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1.
Epidemiology ; 35(4): 489-498, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38567930

ABSTRACT

BACKGROUND: Prepregnancy body mass index (BMI) and gestational weight gain (GWG) are determinants of maternal and child health. However, many studies of these factors rely on error-prone self-reported measures. METHODS: Using data from Life-course Experiences And Pregnancy (LEAP), a US-based cohort, we assessed the validity of prepregnancy BMI and GWG recalled on average 8 years postpartum against medical record data treated as alloyed gold standard ("true") values. We calculated probabilities of being classified into a self-reported prepregnancy BMI or GWG category conditional on one's true category (analogous to sensitivities and specificities) and probabilities of truly being in each prepregnancy BMI or GWG category conditional on one's self-reported category (analogous to positive and negative predictive values). RESULTS: There was a tendency toward under-reporting prepregnancy BMI. Self-report misclassified 32% (95% confidence interval [CI] = 19%, 48%) of those in LEAP with truly overweight and 13% (5%, 27%) with obesity into a lower BMI category. Self-report correctly predicted the truth for 72% (55%, 84%) with self-reported overweight to 100% (90%, 100%) with self-reported obesity. For GWG, both under- and over-reporting were common; self-report misclassified 32% (15%, 55%) with truly low GWG as having moderate GWG and 50% (28%, 72%) with truly high GWG as moderate or low GWG. Self-report correctly predicted the truth for 45% (25%, 67%) with self-reported high GWG to 85% (76%, 91%) with self-reported moderate GWG. Misclassification of BMI and GWG varied across maternal characteristics. CONCLUSION: Findings can be used in quantitative bias analyses to estimate bias-adjusted associations with prepregnancy BMI and GWG.


Subject(s)
Body Mass Index , Gestational Weight Gain , Mental Recall , Self Report , Humans , Female , Pregnancy , Adult , Young Adult , Cohort Studies , United States
2.
PLoS One ; 19(3): e0295825, 2024.
Article in English | MEDLINE | ID: mdl-38507321

ABSTRACT

BACKGROUND: Life course factors may be associated with pre-pregnancy body mass index and gestational weight gain; however, collecting information on pre-pregnancy exposures and pregnancy health in the same cohort is challenging. OBJECTIVES: The Life-course Experiences And Pregnancy (LEAP) study aims to identify adolescent and young adult risk factors for pre-pregnancy weight and gestational weight gain (GWG). We built upon an existing cohort study to overcome challenges inherent to studying life course determinants of pregnancy health. POPULATION: Participants in an ongoing prospective cohort study of weight-related health who identified as women. DESIGN: Retrospective cohort study. METHODS: In 2019-2020, 1,252 women participating since adolescence in a cohort study of weight-related health were invited to complete an online reproductive history survey. Participants who reported a live birth were invited to release their prenatal, delivery, and postpartum medical records for validation of survey reports. Descriptive analyses were conducted to assess the characteristics of the overall cohort and the medical record validation subsample, and to describe adolescent and young adult characteristics of those with high (>80th percentile), moderate (20th-80th percentile), and low (<20th percentile) GWG z-score for gestational age and pre-pregnancy weight status. PRELIMINARY RESULTS: Nine hundred seventy-seven women (78%) completed the LEAP survey and 656 reported a live birth. Of these, 379 (58%) agreed to release medical records, and 250 records were abstracted (66% of the 379). Of the 977 survey respondents 769 (79%) reported attempting a pregnancy, and 656 (67%) reported at least one live birth. The validation subsample was similar to the overall cohort. Women with a high GWG had a higher adolescent BMI percentile and prevalence of unhealthy weight control behaviors than those with moderate or low GWG. CONCLUSIONS: LEAP offers a valuable resource for identifying life course factors that may influence the health of pregnant people and their offspring.


