Don't Ditch the Laptop Just Yet: A Direct Replication of Mueller and Oppenheimer's (2014) Study 1 Plus Mini Meta-Analyses Across Similar Studies

In this direct replication of Mueller and Oppenheimer's (2014) Study 1, participants watched a lecture while taking notes with a laptop (n = 74) or longhand (n = 68). After a brief distraction and without the opportunity to study, they took a quiz. As in the original study, laptop participants took notes containing more words spoken verbatim by the lecturer and more words overall than did longhand participants. However, laptop participants did not perform better than longhand participants on the quiz. Exploratory meta-analyses of eight similar studies echoed this pattern. In addition, in both the original study and our replication, higher word count was associated with better quiz performance, and higher verbatim overlap was associated with worse quiz performance, but the latter finding was not robust in our replication. Overall, results do not support the idea that longhand note taking improves immediate learning via better encoding of information.

Three phylogenetic groups have driven the recent population expansion of Cryptococcus neoformans

Cryptococcus neoformans (C. neoformans var. grubii) is an environmentally acquired pathogen causing 181,000 HIV-associated deaths each year. We sequenced 699 isolates, primarily C. neoformans from HIV-infected patients, from 5 countries in Asia and Africa. The phylogeny of C. neoformans reveals a recent exponential population expansion, consistent with the increase in the number of susceptible hosts. In our study population, this expansion has been driven by three sub-clades of the C. neoformans VNIa lineage; VNIa-4, VNIa-5 and VNIa-93. These three sub-clades account for 91% of clinical isolates sequenced in our study. Combining the genome data with clinical information, we find that the VNIa-93 sub-clade, the most common sub-clade in Uganda and Malawi, was associated with better outcomes than VNIa-4 and VNIa-5, which predominate in Southeast Asia. This study lays the foundation for further work investigating the dominance of VNIa-4, VNIa-5 and VNIa-93 and the association between lineage and clinical phenotype.

Life goes on: the resilience of maternal primary care during the Ebola outbreak in rural Sierra Leone

Setting: All 100 health facilities providing maternal services in Moyamba, Sierra Leone, a rural district that experienced a smaller Ebola outbreak than other areas. Objective: To compare trends in antenatal care (the first and fourth visit [ANC1 and ANC4]), delivery, and postnatal care (PNC1) service utilisation before, during and after the Ebola outbreak (2014-2016). Design: Cross-sectional study using secondary programme data. Results: A total of 211 Ebola cases occurred in Moyamba District. The mean number of monthly ANC visits remained stable over time, except for the subset of care provided via outreach visits where, compared with before the outbreak (n = 390), ANC1 visits declined during (n = 331, P = 0.002) and after the outbreak (n = 342, P = 0.03). Most (>97%) deliveries occurred in health facilities, assisted by maternal and child health aides (>80%). During the outbreak, the mean number of community-based deliveries per month declined from 31 to 21 (P = 0.03), and the mean number of deliveries performed by midwives increased from 49 to 78 (P < 0.001) compared with before the outbreak. Before, during and after Ebola, there was no significant change in the mean number of live births (respectively n = 1134, n = 1110, n = 1162), maternal PNC1 (respectively n = 1110, n = 1105, n = 1165) or neonatal PNC1 (respectively n = 1028, n = 1050, n = 1085). Conclusion: In a rural district less affected by Ebola transmission than other areas, utilisation of maternal primary care remained robust, despite the outbreak.

Ebola and community health worker services in Kenema District, Sierra Leone: please mind the gap!

Setting: All community health workers (CHWs) in rural Kenema District, Sierra Leone. Objective: CHW programmes provide basic health services to fill gaps in human health resources. We compared trends in the reporting and management of childhood malaria, diarrhoea and pneumonia by CHWs before, during and after the Ebola outbreak (2014-2016). Design: Retrospective cross-sectional study using programme data. Results: CHW reporting increased from 59% pre-outbreak to 95% during the outbreak (P < 0.001), and was sustained at 98% post-outbreak. CHWs stopped using rapid diagnostic tests for malaria mid-outbreak, and their use had not resumed post-outbreak. The average monthly number of presumptive treatments for malaria increased from 2931 pre-outbreak to 5013 during and 5331 post-outbreak (P < 0.001). The average number of monthly treatments for diarrhoea and pneumonia decreased from respectively 1063 and 511 pre-outbreak to 547 and 352 during the outbreak (P = 0.01 and P = 0.04). Post-outbreak pneumonia treatments increased (mean 1126 compared to pre-outbreak, P = 0.003), and treatments for diarrhoea returned to pre-outbreak levels (P = 0.2). Conclusion: The CHW programme demonstrated vulnerability, but also resilience, during and in the early period after the Ebola outbreak. Investment in CHWs is required to strengthen the health care system, as they can cover pre-existing gaps in facility-based health care and those created by outbreaks.

Increase in acute malnutrition in children following the 2014-2015 Ebola outbreak in rural Sierra Leone

Setting: All health facility and community malnutrition screening programmes in Tonkolili, a rural Ebola-affected district in Sierra Leone. Objectives: Before the Ebola disease outbreak, Sierra Leone had set a goal to reduce the prevalence of severe acute malnutrition (SAM) in children aged <5 years to <0.2%. We compared the number of children screened, diagnosed and treated for malnutrition before, during and after the outbreak (2013-2016). Design: This was a retrospective cross-sectional study. Results: Health facility screening declined from 16 805 children per month pre-outbreak to 13 510 during the outbreak (P = 0.02), and returned to pre-outbreak levels after the outbreak. Community-based screening remained stable during the outbreak, and increased by 30% post-outbreak (P < 0.001). The proportion diagnosed with moderate acute malnutrition using mid-upper arm circumference increased from respectively 3.6% and 5.1% pre-outbreak in the community and health facilities to 8.2% and 7.9% post-outbreak (P < 0.001, P = 0.003). The proportion of children diagnosed with SAM using a weight-for-age ratio at health facilities increased from 1.5% pre-outbreak to 3.5% post-outbreak (P = 0.003). On average, for every four children diagnosed with SAM per month, one child completed SAM treatment. Conclusion: After a decline in screening during the Ebola outbreak, diagnoses of acute malnutrition increased post-outbreak. Nutrition programmes need to be strengthened to pre-empt such effects in the event of future Ebola outbreaks.

Characteristics and outcomes of women initiating ART during pregnancy versus breastfeeding in Option B+ in Malawi

BACKGROUND

Malawi adopted the PMTCT strategy 'Option B+' in 2011, providing life-long ART for all HIV-infected pregnant and breastfeeding women. We explored differences in characteristics and outcomes of women initiating ART during pregnancy versus breastfeeding.

METHODS

We conducted a retrospective cohort analysis of women in Zomba District, southern Malawi, from January 2012- September 2013. Data were extracted from the Zomba District Observational Cohort Study, a surveillance project collecting data from standardized Ministry of Health ART monitoring tools.

RESULTS

1986 (67.2 %) women initiated ART during pregnancy and 969 (32.8 %) during breastfeeding. Women initiating ART in breastfeeding were more likely to be > 30 years (aOR = 1.33, 95 % CI1.11-1.59, p = 0.003) and have WHO Stage 3/4 (aOR = 2.74, 95 % CI1.94-3.87, p < 0.001). Eighteen (0.6 %) deaths occurred and 942 (31.9 %) women defaulted ART. 'Early' death (< 30 days) occurred in 3 (0.1 %) women and 449 (16.4 %) women defaulted early. Death/default < 30 days was more likely among women initiating ART during pregnancy (aOR 1.62, 95 % CI1.28-2.05, p < 0.001) or < 30 years old (aOR 1.27, 95 % CI 1.02-1.57, p = 0.03) and was less likely among those with WHO Stage 3/4 (aOR 0.30, 95 % CI 0.15-0.60, p < 0.001). Using Kaplan-Meier estimators to investigate time to death/default, we showed a sharp drop in death/default-free survival probability at time zero, yet survival probability decreased in a nearly linear manner after this initial period of high default. Women under 30 years had increased rates of death/default over time (log rank test: p < 0.001), however no significant differences were observed in death/default over time associated with timing of ART initiation, documented clinical stage at initiation, health clinic size or adherence rates.

