A method for increasing 3D body scanning's precision: Gryphon and consecutive scanning

The fashion industry cannot use 3 D Body Scanning to create custom garment patterns because its measurements fail to meet ISO 20685:2010's tolerances. To advance 3 D Body Scanning's precision, we present Gryphon: an algorithm that removes the two most extreme measurements from five body scans; removing potentially erroneous data. We assess Gryphon's precision against current industry practice, determine if consecutive and non-consecutive data capture influences precision, and determine 3 D Body Scanning's inherent imprecision inherent. We analyse 97 participants over 121 industry-standard measurements for consecutive and non-consecutive data-capture through MANOVA statistical analysis. Under current industry practice, only one measurement meets ISO 20685. However, under Gryphon and consecutive scanning, 97.5% of measurements meet ISO 20685. We also prove that the body's in-scan movement does not affect reliability. Ultimately, we offer the fashion industry, ergonomists, and practitioners an accessible method to increase 3 D Body Scanning's precision at a level unavailable under previous methods. Practitioner Summary: Ergonomists need precise data, yet we prove 0% of 3 D Body Scanning's measurements meet ISO 20685's tolerances. Our analysis of 97 participants scans, shows consecutive scanning is necessary to achieve data suitable for anthropometric applications. We develop the Gryphon process with consecutive scanning, making 97.3% of measurements meet ISO 20685. Abbreviations: ISO: International Organisation for Standards; Three Dimensional: 3D; MANOVA: Multivariate analysis of variance.

Assessing the female figure identification technique's reliability as a body shape classification system

This paper demonstrates the effects of slight differences in measurement definitions on resultant body shape classification. Ergonomic researchers consider the Female Figure Identification Technique (FFIT) a 'gold standard' body shape classification system to describe variation in a population's 3 D profile. Nevertheless, researchers use FFIT without a scientific basis or considering their ergonomic suitability. This paper rigorously evaluates FFIT, focussing on ergonomics, garment construction, and scientific research applications. Through analysing 1,679 3 D Body Scans, we assess the level of agreement between the FFIT's body shape classification when measurements placed following FFIT's or SizeUK's guidance. We establish how different interpretations of FFIT's measurement placement cause the same body to be categorised into different shapes - in up to 40% of cases. FFIT omits shoulder measurements that have little relationship to body shape yet are vital in garment construction. Using FFIT with different datasets and definitions, therefore, leads to inconsistent conclusions about shape differences.

Use of Low Molecular Weight Heparin in Pregnancy

In a controlled study of 15 pregnant patients undergoing therapeutic termination of pregnancy, seven received subcutaneously 5,000 anti-FXa units of low molecular weight (LMW) heparin 15 and 3 h prior to the termination, and eight patients acted as controls. Paired maternal and fetal blood samples were taken (before or immediately after the termination) for assay of heparin activity by a chromogenic anti-FXa method sensitive to levels of 0.02 anti-FXa U/ml. LMW heparin was detected in all maternal samples of the test patients but was not detected in any of the fetal samples.

The use of LMW heparin as a thromboprophylactic agent was then evaluated in 11 patients who were known to have a severe thromboembolic tendency, had suffered recurrent miscarriages and had responded poorly to conventional anticoagulation (oral anticoagulant, conventional heparin). All patients receiving LMW heparin in thromboprophylactic doses completed uneventful pregnancies and gave birth to healthy babies (three for the first time) without complication. Bone density scans performed in all patients shortly after the delivery showed normal mineral mass. We conclude that LMW heparin does not cross the placental barrier, and in addition offers satisfactory antithrombotic protection for both maternal and placental circulation. In addition, this study provides preliminary data from 11 patients suggesting LMWH may not give rise to maternal osteoporosis, a finding that now needs further investigation.

Scan posture definition and hip girth measurement: the impact on clothing design and body scanning

Ergonomic measurement is central to product design and development; especially for body worn products and clothing. However, there is a large variation in measurement definitions, complicated by new body scanning technology that captures measurements in a posture different to traditional manual methods. Investigations of hip measurement definitions in current clothing measurement practices supports analysis of the effect of scan posture and hip measurement definition on the circumferences of the hip. Here, the hip girth is a key clothing measurement that is not defined in current body scanning measurement standards. Sixty-four participants were scanned in the standard scan posture of a [TC]² body scanner, and also in a natural posture similar to that of traditional manual measurement collection. Results indicate that scan posture affects hip girth circumferences, and that some current clothing measurement practices may not define the largest lower body circumference. Recommendations are made concerning how the hip is defined in measurement practice and within body scanning for clothing product development. Practitioner Summary: The hip girth is an important measurement in garment design, yet its measurement protocol is not currently defined. We demonstrate that body posture during body scanning affects hip circumferences, and that current clothing measurement practices may not define the largest lower body circumference. This paper also provides future measurement practice recommendations.

Multicentre Trials: Planning and Achieving TOTAL

This article provides an overview for those conducting multicentre rehabilitation trials. It aims to highlight potential problems and difficulties which may not be obvious initially.

TOTAL (Trial of Occupational Therapy and Leisure) was a multicentre rehabilitation trial. The aim was to test whether a leisure-based intervention was more effective than activities of daily living (ADL) based therapy at improving the mood, leisure participation and independence in ADL of stroke patients. During the study period, 466 patients were recruited from five centres in the United Kingdom. Postal assessments were sent out at 6 and 12 months after discharge to evaluate mood, leisure independence and ADL performance.

The possible difficulties in recruiting centres are presented. The problems encountered were staff shortages, insufficient numbers of patients, concern over aspects of the protocol and funding issues. Day-to-day problems in running the trial and how these may be resolved are also discussed, such as access to the trial coordinator, finance, the need for written agreements and regular communication with each centre.

While the complexity of conducting a multicentre trial should not be underestimated, preparation, good planning and an awareness of potential problems makes it a feasible proposition.

User-centred design of neogeography: the impact of volunteered geographic information on users' perceptions of online map 'mashups'

This paper investigates the influence of presenting volunteered and professionally created geographic information to 101 wheelchair users through an interactive website that included information collected by wheelchair-using volunteers. The aim of this experiment was to understand the influence that (1) knowing a map-based website contains volunteered information and (2) actually including volunteered information within an online interactive map (a mashup) have on the perceived trust of the user, described in terms of quality and authority. Analysis using Kruskal-Wallis showed that judgements of currency were influenced by including geo-information from untrained volunteers (volunteered geographic information) within the mashup, but not influenced by the participant being told that the online map contained volunteered information. The participants appeared to make judgements based on what information they saw, rather than what they were told about the source of the information.

PRACTITIONER SUMMARY

Since 2004, information services have combined crowdsourced (volunteered) alongside professional information within online interactive maps. An online experiment presented both of these information types to wheelchair users within a travel context. Including volunteered information was shown to increase the perceptions of how up-to-date the maps were.

The role of VGI and PGI in supporting outdoor activities

This paper explored the question of how volunteered and professional geographic information (VGI and PGI) can be used together in an outdoor recreation context. In particular, consideration is given to what makes each information source valuable to the user, and how this can be used to help developers of GIS provide more useful, usable and satisfying products. The assumption that VGI is inferior to PGI is shown to be unfounded; rather each has its own strengths in describing particular aspects of the user information landscape. Considering the opportunities to influence user activities, both VGI and PGI have a greater ability to influence the user in the planning phase than actually during the activity. The importance of the author of the information (volunteer or professional) is shown to be of less importance to the end-user than the characteristics which describe the information in terms of communication, frequency of updates and accessibility.

