Complex organisational factors influence multidisciplinary care for patients with hip fractures: a qualitative study of barriers and facilitators to service delivery

BACKGROUND

Hip fractures are devastating injuries, with high health and social care costs. Despite national standards and guidelines, substantial variation persists in hospital delivery of hip fracture care and patient outcomes. This qualitative study aimed to identify organisational processes that can be targeted to reduce variation in service provision and improve patient care.

METHODS

Interviews were conducted with 40 staff delivering hip fracture care in four UK hospitals. Twenty-three anonymised British Orthopaedic Association reports addressing under-performing hip fracture services were analysed. Following Thematic Analysis of both data sources, themes were transposed onto domains both along and across the hip fracture care pathway.

RESULTS

Effective pre-operative care required early alert of patient admission and the availability of staff in emergency departments to undertake assessments, investigations and administer analgesia. Coordinated decision-making between medical and surgical teams regarding surgery was key, with strategies to ensure flexible but efficient trauma lists. Orthogeriatric services were central to effective service delivery, with collaborative working and supervision of junior doctors, specialist nurses and therapists. Information sharing via multidisciplinary meetings was facilitated by joined up information and technology systems. Service provision was improved by embedding hip fracture pathway documents in induction and training and ensuring their consistent use by the whole team. Hospital executive leadership was important in prioritising hip fracture care and advocating service improvement. Nominated specialty leads, who jointly owned the pathway and met regularly, actively steered services and regularly monitored performance, investigating lapses and consistently feeding back to the multidisciplinary team.

CONCLUSION

Findings highlight the importance of representation from all teams and departments involved in the multidisciplinary care pathway, to deliver integrated hip fracture care. Complex, potentially modifiable, barriers and facilitators to care delivery were identified, informing recommendations to improve effective hip fracture care delivery, and assist hospital services when re-designing and implementing service improvements.

995 MULTIPLE ORGANISATIONAL FACTORS IMPROVE MULTI-DISCIPLINARY CARE DELIVERY TO PATIENTS WITH HIP FRACTURES: A QUALITATIVE STUDY

Introduction

Hip fractures are devastating injuries which incur high healthcare costs. Despite national standards and guidelines, there is substantial variation in hospital delivery of hip fracture care and in patient outcomes. This study aimed to understand organisational processes that facilitate successful delivery of hip fracture services.

Method

Forty qualitative interviews were conducted with healthcare professionals involved in delivering hip fracture care at four English hospitals. Interview data were supplemented with documentary analysis of 23 anonymised British Orthopaedic Association hospital-initiated peer-review reports of services. Data were analysed thematically, with themes transposed onto key components of the care pathway.

Results

We identified multiple aspects of service organisation that facilitated good care delivery. At admission, standardisation of training in nerve block administration impacted care delivery. During hospital stays, service delivery was improved by integrated, shared-care between orthopaedics and orthogeriatrics, and by strategies to improve trauma list efficiency. Adequately staffed orthogeriatric services and the ‘right’ skills and seniority mix were important to holistic care provision. Placing patients on designated hip fracture wards concentrated staff expertise. Collaborative working was achieved through multi-disciplinary team (MDT) meetings between key staff, protocols and care pathways that defined roles and responsibilities, MDT documentation, ‘joined-up’ IT systems within hospitals and with primary care, and shared working spaces such as shared offices and onwards. Trauma and hip fracture coordinators organised care processes and provided a valuable central point of contact within teams. Nominated leads, representing diverse specialties, worked together in MDT planning meetings to develop joint protocols, establish audit priorities, and agree shared goals. Routine, comprehensive monitoring and evaluation of service delivery, with findings shared throughout the MDT, was beneficial.

Conclusion

Our study has characterised potentially modifiable elements of successful hip fracture service delivery. Findings are intended to help services overcome organisational barriers towards delivery of high-quality hip fracture services.

