Drugs, guns, and violent crime in California

BACKGROUND

There is evidence linking use of controlled substances with perpetration of interpersonal violence. While the United States constitution protects the right to own a firearm, federal law prohibits firearm purchase and possession by persons believed to be at high risk for violence, including those who use controlled substances unlawfully.

METHODS

We report here the results of a 13-year prospective observational study on the risk of violent crime associated with a history of criminal drug charges in a cohort of 79,678 legal purchasers of handguns in California in 2001. The main outcomes were post-purchase charges for any violent crime, violent Crime Index crimes (murder, rape, robbery, aggravated assault), and firearm-related violent crimes. The main exposure of interest was a history of pre-purchase charge(s) for drug-related offenses; we examined as a secondary exposure a history of marijuana-related charges. We estimated adjusted hazard ratios (aHR) with 95 % confidence intervals (CI) using Cox proportional hazards multiple events models.

RESULTS

We found that legal handgun purchasers in California with a history of drug-related charges, even those with marijuana charges only, had triple the risk of a post-purchase violent crime charge compared to purchasers with no criminal charges (drug charges only: aHR=2.9, 95 % CI 2.2-3.8; marijuana charges only: aHR=3.3, 95 % CI 1.8-6.0). In addition, a criminal history of drug charges only vs. no criminal history was associated with increased risk of one or more violent crime charges after the first post-purchase arrest event (aHR=1.6, 95 % CI 1.2-2.3).

CONCLUSION

It is incumbent on researchers and policy makers to understand the nature and causes of this risk in order to take effective steps towards mitigation.

Importance of categories of crime for predicting future violent crime among handgun purchasers in California

BACKGROUND

Prohibiting the purchase and possession of firearms by those at risk of violence is an established approach to preventing firearm violence. Prior studies of legal purchasers have focused on convictions for specific crimes, such as violent misdemeanors and driving under the influence (DUI). We broaden that line of inquiry by investigating and comparing the associations between prior arrests for most categories of crime and subsequent arrest for violent offenses among legal handgun purchasers in California.

METHODS

In this longitudinal cohort study of 79,678 legal handgun purchasers in California in 2001, we group arrest charges prior to their first purchases in 2001 according to categories defined by the Uniform Crime Report (UCR) Handbook. We use a gradient boosting machine to identify categories of offenses that are most important for predicting arrest for violent crime following firearm purchase. For each category identified, we then estimate the difference in risk of subsequent arrest for a violent offense using survival regression models.

RESULTS

We identified eight crime categories with high predictive importance: simple assaults, aggravated assaults, vehicle violations, weapon, other crimes, theft, drug abuse, and DUI. Compared to purchasers with no prior arrests, those with a prior arrest for any one of the eight important categories and no other categories were found to be at increased risk of arrest for a Crime Index-listed violent crime (murder, rape, robbery, aggravated assault), with the greatest estimated risk corresponding to the simple assault UCR category (adjusted hazard ratio 4.0; 95% CI 2.8-5.9). Simple assault was also associated with the greatest risk for subsequent arrest for firearm violence (adjusted hazard ratio 4.6; 95% CI 2.4-9.0) and any violent offense (adjusted hazard ratio 3.7; 95% CI 2.7-5.0).

CONCLUSION

The findings of this study suggest that prior arrests for a broad array of crimes, both violent and non-violent, are associated with risk of subsequent violent crimes, including Crime Index-listed violent crimes and firearm violence, among legal purchasers of firearms. Current policies aimed at restricting access to firearms for individuals at increased risk of violence should be re-examined considering these findings.

Intimate Partner Violence and Subsequent Violent Offending Among Handgun Purchasers

Perpetrators of intimate partner violence (IPV) often reoffend, and firearm access increases risk of severe injury or fatality. Prior research identifies an association between a history of violent misdemeanor convictions among handgun purchasers and increased risk of subsequent arrest for a violent crime; the risk associated specifically with an IPV criminal history remains largely unexplored. The current study examined a cohort of 76,311 California adults who legally purchased a handgun in 2001 and followed them through 2013. Compared with purchasers who had no criminal history at the time of purchase, those with a history of only IPV (n = 178) charges were at increased risk of subsequent arrest for a violent Crime Index crime (murder, rape, robbery, aggravated assault; adjusted hazard ratio [AHR], 2.6; 95% confidence interval [CI]: 1.4-5.1), any violent crime (AHR, 3.2; 95% CI: 2.0-5.1), and an IPV crime (AHR, 5.2; 95% CI: 3.0-9.0). Purchasers with both IPV and non-IPV charges demonstrated the greatest risk of re-arrest relative to those with no criminal history. Despite the strength of the relationship between IPV and subsequent arrest, a small proportion of handgun purchasers with an IPV criminal history were re-arrested for firearm violence crimes, limiting application for risk assessment purposes. Results affirm prior research identifying IPV as a risk factor for future offending.

Prior Drug-Related Criminal Charges and Risk for Intimate Partner Violence Perpetration Among Authorized Purchasers of Handguns in California

Intimate partner violence (IPV) is a considerable public health problem in the US, and evidence suggests that both drugs and firearms contribute to the risk of IPV and its severity. This study uses a retrospective, longitudinal cohort design to explore the association between past arrests, charges incurred in the legal process, and convictions for drug-related crimes, and risk of future arrest for IPV among legal handgun purchasers. The cohort included all legal purchasers of handguns in California in 2001 between the ages of 21 and 49 (n = 79,678), 156 of whom had pre-purchase drug charges and post-purchase IPV charges. We used Cox proportional hazards regression with age at time of handgun purchase, sex, and race/ethnicity, and an array of community characteristics as covariates. Over the study period (2001-2013), in comparison to handgun purchasers who had no charges or convictions prior to their index purchase, risk for future IPV arrest was increased for purchasers whose only prior charges were drug-related (aHR = 3.4 [95% CI: 2.4-4.9]) and purchasers who had both prior drug- and non-drug related charges (aHR = 4.9 [95% CI: 4.1-6.0]). The magnitude of the risk ratio was greater when multiple drug types were involved and when the person had been charged with both the use and sale of drugs. Our findings suggest that, among legal handgun purchasers, prior drug charges are associated with future risk of IPV arrests or convictions. Given the established link between firearm access and IPV severity and fatality, these findings may inform the development and enforcement of policies that reduce firearm access for those at elevated risk of perpetrating intimate partner violence.

Criminal charge history, handgun purchasing, and demographic characteristics of legal handgun purchasers in California

Background

The prevalence and characteristics of handgun purchasers’ criminal charge histories have never been described for a large population of firearm owners, but such information is critical to understanding risk factors for subsequent violence in this population. We sought to characterize legal handgun purchasers in California and compare this group to the state population, to quantify the proportion with a criminal charge history at purchase, and to identify modifiable factors associated with of having such a history.

Methods

This cross-sectional study of all 79,927 legal handgun purchasers aged 21–49 years in California in 2001 used log-linear generalized additive models to identify factors associated with having a criminal charge history at purchase. Subjects are from a longitudinal study of incident criminal activity among handgun purchasers.

Results

The majority (91.03%) of purchasers were male; whites were overrepresented and Hispanics were underrepresented relative to their population size. At the time of purchase, 16.68%  had a criminal charge history and 10.71% had a criminal conviction. Among men with such a history, 31.28% had been charged with a violent crime and 16.54% had been charged with a firearm-related crime. The strongest factor associated with having a criminal charge history was redeeming a pawned handgun (prevalence ratio: 1.82; 95% confidence interval: 1.71, 1.93).

Conclusions

Despite California’s stringent firearm purchase laws, more than 1-in-6 handgun purchasers had a criminal charge history at purchase. This proportion may be higher in states with less restrictive firearm purchasing eligibility criteria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40621-021-00301-5.

Armed and prohibited: characteristics of unlawful owners of legally purchased firearms

BACKGROUND

A substantial proportion of individuals who lawfully purchase firearms later become unlawful owners ('prohibited firearm owners'), usually following events associated with an increased risk for future violence. This high-risk population has not previously been described. We aimed to characterise all individuals in California's Armed and Prohibited Persons System (APPS), a statewide programme for recovering firearms from individuals who legally purchased them and later became prohibited from ownership.

