Multi-modal analysis of inflammation as a potential mediator of depressive symptoms in young people with HIV: The GOLD depression study

People living with HIV are at three times greater risk for depressive symptoms. Inflammation is a notable predictor of depression, and people with HIV exhibit chronic inflammation despite antiretroviral therapy. We hypothesised that inflammatory biomarkers may mediate the association between HIV status and depressive symptoms. Participants (N = 60, 53% girls, median [interquartile range (IQR)] age 15.5 [15.0, 16.0] years, 70% living with HIV, of whom 90.5% were virally-suppressed) completed the nine-item Patient Health Questionnaire (PHQ-9). We measured choline and myo-inositol in basal ganglia, midfrontal gray matter, and peritrigonal white matter using magnetic resonance spectroscopy, and 16 inflammatory proteins in blood serum using ELISA and Luminex™ multiplex immunoassays. Using structural equation mediation modelling, we calculated standardised indirect effect estimates with 95% confidence intervals. Median [IQR] total PHQ-9 score was 3 [0, 7]. HIV status was significantly associated with total PHQ-9 score (B = 3.32, p = 0.022). Participants with HIV showed a higher choline-to-creatine ratio in the basal ganglia than those without HIV (β = 0.86, pFDR = 0.035). In blood serum, participants with HIV showed higher monocyte chemoattractant protein-1 (MCP-1, β = 0.59, pFDR = 0.040), higher chitinase-3 like-1 (YKL-40, β = 0.73, pFDR = 0.032), and lower interleukin-1beta (IL-1β, β = -0.67, pFDR = 0.047) than those without HIV. There were no significant associations of any biomarkers with total PHQ-9 score. None of the indirect effects were significant, mediating <13.1% of the association. Findings remained consistent when accounting for age, gender, and time between neuroimaging and PHQ-9 administration. Using a robust analytical approach in a community-based sample, we have shown that participants living with HIV reported greater depressive symptoms than those without HIV, but we did not find that neuroimaging and blood biomarkers of inflammation significantly mediated this association. Further studies with participants experiencing severe depression may help to elucidate the links between HIV, inflammation, and depression.

Similar cortical morphometry trajectories from 5 to 9 years in children with perinatal HIV who started treatment before age 2 years and uninfected controls

BACKGROUND

Life-long early ART (started before age 2 years), often with periods of treatment interruption, is now the standard of care in pediatric HIV infection. Although cross-sectional studies have investigated HIV-related differences in cortical morphology in the setting of early ART and ART interruption, the long-term impact on cortical developmental trajectories is unclear. This study compares the longitudinal trajectories of cortical thickness and folding (gyrification) from age 5 to 9 years in a subset of children perinatally infected with HIV (CPHIV) from the Children with HIV Early antiRetroviral therapy (CHER) trial to age-matched children without HIV infection.

METHODS

75 CHER participants in follow-up care at FAMCRU (Family Centre for Research with Ubuntu), as well as 66 age-matched controls, received magnetic resonance imaging (MRI) on a 3 T Siemens Allegra at ages 5, 7 and/or 9 years. MR images were processed, and cortical surfaces reconstructed using the FreeSurfer longitudinal processing stream. Vertex-wise linear mixed effects (LME) analyses were performed across the whole brain to compare the means and linear rates of change of cortical thickness and gyrification from 5 to 9 years between CPHIV and controls, as well as to examine effects of ART interruption.

RESULTS

Children without HIV demonstrated generalized cortical thinning from 5 to 9 years, with the rate of thinning varying by region, as well as regional age-related gyrification increases. Overall, the means and developmental trajectories of cortical thickness and gyrification were similar in CPHIV. However, at an uncorrected p < 0.005, 6 regions were identified where the cortex of CPHIV was thicker than in uninfected children, namely bilateral insula, left supramarginal, lateral orbitofrontal and superior temporal, and right medial superior frontal regions. Planned ART interruption did not affect development of cortical morphometry.

CONCLUSIONS

Although our results suggest that normal development of cortical morphometry between the ages of 5 and 9 years is preserved in CPHIV who started ART early, these findings require further confirmation with longitudinal follow-up through the vulnerable adolescent period.

Multivariate approach for longitudinal analysis of brain metabolite levels from ages 5-11 years in children with perinatal HIV infection

Treatment guidelines recommend that children with perinatal HIV infection (PHIV) initiate antiretroviral therapy (ART) early in life and remain on it lifelong. As part of a longitudinal study examining the long-term consequences of PHIV and early ART on the developing brain, 89 PHIV children and a control group of 85 HIV uninfected children (HIV-) received neuroimaging at ages 5, 7, 9 and 11 years, including single voxel magnetic resonance spectroscopy (MRS) in three brain regions, namely the basal ganglia (BG), midfrontal gray matter (MFGM) and peritrigonal white matter (PWM). We analysed age-related changes in absolute metabolite concentrations using a multivariate approach traditionally applied to ecological data, the Correlated Response Model (CRM) and compared these to results obtained from a multilevel mixed effect modelling (MMEM) approach. Both approaches produce similar outcomes in relation to HIV status and age effects on longitudinal trajectories. Both methods found similar age-related increases in both PHIV and HIV- children in almost all metabolites across regions. We found significantly elevated GPC+PCh across regions (95% CI=[0.033; 0.105] in BG; 95% CI=[0.021; 0.099] in PWM; 95% CI=[0.059; 0.137] in MFGM) and elevated mI in MFGM (95% CI=[0.131; 0.407]) among children living with PHIV compared to HIV- children; additionally the CRM model also indicated elevated mI in BG (95% CI=[0.008; 0.248]). These findings suggest persistent inflammation across the brain in young children living with HIV despite early ART initiation.

Study protocol for a phase 2A trial of the safety and tolerability of increased dose rifampicin and adjunctive linezolid, with or without aspirin, for HIV-associated tuberculous meningitis [LASER-TBM]

Background: Tuberculous meningitis (TBM) is the most lethal form of tuberculosis with a mortality of ~50% in those co-infected with HIV-1. Current antibiotic regimens are based on those known to be effective in pulmonary TB and do not account for the differing ability of the drugs to penetrate the central nervous system (CNS). The host immune response drives pathology in TBM, yet effective host-directed therapies are scarce. There is sufficient data to suggest that higher doses of rifampicin (RIF), additional linezolid (LZD) and adjunctive aspirin (ASA) will be beneficial in TBM yet rigorous investigation of the safety of these interventions in the context of HIV associated TBM is required. We hypothesise that increased dose RIF, LZD and ASA used in combination and in addition to standard of care for the first 56 days of treatment with be safe and tolerated in HIV-1 infected people with TBM.

