Iatrogenic Cushing's syndrome related to the interaction between oral budesonide with fluvoxamine: a case report

WHAT IS KNOWN AND OBJECTIVE

Budesonide, an oral glucocorticoid indicated for the treatment of Crohn's disease, rarely interferes with the hypothalamic-pituitary-adrenal axis because more than 80% of it is metabolized by cytochrome P450 enzymes.

CASE SUMMARY

A 33-year-old female patient diagnosed with Crohn's disease, treated with oral budesonide, was admitted for Cushingoid symptoms and signs. The onset coincided with the use of fluvoxamine, a serotonin reuptake inhibitor and also a potent inhibitor of cytochrome P450 enzymes that presumably led to budesonide accumulation.

WHAT IS NEW AND CONCLUSION

Practitioners should take into consideration the possibility of iatrogenic Cushing's syndrome caused by the association of oral budesonide with a P450 cytochrome inhibitor.

Dideoxy DNA sequencing with chemiluminescent detection

Standard dideoxy DNA sequencing can be performed easily and efficiently with nonisotopic, chemiluminescent detection by utilizing primers labeled with biotin in the sequencing reactions. As described in this unit, reaction products are separated by denaturing gel electrophoresis, transferred to a nylon membrane, and detected by first binding a streptavidin-alkaline phosphatase conjugate, then incubating with a chemiluminescent 1,2-dioxetane substrate. The emitted light signal is imaged on standard X-ray film, producing high-resolution DNA sequencing ladders. Indirect alkaline phosphatase-labeling of biotinylated DNA with free streptavidin and biotinylated alkaline phosphatase is also detailed, Finally, the detection of sequencing reactions labeled with other haptens using specific antibody-alkaline phosphatase conjugates is described.

Classification and course of alcohol problems among adolescents in addictions treatment programs

BACKGROUND

This study tested whether adolescents in addictions treatment programs could be reliably classified into milder and more severe alcohol problem categories using latent class analysis, and examined the relation of latent class structure to DSM-IV alcohol diagnoses. Transition probabilities among the latent classes at 1-year follow-up and their predictors were used to characterize the short-term course of alcohol problems.

METHODS

Adolescents recruited from addictions treatment were administered a modified section of the Structured Clinical Interview for the DSM (SCID) alcohol use disorders (AUD) during or shortly after addictions treatment and at 1-year follow-up. DSM-IV lifetime conduct disorder diagnosis was assessed at baseline using a modified version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS).

RESULTS

A 3-class solution that represented increasing severity of alcohol problems (i.e., asymptomatic, mild, and severe) provided the best fit to the alcohol symptom data, and was consistent across gender, ethnicity, and presence of conduct disorder. Cross-classification of latent class membership with DSM-IV alcohol diagnosis indicated only a fair level of agreement. There was an overall decrease in alcohol problem severity from baseline to follow-up. Conditional transition probabilities indicated that males and those with conduct disorder, particularly for those in the severe class at baseline, had a lower likelihood of transitioning to the asymptomatic class at 1-year follow-up.

CONCLUSIONS

The latent class structure of alcohol problems in an adolescent clinical sample was best represented by a 3-class severity-based model. Cross-classification of latent class membership with DSM-IV alcohol diagnosis suggests the potential utility of re-organizing diagnostic criteria to better distinguish the relative severity of abuse and dependence diagnoses. Transitions between latent classes were fairly common at 1-year follow-up, and characterized by a general reduction in alcohol symptoms.

Parental alcoholism and the effects of alcohol on mediated semantic priming

In this study, researchers tested the effects of a moderate dose of alcohol on the spread of activation of associated information in memory using a mediated semantic priming task in which target words are preceded by primes that are either unrelated or indirectly related to the target. Male and female participants with or without a parental history (PH+ and PH-, respectively) of alcoholism were administered the priming task after consuming alcohol or a placebo beverage. Among PH- individuals, alcohol constrained the spread of activation of associated information, as manifested by a reduced priming effect. In contrast, alcohol enhanced priming effects among PH+ participants, though this latter effect appears to be due to a particularly slow response among these individuals to unprimed words. Results are discussed with regard to theories of alcohol's effects on cognitive processes.

A multi-dimensional analysis of cue-elicited craving in heavy smokers and tobacco chippers

AIMS

This research examined the performance of a broad range of measures posited to relate to smoking craving.

DESIGN

Heavy smokers and tobacco chippers, who were either deprived of smoking or not for 7 hours, were exposed to both smoking (a lit cigarette) and control cues.

PARTICIPANTS

Smokers not currently interested in trying to quit smoking (n = 127) were recruited. Heavy smokers (n = 67) averaged smoking at least 21 cigarettes/day and tobacco chippers (n = 60) averaged 1-5 cigarettes on at least 2 days/week.

MEASUREMENTS

Measures included urge rating scales and magnitude estimations, a rating of affective valence, a behavioral choice task that assessed perceived reinforcement value of smoking, several smoking-related judgement tasks and a measure of cognitive resource allocation.

FINDINGS

Results indicated that both deprivation state and smoker type tended to affect responses across these measurement domains.

CONCLUSIONS

Findings support the use of several novel measures of craving-related processes in smokers.

Assessment of alcohol tolerance in adolescents

OBJECTIVE

To improve assessment of the DSM-IV alcohol tolerance criterion in adolescents, this study tested the performance of a minimum percentage increase in drinking quantity, and a proxy measure of tolerance (i.e., average heavy-drinking quantity per occasion) in identifying adolescents with alcohol dependence.

METHOD

Two adolescent samples were examined. In one sample (N = 415, 58% male, 79% white, 57% clinical), a modified version of the SCID was used to determine DSM-IV alcohol diagnoses, and lifetime drinking history data were collected by interview. In the second sample (N = 470, 60% male, 76% white, 100% clinical), the Adolescent Diagnostic Interview was used to determine DSM-IV alcohol diagnoses and to collect data on initial- and current-drinking quantities needed to become intoxicated. The performance of a percentage increase and average heavy-drinking quantity in identifying those with dependence was evaluated using receiver operating characteristic analysis.

RESULTS

The utility of a percentage increase definition was limited by the high degree of variability in initial-drinking quantities. Percentage increase may underassign the tolerance symptom when initial-drinking quantities are high and overassign the symptom when initial-drinking quantities are low. Average heavy-drinking quantity per occasion, combined with a minimum frequency of drinking, demonstrated better performance than any percentage increase definition.

CONCLUSIONS

Alternatives to a change-based (e.g., percentage increase) definition of tolerance warrant study due to limits of change-based definitions when initial-drinking quantity shows a high degree of variability. The variability in initial-drinking quantity may reflect individual differences in initial sensitivity that need to be considered in tolerance assessment.

