A Digital Respiratory Ward in Leicester, Leicestershire, and Rutland, England, for Patients With COVID-19: Economic Evaluation of the Impact on Acute Capacity and Wider National Health Service Resource Use

BACKGROUND

The COVID-19 pandemic stressed global health care systems' acute capacity and caused a diversion of resources from elective care to the treatment of acute respiratory disease. In preparing for a second wave of COVID-19 infections, England's National Health Service (NHS) in Leicester, Leicestershire, and Rutland sought to protect acute capacity in the winter of 2020-2021. Their plans included the introduction of a digital ward where patients were discharged home early and supported remotely by community-based respiratory specialists, who were informed about patient health status by a digital patient monitoring system.

OBJECTIVE

The objective of the digital ward was to maintain acute capacity through safe, early discharge of patients with COVID-19 respiratory disease. The study objective was to establish what impact this digital ward had on overall NHS resource use.

METHODS

There were no expected differences in patient outcomes. A cost minimization was performed to demonstrate the impact on the NHS resource use from discharging patients into a digital COVID-19 respiratory ward, compared to acute care length of stay (LOS). This evaluation included all 310 patients enrolled in the service from November 2020 (service commencement) to November 2021. Two primary methods, along with sensitivity analyses, were used to help overcome the uncertainty associated with the estimated comparators for the observational data on COVID-19 respiratory acute LOS, compared with the actual LOS of the 279 (90%) patients who were not discharged on oxygen nor were in critical care. Historic comparative LOS and an ordinary least squares model based on local monthly COVID-19 respiratory median LOS were used as comparators. Actual comparator data were sourced for the 31 (10%) patients who were discharged home and into the digital ward for oxygen weaning. Resource use associated with delivering care in the digital ward was sourced from the digital system and respiratory specialists.

RESULTS

In the base case, the digital ward delivered estimated health care system savings of 846.5 bed-days and US $504,197 in net financial savings across the 2 key groups of patients-those on oxygen and those not on oxygen at acute discharge (both P<.001). The mean gross and net savings per patient were US $1850 and US $1626 in the base case, respectively, without including any savings associated with a potential reduction in readmissions. The 30-day readmission rate was 2.9%, which was below comparative data. The mean cost of the intervention was US $223.53 per patient, 12.1% of the estimated gross savings. It was not until the costs were increased and the effect reduced simultaneously by 78.4% in the sensitivity analysis that the intervention was no longer cost saving.

CONCLUSIONS

The digital ward delivered increased capacity and substantial financial savings and did so with a high degree of confidence, at a very low absolute and relative cost.

Infection Prevention, Operational Workflows, and Implementation Checklists for Whole-Lung Low-Dose Radiation Therapy (LD-RT) for COVID-19-Related Pneumonia

Purpose/Objective(s)

Low-Dose Radiation Therapy (LD-RT) is an emerging treatment option for patients with COVID-19 related pneumonia. Infectivity of the SARS-CoV-2 virus complicates incorporation of LD-RT into existing radiation oncology clinics.

Materials/Methods

The first phase I/II trial of LD-RT for COVID-19-related pneumonia implemented novel operational protocols to address risk of infection and respiratory events. Patients were transported from hospital rooms to linear accelerators and treated with 0.5 Gy or 1.5 Gy using pre-planned, two-dimensional treatments prepared using diagnostic x-rays and caliper measurements. Workflows were revised over time to balance infection risks with implementation burden.

Results

Between April 24 and December 7, 2020, fifty-two patients were enrolled and forty were treated. The end-to-end process comprised 16 distinct teams and > 120 cooperating staff members (> 50 core radiation oncology staff). The trial was operationalized at two hospitals at the onset of the COVID-19 pandemic, prior to vaccine availability. Teams included trial leadership/screening (n > 4), inpatient floor staff (n > 10), clinical trials staff and coordinators (n = 8), transport (n = 2), radiation therapists (n > 20), respiratory therapists (n = 5), radiation nursing (n > 7), ICU nursing (n = 4), rapid response teams (n = 4), medical physics (n > 4), dosimetry (n > 3), infection prevention (n > 3), environmental services (n > 6), security (n = 7), lab personnel (n = 1), and physicians from radiation oncology (n = 7), infectious diseases (n = 2), pulmonary/critical care medicine (n = 2), anesthesia (n = 2), and internal medicine (n > 20) [total > 120]. All non-intubated patients were transported by a multi-disciplinary team, consisting of a physician, nurse, transporter, infection prevention specialist, and (when needed) a respiratory therapist. Treatments occurred after normal clinic hours, were initiated by team huddles, check lists, and included personal protective equipment supervision at multiple time points. Transport routes were 880 to 1760 feet (0.33 miles) one-way, with 1 to 3 elevator banks and required 20-35 minutes for round-trip transport and treatment. Oxygen supplementation in non-intubated patients ranged from 2 to 15 L/min. One intubated patient was transported with a portable ventilator and accompanying ICU staff. There were no code-level events during transport. No patient-facing staff contracted COVID-19 from trial activities. Workflow burden was successfully reduced and protocols relaxed over time with increased staff experience.

