Reduced immunogenicity of a live Salmonella enterica serovar Typhimurium vaccine in aged mice

Introduction

Non-typhoidal Salmonella (NTS) is responsible for a high burden of foodborne infections and deaths worldwide. In the United States, NTS infections are the leading cause of hospitalizations and deaths due to foodborne illnesses, and older adults (≥65 years) are disproportionately affected by Salmonella infections. Due to this public health concern, we have developed a live attenuated vaccine, CVD 1926 (I77 ΔguaBA ΔclpP ΔpipA ΔhtrA), against Salmonella enterica serovar Typhimurium, a common serovar of NTS. Little is known about the effect of age on oral vaccine responses, and due to the decline in immune function with age, it is critical to evaluate vaccine candidates in older age groups during early product development.

Methods

In this study, adult (six-to-eight-week-old) and aged (18-month-old) C57BL/6 mice received two doses of CVD 1926 (109 CFU/dose) or PBS perorally, and animals were evaluated for antibody and cell-mediated immune responses. A separate set of mice were immunized and then pre-treated with streptomycin and challenged orally with 108 CFU of wild-type S. Typhimurium SL1344 at 4 weeks postimmunization.

Results

Compared to PBS-immunized mice, adult mice immunized with CVD 1926 had significantly lower S. Typhimurium counts in the spleen, liver, and small intestine upon challenge. In contrast, there were no differences in bacterial loads in the tissues of vaccinated versus PBS aged mice. Aged mice exhibited reduced Salmonella-specific antibody titers in the serum and feces following immunization with CVD 1926 compared to adult mice. In terms of T cell responses (T-CMI), immunized adult mice showed an increase in the frequency of IFN-γ- and IL-2-producing splenic CD4 T cells, IFN-γ- and TNF-α-producing Peyer's Patch (PP)-derived CD4 T cells, and IFN-γ- and TNF-α-producing splenic CD8 T cells compared to adult mice administered PBS. In contrast, in aged mice, T-CMI responses were similar in vaccinated versus PBS mice. CVD 1926 elicited significantly more PP-derived multifunctional T cells in adult compared to aged mice.

Conclusion

These data suggest that our candidate live attenuated S. Typhimurium vaccine, CVD 1926, may not be sufficiently protective or immunogenic in older humans and that mucosal responses to live-attenuated vaccines decrease with increasing age.

A Nonlethal Full-Thickness Flame Burn Produces a Seroma Beneath the Forming Eschar, Thereby Promoting Pseudomonas aeruginosa Sepsis in Mice

The World Health Organization estimates ~180,000 deaths occur annually from burn-related injuries. Many victims who survive the initial burn trauma succumb to bacterial infections that lead to sepsis during treatment. Although advancements in burn care continue to improve in high-income countries due to their burn centers and advanced research, low and middle-income countries continue to see high frequencies of burn injuries and burn-related deaths due to secondary infections. Bacterial-derived sepsis is the most life-threatening danger for people that survive burn injuries. Here we provide evidence for the first time that a subeschar seroma forms postburn even in the absence of infection in mice. The seroma fills with a volume estimated at 500 µL of fluid, 25% of the blood supply, free of red blood cells. The seroma fluid supports robust Pseudomonas aeruginosa (PA) growth and contains inflammatory cytokines and chemokines, which recruit immature neutrophils and monocytes to the seroma in the absence of endothelial breakdown. These immune cells fail to contain PA expansion and dissemination. This recruitment of monocytes and immature neutrophils may result in sequestering these critical immune cells away from other tissues during a pivotal time during bacterial dissemination, promoting PA-mediated sepsis.

Improvement in quality of life among Sri Lankan patients with haemorrhoids after invasive treatment: a longitudinal observational study

Background

Haemorrhoids is a common chronic disease that can significantly impact patients’ quality of life. Yet, few studies have evaluated health-related quality of life (HRQoL) of patients with haemorrhoids before and after treatment. This study investigated the HRQoL of patients with haemorrhoids before and after treatment and the change in HRQoL from baseline.

Methods

A prospective observational study of patients with haemorrhoids was conducted at two public hospitals in Kandy, Sri Lanka. Two questionnaires assessing symptom severity and haemorrhoid-specific QoL were administered at initial consultation and at 4- and 8-week follow-ups after treatment (sclerotherapy, rubber band ligation (RBL), haemorrhoidectomy or evacuation of haematoma). The primary outcome was the least squares (LS) change of HRQoL score from baseline, measured using the Short Health Scale adapted for Haemorrhoidal Disease (4 domains: symptom load, interference with daily activities, concern, general well-being).

Results

In 48 patients selected for this study, LS mean change from baseline showed significant improvement in HRQoL across all domains and total Short Health Scale adapted for Haemorrhoidal Disease score at 4- and 8-week follow-ups (P < 0.001). Difference in LS mean change from baseline also showed continued improvement of HRQoL from week 4 to week 8 (P < 0.010). ‘Concern’ showed greatest improvement at 4 and 8 weeks (P < 0.001). Averaged LS mean changes from baseline showed RBL had greater improvement of HRQoL compared with sclerotherapy (P = 0.004).

Conclusion

Patients with haemorrhoids had improved HRQoL after invasive treatment. Haemorrhoid-specific QoL is an important component of the extent of disease and can serve as an aid to guide treatment, assess outcomes and monitor disease.

Understanding immunosenescence and its impact on vaccination of older adults

Older adults are more susceptible to viral and bacterial infection, and experience higher incidence and severity of infectious diseases. Although vaccination is the most logical solution in preventing infectious diseases, primary vaccine responses in individuals aged ≥65 years-old fail to generate complete protection. This is presumably attributed to immunosenescence, a term that describes functional differences associated with the immune system and natural age advancement. Both the innate and adaptive immune systems experience age-related impairments that contribute to insufficient protection following vaccination. This review addresses current knowledge of age-related changes that affect vaccine responsiveness; including the deficits in innate cell functions, dampened humoral and cell-mediated immune responses, current vaccination schedules for older adults, and concludes with potential strategies for improving vaccine efficacy specifically for this age group. Due to an age-related decline in immunity and poor vaccine responses, infectious diseases remain a burden among the aged population.

Accuracy of parent-reported ages and stages questionnaire in assessing the motor and language skills of preterm infants

BACKGROUND

Parent-completed tools like the Ages and Stages Questionnaire Third Edition (ASQ-3) are important in developmental screening. As a screening tool, a high negative predictive value (NPV) is critical to avoid missing the diagnosis of developmental delay. This study evaluated the NPV and accuracy of the ASQ-3 in assessing the development of preterm infants.

METHODS

Infants born at <32 weeks and/or <1250 grams, presenting to the Neonatal Neurodevelopmental Clinic at the Singapore General Hospital for follow-up from January 2014 to June 2017, at 6, 12, and 18 months corrected age, were included. The ASQ-3 and standardized tests - Peabody Developmental Motor Scale-Second Edition (PDMS-2) and Preschool Language Scale, Fourth Edition UK (PLS-4 UK) - were administered. ASQ-3 gross motor and fine motor scores were compared to PDMS-2 at 6 and 12 months, and ASQ-3 communication scores to PLS-4 UK at 18 months.

RESULTS

At 6 months (n = 145), NPV for gross motor and fine motor were 96.4% (accuracy 80.0%) and 95.4% (accuracy 77.2%) respectively. At 12 months (n = 127), NPV for gross motor and fine motor were 88.9% (accuracy 79.8%) and 82.8% (accuracy 74.0%) respectively. At 18 months (n = 113), NPV for language was 56.9% (accuracy 63.7%).

CONCLUSIONS

The ASQ-3 showed high NPV and accuracy in screening gross motor and fine motor skills at 6 and 12 months, but not in screening language skills at 18 months. Judicious use of the ASQ-3 may allow for more effective utilization of resources.

The Health Opportunity Index: Understanding the Input to Disparate Health Outcomes in Vulnerable and High-Risk Census Tracts

The Health Opportunity Index (HOI) is a multivariate tool that can be more efficiently used to identify and understand the interplay of complex social determinants of health (SDH) at the census tract level that influences the ability to achieve optimal health. The derivation of the HOI utilizes the data-reduction technique of principal component analysis to determine the impact of SDH on optimal health at lower census geographies. In the midst of persistent health disparities and the present COVID-19 pandemic, we demonstrate the potential utility of using 13-input variables to derive a composite metric of health (HOI) score as a means to assist in the identification of the most vulnerable communities during the current pandemic. Using GIS mapping technology, health opportunity indices were layered by counties in Ohio to highlight differences by census tract. Collectively we demonstrate that our HOI framework, principal component analysis and convergence analysis methodology coalesce to provide results supporting the utility of this framework in the three largest counties in Ohio: Franklin (Columbus), Cuyahoga (Cleveland), and Hamilton (Cincinnati). The results in this study identified census tracts that were also synonymous with communities that were at risk for disparate COVID-19 related health outcomes. In this regard, convergence analyses facilitated identification of census tracts where different disparate health outcomes co-exist at the worst levels. Our results suggest that effective use of the HOI composite score and subcomponent scores to identify specific SDH can guide mitigation/intervention practices, thus creating the potential for better targeting of mitigation and intervention strategies for vulnerable communities, such as during the current pandemic.

