Endotype evaluation of Hispanic/Latinx-American patients with chronic rhinosinusitis with nasal polyps

KEY POINTS

Hispanic-American patients with chronic rhinosinusitis with nasal polyps have a comparable level of tissue eosinophilia compared to their Caucasian counterparts in the United States. Mixed inflammation involving both neutrophils and eosinophils is more common in this population compared to Caucasians. Findings from this study may indicate that Hispanic-American patients have a unique endotype or endotypes that deserves further investigation.

Sinonasal Symptom Correlation With the Postoperative Polyp Scale (POPS)

BACKGROUND

Commonly used endoscopic nasal polyp grading scales have been shown to correlate poorly with symptom scores and quality of life metrics. The recently described Postoperative Polyp Scale (POPS) is a grading system that more accurately characterizes polyp recurrence in postoperative sinus cavities by describing incremental recurrence in relation to the surgically opened sinus cavities.

OBJECTIVE

The objective of this study was to determine if the POPS correlated with sinonasal symptoms.

METHODS

CRSwNP patients were prospectively administered SNOT-22 questionnaires and graded according to the POPS starting at their 1-month postoperative appointments. Total POPS scores (sum of each side) and Max POPS score (larger value of left and right) were correlated with SNOT-22 total scores and subdomains using Kendall correlation testing.

RESULTS

A total of 127 patients were enrolled in the study. Both Total POPS or Max POPS were significantly correlated to the SNOT-22 total score (P < .001, P < .001), Rhinologic (P < .001, P < .001), Extra-Nasal Rhinologic (P < .001, P < .001), Ear/Facial (P < .001, P < .001), and Psychologic (P = .028, P = .017) subdomains. Kendall's tau indicated strong correlation (≥0.3) with Rhinologic subdomain, moderate correlation (.21-.29) with Extra-Nasal Rhinologic and Ear/Facial subdomains, and weak correlation (.1-.19) with Psychologic subdomain.

CONCLUSION

Previous endoscopic nasal polyp grading scales poorly correlate with symptoms and patient reported outcome measures. The new POPS moderately correlates with the total SNOT-22 score and strongly correlates with the Rhinologic subdomain, indicating that it may have good potential as a tool to evaluate postoperative CRSwNP patients.

Practice Patterns Among Fellowship-Trained Rhinologists: A Survey of Past American Rhinologic Society Fellows

BACKGROUND

The goals of this study were to understand the trends in recent and past rhinology fellows concerning their demographics, goals, and experiences.

METHODS

An anonymous web-based survey was sent to graduates of the 35 rhinology fellowship programs. The survey included questions regarding the scope of practice, research contribution, societal involvement, fellow satisfaction with training, and current practice patterns. Chi-square testing and logistic regression were used to compare variables across cohorts: 0-5 years versus 6+ years from fellowship graduation, gender, and practice settings.

RESULTS

Based on 171 respondents, we found no significant differences in 0-5 versus 6+ year graduates in their desire for an academic job post-fellowship. However, those who graduated 6+ years ago had significantly more success securing one (74% vs 96%, P = 0.004). Between males and females, there were no differences in goal of obtaining an academic job or success in obtaining an academic career. Females were more likely to report they attend academic society meetings regularly. Female rhinologists also reported less satisfaction with overall work-life balance and decreased satisfaction with clinical practice. Physicians in academic settings have poorer work-life balance.

CONCLUSIONS

Our findings suggest that finding an academic job may be more difficult for recent rhinology fellowship graduates, although still very possible for the majority of graduates. Understanding the reason for these changes may provide insight to current rhinology fellowship directors and trainees interested in pursuing fellowship training.

Malpractice Trends Involving Active Surveillance Across Cancers

OBJECTIVE

To characterize malpractice trends related to active surveillance (AS) as a treatment strategy across cancers.

BACKGROUND

Active surveillance is increasingly considered a viable management strategy for low-risk cancers. Since a subset of AS cases will progress, metastasize, or exhibit cancer-related mortality, a significant barrier to implementation is the perceived risk of litigation from missing the window for cure. Data on malpractice trends across cancers are lacking.

METHODS

Westlaw Edge and LexisNexis Advance databases were searched from 1990 to 2022 for malpractice cases involving active surveillance in conjunction with thyroid cancer, prostate cancer, kidney cancer, breast cancer, or lymphoma. Queries included unpublished cases, trial orders, jury verdicts, and administrative decisions. Data were compiled on legal allegations, procedures performed, and verdicts or settlements rendered.

RESULTS

Five prostate cancer cases were identified that pertained to active surveillance. Two cases involved alleged deliberate indifference from AS as a management strategy but were ruled as following the appropriate standard of care. In contrast, 3 cases involved alleged physician negligence for not explicitly recommending AS as a treatment option after complications from surgery occurred. All cases showed documented informed consent for AS, leading to defense verdicts in favor of the physicians. No cases of AS-related malpractice were identified for other cancer types.

CONCLUSIONS

To date, no evidence of successful malpractice litigation for active surveillance in cancer has been identified. Given the legal precedent detailed in the identified cases and increasing support across national guidelines, active surveillance represents a sound management option in appropriate low-risk cancers, with no increased risk of medicolegal exposure.

The utility and accuracy of ChatGPT in providing post-operative instructions following tonsillectomy: A pilot study

OBJECTIVE

To investigate the utility of answers generated by ChatGPT, a large language model, to common questions parents have for their children following tonsillectomy.

METHODS

Twenty Otolaryngology residents anonymously submitted common questions asked by parents of pediatric patients following tonsillectomy. After identifying the 16 most common questions via consensus-based approach, we asked ChatGPT to generate responses to these queries. Satisfaction with the AI-generated answers was rated from 1 (Worst) to 5 (Best) by an expert panel of 3 pediatric Otolaryngologists.

RESULTS

The distribution of questions across the five most common domains, their mean satisfaction scores, and their Krippendorf's interrater reliability coefficient were: Pain management [6, (3.67), (0.434)], Complications [4, (3.58), (-0.267)], Diet [3, (4.33), (-0.357)], Physical Activity [2, (4.33), (-0.318)], and Follow-up [1, (2.67), (-0.250)]. The panel noted that answers for diet, bleeding complications, and return to school were thorough. Pain management and follow-up recommendations were inaccurate, including a recommendation to prescribe codeine to children despite a black-box warning, and a suggested post-operative follow-up at 1 week, rather than the customary 2-4 weeks for our panel.

CONCLUSION

Although ChatGPT can provide accurate answers for common patient questions following tonsillectomy, it sometimes provides eloquently written inaccurate information. This may lead to patients using AI-generated medical advice contrary to physician advice. The inaccuracy in pain management answers likely reflects regional practice variability. If trained appropriately, ChatGPT could be an excellent resource for Otolaryngologists and patients to answer questions in the postoperative period. Future research should investigate if Otolaryngologist-trained models can increase the accuracy of responses.

Ostial Patency Measurements After Endoscopic Sphenoidotomies and Frontal Sinusotomies

BACKGROUND

Sphenoid and frontal sinuses have narrow ostia and are prone to stenosis. However, their relative rates of patency are not well established, and descriptive rates of sphenoid stenosis have never been reported. The objective is to measure the patency of the sphenoid and frontal sinus ostia postoperatively.

METHODS

A prospective multi-institutional cohort study was performed. Ostial patency was measured at surgery and 3 and 6 months postoperatively. Pertinent clinical history such as the presence of nasal polyps and prior history of ESS as well as the use of steroid eluting stents were recorded. Overall stenosis rates were calculated for both the sphenoid and frontal sinuses, and Wilcoxon-Signed Rank Test was used to compare intraoperative and postoperative ostial areas. Factorial Analysis of Variance (ANOVA) was performed to determine effects of 5 clinical factors.