Subject(s)
Gestational Weight Gain , Young Adult , Adolescent , Pregnancy , Female , Humans , Retrospective Studies , Cohort Studies , Prospective Studies , Life Change Events , Reproductive Health , Live Birth , Body Mass Index , Pregnancy Outcome/epidemiology
3.
Am J Epidemiol ; 192(3): 430-437, 2023 02 24.
Article in English | MEDLINE | ID: mdl-36193858

ABSTRACT

Interest in using internet search data, such as that from the Google Health Trends Application Programming Interface (GHT-API), to measure epidemiologically relevant exposures or health outcomes is growing due to their accessibility and timeliness. Researchers enter search term(s), geography, and time period, and the GHT-API returns a scaled probability of that search term, given all searches within the specified geographic-time period. In this study, we detailed a method for using these data to measure a construct of interest in 5 iterative steps: first, identify phrases the target population may use to search for the construct of interest; second, refine candidate search phrases with incognito Google searches to improve sensitivity and specificity; third, craft the GHT-API search term(s) by combining the refined phrases; fourth, test search volume and choose geographic and temporal scales; and fifth, retrieve and average multiple samples to stabilize estimates and address missingness. An optional sixth step involves accounting for changes in total search volume by normalizing. We present a case study examining weekly state-level child abuse searches in the United States during the coronavirus disease 2019 pandemic (January 2018 to August 2020) as an application of this method and describe limitations.


Subject(s)
COVID-19 , Child , Humans , United States , Search Engine , Pandemics , Epidemiologic Studies , Internet
4.
Prev Med ; 163: 107215, 2022 10.
Article in English | MEDLINE | ID: mdl-35998763

ABSTRACT

The COVID-19 pandemic has led to unemployment, school closures, movement restrictions, and social isolation, all of which are child abuse risk factors. Our objective was to estimate the effect of COVID-19 shelter in place (SIP) policies on child abuse as captured by Google searches. We applied a differences-in-differences design to estimate the effect of SIP on child abuse search volume. We linked state-level SIP policies to outcome data from the Google Health Trends Application Programming Interface. The outcome was searches for child abuse-related phrases as a scaled proportion of total searches for each state-week between December 31, 2017 and June 14, 2020. Between 914 and 1512 phrases were included for each abuse subdomain (physical, sexual, and emotional). Eight states and DC were excluded because of suppressed outcome data. Of the remaining states, 38 introduced a SIP policy between March 19, 2020 and April 7, 2020 and 4 states did not. The introduction of SIP generally led to no change, except for a slight reduction in child abuse search volume in weeks 8-10 post-SIP introduction, net of changes experienced by states that did not introduce SIP at the same time. We did not find strong evidence for an effect of SIP on child abuse searches. However, an increase in total search volume during the pandemic that may be differential between states with and without SIP policies could have biased these findings. Future work should examine the effect of SIP at the individual and population level using other data sources.


Subject(s)
COVID-19 , Child Abuse , COVID-19/epidemiology , Child , Child Abuse/prevention & control , Emergency Shelter , Humans , Pandemics , Policy , Search Engine , United States/epidemiology
5.
J Med Internet Res ; 24(6): e36445, 2022 06 13.
Article in English | MEDLINE | ID: mdl-35700024

ABSTRACT

BACKGROUND: The COVID-19 pandemic has created environments with increased risk factors for household violence, such as unemployment and financial uncertainty. At the same time, it led to the introduction of policies to mitigate financial uncertainty. Further, it hindered traditional measurements of household violence. OBJECTIVE: Using an infoveillance approach, our goal was to determine if there were excess Google searches related to exposure to child abuse, intimate partner violence (IPV), and child-witnessed IPV during the COVID-19 pandemic and if any excesses are temporally related to shelter-in-place and economic policies. METHODS: Data on relative search volume for each violence measure was extracted using the Google Health Trends application programming interface for each week from 2017 to 2020 for the United States. Using linear regression with restricted cubic splines, we analyzed data from 2017 to 2019 to characterize the seasonal variation shared across prepandemic years. Parameters from prepandemic years were used to predict the expected number of Google searches and 95% prediction intervals (PI) for each week in 2020. Weeks with searches above the upper bound of the PI are in excess of the model's prediction. RESULTS: Relative search volume for exposure to child abuse was greater than expected in 2020, with 19% (10/52) of the weeks falling above the upper bound of the PI. These excesses in searches began a month after the Pandemic Unemployment Compensation program ended. Relative search volume was also heightened in 2020 for child-witnessed IPV, with 33% (17/52) of the weeks falling above the upper bound of the PI. This increase occurred after the introduction of shelter-in-place policies. CONCLUSIONS: Social and financial disruptions, which are common consequences of major disasters such as the COVID-19 pandemic, may increase risks for child abuse and child-witnessed IPV.


