The Montana Interfacility Blood Network: A Novel Lifesaving "Hand-off" for the Optimal Care of Rural Patients

Purpose

The state of Montana encompasses and defines rural health care as it is known in the United States (US) today. This vast area is punctuated by pockets of health care availability with varying access to blood products for transfusion. Furthermore, timely transport is frequently challenged by weather that may limit air transportation options, resulting in multiple hours in ground transport to definitive care.

Patients and Methods

The Montana State Trauma Care Committee (MT-STCC) developed the Montana Interfacility Blood Network (MT-IBN) to ensure blood availability in geographically distanced cases where patients may otherwise not survive. The index case that led to the formal development of the MT-IBN is described, followed by a second case illustrating the IBN process.

Results

This process and development manuscript details the innovative efforts of MT-STCC to develop this fledgling idea unique to rural US health care. We review guidelines that have been developed to define broad aspects of the MT-IBN including the reason to share resources, proper packaging, paperwork necessary for transfer, and how to provide resources directly to the patient. Finally, we describe implementation within the state.

Conclusion

The MT-IBN was developed by MT-STCC to facilitate the hand-off of lifesaving blood to patients being transported by ground to definitive care in Montana without having to stop at an intermediary facility. This has already led to lives saved in areas that are limited in blood availability due to rurality.

Outcomes in necrotizing soft tissue infections are worse in rural versus urban Montana: a 10-year single center retrospective review

Time to definitive surgical debridement has been recognized as a predictor for morbidity and mortality in necrotizing soft-tissue infections (NSTI). Rural patients are at particular risk due to limited local resources, decreased access to care, and prolonged transport times. The aim of the current study was to examine the outcomes of NSTI requiring surgical treatment in a previously non-described setting. This retrospective study (2010-2020) from a single tertiary care center in Montana reviewed patients ≥18 years old with a NSTI via ICD9/10 codes. Rural-Urban Continuum Codes (RUCC; characterizing counties by population size) were used to distinguish urban versus rural counties. Race (White and American Indian/Alaskan Native (AI/AN)) was self-described. Qualitative and quantitative comparisons between groups were determined using the appropriate two-tailed statistical tests. An aggregate of 177 patients was identified. Mean age in AI/AN was significantly lower (P<0.0001) compared to White patients with no preexisting condition delineation. NSTI demonstrated an elevated incidence in both rural areas and AI/AN patients. Diabetes was also significantly higher (P=0.0073) in rural versus urban patients. Both rural and AI/AN patients faced extended travel distance for treatment. AI/AN patients had a significantly different infection location than White. Furthermore, polymicrobial species were significantly more prevalent in AI/AN patients. Morbidities (defined as septic shock and/or amputation) were significantly higher in AI/AN patients and rural environments (P<0.01). There was no significant difference in all-cause mortality between respective groups. The state of Montana presents unique challenges to optimizing NSTI treatment due to excessive distances to regional tertiary care facilities. This delay in treatment can lead to increased morbidity.

Bringing Trauma Education to the Frontier: Overcoming Distance Barriers Utilizing a Virtual Platform

BACKGROUND

The American College of Surgeons and state regulations mandate that trauma facilities offer trauma-specific continuing education throughout the region they serve. These requirements come with unique challenges when serving a rural and sparsely populated state. A novel approach to providing education was necessitated by the coronavirus disease 2019 pandemic, travel distance, and limited local specialists.

OBJECTIVE

The purpose of this article is to describe the development of a virtual educational program used to improve access to quality trauma education and decrease barriers to obtaining continuing education hours inherent in the region.

METHODS

This article describes the development and implementation of the Virtual Trauma Education program, which provided one free continuing education hour per month from October 2020 to October 2021. The program reached more than 2,000 viewers and established a method to provide continuous monthly educational offerings throughout the region.

RESULTS

After the Virtual Trauma Education program implementation, monthly educational attendance increased from an average of 55 to 190. Viewership data indicate that trauma education across our region is far more robust, available, and accessible using a virtual platform. With more than 2,000 views from October 2020 to October 2021, Virtual Trauma Education offerings have spread far beyond regional borders, reaching 25 states and 169 communities.

CONCLUSION

Virtual Trauma Education delivers easily accessible trauma education and is a program that has proven its sustainability.

A retrospective comparison of the emergent use of fixed-dose four-factor prothrombin complex versus weight-based dosing for intracranial hemorrhage assessing medication delivery time and cost

OBJECTIVES

The goal of this study was to evaluate a low fixed-dose versus weight-based dosing strategy for four-factor prothrombin complex (4F-PCC) time to administration in intracranial hemorrhage (ICH) patients.

METHODS

A retrospective analysis was conducted at a single rural Tertiary referral center in patients ≥18 years old on warfarin with ICH who received 4F-PCC. Continuous variables were summarized using mean (±95% CI) and compared using two-tailed tests; p values ≤0.05 were considered statistically significant.

RESULTS

A total of 46 ICH patients were reversed using 4F-PCC (Fixed, n = 27 and Weight, n = 19). Baseline characteristics were equivalent. Total units of 4F-PCC (mean dose units 2525.1 versus 1623.3) and dose per kg were significantly reduced in the fixed-dose group. Total time from order to delivery was significantly reduced with the fixed-dose strategy (mean time 43.0 versus 29.0 minutes). Hospital length of stay (LOS), intensive care unit LOS, and mortality were equivalent with a similar mechanism. International Normalized Ratio (INR) reversal success (≤1.5) and total INR change was comparable with no difference in adverse thromboses between groups.

CONCLUSIONS

A fixed-dosed strategy reduced time to 4F-PCC administration for warfarin reversal in ICH, as compared to a weight-based strategy; with no increase in LOS, mortality, or need for additional dosing. This also resulted in significant cost savings.

Biodegradable temporising matrix: use of negative pressure wound therapy shows a significantly higher success rate

OBJECTIVE

The purpose of this case series was to evaluate the efficacy of a synthetic biodegradable temporising matrix (BTM; PolyNovo Biomaterials Pty Ltd, Australia) and compare the outcome of BTM patients with and without negative pressure wound therapy (NPWT).

METHOD

A retrospective chart review was conducted on patients admitted with deep full-thickness burns, traumatic or complex wound injuries treated with BTM. Electronic medical records and images were evaluated by a team of clinical professionals. Endpoints included: the measure of successful BTM integration; and comparison between patients treated with and without NPWT. Additional measures were BTM total surface area, BTM sites, timeliness of BTM application and any complications.

RESULTS

A total of 28 patients were evaluated and 23 (82.1%) demonstrated overall successful BTM integration. Patients treated with BTM in conjunction with NPWT (n=16) demonstrated a significantly higher (p=0.046) integration rate compared to patients treated without NPWT (n=12) (93.8% versus 58.3%, respectively). Patients treated with BTM with NPWT continued to successfully integrate and sustain favourable outcomes despite the presence of severe infection or the development of haematomas.

CONCLUSION

A significantly higher integration rate was demonstrated when BTM was used in conjunction with NPWT. The results of this study further support the efficacy of successful integration of BTM as a replacement for tissue loss in the treatment of deep, full-thickness burns, traumatic and complex wound injuries, and particularly favourable outcomes with the use of NPWT. To the best of our knowledge, this is the first reported case series comparing the clinical outcomes of BTM with and without the use of NPWT.

