From mutation to management: Advancing Langerhans cell histiocytosis treatment through combination therapies

The treatment landscape for relapsed Langerhans cell histiocytosis (LCH) is fraught with uncertainty due to a scarcity of data. Karri et al.'s study provides promising evidence that combining MAPK pathway inhibitors with chemotherapy could improve outcomes, even for patients with multiple relapses. Although larger studies are needed, this approach suggests a shift towards more aggressive, potentially curative strategies in the management of LCH. Commentary on: Karri et al. Clinical, radiological and molecular responses to combination chemotherapy with MAPK pathway inhibition in relapsed and refractory Langerhans cell histiocytosis. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19380.

Ibrutinib Is Associated With Increased Cardiovascular Events and Major Bleeding in Older CLL Patients

Background

Early ibrutinib trials showed an association between ibrutinib use and risk of bleeding and atrial fibrillation (AF) in younger chronic lymphocytic leukemia (CLL) patients. Little is known about these adverse events in older CLL patients and whether increased AF rates are associated with increased stroke risk.

Objectives

To compare the incidence of stroke, AF, myocardial infarction, and bleeding in CLL patients treated with ibrutinib with those who were treated without ibrutinib in a linked SEER-Medicare database.

Methods

The incidence rate of each adverse event for treated and untreated patients was calculated. Among those treated, inverse probability weighted Cox proportional hazards regression models were used to calculate HRs and 95% CIs for the association between ibrutinib treatment and each adverse event.

Results

Among 4,958 CLL patients, 50% were treated without ibrutinib and 6% received ibrutinib. The median age at first treatment was 77 (IQR: 73-83) years. Compared with those treated without ibrutinib, those treated with ibrutinib had a 1.91-fold increased risk of stroke (95% CI: 1.06-3.45), 3.65-fold increased risk of AF (95% CI: 2.42-5.49), a 4.92-fold increased risk of bleeding (95% CI: 3.46-7.01) and a 7.49-fold increased risk of major bleeding (95% CI: 4.32-12.99).

Conclusions

In patients a decade older than those in the initial clinical trials, treatment with ibrutinib was associated with an increased risk of stroke, AF, and bleeding. The risk of major bleeding is higher than previously reported and underscores the importance of surveillance registries to identify new safety signals.

Is a spice missing from the recipe? The intra-cellular localization of vanillin biosynthesis needs further investigations

Vanillin is the most popular flavor compound in the world. Substantial effort were made in the last decades to completely elucidate the metabolic pathway that leads to vanillin in plants, with some controversy reported. In V. planifolia, vanillin biosynthesis occurs in plastids or in redifferentiated-plastids termed ''phenyloplasts''. More recently, it was shown that all enzymes required for the conversion of [¹⁴ C]-phenylalanine to [¹⁴ C]-vanillin-glucoside are confined within that organelle. However, knowing that some of these enzymes are cytosolic or ER-membrane bound in most plant species, it raises questions on the interpretation of data obtained from the technique used and on the true localization of the biosynthetic enzymes in V.planifolia. In addition, intense debate has emerged about the real participation of last enzyme of the pathway involving vanillin synthase (VpVAN) in the direct conversion of ferulic acid to vanillin. With the discovery of another enzyme capable of this conversion and the lack of activity of VpVAN in vitro, further disagreement emerged. One additional challenge to VpVAN being necessary and sufficient is that the transcript for this protein is abundant invarious non-vanillin-producing tissues of the vanilla plant. In this viewpoint, we discuss the findings surrounding the cellular-localization and activity of enzymes of vanillin biosynthesis. This will help to further understand the pathway and urge for additional research study to resolve the debate.

Clinical Outcomes and Toxic Effects of Single-Agent Immune Checkpoint Inhibitors Among Patients Aged 80 Years or Older With Cancer: A Multicenter International Cohort Study

Importance

Geriatric (aged ≥80 years) patients are historically underrepresented in cancer clinical trials. Little is known about the efficacy of immune checkpoint inhibitors (ICIs) in geriatric patients. These agents are associated with immune-related adverse events (irAEs), which may be particularly associated with morbidity in this population.

Objective

To provide insight into the clinical outcomes and safety of ICIs among geriatric patients (aged ≥80 years) with cancer.

Design, Setting, and Participants

A Multicenter, international retrospective study of 928 geriatric patients with different tumors treated with single-agent ICIs between 2010 to 2019 from 18 academic centers in the US and Europe. Analyses were conducted from January 2021 to April 2021.

Main Outcomes and Measures

Clinical outcomes and irAE patterns in geriatric patients treated with single-agent ICIs.

Results

Median (range) age of the 928 patients at ICI initiation was 83.0 (75.8-97.0) years. Most patients (806 [86.9%]) were treated with anti-programmed cell death 1 therapy. Among the full cohort, the 3 most common tumors were non-small cell lung cancer (NSCLC, 345 [37.2%]), melanoma (329 [35.5%]), and genitourinary (GU) tumors (153 [16.5%]). Objective response rates for patients with NSCLC, melanoma, and GU tumors were 32.2%, 39.3%, and 26.2%, respectively. Median PFS and OS, respectively, were 6.7 and 10.9 months (NSCLC), 11.1 and 30.0 months (melanoma), and 6.0 and 15.0 months (GU). Within histologically specific subgroups (NSCLC, melanoma, and GU), clinical outcomes were similar across age subgroups (aged <85 vs ≥85 years). Among all 928 patients, 383 (41.3%) experienced ≥1 irAE(s), including 113 (12.2%) that were reported to be grade (G) 3 to 4 based on Common Terminology Criteria for Adverse Events (version 5.0). The median time to irAE onset was 9.8 weeks; 219 (57%) occurred within the first 3 months after ICI initiation. Discontinuation of treatment with ICIs owing to irAEs occurred in 137 (16.1%) patients. There was no significant difference in the rate of irAEs among patients aged younger than 85, 85 to 89, and 90 years or older. Despite the similar rate of G3 or higher irAEs, ICIs were discontinued owing to irAEs more than twice as often among patients aged 90 years or older compared with patients younger than 90 years (30.9% vs 15.1%, P = .008).

