Phase II Study of Hemithoracic Intensity-Modulated Pleural Radiation Therapy (IMPRINT) for Patients with Pleural Metastases from Thymic Malignancies

PURPOSE/OBJECTIVE(S)

Pleural metastases are common sites for recurrence and progression in patients with thymic malignancies. The management of pleural metastases typically involves surgical resection with or without neoadjuvant or adjuvant systemic therapy. After surgical resection of pleural metastases, the 5-year progression-free survival (PFS) rate is about 29-45%. While radiation therapy (RT) is standardly used in the management of locally-advanced thymic malignancies, the role of RT in patients with pleural metastases in unclear. Intensity-modulated pleural radiation therapy (IMPRINT) is a RT technique currently being used to treat malignant pleural mesothelioma (MPM) patients with 2 intact lungs at centers that specialize in MPM treatment. This IMPRINT technique can potentially be extrapolated to thymic patients with pleural metastases. Because the risk of toxicity is of greater concern for thymic patients given their overall relatively favorable prognosis, the rate of toxicity, particularly radiation pneumonitis, needs to be established in the thymic patient population.

MATERIALS/METHODS

This is a single-arm, single institution Phase II study of hemithoracic IMPRINT for patients with pleural metastases from thymic malignancies. The primary endpoint of this study is grade 3 or higher radiation pneumonitis within 4 months of completing RT. Secondary endpoints include any toxicity, progression-free survival, patterns of failure and overall survival. Patients must have a pathologically confirmed diagnosis of a thymic malignancy with radiologic or pathologic evidence of pleural metastases. Thymoma or thymic carcinoma are allowed. Patients may have de novo stage IVA disease or recurrent disease in the pleura. There must be no evidence of extrathoracic metastatic disease or contralateral pleural/pericardial disease. Surgical resection of the pleural nodules (ex: pleurectomy/decortication, debulking/metastasectomy) are allowed. Extrapleural pneumonectomy is not allowed. Patients are excluded if they have undergone prior thoracic radiation therapy preventing hemithoracic pleural IMRT, whereas prior thymic bed radiation and/or prior pleural SBRT are allowed. RT will be administered to the ipsilateral pleura to 50.4 Gy in 28 fractions. An optional dose-painting boost to gross disease up to 60 Gy while respecting normal tissue constraints is allowed. Patients can be treated with photon or proton therapy. Simulation, contouring and RT planning guidelines have been developed. Patients will be followed per protocol at regular intervals for at least 12 months following RT. The expected accrual is 36 patients over 4 years. Further information can be found on clinicaltrials.gov (NCT05354570).

RESULTS

To be determined.

CONCLUSION

To be determined.

"Virtual patch clamp analysis" for predicting the functional significance of pathogenic variants in sodium channels

OBJECTIVE

Opening of voltage-gated sodium channels is crucial for neuronal depolarization. Proper channel opening and influx of Na⁺ through the ion pore, is dependent upon binding of Na⁺ ion to a specific amino-acid motif (DEKA) within the pore. In this study we used molecular dynamic simulations, an advanced bioinformatic tool, to research the dysfunction caused by pathogenic variants in SCN1a, SCN2a and SCN8a genes.

METHOD

Molecular dynamic simulations were performed in six patients: three patients with Dravet syndrome (p.Gly177Ala,p.Ser259Arg and p.Met1267Ile, SCN1a), two patients with early onset drug resistant epilepsy(p.Ala263Val, SCN2a and p.Ile251Arg, SCN8a), and a patient with autism (p.Thr155Ala, SCN2a). After predicting the 3D-structure of mutated proteins by homology modeling, time dependent molecular dynamic simulations were performed, using the Schrödinger algorithm. The opening of the sodium channel, including the detachment of the sodium ion to the DEKA motif and pore diameter were assessed. Results were compared to the existent patch clamp analysis in four patients, and consistency with clinical phenotype was noted.

RESULTS

The Na⁺ ion remained attached to DEKA filter longer when compared to wild type in the p.Gly177Ala, p.Ser259Arg,SCN1a, and p.Thr155Ala, SCN2a variants, consistent with loss-of-function. In contrast, it detached quicker from DEKA than wild type in the p.Ala263Val,SCN2a variant, consistent with gain-of-function. In the p.Met1267Ile,SCN1a variant, detachment from DEKA was quicker, but pore diameter decreased, suggesting partial loss-of-function. In the p.Leu251Arg,SCN8a variant, the pore remained opened longer when compared to wild type, consistent with a gain-of-function. The molecular dynamic simulation results were consistent with the existing patch-clamp analysis studies, as well as the clinical phenotype.

SIGNIFICANCE

Molecular dynamic simulation can be useful in predicting pathogenicity of variants and the disease phenotype, and selecting targeted treatment based on channel dysfunction. Further development of these bioinformatic tools may lead to "virtual patch-clamp analysis".

The associations of CD4 count, CD4/CD8 ratio, and HIV viral load with survival from non-small cell lung cancer in persons living with HIV

HIV status may influence survival from non-small cell lung cancer (NSCLC). Among NSCLC patients in the Bronx, NY, we assessed (1) associations of CD4 count, CD4/CD8 ratio and HIV viral load (VL) with survival and (2) prognostic factors among persons living with HIV (PLWH). We compared survival from NSCLC diagnosis (2004-2017) between HIV-negative persons (HIV-, n=2,881) and PLWH (n=88) accounting for clinical and sociodemographic factors. HIV-survival was also compared with PLWH, dichotomized by CD4 (<200 vs. ≥200cells/µL), CD4/CD8 (median, <0.43 vs. ≥0.43) and VL (<75 vs. ≥75copies/mL) at NSCLC diagnosis. Among PLWH, we assessed the relationships of CD4, CD4/CD8, and VL with survival, adjusting for age, sex, and cancer stage. PLWH with CD4< 200cells/µL had lower survival than HIV- [hazard ratio, 95% confidence interval [HR(95%CI)]=1.86(0.98-3.55)]. Survival was similar between PLWH with CD4≥ 200cells/µL and HIV- [HR(95%CI) = 0.90(0.61-1.33)]. Results were similar when categorizing PLWH by CD4/CD8 [vs. HIV-: low CD4/CD8: HR(95%CI) = 1.74(1.07-3.89); high CD4/CD8: HR(95%CI) = 0.63(0.37-1.07)] and VL [vs. HIV-: <75copies/mL: HR(95%CI) = 0.74(0.46-1.21), ≥75copies/mL: HR(95%CI) = 1.41(0.88-2.27)]. Among PLWH, CD4< 200cells/µL was associated with worse survival [vs. CD4≥ 200cells/µL: HR(95%CI) = 2.37(1.14-4.92)]. CD4, CD4/CD8, and VL may be prognostic markers for PLWH with NSCLC, suggesting immune status may be important in NSCLC survival among PLWH.

