Psychotropic Medication Prescribing: Youth in Foster Care Compared with Other Medicaid Enrollees

Objective: To compare the prevalence of psychotropic medication prescriptions among youth in foster care with those among nonfoster youth on Medicaid. Methods: Children ages 1-18 years in a region of a large southern state who were enrolled in their respective Medicaid plan for at least 30 days between 2014 and 2016 and had at least one health care claim were included. Medicaid prescription claims were categorized by class: alpha agonists, anxiolytics, antidepressants, antipsychotics, mood stabilizers, and stimulants. Primary mental health (MH) or developmental disorder (DD) diagnostic groups were identified for each class. Analyses included chi-square tests, t-tests, Wilcoxon sign rank tests, and logistic regression. Results: A total of 388,914 nonfoster and 8426 children in foster care were included. Overall, 8% of nonfoster and 35% of foster youth were dispensed at least one prescription for a psychotropic medication. Prevalence was higher for youth in care within each drug class and, with one exception, across all age groups. Among children prescribed a psychotropic medication, the mean number of drug classes prescribed was 1.4 (SD 0.8) and 2.9 (SD 1.4) for nonfoster and foster youth, respectively (p < 0.000). Except for anxiolytics and mood stabilizers, more children in foster care were prescribed psychotropic medications without an MH or DD diagnosis. Finally, children in foster care experienced 6.8 (95% CI: 6.5-7.2) times higher odds of being prescribed a psychotropic medication than their nonfoster peers, after controlling for age group, gender, and number of mental and developmental diagnoses. Conclusions: Across all age groups, children in foster care on Medicaid were prescribed psychotropic medications disproportionately more than their nonfoster peers on Medicaid. In addition, children in foster care were significantly more likely to be prescribed psychotropic medication absent an MH or DD diagnosis.

Heightened cocaine-seeking in male rats associates with a distinct transcriptomic profile in the medial prefrontal cortex

Drug overdose deaths involving cocaine have skyrocketed, an outcome attributable in part to the lack of FDA-approved medications for the treatment of cocaine use disorder (CUD), highlighting the need to identify new pharmacotherapeutic targets. Vulnerability to cocaine-associated environmental contexts and stimuli serves as a risk factor for relapse in CUD recovery, with individual differences evident in the motivational aspects of these cues. The medial prefrontal cortex (mPFC) provides top-down control of striatal circuitry to regulate the incentive-motivational properties of cocaine-associated stimuli. Clinical and preclinical studies have identified genetic variations that impact the degree of executive restraint over drug-motivated behaviors, and we designed the present study to employ next-generation sequencing to identify specific genes associated with heightened cue-evoked cocaine-seeking in the mPFC of male, outbred rats. Rats were trained to stably self-administer cocaine, and baseline cue-reinforced cocaine-seeking was established. Rats were phenotyped as either high cue (HC) or low cue (LC) responders based upon lever pressing for previously associated cocaine cues and allowed 10 days of abstinence in their home cages prior to mPFC collection for RNA-sequencing. The expression of 309 genes in the mPFC was significantly different in HC vs. LC rats. Functional gene enrichment analyses identified ten biological processes that were overrepresented in the mPFC of HC vs. LC rats. The present study identifies distinctions in mPFC mRNA transcripts that characterizes individual differences in relapse-like behavior and provides prioritized candidates for future pharmacotherapeutics aimed to help maintain abstinence in CUD. In particular the Htr2c gene, which encodes the serotonin 5-HT_2C receptor (5-HT_2CR), is expressed to a lower extent in HC rats, relative to LC rats. These findings build on a plethora of previous studies that also point to the 5-HT_2CR as an attractive target for the treatment of CUD.

Role of neuropeptide neuromedin U in the nucleus accumbens shell in cocaine self-administration in male rats

The nucleus accumbens shell (NAcSh) and its afferent and efferent neuronal projections control key aspects of motivation for cocaine. A recently described regulator of γ-aminobutyric acid (GABA) projections from the dorsal raphe nucleus (DRN) to the NAcSh (DRN → NAcSh) is the neuropeptide neuromedin U (NMU). Here, we find that systemic administration of NMU decreases breakpoint for cocaine on a progressive ratio schedule of reinforcement in male rats. Employing a retrograde adeno-associated virus (AAV), we found that RNAi-mediated knockdown of the NMU receptor 2 (NMUR2) in afferent DRN projections to the NAcSh increases the breakpoint for cocaine. Our previous studies demonstrated that NMU regulates GABA release in the NAcSh, and our current investigation found that systemic NMU administration suppresses cocaine-evoked GABA release in the NAcSh and increases phosphorylated c-Fos expression in neurons projecting from the NAcSh to the ventral pallidum (VP). To further probe the impact of NMU/NMUR2 on neuroanatomical pathways regulating motivation for cocaine, we employed multi-viral transsynaptic studies. Using a combination of rabies virus and retrograde AAV helper virus, we mapped the impact of NMU across three distinct brain regions simultaneously and found a direct connection of GABAergic DRN neurons to the NAcSh → VP pathway. Together, these data reveal that NMU/NMUR2 modulates a direct connection within the GABAergic DRN → NAcSh → VP circuit that diminishes breakpoints for cocaine. These findings importantly advance our understanding of the neurochemical underpinnings of pathway-specific regulation of neurocircuitry that may regulate cocaine self-administration, providing a unique therapeutic perspective.

Subanesthetic ketamine with an AMPAkine attenuates motor impulsivity in rats

The concept of 'impulse control' has its roots in early psychiatry and today has progressed into a well-described, although poorly understood, multidimensional endophenotype underlying many neuropsychiatric disorders (e.g., attention deficit hyperactivity disorder, schizophrenia, substance use disorders). There is mounting evidence suggesting that the cognitive and/or behavioral dimensions underlying impulsivity are driven by dysfunctional glutamate (Glu) neurotransmission via targeted ionotropic Glu receptor (GluR) [e.g., N-methyl-D-aspartate receptor (NMDAR), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)] mechanisms and associated synaptic alterations within key brain nodes. Ketamine, a noncompetitive NMDAR antagonist and FDA-approved for treatment-resistant depression, induces a 'glutamate burst' that drives resculpting of the synaptic milieu, which lasts for several days to a week. Thus, we hypothesized that single and repeated treatment with a subanesthetic ketamine dose would normalize motor impulsivity. Next, we hypothesized that AMPAR positive allosteric modulation, alone or in combination with ketamine, would attenuate impulsivity and provide insight into the mechanisms underlying GluR dysfunction relevant to motor impulsivity. To measure motor impulsivity, outbred male Sprague-Dawley rats were trained on the one-choice serial reaction time task. Rats pretreated with single or repeated (3 days) administration of ketamine (10 mg/kg; i.p.; 24-h pretreatment) or with the AMPAkine HJC0122 (1 or 10 mg/kg; i.p.; 30-min pretreatment) exhibited lower levels of motor impulsivity vs. control. Combination of single or repeated ketamine plus HJC0122 also attenuated motor impulsivity vs. control. We conclude that ligands designed to promote GluR signaling represent an effective pharmacological approach to normalize impulsivity and subsequently, neuropsychiatric disorders marked by aberrant impulse control.