Methods: In an open-label randomised parallel study, up to 100 participants will receive either; i) standard of care (n=40, control arm), ii) standard of care plus increased dose RIF (35mg/kg) and LZD (1200mg OD for 28 days, 600mg OD for 28 days) (n=30, experimental arm 1), or iii) as per experimental arm 1 plus additional ASA 1000mg OD (n=30, experimental arm 2). After 56 days participants will continue standard treatment as per national guidelines. The primary endpoint is death and the occurrence of solicited treatment-related adverse events at 56 days. In a planned pharmacokinetic (PK) sub-study we aim to assess PK/pharmacodynamic (PD) of oral vs IV rifampicin, describe LZD and RIF PK and cerebrospinal fluid concentrations, explore PK/PD relationships, and investigate drug-drug interactions between LZD and RIF. Safety and pharmacokinetic data from this study will inform a planned phase III study of intensified therapy in TBM.

Clinicaltrials.gov registration: NCT03927313 (25/04/2019)

Cortical structural changes related to early antiretroviral therapy (ART) interruption in perinatally HIV-infected children at 5 years of age

ART interruption in children can occur especially in resource-limited settings for reasons including poor adherence, stock-outs, ART intolerance of non-pediatric formulas and pill size, as well as ultimately to test for HIV remission. Although early ART initiation is now standard of care in pediatric HIV management, very little is known on the effect of early ART initiation or subsequent interruption on brain development. This study aimed to investigate the effect of ART interruption on brain cortical thickness (CT) and folding in a subset of children from the Children with HIV Early antiRetroviral therapy (CHER) trial cohort who all started ART before 18 months of age. CHER participants in the neuroimaging follow-up study had magnetic resonance (MRI) scans on a 3T Siemens Allegra brain scanner at age 5.44 ± 0.37 years. MR images were processed using the automated cross-sectional stream in FreeSurfer v6.0 and vertex wise comparisons of CT and local gyrification indices (LGIs) were performed between HIV+ children and HIV- controls, as well as between HIV+ children on interrupted or continuous ART and controls. HIV+ children (n = 46) showed thicker cortex than HIV- children (n = 29) in bilateral frontal and left temporo-insular regions but lower LGIs in left superior and bilateral medial orbitofrontal cortex extending into rostral anterior cingulate. Children on interrupted ART (n = 21) had thicker cortex than HIV- controls in left frontal and right insular regions, but children on continuous treatment (n = 25) showed no difference from controls. Children on both interrupted and continuous ART showed region-specific alterations in LGI relative to controls. Cortical folding appears more sensitive than CT to early life events including early ART and interruption. However, immune health resilience in children can translate to long term preservation of morphometric brain development, especially for those on early and continuous treatment.

Fetal Alcohol Exposure Alters BOLD Activation Patterns in Brain Regions Mediating the Interpretation of Facial Affect

BACKGROUND

Although deficits in the interpretation of affective facial expressions have been described clinically and in behavioral studies of fetal alcohol spectrum disorders (FASD), effects of prenatal alcohol exposure on the neural networks that mediate affective appraisal have not previously been examined.

METHODS

We administered a nonverbal event-related fMRI affective appraisal paradigm to 64 children (mean age = 12.5 years; 18 with fetal alcohol syndrome (FAS) or partial FAS (PFAS), 18 nonsyndromal heavily exposed (HE), and 28 controls). Happy, sad, angry, fearful, and neutral faces and pixelated control images were presented sequentially in a randomized order. The child indicated whether the currently displayed face showed the same or different affect as the previous one.

RESULTS

Data from whole-brain analyses showed that all groups activated the appropriate face processing neural networks. Region of interest analyses indicated that, compared to HE and control children, the FAS/PFAS group exhibited greater blood oxygenation level-dependent (BOLD) signal changes when processing neutral faces than pixelated images in 2 regions that form part of the visual sensory social brain network, which plays an important role in the initial processing of facial affect. By contrast, BOLD signal when processing angry faces was weaker for the FAS/PFAS group in a region involved in the processing of facial identity and facial expressions and in a region involved in the recognition and selection of behavioral responses to aggressive behavior.

CONCLUSIONS

These findings of greater BOLD signal in the FAS/PFAS group in response to neutral faces suggest less efficient neural processing of more difficult to interpret emotions, and the weaker BOLD response to angry faces suggests altered processing of angry stimuli. Although behavioral performance did not differ in this relatively simple affective appraisal task, these data suggest that in children with FAS and PFAS, the appraisal of neutral affect and anger is likely to be more effortful in more challenging and dynamic social contexts.

An fMRI investigation of neural activation predicting memory formation in children with fetal alcohol spectrum disorders

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Expected brain regions activated during memory formation in FASD and Control children.

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Prenatal alcohol predicted differences in brain activations during memory formation.

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More extensive neural activation during successful memory formation in FAS/PFAS group.

Prenatal alcohol exposure (PAE) is associated with physical anomalies, growth restriction, and a range of neurobehavioral deficits. Although declarative memory impairment has been documented extensively in individuals with fetal alcohol spectrum disorders (FASD), this cognitive process has been examined in only one functional magnetic resonance imaging (fMRI) study, and mechanisms underlying this impairment are not well understood. We used an event-related fMRI design to examine neural activations during visual scene encoding that predict subsequent scene memory in 51 right-handed children (age range = 10–14 years, M = 11.3, SD = 1.3) whose mothers had been recruited and interviewed prospectively about their alcohol use during pregnancy. Following examination by expert dysmorphologists, children were assigned to one of three FASD diagnostic groups: FAS/PFAS (n_FAS = 7; n_PFAS = 4), nonsyndromal heavily exposed (HE; n = 14), and Controls (n = 26). Subsequent memory was assessed in a post-scan recognition test, and subsequent memory activations were examined by contrasting activations during encoding of scenes that were subsequently remembered (hits) to those for incorrectly judged as ‘new’ (misses). Recognition accuracy did not differ between groups. Pooled across groups, we observed extensive bilateral subsequent memory effects in regions including the hippocampal formation, posterior parietal cortex, and occipital cortex—a pattern consistent with previous similar studies of typically developing children. Critically, in the group of children with FAS or PFAS, we observed activations in several additional regions compared to HE and Control groups. Given the absence of between-group differences in recognition accuracy, these data suggest that in achieving similar memory compared to children in the HE and Control groups, children with FAS and PFAS recruit more extensive neural resources to achieve successful memory formation.

