Membrane transporters in cell physiology, cancer metabolism and drug response

By controlling the passage of small molecules across lipid bilayers, membrane transporters influence not only the uptake and efflux of nutrients, but also the metabolic state of the cell. With more than 450 members, the Solute Carriers (SLCs) are the largest transporter super-family, clustering into families with different substrate specificities and regulatory properties. Cells of different types are, therefore, able to tailor their transporter expression signatures depending on their metabolic requirements, and the physiological importance of these proteins is illustrated by their mis-regulation in a number of disease states. In cancer, transporter expression is heterogeneous, and the SLC family has been shown to facilitate the accumulation of biomass, influence redox homeostasis, and also mediate metabolic crosstalk with other cell types within the tumour microenvironment. This Review explores the roles of membrane transporters in physiological and malignant settings, and how these roles can affect drug response, through either indirect modulation of sensitivity or the direct transport of small-molecule therapeutic compounds into cells.

Group vs traditional prenatal care for improving racial equity in preterm birth and low birthweight: the Centering and Racial Disparities randomized clinical trial study

BACKGROUND

The United States has persistently high rates of preterm birth and low birthweight and is characterized by significant racial disparities in these rates. Innovative group prenatal care models, such as CenteringPregnancy, have been proposed as a potential approach to improve the rates of preterm birth and low birthweight and to reduce disparities in these pregnancy outcomes.

OBJECTIVE

This study aimed to test whether participation in group prenatal care would reduce the rates of preterm birth and low birthweight compared with individual prenatal care and whether group prenatal care would reduce the racial disparity in these rates between Black and White patients.

STUDY DESIGN

This was a randomized controlled trial among medically low-risk pregnant patients at a single study site. Eligible patients were stratified by self-identified race and ethnicity and randomly allocated 1:1 between group and individual prenatal care. The primary outcomes were preterm birth at <37 weeks of gestation and low birthweight of <2500 g. The primary analysis was performed according to the intent-to-treat principle. The secondary analyses were performed according to the as-treated principle using modified intent-to-treat and per-compliance approaches. The analysis of effect modification by race and ethnicity was planned.

RESULTS

A total of 2350 participants were enrolled, with 1176 assigned to group prenatal care and 1174 assigned to individual prenatal care. The study population included 952 Black (40.5%), 502 Hispanic (21.4%), 863 White (36.8%), and 31 "other races or ethnicity" (1.3%) participants. Group prenatal care did not reduce the rate of preterm birth (10.4% vs 8.7%; odds ratio, 1.22; 95% confidence interval, 0.92-1.63; P=.17) or low birthweight (9.6% vs 8.9%; odds ratio, 1.08; 95% confidence interval, 0.80-1.45; P=.62) compared with individual prenatal care. In subgroup analysis, greater attendance in prenatal care was associated with lower rates of preterm birth and low birthweight. This effect was most noticeable for the rates of low birthweight for Black participants in group care: intent to treat (51/409 [12.5%]), modified intent to treat (36/313 [11.5%]), and per compliance (20/240 [8.3%]). Although the rates of low birthweight were significantly higher for Black participants than White participants seen in individual care (adjusted odds ratio, 2.00; 95% confidence interval, 1.14-3.50), the difference was not significant for Black participants in group care compared with their White counterparts (adjusted odds ratio, 1.58; 95% confidence interval, 0.74-3.34).

CONCLUSION

There was no difference in the overall rates of preterm birth or low birthweight between group and individual prenatal care. With increased participation in group prenatal care, lower rates of preterm birth and low birthweight for Black participants were observed. The role of group care models in reducing racial disparities in these birth outcomes requires further study.

Healthcare utilisation and unmet health needs in children with intellectual disability: a propensity score matching approach using longitudinal cohort data

BACKGROUND

Health disparities for children with intellectual disabilities can be challenging to measure due to many other factors that can impact health and healthcare use. The aim of the current study was to use longitudinal cohort data to compare children with intellectual disability (ID) in Ireland between 2006 and 2014 on healthcare utilisation and unmet need, at ages 9 and 13, using a propensity score matching (PSM) approach.

METHODS

Using data from the Growing up in Ireland study, PSM was used to identify an appropriate control sample to compare with a sample of children with ID (n = 124). Participants were matched on variables that are known to influence healthcare utilisation to reduce the impact of confounding variables between groups so that differences between the groups can be estimated. Logistic regression was used to estimate effects at ages 9 and 13.

RESULTS

Children with ID were no more likely to have visited a general practitioner or emergency department in the past 12 months than children without ID. They did have a greater likelihood of visiting a doctor in a hospital in the past 12 months and of having an overnight stay in hospital by age 9. Primary caregivers of children with ID were more likely to report unmet health needs at ages 9 and 13.