Isolation and functional assay of the membrane complement inhibitors CD55 (DAF) and CD59 (MIRL)

The complement system is the primary effector of humoral immunity. Because of its enormous destructive capacity, mechanisms for confining the activity of the system to the desired target and elaborate safeguards for protecting self against complement-mediated injury have evolved. Human cells, particularly those found at sites of inflammation (e.g., hematopoietic and endothelial cells), express highly specialized membrane constituents that act independently or in concert with plasma regulatory proteins to inhibit the functional activity of complement. Decay-accelerating factor (DAF), or CD55, directly inhibits the formation and stability of the amplification C3 and C5 convertases of both the classical and the alternative pathways. Failure of a cell to regulate the amplification C3 and C5 convertases allows the generation of the potentially cytolytic membrane attack complex (MAC), or C5b-9 (consisting of the complement components C5b, C6, C7, C8, and C9). The primary cellular regulator of the MAC is the membrane inhibitor of reactive lysis (MIRL), or CD59, which restricts complement-mediated lysis by blocking assembly of the MAC (primarily at the stage of C9 binding and polymerization). This unit provides a basic protocol for isolating CD55 and CD59, along with two support protocols describing separate functional assays for CD59 and CD55.

Development and validation of the Nottingham Leisure Questionnaire (NLQ)

OBJECTIVES

To reduce the length of the Nottingham Leisure Questionnaire (NLQ) in order to make it more suitable for postal use, and to evaluate its test-retest reliability, sensitivity, stability and validity in relation to other measures of activities of daily living (ADL), mood and handicap.

METHOD

The NLQ was shortened and the response categories collapsed. Results from a previous trial which had used the NLQ were reanalysed to establish if significant group differences were maintained. The new version of the NLQ was subsequently tested for test-retest reliability on a new group of patients from the Nottingham stroke register who were asked to complete it twice. The new NLQ and other measures were sent to patients in a multicentre rehabilitation trial (TOTAL) six and twelve months after recruitment for postal completion.

SUBJECTS

One hundred and thirty-seven consecutive patients from the Nottingham stroke register and 466 patients with a stroke in a multicentre rehabilitation trial.

RESULTS

The original NLQ was reduced from 37 to 30 items and from five to three response categories. Data from an earlier study were reanalysed and differences between treatment groups remained. The results of a test-retest analysis using kappa showed that six items had excellent agreement, 15 good and nine fair, suggesting acceptable test-retest reliability. Results from the rehabilitation trial showed that the subjects performed all items and few additional activities were suggested. Higher NLQ scores were associated with higher subscores on the Nottingham Extended Activities of Daily Living Scale (NEADL) and lower NLQ scores with living alone and worse emotional health.

CONCLUSION

The NLQ has been successfully modified for postal self-administration but there is potential for further development.

Relationship of the functional recovery after hip arthroplasty to the neuroendocrine and inflammatory responses

We studied the relationship between the neuroendocrine and inflammatory responses to hip arthroplasty and functional recovery in 102 patients undergoing elective arthroplasty for osteoarthritis. Blood samples were collected for up to 7 days after surgery and analysed for concentrations of norepinephrine, epinephrine, cortisol, interleukin-6 and C-reactive protein. The primary outcome measures were milestones in hospital, times to walk 10 and 25 m, pain on discharge from hospital, and function 1 and 6 months after surgery. Walking distances in hospital were significantly delayed in patients with greater interleukin 6 and C-reactive protein concentrations, but few neuroendocrine measures had significant correlations with functional recovery in hospital. Multivariate analysis showed that the interleukin 6 concentration on day 1 was the unique predictor of time to walk 10 and 25 m, and that the day 2 concentration of C-reactive protein was the unique predictor of pain on discharge from hospital. No significant correlations were found between the inflammatory and neuroendocrine variables and recovery at 1 and 6 months. We conclude that the inflammatory response affects immediate functional recovery after hip arthroplasty.

A multicentre randomized controlled trial of leisure therapy and conventional occupational therapy after stroke. TOTAL Study Group. Trial of Occupational Therapy and Leisure

OBJECTIVE

To evaluate the effects of leisure therapy and conventional occupational therapy (OT) on the mood, leisure participation and independence in activities of daily living (ADL) of stroke patients 6 and 12 months after hospital discharge.

DESIGN

Multicentre randomized controlled trial.

SETTING AND PARTICIPANTS

Four hundred and sixty-six stroke patients from five UK centres.

MAIN OUTCOME MEASURES

The General Health Questionnaire (12 item), the Nottingham Extended ADL Scale and the Nottingham Leisure Questionnaire, assessed by post, with telephone clarification.

RESULTS

Four hundred and forty (94%) and 426 (91%) subjects were alive at 6 and 12 months, respectively. Three hundred and seventy-four (85% of survivors) and 311 (78% of survivors) responded at 6 and 12 month follow-up respectively. At six months and compared to the control group, those allocated to leisure therapy had nonsignificantly better GHQ scores (-1.2: 95% CI -2.9, +0.5), leisure scores (+0.7, 95% CI -1.1, +2.5) and Extended ADL scores (+0.4: 95% CI -3.8, +4.5): the ADL group had nonsignificantly better GHQ scores (-0.1: 95% CI -1.8, +1.7) and Extended ADL scores (+1.4: 95% CI -2.9, +5.6) and nonsignificantly worse leisure scores (-0.3: 95% CI -2.1, +1.6). The results at 12 months were similar.

CONCLUSION

In contrast to the findings of previous smaller trials, neither of the additional OT treatments showed a clear beneficial effect on mood, leisure activity or independence in ADL measured at 6 or 12 months.

Hip and knee arthroplasty: a comparison and the endocrine, metabolic and inflammatory responses

Changes in circulating levels of catecholamines, cortisol, glucose, interleukin-6 and C-reactive protein and in the leucocyte count were investigated for 7 days after surgery in 158 patients undergoing hip or knee arthroplasty. We compared the responses to the two operations, and also examined the effects of pathology (osteoarthritis and rheumatoid arthritis) on the changes associated with knee arthroplasty. Exploratory factor analysis was applied to the data to identify the variables and sampling times that could be used in future to provide a concise description of the response. Patients undergoing knee arthroplasty showed significantly greater changes in noradrenaline, adrenaline and glucose levels, but not in cortisol levels, compared with those undergoing hip arthroplasty. Interleukin-6 and C-reactive protein concentrations were also significantly greater in knee patients than hip patients; however, when corrected for pathology, many of these differences were not significant. Minimal effects of pathology (chronic inflammation with rheumatoid arthritis) were found on the hormonal changes in knee patients. In particular, there was little evidence to support the inference from animal data that the hypothalamic-pituitary-adrenal axis is impaired. The expected increases in interleukin-6 and C-reactive protein concentrations were found in the rheumatoid arthritis patients. Exploratory factor analysis showed that the response could be separated into six components, accounting for 60% of the total variance, and identified the variables and sampling times indicative of each. In conclusion, there are differences in the hormonal, but not inflammatory, responses to hip and knee arthroplasty. Little evidence was found for an important effect of pathology on the changes associated with knee surgery. Factor analysis provided a useful summary of the data.

Paroxysmal nocturnal hemoglobinuria: analysis of the effects of mutant PIG-A on gene expression

Compelling evidence indicates that mutations in PIG-A are necessary for the development of paroxysmal nocturnal hemaglobinuria (PNH), however, it is unclear why mutant PIG-A stem cells have a selective advantage. Further, multiple, discrete PIG-A mutations have been detected in the peripheral blood and bone marrow of patients with PNH, but the contribution of the different mutant clones to hematopoiesis is variable. This observation implies that factors in addition to mutant PIG-A influence the proliferative properties of the abnormal cells. To investigate the etiology of the selective advantage and the clonal dominance in PNH, gene expression in cells with mutant PIG-A was analyzed. Representational difference analysis was used to compare the pattern of cDNA expression between a human lymphoblastoid cell line with mutant PIG-A and its wild-type counterpart. These experiments demonstrated that the pattern of gene expression was different between the two cells lines in that the PIG-A mutant cells failed to express antiquitin mRNA. Transfection of the mutant cells with normal PIG-A restored expression of glycosyl phosphatidylinositol anchored proteins but not antiquitin. These experiments demonstrate that differences in the pattern of gene expression can occur independent of the PIG-A mutation. Depending upon the functional properties of the involved genes, these differences could influence the proliferative properties of PIG-A mutant cells and contribute to the selective advantage and clonal dominance that characterize PNH.

