Development of a calibration chamber to evaluate the performance of low-cost particulate matter sensors

Low-cost particulate matter (PM) air quality sensors are becoming widely available and are being increasingly deployed in ambient and home/workplace environments due to their low cost, compactness, and ability to provide more highly resolved spatiotemporal PM concentrations. However, the PM data from these sensors are often of questionable quality, and the sensors need to be characterized individually for the environmental conditions under which they will be making measurements. In this study, we designed and assessed a cost-effective (∼$700) calibration chamber capable of continuously providing a uniform PM concentration simultaneously to multiple low-cost PM sensors and robust calibration relationships that are independent of sensor position. The chamber was designed and evaluated with a Computational Fluid Dynamics (CFD) model and a rigorous experimental protocol. We then used this new chamber to calibrate 242 Plantower PMS 3003 sensors from two production lots (Batches I and II) with two aerosol types: ammonium nitrate (for Batches I and II) and alumina oxide (for Batch I). Our CFD models and experiments demonstrated that the chamber is capable of providing uniform PM concentration to 8 PM sensors at once within 6% error and with excellent reliability (intraclass correlation coefficient > 0.771). The study identified two malfunctioning sensors and showed that the remaining sensors had high linear correlations with a DustTrak monitor that was calibrated for each aerosol type (R2 > 0.978). Finally, the results revealed statistically significant differences between the responses of Batches I and II sensors to the same aerosol (P-value<0.001) and the Batch I sensors to the two different aerosol types (P-value<0.001). This chamber design and evaluation protocol can provide a useful tool for those interested in systematic laboratory characterization of low-cost PM sensors.

Abstract P3-14-09: Low rates of chronic breast cancer related lymphedema (BCRL) in a cohort of high-Risk patients undergoing prospective surveillance with bioimpedance spectroscopy (BIS)

Background: We report outcomes using prospective BIS surveillance in a high-risk cohort of patients who all underwent axillary lymph node dissection (ALND).

Methods: From 8/2010 through 12/2016, 206 consecutive patients were evaluated with BIS as part of a prospective surveillance program. 30 underwent ALND and constitute the study population. The program included pre-operative BIS measurement as well as post-operative assessments at regular intervals. Patients with L-Dex readings increasing by more than 10 from baseline were considered to have subclinical BCRL and treated with an over-the-counter (OTC) compression sleeve for 4 weeks. For the purpose of this analysis, additional high-risk features were defined as receipt of axillary radiation, a high body mass index (BMI) or the use of taxane based chemotherapy. Chronic BCRL was defined as the need for complex decongestive physiotherapy (CDP).

Results: Median follow-up was 36 months (range: 4.8-122.1 months). The median number of nodes removed was 18 (range: 5-32) and the median number of positive nodes was two. The median age for the cohort was 57.5 years old with 70% of patients undergoing mastectomy and the remainder breast conserving therapy. With respect to additional high-risk features, 77% also received taxane-based chemotherapy, 62% axillary irradiation, and 48% had an elevated BMI. Overall, 86% of patients had at least one additional high-risk feature, 70% at least two, and 23% had all three additional high-risk features. Seven patients (23%) had an elevated L-Dex score at some point during follow-up and underwent intervention with an OTC sleeve for 4 weeks. To date, no patients have required CDP at any time.

Conclusions: Prospective surveillance with BIS in a high-risk cohort of patients all undergoing ALND (plus additional high-risk features) led to no patients requiring CDP. These excellent findings are consistent with growing data supporting the use of BIS in prospective BCRL surveillance programs.

Citation Format: Kaufman D, Shah C, Vicini F. Low rates of chronic breast cancer related lymphedema (BCRL) in a cohort of high-Risk patients undergoing prospective surveillance with bioimpedance spectroscopy (BIS) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-14-09.

Abstract P6-12-03: Utilization of bioimpedance spectroscopy in the prevention of chronic breast cancer related lymphedema

Background: With improved breast cancer outcomes, an increasing focus on sequelae of treatment as part of survivorship has emerged. Breast cancer related lymphedema (BCRL) represents one such sequelae. Increasing data and recent NCCN guidelines support the use of prospective BCRL surveillance to allow for early detection and intervention as a method to reduce chronic, irreversible BCRL. Therefore, this study was performed to evaluate the impact early detection and treatment of BCRL in breast cancer patients undergoing prospective surveillance with bioimpedance spectroscopy (BIS).

