Using extended reality (XR) for medical training and real-time clinical support during deep space missions

Medical events can affect space crew health and compromise the success of deep space missions. To successfully manage such events, crew members must be sufficiently prepared to manage certain medical conditions for which they are not technically trained. Extended Reality (XR) can provide an immersive, realistic user experience that, when integrated with augmented clinical tools (ACT), can improve training outcomes and provide real-time guidance during non-routine tasks, diagnostic, and therapeutic procedures. The goal of this study was to develop a framework to guide XR platform development using astronaut medical training and guidance as the domain for illustration. We conducted a mixed-methods study-using video conference meetings (45 subject-matter experts), Delphi panel surveys, and a web-based card sorting application-to develop a standard taxonomy of essential XR capabilities. We augmented this by identifying additional models and taxonomies from related fields. Together, this "taxonomy of taxonomies," and the essential XR capabilities identified, serve as an initial framework to structure the development of XR-based medical training and guidance for use during deep space exploration missions. We provide a schematic approach, illustrated with a use case, for how this framework and materials generated through this study might be employed.

POS0062 A RISK SCORE TO DETECT SUBCLINICAL RHEUMATOID ARTHRITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE

Background

Despite a high morbi-mortality rate, there are no definite strategy for subclinical interstitial lung disease (ILD) screening in patients with rheumatoid arthritis (RA).

Objectives

Our objectives were: 1. to identify risk factors for subclinical RA-ILD in a prospective discovery cohort (ESPOIR) 2.to develop a risk score for subclinical RA-ILD and 3. to validate the risk score in an independent replication cohort (TRANSLATE 2).

Methods

Patients without pulmonary symptoms from 2 prospective RA cohorts who underwent chest HRCT scans were included. All patients were genotyped for MUC5B rs35705950. A risk score based on independent risk factors for subclinical RA-ILD was developed using multiple logistic regression in the discovery cohort. The risk score was tested for validation in the replication cohort.

Results

Discovery and replication cohorts included 163 and 89 patients, respectively. Subclinical ILD was detected in 19.0% and 16.9% of the patients, respectively. In the discovery cohort, independent risk factors for subclinical RA-ILD were the MUC5B rs35705950 T risk allele (odds ratio [OR]=3.74; 95% confidence interval [CI] [1.37–10.39], male sex (OR=3.93; 95%CI [1.40–11.39]), older age at RA onset (for each year, OR=1.10; 95%CI [1.04–1.16]) and increased mean DAS28-ESR (for each unit, OR=2.03; 95%CI [1.24–3.42]). We developed a risk score for subclinical RA-ILD with AUC=0.82; 95%CI [0.70–0.94] (sensitivity (Se)=71.0%) and specificity (Sp)=79.6%). The risk score was validated in the replication cohort with AUC=0.78; 95%CI [0.65–0.92] (Se=86.7%, Sp=62.2%).

Conclusion

Our risk score could help identifying patients at high-risk for subclinical RA-ILD before the onset of pulmonary symptoms.

Disclosure of Interests

Pierre-Antoine Juge Speakers bureau: AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Consultant of: Bristol Myers Squibb, Benjamin Granger: None declared, Marie-Pierre Debray: None declared, Esther Ebstein: None declared, Fabienne Louis-Sidney: None declared, Joanna KEDRA: None declared, Tracy Doyle: None declared, Raphael Borie: None declared, Arnaud Constantin Consultant of: Abbvie, Amgen, Biogen, BMS, Boehringer Ingelheim, Fresenius Kabi, Galapagos, Janssen, Lilly, Medac, MSD, Mylan, Novartis, Pfizer, Procter & Gamble, Roche, Sanofi, UCB, Viatris, Bernard Combe Consultant of: AbbVie, BMS, Eli-Lilly, Gilead, Janssen, Merck, Novartis, Pfizer, Roche-Chugai, Sanofi, UCB, René-Marc Flipo Consultant of: Abbvie, Janssen, MSD and Pfizer. He reports research grants from Abbvie, Janssen, Novartis and Pfizer, Xavier Mariette Consultant of: BMS, Gilead, Janssen, Pfizer, Samsung, UCB, Olivier VITTECOQ: None declared, Alain Saraux: None declared, Guillermo CARVAJAL ALEGRIA: None declared, Jean Sibilia Consultant of: AbbVie, Lilly, MSD, Amgen, Pfizer, BMS, Janssen, Roche, Sandoz, Sanofi-Genzyme, SOBI, UCB, Novartis, Grant/research support from: AbbVie, Lilly, MSD, Amgen, Pfizer, BMS, Janssen, Roche, Sandoz, Sanofi-Genzyme, SOBI, UCB, Novartis, Francis Berenbaum: None declared, Caroline Kannengiesser: None declared, Catherine Boileau: None declared, Jeffrey Sparks Consultant of: AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Gilead, Inova Diagnostics, Janssen, Optum, and Pfizer, Grant/research support from: National Institute of Arthritis and Musculoskeletal and Skin Diseases (grant numbers R01 AR077607, P30 AR070253, and P30 AR072577), The R. Bruce and Joan M. Mickey Research Scholar Fund, Bristol Myers Squibb,