Dental Extractions under General Anesthesia: New Insights from Process Mining

INTRODUCTION

Tooth extraction under general anesthetic (GA) is a global health problem. It is expensive, high risk, and resource intensive, and its prevalence and burden should be reduced where possible. Recent innovation in data analysis techniques now makes it possible to assess the impact of GA policy decisions on public health outcomes. This article describes results from one such technique called process mining, which was applied to dental electronic health record (EHR) data. Treatment pathways preceding extractions under general anesthetic were mined to yield useful insights into waiting times, number of dental visits, treatments, and prescribing behaviors associated with this undesirable outcome.

METHOD

Anonymized data were extracted from a dental EHR covering a population of 231,760 patients aged 0 to 16 y, treated in the Irish public health care system between 2000 and 2014. The data were profiled, assessed for quality, and preprocessed in preparation for analysis. Existing process mining methods were adapted to execute process mining in the context of assessing dental EHR data.

RESULTS

Process models of dental treatment preceding extractions under general anesthetic were generated from the EHR data using process mining tools. A total of 5,563 patients who had 26,115 GA were identified. Of these, 9% received a tooth dressing before extraction with an average lag time of 6 mo between dressing and extraction. In total, 11,867 emergency appointments were attended by the cohort with 2,668 X-rays, 4,370 prescriptions, and over 800 restorations and other treatments carried out prior to tooth extraction.

DISCUSSION AND CONCLUSIONS

Process models generated useful insights, identifying metrics and issues around extractions under general anesthetic and revealing the complexity of dental treatment pathways. The pathways showed high levels of emergency appointments, prescriptions, and additional tooth restorations ultimately unsuccessful in preventing extractions. Supporting earlier publications, the study suggested earlier screening, preventive initiatives, guideline development, and alternative treatments deserve consideration.

KNOWLEDGE TRANSFER STATEMENT

This study generates insights into tooth extractions under general anesthetic using process mining technologies and methods, revealing levels of extraction and associated high levels of prescriptions, emergency appointments, and restorative treatments. These insights can inform dental planners assessing policy decisions for tooth extractions under general anesthetic. The methods used can be combined with costs and patient outcomes to contribute to more effective decision-making.

'DrinkThink' alcohol screening and brief intervention for young people: a qualitative evaluation of training and implementation

Background

Alcohol Screening and Brief Intervention (ASBI) helps reduce risky drinking in adults, but less is known about its effectiveness with young people. This article explores implementation of DrinkThink, an ASBI co-produced with young people, by health, youth and social care professionals trained in its delivery.

Methods

A qualitative evaluation was conducted using focus groups with 33 staff trained to deliver DrinkThink, and eight interviews with trained participants and service managers. These were recorded, transcribed and a thematic analysis undertaken.

Results

DrinkThink was not delivered fully by health, youth or social care agencies. The reasons for this varied by setting but included: the training staff received, a working culture that was ill-suited to the intervention, staff attitudes towards alcohol which prioritized other health problems presented by young people, over alcohol use.

Conclusions

Implementation was limited because staff had not been involved in the design and planning of DrinkThink. Staffs’ perceptions of alcohol problems in young people and the diverse cultures in which they work were subsequently not accounted for in the design. Co-producing youth focused ASBIs with the professionals expected to deliver them, and the young people whom they target, may ensure greater success in integrating them into working practice.

Exploring experiences of physical activity among people with Alzheimer's disease and their spouse carers: a qualitative study

OBJECTIVES

To improve understanding about the barriers and facilitators to physical activity for people with Alzheimer's disease and their spouse carers, and to consider the development of activity interventions that would be acceptable, sustainable and feasible for both groups.

DESIGN

A qualitative approach, using semi-structured interviews, facilitated exploration of physical activity in a small group of people with Alzheimer's disease and their spouse carers.

SETTING

Participants were recruited from one memory clinic in South West England.

PARTICIPANTS

Potential participants were identified by clinical psychologists at the memory clinic and were given information about participating in the research. Five people with Alzheimer's disease and their spouse carers were subsequently recruited for semi-structured interviews, which took place at the memory clinic. Interviews were audio-recorded and transcribed verbatim.

MAIN OUTCOME MEASURES

Qualitative data were analysed using thematic analysis. Three major themes have been presented.