Determining competence in performing obstetric combined spinal-epidural procedures in junior anesthesiology residents: results from a cumulative sum analysis

BACKGROUND

The epidural anesthesia technique is a challenging skill to master. The Accreditation Council for Graduate Medical Education (ACGME) stipulates that anesthesiology residents must complete 40 epidural procedures by the end of junior residency. The rationale is unknown. The aim of this prospective study was to determine the minimum case experience required to demonstrate competence in performing obstetric combined spinal-epidural procedures among junior residents, using an objective statistical tool, the cumulative sum (CUSUM) analysis.

METHODS

Twenty-four residents, with no prior experience performing epidurals, sequentially recorded all obstetric combined spinal-epidural procedures as a 'success' or 'failure', based on study criteria. Individual CUSUM graphs were plotted, with acceptable and unacceptable failure rates set at 20% and 35%, respectively. The number of procedural attempts necessary to demonstrate competence was determined.

RESULTS

Twenty-four residents (mean (SD) age 29 (2) years) participated in the study. Median (IQR) number of procedures was 78 (66-85), with a median (IQR) success rate of 86% (82-89%). Nineteen of 24 residents required a median (IQR) of 40 (33-50) attempts to demonstrate competence. Five did not achieve procedural competence in the training period. The CUSUM graphs highlighted performance trends that required intervention.

CONCLUSION

Competence was achieved by 19/24 residents after the ACGME-required case experience of 40 combined spinal-epidural procedures, based on a predefined acceptable failure rate of 20%. In our experience, CUSUM analysis is useful in monitoring technical performance over time and should be included as an adjunct assessment method for determining procedural competence.

P259 Adherence to optimal medical therapy in Asian patients with acute myocardial infarction treated with PCI

On Behalf

SingCLOUD collaborators

Background

 Notable regional differences have been observed worldwide in clinical characteristics and outcomes in patients experiencing acute myocardial infarction (AMI). Asian patients present younger and report higher adverse outcomes rates compared to Western cohorts. The reasons are multifactorial, but adherence to medication prescription guidelines is one of the modifiable factors.

Purpose

 Our aim was to study the effect of physician adherence to Optimal Medical Therapy (OMT) prescription guidelines on a MACE outcome in a high-risk group of Asian AMI patients over 1 year following percutaneous coronary intervention (PCI).

Method

 Data for this retrospective study was from the Singapore Cardiac Longitudinal Outcomes Database (SingCLOUD) pilot study involving AMI patients surviving primary PCI at two tertiary centers from 2012 to 2013. Guideline-directed OMT adherence was defined as concurrent prescription of at least one statin plus dual antiplatelet therapy (DAPT – aspirin plus P2Y12-I). Prescription of β-blockers and ACE-i/ARBs was also recorded. Prescription status and MACE (repeat MI, stroke, death) was recorded at discharge, 3, 6 and 9 months, and 1 year following the index discharge. The cumulative effect of OMT adherence at 3, 6, 9 months and 1 year post-discharge was studied by comparing risk of first MACE among patient groups with complete, partial and non-adherence to OMT prescription guidelines.

Results

 2,478 patients, 80.3% males, mean age 60.3 ± 11.7 years were studied. 1094 (44.1%) underwent primary PCI for STEMI. Single drug prescription at discharge for aspirin, P2Y12-I, and statins was 95, 97 and 95.8%, while prescription of β -blockers and ACE-inhibitors was 86.5 and 75.7%. Prescription of statins and aspirin declined gradually while P2Y12-I fell to 67.9% at 6mo and 47.6% at 1 year. Adherence to OMT declined from 92.3% at discharge to 82.1, 58.5, 56.1 and 40.3% at 3, 6, 9 months and 1 year, respectively. Of 342 (13.8%) occurrences of first MACE, 48.5% occurred within 3mo post-discharge. Complete adherence to OMT upon discharge significantly decreased risk of MACE at 3mo (OR = 0.066; 95% CI: 0.054-0.080; p &lt; 0.001) and 12mo (OR = 0.017; 95% CI: 0.010-0.028; p &lt; 0.001) relative to non-adherence.

Conclusion

 Over the course of a year in this high-risk group of PCI-treated AMI patients, there was a reduction in prescription adherence to the minimally essential OMT. Complete OMT adherence is beneficial in reducing MACE. Interventions targeting reasons for non-adherence are important in improving patient outcomes.

Abstract P259 Figure 1 - Medication over 1 year

Periprosthetic Fractures after Total Knee Arthroplasty: the Influence of Pre-Operative Mechanical Factors versus Intraoperative Factors

Introduction: Periprosthetic fractures are a devastating complication following total knee arthroplasty. Little is known about the effect of mechanical factors on the incidence of periprosthetic fractures. The aim of this study was to examine the correlation between pre-operative mechanical factors, like side of surgery, coronal alignment and pre-operative range of motion and intra-operative factors, and the incidence of a periprosthetic fracture, following primary total knee arthroplasty (TKA).

Materials and Methods: Forty-two patients with periprosthetic fractures (PPF) after primary TKA were identified from our hospital arthroplasty registry. These patients were matched two-to-one for gender and age at primary knee arthroplasty to 84 patients without PPF. The incidence of periprosthetic fracture with regards to laterality, coronal alignment and pre-operative range of motion was analysed. Intra-operative factors like implant type, patellar resurfacing and notching were also analysed using logistic regression.

Results: Coronal alignment, pre-operative range of motion and patella resurfacing were not significant predictors of periprosthetic fractures. Anterior femoral notching was found to be significantly higher in the fracture group with an odds ratio of 17. Left sided surgery was also significantly higher in the periprosthetic fracture group.

Conclusion: Periprosthetic fractures are 17 times more likely to occur in a knee with anterior femoral notching. Preoperative factors like coronal alignment and poor preoperative range of motion do not seem to increase the risk of periprosthetic fractures after TKA.

Topical calcineurin inhibitors in eczema and cancer association: A cohort study

INTRODUCTION

Cancer risk associated with topical calcineurin inhibitors (TCIs) remains unclear.

OBJECTIVE

To evaluate the association between TCIs and cancer among patients with atopic and endogenous eczema.

METHODS

Incident cancers were identified from the National Cancer Registry. Data were analyzed using the Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals.

RESULTS

880 unique cases of cancer developed in 66 176 patients from 2004 to 2012. The adjusted HRs for overall malignancy were 0.82 (95%CI 0.44-1.39) for tacrolimus-exposed and 1.30 (95%CI 0.59-2.45) for pimecrolimus-exposed. The only significant cancer association observed was lymphoid leukemia among the tacrolimus-exposed: HR 7.58 (95%CI 1.64-25.8). All affected patients had young-onset B-cell leukemia. Subgroup analysis of pediatric patients (≤16 years) showed significant association between tacrolimus use and B-cell leukemia: HR 26.4 (95%CI 4.77-146).

CONCLUSIONS

In this first Asian study on the risk of TCIs and malignancies, we do not find an association between use of tacrolimus and pimecrolimus in atopic and endogenous eczema and the overall development of malignancies. However, the use of topical tacrolimus was found to be associated with the development of B-cell acute lymphoid leukemia in pediatric eczema patients; further studies are required to investigate if a true association indeed occurs.

Clinical evolution of Parkinson's disease and prognostic factors affecting motor progression: 9-year follow-up study

BACKGROUND AND PURPOSE

There have been few long-term studies that have characterized and charted the clinical progression of Parkinson's disease (PD). This study was therefore undertaken to understand the natural clinical evolution of treated PD patients and to identify the variables that predict greater progression in these patients.

METHODS

A longitudinal linear mixed model analysis of motor score progression was performed on 576 PD patients derived from the National Neuroscience Institute Movement Disorders Database. Clinical and demographic variables were taken at baseline and formed the subgroups for comparison (gender, age at diagnosis, subtype, Mini-Mental State Examination score and baseline motor score). Motor score progression was calculated at each patient follow-up time point as the difference between Unified Parkinson's Disease Rating Scale (UPDRS) motor score at baseline and follow-up scores.