Glutamatergic projections from homeostatic to hedonic brain nuclei regulate intake of highly palatable food

Food intake is a complex behavior regulated by discrete brain nuclei that integrate homeostatic nutritional requirements with the hedonic properties of food. Homeostatic feeding (i.e. titration of caloric intake), is typically associated with hypothalamic brain nuclei, including the paraventricular nucleus of the hypothalamus (PVN). Hedonic feeding is driven, in part, by the reinforcing properties of highly palatable food (HPF), which is mediated by the nucleus accumbens (NAc). Dysregulation of homeostatic and hedonic brain nuclei can lead to pathological feeding behaviors, namely overconsumption of highly palatable food (HPF), that may drive obesity. Both homeostatic and hedonic mechanisms of food intake have been attributed to several brain regions, but the integration of homeostatic and hedonic signaling to drive food intake is less clear, therefore we aimed to identify the neuroanatomical, functional, and behavioral features of a novel PVN → NAc circuit. Using viral tracing techniques, we determined that PVN → NAc has origins in the parvocellular PVN, and that PVN → NAc neurons express VGLUT1, a marker of glutamatergic signaling. Next, we pharmacogenetically stimulated PVN → NAc neurons and quantified both gamma-aminobutyric acid (GABA) and glutamate release and phospho-cFos expression in the NAc and observed a robust and significant increase in extracellular glutamate and phospho-cFos expression. Finally, we pharmacogenetically stimulated PVN → NAc which decreased intake of highly palatable food, demonstrating that this glutamatergic circuitry regulates aspects of feeding.

Long-Chain Omega-3 Fatty Acid Intake Is Associated with Age but not Cognitive Performance in an Older Australian Sample

BACKGROUND

Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) are essential nutrients and may be capable of delaying age-related cognitive decline. However, previous studies indicate that Australians are not meeting recommendations for LCn-3 PUFA intake. The current study therefore examined LCn-3 PUFA intake in an older Australia sample, as well as associations between LCn-3 PUFA intake and cognitive function.

METHODS

Cross-sectional data were collected from 90 adults aged 50 to 80 years. LCn-3 PUFA intake was assessed using a food frequency questionnaire and red blood cell fatty acid profiles were used to calculate the Omega-3 Index (RBC n-3 index). Cognitive function was measured using Addenbrooke's Cognitive Examination-III.

RESULTS

Positive associations were observed between age and RBC n-3 index (b=0.06, 95% CI: 0.01 - 0.10, P=0.01), and age and LCn-3 PUFA intake from fish oil capsules (b=17.5, 95% CI: 2.4 - 32.5 mg/day, P=0.02). When adjusting for LCn-3 PUFA from fish oil capsules, the association between age and RBC n-3 index was no longer significant. No associations were observed between LCn-3 PUFA intake and cognitive function.

CONCLUSION

LCn-3 PUFA and fish oil consumption increased with age in this sample of older Australians, particularly due to supplement intake. However, LCn-3 PUFA intake was not associated with cognitive function.

Combined spinal/caudal catheter anesthesia: extending the boundaries of regional anesthesia for complex pediatric urological surgery

BACKGROUND

Spinal anesthesia (SA) is an established anesthetic technique for short outpatient pediatric urological cases. To avoid general anesthesia (GA) and expand regional anesthetics to longer and more complex pediatric surgeries, the authors began a program using a combined spinal/caudal catheter (SCC) technique.

STUDY DESIGN

The authors retrospectively reviewed the charts of all patients scheduled for surgery under SCC between December 2016 and April 2018 and recorded age, gender, diagnosis, procedure, conversion to GA/airway intervention, operative time, neuraxial and intravenous medications administered, complications, and outcomes. The SCC technique typically involved an initial intrathecal injection of 0.5% isobaric bupivacaine followed by placement of a caudal epidural catheter. At the discretion of the anesthesiologist, patients received 0.5 mg per kilogram of oral midazolam approximately 30 min prior to entering the operating room. One hour after the intrathecal injection, 3% chloroprocaine was administered via the caudal catheter to prolong the duration of surgical block. Intra-operative management included either continuous infusion or bolus dosing of dexmedetomidine, as needed, for patient comfort and to optimize surgical conditions. Prior to removal of caudal catheter in the post-anesthesia care unit, a supplemental bolus dose of local anesthesia was given through the catheter to provide prolonged post-operative analgesia.

RESULTS

Overall, 23 children underwent attempted SCC. SA was unsuccessful in three patients, and surgery was performed under GA. The remaining 20 children all had successful SCC placement. There were 11 girls and nine boys, with a mean age of 16.5 months (3.3-43.8). Surgeries performed under SCC included seven ureteral reimplantations, two ureterocele excisions/reimplantations, two megaureter repairs, four first-stage hypospadias repairs, one distal hypospadias repair, one second-stage hypospadias repair, two feminizing genitoplasties, and one open pyeloplasty. Average length of surgery was 109 min (range 63-172 min). Pre-operative midazolam was given in 13/20 (65%). All SCC patients were spontaneously breathing room air during the operation, and there were no airway interventions. Only one SCC patient received opioids intra-operatively. There were no intra-operative or perioperative complications.

DISCUSSION

This pilot study shows that the technique of SCC allows one to do more complex urologic surgery under regional anesthesia than what would be possible under pure SA alone. The main limitations of the study include the relatively small number of patients and the small median length of the operative procedures. As a proof of concept, however, this does show that complex genital surgery bladder level procedures such as ureteral reimplantation can be performed under regional anesthesia.

CONCLUSION

SCC allows for more complex surgeries to be performed exclusively under regional anesthesia, thus obviating the need for airway intervention, minimizing or eliminating the use of opioids, and thus avoiding known and potential risks associated with GA. The latter is of particular importance given current concerns regarding hypothetical neurocognitive effects of GA on children aged below 3 years.