Effects of assessment frequency on subjective intoxication ratings after alcohol consumption

BACKGROUND

It is common for subjective intoxication measures to be administered frequently throughout an experimental session. It is unclear, however, whether repeated assessments affect the experience of intoxication. This study examined the effect of assessing subjective intoxication levels during alcohol consumption on subsequent perceptions of intoxication after drinking.

METHODS

Forty-two participants consumed a moderate dose of alcohol (men, 82 g/kg; women, 0.74 g/kg) during a 30-min period. Participants either reported or did not report subjective intoxication levels at 10-min intervals during the drinking period. After the drink, all participants rated their level of subjective intoxication on several occasions.

RESULTS

Individuals who reported their intoxication during the drinking period reported higher levels after consumption than did those who did not rate their intoxication during drinking.

CONCLUSIONS

These data suggest the potential for reactivity effects when conducting repeated assessments of perceived subjective intoxication.

Constructive thinking in adolescents with substance use disorders

This study examined the concurrent validity and clinical correlates of the Constructive Thinking Inventory (CTI), a measure of experiential coping, in 551 adolescents aged 14-18 years with and without Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) substance use disorders (SUDs). The CTI was correlated with depression, anxiety, and conduct problems. After controlling for demographics and comorbid lifetime psychiatric disorders, the CTI scales of Behavioral Coping and Categorical Thinking distinguished adolescents with and without SUDs. Implications of these findings for assessment and treatment are discussed.

Course of functioning in adolescents 1 year after alcohol and other drug treatment

Clinical course was studied in 131 male and female adolescents with current alcohol use disorder (AUD) at baseline (BL). Participants were classified into 4 groups according to their diagnosis and drinking pattern 1 year later. The 4 groups were compared with each other and with 37 community control participants. Results showed that over half of the clinical sample no longer had a current AUD at 1 year; about 64% were and 36% were not still drinking. BL discriminators of 1-year status were alcohol dependence, other drug use, and coping. All of the clinical groups tended to show improvement at 1 year in the main dependent variables, and the abstainers' level of drug use and coping were comparable with that of the community participants. These findings suggest that many adolescents improve in functioning during the 1 year after alcohol and drug treatment and that a stress and coping model is useful for studying clinical course of AUDs in adolescents.

A test of the appraisal-disruption model of alcohol and stress

OBJECTIVE

Faced with a large body of contradictory findings, investigators have begun to propose cognitive factors that moderate the effects of alcohol on stress. We tested the hypothesis, stemming from the appraisal-disruption model (ADM), that alcohol would be more likely to reduce stress when consumed prior to exposure to a stressor than when consumed following exposure.

METHOD

Male and female social drinkers (N = 169, 85 men) with or without a parental history of alcoholism were recruited using separate structured clinical interviews with the participant and with a biological parent. Participants drank a moderate dose of alcohol or a placebo in one of two temporal sequences. Stress was induced by asking participants to present a self-disclosing speech about their physical appearance. Stress responses were assessed using four types of measures: self-reported anxiety, pulse rate, facial expression associated with negative affect and threat-related interference on a color-naming task.

RESULTS

Alcohol was generally more likely to attenuate stress responses when initial exposure to a social stressor followed drinking than when it preceded drinking.

CONCLUSIONS

Findings were consistent with predictions stemming from the ADM. Alcohol appears to be more likely to reduce stress when initial stress appraisal occurs during intoxication. In contrast, when initial appraisal occurs prior to drinking, alcohol is less effective in attenuating stress.

Clinical features of pathological gambling in an addictions treatment cohort

This study examined the prevalence and descriptive psychopathology of pathological gambling in a heterogeneous treatment sample of 372 substance users. About 14% of male participants and 10% of female participants were identified as presumptive pathological gamblers (PGs) on the South Oaks Gambling Screen (SOGS). The authors contrasted 49 PGs with 323 participants who were not pathological gamblers (NPGs) on a host of variables measuring premorbid risk, pathological patterns of substance use, consequences of use, and psychiatric comorbidity. PGs showed more disturbance than NPGs on some measures of premorbid risk, pathological substance use, social consequences of use, and psychiatric comorbidity. Gambling status may be an important comorbid condition in addictions treatment settings and a significant covariate in research.

Clinical correlates of heavy tobacco use among adolescents

The primary aim of this study was to determine the clinical factors differentiating adolescents with heavy smoking (> or = 10 cigarettes/day) from adolescents with light smoking. This study involved a study group of 812 adolescents recruited from adolescent alcoholism treatment centers and from the community. Logistic regression analyses demonstrated that adolescents with heavy smoking, compared with adolescents with light smoking, were significantly more likely to demonstrate Caucasian American ethnicity, drug-use disorders, alcohol-use disorders, and conduct disorder. Our findings suggest that the clinical correlates of heavy smoking among adolescents are generally similar to those for smoking at any level (vs. nonsmokers), except that heavy smoking is more strongly associated with Caucasian American ethnicity. Also, depressive disorders were associated with smoking at any level in our sample, but depressive disorders were not associated with heavy smoking.

Reliability and concurrent validity of DSM-IV subclinical symptom ratings for alcohol use disorders among adolescents

BACKGROUND

The concurrent validity of subclinical ratings for psychiatric symptoms can help refine symptom definitions and threshold criteria. However, virtually no research has examined subclinical ratings for DSM-IV symptoms in psychiatric diagnostic interviews. This study examined the frequency, reliability, and concurrent validity of subclinical ratings for 11 symptoms of alcohol use disorders among adolescents.

METHODS

Subjects were 239 male and 164 female adolescents ages 14 to 18 recruited from treatment and community sources. Symptoms and diagnoses were made with an adapted version of the Structured Clinical Interview for the DSM-IV.

RESULTS

Subclinical ratings showed acceptable to high interrater reliability. The proportion of subclinical ratings tended to decrease with increasing levels of alcohol problems. For 10 of the 11 symptoms, subjects with subclinical ratings were distinguished from those with absent and/or those with present ratings. Subjects with subclinical ratings were often distinct from those with present ratings but less often distinct from those with absent ratings.

CONCLUSIONS

For most of the DSM-IV alcohol use disorder symptoms, subclinical ratings appear to be reliable and valid and provide information beyond dichotomous symptom classifications for adolescents. Threshold criteria appear to be appropriate in many cases, but boundaries between absent and subclinical ratings are "fuzzy." Practical and research implications are discussed.