RESULTS

Fifty patients were included. The mean sphenoid sinus ostial area decreased 42.2% in size from baseline to 3 months postoperatively (T0 55.2 ± 28.7 mm vs T3 m 31.8 ± 25.5 mm, P < .001). The mean frontal sinus ostial area decreased 39.8% in size from baseline to 3 months postoperatively (T0 33.7 ± 17.2 mm vs T3 m 19.9 ± 15.1 mm, P < .001). Neither the sphenoid nor the frontal sinus ostial patency demonstrated statistically significant change from 3 to 6 months postoperatively.

CONCLUSION

Both sphenoid and frontal sinus ostia routinely narrow postoperatively, predominately from baseline to 3 months. These findings can serve as a reference for both clinical outcomes and future studies of these surgeries.

Comparative impact of grade on mortality across salivary cancers: A novel, unifying staging system

BACKGROUND

The comparative impact of histologic variants and grade has not been well described.

METHODS

Salivary cancer histologies were profiled using hospital and population-based cancer registries. Multivariable models were employed to assess relationships between histology, grade, and survival.

RESULTS

On univariate analysis, histologic variants exhibited a wide spectrum of mortality risk (5-year overall survival (OS): 86% (acinic cell carcinoma), 78% (mucoepidermoid carcinoma), 72% (adenoid cystic carcinoma), 64% (carcinoma ex-pleomorphic adenoma), 52% (adenocarcinoma NOS), and 47% (salivary duct carcinoma) (p < 0.001). However, on multivariable analysis these differences largely vanished. Worsening grade corresponded with deteriorating survival (5-year OS: 89% [low-grade], 81% [intermediate-grade], 45% [high-grade]; p < 0.001), which was upheld on multivariable analysis and propensity score matching. Recursive partitioning analysis generated TNM + G schema (c-index 0.75) superior to the existing system (c-index 0.73).

CONCLUSION

Grade represents a primary determinant of salivary cancer prognosis. Integrating grade into stage strengthens current staging systems.

Expanded Parameters in Active Surveillance for Low-risk Papillary Thyroid Carcinoma: A Nonrandomized Controlled Trial

Importance

Unlike for prostate cancer, active surveillance for thyroid cancer has not achieved wide adoption. The parameters by which this approach is feasible are also not well defined, nor is the effect of patient anxiety.

Objective

To determine if expanded size/growth parameters for patients with low-risk thyroid cancer are viable, as well as to assess for cohort differences in anxiety.

Design, Setting, and Participants

This prospective nonrandomized controlled trial was conducted at a US academic medical center from 2014 to 2021, with mean [SD] 37.1 [23.3]-month follow-up. Of 257 patients with 20-mm or smaller Bethesda 5 to 6 thyroid nodules, 222 (86.3%) enrolled and selected treatment with either active surveillance or immediate surgery. Delayed surgery was recommended for size growth larger than 5 mm or more than 100% volume growth. Patients completed the 18-item Thyroid Cancer Modified Anxiety Scale over time.

Interventions

Active surveillance.

Main Outcomes and Measures

Cumulative incidence and rate of size/volume growth.

Results

Of the 222 patients enrolled, the median (IQR) age for the study population was 46.8 (36.6-58) years, and 76.1% were female. Overall, 112 patients (50.5%) underwent treatment with active surveillance. Median tumor size was 11.0 mm (IQR, 9-15), and larger tumors (10.1-20.0 mm) comprised 67 cases (59.8%). One hundred one (90.1%) continued to receive treatment with active surveillance, 46 (41.0%) had their tumors shrink, and 0 developed regional/distant metastases. Size growth of more than 5 mm was observed in 3.6% of cases, with cumulative incidence of 1.2% at 2 years and 10.8% at 5 years. Volumetric growth of more than 100% was observed in 7.1% of cases, with cumulative incidence of 2.2% at 2 years and 13.7% at 5 years. Of 110 patients who elected to undergo immediate surgery, 21 (19.1%) had equivocal-risk features discovered on final pathology. Disease severity for all such patients remained classified as stage I. Disease-specific and overall survival rates in both cohorts were 100%. On multivariable analysis, immediate surgery patients exhibited significantly higher baseline anxiety levels compared with active surveillance patients (estimated difference in anxiety scores between groups at baseline, 0.39; 95% CI, 0.22-0.55; P < .001). This difference endured over time, even after intervention (estimated difference at 4-year follow-up, 0.50; 95% CI, 0.21-0.79; P = .001).

Conclusions and Relevance

The results of this nonrandomized controlled trial suggest that a more permissive active surveillance strategy encompassing most diagnosed thyroid cancers appears viable. Equivocal-risk pathologic features exist in a subset of cases that can be safely treated, but suggest the need for more granular risk stratification. Surgery and surveillance cohorts possess oppositional levels of worry, elevating the importance of shared decision-making when patients face treatment equivalence.

Trial Registration

ClinicalTrials.gov Identifier: NCT02609685.

Clinical risk score for individualized risk stratification of patients with clinically suspected myocardial inflammation

Objective

To develop a clinical risk score for individualized risk stratification of patients with clinically suspected myocardial inflammation.

Background

Myocardial inflammation is a prominent cause of non-ischaemic dilated cardiomyopathy, heart failure (HF) and sudden cardiac death.

Methods

This is a prospective multicentre longitudinal study of consecutive patients referred to cardiac magnetic resonance (CMR) with clinically suspected myocardial inflammation between October 2011 and December 2019 as a part of standard diagnostic pathway. Patients were followed up from the date of CMR. The outcome endpoints included major adverse cardiovascular event (MACE, cardiovascular mortality, sudden cardiac death, appropriate device discharge); or death or hospitalisation due to HF). A prognostic model was developed using Cox proportional hazards analysis and validated internally and externally.

Results

The final dataset included 722 subjects (50 years (40–61); males 422 (58%)). During a follow-up period of median 19 (15–23) months, there were 64 (9%) MACE and 130 (18%) HF events. Ten predictor variables qualified for entry into the prognostic model: age, sex, hematocrit, C-reactive protein, high-sensitive troponin-T (TNT), left and right ventricular ejection fraction, native T1 and T2, and late gadolinium enhancement (LGE). The final multivariable Cox regression model included native T2 (Figure 1A), TNT and LGE (Figure 1B) for the primary (Chi-square: 102.0, p&lt;0.001) and secondary endpoint (Chi-square: 166.9, p&lt;0.001), respectively. Cross-validation as well as external validation of the secondary models revealed good performance and no healthcare system effect. Based on the MyoRISK Score, patients were classified into three risk groups with respective event rates for MACE of 0%, 6.3% and 25.1%, and HF endpoint of 1.8%, 17.3% and 44.2%. TNT≥7 pg/ml allowed to efficiently preselect patients prior to CMR.

Conclusions

This is the first systematic assessment of outcomes in patients with clinically suspected myocardial inflammation, providing a non-invasive estimation of the probability of adverse events based on a score using readily available clinical parameters.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): DZHK

Outcomes of cardiovascular magnetic resonance imaging in people living with HIV

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

People living with human immunodeficiency virus (HIV, PLWH) are at increased risk of cardiovascular disease (CVD). HIV infection and accelerated traditional risk factors due to highly-active antiretroviral therapy (HAART) are proposed mechanisms for increased rate of heart failure (HF). The pathophysiological drivers of myocardial dysfunction and worse cardiovascular outcome in HIV remain poorly understood.

Purpose

To examine prognostic relationships of cardiac imaging measures with cardiovascular outcome in PLWH on HAART.

