abundance, and wide geographical range. Periodical cicadas provide the best examples of synchronous periodicity and predator satiation in the animal kingdom, and are excellent illustrations of habitat partitioning (by the three morphologically distinct species groups), incipient species (the year classes or broods), and cryptic species (a newly discovered 13-year species, Magicicada neotredecim). They are particularly useful for exploring questions regarding speciation via temporal isolation, or allochronic speciation. Recently, data were presented that provided strong support for an instance of allochronic speciation by life-cycle switching. This speciation event resulted in the formation of a new 13-year species from a 17-year species and led to secondary contact between two formerly separated lineages, one represented by the new 13-year cicadas (and their 17-year ancestors), and the other represented by the pre-existing 13-year cicadas. Allozyme frequency data, mitochondrial DNA (mtDNA), and abdominal colour were shown to be correlated genetic markers supporting the life-cycle switching/allochronic speciation hypothesis. In addition, a striking pattern of reproductive character displacement in male call pitch and female pitch preference between the two 13-year species was discovered. In this paper we report a strong association between calling song pitch and mtDNA haplotype for 101 individuals from a single locality within the M. tredecim/M. neotredecim contact zone and a strong association between abdomen colour and mtDNA haplotype. We conclude by reviewing proposed mechanisms for allochronic speciation and reproductive character displacement.

Reproductive character displacement and speciation in periodical cicadas, with description of new species, 13-year Magicicada neotredecem

Acoustic mate-attracting signals of related sympatric, synchronic species are always distinguishable, but those of related allopatric species sometimes are not, thus suggesting that such signals may evolve to "reinforce" premating species isolation when similar species become sympatric. This hypothesis predicts divergences restricted to regions of sympatry in partially overlapping species, but such "reproductive character displacement" has rarely been confirmed. We report such a case in the acoustic signals of a previously unrecognized 13-year periodical cicada species, Magicicada neotredecim, described here as a new species (see Appendix). Where M. neotredecim overlaps M. tredecim in the central United States, the dominant male call pitch (frequency) of M. neotredecim increases from approximately 1.4 kHz to 1.7 kHz, whereas that of M. tredecim remains comparatively stable. The average preferences of female M. neotredecim for call pitch show a similar geographic pattern, changing with the call pitch of conspecific males. Magicicada neotredecim differs from 13-year M. tredecim in abdomen coloration, mitochondrial DNA, and call pitch, but is not consistently distinguishable from 17-year M. septendecim; thus, like other Magicicada species, M. neotredecim appears most closely related to a geographically adjacent counterpart with the alternative life cycle. Speciation in Magicicada may be facilitated by life-cycle changes that create temporal isolation, and reinforcement could play a role by fostering divergence in premating signals prior to speciation. We present two theories of Magicicada speciation by life-cycle evolution: "nurse-brood facilitation" and "life-cycle canalization."

Three approaches to use of questioning by clinical lecturers: a pilot study

In the current health care climate nurses require very good problem solving and critical thinking skills. Questioning as a teaching strategy is viewed as one way to promote such student learning. Using a comparative descriptive quantitative and a qualitative approach, this pilot study investigated the types of questions asked of students by lecturers working within the preceptorship model in the clinical setting. A convenience sample of five volunteer nursing lecturers were tape recorded during their interactions with undergraduate students (n = 8). Initially two auditing approaches were used to analyse the interview data: relevant parts of Mogan and Warbinek's (1994) Observation of Nursing Teachers in Clinical Settings instrument (ONTICS Tool) and Craig and Page's (1981) conceptual framework as adapted by Sellappah, Hussey, Blackmore and McMurray (1998). The data were further analysed by qualitative content analysis. This study supported the findings of the ONTICS tool and Sellappah et al's framework that teachers asked predominantly directive style and low level questions. What the two approaches did not adequately capture was the complexity of the lecturers' questioning behaviours or the effects of contextual factors. The content analysis process however, identified three broad categories forming a model that effectively integrated aspects of the context of the lecturer/student interaction. It also represented lecturer questioning behaviours more comprehensively. The preliminary model offered has the potential to highlight the importance of lecturers asking questions that lead students to extend their thinking about practice. It could also contribute to student learning by assisting lecturers to understand the value and critical nature of their questioning and serve as a framework for staff development.

