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Biomedical subjects

G S Smith

Publications and source records attributed to G S Smith.

At least 55 records · Page 3Linked to original sources
PubMed2000

Sports and physical training injury hospitalizations in the army.

INTRODUCTION: Injuries are the leading health problem in the military services. Sports and physical training activities are an area in which a substantial number of injuries can occur. Although athletic injuries are not often investigated in military populations, the Armed Forces database provides a unique opportunity to investigate sports injuries. METHODS: An Army database of all hospital admissions for active duty Army personnel in the 1989-1994 period was used to study injuries resulting from sports and Army physical training. RESULTS: For the 6-year time period reviewed, there were 13,861 hospital admissions for injuries resulting from sports or Army physical training: 94% (13,020) of these admissions were men and 6% (841) were women. The rates of sports injuries were 38 and 18 per 10,000 person-years for men and women, respectively. Sports injuries accounted for an average of 29,435 lost duty days each year: Men lost an average of 13 days per injury and women lost an average of 11 days per injury. Acute musculoskeletal injuries in the categories of fractures, sprains/strains, and dislocations accounted for 82% of all injuries. The knee was the most often injured body area in both genders, with the anterior cruciate ligament (ACL) identified as the most frequently injured body part overall. The top seven injuries were virtually identical for men and women, with only slight variations in order. Although the rates of all hospitalized sports injuries were higher for men than women, women had a higher proportion of ACL injuries from basketball and softball, ankle fractures from softball and head injuries from basketball. For men, football and basketball contributed to the highest rates of injuries. The highest injury rates for women were from Army physical training and basketball. For both men and women, Army physical training was the leading cause of lumbosacral strains. CONCLUSIONS: Sports and Army physical training injuries account for a significant amount of lost duty time and impact military readiness.

Adolescent↗
PubMed2000

Viewpoint: a comparison of cause-of-injury coding in U.S. military and civilian hospitals.

INTRODUCTION: Complete and accurate coding of injury causes is essential to the understanding of injury etiology and to the development and evaluation of injury-prevention strategies. While civilian hospitals use ICD-9-CM external cause-of-injury codes, military hospitals use codes derived from the NATO Standardization Agreement (STANAG) 2050. DISCUSSION: The STANAG uses two separate variables to code injury cause. The Trauma code uses a single digit with 10 possible values to identify the general class of injury as battle injury, intentionally inflicted nonbattle injury, or unintentional injury. The Injury code is used to identify cause or activity at the time of the injury. For a subset of the Injury codes, the last digit is modified to indicate place of occurrence. This simple system contains fewer than 300 basic codes, including many that are specific to battle- and sports-related injuries not coded well by either the ICD-9-CM or the draft ICD-10-CM. However, while falls, poisonings, and injuries due to machinery and tools are common causes of injury hospitalizations in the military, few STANAG codes correspond to these events. Intentional injuries in general and sexual assaults in particular are also not well represented in the STANAG. Because the STANAG does not map directly to the ICD-9-CM system, quantitative comparisons between military and civilian data are difficult. CONCLUSIONS: The ICD-10-CM, which will be implemented in the United States sometime after 2001, expands considerably on its predecessor, ICD-9-CM, and provides more specificity and detail than the STANAG. With slight modification, it might become a suitable replacement for the STANAG.

Causality↗
PubMed2000

X-ray and neutron surface scattering for studying lipid/polymer assemblies at the air-liquid and solid-liquid interfaces.

Simple mono- and bilayers, built of amphiphilic molecules and prepared at air-liquid or solid-liquid interfaces, can be used as models to study such effects as water penetration, hydrocarbon chain packing, and structural changes due to head group modification. In the paper, we will discuss neutron and X-ray reflectometry and grazing incidence X-ray diffraction techniques used to explore structures of such ultra-thin organic films in different environments. We will illustrate the use of these methods to characterize the morphologies of the following systems: (i) polyethylene glycol-modified distearoylphosphatidylethanolamine monolayers at air-liquid and solid-liquid interfaces; and (ii) assemblies of branched polyethyleneimine polymer and dimyristoylphophatidylcholine lipid at solid-liquid interfaces.