METHODS

We used univariate and bivariate statistics to describe and compare prohibited firearm owners in APPS with a random sample of non-prohibited firearm owners in relation to age, sex, race/ethnicity and type of firearms owned as of 1 February 2015. We also characterised the geographical distribution of prohibited firearm owners and described their prohibitions.

RESULTS

Of the 18 976 prohibited firearm owners, most were men (93%), half were white (53%) and the mean age was 47 years. Prohibited firearm owners were more likely to be male and to be black or Hispanic people than non-prohibited owners. Both prohibited and non-prohibited firearm owners had an average of 2.6 firearms, mostly handguns. Nearly half (48%) of prohibited firearm owners had a felony conviction. Extrapolating from our findings, we estimated that there are approximately 100 000 persons in the USA who unlawfully maintained ownership of their firearms following a felony conviction.

CONCLUSIONS

Retention of firearms among persons who become lawfully prohibited from possessing them is common in California. Given the nationwide dearth of a programme to recover such weapons, this is likely true in other states as well.

Association of Prior Convictions for Driving Under the Influence With Risk of Subsequent Arrest for Violent Crimes Among Handgun Purchasers

IMPORTANCE

Alcohol use is a risk factor for firearm-related violence, and firearm owners are more likely than others to report risky drinking behaviors.

OBJECTIVE

To study the association between prior convictions for driving under the influence (DUI) and risk of subsequent arrest for violent crimes among handgun purchasers.

DESIGN

In this retrospective, longitudinal cohort study, 79 678 individuals were followed up from their first handgun purchase in 2001 through 2013. The study cohort included all legally authorized handgun purchasers in California aged 21 to 49 years at the time of purchase in 2001. Individuals were identified using the California Department of Justice (CA DOJ) Dealer's Record of Sale (DROS) database, which retains information on all legal handgun transfers in the state.

EXPOSURES

The primary exposure was DUI conviction prior to the first handgun purchase in 2001, as recorded in the CA DOJ Criminal History Information System.

MAIN OUTCOMES AND MEASURES

Prespecified outcomes included arrests for violent crimes listed in the Crime Index published by the Federal Bureau of Investigation (murder, rape, robbery, and aggravated assault), firearm-related violent crimes, and any violent crimes.

RESULTS

Of the study population (N=79 678), 91.0% were males and 68.9% were white individuals; the median age was 34 (range, 21-49) years. The analytic sample for multivariable models included 78 878 purchasers after exclusions. Compared with purchasers who had no prior criminal history, those with prior DUI convictions and no other criminal history were at increased risk of arrest for a Crime Index-listed violent crime (adjusted hazard ratio [AHR], 2.6; 95% CI, 1.7-4.1), a firearm-related violent crime (AHR, 2.8; 95% CI, 1.3-6.4), and any violent crime (AHR, 3.3; 95% CI, 2.4-4.5). Among purchasers with a history of arrests or convictions for crimes other than DUI, associations specifically with DUI conviction remained.

CONCLUSIONS AND RELEVANCE

This study's findings suggest that prior DUI convictions may be associated with the risk of subsequent violence, including firearm-related violence, among legal purchasers of handguns. Although the magnitude was diminished, the risk associated with DUI conviction remained elevated even among those with a history of arrests or convictions for crimes of other types.

Firearms, alcohol and crime: convictions for driving under the influence (DUI) and other alcohol-related crimes and risk for future criminal activity among authorised purchasers of handguns

Firearm violence frequently involves alcohol, but there are no studies of misuse of alcohol and risk for future violence among firearm owners. We examined the association between prior convictions for alcohol-related crimes, chiefly driving under the influence (DUI), and risk of subsequent arrest among 4066 individuals who purchased handguns in California in 1977. During follow-up through 1991, 32.8% of those with prior alcohol-related convictions and 5.7% of those with no prior criminal history were arrested for a violent or firearm-related crime; 15.9% and 2.7%, respectively, were arrested for murder, rape, robbery or aggravated assault. Prior alcohol-related convictions were associated with a fourfold to fivefold increase in risk of incident arrest for a violent or firearm-related crime, a relative increase greater than that seen for age, sex or prior violence. Prior convictions for alcohol-related crime may be an important predictor of risk for future criminal activity among purchasers of firearms.

Firearms and the incidence of arrest among respondents to domestic violence restraining orders

BACKGROUND

Persons subject to domestic violence restraining orders (DVROs), known as respondents, are generally prohibited from possessing firearms. Efforts to enforce that prohibition have not been evaluated. The study objective was to determine whether associations exist between risk of incident arrest among DVRO respondents and 1) respondents' access to firearms, and 2) law enforcement recovery of firearms from respondents with access to them.

METHODS

This was an observational study of 2,972 DVRO respondents in San Mateo County, California, 525 of whom were linked to firearms by standardized screening procedures. Enrollment occurred from May 2007 to June 2010 and follow-up through September 2010. Follow-up began when DVROs were served (or when issued if no date of service was available); median duration was 689 days. Principal exposures were access to firearms and, for subjects with access to firearms whose DVROs were served, contact by law enforcement personnel to recover those firearms. Main outcome measures were 1) incidence of arrest; 2) relative risk for arrest, adjusted for age, sex, prior criminal history, and duration of follow-up, assessed using logistic regression.

RESULTS

Respondents linked to firearms were older than others and were more likely to have a history of prior arrest (49.7 % and 37.3 %, p < 0.0001). The incidence of arrest was 20.6 % for respondents linked to firearms and 21.1 % for others (p = 0.78). In multivariate models, access to firearms was associated with a modest, generally not statistically significant, decrease in risk for incident arrest. Among respondents who were linked to firearms and whose restraining orders were served, no statistically significant association existed between firearm recovery and risk for incident arrest.

CONCLUSIONS

In this small study of DVRO respondents, findings are inconclusive for an association between access to firearms or firearm recovery and risk of incident arrest. Controlled trials on larger populations are indicated.

Gun suicide by young people in California: descriptive epidemiology and gun ownership

We studied the 336 firearm suicides occurring in California in 1997-1999 to persons under age 21. The gun used was most often owned by the victim or a family member living in the victim's household. Prevention efforts should focus on gun ownership and accessibility.

Risk factors among handgun retailers for frequent and disproportionate sales of guns used in violent and firearm related crimes

OBJECTIVE

To determine the retailer and community level factors associated with frequent and disproportionate sales of handguns that are later used in violent and firearm related crimes (VFC handguns).

DESIGN

Cross sectional. The authors used California records to identify all handguns sold by study subjects during 1996-2000 and federal gun tracing records to determine which of these guns had been recovered by a police agency in the US or elsewhere and traced by 30 September 2003.

SUBJECTS AND SETTING

The 421 licensed gun retailers in California selling at least 100 handguns annually during 1996-2000.

MAIN OUTCOME MEASURE

The number of VFC handguns per 1000 gun years of exposure. Differences are expressed as incidence rate ratios (RR) with 95% confidence intervals (CI).

RESULTS

Subjects accounted for 11.7% of California retailers with handgun sales, 81.5% of handgun sales, and 85.5% of VFC handguns. Among subjects, the 3426 VFC handguns accounted for 48.0% of all traced handguns and 65.0% of those linked to a specified crime. The median VFC handgun trace rate was 0.5/1000 gun years (range 0-8.8). In multivariate analysis, this rate increased substantially for each single-point increase in the percentage of proposed sales that were denied because the purchasers were prohibited from owning guns (RR 1.43; 95% CI 1.32 to 1.56), and was increased for pawnbrokers (RR 1.26; 95% CI 1.02 to 1.55). Community level crime rates and sociodemographics had little predictive value.

CONCLUSIONS

Risk factors, largely determined at the retailer level, exist for frequent and disproportionate sales of handguns that are later used in violent and firearm related crimes. Screening to identify high risk retailers could be undertaken with data that are already available.

People and guns involved in denied and completed handgun sales

OBJECTIVE

Denial of handgun purchases by prohibited people and knowledge of the structure of gun commerce have helped to deter and prevent firearm violence. The authors hypothesize that handguns involved in a denied purchase would more closely resemble those used in crime compared with handguns sold.