CONCLUSIONS

This approach is a novel means of comparing healthcare use in this population by balancing the impact of other factors that may result in inequities, to which children with ID may be more vulnerable.

Enhancing clinician participation in quality improvement training: implementation and impact of an evidence-based initiative to maximise antenatal clinician participation in training regarding women’s alcohol consumption during pregnancy

Background

There are significant challenges in ensuring sufficient clinician participation in quality improvement training. Clinician capability has been identified as a barrier to the delivery of evidence-based care. Clinician training is an effective strategy to address this barrier, however, there are significant challenges in ensuring adequate clinician participation in training. This study aimed to assess the extent of participation by antenatal clinicians in evidence-based training to address alcohol consumption during pregnancy, and to assess differences in participation by profession.

Methods

A 7-month training initiative based on six evidence-based principles was implemented in a maternity service in New South Wales, Australia. Descriptive statistics described participation in training (% attending: any training; six evidence-based principles of training; all principles). Regression analyses examined differences by profession.

Results

Almost all antenatal clinicians participated in some training (182/186; 98%); 69% participated in ≥1 h of training (μ = 88.2mins, SD:56.56). The proportion of clinicians participating in training that satisfied each of the six principles ranged from 35% (training from peers and experts) to 82% (training was educational and instructional). Only 7% participated in training that satisfied all principles. A significantly higher proportion of midwifery compared to medical clinicians participated in training satisfying five of the six training principles.

Conclusions

A training initiative based on evidence-based principles resulted in almost all clinicians receiving some training and 69% participating in at least 1 h of training. Variability between professions suggests training needs to be tailored to such groups. Further research is required to determine possible associations with care delivery outcomes.

Trial registration

Australian and New Zealand Clinical Trials Registry, No. ACTRN12617000882325 (date registered: 16/06/2017).

The preferences of young adults with Type 1 diabetes at clinics using a discrete choice experiment approach: the D1 Now Study

AIM

Attending routine outpatient clinic appointments is a central self-management behaviour of individuals living with Type 1 diabetes. A large number of young adults with Type 1 diabetes disengage from diabetes services, which may contribute to poor psychosocial and diabetes outcomes. The aim of this study is to elicit preferences from young adults with Type 1 diabetes regarding clinic-related services to inform service delivery.

METHODS

A discrete choice experiment was developed to understand the preferences of young adults with Type 1 diabetes for clinic-related services.

RESULTS

Young adults recruited from young adult Type 1 diabetes clinics in 2016 completed the experiment (n = 105). Young adults with Type 1 diabetes showed a preference for shorter waiting times, seeing a nurse and a consultant, relative to a nurse alone, and a flexible booking system compared with fixed appointment times. Results suggest no preference for a nurse and a doctor, relative to a nurse alone, or other optional services (e.g. seeing dietitians or psychologists), type of HbA_1c test and digital blood glucose diaries over paper-based diaries.

CONCLUSION

This study highlights aspects of routine clinic appointments that are valued by young adults living with Type 1 diabetes, namely shorter waiting times at clinic, the option to see both a nurse and consultant at each visit and a flexible clinic appointment booking system. These findings suggest young adults with Type 1 diabetes value convenience and should help services to restructure their clinics to be more responsive to the needs of young adults.

Healthcare utilisation among cancer survivors over 50 years of age

There are now over 104,000 people living in Ireland with a cancer diagnosis. Using The Irish Longitudinal Study on Ageing (TILDA), healthcare utilisation of cancer survivors (aged 50 +) was compared with those without a history of cancer across service providers. Our cancer variable was stratified by time since diagnosis (2-5, 6-10, 11+ years) and type (breast, prostate, colorectal and a miscellaneous group of other cancers). While the probability of cancer survivors accessing GP services was not significant different to respondents without a history of cancer, the probability of an outpatient specialist office visit was 19.5, 11.8 and 14.0 percentage points higher, respectively for those 2-5years, 6-10 years and 11 years or more after their cancer diagnosis and was statistically significant. In Ireland, the pattern of GP and specialist use appears less well defined compared to other European countries. This suggests an overarching policy response is required for cancer survivorship care.

Estimating the health-care usage associated with osteoarthritis and rheumatoid arthritis in an older adult population in Ireland

BACKGROUND

An ageing population leads to increasing prevalence of age-related chronic conditions that present challenges to the health-care services. Despite this, in countries including Ireland, little is known about the health-care impact of conditions such as osteoarthritis or rheumatoid arthritis amongst older adults.

METHODS

A series of count models are developed to investigate the incremental health-care usage of individuals with either osteoarthritis or rheumatoid arthritis on the use of general practitioners (GP) services, outpatients' services, accident and emergency visits and inpatient nights.