RESULTS

The findings illustrate the complex interplay between the overarching themes 'self', 'others' and 'couple' that affect physical activity for both people with Alzheimer's disease and their spouse carers, and which are linked to the progression of dementia.

CONCLUSIONS

An individually tailored approach for couples, which values the role of the carer and accounts for the progressive and changing nature of dementia, should be a guiding principle for intervention design.

A phase I, first in man study of weekly IMC-A12, a fully human insulin like growth factor-I receptor IgG1 monoclonal antibody, in patients with advanced solid tumors

3505

Background: IMC-A12 is a fully human IgG1 monoclonal antibody directed against the human insulin like growth factor-I receptor. The safety and maximum tolerated dose (MTD) of IMC-A12 are being evaluated in an on-going a phase I trial. Methods: Patients (pts) with ECOG PS = 2 and advanced refractory solid tumors receive IMC-A12 weekly for 4 infusions per cycle until progression. After cycle one only, there is a two week observation period. Six cohorts of IMC-A12 are planned at 3, 6, 10, 15, 21, 27mg/kg. Sampling for PK and human anti-human antibodies directed against IMC-A12 occurs before and after the first and fourth doses of each cycle. Results: Fifteen pts have been treated, 7 at 3 mg/g, 4 at 6 mg/kg, 3 at 10 mg/kg and 1 at 15 mg/kg. Data is available for the first 11 pts: 7 male, 4 female, median age 56 years (range: 45–70). Treatment related toxicities for the first 11 pts include: grade 1 pruritis, rash, discolored feces; grade 2 anemia, psoriasis, hyperglycemia, infusion-related reaction; grade 3 hyperglycemia. Four of 11 pts have stable disease: 2 at the 3 mg/kg dose remain stable for >9 months (1 male breast cancer,1 hepatocellular cancer) and 2 at the 6 mg/kg dose (1 bladder, 1 endometrial) were stable after cycle 1. One pt with prostate cancer had >25% decline in PSA and stable radiographic disease at time of study discontinuation (week 5) for DLT. Non-compartmental PK analysis reveals a mean t1/2 of 148 and 209 hrs, mean Cmax of 333 and 415 ug/mL, and mean AUC0-Inf of 51317 and 80727 hr*ug/mL at the 3 and 6 mg/kg dose levels, respectively. Target trough levels have been achieved. Conclusions: Weekly administration of IMC-A12 appears to be well tolerated and the MTD has not been reached. The PK profile is consistent with that of other Mab’s. There is early evidence of clinical activity and correlative IGF biomarker data will be available. IMC-A12 will be further evaluated in prostate, breast, and other cancers.

No significant financial relationships to disclose.

A phase I study of IMC-11F8, a fully human anti-epidermal growth factor receptor (EGFR) IgG1 monoclonal antibody in patients with solid tumors. Interim results

3024

Background: This ongoing phase I study is being conducted to determine the safety profile and recommended dose of IMC-11F8, a fully-human IgG1 monoclonal antibody that targets the EGFR. Methods: Patients (pts) with advanced solid tumors who are refractory to or have no available standard therapy are eligible to receive IMC-11F8 intravenously either weekly or every other week for 6 weeks (1 cycle). The initial cohort of patients will receive 100 mg of IMC-11F8. In the absence of a dose-limiting toxicity (DLT), dose escalation will be 200, 400, 600, 800, and 1000 mg in successive cohorts. Prior to the initial cycle, pts receive one IMC-11F8 infusion at their assigned cohort followed by a 2-week pharmacokinetic (PK) period. Pts with stable disease or better after cycle 1 are eligible to receive additional cycles of IMC-11F8. Results: 31 of 40 pts have been enrolled in the 100-, 200-, 400-, 600-, and 800-mg cohorts. Pt characteristics are M/F 20/11, median age 58 years (37 - 76), median ECOG score 1 (0–2). No DLTs have been observed. Only grade 1/2 skin rashes were reported. The most frequent adverse events were nausea, vomiting, fatigue, and headache. No infusion reactions were observed. 2 pts (1 confirmed) have achieved a PR, 1 pt with melanoma in the 200-mg cohort with 39+ weeks of weekly IMC-11F8 treatment and 1 pt with rectal cancer in the 400-mg cohort with 20+ weeks of IMC-11F8 administered every other week. 5 pts in the 200- to 600-mg cohorts have stable disease and have received from 11+ to 35+ weeks of IMC-11F8 treatment. A noncompartmental analysis of 20 pts demonstrated that IMC-11F8 exhibits nonlinear PK. As IMC-11F8 escalated from 100 to 600 mg, T1/2 increased from 67 to 84 hrs, Cmax increased from 30 to 368 μg/mL, AUCinf increased from 1753 to 67295, and CL decreased from 57.0 to 8.9 mL/hr. Conclusions: These interim results indicate that IMC-11F8 is well tolerated in this patient population. Although a maximum tolerated dose has not been established, IMC-11F8 has shown activity at two different dose levels.