Toward the DSM-V: the Withdrawal-Gate Model versus the DSM-IV in the diagnosis of alcohol abuse and dependence

The Diagtnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) classifies as dependent many cases of mild alcohol problems. DSM-IV diagnoses have modest relationships with predictive and some concurrent validators and often improperly sequence the onset of abuse versus dependence, perhaps due to insufficient emphasis on physiological features. Testing reliability, syndrome prevalence, syndrome sequencing, and concurrent and predictive validity, this study contrasted the DSM-IV with the Withdrawal-Gate Model (WGM), in which alcohol withdrawal is necessary and sufficient for the dependence diagnosis. Clinical samples of adults (baseline n = 318) and adolescents (baseline n = 214) meeting abuse or dependence were assessed for DSM-IV alcohol symptoms and external measures of problem severity and reinterviewed at 6 (adults) and 12 months (adults and adolescents). Among DSM-IV dependent cases, the WGM shifted 32% of adults and 80% of adolescents to the abuse category, making both categories more symptomatically severe, but had a negligible effect on the prevalence of total alcohol diagnoses. The WGM was more reliable than the DSM-IV and temporally sequenced abuse before dependence in a greater number of cases. The WGM was superior to the DSM-IV in concurrent and predictive validity on most measures. Future diagnostic systems may be more reliable and valid if they require evidence of withdrawal for substance dependence.

Anti-restenotic effect of copper-62 liquid-filled balloon in porcine coronary arteries: novel use of a short half-life positron emitter

PURPOSE

To determine the efficacy of the use of copper-62, a positron emitter with a half-life of 9.7 minutes, as an intracoronary brachytherapy (IRBT) source in the prevention of neointima formation (NF) following overstretch balloon injury (BI) in the porcine model.

METHODS AND MATERIALS

Sixteen swine were treated after BI to their left anterior descending (LAD), left circumflex (LCX), and/or right coronary artery (RCA). Twelve of the injured arteries received placebo and 10 received 25 Gy, delivered to 0.5 mm from the surface of the treatment balloon filled with liquid (62)Cu. Dosimetry was based on Monte Carlo calculations. Two weeks after treatment, the animals were sacrificed, and the treated coronaries were perfusion-fixed and stained. Intimal area (IA) and medial fracture length (FL) were analyzed by computer-aided histomorphometry.

RESULTS

The ((62)Zn/(62)Cu) generator, together with a rapid concentration process, was successful in delivering the short-lived (62)Cu at the high concentration required for intravascular brachytherapy (IVBT). The fracture length in the two groups was similar (2.10 +/- 0.57; 2.02 +/- 0.77; p = NS). Arteries studied showed significant reduction in NF (IA: 0.23 +/- 0.47 mm(2) vs. 1.08 +/- 0.57 mm(2); p < 0.01. IA/FL = 0.09 +/- 0.17 mm vs. 0.51 +/- 0.21 mm; p < 0.01).

CONCLUSIONS

This study demonstrated that use of liquid (62)Cu as an IVBT source is safe and feasible. All 16 swine tolerated the treatment well with no radiation-induced side effects or symptoms throughout the 2-week period. The isotope delivered the dose necessary to inhibit NF in the porcine coronary BI model.

The measurement of drug craving

This paper reviews theoretical and methodological issues in the measurement of drug craving, with an emphasis on self-report assessment. Despite the important role that craving plays in many research and clinical settings, the way in which the construct is conceptualized and measured rarely receives sufficient attention. Issues pertinent to conceptualizing craving are identified. Because there is no single perfect measure of craving, it is essential that researchers understand the limitations of each measure. Measurement performance concerns that affect the validity of different measures are reviewed. Non-verbal assessment methods are also reviewed. Research factors that may help determine the optimal measures for a given study are highlighted. It is concluded that advances in assessment will proceed only when combined with additional research and a better theoretical understanding of craving.

Gender differences and similarities in the personality correlates of adolescent alcohol problems

The personality traits of behavioral under-control (BU) and negative emotionality (NE) are associated with alcohol problems. The authors examined gender differences in the associations of BU and NE with alcohol problems in 710 adolescents recruited from community and treatment sources. Multiple measures were used to characterize each construct, and the specified 2-factor model provided a reasonably good fit to the data. ANCOVAs were used to examine each construct by gender across four groups: never-regular drinkers, regular drinkers, and those with DSM-IV alcohol abuse and alcohol dependence. Males had significantly higher BU and lower NE than did females. BU and NE both increased with degree of alcohol problems. However, there was not a significant Gender x Alcohol Group interaction for BU or NE. Although there are gender differences in levels of BU and NE, mechanisms of alcohol involvement related to these 2 personality traits may operate similarly in adolescent males and females.

Chemiluminescent reporter gene assays with 1,2-dioxetane enzyme substrates

1,2-Dioxetane chemiluminescent substrates provide highly sensitive, quantitative detection with simple, rapid assay formats for the detection of reporter enzymes that are widely used in gene expression studies. Chemiluminescent detection methodologies typically provide up to 100-1000x higher sensitivities than can be achieved with the corresponding fluorescent or colorimetric enzyme substrates. The varieties of 1,2-dioxetane substrates available provides assay versatility, allowing optimization of assay formats with the available instrumentation, and are ideal for use in gene expression assays performed in both biomedical and pharmaceutical research. These assays are amenable to automation with a broad range of instrumentation for high throughput compound screening.

Quantitative polymerase chain reaction and solid-phase capture nucleic acid detection

The combination of PCR amplification and chemiluminescent detection of PCR products provides a highly sensitive system for the quantitation of DNA and RNA. The broad dynamic range of the chemiluminescent detection assay simplifies the selection of cycling and concentration parameters critical to harnessing the quantitative aspects of PCR amplification. Detection of 200 amol of PCR product is attained using the described procedures. The tube or microplate format of the assay avoids many of the limitations associated with other methods of PCR quantitation involving gel electrophoresis. This detection methodology can be applied to a variety of quantitative nucleic acid assays, including viral load and gene expression analysis.

DSM-IV learning disorders in 10- to 12-year-old boys with and without a parental history of substance use disorders

This research examined whether learning disorders (LDs) among 10- to 12-year-old boys are related to a parental history of alcohol and other substance use disorders (SUDs). Subjects were boys with (SA+; n = 179) and without (SA-; n = 203) a parental history of SUDs. LD diagnoses were made according to DSM-IV criteria using several standardized intelligence tests, and mother and teacher reports of academic and cognitive difficulties. The results indicated a higher rate of DSM-IV LDs in SA+ compared to SA- boys. This association remained significant after accounting for the effects of socioeconomic status and ethnicity. SA+ boys with a lower socioeconomic status had particularly high rates of LDs (15.3%). The results suggest that LDs are associated with a parental history of SUDs. SA+ children with lower SES may be at particularly high risk for cognitive and academic difficulties.