Open Reduction and Internal Fixation of a Pediatric Talar Body Fracture using a Medial Malleolar Osteotomy – A Case Report

Introduction:Talus fracture injuries are rare and most literature pertains to fractures in skeletally mature adults. It is unusual for pediatric talus fractures to be treated operatively and is normally treated with immobilization. The location of the talus fracture required a medial malleolar osteotomy to facilitate exposure and reduction, which was fixed with temporary smooth K-wires. The authors were unable to identify a previous description of this technique in the literature. Case Report:An 11-year-old female was referred to our hospital due to polytraumatic injuries sustained in a roll-over MVC. A displaced fracture of the talus body was present. Due to the fracture location, a medial malleolar osteotomy was required for exposure. An open reduction and internal fixation was performed using subchondral minifragment screws under general anesthesia. The patient healed uneventfully, regained a normal gait and full, pain-free range of motion. Conclusions:Medial malleolar osteotomy with smooth K-wire fixation appears to be a safe method for gaining access to the talus when required for reduction and/or fixation of pediatric talus fractures. Keywords:Adolescent, talus fracture, osteotomy.

Post-burn temporal dynamics of blood plasma histamine during the initial 6 days from injury

BACKGROUND

Burn injuries can induce distinct, systemic inflammatory and immunological responses which occur acutely up to 72 hrs or chronically after 24 hrs. Previously published literature showed a dramatic increase in whole blood histamine values within 24 hrs of a thermal injury. However, the data is limited due to infrequent monitoring, resulting in statistically insignificant findings. The goal of this study was to determine localized histamine fluctuations for 6 consecutive days in a successive group of patients admitted immediately after a burn.

METHOD

Using blood plasma from 7 patients (average total burn surface area 24.7%), we examined histamine within an average 4.1 (± 0.3) hrs from burn injury, by means of a monoclonal-based competitive binding enzyme immunoassay. Histamine values were normalized to patient baselines prior to determining overall averages. Patient vitals and electrolyte values were extracted from the electronic health record. A two-tailed student t-test was used to compare values with p-value ≤ 0.05 considered statistically significant using statistical software R.

RESULTS

The histamine values were significantly higher than patient baseline values up to 48 hrs (p-value ≤ 0.05), followed by a return to baseline values from approximately 3 days post-injury. Heart rates were within normal values up until 72 hrs. Hematocrit and hemoglobin began within normal values, dropped at 72 hrs, and reduced significantly from 96 hrs post-injury. The electrolyte calcium began within the normal range, and then was significantly less than the baseline value from 96 hrs post-injury.

CONCLUSIONS

We have shown a distinct and significant increase in histamine plasma levels within 48 hrs after a moderate burn injury.

Treatment of a Full-Thickness Burn Injury With NovoSorb Biodegradable Temporizing Matrix and RECELL Autologous Skin Cell Suspension: A Case Series

Dermal substitutes coupled with split thickness skin graft are the primary method of treating most severe full-thickness burns particularly when there is a lack of healthy donor skin. Although dermal replacements optimize functional and aesthetic outcomes in patients, the risk of infection and the amount of time required to process most dermal substitutes delay treatment potentially compromising graft take and the overall healing process. The purpose of this case series is to describe the treatment course of patients with severe burn injuries using a novel synthetic Biodegradable Temporizing Matrix (NovoSorb BTM) in conjunction with RECELL Autologous Cell Harvesting Device, a new methodology allowing for a timely point-of-care preparation of an autologous skin cell suspension in combination with a 3:1 split-thickness skin graft. To the best of our knowledge, this is the first reported case series to describe the treatment algorithm and clinical outcomes of deep full-thickness burns utilizing BTM in conjunction with RECELL ASCS.

Impact of duplicate CT scan rate after implementation of transfer image repository system at a level 1 trauma center

Purpose

The regionalization of trauma in the USA results in frequent transfers of patients from a primary hospital ED to a higher level trauma facility. While many hospitals have a Picture Archive Communication System (PACS) which captures digital radiological images, these are often not available to the receiving institution resulting in duplicate imaging. The state of Arkansas instituted a trauma image repository (TIR) in July 2013. We examined whether implementation of this repository would impact CT scan duplication in the trauma system.

Methods

This was a retrospective analysis of trauma patients transferred from outlying hospitals in Arkansas and Missouri to a single level 1 trauma hospital in Missouri between July 2012 and June 2015. We compared the duplicate CT rate for patients transferred from Arkansas and Missouri hospitals before and after the repository was implemented for Arkansas.

Results

Prior to implementation (July 2012–June 2013) of Arkansas TIR, duplicate CT rates were similar for patients transferred from Arkansas (11.5% ± 2.8) or Missouri (16.3% ± 7.5). Following implementation (July 2013–June 2014), the duplicate CT rate for patients transferred from Arkansas was significantly lower (Arkansas = 10.1% vs. Missouri 16.2%; CI 95%, p = 0.02), and significance continued (Arkansas = 9.0% vs. Missouri = 17.8%; CI 95%, p = 0.02) during follow-up (July 2014–June 2015).

Conclusion

Fewer patients received duplicated scans within the Arkansas as compared with the Missouri-based trauma referral systems regardless of Injury Severity Scores (ISS). Our findings suggest that TIR adoption coupled with PACS improved transferability of radiographic studies and could improve patient care while reducing costs in trauma transfers.

Epinephrine auto-injection radically increases risk for Clostridial infection and necrotizing fasciitis

<em>Clostridial perfringens</em> is a bacteria commonly found on skin flora. Due to the optimal growth environment intramuscular epinephrine injections predispose patients to the rapid development of <em>Clostridial</em> myonecrosis. There have been only four cases, including this one, reported in the last 60 years of pediatric <em>Clostridium perfringens</em> infections post-epinephrine injection. We detail the successful management of a 16 year old, immunocompetent female who developed gas gangrene and necrotizing fasciitis on her thigh secondary to <em>Clostridial</em> infection after utilization of an Epinephrine Auto-Injector and review the pediatric literature of patients with <em>Clostridial perfringens</em> secondary to epinephrine injection. We define common clinical signs and symptoms of <em>Clostridial</em> infection from the review of the literature. The relevance of our findings is to raise awareness among emergency physicians when patients present following an injection in order to reduce diagnostic delay that could result in amputation or death.

Total Retinal Blood Flow in a Nonhuman Primate Optic Nerve Transection Model Using Dual-Beam Bidirectional Doppler FD-OCT and Microsphere Method

PURPOSE

We validated noninvasive Doppler-optical coherence tomography (OCT) blood flow measurements against the terminal microsphere method in a surgical induced optic nerve transection nonhuman primate model.

METHODS

In 6 nonhuman primates, total retinal blood flow (TRBF) was measured with a custom-built dual-beam bidirectional Doppler Fourier Domain (FD)-OCT. Peripapillary retinal nerve fiber layer thickness (RNFLT) was measured by Spectralis spectral-domain (SD)-OCT. Measurements were performed every 10 to 15 days before and after unilateral optic nerve transection (ONT) until RNFLT was reduced by more than 40% from baseline. Before the animals were killed, TRBF was measured using the microsphere technique.

RESULTS

A significant correlation between all arterial and venous Doppler OCT TRBF measurements was found in ONT and contralateral control eyes (both P < 0.01, n = 6). The Bland-Altman analysis showed a bias of 0.57 in the ONT group and 0.02 in the contralateral control group. Also, excellent agreement was observed between Doppler OCT and microsphere measurements (P < 0.01, r = 0.976, bias = 0.54). After ONT, TRBF and RNFLT decreased by -51% ± 42% and -44% ± 2% (n = 5), respectively. In the contralateral control eyes, TRBF and RNFLT were unchanged.

CONCLUSIONS

Very good accordance was found between TRBF measurements, obtained with dual-beam bidirectional Doppler FD-OCT and the microsphere method. It also was possible to monitor changes over time in TRBF after ONT with Doppler OCT. These findings highlight the accuracy and potential of noninvasive Doppler OCT to provide valuable information for detecting early changes in ocular disease in future.