Bruno Crestani Speakers bureau: Boehringer Ingelheim, AstraZeneca, Roche, Sanofi, Grant/research support from: MedImmune, Roche, Boehringer Ingelheim, Bruno Fautrel Consultant of: AbbVie, Amgen, Biogen, BMS, Celgene, Fresenius Kabi, Janssen, Lilly, Medac, MSD, NORDIC Pharma, Novartis, Pfizer, Roche, SOBI, UCB, Grant/research support from: AbbVie, Lilly, MSD, Pfizer, Philippe Dieudé Speakers bureau: Roche – Chugai, Bristol Myers Squibb, Consultant of: Pfizer, Roche – Chugai, Bristol Myers Squibb, Abbvie, MSD, Grant/research support from: Novartis

POS0522 PREVALENCE OF BRONCHIECTASIS IN RHEUMATOID ARTHRITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background:

Bronchiectasis is a known extra-articular manifestation of rheumatoid arthritis (RA) and can lead to decreased quality of life as well as increased risk for infection and mortality. Understanding the burden of bronchiectasis in RA may lead to a better understanding of pathogenesis and improved management. We performed a systematic review and meta-analysis to determine the prevalence of bronchiectasis in RA.

Objectives:

We investigated the prevalence of RA-related bronchiectasis (RA-BR) using a systematic review and meta-analysis.

Methods:

We followed the PRISMA-P 2015 guideline for systematic reviews and registered this analysis (ID#199080) on PROSPERO. We queried PubMed and EMBASE databases using the search strategy “rheumatoid arthritis; AND; bronchiectasis” as of July 31, 2020. The inclusion and exclusion criteria were assessed for study eligibility by two independent abstractors. Exclusion criteria included: (1) non-primary literature (i.e., review articles, editorials); (2) case reports involving less than 5 patients; (3) published in a language other than English; (4) did not relate to both RA and bronchiectasis; and (5) studies not involving humans (e.g., mouse models). After the initial screen, we conducted a full text review to verify that inclusion criteria were met: (1) reported frequency of RA-BR and denominator of all RA patients in the study sample. Data including type of study design, method of RA-BR detection, and RA characteristics were extracted by two independent abstractors. We performed meta-analyses using random effects models to estimate prevalence of RA-BR among RA overall and restricted to retrospective or prospective studies.

Results:

Out of a total of 208 studies, 37 studies were identified that reported frequency of RA-BR among RA. The included studies had heterogeneous methods to identify RA-BR that were based on either clinical or research chest computed tomography (CT) imaging and had varying methods to adjudicate images. Some studies focused on patients with respiratory symptoms or suspected RA-associated interstitial lung disease (RA-ILD). There were a total of 8,646 patients with RA, and 612 were identified as having RA-BR. The pooled overall prevalence of RA-BR in the random effects meta-analysis was 18.2% (95%CI 13.3-23.7%, Figure 1). Among prospective studies (n=24), the prevalence of RA-BR in the meta-analysis was 20.7% (95% CI 14.7-27.4%). Among retrospective studies (n=13) reporting RA-BR, the prevalence was 14.5% (95% CI 7.2-23.7%). Prevalence was lowest in retrospective studies where RA-BR was identified through clinical care (e.g., two large retrospective studies that investigated 4,000 and 1,129 RA patients reported RA-BR prevalence of 0.6% and 2.7%, respectively). The two largest prospective studies that incorporated a research protocol performing chest CT imaging on all enrolled patients investigated 150 and 332 patients with RA and reported a RA-BR prevalence of 8.0% and 9.6%, respectively. Smaller studies of both study design types generally reported higher prevalence of RA-BR.

Figure 1.

Pooled prevalence of RA-related bronchiectasis in RA among all studies identified (n=37).

Conclusion:

The prevalence of RA-BR in this systematic review and meta-analysis was 18.2%, emphasizing that bronchiectasis is a common extra-articular feature of RA. However, some studies may have identified subclinical RA-BR through research imaging or RA-BR may have been secondary to RA-ILD. Future studies should standardize methods to identify RA-BR cases and investigate the natural history and clinical course given the relatively high prevalence that we report.

