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Featured researches published by Laura C. Schall.


Journal of Trauma-injury Infection and Critical Care | 2000

Impact of pediatric trauma centers on mortality in a statewide system.

Douglas A. Potoka; Laura C. Schall; Mary J. Gardner; Perry W. Stafford; Andrew B. Peitzman; Henri R. Ford

Background: Regional pediatric trauma centers (PTC) were established to optimize the care of injured children. However, because of the relative shortage of PTC, many injured children continue to be treated at adult trauma centers (ATC). As a result, a growing controversy has evolved regarding the impact of PTC and ATC on outcome for injured children. Methods: A retrospective analysis of 13,351 injured children entered in the Pennsylvania Trauma Outcome Study between 1993 and 1997 was conducted. Patients were stratified according to mechanism of injury, injury severity, specific organ injury, and type of trauma center: PTC; Level I ATC (ATC I); Level II ATC (ATC II); or ATC with added qualifications to treat children (ATC AQ). Mortality was the major outcome variable measured. Results: Most injured children were treated at a PTC or ATC AQ. The majority of children below 10 years of age were admitted to PTC. Patients treated at PTC and ATC had similar injury severity as determined by median Injury Severity Score, mean Revised Trauma Score, and Glasgow Coma Scale. Overall survival was significantly better at PTC and ATC AQ compared with ATC I and ATC II. Survival for head, spleen, and liver injuries was significantly better at PTC compared with ATC AQ, ATC I, or ATC II. Children who sustained moderate or severe head injuries were more likely to undergo neurosurgical intervention and have a better outcome when treated at a PTC. Despite similar mean Abbreviated Injury Scores for spleen and liver, significantly more children underwent surgical exploration (especially splenectomy) for spleen and liver injuries at ATC compared with PTC. Conclusion: Children treated at PTC or ATC AQ have significantly better outcome compared with those treated at ATC. Severely injured children (Injury Severity Score > 15) with head, spleen, or liver injuries had the best overall outcome when treated at PTC. This difference in outcome may be attributable to the approach to operative and nonoperative management of head, liver, and spleen injuries at PTC.


Journal of Trauma-injury Infection and Critical Care | 2001

Improved functional outcome for severely injured children treated at pediatric trauma centers.

Douglas A. Potoka; Laura C. Schall; Henri R. Ford

BACKGROUND Controversy exists regarding the impact of pediatric trauma centers (PTC) on survival for injured children. However, functional outcome for children treated at PTC compared with adult trauma centers (ATC) has not been evaluated. METHODS An analysis of children entered in the Pennsylvania Trauma Outcome Study between 1993 and 1997 was conducted. Patients were stratified according to type of trauma center: PTC; Level I ATC; Level II ATC; or ATC with added qualifications (AQ). Functional outcome at discharge was analyzed. RESULTS For severely injured children, there was an overall trend toward improved functional outcome at PTC compared with ATC AQ and ATC I, but no difference compared with ATC II. PTC showed improved functional outcome at discharge for head injury compared with ATC AQ and ATC I. CONCLUSION There is an overall trend toward improved functional outcome at discharge for children treated at PTC compared with those treated at ATC AQ and ATC I. Improved outcome for head injury may be a key factor contributing to improved outcome at PTC.


Occupational and Environmental Medicine | 1999

Mortality patterns among workers exposed to acrylamide: 1994 follow up.

Gary M. Marsh; Lorraine J Lucas; Ada O. Youk; Laura C. Schall

OBJECTIVE: To update the mortality experience of a cohort of 8508 workers with potential exposure to acrylamide at three plants in the United States from 1984-94. METHODS: Analyses of standardised mortality ratios (SMR) with national and local rates and relative risk (RR) regression modelling were performed to assess site specific cancer risks by demographic and work history factors, and exposure indicators for acrylamide and muriatic acid. RESULTS: For the 1925-94 study period, excess and deficit overall mortality risks were found for cancer sites of interest: brain and other central nervous system (CNS) (SMR 0.65, 95% confidence interval (95% CI) 0.36 to 1.09), thyroid gland (SMR 2.11, 95% CI 0.44 to 6.17), testis and other male genital organs (SMR 0.28, 95% CI 0.01 to 1.59), and cancer of the respiratory system (SMR 1.10, 95% CI 0.99 to 1.22); however, none was significant or associated with exposure to acrylamide. A previously reported excess mortality risk of cancer of the respiratory system at one plant remained increased among workers with potential exposure to muriatic acid (RR 1.50, 95% CI 0.86 to 2.59), but was only slightly increased among workers exposed or unexposed to acrylamide. In an exploratory exposure-response analysis of rectal, oesophageal, pancreatic, and kidney cancer, we found increased SMRs for some categories of exposure to acrylamide, but little evidence of an exposure-response relation. A significant 2.26-fold risk (95% CI 1.03 to 4.29) was found for pancreatic cancer among workers with cumulative exposure to acrylamide > 0.30 mg/m3.years; however, no consistent exposure-response relations were detected with the exposure measures considered when RR regression models were adjusted for time since first exposure to acrylamide. CONCLUSION: The contribution of 1115 additional deaths and nearly 60,000 person-years over the 11 year follow up period corroborate the original cohort study findings of little evidence for a causal relation between exposure to acrylamide and mortality from any cancer sites, including those of initial interest. This is the most definitive study of the human carcinogenic potential of exposure to acrylamide conducted to date.