Methods: From 8/2010 through 12/2016, 206 patients were evaluated with BIS as part of a prospective surveillance program.The protocol included pre-operative assessment with BIS as well as post-operative assessments with BIS at regular intervals. Patients with L-Dex readings increasing by more than 10 from baseline were considered to have subclinical BCRL and treated with a compression sleeve for 4 weeks. For the purpose of this analysis, high-risk was defined as receipt of ALND, regional nodal irradiation, or taxane chemotherapy. Chronic BCRL was defined as the need for complex decongestive physiotherapy.

Results: A total of 206 patients were analyzed, with a mean age of 61 years old and a median follow up of 25.9 months. Overall, 17% of patients had least one high-risk feature, 8% had two factors, and 7% had all three factors. A total of 21 patients (9.8%) were diagnosed with subclinical BCRL. Increased rates of subclinical BCRL were seen in patients undergoing ALND (23% vs. 7%, p=0.01) with ALND and receipt of RNI associated with development of subclinical BCRL. At last follow-up, no patients had persistent, chronic BCRL following early, conservative intervention measures.

Conclusions: The results of this study support prospective surveillance and early treatment utilizing BIS. Intervention triggered by subclinical BCRL detection with an elevated L-Dex score was associated with a very low rate of chronic BCRL.

Citation Format: Kaufman D, Shah C, Vicini F. Utilization of bioimpedance spectroscopy in the prevention of chronic breast cancer related lymphedema [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-03.

Prolonged norovirus infection after pancreas transplantation: a case report and review of chronic norovirus

Norovirus is a major cause of self-limited gastroenteritis worldwide. Prevention and treatment are thwarted by rapid viral evolution, and thus supportive care remains the mainstay of therapy. Chronic infection in immunocompromised hosts is increasingly described. We report a case of norovirus infection lasting 2543 days in a pancreas transplant recipient. Serial fecal specimens were obtained, from which a map of genetic relatedness was derived. The clinical course was complicated by renal failure that progressed to end-stage renal disease. Minimization of immunosuppression was associated with resolution of the infection. Subsequently, the patient experienced a suspected allograft rejection that did not compromise pancreas function. The patient later underwent living-related renal transplantation without recurrence of enteritis.

Identification of a KIR antisense lncRNA expressed by progenitor cells

Human NK cells express cell surface class I MHC receptors (KIR) in a probabilistic manner. Previous studies have shown that a distal promoter acts in conjunction with a proximal bidirectional promoter to control the selective activation of KIR genes. We report here the presence of an intron 2 promoter in several KIR genes that produces a spliced antisense transcript. This lncRNA transcript contains antisense sequence complementary to KIR-coding exons 1 and 2 as well as the proximal promoter region of the KIR genes. The antisense promoter contains MZF-1 binding sites, a transcription factor found in hematopoietic progenitors and myeloid precursors. The KIR antisense lncRNA was only detected in progenitor cells or pluripotent cell lines, suggesting a function that is specific for stem cells. Overexpression of MZF-1 in developing NK cells led to decreased KIR expression, consistent with a role for the KIR antisense lncRNA in silencing KIR gene expression early in development.

Early metabolic markers that anticipate loss of insulin independence in type 1 diabetic islet allograft recipients

The objective of this study was to identify predictors of insulin independence and to establish the best clinical tools to follow patients after pancreatic islet transplantation (PIT). Sequential metabolic responses to intravenous (I.V.) glucose (I.V. glucose tolerance test [IVGTT]), arginine and glucose-potentiated arginine (glucose-potentiated arginine-induced insulin secretion [GPAIS]) were obtained from 30 patients. We determined the correlation between transplanted islet mass and islet engraftment and tested the ability of each assay to predict return to exogenous insulin therapy. We found transplanted islet mass within an average of 16 709 islet equivalents per kg body weight (IEQ/kg BW; range between 6602 and 29 614 IEQ/kg BW) to be a poor predictor of insulin independence at 1 year, having a poor correlation between transplanted islet mass and islet engraftment. Acute insulin response to IVGTT (AIR(GLU) ) and GPAIS (AIR(max) ) were the most accurate methods to determine suboptimal islet mass engraftment. AIR(GLU) performed 3 months after transplant also proved to be a robust early metabolic marker to predict return to insulin therapy and its value was positively correlated with duration of insulin independence. In conclusion, AIR(GLU) is an early metabolic assay capable of anticipating loss of insulin independence at 1 year in T1D patients undergoing PIT and constitutes a valuable, simple and reliable method to follow patients after transplant.