[Table: see text]

A phase I dose-escalation study of weekly IMC-1121B, a fully human anti-vascular endothelial growth factor receptor 2 (VEGFR2) IgG1 monoclonal antibody (Mab), in patients (pts) with advanced cancer

3032

Background: Anti-VEGFR2 antibodies are effective in a variety of preclinical leukemia and solid tumor models. IMC-1121B is a fully human anti-VEGFR2 IgG1 Mab. Methods: Cohorts of 3–6 pts (ECOG PS ≤ 2) with advanced cancer and no significant cardiovascular, thrombotic or bleeding disorders received escalating doses of IMC-1121B. A single initial dose with extended PK sampling was followed by 4 x weekly infusions per treatment cycle starting at 2mg/kg. 7 dose levels up to a maximum of 16 mg/kg are planned. Human anti-human antibodies (HAHA) directed against IMC-1121B were assessed at baseline and before each Week 4 dose. Tumor response was assessed every 2 cycles. PD analyses include DCE-MRI, serum VEGF and sVEGFR1/2 levels, and peripheral blood mononucleocyte gene expression profiling at baseline and post-dosing. Results: 12 pts (8 M; 4 F), median age 58 years (range: 36–76), have entered the study: cohort 1 (2mg/kg) n=6, cohort 2 (4mg/kg) n=4 and cohort 3 (6mg/kg) n=2. No toxicities ≥ grade 2, considered definitely or probably related to study drug, have occurred. Toxicities ≥ grade 2 possibly drug-related include anorexia, vomiting, anemia, depression, fatigue, and insomnia. To date, there has been one unconfirmed partial response (melanoma) and 5 pts with stable disease for >3 months (colon: 2, breast, gastric, thyroid). Preliminary non-compartmental PK analysis reveals dose-dependent elimination and non-linear exposure, consistent with saturable clearance mechanism(s): mean t1/2 = 63.62, 93.46, 99.63 hrs, mean Cmax = 43.67, 80.25, 264 ug/mL, and AUC0-Inf = 3860, 9242, 27437 hr*ug/mL, at the 2, 4, and 6 mg/kg dose levels, respectively. Conclusions: Weekly administration of IMC-1121B is well tolerated at doses up to 6mg/kg/week. There is early evidence of a non-linear dose-PK relationship. Dose escalation continues. Updated safety, PK, PD, HAHA, and efficacy data will be presented.

[Table: see text]

A reassessment of comparative pregnancy and implantation rates following embryo transfer in recipients vs their infertile donors also trying to conceive in the background of performing salpingectomy for hydrosalpinx

PURPOSE

To compare pregnancy and implantation rates in egg donors trying to conceive vs their recipients in the background of salpingectomy for hydrosalpinx prior to IVF-ET.

METHODS

A retrospective six-year review of all donor egg cycles where the eggs are supplied by an infertile donor trying to conceive herself was carried out. Salpingectomy for hydrosalpinx was performed prior to IVF-ET.

RESULTS

Clinical and delivered pregnancy rates (PRs) following fresh ET were not significantly different in donors vs recipients (60.0%, 45.8% vs 56.8%, 50.8%). Implantation rates were 27.3% vs 32.6%. The respective implantation rates following frozen ET were 13.8% and 14.4%.