Physical illness and disability among elderly people in England and Wales: the Medical Research Council Cognitive Function and Ageing Study. The Analysis Group

STUDY OBJECTIVE

This study was conducted as part of the MRC cognitive function and ageing study. It aimed to estimate the lifetime prevalence of self reported physical illnesses and other health related events, and the prevalence of limiting disability in people over 65 in six areas of England and Wales.

DESIGN

Screening phase of a two stage prevalence study.

SETTING

Geographically delimited areas in four urban and two rural areas including institutions.

PARTICIPANTS

Random population samples of people in their 65th year and above on the sample definition date, interviewed between 1989 and 1994. In Newcastle, Nottingham, and Oxford (urban) and in Cambridgeshire and Gwynedd(rural), the sample was stratified to provide equal numbers in the 65-74 and 75 years and over age groups. In Liverpool (urban), equal numbers in the five year age groups were taken.

MAIN RESULTS

Age standardised prevalences were calculated for each geographical area, sex, and age group (65-74, 75+). Many conditions were more prevalent in the older age group including stroke, Parkinson's disease, arthritis, diabetes, and shingles but hypertension was more common in the younger age group. Conditions that were more prevalent in men included angina, heart attack, stroke, head injury, and peptic ulcers while hypertension, shingles, pernicious anaemia, and thyroid disease were more common in women. There was a complex pattern of area differences for individual conditions. Cambridgeshire had generally low prevalences for many diseases, including vascular problems, Gwynedd and Newcastle had less healthy elderly populations, and Nottingham and Newcastle had the highest percentages of housebound.

CONCLUSIONS

This study provides the most robust available estimates for life-time prevalence of a variety of health conditions on a regional and national basis. It shows the greatly increased prevalence of disability in the very old population, particularly women.

A comparison of the infusion pharmacokinetics and pharmacodynamics of cisatracurium, the 1R-cis 1'R-cis isomer of atracurium, with atracurium besylate in healthy patients

We have compared the pharmacokinetics of cisatracurium with atracurium when given by bolus dose followed by continuous infusion. Twenty healthy patients were anaesthetised with thiopentone, midazolam, fentanyl and 70% nitrous oxide in oxygen. Ten patients (Group C) were randomly allocated to receive cisatracurium 0.1 mg.kg-1 and 10 patients (Group A) were given atracurium 0.5 mg.kg-1. Neuromuscular block was monitored using a mechanomyograph. When the first twitch of the train-of-four had recovered to 5% of control, an infusion of cisatracurium 3 micrograms.kg-1.min-1 was started in Group C and an infusion of atracurium 10 micrograms.kg-1.min-1 was started in Group A. The infusion rates were adjusted to maintain the first twitch of the train-of-four at 5% of control. The times to 90% and maximum depression of the first twitch of the train-of-four were significantly longer after cisatracurium than atracurium (2.2 and 3.4 min compared with 1.3 and 1.8 min, respectively; p < 0.01 in each instance). No significant differences were found in recovery parameters between the two groups. Blood samples were taken at regular intervals following the bolus, during the infusion and for 8 h thereafter. The plasma samples were analysed using high-performance liquid chromatography for cisatracurium and atracurium (using a method which distinguishes between the three geometric isomer groups), laudanosine and monoquaternary alcohol. The results were analysed using the Non-linear Mixed Effects Model program. A two-compartment model was fitted to the data. The different isomer groups of atracurium have different pharmacokinetics, the trans-trans group having the highest clearance (1440 ml.min-1) and the cis-cis group the lowest (499 ml.min-1). The clearance of cisatracurium (425 ml.min-1) is less than that of cis-cis atracurium and its elimination half-life is longer (34.9 min and 21.9 min, respectively). The plasma concentration of laudanosine after cisatracurium was one-fifth of that after atracurium.

Human immunodeficiency virus type 1 incorporates both glycosyl phosphatidylinositol-anchored CD55 and CD59 and integral membrane CD46 at levels that protect from complement-mediated destruction

Human immunodeficiency virus type 1 (HIV-1) can be either resistant or sensitive to complement-mediated destruction depending on the host cells. Incorporation of different levels of host cell CD46, CD55 and CD59 may account for this differential sensitivity to complement. However, it has not been determined whether CD46, CD55 and CD59 can all be incorporated at levels which protect virions. To determine whether each of these proteins can protect HIV-1, virions were derived from CHO cells expressing either human CD46, CD55 or CD59. Virions were shown to incorporate both glycosyl phosphatidylinositol (GPI)-anchored CD55 and CD59 as well as transmembrane CD46. Importantly, all three virus preparations were significantly more resistant to complement lysis than control virus. This study demonstrates that HIV-1 incorporates both transmembrane and GPI-anchored complement control proteins from host cells and that both types of protein increase complement resistance of virus.

The pharmacokinetics and pharmacodynamics of rocuronium in patients with hepatic cirrhosis

AIMS

To determine the effects of hepatic cirrhosis on the pharmacodynamics and pharmacokinetics of rocuronium bromide.

METHODS

We studied 21 healthy patients and 17 patients with mild or moderate cirrhosis (Child-Pugh Class A and B). Patients were premedicated with diazepam orally; anaesthesia was induced with fentanyl and thiopentone, and maintained with isoflurane 0.6% (end-tidal) and nitrous oxide 66% in oxygen. The compound action potential of the adductor pollicis muscle in response to supramaximal stimulation of the ulnar nerve was recorded using the train-of-four (TOF) twitch technique. A bolus dose of rocuronium 0.6 mg kg(-1) was then given. Venous blood samples were taken for up to 8 h, and plasma rocuronium concentrations determined by h.p.l.c.

RESULTS

The time to onset of neuromuscular block and maximal block achieved did not differ between the two groups. The mean (s.d.) recovery times were prolonged in the cirrhotic compared with the healthy group: 25% recovery T1:T0, 53.7 (18.1) vs 42.3 (14.2) min; 50% recovery T1:T0, 73.9 (33.9) vs 52.6 (19.8) min; 75% recovery T1:T0, 84.2 (24.5) vs 66.8 (27.2) min (all P<0.05); recovery of T4:T1 to 70%, 114.9 (31.7) vs 76.1 (28.8) min (P<0.01). A pharmacokinetic and pharmacodynamic model was fitted to the data for each patient. Three compartments were used to model the pharmacokinetic data; an effect compartment was added to model the pharmacodynamic data. Plasma clearance was significantly reduced in the cirrhotic group (2.66 (0.60) vs 3.70 (1.03) ml kg(-1) min (-1); P<0.005). The central (V1) and steady state volumes of distribution (V(ss)) did not differ significantly between the groups. The slow redistribution (t1/2,lambda1) and elimination (t1/2,z) half-lives were both significantly prolonged in cirrhosis (28.3 (12.1) vs 16.8 (4.6) min, P < 0.005; and 143 (80) vs 92 (40) min, P < 0.05 respectively). The exit rate constant for the effect compartment k(eo) was significantly increased in the cirrhotic group (0.25 (0.18) vs 0.16 (0.06) min(-1); P < 0.05), but cirrhosis had no significant effect on the parameters of the concentration-effect relationship Cp(ss)(50) and gamma.