Cognitive analysis of decision support for antibiotic ordering in a neonatal intensive care unit

BACKGROUND

Clinical decision support systems (CDSS) are a method used to support prescribing accuracy when deployed within a computerized provider order entry system (CPOE). Divergence from using CDSS is exemplified by high alert override rates. Excessive cognitive load imposed by the CDSS may help to explain such high rates.

OBJECTIVES

The aim of this study was to describe the cognitive impact of a CPOE-integrated CDSS by categorizing system use problems according to the type of mental processing required to resolve them.

METHODS

A qualitative, descriptive design was used employing two methods; a cognitive walkthrough and a think-aloud protocol. Data analysis was guided by Norman's Theory of Action and a theory of cognitive distances which is an extension to Norman's theory.

RESULTS

The most frequently occurring source of excess cognitive effort was poor information timing. Information presented by the CDSS was often presented after clinicians required the information for decision making. Additional sources of effort included use of language that was not clear to the user, vague icons, and lack of cues to guide users through tasks.

CONCLUSIONS

Lack of coordination between clinician's task-related thought processes and those presented by a CDSS results in excessive cognitive work required to use the system. This can lead to alert overrides and user errors. Close attention to user's cognitive processes as they carry out clinical tasks prior to CDSS development may provide key information for system design that supports clinical tasks and reduces cognitive effort.

Safety and pharmacokinetics of repeat-dose micafungin in young infants

Given the risk of central nervous system infection, relatively high weight-based echinocandin dosages may be required for the successful treatment of invasive candidiasis and candidemia in young infants. This open-label study assessed the safety and pharmacokinetics (PK) of micafungin in 13 young infants (>48 h and <120 days of life) with suspected candidemia or invasive candidiasis. Infants of body weight > or =1,000 and <1,000 g received 7 and 10 mg/kg/day, respectively, for a minimum of 4-5 days. In the 7-mg/kg/day group, the mean baseline weight and gestational age were 2,101 g and 30 weeks, respectively; in the 10-mg/kg/day group, they were 688 g and 25 weeks, respectively. The median pharmacokinetic values for the 7- and 10-mg/kg/day groups, respectively, were as follows: area under the concentration-time curve from 0 to 24 h (AUC(0-24)), 258.1 and 291.2 microg x h/ml; clearance at steady state adjusted for body weight, 0.45 and 0.57 ml/min/kg; maximum plasma concentration, 23.3 and 24.9 micro g/ml; and volume of distribution at steady state adjusted for body weight, 341.4 and 542.8 ml/kg. No deaths or discontinuations from treatment occurred. These data suggest that micafungin dosages of 7 and 10 mg/kg/day are well tolerated and provide exposure levels that have been shown (in animal models) to be adequate for central nervous system coverage.

Dissociation of depletional induction and posttransplant lymphoproliferative disease in kidney recipients treated with alemtuzumab

Transplant patients are at the risk for posttransplant lymphoproliferative disease (PTLD), a virally-driven malignancy. Induction with the depleting antibody preparations Thymoglobulin and OKT3 is associated with PTLD suggesting that the T-cell depletion increases PTLD risk. We therefore studied 59 560 kidney recipients from the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) database for a relationship between induction agent use and PTLD. Two agents with comparable T-cell depletional effects, alemtuzumab and Thymoglobulin, were compared to nondepletional induction agents or no induction. The overall incidence of PTLD was 0.46% and differed significantly by induction strategy (p < 0.01): without induction (0.43%), basiliximab (0.38%), daclizumab (0.33%), Thymoglobulin (0.67%) and alemtuzumab (0.37%). Thymoglobulin was associated with significantly increased PTLD risk (p = 0.0025), but alemtuzumab (p = 0.74), basiliximab (p = 0.33) and daclizumab, which trended toward a protective effect (p = 0.06), were not. Alemtuzumab and Thymoglobulin treated patients did not differ in any established parameter affecting PTLD risk although alemtuzumab is known to have a more pronounced B-cell depleting effect. Interestingly, maintenance therapy with an mTOR inhibitor was strongly associated with PTLD (0.71%, p < 0.0001). Thus, depletional induction is not an independent risk factor for PTLD. Rather, maintenance drug selection or perhaps the balance between B- and T-cell depletion may be more relevant determinants of PTLD risk.