Platelets and DAMI megakaryocytes possess beta-secretase-like activity

We report here the discovery of two novel human platelet and megakaryocytic DAMI cell enzymes that have beta-secretase-like activity. These activities could potentially effect cleavage of the amyloid precursor protein (APP) at the beta-amyloid peptide N-terminus, by an EC 3.4.24.15-like metalloprotease, and the N terminus-1 position, by a serine protease. Thus both enzymes may generate the amyloidogenic beta-peptide. Studies of intact and Triton X-100-lysed DAMI cells, as well as intact versus subcellular fractions of platelets, demonstrate the presence of these proteolytic activities. The resting platelet has (1) a surface serine protease, demonstrated by its ability to cleave a beta-secretase substrate and by its inhibitor sensitivity; and (2) a metalloprotease, recognized by an antibody to EC 3.4.24.15, which resides intracellularly in the alpha-granule membrane, is translocated to the surface on activation, and shows beta-secretase-like activity by cleaving the same substrate. This metalloprotease can also cleave recombinant APP to a potentially amyloidogenic fragment. Surface metalloprotease was identified in DAMI cells by flow cytometry and Western blotting with a specific anti-EC 3.4.24.15 monoclonal antibody, while activity was identified by using two beta-secretase substrates. This article is the first to document two previously unknown endoproteinases with beta-secretase-like activity in platelets and DAMI cells. These proteases are capable of effecting cleavage of APP and could therefore contribute to Abeta deposition in the cerebrovasculature.

Induction of matrix metalloproteinase-2 in human immunodeficiency virus-1 glycoprotein 120 transgenic mouse brains

Human immunodeficiency virus (HIV)-1 can invade the brain and cause degeneration of the central nervous system, resulting in a host of cognitive and motor impairments. HIV-1 glycoprotein 120 (gp120), has been implicated in the neurodegenerative effects of HIV infection. Here, gp120's neurotoxic potential is demonstrated in both transgenic mice and cultured cells. We observed that gp120 causes an induction of matrix metalloproteinase (MMP)-2 activity and protein in transgenic mouse brains and in transfected C6 cells. We propose that induced MMP-2 may contribute to a neurodegenerative environment by degrading extracellular matrix (ECM) fibronectin and type IV collagen.

Blood brain barrier endothelial cells express candidate amyloid precursor protein-cleaving secretases

Proteolytic cleavage of the amyloid precursor protein (A beta PP) results in the generation of the amyloidogenic fragment known as amyloid beta peptide (A beta). Deposition of A beta in the brain parenchyma and cerebrovasculature is a feature of Alzheimer's disease (AD). To date, the process whereby A beta is generated and deposited remains unclear. We have previously established that activated platelets from AD patients retain more A beta PP on their surface than control platelets. We report here that an endothelial cell-derived enzyme can cleave this surface platelet A beta PP. Human blood brain barrier endothelial cells from brains of AD patients were assayed for potential A beta PP-cleaving enzymes using synthetic peptide substrates encompassing the A beta N-terminus cleavage site. A protease activity capable of cleaving A beta PP on the surface of AD platelets was noted. The A beta PP cleavage is partially inhibited by EDTA, by ZincOV, as well as by a specific inhibitor of the Zn metalloprotease E.C.3.4.24.15. Furthermore, the protease is recognized by an antibody directed against it, using immunohistochemistry, Western blot analysis and flow cytometry. The protease is not secreted, but rather resides intracellularly as well as on the surface of the endothelial cells. The data suggest that E.C.3.4.24.15 synthesized by brain endothelial cells may process the platelet-derived A beta PP, yielding fragments which could contribute to cerebrovascular A beta deposits.