Subject(s)
COVID-19 , Child Abuse , Intimate Partner Violence , COVID-19/epidemiology , Child , Humans , Infodemiology , Pandemics , Search Engine , United States
7.
Am J Epidemiol ; 190(10): 2107-2115, 2021 10 01.
Article in English | MEDLINE | ID: mdl-33884408

ABSTRACT

California's Mental Health Services Act (MHSA) substantially expanded funding of county mental health services through a state tax, and led to broad prevention efforts and intensive services for individuals experiencing serious mental disorders. We estimated the associations between MHSA and mortality due to suicide, homicide, and acute effects of alcohol. Using annual cause-specific mortality data for each US state and the District of Columbia from 1976-2015, we used a generalization of the quasi-experimental synthetic control method to predict California's mortality rate for each outcome in the absence of MHSA using a weighted combination of comparison states. We calculated the association between MHSA and each outcome as the absolute difference and percentage difference between California's observed and predicted average annual rates over the postintervention years (2007-2015). MHSA was associated with modest decreases in average annual rates of homicide (-0.81/100,000 persons, corresponding to a 13% reduction) and mortality from acute alcohol effects (-0.35/100,000 persons, corresponding to a 12% reduction). Placebo test inference suggested that the associations were unlikely to be due to chance. MHSA was not associated with suicide. Protective associations with mortality due to homicide and acute alcohol effects provide evidence for modest health benefits of MHSA at the population level.


Subject(s)
Alcohol Drinking/mortality , Homicide/statistics & numerical data , Mental Disorders/mortality , Mental Health Services/statistics & numerical data , Population Health/statistics & numerical data , Suicide/statistics & numerical data , Alcohol Drinking/prevention & control , California/epidemiology , Cause of Death , Health Plan Implementation , Homicide/prevention & control , Humans , Mental Disorders/prevention & control , Mental Health Services/legislation & jurisprudence , United States/epidemiology , Suicide Prevention
8.
Paediatr Perinat Epidemiol ; 35(4): 469-478, 2021 07.
Article in English | MEDLINE | ID: mdl-33689194

ABSTRACT

BACKGROUND: Exposure to fatal police violence may play a role in population-level inequities in risk for preterm delivery. OBJECTIVE: To evaluate whether exposure to fatal police violence during pregnancy affects the hazard of preterm delivery and whether associations differ by race/ethnicity and fetal sex. METHODS: We leveraged temporal variation in incidents of fatal police violence within census tracts to assess whether occurrence of fatal police violence in a person's tract during pregnancy was associated with increased hazard of extremely (20-27 weeks), early (28-31 weeks), moderate (32-33 weeks), and late (32-36 weeks) preterm delivery in California from 2007 to 2015. We used both death records and the Fatal Encounters database to identify incidents of fatal police violence. We estimated hazard ratios (HR) using time-varying Cox proportional hazard models stratified by census tract, controlling for age, race/ethnicity, educational attainment, health insurance type, parity, and the year and season of conception. We further stratified by race/ethnicity and infant sex to evaluate whether there were differential effects by these characteristics. RESULTS: Exposure to an incident of fatal police violence was associated with a small increase in the hazard of late preterm birth using both the death records (N = 376,029; hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.00, 1.10) and the Fatal Encounters data (N = 938,814; HR 1.03, 95% CI 1.00, 1.06). We also observed an association for moderate preterm birth in the Fatal Encounters data (HR 1.06, 95% CI 0.98, 1.15). We did not observe associations for early or extremely preterm birth in either data source. Larger relative hazards of moderate (HR 1.25, 95% CI 0.93, 1.68) and late preterm delivery (HR 1.18, 95% CI 1.05, 1.33) were observed among Black birth parents with female births in the Fatal Encounters data. CONCLUSIONS: Preventing police use of lethal force may reduce preterm delivery in communities where such violence occurs.