RESULTS

The overall annual motor score progression as measured by the change of UPDRS motor scores from baseline ranged from 0.62% to 3.67%. There are three distinct phases: improvement, stability, and steady progression. Patients returned to baseline score 2-2.5 years after diagnosis, with stability lasting to 7 years, followed by a period of steady progression. When analyzed longitudinally, male gender (P < 0.03), older age at diagnosis (P < 0.05), akinetic-rigid subtype (P < 0.04), cognitive impairment (P < 0.005) and lower baseline motor score (P < 0.04) were associated with greater progression of motor scores.

CONCLUSIONS

Our results show that, when measured clinically, motor progression was non-linear and that it occurred in distinct phases, all of which were affected by baseline demographic and clinical variables such as gender, age at diagnosis, disease subtype, cognitive status and baseline motor score.

Mortality of bullous pemphigoid in Singapore: risk factors and causes of death in 359 patients seen at the National Skin Centre

BACKGROUND

Bullous pemphigoid (BP) is the most common autoimmune-mediated subepidermal blistering skin disease and is associated with significant morbidity and mortality.

OBJECTIVES

To determine the 3-year mortality rate, risk factors and causes of death in patients with BP in Singapore, compared with the general population.

METHODS

We conducted a retrospective cohort study of all newly diagnosed patients with BP seen at the National Skin Centre from 1 April 2004 to 31 December 2009. Demographic and clinical data on comorbidities and treatment were recorded. Mortality information was obtained from the National Registry of Diseases.

RESULTS

In total 359 patients were included in our study. The 1-, 2-, 3-year mortality rates were 26·7%, 38·4% and 45·7%, respectively. The 3-year standardized mortality risk for patients with BP was 2·74 (95% confidence interval 2·34-3·19) times higher than for the age- and sex-matched general population. Parkinson disease, heart failure and chronic renal disease were associated with increased mortality, while combination treatment with low-to-moderate-dose corticoste-roids and immunomodulatory agents such as doxycycline and/or nicotinamide was associated with lower mortality. Overall, infections were the most common cause of death (59·8%), with the main causes of death being pneumonia (42·7%), cardiovascular disease (14·6%) and stroke (11·6%).

CONCLUSIONS

This study confirms an increased 3-year mortality rate for patients with BP in Singapore. Risk factors for increased mortality include medical comorbidities, especially neurological, cardiac and renal diseases. Treatment with combination therapy, including the use of low-to-moderate-dose corticosteroid, appeared to decrease mortality risk in patients with BP.

Systematic review of outcomes of liver resection for early hepatocellular carcinoma within the Milan criteria

BACKGROUND

Long-term overall survival after liver resection in patients with hepatocellular carcinoma (HCC) within the Milan criteria has been reported to improve in recent years. This study systematically reviewed the outcomes of surgical resection for HCC in patients with good liver function and meeting the Milan criteria for early HCC, published in the past 10 years.

METHODS

A literature search was conducted in PubMed for papers on outcomes of surgical resection for HCC published between January 2000 and December 2010. Cochrane systematic review methodology was used for this review. The primary outcome was overall survival. Secondary outcomes included operative mortality and disease-free survival. Studies that focused on geriatric populations, paediatric populations, a subset of the Milan criteria (such solitary tumours) or included patients with incidental tumours were excluded, as were case reports, conference abstracts, and studies with a large proportion of Child-Pugh grade C liver cirrhosis or unknown Child-Pugh status.

RESULTS

Of 152 studies reviewed, two randomized clinical trials and 27 retrospective case series were eligible for inclusion. The 5-year overall survival rate after resection of HCC ranged from 27 to 81 (median 67) per cent, and the median disease-free survival rate from 21 to 57 (median 37) per cent. There was a trend towards improved overall survival in recent years. The operative mortality rate ranged from 0 to 5 (median 0·7) per cent.

CONCLUSION

Surgical resection offers good overall survival for patients with HCC within the Milan criteria and with good liver function, although recurrence rates remain high. Outcomes have tended to improve in more recent years.

Single center retrospective analysis of BU-based conditioning regimens in allogeneic transplantation

We performed a single institution retrospective analysis of 114 patients treated with BU-based pretransplant conditioning regimens. Oral BU was administered to 76 patients (total dose 16 mg/kg or 8 mg/kg) and i.v. BU to 38 others (total dose 12.8 mg/kg or 6.4 mg/kg). Either CY (n=74) or fludarabine (n=40) was given in combination with BU. Median age was 35 years in the oral BU group and 48.5 years with i.v. BU (P<0.001). OS and PFS rates at 3-years post HSCT were not different in patients who received either i.v. or oral BU (OS: 41.3 vs 44.0% (P=0.981); PFS: 52.7 vs 54.7% (P=0.526), respectively). The i.v. BU, however, was associated with a significantly shorter time to engraftment (13.5 days vs 16 days, respectively; P<0.001). There were no significant differences in survival or 100-day mortality for patients who received either CY or fludarabine, in combination with BU. After adjustment for confounders, multivariate analysis showed that age of transplant (P=0.002), donor type (sibling or unrelated; P=0.003), GVHD (P<0.05) and route of administration (P=0.023) were significant risk factors for OS. The i.v. BU used in an older age group yielded equivalent survival compared with oral BU used in a younger population.

Phase I trial of pegylated interferon-alpha-2b in young patients with plexiform neurofibromas

OBJECTIVE

Interferon has antiproliferative and antiangiogenic properties. We sought to evaluate preliminary efficacy and determine the recommended phase II dose (RP2D) for pegylated interferon-α-2b (PI) in patients with unresectable progressive or symptomatic plexiform neurofibromas (PN).

METHODS

PI was administered weekly in cohorts of 3-6 patients during the dose-finding phase and continued for up to 2 years. Twelve patients were treated at the RP2D to further evaluate toxicity and activity.

RESULTS

Thirty patients (median age 9.3 years, range 1.9-34.7 years) were enrolled. No dose-limiting toxicity (DLT) was seen in patients treated at the 3 μg/kg dose level (DL) during the first 4 weeks. All 5 patients treated at the 4.5 μg/kg DL came off study or required dose reductions for behavioral toxicity or fatigue. Similar DLT on the 3 μg/kg DL became apparent over time. There was 1 DLT (myoclonus) in 12 patients enrolled at the 1.0 μg/kg DL. Eleven of 16 patients with pain showed improvement and 13 of 14 patients with a palpable mass had a decrease in size. Five of 17 patients (29%) who underwent volumetric analysis had a 15%-22% decrease in volume. Three of 4 patients with documented radiographic progression prior to enrollment showed stabilization or shrinkage.

CONCLUSIONS

The RP2D of PI for pediatric patients with PN is 1 μg/kg/wk. Clinical and radiographic improvement and cessation of growth can occur.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that pegylated interferon-α-2b in patients with unresectable, progressive, symptomatic, or life-threatening PNs results in radiographic reduction or stabilization of PN size.

The effect of retained intramedullary nails on tibial bone mineral density

BACKGROUND

Intramedullary nailing has become a standard treatment for adult tibial shaft fractures. Retained intramedullary nails have been associated with stress shielding, although their long-term effect on decreasing tibial bone mineral density is currently unclear. The purpose of this study was to determine if retained tibial intramedullary nails decrease tibial mineral density in patients with successfully treated fractures.

METHODS

Patients treated with statically locked intramedullary nails for isolated, unilateral tibia shaft fractures were studied. Inclusion required that fracture had healed radiographically and that the patient returned to the pre-injury activity level. Data on patient demographic, fracture type, surgical technique, implant, and post-operative functional status were tabulated. Dual energy X-ray absorptiometry was used to measure bone mineral density in selected regions of the affected tibia and the contralateral intact tibia. Image reconstruction software was employed to ensure symmetry of the studied regions.

FINDINGS

Twenty patients (mean age 43; range 22-77 years) were studied at a mean of 29 months (range 5-60 months) following intramedullary nailing. There was statistically significant reduction of mean bone mineral density in tibiae with retained intramedullary nails (1.02 g/cm(2) versus 1.06 g/cm(2); P=0.04). A significantly greater decrease in bone mineral density was detected in the reamed versus non-reamed tibiae (-7% versus +6%, respectively; P<0.05).

INTERPRETATION

The present study demonstrates a small, but statistically significant overall bone mineral density decrease in healed tibiae with retained nails. Intramedullary reaming appears to be a factor potentiating the reduction of tibia bone mineral density in long-term nail retention.

Can anthropometric measurements and diet analysis serve as useful tools to determine risk factors for insulin-resistant diabetes type 2 among white and black Americans?

OBJECTIVE

Central obesity is implicated in the development of insulin resistance by increasing insulin demand and eventually leading to hyperinsulinemia. Anthropometric measurements have been helpful in determining the risk factors in developing diabetes mellitus type 2. In this study we investigated whether anthropometric measurements differ among diabetics of different races. We also evaluated whether nutrient intake of these individuals was related to anthropometric measurement changes.

