POS1560-HPR “MY GUT FEELING IS…”: IDENTIFYING HOW HEALTHCARE PROFESSIONALS COMMUNICATE ABOUT PAIN IN PAEDIATRIC RHEUMATOLOGY MULTI-DISCIPLINARY TEAM MEETINGS

Background

Multi-disciplinary teams (MDTs) are common in paediatric rheumatology where UK standards of care state that all children/young people should have access to a paediatric rheumatologist, nurse, physiotherapist, occupational therapist and a psychologist. MDTs in paediatric rheumatology regularly meet for the broader purpose of discussing the assessment of and future management plans for children/young people with a range of complex conditions in which chronic pain may feature. The content of these discussions has not been previously researched. Little is known about healthcare professional to healthcare professional communication and how this may influence the care of children/young people with chronic pain.

Objectives

The objective of the current study was to investigate healthcare professionals communication about children and young people with chronic musculoskeletal pain during MDT meetings in paediatric rheumatology.

Methods

This study was a non-participant ethnographic observation of virtual and face-to-face MDT meetings in three paediatric rheumatology centres in the UK. A structured observation checklist was used to capture and organise field notes which were analysed using an inductive thematic approach amongst research team members. Interpretation of field notes was guided by discussions with healthcare professionals from each of the teams involved.

Results

Forty-two healthcare professionals from across the three teams participated. Ten meetings from each team (n=30) were observed, with meetings ranging from 1-2 hours. Analysis was organised into three themes;

1)Describing the child/young person with pain: Healthcare professionals’ perceptions about personality characteristics (e.g. “He is mature”, “She is sensitive”) were frequently used to introduce a child/young person to the team. A child/young person description was always accompanied by a description of parents and perceptions about their behaviour (e.g. “Dad is very disengaged”, “Mum can shout”).

2)Interpreting the pain of the child/young person: A core component of interpretations was professional’s familiarity with the child/young person and parents (e.g., “I haven’t got a handle on them yet”). Professionals also discussed how their interpretations of pain were influenced by “gut feelings” or “vibes that something else is going on at home”.

3)

Managing the child/young person with pain: Healthcare professionals discussed the need for acceptance of pain and treatment from children/young people (e.g., “She wasn’t buying into that”; “He needs to get used to it”). Setting boundaries for children/young people and parents for accessing the team also featured in discussions (e.g., “We need to re-assure them but not always be available”).

Conclusion

This study highlights a range of healthcare professional approaches and processes to communicating about and discussing children/young people with pain at paediatric rheumatology MDT meetings. Findings suggest that healthcare professionals in paediatric rheumatology describe, interpret and manage the child/young person presenting with pain alongside the broader psychosocial (and less frequently the biological) context. These findings will inform the content and methods of a behaviour change intervention to improve pain communication in consultations with children/young people, parents and amongst the paediatric rheumatology team of healthcare professionals in the UK.

Acknowledgements

The authors would like to thank the healthcare professionals for kindly taking the time to take part in this study. The views expressed herein are those of the authors and not necessarily those of the National Health Service, the National Institute for Health Research, or the UK Department of Health. This work was supported by a Foundation Fellowship award from Versus Arthritis (Grant 22433). Aspects of this work were also supported by funding from the Centre for Epidemiology Versus Arthritis (Grant 20380) and the NIHR Manchester Biomedical Research Centre.

Disclosure of Interests

None declared

POS1501-HPR ADDRESSING THE VOCATIONAL DEVELOPMENT OF YOUNG PEOPLE WITH LONG-TERM HEALTH CONDITIONS IN HEALTH CARE SETTINGS: A SYSTEMATIC REVIEW AND MIXED METHODS SYNTHESIS

Background

Long term health conditions (LTHC) such as rheumatic conditions have significant impact on the biopsychosocial development of young people (YP) including vocational development. Educational transitions are prominent during adolescence and young adulthood yet not all transitional care programmes in rheumatology address this area [1].