Conclusion

Whole-lung low-dose radiation therapy (LD-RT) for COVID-19-related pneumonia was successfully incorporated into existing workflows at a major academic university. Forty patients were treated with no code-level events, and no staff contracted the virus during eight months of trial accrual. Instructional materials and implementation check lists are provided.

AB0025 CITRULLINATED-PEPTIDE SPECIFIC CD4+ T CELL RESPONSES IN RHEUMATOID ARHRITIS

Background:

CD4+ T cells reacting to post-translationally modified, citrullinated self-antigens are thought to play a central role in the pathogenesis of rheumatoid arthritis (RA)1. This is evidenced by a strong HLA class II association, the success of therapeutic co-stimulation blockade and the detection of autoantigen specific T-cells using HLA class II multimers2. These cells may represent a target for antigen-specific, tolerogenic therapies and their in-depth phenotyping may provide the means by which to monitor such treatment.

Objectives:

To identify the citrullinated-peptide (cit-peptide) induced cytokine repertoire of antigen-specific memory CD4+ T cells in both healthy controls (HCs) and ACPA positive RA patients using intracellular cytokine staining and flow cytometry. Of note, the HLA-types of both HCs and RA patients were not known.

Methods:

Cryopreserved peripheral blood mononuclear cells (PBMC) from both HCs (n = 8) and RA patients (n = 13) with both early (untreated) and established disease were thawed and labelled with a proliferation tracking dye (PTD). Labelled PBMC were then either incubated alone or with a pool of cit-peptides for 9-days, followed by a 5-hour restimulation with PMA and ionomycin, where cytokine secretion was blocked for the final 4-hours using brefeldin-A. Cells were then harvested, permeabilised and stained for T cell surface markers and intracellular cytokines including IFN-γ, IL-4, IL-21 and IL-17. Stained cells were immediately acquired using a BD Fortessa X20, where antigen-specific CD4+ T cells were identified as the viable CD45RO+ (memory) CD4+ T cell population that had proliferated (PTDlow) in response to the cit-peptides. Stimulation indices (SI) were calculated as the percentage of proliferated memory CD4+ T cells in the stimulated wells divided by the percentage in the unstimulated conditions, and cit-peptide responders were defined as those with an SI > 2.0. Net cytokine production was measured by subtracting the percentage cytokine production from unstimulated CD4+ CD45RO+ PTDlow cells, from those stimulated with the cit-peptides.

Results:

Comparable proliferative responses were observed in both donor groups in response to stimulation with the cit-peptide pool, where 37 % of HCs and 31 % of RA patients responded with an SI > 2.0 (Fig. 1A). While little cytokine production was observed in the cit-peptide responding HC T cells, for responding RA donors, cit-peptide responsive CD4+ memory T cells were predominantly IFN-γ and IL-21 producing (Fig. 1B and 1C). In contrast, these donors did not produce significant levels of either IL-17 or IL-4 (Fig. 1D and 1E).

Conclusion:

Cit-peptides were able to induce proliferation in both HCs and RA memory CD4+ T cells which, amongst the RA donors only, were of a Th1/Tfh subtype. In contrast, and while based only on a small sample, cit-peptides did not induce either IL-17 or IL-4 production in either donor group, suggesting a lack of Th17/Th2 responses. Not all donors responded to the peptide pool, possibly reflecting the limited number of pooled cit-peptides or to a lack of confirmed HLA-DRB1*04:01 positive donors, as peptides were selected for their specificity on this basis. Future work will therefore include HLA-typing, as well as the inclusion of additional citrullinated-epitopes to demonstrate autoreactivity in a wider cross-section of patients. Further phenotyping of the cit-peptide specific T cells will be performed, and future plans will be to study the assay data alongside clinical outcomes to assess its value for immune monitoring.