METHODS

Subjects were recruited from four groups: white control (n = 10), black control (n = 10), white diabetic (n = 5), and black diabetic (n = 10). The diabetic subjects had type 2 diabetes with insulin resistance on insulin monotherapy (age and sex matched). The following determinations were made: diet analysis, body mass index (kg/m(2)), the ratio of waist (umbilical level) to hip (maximum at buttocks) circumference, the ratio of waist to thigh (mid-thigh), and body fat percentage.

RESULTS

The micronutrient consumption was fairly similar in all groups with the exception of vitamin A (greatest consumption in the white control group, P < 0.05; and the lowest consumption in the black control group, P < 0.05). The data also suggested that central obesity (greatest waist-to-hip ratio) was present in the individuals with type 2 diabetes. The higher total fat, including saturated, monounsaturated, polyunsaturated, and cholesterol, intake in the diabetic groups were observed.

CONCLUSION

The type of fat consumed may be as important as the total fat consumption in the development of insulin resistance. The diet analysis can provide valuable information about the dietary habits of an individual and the possible causes of metabolic problems leading to a disease state. However, genetic factors must be considered when looking at diabetes incidence in different ethnic groups. For example, even though the black diabetic group consumed less fat in comparison with the other groups, their body fat percentages were higher. Therefore, we cannot conclude that high fat intake is primarily responsible for increased body fat percentage. Although anthropometric measurements are a useful tool in risk assessment, researchers should consider anatomic differences among different racial groups as covariables. Diet analysis when used in conjunction with anthropometric measurements can serve as a useful tool to detect whether metabolic alterations are related to dietary habits.

Human milk antibacterial factors: the effect of temperature on defense systems

Bovine milk will eventually spoil at refrigeration temperatures, but endogenous or exogenous pathogenic or spoilage bacteria in human milk stored for delayed feeding will die. We investigated the mechanism for these antibacterial properties and their response to high-tempertature, short-time (HTST, 72 degrees C-75 degrees C, 15 sec) and low-temperature long-time (LTLT, 65 degrees C, 30 min) pasteurization. Nonpathogenic Listeria innocua (10(6) cfu/mL) was inoculated into raw and processed bovine and human milk; bacterial plate counts twice weekly determined antibacterial activities. Up to 99% of L. innocua were killed and further growth was inhibited in raw and pasteurized human milk for at least 60 days at 4 degrees C. Reactive IgA antibodies against Listeria antigens were demonstrated by enzyme immunoassay in some human milk samples; sIgA activity against Escherichia coli O antigens was significantly decreased by heat treatments (raw, 1.8; HTST, 1.1; LTLT, 1.3 activity units). Adding human lactoferrin (0.5-20 mg/mL) to the Listeria inoculum (approximately 10(7) cfu/mL) in 1% peptone water did not inhibit bacterial growth.

Growth rates of a human colon adenocarcinoma cell line are regulated by the milk protein alpha-lactalbumin

The whey protein alpha-lactalbumin, derived from human milk, has been shown to inhibit proliferation of mammary epithelial cells and rat kidney cells. We have shown that bovine alpha-lactalbumin also has antiproliferative effects in human colon adenocarcinoma cell lines. During a 5-day dose-dependent growth study, bovine alpha-lactalbumin was added to Caco-2 or HT-29 monolayers in amounts from 5 to 35 microg/mL. Low concentrations of alpha-lactalbumin (10-25 microg/mL) stimulated growth during the first 3 to 4 days. After growing for 4 days, proliferation ceased and viable cell numbers decreased dramatically in the alpha-lactalbumin-treated cultures, suggesting a delayed initiation of apoptosis. This experiment demonstrates the acute bioactive effects of small concentrations of alpha-lactalbumin, compared with the high concentrations of other proteins in the media. These results suggest that alpha-lactalbumin in milk may promote health by inhibiting growth of potential cancer cells. Further studies will identify the role of calcium in the bioactivity of alpha-lactalbumin.

Clinical, genetic, and biochemical characterization of a Leber hereditary optic neuropathy family containing both the 11778 and 14484 primary mutations

Four mitochondrial DNA (mtDNA) mutations at nps 3460, 11778, 14484, and 14459 account for roughly 90% of cases of Leber hereditary optic neuropathy (LHON) and are designated as "primary" LHON mutations since they act as major predisposition factors for LHON. Although each primary mutation can arise independently on different mtDNA backgrounds during human evolution, they characteristically do not co-occur in LHON patients. We report here a family with the simultaneous occurrence of the 11778A and 14484C mutations. Neuro-ophthalmological examination of the proband, a nine-year-old Caucasian female, revealed the bilateral optic atrophy, central scotomas, and reduced visual acuity typical of LHON. Her mother had normal appearing optic discs and is today visually asymptomatic. Analysis of the proband blood mtDNA revealed that she harbored both the 11778A (heteroplasmic, 94% mutant) and the 14484C (homoplasmic mutant) mutation. This genotype was maintained in proband lymphoblasts and transmitochondrial cybrids. The mother also had both mutations, with the 14484C mutation homoplasmic in all cell types examined. However, only 31% of her blood mtDNAs carried the 11778 mutation, which segregated to essentially 100% wild-type in lymphoblast and cybrid mtDNA. Complex I-linked respiration and specific enzyme activity were consistently lowest in proband lymphoblast and cybrid mitochondria compared to those from the mother, 11778A patients, 14484C patients, or controls, thus demonstrating both a deleterious synergistic interaction between the 11778A and 14484C mutations and the magnitude of 11778A-associated complex I dysfunction. Remarkably, spontaneous vision recovery occurred in the proband, highlighting the complexities encountered when associating mtDNA genotype and complex I function with LHON expression.

Ouabain-induced signaling and vascular smooth muscle cell proliferation

The hypothesis of this study is that the sodium pump complex acts as an intracellular signal-transducing molecule in canine vascular smooth muscle cells through its interaction with other membrane and cytoskeletal proteins. We have demonstrated that 1 nm ouabain induced transactivation of the epidermal growth factor receptor (EGFR), resulting in increased proliferation and bromodeoxyuridine (BrdUrd) uptake. Immunoprecipitation and Western blotting showed that the EGFR and Src were phosphorylated within 5 min of 10(-9) m ouabain stimulation. Both ouabain-induced DNA synthesis (BrdUrd uptake) and MAPK42/44 phosphorylation were inhibited by the Src inhibitor PP2, the EGFR kinase inhibitor AG1478, the tyrosine kinase inhibitor genistein, and the MEK1 inhibitor PD98059. Ouabain concentrations higher than 1 nm had little or no stimulating effect on proliferation or BrdUrd uptake but did minimally activate ERK1/2. Thus, low concentrations of ouabain, which do not inhibit the sodium pump sufficiently to perturb the resting cellular ionic milieu, initiate a transactivational signaling cascade leading to vascular smooth muscle cell proliferation.

Pregnant women with chronic hypertension and superimposed pre-eclampsia have high cerebral perfusion pressure

OBJECTIVE

To determine any differences in cerebral perfusion pressure in patients with chronic hypertension compared with those with chronic hypertension and superimposed pre-eclampsia.

DESIGN

A prospective observational study.

SETTING

University hospital clinic and labour and delivery suite.

PARTICIPANTS

Fifteen women with chronic hypertension and 15 with superimposed pre-eclampsia.

METHODS

Transcranial Doppler ultrasound was used to measure blood velocity in the middle cerebral arteries of the patients. Systemic blood pressure in the brachial artery was measured simultaneously. Middle cerebral artery. resistance index, pulsatility index, and cerebral perfusion pressure were calculated and plotted on the same axes as data from normal pregnant women. Cerebral perfusion pressure values outside of the 5th and 95th centiles were regarded as abnormal. Cerebral perfusion pressure data from the chronic hypertension and superimposed pre-eclampsia groups were also expressed in terms of the number of normative standard deviations from the mean value for normal pregnancy (Multiples of the Standard Deviation: MOS). All studies were conducted before labour, under similar conditions, and before volume expansion or treatment. Statistical analysis was by Student's t test and Fisher's exact test as appropriate with significance set at a two-tailed P<0.05.

RESULTS

Patient demographics and blood pressure were not significantly different between the two groups. The resistance index and pulsatility index were not significantly different (neither absolute nor multiples of the standard deviation values). The absolute cerebral perfusion pressure was significantly higher in the patients with superimposed pre-eclampsia. The group of women with superimposed pre-eclampsia had a significantly higher mean value of cerebral perfusion pressure measured as multiples of the standard deviation from the mean value for normal pregnancy, despite there being no blood pressure difference.

CONCLUSIONS

Superimposed pre-eclampsia is associated with significantly higher cerebral perfusion pressure measurements compared with women with uncomplicated chronic hypertension. This is not directly related to a higher blood pressure. The difference in cerebral perfusion pressure may be used to speculate upon the pathophysiology of the increased risk for eclampsia seen in patients with superimposed pre-eclampsia.