Rapid parallel measurements of macroautophagy and mitophagy in mammalian cells using a single fluorescent biosensor

Mitochondrial dysfunction is implicated in many human diseases and occurs in normal aging. Mitochondrial health is maintained through organelle biogenesis and repair or turnover of existing mitochondria. Mitochondrial turnover is principally mediated by mitophagy, the trafficking of damaged mitochondria to lysosomes via macroautophagy (autophagy). Mitophagy requires autophagy, but is itself a selective process that relies on specific autophagy-targeting mechanisms, and thus can be dissociated from autophagy under certain circumstances. Therefore, it is important to assess autophagy and mitophagy together and separately. We sought to develop a robust, high-throughput, quantitative method for monitoring both processes in parallel. Here we report a flow cytometry-based assay capable of rapid parallel measurements of mitophagy and autophagy in mammalian cells using a single fluorescent protein biosensor. We demonstrate the ability of the assay to quantify Parkin-dependent selective mitophagy in CCCP-treated HeLa cells. In addition, we show the utility of the assay for measuring mitophagy in other cell lines, as well as for Parkin-independent mitophagy stimulated by deferiprone. The assay makes rapid measurements (10,000 cells per 6 seconds) and can be combined with other fluorescent indicators to monitor distinct cell populations, enabling design of high-throughput screening experiments to identify novel regulators of mitophagy in mammalian cells.

Systemic gene transfer of binding immunoglobulin protein (BiP) prevents disease progression in murine collagen-induced arthritis

Summary Recombinant human binding immunoglobulin protein (BiP) has previously demonstrated anti-inflammatory properties in multiple models of inflammatory arthritis. We investigated whether these immunoregulatory properties could be exploited using gene therapy techniques. A single intraperitoneal injection of lentiviral vector containing the murine BiP (Lenti-mBiP) or green fluorescent protein (Lenti-GFP) transgene was administered in low- or high-dose studies during early arthritis. Disease activity was assessed by visual scoring, histology, serum cytokine and antibody production measured by cell enzyme-linked immunosorbent assay (ELISA) and ELISA, respectively. Lentiviral vector treatment caused significant induction of interferon (IFN)-γ responses regardless of the transgene; however, further specific effects were directly attributable to the BiP transgene. In both studies Lenti-mBiP suppressed clinical arthritis significantly. Histological examination showed that low-dose Lenti-mBiP suppressed inflammatory cell infiltration, cartilage destruction and significantly reduced pathogenic anti-type II collagen (CII) antibodies. Lenti-mBiP treatment caused significant up-regulation of soluble cytotoxic T lymphocyte antigen-4 (sCTLA-4) serum levels and down-regulation of interleukin (IL)-17A production in response to CII cell restimulation. In-vitro studies confirmed that Lenti-mBiP spleen cells could significantly suppress the release of IL-17A from CII primed responder cells following CII restimulation in vitro, and this suppression was associated with increased IL-10 production. Neutralization of CTLA-4 in further co-culture experiments demonstrated inverse regulation of IL-17A production. In conclusion, these data demonstrate proof of principle for the therapeutic potential of systemic lentiviral vector delivery of the BiP transgene leading to immunoregulation of arthritis by induction of soluble CTLA-4 and suppression of IL-17A production.

MicroRNA responses to focal cerebral ischemia in male and female mouse brain

Stroke occurs with greater frequency in men than in women across diverse ethnic backgrounds and nationalities. Work from our lab and others have revealed a sex-specific sensitivity to cerebral ischemia whereby males exhibit a larger extent of brain damage resulting from an ischemic event compared to females. Previous studies revealed that microRNA (miRNA) expression is regulated by cerebral ischemia in males; however, no studies to date have examined the effect of ischemia on miRNA responses in females. Thus, we examined miRNA responses in male and female brain in response to cerebral ischemia using miRNA arrays. These studies revealed that in male and female brains, ischemia leads to both a universal miRNA response as well as a sexually distinct response to challenge. Target prediction analysis of the miRNAs increased in male or female ischemic brain reveal sex-specific differences in gene targets and protein pathways. These data support that the mechanisms underlying sexually dimorphic responses to cerebral ischemia includes distinct changes in miRNAs in male and female brain, in addition to a miRNA signature response to ischemia that is common to both.

Effect of (S)-3,5-DHPG on microRNA expression in mouse brain

MicroRNAs are small non-coding RNAs that regulate post-transcriptional gene expression. In the short time since the discovery of microRNAs, the literature has burgeoned with studies focused on the biosynthesis of microRNAs, target prediction and binding, and mechanisms of translational repression by microRNAs. Given the prominent role of microRNAs in all areas of cell biology, it is not surprising that microRNAs are also linked to human diseases, including those of the nervous system. One of the least-studied areas of microRNA research is how their expression is regulated outside of development and cancer. Thus, we examined a role for regulation of microRNAs by neurotransmitter receptor activation in mouse brain. We focused on the group I metabotropic glutamate receptors by using intracerebroventricular injection of the selective agonist, (S)-3,5-dihydroxyphenylglycine (DHPG) in mouse brain. We then examined the expression of microRNAs in the cerebral cortex by Ambion and Invitrogen microarrays, and the expression of mature microRNA sequences by SABiosciences qPCR arrays, at 4, 8 and 24 h after DHPG injection. These studies revealed that the largest number of significantly regulated microRNAs was detected 8h after DHPG injection in the microarrays and qPCR arrays. We then used RNA blots to quantify microRNA expression, and in situ hybridization to examine cellular distribution of the microRNAs regulated by DHPG. Bioinformatic analysis of the microRNAs regulated 8 h after DHPG in all three arrays revealed KEGG pathways that are known to correlate with group I mGluR effects, as well as recently described and novel pathways. These studies are the first to show that DHGP regulates the expression of microRNAs in mouse cerebral cortex, and support the hypothesis that group I mGluRs may regulate microRNA expression in mouse brain.

Suppression of TNF receptor-1 signaling in an in vitro model of epileptic tolerance

Tumor necrosis factor-α (TNFα) is a pleiotropic cytokine that can regulate cell survival, inflammation or, under certain circumstances, trigger cell death. Previous work in rat seizure models and analysis of temporal lobe samples from epilepsy patients has suggested seizures activate TNF receptor 1 (TNFR1). Here we explored the activation and functional significance of TNFR1 signaling in the mouse hippocampus using in vitro and in vivo models of seizure-induced neuronal injury. Focal-onset status epilepticus in mice upregulated TNFR1 levels and led to formation of TNFR1-TNFR-associated death domain (TRADD) and TRADD-Fas-associated death domain (FADD) binding. Seizure-like injury modeled in vitro by removal of chronic excitatory blockade in mouse hippocampal neurons also activated this TNFR1 signaling pathway. Prior exposure of hippocampal neurons to a non-harmful seizure episode, via NMDA receptor blockade, 24 h prior to injurious seizures significantly reduced cell death and modeled epileptic tolerance in vitro. TNFR1 complex formation with TRADD and TRADD-FADD binding were reduced in tolerant cells. Finally, TNFR1 signaling and cell death were reduced by PKF-242-484, a dual matrix metaloproteinase/TNFα converting enzyme inhibitor. The present study shows that TNFR1 signaling is activated in mouse seizure models and may contribute to neuropathology in vitro and in vivo while suppression of this pathway may underlie neuroprotection in epileptic tolerance.

Sumo-2/3-ylation following in vitro modeled ischemia is reduced in delayed ischemic tolerance

Several recent studies suggest that sumo-2/3 modification of proteins occurs following harmful ischemia, however, sumo-2/3-ylation may also be associated with hibernation-mediated neuroprotection. Here we investigate the sumoylation of proteins following ischemia and ischemic tolerance using our established in vitro model of ischemia (oxygen and glucose deprivation; OGD). Following harmful ischemia (120 min OGD), we observed a significant increase in the sumo-2/3-ylation of high molecular weight proteins (>85 kDa), but not sumo-1-ylation of proteins. Sumo-2/3-ylation following 120 min OGD was reduced when cultures were preconditioned with non-harmful 30 min OGD 24 h earlier (delayed ischemic tolerance). However, we observed no change in sumo-2/3-ylation in a model of rapid ischemic tolerance. The effects of preconditioning on sumo-2/3-ylation following harmful ischemia were blocked by the protein synthesis inhibitor cycloheximide (1.0 muM), a known inhibitor of delayed ischemic tolerance. In addition, we observed a reduction in sumo-2/3-ylation using hypothermia (4 degrees C 30 min) as the preconditioning stimuli to induce delayed ischemic tolerance. Further studies show that sumo-2/3-ylation occurs during the ischemic insult and that preconditioning does not change expression of the sumo E1- and E2-ligases (UBA2 and Ubc9) or the sumo specific isopeptidases (SenP1-3). While sumo-2/3-ylation is enhanced under conditions of cell stress, it is not yet clear whether this is a cause or consequence of harmful ischemia-induced cell damage.