RESULTS

Both types of arthritic conditions lead to increased usage of GP and outpatients' services but not other hospital services. Differences in entitlements to care, as captured by the presence of a medical card in Ireland, lead to different health-care usage among arthritis sufferers. Translating the additional utilization into cost suggests a combined incremental annual cost of both types of arthritis of €13.6 million.

CONCLUSIONS

Osteoarthritis and rheumatoid arthritis present challenges to health-care services in the context of an ageing population. In the case of Ireland the burden falls predominantly on primary health-care and outpatient services. Within the context of changing health-care service provision in Ireland, the results of this study have implications for future planning of service delivery.

Coping with stress in surgery: the difficulty of measuring non-technical skills

BACKGROUND

Non-technical skills are relevant to surgical performance but are difficult to quantify. The aim of this study was to investigate the relationship between self-efficacy, which is a measure of stress-coping ability, and surgical performance.

METHODS

Two hundred and sixteen basic surgical trainees were assessed on their performance of three bench model-type open and laparoscopic surgical tasks. They also completed a 10-item General Self-Efficacy (GSE) questionnaire to assess their stress-coping abilities. Their assessment scores were correlated with the GSE scores.

RESULTS

The mean GSE score of 31.39 was higher than the recorded population norms. There was no significant correlation between GSE and surgical performance for open or laparoscopic tasks.

CONCLUSION

Junior surgical trainees have high self-belief scores, but these abilities are difficult to measure and quantify. More refined methods may be necessary to measure non-technical skills relevant to surgery.

13q33.2 deletion: a rare cause of ambiguous genitalia in a male newborn with growth restriction

13q deletion is a rare cause of ambiguous genitalia in the male newborn, and can be associated with mental retardation of varying degree, retinoblastoma, and malformations of the brain, eye, genitourinary and gastrointestinal tract, depending on the level of the deletion. We present a male neonate with ambiguous genitalia and IUGR with a 13q33.2 deletion, and a paternal balanced translocation. Microarray analysis found the genes involved to be on chromosome 13 in the region 102989254bp-109214509bp. This deletion encompasses the EFNB2 gene, which has been implicated in genital malformations in 13q deletion cases.

CONCLUSIONS

We find a link between haploinsufficiency of the EFNB2 gene and the presence of ambiguous genitalia and hypospadia in patients with a 13q.33 deletion. This work emphasizes the importance of early diagnosis of this condition due to the link with mental retardation and the need for follow up and management.

Advances in understanding illness anxiety

Illness anxiety, also known in its more severe form as hypochondriasis, is a debilitating and chronic condition in which normal bodily symptoms are misinterpreted as signs of serious medical illness. Patients suffer with the fear that they are ill despite reassurance to the contrary and often overuse medical services in the process. This article critically evaluates the recent literature on illness anxiety and related, medically unexplained symptoms, highlighting new and interesting findings in the areas of prevalence, classification/diagnosis, management, and evidence-based treatment and new frontiers in understanding illness anxiety, such as brain imaging, neuroimmunology, and cyberchondria.

Termination of pregnancy in South Tyneside

We evaluated prospectively, compliance with the Royal College of Obstetricians and Gynaecologists (RCOG) guidelines on termination of pregnancy (TOP) in a cohort of 340 women referred for termination of pregnancy in 2003 at South Tyneside Foundation Trust. The number of referrals represented one-fifth of all births in our unit during the study period. Teenagers were the largest single group of women requesting termination of pregnancy and the majority were nulliparous. There were 85 women who were seeking a repeat termination of pregnancy. The RCOG minimum referral standard was met in 80% of cases. A good number of women were unsure of their menstrual dates and only 5% had used emergency contraception. A total of 96% were either not using contraception, using condoms or taking oral contraceptives irregularly. A total of 50% of the women attended hospital without a Certificate A being completed by the referring practitioner. Surgical termination was preferred over medical termination in the cohort of women who could exercise a choice. It is possible to comply with the RCOG Termination of Pregnancy guidelines to a large extent in a District General Hospital, with some innovation. Close liaison between General Practitioners, Family Planning Clinics and Acute Hospitals is required. The adoption of agreed referral requirements and pathways would help in the delivery of a high quality service as advocated by the guideline.