Adsorption↗
PubMed2000

Esophagogastric fistula secondary to teflon pledget: a rare complication following laparoscopic fundoplication.

Laparoscopic fundoplication has become the standard operation for gastroesophageal reflux disease. In our service, a laparoscopic fundoplication is performed as a 2-cm floppy 360 degrees wrap with division of the short gastric vessels and the fundoplication is sutured using a prolene 2/0 mattress suture (Ethicon, USA) and buttressed laterally with two teflon pledgets (PTFE 1.85 mm; low porosity, Bard, USA). We report a patient with post-operative dysphagia due to an esophagogastric fistula caused by erosion of a teflon pledget. This is the first such case in 734 laparoscopic fundoplications performed between January 1991 and December 1998. Reoperation was required, resulting in a prolonged convalescence. A review of current literature has not revealed any similar cases. Causes for this rare complication are postulated.

Esophageal Fistula↗
PubMed2000

Estimating deaths from industrial injury by capture-recapture: a cautionary tale.

BACKGROUND: Capture-recapture methods are increasingly being used to improve surveillance for a number of diseases. However, concerns persist regarding the validity of estimates obtained. METHOD: Capture-recapture methods were applied to estimate the ability of four separate data sources on occupational fatalities to predict the 237 deaths ('gold standard') we determined from a special in-depth study of medical examiner records. RESULTS AND CONCLUSION: Capture-recapture results based upon the four sources vary according to different models. However, both separately and in aggregate of industry type and cause of death, most models seriously underestimate the gold standard, and give a misleading impression of precision of the estimate of hidden individuals. It is commonly believed that reliable estimates from such methods require lists with high coverage and parsimonious models. Here, to obtain an estimate consistent with the gold standard, the list with almost complete coverage must be discarded and a complex model fitted. It is argued that this conclusion is of widespread application.

Accidents, Occupational↗
PubMed2000

Drowning and alcohol in New Zealand: what do the coroner's files tell us?

OBJECTIVE: To provide a systematic review of the details on alcohol involvement available in the coronial files to determine if there is enough evidence to estimate the role of alcohol in drowning. METHOD: We reviewed the coroner's files of persons 10 years or older who drowned in New Zealand between 1992-1994 inclusive. RESULTS: A total of 320 coroner's files were examined. Blood Alcohol Concentrations (BACs) were taken in 115 cases (36%) and positive for 50% of these. When accounting for the incomplete testing by using all the information on alcohol involvement collected, between 30-40% of the cases were estimated to have a positive BAC and between 17-24% to have a BAC 100 mg/dL or higher. CONCLUSION: The quality and completeness of current coronial information on alcohol involvement in drowning is insufficient to arrive at an accurate estimate of the percentage of drownings where alcohol was a factor. IMPLICATIONS: Coroners should test drowning victims 10 years and older for BAC. These data should be systematically recorded and processed with the goal of determining who should be targeted in drowning and alcohol prevention programs.

Adolescent↗
PubMed2000

Socioeconomic status and injury mortality: individual and neighbourhood determinants.

STUDY OBJECTIVE: This study examined both individual and neighbourhood correlates of injury mortality to better understand the contribution of socioeconomic status to cause specific injury mortality. Of particular interest was whether neighbourhood effects remained after adjusting for individual demographic characteristics and socioeconomic status. DESIGN: Census tract data (measuring small area socioeconomic status, racial concentration, residential stability, urbanisation, and family structure) was merged with the National Health Interview Survey (NHIS) and a file that links the respondents to subsequent follow up of vital status and cause of death data. Cox proportional hazards models were specified to determine individual and neighbourhood effects on homicide, suicide, motor vehicle deaths, and other external causes. Variances are adjusted for the clustered sample design of the NHIS. SETTING: United States, 1987-1994, with follow up to the end of 1995. PARTICIPANTS: From a sample of 472 364 persons ages 18-64, there were 1195 injury related deaths over the follow up period. MAIN RESULTS: Individual level effects were generally robust to the inclusion of neighbourhood level variables in the models. Neighbourhood characteristics had independent effects on the outcome even after adjustment for individual variability. For example, there was approximately a twofold increased risk of homicide associated with living in a neighborhood characterised by low socioeconomic status, after adjusting for individual demographic and socioeconomic characteristics. CONCLUSIONS: Social inequalities in injury mortality exist for both persons and places. Policies or interventions aimed at preventing or controlling injuries should take into account not only the socioeconomic characteristics of people but also of the places in which they live.