Subject(s)
Premature Birth , California/epidemiology , Female , Gestational Age , Humans , Infant, Newborn , Parity , Police , Pregnancy , Premature Birth/epidemiology , Violence
9.
PLoS One ; 16(3): e0248130, 2021.
Article in English | MEDLINE | ID: mdl-33735181

ABSTRACT

BACKGROUND: Firearm dealer density is correlated with firearm interpersonal violence, but no quasi-experimental studies have assessed whether changes in dealer density lead to changes in firearm self-harm injuries and deaths. We assessed whether openings of firearm dealers are associated with short-term changes in local firearm self-harm injury rates. METHODS: We identified 718 openings of firearm dealers in California using licensing data, 2014-2016. We defined exposure regions based on aggregations of zip codes defined by proximity to firearm dealer openings and matched each opening to four control regions on time and determinants of firearm injury. We applied a differences-in-differences approach to compare rates of firearm self-harm, in the month before and after each opening, in places with and without openings. RESULTS: Firearm dealer openings were not associated with acute, local changes in firearm self-harm relative to places without openings (ratio of rate ratio: 0.90 [95% CI:0.68-1.19]). Results were robust to numerous sensitivity and secondary analyses. CONCLUSION: We found no associations of firearm dealer openings with acute, localized firearm self-harm deaths and injuries. Our focus on acute, local effects; broad availability of dealers and firearms; durability of firearms; or strong confounding-control may explain these null findings.


Subject(s)
Firearms , Self-Injurious Behavior , Suicide , Wounds, Gunshot , Adult , Female , Humans , Male , Middle Aged
10.
Am J Public Health ; 109(11): 1605-1611, 2019 11.
Article in English | MEDLINE | ID: mdl-31536413

ABSTRACT

Objectives. To evaluate whether the Operation Peacemaker Fellowship, an innovative firearm violence-prevention program implemented in Richmond, California, was associated with reductions in firearm and nonfirearm violence.Methods. We compiled city- and jurisdiction-level quarterly counts of violent firearm and nonfirearm incidents from statewide records of deaths from and hospital visits for homicide and assault (2005-2016) and from nationwide crime records of homicides and aggravated assaults (1996-2015). We applied a generalization of the synthetic control method to compare observed patterns in firearm and nonfirearm violence after implementation of the program (June 2010) to those predicted in the absence of the program, using a weighted combination of comparison cities or jurisdictions.Results. The program was associated with reductions in firearm violence (annually, 55% fewer deaths and hospital visits, 43% fewer crimes) but also unexpected increases in nonfirearm violence (annually, 16% more deaths and hospital visits, 3% more crimes). These associations were unlikely to be attributable to chance for all outcomes except nonfirearm homicides and assaults in crime data.Conclusions. The Operation Peacemaker Fellowship may have been effective in reducing firearm violence in Richmond but may have increased nonfirearm violence.