Identification of a novel serine protease-like molecule in human brain

Proteolysis of the amyloid beta protein precursor (APP) is a key event in the development of Alzheimer's disease. In our search for proteases that can cleave APP and liberate the amino terminus of the amyloidogenic beta protein, we characterized a calcium-dependent serine protease (CASP) which is present in reactive astrocytes and cross-reacts with anti-cathepsin G antibodies. We wanted to take advantage of this cross-reactivity to clone the cDNA of CASP and eventually evaluate its tissue distribution. Screening of two human fetal brain cDNA libraries with anti-cathepsin G antibodies led to the identification of a cDNA coding for a novel protein whose only homology to known proteins is to the active site of trypsin-type serine proteases. We called this protein the novel serine protease (NSP). NSP exists in at least three differentially spliced forms, one of which is expressed predominantly in brain and testis. Immunohistochemistry and immunoprecipitation with antibodies generated against NSP show that it is expressed and secreted by a variety of cells and that, in brain, it is found primarily in cerebrovascular smooth muscle cells and reactive astrocytes.

Synthesis and secretion of active alpha 1-antichymotrypsin by murine primary astrocytes

Activated astrocytes have been identified as the main source of the serine protease inhibitor alpha 1-antichymotrypsin (ACT), an acute phase protein that is tightly associated with amyloid plaques in Alzheimer's disease (AD) and in normal aged human and monkey brain. We analyzed the synthesis of ACT by cultured murine astrocytes in vitro. The murine astrocytes expressed an ACT-like antigen that crossreacted with antibodies to human ACT. The murine ACT-like protein is secreted by the astrocytes and is able to form an SDS-resistant complex with the serine protease cathepsin G, indicating that the secreted ACT is biologically active. We conclude that cultured primary astrocytes synthesize and secrete murine ACT in an active form. We, therefore, suggest that the ACT present within AD plaques is locally derived from plaque-associated activated astrocytes as a part of a glia-mediated local inflammatory response that is associated with the neurodegeneration seen in AD.

Cardiotonic agents. 6. Histamine analogues as potential cardiovascular selective H2 agonists

Twenty-six alkyl and aralkyl histamine analogues were prepared as potential cardiotonic agents. Compounds were designed to allow interaction with a putative secondary aryl binding site at the H2 receptor, the presence of which was inferred from the structure of cyprohepatadine, which is known to have H2-antagonist properties. The compounds were examined for inotropic activity in ferret papillary muscle. Potent inotropic activity was generally found in N-alkyl- and N,N-dialkylimidazole-4-ethanamines, whereas N-(amidoalkyl)imidazole-4-ethanamines and N-alkylimidazole-4-propanamines were at best weakly active. Five compounds were examined in screens designed to assess hemodynamic effects and gastric acid secretion in vivo. Two of these compounds, alpha-(3-phenyl-2-transpropenyl)-1H-imidazole-4-ethanamine and N-heptyl-1H-imidazole-4-ethanamine, showed positive inotropic activity with minimal effects on heart rate and mean arterial pressure in vivo; however, both compounds were found to stimulate gastric acid secretion. These results demonstrate that selectivity between various H2-receptor-mediated activities can be obtained with substituted histamine analogues.

Cholinergic false transmitters: physiological and biochemical actions in central and peripheral systems

Three N-ethyl substituted analogs of acetylcholine (ACh) were evaluated for potential use as false neurotransmitters to decrease cholinergic transmission. This evaluation included (1) the elevation of arterial blood pressure upon central administration, (2) depression of blood pressure upon intravenous injection and (3) interactions with central muscarinic and peripheral nicotinic receptors. With respect to the central pressor response, ACh, acetylmonoethylcholine (AMECh) and acetyldiethylcholine (ADECh) were full agonists of decreasing potency; acetyltriethylcholine (ATECh) was a partial agonist of considerably lower potency. The duration of response paralleled potency. With respect to the peripheral depressor response, ACh and AMECh were full agonists of equal potency, and ADECh and ATECh were partial agonists of at least 100-fold lower potency. In terms of their affinity for central muscarinic receptors (brainstem and cerebral cortex), the following series was obtained: ACh greater than AMECh much greater than ADECh = ATECh. All of the agents had a greater affinity for muscarinic receptors in the brainstem compared to cortex. Acetylcholine and AMECh recognized multiple receptor binding conformations; the binding of ADECh and ATECh indicated interaction with a single set of equivalent sites. The affinity for nicotinic ACh receptors from the Torpedo electric organ was ACh = AMECh much greater than ADECh; ATECh had little affinity for these receptors. Acetylcholine, AMECh and ADECh stimulated the binding of [3H]phencyclidine to the ion channel of nicotinic receptor (potency series = ACh greater than AMECh = ADECh); ATECh was inactive. Acetylcholine, AMECh and ADECh also induced receptor conversion to a desensitized conformation; ATECh did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Group C Niemann-Pick disease: faulty regulation of low-density lipoprotein uptake and cholesterol storage in cultured fibroblasts