Disclosure of Interests:

Lily Martin: None declared, Lauren Prisco: None declared, Weixing Huang: None declared, Gregory McDermott: None declared, Nancy Shadick Consultant of: Consultant < 5K Bristol-Myers Squibb, Grant/research support from: BMS Amgen Lilly, Mallinckrodt, and Sanofi, Tracy Doyle Consultant of: Boehringer Ingelheim (<5K), Grant/research support from: Bristol Myers Squibb and Genentech, Jeffrey Sparks Consultant of: Bristol-Myers Squibb, Gilead, Inova Diagnostics, Optum, and Pfizer, Grant/research support from: Bristol-Myers Squibb

Computed tomography osteoabsorptiometry-based investigation on subchondral bone plate alterations in sacroiliac joint dysfunction

Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain. Mineralization patterns of the sacroiliac (SIJ) subchondral bone plate (SCB) may reflect long-term adaptations to the loading of the joint. Mineralization densitograms of 27 SIJD patients and 39 controls, were obtained using CT osteoabsorptiometry. Hounsfield unit (HU) values of the SCB mineralization of superior, anterior and inferior regions on the iliac and sacral auricular surfaces were derived and statistically compared between SIJD-affected and control cohorts. Healthy controls showed higher HU values in the iliac; 868 ± 211 (superior), 825 ± 121 (anterior), 509 ± 114 (inferior), than in the sacral side; 541 ± 136 (superior), 618 ± 159 (anterior), 447 ± 91 (inferior), of all regions (p < 0.01). This was similar in SIJD; ilium 908 ± 170 (superior), 799 ± 166 (anterior), 560 ± 135 (inferior), sacrum 518 ± 150 (superior), 667 ± 151 (anterior), 524 ± 94 (inferior). In SIJD, no significant HU differences were found when comparing inferior sacral and iliac regions. Furthermore, HU values in the inferior sacral region were significantly higher when compared to the same region of the healthy controls (524 ± 94 vs. 447 ± 91, p < 0.01). Region mineralization correlated negatively with age (p < 0.01). SIJD-affected joints reflect a high mineralization of the sacral inferior region, suggesting increased SIJD-related mechanical stresses. Age-related SCB demineralization is present in all individuals, regardless of dysfunction.

A Review of Magnetic Particle Imaging and Perspectives on Neuroimaging

Magnetic particle imaging is an emerging tomographic technique with the potential for simultaneous high-resolution, high-sensitivity, and real-time imaging. Magnetic particle imaging is based on the unique behavior of superparamagnetic iron oxide nanoparticles modeled by the Langevin theory, with the ability to track and quantify nanoparticle concentrations without tissue background noise. It is a promising new imaging technique for multiple applications, including vascular and perfusion imaging, oncology imaging, cell tracking, inflammation imaging, and trauma imaging. In particular, many neuroimaging applications may be enabled and enhanced with magnetic particle imaging. In this review, we will provide an overview of magnetic particle imaging principles and implementation, current applications, promising neuroimaging applications, and practical considerations.

Occult hepatitis B virus coinfection in HIV-positive African migrants to the UK: a point prevalence study

Objectives

Occult (surface antigen-negative/DNA-positive) hepatitis B virus (HBV) infection is common in areas of the world where HBV is endemic. The main objectives of this study were to determine the prevalence of occult HBV infection in HIV-infected African migrants to the UK and to determine factors associated with occult coinfection.

Methods

This anonymized point-prevalence study identified Africans attending three HIV clinics, focussing on patients naïve to antiretroviral therapy (ART). Stored blood samples were tested for HBV DNA. Prevalence was calculated in the entire cohort, as well as in subpopulations. Risk factors for occult HBV coinfection were identified using logistic regression analysis.

Results

Among 335 HIV-positive African migrants, the prevalence of occult HBV coinfection was 4.5% [95% confidence interval (CI) 2.8–7.4%] overall, and 6.5% (95% CI 3.9–10.6%) and 0.8% (95% CI 0.2–4.6%) in ART-naïve and ART-experienced patients, respectively. Among ART-naïve anti-HBV core (anti-HBc)-positive patients, the prevalence was 16.4% (95% CI 8.3–25.6%). The strongest predictor of occult coinfection was anti-HBc positivity [odds ratio (OR) 7.4; 95% CI 2.0–27.6]. Median HBV DNA and ALT levels were 54 IU/mL [interquartile range (IQR) 33–513 IU/mL] and 22 U/L (IQR 13–27 U/L), respectively.

Conclusions

Occult HBV coinfection remains under-diagnosed in African HIV-infected patients in the UK. Given the range of HBV DNA levels observed, further studies are warranted to determine its clinical significance and to guide screening strategies and ART selection in these patients.

NADPH-oxidase 2 activation promotes opioid-induced antinociceptive tolerance in mice