References:

[1]Malmström, V et al Nat Rev Immunol. 2017; 17(1):60-75.

[2]Gerstner, C et al BMC Immunol. 2020; 21(27):1-14.

Disclosure of Interests:

Jessica Swift: None declared, James Stanway: None declared, Ioana Nicorescu: None declared, Catharien Hilkens: None declared, Frederik Stevenaert Employee of: Janssen, Amy Anderson Grant/research support from: Pfizer, GSK and Janssen, Arthur Pratt Grant/research support from: Pfizer, GSK and Janssen, John D Isaacs Speakers bureau: Abbvie, Gilead, Roche, UC, Consultant of: Abbvie, Gilead, Roche, UC, Grant/research support from: Pfizer, GSK and Janssen

Figure 1.

Citrullinated-peptide specific memory CD4+ T cell proliferation (A) and net % cytokine production of IFN-γ (B), IL-21 (C), IL-17 (D) and IL-4 (E) positive cells.

Circadian time series proteomics reveals daily dynamics in cartilage physiology

OBJECTIVE

Cartilage in joints such as the hip and knee experiences repeated phases of heavy loading and low load recovery during the 24-h day/night cycle. Our previous work has shown 24 h rhythmic changes in gene expression at transcript level between night and day in wild type mouse cartilage which is lost in a circadian clock knock-out mouse model. However, it remains unknown to what extent circadian rhythms also regulate protein level gene expression in this matrix rich tissue.

METHODS

We investigated daily changes of protein abundance in mouse femoral head articular cartilage by performing a 48-h time-series LC-MS/MS analysis.

RESULTS

Out of the 1,177 proteins we identified across all time points, 145 proteins showed rhythmic changes in their abundance within the femoral head cartilage. Among these were molecules that have been implicated in key cartilage functions, including CTGF, MATN1, PAI-1 and PLOD1 & 2. Pathway analysis revealed that protein synthesis, cytoskeleton and glucose metabolism exhibited time-of-day dependent functions. Analysis of published cartilage proteomics datasets revealed that a significant portion of rhythmic proteins were dysregulated in osteoarthritis and/or ageing.

CONCLUSIONS

Our circadian proteomics study reveals that articular cartilage is a much more dynamic tissue than previously thought, with chondrocytes driving circadian rhythms not only in gene transcription but also in protein abundance. Our results clearly call for the consideration of circadian timing mechanisms not only in cartilage biology, but also in the pathogenesis, treatment strategies and biomarker detection in osteoarthritis.

OP0129 AUTOREACTIVE, CITRULLINATED PEPTIDE-SPECIFIC T CELLS IN RHEUMATOID ARTHRITIS

Background:

Self-reactive CD4+ T cells are thought to play a key role in the pathogenesis of rheumatoid arthritis (RA) and represent a target for antigen-specific, tolerogenic therapies1. Phenotyping such cells could provide the means with which to monitor these treatments. Here, we aimed to demonstrate antigen-induced T cell responses to RA relevant epitopes using peptide stimulation of peripheral blood mononuclear cells (PBMC). Several autoantigens have been described in RA, including various citrullinated peptide (cit-peptide) epitopes2; here we have used a combination of cit-peptides that will be used to load tolerogenic dendritic cells in a forthcoming experimental medicine study (AuToDeCRA II).

Objectives:

To detect peripheral blood T cell proliferation in response to candidate autoantigens in RA patients and healthy controls (HCs) using flow cytometry.

Methods:

PBMC from RA patients and HCs were obtained following informed consent and were cryopreserved. Prior to use, cells were thawed in medium supplemented with human serum and were labelled with a proliferation tracking dye (PTD). 2x105labelled cells were plated into 96 well plates with a minimum of 7 replicates per condition and were either cultured alone or stimulated with individual peptides at varying concentrations or a peptide pool. On day 9, cells from replicate wells were harvested, pooled and stained for surface markers and viability. Samples were acquired on a BD Fortessa X20 and analysis was performed in FlowJo version 10. A manual gating strategy was used to identify CD45RO+ (memory) CD4+ T cells and amongst this population, activated/proliferated cells were defined as CD25+ PTD low. Stimulation indices (SI) were calculated as the percentage of activated/proliferated cells from stimulated wells divided by the percentage from unstimulated wells.

