Social factors influencing antiretroviral therapy (ART) adherence among Black men living with HIV who use illicit drugs

In the United States 1.2 million persons are HIV infected. Among men, HIV rates in Blacks are seven times higher than Whites. More Black men progress to AIDS because of treatment failure and adherence problems. Antiretroviral therapy (ART), the only treatment effective for long term HIV suppression, requires near perfect adherence. Illicit drug use and homelessness pose further challenges. Suboptimal ART adherence leads to HIV mutations that can render entire classes of medication ineffective and transmission of mutated HIV to others in the community. The purpose of this study was to investigate ART adherence behaviors of Black men living with HIV who use illicit drugs. A sample of 160 Black men living with HIV who use illicit drugs was recruited using flyers and snowball sampling. These men completed study questionnaires that included: demographics, the K-10, PSOM and Social Capital Integrated Questionnaire, among others. One-way ANOVAs, multiple regression, and path analysis were used to address the study's research questions. Most of the Black men in this sample were high school graduates and single, with high rates of being marginally housed and homeless. Unemployment and disability were common, and personal and household income was low. The men reported high numbers of sexual partners both over the past year and during their lifetimes, suggesting continued engagement in high risk behaviors. The majority of the men attributed their HIV to heterosexual sex, with sexual commoditization being common. About half of the 105 men currently taking ART reported the current regimen was their first. Patient-provider relationship was positively associated with tolerability of ART. ART adherence was greater with less psychological distress, lower frequency of current illicit drug use, and greater tolerability of ART. Partner status negatively influenced ART adherence. This study of Black men's ART adherence behaviors has implications for public health. It identified social context factors that influence ART adherence among the men and provides evidence to refine existing, or develop new, ART adherence interventions.

Improved sampling, pre-concentration, and detection of hidden explosives and illicit drugs by a novel solid phase microextraction geometry coupled to ion mobility spectrometry

The 9/11 Act mandates the inspection of 100% of cargo shipments entering the U.S. by 2012 and 100% inspection of air cargo by March 2010. So far, only 5% of inbound shipping containers are inspected thoroughly while air cargo inspections have fared better at 50%. Government officials have admitted that these milestones cannot be met since the appropriate technology does not exist. This research presents a novel planar solid phase microextraction (PSPME) device with enhanced surface area and capacity for collection of the volatile chemical signatures in air that are emitted from illicit compounds for direct introduction into ion mobility spectrometers (IMS) for detection. These IMS detectors are widely used to detect particles of illicit substances and do not have to be adapted specifically to this technology. For static extractions, PDMS and sol-gel PDMS PSPME devices provide significant increases in sensitivity over conventional fiber SPME. Results show a 50–400 times increase in mass detected of piperonal and a 2–4 times increase for TNT. In a blind study of 6 cases suspected to contain varying amounts of MDMA, PSPME-IMS correctly detected 5 positive cases with no false positives or negatives. One of these cases had minimal amounts of MDMA resulting in a false negative response for fiber SPME-IMS. A La (dihed) phase chemistry has shown an increase in the extraction efficiency of TNT and 2,4-DNT and enhanced retention over time. An alternative PSPME device was also developed for the rapid (seconds) dynamic sampling and preconcentration of large volumes of air for direct thermal desorption into an IMS. This device affords high extraction efficiencies due to strong retention properties under ambient conditions resulting in ppt detection limits when 3.5 L of air are sampled over the course of 10 seconds. Dynamic PSPME was used to sample the headspace over the following: MDMA tablets (12–40 ng detected of piperonal), high explosives (Pentolite) (0.6 ng detected of TNT), and several smokeless powders (26–35 ng of 2,4-DNT and 11–74 ng DPA detected). PSPME-IMS technology is flexible to end-user needs, is low-cost, rapid, sensitive, easy to use, easy to implement, and effective. ^

The construction and optimization of an ion mobility spectrometer for the analysis of explosives and drugs