CONCLUSIONS

Hepatic elimination is an important pathway in the clearance of rocuronium, and delayed disposition causes the effect to be prolonged.

A role for C5 and C5a-ase in the acute neutrophil response to group B streptococcal infections

Congenic C5-deficient and C5-sufficient mice were infected with group B streptococci (GBS) to determine if the polymorphonuclear leukocyte (PMNL) chemoattractant C5a contributes to PMNL recruitment in GBS infection and if GBS C5a-ase reduces C5a-induced PMNL recruitment in vivo. PMNL accumulation was greater in the peritoneum and air spaces of C5-sufficient mice than in C5-deficient mice. Administration of human C5 to C5-deficient mice caused a significant increase in PMNL recruitment following infection with C5a-ase-negative GBS. GBS C5a-ase did not reduce PMNL accumulation in C5-sufficient mice but reduced PMNL recruitment in C5-deficient mice reconstituted with human C5. These data indicate that C5a is important for rapid PMNL recruitment to sites of GBS infection and that GBS C5a-ase inactivates human, but not murine, C5a in vivo. Reduction of the acute inflammatory response by C5a-ase likely contributes to GBS virulence in human neonates.

Biochemical characterization of procoagulant albumin

Procoagulant albumin (Pro-Alb) is an anionic form of albumin isolated from normal human plasma that regulates vascular endothelial cell hemostatic properties, including induction of tissue factor activity. We investigated the biochemical modification of Pro-Alb that was associated with procoagulant-inducing activity. Tryptic digestion of Pro-Alb identified greatest bioactivity in the carboxy-terminus of the molecule, a region associated with lipid binding sites. Activated charcoal treatment and phopholipase C digestion reduced the procoagulant-inducing activity of Pro-Alb, and Pro-Alb contained 2.3-fold more phosphorus than inactive albumin. We conclude that modification of albumin by phospholipid imparts tissue factor-inducing activity to Pro-Alb.

The role of leisure in stroke rehabilitation

Stroke patients often fail to resume full lives, even if they make a good physical recovery, and social and leisure pursuits show a particular decline. The usual goals of rehabilitation are mobility and independence in self-care, but recovery in a broader sense may be impeded if health professionals concentrate exclusively on these. Leisure has been shown to be closely associated with life satisfaction and would be a worthwhile, and now measurable, goal of rehabilitation. Elderly people show a decline in leisure activity which has been studied extensively and may provide a useful model for the more rapid decline seen in stroke patients. Further research is needed to confirm the finding that specialized occupational therapy can be effective in raising leisure activity, and to show whether this will translate into improved psychological well-being.

Analysis of the gene that encodes the complement regulatory protein, membrane inhibitor of reactive lysis (CD59). Identification of an alternatively spliced exon and characterization of the transcriptional regulatory regions of the promoter

Membrane inhibitor of reactive lysis (MIRL, CD59) is an 18-kDa glycosylphosphatidylinositol-anchored protein that regulates formation of the membrane attack complex of complement. The purpose of these studies was to characterize the gene that encodes CD59. Our experiments redefined the structural organization of the gene by identifying a previously unrecognized alternatively spliced exon. Analysis by PCR of cDNA derived from a variety of cultured human cell lines and from PBMC showed that transcripts containing the alternatively spliced exon sequence were expressed concordantly with transcripts lacking that sequence. Primer extension studies demonstrated that the transcriptional start site of alternatively spliced CD59 mRNA is the same as that of transcripts without the alternatively spliced exon sequence, suggesting that expression of both forms of CD59 mRNA is regulated similarly. Analysis of the promoter region showed that the first 70 nucleotides immediately 5' of the transcriptional start site of the CD59 gene are essential for both constitutive and PMA-responsive transcription; however, responsiveness to PMA is cell line specific. Together, these studies have redefined the organization of the CD59 gene and identified regions of the promoter involved in constitutive and PMA-inducible transcription.

Analysis of the gene that encodes the complement regulatory protein, membrane inhibitor of reactive lysis (CD59). Identification of an alternatively spliced exon and characterization of the transcriptional regulatory regions of the promoter

Membrane inhibitor of reactive lysis (MIRL, CD59) is an 18-kDa glycosylphosphatidylinositol-anchored protein that regulates formation of the membrane attack complex of complement. The purpose of these studies was to characterize the gene that encodes CD59. Our experiments redefined the structural organization of the gene by identifying a previously unrecognized alternatively spliced exon. Analysis by PCR of cDNA derived from a variety of cultured human cell lines and from PBMC showed that transcripts containing the alternatively spliced exon sequence were expressed concordantly with transcripts lacking that sequence. Primer extension studies demonstrated that the transcriptional start site of alternatively spliced CD59 mRNA is the same as that of transcripts without the alternatively spliced exon sequence, suggesting that expression of both forms of CD59 mRNA is regulated similarly. Analysis of the promoter region showed that the first 70 nucleotides immediately 5' of the transcriptional start site of the CD59 gene are essential for both constitutive and PMA-responsive transcription; however, responsiveness to PMA is cell line specific. Together, these studies have redefined the organization of the CD59 gene and identified regions of the promoter involved in constitutive and PMA-inducible transcription.

Syngeneic bone marrow transplantation without conditioning in a patient with paroxysmal nocturnal hemoglobinuria: in vivo evidence that the mutant stem cells have a survival advantage

A 10-year-old girl with paroxysmal nocturnal hemoglobinuria (PNH) received an infusion of syngeneic bone marrow without preparative marrow ablation or immunosuppression. Following transplant, the patient became asymptomatic in concordance with an increase in the percentage of peripheral blood cells with normal expression of glycosyl phosphatidylinositol-anchored proteins (GPI-AP). However, molecular analysis suggested engraftment of a relatively small number of donor stem cells and persistence of an abnormal stem cell with mutant PIG-A. During 17 months of observation, the percentage of cells with normal GPI-AP expression gradually decreased, while intravascular hemolysis progressively increased. Approximately 16.5 months post-transplant, the patient once again became symptomatic. Together, these results indicate that syngeneic marrow infusion provided a clinical benefit by increasing the proportion of erythrocytes with normal expression of GPI-anchored complement regulatory proteins without supplanting the abnormal stem cells. However, evidence of insidious disease progression following the marrow infusion implies that the abnormal stem cells have a survival advantage relative to the transplanted stem cells. Thus, these studies contribute in vivo data in support of the hypothesis that PNH arises as a consequence of a pathological process that selects for hematopoietic stem cells that are GPI-AP-deficient.

Molecular basis of paroxysmal nocturnal hemoglobinuria

The purpose of this review is to summarize recent studies that have led to a more complete understanding of the molecular basis of paroxysmal nocturnal hemoglobinuria (PNH). Somatic mutations of PIG-A arising in pluripotent hematopoietic stem cells are necessary for the development of PNH. PIG-A is an X-linked gene that is essential for synthesis of the glycosyl phosphatidylinositol (GPI) moiety that serves as a membrane anchor for a functionally diverse group of cell surface proteins. Consequently, the progeny of stem cells with mutant PIG-A are deficient in all GPI-anchored proteins (GPI-AP). Among the GPI-AP that are expressed on hematopoietic cells are two important regulators of the complement system, decay-accelerating factor, (CD55) and membrane inhibitor of reactive lysis, (CD59). It is the deficiency of erythrocyte CD55 and CD59 that accounts for the intravascular hemolysis and hemoglobinuria that are the clinical hallmarks of PNH. A remarkable feature of PNH is that the peripheral blood is a mosaic composed of variable proportions of GPI-AP+ and GPI-AP- cells and that, in an individual patient, the GPI-AP- cells can be derived from multiple mutant stem cells. Currently, however, there is no evidence that the PIG-A mutation per se provides a proliferative advantage. Thus, PNH is not a monoclonal disease with a malignant phenotype. Rather, the mutant stem cells appear to dominate hematopoiesis because under some pathological conditions, GPI-AP deficiency is advantageous. The close association of PNH with aplastic anemia suggests that the selection pressure arises as a consequence of a specific type of bone marrow injury.