Cocaine-Evoked Locomotor Activity Negatively Correlates With the Expression of Neuromedin U Receptor 2 in the Nucleus Accumbens

Cocaine use disorder (CUD) is characterized by repeated cycles of drug seeking and drug taking. Currently, there are no available pharmacotherapies to treat CUD, partially due to a lack of a mechanistic understanding of cocaine-evoked alterations in the brain that drive drug-related behaviors. Repeated cocaine use alters expression of numerous genes in addiction-associated areas of the brain and these alterations are in part driven by inter-subject genetic variability. Recent findings have shown the neuropeptide neuromedin U (NMU) and its receptor NMU receptor 2 (NMUR2) decrease drug-related behaviors, but it is unknown if substances of abuse alter NMU or NMUR2 expression. Here, rats were given twice daily saline or cocaine (15 mg/kg, intraperitoneal (IP)) for 5 days and then 7 days with no treatment. All rats were then given a single cocaine treatment and locomotor activity was measured in the acute (non-sensitized) and repeated drug exposure (sensitized) groups. Immediately following locomotor assay, tissue was taken and we demonstrate that accumbal NMUR2 mRNA expression, but not NMU mRNA expression, is negatively correlated with non-sensitized cocaine-evoked locomotor activity, but the correlation is lost following cocaine sensitization. Furthermore, in a separate cohort NMUR2 protein levels also negatively correlated with cocaine-evoked locomotor activity based on immunohistochemical stereology for NMUR2 protein expression. These findings are the first to demonstrate that repeated cocaine exposure causes dysregulated expression of NMUR2 and highlight the deleterious effects of repeated cocaine exposure on neurobiological receptor systems. Restoring the normal function of NMUR2 could be beneficial to the treatment of CUD.

Environmental Enrichment and Social Isolation Mediate Neuroplasticity of Medium Spiny Neurons through the GSK3 Pathway

Resilience and vulnerability to neuropsychiatric disorders are linked to molecular changes underlying excitability that are still poorly understood. Here, we identify glycogen-synthase kinase 3β (GSK3β) and voltage-gated Na+ channel Nav1.6 as regulators of neuroplasticity induced by environmentally enriched (EC) or isolated (IC) conditions-models for resilience and vulnerability. Transcriptomic studies in the nucleus accumbens from EC and IC rats predicted low levels of GSK3β and SCN8A mRNA as a protective phenotype associated with reduced excitability in medium spiny neurons (MSNs). In vivo genetic manipulations demonstrate that GSK3β and Nav1.6 are molecular determinants of MSN excitability and that silencing of GSK3β prevents maladaptive plasticity of IC MSNs. In vitro studies reveal direct interaction of GSK3β with Nav1.6 and phosphorylation at Nav1.6T1936 by GSK3β. A GSK3β-Nav1.6T1936 competing peptide reduces MSNs excitability in IC, but not EC rats. These results identify GSK3β regulation of Nav1.6 as a biosignature of MSNs maladaptive plasticity.

Preclinical modeling of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) represent a heterogeneous group of hematological clonal disorders. Here, we have tested the bone marrow (BM) cells from 38 MDS patients covering all risk groups in two immunodeficient mouse models: NSG and NSG-S. Our data show comparable level of engraftment in both models. The level of engraftment was patient specific with no correlation to any specific MDS risk group. Furthermore, the co-injection of mesenchymal stromal cells (MSCs) did not improve the level of engraftment. Finally, we have developed an in vitro two-dimensional co-culture system as an alternative tool to in vivo. Using our in vitro system, we have been able to co-culture CD34+ cells from MDS patient BM on auto- and/or allogeneic MSCs over 4 weeks with a fold expansion of up to 600 times. More importantly, these expanded cells conserved their MDS clonal architecture as well as genomic integrity.

Cognitive deficits associated with a high-fat diet and insulin resistance are potentiated by overexpression of ecto-nucleotide pyrophosphatase phosphodiesterase-1

There is growing evidence that over consumption of high-fat foods and insulin resistance may alter hippocampal-dependent cognitive function. To study the individual contributions of diet and peripheral insulin resistance to learning and memory, we used a transgenic mouse line that overexpresses ecto-nucleotide pyrophosphatase phosphodiesterase-1 in adipocytes, which inhibits the insulin receptor. Here, we demonstrate that a model of peripheral insulin resistance exacerbates high-fat diet induced deficits in performance on the Morris Water Maze task. This finding was then reviewed in the context of the greater literature to explore potential mechanisms including triglyceride storage, adiponectin, lipid composition, insulin signaling, oxidative stress, and hippocampal signaling. Together, these findings further our understanding of the complex relationship among peripheral insulin resistance, diet and memory.

Can Discipline Education be Culturally Sensitive?

Objectives Inappropriate discipline such as harsh physical punishment is a social determinant of health. The objective was to determine if a brief parent training intervention that teaches discipline strategies is culturally sensitive. Methods English or Spanish-speaking parents of 1-5 year old children viewed a multimedia program that teaches appropriate discipline strategies. The intervention, Play Nicely, was viewed in the exam room before the physician's visit. Parents viewed 4 of 20 discipline strategies of their choosing; the average viewing time was 7 min. Results Of 204 parents eligible to participate, 197 (96 %) completed the study; 41 % were Black, 31 % were White, and 21 % were Hispanic. At least 80 % of parents from each racial/ethnic group reported that the program built their confidence to care for their child, addressed their family needs, explained things in a way they could understand, respected their family values, and was sensitive to their personal beliefs. Overall, 80 % of parents reported that the program answered individual questions. One parent (0.5 %) reported that the program did not respect her family values. Conclusions for Practice Discipline education can be integrated into the pediatric primary care clinic in a way that is family-centered and culturally sensitive for the majority of parents. The results have implications for the development and implementation of population-based parenting programs and the primary prevention of child abuse and violence.

The relationship of TP53 R72P polymorphism to disease outcome and TP53 mutation in myelodysplastic syndromes

Nonsynonymous TP53 exon 4 single-nucleotide polymorphism (SNP), R72P, is linked to cancer and mutagen susceptibility. R72P associations with specific cancer risk, particularly hematological malignancies, have been conflicting. Myelodysplastic syndrome (MDS) with chromosome 5q deletion is characterized by erythroid hypoplasia arising from lineage-specific p53 accumulation resulting from ribosomal insufficiency. We hypothesized that apoptotically diminished R72P C-allele may influence predisposition to del(5q) MDS. Bone marrow and blood DNA was sequenced from 705 MDS cases (333 del(5q), 372 non-del(5q)) and 157 controls. Genotype distribution did not significantly differ between del(5q) cases (12.6% CC, 38.1% CG, 49.2% GG), non-del(5q) cases (9.7% CC, 44.6% CG, 45.7% GG) and controls (7.6% CC, 37.6% CG, 54.8% GG) (P=0.13). Allele frequency did not differ between non-del(5q) and del(5q) cases (P=0.91) but trended towards increased C-allele frequency comparing non-del(5q) (P=0.08) and del(5q) (P=0.10) cases with controls. Median lenalidomide response duration increased proportionate to C-allele dosage in del(5q) patients (2.2 (CC), 1.3 (CG) and 0.89 years (GG)). Furthermore, C-allele homozygosity in del(5q) was associated with prolonged overall and progression-free survival and non-terminal interstitial deletions that excluded 5q34, whereas G-allele homozygozity was associated with inferior outcome and terminal deletions involving 5q34 (P=0.05). These findings comprise the largest MDS R72P SNP analysis.