Today, over 15,000 Ion Mobility Spectrometry (IMS) analyzers are employed at worldwide security checkpoints to detect explosives and illicit drugs. Current portal IMS instruments and other electronic nose technologies detect explosives and drugs by analyzing samples containing the headspace air and loose particles residing on a surface. Canines can outperform these systems at sampling and detecting the low vapor pressure explosives and drugs, such as RDX, PETN, cocaine, and MDMA, because these biological detectors target the volatile signature compounds available in the headspace rather than the non-volatile parent compounds of explosives and drugs.^ In this dissertation research volatile signature compounds available in the headspace over explosive and drug samples were detected using SPME as a headspace sampling tool coupled to an IMS analyzer. A Genetic Algorithm (GA) technique was developed to optimize the operating conditions of a commercial IMS (GE Itemizer 2), leading to the successful detection of plastic explosives (Detasheet, Semtex H, and C-4) and illicit drugs (cocaine, MDMA, and marijuana). Short sampling times (between 10 sec to 5 min) were adequate to extract and preconcentrate sufficient analytes (> 20 ng) representing the volatile signatures in the headspace of a 15 mL glass vial or a quart-sized can containing ≤ 1 g of the bulk explosive or drug.^ Furthermore, a research grade IMS with flexibility for changing operating conditions and physical configurations was designed and fabricated to accommodate future research into different analytes or physical configurations. The design and construction of the FIU-IMS were facilitated by computer modeling and simulation of ion’s behavior within an IMS. The simulation method developed uses SIMION/SDS and was evaluated with experimental data collected using a commercial IMS (PCP Phemto Chem 110). The FIU-IMS instrument has comparable performance to the GE Itemizer 2 (average resolving power of 14, resolution of 3 between two drugs and two explosives, and LODs range from 0.7 to 9 ng). ^ The results from this dissertation further advance the concept of targeting volatile components to presumptively detect the presence of concealed bulk explosives and drugs by SPME-IMS, and the new FIU-IMS provides a flexible platform for future IMS research projects.^

The Construction and Optimization on an Ion Mobility Spectrometer for the Analysis of Explosives and Drugs

Today, over 15,000 Ion Mobility Spectrometry (IMS) analyzers are employed at worldwide security checkpoints to detect explosives and illicit drugs. Current portal IMS instruments and other electronic nose technologies detect explosives and drugs by analyzing samples containing the headspace air and loose particles residing on a surface. Canines can outperform these systems at sampling and detecting the low vapor pressure explosives and drugs, such as RDX, PETN, cocaine, and MDMA, because these biological detectors target the volatile signature compounds available in the headspace rather than the non-volatile parent compounds of explosives and drugs. In this dissertation research volatile signature compounds available in the headspace over explosive and drug samples were detected using SPME as a headspace sampling tool coupled to an IMS analyzer. A Genetic Algorithm (GA) technique was developed to optimize the operating conditions of a commercial IMS (GE Itemizer 2), leading to the successful detection of plastic explosives (Detasheet, Semtex H, and C-4) and illicit drugs (cocaine, MDMA, and marijuana). Short sampling times (between 10 sec to 5 min) were adequate to extract and preconcentrate sufficient analytes (> 20 ng) representing the volatile signatures in the headspace of a 15 mL glass vial or a quart-sized can containing ≤ 1 g of the bulk explosive or drug. Furthermore, a research grade IMS with flexibility for changing operating conditions and physical configurations was designed and fabricated to accommodate future research into different analytes or physical configurations. The design and construction of the FIU-IMS were facilitated by computer modeling and simulation of ion’s behavior within an IMS. The simulation method developed uses SIMION/SDS and was evaluated with experimental data collected using a commercial IMS (PCP Phemto Chem 110). The FIU-IMS instrument has comparable performance to the GE Itemizer 2 (average resolving power of 14, resolution of 3 between two drugs and two explosives, and LODs range from 0.7 to 9 ng). The results from this dissertation further advance the concept of targeting volatile components to presumptively detect the presence of concealed bulk explosives and drugs by SPME-IMS, and the new FIU-IMS provides a flexible platform for future IMS research projects.