Accidents, Traffic↗
PubMed2000

Performance of transgenic corn hybrids in Missouri for insect control and yield.

The efficacy of Bacillus thuringiensis-transformed corn (Zea mays L.) hybrids compared with comparable nontransformed corn hybrids for controlling first- and second-generation European corn borer, Ostrinia nubilalis (Hübner), and second-generation southwestern corn borer, Diatraea grandiosella Dyar, was determined. Yield comparisons were obtained from the same plots of corn hybrids. Both generations of European and the second-generation of southwestern corn borer were effectively controlled, but the Bt hybrids varied in degree of control. Hybrids from Ciba Seeds, DEKALB, and Mycogen had more European corn borer tunneling than those from Novartis or Cargill, and this was generally ascribed to different transgenic events. The Bt-transformed hybrids had virtually no leaf-feeding damage and less tunneling than the non-Bt corn hybrids. Some Bt corn hybrids had no tunneling, whereas other Bt hybrids had a small amount of tunneling. All of the non-Bt hybrids had significant leaf-feeding damage and stalk tunneling from both insects. Only three live European corn borer larvae (stunted) were found in the Bt corn hybrids while splitting stalks to assess tunnel length. When insect damage was significant, and in some evaluations where damage was not significant, differences in yields among hybrids were observed. No significant insect population differences were observed for five genera of beneficial insects for Bt versus non-Bt corn hybrids. Corn hybrids that have been transformed with the Bt gene provide an effective means of control for corn borers and efforts to reduce the likelihood of development of borer resistance are warranted.

Animals↗
PubMed2000

Socioeconomic status and the occurrence of fatal and nonfatal injury in the United States.

OBJECTIVES: This study examined the contribution of socioeconomic status (SES) to the risk of injury mortality and morbidity among working-age adults. METHODS: The sample consisted of respondents to the National Health Interview Survey (1987-1994), and separate analyses were conducted for injury deaths to respondents by linking to the National Death Index. Proportional hazards regression models were used to analyze mortality. Logistic regression models were used to analyze morbidity. RESULTS: The effects of SES varied substantially by cause of injury mortality and indicator of SES. In the multivariate models, blue-collar workers were at significantly increased odds of nonfatal injury. Education was unrelated to total injury morbidity, although associations were observed after stratification of the outcome by severity and place of occurrence. Black persons were at increased risk for homicide, and Black and Hispanic persons were at decreased risk for suicide and nonfatal injuries, after adjustment for SES. CONCLUSIONS: SES is an important determinant of injury, although the effect depends on the indicator of SES and the cause and severity of injury.

Accidents, Traffic↗
PubMed2000

Heavy drinking, alcohol dependence, and injuries at work among young workers in the United States labor force.