CONCLUSIONS

Many women in Malawi started ART during breastfeeding within Option B+ and were older and had more advanced WHO Clinical Staging. This represents a missed PMTCT opportunity to initiate treatment early in pregnancy. Early defaulting is identified as a challenge within Option B+, and was more likely among younger women and those initiating ART in pregnancy. Targeted research to understand factors associated with uptake of ART during pregnancy and retention in care could improve the efficacy of Option B+ in Malawi.

Timing and uptake of ART during treatment for active tuberculosis in HIV co-infected adults in Malawi

SETTING

Uptake of antiretroviral therapy (ART) in patients co-infected with tuberculosis (TB) and the human immunodeficiency virus (HIV) has historically been low in Malawi. In response, the National TB Programme piloted the initiation of ART 2 weeks after initiation of TB treatment in 2008-2009, a change from the prior policy of 2 months.

OBJECTIVE

To determine at programme level if earlier initiation of ART in co-infected patients receiving TB treatment will increase the uptake and continuation of ART.

DESIGN

A prospective observational pilot programme evaluation using routinely collected monitoring data from the first two sites with integrated TB-HIV services in Malawi.

RESULTS

There was wide variability in the ART start time before and after the policy change. Before the policy change, 16% of patients initiated ART by 3 months compared to 24% after the policy change (P < 0.001). The proportion of all co-infected patients on ART increased from 32% before the policy change to 39% after (P < 0.001). Earlier initiation of ART did not increase the occurrence of side effects and did not reduce adherence to TB treatment.

CONCLUSION

Earlier initiation of ART in co-infected patients receiving TB treatment improved the uptake and continuation of ART. Malawi ART guidelines in 2011 were changed from initiating ART after 2 months to as soon as possible after starting anti-tuberculosis treatment.

A review and update on the guidelines for the acute non-operative management of cervical spinal cord injury

Acute traumatic spinal cord injury (SCI) is an important cause of impairment globally with estimates of incidence varying from 10.4 to 83 million inhabitants annually. These injuries typically impact younger individuals, reduce quality of life years, and are costly to patients, with lifetime costs estimated to exceed $ 4 million. Given the lifetime impact of SCI, establishing clear practice guidelines for the acute non-operative management of these injuries remains important. In 2013 the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) released revised guidelines on the topic of Cervical Spinal Cord Injury (SCI). In the present article, we explore the seven general management subsections of the cervical SCI guidelines, review the key literature supporting each recommendation, and review the additional literature since the publication of the 2013 guidelines. Our review found a paucity of significant updates within several of the SCI guideline sections. As a result of our findings we propose a collaborative, multi-institutional prospective study to evaluate many pressing limitations of the current literature. In particular, the development of common data elements that allow consistent, reproducible data collection should be made a priority.

Paediatric cerebral sinovenous thrombosis: findings of the International Paediatric Stroke Study

OBJECTIVES

We evaluated clinical features, treatment practices and early outcome in a multicentre cohort of children with cerebral sinovenous thrombosis (CSVT).

METHODS

Children with CSVT from 10 countries were enrolled from January 2003 to July 2007 in the International Paediatric Stroke Study. We analysed clinical symptoms, underlying conditions, antithrombotic treatment and neurological outcome at hospital discharge in 170 children.

RESULTS

Of 170 children enrolled, 60% were male; median age 7.2 years (IQR 2.9-12.4). Headache, altered consciousness, focal deficits and seizures were common presenting clinical features. Infarction affected 37% and intracranial haemorrhage 31%. Risk factors included chronic disease in 50%; acute systemic illness or head/neck disorders 41%; prothrombotic state 20% and other haematological abnormality 19%. Discharge neurological status was normal in 48%, abnormal in 43% and unknown in 5%. Antithrombotic therapy was common, most often low molecular weight heparin was common, with significant regional variation in treatment practices. Mortality was low (4%) and was associated with no anticoagulation but not underlying chronic disease, anatomic extent of thrombosis or intracranial haemorrhage. Abnormal neurological status at discharge or death was associated with decreased level of consciousness at presentation and the presence of an identified prothrombotic state.

CONCLUSIONS

Our study extends the observations of previously published smaller studies in children with CSVT that this is a morbid disease with diverse underlying causes and risk factors. Divergent treatment practices among highly specialised centres as well as limited data on treatment efficacy and safety suggest that further study of this condition is warranted.

Treatment decision-making among Canadian youth with severe haemophilia: a qualitative approach

The first generation of young men using primary prophylaxis is coming of age. Important questions regarding the management of severe haemophilia with prophylaxis persist: Can prophylaxis be stopped? At what age? To what effect? Can the regimen be individualized? The reasons why some individuals discontinue or poorly comply with prophylaxis are not well understood. These issues have been explored using predominantly quantitative research approaches, yielding little insight into treatment decision-making from the perspectives of persons with haemophilia (PWH). Positioning the PWH as a source of expertise about their condition and its management, we undertook a qualitative study: (i) to explore and understand the lived experience of young men with severe haemophilia A or B and (ii) to identify the factors and inter-relationships between factors that affect young men's treatment decision-making. This manuscript reports primarily on the second objective. A modified Straussian, grounded theory methodology was used for data collection (interviews) and preliminary analysis. The study sample, youth aged 15-29, with severe haemophilia A or B, was chosen selectively and recruited through three Canadian Haemophilia Treatment Centres. We found treatment decision-making to be multi-factorial and used the Framework method to analyze the inter-relationships between factors. A typology of four distinct approaches to treatment was identified: lifestyle routine prophylaxis, situational prophylaxis, strict routine prophylaxis and no prophylaxis. Standardized treatment definitions (i.e.: 'primary' and 'secondary', 'prophylaxis') do not adequately describe the ways participants treat. Naming the variation of approaches documented in this study can improve PWH/provider communication, treatment planning and education.

Plateau of adiposity in Australian children diagnosed with Type 1 diabetes: a 20-year study

AIMS

To examine temporal trends in anthropometry in children with Type 1 diabetes from Sydney, Australia.

METHODS

We conducted a retrospective study in a total of 1975 children with Type 1 diabetes, aged <16 years, between 1990 and 2009. Trends in height, weight and BMI standard deviation score after initial stabilization were examined by age group (<5 years, 5 to <10 years, 10 to 16 years) and time period of diagnosis (T1: 1990-1994, T2: 1995-1999; T3: 2000-2004 and T4: 2005-2009). Factors associated with BMI standard deviation score (time period, age group, gender and socio-economic status) were examined using multivariable linear regression.

RESULTS

The mean BMI standard deviation score (±sd) increased between T1 and T2 (0.54 ± 1.14 vs 0.81 ± 1.14, P = 0.002), but remained steady thereafter (T3: 0.85 ± 1.11, T4: 0.87 ± 1.09; T2 to T4: P = 0.40). Similarly, the prevalence of overweight and obesity increased from T1 to T2 (26 to 35%, P = 0.01), but was unchanged thereafter (T3: 34%, T4: 34%; T2 to T4: P = 0.90). On multivariable regression analysis, a higher BMI standard deviation score was associated with younger age (≥5 years vs <5 years, β=-0.40, 95% CI -0.51 to -0.28, P < 0.001), later time period (T2 to T4 vs T1, β=0.30, 95% CI 0.16-0.45, P < 0.001) and male gender (β=0.25, 95% CI 0.15-0.34, P < 0.001).

CONCLUSION

The prevalence of overweight and obesity has remained unchanged in children at diagnosis of Type 1 diabetes over 15 years. These findings suggest that higher adiposity alone cannot account for the continued rising incidence of Type 1 diabetes in recent years.