The analgesic effectiveness of long-term opioid therapies is compromised by the development of antinociceptive tolerance linked to the overt production of peroxynitrite (ONOO(-), PN), the product of the interaction between superoxide (O2(-), SO) and nitric oxide (NO), and to neuroinflammatory processes. We have recently reported that in addition to post-translational nitration and inactivation of mitochondrial manganese superoxide dismutase (MnSOD), activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase holoenzyme (NOX) in the spinal cord is a major source for the overt production of superoxide-derived PN during the development of morphine-induced antinociceptive tolerance. However, the NOX complex involved in these processes is not known. The objective of these studies is to identify a potential role for the NOX2 complex, an enzyme involved in inflammation. Mice lacking the catalytic subunit of NOX2 (Nox2(-/-)) or its regulatory subunit, p47(phox) (p47(phox)(-/-)), developed antinociceptive tolerance similar to wildtype (wt) mice after 3 days of continuous morphine. However, while wt mice continue to develop tolerance by day six, morphine analgesia was restored in both Nox2(-/-) and p47(phox)(-/-) mice. Moreover, the loss of Nox2 or p47 did not affect acute morphine analgesia in naïve mice. In wt mice, antinociceptive tolerance was associated with increased activation of NOX, nitration of MnSOD, and proinflammatory cytokines production in the spinal cord. These events were markedly attenuated in Nox2(-/-) and p47(phox)(-/-) mice and instead, there was enhanced formation of antiinflammatory cytokine (IL4 and IL10) production. These results suggest that NOX2 activity provides a significant source of superoxide-derived PN to undertake post-translational modifications of mitochondrial MnSOD and to engage neuroinflammatory signaling in the spinal cord associated with opioid-induced antinociceptive tolerance. Thus, NOX2 may provide a potential target for adjuvant therapy to protect opioid analgesia.

Supraspinal inactivation of mitochondrial superoxide dismutase is a source of peroxynitrite in the development of morphine antinociceptive tolerance

Effective treatment of chronic pain with morphine is limited by decreases in the drug's analgesic action with chronic administration (antinociceptive tolerance). Because opioids are mainstays of pain management, restoring their efficacy has great clinical importance. We have recently reported that formation of peroxynitrite (ONOO(-), PN) in the dorsal horn of the spinal cord plays a critical role in the development of morphine antinociceptive tolerance and have further documented that nitration and enzymatic inactivation of mitochondrial superoxide dismutase (MnSOD) at that site provides a source for this nitroxidative species. We now report for the first time that antinociceptive tolerance in mice is also associated with the inactivation of MnSOD at supraspinal sites. Inactivation of MnSOD led to nitroxidative stress as evidenced by increased levels of products of oxidative DNA damage and activation of the nuclear factor poly (ADP-ribose) polymerase in whole brain homogenates. Co-administration of morphine with potent Mn porphyrin-based peroxynitrite scavengers, Mn(III) 5,10,15,20-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP5+) and Mn(III) 5,10,15,20-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (MnTnHex-2-PyP5+) (1) restored the enzymatic activity of MnSOD, (2) attenuated PN-derived nitroxidative stress, and (3) blocked the development of morphine-induced antinociceptive tolerance. The more lipophilic analogue, MnTnHex-2-PyP5+ was able to cross the blood-brain barrier at higher levels than its lipophylic counterpart MnTE-2-PyP5+ and was about 30-fold more efficacious. Collectively, these data suggest that PN-mediated enzymatic inactivation of supraspinal MnSOD provides a source of nitroxidative stress, which in turn contributes to central sensitization associated with the development of morphine antinociceptive tolerance. These results support our general contention that PN-targeted therapeutics may have potential as adjuncts to opiates in pain management.

Temozolomide single-agent chemotherapy for newly diagnosed anaplastic oligodendroglioma

The treatment of patients with anaplastic oligodendroglioma (AO) has been significantly impacted by the molecular detection of loss of sequences on chromosomes 1p and 19q. We performed a clinical trial to prospectively evaluate the safety of treating patients with AO with temozolomide (TMZ) alone in patients with chromosome 1p/19q loss and with chemo-radiation in patients not harboring this loss. Forty-eight patients were enrolled, 36/48 (75%) with evidence of chromosome 1p/19q loss treated with TMZ alone and 12/18 (25%) without such losses, treated with pre-radiation TMZ followed by chemo-radiation. Despite more aggressive treatment, patients without 1p/19q loss had a shorter progression-free survival (PFS) of 13.5 months. With a median follow-up time of 32 months, patients with 1p/19q LOH had a median TTP of 28.7 months. Patients with AO with 1p/19q LOH can be safely treated with single-agent TMZ and do not appear to experience earlier or more frequent tumor progression. This treatment regimen should be studied as part of a formal randomized clinical trial.

Efficacy, safety and patterns of response and recurrence in patients with recurrent high-grade gliomas treated with bevacizumab plus irinotecan

Our objective is to assess treatment efficacy, safety and pattern of response and recurrence in patients with recurrent high-grade glioma treated with bevacizumab and irinotecan. We reviewed retrospectively 51 patients with recurrent high-grade glioma treated with this combination at the Henry Ford Hermelin Brain Tumor Center from 11/15/2005 to 04/01/2008. The 6-month progression-free survival (PFS) for anaplastic gliomas (AGs) was 78.6 and 63.7% for glioblastoma. The median PFS was 13.4 months for AG and 7.6 months for those with glioblastoma. The overall survival rate (OS) at 6 months was 85.7% for AG and 78.0% for glioblastoma. The 12-month OS was 77.9% for AG and 42.6% for glioblastoma. The median OS time for AGs was not reached and was 11.5 months for those with glioblastoma. Thirty-six out of 51 (70.59%) patients demonstrated partial (32/51) or complete (4/51) radiographic response to treatment and 8/51 (15.69%) remained stable. Of the 38 who demonstrated progression on post-gadolinium studies, 23 showed distant progression with or without local recurrence. Seven patients showed progression on FLAIR without concordant findings on post-Gd sequences. Six patients (11.76%) discontinued treatment due to a treatment-emergent adverse event, including one with end-stage renal failure and another with gastric perforation. No symptomatic intracranial hemorrhages were reported. Patients with recurrent high-grade glioma treated with bevacizumab plus irinotecan demonstrate an excellent radiographic response rate and improved clinical outcome when compared to historical data. The high rate of distant tumor progression suggests that tumors may adapt to inhibition of angiogenesis by increased infiltration and vascular co-option.