Objectives

To identify and synthesise the benefits and experiences of addressing the vocational development of YP with LTHC in health care settings.

Methods

A mixed methods synthesis approach [2] was employed. We systematically searched 10 bibliographic databases. Restrictions were applied on publication date (1996-2020) and publication language (English). Articles reporting quantitative and/or qualitative primary research on addressing vocational needs/issues of YP with LTHC in health care settings were included. YP was defined as 10-24 years [3]. Two reviewers independently screened records using predetermined inclusion/exclusion criteria [4]. Quality appraisal was undertaken following study selection. Qualitative data were synthesised thematically. Quantitative data were synthesised narratively, given that a pooled synthesis was not considered appropriate. A cross-study synthesis integrated findings from both the qualitative and quantitative syntheses.

Results

43 articles were included. The quality of qualitative evidence was generally good; but the quality of quantitative evidence was generally poor. The thematic synthesis of stakeholders’ perspectives (n=23 qualitative studies) resulted in seven recommendations for interventions: provide skills training; provide psychological support; offer to liaise with key stakeholders in educational/workplace settings; provide specialist career advice; provide information, signposting and facilitate access to supporting services; provide/facilitate access to social support; provide flexible care and optimal disease management to support education/employment transitions. The narrative synthesis summarised results of 17 interventions (n=20 quantitative studies). The cross-study synthesis mapped interventions against recommendations arising from stakeholders’ perspectives: Four interventions met five recommendations; two interventions met four recommendations; five interventions met three recommendations; six interventions met two recommendations. Transitional care interventions were the type of intervention that most comprehensively met the recommendations. The way in which interventions addressed vocational issues was not always clear, with some interventions addressing them explicitly/directly (reporting vocational intervention components) and others implicitly/indirectly (reporting vocational outcomes only). Interventions where vocational issues were the core, defining component of the intervention were lacking.

Conclusion

Stakeholder evidence suggests vocational development is an important area to address in the care of YP with LTHC such as rheumatic diseases. The resulting set of recommendations provides guidance for future research in this area and transitional care developments in rheumatology. Further work in this area should address these aspects to enable better quality evidence and ensure consistency.

References

[1]Clemente D, Leon L, Foster H, Carmona L, Minden K. Transitional care for rheumatic conditions in Europe: current clinical practice and available resources. Pediatr Rheumatol Online J. 2017 Jun 9;15(1):49.

[2]Kavanagh J, Campbell F, Harden A, Thomas J. Mixed Methods Synthesis: A Worked Example, in: Hannes, K., Craig, L. (Eds.), Synthesizing Qualitative Research: Choosing the Right Approach. Wiley-Blackwell, Chichester, UK, 2012, pp. 113–136

[3]World Health Organization. The second decade: improving adolescent health and development. Geneva, 2001.

[4]Farre A, Lunt L, McDonagh JE. Addressing the vocational development of young people with chronic conditions. PROSPERO 2016 CRD42016051359.

Disclosure of Interests

None declared

Personality dimensions and drug of choice: A descriptive study using Cloninger's temperament and character inventory revised

Personality dimensions related with drug use are novelty seeking, impulsivity and harm avoidance. Studies predicting drug of choice over personality variables are controversial.

Objective

To describe personality profile of drug users in relation to substance of choice.

Aims

To know personality dimension differences according to drug used.

Methods

Cloninger's TCI-R was administered to 218 patients in a dual diagnosis unit.

SPSS was applied.

Results

Of the patients, 33.94% had personality disorder. Principal substances used were alcohol, cocaine and cannabis.

Most of drug users had normal scores in each dimension. No high scores were found in reward dependence, self-directedness and cooperativeness with any drug.

High scores were observed for novelty seeking in 42.9% of timulants users; for arm avoidance in a quarter of cocaine, alcohol and methadone users and for persistence in 18.2% of hypnotics users.