Identification and characterization of an inherited mutation of PIG-A in a patient with paroxysmal nocturnal haemoglobinuria

Analysis of the X-linked gene PIG-A from haemopoietic cells of a female PNH patient showed a homozygous C-55-T substitution that caused replacement of arginine with tryptophan at codon 19. Aval restriction analysis of PIG-A cDNA demonstrated that the patient was homozygous for this mutation, whereas her mother was heterozygous and her father was hemizygous. Flow cytometry, however, showed normal expression of glycosyl phosphatidylinositol anchored proteins on blood cells of the patient's mother and father. Therefore the C-55-T mutation is an inherited sequence variant that does not account for the PNH phenotype of this patient.

Increased lipase inhibition in uremia: identification of pre-beta-HDL as a major inhibitor in normal and uremic plasma

The hypertriglyceridemia commonly observed in uremia has been attributed to an abnormally high inhibitor activity in plasma for lipoprotein lipase (LPL) and hepatic lipase (HL), both of which have a key role in lipoprotein metabolism. The purpose of this investigation was to establish a relationship between plasma lipase inhibitor activity and hypertriglyceridemia, identify the main plasma lipase inhibitor, and determine the basis for the greater inhibitor activity in uremia. In a mixed population of normal (N = 8) and uremic subjects (N = 12), log-transformed plasma triglycerides correlated with both inhibitor activity and uremic status. However, inhibitor activity was the only retained predictor variable for triglycerides in a multiple linear regression model (r = 0.91; P < 0.0001). An inhibitor isolated from normal plasma was identified as a particle containing apolipoprotein A-I (apo A-I) and 3% phospholipid. This particle, which has pre-beta electrophoretic mobility and a Stokes' radius of 54 A, therefore corresponds to a form of the previously described pre-beta-HDL (free apo A-I) in the non-lipoprotein fraction of plasma. Comparison of normal and uremic plasma indicated that the greater lipase inhibitor activity in the latter could be attributed to an increased concentration of apo A-I in the non-lipoprotein fraction of plasma (pre-beta-HDL), as well as to increased inhibition by the uremic lipoproteins. The increased plasma lipase inhibitor activity may be important in the pathogenesis of hypertriglyceridemia in chronic renal failure.

Molecular basis of the heterogeneity of expression of glycosyl phosphatidylinositol anchored proteins in paroxysmal nocturnal hemoglobinuria

The purpose of these studies was to determine the molecular basis of the phenotypic mosaicism that is a defining feature of paroxysmal nocturnal hemoglobinuria (PNH). Analysis of T cell clones from a female patient revealed four distinct phenotypes based on surface expression of glycosyl phosphatidylinositol-anchored proteins (GPI-AP). When PIG-A (the gene that is mutant in PNH) from these clones was analyzed, four discrete somatic mutations were identified. Analysis of X chromosomal inactivation among the abnormal T cell clones was consistent with polyclonality. Together, these studies demonstrate that the phenotypic mosaicism that is characteristic of PNH is a consequence of genotypic mosaicism and that, at least in this case, PNH is a polyclonal rather than a monoclonal disease. That four distinct somatic mutations were present in a single patient suggests that in conditions that predispose to PNH PIG-A may be hypermutable.

Comparison of the pharmacodynamics and pharmacokinetics of an infusion of cis-atracurium (51W89) or atracurium in critically ill patients undergoing mechanical ventilation in an intensive therapy unit

We have studied 12 critically ill, sedated patients who required a neuromuscular blocking drug to assist mechanical ventilation in an intensive care unit. Patients were randomized to receive an infusion of cis-atracurium 0.18 mg kg-1 h-1 (group 1, n = 6) or atracurium 0.6 mg kg-1 h-1 (group 2, n = 6) preceded, if necessary, by a bolus dose of 2 x ED95 of the same drug (cis-atracurium 0.1 mg kg-1 or atracurium 0.5 mg kg-1). Neuromuscular block was monitored using an accelerograph and the infusion rate adjusted regularly so that it was possible to detect the first response to train-of-four (TOF) stimulation of the ulnar nerve at the wrist. Blood samples were obtained for estimation of plasma cis-atracurium and laudanosine concentrations (group 1) or the three groups of atracurium isomers and laudanosine (group 2). There was no apparent haemodynamic or allergic response to either drug. The mean infusion time in group 1 was 37.6 h and in group 2, 27.5 h. On termination of the infusion, the time for the TOF ratio to reach 0.7 was similar in the two groups (group 1 = 60 min; group 2 = 62 min). The mean infusion rate of cis-atracurium was 0.19 mg kg-1 h-1 and of atracurium 0.47 mg kg-1 h-1 (expressed as mg of bis-cation): cis-atracurium was 2.5 times more potent than atracurium. Using the NONMEM program, a single compartment pharmacokinetic model was fitted to the plasma concentrations of cis-atracurium and the cis-cis, cis-trans and trans-trans isomers of atracurium. The mean population pharmacokinetic values for cis-atracurium were: volume of distribution (V) = 21,900 (SEM 416) ml; clearance (Cl) = 549 (79) ml min-1; half-life (T1/2) = 27.6 (3.6) min; and for the three groups of atracurium isomers were: cis-cis, V = 15,100 (720) ml, Cl = 449 (42) ml min-1, T1/2 = 23.4 (1.2) min; cis-trans, V = 18,000 (667) ml, Cl = 1070 (43) ml min-1, T1/2 = 11.7 (0.1); trans-trans, V = 13,100 (1280) ml, Cl = 1560 (55) ml min-1, T1/2 = 5.8 (0.4) min. Plasma laudanosine concentrations were lower in the cis-atracurium (peak value 1.3 micrograms ml-1) than in the atracurium (maximum 4.4 micrograms ml-1) group.

Procoagulant albumin increases vascular endothelial cell prostacyclin secretion

Vascular endothelium regulates multiple aspects of platelet function through secretion of a variety of substances, including von Willebrand factor, nitric oxide, and prostacyclin (PGI2). The objective of this study was to determine whether procoagulant albumin (P-A1), a modified form of albumin present in normal human plasma could modulate endothelial cell secretion of these substances. P-A1 did not affect constitutive secretion of von Willebrand factor or nitric oxide, but did increase PGI2 secretion in a time- and concentration-dependent manner. Pre-treatment of endothelial cells with aspirin, or use of suramin, a broad-specificity inhibitor, prevented the response to P-A1. Prostaglandin H synthase-2 contributed to the P-A1-induced PGI2 secretion. These results indicate that in addition to inducing tissue factor activity and reducing protein C activation and fibrinolysis, P-A1 also modulates vascular endothelial cell PGI2 secretion, and potentially, platelet function.