Conclusions and Relevance

The findings of this international cohort study suggest that treatment with ICIs may be effective and generally well tolerated among older patients with cancer, though ICI discontinuation owing to irAEs was more frequent with increasing age.

239 Efficacy and toxicity of single agent immune checkpoint inhibitors among adults with cancer aged ≥80 years: a multicenter international cohort study

Background

Immune checkpoint inhibitors (ICIs) are approved by the U.S. Food&Drug Administration in over 17 tumor types. Older adult patients make up about a quarter of all cancer patients but are historically understudied in cancer clinical trials. ICIs are associated with immune-related adverse events (irAEs), which may be particularly morbid for older adult patients with underlying comorbidities and impaired functional status. In this study, we provide insight into the real-world safety and efficacy of ICIs among older adult patients (≥80 years) with cancer.

Methods

This is a multicenter, international retrospective study of tumor-agnostic older adult patients with cancer treated with single-agent ICIs between 2010–2019 from 18 academic centers in the U.S. and Europe. A cohort of 928 patients aged ≥80 years during treatment with ICI was assembled and analyzed to evaluate clinical outcomes and irAE patterns in older adult patients treated with single-agent ICIs.

Results

Median age at ICI initiation was 83.0 years (range 75.8–97.0). Most patients (86.9%) were treated with anti-PD-1 therapy. Among the full cohort, the three most common tumors were non-small cell lung cancer (NSCLC, 37.2%,n=345), melanoma (35.5%,n=329), and genitourinary (GU) tumors (16.5%,n=153). Objective response rates for patients with NSCLC, melanoma, and GU tumors were 32.2%, 39.3%, and 26.2%, respectively. Median progression-free survival (PFS) was 6.7 months (95%CI, 5.2–8.6) for patients with NSCLC, 11.1 months (95%CI, 8.9–16.0) for patients with melanoma, and 6.0 months (95% CI, 5.0–10.7) for patients with GU malignancy. Median overall survival (OS) was 10.9 months (95%CI, 8.6–13.1) for patients with NSCLC, 30.0 months (95%CI, 23.6–46.4) for patients with melanoma, and 15.0 months (95%CI 9.1–25.4) for GU patients (Figure 1A-C). Within histology-specific cohorts (NSCLC, melanoma and GU), clinical outcomes were similar across age subgroups (<85,85–89,>90). Among all patients (N=928), 41.3% experienced ≥1 irAE(s), including 12.2% reported to be grade (G)3–4. No irAE-related deaths occurred. The median time to irAE onset was 9.8 weeks; 57% occurred within the first 3 months after ICI initiation. ICI was discontinued due to irAEs in 16.1% patients. There was no significant difference in the rate of irAEs among patients age <85, 85–89, and ≥90 years (p=0.15). Despite similar rates of G3+ irAEs, ICIs were discontinued due to irAE more than twice as often among patients ≥90 years compared to patients <90 years (30.9% vs. 15.1%, p=0.008) (table 1).

Conclusions

ICIs are effective and generally well-tolerated among older patients with cancer. However, ICI discontinuation due to irAE is more frequent with increasing age.

The hypercoagulable state in COVID-19: Incidence, pathophysiology, and management

The 2019 coronavirus disease (COVID-19) presents with a large variety of clinical manifestations ranging from asymptomatic carrier state to severe respiratory distress, multiple organ dysfunction and death. While it was initially considered primarily a respiratory illness, rapidly accumulating data suggests that COVID-19 results in a unique, profoundly prothrombotic milieu leading to both arterial and venous thrombosis. Consistently, elevated D-dimer level has emerged as an independent risk factor for poor outcomes, including death. Several other laboratory markers and blood counts have also been associated with poor prognosis, possibly due to their connection to thrombosis. At present, the pathophysiology underlying the hypercoagulable state is poorly understood. However, a growing body of data suggests that the initial events occur in the lung. A severe inflammatory response, originating in the alveoli, triggers a dysfunctional cascade of inflammatory thrombosis in the pulmonary vasculature, leading to a state of local coagulopathy. This is followed, in patients with more severe disease, by a generalized hypercoagulable state that results in macro- and microvascular thrombosis. Of concern, is the observation that anticoagulation may be inadequate in many circumstances, highlighting the need for alternative or additional therapies. Numerous ongoing studies investigating the pathophysiology of the COVID-19 associated coagulopathy may provide mechanistic insights that can direct appropriate interventional strategies.

Survival from time of transformation in patients with transformed lymphoma at time of diagnosis

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Background: Histologic transformation (HT) to aggressive lymphoma can occur in indolent lymphoma and is considered to convey poor prognosis. Most data come from follicular lymphoma (FL). We conducted a retrospective analysis to compare outcomes of transformed marginal zone lymphoma and lymphoplasmacytic lymphoma (tMZL/LPL) with those of transformed FL (tFL). Methods: We collected data from patients diagnosed with HT between 2000 and 2018. Transformed CLL was excluded. Survival estimates were done with the Kaplan Meier method; comparisons were done with log-rank test. The effect of covariates on OS was evaluated with Cox proportional hazards method. Results: We identified 87 pts (58 tFL, 29 tMZL/LPL). There were no differences in baseline characteristics, except for COO subtype by Hans criteria and circulating IgM. There were no differences in OS or EFS based on the underlying lymphoma subtype (OS: tFL = 60.1m vs. tMZL/LPL = 64.8m, p = 0.53; EFS: tFL = 25.2m vs. tMZL/LPL = 27.6m). Univariate and multivariate analyses identified age at HT (HR for age > 60 = 3.5, 95% CI: 1.7-7.6), poor performance status (HR for ECOG ≥3 = 23, 95% CI: 7.3-70) and having a previous diagnosis of indolent lymphoma (HR for previous diagnosis = 3.7, 95% CI: 1.87-7.4) as adverse risk factors for OS after HT. Pts with previous diagnosis of indolent lymphoma with subsequent HT had inferior OS than pts presenting first with HT (median OS 25m vs. not reached, p < 0.0001); EFS (median EFS for treated pts = 11m vs. 49m). Conclusions: Underlying lymphoma does not affect OS after HT and long term survival can be achieved in pts who receive treatment. tMZL/LPL is more frequently of non-GCB origin has monoclonal IgM. Pts who present with HT as their first lymphoma-related event have better OS. These findings will lead to further exploration of the genetic changes that occur at the time of transformation of indolent lymphomas. [Table: see text]