Results:

Ten RA patients (including early and established disease) were recruited alongside seven HCs. Cit-peptides were initially titrated on an individual basis to determine the optimum concentration for use (n = 2). We then compared stimulation with either single peptides or a pool (n = 2), and found that PBMC stimulated with the pooled cit-peptides had a higher proliferative response. Both single and pooled cit-peptide induced T cell proliferation was observed in both RA and HC samples (Figure 1); the largest responses were seen amongst RA patients, with a maximum stimulation index of 52.4 compared to a maximum of 6.75 in the HC group. Only 1 HC sample responded with an SI greater than 3.0, whereas 50 % of RA patients elicited responses above this. Two of the RA patients failed to respond to the peptide pool (SI < 1.0). Of note, RA patients were not selected on the basis of tissue type whereas selected peptides bind preferentially to class II HLA containing the shared epitope (SE).

Figure 1

Antigen-specific CD4+ CD45RO+ responses of citrullinated peptide stimulated PBMC from HCs and RA patients.

Conclusion:

In non-HLA typed individuals, cit-peptide induced proliferative T cell responses were detectable in both RA patients and HCs, and although SIs overall were higher amongst RA patients this did not reach statistical significance in this small sample. Not all RA patients responded to the peptide pool which may be due to the limited number of citrullinated epitopes used, or to RA patients with a non-SE HLA type. Additional work should establish the need for HLA typing in this assay; around half of seropositive RA patients would be expected to be SE positive3. Furthermore, a wider array of cit-peptides may be needed to demonstrate autoreactivity in a broader cross-section of RA patients. Our future plans are to further phenotype the cellular subsets responding to the peptide pool and to study assay data in the context of clinical outcomes, to assess its utility for immune monitoring.

References:

[1]McInnes, I. B. & Schett, G. N Engl J Med. 2011; 365(23):2205-2219

[2]James, E. Aet al. Arthritis Rheum. 2014; 66(7):1712-1722

[3]Thomson, Wet al. Arthritis Rheum. 1999; 42(4):757-762

Disclosure of Interests:

Jessica Swift: None declared, James Stanway: None declared, Catharien Hilkens: None declared, Amy Anderson: None declared, Arthur Pratt Grant/research support from: Pfizer, GlaxoSmithKlein, John Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche

Correction to "Automatic Quality Assessment of Echocardiograms Using Convolutional Neural Networks: Feasibility on the Apical Four-Chamber View"

In the above paper [1], the first footnote should have indicated the following information: A. H. Abdi and C. Luong are joint first authors.

Passive functional mapping guides electrical cortical stimulation for efficient determination of eloquent cortex in epilepsy patients

Electrical cortical stimulation (ECS) is often used in presurgical evaluation procedures for patients suffering from pharmacoresistant epilepsy. Real-time functional mapping (RTFM) is an alternative brain mapping methodology that can accompany traditional functional mapping approaches like ECS. In this paper, we present a combined RTFM/ECS system that aims to exploit the common ground and the advantages of the two procedures for improved time/effort effectiveness, patients' experience and safety. Using the RTFM and ECS data from four patients who suffer epilepsy, we demonstrate that the RTFM-guided ECS procedure hypothetically reduces the number of electrical stimulations necessary for eloquent cortex detection by 40%.

Facilitating grant proposal writing in health behaviors for university faculty: a descriptive study

Grant proposal writing in the behavioral sciences is important for fiscal reasons and scientific reasons at many universities. This report describes a grant proposal-writing seminar series provided to University faculty (N = 20) and explores factors facilitating and impeding writing. Summary statistics are provided for quantitative data. Free responses were sorted by independent raters into meaningful categories. As a consequence of the training, 45% planned to submit within 18 months; 80% of grant proposals targeted NIH. At 1-year follow-up, 40% actually submitted grants. Factors impeding grant proposal writing included competing professional demands; factors facilitating writing included regularly scheduled feedback on written proposal sections and access to expert collaborators. Obtaining grants generates financial resources, facilitates training experiences, and vastly contributes to the growth and dissemination of the knowledge base in an area.