A nickel-carbon-fibre composite for large adaptive mirrors: fabrication methods and properties

We present results from our recent research into carbon-fibre composite (CFC) mirror fabrication for optical and infra-red applications. In particular this research is aimed towards the next generation of extremely large telescopes to offer an alternative to thin glass shell adaptive secondary mirrors. We address the issues involved with CFC mirror production, in particular the accuracy of the form replication process, a suitable surface for polishing to optical quality, no fibre print-through, environmental stability (shape change due to thermal and moisture variations), material uniformity and lifetime. We have performed experiments into the effectiveness of cold electroplating thick nickel coatings to totally encapsulate the CFC base substrate; the manufacturing procedure and properties of the Ni-CFC mirror are described here.

Ubiquitin-proteasome system as a modulator of cell fate

The ubiquitin-proteasome system is the major non-lysosymal system for degrading proteins in the cell; the work leading to its discovery was awarded the Nobel Prize in Chemistry in 2004. In addition to small ubiquitin-like modifiers (e.g. Sumo and Nedd8), ubiquitin is involved in the complex regulation of the levels and function of many proteins and signaling pathways involved in determining cell fate. The cell death regulatory proteins, such as Bcl-2 family proteins and caspases are targeted for degradation by the ubiquitin proteasome system (UPS). In addition to mediating the degradation of proteins, the UPS regulates function and translocation of proteins, many of which play a role in the determination of cell fate. For example the UPS can regulate the activity of transcription factors, such as P53, NF-kappaB and HIF-1 alpha, which control the expression of protein mediators of cell death. Aberrant UPS function has been reported in multiple neuropathologies including Parkinson's diseases and ischemia. With the number of ubiquitin conjugating and de-conjugating enzymes reaching close to the levels of protein kinases and phosphatases, it is clear that ubiquitination is an important biological regulatory step for proteins.

Peripheral blood mononuclear cell proliferative responses to soluble and particulate heat shock protein 65 in health and inflammatory bowel disease

OBJECTIVES

The aims of this study were to determine, in peripheral blood mononuclear cells (PBMC), whether particulate antigen triggers (i) an amplified cell proliferative response compared to soluble antigen and (ii) a dysfunctional response in cells derived from patients with chronic inflammation and specifically in those with inflammatory bowel disease (IBD).

SUBJECTS

Healthy volunteers (n = 17), inflammatory controls (n = 8) and patients with IBD (n = 17) were recruited from St Thomas' and Guys' Hospital, London, UK.

METHODS

Following optimisation of experimental conditions (0.1-10.0 mug/ml antigen), PBMC were stimulated with (i) 10.0 mug/ml recombinant soluble heat shock protein 65 (hsp 65) and (ii) 1.0 and 10.0 mug/ml hsp 65 conjugated to microparticles (0.5 mum diameter). PBMC proliferative responses were measured by (3)H-Thymidine incorporation at day 5 and results compared between groups using unpaired t-test.

RESULTS

Conjugation to microparticles of low dose hsp 65 significantly increased overall proliferative responses by 2-11 fold compared to soluble antigen alone (p < 0.05). However, no specific PBMC proliferative dysregulation was noted in cells from subjects with IBD.

CONCLUSIONS

Low dose antigen, in microparticulate form, leads to amplified cell proliferation in primary human cells, as showed previously in cell lines and animal studies. However there is no abnormal proliferative response in cells from subjects with IBD.

An investigation of auto-reactivity after head injury

Murine models of CNS injury show auto-reactive T cell responses directed at myelin antigens, associated with improved neuronal survival and functional recovery. This pilot study shows, for the first time, that similar immune responses against myelin occur in human traumatic brain injury (TBI), with an expansion of lymphocytes recognising myelin basic protein observed in 40% of patients studied. "Reactive" patients did not have greater contusion volume on imaging, but were younger than the "unreactive" subgroup and tended towards a more favorable outcome. These findings are consistent with the concept of "beneficial autoimmunity".

Isolated plant mitochondria import chloroplast precursor proteins in vitro with the same efficiency as chloroplasts

Most chloroplast and mitochondrial proteins are synthesized with N-terminal presequences that direct their import into the appropriate organelle. In this report we have analyzed the specificity of standard in vitro assays for import into isolated pea chloroplasts and mitochondria. We find that chloroplast protein import is highly specific because mitochondrial proteins are not imported to any detectable levels. Surprisingly, however, pea mitochondria import a range of chloroplast protein precursors with the same efficiency as chloroplasts, including those of plastocyanin, the 33-kDa photosystem II protein, Hcf136, and coproporphyrinogen III oxidase. These import reactions are dependent on the Deltaphi across the inner mitochondrial membrane, and furthermore, marker enzyme assays and Western blotting studies exclude any import by contaminating chloroplasts in the preparation. The pea mitochondria specifically recognize information in the chloroplast-targeting presequences, because they also import a fusion comprising the presequence of coproporphyrinogen III oxidase linked to green fluorescent protein. However, the same construct is targeted exclusively into chloroplasts in vivo indicating that the in vitro mitochondrial import reactions are unphysiological, possibly because essential specificity factors are absent in these assays. Finally, we show that disruption of potential amphipathic helices in one presequence does not block import into pea mitochondria, indicating that other features are recognized.

Distinct Albino3-dependent and -independent pathways for thylakoid membrane protein insertion

The homologous proteins Oxa1, YidC, and Alb3 mediate the insertion of membrane proteins in mitochondria, bacteria, and chloroplast thylakoids, respectively. Depletion of YidC in Escherichia coli affects the integration of every membrane protein studied, and Alb3 has been shown previously to be required for the insertion of a signal recognition particle (SRP)-dependent protein, Lhcb1, in thylakoids. In this study we have analyzed the "global" role of Alb3 in the insertion of thylakoid membrane proteins. We show that insertion of two chlorophyll-binding proteins, Lhcb4.1 and Lhcb5, is almost totally blocked by preincubation of thylakoids with anti-Alb3 antibodies, indicating a requirement for Alb3 in the insertion pathway. Insertion of the related PsbS protein, on the other hand, is unaffected by Alb3 antibodies, and insertion of a group of SRP-independent, signal peptide-bearing proteins, PsbX, PsbW, and PsbY, is likewise completely unaffected. Proteinase K is furthermore able to completely degrade Alb3, but this treatment does not affect the insertion of these proteins. Among the thylakoid proteins studied here, Alb3 requirement correlates strictly with a requirement for stromal factors and nucleoside triphosphates. However, the majority of proteins tested do not require Alb3 or any other known form of translocation apparatus.

Morbidity of second-look surgery in pediatric central nervous system tumors

The extent of brain tumor resection affects survival. Second-look surgery (resection of residual tumor before radiographic progression) may improve survival by reducing the tumor burden, but the morbidity of the procedure is not known. On chart review of 280 patients with two or more brain tumor operations treated between January 1985 and June 1998, we identified 47 patients with second-look surgery. Lansky and Eastern Cooperative Oncology Group (ECOG) performance scores, as well as perioperative complications were recorded. There were 21 gliomas (6 malignant), 12 medulloblastomas, 3 craniopharyngiomas, 3 ependymomas and 8 miscellaneous tumors. Median time to second surgery was 50 days. Perioperative complications occurred in 45% of patients. There was no significant change in the mean Lansky and ECOG scores 4 and 24 weeks after surgery. Gross total resection (GTR) was achieved in 62% of patients and near total resection (NTR) in 23%, and 15% of patients had subtotal resection. GTR or NTR was achieved in 66% of medulloblastomas and 100% of gliomas. We conclude that second-look surgery by experienced pediatric neurosurgeons has an acceptable morbidity and should be considered in patients with residual tumors.