Genetic individualization of Cannabis sativa by a short tandem repeat multiplex system

Cannabis sativa is the most frequently used of all illicit drugs in the United States. Cannabis has been used throughout history for its stems in the production of hemp fiber, for its seed for oil and food, and for its buds and leaves as a psychoactive drug. Short tandem repeats (STRs), were chosen as molecular markers because of their distinct advantages over other genetic methods. STRs are co-dominant, can be standardized such that reproducibility between laboratories can be easily achieved, have a high discrimination power and can be multiplexed. ^ In this study, six STR markers previously described for Cannabis were multiplexed into one reaction. The multiplex reaction was able to individualize 98 Cannabis samples (14 hemp and 84 marijuana, authenticated as originating from 33 of the 50 United States) and detect 29 alleles averaging 4.8 alleles per loci. The data did not relate the samples from the same state to each other. This is the first study to report a single reaction six-plex and apply it to the analysis of almost 100 Cannabis samples of known geographic collection site. ^

The effects of peer teaching of infant massage on general elf-efficacy and mother infant attachment among mothers in a residential rehabilitation facility for drug addiction and substance abuse

Approximately 200 million people, 5% aged 15-64 worldwide are illicit drug or substance abusers (World Drug Report, 2006). Between 2002 and 2005, an average of 8.2% of 12 year olds and older in the Miami, Fort Lauderdale metropolitan areas used illicit drugs (SAMHSA, 2007). Eight percent of pregnant women, aged 15 to 25, were more likely to have used illicit drugs during pregnancy than pregnant women aged 26 to 44. Alcohol use was 9.8% and cigarette use was 18% for pregnant women aged 15 to 44 (SAMHSA, 2005). Approximately a quarter of annual birth defects are attributed to the exposure of drugs or substance abuse in utero (General Accounting Office, 1991). Physical, psychological and emotional challenges may be present for the illicit drug/substance abuse (ID/SA) mother and infant placing them at a disadvantage early in their relationship (Shonkoff & Marshall, 1990). Mothers with low self efficacy have insecurely attached infants (Donovan, Leavitt, & Walsh, 1987). As the ID/SA mother struggles with wanting to be a good parent, education is needed to help her care for her infant. In this experimental study residential rehabilitating ID/SA mothers peer taught infant massage. Massage builds bonding/attachment between mother and infant (Reese & Storm, 2008) and peer teaching is effective because participants have faced similar challenges and speak the same language (Boud, Cohen, & Sampson 2001). Quantitative data were collected using the General Self-Efficacy and Maternal Attachment Inventory-Revised Scale before and after the 4-week intervention program. A reported result of this study was that empowering ID/SA mothers increased their self-efficacy, which in turn allowed the mothers to tackle challenges encountered and created feelings of being a fit mother to their infants. This research contributes to the existing database promoting evidence-based practice in drug rehabilitation centers. Healthcare personnel, such as nurse educators and maternal-child health practitioners, can develop programs in drug rehabilitation centers that cultivate an environment where the ID/SA rehabilitating mothers can peer teach each other, while creating a support system. Using infant massage as a therapeutic tool can develop a healthy infant and nurture a more positive relationship between mother and infant.

The effects of American Sign Language on general self-efficacy and anxiety among mothers in a residential rehabilitation facility for drug addiction and substance abuse