Ezetimibe-induced hyperlipidaemia

Ezetimibe is intestinally active cholesterol absorption inhibitor used to reduce low-density lipoprotein-cholesterol levels. This case report describes a novel side effect with this agent: ezetimibe-induced hyperlipidaemia in a patient with statin intolerance and familial combined hyperlipidaemia. Ezetimibe therapy induced an asymptomatic 770% increase in triglycerides (TGs) (3.51-27.1 mmol/l) and a 190% increase in total cholesterol (9.8-18.5 mmol/ 1) secondary to an increase (4.6-25.9 micromol/l; 560%) in hepatic cholesterol (lathosterol) synthesis. This lipid profile resolved 9 months after cessation of ezetimibe therapy. This report shows that ezetimibe may have long-lasting effects in man far exceeding its plasma half-life and that ezetimibe monotherapy can induce a large increase in hepatocyte very-low-density lipoprotein synthesis in rare individuals with a consequent mixed hyperlipidaemia or possibly hypercholesterolaemia depending on the metabolism and clearance of TG-rich lipoproteins.

Pancreatic stellate cell activation by ethanol and acetaldehyde: is it mediated by the mitogen-activated protein kinase signaling pathway?

BACKGROUND

Pancreatic fibrosis is a characteristic feature of alcoholic chronic pancreatitis. Recent studies suggest that activated pancreatic stellate cells (PSCs) are the major cell-type involved in pancreatic fibrogenesis. Cultured PSCs become activated when exposed to ethanol or its metabolite acetaldehyde (as indicated by increased alpha-smooth muscle actin [alpha-SMA] expression and increased collagen synthesis). However the intracellular signaling mechanisms responsible for ethanol- or acetaldehyde-induced PSC activation remain to be fully elucidated. One of the major signaling pathways known to regulate protein synthesis in mammalian cells is the mitogen-activated protein kinase (MARK) pathway.

AIMS

To examine the effects of ethanol and acetaldehyde on the MAPK pathway (by assessing the activities of the 3 major subfamilies (extracellular-regulated kinases 1 and 2 [ERK 1/2], JNK and p38 kinase) in PSCs and to examine the role of p38 kinase in mediating the ethanol- and acetaldehyde-induced increase in alpha-SMA expression in activated rat PSCs.

METHODS

Rat PSCs were incubated with ethanol (50 mM) or acetaldehyde (200 microM) for 15 min, 30 min, 60 min, and 24 h; and activities of ERK 1/2, JNK, and p38 kinase were assessed in cell lysates using kinase assays and Western blot. In addition, rat PSCs were treated with the specific p38 MAPK inhibitor SB203580 in the presence or absence of ethanol or acetaldehyde for 24h, and activation of the downstream protein kinase MAPKAP kinase-2 (an indicator of p38 MAPK activity) was assessed by Western blot. Specific inhibitors were also used to inhibit the activity of ERK 1/2 and JNK. Following inhibition of the above signaling pathways, alpha-SMA expression by PSCs was assessed by Western blot.

RESULTS

Ethanol and acetaldehyde increased the activation of all 3 subfamilies (ERK 1/2, JNK and p38 kinase) of the MAPK pathway in PSCs. Treatment of PSCs with SB203580 abolished the ethanol- and acetaldehyde-induced increase in p38 MAPK activity and also prevented the induction of alpha-SMA expression in PSCs. However, inhibition of ERK 1/2 and JNK had no effect on ethanoland acetaldehyde-induced alpha-SMA expression in PSCs.

CONCLUSIONS

(1) The MAP kinase pathway is induced in PSCs after exposure to ethanol or acetaldehyde and this induction is sustained for at least 24h. (2) The p38 MAPK pathway mediates the activation (as indicated by increased alpha-SMA expression) of PSCs by ethanol or acetaldehyde.

Cell migration: a novel aspect of pancreatic stellate cell biology

BACKGROUND

Pancreatic stellate cells (PSCs), implicated as key mediators of pancreatic fibrogenesis, are found in increased numbers in areas of pancreatic injury. This increase in PSC number may be due to increased local proliferation and/or migration of these cells from adjacent areas. The ability of PSCs to proliferate has been well established but their potential for migration has not been examined.

AIMS

Therefore, the aims of this study were to determine whether cultured rat PSCs have the capacity to migrate and, if so, to characterise this migratory capacity with respect to the influence of basement membrane components and the effect of platelet derived growth factor (PDGF, a known stimulant for migration of other cell types).

METHODS

Migration of freshly isolated (quiescent) and culture activated (passaged) rat PSCs was assessed across uncoated or Matrigel (a basement membrane-like substance) coated porous membranes (pore size 8 micro m) in the presence or absence of PDGF (10 and 20 ng/ml) in the culture medium. A checkerboard assay was performed to assess whether the effect of PDGF on PSC migration was chemotactic or chemokinetic.

RESULTS

Cell migration was observed with both freshly isolated and passaged PSCs. However, compared with passaged (culture activated) cells, migration of freshly isolated cells was delayed, occurring only at or after 48 hours of incubation when the cells displayed an activated phenotype. PSC migration through Matrigel coated membranes was delayed but not prevented by basement membrane components. PSC migration was increased by PDGF and this effect was predominantly chemotactic (that is, in the direction of a positive concentration gradient).