Repeatability and reproducibility of prospective motion- and shim corrected 2D glycoCEST MRI

Background

Repeated glycoCEST MRI measurements on the same subject should produce similar results under the same environmental and experimental conditions. However, fluctuations in the static B₀ field, which may occur between and within measurements due to heating of the shim iron or subject motion, may alter results and affect reproducibility. Here we investigate the repeatability and reproducibility of glycoCEST measurements and examine the effectiveness of a real-time shim- and motion navigated chemical exchange saturation transfer (CEST) sequence to improve reproducibility.

Methods

In nine subjects, double volumetric navigated (DvNav)-CEST acquisitions in the calf muscle were repeated five times in each of two sessions-the first without correction, and the second with real-time shim- and motion correction applied. In both sessions a dynamically changing field was introduced by running a 5-minute gradient intensive diffusion sequence. We evaluated the effect of the introduced B₀ inhomogeneity on the reproducibility of glycoCEST, where the small chemical shift difference between the hydroxyl and bulk water protons at 3 T makes CEST quantification extremely sensitive to magnetic field inhomogeneities.

Results

With real-time shim- and motion correction, glycoCEST results were relatively consistent with mean coefficient of variation (CoV) 2.7%±1.4% across all subjects, whereas without correction the results were less consistent with CoV 84%±71%.

Conclusions

Our results demonstrate that real-time shim- and motion correction can mitigate effects of B0 field fluctuations and improve reproducibility of glycoCEST data. This is important when conducting longitudinal studies or when using glycoCEST MRI to assess treatment or physiological responses over time.

Determinants of Radiation Dose in Selective Ophthalmic Artery Chemosurgery for Retinoblastoma

BACKGROUND AND PURPOSE

Retinoblastoma is the most common pediatric ocular neoplasm. Multimodality treatment approaches are commonplace, and selective ophthalmic artery chemosurgery has emerged as a safe and effective treatment in selected patients. Minimizing radiation dose in this highly radiosensitive patient cohort is critical. We explore which procedural factors affect the radiation dose in a single-center cohort of children managed in the UK National Retinoblastoma Service.

MATERIALS AND METHODS

A retrospective review was performed of 177 selective ophthalmic artery chemosurgery procedures in 48 patients with retinoblastoma (2013-2017). Medical records, angiographic imaging, and radiation dosimetry data (including total fluoroscopic screening time, skin dose, and dose-area product) were reviewed.

RESULTS

The mean fluoroscopic time was 13.5 ± 13 minutes, the mean dose-area product was 11.7 ± 9.7 Gy.cm², and the mean total skin dose was 260.9 ± 211.6 mGy. One hundred sixty-three of 177 procedures (92.1%) were technically successful. In 14 (7.9%), the initial attempt was unsuccessful (successful in 13/14 re-attempts). Screening time and radiation dose were associated with drug-delivery microcatheter location and patient age; screening time was associated with treatment cycle.

CONCLUSIONS

In selective ophthalmic artery chemosurgery, a microcatheter tip position in the proximal or ostial ophthalmic artery and patient age 2 years or younger were associated with reduced fluoroscopic screening time and radiation dose; treatment beyond the first cycle was associated with reduced fluoroscopic screening time.

Methamphetamine dependence with and without psychotic symptoms: A multi-modal brain imaging study

OBJECTIVE

Methamphetamine dependence can lead to psychotic symptoms which may be mediated by frontal, striatal, limbic, and thalamic regions. There are few neuroimaging data that allow comparison of individuals with methamphetamine dependence who do, and do not, have psychosis. Two complementary imaging techniques were employed to investigate neurocircuitry associated with methamphetamine dependence with and without psychotic symptoms.

METHODS

Three groups of participants were recruited: methamphetamine dependent (MAA) (N = 11), methamphetamine dependent with psychotic symptoms (MAP) (N = 14), and controls (N = 14). Resting brain glucose metabolism was measured using [¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and cerebral perfusion was assessed using arterial spin labelling (ASL) magnetic resonance imaging.

RESULTS

Methamphetamine abusers (MAA and MAP groups) had decreased glucose metabolism compared to healthy controls in the left insula, left precentral gyrus, and the anterior cingulate cortex. Compared to MAA participants, MAP participants had 1) decreased glucose metabolism in the left precentral gyrus and the left inferior frontal gyrus and 2) increased glucose metabolism in the putamen and pallidum. MAP participants also had increased cerebral perfusion in the right putamen and right pallidum compared to MAA.

CONCLUSION

Findings support the involvement of frontal, striatal, and limbic regions in methamphetamine dependence. Furthermore, they indicate that glucose metabolism and cerebral perfusion in these regions are disrupted in methamphetamine dependent individuals with psychotic symptoms.

Improving access to ART in low-income settings through knowledge transfer: a case study from Zimbabwe

It may be assumed that infertility is not a problem in resource-poor areas where fertility rates are high. However, evidence overwhelmingly shows that childlessness is highly stigmatized in these settings and that women who are unable to bear children suffer significant social and psychological consequences. The World Health Organization has recommended that infertility be considered a global health problem and stated the need for ART to be adapted to low-resource settings. This paper describes a model for improving access to ART in low-resource settings. Experienced ART health professionals from Australia and Italy representing medical science, embryology, nursing and counselling used knowledge transfer to support a clinician, a laboratory scientist and a nurse to establish an ART service in Harare, Zimbabwe. Support and mentorship provided between October 2016 and December 2017 included: hosting the clinician and the embryologist for the new service in established ART clinics for short periods and providing them with dedicated mentorship and training during their stay; funding an experienced embryologist to travel to Zimbabwe (three times) to oversee the setting up of the lab and provide hands-on embryology training; funding a scientist and a nurse to travel to Zimbabwe to troubleshoot and establish protocols for record keeping and psychosocial care; and contributing approximately AUD $15,000 to the purchase of some equipment. By 31 March 2018, the team at IVF Zimbabwe had performed 166 ART procedures, which at time of writing had resulted in 16 births and 4 ongoing pregnancies. This case study demonstrates that with mentorship and modest financial support from ART experts from high-income settings, health professionals in low-income settings can deliver affordable ART with successful outcomes.