Methods

This is a prospective observational longitudinal study using cardiac magnetic resonance (CMR) imaging in consecutive PLHWH on long-term HAART who were screened for underlying CVD and followed up clinically for adjudicated adverse cardiovascular events (cardiovascular mortality, non-fatal acute coronary syndrome, an appropriate device discharge, or a documented HF hospitalization). Imaging protocol included routine assessment of cardiac volumes and function, scar by late gadolinium enhancement, myocardial perfusion and native T1 /T2 mapping. Time-to-event analysis was performed from the index CMR exam to the first single event per patient Systematic risk scores for CVD (Framingham risk score (FRS), Data Collection on Adverse effects of anti-HIV Drugs score, D:A:D and MAGGIC integer score) were calculated using original online calculators.

Results

156 participants (males 62%, 50 [42-57] years of age) were included. 24 events were observed (4 HF deaths, 1 sudden cardiac death, 2 non-fatal acute myocardial infarction, 1 appropriate device discharge and 16 HF hospitalizations) during a median follow-up of 13 [9-19] months. Patients with events had higher native T1 (ms, 1149 [1115-1163] ms vs. 1110 [1075-1138] ms), native T2 (ms, 40 [38-41] vs. 37 [36-39]), LV mass index (g/m², 65 [49-77] vs. 57 [49-64]) p &lt; 0.05 for all). In multivariable analyses, native T1 was independently predictive of adverse events (ChiSq 15.9, p &lt; 0.001, native T1 (10 ms) hazard ratio (95% confidence interval) 1.20 (1.08-1.33), p = 0.001), followed by a model that also included LV mass (ChiSq 17.1, p &lt; 0.001). Traditional cardiovascular risk scores were not predictive of the adverse events.

Conclusions

Native myocardial T1 and LV mass by CMR, as opposed to traditional cardiovascular risk scores, predict cardiovascular outcome in PLWH, together reflecting the pathological myocardial remodeling of myocardial fibrosis and inflammation that potentially explain higher rates of HF in PLWH as compared to the non-infected population. These findings may inform personalized approaches to screening and early intervention to reduce the burden of HF.

Determination of scar area using native and post contrast T1 mapping: a validation study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Goethe University Hospital

Introduction

Late gadolinium enhancement (LGE) with Full Width Half Maximum (FWHM) is the standard imaging method for the measurement of the scar area in ischemic heart disease, a major determinant of adverse outcome. T1 mapping techniques have become increasingly applied in everyday clinical practice. Agreement in area quantification between T1 mapping and LGE for the scar extent has not been systematically assessed.

Purpose

This study aims to ascertain concordance between the area determined by native and post contrast T1 mapping against LGE to determine scar area in patients with a prior myocardial infarction. It also examines intra and inter-observer reproducibility for these two methods.

Methods

Subendocardial scar was evaluated in 132 patients with ischemic heart disease using LGE, native and post contrast T1 mapping in 3 short axis slices. Native and postcontrast T1 mapping was performed using GoetheCVI®MOLLI sequence (Gadovist® 0.1mmol/kg). FWHM method was applied for LGE and compared with the manually delineated area of scar in native and postcontrast T1 mapping acquisitions within the identical slices. The presence of the scar was defined as LGE &gt;3% of the myocardial mass. Bland-Altman methods were employed to assess concordance between techniques and reproducibly between observers.

Results

In comparison to LGE, area measurements in native T1 acquisitions underestimated infarct size (9,1% vs 12,6%, p = 0.01), while postcontrast T1 overestimated it (19,4% vs 12,6%, p &lt; 0.001). The disparity between the measurements was accentuated with larger scar areas (Figure 1). Intraobserver reproducibility (native T1: intra/inter MD ± SD, CoV, postcontrast T1: intra/inter) was similar with both methods, whereas interobserver variability for native T1 mapping acquisition was worse.

Conclusions

We demonstrate that measurements of the area of myocardial scar by T1 mapping acquisitions yield considerably different results in comparison to the standard LGE-based FWHM method. High observer agreement indicates that these differences are genuinely related to the type of the underlying acquisition and the differences in detected signal. The approaches are not interchangeable. However, the importance of these results for predicting patient outcome is yet to be elucidated. Nonetheless, these results were consistent in the inter and intraobserver analysis for post contrast T1 mapping, although native T1 mapping failed to show similar consistency.

Figure 1: Bland-Altmann plot of differences (mean ± upper and lower limit of agreement-LOA) in scar area extent (percentage) between LGE and native T1 mapping (A), LGE and post contrast T1 mapping (B). The difference increases linearly for larger scar areas when using post contrast mapping, which does not apply for native mapping.

Abstract Figure 1

In-depth phenotyping of cardiac diseases by MRI in HIV-positive people reveals diverse and independent forms of myocardial involvement

Background

It is increasingly recognised that non-ischaemic and ischaemic myocardial involvement represent important drivers of cardiac diseases in people living with HIV (PLWH). Non-invasive measurements with cardiac magnetic resonance (CMR) directly inform on the type of myocardial damage.

Purpose

To screen for the prevalence and type of cardiovascular disease (CVD) in PLWH using stress CMR in a cohort with highly active antiretroviral therapy (HAART).

Methods

This prospective cross-sectional study enrolled consecutive PLWH undergoing standardised evaluation for CVD using imaging. All participants underwent a standardised CMR protocol in a 3 Tesla scanner for function and volumes (cine), stress perfusion (regadenosone), scar (late gadolinium enhancement (LGE)), diffuse fibrosis (native T1-mapping) and oedema (native T2-mapping). Blood samples were additionally collected prior to CMR.

Results

141 participants were identified (n=32 in category C/AIDS). 16 patients had previously documented (n=23) myocardial diseases: myocarditis, n=1 non-obstructive coronary artery disease (CAD), n=8 myocardial infarction, n=3 congestive heart failure, n=3, and arrhythmia, n=8. Mean value for hs-cTnT, CRP and NT-proBNP was 9±18ng/l, 0.3±0.6mg/l and 104±229ng/l. 14 subjects had impaired LV-EF (&lt;50%) and 35 presented borderline LV-EF (50–55%). Myocardial LGE was present in 28 patients: non-ischemic pattern, n=16, ischemic pattern, n=11, and both patterns, n=1. Two patients had relevant inducible ischaemia, whereas a pattern of microvascular disease (MVD) was found in 26 patients. 72 subjects had diffuse fibrosis and 25 had active inflammation. Elevated native T1/T2 was significantly associated with low (&lt;350/μl), current, and initial CD4-count (χ2=5.317, p=0.021; χ2=3.841, p=0.050), just as with category C/AIDS (χ2=4.949, p=0.026). Native T2 showed a significant correlation with initial CD4-count (r=−0.252, p=0.008) and current NT-proBNP (r=0.190, p=0.030), but not with other laboratory values.

Conclusions

CMR in PLWH reveal high prevalence of cardiac involvement, which is predominantly non-ischaemic inflammatory in origin. MVD is a major presentation compared to relevant ischaemia due to epicardial CAD. Individual cardiovascular risk assessment in PLWH using CMR may bear a potential for personalised treatment.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The German Centre for Cardiovascular Research (DZHK)

Myocardial fibrosis and inflammation are predictors of heart failure outcomes in people living with HIV

Background

People living with HIV (PLWH) have higher prevalence of heart failure (HF), which cannot be fully related to traditional cardiovascular disease (CVD) risk factor&lt; or coronary artery disease. Tissue characterisation by cardiac magnetic resonance (CMR), such as with T1 and T2 mapping, is a unique diagnostic approach to provide non-invasive insights into the underlying myocardial pathophysiology.