Rhabdoid glioblastoma

Rhabdoid phenotypic change has been described in a number of different neoplasms from diverse organ sites. These tumors share common light and electron-microscopic features, display a polyphenotypic immunohistochemical profile and often show cytogenetic abnormalities of chromosome 22. In the central nervous system (CNS), most rhabdoid tumors occur in the posterior fossa of very young children and are associated with a primitive neuroectodermal tumor (PNET) component and are designated atypical teratoid/rhabdoid tumors. Infrequently, other rhabdoid tumors of the CNS have been described, including rhabdoid meningiomas and malignant rhabdoid tumors of uncertain histogenesis. Several examples of conventional gliomas displaying significant areas with rhabdoid morphology were also presented in an abstract by Kepes and Moral [1991], although never published in final manuscript form. We now detail the case of an 18-year-old male with an aggressive, supratentorial CNS rhabdoid tumor that was associated with an epithelioid glioblastoma and apparently arose from areas of low-grade glioma. The rhabdoid tumor component was present in the original tumor but became more predominant with each of 3 successive resections. No areas of PNET were identified. Electron microscopy and immunohistochemistry showed features classic for rhabdoid tumors and cytogenetic studies demonstrated multiple tumor clones with monosomy 22. This case documents progressive rhabdoid transformation of a glioma, expands the spectrum of CNS tumor types that can display a rhabdoid phenotype and highlights the diagnostic and therapeutic challenges with this type of tumor.

Dietary methionine is involved in the etiology of neural tube defect-affected pregnancies in humans

Research has provided evidence of the role of multivitamin supplementation in the prevention of neural tube defects (NTD). Failure of the neural tube to close is one of the most frequent and severe human developmental defects. The etiology of NTD is complex, encompassing genetic, dietary and environmental factors. The purpose of this study was to explore the relationship between maternal dietary intake of methionine and the risk of having a NTD-affected pregnancy. We hypothesized that women with high maternal dietary methionine intake were at a decreased risk for a NTD. Combinations of methionine, folate and vitamin B-12 intakes and NTD risk were also examined. Data from a 5-y, population-based, case-control study of 170 NTD-affected pregnancies and 269 controls were provided by the South Carolina NTD Surveillance, Prevention, and Research Project. There was a 30-55% lower NTD risk among women whose average daily dietary intake of methionine was greater than the lowest quartile of intake (>1580 mg/d). The odds ratios associated with the three quartiles of methionine intake > 1580 mg/d after adjusting for energy, race and body mass index were 0.72 (P < 0.07), 0.68 (P < 0.07) and 0.45 (P < 0.06), respectively. These findings indicate that a reduction in the risk of having a NTD-affected pregnancy is associated with maternal dietary intake of methionine (3 mo pre- to 3 mo postconception). This finding is consistent with the hypothesis that methionine plays a role in the etiology of NTD and suggests the need for further research in the area of maternal diet and pregnancy.

Human aromatase in high yield and purity by perfusion chromatography and its characterization by difference spectroscopy and mass spectrometry

Expression of human cytochrome P450 aromatase (CYP19A1, aromatase) was accomplished at a high level using a baculovirus expression system in an insect cell suspension culture. Using the relatively new chromatographic technique of perfusion chromatography, a very rapid procedure for purification of the protein from solubilized cells was developed. At extraordinary flow rates of between 3 and 9 column volumes per minute, all chromatographic procedures could be performed, including setup, equilibration, and column regeneration steps, in less than 2 h, not including brief dialysis periods. Total yields were 40-52% and resulted in preparations with specific content values of 17.1 nmol aromatase/mg protein. Final purified preparations showed virtually no typical P450 spectra under standard conditions, but displayed full activity with typical enzyme kinetic parameters. These unusual results suggest that standard methods of P450 measurement are inappropriate when applied to aromatase. The findings are fully consistent with those encountered previously for purified preparations from a human placental source and led us to a new aromatase quantification method based on ligand-induced difference spectroscopy. A new HPLC assay is described which rapidly separates heme and apoprotein while measuring total heme content. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry was employed with both glycosylated and deglycosylated forms of the final purified product to confirm its identity as a glycosylated cytochrome P450.

Bacillus cereus bacteremia and meningitis in immunocompromised children

Two cases of Bacillus cereus meningitis in immunocompromised children at our hospital within a 2-month period prompted us to review B. cereus--related invasive disease. We identified 12 patients with B. cereus isolated in blood cultures from September 1988 through August 2000 at our institution. Three of these patients also had B. cereus isolated from CSF specimens; 1 additional patient had possible CNS involvement (33%, group A), whereas 8 patients had no evidence of CNS involvement (67%, group B). Patients in group A were more likely to have neutropenia at the onset of sepsis and were more likely to have an unfavorable outcome. They were also more likely to have received intrathecal chemotherapy in the week before the onset of their illness. Two patients from group A died. One survived with severe sequelae. The fourth patient had mild sequelae at follow-up. No sequelae or deaths occurred among patients in group B. In patients with unfavorable outcomes, the interval from the time of recognition of illness to irreversible damage or death was short, which demonstrates a need for increased awareness, early diagnosis, and more-effective therapy, particularly that which addresses B. cereus toxins.

Multiple pathways used for the targeting of thylakoid proteins in chloroplasts

The assembly of the chloroplast thylakoid membrane requires the import of numerous proteins from the cytosol and their targeting into or across the thylakoid membrane. It is now clear that multiple pathways are involved in the thylakoid-targeting stages, depending on the type of protein substrate. Two very different pathways are used by thylakoid lumen proteins; one is the Sec pathway which has been well-characterised in bacteria, and which involves the threading of the substrate through a narrow channel. In contrast, the more recently characterised twin-arginine translocation (Tat) system is able to translocate fully folded proteins across this membrane. Recent advances on bacterial Tat systems shed further light on the structure and function of this system. Membrane proteins, on the other hand, use two further pathways. One is the signal recognition particle-dependent pathway, involving a complex interplay between many different factors, whereas other proteins insert without the assistance of any known apparatus. This article reviews advances in the study of these pathways and considers the rationale behind the surprising complexity.

Immediate neurocognitive effects of methylphenidate on learning-impaired survivors of childhood cancer

PURPOSE

To test if methylphenidate (MPH) has an objective beneficial effect on immediate performance on tests of neurocognitive functions among learning-impaired survivors of childhood acute lymphoblastic leukemia (ALL) and malignant brain tumors (BT).

PATIENTS AND METHODS

From July 1, 1997 through December 31, 1998, 104 long-term survivors of childhood ALL or a malignant BT completed neurocognitive screening for learning impairments and concurrent problems with sustained attention. Eligibility criteria for the MPH trial included an estimated intelligence quotient greater than 50, academic achievement in the 16(th) percentile or lower for age in reading, math, or spelling, and an ability to sustain attention on a computerized version of the Conners' Continuous Performance Test (CPT) in the 16(th) percentile or lower for age and sex. Of the 104, 32 (BT, n = 25; ALL, n = 7) were eligible on the basis of these a priori criteria for a randomized, double-blinded, placebo-controlled trial of MPH. The patients ingested a placebo (lactose) or MPH (0.6 mg/kg; 20 mg maximum) and repeated selected portions of the screening battery 90 minutes later.