Subject(s)
Firearms/statistics & numerical data , Health Promotion/organization & administration , Violence/prevention & control , California , Cognitive Behavioral Therapy/organization & administration , Homicide/prevention & control , Homicide/statistics & numerical data , Humans , Mentors , Population Surveillance , Program Evaluation , Social Work/organization & administration , Substance-Related Disorders/therapy
11.
Epidemiology ; 30(5): 713-722, 2019 09.
Article in English | MEDLINE | ID: mdl-31180933

ABSTRACT

BACKGROUND: Community violence is an understudied aspect of social context that may affect risk of preterm birth and small-for-gestational age (SGA). METHODS: We matched California mothers with live singleton births who were exposed to a homicide in their Census tract of residence in 2007-2011 to unexposed mothers within the same tract. We estimated risk differences with a weighted linear probability model, with weights corresponding to the matched data structure. We estimated the average treatment effect on the treated of homicide exposure on the risk of preterm birth and SGA during the preconception period and first and second trimester. RESULTS: We found a small increase in risk of SGA associated with homicide exposure in the first trimester (0.14% [95% confidence interval (CI) = -0.01%, 0.30%]), but not for exposure during the preconception period (-0.01% [95% CI = -0.17%, 0.15%]) or the second trimester (-0.06% [95% CI = -0.23%, 0.11%]). Risk of preterm birth was not affected by homicide exposure. When women were exposed to homicides during all three exposure windows, there was a larger increase in risk of SGA (1.09% [95% CI = 0.15%, 2.03%]) but not preterm birth (0.14% [95% CI = -0.74%, 1.01%]). Exposure to three or more homicides was also associated with greater risk of SGA (0.78% [95% CI = 0.15%, 1.40%]). Negative controls indicated that residual confounding by temporal patterning was unlikely. CONCLUSIONS: Homicide exposure during early pregnancy is associated with a small increased risk of SGA.


Subject(s)
Fetal Growth Retardation/etiology , Homicide/psychology , Infant, Small for Gestational Age , Maternal Exposure/adverse effects , Premature Birth/etiology , Stress, Psychological/etiology , Adult , California , Case-Control Studies , Female , Fetal Growth Retardation/psychology , Humans , Infant, Newborn , Male , Pregnancy , Pregnancy Outcome , Premature Birth/psychology , Regression Analysis , Risk Factors
13.
Prev Med ; 121: 136-140, 2019 04.
Article in English | MEDLINE | ID: mdl-30759367

ABSTRACT

Police use of force is an important public health issue in the US. Recent high-profile incidents suggest a potential link between mental disorders and police use of force, however little research has examined their co-occurrence in the general population. We aimed to assess the overall association between specific mental and substance use disorders (MSUDs) and nonfatal legal intervention injury. We identified nonfatal legal intervention injury cases (n = 90,099) and MSUD diagnoses from all hospital and emergency department (ED) records in California between 2005 and 2014. Age-, sex-, and race-standardized MSUD prevalence estimates among legal intervention injury cases, stratified by inpatient status, were compared to general US population-based estimates from the National Comorbidity Survey Replication. Compared to the general US population, nonaffective psychoses, mood disorders, alcohol use disorders, and drug use disorders were substantially overrepresented among inpatient legal intervention injuries (prevalence difference [PD]: 19.2%, (95% confidence interval [CI]: 18.0, 20.4); PD: 15.3%, (95% CI: 13.9, 16.7); PD: 21.1%, (95% CI: 19.8, 22.4); PD: 29.7%, (95% CI: 28.4, 31.0), respectively). Associations for all except mood disorders were similar but attenuated among ED injury cases. In contrast, anxiety disorders were underrepresented in both inpatient and ED injury cases. Results for mood disorders and suicidal ideation were mixed. In summary, MSUDs characterized by more overt behavioral symptoms were substantially overrepresented among legal intervention injury cases. Findings support the potential importance of interventions to improve treatment and law enforcement recognition of such disorders. Additional research should disentangle the complex relationship between MSUDs and legal intervention injury.