Purpose

To examine prognostic associations of CMR measures, conventional and modified CVD risk scores with HF outcome in PLWH on long-term highly active antiretroviral therapy (HAART).

Methods

Consecutive PLWH underwent prospectively standardized evaluation of HF using CMR, risk scores and blood markers. CMR protocol included T1 and T2 mapping, perfusion and scar imaging. MAGGIC, Framingham and D:A:D risk scores were collected. Primary HF endpoint was defined as hospitalization or mortality due to HF, and time-to-even analysis from the index CMR to the first event per patient was performed.

Results

141 PLWH (61% males, 48.0 [40.1–54.6] years, CD4 count 655 [411–909] cells/μl) were included. 16 HF events were observed (12 hospitalizations and 4 deaths) during a median follow-up of 13 [9–16] months. Baseline myocardial native T1, T2, left ventricular volumes and troponin were significant univariate predictors of the HF endpoint. The only signifcant (p&lt;0.001) independent predictor in the multivariate analysis was myocardial native T1 (T1 ≥4 SD, HR (95% CI): 5.0 [1.8–13.4]). Conventional and modified CVD risk scores showed no prognostic association with HF outcomes.

Conclusions

Our results show that presence and severity of myocardial inflammation and predominantly diffuse fibrosis detected by T2 and T1 mapping strongly relates to HF events in contrast to conventional and traditional CVD risk scores.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The German Centre for Cardiovascular Research (DZHK)

0701 Positive Airway Pressure Therapy To Treat Sleep Disordered Breathing Impacts Number Of Hospitalizations In Patients With Heart Failure

Introduction

Some studies have shown a benefit while others have shown possible harm in patient outcomes when using positive airway pressure therapy (PAP) for treating sleep disordered breathing (SDB) in patients with heart failure (HF). The goal of this study was to evaluate the number of HF-related and all-cause related hospitalizations in patients with HF and SDB on various forms of PAP therapy versus those on no PAP therapy.

Methods

Administrative claims data from the Truven Health MarketScan Database from 1/1/2005- 10/31/2015 were analyzed. Those included were at least 21 years old, were continuously enrolled for 12 months before and 6 months after their index date (date of PAP prescription), had at least two distinct HF-related claims and were prescribed PAP therapy (n=1,324,414). To model the relationship between each device and hospitalization risk, and to account for the longitudinal and correlated nature of these binary outcome data, generalized estimating equations with binomial family, logit link, and unstructured correlation structure were used.

Results

There were a total of 12,538 patients on Bilevel-PAP, 2,700 patients on bilevel-PAP with backup rate, and 57,405 patients on CPAP, and 73,353 patients with HF and comorbid sleep apnea who were not on any treatment. The reduction in HF-related hospitalization for patients with HF and comorbid SDB treated with bilevel-PAP therapy (0.28; 95% CI 0.26, 0.31) was greater than that in patients receiving CPAP (OR 0.46 95% CI 0.43, 0.49), bilevel PAP with back-up rate (0.39; 95% CI 0.32, 0.49), or no PAP treatment (OR 0.54; 95%CI 0.50, 0.57)(P&lt;0.01). Similar trend was observed for all-cause related hospitalizations. All results were adjusted for propensity score and other relevant confounders.

Conclusion

In claims-based analysis of patients with HF and comorbid SDB, bilevel PAP treatment was associated with reduced hospitalizations when compared to CPAP therapy or no PAP treatment.

Support

Phillips Respironics

P5277Head to head comparison of MOLLI sequences against hs-troponin in patients with biopsy proven myocarditis

Introduction

Increase in native T1 mapping values provides insight into presence of disease and its evolution. Despite the surge of evidence, the immediate clinical application of these techniques is complicated by several variants of T1 mapping sequences, whose diagnostic bioequivalence is not known.

Methods

We undertook an intra-individual comparison of two native T1 measurements based on modified Look-Locker (MOLLI) schemes, MOLLI 3(2)3(2)5 (flip angle, FA 50°, T1-FFM) and MOLLI 5(3)3 (FA 35°, T1 Long) in 30 patients with myocarditis proven by left ventricular endomyocardial biopsy. We examined their agreement with high-sensitive troponin T (hs-TnT) levels, as the reference standard for myocyte injury. All patients underwent a routine cardiovascular magnetic resonance (CMR) scan using a 3-Tesla clinical scanner. Native T1 values were estimated using a septal region of interest (ROI) in a single mid ventricular short axis (SAX) slice. Areas of late gadolinium enhancement (LGE) were excluded from ROIs. Venous blood was sampled at the time of the CMR study and hs-TnT analyzed using standardized commercially available test kits. A p value <0.05 was considered statistically significant.

Results

Native T1 by T1-FFM was moderately associated with MOLLI 5(3)3 (FA 35°) (Pearsons r=0.877, p<0.0001), however the Bland Altman analysis showed a poor agreement with a fixed bias of 46ms (p 0.001) and evidence of proportional bias (p 0.008). There was a significant correlation between native T1-FFM and hs-TnT (rho=0,500, p 0.018), whereas T1 Long showed no association (rho=0,374, p 0,086).

Conclusions

Although native T1 by T1 Long showed a moderate correlation with the native T1 FFM in patients with biopsy proven myocarditis, only T1 FFM had a significant correlation with hsTnT suggesting a greater sensitivity for myocardial injury.

5035Comparative assessment of diagnostic algorithms of myocardial inflammation by endomyocardial biopsy and tissue mapping by CMR against high-sensitive troponin in viral myocarditis

Background

Myocarditis is defined by inflammatory involvement of the myocardium, either histologically by evidence of myocardial necrosis and cellular infiltration on endomyocardial biopsy (EMB), or non-invasively by presence of myocardial oedema using tissue mapping with cardiovascular magnetic resonance (CMR). Objective: to undertake intra-individual comparisons of EMB vs. CMR diagnostic algorithms of myocardial inflammation, as well as against an independent gold-standard of myocardial injury, high-sensitive troponin (hs-TropT).

Methods

Prospective multicentre study of consecutive patients (n=109) with clinical diagnosis of myocarditis. EMBs were analysed by 2 reference centres using the ESC diagnostic and their local algorithms. The CMR criteria used sequence-specific cut-offs for native T1 and T2 (standard deviation, SD); myocardial inflammation T1 ≥2SD, T2 ≥2SD and no inflammation: T1 and T2<2SD, with subcategories for acute/high-grade: T1 ≥5SD, T2 ≥2SD; chronic/low-grade: T1 ≥2SD, T2 ≥2SD; healed: T1 <2SD, T2 <2SD but myocardial impairment and non-inflammatory cardiomyopathy: T1 ≥2SD, T2 <2SD.

Results

The agreement between ESC criteria and CMR criteria (AUC: 0.56, p=0.381) was poor. There was a significant agreement between myocardial injury (hs-TropT ≥13.9 ng/L) and CMR criteria (AUC: 0.84, p<0.001), but not ESC algorithm. hs-TropT levels had significant associations with native T1 and T2 (r=0.37 and 0.35, p<0.001), but not with immunohistochemical inflammatory markers. Viral presence was similarly proportioned between inflammatory/non-inflammatory subjects, irrespective of the algorithm.

AUC of CMR and EMB versus hs-TroponinT

Conclusions

Poor agreement between CMR and EMB-based diagnostic algorithms suggests non-overlapping definitions of myocardial inflammatory involvement. Excellent agreement between CMR algorithm and hs-TropT reiterates its high sensitivity for inflammatory myocardial injury.