Low scores were observed for reward dependence in 45% of heroine and hypnotics users; for persistence in 50% of methadone and 32% of cocaine users; for self-directedness in most of types of drug users and for cooperativeness in up to 50% in heroine, hypnotics, stimulants and cocaine users.

Statistical significant differences were observed for cocaine use and high novelty seeking and low cooperation; for non cannabis use and high harm avoidance; for non anfetamine use and low scores in reward dependence; for opiate use and low self-directedness.

Conclusions

Most of patients had normal scores in the different dimensions.

Presence of comorbid personality disorder led us to consider the results with caution.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Descriptive study of hypothyroidism in an acute psychiatric unit in Barcelona

Introduction

Behavioural, psychological and cognitive disturbance have been associated with hypothyroidism, even it has been suggested that this symptoms may remain despite adequate replacement therapy with thyroxine.

Objective

To describe prevalence, sociodemographics and clinical features of patients with hypothyroidism in an acute psychiatric unit.

Aims

To know about the relation between hypothyroidism and psychiatric symptoms.

Methods

Data base collection of all patients admitted between 2010 and 2014 in the acute unit of our psychiatric hospital in Barcelona, was analyzed using SPSS program.

Results

In all 3.1% of the 4536 total patients had hypothyroidism. Among them, 46% were duplicate cases. Mean age was 53 ± 14.27 years. A total of 82.7% were woman. Patients having a TSH lower than 0.30 were 12%, TSH normal were 60.2%, TSH higher than 5 were 27.8%. Most frequent Levothyroxine dosage was: 75 μg (22.1%), 100 μg (19%), 25 μg (12.5%) and 125 μg (12.5%). Diagnosis more frequently associated with hypothyroidism was: Bipolar (26.5%), Schizophrenia (20%), Depression (15.1%), Unspecified psychosis (10%), Personality disorder (10%), Schizoaffective disorder (7.2%), Paranoia 4.3%.

Conclusion

Most of patients were stable of thyroid condition when had been admitted to our hospital. Hypothyroidism could be a relapse factor, even when treatment is adequate. Affective disorders are more frequently related with hypothyroidism (lithium has to be consider a confounding factor).

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Somatostatin for prevention of post-ERCP pancreatitis: a randomized, double-blind trial

BACKGROUND AND STUDY AIMS

Meta-analyses suggest that an intravenous bolus or a high dose continuous infusion of somatostatin reduces the incidence of acute pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). Clinical guidelines, however, do not recommend this prophylaxis. The aim of this randomized, double-blind clinical trial was to evaluate the effect of somatostatin on the incidence of post-ERCP pancreatitis.

PATIENTS AND METHODS

Patients undergoing ERCP at a single center were randomized to either intravenous bolus of somatostatin followed by a short (4-hour) continuous infusion, or to a similar placebo regimen. The primary outcome was post-ERCP pancreatitis, defined as abdominal pain with an amylase level at least three times higher than the upper limit of normality 24 hours after the ERCP and requiring admission for at least 2 days.

RESULTS

A total of 510 patients were enrolled (255 patients per group) and all completed follow-up. The main indications for ERCP were choledocholithiasis (62 %), and biliary malignant stricture (31 %). Post-ERCP pancreatitis occurred in 19 patients (7.5 %) in the somatostatin group and 17 patients (6.7 %) in the placebo group (relative risk [RR] 1.12, 95 % confidence interval [95 %CI] 0.59 - 2.1; P = 0.73). The number of cases of moderate or severe acute pancreatitis was similar in the somatostatin (2.4 %) and the placebo (3.5 %) groups (RR 0.67, 95 %CI 0.24 - 1.85, P = 0.43). No side effects were observed related to the use of somatostatin.

CONCLUSIONS

Administration of an intravenous bolus of somatostatin followed by a short continuous infusion does not reduce the incidence of post-ERCP pancreatitis. Clinical Trials.gov number: NCT01060826.