A prospective cohort of American Indian and Alaska Native people: study design, methods, and implementation

In 2001, the National Cancer Institute funded three centers to test the feasibility of establishing a cohort of American Indian and Alaska Native people. Participating tribal organizations named the study EARTH (Education and Research Towards Health). This paper describes the study methods. A computerized data collection and tracking system was developed using audio computer-assisted survey methodology with touch screens. Data were collected on diet, physical activity, lifestyle and cultural practices, medical and reproductive history, and family history of heart disease, diabetes, and cancer. In addition, a small panel of medical measurements was obtained, including height, weight, waist and hip circumferences, blood pressure, and a lipid panel plus glucose. At the completion of the enrollment visit, data were used to provide immediate health feedback to study participants. During the initial funding period, the authors anticipate enrolling 16,000 American Indian and Alaska Native participants. The age distribution of the study population was similar to that reported in the 2000 US Census for the relevant populations. A component critical to the success of the EARTH Study has been the partnerships with tribal members. The study has focused on involvement of American Indian and Alaska Native communities in development and implementation and on provision of feedback to participants and communities.

Long-term renal allograft function on a tacrolimus-based, pred-free maintenance immunosuppression comparing sirolimus vs. MMF

It is not known how different steroid-free immunosuppressive combinations affect renal graft survival and long-term kidney transplant function. Here we sought to compare the impact on graft survival and long-term graft function of two tacrolimus (Tac)-based, prednisone-free maintenance immunosuppressive protocols: Tac/Mycophenolate Mofetil (MMF) vs. Tac/Sirolimus (SRL). Renal transplant patients given induction therapy with IL2-RA and methylprednisolone on days 0, 1 and 2 post-transplant were prospectively randomized to two maintenance immunosuppressive regimens with Tac/MMF (n = 45) or Tac/SRL (n = 37). During the 3-year follow-up the following data were collected: patient survival, renal allograft survival, incidence of acute rejection and glomerular filtration rate (GFR) at different time-points post-transplant. Cumulative graft survival was significantly different in the two groups: one kidney loss in the Tac/MMF vs. six kidney losses in the Tac/SRL (log-rank test p = 0.04). GFR at different time-points post-transplant was consistently and statistically better in the Tac/MMF than in the Tac/SRL group. The slope of GFR decline per month was flatter in the Tac/MMF than in the Tac/SRL group. This study showed that renal graft survival and graft function were significantly lower in the combination of Tac/SRL than Tac/MMF.

A blinded, randomized, multicenter study of an intravenous Staphylococcus aureus immune globulin

OBJECTIVES

Very low birth weight (VLBW) infants are vulnerable to nosocomial infections and subsequent morbidity; including infections caused by Staphylococcus aureus: 85% of nosocomial S. aureus infections are caused by capsular polysaccharide (CPS) types 5 and 8. Altastaph is a polyclonal investigational human immunoglobulin G (IgG) with high levels of opsonizing S. aureus CPS types 5 and 8 IgG.

METHODS

A Phase 2 clinical trial to assess the safety and kinetics of Altastaph in VLBW infants. Neonates in this multicenter study were randomized to receive two identical 20 ml/kg i.v. infusions of either 0.45% NaCl placebo or 1000 mg Altastaph/kg. Each infant was followed for 28 days after the second infusion or until discharge. Serum S. aureus CPS types 5 and 8 IgG levels were measured preinfusion and at various times after each infusion.