Fatal cerebellar stroke following emergency endovascular stent grafting of a leaking thoracic aortic aneurysm: A case report

Stent-grafting of thoracic aortic diseases has developed as an alternative therapeutic modality in thoracic aneurysm management. Postprocedural complications include mortality, endoleaks, paraplegia and stroke. Other complications that may arise in cases of overstenting the origin of the left subclavian arther include left upper limb ischemia, subclavian steal syndrome and stroke. Posterior circulation strokes due to vertebral artery insufficiency have been reported in the past. In the present case, a fatal stroke caused by a cerebellar infarct culminating in the death of a patient with a leaking thoracic aortic aneurysm is reported. Medical personnel as well as patients should be aware of this possible complication. Vigilance in assessing the contralateral cerebral circulation before the procedure is a prerequisite in less acute circumstances.

Comparison of the relative analgesic efficacies of epidural or intramuscular diamorphine following total knee arthroplasty

BACKGROUND AND OBJECTIVES

Debate has proliferated as to the true site of action of opioids when placed in the epidural space. The aim of this study was to compare the analgesic effects of a bolus of diamorphine given by the epidural or intramuscular route.

METHODS

Sixty patients having elective primary total knee replacements were recruited and randomized to receive epidural or intramuscular diamorphine. A lumbar epidural catheter was sited and 10 mL of bupivacaine 0.5% wt vol-1 was injected. Patients subsequently received diamorphine 5 mg into the epidural space or as an intramuscular injection. Patient-controlled analgesia with intravenous morphine was used for postoperative analgesia. The primary outcome measures included time to first patient-controlled analgesia use and total morphine consumption in 24 h. Secondary end-points considered possible treatment complications.

RESULTS

All primary end-points showed significant differences in favour of epidural diamorphine. Medians for times to first patient-controlled analgesia use and total 24 h morphine requirements were significantly different (P < 0.001) at 418 vs. 198 min and 11 vs. 39 mg, respectively. There were no significant differences in secondary end-points.

CONCLUSIONS

This study has shown the superior analgesic efficacy of epidural diamorphine when compared to intramuscular injection.

Programmed −1 ribosomal frameshifting in the SARS coronavirus

Programmed −1 ribosomal frameshifting is an alternate mechanism of translation used by coronavirus to synthesize replication proteins encoded by two overlapping open reading frames. For some coronaviruses, the mRNA cis-acting stimulatory structures involved in this process have been characterized, but their precise contribution to ribosomal frameshifting is not completely understood. Recently, a novel coronavirus was identified as the causative agent of the severe acute respiratory syndrome. This review describes the mRNA motifs involved in programmed −1 ribosomal frameshifting in this virus.

Paget's disease in New Zealand: evidence for declining prevalence

The prevalence rate of Paget's disease in New Zealand is believed to be among the highest in the world, but recent data suggest that it may have decreased in recent decades. We estimated the current prevalence of Paget's disease in subjects of European origin (>55 years of age) in two New Zealand cities (Dunedin and Auckland) based on review of nearly 2000 pelvic radiographs. Prevalence rate increased with age (p = 0.022) and was higher in men (p = 0.014), but there was no significant difference between the two cities. The Dunedin data were compared with a 1983 survey from the same city, and prevalence was approximately half its previous level (p = 0.012). In Auckland, the prevalence of an isolated raised plasma alkaline phosphatase level (>150 U/L, normal range <120 U/L) was estimated in over 80,000 blood samples processed at a community laboratory. The prevalence of "biochemical Paget's disease," as assessed by this surrogate marker, was very similar to that observed in the radiographic survey in Auckland for subjects <80 years of age, but not for older subjects. We conclude that the prevalence of Paget's disease in New Zealand has declined over the past two decades, indicating that there are important environmental determinants in its development. Biochemical estimates of the prevalence of Paget's disease agree well with radiographic estimates, except in the elderly. The method used herein offers an alternative way of determining the prevalence of Paget's disease.

Modified Norwood operation for hypoplastic left heart syndrome

BACKGROUND

We examined early results in infants with hypoplastic left heart syndrome undergoing the Norwood operation with perioperative use of inhaled nitric oxide and application of extracorporeal membrane oxygenation.