Acknowledgement/Funding

1. National Institute for Health Research (NIHR) Biomedical Research Centre 2. German Centre for Cardiovascular Research (DZHK)

Prevalence of eosinophilic esophagitis: A multicenter study on a pediatric population evaluated at thirty-six Latin American gastroenterology centers

INTRODUCTION AND OBJECTIVE

Eosinophilic esophagitis is a chronic, immune-mediated disease described in case series and publications worldwide. Over the past twenty years, the authors of different studies have attempted to evaluate its incidence and prevalence. The objetive of the present study was to estimate the prevalence of eosinophilic esophagitis in a group of children seen at 36 pediatric gastroenterology centers in ten Latin American countries.

MATERIALS AND METHODS

A multicenter, observational, and cross-sectional study was conducted that estimated the period prevalence of eosinophilic esophagitis in children seen at outpatient consultation and that underwent diagnostic upper gastrointestinal endoscopy for any indication at 36 centers in 10 Latin American countries, within a 3-month time frame.

RESULTS

Between April and June 2016, 108 cases of eosinophilic esophagitis were evaluated. Likewise, an average of 29,253 outpatient consultations and 4,152 diagnostic upper gastrointestinal endoscopies were carried out at the 36 participating centers. The period prevalence of eosinophilic esophagitis in the population studied (n=29,253) was 3.69 cases×1,000 (95% CI: 3.04 to 4.44), and among the children that underwent routine upper gastrointestinal endoscopy (n=4,152), it was 26x1,000 (95% CI: 22.6 to 29.4).

CONCLUSIONS

The general period prevalence of eosinophilic esophagitis in a group of children evaluated at 36 Latin American pediatric gastroenterology centers was 3.69×1,000, and in the children that underwent endoscopy, it was 26×1,000. There was important prevalence variability between the participating countries and centers. The present analysis is the first study conducted on the prevalence of pediatric eosinophilic esophagitis in Latin America.

P5282Comparison of cardiovascular magnetic resonance ejection fraction and left ventricular volumes by long axis feature tracking strain analysis versus standard short axis stack contour tracing

Introduction

Cardiovascular magnetic resonance (CMR) feature tracking (FT) is based on the recognition of endocardial features obtained during standard CMR cine imaging to be tracked and followed throughout the cardiac cycle. Global longitudinal strain (GLS) has been proposed as a superior measure for diagnosis and prognosis than ejection fraction (EF). However, EF remains an important primary parameter to describe cardiac function. A rapid determination of GLS based on three long axis views (LAX) allows for a simultaneous calculation of EF without additional imaging or post-processing promising a significant reduction of scan and post-processing time.

Purpose

The purpose of this work is to compare the LV volumes and EF obtained during assessment of GLS based on CMR feature tracking with standard analysis of a short axis (SAX) stack used as the reference standard.

Methods

75 consecutive patients underwent a routine clinical scan obtaining a full SAX stack as well as 3 standard LAX views using either 3-Tesla or 1,5-Tesla clinical scanners. We determined LV volumes and EF based on the reference standard as well as feature tracking analysis with additional GLS. A p value <0.01 was considered statistically significant.

Results

Mean EF was 45.9% using standard SAX (range, 13%-72%) and 51.1% using triplanar feature tracking (r=0.950; p<0.0001, figure 1A). Bland-Altman analysis showed a systematic bias of 5,27%; without proportional bias (figure 1B). End-diastolic volumes (r=0,975; p<0.0001) and end-systolic volumes (r=0.985; p<0.0001) demonstrated similar results. Mean GLS was −17.3% (range: −30,7% to −3,3%) and was significantly correlated with standard EF (r=−0,884; p<0.0001). Classification of EF into categories: reduced, mid-range or preserved (<40%, 40–49%, ≥50%) remain unchanged in 79% of patients when using EF by feature tracking analysis. Twelve of 16 reclassifications occurred in the mid-range category.

Figure 1

Conclusion

There is a good correlation between EF obtained by rapid post-processing of GLS with EF based on a full SAX stack resulting in an identical categorization in 79% of patients. Reduction of EF within the mid-range might be best assesses by the standard SAX stack.

Finite-difference solution of the Poisson-Boltzmann equation: Complete elimination of self-energy

A new procedure to solve the Poisson-Boltzmann equation is proposed and shown to be efficient. The electrostatic potential due to the reaction field is calculated directly. Self-interactions among the charges are completely eliminated. Therefore, the reference calculation to cancel out the self-energy is not needed. © 1996 by John Wiley & Sons, Inc.

249 BIOPHYSICAL AND BIOCHEMICAL CHARACTERISTICS OF ALPACA SEMEN AFTER COLLECTION BY ELECTROEJACULATION

The collection of alpaca semen presents difficulties because of the characteristics of mounts and copulation time in addition to the high viscosity of semen. The biophysical and biochemical characteristics of alpaca semen were investigated. Semen samples from four adult males from 6 to 7 years of age were collected using an electroejaculation technique. The biophysical parameters measured in seminal plasma included volume, color, sperm concentration, motility, and viscosity, and the biochemical parameters included pH and glucose, calcium, triglyceride, cholesterol, high-density lipoprotein cholesterol, total protein, albumin, alanine transaminase, alkaline phosphatase, and γ-glutamyltranspeptidase concentrations. The mean time for semen collection was 10.3 ± 1.5 min; the volume varied from 1.2 to 3.8 and the colour from clear to milky, and pH was 7.4 ± 0.03. Mean concentration of spermatozoa was 69.3 ± 193 million mL–1, and motility was 52.4 ± 9.7%. Biochemical parameters were glucose (mg dL–1) 8.22 ± 0.77; cholesterol (mg dL–1) 79.78 ± 5.64; triglycerides (mg dL–1) 44.12 ± 7.38; high-density lipoprotein cholesterol (mg dL–1) 4.73 ± 0.30; total protein (g dL–1) 2.36 ± 0.15; albumin (g dL–1) 0.97 ± 0.33; calcium (mg dL–1) 11.77 ± 1.74; alanine transaminase (U L–1) 17.92 ± 9.09; alkaline phosphatase (U L–1) 288.76 ± 279.59; and γ-glutamyltranspeptidase (U L–1) 89.62 ± 39.09. These results provide information on the biophysical and biochemical characteristics of alpaca semen collected by electroejaculation, with variable results in the enzymatic components.

Ion energy distribution functions of low energy beams formed by wire extraction electrodes

The two-electrode extractor system made of 0.1 mm diameter tungsten wires separated by 0.7 mm has formed an argon ion beam with 50 V extraction potential. Energy spreads of the extracted beams were typically less than 2 eV when the beam current density was low. The beam intensity rapidly decreased as the distance between the extractor and the beam detector increased, indicating space charge limited transport of the beam. Problems associated with the emittance measurements are also discussed.

Characteristics of low-energy ion beams extracted from a wire electrode geometry

Beams of argon ions with energies less than 50 eV were extracted from an ion source through a wire electrode extractor geometry. A retarding potential energy analyzer (RPEA) was constructed in order to characterize the extracted ion beams. The single aperture RPEA was used to determine the ion energy distribution function, the mean ion energy and the ion beam energy spread. The multi-cusp hot cathode ion source was capable of producing a low electron temperature gas discharge to form quiescent plasmas from which ion beam energy as low as 5 eV was realized. At 50 V extraction potential and 0.1 A discharge current, the ion beam current density was around 0.37 mA/cm(2) with an energy spread of 3.6 V or 6.5% of the mean ion energy. The maximum ion beam current density extracted from the source was 0.57 mA/cm(2) for a 50 eV ion beam and 1.78 mA/cm(2) for a 100 eV ion beam.