RESULTS

Compared to the 17 patients randomized to the placebo group, the 15 patients randomized to the MPH group had a significantly greater improvement on the CPT for sustained attention (errors of omission, P =.015) and overall index (P =.008) but not for errors of commission (indicative of impulsiveness) nor reaction times. A trend for greater improvement in the MPH group on a measure of verbal memory failed to reach statistical significance. No trend was observed for MPH effectiveness in improving learning of a word association task. No significant side effects from MPH were observed.

CONCLUSION

MPH resulted in a statistically significant improvement on measures of attention abilities that cannot be explained by placebo or practice effects.

Associations between self-reported and objective physical environmental factors and use of a community rail-trail

BACKGROUND

To effectively promote physical activIty, researchers and policy makers have advocated for greater use of environmental approaches, such as the construction of community paths and trails. However, research on the use of these facilities is limited.

METHODS

In this cross-sectional community study, we examined associations between self-reported and objective physical environmental variables and use of the Minuteman Bikeway (Arlington, MA) in a random sample of 413 adults. Sociodemographic and perceived environmental variables were measured with a mail survey during September 1998. Geographic information system (GIS) data were used to geocode survey respondents' homes and create three objective environmental variables: distance to the Bikeway, steep hill barrier, and a busy street barrier.

RESULTS

In logistic models, age and female gender showed statistically significant inverse associations with Bikeway use over the previous 4-week period. Increases in self-reported (OR = 0.65) and GIS distance (OR = 0.57) were associated with decreased likelihood of Bikeway use. Absence of self-reported busy street (OR = 2.01) and GIS steep hill barriers (OR = 1.84) were associated with Bikeway use.

CONCLUSIONS

Environmental barriers such as travel distance and hilly terrain should be considered when planning community trails. A better understanding of such factors may lead to more effective promotion of trail use.

Comparison of single-mother and two-parent families on metabolic control of children with diabetes

OBJECTIVE

To understand the impact of family structure on the metabolic control of children with diabetes, we posed two research questions: 1) what are the differences in sociodemographic, family, and community factors between single-mother and two-parent families of diabetic children? and 2) to what extent do these psychosocial factors predict metabolic control among diabetic children from single-mother and two-parent families?

RESEARCH DESIGN AND METHODS

This cross-sectional study included 155 diabetic children and their mothers or other female caregivers. The children were recruited if they had been diagnosed with diabetes for at least 1 year, had no other comorbid chronic illnesses, and were younger than 18 years of age. Interviews and self-report questionnaires were used to assess individual, family, and community variables.

RESULTS

The findings indicate that diabetic children from single-mother families have poorer metabolic control than do children from two-parent families. Regression models of children's metabolic control from single-mother families indicate that age and missed clinic appointments predicted HbA1c levels; however, among two-parent families, children's ethnicity and adherence to their medication regimen significantly predicted metabolic control.

CONCLUSIONS

This study suggests that children from single-mother families are at risk of poorer metabolic control and that these families have more challenges to face when raising a child with a chronic illness. Implications point to a need for developing strategies sensitive to the challenges of single mothers.

Purification and characterization of hexahistidine-tagged cyclohexanone monooxygenase expressed in Saccharomyces cerevisiae and Escherichia coli

Cyclohexanone monooxygenase (CMO) is a soluble flavoenzyme originally isolated from Acinetobacter spp. which carries out Baeyer-Villiger reactions with cyclic ketone substrates. In the present study we cloned the Acinetobacter CMO gene and modified it for facile purification from heterologous expression systems by incorporation of a His(6)-tag at its C-terminus. A single purification step employing metal (Ni(2+))-affinity column chromatography provided essentially homogeneous enzyme in yields of 69-72%. The properties of the purified, recombinant enzymes (rCMO) were compared with that of native CMO (nCMO) isolated from Acinetobacter cultures grown in the presence of cyclohexanone. The specific activities of His(6)-tagged rCMO and nCMO toward their index substrate, cyclohexanone, were similar and ranged from 14 to 20 micromol/min/mg. nCMO and rCMO from the Escherichia coli expression system exhibited molecular masses, determined by electrospray mass spectrometry, of 60,800 and 61,615 Da, respectively, an increase for the recombinant enzyme equivalent to the mass of the His(6)-tag. However, rCMO expressed in Saccharomyces cerevisiae consistently exhibited a mass some 50 Da larger than rCMO expressed in bacteria. Edman degradation confirmed that rCMO purified from the E. coli system and nCMO shared the same N-terminal sequence, whereas no sequence information could be obtained for rCMO expressed in yeast. Therefore, the yeast-expressed enzyme possesses an additional posttranslational modification(s), possibly acylation, at the N-terminus. Expression in E. coli is the preferred system for future site-directed mutagenesis studies and crystallization efforts.

Influence of family structure on health among youths with diabetes

Type 1 diabetes mellitus is a chronic metabolic disorder and is one of the most common chronic diseases in childhood. The study discussed in this article examined the extent to which family structure is significantly associated with health in youths with Type 1 diabetes. A convenience sample of 155 children with diabetes and their mothers completed face-to-face interviews; multiple regression analyses were conducted. Findings demonstrated that family structure remains a significant predictor of youths' health when statistically controlling for race, child's age, family socioeconomic status, and adherence. Social workers in outpatient medical settings are in a unique position to develop family-oriented strategies targeting this neglected area of primary care.

Brain metastases in paediatric solid tumours

Brain metastases in children with cancer are rare and their incidence is significantly lower (5-10%) than that reported in adults. The development of metastatic brain tumours in children is usually a manifestation of advanced disease and commonly occur after, or at the time of progression at other sites. This review summarises the salient clinical features of the most common paediatric solid tumours that metastasize to the brain including neuroblastoma, musculoskeletal sarcomas, germ cell tumours and melanoma.

Assessment of a two-generation reproductive and fertility study of mercuric chloride in rats

Effects of mercuric chloride (MC) on the reproductive performance of two successive generations of rats was evaluated. F(0) rats were exposed to 0.0:0.0 (males:females), 0.50:0.75 (males:females), 1.00:1.50 (males:females) and 1.50:2.50 (males:females) mg/kg/day MC. Selected parental F(1) males and females were exposed to the same doses received by their parents (F(0)). Significant differences resulting from exposure of the F(0) generation to MC were found in implantation efficiency, fertility, live births and day 4 survival indices, litter size, and the body weight of F(1) pups. However, the continued exposure of the F(1) generation to MC did not affect fertility index or litter size, but did significantly affect implantation efficiency, live births and day 4 survival indices. In F(0) males, body weight and weights of the kidneys, testes, epididymides, prostate and seminal vesicles were significantly different, while in F(1) males, body weight, kidney weight, brain weight, liver weight and the weights of the testes, prostate and seminal vesicles were significantly different. In F(0) females, body weight and the weights of the kidneys, brain and liver were significantly different, while in F(1,) females, body weight, as well as the weights of the kidneys, liver, adrenals, uterus and ovaries were significantly different. These data showed that exposure to MC resulted in more adverse reproductive effects in the first generation and that these effects moderated in the second generation.

The social and cultural context of risk and prevention: food and physical activity in an urban Aboriginal community

One of the key public health challenges facing indigenous and other minority communities is how to develop and implement effective, acceptable, and sustainable strategies for the prevention of non-insulin-dependent diabetes mellitus (NIDDM). In this article, the authors describe how an ethnographic approach was used to contextualize the behavioral risk factors for NIDDM and applied to the development of a more meaningful and appropriate epidemiological risk factor survey instrument for an urban Aboriginal population in Australia. The overall research design comprised a mixture of qualitative and quantitative methods. The ethnographic study showed that the complex web of meanings that tie people to their family and community can and should be taken into account in any social epidemiology of health and illness if the findings are to have any effective and long-term potential to contribute to successful public health interventions targeting these behavioral risk factors.