Sex and Stroke in Thrombolyzed Patients and Controls

Background and Purpose—

We hypothesized that any sex-related difference in outcome poststroke is explained by other prognostic factors and that the response to intravenous recombinant tissue-type plasminogen activator (r-tPA) is equal in males and females after adjustment for such factors.

Methods—

We accessed an independent collection of randomized clinical trials—the VISTA (Virtual International Stroke Trials Archive). Data were preprocessed by selecting complete cases (n=8028) and matching females to males (coarsened exact matching, n=4575, 24.3% r-tPA). Outcome was assessed by the 7-point modified Rankin Scale (mRS) measured at 90 days after ischemic stroke. Relationship among variables was estimated by adjusted regression analysis.

Results—

In nonthrombolyzed patients, ordinal analysis of mRS adjusting for stroke- and sex-related prognostic factors suggested comparable outcomes for females and males (odds ratio, 0.96; 95% confidence interval, 0.85–1.06). Females responded comparably to r-tPA as did males, irrespective of the outcome definition of mRS (ordinal: P Interaction =0.46, relative excess risk because of interaction=0). The number needed to treat was 6.8 and 11.2 for 1 female to achieve mRS score of 0 to 2 and 0 to 1, which was highly congruent with males. Analysis for a nonlinear variation of age-by-sex revealed a good outcome for females <45 years with significant disadvantage thereafter (mRS score of 0–2: P Interaction =0.004). No relationship between sex, r-tPA, and bleeding complications was evident.

Conclusions—

Functional outcome (mRS) without r-tPA was overall similar between the sexes, as was the response to r-tPA. Nonlinear sex-by-age interaction improved estimates of functional independence; this should be considered in sex-related studies in stroke.

β-Blockers, Pneumonia, and Outcome After Ischemic Stroke

Background and Purpose—

Increased sympathetic drive after stroke is involved in the pathophysiology of several complications including poststroke immunudepression. β-Blocker (BB) therapy has been suggested to have neuroprotective properties and to decrease infectious complications after stroke. We aimed to examine the effects of random pre- and on-stroke BB exposure on mortality, functional outcome, and occurrence of pneumonia after ischemic stroke.

Methods—

Data including standard demographic and clinical variables as well as prestroke and on-stroke antihypertensive medication, incidence of pneumonia, functional outcome defined using modified Rankin Scale and mortality at 3 months were extracted from the Virtual International Stroke Trials Archive. For statistical analysis multivariable Poisson regression was used.

Results—

In total, 5212 patients were analyzed. A total of 1155 (22.2%) patients were treated with BB before stroke onset and 244 (4.7%) patients were newly started with BB in the acute phase of stroke. Mortality was 17.5%, favorable outcome (defined as modified Rankin Scale, 0–2) occurred in 58.2% and pneumonia in 8.2% of patients. Prestroke BB showed no association with mortality. On-stroke BB was associated with reduced mortality (adjusted risk ratio, 0.63; 95% confidence interval, 0.42–0.96). Neither prestroke BB nor on-stroke BB showed an association with functional outcome. Both prestroke and on-stroke BB were associated with reduced frequency of pneumonia (adjusted risk ratio, 0.77; 95% confidence interval, 0.6–0.98 and risk ratio, 0.49; 95% confidence interval, 0.25–0.95).

Conclusions—

In this large nonrandomized comparison, on-stroke BB was associated with reduced mortality. Prestroke and on-stroke BB were inversely associated with incidence of nosocomial pneumonia. Randomized trials investigating the potential of β-blockade in acute stroke may be warranted.

Modeling acute respiratory illness during the 2007 San Diego wildland fires using a coupled emissions-transport system and generalized additive modeling

BACKGROUND

A study of the impacts on respiratory health of the 2007 wildland fires in and around San Diego County, California is presented. This study helps to address the impact of fire emissions on human health by modeling the exposure potential of proximate populations to atmospheric particulate matter (PM) from vegetation fires. Currently, there is no standard methodology to model and forecast the potential respiratory health effects of PM plumes from wildland fires, and in part this is due to a lack of methodology for rigorously relating the two. The contribution in this research specifically targets that absence by modeling explicitly the emission, transmission, and distribution of PM following a wildland fire in both space and time.

METHODS

Coupled empirical and deterministic models describing particulate matter (PM) emissions and atmospheric dispersion were linked to spatially explicit syndromic surveillance health data records collected through the San Diego Aberration Detection and Incident Characterization (SDADIC) system using a Generalized Additive Modeling (GAM) statistical approach. Two levels of geographic aggregation were modeled, a county-wide regional level and division of the county into six sub regions. Selected health syndromes within SDADIC from 16 emergency departments within San Diego County relevant for respiratory health were identified for inclusion in the model.

RESULTS

The model captured the variability in emergency department visits due to several factors by including nine ancillary variables in addition to wildfire PM concentration. The model coefficients and nonlinear function plots indicate that at peak fire PM concentrations the odds of a person seeking emergency care is increased by approximately 50% compared to non-fire conditions (40% for the regional case, 70% for a geographically specific case). The sub-regional analyses show that demographic variables also influence respiratory health outcomes from smoke.

CONCLUSIONS

The model developed in this study allows a quantitative assessment and prediction of respiratory health outcomes as it relates to the location and timing of wildland fire emissions relevant for application to future wildfire scenarios. An important aspect of the resulting model is its generality thus allowing its ready use for geospatial assessments of respiratory health impacts under possible future wildfire conditions in the San Diego region. The coupled statistical and process-based modeling demonstrates an end-to-end methodology for generating reasonable estimates of wildland fire PM concentrations and health effects at resolutions compatible with syndromic surveillance data.

Use of Syndromic Surveillance Information for Expanded Assessment of Wildfire Disaster

Objective

This presentation describes how syndromic surveillance information was combined with fire emission information and spatio-temporal fire occurrence data to evaluate, model and forecast climate change impacts on future fire scenarios.

Introduction

Syndromic surveillance information can be a useful for the early recognition of outbreaks, acute public health events and in response to natural disasters. Inhalation of particulate matter from wildland fire smoke has been linked to various acute respiratory and cardiovascular health effects. Historically, wildfire disasters occur across Southern California on a recurring basis. During 2003 and 2007, wildfires ravaged San Diego County and resulted in historic levels of population evacuation, significant impact on air quality and loss of lives and infrastructure. In 2011, the National Institutes of Health-National Institute of Environmental Health Sciences awarded Michigan Tech Research Institute a grant to address the impact of fire emissions on human health, within the context of a changing climate. San Diego County Public Health Services assisted on this project through assessment of population health impacts and provisioning of syndromic surveillance data for advanced modeling.