BACKGROUND: To determine whether heavily drinking and alcohol-dependent workers are at higher risk of occupational injury, we analyzed the nationally representative cohort of people enrolled in the National Longitudinal Survey of Youth since 1979. METHODS: This analysis was restricted to the 8569 respondents in the 1989 annual interview (age 24-32) who were employed during the 6 months before the interview. We studied occupational injuries (excluding sprains or strains) reported within 6 months of the interview in 1989 (cross-sectional analysis) and 1990 (prospective analysis). RESULTS: Among current drinkers, significant two-fold increases in the odds of injury for one or more episodes of heavy drinking were reduced to an odds ratio (OR) of 1.2 (95% confidence interval [CI] = 0.7, 2.1) in the cross-sectional analysis and an OR of 1.6 (CI 1.0, 2.8) in the prospective analysis after adjustment for confounding. No dose-response relationship with the frequency of heavy drinking was found. Alcohol-dependent respondents were not at higher risk of injury in the cross-sectional (OR = 1.1, CI 0.7, 1.8) or prospective (OR = 1.3,CI 0.8, 2.2) analyses after adjustment for confounding. CONCLUSIONS: For young U.S. workers, common occupational injuries (excluding sprains and strains) may not be strongly associated with alcohol dependence. Confounding by other risk factors may explain much of the association between being a heavy drinker and occupational injuries in this population.

Accidents, Occupational↗
PubMed1999

Nonsteroidal anti-inflammatory drugs attenuate epidermal growth factor-induced proliferation independent of prostaglandin synthesis inhibition.

BACKGROUND: The mechanism(s) whereby nonsteroidal anti-inflammatory drugs (NSAIDs) attenuate colorectal tumor growth remains poorly understood. This study determined if NSAIDs decreased epidermal growth factor (EGF)-induced proliferation in human colonic tumor (Caco-2) cells and whether this process involved the inhibition of prostaglandin (PG) synthesis. METHODS: Caco-2 cells were serum-starved (48 h) and subsequently treated (48 h) with either serum-free media or EGF (10 ng/ml) +/- physiologic and noninjurious (as determined by LDH release) concentrations of aspirin, indomethacin, and ibuprofen. PG synthesis was measured by EIA. Proliferation was quantitated with two assays: cellular protein and nucleic acid content. RESULTS: NSAID treatment did not inhibit growth in cells treated with only serum-free media. Cells exposed to EGF demonstrated a significant increase in PGE2, protein, and nucleic acid. Levels of other eicosanoids (PGI2, TXA2) were minimal both before and after EGF treatment. Despite varying degrees of PGE2 inhibition, each NSAID group equally attenuated EGF-induced protein and nucleic acid synthesis. The correlation between PGE2 levels and protein (R2 = 0.56) or nucleic acid (R2 = 0.54) was poor. Finally, the addition of a physiologically appropriate concentration of exogenous PGE2 failed to reverse NSAID-induced growth inhibition. CONCLUSION: These data suggest that NSAIDs, independent of PG synthesis inhibition, attenuate EGF-induced proliferation in Caco-2 cells. This may provide one explanation for how NSAIDs limit colonic neoplasia.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Injuries related to forklifts and other powered industrial vehicles in automobile manufacturing.

BACKGROUND: The Bureau of Labor Statistics (BLS), Census of Fatal Occupational Injuries, estimates that approximately 100 workers are fatally injured each year in forklift and other powered industrial vehicle (PIV) incidents, and an estimated 34,000 work-related injuries involving forklifts are treated in U.S. emergency rooms each year. METHODS: This paper presents a descriptive analysis of 916 incidents involving forklifts and other PIVs that occurred in 54 plants operated by a major U.S. automobile manufacturer over a 3-year period. The injury data were obtained from a company-wide occupational injury and illness surveillance system which was implemented in 1989. RESULTS: The 916 PIV-related incidents resulted in 3 fatalities and 913 nonfatal injuries. The most common incident involved pedestrians (35%) who were struck by a PIV, or the load being carried by a PIV, or a rack or bin that had been struck by a PIV. Of the 913 nonfatal injuries, 41% resulted in an employee missing work and incurred a total of 22,730 lost workdays, an average of 61 days per lost workday incident. CONCLUSIONS: Recommendations are presented to reduce the risk of injury, for example by separating PIV and pedestrian traffic, restricting the use of forklifts in an area where a large number of pedestrians travel and improving the training of all personnel who drive PIVs. Am. J. Ind. Med. 36:513-521, 1999. Published 1999 Wiley-Liss, Inc.