CONCLUSIONS

In the background of salpingectomy for hydrosalpinges the much higher PRs in recipients vs donors is no longer seen. The trend for higher implantation rates in recipients (about 20%) following fresh but not frozen transfer could still reflect some adverse effect of the controlled ovarian hyperstimulation regimen in a minority of women.

An evaluation of the efficacy of using oocyte donors aged 36-39

PURPOSE

To determine if oocyte donors aged 36-39 can provide adequate pregnancy rates for recipients.

METHODS

Retrospective analysis of clinical, ongoing/delivered pregnancy and implantation rates for a group of recipients receiving oocytes from a pilot group of older donors.

RESULTS

Comparable pregnancy and implantation rates were found in recipients transferring embryos derived from donors aged 36-39 as recipients using oocytes from donors < or = 35.

CONCLUSIONS

The demonstration of adequate outcome following embryo transfer from embryos derived from fertilization of oocytes from donors aged 36-39 should expand the pool of donor oocytes and reduce the long waiting times for recipients.

Efficacy of sharing oocytes from compensated donors between two recipients

PURPOSE

To see if sharing of donated oocytes from a compensated donor lowers outcome following embryo transfer compared to recipients keeping all oocytes.

METHOD

Retrospective review. Recipients have the option of keeping all oocytes or sharing to reduce costs.

RESULTS

There were equal clinical, and ongoing/delivered pregnancy rates and implantation rates in the two groups. There were almost twice as many frozen embryos available to recipients who did not share for potential future use.

CONCLUSIONS

Sharing of oocytes between two recipients reduces the financial burden for the recipient without affecting efficacy. Such a policy would make more oocytes available to recipients and thus shorten the long waiting times.

New humanitarianism: does it provide a moral banner for the 21st century?

There is a 'new humanitarianism' for the new millennium. It is 'principled', 'human-rights based' and politically sensitive. Above all it is new. It marks a break from the past and a rejection of the traditional principles that guided humanitarianism through the last century. New humanitarians reject the political naivety of the past, assess the long-term political impact of relief and are prepared to see humanitarian aid used as a tool to achieve human rights and political goals. New Humanitarianism is compelling, in tune with our times and offers a new moral banner for humanitarians to cling to as we enter the new millennium. Or does it? After outlining the key elements of new humanitarianism, including the human rights approach and developmental relief, the paper spells out some of the dangers. The author claims that new humanitarianism results in an overt politicisation of aid in which agencies themselves use relief as a tool to achieve wider political goals. The paper shows how this approach has spawned a new conditionality which allowsfor aid to be withheld and has produced a moral hierarchy of victims in which some are more deserving than others. The paper concludes with a plea for a revival of the principle of universalism as the first step to a new set of principles.

Fresh embryo transfer is more effective than frozen for donor oocyte recipients but not for donors

BACKGROUND

Recipients of donor oocytes need to be synchronized to the donor's cycle if fresh embryos are to be transferred on the cycle of oocyte retrieval. It would be much easier to merely retrieve the oocytes from the donor, fertilize the oocytes with the recipient's male partner's spermatozoa, cryopreserve the embryos, then transfer on an oestrogen/progesterone treatment programme.

METHODS

The IVF outcomes of all patients enrolled in a shared oocyte programme from January 1997 to June 1999 were reviewed. Pregnancy and implantation rates were computed and statistically analysed.

RESULTS

There was a significantly higher clinical pregnancy rate for recipients who had a fresh embryo transfer compared with recipients whose first embryo transfer consisted of frozen/thawed embryos (63.4 versus 43.6%).

CONCLUSIONS

Conception is more likely after fresh than frozen embryo transfer with recipients but is similar to donor conception rates. If a uterine defect, per se, even without the use of the controlled ovarian stimulation regimen, could explain the difference between fresh pregnancy and implantation rates in donors versus recipients, then these same differences would have been seen when comparing frozen transfers, but they were, in fact, similar.

The presence of small uterine fibroids not distorting the endometrial cavity does not adversely affect conception outcome following embryo transfer in older recipients

PURPOSE

To determine if uterine fibroids have a negative impact in older patients having embryo transfer (ET).

