Hospitalization and hospital mortality rates during the first and second waves of the COVID-19 pandemic in Quebec: interrupted time series and decomposition analysis

OBJECTIVES

We investigated hospitalization and hospital mortality rates by cause during the first year of the COVID-19 pandemic in Quebec, Canada.

STUDY DESIGN

Interrupted time series and decomposition analysis.

METHODS

We analyzed hospital mortality during the first (February 25-August 22, 2020) and second waves (August 23, 2020-March 31, 2021), compared with 2019. We identified the cause of death and examined trends using: 1) interrupted time series analysis; 2) log-binomial regression; and 3) decomposition of cause-specific mortality.

RESULTS

Hospitalization rates decreased; however, the proportion of deaths increased from 27.0 per 1000 in 2019 to 35.0 per 1000 in the first wave, for an excess of 8.0 deaths per 1000 admissions. COVID-19 was the cause of a third of excess deaths (2.6 per 1000). Other drivers of excess deaths included respiratory conditions (1.6 deaths per 1000), circulatory disorders (0.6 deaths per 1000), and cancer (0.9 deaths per 1000). COVID-19 was the cause of 58% of excess deaths in the second wave. Interrupted time series regression indicated that the proportion of deaths increased at the outset of the first wave but returned to prepandemic levels before increasing again in the second wave. Compared with 2019, the first wave was associated with 1.31 times (95% confidence interval [CI] 1.28-1.33) and the second wave with 1.17 times (95% CI 1.15-1.19) the risk of death during hospitalization.

CONCLUSIONS

The pandemic was associated with a greater risk of hospital mortality. Excess deaths were driven by COVID-19 but also other causes, including respiratory conditions, circulatory disorders, and cancer.

Four-factor prothrombin complex concentrate administration after expanding intracranial hemorrhage status post administration of andexanet alfa

BACKGROUND

With respect to reversal of life threatening bleeds associated with the use of oral factor Xa inhibitors, current guidelines provide few recommendations for a preferred reversal agent. When the initial reversal agent fails to achieve the desired hemostatic response, there is little to no recommendations for the use of additional reversal agents.

CASE REPORT

An 86-year-old female on apixaban (ELIQUIS) for atrial fibrillation, presented from an outside hospital due to a spontaneous intracranial hemorrhage (sICH). Computed tomography (CT) scan revealed multifocal left sided sICH. Due to use of apixaban in the setting to sICH, patient received andexanet alfa (AA) for reversal. Patient was then transferred and upon arrival to receiving emergency department (ED), repeat CT scans showed an expanding sICH, progression of midline shift, and low-molecular weight heparin levels that were ≥ 2 international units (IU) per milliliter (mL), indicating therapeutic apixaban activity. The patient was subsequently given four-factor prothrombin complex concentrate (4F-PCC). WHY AN EMERGENCY MEDICINE PHYSICIAN SHOULD BE AWARE OF THIS INCLUDE THE FOLLOWING KEY POINTS.

PD-L1 quantification across tumor types using the reverse phase protein microarray: implications for precision medicine

BACKGROUND

Anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-L1) agents are broadly used in first-line and second-line treatment across different tumor types. While immunohistochemistry-based assays are routinely used to assess PD-L1 expression, their clinical utility remains controversial due to the partial predictive value and lack of standardized cut-offs across antibody clones. Using a high throughput immunoassay, the reverse phase protein microarray (RPPA), coupled with a fluorescence-based detection system, this study compared the performance of six anti-PD-L1 antibody clones on 666 tumor samples.

METHODS

PD-L1 expression was measured using five antibody clones (22C3, 28-8, CAL10, E1L3N and SP142) and the therapeutic antibody atezolizumab on 222 lung, 71 ovarian, 52 prostate and 267 breast cancers, and 54 metastatic lesions. To capture clinically relevant variables, our cohort included frozen and formalin-fixed paraffin-embedded samples, surgical specimens and core needle biopsies. Pure tumor epithelia were isolated using laser capture microdissection from 602 samples. Correlation coefficients were calculated to assess concordance between antibody clones. For two independent cohorts of patients with lung cancer treated with nivolumab, RPPA-based PD-L1 measurements were examined along with response to treatment.

RESULTS

Median-center PD-L1 dynamic ranged from 0.01 to 39.37 across antibody clones. Correlation coefficients between the six antibody clones were heterogeneous (range: -0.48 to 0.95) and below 0.50 in 61% of the comparisons. In nivolumab-treated patients, RPPA-based measurement identified a subgroup of tumors, where low PD-L1 expression equated to lack of response.

CONCLUSIONS

Continuous RPPA-based measurements capture a broad dynamic range of PD-L1 expression in human specimens and heterogeneous concordance levels between antibody clones. This high throughput immunoassay can potentially identify subgroups of tumors in which low expression of PD-L1 equates to lack of response to treatment.