Higher bone resorption excretion in South Asian women vs. White Caucasians and increased bone loss with higher seasonal cycling of vitamin D: Results from the D-FINES cohort study

Few data exist on bone turnover in South Asian women and it is not well elucidated as to whether Western dwelling South Asian women have different bone resorption levels to that of women from European ethnic backgrounds. This study assessed bone resorption levels in UK dwelling South Asian and Caucasian women as well as evaluating whether seasonal variation in 25-hydroxyvitamin D [25(OH)D] is associated with bone resorption in either ethnic group. Data for seasonal measures of urinary N-telopeptide of collagen (uNTX) and serum 25(OH)D were analysed from n=373 women (four groups; South Asian postmenopausal n=44, South Asian premenopausal n=50, Caucasian postmenopausal n=144, Caucasian premenopausal n=135) (mean (±SD) age 48 (14) years; age range 18-79years) who participated in the longitudinal D-FINES (Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England) cohort study (2006-2007). A mixed between-within subjects ANOVA (n=192) showed a between subjects effect of the four groups (P<0.001) on uNTX concentration, but no significant main effect of season (P=0.163). Bonferroni adjusted Post hoc tests (P≤0.008) suggested that there was no significant difference between the postmenopausal Asian and premenopausal Asian groups. Season specific age-matched-pairs analyses showed that in winter (P=0.04) and spring (P=0.007), premenopausal Asian women had a 16 to 20nmolBCE/mmol Cr higher uNTX than premenopausal Caucasian women. The (amplitude/mesor) ratio (i.e. seasonal change) for 25(OH)D was predictive of uNTX, with estimate (SD)=0.213 (0.015) and 95% CI (0.182, 0.245; P<0.001) in a non-linear mixed model (n=154). This showed that individuals with a higher seasonal change in 25(OH)D, adjusted for overall 25(OH)D concentration, showed increased levels of uNTX. Although the effect size was smaller than for the amplitude/mesor ratio, the mesor for 25(OH)D concentration was also predictive of uNTX, with estimate (SD)=-0.035 (0.004), and 95% CI (-0.043, -0.028; P<0.001). This study demonstrates higher levels of uNTX in premenopausal South Asian women than would be expected for their age, being greater than same-age Caucasian women, and similar to postmenopausal Asian women. This highlights potentially higher than expected bone resorption levels in premenopausal South Asian women which, if not offset by concurrent increased bone formation, may have future clinical and public health implications which warrant further investigation. Individuals with a larger seasonal change in 25(OH)D concentration showed an increased bone resorption, an association which was larger than that of the 25(OH)D yearly average, suggesting it may be as important clinically to ensure a stable and steady 25(OH)D concentration, as well as one that is high enough to be optimal for bone health.

An evaluation of the psychometric properties of the Indicator of Relative Need (IoRN) instrument

BACKGROUND

The Indicator of Relative Need (IoRN) instrument is designed for both health and social care services to measure function and dependency in older people. To date, the tool has not undergone assessment of validity. We report two studies aimed to evaluate psychometric properties of the IoRN.

METHODS

The first study recruited patients receiving social care at discharge from hospital, those rehabilitating in intermediate care, and those in a rehabilitation at home service. Participants were assessed using the IoRN by a single researcher and by the clinical team at baseline and 8 weeks. Comparator instruments (Barthel ADL, Nottingham Extended ADL and Townsend Disability Scale) were also administered. Overall change in ability was assessed with a 7 point Likert scale at 8 weeks. The second study analysed linked routinely collected, health and social care data (including IoRN scores) to assess the relationship between IoRN category and death, hospitalisation and care home admission as a test of external validity.

RESULTS

Ninety participants were included in the first study, mean age 77.9 (SD 12.0). Cronbach's alpha for IoRN subscales was high (0.87 to 0.93); subscales showed moderate correlation with comparator tools (r = 0.43 to 0.63). Cohen's weighted kappa showed moderate agreement between researcher and clinician IoRN category (0.49 to 0.53). Two-way intraclass correlation coefficients for IoRN subscales in participants reporting no change in ability were high (0.88 to 0.98) suggesting good stability; responsiveness coefficients in participants reporting overall change were equal to or better than comparator tools. 1712 patients were included in the second study, mean age 81.0 years (SD 7.7). Adjusted hazard ratios for death, care home admission and hospitalisation in the most dependent category compared to the least dependent IoRN category were 5.9 (95 % CI 2.0-17.0); 7.2 (95 % CI 4.4-12.0); 1.1 (95 % CI 0.5-2.6) respectively. The mean number of allocated hours of care 6 months after assessment was higher in the most dependent group compared to the least dependent group (5.6 vs 1.4 h, p = 0.005).

CONCLUSIONS

Findings from these analyses support the use of the IoRN across a range of clinical environments although some limitations are highlighted.

David Kirkaldy (1820-1897) and his museum of destruction: the visual dilemmas of an engineer as man of science

This paper examines codes of representation in nineteenth century engineering in Britain in relation to broader visual culture. While engineering was promoted as a rational public enterprise through techniques of spectacular display, engineers who aimed to be taken seriously in the intellectual hierarchies of science had to negotiate suitable techniques for making and using images. These difficulties can be examined in the visual practices that mark the career of engineer David Kirkaldy. Beginning as a bravura naval draughtsman, Kirkaldy later negotiated his status as a serious experimenter in material testing science, changing his style of representation that at first sight seems to be in line with the 'objective' strategy in science of getting nature to represent herself. And although Kirkaldy maintained a range of visual styles to communicate with different audiences, making rhetorical use of several technologies of inscription, from hand drawing to photography, nevertheless, his work does in fact demonstrate new uses of the concept of objectivity in representation when up against the practices of engineering. While these might seem merely pragmatic in comparison to the ethical weight given to the discourse of objective representation in science, in the messy world of collapsing bridges and law suits, virtuous engineers had to develop various forms of visual knowledge as practical science. This was not 'applied science' but a differentiated form of enquiry whose complexities hold as much interest as the better known visual cultures of late nineteenth century science or art.

Spinal dural arteriovenous fistulas: clinical experience with endovascular treatment as a primary therapy at 2 academic referral centers

BACKGROUND AND PURPOSE

Spinal dural arteriovenous fistulas are a rare entity that, if left untreated, can lead to considerable morbidity with progressive spinal cord symptoms. The aim of this study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas that were primarily treated with endovascular embolization.

MATERIALS AND METHODS

A retrospective review was performed of all patients from 1997-2010 who underwent treatment at 2 academic referral centers for a spinal dural arteriovenous fistula. Follow-up was performed by clinical examination, and functional status was measured by use of the Aminoff-Logue Disability Scale, McCormick classification grading, and mRS scores. The nonparametric Wilcoxon signed rank test was used to compare pretreatment and posttreatment Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and mRS scores. P values < .05 were considered significant.

RESULTS

A total of 38 patients were included. Five patients (2 endovascular, 3 surgical) were lost to follow-up and therefore were excluded from the analysis, 29 patients were initially treated from an endovascular approach (9 Onyx, 20 cyanoacrylate), and 4 patients were treated from a standard surgical approach. Five patients in the endovascular group subsequently underwent surgery for various reasons. The clinical improvements in the Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and the mRS scores were statistically significant (P < .05, Wilcoxon signed rank test).