Globally, approximately 208 million people aged 15 and older used illicit drugs at least once in the last 12 months; 2 billion consumed alcohol and tobacco consumption affected 25% (World Drug Report, 2008). In the United States, 20.1 million (8.0%) people aged 12 and older were illicit drug users, 129 million (51.6%) abused alcohol and 70.9 million (28.4%) used tobacco (SAMHSA/OAS, 2008).Usually considered a problem specific to men (Lynch, 2002), 5.2% of pregnant women aged 15 to 44 are also illicit drug and substance abusers (SAMHSA/OAS, 2007). During pregnancy, illicit drugs and substance abuse (ID/SA) can significantly affect a woman and her infant contributing to developmental and communication delays for the infant and influencing parenting abilities (Budden, 1996; March of Dimes, 2006b; Rossetti, 2000). Feelings of guilt and shame and stressful experiences influence approaches to parenting (Ashley, Marsden, & Brady, 2003; Brazelton, & Greenspan, 2000; Ehrmin, 2000; Johnson, & Rosen, 1990; Kelley, 1998; Rossetti, 2000; Velez et al., 2004; Zickler, 1999). Parenthood is an expanded role that can be a trying time for those lacking a sense of self-efficacy and creates a high vulnerability to stress (Bandura, 1994). Residential treatment programs for ID/SA mothers and their children provide an excellent opportunity for effective interventions (Finkelstein, 1994; Social Care Institute for Excellence, 2005). This experimental study evaluated whether teaching American Sign Language (ASL) to mothers living with their infants/children at an ID/SA residential treatment program increased the mothers’ self-efficacy and decreased their anxiety. Quantitative data were collected using the General Self-Efficacy Scale and the State-Trait Anxiety Inventory showing there was both a significant increase in self efficacy and decrease in anxiety for the mothers. This research adds to the knowledge base concerning ID/SA mothers’ caring for their infants/children. By providing a simple low cost program, easily incorporated into existing rehabilitation curricula, the study helps educators and healthcare providers better understand the needs of the ID/SA mothers. This study supports Bandura’s theory that parents who are secure in their efficacy can navigate through the various phases of their child’s development and are less vulnerable to stress (Bandura, 1994).

Social capital, HIV risk behavior and substance use among recent Latino immigrants in South Florida

Social capital, or social cohesion or group connectedness, can influence both HIV risk behavior and substance use. Because recent immigrants undergo a change in environment, one of the consequences can be a change in social capital. There may be an association among changes in social capital, and HIV risk behavior and substance use post immigration. The dissertation focused on the interface of these three variables among recent Latino immigrants (RLIs) in South Florida. The first manuscript is a systematic review of social capital and HIV risk behavior, and served as a partial background for the second and third manuscripts. Twelve papers with a measure of social capital as an independent variable and HIV risk as the dependent variable were included in the analysis. Eleven studies measured social capital at the individual level, and one study measured social capital at the group level. HIV risk was influenced by social capital, but the type of influence was dependent on the type of social capital and on the study population. Cognitive social capital, or levels of collective action, was protective against HIV in both men and women. The role of structural social capital, or levels of civic engagement/group participation, on HIV risk was dependent on the type of structural social capital and varied by gender. Microfinance programs and functional group participation were protective for women, while dysfunctional group participation and peer-level support may have increased HIV risk among men. The second manuscript was an original study assessing changes in social capital and HIV risk behavior pre to post immigration among RLIs in South Florida (n=527). HIV risk behavior was assessed through the frequency of vaginal-penile condom use, and the number of sexual partners. It was a longitudinal study using secondary data analysis to assess changes in social capital and HIV risk behavior pre immigration to two years post immigration, and to determine if there was a relationship between the two variables. There was an 8% decrease in total social capital (p < .05). Reporting of 'Never use' of condoms in the past 90 days increased in all subcategories (p < .05). Single men had a decrease in number of sexual partners (p < .05). Lower social capital measured on the dimension of 'friend and other' was marginally associated with fewer sexual partners. The third manuscript was another original study looking at the association between social capital and substance use among RLIs in South Florida (n=527). Substance use with measured by frequency of hazardous alcoholic drinking, and illicit drug use. It was a longitudinal study of social capital and substance-use from pre to two years post immigration. Post-immigration, social capital, hazardous drinking and illicit drug use decreased (p<.001). After adjusting for time, compared to males, females were less likely to engage in hazardous drinking (OR=.31, p<.001), and less likely to engage in illicit drug use (OR=.67, p=.01). Documentation status was a moderator between social capital and illicit drug use. 'Business' and 'Agency' social capital were associated with changes in illicit drug use for documented immigrants. After adjusting for gender and marital status, on average, documented immigrants with a one-unit increase in 'business' social capital were 1.2 times more likely to engage in illicit drug use (p<.01), and documented immigrants with one-unit increase in 'agency' social capital were 38% less likely to engage in illicit drug use (p<.01). 'Friend and other' social capital was associated with a decrease in illicit drug use among undocumented immigrants. After adjusting for gender and marital status, on average, undocumented immigrants with a one-unit increase in 'friend and other' social capital were 45% less likely to engage in hazardous drinking and 44% less likely to use illicit drugs (p<.01, p<.05). Studying these three domains is relevant because HIV continues to be a public health issue, particularly in Miami-Dade County, which is ranked among other U.S. regions with high rates of HIV/AIDS prevalence. Substance use is associated with HIV risk behavior; in most studies, increased substance use is associated with increased chances of HIV risk behavior. Immigration, which is the hypothesized catalyst for the change in social capital, has an impact on the dynamic of a society. Greater immigration can be burdensome on the host country's societal resources; however immigrants are also potentially a source of additional skilled labor for the workforce. Therefore, successful adaption of immigrants can have a positive influence on receiving communities. With Florida being a major receiver of immigrants to the U.S, this dissertation attempts to address an important public health issue for South Florida and the U.S. at large.