Improving guideline-mandated care of patients with implantable cardiac defibrillators

BACKGROUND/AIMS

Implantable cardiac defibrillators reduce the risk of sudden cardiac death in selected patients. The value of an implantable cardiac defibrillator declines as the patient's disease progresses. Guidelines suggest that the appropriateness of maintaining implantable cardiac defibrillator therapy be regularly reviewed as part of monitoring of the patient's disease trajectory. It is recommended that implantable cardiac defibrillators are deactivated as patients approach the end of life. Patients with a better understanding of their current state of health and the role that the implantable cardiac defibrillator plays within it are more likely to make informed decisions about the timing of deactivation.

METHODS

A quality improvement project was undertaken on appropriate deactivation of implantable cardiac defibrillators within a large tertiary cardiac centre. This was driven by audit data showing inadequate patient communication and documentation around deactivation. Drivers for change included the introduction of electronic data records, clinical review of comorbid patients approaching elective battery change and an ongoing forum for patient and carer education. Measured outcomes included the number of deactivations performed, evidence of patient discussion and consent, and timing of deactivation of the implantable cardiac defibrillator.

RESULTS

There were increased numbers of timely device deactivations undertaken following the interventions with improved documented evidence of patient discussion and consent. The educational forum was received favourably.

CONCLUSIONS

Focused multidisciplinary interventions can impact favourably on appropriate implantable cardiac defibrillator deactivation and improve patient engagement.

Abstract P1-19-20: Safety of palbociclib in African American women with hormone receptor positive HER2 negative advanced breast cancer and benign ethnic neutropenia: PALINA study

Background: There are significant racial disparities in breast cancer outcomes between African American women (AAW) and Caucasian women (CW) in the US. It has been reported that AAW have more chemotherapy dose reductions than CW which results in worse clinical outcomes (Schneider BP et al. JCO Precis Oncol 2017). Given the high incidence of benign ethnic neutropenia (BEN) in AAW, we sought to evaluate the hematological safety of palbociclib in this group of patients. A polymorphism (SNP rs2814778 at chromosome 1q23.2) in the Duffy Antigen Receptor Chemokine (DARC) gene is implicated in the pathophysiology of BEN. AAW have been historically underrepresented in clinical trials including studies that led to the FDA approval of palbociclib. This diversity gap can compromise the generalizability of clinical trial results and further exacerbate minority health disparities.

Methods: PALINA is a phase II study that evaluated the hematological safety of palbociclib with endocrine therapy (ET) in 35 AAW with HR positive HER2 negative advanced breast cancer (ABC) and ANC ≥1,000 cells/mm3. Eligible patients were self-identified as African, African-American or Black, PS 0-2 and had not received a prior CDK4/6 inhibitor (CDK4/6i). Treatment included palbociclib 125mg daily for 21 days followed by 7 days off and either an aromatase inhibitor (AI) or fulvestrant per investigator discretion. Maximum time allowed on study was 12 months. Responding patients could continue palbociclib off trial. Presence of the Duffy null polymorphism as a predictive marker for neutrophil count was assessed at baseline. Metabolite and exosomal signature (proteins and RNA) of drug resistance were also evaluated at different time points and will be reported separately. Primary endpoint was the proportion of patients who completed planned oncologic therapy without the development of a hematological event defined as episodes of febrile neutropenia (FN) or treatment discontinuation due to neutropenia. A two-stage design was used to test if the completion rate of planned oncologic therapy without a hematological event was at least 80% versus if it was below 60%, with 80% power at a significance level of 5%.

Results: 35 women were enrolled from 5 different institutions. Mean age was 64 years (30-90). 9% (3/35) of patients had PS of 2. Visceral involvement was present in 51% (18/35) of patients; 60% (21/35) received an AI and 40% (14/35) received fulvestrant. Baseline median ANC was 3,100 (1,300-11,100) cells/mm3. None of the patients had FN or required discontinuation of therapy due to neutropenia. Grade 3 and 4 neutropenia were experienced by 46% (16/35) and 3% (1/35) of patients respectively. Dose delays occurred in 17 patients, and 13 patients required dose reduction (5 to 100mg and 8 to 75 mg). Clinical benefit rate (CR+PR+SD persisting for ≥6 months) was 70%. Of the 29 patients who have completed study participation, the median time on treatment was 280 days (14, 385) and 15 continued on commercial palbociclib. Last visit on study estimated for 10/2019. The Duffy polymorphism was evaluated in 94% (33/35) of patients. The Duffy null phenotype was present in 58% (19/33) of the patients. Lower baseline ANC (2,400 vs 4,300 cells/mm3, p0.006), grade 3 neutropenia (63.2 vs 21.4%, p0.003) and dose reductions (52.6 vs 7.1%, p0.009) were more common in patients with the Duffy null polymorphism.