Early elevation of albumin excretion rate is associated with poor gluten-free diet adherence in young people with coeliac disease and diabetes

AIMS

There are conflicting data on microvascular complications in coexisting Type 1 diabetes and coeliac disease. We compared complications rates in youth with or without coeliac disease and examined the association between gluten-free diet adherence and complications.

METHODS

This was a comparative study of adolescents (2510 without coeliac disease, 129 with coeliac disease); 60 (47%) did not adhere to a gluten-free diet--defined as elevated anti-tissue transglutaminase or endomysial immunoglobulin A titres. Retinopathy was detected using 7-field fundal photography and albumin excretion rate by timed overnight urine collections, with early elevation defined as albumin excretion rate ≥ 7.5 μg/min. Logistic regression was used to examine the association between complications and explanatory variables, including coeliac disease vs. no coeliac disease, gluten-free diet adherence vs. non-adherence, diabetes duration and HbA1c .

RESULTS

Median age at last assessment was 16.5 years. Those with coeliac disease vs. those without were younger at diabetes diagnosis (7.1 vs. 8.6 years, P < 0.001) and had longer diabetes duration (9.3 vs. 7.2 years, P < 0.001). HbA1c was lower in those with coeliac disease vs. those without (67 vs. 70 mmol/mol, 8.3 vs. 8.6%, P = 0.04) and adherence to a gluten-free diet vs. non-adherence (66 vs. 72 mmol/mol, 8.2 vs. 8.7%, P = 0.003). There were no differences in complication rates between those with coeliac disease vs. those without (retinopathy 22 vs. 23%, elevated albumin excretion rate 31 vs. 28%). Non-adherence to a gluten-free diet was associated with elevated albumin excretion rate (40 vs. 23%, P = 0.04). In multivariable logistic regression, elevated albumin excretion rate was associated with non-adherence to a gluten-free diet (odds ratio 2.37, 95% CI 1.04-5.40, P = 0.04) and diabetes duration (odds ratio 1.13, 95% CI 1.02-1.25, P = 0.03), but not HbA1c .

CONCLUSIONS

While glycaemic control is better in patients with coeliac disease, non-adherence to a gluten-free diet is associated with elevated albumin excretion rate. The possible protection of a gluten-free diet on complications warrants further investigation.

Evaluation of lay health workers' needs to effectively support anti-tuberculosis treatment adherence in Malawi

OBJECTIVE

To identify barriers and facilitators to efforts by lay health workers (LHWs) to support anti-tuberculosis treatment adherence in Malawi to inform the design of a knowledge translation intervention for improving adherence.

DESIGN

Qualitative study utilizing focus groups and interviews conducted with LHWs providing tuberculosis (TB) care in Zomba District, Malawi.

RESULTS

Participants identified lack of knowledge, both general (understanding of TB and its treatment) and job-specific (understanding of tasks such as completion of treatment forms), as the key barrier to LHWs in their role as adherence supporters. Lack of knowledge among LHWs providing TB care was reported to lead to a lack of confidence, conflicting messages given to patients, poor interactions with patients and errors in documentation. In addition to lack of knowledge, a number of system barriers were identified as limiting LHWs' ability to function optimally, including a lack of physical resources, workload, communication delays and ineffective guardians.

CONCLUSION

Our findings suggest a gap between LHW knowledge and their responsibilities as adherence supporters. The results have informed the development of an educational outreach intervention and point-of-care tool, to be evaluated in a randomized trial in Zomba District.

Coeliac disease in Type 1 diabetes from 1990 to 2009: higher incidence in young children after longer diabetes duration

AIMS

To determine the incidence of coeliac disease in young people with Type 1 diabetes and to examine the effect of age at diabetes onset and disease duration.

METHODS

This was a clinic-based observational cohort study of 4379 people aged ≤ 18 years (49% male) between 1990 and 2009 from Sydney, Australia. Screening for coeliac disease was performed at diagnosis and 1-2 yearly using anti-endomysial and/or anti-tissue transglutaminase immunoglobulin A (IgA) antibodies. Coeliac disease was diagnosed by small bowel biopsy based on Marsh score ≥ III.

RESULTS

Coeliac disease was confirmed by biopsy in 185; of these, 61 (33%) were endomysial or tissue transglutaminase IgA antibody-positive at diabetes diagnosis. Mean age at diabetes onset was 6.6 ± 4.0 vs. 8.4 ± 4.1 years in those without coeliac disease (P < 0.001). Mean incidence was 7.7 per 1000 person years (95% CI 6.6-8.9) over 20 years. Incidence was higher in children aged < 5 years at diabetes diagnosis (10.4 per 1000 person years) vs. ≥ 5 years (6.4 per 1000), incidence rate ratio 1.6 (95% CI 1.2-2.2, P = 0.002). Coeliac disease was diagnosed after 2, 5 and 10 years of diabetes in 45, 78 and 94% of cases, respectively. Median time to coeliac disease diagnosis was longer in children aged < 5 years at diabetes onset (3.3 years) compared with older children (0.7 years, P < 0.001).

CONCLUSIONS

Coeliac disease is common in young people with Type 1 diabetes; the risk is greatest with diabetes onset < 5 years, but after longer diabetes duration. Screening for coeliac disease should be performed at diabetes diagnosis and for at least 10 years in young children.

Simplified methods of determining treatment retention in Malawi: ART cohort reports vs. pharmacy stock cards

SETTING

Rapid scale-up of antiretroviral therapy (ART) has challenged the health system in Malawi to monitor large numbers of patients effectively.

OBJECTIVE

To compare two methods of determining retention on treatment: quarterly ART clinic data aggregation vs. pharmacy stock cards.

DESIGN

Between October 2010 and March 2011, data on ART outcomes were extracted from monitoring tools at five facilities. Pharmacy data on ART consumption were extracted. Workload for each method was observed and timed. We used intraclass correlation and Bland-Altman plots to compare the agreeability of both methods to determine treatment retention.

RESULTS

There is wide variability between ART clinic cohort data and pharmacy data to determine treatment retention due to divergence in data at sites with large numbers of patients. However, there is a non-significant trend towards agreeability between the two methods (intraclass correlation coefficient > 0.9; P > 0.05). Pharmacy stock card monitoring is more time-efficient than quarterly ART data aggregation (81 min vs. 573 min).

CONCLUSION

In low-resource settings, pharmacy records could be used to improve drug forecasting and estimate ART retention in a more time-efficient manner than quarterly data aggregation; however, a necessary precondition would be capacity building around pharmacy data management, particularly for large-sized cohorts.

Reasons for accepting or refusing HIV services among tuberculosis patients at a TB-HIV integration clinic in Malawi

SETTING

In Malawi, human immunodeficiency virus (HIV) prevalence among newly registered tuberculosis (TB) patients is 60-70%. In 2008, an integrated TBHIV clinic was established at a central hospital in Zomba. Despite the integration of TB-HIV activities and improved HIV service uptake, unacceptably high proportions of HIV-positive TB patients are still not receiving antiretroviral therapy (ART).

OBJECTIVE

To identify factors that motivate or discourage TB patients from accepting HIV services.

DESIGN

Retrospective analysis of patients registered for TB treatment (not yet on ART) between April 2008 and March 2009; qualitative interviews of 99 patients on TB treatment.

RESULTS

Of 1773 newly registered TB patients who were not already on ART at the time of TB registration, 86% accepted HIV testing and counselling. Among HIV-positive TB patients, 38% started ART during or after anti-tuberculosis treatment. Young adults aged 15- 24 years were least likely to initiate ART. Motivation for accepting ART during TB treatment included prospects of regaining good health and longer life, and counselling by health care providers. Barriers to ART uptake included not being offered ART, high CD4 count, drug stockouts and fear of drug toxicities/interactions.

CONCLUSION

Several factors that undermine uptake of ART have been highlighted; targeted measures urgently need to be addressed by TB-HIV programmes to overcome these barriers.