Methods

Various historical data sets were used during this study. These included: emergency department syndromic surveillance from 17 hospitals, as well as air quality and particulate matter, meteorological, wildland burn fuel, and atmospheric dispersion data. The study area was San Diego County. These data were linked temporally and spatially to create statistical models based on selected modeling approaches including generalized additive modeling. Future fire frequency was modeled for the entire region to determine the impacts of climate change on future fire and health outcomes. Modeling based upon previous fire occurrence was used to develop models for future fire indexes, risk of ignition, potential burning, and fire weather.

Results

Several models were developed to produce expected respiratory health impacts under future climate conditions for the San Diego County region. Model results showed that at peak fire particulate concentrations, the odds of a person seeking emergency care increased by approximately 50% compared to non-fire conditions. Also developed was a model to forecast future fire occurrence based on regional climate model predictions. This forecast covering the next the next three decades reveals that San Diego County will experience approximately two extreme fire seasons each decade by 2040.

Conclusions

Syndromic surveillance data are useful during disasters for situational awareness. These data may also provide value for post-disaster analytic work and predictive modeling for future disasters. This study demonstrates utility of syndromic data for collaborative work resulting in better understanding of environmental interactions on human health. We do know that wildfire occurs with some degree of historic regularity and these results may be useful for preparedness planning. We also know the conditions which must be present for medium to high wildland fire impact upon the population. This study further supports the notion that agencies should be able to strategically deploy resources and messaging immediately preceding the fire period with the goal of reducing human health risk factors and encouraging changes in community behaviors before, during and after a fire. Future fire model shows San Diego County will experience approximately two extreme fire seasons each decade by 2040. This project also promoted collaboration between public health and environmental health entities to better understand determinants of health during a disaster. In addition to developing a better understanding of the consequences of climate change on fire-induced respiratory illness, the project funding has provided support for San Diego County to improve their syndromic surveillance capacity and infrastructure.

Acute Cerebrovascular Disease in the Young

Background and Purpose—

Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients.

Methods—

Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol.

Results—

Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%–0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18–24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%).

Conclusions—

Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies.

Clinical Trial Registration Information—

URL: http://www.clinicaltrials.gov .Unique identifier: NCT00414583

The first cases of 2009 pandemic influenza A (H1N1) virus infection in the United States: a serologic investigation demonstrating early transmission

BACKGROUND

The first two laboratory-confirmed cases of 2009 pandemic influenza A (H1N1) virus (H1N1pdm09) infection were detected in San Diego (SD) and Imperial County (IC) in southern California, April 2009.

OBJECTIVES

To describe H1N1pdm09 infections and transmission early in the 2009 H1N1 pandemic.

PATIENTS/METHODS

We identified index case-patients from SD and IC with polymerase chain reaction (PCR)-confirmed H1N1pdm09 infections and investigated close contacts for a subset of case-patients from April 17-May 6, 2009. Acute and convalescent serum was collected. Serologic evidence for H1N1pdm09 infection was determined by microneutralization and hemagglutination inhibition assays.

RESULTS

Among 75 close contacts of seven index case-patients, three reported illness onset prior to patient A or B, including two patient B contacts and a third with no links to patient A or B. Among the 69 close contacts with serum collected >14 days after the onset of index case symptoms, 23 (33%) were seropositive for H1N1pdm09, and 8 (35%) had no fever, cough, or sore throat. Among 15 household contacts, 8 (53%) were seropositive for H1N1pdm09. The proportion of contacts seropositive for H1N1pdm09 was highest in persons aged 5-24 years (50%) and lowest in persons aged ≥ 50 years (13%) (P = 0·07).

CONCLUSIONS

By the end of April 2009, before H1N1pdm09 was circulating widely in the community, a third of persons with close contact to confirmed H1N1pdm09 cases had H1N1pdm09 infection in SD and IC. Three unrelated clusters during March 21-30 suggest that transmission of H1N1pdm09 had begun earlier in southern California.

Emergency health risk communication during the 2007 San Diego wildfires: comprehension, compliance, and recall

In October 2007, wildfires burned nearly 300,000 acres in San Diego County, California. Emergency risk communication messages were broadcast to reduce community exposure to air pollution caused by the fires. The objective of this investigation was to determine residents' exposure to, understanding of, and compliance with these messages. From March to June 2008, the authors surveyed San Diego County residents using a 40-question instrument and random digit dialing. The 1,802 respondents sampled were predominantly 35-64 years old (65.9%), White (65.5%), and educated past high school (79.0%). Most (82.5%) lived more than 1 mile away from the fires, although many were exposed to smoky air for 5-7 days (60.7%) inside and outside their homes. Most persons surveyed reported hearing fire-related health messages (87.9%) and nearly all (97.9%) understood the messages they heard. Respondents complied with most to all of the nontechnical health messages, including staying inside the home (58.7%), avoiding outdoor exercise (88.4%), keeping windows and doors closed (75.8%), and wetting ash before cleanup (75.6%). In contrast, few (<5%) recalled hearing technical messages to place air conditioners on recirculate, use High-Efficiency Particulate Air filters, or use N-95 respirators during ash cleanup, and less than 10% of all respondents followed these specific recommendations. The authors found that nontechnical message recall, understanding, and compliance were high during the wildfires, and reported recall and compliance with technical messages were much lower. Future disaster health communication should further explore barriers to recall and compliance with technical recommendations.

Transmission of 2009 pandemic influenza A (H1N1) virus among healthcare personnel-Southern California, 2009

OBJECTIVE

In April 2009, 2009 pandemic influenza A (H1N1) (hereafter, pH1N1) virus was identified in California, which caused widespread illness throughout the United States. We evaluated pH1N1 transmission among exposed healthcare personnel (HCP) and assessed the use and effectiveness of personal protective equipment (PPE) early in the outbreak.

DESIGN

Cohort study.

SETTING

Two hospitals and 1 outpatient clinic in Southern California during March 28-April 24, 2009.

PARTICIPANTS

Sixty-three HCP exposed to 6 of the first 8 cases of laboratory-confirmed pH1N1 in the United States.

METHODS

Baseline and follow-up questionnaires were used to collect demographic, epidemiologic, and clinical data. Paired serum samples were obtained to test for pH1N1-specific antibodies by microneutralization and hemagglutination-inhibition assays. Serology results were compared with HCP work setting, role, and self-reported PPE use.

RESULTS

Possible healthcare-associated pH1N1 transmission was identified in 9 (14%) of 63 exposed HCP; 6 (67%) of 9 seropositive HCP had asymptomatic infection. The highest attack rates occurred among outpatient HCP (6/19 [32%]) and among allied health staff (eg, technicians; 8/33 [24%]). Use of mask or N95 respirator was associated with remaining seronegative (P = .047). Adherence to PPE recommendations for preventing transmission of influenza virus and other respiratory pathogens was inadequate, particularly in outpatient settings.

CONCLUSIONS

pH1N1 transmission likely occurred in healthcare settings early in the pandemic associated with inadequate PPE use. Organizational support for a comprehensive approach to infectious hazards, including infection prevention training for inpatient- and outpatient-based HCP, is essential to improve HCP and patient safety.