Gender differences and similarities in the personality correlates of adolescent alcohol problems

The personality traits of behavioral under-control (BU) and negative emotionality (NE) are associated with alcohol problems. The authors examined gender differences in the associations of BU and NE with alcohol problems in 710 adolescents recruited from community and treatment sources. Multiple measures were used to characterize each construct, and the specified 2-factor model provided a reasonably good fit to the data. ANCOVAs were used to examine each construct by gender across four groups: never-regular drinkers, regular drinkers, and those with DSM-IV alcohol abuse and alcohol dependence. Males had significantly higher BU and lower NE than did females. BU and NE both increased with degree of alcohol problems. However, there was not a significant Gender x Alcohol Group interaction for BU or NE. Although there are gender differences in levels of BU and NE, mechanisms of alcohol involvement related to these 2 personality traits may operate similarly in adolescent males and females.

Inter-rater reliability of the SCID alcohol and substance use disorders section among adolescents

Diagnostic interviews for substance use disorders tend to have high reliability among adults. We examined the inter-rater reliability of the substance use disorders section of the Structured Clinical Interview for the DSM, using 46 male and 25 female adolescent drinkers recruited from community and treatment sources. Inter-rater reliability was high for individual DSM-IV alcohol symptoms (kappa=0.84-1.0) and diagnoses (kappa=0.94), and for other substance use disorder diagnoses (kappa=0.82-1.0).

Diagnostic concordance of DSM-III, DSM-III-R, DSM-IV and ICD-10 alcohol diagnoses in adolescents

OBJECTIVE

Little is known about the validity of diagnostic criteria for alcohol use disorders (AUDs) when applied to adolescents. This study examined the diagnostic concordance of DSM-III, DSM-III-R, DSM-IV and ICD-10 AUDs in a sample of adolescents with a broad range of alcohol problem severity.

METHOD

Participants were 413 adolescents (250 male), ages 13 to 19, drawn from clinical and community sources. AUDs were assessed using the Structured Clinical Interview for the DSM (SCID), modified to make diagnoses in the four nosological systems. Diagnostic agreement for lifetime diagnoses was quantified with the kappa statistic.

RESULTS

Agreement was fair to high across the three categories of alcohol dependence, alcohol abuse and no alcohol diagnosis (kappa = 0.51 to 0.76); for alcohol dependence (kappa = 0.51 to 0.83); and for the categories of any AUD versus no AUD (kappa = 0.55 to 0.96). Concordance was very low for alcohol abuse diagnoses (kappa = 0.10 to 0.23), with the exception of DSM-III-R and DSM-IV (kappa = 0.62). Dependence was superior to abuse in the degree of temporal overlap in diagnostic agreements.

CONCLUSIONS

Similar to findings with adults, diagnostic concordance among adolescents tended to be fair to high for alcohol dependence and very low for alcohol abuse. The data highlight the inconsistency across nosological systems in the conceptual framework and definition of the alcohol abuse category.

Performance of a 62Zn/62Cu generator in clinical trials of PET perfusion agent 62Cu-PTSM

The 62Zn/62Cu PET generator can be inexpensively produced and distributed from a single production site operating under typical good manufacturing practice guidelines. It therefore has the potential to greatly facilitate development of clinically practical PET. We report generator performance in a study in which 62Cu-pyruvaldehyde-bis(n4-methylthiosemicarbazone (PTSM) myocardial perfusion imaging is compared with 99mTc-sestamibi in the diagnosis of coronary artery disease. The 62Zn/62Cu generator is an improved version of a previously reported system that employs automated synthesis of 62Cu-PTSM. With this approach, the cumbersome step of 18C purification has been eliminated.

METHODS

The 62Zn (9.3 h half-life) parent isotope is prepared by proton bombardment of natural copper at 33 MeV. A typical target irradiated with 37.5 microA/h is delivered by 12:00 PM on the day it is to be processed. Purified 62Zn obtained from the target is loaded onto the generator column in 2 mol/L HCl. The generator is eluted using an internal three-channel peristaltic pump, which delivers 2.25 mL eluant (1.8 mol/L NaCl, 0.2 mol/L HCl) through the generator column to elute the 62Cu in 40 s. The same pump simultaneously pumps an equal volume of buffer (0.4 mol/L NaOAc) and 1 mL ligand solution (2 ppm PTSM, 2% EtOH) passing it through a septum into a 35-cc syringe preloaded with 28 mL sterile water. This solution is thoroughly mixed by agitation of the syringe and injected as a bolus through a 0.2 microm filter. The generator is eluted twice before shipping, providing quality assurance samples, and shipped to the clinical site by overnight delivery. Complete quality assurance testing is performed the evening before the generator reaches the clinical site.

RESULTS

A total of 34 generators have been produced and shipped to 2 clinical sites for a phase III Food and Drug Administration study. The load activity on the generators at 8:00 AM the day of clinical use was 1.7+/-0.2 GBq (46.7+/-5.6 mCi), and yield was 72%+/-16%. Breakthrough of 62Zn was undetectable by high-purity germanium spectroscopy for all units. Radiochemical purity was 95.4%+/-2.4%. Volume delivered, pH, sterility, and bacterial endotoxin tests yielded passing results on all generators. The entire process of generator production, from target receipt to generator shipment, took less than 6 h and cost approximately $1000, including shipping charges and cyclotron cost. A total of 68 patients were injected with 2 62Cu-PTSM doses, with a mean injected activity of 0.8+/-0.2 GBq (20.5+/-5.3 mCi) with no adverse side effects.

CONCLUSION

Results of this work confirm that the 62Zn/62Cu generator is an easily produced, transportable, and inexpensive source of PET radiopharmaceuticals, which can expand the field of clinical PET imaging by providing radiopharmaceuticals to sites not associated with cyclotrons.

Risky sexual behaviors among adolescents with alcohol use disorders

Little is known about risky sexual activity among adolescents with alcohol use disorders. This study of 371 adolescent drinkers found that those with alcohol disorders were more likely than other drinkers to be sexually active, to have greater numbers of partners, and to initiate sexual activity at slightly younger ages. Independent of alcohol group, females were more likely than males to have unprotected sexual encounters.

Diagnostic orphans: adolescents with alcohol symptom who do not qualify for DSM-IV abuse or dependence diagnoses

OBJECTIVE

Little is known about the validity of the DSM-IV criteria for alcohol use disorders when applied to adolescents. This report describes a group of "diagnostic orphans," adolescents with one or two DSM-IV alcohol dependence symptoms who do not meet the DSM-IV criteria for alcohol abuse or alcohol dependence.

METHOD

The study included 199 male and 173 female subjects aged 13-19 years. All subjects were regular drinkers, recruited from community sources and alcohol treatment programs. At baseline and at 1-year follow-up, DSM-IV alcohol use disorders were assessed with a version of the Structured Clinical Interview for DSM-III-R, modified for DSM-IV criteria.