RESULTS

Of 206 neonates, 158 received both infusions. Adverse events were similar in the two treatment groups. Six subjects (3% in each group) discontinued owing to an adverse event. Geometric mean anti-type 5 IgG levels were 402 and 642 mcg/ml 1 day following infusion of the first (day 0) and Second (day 14) doses, respectively, in neonates < or =1000 g and slightly higher in neonates 1001 to 1500 g. Trough levels before second infusion were 188 mcg/ml. Type 8 IgG levels were similar. Geometric mean IgG levels among placebo recipients were consistently <2 and <5 mcg/ml for types 5 and 8 in both weight groups. Three episodes of S. aureus bacteremia occurred in each arm.

CONCLUSIONS

Infusion of Altastaph in VLBW neonates resulted in high levels of specific S. aureus types 5 and 8 CPS IgG. The administration of this anti-staphylococcal hyperimmune globulin was well tolerated in this population.

Single vs. dual vessel porcine extracorporeal liver perfusion

BACKGROUND

The use of porcine extracorporeal liver perfusion (PECLP) to provide temporary hepatic support for patients in fulminant hepatic failure has been limited by the fact that individual perfusions can be sustained for only a few hours. Inadequate liver function and/or hemodynamic instability are the major contributing factors for early interruption of PECLP. Recent reports suggest that the choice of single (portal vein only) vs dual (portal vein and hepatic artery) vessel perfusion may influence the duration of perfusion. We hypothesize that PECLP with single vessel perfusion (SVP) is associated with worse liver function and greater hemodynamic instability than PECLP with dual vessel perfusion (DVP).

MATERIALS AND METHODS

To eliminate the potentially confounding influences of liver failure and xenograft rejection, liver isografts procured from White-Landrace pig donors were perfused by either SVP or DVP via an extracorporeal circuit established with normal White-Landrace pig recipients. The function of perfused livers was evaluated by measuring production of bile and Factors V and VIII, clearance of ammonia and lactate, and extraction of O(2) at baseline and at 0, 1, 3, 6, 12, and 24 h after initiation of PECLP. The impact of PECLP on recipient hemodynamic status was assessed by monitoring BP, heart rate, urine output, O(2) saturation, etc. Among other parameters evaluated were serum albumin and total protein and hepatic release of IL-1beta and nitric oxide to assess their possible contributions to hemodynamic instability.

RESULTS

DVP and SVP livers cleared ammonia and lactate similarly. Both approaches were associated with progressive hypoalbuminemia and hypoproteinemia. DVP livers produced more bile and Factor V and were associated with less recipient hypotension and IL-1beta and NO release than SVP livers.

CONCLUSIONS

Livers with DVP function better than livers with SVP. The duration of PECLP can be limited by recipient hypotension, although this complication is less severe with DVP than with SVP.

Fluconazole prophylaxis against fungal colonization and infection in preterm infants

BACKGROUND

Invasive fungal infection is associated with substantial morbidity and mortality in preterm infants. We evaluated the efficacy of prophylactic fluconazole in preventing fungal colonization and invasive infection in extremely-low-birth-weight infants.

METHODS

We conducted a prospective, randomized, double-blind clinical trial over a 30-month period in 100 preterm infants with birth weights of less than 1000 g. The infants were randomly assigned during the first five days of life to receive either intravenous fluconazole or placebo for six weeks. We obtained weekly surveillance cultures from all patients.

RESULTS

The 50 infants randomly assigned to fluconazole and the 50 control infants were similar in terms of birth weight, gestational age at birth, and base-line risk factors for fungal infection. During the six-week treatment period, fungal colonization was documented in 30 infants in the placebo group (60 percent) and 11 infants in the fluconazole group (22 percent; difference in risk, 0.38; 95 percent confidence interval, 0.18 to 0.56; P=0.002). Invasive fungal infection with positive growth of fungal isolates from the blood, urine, or cerebrospinal fluid developed in 10 infants in the placebo group (20 percent) and none of the infants in the fluconazole group (difference in risk, 0.20; 95 percent confidence interval, 0.04 to 0.36; P=0.008). The sensitivities of the fungal isolates to fluconazole did not change during the study, and no adverse effects of the fluconazole therapy were documented.