Invasive group A streptococcal infection concurrent with 2009 H1N1 influenza

We describe 10 patients with 2009 H1N1 influenza and concurrent invasive group A streptococcal infection with marked associated morbidity and mortality. Seven patients required intensive care, 8 required mechanical ventilation, and 7 died. Five of the patients, including 4 of the fatalities, were previously healthy.

Antigenic and genetic characteristics of swine-origin 2009 A(H1N1) influenza viruses circulating in humans

Since its identification in April 2009, an A(H1N1) virus containing a unique combination of gene segments from both North American and Eurasian swine lineages has continued to circulate in humans. The lack of similarity between the 2009 A(H1N1) virus and its nearest relatives indicates that its gene segments have been circulating undetected for an extended period. Its low genetic diversity suggests that the introduction into humans was a single event or multiple events of similar viruses. Molecular markers predictive of adaptation to humans are not currently present in 2009 A(H1N1) viruses, suggesting that previously unrecognized molecular determinants could be responsible for the transmission among humans. Antigenically the viruses are homogeneous and similar to North American swine A(H1N1) viruses but distinct from seasonal human A(H1N1).

A defect in the thymidine kinase 2 gene causing isolated mitochondrial myopathy without mtDNA depletion

Isolated mitochondrial myopathies (IMM) are either due to primary defects in mtDNA, in nuclear genes that control mtDNA abundance and structure such as thymidine kinase 2 (TK2), or due to CoQ deficiency. Defects in the TK2 gene have been found to be associated with mtDNA depletion attributed to a depleted mitochondrial dNTP pool in non-dividing cells. We report an unusual case of IMM, homozygous for the H90N mutation in the TK2 gene but unlike other cases with the same mutation, does not demonstrate mtDNA depletion. The patient's clinical course is relatively mild and a muscle biopsy showed ragged red muscle fibers with a mild decrease in complexes I and an increase in complexes IV and II activities. This report extends the phenotypic expression of TK2 defects and suggests that all patients who present with an IMM even with normal quantities of mtDNA should be screened for TK2 mutations.

A randomized phase II trial comparing pulsed erlotinib before or after carboplatin and paclitaxel in patients with stage IIIB or IV non-small cell lung cancer

7619

Background: A randomized phase 3 trial failed to show any improvement in response rate (RR) or overall survival (OS) when erlotinib was added to carboplatin and paclitaxel (TRIBUTE). However, preclinical data suggested that administration of erlotinib before or after chemotherapy may improve efficacy of chemotherapy [Gumerlock et al ASCO 2003, Solit et al Clin Can Res 2005]. We designed this trial to test the hypothesis that administration of pulsed erlotinib prior to or following chemotherapy would improve the response rate in patients with advanced NSCLC. Methods: All patients had chemotherapy naive, stage IIIB or IV NSCLC and were former or current smokers. All patients received carboplatin (AUC 6) and paclitaxel (200 mg/m2). Patients were randomly assigned to one of three arms: erlotinib 150 mg days 1,2, and chemotherapy on day 3; erlotinib 1500 mg days 1, 2 and chemotherapy on day 3; or chemotherapy on day 1 and erlotinib 1500 mg on days 2,3. Patients received up to six 21-day cycles of treatment. The primary endpoint was overall RR (CR+PR) using RECIST. We planned to enroll 29 patients to each arm in a “pick the winner” design comparing arms to the chemotherapy alone arm of TRIBUTE (RR 19%) with a desirable RR of 50%. Results: Eighty-seven patients were randomized to 3 arms. Accrual is complete. The most common grade 3/4 toxicities were neutropenia (39%), fatigue (15%), and anemia (12%). Grade 3/4 rash or diarrhea were uncommon. Conclusions: Treatment with erlotinib before (150 mg on days 1 and 2 or 1500 mg on days 1 and 2) or after (1500 mg on days 2 and 3) administration of carboplatin and paclitaxel failed to improve response rates compared to TRIBUTE. The benefit of pulsatile administration of erlotinib predicted by preclinical models was not evident in this clinical trial. Supported by Genentech, Inc.

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Recovery of Salmonella, Listeria monocytogenes, and Mycobacterium bovis from cheese entering the United States through a noncommercial land port of entry

A joint multiagency project was initiated in response to a Salmonella outbreak in San Diego County, California, in 2004. Samples of cheese were collected during four 1-day operations at the San Ysidro port of entry, along the United States-Mexico border. Surveyed participants were persons crossing the border as pedestrians or in vehicles who had a minimum of 2.27 kg of cheese, which may suggest a potential diversion to illegal marketing. In addition, data were collected about the cheese to identify risk factors for cheese contamination. Two hundred four cheese samples were submitted to the California Animal Health and Food Safety Laboratory System-San Bernardino Branch and analyzed for potential food pathogens. Ninety-four percent (190 of 203) of the samples tested positive for alkaline phosphatase. Salmonella was detected from 13% (27 of 204) of the samples comprising 11 serogroups and 28 serotypes. Pulsed-field gel electrophoresis DNA fingerprinting analysis, performed following standardized methods, determined that an isolate obtained from this study had an indistinguishable pattern from a recent Salmonella enterica serovar Typhimurium var. Copenhagen epidemic in the San Diego County that was linked to 14 illnesses. Listeria spp. were detected from 4% (8 of 204) of the samples, and of these, half were identified as L. monocytogenes. Escherichia coli O157:H7 was not detected from any of the samples. Mycobacterium bovis was detected from one panela-style cheese sample. Nine additional samples yielded Mycobacterium spp.

Recovery of Mycobacterium bovis from soft fresh cheese originating in Mexico

Recent outbreaks of human tuberculosis in the United States caused by Mycobacterium bovis have implicated cheese originating in Mexico as a source of these infections. A total of 203 samples of cheese originating in Mexico were cultured, and M. bovis was recovered from one specimen. Therefore, M. bovis can be recovered from cheese and may be a source of human infections.

Quarantine stressing voluntary compliance

A 1-day table-top exercise in San Diego, California, in December 2004 emphasized voluntary compliance with home quarantine to control an emerging infectious disease outbreak. The exercise heightened local civilian-military collaboration in public health emergency management. Addressing concerns about lost income by residents in quarantine was particularly challenging.

2004 California pediatric West Nile virus case series

Relatively few pediatric West Nile virus cases have been recognized in the United States since the virus was first identified in 1999. We reviewed the clinical characteristics of 23 cases in pediatric patients that occurred in California in 2004 to better understand the infection in this population.

Hepatitis A in Hispanic children who live along the United States-Mexico border: the role of international travel and food-borne exposures

OBJECTIVES

Hispanic children who live along the United States-Mexico border historically have had among the highest hepatitis A rates in the United States, but risk factors have not been well characterized. The objective of this study was to examine risk factors associated with acute hepatitis A virus (HAV) infection in Hispanic children who live along the United States-Mexico border in San Diego County, California.