METHODS

Comparison of clinical and viable pregnancy rates, implantation rates, and spontaneous abortion rates in older (>35) oocyte or embryo recipients with uterine leiomyomata compared to comparable patients without fibroids.

RESULTS

The clinical pregnancy rate per transfer was 56% in the fibroid group vs 64% for the controls. Implantation rates were also very similar (33 vs 32%7). There were no spontaneous abortion or preterm deliveries <32 weeks in the fibroid group and the average term of pregnancies was also similar.

CONCLUSION

Small fibroids not distorting the uterine cavity do not seem to negatively affect conception outcome even in older women.

Time course of osteocalcin, bone-specific alkaline phosphatase, and C-terminal procollagen peptide during callus distraction

This study involved 15 patients who were undergoing extremity lengthening by callus distraction. Blood samples and radiographs of the callus distraction segment were obtained before surgery, every 2 weeks during the distraction phase, and every 4 weeks between the end of distraction and removal of the fixator. A digital radiograph analysis system was used to determine the radiographic density of the callus distraction segments. In addition, the serum parameters osteocalcin, bone-specific alkaline phosphatase, and C-terminal procollagen peptide (PICP) were evaluated. The radiographic density was constant during the distraction phase, but increased logarithmically during the consolidation period. Similar kinetics were observed for osteocalcin, with an average coefficient of correlation between these two parameters of 0.66+/-0.15. PICP levels rose rapidly after surgery and increased further during the consolidation period. Serum levels of bone-specific alkaline phosphatase were not uniform between patients, and there was no correlation to the kinetics of radiographic density or the other serum parameters. The similarity between radiographic density and osteocalcin kinetics, as well as the rapid postoperative increase in PICP, imply that further information may be obtained about osteoneogenesis from the study of these two serum parameters.

Focus on: The Methodist Hospital, Houston, Texas, Biomedical Instrumentation Department

The Methodist Hospital in Houston, Texas, is a 1,527-bed, tertiary care teaching hospital that is both a national and international referral center for medical care in many medical and surgical specialties. The Biomedical Instrumentation Department provides services throughout the hospital in all aspects of clinical equipment management and clinical engineering. With 29 employees and an annual budget of $2.1 million, the department enhances efficiency in the delivery of quality medical care.

Developing a model for technology assessment. A system helps its facilities prepare for technological change

In 1991 the Franciscan Health System (FHS), Philadelphia, created a Technology Assessment Task Force to support specific goals and strategies in the FHS strategic plan and to help prepare its members for technological change. Because FHS is a large and diverse system, with facilities in seven states both on the East Coast and in the Pacific Northwest, the task force needed to develop flexible recommendations with broad applicability. The task force recommended a time-phased approach for changing the way technology is identified, acquired, and used in FHS organizations. Key recommendations included (1) creating a standing FHS technology steering committee, (2) implementing a technology assessment model for selected technology activities, (3) sponsoring systemwide technology conferences, and (4) reviewing FHS technology actions, revising as appropriate. The system and hospital leadership adopted the task force's recommendations and are now implementing them.

Purification of human leukocyte interferon alpha by carboxymethyl controlled pore glass bead chromatography

Human leukocyte-derived alpha interferon [HuIFN-alpha(Le)] has been purified and/or concentrated on Carboxymethyl derivatized Controlled Pore Glass (CML-CPG240) beads. These glass beads adsorb HuIFN-alpha(Le) efficiently at acid pH and at physiological ionic strengths. Elution of HuIFN-alpha(Le) may be accomplished by several methods. Using buffers at relatively high ionic strengths (approximately 0.6 M) and pH values ranging from 2.6 to 6.9 for elution, preparations with specific activities of 10(5)-10(6) IU/mg were obtained with approximately 90 percent recoveries. Alternatively, using elution buffers at the same high ionic strength and at pH values ranging from 7.0 to 8.0, five-fold or better concentration and complete recovery of crude HuIFN-alpha(Le) were achieved. The resulting preparations were suitable for direct application to an antibody affinity chromatography column.