METHODS

Medical records were reviewed retrospectively.

RESULTS

Between April 1997 and March 2001, 50 infants underwent a modified Norwood operation for hypoplastic left heart syndrome. Mean age at operation was 7.5 +/- 5.7 days, and mean weight was 3.1 +/- 0.5 kg. Five infants had a delayed operation because of sepsis. The mean diameter of the ascending aorta by echocardiography was 3.6 +/- 1.8 mm. Ductal cannulation was used to establish cardiopulmonary bypass in all patients. Mean circulatory arrest time was 39.4 +/- 4.8 minutes. The size of the pulmonary-systemic shunt was 3.0 mm in 6 infants, 3.5 mm in 37, and 4.0 mm in 7. Infants with persistent hypoxia (partial pressure of oxygen < 30 mm Hg) received nitric oxide after they were weaned from cardiopulmonary bypass. Extracorporeal membrane oxygenation was initiated in 8 infants in the pediatric intensive care unit primarily for low cardiac output and in 8 in the operating room because of the inability to separate them from cardiopulmonary bypass. The 30-day mortality rate was 22% (11 of 50 patients), and the hospital mortality rate was 32% (16 of 50 patients). Mean follow-up was 17 months. Ten patients (20%) underwent stage-two repair, with one operative death. One survivor had a Fontan procedure, and 2 underwent heart transplantation, with one death.

CONCLUSIONS

Early application of extracorporeal membrane oxygenation for hemodynamic instability and selective use of nitric oxide for persistent hypoxia in the immediate postoperative period may improve survival of patients with hypoplastic left heart syndrome. Renal failure requiring hemofiltration during extracorporeal membrane oxygenation (p < 0.05) and cardiopulmonary arrest in the pediatric intensive care unit (p < 0.05) were predictors of hospital mortality.

True aneurysm of a femoropopliteal vein graft

Aneurysmal dilatation of saphenous vein grafts mostly represent thin-walled pseudoaneurysms at anastomotic sites. True aneurysmal dilatation of femoropopliteal bypass vein grafts is rare. We report this unusual case, which was repaired with a prosthetic graft.

Long-term results of local recurrence after breast conservation treatment for invasive breast cancer

PURPOSE

The outcome for women with a local failure after breast conservation treatment is not well described in the literature. Because local recurrence is a potentially salvageable event, this study was performed to evaluate the outcome of patients with local recurrence after breast conservation surgery and definitive radiation treatment.

METHODS AND MATERIALS

The study population consisted of 112 patients with ipsilateral breast tumor recurrence. There were 100 isolated local recurrences and 12 local-plus-regional recurrences. There were 93 invasive local recurrences and 19 DCIS (ductal carcinoma in situ) local recurrences. Local recurrences were detected by physical examination alone in 42 patients, mammography alone in 47 patients, and both modalities in 23 patients. All patients were initially treated with breast conservation treatment with or without systemic therapy and subsequently treated at the time of local recurrence with salvage mastectomy with or without systemic therapy. The mean and median follow-up times after local recurrence were 49 and 44 months, respectively.

RESULTS

For the entire group of 112 patients, the overall survival at 10 years after local recurrence was 69%, the cause-specific survival was 71%, and the freedom from distant metastases was 47%. For the 93 patients with an invasive local recurrence, the overall survival at 10 years was 64%, cause-specific survival was 67%, and freedom from distant metastases was 44%. For the 93 patients with an invasive local recurrence, interval from diagnosis to local recurrence (< or =2 years vs. 2.1-5 years vs. >5 years) predicted for overall survival at 5 years (65% vs. 84% vs. 89%; p = 0.03). Method of detection of local recurrence (physical examination vs. mammography vs. both methods) also predicted for 5-year overall survival (73% vs. 91% vs. 93%, respectively; p = 0.04). On multivariable analysis, interval from diagnosis to local recurrence was an independent predictor of overall survival (p = 0.03). Method of detection of local recurrence (physical examination vs. mammography vs. both methods) was borderline in predicting for 5-year cause-specific survival (73% vs. 91% vs. 93%, respectively; p = 0.06). Similarly, interval from diagnosis to local recurrence (< or =2 years vs. 2.1-5 years vs. >5 years) was a borderline predictor of 5-year cause-specific survival (65% vs. 84% vs. 89%; p = 0.08). No factors that predicted for freedom from distant metastases were identified. There were three second locoregional failures on the chest wall. Two of the 19 patients with a DCIS local recurrence have died of metastatic breast cancer. Death was probably not related to their local recurrence, but rather a result of persistent risk from an invasive primary cancer.

CONCLUSIONS

This analysis provides long-term data after salvage treatment for patients who experience local recurrence after breast conservation treatment. The variables of method of detection and interval from diagnosis to local recurrence are identified as having prognostic significance for overall and cause-specific survival. In view of the potential for long-term survival, aggressive attempt at salvage treatment is warranted for the patient with local recurrence after breast conservation treatment. Second local recurrence after salvage mastectomy is an uncommon event. Although DCIS local recurrences may not in themselves cause an increase in the risk of mortality, the risk from the primary invasive cancer persists.