CONCLUSIONS

We conclude that endovascular treatment of spinal dural arteriovenous fistulas can result in good clinical outcomes. Surgery remains the treatment of choice when safe embolization of the proximal radicular draining vein cannot be obtained or because the shunting artery of the spinal dural arteriovenous fistula also supplies the anterior spinal, posterior spinal, or a radiculomedullary artery.

Cyclooxygenase-2 gene expression in human breast cancer

Expression of the inducible isoform of the cyclooxygenase gene (PGHS-2, COX-2) which codes for the enzyme that catalyzes formation of prostaglandins, was detected in 13/13 human breast tumors of high grade but not in samples of normal breast tissue. There was a statistically significant linear association between COX-2 gene expression and high (>50%) tumor cell density (p<0.01), with COX-2 protein localized to tumor cells. These results indicate that COX-2 gene expression may be useful as a molecular biomarker for human breast tumors and may also predict sensitivity to treatment with nonsteroidal anti-inflammatory drugs.

Growth arrest of DMBA-induced mammary carcinogenesis with ibuprofen treatment in female Sprague-Dawley rats

We examined effects of ibuprofen on the growth and development of DMBA-induced mammary cancers in mature female Sprague-Dawley rats. Ibuprofen was added to the standard diet at approximately 1,000 mg/kg rodent chow, resulting in an average daily dose of 25 mg per day per 0.25 kg rat. After five weeks of ibuprofen treatment, there was a 37% reduction in tumor volume compared to a 260% increase in the volume of tumors in untreated rats (p<0.001). These results suggest that ibuprofen may have potential in the chemoprevention and treatment of breast cancer.

Altered prefrontal cortical function during processing of fear-relevant stimuli in pregnancy

In non-pregnant individuals, the prefrontal cortex (PFC) is involved in the regulation of emotion, and appears to play a role in anxiety. Near-infrared spectroscopy (NIRS) detects cortical neural activation without harmful radiation making it safe for use in pregnancy. The aims of this study were to assess neural circuitry involved in processing fear-relevant stimuli during pregnancy using NIRS, and to determine associations between activation of this circuitry, distress and anxiety symptoms, attention to threat, cortisol, estrogen, progesterone and testosterone levels. There was significant activation of the PFC in response to fearful faces compared to rest in both pregnant and control groups. Within pregnancy, the activation was most pronounced at trimester 2, compared to the other trimesters. In pregnant women only (all trimesters), PFC activation was significantly associated with increased distress and anxiety, but with decreased selective attention to masked fear. PFC activation was also significantly associated with increased levels of cortisol and testosterone in pregnancy. PFC function appears to be altered during processing of fear-relevant stimuli in pregnancy. Changes in hormone levels may lead to changes in PFC function, and in turn to changes in cognitive-affective processing and anxiety. Further work is needed, however, to explore precisely how PFC function is altered in pregnancy; it is possible that certain changes reflect altered processing of threat stimuli, while others reflect attempts to compensate for distressing and anxious symptoms that emerge during pregnancy.

Abstract P4-04-05: Histone Deacetylase Inhibitors Increase Markers of the Dedifferentiated Cancer Stem Cell Phenotype in Human Breast Cancer Cells

It has been suggested that differentiated cancer cells can de-differentiate into the cancer stem cell phenotype (Meyers et al., 2009; Gupta et al., 2009) and that Histone Deacetylase (HDAC) inhibitors enable efficient induction of pluripotent stem cells from adult fibroblasts (Huangfu et al., 2009). Moreover, we have recently demonstrated that the HDAC inhibitor valproic acid radiosensitized breast cancer cells grown on plastic with serum while it radioprotected breast cancer cells grown in stem cell promoting culture conditions (Debeb et al., 2010). Based on these data, we hypothesized that HDAC inhibitors increase the cancer stem cell population via dedifferentiation of differentiated cancer cells. To examine our hypothesis, Sum159 breast cancer cells were FACS-sorted based on ALDH activity and subsequently treated with one of two HDAC inhibitors, valproic acid or SAHA (suberoylanilide hydroxamic acid). After sorting, ALDH-negative cells were treated either with valproic acid, SAHA, or vehicle. After a week, the percentage of ALDH-positive cells (passage 0, P0) was examined with flow cytometry while the remaining cells were passaged and incubated with and without valproic acid or SAHA for a week and the percentage of ALDH-positive cells again evaluated (P1). This was repeated for the third time (P2). Samples from each generation were also collected to examine the protein expression. On average, a 3-fold increase in ALDH positive cells was seen in valproic acid-treated cells (35.6% vs.12.6%) and a 1.5-fold increase in SAHA-treated cells (41% vs. 28%) compared to vehicle-treated controls. This effect was maintained through multiple passages. Moreover, the expression of Beta-catenin and EMT associated genes like vimentin, fibronectin, n-cadherin, which have been implicated in generating cancer stem cells was significantly increased withtreatment in initial and passaged cells. Further functional endpoint studies are needed to validate these in vitro marker-based findings.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-04-05.

p53 Mutation in Inflammatory Breast Cancer Cell Lines

Background: Inflammatory breast cancer (IBC) is the most aggressive manifestation of primary breast cancer and represents 1% to 2% of primary breast cancer in the United States. IBC is characterized by an acute inflammation of the skin of the affected breast generally believed to be caused by blockage of the dermal lymphatics by tumor emboli. Wild type (WT) p53 is a tumor suppressor gene, which induces apoptosis and p53 mutations are associated with poor prognosis in breast cancer. Compared with locally advanced breast cancers, IBC patients have higher levels of mutated p53 protein that has been associated with more aggressive tumors, anthracycline resistance, shorter progression free survival, shorter overall survival, and less favorable long-term outcome. The aim of this study was to determine if there are unique genetic variations in IBC cell lines that would provide specific genetic p53 mutations that could be exploited for targeted therapy with the intent of improving response to treatment and overall survival in IBC.Materials and Methods: Genomic DNA was extracted from six breast cancer cell lines (MDA-453, SUM149, MCF-7, KPL4, MDA321, and SUM190) and the immortalized human mammary epithelial cells (HMLE) using the Qiagen DNA Blood Mini Kit (Valencia, CA). Among the 6 breast cancer cell lines, KPL-4, SUM149 and SUM190 are IBC cell lines; MDA231 and SUM149 have basal-like phenotype; MCF-7 has wild-type p53; SUM190 and KPL-4 are Her2 amplified. The DNA purity and concentration were determined by spectrophotometric measurements of absorbance at 260nm and 280 nm. Polymerase chainreaction (PCR) was performed to amplify the fragments of exons 2-11 of the p53gene using consensus primers. The PCR products were scanned and identified using the Agilent Bioanalyzer 2100. DNA sequencing was performed on PCR products in the ABI PRISM 310 Genetic Analyzer. The BLAST search was used to identify p53 mutations compared with the reference sequence, X54156, from Genbank.Results: We screened 2-11 exon sequences of the p53 gene in the 7 human breast cell lines. We identified two IBC cell lines (SUM149, SUM-190) with a p53 gene alteration that predicted a change in the encoded protein, SUM149 at exon 7 (ATG to ATA, Met-237-Ile) and SUM190 at exon 9 (CAG to TAG, Gln -317-stop). Both mutations have been previously reported. Five nonsense mutations were identified in two other cell lines, MDA-453 and MDA321. No mutations were identified in KPL4 and HMLE cells.Conclusions: The p53 mutation profile in breast cancer cell lines suggests an additional biological feature for the characterization of IBC. Furthermore, these data support the previously reported association between p53 status and chemo- and radioresistance in this disease responsible for poor prognosis. Therapies directed to restore p53 function should be explored in IBC models and in clinical trials.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3161.