Gallium ion extraction from a plasma sputter-type ion source

A broad mixed ion beam containing positive ions of gallium (Ga) was produced with a plasma sputter-type ion source. Liquid Ga was suspended on a tungsten reservoir to be sputtered and postionized in argon (Ar) plasma excited by a radio frequency (rf) power at 13.56 MHz. Optical emission spectra from the plasma near the Ga sputtering target had indicated that the release of Ga into plasma increased with increasing negative bias to the sputtering target. The ratio of Ga(+) current to Ar(+) current was measured to be about 1% with a quadrupole mass analyzer at 100 V extraction voltage for incident rf power as low as 30 W. Ions in the plasma were extracted through a pair of multiaperture electrodes. The homogeneity of Ga flux was examined by making a Ga deposition pattern on a glass substrate located behind the extractor electrodes.

Toxicity of the lichen secondary metabolite (+)-usnic acid in domestic sheep

Toxicity following ingestion of the vagrant, foliose lichen Xanthoparmelia chlorochroa was identified as the putative etiology in the death of an estimated 400-500 elk on the Red Rim-Daley Wildlife Habitat Management Area in Wyoming during the winter of 2004. A single, unsubstantiated report in 1939 attributed toxicity of X. chlorochroa in cattle and sheep to usnic acid, a common lichen secondary metabolite. To test the hypothesis that usnic acid is the proximate cause of death in animals poisoned by lichen, domestic sheep were dosed PO with (+)-usnic acid. Clinical signs in symptomatic ewes included lethargy, anorexia, and signs indicative of abdominal discomfort. Serum creatine kinase, aspartate aminotransferase, and lactate dehydrogenase activities were considerably elevated in symptomatic sheep. Similarly, only symptomatic ewes exhibited appreciable postmortem lesions consisting of severe degenerative appendicular skeletal myopathy. The median toxic dose (ED(50)) of (+)-usnic acid in domestic sheep was estimated to be between 485 and 647 mg/kg/day for 7 days.

Organochlorine and organophosphoric insecticides, herbicides and heavy metals residue in industrial wastewaters in Cyprus

Most industries in Cyprus possess permits either for disposal at central wastewater treatment plants (the treated effluent of which is reused or disposed into the sea), or discharge on soil, or reuse either for irrigation or groundwater recharge or discharge into the sea. A preliminary investigation undertaken by the University of Cyprus in regards to dangerous substances was the first step towards establishing a new licensing and monitoring system. Liquid-liquid extraction was used for the extraction of the selected pesticides from wastewaters. Gas chromatography with two different detection methods (ECD and FTD) was applied for the determination of 17 pesticides (12 organochlorine insecticides, 3 organophosphoric insecticides and 2 herbicides). In addition ICP and a mercury evaporation unit were used to determine the concentrations of heavy metals in the samples. The results revealed the presence of several priority substances in wastewaters, in most cases at concentrations well below the regulatory limits. Non-compliance was observed for a limited number of metals. Sixteen out of 17 organic substances that were monitored for 1-year period time were traced in different wastewater streams. What was found out is that there is a need to expand the analytical determinations and the monitoring to more wastewater streams and more priority substances, in order to safeguard the water resources in Cyprus.

The diversification of psychology: a multicultural revolution

The National Multicultural Conference and Summit was held in January 1999 in Newport Beach, California. Hosted by Divisions 17 (Counseling Psychology), 35 (Society for the Psychology of Women), and 45 (Society for the Psychological Study of Ethnic Minority Issues), the event drew support from many American Psychological Association (APA) divisions and other major organizations and sponsors. Approximately 550 psychologists and graduate students attended the conference, which was intended to (a) examine state-of-the-art issues in ethnic minority psychology, (b) identify barriers to becoming a multicultural profession, and (c) forge alliances for political action and advocacy. The summit participants unanimously endorsed resolutions aimed at implementing cultural competence in all psychological endeavors. Multicultural themes arising from the summit included the diversification of the United States; the facilitation of difficult dialogues on race, gender, and sexual orientation; spirituality as a basic dimension of the human condition; the invisibility of monoculturalism and Whiteness; and the teaching of multiculturalism and diversity. APA was strongly encouraged to take the lead in seeing that multicultural competence becomes a defining feature of psychological practice, education and training, and research.

Humanization and characterization of the anti-HLA-DR antibody 1D10

1D10 is a previously described antibody that binds to cells from a majority of B-cell malignancies. The current studies were designed to further evaluate the antigen specificity of 1D10 and its potential as an immunotherapeutic agent. Studies with transfectants and immunoprecipitation demonstrated that 1D10 recognizes some, but not all, of the human HLA-DR beta chains. Both normal and malignant B cells can express the 1D10 antigen. A humanized version of 1D10 was produced using CDR grafting. The resulting antibody has an affinity that is similar to that of the parental murine antibody. In addition, the humanized antibody is capable of inducing complement-mediated cytotoxicity, antibody-dependent cell cytotoxicity, and direct apoptosis of 1D10-expressing B cells. Based on these in vitro anti-tumor activities, we conclude humanized 1D10 deserves further evaluation as an immunotherapeutic agent.

The effects of continuous blood gas monitoring during cardiopulmonary bypass: a prospective, randomized study--Part II

The impact of blood gas management during cardiopulmonary bypass (CPB) on patient care has not been examined and remains controversial. The purpose of this study was to determine whether precise blood gas management during CPB influences patient outcome. Fifty-nine patients were enrolled in an Institutional Review Board-approved, prospective, randomized study. An in-line blood gas monitor (CDI 500) was placed into the arterial and venous lines for all patients. Blood gas monitoring in the control group was managed by intermittent sampling (every 20-30 min), while the treatment group was managed with continuous monitoring. Blood gas control and measured parameters were as follows: pH 7.40 +/- 0.05, PaCO2 40 +/- 5 mmHg, PaO2 200 +/- 50 mmHg. The treatment group had the CDI 500 guide clinical decisions. Compared to the control group, the treatment group consisted of significantly more diabetic (7% vs. 47%, p < or = 0.001), renal failure (3% vs. 13%, p < or = 0.01), and chronic obstructive pulmonary disease patients (7% vs. 20%, p < or = 0.01). Internal thoracic artery utilization was higher in treatment patients than control patients (67% vs. 95%, p < or = 0.02). No other differences existed in demographic, pharmacological, surgical, or anesthetic parameters. In the perioperative period, the control group required antiarrythmic support more frequently than the treatment group (10% vs. 0%, p < or = 0.05). Compared to the control group, the treatment group required antiarrythmic (18% vs. 10%, p < or = 0.05) and cardiac glycoside therapy (11% vs. 0%, p < or = 0.05) less frequently in the postoperative period. Although treatment patients required less intraoperative pacing and cardioversion and spent less time on mechanical ventilation, in the intensive care unit (ICU), and in the hospital than control patients, statistical significance was not achieved. In conclusion, the use of continuous, in-line blood gas monitoring resulted in improvement in a number of postoperative outcome variables, although ICU and hospital stay was not effected.