Unfractionated heparin dosing in young infants: clinical outcomes in a cohort monitored with anti-factor Xa levels

BACKGROUND

Unfractionated heparin (UFH) is a widely used anticoagulant. Current American College of Chest Physicians guidelines for infants extrapolated from adults recommend 28 U kg(-1) h(1) of UFH to achieve an anti-factor Xa level of 0.35-0.7 IU mL(-1).

OBJECTIVE

To assess the profile of anti-FXa-based UFH dosing guidelines in infants.

PATIENTS/METHODS

We included all infants aged < 6 months treated with per-protocol intravenous UFH at the Hospital for Sick Children, Toronto, over a 3.5-year period.

RESULTS

Of 100 infants, 11% achieved sustained therapeutic anti-FXa levels with current dose recommendations. Only 15% achieved target anti-FXa levels within 24 h with per-protocol dose escalations. Seventeen per cent of patients never achieved therapeutic anti-FXa levels, despite up to 60 days of therapy and triple the recommended dose. The median dose needed to achieve therapeutic anti-FXa levels in the remaining 83 infants was 33 U kg(-1) h(-1) (interquartile range, 30-36). Two in three infants had decreased thrombus size at completion of therapy and no thrombus progression/recurrence, and 11/100 infants suffered major bleeding. Without exclusion of extracorporeal membrane oxygenation patients, an activated partial thromboplastin time (APTT) of > 180 s was detected as a risk factor for major bleeding.

CONCLUSIONS

UFH monitoring is challenging in infants. Despite their delay in reaching therapeutic anti-FXa levels, infants monitored with the adult-based anti-FXa range have a high thrombus resolution rate, no thrombus progression, but a relatively high bleeding rate. Extreme APTT elevation may contribute to this bleeding risk, particularly in critically ill patients. Current UFH guidelines for young infants may still be inadequate, and laboratory methods with age-appropriate ranges may be required to further improve clinical outcomes within this population.

Hypofractionated accelerated radiotherapy with concurrent carboplatin for locally advanced squamous cell carcinoma of the head and neck

AIMS

Hypofractionated accelerated radiotherapy with concurrent carboplatin utilises both advantages of altered fractionation and synchronous chemotherapy to maximise local control in locally advanced head and neck cancer. Such fractionation schedules are increasingly used in the intensity-modulated radiotherapy era and the aim of this study was to determine the outcome of hypofractionated accelerated radiotherapy with carboplatin.

MATERIALS AND METHODS

One hundred and fifty consecutive patients with squamous cell carcinoma of the larynx, oropharynx, oral cavity and hypopharynx (International Union Against Cancer [IUAC] stage II-IV) treated with 55Gy in 20 fractions over 25 days with concurrent carboplatin were analysed. Outcome measures were 2 year overall survival, local control and disease-free survival.

RESULTS

The median follow-up in surviving patients was 25 months. IUAC stages: II n=15; III n=42; IV n=93. Two year overall survival for all patients was 74.9% (95% confidence interval 66.0-81.7%). Two year local control was 78.3% (95% confidence interval 69.6-84.8%). Two year disease-free survival was 67.2% (95% confidence interval 58.3-74.7%). There were 135 patients with stage III and IV disease. For these patients, the 2 year overall survival, local control and disease-free survival were 74.3% (95% confidence interval 64.7-81.6%), 79.1% (95% confidence interval 69.8-85.9%) and 67.6% (95% confidence interval 58.0-75.4%), respectively. Prolonged grade 3 and 4 mucositis seen at ≥4 weeks were present in 9 and 0.7%, respectively. Late feeding dysfunction (determined by dependence on a feeding tube at 1 year) was seen in 13% of the surviving patients at 1 year.

CONCLUSION

Hypofractionated accelerated radiotherapy with concurrent carboplatin achieves a high local control. This regimen should be considered for a radiotherapy dose-escalation study using intensity-modulated radiotherapy.

Undetected factor VIII in a patient with type 3 von Willebrands disease mistaken as severe haemophilia A

von Willebrand disease (VWD) type 3 is a rare disorder characterized by absent or <0.1 UmL(-1) of ristocetin cofactor (VWF:RCo), and a very low level of factor VIII (FVIII:C). A total absence of FVIII:C has never been reported in type 3 VWD. This case illustrates the effect of severe von Willebrand factor (VWF) deficiency on the factor VIII level.

Utilization of recombinant activated factor VII in southern Ontario in 85 patients with and without haemophilia

Recombinant activated factor VII (rFVIIa) is licensed for the treatment of bleeding in individuals with haemophilia and inhibitors. The use of rFVIIa appears to be increasing, and an increase in unlicensed use is suspected. There are currently few data about the specific indications for its use. The aim of this study was to describe the patterns of utilization of rFVIIa. We performed a retrospective cohort study using rFVIIa infusion data collected prospectively and clinical data collected retrospectively. Patients were identified using a tracking system designed to account for use of all coagulation factor concentrates issued in southern Ontario. Between 1 January 2001 and 31 December 2005, 85 patients received rFVIIa. 1164 infusions were given (8246.4 mg). Haemophilia patients with inhibitors accounted for 82.9% of rFVIIa infused and represented 8.2% of patients. The total amount of rFVIIa used increased each year from 2001 to 2004 and then decreased in 2005. The total number of infusions of rFVIIa administered annually increased. Both on-label and off-label use of rFVIIa increased. The number of patients with haemophilia receiving rFVIIa remained small and constant. The number of patients receiving rFVIIa for off-label indications increased markedly. Most rFVIIa infusions were given for licensed indications; however, these infusions represented <10% of patients treated. Overall, the utilization of rFVIIa is increasing, mostly for approved indications; however, the number of patients being prescribed rFVIIa for off-label indications has increased. The tracking system used in this study is a valuable tool to describe ongoing utilization patterns of rFVIIa.

Keyhole technique for autologous brachiobasilic transposition arteriovenous fistula

BACKGROUND

Autologous brachiobasilic transposition arteriovenous fistulas (AVFs) are desirable but require long incisions and extensive surgical dissection. To minimize the extent of surgery, we developed a catheter-based technique that requires only keyhole incisions and local anesthesia.

METHODS

The technique involves exposure and division of the basilic vein at the elbow. A guidewire is introduced into the vein, and a 6F "push catheter" is advanced over the guidewire and attached to the vein with sutures. Gently pushing the catheter proximally inverts, or intussuscepts, the vein. Side branches that are felt as resistances when pushing the catheter forward are localized, clipped, and divided under direct vision. Throughout the procedure, the endothelium always remains intraluminal. The basilic vein is externalized at the axilla without dividing it proximally and is tunneled subcutaneously, where it is anastomosed to the brachial artery.

RESULTS

Thirty-two patients underwent the procedure--31 as outpatients. The mean duration of operation was less than 90 minutes. All patients tolerated the procedure well, and 31 required only intravenous sedation and local anesthesia. At a mean follow-up of 8 months, the primary patency rate of AVFs in patients with basilic vein diameters of 4 mm or more on preoperative duplex ultrasonography was 80%, vs 50% for those with vein diameters less than 4 mm. Overall, 78% of patent AVFs were being successfully accessed and 22% were still maturing at last follow-up.

CONCLUSIONS

Autologous brachiobasilic transposition AVFs can be created by using catheter-mediated techniques that facilitate the mobilization and tunneling of the basilic vein through small incisions. Medium-term data suggest that the inversion method results in acceptable maturation and functionality of AVFs created with this technique.