DESIGN

Cross sectional.

SETTING

Denied and completed handgun sales in California, 1998-2000.

MAIN OUTCOME MEASURES

Handgun and purchaser characteristics of denied and completed sales were compared. In particular, handgun characteristics most closely associated with crime guns (type, caliber, barrel length, price) were examined.

RESULTS

Compared with handguns sold, handguns in denied sales were somewhat more likely to be semiautomatic pistols (74.6% v 69.4%), to have short barrels (25.9% v 22.2%), and be of medium caliber (48.9% v 37.3%). Ten percent of the handguns in denied sales and 3.4% of handguns sold were identified as inexpensive.

CONCLUSIONS

The characteristics of denied handguns are similar to those seen among crime guns. Both groups of guns may reflect the desirability for criminal purposes of pistols, which have larger ammunition capacities than other handguns, and short barrels, which increase their ability to be concealed.

The life cycle of crime guns: a description based on guns recovered from young people in California

STUDY OBJECTIVE

We describe the life cycle of crime guns recovered from young people-the movement of those guns from manufacture to criminal use-and identify associations between the characteristics of those guns and their possessors, purchasers, sellers, and places of origin.

METHODS

This is a cross-sectional study of data from gun ownership tracing records compiled by the Bureau of Alcohol, Tobacco, Firearms and Explosives for 2,121 crime guns recovered in California from persons younger than 25 years and traced in 1999. Purchaser and seller data for handguns were updated when possible by linking to California handgun sales records.

RESULTS

The 2,121 traced guns were recovered from 1,717 young people. Guns recovered from persons aged 21 to 24 years were most frequently also purchased by persons aged 21 to 24 years; those recovered from persons younger than 18 years were most often purchased by persons aged 45 years or older. Small-caliber handguns made up 41.0% of handguns recovered from persons younger than 18 years but 25.2% of handguns recovered from persons aged 21 to 24 years. The median time from sale to recovery (commonly called time to crime) for all guns was 6.4 years (interquartile range 2.7 to 12.4 years). A time to crime of less than 3 years, suggesting deliberate gun trafficking, was observed for 17.3% of guns recovered from persons younger than 18 years but 34.6% of guns recovered from persons aged 21 to 24 years. Ten retailers who sold 10 or more traced guns accounted for 13.1% of all guns traced to a retailer. Handguns whose purchaser and possessor were the same person were more likely than others to be large-caliber semiautomatic pistols (29.3% and 11.7%, respectively); their median time to crime was 0.2 years (69 days).

CONCLUSION

Analysis of crime-gun ownership traces reveals patterns that may help refine gun violence prevention efforts and render them more effective.

Association between handgun purchase and mortality from firearm injury

OBJECTIVE

To determine the association between mortality from violent or firearm related injury and previous handgun purchase.

METHODS

Case-control study of 213 466 Californians ages 21 and older who died in 1998; cases were the 4728 violent or firearm related injury deaths, with subsets by specific cause and means of death, and controls were the 208 738 non-injury deaths. The exposure of interest was the purchase of a handgun during 1996-98. The main outcome measure was the odds ratio for handgun purchase, adjusted for age, sex, race, education, and marital status.

RESULTS

Handgun purchase was more common among persons dying from suicide (odds ratio (OR) 6.8; 95% confidence interval (CI) 5.7 to 8.1) or homicide (OR 2.4, 95% CI 1.6 to 3.7), and particularly among those dying from gun suicide (OR 12.5; 95% CI 10.4 to 15.0) or gun homicide (OR 3.3; 95% CI 2.1 to 5.3), than among controls. No such differences were seen for non-gun suicide or homicide. Among women, those dying from gun suicide were much more likely than controls to have purchased a handgun (OR 109.8; 95% CI 61.6 to 195.7). Handgun purchasers accounted for less than 1% of the study population but 2.4% of gun homicides, 14.2% of gun suicides, and 16.7% of unintentional gun deaths. Gun suicide made up 18.9% of deaths among purchasers but only 0.6% of deaths among non-purchasers.

CONCLUSION

Among adults who died in California in 1998, those dying from violence were more likely than those dying from non-injury causes to have purchased a handgun.

Chemoattraction of femoral CD34+ progenitor cells by tumor-derived vascular endothelial cell growth factor

Patients and animals with GM-CSF-producing tumors have an increased number of mobilized CD34+ progenitor cells within their peripheral blood and tumor tissue. These CD34+ cells are inhibitory to the activity of intratumoral T-cells. The present study used the murine Lewis lung carcinoma (LLC) model to assess mechanisms that could lead to the accumulation of CD34+ cells within the tumor tissue. In vitro analyses showed that LLC tumor explants released chemoattractants for normal femoral CD34+ cells. The LLC tumor cells contributed to the production of this activity since CD34+ cell chemoattractants were also released by cultured LLC cells. Antibody neutralization studies showed that most, although not all, of the chemotactic activity that was produced by LLC cells could be attributed to VEGF. In vivo studies with fluorescent-tagged CD34+ cells showed their accumulation within the tumor tissue, but not within the lungs, spleen or bone marrow, suggesting a selective accumulation within the tumor. Whether or not VEGF could chemoattract CD34+ cells in vivo was measured with a VEGF-containing Matrigel plug assay. Infusion of fluorescent-tagged CD34+ cells into mice after the plugs became vascularized revealed the accumulation of fluorescent-tagged cells within the plugs. However, these CD34+ cells failed to accumulate within the VEGF-containing Matrigel plugs when they were infused together with neutralizing anti-VEGF antibody. Through a combination of in vitro and in vivo analyses, the LLC cells were shown to be capable of chemoattracting CD34+ cells, with most of the tumor-derived chemotactic activity being due to tumor release of VEGF.

Subsequent criminal activity among violent misdemeanants who seek to purchase handguns: risk factors and effectiveness of denying handgun purchase

CONTEXT

Some states prohibit the purchase of handguns by persons convicted of selected misdemeanor crimes, but most do not. California has denied handgun purchases by violent misdemeanants since 1991; the effectiveness of these policies is unknown.

OBJECTIVE

To determine the risk factors for new criminal activity among violent misdemeanants who seek to purchase handguns and whether denial of handgun purchase by violent misdemeanants affects their risk of arrest for new crimes, particularly gun and/or violent crimes.

DESIGN

Retrospective, population-based cohort study.

SETTING AND SUBJECTS

Persons aged 21 to 34 years who sought to purchase a handgun through a licensed dealer in California during 1989-1991 and who had at least 1 violent misdemeanor conviction in the preceding 10 years. The study cohorts consisted of 986 persons whose purchase applications were made in 1991 and were denied (denied persons) and 787 persons whose purchase applications were made in 1989-1990 and were approved (purchasers).

MAIN OUTCOME MEASURES

Incidence and relative risk of first arrest in California for new gun and/or violent crimes and for nongun, nonviolent crimes during a 3-year follow-up after actual or attempted handgun purchase.

RESULTS

During the 3-year follow-up, 546 (33.0%) of 1654 subjects with follow-up information were arrested for a new crime, including 296 (31.9%) of 927 denied persons and 250 (34.4%) of 727 purchasers. After adjusting for differences in age, sex, and prior criminal history, purchasers were more likely than denied persons to be arrested for new gun and/or violent crimes (relative hazard [RH], 1.29; 95% confidence interval [CI], 1.04-1.60), but not for nongun, nonviolent crimes (RH, 0.96; 95% CI, 0.78-1.19). In both groups, risk of arrest was strongly related to age and number of convictions accrued prior to actual or attempted handgun purchase.

CONCLUSION

Our results indicate that denial of handgun purchase to violent misdemeanants is associated with a specific decrease in risk of arrest for new gun and/or violent crimes.