RESULTS

Diagnostic orphans represented 31% of the drinkers without an alcohol use disorder. The orphans were similar to the alcohol abusers and dissimilar to the other drinkers in alcohol and substance use patterns and in the course of alcohol problems over 1 year.

CONCLUSIONS

The results indicate limitations of the DSM-IV criteria for alcohol use disorders when applied to adolescents. Diagnostic orphans should be considered separately from other drinkers in research and treatment efforts.

Three-dimensional reconstructions from cryoelectron microscopy images reveal an intimate complex between helicase DnaB and its loading partner DnaC

BACKGROUND

DNA helicases play a fundamental role in all aspects of nucleic acid metabolism and defects in these enzymes have been implicated in a number of inherited human disorders. DnaB is the major replicative DNA helicase in Escherichia coli and has been used as a model system for studying the structure and function of hexameric helicases. The native protein is a hexamer of identical subunits, which in solution forms a complex with six molecules of the loading protein DnaC. DnaB is delivered from this complex onto the DNA template, with the subsequent release of DnaC. We report here the structures of the DnaB helicase hexamer and its complex with DnaC under a defined set of experimental conditions, as determined by three-dimensional cryoelectron microscopy. It was hoped that the structures would provide insight into the mechanisms of helicase activity.

RESULTS

The DnaB structure reveals that six DnaB monomers assemble as three asymmetric dimers to form a polar, ring-like hexamer. The hexamer has two faces, one displaying threefold and the other sixfold symmetry. The six DnaC protomers bind tightly to the sixfold face of the DnaB hexamer. This is the first report of a three-dimensional structure of a helicase obtained using cryoelectron microscopy, and the first report of the structure of a helicase in complex with a loading protein.

CONCLUSIONS

The structures of the DnaB helicase and its complex with DnaC reveal some interesting structural features relevant to helicase function and to the assembly of the two-protein complex. The results presented here provide a basis for a more complete understanding of the structure and function of these important proteins.

Diagnosis and assessment of alcohol use disorders among adolescents

The diagnostic criteria for alcohol use disorders (AUDs) (i.e., alcohol abuse and alcohol dependence) as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) were developed largely from research and clinical experience with adults. Little is known about the validity of these criteria when applied to adolescents. Recent epidemiological and clinical studies of AUDs and their symptoms among adolescents have indicated that the DSM-IV criteria have significant limitations when applied to this age group. Diagnostic interviews and screening tools for adolescent AUDs are discussed. Numerous instruments are available that have shown moderate-to-high reliability and validity in assessing AUDs among adolescents.

Immediate, quantitative estimation of blood alcohol concentration from saliva

OBJECTIVE

Reliable, valid, and noninvasive methods to quantitatively estimate blood alcohol concentration (BAC) are important in forensic, work place, medical and research settings. To date, noninvasive methods for quantitatively estimating BAC have primarily used breath testing. This study evaluated a new device for estimating BAC via saliva that is unique in providing on-the-spot, quantitative results in 2 minutes. The Q.E.D-A150 test (STC Technologies, Inc., Bethlehem, Pa.) is based on the enzymatic oxidation of alcohol by alcohol dehydrogenase. Saliva alcohol concentration (SAC) is read directly from the test device.

METHOD

In each of three sessions, 24 male and 15 female social drinkers, aged 21-28 years, provided yoked breath and saliva samples prior to, and at five times following, a dose of 1.0 g (men) or 0.9 g (women) alcohol per kg lean body mass.

RESULTS

Intertest reliability, determined by two simultaneous saliva samples, was very high for each measurement time (r's = .97 to .99), for each subject (4's = .95 to .99) and across all observations (r = .98). The coefficient of variation was below 5% in 97% of paired observations. The correlation between breath and saliva estimates was .94 across all observations and ranged from .92 to .98 across measurement times. The difference between breath and saliva estimates was significantly larger on the ascending limb than on the descending limb of the blood alcohol curve at comparable BACs. On the average, SAC estimates were 6 mg/dl higher than breath during ascending BACs and 3 mg/dl higher than breath during descending BACs. Individual differences in the ratio of SAC to breath measures of BAC ranged from 0.99 to 1.15 (average = 1.06). Test performance was not affected by gender, drinking pattern or cigarette smoker status.

CONCLUSIONS

The Q.E.D.-A150 device had good reliability and validity for the noninvasive, quantitative estimation of BACs.

Alterations in hippocampal non-phosphorylated MAP2 protein expression in schizophrenia

Microtubule-associated proteins (MAPs) are central to the development of normal neuronal cytoarchitecture and have been suggested in previous studies to be altered in schizophrenia. We investigated hippocampal phosphorylated and non-phosphorylated MAP2 expression in schizophrenia in relation to neuronal orientation and interneuronal distance. One paraffin embedded mid-hippocampal block was obtained from each of 8 schizophrenic and 11 control postmortem brains and immunohistochemistry for the phosphorylated and non-phosphorylated forms of MAP2 performed. Within the corona ammonis (CA) subregions and the subiculum, we assessed densitometry readings for non-phosphorylated MAP2-positive neurones (MAP2-NP), and counted the number of neurones immunopositive for phosphorylated MAP2 (MAP2-P). Using image analysis computer software we measured interneuronal distances and neuronal orientation. While there were no overall alterations in densitometric density of MAP2-NP neurones in any hippocampal subregions, we found a left-sided increase in densitometric density of MAP2-NP neurones within the subiculum (F = 8.740, P < 0.021), and the CA1 (F = 7.044, P < 0.033) of schizophrenic subjects which were unrelated to age, postmortem interval or neuroleptic exposure. There was no accompanying alteration of interneuronal distances, neuronal orientation. The findings support previous work demonstrating altered subicular MAP2 expression in schizophrenia and indicate that the finding may be lateralised. However, in contrast to previous investigations, we have demonstrated this alteration in MAP2 expression is due to an increase in the non-phosphorylated form of MAP2, rather than a decrease in total MAP2 expression. These findings suggest that cytoskeletal assembly is abnormal in schizophrenia and generate testable hypotheses regarding the developmental basis of the disorder.

Staging in the onset of DSM-IV alcohol symptoms in adolescents: survival/ hazard analyses

OBJECTIVE

This research examined staging in the time to onset of DSM-IV alcohol symptoms in adolescents. Consistent staging in the onset of symptoms provides important tests of the construct validity of diagnostic systems, and aids the development of early case identification strategies.

METHOD

The Structured Clinical Interview for the DSM (SCID), adapted to assess DSM-IV alcohol abuse and dependence symptoms, was used to determine time to symptom onset in 102 male and 97 female adolescent drinkers with and without alcohol use disorders. The sample provided a broad range of drinking practices and alcohol-related problems. Symptom onset patterns were examined using survival-hazard analyses.