Improved dynamic headspace sampling and detection using capillary microextraction of volatiles coupled to gas chromatography mass spectrometry

Sampling and preconcentration techniques play a critical role in headspace analysis in analytical chemistry. My dissertation presents a novel sampling design, capillary microextraction of volatiles (CMV), that improves the preconcentration of volatiles and semivolatiles in a headspace with high throughput, near quantitative analysis, high recovery and unambiguous identification of compounds when coupled to mass spectrometry. The CMV devices use sol-gel polydimethylsiloxane (PDMS) coated microglass fibers as the sampling/preconcentration sorbent when these fibers are stacked into open-ended capillary tubes. The design allows for dynamic headspace sampling by connecting the device to a hand-held vacuum pump. The inexpensive device can be fitted into a thermal desorption probe for thermal desorption of the extracted volatile compounds into a gas chromatography-mass spectrometer (GC-MS). The performance of the CMV devices was compared with two other existing preconcentration techniques, solid phase microextraction (SPME) and planar solid phase microextraction (PSPME). Compared to SPME fibers, the CMV devices have an improved surface area and phase volume of 5000 times and 80 times, respectively. One (1) minute dynamic CMV air sampling resulted in similar performance as a 30 min static extraction using a SPME fiber. The PSPME devices have been fashioned to easily interface with ion mobility spectrometers (IMS) for explosives or drugs detection. The CMV devices are shown to offer dynamic sampling and can now be coupled to COTS GC-MS instruments. Several compound classes representing explosives have been analyzed with minimum breakthrough even after a 60 min. sampling time. The extracted volatile compounds were retained in the CMV devices when preserved in aluminum foils after sampling. Finally, the CMV sampling device were used for several different headspace profiling applications which involved sampling a shipping facility, six illicit drugs, seven military explosives and eighteen different bacteria strains. Successful detection of the target analytes at ng levels of the target signature volatile compounds in these applications suggests that the CMV devices can provide high throughput qualitative and quantitative analysis with high recovery and unambiguous identification of analytes.

The Effects of American Sign Language on General Self- Efficacy and Anxiety Among Mothers in a Residential Rehabilitation Facility for Drug Addiction and Substance Abuse

Globally, approximately 208 million people aged 15 and older used illicit drugs at least once in the last 12 months; 2 billion consumed alcohol and tobacco consumption affected 25% (World Drug Report, 2008). In the United States, 20.1 million (8.0%) people aged 12 and older were illicit drug users, 129 million (51.6%) abused alcohol and 70.9 million (28.4%) used tobacco (SAMHSA/OAS, 2008).Usually considered a problem specific to men (Lynch, 2002), 5.2% of pregnant women aged 15 to 44 are also illicit drug and substance abusers (SAMHSA/OAS, 2007). During pregnancy, illicit drugs and substance abuse (ID/SA) can significantly affect a woman and her infant contributing to developmental and communication delays for the infant and influencing parenting abilities (Budden, 1996; March of Dimes, 2006b; Rossetti, 2000). Feelings of guilt and shame and stressful experiences influence approaches to parenting (Ashley, Marsden, & Brady, 2003; Brazelton, & Greenspan, 2000; Ehrmin, 2000; Johnson, & Rosen, 1990; Kelley, 1998; Rossetti, 2000; Velez et al., 2004; Zickler, 1999). Parenthood is an expanded role that can be a trying time for those lacking a sense of self-efficacy and creates a high vulnerability to stress (Bandura, 1994). Residential treatment programs for ID/SA mothers and their children provide an excellent opportunity for effective interventions (Finkelstein, 1994; Social Care Institute for Excellence, 2005). This experimental study evaluated whether teaching American Sign Language (ASL) to mothers living with their infants/children at an ID/SA residential treatment program increased the mothers’ self-efficacy and decreased their anxiety. Quantitative data were collected using the General Self-Efficacy Scale and the State-Trait Anxiety Inventory showing there was both a significant increase in self efficacy and decrease in anxiety for the mothers. This research adds to the knowledge base concerning ID/SA mothers’ caring for their infants/children. By providing a simple low cost program, easily incorporated into existing rehabilitation curricula, the study helps educators and healthcare providers better understand the needs of the ID/SA mothers. This study supports Bandura’s theory that parents who are secure in their efficacy can navigate through the various phases of their child’s development and are less vulnerable to stress (Bandura, 1994).