CONCLUSIONS

(i) PSCs have the capacity to migrate. (ii) Activation of PSCs appears to be a prerequisite for migration. (iii) PDGF stimulates PSC migration and this effect is predominantly chemotactic.

IMPLICATION

Chemotactic factors released during pancreatic injury may stimulate the migration of PSCs through surrounding basement membrane towards affected areas of the gland.

Life-sustaining treatment and assisted death choices in depressed older patients

OBJECTIVES

The major purpose of this study was to examine the effect of depressed mood in older, medically ill, hospitalized patients on their preferences regarding life-sustaining treatments, physician-assisted suicide (PAS), and euthanasia and to determine the degree to which financial constraints affected their choices.

DESIGN

Cross-sectional study.

SETTING

General medical hospital.

PARTICIPANTS

One hundred fifty-eight medically hospitalized, nondemented patients age 60 or older, mean age 74.1 (range 60-94). The sample was divided, based on Center for Epidemiologic Studies-Depression (CES-D) scores, into a depressed group (n = 71) and a nondepressed control group.

MEASUREMENTS

Subjects underwent a structured interview evaluating their life-sustaining treatment choices and whether they would accept or refuse PAS or euthanasia under a variety of hypothetical conditions. These choices were reevaluated with the introduction of financial impact. In addition, assessment included measures of depression, suicide, cognition, social support, functioning, and religiosity.

RESULTS

Depression was found to be highly associated with acceptance of PAS and euthanasia in most hypothetical clinical scenarios in addition to patients' current condition. Compared with nondepressed people, depressed respondents were 13 times as likely to accept PAS when considering their current condition (95% confidence interval [CI] 1.68-110.98), and over twice as likely to accept PAS when facing a hypothetical terminal illness or coma. Depression alone was weakly associated with life-sustaining treatment choices but, when financial impact was introduced, significantly more depressed subjects refused treatment options they had previously desired than did nondepressed subjects. The presence of suicidal ideation, even passive ideation, was strongly predictive of life-sustaining treatment refusals and increased interest in PAS and euthanasia. Depression's effect on acceptance of PAS was confirmed by logistic regression, which also showed that religious coping was significantly correlated with less interest in PAS in two hypothetical scenarios. CONCLUSION. Depressed subjects and even subjects with subtle, passive suicidal ideation were markedly more interested in PAS and euthanasia than nondepressed subjects in hypothetical situations. Depressed subjects were also particularly vulnerable to rejecting treatments if financial consequences might have resulted.

The effect of change of renal replacement therapy on serum lipoprotein (a) concentration

Lipoprotein (a) [Lp(a)] is an independent atherogenic risk factor. Lp(a) levels are elevated in patients on renal replacement therapy (RRT). This study looked at the effect of change of RRT on serum lipid and Lp(a) levels. Three groups were identified: (1) patients on dialysis who were transplanted; (2) those who had lost their transplants through immunorejection; (3) those who changed from continuous ambulatory peritoneal dialysis (CAPD) to hemodialysis (HD). All Lp(a) measurements were taken at least 3 months after the change of therapy. Our results were as follows: Group A (n = 21): 8 CAPD and 13 HD patients were transplanted. Median Lp(a) levels fell posttransplantation in the CAPD group (15.6 mg/dL vs 11.4 mg/dL, p = 0.04). The HD group showed a rise in cholesterol, low-density (LDL) and high-density lipoprotein (HDL) levels, with no change in Lp(a) levels. Group B (n = 11): 7 patients started CAPD and 4 HD. Overall, there was a marked increase in Lp(a) levels: median 38.2 mg/dL vs 55.9 mg/dL (p = 0.04), reflecting an increase in those starting CAPD (27.8 mg/dL vs 60.0 mg/dL, p = 0.01), with little change in the HD group (40.45 mg/dL vs 40.05 mg/dL). However, there was a decrease in cholesterol (7.4 mmol/L vs 5.1 mmol/L, p = 0.002) and LDL (5.5 mmol/L vs 3.3 mmol/L, p = 0.004). Group C (n = 16): 16 patients changed from CAPD to HD. Lp(a) levels were higher while on CAPD, as compared to when on HD (58.9 mg/dL vs 49 mg/dL, p = 0.03). Cholesterol (6.62 mmol/L vs 5.26 mmol/L, p = 0.006) and LDL (4.48 mmol/L vs 3.40 mmol/L, p = 0.004) were also higher when on CAPD. In conclusion, serum Lp(a) levels are clearly affected by the mode of the RRT, being highest in CAPD, and decline after transplantation or conversion to HD. Atherogenic risk is thus likely to differ between the modes of RRT and may be greatest for those on CAPD.