Absenteeism↗
PubMed1999

A case-control study of forklift and other powered industrial vehicle incidents.

BACKGROUND: This study examined risk factors associated with forklift and other powered industrial vehicle (PIV) collision injuries with an emphasis on the design of factory traffic systems, the loading and safety features of PIVs, and the characteristics of the drivers. METHODS: A case-control study examined risk factors for circumstances of injury-producing PIV incidents at eight automotive manufacturing plants between July 1992 and March 1995. A computerized safety and health surveillance system identified 171 incidents where a PIV (forklift 70%, personnel carriers 15%, other 15%) was involved in a collision incident. Site visits were conducted to collect data regarding the factory environment at the collision site, the PIVs involved in the incidents, and driver characteristics. These data were compared with information collected from a random sample of comparison worksites, PIVs, and PIV drivers who had not been involved in a PIV-related incident in the prior 3 years. RESULTS: In half of the cases (86 of 171), an employee (pedestrian) was struck by a PIV or an object being carried by the PIV. The presence of an obstruction that restricted the aisle width increased the odds of a collision incident 1.89 times (95% CI=1.22, 2.86). The presence of overhead mirrors at intersections and blind corners with limited visibility reduced the odds of a PIV collision incident by a third (OR=0.33, 95% CI=0.16, 0.68). When carrying a load, the odds of a PIV being involved in a collision was 1.58 (95% CI=1.03, 2.41) times greater than an unloaded one. CONCLUSIONS: Changes in the factory environment, vehicle safety features, and driver and pedestrian training are suggested to reduce the risk of PIV incidents. Am. J. Ind. Med. 36:522-531, 1999. Published 1999 Wiley-Liss, Inc.

Accidents, Occupational↗
PubMed1999

Polymer-cushioned bilayers. I. A structural study of various preparation methods using neutron reflectometry.

This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine (DMPC) bilayer onto a polyethylenimine (PEI)-coated quartz substrate were examined: 1) vesicle adsorption onto a previously dried polymer layer; 2) vesicle adsorption onto a bare substrate, followed by polymer adsorption; and 3, 4) Langmuir-Blodgett vertical deposition of a lipid monolayer spread over a polymer-containing subphase to form a polymer-supported lipid monolayer, followed by formation of the outer lipid monolayer by either 3) horizontal deposition of the lipid monolayer or 4) vesicle adsorption. We show that the initial conditions of the polymer layer are a critical factor for the successful formation of our desired structure, i.e., a continuous bilayer atop a hydrated PEI layer. Our desired structure was found for all methods investigated except the horizontal deposition. The interaction forces between these polymer-supported bilayers are investigated in a separate paper (Wong, J. Y., C. K. Park, M. Seitz, and J. Israelachvili. 1999. Biophys. J. 77:1458-1468), which indicate that the presence of the polymer cushion significantly alters the interaction potential. These polymer-supported bilayers could serve as model systems for the study of transmembrane proteins under conditions more closely mimicking real cellular membrane environments.

Adsorption↗
PubMed1999

Trauma-related hospitalizations among urban adolescents in New Zealand: priorities for prevention.

PURPOSE: To: (a) determine the magnitude, characteristics, and in-patient costs of injury among hospitalized urban adolescents in New Zealand (NZ); (b) identify regional priorities for injury prevention and investigative research; and (c) compare the study findings with published data from other industrialized countries. METHODS: The 1989-1993 files of the NZ Hospital Discharge Database were accessed to identify and analyze trauma-related admissions of adolescents residing in NZ's largest metropolitan region. RESULTS: The estimated 9569 hospitalizations for injury accounted for one-fourth of all adolescent admissions in the region, a mean annual hospitalization rate of 1292/100,000 population and a minimum annual cost of NZ $5.8 million for in-patient care. Males and indigenous Maori youth had comparatively higher rates of hospitalizations for most major causes of injury. Falls, pedal cyclist injury, cuts, and piercing injuries were leading causes of hospitalization for trauma in early adolescence. Admission rates for motorcylist and other motor vehicle occupant trauma and self-inflicted injury increased substantially among older adolescents. Sport and recreational activities comprised at least one-sixth of injury admissions. CONCLUSIONS: The overall rates of injury resulting in hospitalization among Auckland adolescents were comparable to those reported from Australia and France, but higher than those from the United States, Canada, and Israel. By identifying priority issues and high-risk groups, this study provides a foundation for regional injury control initiatives. It also demonstrates the utility and limitations of E-coded hospital discharge registries in defining the burden of serious nonfatal trauma.