Leadership, governance and management in dental education - new societal challenges

Dental schools around the world face new challenges that raise issues with regard to how they are governed, led and managed. With rapid societal changes, including globalization and consumerism, the roles of universities and their funding have become intensely debated topics. When financial burdens on universities increase, so does the pressure on dental schools. This is exacerbated by the relative expense of running dental schools and also by the limited understanding of both university managers and the public of the nature and scope of dentistry as a profession. In these circumstances, it is essential for dental schools to have good systems of leadership and management in place so that they can not only survive in difficult times, but flourish in the longer term. This paper discusses the concept of governance and how it relates to leadership, management and administration in dental schools and hospitals. Various approaches to governance and management in dental schools on different continents and regions are summarized and contrasted. A number of general governance and leadership issues are addressed. For example, a basic principle supported by the Working Group is that an effective governance structure must link authority and responsibility to performance and review, i.e. accountability, and that the mechanism for achieving this should be transparent. The paper also addresses issues specific to governing, leading and managing dental schools. Being a dean of a modern dental school is a very demanding role and some issues relating to this role are raised, including: dilemmas facing deans, preparing to be dean and succession planning. The importance of establishing a shared vision and mission, and creating the right culture and climate within a dental school, are emphasized. The Working Group advocates establishing a culture of scholarship in dental schools for both teaching and research. The paper addresses the need for effective staff management, motivation and development, and highlights the salience of good communication. The Working Group suggests establishing an advisory board to the dean and school, including lay persons and other external stakeholders, as one way of separating governance and management to some extent and providing some checks and balances within a dental school. Several other suggestions and recommendations are made about governance, management and leadership issues, including the need for schools to promote an awareness of their roles by good communication and thereby influence perceptions of others about their roles and values.

Paranodal pathology in Tangier disease with remitting-relapsing multifocal neuropathy

Pathological studies of a sural nerve biopsy in a man with Tangier disease presenting as a remitting-relapsing multifocal neuropathy showed abnormalities in the paranodal regions, including lipid deposition (65%) and redundant myelin foldings, with various degrees of myelin splitting and vesiculation (43%) forming small tomacula and abnormal myelin terminal loops (4%). The internodal regions were normal in the majority of myelinated fibres. Abnormal lipid storage was also present in the Schwann cells of the majority of unmyelinated fibres (67%). The evidence suggests that the noncompacted myelin region of the paranode is a preferential site for lipid storage in the myelinated Schwann cell, and that the space-occupying effects of the cholesterol esters leads to paranodal malfunction and tomacula formation as the pathological basis for the multifocal relapsing-remitting clinical course.

Focal myelin swellings and tomacula in anti-MAG IgM paraproteinaemic neuropathy: novel teased nerve fiber studies

Focal myelin swellings and tomacula in teased nerve fibers from a case of IgM anti-myelin-associated glycoprotein (MAG) paraproteinaemic neuropathy were examined using a novel technique. Five different morphologic abnormalities were identified--myelin sheath outfolding, myelin sheath infolding, enlargement of the adaxonal space, myelin degeneration, multiple increased concentric loops--and a combination of these structural abnormalities often occur in association with myelin degeneration. Similar structural changes were found in externally normal segments of teased fibers without evidence of myelin swelling or tomacula from the same case. These structural abnormalities are consistent with a disturbance of the normal adhesion functions of MAG in the maintenance of axon-myelin relationships.

A novel method for correlating internal and external structure of individual myelinated nerve fibres

A new method is described that enables longitudinal and cross sections of an individual nerve fibre to be cut at multiple specified sites along the fibre by the use of a unique marker system. In this way the internal structure of the fibre can be correlated with the external appearance. Individual myelinated nerve fibres are teased apart in epoxy resin and mounted onto a carbon-coated slide, and after orientation and marking of specific sites of interest are snap frozen to liberate the orientated and marked fibres for embedding on the surface of an epoxy resin block for subsequent longitudinal or transverse sectioning. This method is particularly useful for the correlative study of the myelin-axon relationships.

EASY--an Expert Analysis SYstem for interpreting database search outputs

With the ever-increasing need to handle large volumes of sequence data efficiently and reliably, we have developed the EASY system for performing combined protein sequence and pattern database searches. EASY runs searches simultaneously and distils results into a concise 1-line diagnosis. By bringing together results of several different analyses, EASY provides a rapid means of evaluating biological significance, minimising the risk of inferring false relationships, for example from relying exclusively on top BLAST hits. The program has been tested using a variety of protein families and was instrumental in resolving family assignments in a major update of the PRINTS database.