Incubation of mutant Niemann-Pick C fibroblasts with low-density lipoprotein (LDL) resulted in excessive internalization of lipoprotein and extensive cellular over-accumulation of unesterified cholesterol. The uptake of LDL by the mutant cells appeared to occur through the classic LDL receptor pathway and internalized lipoprotein was processed in lysosomes. Lipoprotein uptake into mutant cells was associated with delays in the initiation of established cellular cholesterol homeostatic responses. Subcellular fractionation of mutant Niemann-Pick C fibroblasts accumulating LDL-cholesterol showed excess unesterified sterol to be localized in the light lysosome-light membrane region of a Percoll gradient, and revealed that cholesterol storage was associated with a specific alteration in the normal profiles of lysosomal marker enzymes.

Spinal cholinergic neurons and the expression of morphine withdrawal symptoms in the rat

Behavioral and autonomic signs of the morphine withdrawal syndrome were measured in dependent rats injected with the opiate antagonist naloxone. The purpose of this study was to determine whether spinal cholinergic pathways play a role in the expression of spinally mediated withdrawal symptoms. Intrathecal (i.t.) administration of 1 microgram carbachol or 5 micrograms neostigmine resulted in increases in mean arterial pressure (MAP) of 32 and 45 mm Hg, respectively, in conscious, freely moving rats. The pressor response to carbachol began almost immediately after injection, but that to neostigmine was delayed in onset. Both responses were completely abolished following i.v. injection of 2 mg/kg atropine. However, in spinal-transected (C-1), ventilated rats, i.t. injection of carbachol or neostigmine resulted in only small, transient increases in MAP. Intraarterial (i.a.) injection of 0.5 mg/kg naloxone to morphine-dependent rats resulted in an immediate increase in MAP (to 33 mm Hg) that lasted at least 1 hr. This was accompanied by classical behavioral signs of withdrawal. Pretreatment of dependent rats with i.t. injection of atropine or hemicholinium-3 (HC-3) significantly reduced the pressor and several behavioral responses elicited by naloxone. In contrast, when morphine-dependent, spinal-transected rats were pretreated with i.t. injection of cholinergic antagonists, i.a. injection of naloxone resulted in an enhanced MAP response. Finally, in intact dependent rats, i.t. injection of naloxone (6 micrograms) produced a 14 mm Hg increase in MAP that was significantly augmented (21 mm Hg) following i.t. pretreatment with HC-3.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous morphine withdrawal from the rat spinal cord

A characteristic and reproducible sign of narcotic withdrawal is the naloxone induced increase in arterial pressure. In morphine-dependent rats allowed to undergo spontaneous withdrawal (6-24 h) and then transected at the spinal C-1 level, arterial pressure was maintained at a significantly higher level than either spinal-transected nondependent controls or morphine-dependent, spinal-transected rats pithed from C-1 to L-4. These findings indicate that the morphine-dependent spinal cord, independent of supraspinal influences, is able to exhibit an autonomic component of spontaneous withdrawal.

Dorsal root lesions block the expression of morphine withdrawal elicited from the rat spinal cord

Evidence has been accumulating to indicate that the spinal cord plays an important role in the expression of several narcotic abstinence signs in the intact animal. One characteristic and reproducible withdrawal sign which can be elicited in both intact and spinal-transected dependent rats is the naloxone-induced increase in arterial blood pressure. Employing this model, this autonomic component of narcotic withdrawal was quantitated in dependent spinal (C1)-transected rats with intact dorsal roots and in those with surgical lesions of the dorsal roots from T3 to L4. The withdrawal-associated hypertension observed in animals with intact dorsal roots was abolished in the rats having the lesioned roots. The central spinal location of the opiate receptors mediating the naloxone response was confirmed by experiments demonstrating the failure of a selective peripherally acting narcotic antagonist to elicit a comparable withdrawal response. It was concluded that continuous afferent input and spinal opiate receptors are requirements for the expression of spinal narcotic withdrawal.