Vitamin D3 treatment to diminish the levels of immune suppressive CD34+ cells increases the effectiveness of adoptive immunotherapy

Tumor growth can increase the number of immature bone marrow-derived CD34+ cells that exhibit natural suppressor (NS) activity toward T-cell function. Using a metastatic Lewis lung carcinoma (LLC-LN7) tumor model, these CD34+ NS cells were shown to be present within the s.c. primary tumor tissue, but their levels declined after treatment with the inducer of myeloid cell differentiation, vitamin D3. Therefore, studies determined whether vitamin D3 treatment to diminish the CD34+ NS cell levels in LLC-LN7-bearing mice would enhance (a) intratumoral immune reactivity and (b) the antitumor activity of adoptive therapy consisting of tumor-reactive lymph node cells. The results showed that vitamin D3 treatment alone increased the intratumoral CD8+ cell content and the activity of the intratumoral infiltrate, as detected by production of interferon-gamma and expression of the p55 IL-2 receptor. Although vitamin D3 treatment had no effect on the size of the primary tumor, it lessened the extent of tumor metastasis. Treating mice with the combination of vitamin D3 and adoptive immunotherapy significantly reduced metastasis in mice with established tumors, and reduced both metastasis and locoregional recurrence after surgical excision of the primary tumor. These studies demonstrate that vitamin D3 treatment increases intratumoral T-cell immune reactivity, and that coupling vitamin D3 treatment to diminish levels of CD34+ NS cells with adoptive immunotherapy enhances the effectiveness of the adoptively transferred tumor-reactive lymph node cells at limiting both metastasis and locoregional tumor recurrence.

Polygalacturonase gene expression in kiwifruit: relationship to fruit softening and ethylene production

In kiwifruit, much of the softening process occurs prior to the respiratory climacteric and production of ethylene. This fruit therefore represents an excellent model system for dissecting the process of softening in the absence of endogenous ethylene production. We have characterized the expression of three polygalacturonase (PG) cDNA clones (CkPGA, B and C) isolated from fruit of Actinidia chinensis. Expression of CkPGA and B was detected by northern analysis only in fruit producing endogenous ethylene, and by RT-PCR in other tissues including flower buds, petals at anthesis, and senescent petals. CkPGA promoter fragments of 1296, 860 and 467 bp fused to the beta-glucuronidase (uidA) reporter gene directed fruit-specific gene expression during the climacteric in transgenic tomato. CkPGC gene expression was observed in softening fruit, and reached maximum levels (50-fold higher than for CkPGA and B) as fruit passed through the climacteric. However, expression of this gene was also readily detected during fruit development and in fruit harvested prior to the onset of softening. Using RT-PCR, expression of CkPGC was also detected at low levels in root tips and in senescent petals. These results suggest that PG expression is required not only during periods of cell wall degeneration, but also during periods of cell wall turnover and expansion.

Cultures derived from peripheral blood CD34+ progenitor cells of head and neck cancer patients and from cord blood are functionally different

Patients with head and neck squamous cell carcinoma (HNSCC) have profound immune defects mediated, in part, by an increased number of immune suppressive CD34+ progenitor cells in their peripheral blood and tumor. One means of overcoming this immune suppression is to stimulate the CD34+ cells to differentiate into more mature, nonsuppressive progeny such as dendritic cells or monocytes. This study determined that CD34+ cells from the peripheral blood of HNSCC patients have the same potential to differentiate into dendritic cells as do human umbilical cord blood CD34+ cells following 12-16 days of culture with a cytokine cocktail. When compared functionally, the cultures that developed from CD34+ cells of cord blood were able to induce an allostimulatory response in naive T-cells, while the cultures that developed from patient CD34+ cells lacked allostimulatory ability. Both cultures expressed class II MHC (HLA-DR), but the proportion of cells expressing the costimulatory molecules CD80 and CD86 was significantly less in cultures that developed from HNSCC-patient CD34+ cells. Therefore, although the CD34+ cells from the peripheral blood of HNSCC patients can differentiate into dendritic cells, their allostimulatory capabilities are impaired, raising the question of their potential effectiveness in stimulating antitumor immune responses.

The impact of childhood foster care and other out-of-home placement on homeless women and their children

OBJECTIVE

This study compares homeless women who had childhood histories of foster care or other out-of-home placement to those who have not.

METHOD

A countywide probability sample of homeless women (n = 179) received structured interviews.

RESULTS

One-third of homeless women reported being raised apart from their parents. Among women with children under age 18, most (61.5%) had children who had lived in foster care or other out-of-home placements. Variables associated with homeless mothers' children living in foster care or other out-of-home placements were: Child was school-age, mother was age 35 or older, mother had a current alcohol or drug use disorder, mother experienced childhood sexual abuse, and mother ran away from home (when under age 18).

CONCLUSIONS

Parenting is difficult for homeless mothers who may need to place their children with others to facilitate school attendance. Parent-child interaction may be problematic in family shelters where privacy is rare. Thus, programs promoting family preservation for homeless mothers should provide parenting support as well as permanent housing.

Skewed differentiation of bone marrow CD34+ cells of tumor bearers from dendritic toward monocytic cells, and the redirection of differentiation toward dendritic cells by 1alpha,25-dihydroxyvitamin D3

Tumor presence is detrimental to the development of antigen-presenting dendritic cells. Since dendritic cells can arise from CD34+ precursor cells, the present study assessed the capacity of bone marrow CD34+ cells from tumor bearers to develop into dendritic cells when cultured in the absence of either tumor cells or their products. Culturing bone marrow CD34+ cells from mice bearing Lewis lung carcinomas yielded a lower number of dendritic cells than arose from CD34+ cells of normal mice. This reduced yield of dendritic cells was associated with a shift to development of monocytic cells and a reduced antigen presenting capability by the cultures. When the CD34+ cell cultures from tumor bearers were supplemented with the differentiation-inducing hormone 1alpha,25-dihydroxyvitamin D3, there was the restoration of dendritic cell development and antigen presenting ability. These results show that CD34+ cells from tumor bearers remain defective in their development into dendritic cells even when cultured outside the tumor environment, but development of dendritic cells can be restored with 1alpha,25-dihydroxyvitamin D3.

Increased resistance to apoptosis by bone marrow CD34(+)progenitor cells from tumor-bearing mice

Tumors, such as the murine Lewis lung carcinoma (LLC), produce granulocyte-macrophage colony-stimulating factor (GM-CSF), which increases the proportion of CD34(+) hematopoietic progenitor cells in the bone marrow and in the periphery. This increase in peripheral CD34(+) cells had been attributed to the growth-promoting and mobilizing effects of the tumor-derived GM-CSF. However, the possibility that the CD34(+) cells of tumor bearers might have enhanced survival abilities had not been considered. The present studies showed a significant baseline level of apoptotic cells in short-term (5-day) cultures of normal CD34(+) cells containing GM-CSF plus stem cell factor (SCF), and a markedly greater level of apoptosis in cytokine-deficient cultures. In contrast, CD34(+) cells from tumor bearers did not undergo such levels of apoptosis, even in the absence of cytokines. This resistance to apoptosis could be conferred to normal CD34(+) cells by culture with LLC-conditioned medium. Studies to elucidate possible mechanisms for the resistance to apoptosis by tumor-exposed CD34(+) cells showed increased levels of the pro-life gene product bcl-2. Finally, the resistance of tumor-exposed CD34(+) cells to ligation of the Fas receptor, a known apoptotic trigger in hematopoietic cells, was compared with that of control CD34(+) cultures. Whereas approximately half of the normal CD34(+) cells underwent apoptosis in response to Fas ligation, the tumor-exposed CD34(+) cells resisted apoptosis, even though their surface Fas expression was greater than that of normal CD34(+) cells. Thus, our results show that the increased level of CD34(+) cells in tumor bearers is due not only to an increased growth and mobilization of CD34(+) cells as previously thought, but also may be due to an increased resistance to apoptosis that is conferred by tumor-derived products and is associated with increased expression of bcl-2.