Up-regulation of p21WAF1/CIP1 in psoriasis and after the application of irritants and tape stripping

p21WAF1/CIP1 is a nucleoprotein that was initially characterized by its ability to be regulated transcriptionally by p53 and by its ability to mediate growth arrest by binding to cyclin-dependent kinases. Although p21WAF1/CIP1 is thought to mediate the effects of p53 in causing growth arrest, p21WAF1/CIP1 is also regulated in a p53-independent manner, e.g., during terminal differentiation of some cell lines. Growth factors including epidermal growth factor also induce p21WAF1/CIP1 through p53-independent pathways. Because the epidermal growth factor signaling pathway is abnormal in psoriatic epidermis, we studied p21WAF1/CIP1 expression, using in situ hybridization and immunohistochemistry, in psoriasis. Both p21WAF1/CIP1 mRNA and protein were significantly elevated in untreated psoriatic plaques compared with uninvolved psoriatic skin (p < 0.0001), with the up-regulation of p21WAF1/CIP1 being predominantly suprabasal. This increase was accompanied by a small increase in p53 protein expression of uncertain significance. Furthermore, p21WAF1/CIP1 expression was induced in skin after sellotape stripping and by the application of agents, such as dithranol, that are capable of inducing hyperproliferation. The pattern of p21WAF1/CIP1 expression observed is consistent with a role in induction and maintenance of differentiation. Our experiments, however, cannot determine whether the abnormalities of p21WAF1/CIP1 epidermal expression in psoriasis and after insult are independent of changes in p53 expression.

Lipoprotein (a): a prothrombotic risk factor for coronary artery disease

New data on the interactions between lipoprotein (a) [Lp(a)] and the coagulation-fibrinolytic system, which emphasize the importance of the activity of lysine-binding sites on apolipoprotein (a) [apo(a)], provide an increasingly strong basis for the role of Lp(a) in thrombosis. Further insights into the genetic control of Lp(a) levels show that inherited factors other than the size of the apo(a) gene are important. The clinical relationship between Lp(a) and coronary heart disease has been more firmly established by two further large prospective cohort studies. The consensus that the concentration of Lp(a) does not predict the outcome of thrombolytic therapy still holds, although Lp(a) does affect endogenous fibrinolysis after myocardial infarction. The effect of Lp(a) on mortality should soon be known.

Tuberculin sensitivity and the BCG scar in tuberculosis contacts

SETTING

Tuberculosis clinic, St Vincents Hospital, Dublin.

OBJECTIVE

To determine the influence of past BCG vaccination on tuberculin sensitivity in tuberculosis contacts.

DESIGN

Prospective cohort study of tuberculin sensitivity using the Mantoux technique (5 TU).

RESULTS

In 1050 contacts of 96 cases of tuberculosis, BCG scars were noted in 76% of the contacts. Approximately 50%, 30% and 20% of the contacts respectively had negative (0-4 mm), positive (5-14 mm) and strongly positive (15+ mm) Mantoux responses. The presence of a BCG scar was not found to significantly influence the degree of tuberculin sensitivity. The degree of tuberculin sensitivity increased after 20 years and decreased after 60 years of age. Contacts of sputum-positive cases of tuberculosis had larger Mantoux responses.

CONCLUSIONS

The study suggests that age of the contact and sputum status of the index case are important determinants of the degree of tuberculin sensitivity. Attributing a 'positive' Mantoux response to past BCG vaccination may be encouraging a false sense of security in contacts recently exposed to an infectious case of tuberculosis. Contact management guidelines may need to be reviewed and perhaps modified to reflect this finding.

Implantation of encapsulated catecholamine and GDNF-producing cells in rats with unilateral dopamine depletions and parkinsonian symptoms