CONCLUSIONS

Prophylactic administration of fluconazole during the first six weeks of life is effective in preventing fungal colonization and invasive fungal infection in infants with birth weights of less than 1000 g.

Palliative care by family physicians in the 1990s. Resilience amid reform

OBJECTIVE

To explore issues family physicians face in providing community-based palliative care to their patients in the context of a changing health care system.

DESIGN

Focus groups.

SETTING

Small (< 10,000 population), medium-sized (10,000 to 50,000), and large (> 50,000) communities in Nova Scotia.

PARTICIPANTS

Twenty-five men and women physicians with varying years of practice experience in both solo and group practices.

METHOD

A semistructured approach was used, asking physicians to reflect on recent palliative care experiences in order to explore issues of care.

MAIN FINDINGS

Five themes emerged from the discussions: resources needed, availability of family support, time and money supporting physicians' activities, symptom control for patients, and physicians' emotional reactions to caring for dying patients.

CONCLUSION

With downsizing of hospitals and greater emphasis on community-based care, the issues identified in this study will need attention, particularly in designing an integrated service delivery model for palliative care.

High-dose methotrexate for isolated central nervous system relapse in patients with testicular non-Hodgkin's lymphoma

Four consecutive patients with testicular non-Hodgkin's lymphoma who initially achieved a complete response to treatment with standard combination therapy later developed isolated central nervous system (CNS) relapses. At the time of CNS relapse, staging evaluations were negative for lymphoma outside the nervous system in all 4 patients. These patients were treated with high-dose intravenous methotrexate alone, and a complete remission was achieved in all 4 patients.

Malignant fibrous histiocytoma arising in the upper posterior triangle of the neck

We describe the case of a 59-year-old man who came to us with a right neck mass of 4 to 5 months' duration. A histologic diagnosis of malignant fibrous histiocytoma was made, and the patient underwent wide local excision and neck dissection followed by postoperative radiation therapy. We briefly discuss the characteristics and treatment of this rare entity.

Emergent patterns of feedback strategies in performing a closed motor skill

This sturdy identified self-chosen patterns of feedback usage and how they influenced accuracy and consistency in performing a closed motor skill. Learners completed 100 practice trials with 25 opportunities to receive knowledge of results (KR), the timing of which was self-chosen, followed by 25 no KR retention trials. The study identified two patterns of self-chosen KR, namely, a faded frequency pattern and a reversed faded frequency pattern. Analyses of variance indicated a significant trial block effect for accuracy in acquisition and no significant main effects or interactions associated with self-chosen patterns of KR. Quantification of regularity of KR patterns yielded correlations indicating that less regularity was associated with greater accuracy in performing the task. These results were congruent with previous research on self chosen feedback.

From death and disability to patient empowerment: an interprofessional partnership to achieve cardiovascular health in Canada

This paper proposes a paradigm shift in health care from a focus on death and disability to one on health empowerment resulting in improved cardiovascular lifestyles for all Canadians. It describes a national interprofessional initiative to achieve this new vision in the area of cardiovascular health promotion. Achieving Cardiovascular Health in Canada (ACHIC) is a partnership of health professional associations and other health advocate groups whose vision is to promote optimal cardiovascular health (including cerebrovascular health) for all Canadians through interprofessional partnership initiatives and support systems. ACHIC's objectives are to: 1) identify system barriers and supports to cardiovascular health; 2) develop strategies that will have a positive impact on the practices of health professionals/educators in the promotion of cardiovascular health; 3) develop an interprofessional national approach to support strategies to achieve cardiovascular health in Canada; and 4) support the development and delivery of consistent, evidence-based messages by health professionals/educators for promotion of cardiovascular health.

Alcohol withdrawal after open aortic surgery

This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.

Diagnostic accuracy of simpson atherectomy catheter biopsy in detecting pancreaticobiliary malignancy

OBJECTIVE

Impressive advances have been made in imaging the biliary tree by various modalities in the last few decades. However, the histological diagnosis of stenosing lesions in the biliary ductal system has remained difficult and unreliable. Application of Simpson atherectomy catheter biopsy in obtaining accurate histological diagnosis of bile duct lesions appears promising. The purpose of our study was to determine the clinical accuracy of the Simpson atherectomy catheter biopsy in the evaluation of bile duct strictures.