METHODS

In this case-control study, hepatitis A cases among Hispanic children who were younger than 18 years reported from June 1998 through August 2000 were matched by age group and exposure period to Hispanic children who were susceptible to HAV infection. Participants and their families were interviewed about demographic information and potential sources of HAV infection, including attending child care, food and waterborne exposures, cross-border and other international travel, and travel-related activities.

RESULTS

Participants included 132 children with hepatitis A and 354 control subjects. The median age of study participants was 7 years (range: 1-17). Sixty-seven percent of case-patients traveled outside the United States during the incubation period, compared with 25% of the children without hepatitis A (odds ratio [OR]: 6.3; 95% confidence interval [CI]: 4.0-9.7); all children, except 1, had traveled to Mexico. In multivariate analysis, hepatitis A was associated with having eaten food from a taco stand or street food vendor (adjusted OR: 17.0; 95% CI: 4.1-71.1) and having eaten salad/lettuce (adjusted OR: 5.2; 95% CI: 1.3-20.1) during travel.

CONCLUSIONS

Hepatitis A among Hispanic children who live in an urban area of the United States-Mexico border is associated with cross-border travel to Mexico and food-borne exposures during travel. Travelers to areas where hepatitis A is endemic should receive hepatitis A vaccine before travel.

Phase II trial of branched peginterferon-alpha 2a (40 kDa) for patients with advanced renal cell carcinoma

BACKGROUND

Peginterferon-alpha 2a (40 kDa), PEGASYS(TM) (PEG-IFN), is a modified form of recombinant human interferon (IFN)-alpha 2a with sustained absorption and prolonged half-life after subcutaneous administration. A phase II trial was conducted in previously untreated patients with advanced renal cell carcinoma (RCC) to assess efficacy, toxicity and pharmacokinetic profile.

PATIENTS AND METHODS

Forty previously untreated patients with advanced RCC were enrolled on this multicenter trial. The median age was 60 years and 63% had prior nephrectomy. PEG-IFN was administered at a dose of 450 micro g/week on a weekly basis by subcutaneous injection. Serial venous blood samples were drawn to assess concentrations of PEG-IFN.

RESULTS

Five (13%) patients achieved a major response (four partial and one complete). The median time to progression was 3.8 months, and 63% of patients were alive at 1 year. The toxicity profile was mostly mild to moderate in intensity. Toxicity higher than grade 2 included neutropenia (six patients), fatigue/asthenia (four patients), nausea/vomiting (three patients) and elevated hepatic transaminase concentrations (four patients). Serum drug levels were studied in all patients; mean C(max) at week 1 was 19 ng/ml, and levels were sustained at close to peak over 1 week. With chronic dosing, drug concentration was increased 3-fold, and steady state was achieved in 5-9 weeks.

CONCLUSIONS

The sustained maintenance of serum levels of PEG-IFN allows once-weekly dosing. The efficacy and tolerability profile was qualitatively similar to standard IFN-alpha, and adverse events were mostly mild to moderate in nature.

Computerized weight loss intervention optimizes staff time: the clinical and cost results of a controlled clinical trial conducted in a managed care setting

OBJECTIVE

To evaluate the costs and effects of incremental components of a weight-loss program.

DESIGN

A 3-arm, 12-month randomized controlled clinical trial to evaluate 3 incremental levels of intervention intensity.

SUBJECTS/SETTING

The study included 588 individuals (BMI > 25 kg/m2) in a freestanding health maintenance organizalion and achieved an 81% completion rate.

INTERVENTION

Using a cognitive behavioral approach for tailoring lifestyle modification goals, the incremental levels of intervention included a) a workbook alone, b) the addition of computerized tailoring using onsite computer kiosks with touch screen monitors, and c) the addition of both computers and staff consultation.

MAIN OUTCOME MEASURES

Endpoints included weight parameters, lipid profile, plasma glucose, blood pressure, intervention costs, dietary intake, and physical activity.

STATISTICAL ANALYSIS PERFORMED

Study endpoints were analyzed using analysis of variance for normally distributed variables and analysis of covariance to control for any baseline differences. Regression and correlation analysis assessed the relationship between weight loss and other variables.

RESULTS

For the increasing levels of intervention intensity, the mean 12-month weight losses were 2.2, 4.7, and 7.4 pounds, with the respective cost per participant being $12.33, $41.99, and $133.74. The decreases in mean BMIs for these respective intervelation levels were 0.4, 0.9 and 1.2. All groups reported a decrease in energy and fat intake and an increase in blocks walked (P<.01). Intervention variables that correlated with weight loss included more computer log-ons, achieving computer-selected goals, more self-monitoring, increased walking, and decreased energy and fat intake, as well as higher attendance in staff consultation group sessions for that treatment condition. Weight loss correlated with decreases in fasting glucose and blood pressure.

APPLICATIONS/CONCLUSIONS

In a weight-loss program, computers can facilitate selecting behavioral change goals. More frequent usage resulted in greater weight loss. Staff counseling to augment the computer intervention achieved the most weight loss.

Preventing transmission of hepatitis B virus from people with chronic infection

BACKGROUND

People with chronic hepatitis B virus (HBV) infection are the major source of HBV transmission in the United States. The Public Health Service recommends prevention counseling for HBV-infected people and vaccination of their household contacts and sexual partners.

OBJECTIVES

To describe the implementation of these recommendations by community physicians.

METHODS

Telephone survey of 69 people with chronic HBV infection and their healthcare providers, October 1997 through November 1997, in San Diego, California.

MAIN OUTCOME MEASURES

Counseling of people with chronic HBV infection and vaccination of their household contacts and sexual partners.

RESULTS

Forty-three percent of providers reported providing prevention counseling to their HBV-infected patients to reduce transmission; 16% of patients reported receiving counseling. For the 32 pairs for which both the patient and provider could be reached and the patients were aware of their HBV infection, 20 (63%) providers reported counseling patients, and 10 (50%) of these providers' patients reported receiving counseling. Fifty-five percent of providers recommended vaccination of contacts; 13% of eligible adult household contacts and sexual partners and 20% of eligible child household contacts had begun hepatitis B vaccination.

CONCLUSIONS

Prevention counseling of people with chronic HBV infection and vaccination of their contacts occur infrequently despite guidelines and an effective vaccine. Collaborative efforts between providers and people involved in public health are needed to improve delivery of these preventive health services.

Phase I trial of 40-kd branched pegylated interferon alfa-2a for patients with advanced renal cell carcinoma

PURPOSE

Pegylated (40 kd) interferon alfa-2a (IFNalpha2a) (PEGASYS, Hoffman-La Roche, Nutley, NJ; PEG-IFN) is a modified form of recombinant human IFNalpha2a with sustained absorption and prolonged half-life after subcutaneous administration. A phase I study of PEG-IFN with pharmacokinetic and pharmacodynamic evaluations was conducted in previously untreated patients with advanced renal cell carcinoma (RCC).