Dendritic cell differentiation pathways of CD34+ cells from the peripheral blood of head and neck cancer patients

Patients with head and neck squamous cell carcinoma (HNSCC) have increased levels of immune-suppressive peripheral blood CD34+ cells. This study showed that the peripheral blood CD34+ cells of HNSCC patients are capable of differentiating into dendritic cells. Because CD34+ cells can differentiate through several pathways into dendritic cell subpopulations, the intermediate cells through which the blood CD34+ cells of HNSCC patients differentiate were identified. After 6-7 days of culturing the CD34+ cells of HNSCC patients with granulocyte-macrophage colony-stimulating factor, stem cell factor, and tumor necrosis factor at, there appeared CD14+CD1a+ and a lesser proportion of CD14(-)CD1a+ cells resembling the precursor cells of the bipotential and committed dendritic cell differentiation pathways that have been described for cord blood CD34+ cells. To functionally analyze whether these populations were in fact precursor cells, they were isolated and cultured for an additional 10-12 days. Each of these populations was shown to function as precursor cells because they were able to develop into cells that resembled dendritic cells, although a higher proportion developed from the CD14-CD1a+ cells. In contrast, expression of the dendritic activation/maturation marker CD83 was highest on the cells that developed from CD14+CD1a+ cells. Thus, the CD34+ cells whose levels are increased in HNSCC patients can develop into both committed and bipotential dendritic precursor cells, which can subsequently give rise to dendritic cells.

Effectiveness of denial of handgun purchase to persons believed to be at high risk for firearm violence

OBJECTIVES

The purpose of this study was to determine whether denial of handgun purchase is an effective violence prevention strategy.

METHODS

Individuals denied handgun purchase because of a prior felony conviction and handgun purchasers with a felony arrest at time of purchase were examined.

RESULTS

Relative to those denied purchase, handgun purchasers were found to be at greater risk for subsequent offenses involving a gun (relative risk [RR] = 1.21, 95% confidence interval [CI] = 1.08, 1.36) or violence (RR = 1.24, 95% CI = 1.11, 1.39), after adjustment for number of prepurchase weapon/violence charges.

CONCLUSIONS

Denial of handgun purchase to persons with a prior felony conviction may lower their rate of subsequent criminal activity.

Prior misdemeanor convictions as a risk factor for later violent and firearm-related criminal activity among authorized purchasers of handguns

CONTEXT

Under current federal law, many persons with prior convictions for misdemeanor offenses pass criminal records background checks and legally purchase handguns.

OBJECTIVE

To determine whether authorized handgun purchasers with prior misdemeanor convictions are more likely than those with no criminal history to be charged with new crimes, particularly offenses involving firearms and violence.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

A total of 5923 authorized purchasers of handguns in California in 1977 who were younger than 50 years, identified by random sample.

MAIN OUTCOME MEASURES

Incidence and relative risk (RR) of first charges for new criminal offenses after handgun purchase.

RESULTS

Of the 5923 authorized purchasers, 3128 had at least 1 conviction for a misdemeanor offense prior to handgun purchase, and 2795 had no prior criminal history. Follow-up to the end of the 15-year observation period or to death was available for 77.8% of study subjects and for a median 8.9 years for another 9.6%. Handgun purchasers with at least 1 prior misdemeanor conviction were more than 7 times as likely as those with no prior criminal history to be charged with a new offense after handgun purchase (RR, 7.5; 95% confidence interval [CI], 6.6-8.7). Among men, those with 2 or more prior convictions for misdemeanor violence were at greatest risk for nonviolent firearm-related offenses such as weapon carrying (RR, 11.7; 95% CI, 6.8-20.0), violent offenses generally (RR, 10.4; 95% CI, 6.9-15.8), and Violent Crime Index offenses (murder or non-negligent manslaughter, forcible rape, robbery, or aggravated assault) (RR, 15.1; 95% CI, 9.4-24.3). However, even handgun purchasers with only 1 prior misdemeanor conviction and no convictions for offenses involving firearms or violence were nearly 5 times as likely as those with no prior criminal history to be charged with new offenses involving firearms or violence.

CONCLUSIONS

Handgun purchasers with prior misdemeanor convictions are at increased risk for future criminal activity, including violent and firearm-related crimes.

Apple ACC-oxidase and polygalacturonase: ripening-specific gene expression and promoter analysis in transgenic tomato

Levels of 1-aminocyclopropane-1-carboxylate (ACC) oxidase and polygalacturonase (PG) mRNAs were characterized during ripening of Royal Gala, Braeburn and Granny Smith apples. Both ACC-oxidase and PG mRNAs were up-regulated in ripening fruit of all three cultivars. Expression in Royal Gala was detected earlier than in Braeburn and Granny Smith, relative to internal ethylene concentration. Genomic clones corresponding to the ACC-oxidase and PG mRNAs expressed in ripe apple fruit were isolated and ca. 2 kb of each promoter was sequenced. The start point of transcription in each gene was mapped by primer extension, and sequences homologous to elements in other ethylene-responsive or PG promoters were identified. The fruit specificity of the apple ACC-oxidase and PG promoters was investigated in transgenic tomato plants using a nested set of promoter fragments fused to the beta-glucuronidase (gusA) reporter gene. For the ACC-oxidase gene, 450 bp of 5' promoter sequence was sufficient to drive GUS expression, although this expression was not specific to ripening fruit. Larger fragments of 1966 and 1159 bp showed both fruit and ripening specificity. For the PG gene, promoter fragments of 1460 and 532 bp conferred ripening-specific expression in transgenic tomato fruit. However GUS expression was down-regulated by 2356 bp of promoter, suggesting the presence of a negative regulatory element between positions -1460 and -2356.

Criminal activity and assault-type handguns: a study of young adults

STUDY OBJECTIVE

We studied a population of young adults who legally purchased handguns to determine whether an association exists between the purchase of an assault-type handgun and prior or subsequent criminal activity.

METHODS

We conducted a longitudinal study of 5,360 legally authorized purchasers of handguns in California in 1988 who were younger than 25 years at the time of purchase. Our main outcome measures were (1) adjusted relative risk (RR) for the purchase of an assault-type handgun for subjects with a criminal history compared with subjects without such a history and (2) adjusted RR for new criminal activity during the 3 years after handgun purchase for purchasers of assault-type handguns compared with purchasers of other handguns. RRs were adjusted for sex and race/ethnicity.

RESULTS

Handgun purchasers with a criminal history were more likely than those with no criminal history to purchase assault-type handguns (4.6% and 2.0%, respectively; RR = 2.0; 95% confidence interval [CI] 1.5 to 2.8). Among handgun purchasers who had a criminal history, purchasers of assault-type handguns were more likely than purchasers of other handguns to be charged with new offenses (RR = 1.5; 95% CI, 1.3 to 1.9), including offenses involving firearms of violence (RR = 1.7; 95% CI, 1.3 to 2.20. Among those who had previously been charged with Violent Crime Index offenses (murder, rape, robbery, aggravated assault), those who purchased assault-type handguns were more than twice as likely as purchasers of other handguns to be charged with a new offense (RR = 2.3; 95% CI, 1.5 to 3.4) and three times as likely to be charged with a new offense involving firearms or violence (RR = 3.0, 95% CI, 1.9 to 4.6).

CONCLUSION

In this population, the purchase of an assault-type handgun was associated with both prior and subsequent criminal activity.

Failure of tumor-reactive lymph node cells to kill tumor in the presence of immune-suppressive CD34+ cells can be overcome with vitamin D3 treatment to diminish CD34+ cell levels

Growth of Lewis lung carcinoma (LLC-LN7) tumors results in an increase in CD34+ granulocyte-macrophage progenitor cells having natural suppressor (NS) activity. These CD34+ NS cells were capable of inhibiting the cytotoxic activity of tumor-reactive lymph node cells. In vivo studies showed that adoptive treatment of LLC-LN7 tumor-bearing mice with tumor-reactive lymph node cells plus IL-2 failed to reduce the development of metastases. Studies were conducted to determine if diminishing the levels of CD34+ NS cells would allow for improved anti-tumor effectiveness of the adoptively transferred cells. The suppressive activity of CD34+ cells toward the cytolytic activity of tumor-reactive lymph node cells could be blocked by in vitro culture of CD34+ cells with the differentiation-inducing hormone 1alpha,25-dihydroxyvitamin D3. Similarly, treatment of LLC-LN7-bearing mice with vitamin D3 alone diminished the levels of CD34+ NS cells within regional lymph nodes, spleens and tumors. This treatment resulted in an increased immune reactivity to autologous tumor, as shown by the production of IFN-gamma by lymph node cells in response to the presence of LLC-LN7 cells. The extent of tumor metastasis in mice receiving vitamin D3 treatment was also reduced. When tumor-reactive lymph node cells were adoptively transferred into these LLC-LN7-bearing mice that were receiving vitamin D3 treatment, there resulted a pronounced synergistic reduction in tumor metastasis. The results of this study show that treatment of tumor bearers with vitamin D3 to eliminate CD34+ NS cells improves the anti-tumor effectiveness of adoptively transferred tumor-reactive lymph node cells.