The Effects of Peer Teaching of Infant Massage on General Self-Efficacy and Mother Infant Attachment Among Mothers in a Residential Rehabilitation Facility for Drug Addiction and Substance Abuse

Approximately 200 million people, 5% aged 15-64 worldwide are illicit drug or substance abusers (World Drug Report, 2006). Between 2002 and 2005, an average of 8.2% of 12 year olds and older in the Miami, Fort Lauderdale metropolitan areas used illicit drugs (SAMHSA, 2007). Eight percent of pregnant women, aged 15 to 25, were more likely to have used illicit drugs during pregnancy than pregnant women aged 26 to 44. Alcohol use was 9.8% and cigarette use was 18% for pregnant women aged 15 to 44 (SAMHSA, 2005). Approximately a quarter of annual birth defects are attributed to the exposure of drugs or substance abuse in utero (General Accounting Office, 1991). Physical, psychological and emotional challenges may be present for the illicit drug/substance abuse (ID/SA) mother and infant placing them at a disadvantage early in their relationship (Shonkoff & Marshall, 1990). Mothers with low self efficacy have insecurely attached infants (Donovan, Leavitt, & Walsh, 1987). As the ID/SA mother struggles with wanting to be a good parent, education is needed to help her care for her infant. In this experimental study residential rehabilitating ID/SA mothers peer taught infant massage. Massage builds bonding/attachment between mother and infant (Reese & Storm, 2008) and peer teaching is effective because participants have faced similar challenges and speak the same language (Boud, Cohen, & Sampson 2001). Quantitative data were collected using the General Self-Efficacy and Maternal Attachment Inventory-Revised Scale before and after the 4-week intervention program. A reported result of this study was that empowering ID/SA mothers increased their self-efficacy, which in turn allowed the mothers to tackle challenges encountered and created feelings of being a fit mother to their infants. This research contributes to the existing database promoting evidence-based practice in drug rehabilitation centers. Healthcare personnel, such as nurse educators and maternal-child health practitioners, can develop programs in drug rehabilitation centers that cultivate an environment where the ID/SA rehabilitating mothers can peer teach each other, while creating a support system. Using infant massage as a therapeutic tool can develop a healthy infant and nurture a more positive relationship between mother and infant.

Social Capital, HIV Risk Behavior and Substance Use among Recent Latino Immigrants in South Florida