PATIENTS AND METHODS

Twenty-seven patients were enrolled onto cohorts of three or six patients. PEG-IFN was administered on a weekly basis by subcutaneous injection. The dose was escalated from 180 microg/wk to a maximum of 540 microg/wk in 90-microg increments. Serial venous blood samples were drawn to assess concentrations of PEG-IFN and two immunologic surrogates, neopterin and 2'-5' oligoadenylate synthetase (OAS).

RESULTS

The maximum-tolerated dose was determined as 540 microg/wk, because two patients experienced dose-limiting toxicity within 28 days of starting treatment. One developed serum grade 3 ALT elevation, and a second developed grade 3 fatigue. Six patients were treated at 450 microg/wk without dose-limiting toxicity. Over the course of treatment, the side-effect profile was mostly mild to moderate in intensity. Adverse events included fatigue, fever, headache, myalgia, nausea, and decreased appetite. Five patients (19%) achieved a partial response. The mean maximum serum concentration increased from 5.0 to 27 ng/mL, and mean area under the curve increased from 247 to 2,981 ng/h/mL, with dose escalation from 180 microg/wk to 540 microg/wk. Serum concentration of PEG-IFN was sustained at close to peak during the dosing interval, and steady-state was achieved in approximately 5 weeks. The immunologic surrogates, neopterin and OAS, were induced at all doses with a sustained concentration profile similar to PEG-IFN.

CONCLUSION

PEG-IFN is a modified form of IFNalpha2a with distinct pharmacokinetic advantages and immunomodulatory and antitumor activity for patients with advanced RCC. A dose of 450 microg/wk by subcutaneous administration was determined as a suitable dose for further study. PEG-IFN is more convenient to administer than IFNalpha and has potential for increased efficacy, less toxicity, or both. The efficacy and toxicity of PEG-IFN will be further assessed in clinical trials and compared with IFNalpha.

The effector loop and prenylation site of R-Ras are involved in the regulation of integrin function

The closely related small GTP-binding proteins H-Ras and R-Ras have opposing effects on the regulation of integrin cell adhesion receptors. To gain insight into the properties of R-Ras with respect to the regulation of integrin function and interactions with downstream effectors we performed an analysis of R-Ras variants containing mutations in the effector binding domain and C-terminal prenylation site. We found that the activation of the downstream effector PI 3-kinase was sensitive to mutations in the effector binding domain, as was the binding to the effectors, Ral-GDS, Raf-1 and the novel effector Nore1. Furthermore, specific mutations in the effector binding loop and C-terminal prenylation motif impaired the ability of R-Ras to regulate integrin function in CHO cells. However, the ability of the R-Ras effector loop mutants to bind, and activate known effectors did not correlate with their ability to regulate integrin function. Thus, the known R-Ras effectors are not critical for regulating integrin activation, at least in CHO cells. Consequently, these studies provide insight into the structural basis of the interactions between R-Ras and its candidate effectors and suggest the existence of novel mechanisms through which this GTPase could regulate cell adhesion.

Effectiveness of influenza vaccination of day care children in reducing influenza-related morbidity among household contacts

CONTEXT

A growing proportion of young children in the United States participate in day care, and these children are considered to be at high risk for influenza infection. Whether vaccinating day care children reduces household transmission of influenza is not known.

OBJECTIVE

To evaluate the effect of vaccinating day care children on reducing influenza-related morbidity among their household contacts.

DESIGN

Single-blind, randomized controlled trial conducted during the 1996-1997 influenza season.

SETTING

Ten day care centers for children of US Navy personnel in San Diego, Calif.

PARTICIPANTS

A total of 149 day care attendees (aged 24-60 months) and their families were randomized; 127 children and their 328 household contacts received 2 vaccine doses and were included in the analysis.

INTERVENTIONS

Inactivated influenza vaccine was administered to 60 children with 162 household contacts, and hepatitis A vaccine as a control was administered to 67 age-matched children with 166 household contacts.

MAIN OUTCOME MEASURES

Information regarding febrile respiratory illnesses and related morbidity for household contacts of influenza-vaccinated vs control children (subgrouped by influenza-vaccinated and unvaccinated contacts), obtained by telephone interviews with parents every 2 weeks from November 1996 through April 1997.

RESULTS

Influenza-unvaccinated household contacts (n = 120) of influenza-vaccinated day care children had 42% fewer febrile respiratory illnesses (P =.04) compared with unvaccinated household contacts of control children. Among school-aged household contacts (aged 5-17 years), there was an 80% reduction among contacts of vaccinated children (n = 28) vs contacts of unvaccinated children (n = 31) in febrile respiratory illnesses (P =.01), as well as reductions of more than 70% in school days missed (P =.02), reported earaches (P =.02), physician visits (P =.007), physician-prescribed antibiotics (P =.02), and adults who missed work to take care of ill children (P =.04).

CONCLUSIONS

These results indicate that vaccinating day care children against influenza helps reduce influenza-related morbidity among their household contacts, particularly among school-aged contacts. Future studies should be conducted in civilian populations to assess the full effect of vaccinating day care children against influenza. JAMA. 2000;284:1677-1682.

Phase II trial of pyrazoloacridine in patients with cisplatin-refractory germ cell tumors

Thirteen patients with cisplatin-refractory germ cell tumors were treated on a Phase II trial with pyrazoloacridine. Pyrazoloacridine was given intravenously at 600 mg/m2 every three weeks. The median nadir leucocyte count was 2.5 cells/mm3, hemoglobin was 10.8 g/dl, and platelet count was 126,000 cells/m3. None of the thirteen evaluable patients achieved a major response. Pyrazoloacridine is not efficacious in the treatment of cisplatin-refractory germ cell tumors.

Lack of association between Kawasaki syndrome and Chlamydia pneumoniae infection: an investigation of a Kawasaki syndrome cluster in San Diego County

BACKGROUND

The etiology of Kawasaki syndrome (KS), the leading cause of acquired coronary artery disease in children, is unknown. Recent studies have suggested that Chlamydia pneumoniae, a common respiratory pathogen associated with an increased risk of heart disease, might lead to KS.

OBJECTIVE

To assess whether KS was associated with an elevated risk of having a current or antecedent infection with C. pneumoniae.

METHODS

Blood, urine and pharyngeal specimens from KS patients in San Diego County, CA, during a period of high KS incidence were analyzed for evidence of recent C. pneumoniae infection by culture, PCR and serology. Specimens collected from two control groups, family members of KS patients and age-matched children attending outpatient clinics for well child visits, were similarly analyzed.