Host cell-derived complement control proteins CD55 and CD59 are incorporated into the virions of two unrelated enveloped viruses. Human T cell leukemia/lymphoma virus type I (HTLV-I) and human cytomegalovirus (HCMV)

The current study was undertaken to determine whether the human T cell leukemia/lymphoma oncovirus type I (HTLV-I) and the herpesvirus human cytomegalovirus (HCM) incorporate host cell-derived C regulatory proteins. Our experiments showed that both CD59 and CD55 were associated with the external membrane of HTLV-I derived from MT2 cells, since virus could be captured by mAbs to these proteins, and antisera to CD55 and CD59 induced C-mediated lysis of HTLV-I virions. Additionally, both CD55 and CD59 were detected by immunoblot analysis of purified HTLV-I. Purified HCMV produced in human foreskin fibroblasts (HFF) also contained both CD55 and CD59, as detected by immunoblot analysis. However, treatment with anti-CD55, but not anti-CD59, reduced the HCMV infectious titer in the presence of C. Additional studies determined whether HTLV-I-associated CD55 and CD59 participated in the resistance of the virus to C-mediated lysis. Treatment of virus with phosphatidylinositol-specific phospholipase C (PI-PLC), which removes glycosylphosphatidylinositol-anchored CD55 and CD59, increased the sensitivity of HTLV-I to C-mediated destruction in the presence of anti-HTLV-I Abs. Reconstitution of PI-PLC-treated virus with purified CD55 and CD59 restored resistance to C. These experiments show that HTLV-I and HCMV acquire C control proteins from host cells. Together with our previous experiments showing that both CD55 and CD59 are present on HIV-1, these studies demonstrate a mechanism by which a variety of enveloped viruses may acquire resistance to C-mediated destruction.

Host cell-derived complement control proteins CD55 and CD59 are incorporated into the virions of two unrelated enveloped viruses. Human T cell leukemia/lymphoma virus type I (HTLV-I) and human cytomegalovirus (HCMV)

The current study was undertaken to determine whether the human T cell leukemia/lymphoma oncovirus type I (HTLV-I) and the herpesvirus human cytomegalovirus (HCM) incorporate host cell-derived C regulatory proteins. Our experiments showed that both CD59 and CD55 were associated with the external membrane of HTLV-I derived from MT2 cells, since virus could be captured by mAbs to these proteins, and antisera to CD55 and CD59 induced C-mediated lysis of HTLV-I virions. Additionally, both CD55 and CD59 were detected by immunoblot analysis of purified HTLV-I. Purified HCMV produced in human foreskin fibroblasts (HFF) also contained both CD55 and CD59, as detected by immunoblot analysis. However, treatment with anti-CD55, but not anti-CD59, reduced the HCMV infectious titer in the presence of C. Additional studies determined whether HTLV-I-associated CD55 and CD59 participated in the resistance of the virus to C-mediated lysis. Treatment of virus with phosphatidylinositol-specific phospholipase C (PI-PLC), which removes glycosylphosphatidylinositol-anchored CD55 and CD59, increased the sensitivity of HTLV-I to C-mediated destruction in the presence of anti-HTLV-I Abs. Reconstitution of PI-PLC-treated virus with purified CD55 and CD59 restored resistance to C. These experiments show that HTLV-I and HCMV acquire C control proteins from host cells. Together with our previous experiments showing that both CD55 and CD59 are present on HIV-1, these studies demonstrate a mechanism by which a variety of enveloped viruses may acquire resistance to C-mediated destruction.

Pharmacokinetics of 1R-cis 1'R-cis atracurium besylate (51W89) and plasma laudanosine concentrations in health and chronic renal failure

To ascertain the effects of chronic renal failure on the pharmacokinetics of 1R-cis 1'R-cis atracurium besylate (a stereoisomer, designated 51W89), we gave a bolus dose of 0.1 mg kg-1 (2 x ED95) to 17 patients with end-stage renal failure and to 15 patients with normal renal function undergoing elective surgery. All patients received thiopentone, fentanyl and midazolam i.v. and 70% nitrous oxide in oxygen. Blood samples were obtained over 8 h and plasma analysed for 51W89 and laudanosine concentration, using high pressure liquid chromatography. A two-compartment model was fitted to the 51W89 plasma concentration data using the NONMEM program, to estimate pharmacokinetic variables and to determine the influence of renal failure, age, weight and sex. Clearance of 51W89 was found to be reduced by 13% in renal failure. The typical value of T1/2 beta was 4.2 min longer in renal failure than in the healthy patients (34.2 vs 30.0 min, P < 0.005). In the healthy patients, clearance of 51W89 was greater in males, but it decreased with increasing age by approximately 1.5 ml min-1 yr-1. Mean plasma laudanosine concentrations were significantly higher in the renal failure group; nevertheless, they were approximately one-tenth of those reported after atracurium.

Role of virion-associated glycosylphosphatidylinositol-linked proteins CD55 and CD59 in complement resistance of cell line-derived and primary isolates of HIV-1

This study investigates whether cell-derived glycosylphosphatidylinositol-linked complement control proteins CD55 and CD59 can be incorporated into HIV-1 virions and contribute to complement resistance. Virus was prepared by transfection of cell lines with pNL4-3, and primary isolates of HIV-1 were derived from patients' PBMCs. Virus was tested for sensitivity to complement-mediated virolysis in the presence of anti-gp160 antibody. Viral preparations from JY33 cells, which lack CD55 and CD59, were highly sensitive to complement. HIV-1 preparations from H9 and U937 cells, which express low levels of CD55 and CD59, had intermediate to high sensitivity while other cell line-derived viruses and primary isolates of HIV-1 were resistant to complement-mediated virolysis. Although the primary isolates were not lysed, they activated complement as measured by binding to a complement receptor positive cell line. While the primary isolates were resistant to lysis in the presence of HIV-specific antibody, antibody to CD59 induced lysis. Likewise, antibody to CD55 and CD59 induced lysis of cell line-derived virus. Western blot analysis of purified virus showed bands corresponding to CD55 and CD59. Phosphatidylinositol-specific phospholipase C treatment of either cell line-derived or primary isolates of HIV-1 increased sensitivity to complement while incubation of sensitive virus with purified CD55 and CD59 increased resistance to complement. These results show that CD55 and CD59 are incorporated into HIV-1 particles and function to protect virions from complement-mediated destruction, and they are the first report of host cell proteins functioning in protection of HIV-1 from immune effector mechanisms.

Pharmacokinetics of 51W89: preliminary data

The pharmacokinetics of the 1R cis-1'R cis-isomer of atracurium (51W89) and its metabolite, laudanosine, were studied in 11 healthy patients with normal renal function and in 12 patients with chronic renal failure undergoing regular dialysis. A bolus dose of 51W89 (0.1 mg/kg) was given, and the plasma concentration was measured at regular intervals for 480 min. The elimination half-life of 51W89 was significantly longer in renal failure patients than in healthy controls (38.9 min vs 30.6 min; P < 0.05). The plasma laudanosine levels were lower than those reported after an equipotent dose of atracurium besylate. 51W89 may have a prolonged effect in renal failure patients.

Pharmacokinetics and pharmacodynamics of the three isomers of mivacurium in health, in end-stage renal failure and in patients with impaired renal function

We have studied the pharmacokinetics of cis-trans, trans-trans and cis-cis mivacurium in nine healthy patients (creatinine clearance 66-133 ml min-1), in seven patients with end-stage renal failure requiring dialysis (creatinine clearance 4-11 ml min-1) and in seven patients with impaired renal function (creatinine clearance 32-49 ml min-1), during thiopentone-fentanyl-midazolam-nitrous oxide-oxygen anaesthesia. Mivacurium chloride was infused at a rate of 15 micrograms kg-1 min-1 for 10 min, 7.5 micrograms kg-1 min-1 for a further 10 min, and then at a rate adjusted to maintain T1/T0 at 5%. The minimum duration of infusion was 60 min (range 60-235 min). The plasma concentration of the three isomers was measured at regular intervals throughout the infusion, and for up to 300 min after the infusion was stopped. Compartmental analysis of the resulting isomer profiles was undertaken: one- and two-compartment models were fitted to derive clearance, volume of distribution and terminal elimination half-life. Clearance of the cis-cis isomer was reduced significantly in the renal failure (median 2.4 (range 2.1-2.6) ml kg-1 min-1) and intermediate renal function groups (2.1 (2.0-2.9) ml kg-1 min-1), compared with healthy patients (3.8 (2.6-4.9) ml kg-1 min-1) (P < 0.01 in each case).(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacodynamics of the 1R cis-1'R cis isomer of atracurium (51W89) in health and chronic renal failure