Venous thrombosis in children

Venous thromboembolic (VTE) events are being increasingly diagnosed in systemic and cerebral vessels in children. Systemic VTE are increasing in children as a result of therapeutic advances and improved clinical acumen in primary illnesses that previously caused mortality. The epidemiology of systemic VTE has been studied in international registries. In children older than 3 months, teenagers are the largest group developing VTE. The most common etiologic factor is the presence of central venous lines. Clinical studies have determined the most sensitive diagnostic method for diagnosing upper system VTE are ultrasound for jugular venous thrombosis and venography for intrathoracic vessels. However, the most sensitive diagnostic methods for lower system VTE and pulmonary embolism (PE) have not been established. Treatment studies for VTE consist of inadequately powered randomized controlled trials or prospective cohort studies. The long-term outcome of systemic VTE, post-thrombotic syndrome, has been reported in children. Cerebral sinovenous thrombosis (CSVT) is becoming increasingly diagnosed in children due to the recognition of the associated subtle clinical symptoms and improved cerebrovascular imaging. The etiology of CSVT includes thrombophilia, head and neck infections, and systemic illness. Estimates of the incidence and outcome of childhood CSVT have recently become available through the Canadian Pediatric Ischaemic Stroke Registry. Clinical studies have not yet been carried out in children to determine the best method of diagnosis or treatment. There have only been case-series studies carried out in the treatment of CSVT. Properly designed clinical trials are urgently required in children with systemic VTE/PE and CSVT to define the best methods of diagnosis, treatment and long-term management.

Thromboembolic disease and antithrombotic therapy in newborns

This update uses an evidence based approach to analyze and present the epidemiology of neonatal thrombosis, etiologies, currently used techniques for diagnosis with their limitations, and current therapeutic approaches. In addition, the approaches to both prevention and optimal therapies are discussed. In Section I Dr. Paul Monagle addresses the epidemiology of neonatal thrombosis outside of the central nervous system in both arterial and venous locations, and those that occur in utero. The specific contributions of catheters and congenital prothrombotic disorders are delineated. Dr. Monagle also describes currently used techniques for the diagnosis of thrombotic events as well as their limitations and the current therapeutic approaches. In Section II, Dr. Gabrielle deVeber reviews the epidemiology of neonatal thrombosis within the central nervous system, in both arterial and venous locations and those that occur in utero. The neurological presentation, risk factors including congenital prothrombotic disorders, anatomical distribution, diagnostic tests, use of antithrombotic therapy and neurologic outcome of neonates with either sinovenous thrombosis or arterial ischemic stroke are discussed. In Section III, Dr. Anthony Chan reviews the current approaches to the prevention and treatment of neonatal thrombosis. Information on the differences in the response of neonates compared to adults to antithrombotic therapy and new approaches to the prevention and treatment of thrombosis in neonates are emphasized.

An artificial intelligent algorithm for tumor detection in screening mammogram

Cancerous tumor mass is one of the major types of breast cancer. When cancerous masses are embedded in and camouflaged by varying densities of parenchymal tissue structures, they are very difficult to be visually detected on mammograms. This paper presents an algorithm that combines several artificial intelligent techniques with the discrete wavelet transform (DWT) for detection of masses in mammograms. The AI techniques include fractal dimension analysis, multiresolution markov random field, dogs-and-rabbits algorithm, and others. The fractal dimension analysis serves as a preprocessor to determine the approximate locations of the regions suspicious for cancer in the mammogram. The dogs-and-rabbits clustering algorithm is used to initiate the segmentation at the LL subband of a three-level DWT decomposition of the mammogram. A tree-type classification strategy is applied at the end to determine whether a given region is suspicious for cancer. We have verified the algorithm with 322 mammograms in the Mammographic Image Analysis Society Database. The verification results show that the proposed algorithm has a sensitivity of 97.3% and the number of false positive per image is 3.92.

The use of alteplase to restore patency of central venous lines in pediatric patients: a cohort study

We evaluated the efficacy and safety of alteplase to restore central venous line (CVL) patency in a consecutive cohort study. A uniform, weight-dependent protocol for alteplase administration was established prospectively. For children < or =10 kg, a dose of 0.5 mg was used; for children >10 kg, doses of 1 to 2 mg were used. The alteplase remained instilled for 1 to 4 hours or overnight. Retrospective data accrual found that 25 children received alteplase for a total of 34 courses; 29 (85%) of the 34 courses of alteplase completely restored CVL patency. Alteplase appears to be a safe and effective thrombolytic agent for CVL patency restoration in children.

Loss of T-cell receptor-CD3zeta and T-cell function in tumor-infiltrating lymphocytes but not in tumor-associated lymphocytes in ovarian carcinoma

BACKGROUND

Impaired T-cell function has been noted in tumor-infiltrating lymphocytes (TIL). Recently, loss of function was found to be associated with modifications in T-cell receptor complex (TCR)-mediated signaling. A common feature is loss or reduced expression levels of the signaling chain, TCRzeta. We evaluated whether loss of function in TIL and tumor-associated lymphocytes (TAL) from patients with ovarian cancer is associated with changes in TCRzeta expression, and which factors can cause these defects.

METHODS

TIL and TAL were isolated from multiple patients and evaluated for their proliferative capacity by stimulation with a polyclonal stimulus. In addition, expression of TCRzeta and CD3epsilon was evaluated in fresh TIL and TAL by the Western blot technique. Finally, various conditions within a tumor environment were tested for their effect on TCRzeta and CD3epsilon.

RESULTS

TIL, but not TAL, were significantly impaired in their proliferative response, even when both populations were derived from the same patient (P <.05). Reduced proliferation levels were associated with loss of expression of TCRzeta but not of CD3epsilon. Exposure of normal T cells to relative ischemia or heat shock, or culture in medium without IL-2, did not significantly reduce expression of TCRzeta compared with CD3epsilon. However, coculture of T cells with tumor-derived macrophages or tumor-derived factors led to a selective loss of TCRzeta compared with CD3epsilon (P <.05). Further analysis suggested that oxides such as hydrogen peroxide secreted by macrophages may be responsible for loss of TCRzeta and high molecular weight factors secreted by certain tumors.

CONCLUSIONS

TIL but not TAL show impaired T-cell function, which is associated with loss of TCRzeta. In addition to macrophages secreting oxides, loss of TCRzeta may be caused by tumor-derived soluble factors.

De novo mutation in the mitochondrial tRNALeu(UUR) gene (A3243G) with rapid segregation resulting in MELAS in the offspring

A 14-year-old Chinese boy with a normal perinatal and early developmental history presented at 5 years of age with migraine, intractable epilepsy, ataxia, supraventricular tachycardia, paralytic ileus and progressive mental deterioration. Computerized tomography revealed multiple cerebral infarcts in the parieto-occipital region without basal ganglial calcification. Magnetic resonance imaging showed increased signal intensity in T2 weighted images in the same regions. A cerebral digital subtraction angiogram was normal. Venous lactate, pyruvate, lactate to pyruvate ratio and cerebrospinal fluid lactate were elevated. Muscle biopsy did not reveal any ragged red fibres; dinucleotide-tetrazolium reductase activity was normal. Mitochondrial DNA analysis detected an adenine to guanine mutation at nucleotide position 3243 of tRNALeu(UUR). All four tissues analysed demonstrated heteroplasmy: leucocyte 56%, hair follicle 70%; buccal cell 64%; muscle 54%. The mother and brother of the proband, both asymptomatic, were also found to have a heteroplasmic A3243G mutation in the leucocytes, hair follicle and buccal cells. Other members of the maternal lineage, including the maternal grandmother, did not have the mutation. This report describes a patient with mitochondrial encephalopathy, lactic acidosis, stroke-like episodes, who presented with multisystem involvement. The absence of ragged red fibres in muscle biopsy did not preclude the diagnosis. Mutational analysis of mitochondrial DNA conveniently confirmed the diagnosis of the disorder. A de novo mutation is demonstrated in this family.