Foreign body reaction to hemostatic materials mimicking recurrent brain tumor. Report of three cases

Chemical agents routinely used in neurosurgery to achieve intraoperative hemostasis can cause a foreign body reaction, which appears on magnetic resonance (MR) images to be indistinguishable from recurrent tumor. Clinical and/or imaging evidence of progression of disease early after surgical resection or during aggressive treatment may actually be distinct features of granuloma in these circumstances. A series of three cases was retrospectively analyzed for clinical, imaging, surgical, and pathological findings, and the consequences they held for further disease management. All patients were boys (3, 3, and 6 years of age, respectively) and all harbored primitive neuroectodermal tumors. Two tumors were located in the posterior fossa and one was located in the right parietal lobe. Two boys exhibited clinical symptoms, which were unexpected under the circumstances and prompted new imaging studies. One patient was asymptomatic and imaging was performed at planned routine time intervals. The MR images revealed circumscribed, streaky enhancement in the resection cavity that was suggestive of recurrent disease. This occurred 2 to 7 months after the first surgery. At repeated surgery, the resected material had the macroscopic appearance of gelatin sponge in one case and firm scar tissue in the other cases. Histological analysis revealed foreign body granulomas in the resected material, with Gelfoam or Surgicel as the underlying cause. No recurrent tumor was found and the second surgery resulted in imaging-confirmed complete resection in all three patients. Because recurrent disease was absent, the patients continued to participate in their original treatment protocols. All patients remain free from disease 34, 32, and 19 months after the first operation, respectively. During or after treatment for a central nervous system neoplasm, if unexpected clinical or imaging evidence of recurrence is found, a second-look operation may be necessary to determine the true nature of the findings. If the resection yields recurrent tumor, additional appropriate oncological treatment is warranted, but if a foreign body reaction is found, potentially harmful therapy can be withheld or postponed.

The development of the black blow fly, Phormia regina (Meigen)

The black blow fly, Phormia regina (Meigen) is a primary species commonly utilized to indicate a postmortem interval, or more appropriately a "time since colonization". Due to the importance of this species as a secondary myiasis producer in livestock operations, and more recently as a time since death indicator in the field of forensic entomology, a considerable amount of data on its growth and development has been generated. However, the developmental time as reported by these studies varies greatly, and current more detailed data is needed for use in medicocriminal entomology. Hourly developmental data is presented under constant temperatures of 10, 15, 20, 25, 30, 35 and 40 degrees C, and cyclic temperatures of 10-15, 15-25, 25-35 and 35-45 degrees C. This study is in agreement with the results reported by Kamal [Comparative study of thirteen species of sarcosaprophagous Calliphoridae and Sarcophagidae (Diptera). I. Bionomics, Ann. Entomol. Soc. Am. 51 (1958) 261] and Melvin [Incubation period of eggs of certain musciod flies at different constant temperatures, Ann. Entomol. Soc. Am. 27 (1934) 406] only at temperatures of 25 degrees C and below. Bishopp [Flies which cause myiasis in man and animals: some aspects of the problem, J. Econ. Entomol. 8 (1915) 317] reported a shorter developmental duration for larval stages than what was produced with our laboratory rearings.

Novel mtDNA mutations and oxidative phosphorylation dysfunction in Russian LHON families

Leber's hereditary optic neuropathy (LHON) is characterized by maternally transmitted, bilateral, central vision loss in young adults. It is caused by mutations in the mitochondrial DNA (mtDNA) encoded genes that contribute polypeptides to NADH dehydrogenase or complex I. Four mtDNA variants, the nucleotide pair (np) 3460A, 11778A, 14484C, and 14459A mutations, are known as "primary" LHON mutations and are found in most, but not all, of the LHON families reported to date. Here, we report the extensive genetic and biochemical analysis of five Russian families from the Novosibirsk region of Siberia manifesting maternally transmitted optic atrophy consistent with LHON. Three of the five families harbor known LHON primary mutations. Complete sequence analysis of proband mtDNA in the other two families has revealed novel complex I mutations at nps 3635A and 4640C, respectively. These mutations are homoplasmic and have not been reported in the literature. Biochemical analysis of complex I in patient lymphoblasts and transmitochondrial cybrids demonstrated a respiration defect with complex-I-linked substrates, although the specific activity of complex I was not reduced. Overall, our data suggests that the spectrum of mtDNA mutations associated with LHON in Russia is similar to that in Europe and North America and that the np 3635A and 4640C mutations may be additional mtDNA complex I mutations contributing to LHON expression.

Response of avian embryonic brain to spatially segmented x-ray microbeams

Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue. i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam irradiation as compared with broad beam irradiation.

Regulation of Na(+) pump expression by vascular smooth muscle cells

The Na(+) pump and its regulation is important for maintaining membrane potential and transmembrane Na(+) gradient in all mammalian cells and thus is essential for cell survival and function. Vascular smooth muscle cells (VSMC) have a relatively low number of pump sites on their membrane compared with other cells. We wished to determine the mechanisms for regulating the number of pump sites in these cells. We used canine saphenous vein VSMC cultured in 10% serum and passaged one time. These cells were subcultured in 5% serum media with low K(+) (1 mM vs. control of 5 mM), and their pump expression was assessed. These VSMC upregulated their pump sites as early as 4 h after treatment (measured by [(3)H]ouabain binding). At this early time point, there was no detectable increase in protein expression of either alpha(1)- or beta(1)-subunits of the pump shown by Western blots. When the cells were treated with the phosphoinositide 3-kinase (PI-3-K) inhibitor LY-294002 (which is known to inhibit cytoplasmic transport processes) in low-K(+) media, the pump site upregulation was inhibited. These data suggest that the low-K(+)-induced upregulation of Na(+) pump number can occur by translocation of preformed pumps from intracellular stores.

Low concentrations of ouabain induce vascular smooth muscle cell proliferation

Ouabain is a well known inhibitor of the Na+ pump in all mammalian cells. We have demonstrated that ouabain at concentrations below those which inhibit the pump, i.e. 0.1 nM and 1.0 nM, induce proliferation of saphenous vein smooth muscle cells as measured by bromodeoxyuridine (BrdU) uptake. Ouabain at these low concentrations also activated MAPK. Proliferating concentrations of the drug did not increase levels of Ca(i)2+, suggesting no effect of this ion in the process. In addition, incubation of the cells in low levels of K+, which has been shown to inhibit the pump, had no effect on proliferation. These data show that low concentrations of ouabain that do not inhibit the Na+ pump can activate proliferation of vascular smooth muscle cells, suggesting that the pump complex may act as a transducing receptor.

Changes in flow velocity, resistance indices, and cerebral perfusion pressure in the maternal middle cerebral artery distribution during normal pregnancy

BACKGROUND

There are few longitudinal data currently available detailing the normal changes in maternal cerebral hemodynamics during human pregnancy. This lack of information limits the study of pregnancy-associated cerebrovascular adjustments and, in particular, preeclampsia, where the brain appears to be especially susceptible to ischemic and encephalopathic injury. Our objective was to define the hemodynamic changes, specifically velocity, resistance indices, and cerebral perfusion pressure, in the middle cerebral artery (MCA) distribution of the brain during normal pregnancy.

METHODS AND MATERIALS

Transcranial Doppler ultrasound was used to determine the systolic, diastolic and mean blood velocities in the middle cerebral arteries in non-laboring women studied longitudinally during normal gestation. The resistance index (RI), pulsatility index (PI), and cerebral perfusion pressure (CPP) were calculated using the velocity and blood pressure data. Data were analyzed using a longitudinal statistical model incorporating random patient effects and a homoscedastic (compound symmetric) variance-covariance structure over time (gestational age). The predicted mean value (Least Squares Mean), and the 5th and 95th percentiles, were defined for normal pregnancy.

RESULTS

MCA systolic velocity decreased (24%) as did the mean velocity (17%). The diastolic velocity did not change significantly. The MCA RI decreased by 19% and the PI decreased by 25%. The MCA CPP increased by 52% between 12 and 40 weeks of gestation.