Trying to keep a balance: the meaning of health and diabetes in an urban aboriginal community

Although the predominant paradigm of epidemiological investigation continues to focus narrowly on the individual and on individual risk factors, there is a growing body of work that calls for a rethinking of the current epidemiological models. In this paper we illustrate the need for a more comprehensive epidemiological approach towards understanding the risks for diabetes, by exploring the lived experiences of diabetes and lay meanings of risk among Aborigines living in Melbourne, Australia. Ethnographic fieldwork was conducted within the Melbourne Aboriginal community in the state of Victoria over a 22-month period (1994-1996). Melbourne Aborigines see non-insulin dependent diabetes mellitus (NIDDM) as the result of living a life out of balance, a life of lost or severed connections with land and kin and a life with little control over past, present or future. The lay model regarding diabetes that is derived from the narratives of Melbourne Aborigines, consists of three levels of connectedness important in determining an individual's susceptibility not only to diabetes but to all disease--(1) family, (2) community and (3) society. This structure of interactive systems at successive levels from the individual to the population fits within the framework of an ecological paradigm. The strength of ethnography as applied to epidemiology is that it has the capacity to discover previously unknown components of a system at several different levels, and to build models to explain how these components interact. This framework, developed using an ethno-epidemiological approach, has application in other indigenous populations who have been dispossessed of their land, their pasts and their future. There is great potential to apply this approach to the major public health challenges presented by rapid global socio-cultural and environmental change that are impacting negatively on population health.

Imaging aspects of neurologic emergencies in children treated for non-CNS malignancies

There is a paucity of radiologic literature addressing neurologic emergencies in children receiving therapy for non-CNS primary malignancies. In the acute setting, many of these children present to local community hospitals. This pictorial is from a single institutional experience describing the spectrum of neurologic emergencies seen in children with non-CNS cancers. We hope to familiarize pediatric radiologists with these entities in order to expedite diagnosis, facilitate treatment, and minimize morbidity and mortality that may be associated with these complications.

Further analysis of the involvement of the envelope anion channel PIRAC in chloroplast protein import

The ability of preferredoxin to inactivate a 50-pS anion channel of the chloroplast inner membrane in the presence of an energy source was investigated using single-channel recordings. It was found that preferredoxin cannot inactivate the channel when GTP is the only energy source present. From this it is concluded that the precursor has to interact with the, translocon of the inner membrane of chloroplasts (Tic) complex to be able to inactivate the 50-pS anion channel. The ability of two mutants of preferredoxin with deletions in their transit sequence to inactivate the channel was also tested. Both mutants have been shown to have a similar binding affinity for the chloroplast envelope, but only one is able to fully translocate. The mutants were both able to inactivate the channel in a similar manner. From this it is concluded that full translocation is not necessary for the inactivation of the channel. It is also shown that preferredoxin is capable of inactivating the 50-pS anion channel in the chloroplast-attached configuration as was previously found in the inside-out configuration. From this it is concluded that stromal factors do not influence the protein-import-induced inactivation of the 50-pS anion channel of the chloroplast inner membrane. Finally the effect of the anion channel blocker 4, 4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) on the channel activity and on protein import was investigated. It was found that DIDS blocked the channel. Furthermore the addition of the channel blocker reduces the efficiency of import to 52%. This leads to the conclusion that correct functioning of the channel is important for protein import.

Agency-based tracking of difficult-to-follow populations: runaway and homeless youth programs in St. Louis, Missouri

OBJECTIVES

This study explored agency-based tracking methods for one of the most difficult-to-follow populations: runaway and homeless youth.

METHODS

A total of 118 program discharges from three federally funded agencies serving runaway/ homeless youth in St. Louis, Missouri were tracked for a follow-up study of this population. Agency staff attempted to locate and interview program participants three months post-discharge using a protocol that systematically varied times and location of contact attempts. Separate analyses were conducted to compare the group of subjects whose locations were ascertained with those who were not, and who were successfully interviewed with those who were not. Variables related to the tracking protocol and individual descriptive and service use variables were examined in these analyses.

RESULTS

Sixty-nine percent of the sample was successfully located and fifty-nine percent interviewed. Significant findings included: fewer contact attempts over fewer days were made for individuals successfully interviewed, individuals tracked through Division of Family Services were less likely to be both located and interviewed, and individuals successfully located were significantly younger.

CONCLUSIONS

This report provides encouraging evidence that even relatively unsophisticated protocols for tracking agency clients developed in collaboration with community agencies can--with consistent implementation--yield follow-up samples that are acceptably representative of program participants.

Tamoxifen and carboplatin for children with low-grade gliomas: a pilot study at St. Jude Children's Research Hospital

PURPOSE

The authors conducted a single-arm, prospective study using tamoxifen and carboplatin for the treatment of children with progressive or symptomatic low-grade gliomas.

PATIENTS AND METHODS

Fourteen children with consecutively diagnosed cases of low-grade glioma were enrolled in this Study; all patients were younger than 14 years. One patient was excluded after induction chemotherapy because of the diagnosis of a nonmalignant condition. Patients were treated with daily tamoxifen (20 mg/m2 administered twice per day) in addition to targeted, monthly intravenous carboplatin at an area under the curve (AUC) exposure of 6.5 mg/mL x minute for 1 year or until they had clinical or radiologic evidence of disease progression.

RESULTS

The median age at diagnosis was 5.3 years, the median age at initiation of chemotherapy was 8.3 years. Eight patients had tumors of the hypothalamus/optic pathway, two patients had thalamic tumors, and one patient each had tumors in the temporal lobe, tectum, and brain stem. Tumor histologic findings included fibrillary astrocytoma (n = 2), juvenile pilocytic astrocytoma (n = 6), and oligodendroglioma (n = 1). The best response to therapy was a partial response in two patients, stable disease in nine patients, and progressive disease in two patients. The overall survival at 3 years is 69%. The 3-year progression-free survival is 47%. Tamoxifen and carboplatin chemotherapy did not result in a significant number of objective responses in children with low-grade gliomas. The progression-free survival is similar to that of other published series. Nonmyelosuppressive agents such as tamoxifen deserve additional evaluation in the treatment of children with low-grade gliomas.

Opiate-induced analgesia is increased and prolonged in mice lacking P-glycoprotein

BACKGROUND

P-glycoprotein is a transmembrane protein expressed by multiple mammalian cell types, including the endothelial cells that comprise the blood-brain-barrier. P-glycoprotein functions to actively pump a diverse array of xenobiotics out of the cells in which it is expressed. The purpose of this study was to determine if P-glycoprotein alters the analgesic efficacy of clinically useful opioids.

METHODS

Using a standard hot-plate method, the magnitude and duration of analgesia from morphine, morphine-6-glucuronide, methadone, meperidine, and fentanyl were assessed in wild-type Friends virus B (FVB) mice and in FVB mice lacking P-glycoprotein [mdr1a/b(-/-)]. Analgesia was expressed as the percent maximal possible effect (%MPE) over time, and these data were used to calculate the area under the analgesia versus time curves (AUC) for all opioids studied. In addition, the effect of a P-glycoprotein inhibitor (cyclosporine, 100 mg/kg) on morphine analgesia in both wild-type and mdr knockout mice was also determined.

RESULTS

Morphine induced greater analgesia in knockout mice compared with wild-type mice (AUC 6,450 %MPE min vs. 1,610 %MPE min at 3 mg/kg), and morphine brain concentrations were greater in knockout mice. Analgesia was also greater in knockout mice treated with methadone and fentanyl but not meperidine or morphine-6-glucuronide. Cyclosporine pretreatment markedly increased morphine analgesia in wild-type mice but had no effect in knockout mice.

CONCLUSIONS

These results suggest that P-glycoprotein acts to limit the entry of some opiates into the brain and that acute administration of P-glycoprotein inhibitors can increase the sensitivity to these opiates.