Conclusion: This is the first trial specifically designed to evaluate the hematologic toxicity of a CDK4/6i in AAW. Although patients with the Duffy null phenotype had more dose reductions and treatment delays due to neutropenia, this did not result in episodes of FN or treatment discontinuation due to neutropenia. This analysis suggests that palbociclib with ET is safe in AAW including those with the Duffy null phenotype.

Citation Format: Filipa Lynce, Rebecca Zhuo, Matthew Blackburn, Christopher Gallagher, Olwen Hahn, Maysa Abu-Khalaf, Mahsa Mohebtash, Tianmin Wu, Paula Pohlmann, Asma Dilawari, Shruti Tiwari, Ami Chitalia, Robert Warren, Ming Tan, Ayesha Shajahan-Haq, Claudine Isaacs. Safety of palbociclib in African American women with hormone receptor positive HER2 negative advanced breast cancer and benign ethnic neutropenia: PALINA study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-19-20.

Safety and efficacy of immune checkpoint inhibitors (ICIs) in cancer patients with HIV, hepatitis B, or hepatitis C viral infection

Background

Patients with chronic viral infections including human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV) are at increased risk of developing malignancies. The safety and efficacy of ICI therapy in patients with both cancer and chronic viral infections is not well established as most clinical trials of ICIs excluded these patient populations.

Methods

We performed a retrospective analysis of patients with advanced-stage cancers and HIV, HBV, or HCV infection treated with ICI therapy at 5 MedStar Health hospitals from January 2011 to April 2018.

Results

We identified 50 patients including 16 HIV, 29 HBV/HCV, and 5 with concurrent HIV and either HBV or HCV. In the HIV cohort (n = 21), any grade immune-related adverse events (irAEs) were 24% with grade ≥ 3 irAEs 14%. Among 5 patients with matched pre/post-treatment results, no significant changes in HIV viral load and CD4+ T-cell counts were observed. RECIST confirmed (n = 18) overall response rate (ORR) was 28% with 2 complete responses (CR) and 3 partial responses (PR). Responders included 2 patients with low baseline CD4+ T-cell counts (40 and 77 cells/ul, respectively). In the HBV/HCV cohort (n = 34), any grade irAEs were 44% with grade ≥ 3 irAEs 29%. RECIST confirmed ORR was 21% (6 PR). Among the 6 patients with known pre/post-treatment viral titers (2 HCV and 4 HBV), there was no evidence of viral reactivation.

Conclusions

Our retrospective series is one of the largest case series to report clinical outcomes among HIV, HBV and HCV patients treated with ICI therapy. Toxicity and efficacy rates were similar to those observed in patients without chronic viral infections. Viral reactivation was not observed. Tumor responses occurred in HIV patients with low CD4 T-cell counts. While prospective studies are needed to validate above findings, these data support not excluding such patients from ICI–based clinical trials or treatment.

Abstract 3230: Safety and efficacy of immune checkpoint inhibitors (ICIs) in patients with HIV, hepatitis B, or hepatitis C viral infections

Background: Immune checkpoint inhibitors (ICIs) have become standard of care for many malignancies. However, patients (pts) with human immunodeficiency virus (HIV), hepatitis B (HBV), and hepatitis C (HCV) were excluded from many clinical trials. Therefore, the safety and efficacy of ICI therapy in these patient populations is not well characterized.

Methods: We performed a retrospective analysis of pts with HIV, HBV, or HCV treated with ICI therapy at five MedStar Health hospitals from January 2011 to April 2018. The incidence of immune-related adverse events (irAEs) per CTCAE4.03, objective response rate (ORR) per RECIST v1.1, changes in viral status and CD4 T-cell counts during treatment were analyzed.