Newborn pulse oximetry screening to detect critical congenital heart disease

OBJECTIVES

To describe current practice and clarify provider opinion in the US with regard to newborn pulse oximetry screening (NPOx) for critical congenital heart disease.

STUDY DESIGN

An internet-based questionnaire was forwarded to general pediatricians, neonatologists, and family medicine physicians. Physicians were surveyed regarding involvement in newborn medicine, knowledge of NPOx recommendations, and opinions regarding screening. NPOx protocol specifics were also queried.

RESULTS

Survey responses (n = 481) were received with 349 respondents involved in newborn medicine. Forty-nine percent (95% CI 44%-54%) of those involved in newborn medicine practice at a hospital with a NPOx protocol. Sixty-six percent of providers endorsed it as an effective tool, 20% required more education, 11% questioned its sensitivity, and 3% had no opinion. Sixty-five percent of providers were aware of recent state legislation mandating its use and 46% reported awareness of the addition of NPOx to the Recommended Uniform Screening Panel. Eighty-four percent of providers who practice at a hospital without a NPOx protocol were interested in its implementation. NPOx protocols varied and were not uniform with differences in time of test, location of probe, and values considered positive.

CONCLUSIONS

NPOx has grown in its prevalence and acceptance in clinical practice, yet is far from universal in its application and design despite the recent American Academy of Pediatrics endorsement and its addition to the Recommended Uniform Screening Panel. The majority of physicians involved in newborn medicine deemed it an effective tool.

Protective Behavioral Strategies, Social Norms, and Alcohol-Related Outcomes

The present study examined the unique contributions of protective behavioral strategies and social norms in predicting alcohol-related outcomes. Participants were 363 students from a large public university in the Midwest who reported at least one binge-drinking episode (5+/4+ drinks for men/women in one sitting) in the past 30 days. Data were collected 1/2010-3/2011. We used SEM to test models where protective behavioral strategies (PBS) and social norms were predictors of both alcohol use and alcohol-related problems, after controlling for the effects of gender. Both PBS and descriptive norms had relationships with alcohol use. PBS also had a relationship with alcohol-related problems. Overall, the findings suggest that PBS and social norms have unique associations with distinct alcohol-related outcomes.

Examining a curvilinear model of readiness to change and alcohol consumption

Research examining the relationship between readiness to change and alcohol consumption among college students is inconsistent. The purpose of the present study was to extend these findings, using two different measures of readiness to change. We hypothesized a curvilinear effect would occur such that the relationship between readiness to change and alcohol use would be relatively low for students low and high on readiness to change, whereas the relationship would be relatively high for those with moderate levels of readiness to change. Data were collected from two studies: Study 1 consisted of 263 undergraduate students and Study 2 consisted of 245 undergraduates participating in either intercollegiate or recreational athletics at three US universities. In Study 1, we examined the association between both linear and quadratic scores on a readiness to change measure and alcohol use. In Study 2, we examined the relationship between scores on a stage of change measure that included subscales indicative of different levels of readiness to change and alcohol use. The pattern of relationships supported the existence of an effect where the highest levels of alcohol use occurred among those with scores representing moderate levels of readiness to change.

The efficacy of single-component brief motivational interventions among at-risk college drinkers

OBJECTIVE

College students are an at-risk population for heavy drinking and negative alcohol-related outcomes. Research has established that brief, multicomponent motivational interviewing-based interventions can be effective at reducing alcohol use or related problems, but less is known about the efficacy of individual components within these interventions. The purpose of this study was to test the efficacy of 2 single-component, in-person, brief (15-20 min) alcohol interventions: personalized normative feedback (PNF) and protective behavioral strategies feedback (PBSF).

METHOD

Data were collected on 365 undergraduate students from a large Midwestern university (65% women; 89% White) who were randomly assigned to 1 of 3 conditions: PNF, PBSF, or alcohol education (AE). Participants completed measures of alcohol use, alcohol-related problems, social norms, and protective behavioral strategies.

RESULTS

Results indicated that the PNF intervention was efficacious relative to the other conditions at reducing alcohol use and that its effects at 6-month follow-up were mediated by changes in perceived norms at the 1-month follow-up. The PBSF intervention was not efficacious at reducing alcohol use or alcohol-related problems.

CONCLUSIONS

These findings provide support for the efficacy of an in-person PNF intervention and theoretical support for the hypothesized mechanisms of change in the intervention. Implications for researchers and clinicians are discussed.

Marijuana use, driving, and related cognitions

The purpose of the present study was to examine cognitive risk factors for driving after use of marijuana. We tested whether marijuana outcome expectancies and specific cognitions about driving after marijuana use were uniquely associated with the likelihood and frequency of driving while high (DWH) and riding with a high driver (RWHD). Participants were college students recruited from introductory psychology classes at a Midwestern university who reported ever using marijuana in their lifetime and reported having access to a car or driving at least once a month (n = 506). Greater perceived dangerousness of DWH was associated with decreased likelihood of DWH and RWHD. Negative marijuana expectancies were associated with decreased likelihood of DWH, and social norms were associated with decreased likelihood of RWHD. All cognitive predictors were associated with decreased frequency of DWH and RWHD for individuals with the propensity to engage in these behaviors. Findings suggest interventions to reduce risk of DWH and RWHD may benefit from targeting general expectancies about the negative effects of marijuana. Similarly, results suggest increasing students' knowledge of the potential danger of DWH may help to reduce the likelihood and frequency of DWH and RWHD.

Assessing the Dependability of Drinking Motives via Generalizability Theory

This study assessed the score reliability of the Drinking Motives Questionnaire-Revised (DMQ-R) via generalizability theory. Participants (n = 367 college students) completed the DMQ-R at three time points. Across subscale scores, persons, persons × occasions, and persons × items interactions accounted for meaningful variance. Findings illustrate advantages of generalizability theory-based techniques.