CNS germinoma: disease control and long-term functional outcome for 12 children treated with craniospinal irradiation

PURPOSE

To provide evidence that radiation therapy alone in the form of craniospinal irradiation (CSI) and a boost to the primary site of disease provides effective disease control and limited additional morbidity for patients with CNS germinoma.

METHODS AND MATERIALS

Twelve patients with a median age of 12 years (range 9-16 years) with CNS germinoma were treated with CSI (median 25.6 Gy, range 23.4-32 Gy) and a boost to the primary site of disease (50.4 Gy, range 45-54 Gy) between January 1987 and June 1998. All patients were biopsied prior to radiation therapy and none received chemotherapy. No patients were lost to follow-up and the majority had long-term (> 45 month) pre- and postirradiation endocrine and psychology assessment.

RESULTS

All 12 patients are alive and no failures have occurred with a median follow-up of 69 months (range 14-143 months). Preirradiation endocrine deficiencies were present in 6 of 6 suprasellar tumors and 1 of 6 pineal tumors; with follow-up there was no substantial difference between age and gender adjusted pre- and postirradiation stature and weight. With long-term follow-up, there were no significant differences between pre- and postirradiation full-scale, verbal, and performance IQ scores.

CONCLUSIONS

This study confirms the ability of radiation therapy alone to achieve disease control with a high rate of success in pediatric patients and demonstrates that the treatment toxicity faced by these patients may be less than anticipated. Because these patients present with substantial preexisting morbidity at diagnosis and may be of an age where the potential for radiation-related side effects is relatively small, the superiority of treatment alternatives may be difficult to prove.

Association of very low birth weight with exposures to environmental sulfur dioxide and total suspended particulates

This paper presents results of a population-based case-control study of the association between maternal exposures to environmental sulfur dioxide and total suspended particulates (TSP) and risk for having a very low birth weight (VLBW) baby, i.e., one weighing less than 1,500 g at birth. The study, which took place between April 1, 1986 and March 30, 1988, comprised 143 mothers of VLBW babies and 202 mothers of babies weighing 2,500 g or more living in Georgia Health Care District 9. Environmental exposure estimates (microg/m3) were obtained through environmental transport modeling that allowed us to assign environmental sulfur dioxide and TSP exposure estimates at the birth home of each study subject. Exposures less than or equal to 9.94 microg/m3, the median of TSP and sulfur dioxide exposures for the controls, were considered as referent exposures. Exposures to atmospheric TSP and sulfur dioxide above the 95th percentile (56.75 microg/m3) yielded an adjusted odds ratio of 2.88 (95% confidence interval (CI): 1.16, 7.13), that from above the 75th to the 95th percentile (25.18-56.75 microg/m3) yielded an adjusted odds ratio of 1.27 (95% CI: 0.68, 2.37), and that from above the median (9.94 microg/m3) to the 75th percentile, an adjusted odds ratio of 0.99 (95% CI: 0.51, 1.72). The trend demonstrated in these adjusted estimates suggests an association between VLBW and maternal exposures to high levels of air pollution.

The route of administration of an immunodominant peptide derived from heat-shock protein 65 dramatically affects disease outcome in pristane-induced arthritis

Previous studies have shown that immunization of mice with an immunodominant epitope from heat-shock protein 65 (hsp 65) (amino acids 261-271) can protect from the development of pristane-induced arthritis (PIA) and this protection is mediated by an antigen-specific T helper type 2 (Th2) cytokine response. Here we confirm these findings and show that frequent intranasal administration of this peptide exacerbates disease. In naive mice given peptide intranasally an antigen-specific T-cell population is systemically activated similar to that induced by peptide immunization in incomplete Freund's adjuvant. Thus, a paradox exists whereby apparently similar peptide-specific populations are either associated with protection from, or exacerbation of, PIA. However, comparison of cytokine profiles reveals differences between these two cell populations. Peptide inhalation induces the production of Th1-type cytokines (interferon-gamma) whereas intraperitoneal immunization leads to the production of Th2-type cytokines (interleukin-4, interleukin-5 and interleukin-10) by splenic T cells upon stimulation with peptide. Thus, for the application of nasal 'tolerance' in clinical medicine, it is important to identify antigens and dosing regimes that counteract but do not activate adverse immune responses.

Relationship between disease severity and responses by blood mononuclear cells from patients with rheumatoid arthritis to human heat-shock protein 60

The hypothesis that T-cell responses to the 60 000 MW family of heat-shock proteins (hsp) may be related to the severity of rheumatoid arthritis (RA) was examined. Peripheral blood mononuclear cells (PBMC) from most normal individuals and both early and established RA patients proliferated in vitro in response to human hsp 60 and mycobacterial hsp 65 as well as tetanus toxoid (TT) and mycobacterial purified protein derivative (PPD). PBMC from some patients with established RA gave responses to hsp 60 that were above the normal range and/or peaked earlier than PBMC from normal individuals. The responses of PBMC from established RA to hsp 65, but not PPD or TT, were also higher than those from normal individuals, but the peak responses to all three antigens appeared delayed. Thus a selective increase in responsiveness to hsp 60 develops with disease duration in many RA patients. Six assessments of disease activity and severity were made but apart from rheumatoid factor titre, they were unrelated to the proliferative response. Similarly, disease activity and severity did not differ between those RA patients whose hsp 60 stimulated cells produced interferon-gamma and those who did not, although patients whose hsp 60-stimulated T cells produced interleukin-4 (IL-4) and/or IL-10, appeared to have less disease activity and severity than those who did not. Significant negative correlations were found between IL-10 production by hsp 60-stimulated cells and disease assessments. It is considered that RA is less severe in those patients whose hsp 60-stimulated cells produce T-helper 2 type cytokines.

Pediatric low-grade and ependymal spinal cord tumors

Our institutional experience with pediatric spinal cord tumors includes 25 patients with the diagnosis of ependymoma (EP; n = 4), myxopapillary ependymoma (MPEP; n = 4), juvenile pilocytic astrocytoma (JPA; n = 5), nonpilocytic astrocytoma (WHO grade I or II, n = 6), and other nonastrocytic spinal cord tumors (n = 6) treated during the period 1974-1999. Nineteen patients required radiation therapy (RT). The median progression-free survival following RT was 65 months (range 1-206 months). Seven patients recurred at an average of 22 months. The EP patients recurred at an average of 8.5 months, while the patients with low-grade astrocytoma recurred at an average of 42 months. Including the 6 nonsurviving patients, the median overall survival was 96 months. Two EP patients died with a progression-free survival of 9 months. One patient with MPEP died of other causes at 7 months. The treatment of pediatric spinal cord tumors should be individualized based on the histologic type. Radical surgery is indicated for nonmyxopapillary EP and low-grade astrocytic tumors. The need for adjuvant therapy most often depends on the extent of resection as well as the tumor type. Patients with disseminated EP, MPEP, JPA and nonpilocytic astrocytoma may achieve long-term progression-free survival with craniospinal irradiation.

Estimating environmental exposures to sulfur dioxide from multiple industrial sources for a case-control study

This paper first discusses how population exposures to environmental pollutants are estimated from environmental monitoring data and the problems that are encountered in estimating risk from pollutants on the basis of ecologic studies. We then present a technique of estimating individualized exposures to an atmospheric pollutant, sulfur dioxide (SO2), through atmospheric transport modeling for a case-control study. The transport model uses the quantities of SO2 released from 30 geographically identified industrial facilities and meteorological data (wind speed and direction) to predict the downwind ground-level concentrations of SO2 at geographically identified residences, receptors, of 797 study subjects. A distribution of facility SO2 emissions, uncertainties in effective stack height, and model uncertainty are incorporated to examine the uncertainty in the predicted versus ambient monitoring SO2 levels, and to generate an exposure uncertainty distribution for both the cases and controls. The transport model's accuracy is evaluated by comparing recorded ambient measurements of SO2 with the model's predicted SO2 estimates at geographically identified ambient monitoring stations.