Prothrombotic disorders and ischemic stroke in children

Childhood ischemic stroke, including arterial ischemic stroke (AIS) and sinovenous thrombosis (SVT), is relatively rare in children but can result in devastating morbidity and mortality. An understanding of the etiology of childhood stroke is important because strategies for primary and secondary prevention can be devised. Prothrombotic disorders may contribute to the etiology of childhood stroke, and include deficiencies of antithrombin, protein C, protein S, plasminogen, and presence of Factor V Leiden, Prothrombin gene G20210A, dysfibrinogenemia, antiphospholipid antibodies, hyperhomocysteinemia, and elevated lipoprotein (a). The overall incidence of prothrombotic disorders in childhood AIS is estimated to be 20% to 50% in most studies and, in childhood SVT, to be 33% to 99%. In addition, hyperlipidemia, polycythemia, iron deficiency anemia, and platelet disorders may result in a prothrombotic state associated with ischemic stroke. The etiologic contribution of these prothrombotic disorders to initial and recurrent stroke has not been clearly defined; however, additional risk factors are usually present in affected children. Given the prevalence of prothrombotic disorders in childhood stroke, and their likely causative role, children with stroke should be screened for prothrombotic disorders. Future prospective and multicenter studies will elucidate the contribution of specific prothrombotic disorders to initial and recurrent stroke, and optimal therapy.

Preoperative chemotherapy and pelvic radiation for tethered or fixed rectal cancer: a phase II dose escalation study

PURPOSE

To study the impact of preoperative radiation dose escalation and postoperative adjuvant chemotherapy on the outcome of tethered and fixed rectal carcinoma.

METHODS AND MATERIALS

We have treated 156 patients with 3 consecutive preoperative chemoradiation protocols with escalating treatment intensity. Schedule 1 consisted of 40 Gy radiation with concurrent 5-fluorouracil (5-FU) infusion and mitomycin C. Schedule 2 used a sandwich design with preoperative (40 Gy) and postoperative (18 Gy) radiation with concomitant 5-FU infusion, leucovorin, and mitomycin C. In schedule 3, the preoperative radiation dose was increased to 50 Gy and adjuvant 5-FU/leucovorin chemotherapy was added following surgery. There were 54, 27, and 75 patients treated in schedules 1, 2, and 3, respectively.

RESULTS

The resectability was 91% for schedule 1 and 100% for both schedules 2 and 3. A dose-response relationship was observed between the radiation dose and the tumor downstaging and local control. The pathological complete response (T0N0M0) rates for schedules 1, 2, and 3 were 4%, 15%, and 25%, respectively. The respective rates of tumor downstaging were 41%, 33%, and 68%, respectively. The 5-year local relapse-free rates were 67% for schedule 1 (40 Gy), 96% for schedule 2 (58 Gy), and 92% for schedule 3 (50 Gy) (p = 0.0011). The addition of postoperative chemotherapy appeared to improve both the survival and the relapse-free survival. The 5-year survival was increased from 52% to 84% (p = 0.0004) and the 5-year progression-free survival was improved from 48% to 74% (p = 0.0008).

CONCLUSION

Preoperative 5-FU infusion, leucovorin, mitomycin C, and 50-Gy pelvic radiation, followed by postoperative bolus 5-FU/leucovorin chemotherapy, appeared to be an effective treatment for tethered/fixed rectal cancers. However, its therapeutic efficacy could only be validated in randomized studies.

Craniofacial dysmorphism, agenesis of the corpus callosum and ocular colobomas: Temtamy syndrome?

A possible new case of Temtamy syndrome is described in a male child. Clinical features of the present case and those described by Temtamy are discussed.

Stability and sterility of recombinant tissue plasminogen activator at -30 degrees C

We assessed whether frozen recombinant tissue plasminogen activator (rt-PA) remains stable and sterile for up to 22 weeks at -30 degrees C. Our findings confirm that rt-PA is a cost-effective alternative to urokinase for restoring patency to occluded central venous catheters.

Dietary fibre intake and constipation in children with severe developmental disabilities

OBJECTIVE

Constipation is a common problem in children with severe developmental disabilities (DD). This study aimed to evaluate fibre intake of severe DD children living in a residential institution, and the possibility of reducing the use of laxatives by increasing their fibre intake.

METHODOLOGY

A baseline study was performed to evaluate the fibre and macronutrient intake in a group of severe DD children. Nutrients including fibre for a standard serving in each meal were calculated and daily macronutrients and fibre intake were estimated. An intervention study was then carried out to evaluate whether increasing fibre intake could relieve constipation. A total of 20 children aged between 3 and 17 years were assessed over a 4-month period. In a residential unit for severe DD children, laxatives were routinely prescribed if there was no spontaneous bowel motion for two consecutive days. Fibre intake was increased in stages by adding All-Bran(R) (Kellogg Company, Battle Creek, MI, USA) and desserts. The mean number of laxative usage per week per child in the different stages were then compared.

RESULTS

The baseline fibre intake was found to be approximately 2 g/day. The mean number of laxatives required per week per child decreased significantly from a baseline value of 1.22 (about 5 laxatives/month) (standard deviation (SD) = 0.36)) to 0.90 (about 3. 5 laxatives/month) (SD = 0.75) in the first stage, and 0.71 (about 3 laxatives/month) (SD = 0.40) in the second stage. Using paired t-test, the difference was statistically significant when compared with the baseline: P < 0.05 for the first, and P < 0.01 for the second stage of fibre supplementation.

CONCLUSION

Very low daily intake of fibre of 2 g/day was documented. Relief of constipation and a significant reduction in the usage of laxatives was demonstrated by increasing fibre intake to 17 g/day (stage 1). Increasing fibre intake further to 21 g/day (stage 2), showed a further reduction in the use of laxatives. There was, however, no statistical significance between stage 1 and stage 2 of fibre supplementation. Alternative ways to further relieve constipation in severe DD children require further studies.

Beneficial effects of increasing monounsaturated fat intake in adolescents with type 1 diabetes

This study aimed to increase the monounsaturated fat content in the diet of outpatient adolescents with type 1 diabetes and to examine the metabolic effects after 12 weeks. Twenty-three adolescents were randomly allocated to either a high monounsaturated fat diet or a control diet. Their mean age was 16.9 (S.D. 2.1) years and median HbA(1c) was 9.1% [IQR 7.9-10.4%]. Dietary targets were not reached judged by their 4-day food diaries. However, the whole study group had a significant increase in monounsaturated fat as indexed by red cell phospholipid fatty acids (RCFAs), with an increase of n-9 RCFAs from 14.9% [IQR: 14.5-21.7%] to 21.7% [IQR: 18.8-25.6%] (P=0.002). Changes in n-9 RCFAs were inversely related to changes in HbA(1c) (R(2)=0.26, P=0.02), such that a 10% increase in n-9 RCFAs corresponded to a 0.64% improvement (decrease) in HbA(1c). Changes in n-9 RCFAs were also inversely related to changes in plasma total cholesterol (R(2)=0.38, P=0.002) and plasma LDL cholesterol (R(2)=0. 21, P=0.03). These changes were not associated with changes in insulin dose, body weight or physical activity. Overall, the results demonstrate that a modest increase in the monounsaturated fat content of an adolescent diet has the potential to improve glycaemic control and lipid profile.

Whole blood heparin concentrations do not correlate with plasma antifactor Xa heparin concentrations in pediatric patients undergoing cardiopulmonary bypass

This study was designed to test the validity of whole blood heparin concentration (WHBC) measurements using an on-site protamine titration assay with the Hepcon instrument (Medtronic Blood Management, Parker, CO, USA) in pediatric patients less than 1 year old undergoing cardiopulmonary bypass (CPB). The validity of the Hepcon measurements was examined via a test of correlation with the gold standard plasma antifactor Xa activity (anti-Xa) assay. Fifty-one patients (23 females and 28 males) under 1 year old (mean age 5.3 months) were studied prospectively. Blood samples were taken at 5 min into CPB and at the end of CPB for the WBHC, plasma anti-Xa activity, and hematocrit (Hct). The WBHC was converted to plasma heparin level using a formula taking into account the collection of blood into citrate solution and the effect of the citrate on the hematocrit. While a nonparametric statistical analysis revealed that the mean corrected values from the Hepcon instrument were not significantly different from the mean anti-Xa values (p = 0.070 at 5 min on CPB, p = 0.518 at the end of CPB), there was no significant correlation between these values at either 5 min into CPB (r = 0.113, p = 0.429) or at the end of CPB (r = -0.247, p = 0.080). The lack of correlation between the two assays may be related to the extreme hemodilution observed during CPB in small children, which leads to very low concentrations of coagulation proteins. Due to this discrepancy, whole blood heparin monitors should be further evaluated in children undergoing CPB.