RESULTS

Survival and hazard data suggested three stages of alcohol problems distinguished by time to onset: heavy and heedless drinking with associated social and role obligation problems, psychological dependence, and withdrawal. This three-stage model fit both the male and female data, and described staging patterns in 70% of the subjects.

CONCLUSIONS

The symptom onset model suggested a first stage of adolescent alcohol symptoms characterized by heavy and heedless drinking with associated interpersonal and role obligation problems. The data did not support the construct validity of DSM-IV alcohol abuse when applied to adolescents, and suggested staging among DSM-IV alcohol dependence symptoms. Implications for the diagnosis and early identification of adolescent alcohol problems are discussed.

Chemiluminescence: sensitive detection technology for reporter gene assays

A series of enzyme-activated chemiluminescence-based assays of reporter gene expression, useful in many biomedical applications, has been developed. The chemiluminescence detection systems for beta-galactosidase, beta-glucuronidase (GUS), and secreted placental alkaline phosphatase (SEAP) reporter enzymes are all based on use of 1,2-dioxetane substrates. This detection technology also permits the combined luminescence detection of two different reporter enzymes in the same tube, e.g., a dual assay for beta-galactosidase and luciferase. The sensitivity of these chemiluminescence assays is several orders of magnitude greater than that of conventional colorimetric or fluorometric detection methods; e.g., the detection limit for beta-galactosidase by the chemiluminescence assay is 8 fg and by a fluorometric assay is 2 pg. Furthermore, chemiluminescence enables detection of beta-galactosidase, GUS, and SEAP enzyme concentrations over a dynamic range of more than five to six orders in magnitude. These assays offer highly sensitive, quantitative, rapid, nonisotopic detection of reporter enzymes that are widely used in both mammalian cells and plant cells.

Chemiluminescence: sensitive detection technology for reporter gene assays

A series of enzyme-activated chemiluminescence-based assays of reporter gene expression, useful in many biomedical applications, has been developed. The chemiluminescence detection systems for beta-galactosidase, beta-glucuronidase (GUS), and secreted placental alkaline phosphatase (SEAP) reporter enzymes are all based on use of 1,2-dioxetane substrates. This detection technology also permits the combined luminescence detection of two different reporter enzymes in the same tube, e.g., a dual assay for beta-galactosidase and luciferase. The sensitivity of these chemiluminescence assays is several orders of magnitude greater than that of conventional colorimetric or fluorometric detection methods; e.g., the detection limit for beta-galactosidase by the chemiluminescence assay is 8 fg and by a fluorometric assay is 2 pg. Furthermore, chemiluminescence enables detection of beta-galactosidase, GUS, and SEAP enzyme concentrations over a dynamic range of more than five to six orders in magnitude. These assays offer highly sensitive, quantitative, rapid, nonisotopic detection of reporter enzymes that are widely used in both mammalian cells and plant cells.

Polydrug use in adolescent drinkers with and without DSM-IV alcohol abuse and dependence

Alcohol and other substance use disorders are highly comorbid, but little is known about patterns of polydrug use in adolescents with different levels of alcohol involvement. This research examined patterns and correlates of polydrug use in 176 adolescent drinkers with DSM-IV alcohol dependence (n = 61), alcohol abuse (n = 57), and no alcohol diagnosis (n = 58). Alcohol and other Substance Use Disorders were assessed using a modified version of the Structured Clinical Interview for the DSM. Lifetime histories of alcohol use and other drug use were assessed using a structured interview. Subjects also completed a questionnaire measure of the frequency of use of specific alcohol-drug combinations. The total number of illicit drugs ever used was greater in the alcohol dependence (mean = 3.8, SD = 2.1) and abuse groups (mean = 3.0, SD = 2.1), compared with the no-alcohol diagnosis group (mean = 1.9, SD = 1.3). Consistent with previous findings, there was a consistent pattern in the age of onset of psychoactive substance use: alcohol, followed by marijuana, followed by other drugs. The recent use of alcohol and other drugs in combination was reported by a greater percentage of subjects in the alcohol dependence (69%) and abuse groups (72%), compared with drinkers without an alcohol diagnosis (45%). The most common alcohol-drug combination was alcohol with marijuana (58% of the total sample), followed by alcohol-hallucinogens (16%). The frequency and extent of polydrug use was associated with being older and having higher levels of behavioral undercontrol and negative emotionality. Adolescent polydrug use, particularly the use of alcohol and other drugs in combination, is an important area for research, treatment, and prevention.

Dual luminescence-based reporter gene assay for luciferase and beta-galactosidase

A unique combined luminescence assay for firefly (Photinus pyralis) luciferase and beta-galactosidase (beta-gal) reporter gene products is described. Luciferase and beta-gal activities are determined with the same aliquot of cell lysate prepared from cells contransfected with both reporter genes, thereby reducing manual labor and increasing experimental accuracy. With the Dual-Light assay system, luciferase activity is measured first with an enhanced luciferase assay, followed by quantitation of beta-gal with Galacton-Plus chemiluminescent substrate and Sapphire-II enhancer. Highly sensitive detection of luciferase (2 fg) and beta-gal (8 fg) is achieved with a dynamic range over seven orders of magnitude of enzyme concentration. Comparative analysis of both independent and combined (Dual-Light) detection methods for cells contransfected with luciferase and beta-gal reporter genes is also described.

Executive cognitive functioning and aggressive behavior in preadolescent boys at high risk for substance abuse/dependence

OBJECTIVE

This study had three purposes; (1) to assess the underlying factor structure of a battery of neuropsychological tests putatively measuring executive cognitive functioning (ECF) in a sample of boys at high and low risk for substance abuse/dependence; (2) to assess the relationship between ECF and aggressive behavior; and (3) to determine the interactive effects of ECF and a family history (FH) of substance dependence on aggressive behavior.

METHOD

Multiple measures of ECF and aggressive behavior were used to test these relationships in a sample of 291 10-12 year old boys with and without a FH of substance dependence.

RESULTS

Analyses indicated that the measures of ECF loaded on one factor. ECF was related to aggressive behavior even when accounting for IQ and SES. The interaction between ECF and a FH of substance dependence was also associated with aggressive behavior.

CONCLUSIONS

The central finding of this investigation indicates that ECF and its interaction with a FH of substance dependence are associated with aggressive behavior. These results suggest that violence prevention and treatment efforts in high risk groups should incorporate cognitive habilitation focusing on training in ECFs.