Studies in rodents suggest that PC12 cells, encapsulated in semipermeable ultrafiltration membranes and implanted in the striatum, have some potential efficacy for the treatment of age- and 6-OHD-induced sensorimotor impairments (22, 70, 71, 74). The objectives of this study were to: (1) determine if baby hamster kidney cells engineered to secrete glial cell line-derived neurotrophic factor (BHK-GDNF) would survive encapsulation and implantation in a dopamine-depleted rodent striatum, (2) compare polymer-encapsulated PC12 and PC12A cells in terms of their ability to survive and produce catecholamines in vivo in a dopamine-depleted striatum, and (3) determine if BHK-GDNF, PC12, or PC12A cells reduce parkinsonian symptoms in a rodent model of Parkinson's disease. Capsules with BHK-GDNF or PC12 cells contained viable cells after 90 days in vivo, with little evidence of host tissue damage/gliosis. In rats with tyrosine hydroxylase (TH)-positive fibers remaining in the lesioned striatum, there was TH-positive fiber ingrowth into the membranes of the BHK-GDNF capsules. PC12-containing capsules had higher basal release of both dopamine and L-DOPA after 90 days in vivo than before implantation, while basal release of both dopamine and L-DOPA decreased in the PC12A-containing capsules. Both encapsulated PC12 and PC12A cells, but not encapsulated BHK-GDNF cells, decreased apomorphine-induced rotations. Parkinsonian symptoms (akinesia, freezing/bracing, sensorimotor neglect) related to the extent of dopamine depletion were evident even in rats with dopamine depletions of only 25%. Evidence that encapsulated cells may attenuate these parkinsonian symptoms was not detected but most of the rats were more severely depleted of dopamine than Parkinson's patients (less than 2% dopamine remaining in the entire striatum), and these tests were not sensitive to differences between rats with less than 10% dopamine remaining. These results suggest that cell encapsulation technology can safely provide site-specific delivery of dopaminergic agonists or growth factors within the CNS, without requiring suppression of the immune system, and without using fetal tissue. Of the three types of encapsulated cells examined in the present study, PC12 cells seem to offer the most therapeutic potential in rats with severe dopamine depletions.

Autocrine growth stimulation of human renal Wilms' tumour G401 cells by a gastrin-like peptide

The role of gastrin in the control of growth of renal G401 cells isolated from a human nephroblastoma (Wilms' tumour) was investigated. G401 cell growth was enhanced in the presence of exogenous gastrin. Addition of anti-gastrin antibodies to serum-free medium significantly inhibited the growth of G401 cells. G401 cells contained the equivalent of 4.3 pg/10(6) cells of gastrin, and serum-free medium collected over 48 hr from G401 cells contained the equivalent of 38 ng/10(6) cells of gastrin, as determined by radioimmunoassay. Growth of G401 cells was inhibited in a concentration-related way by a variety of gastrin/CCK receptor antagonists. Devazepide and proglumide were, respectively, the most and the least potent inhibitors of G401 cell growth (potency order devazepide > L-365,260 = lorglumide > loxiglumide > benzotript > proglumide). These gastrin/CCK receptor antagonists had similar growth-inhibitory activities in human colonic adenocarcinoma HCT-116 cells. Growth of HCT-116 cells was stimulated to a lesser extent, as compared with G401 cells, by exogenous gastrin, and endogenous gastrin was not detectable in HCT-116 cells. The results are consistent with a role for a gastrin-like peptide in the control of growth of a renal cell line. The data suggest that gastrin/CCK receptor antagonists warrant further investigation as therapeutic agents for the control of gastrin-responsive tumours derived from outside, as well as inside, the gastrointestinal tract, including tumours derived from the kidney.

Lipoprotein lipase activity in patients with combined hyperlipidaemia

The aetiology of familial combined hyperlipidaemia remains obscure, with both genetic and environmental factors contributing to the phenotype, which is frequently associated with premature coronary heart disease. We have studied lipoprotein lipase (LPL) activity and hepatic lipase (HL) activity in patients with coronary heart disease to determine whether variation in lipase activities contributes to this phenotype. Forty-one patients (mean age 50 years; 30 male) were selected on the basis of cholesterol levels above 6.5 mmol/l and triglyceride levels above 2.2 mmol/l, with apoprotein B values over the 90th percentile. There was a family history of premature coronary heart disease in 78% and a personal history in 64%, at mean age 44, the patient group therefore predominantly corresponded to the common definition of familial combined hyperlipidaemia, appropriate in the absence of molecular markers. None of the patients was diabetic; hypertension and smoking were not over represented. Blood samples were taken following intravenous administration of heparin (100 IU/kg body wt), and LPL and HL activities were measured. Mean post-heparin LPL was significantly lower in patients than controls 10 min after heparin administration (2.98 +/- 1.04 and 3.86 +/- 0.93 mumol ml-1 h-1, respectively, P = 0.001), and 37% patients had values below the 10th percentile of controls. Both male and female patients had significantly higher HL activities than their respective controls at 5, 10, 20 and 30 minutes post-heparin. As expected, both female patients and controls had lower HL activities than males, although this sex difference did not reach statistical significance in the patient group.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of child and parent ratings of disability and pain in juvenile chronic arthritis

OBJECTIVE

To assess parent-child agreement of child disability and pain.

METHODS

Twenty children with juvenile chronic arthritis aged between 8 and 16 years and their mothers were assessed using a recently developed measure of child disability and pain.

RESULTS

Results demonstrated a high level of agreement between children and their mothers with respect to disability. However, there was no correlation between the children's and their mothers' assessment of pain.

CONCLUSION

This suggests that parents of children with chronic arthritis give accurate information regarding disability, but not regarding pain.