Results: A total of 50 pts were identified; (21 HIV, 4 HIV/HCV, 1 HIV/HBV, 15 HBV, 22 HCV, and 3 HBV/HCV) treated with anti-PD-(L)1 monotherapy (43) or in combination with ipilimumab (1) or chemotherapy (6). In the HIV group (21), the median age was 62 (29-85), 52% were male, 33% white, and 67% African American (AA). Tumor types included non-small-cell lung carcinoma (NSCLC; n=12), Hodgkin’s lymphoma and anal carcinoma (2 each), head and neck cancer, colorectal cancer, renal cell carcinoma (RCC), Burkitt’s lymphoma, and hepatocellular carcinoma (HCC) (one each). Any grade irAEs was 24% (5), and grade ≥ 3 irAEs was 10% (hepatitis and pneumonitis). Four pts had elevated HIV viral loads at baseline; 2 of 2 assessed had decreased levels after starting ICI therapy without changes in their antiretroviral therapy. Nine pts maintained an undetectable HIV viral load during ICI therapy. CD4 T-cell counts improved in 5 pts and decreased in 6 pts during ICI therapy. The ORR in response-evaluable pts for the entire group (16) was 25% (1 CR, 3 PR, 4 SD, and 8 PD). In the HBV/HCV cohort (34), median age was 62 (37-77), 71% were male, 24% white, and 50% AA. Tumor types included HCC (16), NSCLC (10), RCC (3), and head & neck, gastric and small cell lung cancer, one each. Any grade irAEs were noted in 50% (17) and grade ≥3 in 26% [colitis (2), hepatitis (3), pneumonitis, diabetic ketoacidosis, neurological weakness and rash, one each]. Of 15 HBV pts, 4 pts had detectable, and 8 pts had undetectable viral load before initiation of ICI. Among 4 pts with detectable viral load, no transaminitis was observed. Of 22 HCV pts, 9 were previously treated, 11 were untreated and no data available in 2. Among 4 pts with pre- and post-viral loads, 2 untreated pts’ viral loads showed small improvement and other 2 previously treated pts’ viral loads remained undetectable. The ORR in response-evaluable pts for the entire group (27) was 22% (6 PR, 7 SD, and 14 PD) and HCC pts (13) treated with anti-PD-(L)1 monotherapy was 23% (3 PR, 3 SD, and 7 PD).

Conclusion: ICI therapy was not associated with any new safety signal in pts with HIV, HBV, or HCV infection with no evidence of viral reactivation. Prospective trials are needed to validate the above findings.

Citation Format: Neil J. Shah, Ghassan AL-Shbool, Matthew Blackburn, Michael Cook, William J. Kelly, Anas Belouali, Sebastian Ochoa, Bradley S. Colton, Jeevan Puthiamadathil, Michael T. Serzan, Alice R. Knoedler, Stephen V. Liu, Michael J. Pishvaian, Mahsa Mohebtash, Subha Madhavan, Aiwu R. He, Michael B. Atkins, Geoffrey T. Gibney, Chul Kim. Safety and efficacy of immune checkpoint inhibitors (ICIs) in patients with HIV, hepatitis B, or hepatitis C viral infections [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3230.

The impact of using a closed-loop system on food choices and eating practices among people with Type 1 diabetes: a qualitative study involving adults, teenagers and parents

AIMS

We explored whether, how and why moving onto and using a hybrid day-and-night closed-loop system affected people's food choices and dietary practices to better understand the impact of this technology on everyday life and inform recommendations for training and support given to future users.

METHODS

Twenty-four adults, adolescents and parents were interviewed before commencing use of the closed-loop system and following its 3-month use. Data were analysed thematically and longitudinally.

RESULTS

While participants described preparing and/or eating similar meals to those consumed prior to using a closed-loop, many described feeling more normal and less burdened by diabetes in dietary situations. Individuals also noted how the use of this technology could lead to deskilling (less precise carbohydrate counting) and less healthy eating (increased snacking and portion sizes and consumption of fatty, energy-dense foods) because of the perceived ability of the system to deal with errors in carbohydrate counting and address small rises in blood glucose without a corrective dose needing to be administered.

CONCLUSIONS

While there may be quality-of-life benefits to using a closed-loop, individuals might benefit from additional nutritional and behavioural education to help promote healthy eating. Refresher training in carbohydrate counting may also be necessary to help ensure that users are able to undertake diabetes management in situations where the technology might fail or that they take a break from using it.

Real-world outcomes of underrepresented patient populations treated with immune checkpoint inhibitors (ICIs): African American descent, poor ECOG performance status, and chronic viral infections

2587

Background: ICIs have now become standard of care treatment for multiple malignancies. However, patients (pts) who are African American decent (AA), have a poor ECOG performance status (PS) or chronic viral infections [human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV)] were underrepresented in early clinical trials with ICIs and outcome data in these pt populations is not well reported. Methods: We performed a retrospective analysis of pts treated with ICIs (anti-PD(L)-1, anti-CTLA-4, or combination ICIs) across five MedStar Health hospitals from January 2011 to April 2018. Investigator-assessed best responses were noted. CTCAE v4.03 was used to capture immune-related adverse events (irAEs). Results: We identified 765 pts treated with 829 unique ICIs therapies across different malignancies. A total of 203 AA pts, 178 pts with a pre-treatment ECOG PS ≥2, 21pts with HIV, and 50 pts with HBV/HCV were noted. Any grade and grade ≥ 3 irAEs in the HIV cohort were 24% and 10% with an ORR of 29%. Any grade and grade ≥ 3 irAEs in HBV/HCV were 50% and 26% with an ORR of 21%. No viral reactivation or changes in pts anti-viral medications were noted during ICIs treatment. The ORR in AA pts was 35%. Any grade and grade ≥ 3 irAEs in the AA cohort were 27% and 8%, respectively. The ORR in pts with ECOG PS ≥2 was 14%. Any grade and grade ≥ 3 irAEs in this cohort were 20% and 4%. Similar trends were seen in the subset of patients with NSCLC treated with anti-PD(L)1 monotherapy (Table). Outcomes of NSCLC pts treated with anti-PD(L)-1 monotherapy. Conclusions: ICI therapy was not associated with any new safety signal in the above underrepresented populations. Prospective studies are needed to validate this data.[Table: see text]