Do protective behavioral strategies moderate the relationship between negative urgency and alcohol-related outcomes among intercollegiate athletes?

OBJECTIVE

The purpose of this study was to examine the moderating effect of protective behavioral strategies on the relationship between negative urgency and alcohol outcomes.

METHOD

Participants were college students who endorsed participating in club/intramural or varsity athletics. The students (N = 234; 73.9% female) completed measures of negative urgency, protective behavioral strategies, alcohol use, and alcohol-related problems. Separate hierarchical multiple regression analyses were conducted for each subscale of the Protective Behavioral Strategies Scale to test for moderation.

RESULTS

Results indicated that protective behavioral strategies aimed at serious harm reduction moderated the relationship between negative urgency and alcohol use, whereas strategies aimed at avoiding excessive or rapid drinking moderated the relationship between negative urgency and alcohol-related problems. Strategies that involved planning drinking activities in advance did not moderate the relationship between negative urgency and alcohol outcomes.

CONCLUSIONS

The current investigation provides further evidence for the role of protective behavioral strategies against known risk factors for alcohol use and related problems. Further, the paper suggests that type of strategy used matters when attempting to mitigate the relationship between negative urgency and alcohol outcomes. Limitations and future directions are discussed.

Ergolytic/ergogenic effects of creatine on aerobic power

This study evaluated the effects of creatine (Cr) loading and sex differences on aerobic running performance. 27 men (mean±SD; age: 22.2±3.1 years, ht: 179.5±8.7 cm, wt: 78.0±9.8 kg) and 28 women (age: 21.2±2.1 years, ht: 166.0±5.8 cm, wt: 63.4±8.9 kg) were randomly assigned to either creatine (Cr, di-creatine citrate; n=27) or a placebo (PL; n=28) group, ingesting 1 packet 4 times daily (total of 20 g/day) for 5 days. Aerobic power (maximal oxygen consumption: VO2max) was assessed before and after supplementation using open circuit spirometry (Parvo-Medics) during graded exercise tests on a treadmill. 4 high-speed runs to exhaustion were conducted at 110, 105, 100, and 90% of peak velocity to determine critical velocity (CV). Distances achieved were plotted over times-to-exhaustion and linear regression was used to determine the slopes (critical velocity, CV) assessing aerobic performance. The results indicated that Cr loading did not positively or negatively influence VO2max, CV, time to exhaustion or body mass (p>0.05). These results suggest Cr supplementation may be used in aerobic running activities without detriments to performance.

Predictors of alcohol-related outcomes in college athletes: the roles of trait urgency and drinking motives

Research has shown that college students participating in athletics drink more than other students, yet relatively few studies have examined variables that are associated with alcohol-related outcomes among this population. The purpose of this study was to examine the relationships among trait urgency, general drinking motives and sport-related drinking motives, and both alcohol use and alcohol-related problems. Data were collected from 198 college students participating in either intercollegiate or recreational athletics at three U.S. universities. Structural equation modeling was used to examine a series of theoretically derived explanatory models. All variables included in the model were directly associated with alcohol use and/or alcohol-related problems. The specific patterns of relationships differed across the motives and trait urgency variables. Sport-related coping motives, sport-related positive reinforcement motives, and general enhancement motives had direct relationships with alcohol use, while trait urgency, general coping motives, and sport-related positive reinforcement motives had direct relationships with alcohol-related problems. Several indirect effects on alcohol use and alcohol-related problems were also found. This study suggests that general drinking motives, sport-related drinking motives, and trait urgency all serve as important predictors of alcohol-related outcomes in college athletes.

Moderators of the relationship between physical activity and alcohol consumption in college students

OBJECTIVE

Among college students, several studies have found a positive relationship between physical activity and alcohol use. The current study tested gender, Greek status, and ethnicity as potential moderators of the physical activity-alcohol use relationship.

PARTICIPANTS

Participants were college freshmen (n = 310) endorsing alcohol/drug use.

METHODS

Students completed questionnaires assessing a number of health behaviors.

RESULTS

Results indicated that gender and Greek status were significant moderators of the relationship between physical activity and alcohol consumption. There was a positive relationship between physical activity and alcohol use for men and Greeks, but not for females and non-Greeks.

CONCLUSIONS

These findings suggest that exercise does not serve as a protective factor for any of the subgroups of college students studied and is positively associated with drinking among college students who are men and/or involved with the Greek system.

Reinforcing efficacy moderates the relationship between impulsivity-related traits and alcohol use

Studies have shown that impulsivity-related traits are associated with alcohol use among college students. It is possible that individual differences in susceptibility to reinforcement from alcohol, which reflects the extent to which an individual values alcohol, moderates this relationship. Data were collected from 255 college students at a large, urban university who reported consuming alcohol at least once in the past 30 days. Two impulsivity-related-traits, Urgency and Sensation Seeking, were examined, as well as the reinforcing efficacy indices of Omax (maximum alcohol expenditure) and Demand Intensity (consumption when price = zero). Findings indicated that Omax moderated the relationship between both impulsivity-related traits and alcohol consumption, and between Urgency and alcohol-related problems. Demand Intensity also moderated the relationship between both impulsivity-related traits and alcohol use, but did not moderate the relationship between either trait and alcohol-related problems. Results from this study suggest that college students high in certain impulsivity-related traits and for whom alcohol is a highly valued reinforcer have a high risk for excessive alcohol consumption and an increased probability of experiencing negative alcohol-related problems.

Acute effects of passive stretching vs vibration on the neuromuscular function of the plantar flexors

This study examined the acute effects of passive stretching (PS) vs prolonged vibration (VIB) on voluntary peak torque (PT), percent voluntary activation (%VA), peak twitch torque (PTT), passive range of motion (PROM), musculotendinous stiffness (MTS), and surface electromyographic (EMG) and mechanomyographic (MMG) amplitude of the medial gastrocnemius (MG) and soleus (SOL) muscles during isometric maximal voluntary contractions (MVCs) of the plantar flexors. Fifteen healthy men performed the isometric MVCs and PROM assessments before and after 20 min of PS, VIB, and a control (CON) conditions. There were 10% and 5% decreases in voluntary PT, non-significant 3% and 2% decreases in %VA, 9-23% decreases in EMG amplitude of the MG and SOL after the PS and VIB, respectively, with no changes after the CON. PROM increased by 19% and MTS decreased by 38% after the PS, but neither changed after the VIB or CON conditions. Both PS and VIB elicited similar neural deficits (i.e., gamma loop impairment) that may have been responsible for the strength losses. However, mechanical factors related to PROM and MTS cannot be ruled out as contributors to the stretching-induced force deficit.