CONCLUSIONS

The normative ranges for MCA velocity, RI, and CPP have been defined in normal human pregnancy using longitudinally collected data. By having a defined normal range, identification of abnormalities in cerebral hemodynamics during pregnancy is now possible, and this may help researchers and clinicians to elucidate etiologies and treatments for pregnancy-related pathophysiologic states such as preeclampsia

Functional analysis of lymphoblast and cybrid mitochondria containing the 3460, 11778, or 14484 Leber's hereditary optic neuropathy mitochondrial DNA mutation

Leber's hereditary optic neuropathy (LHON) is a form of blindness caused by mitochondrial DNA (mtDNA) mutations in complex I genes. We report an extensive biochemical analysis of the mitochondrial defects in lymphoblasts and transmitochondrial cybrids harboring the three most common LHON mutations: 3460A, 11778A, and 14484C. Respiration studies revealed that the 3460A mutation reduced the maximal respiration rate 20-28%, the 11778A mutation 30-36%, and the 14484C mutation 10-15%. The respiration defects of the 3460A and 11778A mutations transferred in cybrid experiments linking these defects to the mtDNA. Complex I enzymatic assays revealed that the 3460A mutation resulted in a 79% reduction in specific activity and the 11778A mutation resulted in a 20% reduction, while the 14484C mutation did not affect the complex I activity. The enzyme defect of the 3460A mutation transferred with the mtDNA in cybrids. Overall, these data support the conclusion that the 3460A and 11778A mutants result in complex I defects and that the 14484C mutation causes a much milder biochemical defect. These studies represent the first direct comparison of oxidative phosphorylation defects among all of the primary LHON mtDNA mutations, thus permitting insight into the underlying pathophysiological mechanism of the disease.

Painful chewing and blindness: signs and symptoms of temporal arteritis

BACKGROUND

This case report illustrates the need to consider temporal arteritis in the differential diagnosis of jaw or tooth pain. This disease affects the cranial arteries, more frequently in women and usually in those older than age 60 years, causing jaw pain, visual symptoms, headache, scalp pain and sometimes blindness.

CASE DESCRIPTION

A 71-year-old man had jaw pain that increased with chewing and speaking, scalp tenderness and dimming vision. A temporal artery biopsy confirmed the diagnosis of temporal arteritis. Treatment with decreasing amounts of oral steroids over 23 months was successful in relieving his signs and symptoms and in saving his vision.

CLINICAL IMPLICATIONS

Patients with this disease may seek care from their dentist first. Jaw or tooth pain is the most reliable clinical symptom in the diagnosis of temporal arteritis. Diagnosis and timely referral for treatment with oral steroids can prevent blindness.

Primitive neuroectodermal tumors of the brainstem: investigation of seven cases

OBJECTIVE

We discuss the clinical aspects, pathology, and molecular genetics of 7 patients with primitive neuroectodermal tumors (PNETs) arising in the brainstem that were treated at our institution from 1986 through 1995. Most neuro-oncologists avoid performing biopsies in children with pontine tumors. This article raises the question as to whether biopsies should be performed, because treatment recommendations might differ if a PNET was diagnosed rather than a pontine glioma.

PATIENTS AND METHODS

We reviewed the clinical neuro-oncology database and the files of the Division of Neuropathology at New York University Medical Center from 1986 through 1995 and identified 7 histologically confirmed PNETs arising in the brainstem among 146 pediatric brainstem tumors. The clinical, neuroradiological, and neuropathological data were reviewed. Postmortem examinations were performed in 2 cases. Formalin-fixed, paraffin-embedded tumor tissues were also available in 6 of 7 patients that were tested for p53 gene mutations using single-strand conformation polymorphism analysis. We also tested 9 cerebellar PNETs, 9 brainstem gliomas, and 3 normal brains for p53 gene mutations as controls.

RESULTS

All 7 patients presented with focal cranial nerve deficits, and 2 were also hemiparetic. The median age at diagnosis was 2.7 (1-8 years). Magnetic resonance imaging (MRI) characteristics included a focal intrinsic exophytic nonenhancing brainstem lesion that had low T1-weighted and high T2-weighted signals. Hydrocephalus was present in 5 patients at diagnosis, 3 of whom had leptomeningeal dissemination. Meningeal dissemination occurred later in the course of the disease in 3 other patients. Five children required shunts at diagnosis and another 2 at recurrence. Despite therapy, all 7 PNET patients died within 17 months of diagnosis with a mean survival of 8 (4-17) months. No mutation in the p53 gene was detected.

CONCLUSIONS

Brainstem PNETs tend to arise at a younger age than brainstem gliomas and medulloblastomas. The MRI pattern suggests a localized rather than a diffuse intrinsic nonenhancing brainstem tumor. Like other PNETs, brainstem PNETs have a high predilection to disseminate within the central nervous system. The absence of p53 mutations is similar to other PNETs. Despite their origin close to the cerebellum, brainstem PNETs exhibit a more aggressive behavior and result in worse clinical outcomes than do cerebellar PNETs.

Radical excision of intramedullary spinal cord tumors: surgical morbidity and long-term follow-up evaluation in 164 children and young adults

OBJECT

The majority of intramedullary spinal cord tumors (IMSCT) in children and young adults are low-grade gliomas. Radical resection of similar tumors in the cerebral hemisphere or cerebellum is usually curative; however, the conventional management for IMSCTs remains partial resection followed by radiotherapy because of the concern for surgical morbidity. Nevertheless, radical resection of IMSCTs without routine adjuvant treatment has been the rule at our institution since 1980. In an attempt to resolve this controversy, the long-term morbidity and survival in a large series of children have been retrospectively reviewed.

METHODS

The database records and current status of 164 patients 21 years of age and younger in whom an IMSCT was resected were reviewed. A gross-total resection (>95%) was achieved in 76.8% of the surgical procedures. Subtotal resections (80-95%) were performed in 20. 1%. The majority of patients (79.3%) had histologically low-grade lesions. There were no deaths due to surgery. When comparing the preoperative and 3-month postoperative functional grades, 60.4% stayed the same, 15.8% improved, and 23.8% deteriorated. Only 13 patients deteriorated by more than one functional grade. Patients with either no deficits or only mild deficits before surgery were rarely injured by the procedure, reinforcing the importance of early diagnosis and treatment. The major determinant of long-term patient survival was histological composition of the tumor. The 5-year progression-free survival rate was 78% for patients with low-grade gliomas and 30% for those with high-grade gliomas. Patients in whom an IMSCT was only partially resected (<80%) fared significantly worse.

CONCLUSIONS

The long-term survival and quality of life for patients with low-grade gliomas treated by radical resection alone is comparable or superior to minimal resection and radiotherapy. The optimum therapy for patients with high-grade gliomas is yet to be determined.

Late effects of therapy of thalamic and hypothalamic tumors in childhood: vascular, neurobehavioral and neoplastic

The late effects in children with hypothalamic and thalamic tumors relate to the effects of the tumor on the surrounding brain, the effects of surgery, radiotherapy (RT) and, to a lesser extent, chemotherapy. The clinical manifestations of late effects include endocrinologic dysfunction, neurocognitive sequelae, behavioral problems and second neoplasia. The prevention of late effects is an integral part of current treatment strategies. Early diagnosis, a rational use of surgery, and deferral of RT are the mainstays of the modern treatment in these patients. The improvement of RT techniques and the use of radioprotective compounds may further help spare normal brain tissue. A better understanding of chemotherapy use and the development of newer agents may increase efficacy, reduce side effects and allow deferral of RT in a greater percentage of patients. Finally, an aggressive management of endocrinological problems, physical and cognitive rehabilitation as well as psychological and school support help provide these children with maximal function within their potential.

Low-stage medulloblastoma: final analysis of trial comparing standard-dose with reduced-dose neuraxis irradiation

PURPOSE

To evaluate prospectively the effects on survival, relapse-free survival, and patterns of relapse of reduced-dose (23.4 Gy in 13 fractions) compared with standard-dose (36 Gy in 20 fractions) neuraxis irradiation in patients 3 to 21 years of age with low-stage medulloblastoma, minimal postoperative residual disease, and no evidence of neuraxis disease.

PATIENTS AND METHODS

The Pediatric Oncology Group and Children's Cancer Group randomized 126 patients to the study. All patients received posterior fossa irradiation to a total dose of 54 Gy in addition to the neuraxis treatment. Patients were staged postoperatively with contrast-enhanced cranial computed tomography, myelography, and CSF cytology. Of the registered patients, 38 were ineligible.

RESULTS

The planned interim analysis that resulted in closure of the protocol showed that patients randomized to the reduced neuraxis treatment had increased frequency of relapse. In the final analysis, eligible patients receiving standard-dose neuraxis irradiation had 67% event-free survival (EFS) at 5 years (SE = 7.4%), whereas eligible patients receiving reduced-dose neuraxis irradiation had 52% event-free survival at 5 years (SE = 7.7%) (P =.080). At 8 years, the respective EFS proportions were also 67% (SE = 8.8%) and 52% (SE = 11%) (P =.141). These data confirm the original one-sided conclusions but suggest that differences are less marked with time.

CONCLUSION

Reduced-dose neuraxis irradiation (23.4 Gy) is associated with increased risk of early relapse, early isolated neuraxis relapse, and lower 5-year EFS and overall survival than standard irradiation (36 Gy). The 5-year EFS for patients receiving standard-dose irradiation is suboptimal, and improved techniques and/or therapies are needed to improve ultimate outcome. Chemotherapy may contribute to this improvement.