Suppression of mesenchymal phenotype in inflammatory breast cancer by EGFR tyrosine kinase inhibitor erlotinib: a novel approach to suppressing metastasis

Abstract #2042

Background: Inflammatory breast cancer (IBC) is a rare subtype well known for its propensity for rapid metastasis. The cause of this rapid metastasis in IBC is unknown. An immunohistochemical analysis of 44 cases of IBC showed HER2 overexpression in 48% of patients and epidermal growth factor receptor (EGFR) overexpression in 30% of patients. EGFR overexpression was the only poor prognostic factor: the 5-year overall survival rate was significantly lower for women with EGFR-positive disease than for women with EGFR-negative disease (P=0.01). HER2 overexpression was not a prognostic factor. The association between EGFR overexpression and increased risk of death indicated that EGFR may represent a potential therapeutic target in IBC. We hypothesized that suppression of the EGFR pathway inhibits proliferation and metastasis of IBC.&#x2028; Methods: SUM149 IBC cells, which express low levels of HER2 and high levels of EGFR, were treated with siRNA against EGFR and with the EGFR tyrosine kinase inhibitor erlotinib.&#x2028; Results: EGFR siRNA knockdown (but not non-targeting siRNA control) inhibited the proliferation of SUM149 cells. SUM149 cells were sensitive to EGFR tyrosine kinase inhibitor erlotinib in a 2-dimensional (2-D) culture system (median inhibitory concentration [IC50] = 0.90 µM). When we activated ERK by transfecting constitutively active MEK1 in SUM149 cells, the cells showed more resistance to erlotinib. Moreover, ERK siRNA knockdown sensitized SUM149 cells to erlotinib. Further, when we cultured the SUM149 cells in matrigel by using the 3-D culture system (100% matrigel in the bottom layer and cultured medium with 5% FBS and 2% matrigel in the top layer), erlotinib treatment changed the molecular phenotype of SUM149 cells from mesenchymal (a phenotype characterized by low beta-catenin expression and high vimentin and fibronectin expression) to epithelial (recovery of beta-catenin to the sites of cell-cell contacts; downregulation of fibronectin). This reversal of the mesenchymal phenotype, a hallmark of inhibition of epithelial-to-mesenchymal transition (EMT), was ERK dependent. Interestingly, the erlotinib concentration that inhibited the mesenchymal phenotype (0.1 mcM) was one log lower than the concentration that inhibited proliferation (1 mcM).&#x2028; Conclusion: Inhibition of tumor growth and EMT in SUM149 IBC cell lines is dependent on the ERK pathway through the EGFR pathway. The erlotinib dose needed to produce an anti-mesenchymal effect is much lower than the cytotoxic dose. Thus, we speculate ERK pathway to be important in inhibiting metastasis in IBC. We are currently investigating the effects of erlotinib in a xenograft model of IBC. Our study provides a rationale for developing novel treatment strategies targeting the EGFR and ERK pathways to inhibit the growth and metastasis of IBC.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2042.

A multistage nanodelivery system for therapeutic applications and medical imaging: in vivo biodistribution and efficacy study in a murine orthotopic breast cancer model

Abstract #2160

The ability to deliver therapeutic compounds specifically to diseased sites is crucial for effectively treating human illnesses. Nanotechnology is emerging as a tool for resolving challenges in the delivery of poorly administrable drugs by transforming them into nanometer-sized particles (nanotherapeutics). The progress thus far gave rise to a large number of nanotherapeutics, but the accomplishment of the original objective, which is to increase drug concentration at target sites, has not been fully realized. A series of biological barriers pose as insurmountable obstacles which limit or completely abolish the ability to selectively deliver a therapeutic agent. We hypothesized that a multi-stage system for systemic delivery (MSDS) could be designed to interact with and successfully overcome sequential biological barriers. We developed a MSDS using biodegradable, biocompatible silicon particles optimally sized and shaped to travel into the blood flow, avoid RES, marginate and adhere to tumor vasculature. The first stage carriers (FSCs) contain nanopores of specific size that can load, carry, release over time, and deliver multiple types of second stage nanoparticles (SSNs). The nanoparticles can be optimized to reach, through vessels fenestrations, the tumor environment and finally release their therapeutic payload into target cells.&#x2028; &#x2028; The ease in chemically modifying the silicon surface permits the attachment of fluorescent and radiolabeled imaging molecules to the FSCs. Fluorescent and magnetic SSNs can be loaded into the pores of the FSCs. Once assembled, the resulting MSDS can be imaged using different in vivo imaging modalities from its administration to its final localization into the body. We further modified our FSCs with PEG molecules to increase their circulation time and with antibodies directed against the VEGFR2 membrane protein to increase the localization of the MSDS in tumor associated vessels. We monitored the biodistribution of all MSDSs and characterized their biocompatibility in the different tissues. Finally, we loaded the pores of the FSCs with a lipidic nanoformulation of the potent anti cancer drug doxorubicin (dox-liposomes and dox-micelles) and followed the efficacy of this treatment. Taken together, these studies provide first time evidence that silicon nanoporous particles can be used as effective carriers for the simultaneous delivery of different nanotherapeutics in vivo.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2160.