Social capital, or social cohesion or group connectedness, can influence both HIV risk behavior and substance use. Because recent immigrants undergo a change in environment, one of the consequences can be a change in social capital. There may be an association among changes in social capital, and HIV risk behavior and substance use post immigration. The dissertation focused on the interface of these three variables among recent Latino immigrants (RLIs) in South Florida. The first manuscript is a systematic review of social capital and HIV risk behavior, and served as a partial background for the second and third manuscripts. Twelve papers with a measure of social capital as an independent variable and HIV risk as the dependent variable were included in the analysis. Eleven studies measured social capital at the individual level, and one study measured social capital at the group level. HIV risk was influenced by social capital, but the type of influence was dependent on the type of social capital and on the study population. Cognitive social capital, or levels of collective action, was protective against HIV in both men and women. The role of structural social capital, or levels of civic engagement/group participation, on HIV risk was dependent on the type of structural social capital and varied by gender. Microfinance programs and functional group participation were protective for women, while dysfunctional group participation and peer-level support may have increased HIV risk among men. The second manuscript was an original study assessing changes in social capital and HIV risk behavior pre to post immigration among RLIs in South Florida (n=527). HIV risk behavior was assessed through the frequency of vaginal-penile condom use, and the number of sexual partners. It was a longitudinal study using secondary data analysis to assess changes in social capital and HIV risk behavior pre immigration to two years post immigration, and to determine if there was a relationship between the two variables. There was an 8% decrease in total social capital (p ˂ .05). Reporting of ‘Never use’ of condoms in the past 90 days increased in all subcategories (p ˂ .05). Single men had a decrease in number of sexual partners (p ˂ .05). Lower social capital measured on the dimension of ‘friend and other’ was marginally associated with fewer sexual partners. The third manuscript was another original study looking at the association between social capital and substance use among RLIs in South Florida (n=527). Substance use with measured by frequency of hazardous alcoholic drinking, and illicit drug use. It was a longitudinal study of social capital and substance-use from pre to two years post immigration. Post-immigration, social capital, hazardous drinking and illicit drug use decreased (p˂.001). After adjusting for time, compared to males, females were less likely to engage in hazardous drinking (OR=.31, p˂.001), and less likely to engage in illicit drug use (OR=.67, p=.01). Documentation status was a moderator between social capital and illicit drug use. ‘Business’ and ‘Agency’ social capital were associated with changes in illicit drug use for documented immigrants. After adjusting for gender and marital status, on average, documented immigrants with a one-unit increase in ‘business’ social capital were 1.2 times more likely to engage in illicit drug use (p˂.01), and documented immigrants with one-unit increase in ‘agency’ social capital were 38% less likely to engage in illicit drug use (p˂.01). ‘Friend and other’ social capital was associated with a decrease in illicit drug use among undocumented immigrants. After adjusting for gender and marital status, on average, undocumented immigrants with a one-unit increase in ‘friend and other’ social capital were 45% less likely to engage in hazardous drinking and 44% less likely to use illicit drugs (p˂.01, p˂.05). Studying these three domains is relevant because HIV continues to be a public health issue, particularly in Miami-Dade County, which is ranked among other U.S. regions with high rates of HIV/AIDS prevalence. Substance use is associated with HIV risk behavior; in most studies, increased substance use is associated with increased chances of HIV risk behavior. Immigration, which is the hypothesized catalyst for the change in social capital, has an impact on the dynamic of a society. Greater immigration can be burdensome on the host country’s societal resources; however immigrants are also potentially a source of additional skilled labor for the workforce. Therefore, successful adaption of immigrants can have a positive influence on receiving communities. With Florida being a major receiver of immigrants to the U.S, this dissertation attempts to address an important public health issue for South Florida and the U.S. at large.

Improved Dynamic Headspace Sampling and Detection using Capillary Microextraction of Volatiles Coupled to Gas Chromatography Mass Spectrometry

Sampling and preconcentration techniques play a critical role in headspace analysis in analytical chemistry. My dissertation presents a novel sampling design, capillary microextraction of volatiles (CMV), that improves the preconcentration of volatiles and semivolatiles in a headspace with high throughput, near quantitative analysis, high recovery and unambiguous identification of compounds when coupled to mass spectrometry. The CMV devices use sol-gel polydimethylsiloxane (PDMS) coated microglass fibers as the sampling/preconcentration sorbent when these fibers are stacked into open-ended capillary tubes. The design allows for dynamic headspace sampling by connecting the device to a hand-held vacuum pump. The inexpensive device can be fitted into a thermal desorption probe for thermal desorption of the extracted volatile compounds into a gas chromatography-mass spectrometer (GC-MS). The performance of the CMV devices was compared with two other existing preconcentration techniques, solid phase microextraction (SPME) and planar solid phase microextraction (PSPME). Compared to SPME fibers, the CMV devices have an improved surface area and phase volume of 5000 times and 80 times, respectively. One (1) minute dynamic CMV air sampling resulted in similar performance as a 30 min static extraction using a SPME fiber. The PSPME devices have been fashioned to easily interface with ion mobility spectrometers (IMS) for explosives or drugs detection. The CMV devices are shown to offer dynamic sampling and can now be coupled to COTS GC-MS instruments. Several compound classes representing explosives have been analyzed with minimum breakthrough even after a 60 min. sampling time. The extracted volatile compounds were retained in the CMV devices when preserved in aluminum foils after sampling. Finally, the CMV sampling device were used for several different headspace profiling applications which involved sampling a shipping facility, six illicit drugs, seven military explosives and eighteen different bacteria strains. Successful detection of the target analytes at ng levels of the target signature volatile compounds in these applications suggests that the CMV devices can provide high throughput qualitative and quantitative analysis with high recovery and unambiguous identification of analytes.