Executive cognitive functioning predicts reactive aggression in boys at high risk for substance abuse: a prospective study

This study assessed the ability of executive cognitive functioning (ECF) to predict reactive aggression in boys at high and low risk for substance abuse using a 2-year prospective design. ECF is defined as the self-regulation of goal-directed behavior. Reactive aggression involves impulsive hostile reactions committed with little forethought. ECF was measured using five neuropsychological tests in 198 10- to 12-year-old boys with (SA+) and without (SA-) a paternal history of substance abuse/dependence. Reactive aggression was measured, 2 years later, using a composite index of items derived from two self-report measures. It was hypothesized that ECF would predict reactive aggression, and that this relation would be stronger for the SA+ compared with the SA- boys. SA+ subjects demonstrated lower ECF scores and higher reactive aggression scores, compared with SA- controls. ECF predicted reactive aggression in the SA+ group (beta = 0.37, p = 0.001), but not in the SA- group (beta = 0.09, p = NS). This suggests that compromised ECF may be a risk factor for reactive aggression in SA+ youth. The hypothesis that the relation between ECF and reactive aggression is a manifestation of a mild dysfunction of the prefrontal cortex is discussed.

Polydrug use in an inpatient treatment sample of problem drinkers

Over the past 30 years in the United States, there have been marked secular increases in polydrug use. Alcohol and other substance use disorders are highly comorbid. Yet, little research has characterized patterns of polydrug use in persons with alcohol dependence. In particular, little is known about this population's use of alcohol and other drugs in combination or on the same day, which is termed simultaneous polydrug use (SPU). This research assessed patterns of SPU in 212 problem drinkers who participated in an alcohol treatment outcome study. Subjects were given a Time-Line Follow-Back interview that assessed the use of alcohol and nine other drug classes for each day of the 120 days before treatment entry. A majority of subjects (61%) reported SPU during this assessment interval. Subjects who reported SPU were disproportionately younger, male, and unmarried, compared with those who did not report SPU. The most common alcohol/drug combinations were alcohol with cocaine (60% of subjects who reported SPU), alcohol with marijuana (51% of SPU subjects), and alcohol with sedatives (31% of SPU subjects). The most common three-drug combination was alcohol, cocaine, and marijuana (23% of SPU subjects). Alcohol use and drug use were associated at the event level, significantly more than association predicted by the base rates of the individual behaviors. Time-Line Follow-Back data correlated highly with a questionnaire measure of SPU. Results indicate that polydrug use is an important focus for assessment and intervention in alcohol treatment programs.

Patterns of DSM-IV alcohol abuse and dependence symptoms in adolescent drinkers

OBJECTIVE

Diagnostic criteria for alcohol use disorders have largely been developed from research and clinical experience with adults. This research was designed to describe patterns of DSM-IV alcohol use disorder symptoms, and other problem domains, in adolescents with alcohol problems.

METHOD

A modified version of the Structured Clinical Interview for the DSM (SCID) was used to assess DSM-IV alcohol abuse and alcohol dependence symptoms in 91 male and 90 female adolescent drinkers with various levels of alcohol consumption and alcohol-related problems. The SCID was expanded to assess other alcohol problem domains thought to be relevant for adolescents.

RESULTS

DSM-IV dependence symptoms showed moderate to high covariation, supporting the utility of the alcohol dependence construct in adolescence. Compared to previous reports from adult samples, some symptoms were relatively infrequent (e.g., withdrawal, medical problems). Tolerance had low specificity for the diagnosis of alcohol dependence. There was significant heterogeneity in the symptomatology of subjects with DSM-IV alcohol abuse. Although they are not in the DSM-IV criteria, alcohol-related blackouts, craving and risky sexual behavior were common in adolescents with DSM-IV alcohol dependence and abuse diagnoses.

CONCLUSIONS

The data generally support the utility of DSM-IV criteria for alcohol dependence among adolescents. However, tolerance, withdrawal and medical problems appear to present differently in adolescents than has been reported in adults. Those with DSM-IV alcohol abuse diagnoses had very heterogeneous patterns of symptomatology, suggesting limitations of the criteria for DSM-IV alcohol abuse in adolescence. Alcohol-related blackouts, craving and risky sexual behavior are common among adolescents with alcohol use disorders and are an important focus for assessment and treatment efforts.

Salivary cortisol responses and the risk for substance abuse in prepubertal boys

Investigations of adults with a psychoactive substance use disorder (PSUD) or antisocial behavior have reported diminished secretion of the adrenal "stress" hormone, cortisol. Consequently, we determined whether prepubertal sons of PSUD fathers, at high risk for later PSUD, differed from controls on salivary cortisol concentrations before, and after, an anticipated stressor. The roles of problematic behavioral disposition and state anxiety in the cortisol responses were also examined. A significant risk-group x time interaction for salivary cortisol concentrations was found, with high-risk boys secreting less salivary cortisol than controls when anticipating the task. High-risk boys also had significantly higher scores for aggressive delinquency and impulsivity that wholly accounted for the risk-group x time effect on salivary cortisol. Thus, cortisol hyporesponsivity was associated with the dysregulated behaviors prevalent among high-risk boys. The results suggest that cortisol hyporesponsivity could be a "marker" for later antisociality and PSUD.

Cpn60 is exclusively localized into mitochondria of rat liver and embryonic Drosophila cells

Several reports have claimed that the mitochondrial chaperonin cpn60, or a close homolog, is also present in some other subcellular compartments of the eukaryotic cell. Immunoelectron microscopy studies, using a polyclonal serum against cpn60, revealed that the protein is exclusively localized within the mitochondria of rat liver and embryonic Drosophila cells (SL2). Furthermore, no cpn60 immunoreactive material could be found within the nucleus of SL2 cells subjected to a 1 h 37 degrees C heat-shock treatment. In contrast to these findings, immunoelectron microscopy studies, using a cpn60 monoclonal antibody, revealed mitochondrial and extramitochondrial (plasma membrane, nucleus) immunoreactive material in rat liver cells. Surprisingly, the monoclonal antibody also reacted with fixed proteins of the mature red blood cell. The monoclonal antibody, as well as cpn60 polyclonal sera, only recognize mitochondrial cpn60 in Western blots of liver proteins. Furthermore, none of the cpn60 antibodies used in this study recognized blotted proteins from rat red blood cells. Therefore, we suggest that the reported extramitochondrial localization of cpn60 in metazoan cells may be due to cross-reactivity of some of cpn60 antibodies with conformational epitopes also present in distantly related cpn60 protein homologs that are preserved during fixation procedures of the cells.