Prognostic value of baseline elevated red cell distribution width in DLBCL

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Background: Elevated red cell distribution width (RDW) has been associated with all-cause mortality, risk of developing cancer and cancer mortality in large retrospective studies. The underlying mechanism may be due to inflammatory and nutritional abnormalities. We hypothesized DLBCL patients with an elevated RDW at the time of diagnosis would have a worse prognosis. Methods: A retrospective single-institution study included 541 DLBCL patients diagnosed between 2001 and 2016. RDW over 14.5% was considered high, as this was the upper limit of normal at our institution. The overall and progression free survival was estimated using Kaplan-Meier methods, and the difference between groups was compared using the log-rank test. Univariate and multivariate analyses were performed with Cox proportional hazards regression. Results: We identified 410 DLBCL pts with available baseline RDW, 229 (56%) had RDW > 14.5. Median follow up from diagnosis was 60 months. The complete response rate was 63.8% in the group with high RDW (n = 152) and 88.4% in the normal RDW group (n = 216, p < 0.0001) . For patients with high RDW, 1-year overall survival (OS) was 65% (95%CI 0.58-0.72) vs 90% (95%CI 0.87-0.94) for pts with normal RDW < / = 14.5; 2-year OS was 57% (95%CI 0.50-0.65) vs 84% (95%CI 0.79-0.89), respectively (p < 0.0001). This difference remained statistically significant when the analysis was restricted to patients treated with anthracycline-containing regimens given with curative intent (2y OS = 66% vs. 87.5%, p < 0.0001). Univariate analysis revealed that R-IPI, high RDW, elevated LDH, albumin < 3.5mg/dl, Hgb < 10g/dl, advanced stage disease, bulky disease, extra nodal disease, and ECOG performance status 3-4 were associated with worse OS. In multivariate analysis, older age (HR 2.07, 95%CI 1.38-3.1), high RDW (HR 1.68, 95%CI 1.15-2.5), albumin < 3.5mg/dl (HR 1.76, 95%CI 1.18-2.6) and ECOG 3-4 (HR 2.47, 95%CI 1.47-4.2) were independent prognostic factors for OS. Conclusions: High RDW is associated with worse response rates and independently associated with worse OS in patients with DLBCL. Based on our study, DLBCL patients with high RDW at diagnosis should be considered at higher risk of mortality and treatment failure. Further research is needed to clarify the underlying mechanism and to evaluate the utility of incorporating RDW into prognostic indices.

Classifying continuous, real-time e-nose sensor data using a bio-inspired spiking network modelled on the insect olfactory system

In many application domains, conventional e-noses are frequently outperformed in both speed and accuracy by their biological counterparts. Exploring potential bio-inspired improvements, we note a number of neuronal network models have demonstrated some success in classifying static datasets by abstracting the insect olfactory system. However, these designs remain largely unproven in practical settings, where sensor data is real-time, continuous, potentially noisy, lacks a precise onset signal and accurate classification requires the inclusion of temporal aspects into the feature set. This investigation therefore seeks to inform and develop the potential and suitability of biomimetic classifiers for use with typical real-world sensor data. Taking a generic classifier design inspired by the inhibition and competition in the insect antennal lobe, we apply it to identifying 20 individual chemical odours from the timeseries of responses of metal oxide sensors. We show that four out of twelve available sensors and the first 30 s (10%) of the sensors' continuous response are sufficient to deliver 92% accurate classification without access to an odour onset signal. In contrast to previous approaches, once training is complete, sensor signals can be fed continuously into the classifier without requiring discretization. We conclude that for continuous data there may be a conceptual advantage in using spiking networks, in particular where time is an essential component of computation. Classification was achieved in real time using a GPU-accelerated spiking neural network simulator developed in our group.

Reaching control of a full-torso, modelled musculoskeletal robot using muscle synergies emergent under reinforcement learning

'Anthropomimetic' robots mimic both human morphology and internal structure-skeleton, muscles, compliance and high redundancy--thus presenting a formidable challenge to conventional control. Here we derive a novel controller for this class of robot which learns effective reaching actions through the sustained activation of weighted muscle synergies, an approach which draws upon compelling, recent evidence from animal and human studies, but is almost unexplored to date in the musculoskeletal robot literature. Since the effective synergy patterns for a given robot will be unknown, we derive a reinforcement-learning approach intended to allow their emergence, in particular those patterns aiding linearization of control. Using an extensive physics-based model of the anthropomimetic ECCERobot, we find that effective reaching actions can be learned comprising only two sequential motor co-activation patterns, each controlled by just a single common driving signal. Factor analysis shows the emergent muscle co-activations can be largely reconstructed using weighted combinations of only 13 common fragments. Testing these 'candidate' synergies as drivable units, the same controller now learns the reaching task both faster and better.