Timing of enteral nutrition in acute pancreatitis: meta-analysis of individuals using a single-arm of randomised trials

INTRODUCTION

In acute pancreatitis, enteral nutrition (EN) reduces the rate of complications, such as infected pancreatic necrosis, organ failure, and mortality, as compared to parenteral nutrition (PN). Starting EN within 24 h of admission might further reduce complications.

METHODS

A literature search for trials of EN in acute pancreatitis was performed. Authors of eligible trials were requested to provide the data of all patients in the EN-arm of their trials. A meta-analysis of individual patient data was performed. The cohort of patients with EN was divided into patients receiving EN within 24 h or after 24 h of admission. Multivariable logistic regression, adjusting for predicted disease severity and trial, was used to study the effect of timing of EN on a composite endpoint of infected pancreatic necrosis, organ failure, or mortality.

RESULTS

Observational data from 165 individuals from 8 randomised trials were obtained; 100 patients with EN within 24 h and 65 patients with EN after 24 h of admission. In the multivariable model, EN started within 24 h of admission compared to EN started after 24 h of admission, reduced the composite endpoint from 45% to 19% (adjusted odds ratio [OR] of 0.44; 95% confidence interval [CI] 0.20-0.96). Within the composite endpoint, organ failure was reduced from 42% to 16% (adjusted OR 0.42; 95% CI 0.19-0.94).

CONCLUSIONS

In this meta-analysis of observational data from individuals with acute pancreatitis, starting EN within 24 h after hospital admission, compared with after 24 h, was associated with a reduction in complications.

Common CFTR haplotypes and susceptibility to chronic pancreatitis and congenital bilateral absence of the vas deferens

CFTR mutations enhance susceptibility for idiopathic chronic pancreatitis (ICP) and congenital bilateral absence of the vas deferens (CBAVD); however, it is unknown why CFTR heterozygotes are at increased disease risk. We recently showed that common CFTR variants are associated with aberrantly spliced transcripts. Here, we genotyped for common CFTR variants and tested for associations in two ICP (ICP-A: 126 patients, 319 controls; ICP-B: 666 patients, 1,181 controls) and a CBAVD population (305 patients, 319 controls). Haplotype H10 (TG11-T7-470V) conferred protection (ICP-A: OR 0.19, P<0.0001; ICP-B: OR 0.78, P = 0.06; CBAVD OR 0.08, P<0.001), whereas haplotype H3 (TG10-T7-470M) increased disease risk (ICP-A: OR 8.34, P = 0.003; ICP-B: OR 1.88, P = 0.007; CBAVD: OR 5.67, P = 0.01). The risk of heterozygous CFTR mutations carriers for ICP (OR 2.44, P<0.001) and CBAVD (OR 14.73, P<0.001) was fully abrogated by the H10/H10 genotype. Similarly, ICP risk of heterozygous p.Asn34Ser SPINK1 mutation carriers (OR 10.34, P<0.001) was compensated by H10/H10. Thus, common CFTR haplotypes modulate ICP and CBAVD susceptibility alone and in heterozygous CFTR and p.Asn34Ser mutation carriers. Determination of these haplotypes helps to stratify carriers into high- and low-risk subjects, providing helpful information for genetic counseling.

Alloreaction increases or restores CD40, CD54, and/or HLA molecule expression in acute myelogenous leukemia blasts, through secretion of inflammatory cytokines: dominant role for TNFβ, in concert with IFNγ

We have previously reported that alloreaction can lead to activation of dendritic cells through secretion of inflammatory cytokines. Here, we addressed whether alloreaction-derived cytokines may also lead to acute myelogenous leukemia (AML) blast differentiation. With this aim, supernatant (sn) harvested from major or minor histocompatibility antigen-mismatched mixed lymphocyte reaction (MLR) were used to culture French American Bristish (FAB) type M4 or M5 AML blasts. Our results showed that the secreted factors induced upregulation of CD40, CD54, and/or HLA molecules in AML blasts. Protein fractionation, blockade experiments and exogenous cytokine reconstitution demonstrated the involvement of TNF in the upregulation of CD54, CD40 and HLA-class II molecules, and of IFNgamma in the increase of HLA-class I and class II molecule expression. But, in line of its much higher levels of secretion, TNFbeta, rather than TNFalpha, was likely to play a preponderant role in AML blast differentiation. Moreover TNFbeta and IFNgamma were also likely to be involved in the AML blast differentiation-mediated by HLA-identical donor T-cell alloresponse against recipient AML blasts. In conclusion, we show herein that upon allogeneic reaction, TNFbeta secretion contributes, in concert with IFNgamma, to increase or restore surface molecules involved in AML blast interaction with T cells.