Effects of creatine supplementation on the onset of neuromuscular fatigue threshold and muscle strength in elderly men and women (64 - 86 years)

OBJECTIVES

This study examined the effects of 14 days of creatine supplementation on the physical working capacity at fatigue threshold (PWCFT), maximal isometric grip strength (GRIP), sit-to-stand (STS), and body weight (BW) in elderly men and women.

DESIGN

Using a double blind cross-over design, fifteen men (n = 7) and women (n = 8) (age +/- SD = 74.5 +/- 6.4 yrs) were randomly assigned to either the creatine (CR) (20g.d-1 during week 1 decreasing to 10g.d-1 at week 2) or Placebo (PL) group. After a 4 to 6 week washout period, the subjects were assigned the other treatment. Before (pre) and after (post) the supplementation period, participants performed a discontinuous, cycle ergometry test to determine the PWCFT. In addition, subjects performed STS, GRIP, BW test prior to and post treatment.

SETTING

Southeastern part of the United States.

RESULTS

Significant increases in GRIP (6.7%) and PWCFT (15.6%) from pre- to post-supplementation were found for the CR (p < 0.05) treatment, but no change for the PL treatment was observed. However, no significant change (p superior 0.05) was noted for STS or BW for either treatment.

CONCLUSION

These findings suggest that 14 days of CR supplementation may increase upper body grip strength and increase physical working capacity by delaying neuromuscular fatigue in the elderly men and women in this study. While more research is needed, CR supplementation may improve upper body grip strength and lower body muscle endurance which may be important for maintaining health and independent living in elderly men and women.

GST CYP and PON1 polymorphisms in farmers attributing ill health to organophosphate-containing sheep dip

Previously we reported that in sheep dippers exposed to organophosphates the frequency of paraoxonase (PON1) polymorphisms differed between those with or without self-reported ill health. We have now examined whether polymorphisms in other genes involved in xenobiotic metabolism alter disease risk in this population. There were elevated but non-significant risks associated with the CYP2D6 WT genotype (odds ratio (OR) 1.47, 95% CI 0.83-2.60), or a GSTP1*B or *C allele (OR 1.37, 95% CI 0.88-2.01) or being GSTM1*2/GSTT1*2 homozygous (OR 1.61, 95% CI 0.74-3.48). Similar results were generally obtained after the exclusion of subjects to obtain a more homogenous case-referent population: for double null GSTM1 and GSTT1 homozygotes the OR was 2.06 (95% CI 0.85-2.04). In those also likely to have been exposed to diazinon, risks associated with a GSTP1*B or *C allele (OR 1.82, 95% CI 0.92-3.63) or a GSTM1*2/GSTT1*2 homozygous (OR 2.60, 95% CI 0.72-10.42) were elevated but not to a significant extent. Risk associated with PON1 genotype and phenotype varied with CYP2D6 and GSTP1 genotype but not consistently with a priori hypotheses. Further work is necessary to delineate more clearly pathways of organophosphate activation and non-PON1 pathways of detoxification and to confirm whether CYP and GST polymorphisms alter disease risk in populations exposed to organophosphates.

Paraoxonase polymorphisms and self-reported chronic ill-health in farmers dipping sheep

BACKGROUND

Serum paraoxonase (PON1) provides protection against organophosphate induced toxicity. Recently we reported that the frequency of paraoxonase polymorphisms in sheep dippers with self-reported chronic ill-health differed from that in dippers with a similar dipping history but no ill-health. As these analyses may have included subjects with conditions unrelated to organophosphate exposure, the aim of this study was to examine whether the risk associated with PON1 polymorphisms varied using a more homogenous case and referent population.

METHODS

Each subject completed a detailed symptom questionnaire and their general practitioner was asked whether there was any history of neurological disease that could be confused with the effects of organophosphate poisoning. Subjects were then excluded both on clinical grounds and where identified as atypical on discriminant analysis.

RESULTS

Risk associated with the PON1 192 and 55 genotypes altered little with these changes in the population.

CONCLUSIONS

These findings are consistent with the hypothesis that organophosphates contribute to the self-reported ill-health of sheep dippers.

Gene therapy progress and prospects: gene therapy of lysosomal storage disorders

Despite disappointments with early clinical studies, there is continued interest in the development of gene therapy for the group of metabolic diseases referred to as lysosomal storage disorders (LSDs). The LSDs are monogenic and several small and large, representative animal models of the human diseases are available. Further, the successful reconstitution of only low and unregulated tissue levels of the affected lysosomal enzymes are expected to be sufficient to correct the disease at least in the case of some of the LSDs. For these reasons, they are perceived as good models for the evaluation of different gene delivery vectors and of different strategies for treating chronic genetic diseases by gene transfer. In this review, we will highlight the progress that has been made over the past 2 years in preclinical research for this group of disorders and speculate on future prospects.

Evaluation of inherent performance of intelligent medical decision support systems: utilising neural networks as an example

Researchers who design intelligent systems for medical decision support, are aware of the need for response to real clinical issues, in particular the need to address the specific ethical problems that the medical domain has in using black boxes. This means such intelligent systems have to be thoroughly evaluated, for acceptability. Attempts at compliance, however, are hampered by lack of guidelines. This paper addresses the issue of inherent performance evaluation, which researchers have addressed in part, but a Medline search, using neural networks as an example of intelligent systems, indicated that only about 12.5% evaluated inherent performance adequately. This paper aims to address this issue by concentrating on the possible evaluation methodology, giving a framework and specific suggestions for each type of classification problem. This should allow the developers of intelligent systems to produce evidence of a sufficiency of output performance evaluation.

Implementation of intelligent decision support systems in health care

The full implementation of any intelligent system in health care, which is designed for decision support, has several stages, from initial problem identification through development and, finally, cost-benefit analysis. Central to this is formal objectivist evaluation with its core component of inherent performance of the outputs from these systems. A Medline survey of one type of intelligent system is presented, which demonstrates that this issue is not being addressed adequately. Lack of criteria for dealing with the outputs from these "black box" systems to prescribe adequate levels of inherent performance may be preventing their being accepted by those in the health-care domain and, thus, their being applied widely in the field.