Rare germline mutations in the BRCA2 gene are associated with early-onset prostate cancer

Studies of families who segregate BRCA2 mutations have found that men who carry disease-associated mutations have an increased risk of prostate cancer, particularly early-onset disease. A study of sporadic prostate cancer in the UK reported a prevalence of 2.3% for protein-truncating BRCA2 mutations among patients diagnosed at ages ⩽55 years, highlighting the potential importance of this gene in prostate cancer susceptibility. To examine the role of protein-truncating BRCA2 mutations in relation to early-onset prostate cancer in a US population, 290 population-based patients from King County, Washington, diagnosed at ages <55 years were screened for germline BRCA2 mutations. The coding regions, intron–exon boundaries, and potential regulatory elements of the BRCA2 gene were sequenced. Two distinct protein-truncating BRCA2 mutations were identified in exon 11 in two patients. Both cases were Caucasian, yielding a mutation prevalence of 0.78% (95% confidence interval (95%CI) 0.09–2.81%) and a relative risk (RR) of 7.8 (95%CI 1.8–9.4) for early-onset prostate cancer in white men carrying a protein-truncating BRCA2 mutation. Results suggest that protein-truncating BRCA2 mutations confer an elevated RR of early-onset prostate cancer. However, we estimate that <1% of early-onset prostate cancers in the general US Caucasian population can be attributed to these rare disease-associated BRCA2 mutations.

The effect of deep brain stimulation on quality of life in movement disorders

Deep brain stimulation (DBS) is a viable treatment alternative for patients with Parkinson's disease (PD), essential tremor (ET), dystonia, and cerebellar outflow tremors. When poorly controlled, these disorders have detrimental effects on the patient's health related quality of life (HRQoL). Instruments that measure HRQoL are useful tools to assess burden of disease and the impact of therapeutic interventions on activities of daily living, employment, and other functions. We systematically and critically reviewed the literature on the effects of DBS on HRQoL in PD, ET, dystonia, and cerebellar outflow tremor related to multiple sclerosis.

National level promotion of physical activity: results from England's ACTIVE for LIFE campaign

STUDY OBJECTIVE

To assess the impact of a national campaign on awareness of the campaign, change in knowledge of physical activity recommendations and self reported physical activity.

DESIGN

three year prospective longitudinal survey using a multi-stage, cluster random probability design to select participants.

SETTING

England.

PARTICIPANTS

A nationally representative sample of 3189 adults aged 16-74 years.

MAIN OUTCOME MEASURES

Awareness of the advertising element of the campaign, changes in knowledge of physical activity recommendations for health and self reported physical activity.

RESULTS

38% of participants were aware of the main advertising images, assessed six to eight months after the main television advertisement. The proportion of participants knowledgeable about moderate physical activity recommendations increased by 3.0% (95% CI: 1.4%, 4.5%) between waves 1 and 2 and 3.7% (95% CI: 2.1%, 5.3%) between waves 1 and 3. The change in proportion of active people between baseline and waves 1 and 2 was -0.02 (95% CI: -2.0 to +1.7) and between waves 1 and 3 was -9.8 (-7.9 to -11.7).

CONCLUSION

The proportion of participants who were knowledgeable about the new recommendations, increased significantly after the campaign. There was however, no significant difference in knowledge by awareness of the main campaign advertisement. There is no evidence that ACTIVE for LIFE improved physical activity, either overall or in any subgroup.

Alkaline response genes of Saccharomyces cerevisiae and their relationship to the RIM101 pathway

Environmental pH exerts broad control over growth and differentiation, but the molecular responses to external pH changes are poorly understood. Here we have used open reading frame macroarray hybridization to identify alkaline response genes in Saccharomyces cerevisiae. Northern or lacZ fusion assays confirmed the alkaline induction of two ion pump genes (ENA1 and VMA4), several ion limitation genes (CTR3, FRE1, PHO11/12, and PHO84), a siderophore-iron transporter gene (ARN4/ENB1), two transcription factor genes (NRG2 and TIS11), and two predicted membrane protein genes (YAR068W/YHR214W and YOL154W). Unlike ENA1 and SHC1, these new alkaline response genes are not induced by high salinity. The known pH-responsive genes in other fungi depend on the conserved PacC/Rim101p transcription factor, but induction of several of these new genes relied upon Rim101p-independent pH signaling mechanisms. Rim101p-dependent genes were also dependent on Rim13p, a protease required for Rim101p processing. The Rim101p-dependent gene VMA4 is required for growth in alkaline conditions, illustrating how Rim101p may control adaptation. Because Rim101p activates ion pump genes, we tested the role of RIM101 in ion homeostasis and found that RIM101 promotes resistance to elevated cation concentrations. Thus, gene expression surveys can reveal new functions for characterized transcription factors in addition to uncovering physiological responses to environmental conditions.

Inability of five-month-old infants to retrieve a contiguous object: a failure of conceptual understanding or of control of action?

Infants of 5 to 6 months of age can retrieve a free-standing object, but fail to retrieve the same object from atop a slightly larger object. The accepted explanation has been that the infants do not understand that an object continues to exist independently when placed upon another. Predictions based on that explanation were tested against the hypothesis that infants' problem consists of lack of precision in visually guided reaching and lack of ability to inhibit reflexive reactions to touch. Twelve infants each at 5 and 7 months of age were tested on 16 trials. More 5-month-olds succeeded, in less time, and with fewer touches to an edge of the base, on trials more forgiving of an imprecise reach than on less forgiving trials. Success in retrieving objects close in size and fully contiguous with their bases was seen even at 5 months when the demands on skill in reaching were reduced. It is proposed that when 5-month-old infants fail to retrieve one object placed upon another, it is not because of a lack of conceptual understanding, but because they lack the skill to reach to the top object without accidentally touching an edge of the base en route.