Broadening the Debate About Post-trial Access to Medical Interventions: A Qualitative Study of Participant Experiences at the End of a Trial Investigating a Medical Device to Support Type 1 Diabetes Self-Management

Increasing ethical attention and debate is focusing on whether individuals who take part in clinical trials should be given access to post-trial care. However, the main focus of this debate has been upon drug trials undertaken in low-income settings. To broaden this debate, we report findings from interviews with individuals (n = 24) who participated in a clinical trial of a closed-loop system, which is a medical device under development for people with type 1 diabetes that automatically adjusts blood glucose to help keep it within clinically recommended ranges. Individuals were recruited from UK sites and interviewed following trial close-out, at which point the closed-loop had been withdrawn. While individuals were stoical and accepting of the requirement to return the closed-loop, they also conveyed varying degrees of distress. Many described having relaxed diabetes management practices while using the closed-loop and having become deskilled as a consequence, which made reverting back to pre-trial regimens challenging. Participants also described unanticipated consequences arising from using a closed-loop. As well as deskilling, these included experiencing psychological and emotional benefits that could not be sustained after the closed-loop had been withdrawn and participants reevaluating their pre- and post-trial life in light of having used a closed-loop and now perceiving this life much more negatively. Participants also voiced frustrations about experiencing better blood glucose control using a closed-loop and then having to revert to using what they now saw as antiquated and imprecise self-management tools. We use these findings to argue that ethical debates about post-trial provisioning need to be broadened to consider potential psychological and emotional harms, and not just clinical harms, that may result from withdrawal of investigated treatments. We also suggest that individuals may benefit from information about potential nonclinical harms to help make informed decisions about trial participation.

Patients' and caregivers' experiences of using continuous glucose monitoring to support diabetes self-management: qualitative study

BACKGROUND

Continuous glucose monitoring (CGM) enables users to view real-time interstitial glucose readings and provides information on the direction and rate of change of blood glucose levels. Users can also access historical data to inform treatment decisions. While the clinical and psychological benefits of CGM are well established, little is known about how individuals use CGM to inform diabetes self-management. We explored participants' experiences of using CGM in order to provide recommendations for supporting individuals to make optimal use of this technology.

METHODS

In-depth interviews (n = 24) with adults, adolescents and parents who had used CGM for ≥4 weeks; data were analysed thematically.

RESULTS

Participants found CGM an empowering tool because they could access blood glucose data effortlessly, and trend arrows enabled them to see whether blood glucose was rising or dropping and at what speed. This predicative information aided short-term lifestyle planning and enabled individuals to take action to prevent hypoglycaemia and hyperglycaemia. Having easy access to blood glucose data on a continuous basis also allowed participants to develop a better understanding of how insulin, activity and food impacted on blood glucose. This understanding was described as motivating individuals to make dietary changes and break cycles of over-treating hypoglycaemia and hyperglycaemia. Participants also described how historical CGM data provided a more nuanced picture of blood glucose control than was possible with blood glucose self-monitoring and, hence, better information to inform changes to background insulin doses and mealtime ratios. However, while participants expressed confidence making immediate adjustments to insulin and lifestyle to address impending hypoglycaemia and hypoglycaemia, most described needing and expecting health professionals to interpret historical CGM data and determine changes to background insulin doses and mealtime ratios. While alarms could reinforce a sense of hypoglycaemic safety, some individuals expressed ambivalent views, especially those who perceived alarms as signalling personal failure to achieve optimal glycaemic control.

CONCLUSIONS

CGM can be an empowering and motivational tool which enables participants to fine-tune and optimize their blood glucose control. However, individuals may benefit from psycho-social education, training and/or technological support to make optimal use of CGM data and use alarms appropriately.