The effects of continuous blood gas monitoring during cardiopulmonary bypass: a prospective, randomized study--Part I

The use of continuous in-line blood gas management (CILBGM) is steeped in controversy concerning its potential utility and impact on patient outcomes. The purpose of this study was to determine whether the use of CILBGM results in improved quality of patient care. Fifty-nine patients were enrolled in a Institutional Review Board-approved, prospective, randomized study. An in-line blood gas monitor (CDI 500) was placed into the arterial and venous lines for all patients. Blood gas monitoring in the control group was managed by intermittent sampling (every 20-30 min), while the treatment group was managed with continuous monitoring. There were no differences between groups in preoperative, surgical, anesthetic, or perfusion variables. The accuracy of the in-line monitor was comparable to laboratory analysis for arterial blood gas parameters (N = 160; pH bias = 0.00; PaCO2 bias = -1.1 mmHg; and PaO2 bias = 0.7 mmHg). There was less deviation from target values (pH = 7.40, PaCO2 = 40 mmHg, PaO2 = 150-200 mmHg) when in-line monitoring was used versus intermittent sampling (N = 784; pH deviation = 0.05 +/- 0.03 vs. 0.03 +/- 0.01, p < 0.0001; PaCO2 deviation = 4.0 +/- 2.9 mmHg vs. 2.0 +/- 0.9 mmHg, p < 0.0001; and PaO2 deviation = 22.7 +/- 16.9 mmHg vs. 11.7 +/- 8.3 mmHg, p < 0.0001). In conclusion, the results of part I of this study demonstrate that the use of CILBGM results in more accurate blood gas management during CPB.

HuM291, a humanized anti-CD3 antibody, is immunosuppressive to T cells while exhibiting reduced mitogenicity in vitro

BACKGROUND

OKT3, a mouse monoclonal antibody (Ab) specific for the human CD3 complex on T cells, is a potent immunosuppressive agent used for the treatment of acute allograft rejection. The utility of the drug has been limited by a neutralizing anti-mouse Ab response and adverse side effects resulting from T cell activation and systemic cytokine release. T cell activation is caused by OKT3-mediated cross-linking of T cells and Fc receptor-bearing cells. Studies in the mouse model have shown that global T cell activation is not necessary for immunosuppression, as Fc receptor-nonbinding anti-CD3 Abs can suppress graft rejection in the absence of the activation effects seen with Fc receptor-binding Abs. Thus, a humanized anti-CD3 antibody with a low affinity for Fc receptors might improve immunosuppressive therapy by reducing the side effects associated with OKT3.

METHODS

We developed a mouse monoclonal Ab, M291, which competes with OKT3 for binding to T cells. Humanized, complementary-determining region-grafted versions of M291 featuring various Fc were engineered, including a previously described IgG2 mutant deficient in Fc receptor binding (HuM291).

RESULTS

Compared with OKT3 and HuM291-IgG1, HuM291 was significantly less mitogenic to T cells in vitro and induced the release of much lower levels of the cytokines tumor necrosis factor-alpha, interferon-gamma, and interleukin-10. Despite this reduction in T cell activation, HuM291 retained the ability to modulate the CD3 complex and inhibit the mixed lymphocyte reaction.

CONCLUSIONS

When evaluated in vivo, HuM291 may be an immunosuppressive agent associated with less of the acute toxicity and immunogenicity seen with OKT3 therapy.

Properties and pharmacokinetics of two humanized antibodies specific for L-selectin

BACKGROUND

The participation of L-selectin in leukocyte recruitment during inflammation has suggested the use of L-selectin inhibitors as potential anti-inflammatory therapeutics. Blocking monoclonal antibodies could serve as such therapeutic agents, particularly if humanized to reduce their immunogenicity and improve their serum half-life.

OBJECTIVES

For this purpose, two mouse monoclonal antibodies, DREG-55 and DREG-200, that block human L-selectin were humanized and characterized.

STUDY DESIGN

The resulting humanized antibodies, HuDREG-55 and HuDREG-200, constructed with human IgG4 constant regions, were evaluated for their specificity, affinity and ability to block L-selectin-dependent adhesion in in vitro assays. Their pharmacokinetic behavior in rhesus monkeys was also studied.

RESULTS

HuDREG-55 and HuDREG-200 were found to retain the specificity and affinity, within 2-fold, of the parent murine antibodies. HuDREG-55 and HuDREG-200 block L-selectin-dependent adhesion of human lymphocytes to high endothelial venules in frozen sections of lymph nodes. In addition, HuDREG-55 and HuDREG-200 are inhibitory in a novel L-selectin-dependent adhesion assay. This assay utilizes flow cytometry to measure binding of polymerized liposomes containing an analog of sialyl Lewis X, sialyl Lewis X glycoliposomes, to peripheral blood neutrophils and lymphocytes. Studying the pharmacokinetics of HuDREG-55 and HuDREG-200 in rhesus monkeys showed terminal elimination half-lives at 12.0 and 20.3 days, respectively.

CONCLUSION

The shorter terminal elimination half-life of HuDREG-55 in rhesus monkeys may be due to the ability of HuDREG-55 but not HuDREG-200 to bind rhesus monkey L-selectin.

Comparison of the three-dimensional structures of a humanized and a chimeric Fab of an anti-gamma-interferon antibody

The objective of this work is to compare the three-dimensional structures of "humanized" and mouse-human chimeric forms of a murine monoclonal antibody elicited against human gamma-interferon. It is also to provide structural explanations for the small differences in the affinities and biological interactions of the two molecules for this antigen. Antigen-binding fragments (Fabs) were produced by papain hydrolysis of the antibodies and crystallized with polyethylene glycol (PEG) 8,000 by nearly identical microseeding procedures. Their structures were solved by X-ray analyses at 2.9 A resolution, using molecular replacement methods and crystallographic refinement. Comparison of these structures revealed marked similarities in the light (L) chains and near identities of the constant (C) domains of the heavy (H) chains. However, the variable (V) domains of the heavy chains exhibited substantial differences in the conformations of all three complementarity-determining regions (CDRs), and in their first framework segments (FR1). In FR1 of the humanized VH, the substitution of serine for proline in position 7 allowed the N-terminal segment (designated strand 4-1) to be closely juxtaposed to an adjacent strand (4-2) and form hydrogen bonds typical of an antiparallel beta-pleated sheet. The tightening of the humanized structure was relayed in such a way as to decrease the space available for the last portion of HFR1 and the first part of HCDR1. This compression led to the formation of an alpha-helix involving residues 25-32. With fewer steric constraints, the corresponding segment in the chimeric Fab lengthened by at least 1 A to a random coil which terminated in a single turn of 310 helix. In the humanized Fab, HCDR1, which is sandwiched between HCDR2 and HCDR3, significantly influenced the structures of both regions. HCDR2 was forced into a bent and twisted orientation different from that in the chimeric Fab, both at the crown of the loop (around proline H52a) and at its base. As in HCDR1, the last few residues of HCDR2 in the humanized Fab were compressed into a space-saving alpha-helix, contrasting with a more extended 310 helix in the chimeric form. HCDR3 in the humanized Fab was also adjusted in shape and topography. The observed similarities in the functional binding activities of the two molecules can be rationalized by limited induced fit adjustments in their structures on antigen binding. While not perfect replicas, the two structures are testimonials to the progress in making high affinity monoclonal antibodies safe for human use.

Comparative study of 2 variants of a modified esophageal transection in the Sugiura-Futagawa operation

OBJECTIVE

To compare 2 techniques of esophageal transection in our modification of the Sugiura-Futagawa procedure for the treatment of bleeding portal hypertension in low-risk patients who cannot undergo surgery to have shunts placed.

DESIGN

A prospective controlled trial comparing 2 variants of transection (classic, complete section of the anterior muscularis externa and whole mucosa; modified, placement of a circumferential running suture without opening the mucosa).

SETTING

Academic university hospital.

PATIENTS

Eighty-three low-risk patients (Child-Pugh score A and B) with a history of bleeding portal hypertension were operated on (35 classic, 48 modified transections) between 1989 and 1996. Both groups were comparable.

MAIN OUTCOME MEASURES

Postoperative dehiscence of the transection was evaluated as well as fistulization, postoperative stenosis, rebleeding, postoperative endoscopic findings, survival, and mortality.