Benefits of osteopathic manipulative treatment for hospitalized elderly patients with pneumonia

While osteopathic manipulative treatment (OMT) is thought to be beneficial for patients with pneumonia, there have been few clinical trials--especially in the elderly. The authors' pilot study suggested that duration of intravenous antibiotic use and length of hospital stay were promising measures of outcome. Therefore, a larger randomized controlled study was conducted. Elderly patients hospitalized with acute pneumonia were recruited and randomly placed into two groups: 28 in the treatment group and 30 in the control group. The treatment group received a standardized OMT protocol, while the control group received a light touch protocol. There was no statistical difference between groups for age, sex, or simplified acute physiology scores. The treatment group had a significantly shorter duration of intravenous antibiotic treatment and a shorter hospital stay.

Auditing mortality from upper gastrointestinal haemorrhage: impact of a high dependency unit

BACKGROUND

A retrospective audit conducted at our district general hospital indicated that mortality from upper gastrointestinal (GI) haemorrhage was above that reported from nearby centres.

OBJECTIVES

To assess the impact of establishing a high dependency unit (HDU) and agreed management protocol on subsequent mortality from upper GI haemorrhage at our hospital.

DESIGN

Prospective audits were conducted before and after the establishment of an HDU. All acute admissions, as well as established inpatients with haematemesis and/or melaena, were examined for fitness for endoscopy, comorbidity, underlying diagnosis and the need for surgery.

SUBJECT

Over a two-year period, 524 patients were studied in the two audits. Risk scores were calculated and the 30-day mortality from all causes assessed.

RESULTS

There was a trend towards higher age and comorbidity during the second audit. Mortality was 9% and 10% during the first and second audits, respectively.

CONCLUSIONS

An increasing proportion of patients with bleeding are elderly and have associated comorbidity. Establishment of an HDU and agreed protocol did not reduce mortality at our centre.

Factors influencing palliative care. Qualitative study of family physicians' practices

OBJECTIVE

To examine factors that influence family physicians' decisions to practise palliative care.

DESIGN

Qualitative method of in-depth interviews.

SETTING

Southwestern Ontario.

PARTICIPANTS

Family physicians who practise palliative care on a full-time basis, who practise on a part-time basis, or who have retired from active involvement in palliative care.

METHOD

Eleven in-depth interviews were conducted to explore factors that influence family physicians' decisions to practise palliative care and factors that sustain their interest in palliative care. All interviews were audiotaped and transcribed verbatim. The analysis strategy used a phenomenological approach and occurred concurrently rather than sequentially. All interview transcriptions were read independently by the researchers, who then compared and combined their analyses. Final analysis involved examining all interviews collectively, thus permitting relationships between and among central themes to emerge.

MAIN OUTCOME FINDINGS

The overriding theme was a common philosophy of palliative care focusing on acceptance of death, whole person care, compassion, communication, and teamwork. Participants' philosophies were shaped by their education and by professional and personal experiences. In addition, participants articulated personal and systemic factors currently affecting their practice of palliative care.

CONCLUSIONS

Participants observed that primary care physicians should be responsible for their patients' palliative care within the context of interdisciplinary teams. For medical students to be knowledgeable and sensitive to the needs of dying patients, palliative care should be given higher priority in the curriculum. Finally, participants argued compellingly for transferring the philosophy of palliative care to the overall practice of medicine.

Signet-ring carcinoma of the prostate

A case of prostatic signet-ring adenocarcinoma is described in a man with a history of open prostatectomy for prostate carcinoma (18 years previously). Immunostaining confirmed the prostatic origin of the signet-ring tumor which stained for prostatic acid phosphatase (PSAP) and prostate specific antigen (PSA). Cytokeratin immunostaining showed the vacuoles to be true lamina with clear and distinct outlines, the feature confirmed by ultrastructural examination. This aggressive tumor is an uncommon but distinct variant of primary prostatic carcinoma which should be distinguished from artefactual vacuolation of tumor, inflammatory and stromal cells, and metastatic disease.