Informing climate models with rapid chamber measurements of forest carbon uptake

Models predicting ecosystem carbon dioxide (CO₂ ) exchange under future climate change rely on relatively few real-world tests of their assumptions and outputs. Here, we demonstrate a rapid and cost-effective method to estimate CO₂ exchange from intact vegetation patches under varying atmospheric CO₂ concentrations_. We find that net ecosystem CO₂ uptake (NEE) in a boreal forest rose linearly by 4.7 ± 0.2% of the current ambient rate for every 10 ppm CO₂ increase, with no detectable influence of foliar biomass, season, or nitrogen (N) fertilization. The lack of any clear short-term NEE response to fertilization in such an N-limited system is inconsistent with the instantaneous downregulation of photosynthesis formalized in many global models. Incorporating an alternative mechanism with considerable empirical support - diversion of excess carbon to storage compounds - into an existing earth system model brings the model output into closer agreement with our field measurements. A global simulation incorporating this modified model reduces a long-standing mismatch between the modeled and observed seasonal amplitude of atmospheric CO₂ . Wider application of this chamber approach would provide critical data needed to further improve modeled projections of biosphere-atmosphere CO₂ exchange in a changing climate.

Surveys, simulation and single-cell assays relate function and phylogeny in a lake ecosystem

Much remains unknown about what drives microbial community structure and diversity. Highly structured environments might offer clues. For example, it may be possible to identify metabolically similar species as groups of organisms that correlate spatially with the geochemical processes they carry out. Here, we use a 16S ribosomal RNA gene survey in a lake that has chemical gradients across its depth to identify groups of spatially correlated but phylogenetically diverse organisms. Some groups had distributions across depth that aligned with the distributions of metabolic processes predicted by a biogeochemical model, suggesting that these groups performed biogeochemical functions. A single-cell genetic assay showed, however, that the groups associated with one biogeochemical process, sulfate reduction, contained only a few organisms that have the genes required to reduce sulfate. These results raise the possibility that some of these spatially correlated groups are consortia of phylogenetically diverse and metabolically different microbes that cooperate to carry out geochemical functions.

Possible involvement of the phloem lectin in long-distance viroid movement

Incubation with cucumber phloem exudate in vitro results in a dramatic decrease in the electrophoretic mobility of Hop stunt viroid. UV cross-linking and a combination of size exclusion and ion exchange chromatography indicate that this phenomenon reflects a previously unsuspected ability of phloem protein 2, a dimeric lectin and the most abundant component of phloem exudate, to interact with RNA. In light of its demonstrated ability to move from cell to cell via plasmodesmata as well as long distances in the phloem, our results suggest that phloem protein 2 may facilitate the systemic movement of viroids and, possibly, other RNAs in vivo.

Scale-up of filamentous organisms from tubes and shake-flasks into stirred vessels

The choice of small-scale fermentation systems contributes significantly to a successful scale-up. Creasing of flasks and the chosen shaker parameters influence the production of secondary metabolites in a strain- and even compound-specific manner. Using actinomycetes and fungi as model organisms the influence of the small-scale fermentation system on the production of various secondary metabolites is described and the effects on screening success and scale-up are considered.

Glypican-3 (GPC3) expression in human placenta: localization to the differentiated syncytiotrophoblast

The expression of glypican-3 (GPC3), a heparan-sulfate proteoglycan associated with the Simpson-Golabi-Behmel fetal overgrowth syndrome, was studied in normal human placental tissue and cell lines derived from human placentae. Cytotrophoblasts derived from term placentae expressed GPC3 mRNA at low levels in culture. GPC3 mRNA expression increased markedly during trophoblast differentiation. By contrast, fibroblast cell lines derived from normal placentae did not express GPC3 in culture. Similarly, choriocarcinoma cell lines derived from human placentae (BeWo, JAR, and JEG) failed to express GPC3 mRNA. In situ hybridization confirmed the localization of GPC3 mRNA to the syncytiotrophoblast. Furthermore, immunohistochemical staining of paraffin imbedded placental tissue demonstrated intense staining of the syncytiotrophoblast cell layer and less intense staining of cytotrophoblasts. No staining of mesenchymal elements was noted. These data confirm the presence of GPC3 in human placenta and suggest it is expressed by the differentiated syncytiotrophoblast at term.

Secreted proteases from Photorhabdus luminescens: separation of the extracellular proteases from the insecticidal Tc toxin complexes

Photorhabdus luminescens secretes both high molecular weight insecticidal toxin complexes and also a range of extracellular proteases into culture broth. Previous studies by others have suggested that insecticidal activity of the broth is associated with these proteases. However, by gene cloning and targeted knock-out, we have previously shown that oral insecticidal activity is associated with high molecular weight 'toxin complexes' (Tc) encoded by toxin complex or tc genes. Here we further clarify this distinction by biochemically separating the protease fractions away from the oral insecticidal activity of the Tc proteins. We purified three distinct protease fractions from the broth: one consisting of a single species of 55 kDa and two of several putatively related species of approximately 40 kDa. All of these clearly separate from the oral insecticidal activity associated with the high molecular weight Tc proteins and also show no effect on insect weight gain following injection into the haemocoel. Here we examine the substrate preferences and inhibitor profiles of these protease fractions and discuss their relationship with those previously described from other P. luminescens strains and phase variants.