Aggressivity among sons of substance-abusing fathers: association with psychiatric disorder in the father and son, paternal personality, pubertal development, and socioeconomic status

An association between childhood aggression and risk for subsequent development of a substance abuse disorder is now well-accepted. In order to better understand the relationship between the presence of paternal substance abuse and aggression among their offspring, 10-12 year old sons of fathers with (n = 34) and without (n = 39) a history of a substance abuse disorder were contrasted on demographics, aggressivity, biological indices of reproductive maturation, and the presence of psychiatric diagnoses. In addition, personality factors, the potential for physical abuse, and psychiatric diagnoses were also ascertained among their fathers. Sons of substance-abusing fathers were found to be significantly more aggressive than sons of nonsubstance abusers. However, they also differed from comparison boys on the basis of SES and school grade attained, as well as the proportion with specific psychiatric disorders. Substance-abusing fathers differed from nonsubstance-abusing men in terms of personality factors and the presence of specific psychiatric disorders, including antisocial personality. They also showed significantly higher child abuse potential scores. A multiple regression analysis of factors contributing to aggression in the boys revealed that a paternal personality factor characterized by stress reactivity, alienation, and aggression was the most robust contributor to aggression among the boys. The boys' diagnoses of attention deficit disorder, oppositional defiant disorder, and lower household socioeconomic status were also significant predictors of aggressivity. Contrary to expectations, paternal, psychiatric diagnoses, substance abuse status, and potential for physical abuse were noncontributory. The results suggest potential mechanisms by which both aggression and risk for substance abuse may be transmitted from father to son.

Quantitation of PCR products with chemiluminescence

Quantitative PCR and reverse transcription PCR (RT-PCR) are widely used in biomedical, industrial and other research applications to determine the number of RNA or DNA molecules of a specific type and/or sequence in a sample of interest. We have developed an assay system to accurately quantitate PCR products that utilizes solid-phase capture and an enzyme-linked chemiluminescent detection method. The entire assay is performed in a single tube or microplate well. Biotinylated PCR products are quantitated by capture onto a streptavidin-coated surface, followed by hybridization of an internal fluorescein-labeled oligonucleotide probe and subsequent detection with an anti-fluorescein-alkaline phosphatase conjugate and CSPD chemiluminescent substrate. Light signal is measured in a luminometer. The assay sensitivity enables accurate quantitation of target DNA because the measurement is performed on product generated during the exponential phase of amplification. The broad dynamic range of the assay, which is greater than three orders of magnitude of PCR product concentration, simplifies the determination of the number of amplification cycles necessary for accurate quantitation of target molecules. The PCR-Light system is an ultrasensitive, non-isotopic and rapid assay for PCR product detection that also has general application to solution hybridization assays and other quantitation methods.

Differential expression of guanosine triphosphate binding proteins in men at high and low risk for the future development of alcoholism

We evaluated G-proteins that are components of adenylyl cyclase (AC) signal transduction in erythrocyte and lymphocyte membranes from 26 family history positive (FHP) non-alcoholic and 26 family history negative (FHN) nonalcoholic subjects. Subjects were classified as FHP if their father met criteria for alcohol dependence; as FHN, if there was no history of alcoholism in any first or second degree relatives. Immunoblot analysis indicated that levels of erythrocyte membrane Gs alpha from FHP subjects were greater than levels in FHN subjects (171 +/- 11 vs 100 +/- 6, P < 0.001). To confirm the results of the immunoblot analysis, Gs alpha was quantitated by cholera toxin-dependent [32P]ADP-ribosylation. Levels of erythrocyte [32P]ADP-ribose-Gs alpha from FHP subjects were greater than levels in FHN subjects (236 +/- 28 vs 100 +/- 14, P < 0.001). Gs alpha levels did not correlate with age or alcohol consumption. By contrast to differences in Gs alpha, immunoblot analysis showed similar levels of Gi(2)alpha and Gi(3)alpha in erythrocyte membranes of FHP and FHN subjects. Pertussis toxin-catalyzed [32P]ADP-ribosylation of Gi-like G-proteins confirmed the immunoblot observations. Lastly, compared to FHN subjects, FHP subjects had enhanced Gs alpha expression in lymphocyte membranes as well (138 +/- 11 vs 100 +/- 5.5; P < 0.02). In summary, compared to FHN nonalcoholic men, FHP nonalcoholic men had greater levels of the stimulatory G-protein, Gs alpha, in erythrocyte and lymphocyte membranes. Enhanced expression of Gs alpha may be a marker of increased risk for the future development of alcoholism.

Characterization of a human astrovirus serotype 2 structural protein (VP26) that contains an epitope involved in virus neutralization

An improved purification procedure for human astrovirus serotype 2 (H-Ast2) has facilitated the isolation of a neutralizing monoclonal antibody (PL-2) directed against one of the major structural proteins (VP26) of H-Ast2. A minor component (VP29) of the virus particles is also recognized by PL-2 antibody. Immunofluorescent staining indicated that VP26 (and/or VP29) has mainly a cytoplasmic location in LLCMK2-infected cells. Immunoelectron microscopy demonstrated that the PL-2 epitope was present in the surface of astrovirus particles. Pulse-chase radiolabeling and immunoprecipitation of H-Ast2-infected cell extracts identified a P86 precursor of VP26. Several intermediate protein species (P74 to P35) that shared the PL-2 epitope were also identified in the infected cells. Finally, partial N-terminal sequencing of VP29 and VP26 polypeptides demonstrated that they originated by alternative processing of P86 after residues 361 and 394, respectively. These results corroborate the location of the astrovirus structural genes at the 3' end of the viral genome included in the previously identified 2.8-kb subgenomic RNA.

Imaging of chemiluminescent signals with cooled CCD camera systems

We investigated imaging of chemiluminescent signals from 1,2-dioxetanes with cooled CCD cameras. Non-radioactive detection methods for biomolecules utilizing these chemiluminescent substrates for alkaline phosphatase have been developed. Applications which have been successfully adapted to this technology include Southern and Northern blotting, immunoblotting, ELISA methods and DNA sequencing. Dephosphorylation of the dioxetane CSPD by alkaline phosphatase generates an unstable anion that decomposes resulting in light production. The wavelength of the emitted light is approximately 460 nm. We have utilized Photometrics Star and MXC 200L cooled CCD cameras for direct imaging of chemiluminescent signals. Benefits of utilizing a CCD detector include rapid data digitization and more accurate quantitation of chemiluminescent signals compared to film-based densitometry owing to the significantly greater dynamic range. Chemiluminescent images from dot blots of biotinylated DNA, Southern blots and DNA sequencing gel blots were obtained. In a chemiluminescent microtitre plate assay, serial dilutions of alkaline phosphatase spanning four orders of magnitude can be detected. Our results indicate that the digitization of chemiluminescent signal data with cooled CCD cameras is an excellent alternative to 32P detection methods utilizing storage phosphor screen imaging systems.