Subject(s)
Criminals/psychology , Mental Disorders/epidemiology , Police/psychology , Substance-Related Disorders/epidemiology , Wounds and Injuries/epidemiology , Wounds and Injuries/psychology , Adolescent , Adult , Aged , California/epidemiology , Criminals/statistics & numerical data , Diagnosis, Dual (Psychiatry) , Emergency Service, Hospital , Female , Humans , Male , Mental Disorders/psychology , Middle Aged , Substance-Related Disorders/psychology , Violence/statistics & numerical data , Young Adult
16.
Epidemiology ; 29(5): 697-706, 2018 09.
Article in English | MEDLINE | ID: mdl-29889134

ABSTRACT

BACKGROUND: Self-harm is a leading cause of morbidity and mortality. Exposure to community violence is an important and potentially modifiable feature of the social environment that may affect self-harm, but studies to date are limited in the samples and outcomes examined. METHODS: We conducted a population-based, nested case-control study. Cases were all deaths and hospital visits due to self-harm in California, 2006-2013. We frequency-matched California resident population-based controls from the American Community Survey to cases on age, gender, race/ethnicity, and year of survey/injury. We assessed past-year community violence using deaths and hospital visits due to interpersonal violence in the community of residence. We estimated risk difference parameters that were defined to avoid extrapolation and to capture associations between changes in the distribution of community violence and the population-level risk of self-harm. RESULTS: After adjustment for confounders, setting past-year community violence to the lowest monthly levels observed within each community over the study period was associated with a 30.1 (95% confidence interval = 29.6, 30.5) per 100,000 persons per year lower risk of nonfatal self-harm but no difference in the risk of fatal self-harm. Associations for a parameter corresponding to a hypothetical violence prevention intervention targeting high-violence communities indicated a 5% decrease in nonfatal self-harm at the population level. In sensitivity analyses, results were robust. CONCLUSIONS: This study strengthens evidence on the relationship between community violence and self-harm. Future research should investigate reasons for differential associations by age and gender and whether community violence prevention programs have meaningful impacts on self-harm.


Subject(s)
Exposure to Violence/statistics & numerical data , Suicide, Attempted/statistics & numerical data , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , California/epidemiology , Case-Control Studies , Exposure to Violence/psychology , Female , Humans , Male , Middle Aged , Risk Factors , Sex Factors , Suicide/psychology , Suicide/statistics & numerical data , Suicide, Attempted/psychology , Young Adult
17.
Epidemiology ; 29(5): 695-696, 2018 09.
Article in English | MEDLINE | ID: mdl-29889686
18.
Epidemiology ; 29(5): 684-691, 2018 09.
Article in English | MEDLINE | ID: mdl-29889688

ABSTRACT

BACKGROUND: Community violence may affect a broad range of health outcomes through physiologic stress responses and changes in health behaviors among residents. However, existing research on the health impacts of community violence suffers from problems with bias. METHODS: We examined the relations of acute changes in community violence with hospital visits and deaths due to stress-responsive diseases (mental, respiratory, and cardiac conditions) in statewide data from California 2005-2013. The community violence exposure was measured as both binary spikes and continuous acute changes. We applied a combined fixed-effects and time-series design that separates the effects of violence from those of community- and individual-level confounders more effectively than past research. Temporal patterning was removed from community violence rates and disease rates in each place using a Kalman smoother, resulting in residual rates. We used linear regression with place fixed-effects to examine within-place associations of acute changes in community violence with residual rates of each outcome, controlling for local time-varying covariates. RESULTS: We found acute increases in hospital visits and deaths due to anxiety disorders (0.31 per 100,000; 95% confidence interval [CI] = 0.02, 0.59), substance use (0.47 per 100,000; 95% CI = 0.14, 0.80), asthma (0.56 per 100,000; 95% CI = 0.16, 0.95), and fatal acute myocardial infarction (0.09 per 100,000; 95% CI = 0.00, 0.18) co-occurring with violence spikes. The pattern of findings was similar for the exposure of continuous acute violence changes. CONCLUSIONS: Although the associations were small, the identified increases in stress-responsive conditions suggest the possibility of health impacts of acute changes in community violence.