Performance evaluation of artificial intelligence classifiers for the medical domain

The application of artificial intelligence systems is still not widespread in the medical field, however there is an increasing necessity for these to handle the surfeit of information available. One drawback to their implementation is the lack of criteria or guidelines for the evaluation of these systems. This is the primary issue in their acceptability to clinicians, who require them for decision support and therefore need evidence that these systems meet the special safety-critical requirements of the domain. This paper shows evidence that the most prevalent form of intelligent system, neural networks, is generally not being evaluated rigorously regarding classification precision. A taxonomy of the types of evaluation tests that can be carried out, to gauge inherent performance of the outputs of intelligent systems has been assembled, and the results of this presented in a clear and concise form, which should be applicable to all intelligent classifiers for medicine.

The pigmented "black" neuroendocrine tumor of the pancreas: a question of origin

BACKGROUND

Pigmented neoplasms are extremely rare in the pancreas, and, when black pigment is identified, it often suggests the diagnosis of metastatic melanoma. The authors describe two patients with pigmented "black" neuroendocrine tumors of the pancreas. One patient had an incidental (0.5 cm) finding, and the second patient had a well-demarcated, 4.5-cm mass identified by computerized tomography that was consistent with an islet cell tumor.

METHODS

The two neoplasms were resected surgically and studied by light microscopy using hematoxylin and eosin (H&E), Fontana-Masson, and iron stains. The neoplasms were examined immunohistochemically, and ultrastructural analysis was performed.

RESULTS

H&E stains revealed nests of well-differentiated cells with small, round, centrally placed nuclei. The cytoplasm of the neoplastic cells was pink and granular and contained abundant brown-black pigment. Angiolymphatic and perineural invasion were identified in the larger neoplasm. Both neoplasms demonstrated a positive reaction with a Fontana-Masson stain, which was susceptible to bleaching, and a negative reaction to an iron stain. Immunohistochemical stains showed that neoplastic cells expressed chromogranin and synaptophysin but did not express HMB-45, S-100 protein, glucagon, or insulin. Ultrastructural examination revealed regular neurosecretory granules (100-150 nm) and large, irregularly shaped, electron-dense granules with small lipid inclusions consistent with lipofuscin.

CONCLUSIONS

These pigmented pancreatic neoplasms are similar histologically and radiographically to the "black adenoma" of the adrenal gland. It is important to recognize these tumors, because they may mimic metastatic melanoma.

Sorption and mobility of dithiopyr in golf course greens rooting medium

Sorption and mobility of dithiopyr in golf course greens rooting medium (RM) were studied. The sorption increased from 20 to 27 degrees C at 24 h after treatment (HAT) and reached equilibrium in 48 HAT at 20 degrees C. The sorption isotherms had Freundlich values (KF) of 1122, 27.44 to 35.16, and 0.053 to 0.168 for peat moss, the RM, and quartz sand, respectively, and solid to aqueous phase partition coefficients (Kd) of 470 to 1706 L/kg, 14.61 to 84.4 L/kg, and 0.07 to 0.29 L/kg for peat moss, RM, and quartz sand, respectively. Generally, higher dithiopyr concentration in the aqueous solution and the reduced pH of the solution corresponded to the higher Kd values. The average values for dispersion (D, cm2/min), retardation coefficient (R), beta, and omega parameters for solute transport in the RM lysimeter; obtained from CXTFIT curve fitting of Br- breakthrough curves; were 0.95, 1.01, 1, and 93.89, respectively. After elutriation by 18 L of aqueous KNO3 (10 mM), greater than 90% of the added dithiopyr remained in the top 10 cm of the RM lysimeter and no detectable dithiopyr was present at depths beyond 35 cm. The lysimeter effluent contained dithiopyr at concentrations less than 3.5 microg/L. The R value obtained from CXFIT curve fitting is 38.5. Results from both sorption and mobility experiments indicated that dithiopyr is quite immobile in golf course greens RM and has minimal potential for movement into surface water drainage or ground water.

Aerosol and lobar administration of a recombinant adenovirus to individuals with cystic fibrosis. II. Transfection efficiency in airway epithelium

A phase I clinical trial was conducted in which recombinant adenovirus containing the cystic fibrosis trans-membrane regulator (CFTR) (Ad2/CFTR) was administered by bronchoscopic instillation or aerosolization to the lungs of cystic fibrosis (CF) patients. In this paper, we evaluate the efficiency of Ad2/CFTR-mediated transduction of bronchial airway cells. The ability of an Ad2/CFTR vector to transduce airway cells was first evaluated in patients to whom the vector was administered by bronchoscopic instillation. Cells at the administration site were collected 2 days after treatment by bronchoscopic brushing. Ad2-specific CFTR DNA was detected in four of five individuals by PCR, and Ad2-specific CFTR RNA was detected in three of five individuals by RT-PCR. Ad2/CFTR-mediated transduction of airway epithelial cells was then determined in CF individuals receiving this vector by aerosol inhalation. Ad2-specific CFTR DNA was detected in 13 of 13 individuals 2 days after aerosolization, and in 3 of 5 individuals 7 days after aerosolization. Ad2-specific RNA was detected in 4 of 13 individuals on day 2, but was not detected in the 5 individuals tested on day 7. The percentage of airway epithelial cells containing nuclear-localized vector DNA was < or =2.4% as determined by fluorescence in situ hybridization (FISH). However, in some cases, a high percentage of nonepithelial mononuclear cells or squamous metaplastic epithelial cells was infected with the adenoviral vector. In conclusion, aerosol administration is a feasible means to distribute adenoviral vectors throughout the conducting airways, but improvements in adenovirus-mediated transduction of airway epithelial cells are necessary before gene therapy for CF will be effective.

Aerosol and lobar administration of a recombinant adenovirus to individuals with cystic fibrosis. I. Methods, safety, and clinical implications

Cystic fibrosis (CF), an autosomal recessive disorder resulting from mutations in the cystic fibrosis trans-membrane conductance regulator (CFTR) gene, is the most common lethal genetic illness in the Caucasian population. Gene transfer to airway epithelium, using adenoviruses containing normal CFTR cDNA, leads to transient production of CFTR mRNA and, in some studies, to correction of the airway epithelial ion transport defect caused by dysfunctional CFTR. Inflammatory responses to the adenoviral vector have been reported, particularly at high viral titers. We evaluated the effects of adenovirus-mediated CFTR gene transfer to airway epithelium in 36 subjects with CF (34 individuals, 2 of whom received two separate doses of vector), 20 by lobar instillation and 16 by aerosol administration. Doses ranged from 8 x 10(6) to 2.5 x 10(10) infective units (IU), in 0.5-log increments. After lobar administration of low doses there were occasional reports of cough, low-grade temperature, and myalgias. At the highest lobar dose (2.5 x 10(9) IU) two of three patients had transient myalgias, fever, and increased sputum production with obvious infiltrates on CT scan. After aerosol administration there were no significant systemic symptoms until the 2.5 x 10(10) IU dose, when both patients experienced myalgias and fever that resolved within 24 hr. There were no infiltrates seen on chest CT scans in any of the patients in the aerosol administration group. There were no consistent changes in pulmonary function tests or any significant rise in serum IgG or neutralizing antibodies in patients from either group. Serum, sputum, and nasal cytokines, measured before and after vector administration, showed no correlation with adenoviral dose. Gene transfer to lung cells was inefficient and expression was transient. Cells infected with the vector included mononuclear inflammatory cells as well as cuboidal and columnar epithelial cells. In summary, we found no consistent immune response, no evidence of viral shedding, and no consistent change in pulmonary function in response to adenovirus-mediated CFTR gene transfer. At higher doses there was a mild, nonspecific inflammatory response, as evidenced by fevers and myalgias. Overall, vector administration was tolerated but transfer of CFTR cDNA was inefficient and transgene expression was transient for the doses and method of administration used here.