Initiation of reverse transcription during cell-to-cell transmission of human immunodeficiency virus infection uses pre-existing reverse transcriptase

H3B cells, a laboratory clone of H9 cells persistently infected with the HTLV-IIIB strain of human immunodeficiency virus (HIV), contained significant levels of cell-associated reverse transcriptase (RT) activity measured by in vitro assays using either exogenous or endogenous templates. The cell-associated RT activity detected using exogenous template was almost wholly in a soluble (non-sedimentable) form whereas endogenous activity sedimented as a particulate structure associated with viral RNA. Despite this, H3B cells did not contain episomal HIV DNA detectable by Southern blot, indicating that in vivo reverse transcription was not occurring to any significant extent in these cells. However, when susceptible HUT 78 cells were infected by co-cultivation with H3B cells, dramatic synthesis of episomal HIV DNA occurred. Concurrently with this de novo initiation of reverse transcription, however, we found no detectable change in intracellular levels or cleavage profiles of immunoprecipitable RT polypeptides. Finally, actinomycin D pre-treatment of H3B cells to prevent de novo transcription from donor cell proviral DNA after co-cultivation did not affect the initiation of in vivo reverse transcription following cell-to-cell HIV infection. These results demonstrated that cells persistently infected with HIV contained significant fully cleaved cell-associated RT in a form that was active in vitro but not in vivo and that following cell-to-cell transmission of HIV infection to susceptible cells, de novo reverse transcription was initiated without detectable evidence of further synthesis or proteolytic processing of HIV RT. The nature of this initiation process requires further study.

Identification of the microsporidian parasite, Enterocytozoon bieneusi in faecal samples and intestinal biopsies from an AIDS patient

The microsporidian parasite, Enterocytozoon bieneusi, is currently recognized as a potentially important cause of chronic diarrhoea in patients infected with the human immunodeficiency virus (HIV). Faecal concentrates from a 38-year-old, HIV-seropositive patient examined by light and electron microscopy revealed the presence of numerous microsporidian spores. The structural characteristics of the spores were consistent with those previously described for Enterocytozoon bieneusi. Each spore contained a single nucleus, a posterior vacuole and a polar filament with 6-7 overlapping coils which appeared in cross-section as a series of 3 doublets. Mature spores were surrounded by an inner unit membrane, an electron-lucent endospore and a thin, electron-dense exospore. The identity of the parasite was confirmed by the detection of unique endogenous developmental stages in duodenal biopsies. Both proliferative and sporogonial plasmodia (meronts and sporonts) were observed and all stages were monokaryotic (single nucleus) and apansporoblastic (sporophorous vesicle absent). Proliferative and sporogonial plasmodia divided by plasmotomy and spore organelles (polar filament, attachment disc and polaroplast) were well developed prior to fission of the sporogonial plasmodium.

Early results of combined electrohydraulic shock-wave lithotripsy and oral litholytic therapy of gallbladder stones at the University of Iowa

One hundred thirty-three patients were entered into a randomized, double-blind, placebo-controlled trial of extracorporeal shock-wave lithotripsy for symptomatic gallstones versus extracorporeal shock-wave lithotripsy plus adjuvant litholytic therapy with ursodeoxycholic acid (UDCA). Six months after lithotripsy, patients receiving placebo were crossed over to UDCA therapy without unblinding the study. One hundred sixteen patients have completed 6 months of follow-up. Five patients were dropped from the study. Nine percent have required cholecystectomy (11 patients with biliary colic and 1 with acute cholecystitis). Ninety-one patients had a solitary stone (64 patients had stones less than or equal to 20 mm and 27 patients had stones greater than 20 mm in diameter), and 25 patients had two to three stones. Fifty percent were retreated. Cumulative stone-free rates at 6, 12, and 18 months were 26%, 39%, and 41%, respectively. At 6 months there was a significant advantage for patients treated with UDCA versus placebo (36% vs 17% were stone free) that had disappeared by 12 months (placebo-treated patients had received 6 months of UDCA). Patients with solitary stones equal to or less than 20 mm in diameter treated with UDCA had stone-free rates at 6, 12, and 18 months of 58%, 58%, and 62%, respectively, versus 27%, 56%, and 50%. The difference was significant only at the 6- month follow-up. Stone-free rates for patients with large solitary stones and multiple stones were very low. Extracorporeal shock-wave lithotripsy is both safe and effective therapy for treatment of symptomatic gallstones in patients with a solitary stone equal to or less than 20 mm in diameter. UDCA markedly improves the efficiency of the procedure and results in a stone-free gallbladder sooner.