Influence of exogenous factor VIIa on thrombin generation in cord plasma of full-term and pre-term newborns

Factor (F) VIIa has been used to treat adults and children with a variety of bleeding disorders. The results from these studies cannot be extrapolated to newborns because their hemostatic system differs significantly from adults, which may influence the effects of FVIIa on thrombin (IIa) generation. We compared the effects of FVIIa concentrates on IIa generation in plasmas from adults, full-term newborns and pre-term newborns. Defibrinated plasma (using arvin) from adults, or umbilical cords from full-term or pre-term deliveries was supplemented with FVIIa (Novo Nordisk, Bagsvaerd, Denmark), mixed with dilute thromboplastin reagent, and the resultant reaction mixture subsampled periodically into ethylenediamine tetraacetic acid, followed by measurement of total IIa activity (S-2238). Thrombin-alpha2 macroglobulin complexes, determined as residual activity after neutralization with heparin and antithrombin, were subtracted from total IIa to give free IIa. Prothrombin (FII) and inhibitor complexes were measured by enzyme-linked immunosorbent assays. Addition of FVIIa caused a reduction in the lag phase for the appearance of free IIa and consumption of FII, which was more pronounced in newborn plasma. There was no increase in peak IIa levels regardless of the amount of FVIIa added. Final inhibitor complex concentrations were increased in plasmas from adults compared with newborns, likely reflecting higher plasma concentrations of FII in adults. Generation of IIa was more rapid in pre-term plasma compared with that in adult and full-term cord plasmas due to increased endogenous tissue factor (TF). In summary, FVIIa enhanced IIa generation in plasma from different age groups, with the effect being more pronounced in plasma from pre-term newborns, possibly due to increased levels of plasma TF.

The use of low molecular weight heparin in pediatric patients: a prospective cohort study

OBJECTIVE

Low molecular weight heparins (LMWHs) offer several advantages over standard anticoagulant therapy (unfractionated heparin/warfarin) including predictable pharmacokinetics, minimal monitoring, and subcutaneous administration. Our objective was to determine the safety and efficacy of LMWHs in children.

METHODS

A prospective cohort of children treated with the LMWH enoxaparin (Rhone Poulenc Rorer) was monitored at the Hospital for Sick Children, Toronto, Canada, from March 1994 until July 1997.

RESULTS

There were 146 courses of LMWH administered for treatment and 31 courses for prophylaxis of thromboembolic events (TEs). Clinical resolution of TEs occurred in 94% of children receiving therapeutic doses of LMWH, and 96% of children receiving prophylactic doses of LMWH had no symptoms of recurrent or new TEs. Major bleeding occurred in 5% of children receiving therapeutic doses. Recurrent or new TEs occurred in 1% and 3% of children receiving therapeutic and prophylactic doses of LMWH, respectively.

CONCLUSION

LMWH appears to be efficacious and safe for both management and prophylaxis of TEs. The results of this cohort study justify a randomized controlled trial comparing LMWH with standard therapy for the management of TEs in children.

B7.1 costimulation increases T-cell proliferation and cytotoxicity via selective expansion of specific variable alpha and beta genes of the T-cell receptor

BACKGROUND

Optimal T-cell activation requires not only ligation of the T-cell receptor (TcR) but also delivery of costimulatory signals by various accessory molecules. The interaction of the costimulatory molecule B7.1 (CD80) with its receptor CD28 provides a strong positive signal to T cells.

METHODS

The B7.1 gene was transduced into cultured human ovarian, breast, and pancreatic tumor cells by using a retroviral vector. Autologous as well as allogeneic naive T-cells were stimulated with either wild-type or B7.1-transduced tumor cells in a mixed lymphocyte tumor cell culture (MLTC). In addition to cytolytic activity, T-cell proliferation, T-cell subset composition, and the frequencies of TcR variable (V) alpha and beta genes were compared in T cells from both types of MLTC.

RESULTS

Introduction of the B7.1 gene into tumor cells was successful in all tumors to a varying degree. Those tumors expressing high levels of B7.1 induced significantly higher levels of T-cell proliferation than wild-type tumor cells. T-cell subset composition did not markedly differ between T cells stimulated with wild-type tumor cells or B7.1-expressing tumor cells. However, T cells stimulated with B7.1-expressing tumor cells showed a significantly increased cytolytic potential. The increased cytotoxic T lymphocyte activity was associated with a higher frequency of specific TcR V alpha and V beta genes. In addition, B7.1 costimulation promoted oligoclonality among the responding T cells.

CONCLUSIONS

These data suggest that costimulation through B7.1 promotes T-cell proliferation and cytotoxic activity through clonal expansions of T cells bearing antigen-specific TcR V alpha and V beta genes and through promotion of oligoclonality. The data also suggest that promoting B7.1-mediated costimulation is an important aspect of immune therapies.

Analysis of warfarin therapy in pediatric patients: A prospective cohort study of 319 patients

This study details warfarin use in a large pediatric population followed in a central anticoagulation clinic. A prospective, consecutive cohort of nonselected children were studied. Patients were divided into groups by age, target international normalized ratio (INR) range, disease, medications, and vitamin K supplemented enteral nutrition use. Groups were analyzed on multiple aspects of warfarin therapy using multivariate methods. A total of 319 patients received 352 warfarin courses representing 391 treatment years. Age independently influenced all aspects of therapy. When compared with all older children, the </=1 year of age group required increased warfarin doses, longer overlap with heparin, longer time to achieve target INR ranges, more frequent INR testing and dose adjustments, and fewer INR values in the target range. Although significantly different than children </=1 year, children 1 to 6 years of age showed the same findings when compared with 7- to 18-year-olds. Fontan patients required 25% decreased dosage as compared with other congenital heart disease patients. Children on corticosteroids had less INRs in the target range and children on phenobarbital/carbamazepine required increased maintenance dosages of warfarin. Also, patients receiving enteral nutrition required increased dosages of warfarin. Serious bleeding occurred in 2 children (0.5% per patient year). Recurrent thromboembolic events (TEs) occurred in 8 children. Two children had recurrences while receiving warfarin (1.3% per patient year). This study outlines the profound effect of age and relative complexity of clinical management of warfarin therapy in children.

Weekly telephone contact does not enhance the compliance of home apnea monitoring

OBJECTIVE

To evaluate the effect of weekly telephone contact with families in enhancing the use of home apnea monitors.

STUDY DESIGN

This was a prospective, randomized, single-blinded study of 65 infants who were prescribed home apnea monitoring at the time of initial discharge from the hospital. Exclusion criteria included participation in any other study involving home monitoring or nonavailability of home telephone. Infants were randomized either to the "standard" or "telephone" group by a stratified balanced block technique. All families were instructed to use the monitor during the first 4-week period at all times except during bathing and during the second 4-week period at all unattended times and at night. The families in the telephone group were contacted weekly for 8 weeks. The telephone interview reviewed the events of the previous week but did not include specific encouragement to use the monitor. Both groups received routine pediatric care and follow-up at our high-risk premature clinic. The primary outcome measure was compliance measured as the percentage of time as well as the hours per day that the infant spent on the monitor as recorded by the documented monitor.