We have studied the pharmacodynamics of the 1R cis-1'R cis isomer of atracurium (51W89) in 15 healthy subjects and in 17 patients with chronic renal failure using a bolus dose of 51W89 0.1 mg kg-1 (2 x ED95). Fifteen patients with normal renal function were investigated also using an approximately equipotent dose of atracurium (0.4 mg kg-1). The compound surface action potential of the adductor pollicis muscle, in response to train-of-four stimulation of the ulnar nerve at the wrist, was recorded until recovery of the height of the first response of the train-of-four compared with baseline (T1:T0) had reached at least 85% and the train-of-four ratio (T4:T1) at least 80%. In the healthy and renal failure patients who received 51W89, there were no significant differences in any of the onset or recovery variables except for the time to 90% depression of T1:T0, which was longer in patients with renal failure (mean 3.7 min vs 2.4 min; P < 0.05). Of the healthy patients who were given either 51W89 or atracurium, there were no significant differences in the onset data, except for time to maximum block, which was longer in the 51W89 group (mean 7.7 min vs 6.2 min; P < 0.01). The mean times to 10%, 25%, 50% and 75% recovery of T1:T0 and the time for T4:T1 > 70% were significantly longer in patients receiving 51W89.(ABSTRACT TRUNCATED AT 250 WORDS)

Soluble complement receptor type 1 inhibits complement activation induced by hemodialysis membranes in vitro

A variety of bioincompatible events that occur during hemodialysis have been attributed to complement activation. However, cause-effect relationships have been based primarily on indirect evidence and the results of in vitro studies, because an acceptable method for inhibiting complement activation during clinical hemodialysis has been unavailable. Methods for inactivating complement in vitro are available, but the most commonly used of these techniques (heat inactivation and chelation of divalent cations) lack specificity. A recombinant, soluble form of human complement receptor type 1 (sCR1) has been developed recently and shown to inhibit complement activation in vivo. Here, we report studies aimed at determining the effects of sCR1 on dialysis-induced complement activation and neutrophil degranulation. In a concentration dependent fashion, sCR1 inhibited plasma complement activation by cuprophan membrane in vitro. Using a maximally inhibitory concentration (30 micrograms/ml), sCR1 blocked generation of C3a(desArg) by cuprophan, cellulose acetate, and polymethylmethacrylate membranes by 90%, 84%, and 84%, respectively. In contrast, elastase release (a measure of neutrophil degranulation) was inhibited by 70%, 70%, and 44%, respectively, suggesting that dialysis-induced neutrophil activation is mediated in part by noncomplement dependent mechanisms. Both heat- and EDTA-treatment of plasma abolished dialysis membrane-induced complement activation, but these treatments also affected noncomplement dependent components of the degranulation process. These observations show that, compared with other commonly used methods for inhibiting dialysis induced complement activation, sCR1 is more specific. An additional advantage of sCR1 is its potential for use in the clinical setting.

Pharmacokinetics of the three isomers of mivacurium and pharmacodynamics of the chiral mixture in hepatic cirrhosis

We have studied the pharmokinetics of cis-trans, trans-trans and cis-cis mivacurium in 10 healthy subjects and 11 patients with mild or moderate hepatic cirrhosis, during nitrous oxide-oxygen-isoflurane anaesthesia. Mivacurium 15 micrograms kg-1 min-1 was infused for 10 min (total dose 0.15 mg kg-1) and the plasma concentration of the three isomers measured at regular intervals for 190 min. The electromyographic response to the drug was also measured. Compartmental analysis of the resulting isomer profiles was undertaken: one- and two-compartment models were fitted to derive clearance, volume of distribution and half-life. Clearance of the cis-trans and trans-trans isomers was reduced significantly in the cirrhotic compared with the healthy group: cis-trans (median (range)) 44 (15-121) ml kg-1 min-1 vs 95 (57-213) ml kg-1 min-1 (P < 0.05); trans-trans 32 (12-64) ml kg-1 min-1 vs 70 (34-101) ml kg-1 min-1 (P < 0.05). The difference in the clearance of the cis-cis isomer in the cirrhotic (4.2 (2.9-12.1) ml kg-1 min-1) compared with the healthy group (5.2 (2.9-8.9) ml kg-1 min-1) was not significant with this sample size. Clearance of each isomer correlated significantly with plasma cholinesterase activity: cis-trans r = 0.73, P < 0.001; trans-trans r = 0.69, P < 0.001; cis-cis r = 0.48, P < 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)

Bioassay of procoagulant albumin in human plasma

Procoagulant albumin (P-Al) is present in normal human plasma and increases monocyte and endothelial cell expression of tissue factor activity. To develop a bioassay for P-Al, we partially purified plasma from healthy volunteers and several patient groups using BaCl2 and (NH4)2SO4 precipitation. The samples were assayed for tissue factor (TF) inducing activity, expressed as a percentage increase compared to a serum-free media control. Over six months, the assay was reproducible in stored samples and in serial samples from normal volunteers. The plasma P-Al activities of 35 volunteers averaged 141 +/- 8.2% (SEM). There was no diurnal variation. There was no difference in the P-Al activity after a 12 hour fast and 2 hours after a large meal in 4 healthy volunteers. There was no increase in activity (r = 0.16) with the subject's age. The average activity from 16 poorly-controlled diabetics was 131 +/- 11% (SEM). No alteration in activity was seen with samples from patients with uremia, liver dysfunction, hemophilia, thrombotic events, or adenocarcinoma. These results indicate that P-Al activity can be bioassayed in individual patient samples; however, pathologic states associated with abnormal P-Al-induced tissue factor activity presently remain unidentified.

Host cell components affect the sensitivity of HIV type 1 to complement-mediated virolysis

An infection-competent, full-length HIV-1 clone (pNL4-3) was expressed in seven human cell lines and in peripheral blood mononuclear cells in order to assess the contribution of host cell components toward interaction of free virus with the complement system. HIV-1 expressed in the H9 cell line, which is frequently used for in vitro infection, was relatively susceptible to complement-mediated virolysis in the presence of both HIV antibody-positive patient serum and an anti-V3 monoclonal antibody. Expression of complement receptors 1, 2, and 3, complement control proteins membrane inhibitor of reactive lysis (MIRL, CD59) and decay-accelerating factor (DAF, CD55), and HLA-DR was assessed on host cells. There was an inverse relationship between the sensitivity of virus to complement and the amount of expression of MIRL and DAF on cells. HIV derived from the JY cell line and the mutant JY33 cell line, which is deficient in expression of phosphatidylinositol (PI)-linked proteins including MIRL and DAF, were also evaluated for complement-mediated virolysis. Virus expressed in the mutant cell line was more sensitive to antibody-independent as well as antibody-dependent complement-mediated virolysis than virus expressed in the wild-type cells. Direct demonstration of the presence of MIRL and DAF on the viral surface was obtained by showing that anti-MIRL or anti-DAF antibody induced complement-mediated virolysis. These experiments show that the host cell type can substantially influence the susceptibility of HIV to complement-mediated virolysis and suggest that PI-linked complement control proteins play an important role in this resistance.