RESULTS

Thirteen cases were identified. Forty-five outpatient controls and an average of three family members per patient were enrolled in the study. All specimens tested negative for the presence of C. pneumoniae by PCR and culture except for one blood specimen from the mother of a case-patient. Serologic analysis of patients and a subset of outpatient and family controls revealed no evidence of current C. pneumoniae infection; 4 of 13 adult family controls had IgG titers consistent with past exposure to C. pneumoniae. Case patients were no more likely than outpatient controls to have had a respiratory illness in the preceding 2 months (11 of 13 patients vs. 35 of 45 controls; odds ratio, 1.57; 95% confidence interval, 0.3 to 11.9).

CONCLUSIONS

We found no evidence that C. pneumoniae infection was associated with KS.

Cyclic AMP induces apolipoprotein E binding activity and promotes cholesterol efflux from a macrophage cell line to apolipoprotein acceptors

RAW 264 mouse macrophage cells were stably transfected with human apolipoprotein E (apoE) expression vectors. Clonal derivatives were characterized for expression of the human apoE2, apoE3, and apoE4 isoforms. An apoE4-expressing clonal cell line and a non-expressing clonal control cell line were loaded overnight with either [3H]cholesterol or [3H]choline. The cells were washed and incubated for 24 h in serum-free medium with or without the addition of 8-bromo-cyclic AMP (8-Br-cAMP). Only the apoE-secreting cells and only in the presence of 8-Br-cAMP released large amounts of labeled cholesterol or phosphatidylcholine into the medium. Mass analyses of cellular free and esterified cholesterol confirmed the results of the labeling studies; a decrease in cellular cholesterol content was observed in the 8-Br-cAMP-treated apoE-secreting cells, concurrent with an increase in cholesterol found in the medium. FPLC analysis of the medium demonstrated that 8-Br-cAMP treatment of the apoE-secreting cells led to an increased size fraction and amount of a peak of secreted cholesterol which comigrated with apoE. The 8-Br-cAMP-mediated increase in cholesterol efflux was also observed in non-apoE-secreting cells incubated with exogenous apoE or apoAI, and the effect of apoE was saturable. The apoE2, apoE3, and apoE4 isoforms were equally efficient in promoting 8-Br-cAMP-dependent cholesterol efflux. Reductive methylation of apoE abolished its ability to promote 8-Br-cAMP-dependent cholesterol efflux. Brefeldin A and monensin, inhibitors of protein processing through the Golgi, both blocked the 8-Br-cAMP stimulation of cholesterol efflux to exogenous apoE. 8-Br-cAMP induced specific apoE and apoAI binding, but not apoE degradation, by the RAW cells. We present a model wherein cAMP induces a membrane apolipoprotein receptor that does not lead to endocytosis and degradation, but instead promotes the transfer of lipids to apolipoproteins, which can then be released from the cell.

Resuscitative hypothermia

Resuscitative (postinsult) hypothermia is less well studied than protective-preservative (pre- and intra-arrest) hypothermia. The latter is in wide clinical use, particularly for protecting the brain during cardiac surgery. Resuscitative hypothermia was explored in the 1950s and then lay dormant until the 1980s when it was revived. This change occurred through the discoveries of brain damage mitigating effects after cardiac arrest in dogs, and after forebrain ischemia in rats, of mild (34 degrees C) hypothermia (which is safe), and of benefits derived from moderate hypothermia (30 degrees C) after traumatic brain injury or focal brain ischemia in various species. The idea that protection-preservation or resuscitation by hypothermia is mainly explained by its ability to reduce cerebral oxygen demand has been replaced by an increasingly documented synergism of many beneficial mechanisms. Deleterious chemical cascades during and after these insults are suppressed even by mild hypothermia. Prolonged moderate hypothermia carries some risks, e.g., arrhythmias, infection and coagulopathies. These side effects need further study. In global brain ischemia, protective-preservative mild hypothermia provides lasting mitigation of brain damage. Resuscitative mild hypothermia, however, may be beneficial in terms of long-term outcome or may merely delay the inevitable loss of selectively vulnerable neurons. Even if the latter is true, mild hypothermia may extend the therapeutic window for other interventions. This extension of the therapeutic window requires further documentation. After normothermic cardiac arrest of 11 mins in dogs, mild resuscitative hypothermia from 15 mins to 12 hours after reperfusion plus cerebral blood flow promotion normalized functional recovery with the least histologic damage seen thus far. Optimal duration of, and rewarming methods from, resuscitative hypothermia need clarification. The earliest possible induction of mild hypothermia after cardiac arrest seems desirable. Head-neck surface cooling alone is too slow. Among many clinically feasible rapid cooling methods, carotid cold flush and peritoneal cooling look promising. After traumatic brain injury or focal brain ischemia, which seem to still benefit from even later cooling, surface cooling methods may be adequate. Resuscitative hypothermia after cardiac arrest, traumatic brain injury, or focal brain ischemia should be considered for clinical trials.

Cerebral resuscitation from cardiac arrest: pathophysiologic mechanisms

Both the period of total circulatory arrest to the brain and postischemic-anoxic encephalopathy (cerebral postresuscitation syndrome or disease), after normothermic cardiac arrests of between 5 and 20 mins (no-flow), contribute to complex physiologic and chemical derangements. The best documented derangements include the delayed protracted inhomogeneous cerebral hypoperfusion (despite controlled normotension), excitotoxicity as an explanation for selectively vulnerable brain regions and neurons, and free radical-triggered chemical cascades to lipid peroxidation of membranes. Protracted hypoxemia without cardiac arrest (e.g., very high altitude) can cause angiogenesis; the trigger of it, which lyses basement membranes, might be a factor in post-cardiac arrest encephalopathy. Questions to be explored include: What are the changes and effects on outcome of neurotransmitters (other than glutamate), of catecholamines, of vascular changes (microinfarcts seen after asphyxia), osmotic gradients, free-radical reactions, DNA cleavage, and transient extracerebral organ malfunction? For future mechanism-oriented studies of the brain after cardiac arrest and innovative cardiopulmonary-cerebral resuscitation, increasingly reproducible outcome models of temporary global brain ischemia in rats and dogs are now available. Disagreements exist between experienced investigative groups on the most informative method for quantitative evaluation of morphologic brain damage. There is agreement on the desirability of using not only functional deficit and chemical changes, but also morphologic damage as end points.