The implementation of a new parallel child health record

After a decade of research, the parent-held Personal Child Health Record was introduced in some parts of the United Kingdom in 1991, coinciding with the enforcement of the Children Act 1989. It was designed as the main record of a child's health and development, to be used until adulthood and to be held by parents. Several Health Care Trusts have since discovered a need to maintain parallel records in the best interests of children. Barnet introduced the 'Joint Professional Record' in 1995 for selected children, such as children on the Child Protection Register. The Joint Professional Record (JPR) is a single, clinic-held, parallel record for multidisciplinary use. We undertook a programme of audit and staff seminars to develop and evaluate use of the JPR. We discuss, below, the impact of this record on professional working relationships and consider the implications of its use as a confidential record and within our policy of working in partnership with parents. In our experience, the JPR has proved a useful adjunct to clinical supervision in the arena of Child Protection and is appropriately used for children in need of protection and those with 'special needs'.

Insecticidal toxins from the bacterium Photorhabdus luminescens

Transgenic plants expressing Bacillus thuringiensis (Bt) toxins are currently being deployed for insect control. In response to concerns about Bt resistance, we investigated a toxin secreted by a different bacterium Photorhabdus luminescens, which lives in the gut of entomophagous nematodes. In insects infected by the nematode, the bacteria are released into the insect hemocoel; the insect dies and the nematodes and bacteria replicate in the cadaver. The toxin consists of a series of four native complexes encoded by toxin complex loci tca, tcb, tcc, and tcd. Both tca and tcd encode complexes with high oral toxicity to Manduca sexta and therefore they represent potential alternatives to Bt for transgenic deployment.

Regulation of dopa decarboxylase expression during colour pattern formation in wild-type and melanic tiger swallowtail butterflies

The eastern tiger swallowtail butterfly Papilio glaucus shows a striking example of Batesian mimicry. In this species, females are either wild type (yellow and black) or melanic (where most of the yellow colour is replaced by black). In order to understand how these different colour patterns are regulated, we examined the temporal order of wing pigment synthesis via precursor incorporation studies, enzyme assays, and in situ hybridisation to mRNA encoding a key enzyme, dopa decarboxylase. We show that dopa decarboxylase provides dopamine to both of the two major colour pigments, papiliochrome (yellow) and melanin (black). Interestingly, however, dopa decarboxylase activity is spatially and temporally regulated, being utilised early in presumptive yellow tissues and later in black. Further, in melanic females, both dopa decarboxylase activity and early papiliochrome synthesis are suppressed in the central forewing and this normally yellow area is later melanised. These results show that the regulation of enzyme synthesis observed in the yellow/black pattern of a single wing, is similar to that involved in melanism. We infer that dopa decarboxylase activity must be regulated in concert with downstream enzymes of either the melanin and/or the papiliochrome specific pathways, forming part of a developmental switch between yellow or black. This modification of multiple enzyme activities in concert is consistent with a model of melanisation involving coordinate regulation of the underlying synthetic pathways by a single Y-linked (female) factor.

'Sexuality, disability and abuse: advice for life ... not just for kids'!

This annotation addresses the debate about the availability, taboos, choices and risks concerning the sexuality and abuse of young disabled people. It highlights the vulnerability of some disabled young people and discusses the dilemmas of maintaining the disabled person's dignity, safeguarding his/her independence and recognizing the need for appropriate sex education while providing protection from abuse. It is suggested that statutory agencies as well as legislation should assume greater responsibility for protecting and safeguarding the interests of disabled youngsters, some of whom may risk physical, emotional and sexual abuse beyond childhood. The manner in which sexuality and abuse are dealt with often reflects the way disabled people are regarded by the society. This paper attempts to address some of the legal and conceptual issues surrounding this area.

Adults with spina bifida and/or hydrocephalus

Recent advances in medical technology enable many children with complex disabilities to survive into adulthood and to have certain expectations of life. One of these expectations is the continuity of specialist health care in an adult setting. This paper describes a new out-patient service which aims to provide optimum care, continuity and consistency of service for adults with spina bifida and/or hydrocephalus. The need for specialist health input into this service, in order to monitor the neurological, urological and psychosocial complications often associated with spina bifida and/or hydrocephalus is recognised. In one year (1992), 86 young adults with spina bifida and/or hydrocephalus attended for annual or more frequent assessment, either independently or with their families or carers. A variety of health and social problems were treated. In response to demand, a multi-disciplinary assessment unit, which includes the services of both medical and nursing specialists, occupational and physiotherapists, psychologists and access to specialist surgical opinions has recently opened at the Chelsea and Westminster Hospital. This new service attempts to meet some of the needs described in the outpatient audit. Adults with other disabilities are requesting to use this service. A longitudinal study to monitor quality, and outcome is indicated from this initial survey.