Mutations of the INI1 rhabdoid tumor suppressor gene in medulloblastomas and primitive neuroectodermal tumors of the central nervous system

Germ-line and somatic mutations of the hSNF5/INI1 gene have been reported in atypical teratoid/rhabdoid tumors (AT/RTs) of the brain, consistent with its role as a tumor suppressor gene. In the present study, we determined the frequency of deletions and mutations of INI1 in 52 children whose original diagnosis was medulloblastoma (MB) or primitive neuroectodermal tumor (PNET) of the central nervous system. Mutations were detected in DNA isolated from four tumors, all from children less than 3 years of age at diagnosis. Two of the four were reviewed and reclassified as atypical teratoid tumor, whereas there was insufficient material to establish this diagnosis in the two remaining cases. The relatively low frequency of mutations, even in a large series of infants, suggests that loss of sequences from chromosome 22 and/or mutations of INI1 do not account for the poor prognosis of children with MB or PNET who are less than 3 years of age at diagnosis. Nevertheless, chromosome 22 deletion and INI1-mutation analysis of infants with MB/PNET should be considered for all children who are less than 1 year of age. Detection of these mutations suggests that the child has an AT/RT, rather than a MB/PNET, a finding with important prognostic value.

Expression of plasma membrane calcium ATPases in phenotypically distinct canine vascular smooth muscle cells

Our laboratory has identified at least two types of vascular smooth muscle cells (VSMCs) that exist in canine arteries and veins: type 1 cells, located in the media express muscle specific proteins but do not proliferate in culture; and type 2 cells, located in both media and adventitia, do not express muscle specific protein but proliferate in culture. Plasma membrane Ca(2+)-ATPases (PMCAs) have been implicated in proliferation control. The present study examines the expression of PMCA isoforms and calmodulin-binding domain splice variants in these two types of canine VSMCs. PMCA protein was found in both type 1 and type 2 cells. Reverse transcriptase-polymerase chain reaction assays were developed for canine PMCA calmodulin-binding domain splice variants. We cloned and sequenced isolates corresponding to PMCA1b, 4a and 4b from canine VSMCs. PMCA 2 and 3 were not detected. Freshly isolated type 1 cells expressed PMCA 1b, 4a and 4b, while freshly isolated type 2 cells expressed PMCA1b and 4b. Upon placement in culture, type 2 cells originating from either carotid artery or saphenous vein demonstrated a time-dependent upregulation of PMCA4a mRNA. Treatment with the phosphoinositide 3-kinase inhibitor wortmannin produced concentration-dependent inhibition of both PMCA4a upregulation and [(3)H]thymidine incorporation. These findings suggest a role for phosphoinositide 3-kinase in regulating PMCA expression, which may be important in the control of Ca(2+)-sensitive VSMC functions.

Etoposide with or without mannitol for the treatment of recurrent or primarily unresponsive brain tumors: a Children's Cancer Group Study, CCG-9881

PURPOSE

This study was undertaken to evaluate the response of recurrent brain tumors to intravenous etoposide and to evaluate the efficacy of mannitol in augmenting etoposide's tumoricidal effect.

PATIENTS AND METHODS

Ninety-nine children between one and 21 years of age with recurrent brain tumors were randomly assigned to treatment with intravenous etoposide 150 mg/M2, with or without mannitol 15 gm/M2, daily for five days every three weeks for one year or until disease progression or death. Computerized tomographic (CT) or magnetic resonance image (MRI) scans, obtained after three cycles of therapy, were compared with pre-therapy scans. Scans were centrally reviewed.

RESULTS

Of 87 evaluable patients, 12 (13.8%) were determined to have had an objective response by the institutional radiologist. On central review, 7/66 (10.6%) responses were documented. Responses in centrally reviewed patients were observed in 2/12 (16.7%) low grade astrocytomas, 4/26 (15.4%) medulloblastoma or primitive neuroectodermal tumors (PNET), 1/13 (7.7%) high grade astrocytomas and 0/15 (0%) brain stem gliomas. Survival at one year was 53% (SE 12%) for low grade astrocytomas, 38% (SE 7%) for medulloblastoma or PNET, 28% (SE 10%) for high grade astrocytomas and 9% (SE 5%) for brain stem gliomas. An effect of mannitol was not observed.

CONCLUSION

Intravenous etoposide has a low level of activity in the treatment of recurrent low grade astrocytomas and medulloblastoma or PNET. The efficacy of this agent was not enhanced by the coincident intravenous administration of mannitol.

Insulin increases NO-stimulated guanylate cyclase activity in cultured VSMC while raising redox potential

Insulin acutely stimulates cyclic guanosine monophosphate (cGMP) production in primary confluent cultured vascular smooth muscle cells (VSMC) from canine femoral artery, but the mechanism is not known. These cells contain the inducible isoform of nitric oxide (NO) synthase (iNOS), and insulin-stimulated cGMP production in confluent cultured cells is blocked by the NOS inhibitor, N(G)-monomethyl-L-arginine (L-NMMA). In the present study, it is shown that iNOS is also present in freshly dispersed VSMC from this artery, indicating that iNOS expression in cultured VSMC is not an artifact of the culture process. Insulin did not stimulate NOS activity in primary confluent cultured cells because it did not affect citrulline or combined NO(-)(3)/NO(-)(2) production. To see whether insulin required the permissive presence of NO to stimulate cGMP production, iNOS and basal cGMP production were inhibited with L-NMMA, and the cells were incubated with or without 1 nM insulin and/or the NO donor, S-nitroso-N-acetyl-D,L-penicillamine (SNAP) at a concentration (0.1 microM) that restored cGMP production to the basal value. In the presence of L-NMMA, insulin no longer affected cGMP production but when insulin was added to L-NMMA plus SNAP, cGMP production was increased by 69% (P < 0.05 vs. L-NMMA plus SNAP). Insulin, which increases glucose uptake by these cells, increased the cell lactate content and the lactate-to-pyruvate ratio (LPR) by 81 and 97%, respectively (both P < 0.05), indicating that the hormone increased aerobic glycolysis and the redox potential. The effects of insulin on LPR and cGMP production were blocked by removing glucose or by adding 2-deoxyglucose to the incubation media and were duplicated by the reducing substrate, beta-hydroxybutyrate. We conclude that insulin does not acutely affect iNOS activity in these VSMC but it does augment cGMP production induced by the NO already present in the cell while increasing aerobic glycolysis and the cell redox potential.

Protein kinase C mediates insulin-inhibited Ca2+ transport and contraction of vascular smooth muscle

Insulin acutely inhibits contraction of primary cultured vascular smooth muscle (VSM) cells from canine femoral artery by inhibiting contractile agonist-induced Ca2+ influx. Insulin also inhibits contraction at step(s) distal to intracellular Ca2+ concentration (Ca2+i) by stimulating cyclic guanosine monophosphate (GMP) production. We wished to see whether these effects of insulin are mediated by protein kinase C (PKC). Ca2+ influx was assessed by measuring the rate of fluorescence quenching of intracellular fura 2 by extracellular Mn2+. We found that 10 micromol/L serotonin (5-HT) stimulated Mn2+ influx 3-fold, and 1 nmol/L insulin inhibited the 5-HT-stimulated component of Mn2+ influx by 63% (P < .05), but insulin had no effect in the presence of 1 micromol/L staurosporine, an inhibitor of PKC. In the absence of insulin, preincubating cells with 0.1 micromol/L phorbol 12-myristate 13-acetate (PMA) for 5 min inhibited the 5-HT-stimulated component of Mn2+ influx by 69% (P < .05). Insulin inhibited cell contraction induced by raising Ca2+i to supraphysiologic levels with ionomycin by 75% (P < .05). We also noted that 10(-6) mol/L calphostin C, another PKC inhibitor, or 16-h preincubation with PMA completely blocked this effect of insulin. Finally, 10-min exposure to insulin or PMA increased cyclic GMP production in ionomycin-treated cells by 50% and 64%, respectively (both P < .05). We conclude that insulin inhibits VSM cell contraction by inhibiting 5-HT-stimulated Ca2+ influx and also at step(s) distal to Ca2+i by a PKC-dependent mechanism.