Antibodies to carbonic anhydrase and IgG4 levels in idiopathic chronic pancreatitis: relevance for diagnosis of autoimmune pancreatitis

BACKGROUND

Increased serum antibodies against carbonic anhydrase II (CA-II Ab) or IgG4 levels have been reported in cases of autoimmune chronic pancreatitis (ACP).

AIM

To assess the relevance of serum CA-II Ab and IgG4 levels for the diagnosis of ACP in idiopathic CP (ICP) versus alcoholic CP and Sjogren's syndrome (SS).

SUBJECTS

This was a multicentre study involving 227 subjects divided into four groups: ICP (n = 54), normal controls (n = 54, paired by age and sex with ICP patients), alcoholic CP (n = 86), and SS (n = 33).

METHODS

CA-II Ab was measured by ELISA and confirmed by western blotting. A score of easy clinical use with major clinical, morphological, and biochemical parameters for the diagnosis of ACP was applied.

RESULTS

The percentage of patients with increased serum CA-II Ab was higher in the ICP group (28%) than in controls (1.9%) and in patients with alcoholic CP (10.5%), but lower than in patients with SS (64%). The proportion with elevated IgG4 levels was higher in the ICP group (15%) compared with controls (1.9%) and SS (0%) but not significantly different from alcoholic CP (8%). Most ICP patients (7/8) with high IgG4 levels exhibited increased CA-II Ab and a compatible ACP score. A definitive diagnosis of ACP by histological analysis was associated with other autoimmune disorders, an increase in both serum IgG4 and CA-II Ab levels, and IgG4 positive plasma cells.

CONCLUSIONS

The increase in serum IgG4 levels was strongly associated with elevated CA-II Ab levels, manifestations compatible with ACP, and lymphoplasmacytic infiltration when surgical specimens were available.

Human mesenchymal stem cells suppress induction of cytotoxic response to alloantigens

Mesenchymal stem cells (MSC) fail to induce allogeneic responses in mixed lymphocyte reaction assays. Because MSC express HLA class I molecules, here we investigated whether they could be recognized as allogeneic targets by cytolytic T lymphocytes (CTL). With this aim, CTL precursor (CTLp) frequencies were measured following stimulation of T cells with either allogeneic mononuclear cells (MNC) or MSC originated from the same human bone marrow donor. Lysis of MSC was measured at day 10 of culture in standard chromium release assays. In addition, allogeneic PHA blast T cells or B-EBV lymphoblastoid cell lines (LCLs) generated from the same donor were used as positive controls of lysis. Our results showed that when allogeneic MNC were used to stimulate T cells, a high CTLp frequency was detected towards MSC targets. However, when MSC were used as stimulators, CTLp frequencies were markedly altered whatever the targets used, i.e.: MSC, PHA blast T cells or EBV-B LCLs. Moreover, when graded concentrations of MSC were added together with MNC upon stimulation of alloreactive T cells, we observed a dose-dependent decrease in CTLp frequencies towards MSC targets. This inhibition of MSC lysis was partially overcome by adding exogenous rh-IL-2 from the beginning of cultures. In addition, this suppressive effect was totally reproduced when, instead of MSC, supernatant harvested from MSC cultures was added to allogeneic MNC, upon stimulation of alloreactive T cells. In conclusion, our results demonstrate that MSC which can be recognized as targets by pre-activated alloreactive CTLs, may be able to suppress differentiation of CTL precursors into CTL effectors through secretion of suppressive factors.