Physiological responses to 90 min of simulated dinghy sailing

A dinghy sailing race protocol was developed from video analysis of elite Laser class sailors competing in fairly windy (> 12 knots) national level races. A dinghy sailing ergometer was constructed for use with a 90 min protocol. Subjects watched a video of a Laser dinghy skipper sailing (on-water) according to the protocol while themselves hiking (leaning out) from the ergometer and simulating their normal on-water movements in tandem with the video. This simulation was used to examine physiological responses to dinghy sailing and factors correlated with hiking performance in 10 of Australia's top 30 Laser dinghy sailors. Simulated dinghy sailing elicited a large blood pressure response but a low rate of aerobic and anaerobic metabolism. During the 20 min upwind legs, the mean (+/- S.E.M.) systolic and diastolic blood pressures were 172 +/- 18 and 100 +/- 14 mmHg respectively, and mean arterial blood pressure (MABP) was 123 +/- 14 mmHg. Oxygen uptake during the simulated upwind legs was 1.12 +/- 0.22 1 min-1. Both blood pressure and VO2 were significantly lower during the 12 min reaching legs. The mean of the blood lactate concentrations measured 1 min following each of the upwind legs was 2.32 +/- 0.81 mM. Isometric knee extension strength (at 130 degrees) and the length to which subjects set the hiking strap on the ergometer were moderately related to upwind hiking performance (knee extension strength and upwind hiking strap tension, r = 0.62; hiking strap length and upwind righting moment, r = 0.66; both P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The declining marital-status earnings differential

"Earnings differentials between married and unmarried [U.S.] men have been declining since the late 1960s. We consider two possible explanations for this decline: changes in the nature of selection into marriage; and changes in role specialization within marriage. Our analysis of changes in marriage differentials within cohorts supports only a small contribution of changes in selection. There is some evidence that differences in human-capital investment between married and unmarried men have fallen over time, but this effect has apparently been largely offset by increases in the return to that human capital." This is a revised version of a paper originally presented at the 1991 Annual Meeting of the Population Association of America.

Pharmacokinetics of prednisolone in children with acute lymphoblastic leukaemia

The pharmacokinetics of soluble oral prednisolone were studied during induction therapy in six children with acute lymphoblastic leukaemia. There was a three- to four-fold variation in the pharmacokinetics of total and free prednisolone. For total prednisolone, the mean elimination half-life was relatively short (1.37 h) and the total clearance, relatively high (15.1 ml min-1 kg-1). The mean free fraction was high (0.37).

An investigation of factors affecting progress of patients on a stroke unit

The aim of the study was to identify factors affecting the progress in physical abilities and activities of daily living of patients admitted to a stroke unit. A series of 70 patients admitted consecutively were assessed on a series of tests of motor, functional and cognitive abilities at admission. They were assessed for level of motor abilities and activities of daily living at discharge and 9 months after stroke. Predictive equations were developed which account for between 61% and 33% of the variance in motor abilities and activities of daily living at discharge and at 9 months after stroke. The most important factor influencing outcome was the degree of motor loss.

Gender differences in peak acetaldehyde concentration after an acute dose of ethanol

Acetaldehyde, the first metabolite of ethyl alcohol, is found in higher concentrations in alcoholics and heavy drinkers after alcohol ingestion than in social drinkers or abstainers. This experiment investigated gender differences related to acetaldehyde. Seventy-nine adult social drinkers (38 females and 41 males) were tested after an overnight fast and at least 4 hours food deprived with 0.52 g/kg ethanol in water (20% alcohol by volume). Blood alcohol and acetaldehyde concentrations from breath samples were determined every 5 minutes post-drink for 40 minutes with a gas chromatograph. The drink was consumed over a 5-minute period. Half of each group ran 30-140 miles per week. The other half were controls. A significant overall gender difference in peak acetaldehyde concentration was obtained (p less than 0.5), with males showing higher values than females. Among athletes, these gender differences were greater (p less than 0.002). Among controls the gender differences were in the same direction but they were not significant. Groups did not differ reliably on age (M = 32.88 years, F = 31.13 years), drinking history (M = 2.07, F = 1.92) or lean body mass (M = 43.1, F = 43.1). Groups did not differ on time to peak blood alcohol concentrations (M = 30.98 min, F = 31.58 min). The results have implications for gender differences in alcoholism and biological sensitivity to alcohol.