Weapons of choice: previous criminal history, later criminal activity, and firearm preference among legally authorized young adult purchasers of handguns

OBJECTIVE

To determine whether there is an association between criminal activity and preference for a particular class of handgun among young adults who purchase handguns legally.

DESIGN

Historical cohort study.

MATERIALS AND METHODS

Subjects were 5,360 authorized purchasers of handguns in California in 1988 who were 21 to 25 years of age, divided into two groups: all eligible purchasers with a previous criminal history (n = 2,765), and a random sample of purchasers with no such history (n = 2,595). Handguns were classified as small and inexpensive or larger and expensive. Associations were assessed by relative risks adjusted for gender and race or ethnicity.

MEASUREMENTS AND MAIN RESULTS

Handgun purchasers with a previous criminal history were more likely than those without such a history to purchase a small, inexpensive handgun (relative risk (RR) = 1.28; 95% confidence interval (CI), 1.16-1.42). Among handgun purchasers with no previous criminal history, those who purchased a small, inexpensive handgun were more likely than purchasers of other handguns to be charged with new crimes after handgun purchase (RR = 1.73; 95% CI, 1.34-2.24) and were nearly twice as likely to charged with new crimes involving firearms or violence (RR = 1.93; 95% CI, 1.38-2.69).

CONCLUSION

In this population, criminal activity both before and after handgun purchase was associated with a preference for small, inexpensive handguns.

Increased presence of CD34+ cells in the peripheral blood of head and neck cancer patients and their differentiation into dendritic cells

Patients with head and neck squamous cell carcinoma (HNSCC) have profound immune deficiencies. In 65% of these patients, there is an increased intra-tumoral presence of immune-suppressive CD34+ progenitor cells. The goal of the present study was to determine whether CD34+ cell levels were also increased in the peripheral blood of HNSCC patients and if these immune-suppressive cells could be differentiated into dendritic cells. Our results showed that CD34+ cell levels are increased in the peripheral blood of HNSCC patients. To assess if these CD34+ cells could differentiate into dendritic cells, they were isolated from the blood of HNSCC patients and cultured for 12 days with various cytokine combinations. Culturing CD34+ cells with stem cell factor (c-kit ligand) plus granulocyte-macrophage colony-stimulating factor resulted in the appearance of a significant proportion of cells expressing phenotypic markers characteristic of dendritic cells. Also, including tumor necrosis factor-alpha yielded a significant proportion of cells resembling the bipotential precursor cells for dendritic cells and monocytes (CD14+CD1a+), in addition to the dendritic-like cells. When the differentiation inducer 1alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] was added along with the cytokine combinations, the yield of cells having characteristics of dendritic cells was further increased. Cells that were derived from CD34+ cell cultures containing 1,25(OH)2D3 had a more potent capacity to present the recall antigen tetanus toxoid to autologous peripheral blood leukocytes and to stimulate a mixed leukocyte response compared to cultures to which 1,25(OH)2D3 had not been added. Our results show that CD34+ cells, whose frequency is increased in HNSCC patients, can be differentiated into cells that phenotypically and functionally resemble dendritic cells and that 1,25(OH)2D3 accentuates this differentiation.

Vitamin D3 and ceramide reduce the invasion of tumor cells through extracellular matrix components by elevating protein phosphatase-2A

Increasing phosphorylation reactions by protein kinase A (PKA) or reducing dephosphorylation reactions of protein phosphatase-2A (PP-2A) increases the invasiveness of Lewis lung carcinoma (LLC) cells, as measured by their capacity to traverse extracellular matrix (ECM)-coated filters. Metastatic LLC-LN7 variants have reduced PP-2A activity when compared to nonmetastatic LLC-C8 variants. Immunoblotting showed that this reduced level of PP-2A activity was not due to reduced levels of the PP-2A catalytic (C) subunit. The cellular PP-2A activity could be stimulated by addition of C2-ceramide to LLC-LN7 lysates, or by incubating cells with either C2-ceramide or with a noncalcemic analog of vitamin D3, which has previously been shown to stimulate the release of ceramide. These treatments to elevate PP-2A activity in metastatic LLC-LN7 cells resulted in a decline in their capacity to invade through select (ECM) components, particularly through vitronectin and laminin. Underscoring the importance of PP-2A in limiting the invasiveness of tumor cells was the demonstration that LLC-LN7 cell transfectants overexpressing the PP-2A C alpha subunit were less invasive through ECM components than the wild-type cells. Invasion by these cells was further reduced by additionally increasing PP-2A activity by incubation with C2-ceramide or the vitamin D3 analog. These results suggest a role of a vitamin D3/ceramide/PP-2A pathway in limiting the invasiveness of tumor cells through select ECM components.

Myeloid differentiation treatment to diminish the presence of immune-suppressive CD34+ cells within human head and neck squamous cell carcinomas

Within human head and neck squamous cell carcinomas (HNSCC) that produce granulocyte-macrophage CSF are CD34+ cells that exhibit natural suppressive (NS) activity. The present study aimed to identify how these NS cells mediate suppression and how to diminish their presence. CD34+ cells that were immunomagnetically isolated from fresh surgical HNSCC specimens produced a soluble product that blocked normal T cell stimulation through the TCR/CD3 complex. This inhibitory activity could be neutralized with Abs to TGF-beta1. Since prior studies showed that the CD34+ NS cells within HNSCC cancers are myelomonocytic progenitor cells, the feasibility of using cytokines that can induce myeloid cell differentiation to diminish the presence of CD34+ NS cells was tested. Adding low doses of 100 U/ml IFN-gamma plus 10 U/ml TNF-alpha to bulk cultures of dissociated HNSCC cancers diminished the frequency of CD34+ cells. Studies with CD34+ cells that were isolated from the HNSCC cancers showed that this cytokine treatment induced differentiation of the CD34+ cells predominantly into monocytic cells. The consequence of treating CD34+ NS cells with the myeloid differentiation treatment was the loss of suppressive activity, a decline in TGF-beta production, and the production of TNF-alpha by the resulting monocytic cells. In HNSCC bulk cultures containing high levels of CD34+ NS activity, IFN-gamma/TNF-alpha not only reduced CD34+ cell levels, but also increased the capacity of the intratumoral T cells to express the p55 IL-2R. These studies show that IFN-gamma/TNF-alpha can induce differentiation of TGF-beta-secreting CD34+ NS cells into nonsuppressive monocytic cells that secrete TNF-alpha.

Myeloid differentiation treatment to diminish the presence of immune-suppressive CD34+ cells within human head and neck squamous cell carcinomas

Within human head and neck squamous cell carcinomas (HNSCC) that produce granulocyte-macrophage CSF are CD34+ cells that exhibit natural suppressive (NS) activity. The present study aimed to identify how these NS cells mediate suppression and how to diminish their presence. CD34+ cells that were immunomagnetically isolated from fresh surgical HNSCC specimens produced a soluble product that blocked normal T cell stimulation through the TCR/CD3 complex. This inhibitory activity could be neutralized with Abs to TGF-beta1. Since prior studies showed that the CD34+ NS cells within HNSCC cancers are myelomonocytic progenitor cells, the feasibility of using cytokines that can induce myeloid cell differentiation to diminish the presence of CD34+ NS cells was tested. Adding low doses of 100 U/ml IFN-gamma plus 10 U/ml TNF-alpha to bulk cultures of dissociated HNSCC cancers diminished the frequency of CD34+ cells. Studies with CD34+ cells that were isolated from the HNSCC cancers showed that this cytokine treatment induced differentiation of the CD34+ cells predominantly into monocytic cells. The consequence of treating CD34+ NS cells with the myeloid differentiation treatment was the loss of suppressive activity, a decline in TGF-beta production, and the production of TNF-alpha by the resulting monocytic cells. In HNSCC bulk cultures containing high levels of CD34+ NS activity, IFN-gamma/TNF-alpha not only reduced CD34+ cell levels, but also increased the capacity of the intratumoral T cells to express the p55 IL-2R. These studies show that IFN-gamma/TNF-alpha can induce differentiation of TGF-beta-secreting CD34+ NS cells into nonsuppressive monocytic cells that secrete TNF-alpha.