RESULTS

Fistulization was observed in 1 (2%) of the patients in the modified group, and dehiscence in 1 patient (2%). In the classic group, 3 (8%) of the patients had dehiscence (relative risk, 2.6) and 1 (2%) of the patients, fistulization. No differences were observed regarding rebleeding (6 patients [6%] vs 5 patients [7%]), postoperative stenosis (4 patients [8%] vs 5 patients [10%]), postoperative endoscopic findings, survival, and mortality (early and late).

CONCLUSION

The modified variant of the transection has a lower frequency of postoperative dehiscence, with the same long-term results.

Humanization and pharmacokinetics of a monoclonal antibody with specificity for both E- and P-selectin

E- and P-selectin (CD62E and CD62P) are cell adhesion molecules that mediate leukocyte-endothelial cell and leukocyte-platelet interactions and are involved in leukocyte recruitment during inflammation. We previously developed a murine mAb, EP-5C7 (or mEP-5C7), that binds and blocks both E- and P-selectin. When used in humans, murine mAbs have short circulating half-lives and generally induce potent human anti-mouse Ab responses. We therefore engineered a humanized, complementarity determining region-grafted version of mEP-5C7 incorporating human gamma4 heavy and kappa light chain constant regions (HuEP5C7.g4). HuEP5C7.g4 retains the specificity and avidity of mEP-5C7, binding to human E- and P-selectin but not to human L-selectin, and blocking E- and P-selectin-mediated adhesion. Surprisingly, when administered to rhesus monkeys, HuEP5C7.g4 was eliminated from the circulation very rapidly, even faster than the original murine Ab. To isolate the cause of the short serum half-life of HuEP5C7.g4, several Ab variants were constructed. A chimeric IgG4 Ab was made by replacing the humanized V regions with murine V regions. A humanized IgG2 Ab, HuEP5C7.g2, was also made by replacing the human gamma4 with a gamma2 constant region. Results from pharmacokinetic studies in rhesus monkeys demonstrated that the chimeric IgG4 is also rapidly eliminated rapidly from serum, similar to the humanized IgG4 Ab, while the humanized IgG2 Ab displays a long circulation half-life, typical of human Abs.

Is splenectomy necessary in devascularization procedures for treatment of bleeding portal hypertension?

OBJECTIVE

To investigate whether splenectomy as a part of devascularization procedures is necessary.

DESIGN

Prospective, controlled, randomized trial.

SETTING

University hospital, referral center.

PATIENTS

A total of 55 patients (Child-Pugh class A and B) with a history of bleeding portal hypertension were treated by means of a modified Sugiura-Futagawa procedure. Twenty-three patients underwent splenectomy and 22 did not.

METHODS

Postoperative outcome was recorded and comparison of the 2 groups was done with the Fisher exact test. Kaplan-Meier survival curves were constructed. Main outcome and postoperative differences between the patients who underwent splenectomy and those who did not were investigated.

RESULTS

Both groups were comparable in the postoperative period. Significant differences were observed in transfusion requirements and postoperative portal vein thrombosis, both favoring the group without splenectomy. No differences in rebleeding, encephalopathy rate, operative time, or postoperative complications were observed.

CONCLUSION

Splenectomy is not routinely necessary in devascularization procedures for bleeding portal hypertension.

Epithelioid hemangioendothelioma of soft tissue: report of a case with ultrastructural observations

The ultrastructure of an epithelioid hemangioendothelioma arising in the soft tissues of the neck of an 18-year-old female is reported. Comparison with similar tumors in other sites from the authors' electron microscopy files indicates that diffuse nonspecific intermediate filaments, pinocytotic vesicles, intracytoplasmic lumens, and pericytic cells are frequent but variable features of this neoplasm.

Measurement of micronucleated erythrocytes and DNA damage during chronic ingestion of phenolphthalein in transgenic female mice heterozygous for the p53 gene

Phenolphthalein, a common ingredient in nonprescription laxatives and a multisex, multispecies rodent carcinogen, was evaluated under chronic exposure conditions for genotoxicity in transgenic female mice heterozygous for the p53 gene (heterozygous TSG-p53 mice). Phenolphthalein was administered in the diet at 200, 375, 750, 3,000, and 12,000 ppm (corresponding to a time-weighted average of 37, 71, 146, 569, and 2,074 mg/kg/day, respectively) for 6 months (183 days). On days 39, 92, 137, and 183 of treatment, peripheral blood samples were collected and evaluated for the frequency of micronucleated polychromatic and normochromatic erythrocytes (MN-PCE and MN-NCE, respectively), the percentage of PCE (%PCE) among total erythrocytes, and the extent of DNA damage (single strand breaks, alkali labile sites, DNA crosslinking) in leukocytes. In addition, the extent of DNA damage was evaluated in liver parenchymal cells sampled from mice at the end of the 6-month treatment period. DNA damage was evaluated using the alkaline (pH > 13) Single Cell Gel (SCG) assay. In addition, using a modified SCG technique, the frequencies of leukocytes and liver parenchymal cells with extremely low molecular weight DNA (indicative of apoptosis and/or necrosis) were determined. At each sample time, phenolphthalein induced a highly significant, dose-dependent increase in the frequency of MN-PCE and MN-NCE and in %PCE. Maximal induction of MN-PCE and %PCE decreased with increasing treatment duration, most likely due to a treatment duration-dependent decrease in the relative amount of ingested phenolphthalein. A comparative analysis of the kinetochore status of MN in erythrocytes sampled from control mice and mice ingesting phenolphthalein at 12,000 ppm for 183 days indicates that the induced MN resulted predominantly but not exclusively from numerical chromosomal damage. The analysis for increased levels of DNA damage in blood leukocytes was inconclusive, with a small but statistically significant increase in DNA migration on days 39 and 137 but not on days 92 and 183. The extent of DNA migration in liver parenchymal cells sampled from mice at the end of treatment was not altered significantly. The frequencies of apoptotic and/or necrotic leukocytes and liver parenchymal cells were not increased among mice ingesting phenolphthalein. The lowest effective dose at which a significant genotoxic response (i.e., the induction of MN-NCE) was detected was 200 ppm, the lowest dose tested in this study. This dose in mice is comparable to doses (on a mg/m2 basis) experienced by humans.

Chemolithotrophic bacteria in copper ores leached at high sulfuric Acid concentration

Extensive bacterial growth was observed when copper sulfide ores were leached with 0.6 N sulfuric acid. The bacterial population developed in this condition was examined by characterization of the spacer regions between the 16S and 23S rRNA genetic loci obtained after PCR amplification of the DNA extracted from the leached ore. The spacers observed had the sizes found in strains of "Leptospirillum ferrooxidans" and Thiobacillus thiooxidans, except for a larger one, approximately 560 bp long, that was not observed in any of the strains examined, including those of Thiobacillus ferrooxidans. The bacteria with this last spacer were selected after culturing in mineral and elemental sulfur media containing 0.7 N sulfuric acid. The spacer and the 16S ribosomal DNA of this isolate were sequenced and compared with those in species commonly found in bioleaching processes. Though the nucleotide sequence of the spacer showed an extensive heterologous region with T. thiooxidans, the sequence of its 16S rDNA gene indicated a close relationship (99.85%) with this species. These results indicate that a population comprised of bacterial strains closely related to T. thiooxidans and of another strain, possibly related to "L. ferrooxidans," can develop during leaching at high sulfuric acid concentration. Iron oxidation in this condition is attributable to "L. ferrooxidans" and not T. ferrooxidans, based on the presence of spacers with the "L. ferrooxidans" size range and the absence of spacers characteristic of T. ferrooxidans.