Subject(s)
Emergency Service, Hospital/statistics & numerical data , Stress, Psychological/mortality , Violence/statistics & numerical data , Bias , California/epidemiology , Facilities and Services Utilization/statistics & numerical data , Humans , Stress, Psychological/complications , Stress, Psychological/epidemiology , Violence/psychology
19.
Ann Intern Med ; 167(12): 837-844, 2017 Dec 19.
Article in English | MEDLINE | ID: mdl-29059689

ABSTRACT

BACKGROUND: Gun shows are an important source of firearms, but no adequately powered studies have examined whether they are associated with increases in firearm injuries. OBJECTIVE: To determine whether gun shows are associated with short-term increases in local firearm injuries and whether this association differs by the state in which the gun show is held. DESIGN: Quasi-experimental. SETTING: California. PARTICIPANTS: Persons in California within driving distance of gun shows. MEASUREMENTS: Gun shows in California and Nevada between 2005 and 2013 (n = 915 shows) and rates of firearm-related deaths, emergency department visits, and inpatient hospitalizations in California. RESULTS: Compared with the 2 weeks before, postshow firearm injury rates remained stable in regions near California gun shows but increased from 0.67 injuries (95% CI, 0.55 to 0.80 injuries) to 1.14 injuries (CI, 0.97 to 1.30 injuries) per 100 000 persons in regions near Nevada shows. After adjustment for seasonality and clustering, California shows were not associated with increases in local firearm injuries (rate ratio [RR], 0.99 [CI, 0.97 to 1.02]) but Nevada shows were associated with increased injuries in California (RR, 1.69 [CI, 1.16 to 2.45]). The pre-post difference was significantly higher for Nevada shows than California shows (ratio of RRs, 1.70 [CI, 1.17 to 2.47]). The Nevada association was driven by significant increases in firearm injuries from interpersonal violence (RR, 2.23 [CI, 1.01 to 4.89]) but corresponded to a small increase in absolute numbers. Nonfirearm injuries served as a negative control and were not associated with California or Nevada gun shows. Results were robust to sensitivity analyses. LIMITATION: Firearm injuries were examined only in California, and gun show occurrence was not randomized. CONCLUSION: Gun shows in Nevada, but not California, were associated with local, short-term increases in firearm injuries in California. Differing associations for California versus Nevada gun shows may be due to California's stricter firearm regulations. PRIMARY FUNDING SOURCE: National Institutes of Health; University of California, Berkeley; and Heising-Simons Foundation.


Subject(s)
Firearms/statistics & numerical data , Wounds, Gunshot/epidemiology , California/epidemiology , Firearms/legislation & jurisprudence , Humans , Nevada/epidemiology , Risk Factors , Wounds, Gunshot/mortality
20.
Anal Biochem ; 421(2): 385-90, 2012 Feb 15.
Article in English | MEDLINE | ID: mdl-22206937

ABSTRACT

Biomolecular interaction is a fundamental mechanism involved in many critical biological processes including gene transcription, translation, and cell signaling networks. Many basic proteins, such as histones, transcription factors, and ribosomal proteins, participate in the interaction of these processes. Surface plasmon resonance (SPR) has been used as a "gold" standard to measure biomolecular interactions. One key issue in SPR assay is how to immobilize ligand without affecting its conformation and biological activity. In this study, we developed a novel method for measuring bindings to basic proteins by SPR, wherein the naturally positive charge of basic protein was utilized to immobilize ligand. The electrostatic interaction between the basic proteins and the negatively charged C1 chip surface (Biacore, GE) generated a specific and stable immobilization without any modification; sodium dodecyl sulfate was identified to be efficient enough for the complete regeneration that allows fresh ligand to be immobilized in each cycle for an optimal kinetic assay. With those parameters determined, an efficient, fast, and reversible method was established to measure bindings to basic proteins under physiological conditions. This new method is widely applicable to the study of binding kinetics between protein-, DNA-, or RNA- and basic protein.


Subject(s)
Proteins/metabolism , Surface Plasmon Resonance/methods , Protein Binding , Sodium Dodecyl Sulfate/chemistry
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