Sources of phosphorus lost from a grazed pasture receiving simulated rainfall

Nutrients exported from grazing systems contribute to eutrophication of surface waters. In this study the contributions of soil, pasture-plants, and dung to P exports in overland flow were compared using simulated rainfall. The treatments were (i) grazed pasture-plants (isolated from soil by application of petrolatum to the soil surface), (ii) grazed pasture-plants and supporting soil, (iii) grazed pasture-plants and soil and treading, and (iv) grazed pasture-plants and soil and treading and dung. In general, dissolved reactive P (DRP) accounted for the majority of the P exported and P losses decreased in the order: treading and dung treatment>treading>pasture-plants and soil>pasture-plants. Very little dissolved organic P was lost in overland flow and the effects of treading diminished with time. Over a normal grazing cycle (30 d), the portion of P lost from pasture-plants was approximately half that lost from pasture-plants and soil, one-third that lost from treaded pasture-plants and soil, and one-quarter that lost from treaded pasture-plants, soil, and dung. The DRP in the pasture-plants treatment was approximately half that in the pasture-plants and soil treatment and suggests that a significant portion of the P exported from these systems is derived directly from pasture-plants. Due to higher proportions of particulate P (PP) in the treaded and dung treatments, DRP accounted for less of total P than in the pasture-plants and pasture-plants and soil treatments. Lower infiltration capacities probably caused by mechanical disaggregation at the soil surface are consistent with the higher proportions of PP in the treading treatments. These results were used to estimate P exports from a field trial site in Southland, New Zealand. The results suggested that P export attributable to fertilizer, dung, pasture-plants, and soil components were approximately 10, 30, 20, and 40%, respectively. These results suggest that since 90% of the P exports are derived from the soil-plant system and dung returns, managements to lessen P exports should continue to focus on maintaining soil P within the optimal range for pasture-plant production and maintaining soil surface properties that maximize infiltration and minimize overland flow.

Growing skull fracture in the absence of a dural tear

A case of growing skull fracture associated with unrecognized extradural haematoma is presented together with the relevant radiology. The pathophysiology of growing skull fracture is reviewed in light of this previously unreported case.

Two knees or not two knees? Patient costs and outcomes following bilateral and unilateral total knee joint replacement surgery for OA

AIMS

This study aims to address medical and non-medical direct costs and health outcomes of bilateral and unilateral total knee replacement from the patients' perspective during the first year post-surgery.

METHODS

Osteoarthritis patients undergoing primary unilateral total knee or bilateral total knee replacement (TKR) surgery at three Sydney hospitals were eligible. Patients completed questionnaires pre-operatively to record expenses during the previous three months and health status immediately prior to surgery. Patients then maintained detailed prospective cost diaries and completed SF-36 and WOMAC Index each three months for the first post-operative year.

RESULTS

Pre-operatively, no significant differences in health status were found between patients undergoing unilateral TKR and bilateral TKR. Both unilateral and bilateral TKR patients showed improvements in pain, stiffness and function from pre-surgery to 12 months post-surgery. Patients who had bilateral TKR spent an average of 12.3 days in acute hospital and patients who had unilateral TKR 13.6 days. Totally uncemented prostheses were used in 6% of unilateral replacements and 48% of bilateral replacements. In hospital, patients who had bilateral TKR experienced significantly more complications, mainly thromboembolic, than patients who had unilateral TKR. Regression analysis showed that for every one point increase in the pre-operative SF-36 physical score (i.e. improving physical status) out-of-pocket costs decreased by 94%. Out-of-pocket costs for female patients were 3.3 times greater than for males.

CONCLUSION

Patients undergoing bilateral TKR and unilateral TKR had a similar length of stay in hospital and similar out-of-pocket expenditures. Bilateral replacement patients reported better physical function and general health with fewer health care visits one year post procedure. Patients requiring bilateral TKR have some additional information to aid their decision making. While their risk of peri-operative complications is higher, they have an excellent chance of good health outcomes at 12 months and are not going to be doubly "out-of-pocket" for the experience.

Unbalanced growth in mouse cells with amplified dhfr genes

When grown in the absence of methotrexate, cells carrying unstably amplified dihydrofolate reductase (dhfr) genes have a growth disadvantage that is a function of their level of gene amplification. Although this growth disadvantage is thought to drive the loss of unstably amplified dhfr genes in the absence of methotrexate, its mechanism is not understood. The present studies of murine cell lines with different levels of dhfr gene amplification demonstrate that such cells experience increased unbalanced growth (excess RNA and protein content relative to DNA content) with increased levels of dhfr gene amplification. Stathmokinetic analysis of a cell line with unstably amplified dhfr genes showed that the unbalanced growth was associated with a very low rate of G1/S transit, which suggests that amplified DNA sequences may activate a cell cycle checkpoint at the G1/S boundary. Hydroxyurea, which is known to induce rapid elimination of amplified genes at sub-cytotoxic concentrations, also inhibits the cell cycle at the G1/S transition and causes unbalanced growth. Earlier work has shown that hydroxyurea selectively targets those cells within the heterogeneous drug resistant cell populations which have the highest amplified gene dosage. The finding that unstable gene amplification and hydroxyurea have similar effects on the cell suggests that hydroxyurea may achieve this selective targeting by pushing those cells with the highest levels of gene amplification over a critical stress threshold to cause growth arrest or cell death.

Scoring systems for grading deep leg vein thrombosis

A scoring system could be used in all situations where grading of deep leg vein thrombosis (DVT), including mapping of its distribution, is needed. It should also be used in epidemiological studies of DVT in further analysis of different risk groups suffering from DVT. Several scoring systems have been developed during the last three decades but have resulted in various complex and impractical systems. A scoring system should be easy to follow without any risk of misunderstanding and misinterpretation. All vein segments of importance should be defined and be possible to be included. This review describes and compares the scoring systems according to Marder et al., Arnesen et al., a subcommittee of venous disease and Björgell et al.

Radiology of the spleen

The spleen is generally not considered a challenge to the radiologist. Most often it poses a problem by anomalies or an irregular but normal contrast enhancement; however, a variety of inflammatory, infectious and neoplastic diseases may involve the spleen. CT and ultrasonography are screening modalities for the spleen. For problem solving, MR imaging can be helpful, especially due to its free choice of the imaging plane and because of the high resolution in contrast MR imaging. Splenic angiography as a diagnostic tool has generally been replaced by CT, ultrasound, or MR and is now used as an interventional method, e. g., in non-surgical management of patients with chronic idiopathic thrombocytopenia or in patients with splenic trauma. This article reviews the radiology of the spleen, including anatomy, embryology, splenomegaly, splenic injury, infarction, cysts, tumors, abscesses, sarcoidosis, and AIDS. Knowledge about the use of different imaging modalities and underlying gross and microscopic pathologic features leads to a better understanding of the radiologic findings.