A single-transformation gene function test in diploid Candida albicans

The fungal pathogen Candida albicans is naturally diploid, and current gene disruption strategies require two successive transformations. We describe here a genetic construct (UAU1) for which two copies may be selected. Insertion of UAU1 into one genomic site, after a single transformation, allows selection for segregants with two copies of the insertion. Major classes of segregants are those carrying homozygous insertion mutations and allelic triplications, which have two insertion alleles and a wild-type allele. Thus nonessential and essential genes may be distinguished rapidly through PCR tests for homozygosis and triplication. We find that homozygous mutations may be isolated at three nonessential loci (ADE2, RIM20, and YGR189), while only allelic triplications were found at two essential loci (SNF1 and CDC28). We have unexpectedly isolated homozygous mutants with mutations at CDC25; they are viable but defective in filamentation on serum-containing medium. The UAU1 cassette is thus useful to assess rapidly the essentiality of C. albicans genes.

Close interrelation of motor development and cognitive development and of the cerebellum and prefrontal cortex

Motor development and cognitive development may be fundamentally interrelated. Contrary to popular notions that motor development begins and ends early, whereas cognitive development begins and ends later, both motor and cognitive development display equally protracted developmental timetables. When cognitive development is perturbed, as in a neurodevelopmental disorder, motor development is often adversely affected. While it has long been known that the striatum functions as part of a circuit with dorsolateral prefrontal cortex, it is suggested here that the same is true for the cerebellum and that the cerebellum may be important for cognitive as well as motor functions. Like prefrontal cortex, the cerebellum reaches maturity late. Many cognitive tasks that require prefrontal cortex also require the cerebellum. To make these points, evidence is summarized of the close co-activation of the neocerebellum and dorsolateral prefrontal cortex in functional neuroimaging, of similarities in the cognitive sequelae of damage to dorsolateral prefrontal cortex and the neocerebellum, of motor deficits in "cognitive" developmental disorders, and of abnormalities in the cerebellum and in prefrontal cortex in the same developmental disorders.

An audit of subcutaneous syringe drivers in a non-specialist hospital

The use of syringe drivers as a method of drug delivery to control symptoms in palliative care is a common and accepted practice, but one which has evolved rather than been subject to close multiprofessional scrutiny and guideline formation. There is evidence that adverse incidents may arise as a result of syringe driver use (Medical Devices Agency (MDA), 1998), for example, errors in drug calculations, drug stability, equipment failure (including disconnection) and the wrong rate of infusion. Inadequate user training, poor servicing of equipment and inadequate documentation and record keeping are all thought to be contributing factors (MDA, 1998). In the hospital where this audit was carried out, syringe drivers are used to administer drugs to patients with cancer during the palliative phase of illness. The purpose of this clinical audit was to establish the standard of current practice in wards where syringe drivers were being used. A retrospective study of 13 cases of syringe driver use is presented. The results highlight many areas of unregulated practice with regard to setting up, monitoring and maintenance of syringe drivers. The choice of drugs and doses prescribed, evaluation of treatment responses and review of treatment regimens were also areas of concern. Guidelines for the use of syringe drivers in non-specialist hospitals are put forward.

Infratentorial and supratentorial leukoencephalopathy associated with vitamin B12 deficiency

BACKGROUND

Striking cerebral white matter abnormalities involving supratentorial regions seen on magnetic resonance imaging (MRI) scans have been described in patients with vitamin B12 deficiency. Severe involvement of infratentorial structures with partial reversibility has not been previously documented.

OBSERVATION

A 54-year-old man experienced severe weight loss, associated with dementia and focal deficits. Laboratory analysis showed a severe vitamin B12 deficiency and elevated serum homocysteine. MRI scans showed a severe and diffuse white matter abnormal signal involving both the supra- and infratentorial compartments. Vitamin B12 supplementation resulted in a mild improvement in cognitive deficits and a marked resolution of imaging abnormalities.

CONCLUSION

Leukoencephalopathy and dementia should raise the suspicion of a vitamin B12 deficiency because vitamin B12 supplementation may result in at least partial clinical improvement.

The prevalence and types of coronary artery anomalies in Northern Ireland

Coronary artery anomalies are uncommon, with a reported prevalence ranging from 0.2% to 1.6%. It is important that those who undertake coronary angiographic procedures are aware of the spectrum of these anomalies. Interventional percutaneous coronary revascularisation procedures are widely used in the management of patients with symptomatic coronary atherosclerosis. The presence of a coronary artery anomaly may make these procedures technically challenging. We have reviewed the Cardiac catheterisation database at the Royal Victoria Hospital, Belfast, and report the prevalence and types of these anomalies.

Close interrelation of motor development and cognitive development and of the cerebellum and prefrontal cortex

Motor development and cognitive development may be fundamentally interrelated. Contrary to popular notions that motor development begins and ends early, whereas cognitive development begins and ends later, both motor and cognitive development display equally protracted developmental timetables. When cognitive development is perturbed, as in a neurodevelopmental disorder, motor development is often adversely affected. While it has long been known that the striatum functions as part of a circuit with dorsolateral prefrontal cortex, it is suggested here that the same is true for the cerebellum and that the cerebellum may be important for cognitive as well as motor functions. Like prefrontal cortex, the cerebellum reaches maturity late. Many cognitive tasks that require prefrontal cortex also require the cerebellum. To make these points, evidence is summarized of the close co-activation of the neocerebellum and dorsolateral prefrontal cortex in functional neuroimaging, of similarities in the cognitive sequelae of damage to dorsolateral prefrontal cortex and the neocerebellum, of motor deficits in "cognitive" developmental disorders, and of abnormalities in the cerebellum and in prefrontal cortex in the same developmental disorders.