RESULTS

The telephone (n = 30) and standard (n = 32) groups were similar (p > 0.10) with respect to birth weight (1567 +/- 778 versus 1710 +/- 777 gm), gestational age (30.9 +/- 4.2 versus 31.1 +/- 4.6 weeks), maternal age (24.9 +/- 6.0 versus 25.3 +/- 5.4 years), and commercial insurance (46.7% versus 46.9%), a marker of higher socioeconomic status. Compliance of the telephone versus the standard group was similar during the first 4-week period (74.7 +/- 24.9 versus 75 +/- 27.8%, p = 0.85) (17.9 +/- 5.9 versus 18.2 +/- 6.6 hours/day), the second 4 week period (63.4 +/- 29.1 versus 58.9 +/- 30.9%, p = 0.59) (15.2 +/- 7.0 versus 14.1 +/- 7.4 hours/day) and the entire 8-week period (69.3 +/- 24.7 versus 67.7 +/- 26.2%, p = 0.82, Mann-Whitney U-test) (16.7 +/- 6.0 versus 16.1 +/- 6.5 hours/day), respectively. An abnormal pneumocardiogram at the time of discharge was the only identified factor that improved the compliance for the entire 8-week period (73.1 +/- 22 versus 52.1 +/- 28.5%, p = 0.02) (17.5 +/- 5.2 versus 12.5 +/- 6.8 hours/day) and the first 4-week period of monitoring (81.7 +/- 22.9 versus 59.5 +/- 31.3%, p = 0.01) (19.6 +/- 5.5 versus 14.2 +/- 7.5 hours/day).

CONCLUSION

Weekly telephone contact, without specific encouragement to use the monitor, did not improve compliance. Compliance was greater in subjects who had abnormal pneumocardiogram results at the time of discharge from hospital regardless of their telephone/standard group assignment. We speculate that in this already compliant population, more targeted advice is necessary to increase compliance.

Efficacy of dorsal pedal artery bypass in limb salvage for ischemic heel ulcers

PURPOSE

Although pedal artery bypass has been established as an effective and durable limb salvage procedure, the utility of these bypass grafts in limb salvage, specifically for the difficult problem of heel ulceration, remains undefined.

METHODS

We retrospectively reviewed 432 pedal bypass grafts placed for indications of ischemic gangrene or ulceration isolated to either the forefoot (n = 336) or heel (n = 96). Lesion-healing rates and life-table analysis of survival, patency, and limb salvage were compared for forefoot versus heel lesions. Preoperative angiograms were reviewed to evaluate the influence of an intact pedal arch on heel lesion healing.

RESULTS

Complete healing rates for forefoot and heel lesions were similar (90.5% vs 86.5%, P =.26), with comparable rates of major lower extremity amputation (9.8% vs 9.3%, P =.87). Time to complete healing in the heel lesion group ranged from 13 to 716 days, with a mean of 139 days. Preoperative angiography demonstrated an intact pedal arch in 48.8% of the patients with heel lesions. Healing and graft patency rates in these patients with heel lesions were independent of the presence of an intact arch, with healing rates of 90.2% and 83.7% (P =.38) and 2-year patency rates of 73.4% and 67.0% in complete and incomplete pedal arches, respectively. Comparison of 5-year primary and secondary patency rates between the forefoot and heel lesion groups were essentially identical, with primary rates of 56.9% versus 62.1% (P =.57) and secondary rates of 67.2% versus 60.3% (P =.50), respectively.

CONCLUSION

Bypass grafts to the dorsalis pedis artery provide substantial perfusion to the posterior foot such that the resulting limb salvage and healing rates for revascularized heel lesions is excellent and comparable with those observed for ischemic forefoot pathology.

Soluble MUC1 secreted by human epithelial cancer cells mediates immune suppression by blocking T-cell activation

Solid tumors may secrete factors that mediate immune suppression in patients. We investigated the effect of supernatants from 25 human tumor cell lines on T-lymphocytes from healthy donors. A profound inhibition of proliferation, cytokine secretion and cytotoxic activity was seen when T-cells were cultured in concentrated tumor supernatants from 6 cell lines fractionated into high (>100 kDa) m.w. molecules. Interestingly, the inhibitory effects were reversed when the tumor supernatant was removed. Cell cycle studies of inhibited T-cells showed most of them were growth arrested in the G(0)/G(1) phase similar to naïve T-cells. In addition, these T-cells did not express IL2-receptors and expression of CD54 (ICAM-1) and CD58 (LFA-3) resembled that of resting T-cells. Protein gel electrophoresis of the tumor supernatants and western blot analysis demonstrated the presence of soluble MUC1 in the inhibitory tumor supernatants but not in control supernatant. Most importantly, depletion of soluble MUC1 by immunoprecipitation from the tumor supernatants neutralized the inhibitory effects on T-lymphocytes. Therefore, our results show that MUC1 shed by cultured epithelial tumor cells mediates inhibition of T-cell proliferation and function by inducing cell growth arrest.

Early-infantile galactosialidosis: prenatal presentation and postnatal follow-up

Galactosialidosis (GS) is an autosomal recessive condition caused by combined deficiency of the lysosomal enzymes beta-galactosidase and alpha-neuraminidase. The combined deficiency has been found to result from a defect in protective protein/cathepsin A (PPCA), an intralysosomal protein which protects these enzymes from premature proteolytic processing. The most severe form of GS, the early-infantile form, results in early onset of edema, ascites, visceromegaly, and skeletal dysplasia. We report a case of early-infantile GS in a male infant who presented with nonimmune fetal hydrops (NIH), "coarse" facial appearance, massive fluid-filled inguinal hernias, multiple telangiectasia, and diffuse hypopigmentation; he subsequently developed visceromegaly. The diagnosis of GS was confirmed biochemically and the defect in PPCA characterized at the protein level. Examination of fetal peripheral blood smears sampled at 30 weeks gestation demonstrated vacuolation of lymphocytes, suggesting blood film examination may be a useful screening tool for cases of NIH where a metabolic disorder is suspected. Skeletal radiography at birth demonstrated punctate epiphyses of the femora, calcanei, and sacrum. We present a discussion of and differential diagnosis for this radiographic finding. To the best of our knowledge, this is the first case of early-infantile GS presenting with stippled epiphyses.

A near-resonance solution to the bloch equations and its application to RF pulse design

A near-resonance expansion of the solution to the Bloch equations in the presence of a radiofrequency (RF) pulse is presented in this paper. The first-order approximation explicitly demonstrates the nonlinear nature of the Bloch equations and precisely relates the excitation profile with the RF pulse when the flip angle is less than pi/2. As an application of this solution, we present a procedure for designing RF pulses to generate symmetric excitation profiles with arbitrary shapes for new encoding approaches such as wavelet encoding. Copyright 1999 Academic Press.

Detection of cancerous masses for screening mammography using discrete wavelet transform-based multiresolution Markov random field

When cancerous masses are embedded in and camouflaged by varying densities of parenchymal tissue structures, they are difficult to visually detect on mammograms. We present a novel algorithm based on the discrete wavelet transform (DWT) and multiresolution markov random field (MMRF) that will single out the suspicious masses to assist the attending radiologist in making decisions.

Limited joint mobility in the hands and feet of adolescents with Type 1 diabetes mellitus

AIMS

Limited joint mobility (LJM) in the foot has not been assessed in adolescents with Type 1 diabetes mellitus (DM) but is associated with neuropathic ulceration in adults. This study was designed to determine the presence of LJM in adolescents with Type 1 DM and its association with microvascular disease.

METHODS

The hands, feet and hips were examined in 302 diabetic adolescents and 51 nondiabetic controls (aged 11.5-20 years). LJM was defined as less than the fifth percent reference for controls.

RESULTS

Reduced motion was found in 35% of diabetic adolescents at the subtalar (ST) joint, 18% at the first metatarsophalangeal (MTP) joint, 26% at the fifth metacarpophalangeal (MCP) joint and 13% had limited passive extension of the interphalangeal (IP) joints of the hands. Limited passive IP joint extension of the hands was not present in the controls. Limited active IP joint extension, a positive 'prayer sign', occurred in 35% of diabetic adolescents and 14% of controls. Diabetic adolescents showing LJM in any of these areas, except the prayer sign, were more likely to have retinopathy (odds ratio 2.53, CI: 1.53-4.18). Those with LJM in the foot were more likely to have albumin excretion rates >7.5 microg/min (OR 2.06, CI: 1.16-3.68).

CONCLUSION

LJM in the feet of adolescents with Type 1 DM is associated with microvascular disease and is a useful routine clinical measure.