Increased recurrence and metastasis in patients whose primary head and neck squamous cell carcinomas secreted granulocyte-macrophage colony-stimulating factor and contained CD34+ natural suppressor cells

Human head and neck squamous cell carcinomas (HNSCC) that produce high levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) have been shown to contain CD34+ natural suppressor cells that inhibit the activity of intratumoral T-cells. The present study evaluated whether GM-CSF production and the presence of CD34+ cells within primary HNSCC would translate into increased recurrence, metastasis or cancer-related death during the 2 years following surgical excision. Freshly excised primary HNSCC of 20 patients that subsequently developed disease, and of 17 patients that remained with no evidence of disease were analyzed for production of GM-CSF and for CD34+ cell content. The cancers of patients that subsequently developed recurrences or metastatic disease produced almost 4-fold the levels of GM-CSF and had approximately 2.5-fold the number of CD34+ cells as did cancers of patients that remained disease-free. In a second method of analysis, the prognostic significance of high vs. low GM-CSF and CD34+ cell values was evaluated. These analyses showed that patients whose cancers produced high GM-CSF levels or had a high CD34+ cell content had a disproportionately high incidence of recurrence or metastatic disease (94% and 100%, respectively), while the majority of patients whose primary cancers produced low levels of GM-CSF or had a low CD34+ cell content remained disease-free (16% and 19%, respectively). Our results indicate that the presence of CD34+ cells in GM-CSF-producing HNSCC is associated with a poorer prognosis for the cancer patients and suggest the utility of these parameters as prognostic indicators of outcome. Mechanistically, our results suggest that the presence of immune suppressive CD34+ cells in GM-CSF-producing HNSCC leads to increased tumor recurrence or metastasis.

Automating the business office

To measure the success of automating the business office with electronic billing and document management systems, the hospital's original goals were reviewed: Had the number of FTEs been maintained or reduced: Yes--claims volume is up 58% over 6 years with a 22% reduction in FTEs (see Exhibit 3). Was the cost of maintaining the paper filing system reduced? Yes--and the cost saving from the hospital's document imaging system will allow a 4.4 year payback. Is better customer service being provided? Yes--online access to patient demographic and financial information has improved response time. Having met all its goals, North Kansas City Hospital considers the installation of both systems to have been complete success. The facility expects to continue expansion of the document management system into accounts payable, payroll, home health, and other document-intensive areas to achieve further cost savings in the future.

Mechanisms of immune suppression in patients with head and neck cancer: influence on the immune infiltrate of the cancer

Freshly excised human head and neck cancers (219 primary cancers; 64 metastatic lymph node cancers) were analyzed for the immune inhibitory mediators released from the cancer tissues and the immune infiltrate within the tumor. Significant levels of the immune inhibitory mediators transforming growth factor-beta (TGF-beta), prostaglandin E2 (PGE2) and interleukin-10 (IL-10) were released from these cancers. Also released was granulocyte-macrophage colony-stimulating factor (GM-CSF), whose secretion was associated with an intratumoral presence of CD34+ cells. We have previously shown that CD34+ cells within human head and neck cancers are immune inhibitory granulocyte-macrophage progenitor cells. The presence of TGF-beta, PGE2 and IL-10 was associated with a reduced content of CD8+ T-cells within the cancers. The CD4+ cell content appeared to be less affected by these immune inhibitory mediators. Instead, parameters indicative of CD4+ cell function (p55 IL-2 receptor expression, release of IL-2 and IFN-gamma) were diminished in cancers that released higher levels of TGF-beta, IL-10 and GM-CSF and had a higher CD34+ cell content. Furthermore, metastatic cancers released higher levels of the soluble immune inhibitory mediators and lower levels of IFN-gamma and IL-2 than did primary cancers, although CD34+ cells were similarly present in both primary and metastatic cancers. Our results show that human head and neck cancers have a multiplicity of non-mutually exclusive mechanisms of immune suppression that are most prominently associated with reduced CD8+ cell influx and reduced influx and altered function of intratumoral CD4+ cells.

Vitamin D3 treatment of tumor bearers can stimulate immune competence and reduce tumor growth when treatment coincides with a heightened presence of natural suppressor cells

By secreting granulocyte-macrophage colony-stimulating factor (GM-CSF), Lewis lung carcinoma tumors induce immune suppressive granulocyte-macrophage progenitor cells. Treating mice having established tumors and high levels of suppressor activity with vitamin D3 eliminated suppressor activity, increased anti-tumor immunity, induced an immune stimulatory cell population, and reduced tumor growth. When instead, the vitamin D3 treatment was initiated earlier, when implanted tumors first became detectable and when natural suppressor activity was less prominent, the treatment had no effect. Thus, vitamin D3 treatment can stimulate the immune competence of tumor bearers when treatment is targeted to coincide with a heightened presence of GM-CSF-induced suppressor cells.

Immune modulation by interleukin-12 in tumor-bearing mice receiving vitamin D3 treatments to block induction of immunosuppressive granulocyte/macrophage progenitor cells

Lewis lung carcinoma (LLC-LN7) tumors stimulate myelopoiesis and increase the presence of granulocyte/macrophage (GM) progenitor cells having natural suppressor activity. Treatment of these tumor-bearing mice with interleukin-12 (IL-12) resulted in minimal immune modulation. The objective of this study was to determine whether eliminating natural suppressor activity would allow for immune stimulation by IL-12. Treatment of LLC-LN7 tumor-bearing mice with vitamin D3 eliminated natural suppressor activity. In mice that were first treated with vitamin D3 and then also with IL-12, there was stimulation of splenic T cell proliferation in response to immobilized anti-CD3 plus IL-2. In addition, spleen and lymph node cells from vitamin-D3/IL-12-treated tumor-bearing mice became stimulated in response to autologous tumor to produce interferon gamma (IFN gamma), although IL-2 production was not stimulated. A prominent effect of the combined vitamin-D3/IL-12 treatment regimen was the synergistic augmentation of autologous tumor-specific cytolytic activity within the regional lymph nodes. The generation of these tumor-specific effector cells required the presence of the tumor mass since such activity was not elicited in the lymph nodes of mice from which the tumors had been surgically excised. The results of this study show that, after treatment of tumor bearers with vitamin D3 to eliminate GM-suppressor cells, IL-12 can induce select regional antitumor immune responses, particularly IFN gamma production and cytolysis by regional lymph node cells of autologous tumor.

Influence of chlorobenzoates on the utilisation of chlorobiphenyls and chlorobenzoate mixtures by chlorobiphenyl/chlorobenzoate-mineralising hybrid bacterial strains

Chlorobenzoates (CBA) arise as intermediates during the degradation of polychlorinated biphenyls (PCBs) and some chlorinated herbicides. Since PCBs were produced as complex mixtures, a range of mono-, di-, and possibly trichloro-substituted benzoates would be formed. Chlorobenzoate degradation has been proposed to be one of the rate-limiting steps in the overall PCB-degradation process. Three hybrid bacteria constructed to have the ability to completely mineralise 2-, 3-, or 4-monochlorobiphenyl respectively, have been studied to establish the range of mono- and diCBAs that can be utilised. The three strains were able to mineralise one or more of the following CBAs: 2-, 3-, and 4-monochlorobenzoate and 3,5-dichlorobenzoate. No utilisation of 2,3-, 2,5-, 2,6-, or 3,4-diCBA was observed, and only a low concentration (0.11 mM) of 2,4-diCBA was mineralised. When the strain with the widest substrate range (Burkholderia cepacia JHR22) was simultaneously supplied with two CBAs, one that it could utilise plus one that it was unable to utilise, inhibitory effects were observed. The utilisation of 2-CBA (2.5 mM) by this strain was inhibited by 2,3-CBA (200 microM) and 3,4-CBA (50 microM). Although 2,5-cba and 2,6-cba were not utilised as carbon sources by strain jhr22, they did not inhibit 2-cba utilisation at the concentrations studied, whereas 2,4-cba was co-metabolised with 2-cba. The utilisation of 2-, 3-, and 4-chlorobiphenyl by strain JHR22 was also inhibited by the presence of 2,3- or 3,4-diCBA. We conclude that the effect of the formation of toxic intermediates is an important consideration when designing remediation strategies.