Initial management of children with hypothalamic and thalamic tumors and the modifying role of neurofibromatosis-1

Diencephalic gliomas may be grouped into 2 clinical categories. Optic pathway/hypothalamus gliomas (OPG) arise primarily from a slower-growing juvenile pilocytic astrocytoma, and thalamic gliomas arise primarily from a fibrillary astrocytoma which can become clinically and histologically more aggressive. Children with OPG have an excellent long-term prognosis with a 10-year survival of over 85%. The major therapeutic challenge for these patients is to maximize their quality of life by preserving visual and endocrine function while minimizing treatment-related morbidity. Treatment is often initiated at diagnosis in infants and toddlers who have a major visual impairment or the diencephalic syndrome. The judicious application of chemotherapy may serve to forestall the need for radiotherapy or surgery. Children with neurofibromatosis-1 (NF-1) usually have a more indolent course. Tumors may grow more slowly or occasionally regress spontaneously. However, over 90% of children with OPG without NF-1 will require some form of therapy. Patients with thalamic gliomas present with a shorter history, often with hydrocephalus. Surgical intervention is often required to relieve intracranial pressure and establish the histologic identity of the tumor. Over 75% of these tumors will become locally aggressive. Current multimodality therapy is relatively ineffective. The bithalamic variant behaves similarly to a pontine glioma.

Insulin inhibits migration of vascular smooth muscle cells with inducible nitric oxide synthase

Vascular smooth muscle cell (VSMC) migration participates in atherosclerosis and arterial restenosis after balloon angioplasty. Because these processes are enhanced in insulin-resistant states, our goal was to determine whether insulin affects VSMC migration and, if so, how. The migration of primary cultured VSMCs from canine femoral artery was measured with the use of a wound migration assay and related to cGMP levels. Insulin (1 nmol/L) did not affect migration or cGMP production in control cells. When inducible nitric oxide synthase (iNOS) was induced by 24-hour preincubation with lipopolysaccharide and interleuken-1beta, basal migration decreased, cGMP production increased, and insulin inhibited migration by >90% and stimulated cGMP production by 3-fold. The nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine blocked the affect of insulin on the migration of VSMCs with iNOS. 8-Bromo-cGMP inhibited VSMC migration in control cells, and 1-H-1[1,2,4]oxadiazolo-[4, 3a]quinoxolin-1-one, a selective inhibitor of guanylate cyclase, blocked the inhibition by insulin of migration of cells with iNOS. We conclude that insulin does not normally affect cGMP production or the migration of these VSMCs. However, after the induction of iNOS, insulin stimulates cGMP production and inhibits migration via an NOS-and a cGMP-dependent mechanism.

Cardiovascular demands of competition on low-goal (non-elite) polo ponies

Knowledge of the competitive demands of different sports or activities is important for designing appropriate training programmes to ensure that animals reach a sufficient level of fitness to reduce the risk of overexertion and injury or illness and to achieve the best possible performance in relation to an individual's genetic potential. Whilst the physiological demands of many equestrian sports have been described, to the best of our knowledge the cardiovascular demands of polo have not. The aims of the present study were therefore to record heart rate during and after competitive polo games in a group of low-goal (non-elite) polo ponies in order to describe the absolute heart rates during play, the relationship of these heart rates to maximal heart rate and the characteristics of a typical chukka in terms of effort. Six low-goal polo ponies were studied during a total of 59 chukkas. Heart rate was monitored continuously before, during and after competition using a commercial heart rate monitor. Maximal heart rate was determined with field and treadmill incremental exercise tests and used to express work intensity in terms of time during play that each ponies heart rate was less than 75% HRmax, between 75 and 90% HRmax and greater than 90% HRmax. Mean maximum heart rate was not different during play or during field and treadmill exercise tests; 215+/-7 (mean +/- s.d.), 211+/-7 and 213+/-2 beats/min, respectively (P>0.05). Mean heart rate for all ponies over all chukkas was 166+/-6 beats/min with a mean chukka duration of 611+/-18 s. Of this time, 44+/-7% of the time was spent below 75% HRmax, 39+/-8% between 75 and 90% HRmax and 17+/-8% of time above 90% HRmax. When only one chukka had been played, there was a good correlation between mean heart rate during play and 3 min recovery heart rate (r = 0.63, P<0.001). Based on these observations, it is proposed that low-goal polo places moderate to high stress on the cardiovascular system.

Dose-intensive, time-compressed procarbazine, CCNU, vincristine (PCV) with peripheral blood stem cell support and concurrent radiation in patients with newly diagnosed high-grade gliomas

The dose intensity of the PCV regimen can be doubled using peripheral blood stem cell (PBSC) support. This study sought to determine the feasibility of giving dose-intensive PCV concurrently with radiation therapy. Twelve patients, age 3.2-22.7 years, median 7.5 years, with newly diagnosed high grade gliomas were enrolled. Diagnoses included diffuse intrinsic brainstem gliomas (BSG) (n = 6), glioblastoma (n = 4), anaplastic astrocytoma (n = 2). PBSCs were harvested prior to chemotherapy with G-CSF priming. Chemotherapy consisted of CCNU 130 mg/m2 and vincristine 1.5 mg/m2 on day 0, and procarbazine 150 mg/m2 on days 1-7. PBSCs were reinfused on day 9 of each course. Four courses of chemotherapy were administered every 28 days or when blood counts recovered. The first course was administered the week prior to RT, the second course began on week 3 of RT and the third and fourth course were given after RT. Hematologic toxicity was mild and the majority of courses were given on schedule. Five of six patients with diffuse BSG showed clinical improvement and three showed a radiographic response; however, only one remains alive 12+ months from diagnosis. All four patients with non-brainstem large-volume tumors showed clinical deterioration and radiographic progression during or shortly after RT. MRI scans showed massive edema and enhancement. Median time to radiographic progression was five months. Median overall survival was 11 months. We conclude that dose-intensive, time-compressed PCV given concurrently with large-volume RT appears to result in unacceptable toxicity in patients with large residual tumors.

Treatment of children with medulloblastomas with reduced-dose craniospinal radiation therapy and adjuvant chemotherapy: A Children's Cancer Group Study

PURPOSE

Medulloblastoma is the most common malignant brain tumor of childhood. After treatment with surgery and radiation therapy, approximately 60% of children with medulloblastoma are alive and free of progressive disease 5 years after diagnosis, but many have significant neurocognitive sequelae. This study was undertaken to determine the feasibility and efficacy of treating children with nondisseminated medulloblastoma with reduced-dose craniospinal radiotherapy plus adjuvant chemotherapy.

PATIENTS AND METHODS

Over a 3-year period, 65 children between 3 and 10 years of age with nondisseminated medulloblastoma were treated with postoperative, reduced-dose craniospinal radiation therapy (23.4 Gy) and 55.8 Gy of local radiation therapy. Adjuvant vincristine chemotherapy was administered during radiotherapy, and lomustine, vincristine, and cisplatin chemotherapy was administered during and after radiation.

RESULTS

Progression-free survival was 86% +/- 4% at 3 years and 79% +/- 7% at 5 years. Sites of relapse for the 14 patients who developed progressive disease included the local tumor site alone in two patients, local tumor site and disseminated disease in nine, and nonprimary sites in three. Brainstem involvement did not adversely affect outcome. Therapy was relatively well tolerated; however, the dose of cisplatin had to be modified in more than 50% of patients before the completion of treatment. One child died of pneumonitis and sepsis during treatment.

CONCLUSION

These overall survival rates compare favorably to those obtained in studies using full-dose radiation therapy alone or radiation therapy plus chemotherapy. The results suggest that reduced-dose craniospinal radiation therapy and adjuvant chemotherapy during and after radiation is a feasible approach for children with nondisseminated medulloblastoma.

Recommended approaches for the laboratory measurement of homocysteine in the diagnosis and monitoring of patients with hyperhomocysteinaemia

Several recent studies have indicated that an increased concentration of plasma homocysteine is an independent risk factor for the premature development of vascular disease. These important findings emphasize the need for careful selection of an appropriate analytical approach to diagnose and treat individuals who may be at risk. We compared the results obtained from the measurement of plasma total homocysteine (free + protein-bound fractions) by high-performance liquid chromatography (HPLC) with the measurement of plasma free homocystine (free fraction) by conventional ion-exchange chromatography in 10 patients with inherited defects of homocysteine metabolism and 13 obligate heterozygote individuals. This study can be used to formulate recommendations on the appropriate use of these assays in different clinical circumstances. Our results show that the concentration of total plasma homocysteine must exceed 60 mumol/L before plasma free homocystine becomes detectable by conventional ion-exchange chromatography. Similarly, assessment of the urinary excretion of homocysteine in these patients indicates that it may not become consistently detectable by conventional ion-exchange chromatography or HPLC until plasma total homocysteine exceeds 150 mumol/L. On this basis, while most patients with classical homocystinuria would be detected by analysis of plasma using conventional ion-exchange chromatography or by measurement of of the urinary homocysteine excretion, occasional patients would be missed. When monitoring patients receiving treatment for classical homocystinuria, in whom metabolic control is good, and when investigating individuals with a suspected inherited defect of cobalamin or folate metabolism, a method which measures plasma total homocysteine should be used. The identification of moderate hyperhomocysteinaemia of undefined cause investigated in relation to a history of early vacsular disease can only be identified by this approach.