METHODS

A retrospective study of medical records of patients who underwent bile duct biopsy by atherectomy catheter was conducted between 1991 and 1999. During this period, 53 patients underwent 56 endoluminal bile duct biopsies with an atherectomy catheter as part of an obstructive jaundice workup. Histological diagnosis on biopsy was confirmed by subsequent surgical biopsy and/or clinical follow-up.

RESULTS

Fifty-four (96%) bile duct biopsies were technically successful in terms of yielding a histological diagnosis. Thirty-one of the 56 (55%) biopsy specimens were positive for malignancy (27 adenocarcinoma, two islet cell-carcinoids, one small cell carcinoma, and one malignant lymphoma). Four (7%) were read by the pathologist as highly suspicious for malignancy, and 19 (34%) specimens were considered negative for malignancy. Sensitivity of atherectomy catheter endoluminal biliary biopsy in this study was 97% with a specificity of 100%. In addition, the positive predictive and negative predictive values of this modality were 100% and 93%, respectively.

CONCLUSIONS

Endoluminal bile duct biopsy by Simpson atherectomy catheter appears to be a highly sensitive and specific method for establishing histological diagnosis of stenosing lesions in the biliary ductal system.

Family Medicine residents' knowledge and attitudes about end-of-life care

The medical management of end-of-life symptoms, and the psychosocial care of the dying and their families have not been a specific part of the curriculum for undergraduate medical students or residency training programs. The purpose of our research was to assess family medicine residents' knowledge of and attitudes toward care of the dying. All entering (PGY1) and exiting (PGY2) residents of the Dalhousie University Family Medicine Residency Program were given a 50-item survey on end-of-life care. They survey contains two 25-item subscales concerning attitudes/opinions toward end-of-life care, and knowledge about care. Thirty-one of the 33 entering PGY1s 94%) and 26 of the 30 exiting PGY2s (86%) completed the surveys. Overall attitude scores were felt to be high among both groups, with little difference between them. Areas of concern regarding the adequacy of knowledge were found in relation to managing opioid drugs and the symptom of dyspnea. Interventions are now in development to address these issues in the residency program. In an era of subspecialties, the challenge of integrating these areas into the curriculum without creating rotations in specialist palliative care is an issue faced by most family medicine residency programs.

Paclitaxel, estramustine phosphate, and carboplatin in patients with advanced prostate cancer

PURPOSE

To determine the safety and activity of weekly paclitaxel in combination with estramustine and carboplatin (TEC) in patients with advanced prostate cancer.

PATIENTS AND METHODS

In a dose-escalation study, patients with advanced prostate cancer were administered paclitaxel (weekly 1-hour infusions of 60 to 100 mg/m(2)), oral estramustine (10 mg/kg), and carboplatin (area under the curve, 6 mg/mL-min every 4 weeks). Paclitaxel levels were determined 0, 30, 60, 90, and 120 minutes and 18 hours after infusion, and a concentration-time curve was estimated. Once a safe dose was established, a multi-institutional phase II trial was conducted in patients with progressive androgen-independent disease.

RESULTS

Fifty-six patients with progressive androgen-independent disease were treated for a median of four cycles. The dose of paclitaxel was escalated from 60 to 100 mg/m(2) without the occurrence of DLT. Posttherapy decreases in serum prostate-specific antigen levels of 50%, 80%, and 90% were seen in 67%, 48%, and 39% (95% confidence interval, 55% to 79%, 35% to 61%, 26% to 52%) of the patients, respectively. Of the 33 patients with measurable disease, two (6%) had a complete response and 13 (39%) had a partial response. The overall median time to progression was 21 weeks, and the median survival time for all patients was 19.9 months. Major grade 3 or 4 adverse effects were thromboembolic disease (in 25% of patients), hyperglycemia (in 38%), and hypophosphatemia (in 42%). Significant leukopenia, thrombocytopenia, and peripheral neuropathy were not observed.

CONCLUSION

TEC has significant antitumor activity and is well tolerated in patients with progressive androgen-independent prostate cancer.