Early developments in the ability to understand the relation between stimulus and reward

Delayed nonmatching to sample (DNMS) is used to test the recognition memory function dependent on the medial temporal lobe. Children cannot succeed on this task until about 21 months. Because robust recognition is present well before then, the late emergence of another ability must account for the late success on DNMS. Evidence is presented here that the critical late-maturing competence is the ability to grasp the relation between stimulus and reward--that is, to understand that the stimulus is a symbol or marker for the reward. Infants of 9 and 12 months were tested on 3 conditions of DNMS. A sample object was presented. After a delay, the sample and a novel object appeared; choice of the novel object was rewarded. In the standard task, the reward was in a well beneath the stimulus. In the verbal-reward condition the reward was not a separate object but was praise and applause. In the Velcro condition, the reward, although a separate and separable object, was attached to the base of the stimulus. Most infants at both ages succeeded in the verbal-reward and Velcro conditions but not in the standard condition.

Early developments in the ability to understand the relation between stimulus and reward

Delayed nonmatching to sample (DNMS) is used to test the recognition memory function dependent on the medial temporal lobe. Children cannot succeed on this task until about 21 months. Because robust recognition is present well before then, the late emergence of another ability must account for the late success on DNMS. Evidence is presented here that the critical late-maturing competence is the ability to grasp the relation between stimulus and reward--that is, to understand that the stimulus is a symbol or marker for the reward. Infants of 9 and 12 months were tested on 3 conditions of DNMS. A sample object was presented. After a delay, the sample and a novel object appeared; choice of the novel object was rewarded. In the standard task, the reward was in a well beneath the stimulus. In the verbal-reward condition the reward was not a separate object but was praise and applause. In the Velcro condition, the reward, although a separate and separable object, was attached to the base of the stimulus. Most infants at both ages succeeded in the verbal-reward and Velcro conditions but not in the standard condition.

Cognitive deficits in a genetic mouse model of the most common biochemical cause of human mental retardation

Phenylalanine hydroxylase (Pah)-deficient "PKU mice" have a mutation in the Pah gene that causes phenylketonuria (PKU) in humans. PKU produces cognitive deficits in humans if it is untreated. We report here the first evidence that the genetic mouse model of PKU (Pah(enu2)) also produces cognitive impairments. PKU mice were impaired on both odor discrimination reversal and latent learning compared with heterozygote littermates and with wild-type mice of the same BTBR strain. A small container of cinnamon-scented sand was presented on the right or left, and nutmeg-scented sand was presented on the other side; left-right location varied over trials. Digging in sand of the correct scent was rewarded by finding phenylalanine-free chocolate. To prevent scent cuing, new containers were used on every trial, and both containers always contained chocolate. Digging in the incorrect choice was stopped before the chocolate was uncovered. Once criterion was reached, the other scent was rewarded. PKU mice were impaired on reversals 2, 3, and 4. They were also impaired in latent learning. On day 1, half the mice were allowed to explore a maze and discover the location of water. On day 2, all mice were water-deprived and were placed in the maze. Whereas pre-exposed wild-type and heterozygous mice showed evidence that they remembered the location of the water and hence could find the water faster on day 2, pre-exposed PKU mice showed no significant benefit from their pre-exposure on day 1.

Prefrontal cortex cognitive deficits in children treated early and continuously for PKU

To begin to study the importance of dopamine for executive function abilities dependent on prefrontal cortex during early childhood, the present investigation studied children in whom we predicted reduced dopamine in prefrontal cortex but otherwise normal brains. These are children treated early and continuously for the metabolic disorder phenylketonuria (PKU). Untreated PKU is the most common biochemical cause of mental retardation. The root problem is an inability to convert one amino acid, phenylalanine (Phe), into another, tyrosine (Tyr), the precursor of dopamine. Phe levels in the bloodstream soar; Tyr levels fall. Treatment with a diet low in Phe reduces the Phe:Tyr imbalance but cannot eliminate it. We hypothesized that the resultant modest elevation in the ratio of Phe to Tyr in the blood, which results in slightly less Tyr reaching the brain, uniquely affects the cognitive functions dependent on prefrontal cortex because of the special sensitivity of prefrontally projecting dopamine neurons to small decreases in Tyr. In a 4-year longitudinal study, we found that PKU children whose plasma Phe levels were three to five times normal (6-10 mg/dl) performed worse than other PKU children with lower Phe levels, matched controls, their own siblings, and children from the general population on tasks that required the working memory and inhibitory control abilities dependent on dorsolateral prefrontal cortex. The impairment was as evident in our oldest age range (3 1/2-7 years) as it was in the youngest (6-12 months). The higher a child's Phe level, the worse that child's performance. Girls were more adversely affected than boys. The deficit appears to be selective, affecting principally one neural system, since even PKU children with Phe levels three to five times normal performed well on the 13 control tasks. Clinical implications for the treatment of PKU and other neurodevelopmental disorders are discussed.

Ischemic left ventricular free wall rupture: prediction, diagnosis, and treatment

Left ventricular free wall rupture is the third leading complication and the second most common cause of death after myocardial infarction. Its occurrence has been considered an unpredictable event usually leading to death. An increased appreciation for the clinical presentation of this syndrome and the nearly ubiquitous use of echocardiography have fostered a rise in the antemortem diagnosis of left ventricular free wall rupture, allowing the possibility of operative repair. Despite the increased reporting of left ventricular free wall rupture, the experience of any one surgeon or surgical group tends to be quite small. We review the current status of rupture prediction, clinical presentation, diagnosis, and treatment options. A recent case of left ventricular free wall rupture referred to the Baylor Cardiothoracic Surgery Group with the misdiagnosis of ruptured dissection of the ascending thoracic aorta is presented to illustrate our approach to this clinical situation.