Journal of Trauma-injury Infection and Critical Care | 1999

Management of Blunt Pancreatic Injury in Children

Evan P. Nadler; Mary J. Gardner; Laura C. Schall; James M. Lynch; Henri R. Ford

BACKGROUND AND METHODS Controversy persists regarding the management of pancreatic transection. Over the past 10 years, 51 patients admitted to the Childrens Hospital of Pittsburgh sustained blunt pancreatic injuries. We reviewed their medical records to clarify the optimal management strategy and to define distinguishing characteristics, if any, of patients with pancreatic transection. RESULTS Patients who sustained pancreatic transection had a significantly higher Injury Severity Score, length of stay, serum amylase, and serum lipase, than those patients who sustained pancreatic contusion. Patients who underwent laparotomy within 48 hours of injury for pancreatic transection had a significantly shorter length of stay than those who underwent laparotomy more than 48 hours after injury. CONCLUSION Serum amylase greater than 200 and serum lipase greater than 1,800 may be useful clinical markers for major pancreatic ductal injury when combined with physical examination. Early operative intervention for pancreatic transection results in shorter length of stay and fewer complications.


Journal of Trauma-injury Infection and Critical Care | 2000

Risk factors and predictors of mortality in children after ejection from motor vehicle crashes.

Michael G. Scheidler; Barbara L. Shultz; Laura C. Schall; Henri R. Ford

PURPOSE Mortality after ejection from a motor vehicle crash (MVC) has been studied extensively in adults. The magnitude of this problem in children is relatively unknown. We retrospectively examined fatalities resulting from ejection after MVC in the state of Pennsylvania to define risk factors and predictors of mortality in children. METHODS The records for all patients 0 to 16 years of age involved in an MVC and entered in the Pennsylvania Trauma Outcome Study between 1993 and 1997 were reviewed. We examined mortality, length of hospitalization, major injuries sustained, and impact of safety restraint devices. Significant differences were determined using chi2 test. RESULTS There were 2,298 children involved in MVCs during this period; 189 were ejected. A total of 77% of the ejected passengers were greater than 10 years of age, 16% were 0 to 4 years of age, and 7% were 5 to 9 years of age. Overall, 88% of the ejected occupants were unrestrained. Ejection nearly tripled the overall mortality rate and significantly increased the Injury Severity Score for each age group. Infants and children 0 to 4 years of age had the highest fatality rate despite having a lower Injury Severity Score than all other age groups. Head injuries accounted for the majority of deaths in all age groups. Children older than 10 years of age had a higher incidence of associated chest, abdominal, and pelvic injuries. CONCLUSION Our data show that most children ejected from MVCs were either unrestrained or improperly restrained. Head injuries were the most common cause of death in all age groups. Greater public awareness through educational programs targeting parents and children at risk may reduce this serious problem.


Annals of Epidemiology | 2001

Utilizing Multiple Vital Status Tracing Services Optimizes Mortality Follow-up in Large Cohort Studies

Laura C. Schall; Jeanine M. Buchanich; Gary M. Marsh; Gina M Bittner

PURPOSE To compare the three national-scale death identification services used in our two-stage vital status tracing protocol, Pension Benefit Information Company (PBI), Social Security Administration (SSA), and the Health Care Financing Administration (HCFA), with respect to death identification and confirmation rate, and relevant demographic variables. METHODS Information on 31,223 subjects with unconfirmed vital status in an ongoing occupational cohort mortality study was simultaneously submitted to PBI, SSA, and HCFA to identify subjects deceased as of December 31, 1992. Subjects whose dates of death were between 1979 and 1992 were then sent to the National Death Index (NDI) to obtain death certificate numbers and supplemental states of death. RESULTS PBI identified and confirmed the highest number deaths in this cohort. PBI and SSA identified a higher proportion of deaths for persons who died in earlier years and/or who died at a younger age, for both confirmed and unconfirmed deaths. HCFA identified fewer deaths overall and had a smaller proportion of unconfirmed deaths. These deaths occurred in later years among older subjects and had the highest proportion of females. NDI provided exact matches for 92-96% of deaths identified by each of the three services. CONCLUSIONS PBI was the most comprehensive service, especially for identifying younger subjects and those with an earlier date of death, while HCFA may help to identify deceased female subjects. SSA data can be purchased and used for periodic updates or interactively to identify deaths among subjects with poor identifiers (such as incorrect or missing social security numbers or misspelled names). Because each service makes a valuable contribution to the identification of deceased cohort subjects, all three should be considered for optimal mortality follow-up.