Cyclosporin A inhibits dendritic cell maturation promoted by TNF-alpha or LPS but not by double-stranded RNA or CD40L

Here, we investigated the influence of cyclosporin A (CsA) on dendritic cell (DC) generation. With this aim, human DC were propagated from monocytes in serum-free medium with granulocyte macrophage-colony stimulating factor and interleukin-4. DC were then exposed to tumor necrosis factor alpha (TNF-alpha) for maturation. Our results show that CsA does not impair commitment of monocytes into DC, as assessed by loss of CD14 and increase of CD40 and CD1a. However, TNF-alpha-induced DC maturation was affected, as CsA-treated DC expressed lower levels of human leukocyte antigen and costimulatory molecules but sustained levels of CD1a, and less DC expressed DC-lysosomal-associated-membrane-protein (LAMP) and CD83. Accordingly, CsA inhibited the allostimulatory and accessory cell functions of DC. Surprisingly, when other maturation stimuli were used, we observed that CsA significantly inhibited maturation induced by lipopolysaccharides but not by polyribocytidylic acid or CD40 ligand, as assessed by DC phenotype and functions. Therefore, our results indicate that CsA may differentially affect DC maturation.

Generation of helper and cytotoxic CD4+T cell clones specific for the minor histocompatibility antigen H-Y, after in vitro priming of human T cells by HLA-identical monocyte-derived dendritic cells

BACKGROUND

There is now convincing evidence that minor histocompatibility antigens (mHag) may play a significant role in the pathogenesis of graft-versus-host disease after HLA-identical bone marrow transplantation. Indeed, in this clinical situation, T cells specific for mHag have been isolated. Here, we addressed whether one can generate mHag-specific T cells in vitro, without any in vivo immunization, among healthy blood donors.

METHODS

We used monocyte-derived dendritic cells (Mo-DCs) as antigen presenting cells to induce primary responses between healthy HLA-identical siblings, in mixed lymphocyte dendritic cell reactions (MLDCRs).

RESULTS

We show that CD4+ T-cell clones, specific for the mHag H-Y, can be generated in vitro. These clones were derived from a gender-mismatched positive MLDCR pair of HLA-identical siblings and were restricted by the HLA DQB1*0502 molecule. In addition, these CD4+ T clones were also able to lyse allogeneic targets with the same pattern of restriction and specificity than helper function. Finally, acute myeloid leukemia (AML) blast cells were susceptible to lysis by these clones.

CONCLUSIONS

Altogether, these results predict that Mo-DCs could help to generate class II-associated, mHag-specific, T-cell lines or clones in vitro, between healthy blood donors, without any need of transplantation-mediated immunization.

Bombesin inhibits growth of pancreatic ductal adenocarcinoma (H2T) in nude mice

Bombesin (BBS), a tetradecapeptide, stimulates growth of various types of cells, including fibroblasts and human small cell lung cancer, and has been termed the universal "on-switch" due to its ability to stimulate the release of numerous hormones. In addition, BBS receptors have been identified in normal and neoplastic pancreatic tissue. A pancreatic ductal adenocarcinoma cell line (H2T), established in our laboratory, possesses specific binding sites for BBS. The purpose of this study was to examine the effect of BBS on the growth of H2T tumors transplanted into athymic nude mice. H2T cells (5 x 10(6) cells/mouse) were injected s.c. into the interscapular region of the nude mice and then the mice were randomized into two groups (n = 10/group). Mice received either 0.1 ml of saline with 0.1% bovine serum albumin (BSA) (control) or 0.1 ml BBS (5 micrograms/kg) intraperitoneally, three times/day. Tumor area was measured twice weekly until the mice were killed (day 32), when tumor and normal pancreas were removed, weighted, and assayed for DNA and protein content. Administration of BBS significantly inhibited H2T tumor area, weight, and DNA and protein content. Conversely, growth of normal pancreas, removed as an in vivo bioassay so as to ensure the efficacy of BBS, was stimulated. We conclude that BBS is a growth inhibitory factor for H2T tumors and that different mechanisms may be responsible for the differential growth effects elicited by normal and neoplastic pancreas in response to BBS.