Brachytherapy for head and neck cancer: a case study

Brachytherapy currently is being used as a treatment modality for head and neck cancer. A case study is presented to illustrate the treatment and safety procedures required when brachytherapy is delivered. A multidisciplinary approach is essential to ensure that family and staff exposure to radiation is minimized. Nursing care considerations include preventing airway impairment, maintaining hydration, developing alternative communication methods, pain management, and bowel preparation. Through intensive patient, family, and staff education, patients with head and neck cancer can be treated with brachytherapy safely and effectively.

Transesophageal echocardiography in pediatric congenital heart disease

The uses of transesophageal echocardiography have expanded dramatically over the last decade. With advances in technology, this imaging modality has become readily available for evaluation of the complex pediatric population with congenital heart disease. This article discusses the many uses of transesophageal echocardiography in this population, in the outpatient setting, in the peri-operative period, and in the cardiac catheterization laboratory.

Co-occurrence of abuse of different drugs in men: the role of drug-specific and shared vulnerabilities

BACKGROUND

Previous research has demonstrated genetic and environmental influences on abuse of individual substances, but there is less known about how these factors may influence the co-occurrence of abuse of different illicit drugs.

METHODS

We studied 3372 male twin pairs from the Vietnam Era Twin Registry. They were interviewed using the Diagnostic Interview Schedule, Version III, Revised to investigate the extent to which the abuse of different categories of drugs occurs together within an individual, as well as the possibility that genetic and environmental factors are responsible for observed co-occurrence. Co-occurrence was quantified using odds ratios and conditional probabilities. Multivariate biometrical modeling analyses were used to assess genetic and environmental influences on co-occurrence.

RESULTS

Abusing any category of drug was associated with a marked increase in the probability of abusing every other category of drugs. We found evidence for a shared or common vulnerability factor that underlies the abuse of marijuana, sedatives, stimulants, heroin or opiates, and psychedelics. This shared vulnerability is influenced by genetic, family environmental, and nonfamily environmental factors, but not every drug is influenced to the same extent by the shared vulnerability factor. Marijuana, more than other drugs, was influenced by family environmental factors. Each category of drug, except psychedelics, had genetic influences unique to itself (ie, not shared with other drug categories). Heroin had larger genetic influences unique to itself than did any other drug.

CONCLUSION

There are genetically and environmentally determined characteristics that comprise a shared or common vulnerability to abuse a range of illicit drugs.

Interaction of beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluoro-CTP with human immunodeficiency virus-1 reverse transcriptase and human DNA polymerases: implications for human immunodeficiency virus drug design

The work reported in this article has evaluated the relative molecular activity of the 5'-triphosphate of a novel beta-L-nucleoside with an unsaturated ribose residue, beta-L-2', 3'-dideoxy-2',3'-didehydro-5-fluorocytidine (beta-L-Fd4CTP), with that of beta-L-2',3'-dideoxy-5-fluorocytidine (beta-L-FddCTP) and 2', 3'-dideoxycytidine (ddCTP), on DNA strand elongation by human immunodeficiency virus-1 reverse transcriptase (HIV RT) and human DNA polymerases alpha (pol alpha), beta (pol beta), gamma (pol gamma), and epsilon (pol epsilon). The concentrations of beta-L-Fd4CTP that inhibited the yield of products by 50% were 0.20 micro M, 1.8 micro M, and 4.0 micro M for HIV RT, pol gamma, and pol beta, respectively. The beta-L-Fd4CTP at a concentration as high as 40 micro M had no inhibitory effect on pol epsilon, but could inhibit pol alpha by 10-20% at 20 micro M. The Km and relative Vmax values of beta-L-Fd4CTP, beta-L-FddCTP, and ddCTP for incorporation into the standing start point of 5'-[32P]-oligonucleotide primer annealed with M13mp19 phage DNA by HIV RT and human DNA polymerases were evaluated. The efficiency of incorporation (Vmax/Km) of beta-L-Fd4CTP by HIV RT was about 4-fold and 12-fold higher than that of ddCTP and beta-L-FddCTP, respectively. In contrast, the Vmax/Km ratio of beta-L-Fd4CTP for pol gamma was 7-fold lower than that of ddCTP, but 4-fold higher than that of beta-L-FddCTP. Pol alpha could use beta-L-Fd4CTP as a substrate, but only at a high concentration (>20 micro M). Incorporation of beta-L-Fd4CTP by pol epsilon could not be detected. A hypothesis about the preferable recognition of the 2',3'-dideoxy-2',3'-didehydro- structure of beta-L-Fd4CTP to that of the 2',3'-dideoxy-structure of beta-L-FddCTP by HIV RT is discussed.

Usefulness of positive troponin-T and negative creatine kinase levels in identifying high-risk patients with unstable angina pectoris

Troponin-T was measured in patients with chest pain and negative creatine phosphokinase-MB isoenzymes. Patients with elevated troponin-T had a significantly greater risk of cardiac events over the next 6 months than patients with normal troponin-T.