40 years of the British Medical Association film competition

Since its inception in 1957 the BMA's annual film competition has fulfilled three roles--promoting the effective use of film and video in medical education, encouraging the production of high quality audiovisual material, and helping to increase the holdings of its film library. The BMA awards recognise programmes for their clinical accuracy, educational value and creative use of the medium.

Paths to Success

The Class of ′71 is a longitudinal study following the educational and career paths of a group of Australians over the years from secondary school to mid-adulthood. This article is the second of a two-part series detailing the results of this study. In Part 1, which appeared in the Spring 1995 edition of this journal, factors associated with career outcomes, measured 20 years after secondary school, were detailed. In this article, findings that relate to intergenerational mobility, the association of unemployment with career outcomes, the match between occupational aspirations and achievements, and factors the respondents believed were influential regarding career outcomes are reported.

Role of adhesion molecules in leukocyte binding to endothelial cells adherent to vascular grafts

BACKGROUND

The localization of leukocytes to vascular grafts is an essential part of healing and infection resistance. The mechanisms involved in this process are only partly understood.

STUDY DESIGN

Human saphenous vein endothelial cells (HSVEC) were grown on control polystyrene culture ware and expanded polytetrafluoroethylene (ePTFE). The binding of monoclonal antibodies against the intercellular adhesion molecule (ICAM-1) and the E-selectin by adherent HSVEC was determined by flow cytometry. Peripheral blood leukocytes (PBL) were cocultured with HSVEC adherent to ePTFE and leukocyte binding was determined with and without the addition of a protein kinase C inhibitor.

RESULTS

HSVEC adherent to ePTFE constitutively bound anti-ICAM-1 antibodies, which were attenuated by the protein kinase C inhibitor, H-7. HSVEC adherent to ePTFE bound significantly greater numbers of leukocytes than those on control (58 versus 41 percent, p < 0.05). Incubation with H-7 decreased leukocyte binding to HSVEC significantly (p < 0.005). Coculture of PBL with HSVEC adherent to ePTFE caused a tenfold increase in binding of anti-E-selectin antibodies (p < 0.0005).

CONCLUSIONS

These data indicate that PBL binding to HSVEC adherent to ePTFE is, at least in part, ICAM-1 to HSVEC adherent to ePTFE is, at least in part, ICAM-1 and E-selection dependent.

Isolation and Structure Determination of Demethylchodatin—a New Lichen Xanthone

The structure of demethylchodatin, a xanthone from the lichen Lecanora pachysoma, has been established by X-ray analysis of the corresponding triacetate derivative. Crystals of demethylchodatin triacetate are monoclinic, P 21/a, a 10.120(3), b 11.278(3), c 19.173(4) Ǻ, β 94.68(3)°; Z 4. Refinement of 1411 data with I > 3σ(I) gave conventional R factors of 0.041 and 0.033.

Expression of the 40 kD protein in DLD-1 colon cancer cells and the effect of cytokines

We recently reported the presence of an organ-specific 40 kD colonic protein which acts as an autoantigen(s) in patients with ulcerative colitis. Using a specific monoclonal antibody directed against 40 kD protein (7E12H12, IgM isotype), in conjunction with immunocytochemistry and flow cytometry, we examined the presence of the 40 kD protein on human colon cancer cells, DLD-1, and also characterized the ability of cytokines, IFN-gamma and tumour necrosis factor, to modulate the expression of this protein on these tumour cells. The presence of the 40 kD protein was localized to the plasma membrane; less was present within the cytoplasm. Following exposure to IFN-gamma (10-1000 U/ml), DLD-1 colon tumour cells showed a dose- and time-dependent increase in 7E12H12 antibody associated immunofluorescence, with the maximum 7E12H12 antibody binding observed with 100 U/ml IFN-gamma at 48 h. In contrast, tumour necrosis factor did not alter the levels of anti-40 kD antibody binding over that of control cells. Since IFN-gamma is also known to induce class II major histocompatibility antigens, we examined the possibility of cross-reactivity of HLA class II antigens and Mr 40 kD epitope. Neither pre-incubation of DLD-1 colon tumour cells with anti-HLA class II antibodies followed by 7E12H12 nor co-incubation of both antibodies altered the amount of 7E12H12 antibody binding. Using a direct ELISA, a highly enriched preparation of Mr 40 kD protein reactive to anti-40 kD antibody did not react with HLA class II antibodies. The present results suggest that 40 kD protein is present on DLD-1 human colon tumour cells and that although the 40 kD protein epitope expression is increased by the lymphocyte-derived cytokine, IFN-gamma, the epitope is separate and distinct from the class II HLA antigens. Further studies on the 40 KD protein may elucidate its autoantigenic role in the pathogenesis of inflammatory bowel disease.

Stimulatory effects of FK156 in a panel of tests designed to detect changes in immune function

There is a need to evaluate the utility of experimental models in immune function assessment if these are to be accepted in preclinical safety studies. We have evaluated a panel of tests measuring cellularity and functions of the lymphoid system in the Fischer rat in order to determine whether they would detect immunostimulation, rather than suppression. Injection of the peptide immunostimulant FK156 (D-lactyl-L-alanyl-y-D-glutamyl-(L)-meso-diaminopimelyl- (L)-glycine) increased the numbers of macrophages recovered from the peritoneal cavity, and stimulated their activity, as measured by chemiluminescence, adherence, and secretion of interleukin 1. In vitro, T lymphocytes had an increased background incorporation of tritiated thymidine, increased response to sub-optimal concentrations of concanavalin A, and an increase in secretion of interleukin 2 at optimal concentrations of concanavalin A. There was no change in the proliferative responses of B lymphocytes in vitro. Antibody responses to tetanus toxoid in vivo were increased. These changes were not reflected in consistent, statistically significant alterations in the numbers of lymphocytes bearing either lineage markers or the interleukin 2 receptor as a marker of activation.

A classification of prescription errors

Three independent methods of study of prescription errors led to the development of a classification of errors based on the potential effects and inconvenience to patients, pharmacists and doctors. Four types of error are described: type A (potentially serious to patient); type B (major nuisance - pharmacist/doctor contact required); type C (minor nuisance - pharmacist must use professional judgement); and type D (trivial). The types of frequency of errors are detailed for a group of eight principals from one health centre. There were a total of 504 errors from 15,916 prescription items (3.17%) during a three month observation period. A close correspondence was found between individual doctor's types of error rates, suggesting that doctors who make type C and D errors are also likely to make type B (major nuisance) errors. A system of feedback of errors from each doctor was devised. No significant reduction was seen in error rates, possibly because the group of self selected doctors taking part had low error rates initially. It is suggested that pharmacists and doctors should work closely together to prevent the potentially harmful consequences of prescription errors.