Cerebral resuscitation from cardiac arrest: treatment potentials

In 1961, in Pittsburgh, PA, "cerebral" was added to the cardiopulmonary resuscitation system (CPR --> CPCR). Cerebral recovery is dependent on arrest and cardiopulmonary resuscitation times, and numerous factors related to basic, advanced, and prolonged life support. Postischemic-anoxic encephalopathy (the cerebral postresuscitation disease or syndrome) is complex and multifactorial. The prevention or mitigation of this syndrome requires that there be development and trials of special, multifaceted, combination treatments. The selection of therapies to mitigate the postresuscitation syndrome should continue to be based on mechanistic rationale. Therapy based on a single mechanism, however, is unlikely to be maximally effective. For logistic reasons, the limit for neurologic recovery after 5 mins of arrest must be extended to achieve functionally and histologically normal human brains after 10 to 20 mins of circulatory arrest. This goal has been approached, but not quite reached. Treatment effects on process variables give clues, but long-term outcome evaluation is needed for documentation of efficacy and to improve clinical results. Goals have crystallized for clinically relevant cardiac arrest-intensive care outcome models in large animals. These studies are expensive, but essential, because positive treatment effects cannot always be confirmed in the rat forebrain ischemia model. Except for a still-elusive breakthrough effect, randomized clinical trials of CPCR are limited in their ability to statistically document the effectiveness of treatments found to be beneficial in controlled outcome models in large animals. Clinical studies of feasibility, side effects, and acceptability are essential. Hypertensive reperfusion overcomes multifocal no-reflow and improves outcome. Physical combination treatments, such as mild resuscitative (early postarrest) hypothermia (34 degrees C) plus cerebral blood flow promotion (e.g., with hypertension, hemodilution, and normocapnia), each having multiple beneficial effects, achieved complete functional and near-complete histologic recovery of the dog brain after 11 mins of normothermic, ventricular fibrillation cardiac arrest. Calcium entry blockers appear promising as a treatment for postischemic-anoxic encephalopathy. However, the majority of single or multiple drug treatments explored so far have failed to improve neurologic outcome. Assembling and evaluating combination treatments in further animal studies and determining clinical feasibility inside and outside hospitals are challenges for the near future. Treatments without permanent beneficial effects may at least extend the therapeutic window. All of these investigations will require coordinated efforts by multiple research groups, pursuing systematic, multilevel research--from cell cultures to rats, to large animals, and to clinical trials. There are still many gaps in our knowledge about optimizing extracerebral life support for cerebral outcome.

A cluster of Escherichia coli O157:H7 infections with the hemolytic-uremic syndrome and death in California. A mandate for improved surveillance

In mid-January 1993, an outbreak of Escherichia coli O157:H7 infections associated with eating hamburger patties at a fast-food restaurant chain (chain A) was reported in Washington State. From mid-December to mid-January, 9 cases of E coli O157:H7-associated bloody diarrhea and the hemolytic-uremic syndrome had been reported in San Diego County, California. A total of 34 persons had bloody diarrhea, the hemolytic-uremic syndrome, or E coli O157:H7 organisms isolated from stool during the period November 15, 1992, through January 31, 1993. Organisms of E coli O157:H7 identified from 6 persons were indistinguishable from those of the Washington outbreak strain. Illness was associated with eating at chain A restaurants in San Diego (odds ratio, 13; 95% confidence interval, 1.7, 99) and with eating regular-sized hamburgers (odds ratio, undefined; lower-limit 95% confidence interval, 1.3). Improved surveillance by mandating laboratory- and physician-based reporting of cases of E coli O157:H7 infection and the hemolytic-uremic syndrome might have alerted health officials to this outbreak sooner, which could have resulted in earlier investigation and the institution of measures to prevent more cases.

Cytochrome P450 1A1 promoter as a genetic switch for the regulatable and physiological expression of a plasma protein in transgenic mice

Transgenic and gene knockout techniques allow for in vivo study of the consequences of adding or subtracting specific genes. However, in some instances, such as the study of lethal mutations or of the physiological consequences of changing gene expression, turning on and off an introduced gene at will would be advantageous. We have used cytochrome p450 1A1 promoter to drive expression of the human apolipoprotein E (apoE) gene in transgenic mice. In six independent lines, robust expression of the transgene depended upon injection of the inducer beta-naphthoflavone, whereas the seventh line had high basal expression that was augmented further by the inducer. The low level of basal expression in an inducer-dependent line was confirmed upon breeding the transgene onto the hypercholesterolemic apoE-deficient background. In the basal state transgene expression was physiologically insignificant, as these mice were as hypercholesterolemic as their nontransgenic apoE-deficient littermates. When injected with the inducer, plasma cholesterol levels of the transgenic mice decreased dramatically as apoE expression was induced to yield greater than physiological levels in plasma. The inducer could pass transplacentally from an injected mother to her fetuses with concomitant induction of fetal transgene mRNA. Inducer could also pass via breast milk from an injected mother to her suckling neonatal pups, giving rise to the induction of human apoE in neonate plasma. These finding suggest a strategy to temporarily ameliorate genetic deficiencies that would otherwise lead to fetal or neonatal lethality.

Decreased atherosclerosis in mice deficient in both macrophage colony-stimulating factor (op) and apolipoprotein E

To develop a murine model system to test the role of monocyte-derived macrophage in atherosclerosis, the osteopetrotic (op) mutation in the macrophage colony-stimulating factor gene was bred onto the apolipoprotein E (apoE)-deficient background. The doubly mutant (op/apoE-deficient) mice fed a low-fat chow diet had significantly smaller proximal aortic lesions at an earlier stage of progression than their apoE-deficient control littermates. These lesions in the doubly mutant mice were composed of macrophage foam cells. The op/apoE-deficient mice also had decreased body weights, decreased blood monocyte differentials, and increased mean cholesterol levels of approximately 1300 mg/dl. Statistical analysis determined that atherosclerosis lesion area was significantly affected by the op genotype and gender. The confounding variables of body weight, plasma cholesterol, and monocyte differential, which were all affected by op genotype, had no significant additional effect on lesion area once they were adjusted for the effects of op genotype and gender. Unexpectedly, there was a significant inverse correlation between plasma cholesterol and lesion area, implying that each may be the result of a common effect of macrophage colony-stimulating factor levels. The data support the hypothesis that macrophage colony-stimulating factor and its effects on macrophage development and function play a key role in atherogenesis.

Transmission of Plasmodium vivax malaria in San Diego County, California, 1986

Between 18 June and 20 September 1986, 28 cases of Plasmodium vivax malaria were documented in Carlsbad, California, a coastal town north of San Diego. Malaria occurred in 1 local resident who had no risk factors, a second local resident who had traveled to a malarious area 9 months earlier, and 26 Mexican migrant workers (MWs). Among the 28 cases, 27 lived in a square mile marshy area where Anopheles hermsi, a newly described American species of the Anopheles maculipennis group, was known to be breeding. An investigation of MWs residing in the affected area was done to determine the extent of the outbreak and to identify risk factors for acquiring malaria. We interviewed and drew blood from 304 healthy MWs and 17 (65%) of the MWs with malaria. Fluorescent antibody titers to P. vivax greater than or equal to 1:256 occurred in 14 (82%) of the 17 MWs with malaria tested and 9 (3%) of the healthy MWs. The principal risk factor identified for contracting malaria was sleeping outside on a hillside adjacent to the marshy area. Malaria in a local resident with no malaria risk factors and the clustering in time and place of 26 cases suggest that P. vivax malaria was introduced and local transmission was sustained through several generations, producing the largest outbreak of introduced malaria in the United States since 1952.