Suppression of T cell proliferation by tumor-induced granulocyte-macrophage progenitor cells producing transforming growth factor-beta and nitric oxide

Production of high levels of granulocyte-macrophage CSF (GM-CSF) by LLC-LN7 tumors results in myelopoietic stimulation and an increase in cells having natural suppressor (NS) activity. Prior studies showed these NS cells could be isolated from the bone marrow of tumor-bearing mice with an Ab (ER-MP12) that recognized GM-progenitor cells. The present study showed these cells to also be in the spleen, lymph node, and tumor, and that treatment of tumor-bearing mice with low doses of IFN-gamma plus TNF-alpha reduced the frequency of E-MP12+ cells. Studies focused on characterizing the intratumoral ER-MP12+ cells and the mechanism by which they suppress T cell proliferation. When isolated and seeded in soft agar with CSF-containing LLC-LN7 supernatants, the ER-MP12+ cells grew into colonies, most of which contained both granulocytic and monocytic cells. Tumor-derived ER-MP12+ cells and their culture supernatants were suppressive to T cell proliferation. Among the factors produced by ER-MP12+ cells were TGF-beta, nitric oxide (NO), IL-10, and prostaglandin E2 (PGE2). However, it was TGF-beta and NO that mediated the suppression of T cell proliferation by ER-MP12+ cells. Intratumoral ER-MP12+ cells could be maintained as suppressive blastlike cells for at least 4 days in cultures containing CSFs, but adding IFN-gamma plus TNF-alpha to these cultures caused their differentiation mainly into nonsuppressive TNF-alpha-secreting monocytic cells. These results show that intratumoral ER-MP12+ cells having homology to GM-progenitor cells suppress T cell function by producing TGF-beta and NO. IFN-gamma/TNF-alpha treatment stimulates their differentiation and shift from production of TGF-beta and NO to production of TNF-alpha.

Suppression of T cell proliferation by tumor-induced granulocyte-macrophage progenitor cells producing transforming growth factor-beta and nitric oxide

Production of high levels of granulocyte-macrophage CSF (GM-CSF) by LLC-LN7 tumors results in myelopoietic stimulation and an increase in cells having natural suppressor (NS) activity. Prior studies showed these NS cells could be isolated from the bone marrow of tumor-bearing mice with an Ab (ER-MP12) that recognized GM-progenitor cells. The present study showed these cells to also be in the spleen, lymph node, and tumor, and that treatment of tumor-bearing mice with low doses of IFN-gamma plus TNF-alpha reduced the frequency of E-MP12+ cells. Studies focused on characterizing the intratumoral ER-MP12+ cells and the mechanism by which they suppress T cell proliferation. When isolated and seeded in soft agar with CSF-containing LLC-LN7 supernatants, the ER-MP12+ cells grew into colonies, most of which contained both granulocytic and monocytic cells. Tumor-derived ER-MP12+ cells and their culture supernatants were suppressive to T cell proliferation. Among the factors produced by ER-MP12+ cells were TGF-beta, nitric oxide (NO), IL-10, and prostaglandin E2 (PGE2). However, it was TGF-beta and NO that mediated the suppression of T cell proliferation by ER-MP12+ cells. Intratumoral ER-MP12+ cells could be maintained as suppressive blastlike cells for at least 4 days in cultures containing CSFs, but adding IFN-gamma plus TNF-alpha to these cultures caused their differentiation mainly into nonsuppressive TNF-alpha-secreting monocytic cells. These results show that intratumoral ER-MP12+ cells having homology to GM-progenitor cells suppress T cell function by producing TGF-beta and NO. IFN-gamma/TNF-alpha treatment stimulates their differentiation and shift from production of TGF-beta and NO to production of TNF-alpha.

Treating tumor-bearing mice with vitamin D3 diminishes tumor-induced myelopoiesis and associated immunosuppression, and reduces tumor metastasis and recurrence

Metastatic Lewis lung carcinoma (LLC-LN7) tumors that secrete granulocyte/macrophage-colony-stimulating factor (GM-CSF) stimulate myelopoiesis and induce bone marrow-derived immunosuppressor cells that are homologous to granulocyte/macrophage progenitor cells. In vitro treatment of the LLC-LN7 cells with 1 alpha,25-dihydroxyvitamin D3 reduced tumor cell production of suppressor-inducing activity, although suppressor-inducing activity could be restored by reconstituting the tumor supernatants with recombinant GM-CSF. Treatment of mice having LLC-LN7 tumors with vitamin D3 reduced tumor production of GM-CSF and the frequency of myeloid progenitor cells. This was associated with a reduction in immunosuppressor activity and an increase in T cell function. Vitamin D3 treatment of mice having palpable tumors transiently retarded tumor growth, but caused a prominent reduction in tumor metastasis. Treating mice with vitamin D3 after tumor excision resulted in a reduction in the tumor-induced myelopoietic stimulation and associated immunosuppressive activity, and enhanced T cell function. These mice had a markedly reduced incidence of tumor recurrence. The results of this study suggest that vitamin D3 treatment of mice with GM-CSF-secreting tumors can interrupt the myelopoiesis-associated immunosuppressor cascade and, in turn, reduce tumor metastasis and recurrence.

Ineffective immune enhancement by IL-12 in tumor-bearing mice whose immune depression is mediated by suppressive granulocyte-macrophage progenitor cells

Lewis lung carcinoma (LLC-LN7) tumors stimulate myelopoiesis and induce immunosuppressive granulocyte-macrophage (GM)-progenitor cells. Treating mice having palpable tumors with IL-12 enhanced the frequency of GM-progenitors and did not diminish GM-suppressor activity. Proliferation of splenic T-cells of tumor-bearers to Con-A or to anti-CD3 plus IL-2 was suppressed; this was not enhanced by IL-12 treatment. Also not stimulated was T-cell secretion of IL-2 in response to autologous tumor, or the intratumoral T-cell content. IL-12 slightly increased splenic IFN-gamma secretion, and increased cytotoxicity of lymph node (but not spleen) cells toward autologous tumor. In these tumor-bearing mice that were immune depressed as a result of GM-suppressor cells, immune modulatory effects of IL-12 were marginal and did not affect tumor size or metastasis.

Immune parameters of mice bearing human head and neck cancer

A xenogeneic human head and neck squamous cell carcinoma (HNSCC) model in immunocompetent mice was evaluated for its requirement of cyclosporine for progressive tumor growth. Tumor growth and T cell functions were assessed in mice receiving cyclosporine treatment for various lengths of time. Tumor cells were injected s.c. on day 1 and cyclosporine was injected i.p. daily on days 1, 1-7, 1-14, 1-21, or for the entire 28 days of tumor growth. All mice developed tumors. These tumors were confirmed to be squamous carcinomas of human origin histologically and by positive staining for human MHC class I antigen expression. Tumors were largest in mice that received cyclosporine for days 1-21 or days 1-28. Increased tumor size was associated with increased serum levels of tumor-reactive antibodies, an increased intratumoral frequency of CD4+ and CD8+ cells, but a diminished production of interleukin-2 (IL-2) by the tumor infiltrate. Also correlating with increasing tumor size was splenomegaly, a decline in the frequency, but not the absolute levels, of splenic CD4+ and CD8+ cells, and a diminished capacity to proliferate in response to concanavalin A and to be stimulated to secrete IL-2. The HNSCC tumors contributed to the immune decline since T cell functions were more depressed in the tumor bearers than in control mice receiving only cyclosporine treatment. These results demonstrate that human HNSCC tumor xenografts can grow in mice even with limited cyclosporine treatment, and that the survival of these xenografts may, in part, be due to a tumor-induced decline in select T cell functions.