Paroxysmal nocturnal hemoglobinuria and complement-mediated erythrocyte damage

The erythrocytes of paroxysmal nocturnal hemoglobinuria are abnormally sensitive to complement-mediated lysis because they are deficient in membrane proteins that regulate the functional activity of complement. All the deficient proteins in paroxysmal nocturnal hemoglobinuria share the common structural feature of being anchored to the cell surface by a glycosyl phosphatidylinositol moiety. Recent studies showed that the first intermediate in the pathway of the glycosyl phosphatidylinositol anchor synthesis is not formed in paroxysmal nocturnal hemoglobinuria cells. This observation suggests that the molecular basis of paroxysmal nocturnal hemoglobinuria is due to an abnormality involving a gene that encodes a protein essential for the normal biosynthesis of the first intermediate. By using expression cloning, the complementary DNA (called phosphatidylinositol glycan class A [PIG-A]) that corrects the abnormality in glycosyl phosphatidylinositol-anchor synthesis in paroxysmal nocturnal hemoglobinuria cells was identified. Subsequent studies showed that the PIG-A gene is located on the X chromosome. Together, these studies provided a molecular explanation for paroxysmal nocturnal hemoglobinuria.

Memory for auditory material presented during anaesthesia

We have assessed postoperative memory for lists of 10 neutral words, presented by tape recording, in patients anaesthetized by a standardized technique comprising thiopentone 5 mg kg-1, midazolam 0.07 mg kg-1, fentanyl 3 micrograms kg-1 and 70% nitrous oxide in oxygen, using both free recall and a test in which the subject was asked to indicate the presented words from a larger list. Twenty-four patients were exposed to one of four tape-recorded lists of words and 24 were presented with a blank tape. There was no instance of free recall of presented words. Analysis of the responses in the implicit memory test revealed no difference between the performance of the patients who had been exposed to a word list and those who had not.

CD11b/CD18 integrin and a beta-glucan receptor act in concert to induce the synthesis of platelet-activating factor by monocytes

We determined the mechanism by which opsonized zymosan particles, which are derived from yeast and composed of carbohydrate polymers, stimulate platelet-activating factor (PAF) synthesis by monocytes. A role for CD11b/CD18 was demonstrated because antibodies to this integrin decreased PAF synthesis, zymosan bearing only a ligand for CD11b/CD18 (iC3b) induced the synthesis of PAF, and monocytes that did not express CD11b/CD18 produced much less PAF than control monocytes. Ligation of CD11b/CD18 was not sufficient for PAF synthesis suggesting that an additional receptor was involved. Monocytes are known to bind beta-glucan which is a major component of zymosan. Opsonized beta-glucan particles stimulated the synthesis of PAF, and a soluble form of beta-glucan partially inhibited PAF synthesis in response to opsonized zymosan. Two lines of evidence suggested that the beta-glucan receptor mediating this response was distinct from CD11b/CD18. First, CD11b/CD18-deficient monocytes produced PAF when stimulated by zymosan opsonized with isolated C3b, a molecule that binds to complement receptor type 1 (CD35). Second, inducing contact of monocytes with zymosan by centrifugation resulted in PAF synthesis that was not inhibited by antibodies to CD11b/CD18. The combination of soluble beta-glucan and antibodies to CD11b/CD18 completely blocked PAF synthesis in response to opsonized zymosan. Together, these results demonstrate that induction of maximal PAF synthesis by serum-opsonized zymosan requires the concerted interactions of monocyte receptors for iC3b and beta-glucan. Additionally, they suggest that CD11b/CD18 facilitates binding of the particle and that a beta-glucan receptor transduces the activation signal.

CD11b/CD18 integrin and a beta-glucan receptor act in concert to induce the synthesis of platelet-activating factor by monocytes

We determined the mechanism by which opsonized zymosan particles, which are derived from yeast and composed of carbohydrate polymers, stimulate platelet-activating factor (PAF) synthesis by monocytes. A role for CD11b/CD18 was demonstrated because antibodies to this integrin decreased PAF synthesis, zymosan bearing only a ligand for CD11b/CD18 (iC3b) induced the synthesis of PAF, and monocytes that did not express CD11b/CD18 produced much less PAF than control monocytes. Ligation of CD11b/CD18 was not sufficient for PAF synthesis suggesting that an additional receptor was involved. Monocytes are known to bind beta-glucan which is a major component of zymosan. Opsonized beta-glucan particles stimulated the synthesis of PAF, and a soluble form of beta-glucan partially inhibited PAF synthesis in response to opsonized zymosan. Two lines of evidence suggested that the beta-glucan receptor mediating this response was distinct from CD11b/CD18. First, CD11b/CD18-deficient monocytes produced PAF when stimulated by zymosan opsonized with isolated C3b, a molecule that binds to complement receptor type 1 (CD35). Second, inducing contact of monocytes with zymosan by centrifugation resulted in PAF synthesis that was not inhibited by antibodies to CD11b/CD18. The combination of soluble beta-glucan and antibodies to CD11b/CD18 completely blocked PAF synthesis in response to opsonized zymosan. Together, these results demonstrate that induction of maximal PAF synthesis by serum-opsonized zymosan requires the concerted interactions of monocyte receptors for iC3b and beta-glucan. Additionally, they suggest that CD11b/CD18 facilitates binding of the particle and that a beta-glucan receptor transduces the activation signal.

4-Hydroxytamoxifen, an active metabolite of tamoxifen, does not alter the radiation sensitivity of MCF-7 breast carcinoma cells irradiated in vitro

The effect of 4-hydroxytamoxifen (4OH-TAM), the potent anti-estrogenic metabolite of tamoxifen, on the radiosensitivity of MCF-7 cells irradiated in vitro was determined. Radiation dose response curves were generated for MCF-7 cells maintained and irradiated in phenol red-free medium containing 10(-10) M estradiol (E2) with or without 10(-7) M 4OH-TAM. Immediately after irradiation cells were transferred to medium containing 10(-10) ME2 supplemented with bovine serum to stimulate colony formation. Estradiol-stimulated cell proliferation was inhibited by 10(-7) M 4OH-TAM, but radiation sensitivity was not significantly altered (p > 0.3). Continued incubation in the absence of E2 for an additional 24 hours after irradiation likewise failed to alter the radiosensitivity of 4OH-TAM-treated MCF-7 cells. These studies indicate that growth-inhibitory concentrations of the anti-estrogen 4OH-TAM do not modify the in vitro radiation sensitivity of this line of human breast carcinoma cells.

Aberrant regulation of complement by the erythrocytes of hereditary erythroblastic multinuclearity with a positive acidified serum lysis test (HEMPAS)

Susceptibility to hemolysis in acidified serum is a pathognomonic feature of hereditary erythroblastic multinuclearity with a positive acidified serum lysis test (HEMPAS, congenital dyserythropoietic anemia type II). The purpose of the studies reported herein was to determine if aberrant regulation of complement contributes to the susceptibility of HEMPAS erythrocytes to acidified serum lysis. The results of these experiments have demonstrated that regulation of both the C3 convertase of the alternative pathway and the membrane attack complex of complement by HEMPAS erythrocytes is aberrant. However, these abnormalities are not a consequence of quantitative or functional deficiencies of the erythrocyte complement-regulatory proteins, decay accelerating factor (DAF, CD55), or membrane inhibitor of reactive lysis (MIRL, CD59). Our recent studies have shown that glycophorin A (GPA), the major erythrocyte sialoglycoprotein is a complement regulatory protein. Analysis by radioimmunoprecipitation suggested that GPA on HEMPAS erythrocytes is abnormally glycosylated. Further analysis indicated that the abnormality involves the O-linked oligosaccharide moiety. Together, these studies show that complement regulation by HEMPAS erythrocytes is abnormal and that constituents other than DAF and MIRL participate in controlling complement activation on the erythrocyte membrane. Additionally, these studies suggest that the glycosylation defect that is characteristic of HEMPAS involves GPA.