A comparative study on two radioimmunoassays with cloned human interferon-alpha

We report here on the development of (a) a double-antibody radioimmunoassay and (b) a solid-phase radioimmunoassay for cloned human interferon-alpha (leukocyte) [HuIFN-alpha(Le)]. We present the results of titrations of human interferon-alpha-2 (HuIFN-alpha 2) using either method under experimental and optimized conditions. A comparative study of the two methods indicates that (a) the double-antibody procedure is 200-fold more economical of antibody when quantitations are carried out within an optimal range of 0.05--1.0 ng; (b) the double-antibody method is fivefold more sensitive than the solid-phase method, its sensitivity being within the range of the antiviral assays for interferons; and (c) the solid-phase assay is significantly faster. The data also support the presence in human serum of a factor(s) that decreases the maximal amount of HuIFN-alpha 2 bound to antibody. We conclude that these radioimmunoassays are superior to biological assays for the quantitation of interferon-alpha polypeptides from the standpoints of objectivity and reproducibility as well as time and effort required.

Mouse monoclonal antibody with specificity for human interferon gamma

We developed a monoclonal antibody (MAb) specific for human interferon gamma (HuIFN-gamma) by hybridizing cells from the NS-1 myeloma cell line with spleen lymphocytes from BALB/c mice immunized with partially purified HuIFN-gamma. Hybridoma culture supernatants were screened for neutralization of antiviral activity of HuIFN-gamma by the method determining the inhibition of nucleic acid synthesis assay (INAS), employing human fibroblasts infected with encephalomyocarditis virus (EMC). Clones exhibiting neutralization of antiviral activity of HuIFN-gamma were recloned, retested and an MAb with maximum neutralization activity was selected. This MAb was of IgM subclass and was specific for HuIFN-gamma. Antiviral activities either of human leukocyte-derived (HuIFN-alpha) or human fibroblast-derived interferon (HuIFN-beta) were not affected by this monoclonal antibody as determined by the INAS test. The specificity of the MAb for HuIFN-gamma was further confirmed by an indirect immunoprecipitation method, where monoclonal antibody-HuIFN-gamma complexes were immunoprecipitated with rabbit anti-mouse immunoglobulin and remaining IFN activity in the supernatants was determined by virus yield reduction assay. Ammonium sulfate precipitated preparations of this MAb were able to significantly increase (range of 230- to 1300-fold) the virus yield when compared with that obtained in the presence of IFN-gamma. SDS-PAGE analysis revealed that the MAb immunoprecipitates a molecule of Mr = 47 kD under nonreducing conditions. Under reducing conditions, two additional bands of Mr = 26 kD (major band) and Mr = 21 kD (minor band) were observed. A sepharose affinity column was constructed using this MAb and was able to retain approximately 60% of the partially purified HuIFN-gamma preparation applied. Significant amounts of HuIFN-gamma were eluted by increasing the ionic strength and decreasing the pH. HuIFN-alpha and HuIFN-beta were not retained by this column.

Radiation damage due to knock-on processes on carbon foils cooled to liquid helium temperature

Radiation damage on a holey carbon foil was investigated in an electron microscope with a superconducting lens system, where the temperature of the specimen and its environment initially was 4 K. Due to an electron dose of 2 X 10(4) As/cm2 the diameter of a hole increased 5 nm. Rough calculations show that this increase can be ascribed to knock-on processes. Estimates of the rise in specimen temperature during the irradiation are given.

Laboratory evaluation of pressure transducer domes containing a diaphragm

Pressure transducers are being used with increasing frequency in patient care. The recent availability of sterile transducer domes containing a diaphragm provides a means for reducing the risk of bacteremia when using these devices. The present studies measured the effect of diaphragm domes on the accuracy of pressure measurement. The sensitivity and frequency responses of 5 pressure transducers utilizing diaphragm and nondiaphragm domes were compared. The results indicate that the type of dome utilized and the method of dome application can significantly modify pressure transducer performance. The data are useful in providing optimal accuracy and reliability of pressure measurments when using a diaphragm dome, pressure transducer combination.