Release of neuronotrophic factor from rabbit corneal epithelium during wound healing and nerve regeneration

Epithelial neuronotropic factor (ENF) is secreted by cultured epithelial cells of rabbit cornea and conjunctiva, and is active in promoting survival and inducing neurite outgrowth of cultured trigeminal neurons. This study evaluated the relation of ENF to corneal nerve regeneration utilizing a model of heptanol-induced epithelial wounding. The organ culture technique was used to collect ENF from the intact corneal epithelium, and a neuronal bioassay was utilized to quantify ENF. The results revealed no change in ENF secretion either during initial wound closure or after 1 week, when the epithelium had regenerated. However, ENF secretion was elevated 2.4 times in 2 weeks after wounding. Morphometric analysis of corneal nerves stained by gold chloride impregnation showed that the first sign of regeneration of intraepithelial nerves was observed after 2 weeks, and the normal pattern of epithelial neural density was re-established after 3 weeks. However, the neural density was still subnormal (35-47% less than the control) in the wounded epithelium up to 4 weeks after wounding. Thus it appears that a surge in ENF secretion occurred after epithelial regeneration but before nerve regeneration. The results suggest that ENF may mediate corneal nerve regeneration.

A randomized study of the impact of home health aides on diabetic control and utilization patterns

Home health aides were offered to half of a group of 227 low-income diabetic clinic patients; in the group offered aides, fasting blood sugar (FBS) declined when compared to control group (10.1 mg/dl vs an increase of 5.1 mg/dl), and missed clinic appointments and emergency room use also decreased. The group of 44, who, upon offer of an aide actually accepted one, showed a significant increase in eye clinic appointments as well as the greatest decline in FBS (13.9 mg/dl).

Appraisal of a new test: Between-technician variation in the measurement of closing volume

To determine the between-technician variation in the measurement of closing volume, 24 subjects were divided into 3 blocks of 8 subjects each. Each block was then tested by a pair of technicians. Each of the 3 technicians involved in the study tested 16 subjects. It was later necessary to reject the tracings of 2 subjects in one of the 3 blocks, leaving 22 for analysis. The N2 method of determining closing volume was used. The statistical analysis was performed separately on the following measures derived from the tracings: expired vital capacity, planimetry of the area under the curve, total lung capacity, closing volume as a per cent of expired vital capacity, and closing capacity as a per cent of total lung capacity. All tracings were assessed by each technician. Two separate analyses of variance were then carried out to determine, respectively, the components of variance in the administration of the test and in the interpretation of the tracings. Because different persons were able to administer the test the same way, it seems that closing volume poses no problem in administration, provided that instructions as to how to perform the test are closely followed. In the interpretation of the tracings, significant differences were found for all measures, except planimetry; however, not all of these have the same practical implications. Some tracings were found "difficult" to interpret and contributed more to the over-all variation than did others. When making use of a new test in a population study, the between-technician variation should be determined before the study is begun.

The N2 closing volume test in population studies: sources of variation and reproducibility

Sources of variation in the nitrogen closing volume test and derived measurements were examined in the results of 13 subjects, each of whom performed 3 sequential trials on 2 occasions 30 to 60 minutes apart, on 2 separate days 1 week apart (156 trials in all). Results were examined to evaluate the relative sensitivity of the various measurements for differences between sujbects and, by implication, their potential value in population studies. Using the ratio of signal (between-subject variance) to noise (within-subject variance) as the criterion, the sensitivities of the ratio of closing volume to vital capacity (CV/VC,%) and the ratio of closing capacity to total lung capacity (CC/TLC,%) were comparable; contrary to expectation, sensitivity decreased rather than increased with side-by-side compared to independent tracing analysis. Comparison of various test schedules showed the greatest sensitivity when the mean of 3 measurements was used, with a single measurement of CV/VC,% being only one-third as sensitive, and a single measurement of CC/TLC,% being one-half as sensitive as the mean. In addition, the validity of the measurements of total lung capacity from nitrogen dilution in a single oxygen breath was confirmed by the demonstration of good agreement with helium dilution values.

Rheumatic complaints and pulmonary response to chrysotile dust inhalation in the mines and mills of Quebec

In 1967-68 an age-stratified random sample of 1069 current workers in Quebec asbestos mines and mills was surveyed. Questions concerning rheumatic complaints were included in a modified MRC questionnaire used at that time, and on this basis a rheumatic severity gradient was devised. No relationship could be detected between rheumatic complaints and pulmonary radiologic response to chrysotile dust exposure, despite implications in the literature that such a relationship might exist.