Comprehensive forensic toxicological analysis of designer drugs

New designer drugs are constantly emerging onto the illicit drug market and it is often difficult to validate and maintaincomprehensive analytical methods for accurate detection of these compounds. Generally, toxicology laboratories utilize a screening method, such as immunoassay, for the presumptive identification of drugs of abuse. When a positive result occurs, confirmatory methods, such as gas chromatography (GC) or liquid chromatography (LC) coupled with mass spectrometry (MS), are required for more sensitive and specific analyses. In recent years, the need to study the activities of these compounds in screening assays as well as to develop confirmatory techniques to detect them in biological specimens has been recognized. Severe intoxications and fatalities have been encountered with emerging designer drugs, presenting analytical challenges for detection and identification of such novel compounds. The first major task of this research was to evaluate the performance of commercially available immunoassays to determine if designer drugs were cross-reactive. The second major task was to develop and validate a confirmatory method, using LC-MS, to identify and quantify these designer drugs in biological specimens.^ Cross-reactivity towards the cathinone derivatives was found to be minimal. Several other phenethylamines demonstrated cross-reactivity at low concentrations, but results were consistent with those published by the assay manufacturer or as reported in the literature. Current immunoassay-based screening methods may not be ideal for presumptively identifying most designer drugs, including the "bath salts." For this reason, an LC-MS based confirmatory method was developed for 32 compounds, including eight cathinone derivatives, with limits of quantification in the range of 1-10 ng/mL. The method was fully validated for selectivity, matrix effects, stability, recovery, precision, and accuracy. In order to compare the screening and confirmatory techniques, several human specimens were analyzed to demonstrate the importance of using a specific analytical method, such as LC-MS, to detect designer drugs in serum as immunoassays lack cross-reactivity with the novel compounds. Overall, minimal cross-reactivity was observed, highlighting the conclusion that these presumptive screens cannot detect many of the designer drugs and that a confirmatory technique, such as the LC-MS, is required for the comprehensive forensic toxicological analysis of designer drugs.^

Rapid inline derivatization of primary and secondary amine containing drugs by capillary electrophoresis with laser-induced fluorescence

Despite the ongoing "war on drugs" the seizure rates for phenethylamines and their analogues have been steadily increasing over the years. The illicit manufacture of these compounds has become big business all over the world making it all the more attractive to the inexperienced "cook". However, as a result, the samples produced are more susceptible to contamination with reactionary byproducts and leftover reagents. These impurities are useful in the analysis of seized drugs as their identities can help to determine the synthetic pathway used to make these drugs and thus, the provenance of these analytes. In the present work two fluorescent dyes, 4-fluoro-7-nitrobenzofurazan and 5-(4,6-dichlorotriazinyl)aminofluorescein, were used to label several phenethylamine analogues for electrophoretic separation with laser-induced fluorescence detection. The large scale to which law enforcement is encountering these compounds has the potential to create a tremendous backlog. In order to combat this, a rapid, sensitive method capable of full automation is required. Through the utilization of the inline derivatization method developed whereby analytes are labeled within the capillary efficiently in a minimum span of time, this can be achieved. The derivatization and separation parameters were optimized on the basis of a variety of experimentally determined factors in order to give highly resolved peaks in the fluorescence spectrum with limits of detection in the low µg/mL range.