Assessment of cognitive function in patients with systemic lupus erythematosus

The spectrum of central nervous system manifestations of systemic lupus erythematosus (SLE) is very broad and has been found to include subtle subclinical cognitive dysfunction which may be detected only by the lengthy process of detailed neuropsychological evaluation. This study reports the value of estimating premorbid intelligence as a simple yet effective means of screening for subclinical cognitive dysfunction. Twenty one female patients with clinically quiescent SLE underwent neuropsychological examination at entry to the study. In all patients, this examination included measurement of full-scale intelligence quotient (IQ), verbal and performance IQ as well as verbal and visual memories. In addition, premorbid intelligence was estimated using the Schonell graded word reading test. Nine patients (43%) gave a history of neuropsychiatric (NP) disease. No difference was identified between the results of the neuropsychological evaluation in these 9 patients and in either the other SLE patients or in age and sex matched control patients. Sixteen patients were re-evaluated 1 year later. A comparison of measured full-scale IQ with the estimated premorbid intelligence identified a subgroup of 3 patients who demonstrated a significant reduction in intelligence. Unlike the other 13 patients, these 3 patients had multiple (3 or more) other features of cognitive impairment.

Communication skills training in undergraduate medicine: attitudes and attitude change

The importance of communication skills training in undergraduate medical education is now widely accepted. However little is known about student attitudes towards their own communication skills and whether their attitudes changes as a result of participating in communication skills courses. The aim of the present study was to identify these attitudes prior to commencing such a course and to further evaluate changes in these attitudes on completion of the course. Results demonstrated an improvement in perceived confidence regarding a number of specific communication skills. The study provides further evidence of the value of such courses in undergraduate medical training.

Hearing loss in the child following streptomycin administration during pregnancy

The risk of deafness developing in the unborn child following the use of streptomycin (SM) during pregnancy remains uncertain. We have followed up 30 children whose mothers received SM during pregnancy. One child (3pc), whose mother received SM during the first trimester of pregnancy, had profound unilateral hearing loss which could possibly be ascribed to SM. This child had however, in addition, features of congenital hypotonia and a unilateral single crease. Two further children had conductive deafness which could not be due to SM, associated with serious otitis media. Although the risk to the foetus of hearing loss following the use of SM during pregnancy appears relatively low it should, where possible, be avoided during the first trimester of pregnancy.

Communication skills training in undergraduate medicine

Good communication with patients is now recognised as the cornerstone in effective medical practice. Medical students do not automatically acquire the art of good communication through clinical training. A new course to promote the development of communication skills at undergraduate level is described. The course was provided at the juncture between pre-clinical and clinical training. Course evaluation illustrated the value of the course as perceived by students themselves and highlighted the areas of greatest need for students in communication skills training.

Psychological and behavioral factors in dermatitis

Dermatitis and eczema are described in terms of physiological, psychological, and behavioral characteristics in the sparse psychological literature on this phenomenon. Knowledge is quite limited. Lacking are prospective studies that might demonstrate whether the psychological and behavioral characteristics ate etiological and not merely descriptive. Given the number of persons estimated to experience symptoms of dermatitis (7 to 24 per 1000), further research is warranted on the relationship among dermatitis, scratching, and the psychological factors of stress, aggression, hostility, or other moods. Methodological suggestions and an experimental design are proposed.

Autofluorescence of clofazimine in discoid lupus erythematosus

A 70-year-old woman developed dark reddish blue pigmentation in scarred areas of discoid lupus erythematosus after taking clofazimine intermittently over a period of 10 years. Although light microscopy of routinely processed tissue failed to define the cause of the pigment, fluorescent microscopy showed vivid red deposits concentrated around larger vessels within the dermis. These deposits were shown to correspond to birefringent red clofazimine crystals on fresh frozen sections. Although the hyperpigmentation may clinically resemble melanin, biopsy specimens from our patient revealed a loss of melanin pigment in lesional skin, suggesting a primary role for clofazimine in producing the color changes observed.

Neurotropic Melanoma. A variant of desmoplastic melanoma

In ten cases of neurotropic melanoma, patients presented with nodules composed of amelanotic, deeply infiltrating neuroid fascicles. Only four cases were clinically suggestive of melanoma. In eight of the tumors, a precursor lesion was found histologically and provided a major clue to the diagnosis. In seven cases, the dysplastic precursor was lentiginous, while a superficial spreading pattern was present in one. Initial surgery was often inadequate because of the difficulty in defining tumor margins and the lack of pigment. In seven of the tumors, S100 protein was demonstrated within the invasive spindle cell component by the immunoperoxidase method. This finding was negative in three cases, two of which showed positive staining of the precursor and nerve filaments, indicating that the absence of S100 protein cannot be used as an exclusion criterion for neurotropic melanoma.