Bombesin stimulates growth of colon cancer in mice and decreases their survival

Bombesin (BBS) stimulates cellular proliferation of both normal and transformed cells. The mouse colon cancer cells (MC-26) possess specific binding sites for BBS. The purpose of this study, therefore, was to examine the effect of chronic administration of BBS on in vivo growth of MC-26 tumours in Balb/c mice and on survival of tumour-bearing mice. Three groups of mice (n = 10 each) inoculated with MC-26 cells received either saline containing 0.1% bovine serum albumin (BSA), or BBS (5 micrograms kg-1 or 20 micrograms kg-1) dissolved with 0.1% BSA saline by intraperitoneal route three times a day for 15 days. BBS increased weight, DNA and RNA contents of MC-26 tumours. To examine the effect of BBS on survival rates of mice with MC-26 tumours, three groups of mice (n = 20 each) were treated for 31 days, as above. One group of mice inoculated with MC-26 cells received 0.1% BSA saline; the other group of MC-26-inoculated mice and the control group without tumour received BBS (5 micrograms kg-1) dissolved with 0.1% BSA saline. BBS significantly decreased the survival rate of mice bearing MC-26 tumours (median survival; saline group: 42.5 days, BBS group: 32.0 days, P = 0.037). None of the mice in the control group died during the experiment. BBS may stimulate in vivo growth of MC-26 cells through specific receptors.

Amiloride inhibits the growth of human colon cancer cells in vitro

Cytoplasmic alkalinization induced by activation of the Na+/H+ antiport plays an essential role in the initiation of cell proliferation. In the present study we examined the effects of amiloride, a specific and reversible inhibitor of Na+/H+ antiporter, on the growth of human colon cancer cells (HT-29). Amiloride (50-800 microM) inhibited the growth of HT-29 cells in a dose-dependent fashion. Forty-three percent inhibition of growth was found at an amiloride concentration of 400 microM after 4 days of treatment. The inhibitory effect of amiloride on growth of HT-29 cells was reversible since removal of amiloride by a media change after 48 h treatment lead to rapid regrowth to control levels. The reversibility of growth inhibition suggests that amiloride is not a non-specific cytotoxin for HT-29 cells. We examined the possible mechanisms for the inhibitory effects of amiloride. Amiloride (400 microM) completely abolished serum-stimulated ODC activity and inhibited difluoromethylornithine (DMFO)-stimulated putrescine uptake by 56%. We conclude that amiloride inhibits the in vitro growth of human colon cancer cells; since ODC-activity and polyamine transport were both inhibited, the inhibitory effects may be mediated in part by polyamine-dependent processes. Amiloride may be a useful agent in the treatment of colon cancer.

HLA-DRw11, DQw7 has four cellular subtypes revealed by homozygous typing cells and undetected by restriction fragment length polymorphism

HLA-DRw11 is in strong linkage disequilibrium with DQw7. We have investigated the heterogeneity of DRw11, DQw7 by cellular typing and by HLA cDNA probes. The results obtained by local and other homozygous typing cells in four informative Caucasoid families and 20 genotyped individuals demonstrate the existence of at least four different cellular subtypes. The frequency of DRw11, DQw7 is 25.7% with the following distribution of subtypes: Dw5 (17.3%), JAC (4.2%), JVM (2.8%), TIS (0.7%), and blank (0.7%). JVM (10W 9039) has been previously described; TIS (10W 9042) and JAC are postulated new specificities from our laboratory. None of these subtypes typed for DRw11, DQw1 cells. The cellular heterogeneity contrasts with the absence of polymorphism observed by serology and by restriction fragment length polymorphism after hybridization with DRB, DQA, and DQB probes. Variation in amino acids of the DRB1 chain has been reported for at least three variants: Dw5, JVM, and TIS (more recently).