Journal of Trauma-injury Infection and Critical Care | 2002

A new method for estimating probability of survival in pediatric patients using revised TRISS methodology based on age-adjusted weights

Laura C. Schall; Douglas A. Potoka; Henri R. Ford

BACKGROUND TRISS methodology estimates probability of survival (P(s)) based on coefficients derived largely from adult data. We developed a novel pediatric age-specific method to estimate P(s). METHODS The Pennsylvania Trauma Outcome Study database was queried for pediatric patients injured between 1993 and 1996 (n = 9730). P(s) derived from the Pediatric Age-Adjusted TRISS (PAAT) methodology was generated using our Age-Specific Pediatric Trauma Score and Injury Severity Score with corresponding weights. A test data set of 7138 pediatric patients entered in the Pennsylvania Trauma Outcome Study from 1997 to 1999 was used to compute an expected number of survivors for PAAT, TRISS, and ASCOT (A Severity Characteristic of Trauma). Observed and expected survival were compared for blunt injured patients, for head injured patients, and by age category. RESULTS PAAT showed no significant difference between observed and expected survival. TRISS and ASCOT significantly underestimated overall survival: across age groups, for blunt injuries, for head injuries, and for patients whose P(s) was less than 91%. CONCLUSION PAAT offers a more reliable methodology than TRISS and ASCOT for comparing pediatric trauma outcomes.


American Journal of Industrial Medicine | 1999

Mortality among chemical plant workers exposed to acrylonitrile and other substances

Gary M. Marsh; Mary Jean Gula; Ada O. Youk; Laura C. Schall

OBJECTIVES To examine the association between exposure to acrylonitrile (AN) and cancer mortality by performing an independent and extended historical cohort study of workers from a chemical plant in Lima, Ohio included in a recent NCI-NIOSH study. METHODS Subjects were 992 white males who were employed for three or more months between 1960 and 1996. We identified 110 deaths and cause of death for 108. Worker exposures were estimated quantitatively for AN and qualitatively for nitrogen products. Statistical analyses included U.S. and local county-based SMRs and internal relative risk regression of internal cohort rates. RESULTS No statistically significant excess mortality risks were observed among the total cohort for the cancer sites implicated in previous studies: stomach, lung, breast, prostate, brain, and hematopoietic system. We observed a statistically significant bladder cancer excess based on four deaths (SMR=7.01, 95% CI=1.91-17.96) among workers not exposed to AN. Among 518 AN-exposed workers, we observed a not statistically significant excess of lung cancer based on external (SMR=1.32, 95% CI=.60-2.51) and internal (RR=1.98, 95% CI=.60-6.90) comparisons. Although the trends were not statistically significant, exposure-response analyses of internal cohort rates showed monotonically increasing lung cancer rate ratios with increasing AN exposure, with RRs exceeding 2.0 in the highest exposure categories. CONCLUSIONS With the possible exception of lung cancer, this study provides little evidence that exposure to AN at levels experienced by Lima plant workers is associated with an increased risk of death from any cause including the implicated cancer sites.


Surgical Infections | 2000

Transcellular transport is not required for transmucosal bacterial passage across the intestinal membrane ex vivo.

Evan P. Nadler; Leonard L. Go; Donna Beer-Stolz; Simon Watkins; Laura C. Schall; Patricia Boyle; Henri R. Ford

The mechanisms underlying the process of bacterial translocation are poorly defined. Possible routes for transmucosal passage of bacteria include transcellular and paracellular channels. Bacterial engulfment is a prerequisite for transcellular transport. To determine whether transcellular transport is required for transmucosal bacterial passage, we examined the effect of various inhibitors of endocytosis, such as colchicine, cytochalasin B, and sodium fluoride on transmucosal passage of bacteria across an ileal mucosal membrane mounted in the Ussing chamber. Colchicine and sodium fluoride increased the rate of decline of the potential difference across the membranes. However, neither colchicine, cytochalasin B, nor sodium fluoride affected the incidence of transmucosal bacterial passage. Sodium fluoride, which depletes intracellular ATP, significantly decreased the number of bacteria that passed per membrane. Our data suggest that transcellular transport may not be required for spontaneous transmucosal passage of bacteria, and furthermore bacterial passage may be, at least in part, an energy-dependent process.


Journal of Pediatric Surgery | 2001

Intestinal cytokine gene expression in infants with acute necrotizing enterocolitis: interleukin-11 mRNA expression inversely correlates with extent of disease.

Evan P. Nadler; Ala Stanford; Xiao-Ru Zhang; Laura C. Schall; Sean Alber; Simon C. Watkins; Henri R. Ford

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Henri R. Ford

Children's Hospital Los Angeles

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Gary M. Marsh

University of Pittsburgh

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Evan P. Nadler

Children's National Medical Center

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Ada O. Youk

University of Pittsburgh

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Ala Stanford

University of Pittsburgh

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James M. Lynch

University of Pittsburgh

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