Evidence for the importance of dopamine for prefrontal cortex functions early in life

There is considerable evidence that dorsolateral prefrontal cortex subserves critical cognitive abilities even during early infancy and that improvement in these abilities is evident over roughly the next 10 years. We also know that (a) in adult monkeys these cognitive abilities depend critically on the dopaminergic projection to prefrontal cortex and (b) the distribution of dopamine axons within dorsolateral prefrontal cortex changes, and the level of dopamine increases, during the period that infant monkeys are improving on tasks that require the cognitive abilities dependent on prefrontal cortex. To begin to look at whether these cognitive abilities depend critically on the prefrontal dopamine projection in humans even during infancy and early childhood we have been studying children who we hypothesized might have a selective reduction in the dopaminergic innervation of prefrontal cortex and a selective impairment in the cognitive functions subserved by dorsolateral prefrontal cortex. These are children treated early and continuously for the genetic disorder, phenylketonuria (PKU). In PKU the ability to convert the amino acid, phenylalanine (Phe), into another amino acid, tyrosine (Tyr), is impaired. This causes Phe to accumulate in the bloodstream to dangerously high levels and the plasma level of Tyr to fall. Widespread brain damage and severe mental retardation result. When PKU is moderately well controlled by a diet low in Phe (thus keeping the imbalance between Phe and Tyr in plasma within moderate limits) severe mental retardation is averted, but deficits remain in higher cognitive functions. In a four-year longitudinal study we have found these deficits to be in the working memory and inhibitory control functions dependent upon dorsolateral prefrontal cortex in PKU children with plasma Phe levels 3-5 times normal. The fact that even infants showed these impairments suggests that dopaminergic innervation to prefrontal cortex is critical for the proper expression of these abilities even during the first year of life. To test the hypothesis about the underlying biological mechanism we have created the first animal model of early and continuously treated PKU. As predicted, the experimental animals had reduced levels of dopamine and the dopamine metabolite, homovanillic acid (HVA), in prefrontal cortex and showed impaired performance on delayed alternation, a task dependent on prefrontal cortex function. Noradrenaline levels were unaffected; however some reduction in serotonin levels and in dopamine levels outside the prefrontal cortex was found. If prefrontal cortex functions are vulnerable in children with a moderate plasma Phe:Tyr imbalance because of the special properties of the dopamine neurons that project to prefrontal cortex, then other dopamine neurons that share those same properties should also be vulnerable in these children. The dopamine neurons in the retina share these properties (i.e. unusually high firing and dopamine turnover rates), and we have found that PKU children with plasma Phe levels 3-5 times normal are impaired in their contrast sensitivity, a behavioural measure sensitive to retinal dopamine levels.

Mutations in the activin receptor-like kinase 1 gene in hereditary haemorrhagic telangiectasia type 2

Hereditary haemorrhagic telangiectasia, or Osler-Rendu-Weber (ORW) syndrome, is an autosomal dominant vascular dysplasia. So far, two loci have been demonstrated for ORW. Linkage studies established an ORW locus at chromosome 9q3; endoglin was subsequently identified as the ORW1 gene. A second locus, designated ORW2, was mapped to chromosome 12. Here we report a new 4 cM interval for ORW2 that does not overlap with any previously defined. A 1.38-Mb YAC contig spans the entire interval. It includes the activin receptor like kinase 1 gene (ACVRLK1 or ALK1), a member of the serine-threonine kinase receptor family expressed in endothelium. We report three mutations in the coding sequence of the ALK1 gene in those families which show linkage of the ORW phenotype to chromosome 12. Our data suggest a critical role for ALK1 in the control of blood vessel development or repair.

Development of an aspect of executive control: development of the abilities to remember what I said and to "do as I say, not as I do"

Luria's tapping test (tap once when E taps twice, tap twice when E taps once) was administered to 160 children (80 males, 80 females) between 3 1/2 to 7 years old. Older children were faster and more accurate than younger children, with most of the improvement occurring by the age of 6. All children tested demonstrated understanding of the instructions during the pretest, and most started out performing well, but younger subjects could not sustain this. Over the 16 trials, percentage of correct responses decreased, especially among younger subjects. Performance here was compared with performance on the day-night Stroop-like task. The most common error on both tasks was to comply with only one of the two rules. Other errors included tapping many times regardless of what the experimenter did and doing the same thing as the experimenter, rather than the opposite. It is suggested that the tapping task requires both the ability to hold two rules in mind and the ability to inhibit a strong response tendency, that these abilities improve between 3-6 years of age, and that this improvement may reflect important changes within frontal cortex during this period of life.

Impaired sensitivity to visual contrast in children treated early and continuously for phenylketonuria

Contrast sensitivity was assessed in 47 children aged 5.4-9.8 years: 12 with phenylketonuria (PKU), six unaffected siblings and 29 children from the general population. Children with PKU, despite early and continuous treatment and despite phenylalanine (Phe) levels within accepted limits, were impaired across the range of spatial frequencies [1.5-18.0 cycles per degree of visual angle (c.p.d.)]. They were most impaired at the next to the highest spatial frequency, where "group' accounted for 70% of the variance in sensitivity to contrast, controlling for acuity, sex, age and test site. Never, at any spatial frequency, was the contrast sensitivity of any PKU subject better than that of his or her sibling. All subjects were tested under conditions of 20/20 vision, with correction if needed. The mean IQ of PKU subjects was 99; IQ was not significantly related to contrast sensitivity performance. We interpret these findings as support for Diamond's hypothesis that moderately elevated plasma Phe levels (3-5 x normal), combined with reduced plasma tyrosine (Tyr), moderately reduce the levels of Tyr reaching the eye and brain, which adversely affects those dopamine neurons that fire and turn over dopamine most rapidly (the dopamine neurons in the retina and those projecting to prefrontal cortex). This would lead to the deficit in contrast sensitivity found here and to the selective deficit in prefrontal cortex cognitive functions previously reported in PKU children under moderately good dietary control.