Changing care staff approaches to the prevention and management of aggressive behaviour in a residential treatment unit for persons with mental retardation and challenging behaviour

The impact of a new training procedure aimed at improving staff skills in the preventative and reactive management of severely challenging behaviours was investigated within a six-place residential treatment unit. The results showed that there was some evidence to support the notion that the training reduced the number of behavioural incidents for most residents. The rates of major reactive strategy use (restraint and emergency medication) also declined over time, as did rates of staff and resident injury. Although only a limited number of these changes showed statistically significant correlations with time, it is argued that they were clinically significant when viewed against the complexity of the client group under study.

Reversible acute renal failure induced by losartan in a renal transplant recipient

A 56-year-old man who received a live-related renal transplant in 1988 was started in 1995 on the selective angiotensin II antagonist losartan (Dupont-Merke) to treat worsening hypertension. Two months later because of pulmonary oedema, loop diuretics were started. Within two weeks, serum creatinine had increased from 245 to 571 mumol/l, and the patient became oliguric. A systolic bruit was noted over the graft. Renal angiography showed a 90% stenosis of the transplant renal artery. Losartan was withdrawn, with prompt improvement in renal function. A successful percutaneous transluminal angioplasty performed a few days later resulted in further improvement in renal function accompanied by a significant diuresis.

Movement of yeast cortical actin cytoskeleton visualized in vivo

Fusion proteins between the green fluorescent protein (GFP) and the cytoskeleton proteins Act1p (actin), Sac6p (yeast fimbrin homolog), and Abp1p in budding yeast (Saccharomyces cerevisiae) localize to the cortical actin patches. The actin fusions could not function as the sole actin source in yeast, but fusions between the actin-binding proteins Abp1p and Sac6p complement fully the phenotypes associated with their gene deletions. Direct observation in vivo reveals that the actin cortical patches move. Movement of actin patches is constrained to the asymmetric distribution of the patches in growing cells, and this movement is greatly reduced when metabolic inhibitors such as sodium azide are added. Fusion protein-labeled patches are normally distributed during the yeast cell cycle and during mating. In vivo observation made possible the visualization of actin patches during sporulation as well.

Pulmonary vein stenosis

Pulmonary vein stenosis (PVS) is a rare disorder. Accurate diagnosis often requires anatomical examination. We report four children with pulmonary vein stenosis. Autopsy showed bilateral lesions in two patients who were thought clinically to have unilateral disease. A diagnosis of PVS was made at autopsy in the third case. Intimal and medial fibromuscular proliferation was noted in extrapulmonary and intrapulmonary veins. Some of the fibromuscular proliferation were eccentric, resembling organized thrombi. In one case a focal organizing thrombus was found in a clinically unobstructed but anatomically narrowed veno-atrial junction. In another case injection of contrast medium into the stenotic pulmonary vein (PV) showed anastomosis between PV and bronchial vessels as well as small pulmonary arteries. Bilateral hypertensive arteriopathy was observed in unilateral and bilateral PVS. Our histological finding of intrapulmonary venous lesions in the lobes in which PVS was not detected clinically suggests that during surgical correction of unilateral PVS multiple biopsies of the opposite lung may help to evaluate possible bilateral disease. Our study also suggests that thrombosis in a stenotic pulmonary vein may further compromise the lumen and contribute to the progression of pulmonary vein obstruction. The possible pathogenesis of bilateral pulmonary hypertensive arteriopathy in unilateral PVS also is discussed.

Immunohistochemical localization of proliferating cells, basic fibroblast growth factor and Fos protein following iliac artery balloon angioplasty in hypercholesterolemic rabbits

The restenotic process in iliac arteries of hyperlipidemic rabbits following balloon angioplasty was evaluated in a temporal sequence by monitoring smooth muscle cell (SMC) proliferation (proliferating cell nuclear antigen -PCNA marker), growth factor (basic fibroblast growth factor -bFGF) production, and Fos oncogene protein expression using immunohistochemical methods. The percutaneous transluminal angioplasty was performed in iliac artery of rabbits fed a 1% cholesterol diet, with a balloon catheter inflated from 4 to 8 atm for 2 min under cineangiographic control until an acceptable (at least 50% stenosis reduction) result was obtained. The morphometric analysis indicated that the number of PCNA-positive cells in contralateral control arteries was low, but was increased in balloon-injury. The bFGF-positive labeled cells were localized in the media and in recently-migrated SMCs within the intima. Two days following angioplasty these cells were more abundant and scattered in the entire neo-intima. After 14 days their number was still higher than that of the controls. Cellular Fos protein expression was detected in the intima and, to a lesser extent, in the media 2 hours after angioplasty. These data suggest that early expression of Fos protein and bFGF in iliac arteries of hyperlipidemic rabbits following balloon angioplasty could be involved in development of restenosis in this animal model.