Characterization of the zinc sites in cobalamin-independent and cobalamin-dependent methionine synthase using zinc and selenium X-ray absorption spectroscopy

X-ray absorption spectroscopy has been used to investigate binding of selenohomocysteine to cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthase enzymes of Escherichia coli. We have shown previously [Peariso et al. (1998) J. Am. Chem. Soc. 120, 8410-8416] that the Zn sites in both enzymes show an increase in the number of sulfur ligands when homocysteine binds. The present data provide direct evidence that this change is due to coordination of the substrate to the Zn. Addition of L-selenohomocysteine to either MetE or the N-terminal fragment of MetH, MetH(2-649), causes changes in the zinc X-ray absorption near-edge structure that are remarkably similar to those observed following the addition of L-homocysteine. Zinc EXAFS spectra show that the addition of L-selenohomocysteine changes the coordination environment of the zinc in MetE from 2S + 2(N/O) to 2S + 1(N/O) + 1Se and in MetH(2-649) from 3S + 1(N/O) to 3S + 1Se. The Zn-S, Zn-Se, and Se-S bond distances determined from the zinc and selenium EXAFS data indicate that the zinc sites in substrate-bound MetE and MetH(2-649) both have an approximately tetrahedral geometry. The selenium edge energy for selenohomocysteine shifts to higher energy when binding to either methionine synthase enzyme, suggesting that there is a slight decrease in the effective charge of the selenium. Increases in the Zn-Cys bond distances upon selenohomocysteine binding together with identical magnitudes of the shifts to higher energy in the Se XANES spectra of MetE and MetH(2-649) suggest that the Lewis acidity of the Zn sites in these enzymes appears the same to the substrate and is electronically buffered by the Zn-Cys interaction.

Protonation state of methyltetrahydrofolate in a binary complex with cobalamin-dependent methionine synthase

N5-Methyltetrahydrofolate (CH(3)-H(4)folate) donates a methyl group to the cob(I)alamin cofactor in the reaction catalyzed by cobalamin-dependent methionine synthase (MetH, EC 2.1.1.3). Nucleophilic displacement of a methyl group attached to a tertiary amine is a reaction without an obvious precedent in bioorganic chemistry. Activation of CH(3)-H(4)folate by protonation prior to transfer of the methyl group has been the favored mechanism. Protonation at N5 would lead to formation of an aminium cation, and quaternary amines such as 5,5-dimethyltetrahydropterin have been shown to transfer methyl groups to cob(I)alamin. Because CH(3)-H(4)folate is an enamine, protonation could occur either at N5 to form an aminium cation or on a conjugated carbon with formation of an iminium cation. We used (13)C distortionless enhancement by polarization transfer (DEPT) NMR spectroscopy to infer that CH(3)-H(4)folate in aqueous solution protonates at N5, not on carbon. CH(3)-H(4)folate must eventually protonate at N5 to form the product H(4)folate; however, this protonation could occur either upon formation of the binary enzyme-CH(3)-H(4)folate complex or later in the reaction mechanism. Protonation at N5 is accompanied by substantial changes in the visible absorbance spectrum of CH(3)-H(4)folate. We have measured the spectral changes associated with binding of CH(3)-H(4)folate to a catalytically competent fragment of MetH over the pH range from 5.5 to 8.5. These studies indicate that CH(3)-H(4)folate is bound in the unprotonated form throughout this pH range and that protonated CH(3)-H(4)folate does not bind to the enzyme. Our observations are rationalized by sequence homologies between the folate-binding region of MetH and dihydropteroate synthase, which suggest that the pterin ring is bound in the hydrophobic core of an alpha(8)beta(8) barrel in both enzymes. The results from these studies are difficult to reconcile with an S(N)2 mechanism for methyl transfer and suggest that the presence of the cobalamin cofactor is important for CH(3)-H(4)folate activation. We propose that protonation of N5 occurs after carbon-nitrogen bond cleavage, and we invoke a mechanism involving oxidative addition of Co(1+) to the N5-methyl bond to rationalize our results.

L-Selenohomocysteine: one-step synthesis from L-selenomethionine and kinetic analysis as substrate for methionine synthases

A single-step convenient synthesis of L-selenohomocysteine (SeHcy) from L-selenomethionine (SeMet) using sodium in liquid ammonia is described. Methionine synthases convert SeHcy to SeMet at rates comparable to their rates of conversion of L-homocysteine (Hcy) to L-methionine (Met). This study suggests that SeHcy generated from SeMet metabolism can be efficiently recycled to SeMet in mammals.

The importance of local data in unintended pregnancy prevention programming

OBJECTIVE

Lack of local data on pregnancy intendedness poses a serious problem for those responsible for regional program development and evaluation. This article demonstrates how the Boulder County Health Department addressed this problem by conducting its own assessment. The information gathered served as the basis for collaborative population-based programming and policy development aimed at decreasing unintended pregnancy in the county.

METHODS

A random-digit-dial telephone survey of 300 men and 300 women was conducted to estimate the prevalence of unintended pregnancy and establish groups at highest risk. Qualitative data regarding the psychosocial and contextual factors associated with unintended pregnancy were gathered in six focus groups conducted with 46 males and females aged 18-28 who had experienced an unintended pregnancy.

RESULTS

The prevention strategies identified by the focus group participants lead to the development of locally relevant interventions among specific high-risk populations identified in the telephone survey. Programmatic and policy initiatives included raising awareness among key service providers and the community at large, creative means of bringing information and resources to those at risk, strengthening the delivery of clinical services, and promoting school involvement in unintended pregnancy prevention.

CONCLUSION

Maternal and child health authorities should encourage the collection and use of pregnancy intendedness data at the local level.