Adolescent↗
PubMed1999

Prostaglandins protect human intestinal cells against ethanol injury by stabilizing microtubules: role of protein kinase C and enhanced calcium efflux.

Prostaglandins (PG) protect gastrointestinal cells against damage induced by ethanol (EtOH) and other noxious agents, a process termed cytoprotection. The present study investigated the relationships between microtubule (MT) stability, protein kinase C (PKC) activation, and calcium efflux as a possible mechanism of PG's protective action using a human colonic cell line (Caco-2) exposed to known damaging concentrations of EtOH (7.5% and 10%). Preincubation of Caco-2 cells with 16,16-dimethyl-PGE2 (PG, 2.6 microM) significantly increased PKC activity in these cells. Pretreatment of Caco-2 cells with 50 microM OAG (a synthetic diacylglycerol and PKC activator) or 30 nM TPA (a direct PKC activator) prior to exposure to 7.5% or 10% EtOH for 5 min significantly reduced cell injury, as determined by trypan blue exclusion, and increased MT stability, as confirmed by confocal microscopy. Pretreatment of Caco-2 cells with 4 alpha-PDD (an inactive phorbol ester, 20 nM) failed to prevent cell injury and disruption of the MT cytoskeleton. Preincubation with staurosporine (a PKC inhibitor, 3 nM) abolished the protective effects of PG in cells exposed to 7.5% and 10% EtOH. Incubation of Caco-2 cells with A23187 (a Ca2+ ionophore), similar to 10% EtOH, caused a significant reduction in cell viability and MT stability. Preincubation with A23187 in combination with PG or OAG prior to subsequent exposure to EtOH significantly abolished the protective effects of PG or OAG pretreatment. Finally, pretreatment with OAG, TPA, or PG resulted in significant increases in calcium-45 efflux, which correlated with increased stability of the MT cytoskeleton. These data suggest that PG possesses direct protective effects against EtOH injury in Caco-2 cells and may act by stabilizing MT through the PKC signal transduction pathway and/or stimulation of calcium efflux from the cells.

Caco-2 Cells↗
PubMed1999

Laparoscopic v laparoscopy-assisted donor nephrectomy in the porcine model.

PURPOSE: Laparoscopic donor nephrectomy is an established procedure in the porcine model. We sought to compare intraoperative variables between live laparoscopic (LAP) and laparoscopy-assisted (LAP-A) donor nephrectomy. MATERIALS AND METHODS: Eight domestic pigs underwent either traditional laparoscopic donor nephrectomy (N = 4) or laparoscopy-assisted donor nephrectomy (N = 4) using the Pneumosleeve followed by conventional heterotopic autotransplantation. RESULTS: No significant differences were noted between the groups with regard to vessel length, ureteral length, or postoperative urine output. The operating room time was 108+/-12 minutes in the LAP group v 75.8+/-10.3 minutes in the LAP-A group (P = 0.0065). Although the difference was not statistically significant, warm ischemic time, tended to be lower in the LAP-A than the LAP group: 70+/-3.0 seconds v 135+/-57 seconds, respectively (P = 0.059). Graft survival was identical in the two groups. CONCLUSION: Laparoscopy-assisted (via Pneumosleeve) live donor nephrectomy shortens the operative time without affecting graft survival in the domestic swine model.

Animals↗