Retinoic acid enhances the effect of collagen on bone union, following induced non-union defect in guinea pig ulna

OBJECTIVE AND DESIGN

The aim of the present study is to evaluate the involvement of retinoic acid and collagen in wound healing, by combining them in a therapeutic modality for treating a non-union bone defect in a guinea-pig ulnar-bone model.

METHODS

a 4-mm disc was excised from the guinea-pig's ulnar-bone, and the space formed between the two ulnar fragments was filled with either collagen solution, retinoic acid solution or a combination of both. The guinea-pigs were sacrificed 2 or 6 weeks later, and the defected ulnar bones were studied by X-ray, by histology and by computerized histomorphometry.

RESULTS

After 6 weeks, the long bone area fraction within the histological sections of the bone, was increased after treatment with this mixture by 180%, as compared to the untreated controls. The cartilage area in those sections was decreased by 44% after the combined treatment, as compared to increases of 133% and 182% following treatments with collagen alone.

CONCLUSION

These findings demonstrate that addition of 500 IU of retinoic acid to collagen at a site of a bone defect, is superior to either agent in enhancing regeneration of new bone, achieving union across the defect and leading to its complete repair.

Vinorelbine and estramustine in androgen-independent metastatic prostate cancer: a phase II study

BACKGROUND

The aim of this study was to determine the safety and activity of vinorelbine in combination with estramustine in men with androgen-independent metastatic prostate cancer.

METHODS

Twenty-five men with androgen-independent metastatic prostate cancer were treated with the combination of vinorelbine and estramustine. Vinorelbine 25 mg/m(2) was administered by intravenous bolus on Days 1 and 8. Estramustine 140 mg was administered three times a day by mouth on Days 1 through 14. Treatment was repeated every 21 days.

RESULTS

A total of 132 cycles of treatment were administered. The median number of cycles per patient was 5 (range: 1-16). Mild Grade 1 or 2 gastrointestinal toxicity and fatigue were the most common adverse effects. Hematologic toxicity was minimal. Treatment resulted in a sustained > 50% decrease in serum prostate-specific antigen (PSA) in 6 of 25 patients (24% of patients; 95% confidence interval (CI) 9-45%). The median duration of PSA response was 10 weeks (range: 3-39 weeks). Of the five men with bidimensionally measurable disease, none achieved a complete or partial response. There were no documented improvements in post-treatment bone scans. Median overall survival time was 14.1 months.

CONCLUSIONS

The combination of vinorelbine and estramustine is a well-tolerated and modestly active regimen in men with androgen-independent metastatic prostate cancer.

Synthetic peptides which inhibit the interaction between C1q and immunoglobulin and prolong xenograft survival

BACKGROUND

Acute vascular xenograft rejection (AVXR), also termed delayed xenograft rejection (DXR), occurs when hyperacute rejection (HAR) is prevented by strategies directed at xenoreactive natural antibodies and/or complement activation. We have hypothesized that AVXR/DXR is initiated in part by early components of the complement cascade, notably C1q. We have developed synthetic peptides (termed CBP2 and WY) that interfere with the interaction between C1q and antibody.

METHODS

CBP2 and the WY-conjugates were used as inhibitors of immunoglobulin aggregate binding to solid phase C1q. Inhibition of complement activation by the peptides of the classical system was determined using lysis assays with sensitized sheep red blood cells or porcine aortic endothelial cells as targets and of the alternate complement pathway using guinea pig red blood cells as targets. Two transplant models were used to study the effects of administering peptides to recipients: rat heart transplant to presensitized mouse, and guinea heart transplant to PVG C6-deficient rats.

RESULTS

CBP2 and WY-conjugates inhibited immunoglobulin aggregate binding to C1q. The peptides also inhibited human complement-mediated lysis of sensitized sheep red blood cells and porcine aortic endothelial cells in a dose-dependent manner and the WY-conjugates prevented activation of the alternate complement pathway as shown by inhibition of guinea pig red blood cells lysis with human serum. In addition, the use of the peptides and conjugates resulted in significant prolongation of xenograft survival.

CONCLUSIONS

The CBP2 and WY peptides exhibit the functional activity of inhibition of complement activation. These peptides also prolong xenograft survival and thus provide reagents for the study of the importance of C1q and other complement components in transplant rejection mechanisms.