Diversity among DRw13 DQw7 haplotypes as revealed by serology Dw typing and restriction fragment length polymorphism

HLA-DRw13 is in linkage disequilibrium with DQw6; an unusual association, DRw13 DQw7, is found in 2% of our Caucasoid population. Investigation of genotyped individuals and of families by two allosera and by Dw typing revealed two subtypes: one recognized by homozygous typing cell HAG and by two allosera, the other subtype remained unreactive with both reagents. Analysis of DNA fragments with DNA probes indicated that the HAG-negative subset had DNA fragments in common with DRw6 while the HAG-positive subset shared DNA fragments with DR5. However, all DRw13 DQw7 cells are Dw24 as seen by hybridization with DRB probe.

Cellular and serological subtypes of HLA-DR2

HLA-DR2 and its subtypes were investigated in informative families and unrelated Caucasoid individuals. Serological and cellular typing indicate that DR2 can be divided into DR2 long and DR2 short (sh), each of which can be further subdivided either by HLA-D typing or primed lymphocyte reagents. DR2 long includes Dw2, Dw12 and a new subtype temporarily called D-GEN. The cellular equivalent of DR2sh was recognized by mixed lymphocyte culture (MLC) practised in a family (family FJO); the typing cell individualized was termed FJO. The reactivity of this cell is compared with similar DR2sh varieties described in other laboratories: MN2 (Bach, Minneapolis), AZH (Brautbar, Jerusalem), DB9 (Layrisse, Caracas). The distinction between FJO, MN2 and AZH is not clear, suggesting the existence of shared epitopes; DB9 cells gave typing responses only in family FJO but typed no one else in our panel. Primed cellular reagents FJO anti Dw2 and Dw2 anti FJO when tested against DR2 subtypes support the distinction between DR2 long and DR2sh. The use of these subgroups of DR2 in functional studies, the biochemical analysis of their class II molecules, the pattern of their DNA recombinant fragments and the correlation established with some diseases will be discussed, since they further contribute to the cleavage between DR2 subtypes.

A division of HLA-DQw1 associated with DR1, DR1x-DQw1, DR2 short, DRw10, and DRw14. I. Definition by alloantiserum LY 1327

We have identified an alloantiserum, LY 1327, directed against part of DQw1-positive cells. This split of DQw1 includes DR1, DR1x, DR2sh, DRw10, and DRw14; the other DQ-associated specificities, -DR2 long and DRw13, are unreactive. Segregation was ascertained in 11 informative Caucasoid families and in 33 genotyped individuals. DR1x refers to a specificity typing as DR blank DQw1, detected by certain anti-DR1 sera and recognized cellularly by HTC DwBON DR blank DQw1 (A. Cambon, Toulouse). Biochemical analysis by two-dimensional gel electrophoresis and DNA analysis by restriction fragment length polymorphism will be discussed since they support the existence of this division of DQw1.

A possible new HLA-DR allele

In routine screening of anti-HLA DR reagents, serum 901 was obtained from a woman of negroid origin ten days after delivery of a second child. The spouse was also of black origin. This serum contained polyspecific HLA A and B antibodies. After platelet absorption it reacted with the B cells of 10 out of 119 European Caucasoid panel donors (8.4%) typed for DR1 to DRW10 and for MT1, MT2. Each of these ten donors had only one recognized DR antigen, the other was "blank." Serum 901 gave negative reactions with the homozygous typing cells (HTC) DW1 to DW8. In 18 normal informative Caucasoid families, serum 901 recognized one HLA haplotype in one (or both) parents and segregated with this haplotype in one or more than one child. In one family in which both parents reacted with serum 901, two children were homozygous for this marker and reacted as HTCs. One of these HTCs typed as DW9 and was found to be identical to a DW9.HTC (8W207).