Supraspinal and spinal mediation of naloxone-induced morphine withdrawal in rats

Unanesthetized rats, made physically dependent over 5 days by chronic intra-arterial infusion of increasing concentrations of morphine (35-100 mg/kg/day) underwent withdrawal by naloxone (6 micrograms) injection into either the lateral ventricle (i.c.v.), fourth ventricle (V4), intrathecal subarachnoid space (i.t.), or intra-arterially (i.a.) and were evaluated for cardiovascular and behavioral signs of precipitated abstinence. Naloxone i.c.v. produced a significantly greater increase in the magnitude and duration of withdrawal hypertension than did V4 injection. Naloxone i.t. produced a distinctively different, persistent, pressor response as compared to i.c.v., V4 or i.a. routes of administration, although no quantitative differences in behavioral signs of withdrawal were observed. Morphine-dependent, spinal transected (C1) animals generated an augmented pressor response to i.c.v. or i.t. naloxone. This pressor response was accompanied by a significant reduction in core temperature (0.50-0.79 degrees C). Both the naloxone-induced pressor and hypothermic responses were abolished by ganglionic (hexamethonium, 100 mg/kg, i.a.) or peripheral alpha-adrenergic (phentolamine 4 mg/kg, i.a.) blockade. The hypertensive and hypothermic effects of naloxone also were prevented in transected dependent rats by prior spinal pithing. We conclude that in morphine-dependent rats: supraspinal sites rostral to the V4 mediate a more intense naloxone-induced pressor response than caudal regions; cardiovascular and behavioral signs of withdrawal can be precipitated via the spinal cord of intact animals; and the production of withdrawal hypertension and hypothermia in spinal transected morphine-dependent rats indicates that these abstinence signs can be mediated through neuronal pathways within the spinal cord.

A comparison of the inhibitory effects of clonidine and guanfacine on the behavioral and autonomic components of morphine withdrawal in rats

Intravenous administration of naloxone (0.5 mg/kg) to morphine dependent rats elicited classical autonomic and behavioral symptoms of narcotic abstinence including hypertension, tachycardia, withdrawal body shakes, escape attempts, diarrhea, etc. Pretreatment of dependent rats with either clonidine (3-90 micrograms/kg) or guanfacine (3-900 micrograms/kg) produced a dose-dependent reduction in the hypertensive response to subsequent injection of naloxone. Clonidine was about 12 times more potent than guanfacine in inhibiting this autonomic symptom of withdrawal. Both drugs were less effective at blocking body shakes and escapes, however, when all symptoms were combined in a ranked score, guanfacine was less effective than clonidine at reducing the ranked abstinence intensity score. Since clonidine blocked the autonomic component of withdrawal at doses more consistent with its clinical anti-withdrawal actions, it is possible that 1) measurement of behavioral signs of withdrawal in rats is a less sensitive index than is measurement of autonomic changes associated with withdrawal, or, 2) a reduction in autonomic outflow in general is most relevant to suppressing the apparent intensity of the abstinence syndrome.

Pharmacokinetics of sulbactam in humans

Sulbactam, a new beta-lactamase inhibitor, has pharmacokinetic characteristics in humans similar to those of ampicillin and amoxicillin. Its half-life in humans is approximately 1 h. In a two-compartment pharmacokinetic model, the apparent volume of distribution for the central compartment is approximately 12 liters, and half of the dose is found in the central compartment in the postdistributive phase. Approximately 75% of a parenteral dose is excreted unchanged in urine. The coadministration of sulbactam with ampicillin, penicillin G, or cefoperazone has essentially no effect upon the kinetics of either the beta-lactam antibiotic or sulbactam.