High prevalence of multidrug-resistant Streptococcus pneumoniae among children in a rural Kentucky community

In 1992 drug-resistant Streptococcus pneumoniae was cultured with increasing frequency from aspirates of middle ear fluid from children with acute otitis media in a rural Kentucky community. To determine the prevalence of carriage of drug-resistant S. pneumoniae in the community, we obtained nasopharyngeal swabs from 158 (70%) of 227 children attending a child daycare center and from 82 children attending the county health center. S. pneumoniae was isolated from 126 children. Among 123 isolates tested 65 (53%) were penicillin-resistant, including 41 (33%) strains that were highly resistant; 61 (50%) were multidrug-resistant. Serotypes 19F, 6B, 23F and 6A comprised 89% of the penicillin-resistant isolates. Detection of a variety of serotypes and drug resistance patterns among nasopharyngeal isolates of S. pneumoniae suggests that multidrug-resistant pneumococcal strains are endemic in this community. Surveillance for drug-resistant pneumococci with the use of respiratory secretions obtained by nasopharyngeal swab may provide useful information on the prevalence of drug-resistant strains causing invasive disease and otitis media. Such information could be used to guide empiric therapy of pneumococcal infections.

Evidence of robust recognition memory early in life even when assessed by reaching behavior

Infants of only 5-6 months prefer to look at something new when given the choice of looking at a stimulus shown earlier or something new, even after a long delay (the visual paired comparison task). However, if infants must reach and displace a stimulus to retrieve a reward, even 18-month-olds respond randomly when given the choice of reaching to the stimulus shown earlier or to something new, even after a brief delay (the delayed nonmatching to sample task). To investigate this paradox we modified the delayed nonmatching to sample task to make it more similar to visual paired comparison. Each stimulus served as its own reward; no rewards were hidden under any stimuli. Infants were habituated to a sample object, a delay was imposed, and then the sample and a new object were presented. Infants could choose to look at (in visual paired comparison) or reach for (in delayed nonmatching to sample (stimulus = reward)) either object. One hundred twenty infants were tested: 60 (20 each at 4, 6, and 9 months) on visual paired comparison and 60 (20 each at 6, 9, and 12 months) on delayed nonmatching to sample (stimulus = reward). The same 10 pairs of stimuli were used on both tasks. Each subject was tested twice at all five delays (10, 15, 60, 180, and 600 s). At even the youngest age that reaching was tested (6 months), infants showed evidence of recognition memory on the reaching task at delays at least as long as those at which they demonstrated recognition memory on the looking task. Indeed, when subjects reached, not in order to obtain something else, but to obtain the stimulus itself, they succeeded on a recognition memory task even at delays 10 min long very early in life.

Microdissection and microcloning of chromosomal alterations in human breast cancer

The recognition of recurring sites of chromosome changes in malignancies has greatly facilitated the identification of genes implicated in the pathogenesis of human cancers. Based especially upon recent studies [1-4], it appears increasingly likely that a subset of recurring chromosome alterations will be recognized in human breast cancer. Currently recognized chromosome changes characterizing breast carcinoma include the recognition of cytologic features of gene amplification (e.g. double minutes [dmins] and homogeneously staining regions [HSRs]) [5-8]. As these and other chromosome regions are implicated in recurring abnormalities in breast cancer, it will become increasingly important to have band- or region-specific genomic libraries and probes in order to facilitate high resolution physical mapping and ultimately to clone breast cancer related genes [9]. Toward this end an important recent development in physical mapping has been the establishment of chromosome microdissection as a rapid and reproducible approach to rapidly isolate and characterize chromosome region-specific DNA, greatly facilitating the initial steps in positional cloning of disease-related genes [10-13]. In this brief report, we will highlight the application of chromosome microdissection to the generation of region-specific probes for both fluorescent in situ hybridization (FISH) and the generation of genomic microclone libraries. Additionally, efforts using this methodology to generate a microclone library encompassing the early onset breast/ovarian cancer (BRCA1) gene will be presented.

Young children's performance on a task sensitive to the memory functions of the medial temporal lobe in adults--the delayed nonmatching-to-sample task--reveals problems that are due to non-memory-related task demands

Delayed nonmatching-to-sample performance was examined in children and found to be poor from 12 months until almost 2 years even at 5-s delay, although 5 s is well within such children's memory capacity. After 12 months of age, performance did not differ by delay (5 or 30 s). Because children's problems seemed largely unrelated to the task's memory demands, the 2 final studies explored the role of other cognitive abilities (deduction of an abstract rule, speed of processing, and resistance to interference or distraction). Telling children the rule or quadrupling sample presentation time had little effect. Because a salient stimulus (the reward) might interfere with keeping one's attention on the sample, the reward was omitted during initial sample presentation. This helped; at the 5-s delay, 15-month-olds performed at least as well as 21-month-olds in the basic condition, and 12-month-olds performed almost as well. Implications for the cognitive abilities improving during the 2nd year and for the functions of the medial temporal lobe are discussed.

Phenylalanine levels of 6-10 mg/dl may not be as benign as once thought

Results of a longitudinal study of children treated early and continuously for phenylketonuria (PKU) indicated that those children whose plasma phenylalanine (Phe) levels were approximately 3-5 times normal (6-10 mg/dl; levels previously considered safe in the US) were impaired in cognitive functions dependent on prefrontal cortex. In particular, the children had difficulty when required to hold information in the mind and, at the same time, exercise inhibitory control to resist doing what might be their first inclination. The deficits were evident in relation to each of several comparison groups and at all three age ranges (infants, toddlers and young children). The deficits appeared to be selective in that the same children who were impaired on the prefrontal cortex tests performed normally on the control tests. Since most of the control tasks tap functions dependent on parietal cortex or the medial temporal lobe, these results suggest that those functions are spared. To investigate the biological mechanism causing these cognitive deficits, we created an animal model of early-treated PKU. The results indicated that rats whose plasma Phe levels were mildly, but chronically, elevated had cognitive deficits (impaired performance on a behavioral task dependent on frontal cortex (delayed alternation)) and neurochemical changes (most notably, reduced dopamine metabolism in frontal cortex).